1
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Miller LM, Austin CN, Reddy RP, Fogg DN, Nazzal EM, Herman ZJ, Como M, Lin A. Preoperative factors associated with 180°, 270°, and 360° labral tears. J Shoulder Elbow Surg 2024; 33:S37-S42. [PMID: 38485081 DOI: 10.1016/j.jse.2024.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 02/28/2024] [Accepted: 03/05/2024] [Indexed: 04/23/2024]
Abstract
BACKGROUND Large, circumferential glenoid labral tears are an uncommon injury affecting young, athletic patients. There are limited data describing the clinical presentation of patients with larger tears, especially 270° and 360° labral tears. Additionally, examination and imaging findings have poor reliability in diagnosing these tears. The purpose of this study was to determine the clinical presentation among patients presenting with small (less than 180°), medium (180°-270°), and large (270°-360°) labral tears. METHODS This is a retrospective comparative study of consecutive patients surgically managed by a single shoulder surgeon for all glenoid labral tears from 2018-2022. The primary outcome was demographic and preoperative clinical risk factors. Demographic data including age, sex, hand dominance, body mass index, as well as clinical presentation (subluxation vs. dislocation, instability history, and participation in contact sports) were recorded. RESULTS A total of 188 patients met the inclusion criteria: 101 of 188 (53.70%) patients with small tears, 43 of 188 (22.90%) patients with medium tears, and 44 of 188 (23.40%) patients with large tears. Individuals with large and medium-sized labral tears were more likely to have participated in contact sports compared to those with smaller labral tears (P = .003). Medium and smaller tears were more likely to present as dominant-side injury (P = .02). Furthermore, medium and large tears were more likely to present with anterior instability symptoms compared with smaller tears, which more frequently presented with posterior instability and pain (P = .003). CONCLUSION Males participating in contact sports were the most common demographic population presenting with large, 270°-360° labral tears. Instability was the primary complaint rather than pain, and compared with small tears, medium and large tears were more likely to present with primary anterior instability. Although arthroscopic repair of 270°-360° labral tears can yield excellent clinical outcomes similar to smaller tears, identifying factors associated with larger glenoid labral tears may help in surgical planning and patient counseling.
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Affiliation(s)
- Liane M Miller
- Department of Orthopaedic Surgery, UPMC Freddie Fu Sports Medicine Center, Pittsburgh, PA, USA
| | - Confidence Njoku Austin
- Department of Orthopaedic Surgery, UPMC Freddie Fu Sports Medicine Center, Pittsburgh, PA, USA
| | - Rajiv P Reddy
- Department of Orthopaedic Surgery, UPMC Freddie Fu Sports Medicine Center, Pittsburgh, PA, USA
| | - David N Fogg
- Texas Tech University Health Sciences Center, El Paso, TX, USA
| | - Ehab M Nazzal
- Department of Orthopaedic Surgery, UPMC Freddie Fu Sports Medicine Center, Pittsburgh, PA, USA
| | - Zachary J Herman
- Department of Orthopaedic Surgery, UPMC Freddie Fu Sports Medicine Center, Pittsburgh, PA, USA
| | - Matthew Como
- Department of Orthopaedic Surgery, UPMC Freddie Fu Sports Medicine Center, Pittsburgh, PA, USA
| | - Albert Lin
- Department of Orthopaedic Surgery, UPMC Freddie Fu Sports Medicine Center, Pittsburgh, PA, USA.
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2
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Lemmon EA, Bonnevie ED, Patel JM, Miller LM, Mauck RL. Transient inhibition of meniscus cell migration following acute inflammatory challenge. J Orthop Res 2023; 41:2055-2064. [PMID: 36866823 PMCID: PMC10750267 DOI: 10.1002/jor.25545] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 01/23/2023] [Accepted: 03/01/2023] [Indexed: 03/04/2023]
Abstract
Meniscus tears represent a common orthopedic injury that often requires surgery to restore pain-free function. The need for surgical intervention is due, in part, to the inflammatory and catabolic environment that inhibits meniscus healing after injury. In other organ systems, healing is dependent on the migration of cells to the site of injury; however, in the meniscus, it is currently unknown how the microenvironment dictates cell migration in the postinjury inflamed setting. Here, we investigated how inflammatory cytokines alter meniscal fibrochondrocyte (MFC) migration and sensation of microenvironmental stiffness. We further tested whether an FDA approved interleukin-1 receptor antagonist (IL-1Ra; Anakinra) could rescue migratory deficits caused by inflammatory challenge. When cultured in the presence of inflammatory cytokines (tumor necrosis factor-α [TNF-α] or interleukin-1β [IL-1β]) for 1 day, MFC migration was inhibited for 3 days before returning to control levels at Day 7. This migratory deficit was clear in three-dimensional as well, where fewer MFCs exposed to inflammatory cytokines migrated from a living meniscal explant compared with control. Notably, addition of IL-1Ra to MFCs previously exposed to IL-1β restored migration to baseline levels. This study demonstrates that joint inflammation can have negative impacts on meniscus cell migration and mechanosensation, affecting their potential for repair, and that resolution of this inflammation with concurrent anti-inflammatories can reverse these deficits. Future work will apply these findings to mitigate the negative consequences of joint inflammation and promote repair in a clinically relevant meniscus injury model.
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Affiliation(s)
- Elisabeth A. Lemmon
- University of Pennsylvania Perelman School of Medicine, Department of Orthopaedic Surgery, Philadelphia, Pennsylvania, USA
| | - Edward D. Bonnevie
- University of Pennsylvania Perelman School of Medicine, Department of Orthopaedic Surgery, Philadelphia, Pennsylvania, USA
| | - Jay M. Patel
- Department of Orthopaedics, Emory University, Decatur, Georgia, USA
| | - Liane M. Miller
- University of Pennsylvania Perelman School of Medicine, Department of Orthopaedic Surgery, Philadelphia, Pennsylvania, USA
| | - Robert L. Mauck
- University of Pennsylvania Perelman School of Medicine, Department of Orthopaedic Surgery, Philadelphia, Pennsylvania, USA
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3
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Patel JM, Sennett ML, Martin AR, Saleh KS, Eby MR, Ashley BS, Miller LM, Dodge GR, Burdick JA, Carey JL, Mauck RL. Resorbable Pins to Enhance Scaffold Retention in a Porcine Chondral Defect Model. Cartilage 2021; 13:1676S-1687S. [PMID: 33034511 PMCID: PMC8804863 DOI: 10.1177/1947603520962568] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
OBJECTIVE Cartilage repair strategies have seen improvement in recent years, especially with the use of scaffolds that serve as a template for cartilage formation. However, current fixation strategies are inconsistent with regards to retention, may be technically challenging, or may damage adjacent tissues or the implant itself. Therefore, the goal of this study was to evaluate the retention and repair potential of cartilage scaffolds fixed with an easy-to-implement bioresorbable pin. DESIGN Electrospun hyaluronic acid scaffolds were implanted into trochlear groove defects in 3 juvenile and 3 adult pigs to evaluate short-term retention (2 weeks; pin fixation vs. press-fit and fibrin fixation) and long-term repair (8 months; scaffold vs. microfracture), respectively. RESULTS For the retention study, press-fit and fibrin fixation resulted in short-term scaffold dislodgment (n = 2 each), whereas pin fixation retained all scaffolds that were implanted (n = 6). Pin fixation did not cause any damage to the opposing patellar surface, and only minor changes in the subchondral bone were observed. For long-term repair, no differences were observed between microfracture and scaffold groups, in terms of second-look arthroscopy and indentation testing. On closer visualization with micro computed tomography and histology, a high degree of variability was observed between animals with regard to subchondral bone changes and cartilage repair quality, yet each Scaffold repair displayed similar properties to its matched microfracture control. CONCLUSIONS In this study, pin fixation did not cause adverse events in either the short- or the long-term relative to controls, indicating that pin fixation successfully retained scaffolds within defects without inhibiting repair.
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Affiliation(s)
- Jay M. Patel
- McKay Orthopaedic Research Laboratory,
Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA,
USA,Translational Musculoskeletal Research
Center, Corporal Michael J Crescenz VA Medical Center, Philadelphia, PA, USA
| | - Mackenzie L. Sennett
- McKay Orthopaedic Research Laboratory,
Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA,
USA,Translational Musculoskeletal Research
Center, Corporal Michael J Crescenz VA Medical Center, Philadelphia, PA, USA,Penn State College of Medicine,
Pennsylvania State University, Hershey, PA, USA
| | - Anthony R. Martin
- McKay Orthopaedic Research Laboratory,
Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA,
USA,Translational Musculoskeletal Research
Center, Corporal Michael J Crescenz VA Medical Center, Philadelphia, PA, USA,Miller School of Medicine, University of
Miami, Miami, FL, USA
| | - Kamiel S. Saleh
- McKay Orthopaedic Research Laboratory,
Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA,
USA,Translational Musculoskeletal Research
Center, Corporal Michael J Crescenz VA Medical Center, Philadelphia, PA, USA
| | - Michael R. Eby
- McKay Orthopaedic Research Laboratory,
Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA,
USA
| | - Blair S. Ashley
- McKay Orthopaedic Research Laboratory,
Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA,
USA
| | - Liane M. Miller
- McKay Orthopaedic Research Laboratory,
Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA,
USA,Translational Musculoskeletal Research
Center, Corporal Michael J Crescenz VA Medical Center, Philadelphia, PA, USA
| | - George R. Dodge
- McKay Orthopaedic Research Laboratory,
Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA,
USA,Translational Musculoskeletal Research
Center, Corporal Michael J Crescenz VA Medical Center, Philadelphia, PA, USA
| | - Jason A. Burdick
- McKay Orthopaedic Research Laboratory,
Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA,
USA,Translational Musculoskeletal Research
Center, Corporal Michael J Crescenz VA Medical Center, Philadelphia, PA, USA,Department of Bioengineering, University
of Pennsylvania, Philadelphia PA
| | - James L. Carey
- McKay Orthopaedic Research Laboratory,
Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA,
USA
| | - Robert L. Mauck
- McKay Orthopaedic Research Laboratory,
Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA,
USA,Translational Musculoskeletal Research
Center, Corporal Michael J Crescenz VA Medical Center, Philadelphia, PA, USA,Department of Bioengineering, University
of Pennsylvania, Philadelphia PA,Robert L. Mauck, 308A Stemmler Hall, 3450
Hamilton Walk, Philadelphia, PA, 19104, USA.
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4
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Bansal S, Meadows KD, Miller LM, Saleh KS, Patel JM, Stoeckl BD, Lemmon EA, Hast MW, Zgonis MH, Scanzello CR, Elliott DM, Mauck RL. Six-Month Outcomes of Clinically Relevant Meniscal Injury in a Large-Animal Model. Orthop J Sports Med 2021; 9:23259671211035444. [PMID: 34796238 PMCID: PMC8593308 DOI: 10.1177/23259671211035444] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 05/04/2021] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND The corrective procedures for meniscal injury are dependent on tear type, severity, and location. Vertical longitudinal tears are common in young and active individuals, but their natural progression and impact on osteoarthritis (OA) development are not known. Root tears are challenging and they often indicate poor outcomes, although the timing and mechanisms of initiation of joint dysfunction are poorly understood, particularly in large-animal and human models. PURPOSE/HYPOTHESIS In this study, vertical longitudinal and root tears were made in a large-animal model to determine the progression of joint-wide dysfunction. We hypothesized that OA onset and progression would depend on the extent of injury-based load disruption in the tissue, such that root tears would cause earlier and more severe changes to the joint. STUDY DESIGN Controlled laboratory study. METHODS Sham surgeries and procedures to create either vertical longitudinal or root tears were performed in juvenile Yucatan mini pigs through randomized and bilateral arthroscopic procedures. Animals were sacrificed at 1, 3, or 6 months after injury and assessed at the joint and tissue level for evidence of OA. Functional measures of joint load transfer, cartilage indentation mechanics, and meniscal tensile properties were performed, as well as histological evaluation of the cartilage, meniscus, and synovium. RESULTS Outcomes suggested a progressive and sustained degeneration of the knee joint and meniscus after root tear, as evidenced by histological analysis of the cartilage and meniscus. This occurred in spite of spontaneous reattachment of the root, suggesting that this reattachment did not fully restore the function of the native attachment. In contrast, the vertical longitudinal tear did not cause significant changes to the joint, with only mild differences compared with sham surgery at the 6-month time point. CONCLUSION Given that the root tear, which severs circumferential connectivity and load transfer, caused more intense OA compared with the circumferentially stable vertical longitudinal tear, our findings suggest that without timely and mechanically competent fixation, root tears may cause irreversible joint damage. CLINICAL RELEVANCE More generally, this new model can serve as a test bed for experimental surgical, scaffold-based, and small molecule-driven interventions after injury to prevent OA progression.
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Affiliation(s)
- Sonia Bansal
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA.,Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kyle D. Meadows
- Department of Biomedical Engineering, University of Delaware, Newark, Delaware, USA
| | - Liane M. Miller
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA
| | - Kamiel S. Saleh
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA
| | - Jay M. Patel
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA
| | - Brendan D. Stoeckl
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA
| | - Elisabeth A. Lemmon
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA
| | - Michael W. Hast
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA.,Biedermann Lab for Orthopaedic Research, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Miltiadis H. Zgonis
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA
| | - Carla R. Scanzello
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA.,Division of Rheumatology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Dawn M. Elliott
- Biedermann Lab for Orthopaedic Research, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Robert L. Mauck
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, Pennsylvania, USA.,Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Robert L. Mauck, PhD, Department of Orthopedic Surgery, University of Pennsylvania, 3450 Hamilton Walk, 371 Stemmler Hall, Philadelphia, PA 19104, USA () (Twitter: @MauckLab)
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5
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Stoeckl BD, Zlotnick HM, Farrell MJ, Fryhofer GW, Hast MW, Miller LM, Sennett ML, Baxter JR, Schaer TP, Mauck RL, Steinberg DR. The porcine accessory carpal bone as a model for biologic joint replacement for trapeziometacarpal osteoarthritis. Acta Biomater 2021; 129:159-168. [PMID: 34022466 DOI: 10.1016/j.actbio.2021.05.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 04/15/2021] [Accepted: 05/07/2021] [Indexed: 11/19/2022]
Abstract
Given its complex shape and relatively small size, the trapezium surface at the trapeziometacarpal (TMC) joint is a particularly attractive target for anatomic biologic joint resurfacing, especially given its propensity to develop osteoarthritis, and the limited and sub-optimal treatment options available. For this to advance to clinical translation, however, an appropriate large animal model is required. In this study, we explored the porcine accessory carpal bone (ACB) as a model for the human trapezium. We characterized ACB anatomy, geometry, joint and tissue-scale mechanics, and composition across multiple donors. We showed that the ACB is similar both in size, and in the saddle shape of the main articulating surface to the human trapezium, and that loads experienced across each joint are similar. Using this information, we then devised a fabrication method and workflow to produce patient-specific tissue-engineered replicas based on CT scans, and showed that when such replicas are implanted orthotopically in an ex vivo model, normal loading is restored. Data from this study establish the porcine ACB as a model system in which to evaluate function of engineered living joint resurfacing strategies. STATEMENT OF SIGNIFICANCE: Biologic joint resurfacing, or the replacement of a joint with living tissue as opposed to metal and plastic, is the holy grail of orthopaedic tissue engineering. However, despite marked advances in engineering native-like osteochondral tissues and in matching patient-specific anatomy, these technologies have not yet reached clinical translation. Given its propensity for developing osteoarthritis, as well as its small size and complex shape, the trapezial surface of the trapeziometacarpal joint at the base of the thumb presents a unique opportunity for pursuing a biologic joint resurfacing strategy. This work establishes the porcine accessory carpal bone as an animal model for the human trapezium and presents a viable test-bed for evaluating the function of engineered living joint resurfacing strategies.
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Affiliation(s)
- Brendan D Stoeckl
- Mckay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA; Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA; Department of Bioengineering, University of Pennsylvania, Philadelphia, PA
| | - Hannah M Zlotnick
- Mckay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA; Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA; Department of Bioengineering, University of Pennsylvania, Philadelphia, PA
| | - Megan J Farrell
- Mckay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA; Department of Bioengineering, University of Pennsylvania, Philadelphia, PA
| | - George W Fryhofer
- Mckay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA; Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA
| | - Michael W Hast
- Mckay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA
| | - Liane M Miller
- Mckay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA; Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA
| | - Mackenzie L Sennett
- Mckay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA; Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA
| | - Josh R Baxter
- Mckay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA
| | - Thomas P Schaer
- Department of Clinical Studies New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA
| | - Robert L Mauck
- Mckay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA; Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA; Department of Bioengineering, University of Pennsylvania, Philadelphia, PA
| | - David R Steinberg
- Mckay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, University of Pennsylvania, Philadelphia, PA; Department of Clinical Studies New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, Kennett Square, PA.
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6
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Patel JM, Loebel C, Saleh KS, Wise BC, Bonnevie ED, Miller LM, Carey JL, Burdick JA, Mauck RL. Tissue Engineering: Stabilization of Damaged Articular Cartilage with Hydrogel‐Mediated Reinforcement and Sealing (Adv. Healthcare Mater. 10/2021). Adv Healthc Mater 2021. [DOI: 10.1002/adhm.202170049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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7
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Patel JM, Loebel C, Saleh KS, Wise BC, Bonnevie ED, Miller LM, Carey JL, Burdick JA, Mauck RL. Stabilization of Damaged Articular Cartilage with Hydrogel-Mediated Reinforcement and Sealing. Adv Healthc Mater 2021; 10:e2100315. [PMID: 33738988 DOI: 10.1002/adhm.202100315] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Indexed: 01/08/2023]
Abstract
Cartilage injuries and subsequent tissue deterioration impact millions of patients. Since the regeneration of functional hyaline cartilage remains elusive, methods to stabilize the remaining tissue, and prevent further deterioration, would be of significant clinical utility and prolong joint function. Finite element modeling shows that fortification of the degenerate cartilage (Reinforcement) and reestablishment of a superficial zone (Sealing) are both required to restore fluid pressurization within the tissue and restrict fluid flow and matrix loss from the defect surface. Here, a hyaluronic acid (HA) hydrogel system is designed to both interdigitate with and promote the sealing of the degenerated cartilage. Interdigitating fortification restores both bulk and local pericellular tissue mechanics, reestablishing the homeostatic mechanotransduction of endogenous chondrocytes within the tissue. This HA therapy is further functionalized to present chemo mechanical cues that improve the attachment and direct the response of mesenchymal stem/stromal cells at the defect site, guiding localized extracellular matrix deposition to "seal" the defect. Together, these results support the therapeutic potential, across cell and tissue length scales, of an innovative hydrogel therapy for the treatment of damaged cartilage.
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Affiliation(s)
- Jay M. Patel
- McKay Orthopaedic Research Laboratory Department of Orthopaedic Surgery University of Pennsylvania 3450 Hamilton Walk, 371 Stemmler Hall Philadelphia PA 19104 USA
- Translational Musculoskeletal Research Center Corporal Michael J Crescenz VA Medical Center 3900 Woodland Avenue Philadelphia PA 19104 USA
- Department of Orthopaedics Emory University School of Medicine 201 Dowman Drive Atlanta GA 30322 USA
| | - Claudia Loebel
- Translational Musculoskeletal Research Center Corporal Michael J Crescenz VA Medical Center 3900 Woodland Avenue Philadelphia PA 19104 USA
- Department of Bioengineering University of Pennsylvania 210 South 33 Street, Suite 240 Skirkanich Hall Philadelphia PA 19104‐6321 USA
| | - Kamiel S. Saleh
- McKay Orthopaedic Research Laboratory Department of Orthopaedic Surgery University of Pennsylvania 3450 Hamilton Walk, 371 Stemmler Hall Philadelphia PA 19104 USA
- Translational Musculoskeletal Research Center Corporal Michael J Crescenz VA Medical Center 3900 Woodland Avenue Philadelphia PA 19104 USA
| | - Brian C. Wise
- McKay Orthopaedic Research Laboratory Department of Orthopaedic Surgery University of Pennsylvania 3450 Hamilton Walk, 371 Stemmler Hall Philadelphia PA 19104 USA
| | - Edward D. Bonnevie
- McKay Orthopaedic Research Laboratory Department of Orthopaedic Surgery University of Pennsylvania 3450 Hamilton Walk, 371 Stemmler Hall Philadelphia PA 19104 USA
- Translational Musculoskeletal Research Center Corporal Michael J Crescenz VA Medical Center 3900 Woodland Avenue Philadelphia PA 19104 USA
| | - Liane M. Miller
- McKay Orthopaedic Research Laboratory Department of Orthopaedic Surgery University of Pennsylvania 3450 Hamilton Walk, 371 Stemmler Hall Philadelphia PA 19104 USA
| | - James L. Carey
- McKay Orthopaedic Research Laboratory Department of Orthopaedic Surgery University of Pennsylvania 3450 Hamilton Walk, 371 Stemmler Hall Philadelphia PA 19104 USA
| | - Jason A. Burdick
- McKay Orthopaedic Research Laboratory Department of Orthopaedic Surgery University of Pennsylvania 3450 Hamilton Walk, 371 Stemmler Hall Philadelphia PA 19104 USA
- Translational Musculoskeletal Research Center Corporal Michael J Crescenz VA Medical Center 3900 Woodland Avenue Philadelphia PA 19104 USA
- Department of Bioengineering University of Pennsylvania 210 South 33 Street, Suite 240 Skirkanich Hall Philadelphia PA 19104‐6321 USA
| | - Robert L. Mauck
- McKay Orthopaedic Research Laboratory Department of Orthopaedic Surgery University of Pennsylvania 3450 Hamilton Walk, 371 Stemmler Hall Philadelphia PA 19104 USA
- Translational Musculoskeletal Research Center Corporal Michael J Crescenz VA Medical Center 3900 Woodland Avenue Philadelphia PA 19104 USA
- Department of Bioengineering University of Pennsylvania 210 South 33 Street, Suite 240 Skirkanich Hall Philadelphia PA 19104‐6321 USA
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8
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Bansal S, Miller LM, Patel JM, Meadows KD, Eby MR, Saleh KS, Martin AR, Stoeckl BD, Hast M, Elliott DM, Zgonis MH, Mauck RL. Transection of the medial meniscus anterior horn results in cartilage degeneration and meniscus remodeling in a large animal model. J Orthop Res 2020; 38:2696-2708. [PMID: 32285971 PMCID: PMC7735384 DOI: 10.1002/jor.24694] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 03/06/2020] [Accepted: 03/25/2020] [Indexed: 02/04/2023]
Abstract
The meniscus plays a central load-bearing role in the knee joint. Unfortunately, meniscus injury is common and can lead to joint degeneration and osteoarthritis (OA). In small animal models, progressive degenerative changes occur with the unloading of the meniscus via destabilization of the medial meniscus (DMM). However, few large animal models of DMM exist and the joint-wide initiation of the disease has not yet been defined in these models. Thus, the goal of this study is to develop and validate a large animal model of surgically induced DMM and to use multimodal (mechanical, histological, and magnetic resonance imaging) and multiscale (joint to tissue level) quantitative measures to evaluate degeneration in both the meniscus and cartilage. DMM was achieved using an arthroscopic approach in 13 Yucatan minipigs. One month after DMM, joint contact area decreased and peak pressure increased, indicating altered load transmission as a result of meniscus destabilization. By 3 months, the joint had adapted to the injury and load transmission patterns were restored to baseline, likely due to the formation and maturation of a fibrovascular scar at the anterior aspect of the meniscus. Despite this, we found a decrease in the indentation modulus of the tibial cartilage and an increase in cartilage histopathology scores at 1 month compared to sham-operated animals; these deleterious changes persisted through 3 months. Over this same time course, meniscus remodeling was evident through decreased proteoglycan staining in DMM compared to sham menisci at both 1 and 3 months. These findings support that arthroscopic DMM results in joint degeneration in the Yucatan minipig and provide a new large animal testbed in which to evaluate therapeutics and interventions to treat post-traumatic OA that originates from a meniscal injury.
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Affiliation(s)
- Sonia Bansal
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA.,Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Liane M. Miller
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA
| | - Jay M. Patel
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA
| | - Kyle D. Meadows
- Department of Biomedical Engineering, University of Delaware, Newark, DE 19716, USA
| | - Michael R. Eby
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA
| | - Kamiel S. Saleh
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA
| | - Anthony R. Martin
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA
| | - Brendan D. Stoeckl
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA
| | - Michael Hast
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA.,Biedermann Lab for Orthopaedic Research, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Dawn M. Elliott
- Department of Biomedical Engineering, University of Delaware, Newark, DE 19716, USA
| | - Miltiadis H. Zgonis
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA
| | - Robert L. Mauck
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.,Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA 19104, USA.,Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104, USA
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9
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Heo SJ, Song KH, Thakur S, Miller LM, Cao X, Peredo AP, Seiber BN, Qu F, Driscoll TP, Shenoy VB, Lakadamyali M, Burdick JA, Mauck RL. Nuclear softening expedites interstitial cell migration in fibrous networks and dense connective tissues. Sci Adv 2020; 6:eaax5083. [PMID: 32596438 PMCID: PMC7304973 DOI: 10.1126/sciadv.aax5083] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 04/28/2020] [Indexed: 05/22/2023]
Abstract
Dense matrices impede interstitial cell migration and subsequent repair. We hypothesized that nuclear stiffness is a limiting factor in migration and posited that repair could be expedited by transiently decreasing nuclear stiffness. To test this, we interrogated the interstitial migratory capacity of adult meniscal cells through dense fibrous networks and adult tissue before and after nuclear softening via the application of a histone deacetylase inhibitor, Trichostatin A (TSA) or knockdown of the filamentous nuclear protein Lamin A/C. Our results show that transient softening of the nucleus improves migration through microporous membranes, electrospun fibrous matrices, and tissue sections and that nuclear properties and cell function recover after treatment. We also showed that biomaterial delivery of TSA promoted in vivo cellularization of scaffolds by endogenous cells. By addressing the inherent limitations to repair imposed by nuclear stiffness, this work defines a new strategy to promote the repair of damaged dense connective tissues.
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Affiliation(s)
- Su-Jin Heo
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA, USA
- Center for Engineering Mechanobiology, University of Pennsylvania, Philadelphia, PA USA
| | - Kwang Hoon Song
- Center for Engineering Mechanobiology, University of Pennsylvania, Philadelphia, PA USA
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, USA
| | - Shreyasi Thakur
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Liane M. Miller
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA, USA
| | - Xuan Cao
- Center for Engineering Mechanobiology, University of Pennsylvania, Philadelphia, PA USA
- Department of Materials Science Engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, USA
| | - Ana P. Peredo
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA, USA
| | - Breanna N. Seiber
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA, USA
| | - Feini Qu
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA, USA
| | - Tristan P. Driscoll
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA, USA
| | - Vivek B. Shenoy
- Center for Engineering Mechanobiology, University of Pennsylvania, Philadelphia, PA USA
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, USA
- Department of Materials Science Engineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, USA
| | - Melike Lakadamyali
- Center for Engineering Mechanobiology, University of Pennsylvania, Philadelphia, PA USA
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jason A. Burdick
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA, USA
- Center for Engineering Mechanobiology, University of Pennsylvania, Philadelphia, PA USA
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, USA
| | - Robert L. Mauck
- McKay Orthopaedic Research Laboratory, Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Translational Musculoskeletal Research Center, Corporal Michael J. Crescenz VA Medical Center, Philadelphia, PA, USA
- Center for Engineering Mechanobiology, University of Pennsylvania, Philadelphia, PA USA
- Department of Bioengineering, School of Engineering and Applied Science, University of Pennsylvania, Philadelphia, PA, USA
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10
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Miller LM, Utz RL, Supiano KP, Lund DA, Caserta MS. PROFILES OF FAMILY CAREGIVERS PRIOR TO THE DEATH OF A SPOUSE AND THE RISK FOR DEVELOPING PROLONGED GRIEF. Innov Aging 2018. [DOI: 10.1093/geroni/igy023.774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- L M Miller
- University of Utah, College of Nursing, Portland, Oregon, United States
| | - R L Utz
- Department of Sociology, University of Utah, Salt Lake City, UT, USA; Center on Aging, University of Utah, Salt Lake City, UT, USA
| | - K P Supiano
- FT, College of Nursing, University of Utah, Salt Lake City, UT, USA
| | - D A Lund
- Department of Sociology, California State University, San Bernardino, CA, USA
| | - M S Caserta
- College of Nursing, University of Utah, Salt Lake City, UT, USA; Center on Aging, University of Utah, Salt Lake City, UT, USA
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11
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Miller LM, Utz R. IDENTIFYING AND ASSESSING FAMILY MEMBERS AT INCREASED RISK FOR ADVERSE BEREAVEMENT-RELATED OUTCOMES. Innov Aging 2018. [DOI: 10.1093/geroni/igy023.773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- L M Miller
- University of Utah, College of Nursing, Portland, Oregon
| | - R Utz
- University of Utah, Department of Sociology, Salt Lake City, Utah
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12
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Shoup LM, Miller LM, Srinivasan M, Ireland FA, Shike DW. Effects of cows grazing toxic endophyte-infected tall fescue or novel endophyte-infected tall fescue in late gestation on cow performance, reproduction, and progeny growth performance and carcass characteristics. J Anim Sci 2017; 94:5105-5113. [PMID: 28046145 DOI: 10.2527/jas.2016-0819] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Very little is known regarding the effects of cow exposure to toxic ergot alkaloids in late gestation and the subsequent, long-term effects on progeny. Therefore, the objectives were to determine the effects of grazing toxic endophyte-infected tall fescue () or novel endophyte-infected tall fescue during late gestation on cow BW, BCS, hair coat score (HCS), respiration rates, milk production, and reproduction and on growth performance and carcass characteristics of progeny. Eighty gestating, Angus × Simmental cows (age = 6.68 ± 0.32 yr; 588 ± 16 kg initial BW; initial BCS = 5.66 ± 0.28) were stratified by initial BW and allocated into 8 pasture groups (10 cows/group) with 4 groups per treatment. Each group was allotted to 1 of 2 grazing treatments: toxic endophyte-infected tall fescue ('Kentucky-31'; E+) or novel endophyte-infected tall fescue ('Jesup MaxQ'; NOV). Cows were placed on grazing treatments at 110 ± 6 d prepartum (May 28, 2014) and remained on treatment until the end of the calving period (October 8, 2014; 23 ± 6 d postpartum). Cow BW and BCS did not diverge ( ≥ 0.15) at any time point among grazing treatments. However, cows grazing E+ had increased ( < 0.05) respiration rates and HCS and reduced ( < 0.05) prolactin concentration compared with cows grazing NOV. Calf birth BW, Julian calving date, milk production, AI conception rate, and overall pregnancy rate did not differ ( ≥ 0.23) by grazing treatment. In a subsequent grazing period of the progeny, dam grazing treatment did not affect ( ≥ 0.14) respiration rates, HCS, or prolactin concentration of the progeny when all progeny grazed E+ pastures. However, progeny born to dams grazing NOV tended ( > 0.06 to ≤0.10) to have increased BW at 70 ± 6 d of age, 205 d (adjusted weaning BW), and throughout the postweaning calf grazing period. Despite a tendency for BW to differ throughout the postweaning calf grazing period, finishing phase performance and carcass characteristics of progeny did not differ ( ≥ 0.20) between dam grazing treatment. In conclusion, results indicate that by the time progeny enter the feedlot and are finished on a high-grain diet, any fetal programming effects are minimal.
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13
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Gaskill CL, Miller LM, Mattoon JS, Hoffmann WE, Burton SA, Gelens HCJ, Ihle SL, Miller JB, Shaw DH, Cribb AE. Liver Histopathology and Liver and Serum Alanine Aminotransferase and Alkaline Phosphatase Activities in Epileptic Dogs Receiving Phenobarbital. Vet Pathol 2016; 42:147-60. [PMID: 15753468 DOI: 10.1354/vp.42-2-147] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Phenobarbital (PB) therapy is frequently associated with elevated serum alanine aminotransferase (ALT) and alkaline phosphatase (AP) activities in dogs without clinical signs of liver disease. The goal of this study was to determine if increased serum ALT and AP activities in clinically healthy PB-treated epileptic dogs are due to hepatic enzyme induction or to subclinical liver injury. Liver biopsies were obtained from 12 PB-treated dogs without clinical signs of liver disease but with elevated serum ALT and/or AP activities or both. Liver biopsies were obtained from eight healthy control dogs not receiving PB. Biopsies were evaluated histopathologically (all dogs) and liver homogenates were assayed for ALT (all dogs) and AP (six treated dogs, all controls) activities. As a positive control, liver cytochrome P4502B, an enzyme known to be induced by PB, was measured by benzyloxyresorufin- O-dealkylase activity and immunoblotting (five treated dogs, all controls). Serum AP isoenzyme analyses were performed. Results showed that ALT and AP activities in liver homogenates were not increased in treated dogs compared with controls, whereas the positive control for induction, CYP2B, was dramatically increased in treated dogs. Histopathological examination of liver biopsies revealed more severe and frequent abnormalities in treated dogs compared to controls, but similar types of abnormalities were found in both groups. Serum AP isoenzyme analyses in treated dogs demonstrated increased corticosteroid-induced and liver isoenzyme activities compared to controls. Results do not support induction of ALT or AP in the liver as the cause of elevated serum activities of these enzymes due to PB.
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Affiliation(s)
- C L Gaskill
- Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, 550 University Avenue, Charlottetown, Prince Edward Island, C1A 4P3, Canada.
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Jahangiri A, Wagner JR, Han SW, Tran MT, Miller LM, Chen R, Tom MW, Ostling LR, Kunwar S, Blevins L, Aghi MK. Improved versus worsened endocrine function after transsphenoidal surgery for nonfunctional pituitary adenomas: rate, time course, and radiological analysis. J Neurosurg 2015; 124:589-95. [PMID: 26252454 DOI: 10.3171/2015.1.jns141543] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
OBJECTIVE The impact of transsphenoidal surgery for nonfunctional pituitary adenomas (NFAs) on preoperative hypopituitarism relative to the incidence of new postoperative endocrine deficits remains unclear. The authors investigated rates of hypopituitarism resolution and development after transsphenoidal surgery. METHODS Over a 5-year period, 305 transsphenoidal surgeries for NFAs performed at The California Center for Pituitary Disorders were retrospectively reviewed. RESULTS Patients with preoperative endocrine deficits (n = 153, 50%) were significantly older (mean age 60 vs 54 years; p = 0.004), more frequently male (65% vs 44%; p = 0.0005), and had larger adenomas (2.4 cm vs 2.1 cm; p = 0.02) than patients without preoperative deficits (n = 152, 50%). Of patients with preoperative endocrine deficits, 53% exhibited symptoms. Preoperative deficit rates were 26% for the thyroid axis; 20% and 16% for the male and female reproductive axes, respectively; 13% for the adrenocorticotropic hormone (ACTH)/cortisol axis, and 19% for the growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis. Laboratory normalization rates 6 weeks and 6 months after surgery without hormone replacement were 26% and 36% for male and 13% and 13% for female reproductive axes, respectively; 30% and 49% for the thyroid axis; 3% and 3% for the cortisol axis; and 9% and 22% for the IGF-1 axis (p < 0.05). New postoperative endocrine deficits occurred in 42 patients (13.7%). Rates of new deficits by axes were: male reproductive 3% (n = 9), female reproductive 1% (n = 4), thyroid axis 3% (n = 10), cortisol axis 6% (n = 19), and GH/IGF-1 axis 4% (n = 12). Patients who failed to exhibit any endocrine normalization had lower preoperative gland volumes than those who did not (0.24 cm(3) vs 0.43 cm(3), respectively; p < 0.05). Multivariate analyses revealed that no variables predicted new postoperative deficits or normalization of the female reproductive, cortisol, and IGF-1 axes. However, increased preoperative gland volume and younger age predicted the chances of a patient with any preoperative deficit experiencing normalization of at least 1 axis. Younger age and less severe preoperative hormonal deficit predicted normalization of the thyroid and male reproductive axes (p < 0.05). CONCLUSIONS After NFA resection, endocrine normalization rates in this study varied with the hormonal axis and were greater than the incidence of new endocrine deficits. Low preoperative gland volume precluded recovery. Patient age and the severity of the deficiency influenced the recovery of the thyroid and male reproductive axes, the most commonly impaired axes and most likely to normalize postoperatively. This information can be of use in counseling patients with hypopituitarism who undergo NFA surgery.
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Affiliation(s)
- Arman Jahangiri
- Department of Neurosurgery and The California Center for Pituitary Disorders, University of California, San Francisco, California
| | - Jeffrey R Wagner
- Department of Neurosurgery and The California Center for Pituitary Disorders, University of California, San Francisco, California
| | - Sung Won Han
- Department of Neurosurgery and The California Center for Pituitary Disorders, University of California, San Francisco, California
| | - Mai T Tran
- Department of Neurosurgery and The California Center for Pituitary Disorders, University of California, San Francisco, California
| | - Liane M Miller
- Department of Neurosurgery and The California Center for Pituitary Disorders, University of California, San Francisco, California
| | - Rebecca Chen
- Department of Neurosurgery and The California Center for Pituitary Disorders, University of California, San Francisco, California
| | - Maxwell W Tom
- Department of Neurosurgery and The California Center for Pituitary Disorders, University of California, San Francisco, California
| | - Lauren R Ostling
- Department of Neurosurgery and The California Center for Pituitary Disorders, University of California, San Francisco, California
| | - Sandeep Kunwar
- Department of Neurosurgery and The California Center for Pituitary Disorders, University of California, San Francisco, California
| | - Lewis Blevins
- Department of Neurosurgery and The California Center for Pituitary Disorders, University of California, San Francisco, California
| | - Manish K Aghi
- Department of Neurosurgery and The California Center for Pituitary Disorders, University of California, San Francisco, California
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15
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Jahangiri A, Wagner J, Han SW, Tran MT, Miller LM, Tom MW, Ostling LR, Kunwar S, Blevins L, Aghi MK. Rate and Time Course of Improvement in Endocrine Function After More Than 1000 Pituitary Operations. Neurosurgery 2014; 61 Suppl 1:163-6. [DOI: 10.1227/neu.0000000000000405] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Arman Jahangiri
- Department of Neurosurgery and The California Center for Pituitary Disorders, University of California at San Francisco, San Francisco, California
| | - Jeffrey Wagner
- Department of Neurosurgery and The California Center for Pituitary Disorders, University of California at San Francisco, San Francisco, California
| | - Sung Won Han
- Department of Neurosurgery and The California Center for Pituitary Disorders, University of California at San Francisco, San Francisco, California
| | - Mai T. Tran
- Department of Neurosurgery and The California Center for Pituitary Disorders, University of California at San Francisco, San Francisco, California
| | - Liane M. Miller
- Department of Neurosurgery and The California Center for Pituitary Disorders, University of California at San Francisco, San Francisco, California
| | - MaxwelL W. Tom
- Department of Neurosurgery and The California Center for Pituitary Disorders, University of California at San Francisco, San Francisco, California
| | - Lauren R. Ostling
- Department of Neurosurgery, University of Cincinnati, Cincinnati, Ohio
| | - Sandeep Kunwar
- Department of Neurosurgery and The California Center for Pituitary Disorders, University of California at San Francisco, San Francisco, California
| | - Lewis Blevins
- Department of Neurosurgery and The California Center for Pituitary Disorders, University of California at San Francisco, San Francisco, California
| | - Manish K. Aghi
- Department of Neurosurgery and The California Center for Pituitary Disorders, University of California at San Francisco, San Francisco, California
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Jahangiri A, Wagner J, Han SW, Zygourakis CC, Han SJ, Tran MT, Miller LM, Tom MW, Kunwar S, Blevins LS, Aghi MK. Morbidity of repeat transsphenoidal surgery assessed in more than 1000 operations. J Neurosurg 2014; 121:67-74. [DOI: 10.3171/2014.3.jns131532] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
While transsphenoidal surgery is associated with low morbidity, the degree to which morbidity increases after reoperation remains unclear. The authors determined the morbidity associated with repeat versus initial transsphenoidal surgery after 1015 consecutive operations.
Methods
The authors conducted a 5-year retrospective review of the first 916 patients undergoing transsphenoidal surgery at their institution after a pituitary center of expertise was established, and they analyzed morbidities.
Results
The authors analyzed 907 initial and 108 repeat transsphenoidal surgeries performed in 916 patients (9 initial surgeries performed outside the authors' center were excluded). The most common diagnoses were endocrine inactive (30%) or active (36%) adenomas, Rathke's cleft cysts (10%), and craniopharyngioma (3%). Morbidity of initial surgery versus reoperation included diabetes insipidus ([DI] 16% vs 26%; p = 0.03), postoperative hyponatremia (20% vs 16%; p = 0.3), new postoperative hypopituitarism (5% vs 8%; p = 0.3), CSF leak requiring repair (1% vs 4%; p = 0.04), meningitis (0.4% vs 3%; p = 0.02), and length of stay ([LOS] 2.8 vs 4.5 days; p = 0.006). Of intraoperative parameters and postoperative morbidities, 1) some (use of lumbar drain and new postoperative hypopituitarism) did not increase with second or subsequent reoperations (p = 0.3–0.9); 2) some (DI and meningitis) increased upon second surgery (p = 0.02–0.04) but did not continue to increase for subsequent reoperations (p = 0.3–0.9); 3) some (LOS) increased upon second surgery and increased again for subsequent reoperations (p < 0.001); and 4) some (postoperative hyponatremia and CSF leak requiring repair) did not increase upon second surgery (p = 0.3) but went on to increase upon subsequent reoperations (p = 0.001–0.02). Multivariate analysis revealed that operation number, but not sex, age, pathology, radiation therapy, or lesion size, increased the risk of CSF leak, meningitis, and increased LOS. Separate analysis of initial versus repeat transsphenoidal surgery on the 2 most common benign pituitary lesions, pituitary adenomas and Rathke's cleft cysts, revealed that the increased incidence of DI and CSF leak requiring repair seen when all pathologies were combined remained significant when analyzing only pituitary adenomas and Rathke's cleft cysts (DI, 13% vs 35% [p = 0.001]; and CSF leak, 0.3% vs 9% [p = 0.0009]).
Conclusions
Repeat transsphenoidal surgery was associated with somewhat more frequent postoperative DI, meningitis, CSF leak requiring repair, and greater LOS than the low morbidity characterizing initial transsphenoidal surgery. These results provide a framework for neurosurgeons in discussing reoperation for pituitary disease with their patients.
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Jahangiri A, Wagner J, Tran MT, Miller LM, Tom MW, Kunwar S, Blevins L, Aghi MK. Factors predicting postoperative hyponatremia and efficacy of hyponatremia management strategies after more than 1000 pituitary operations. J Neurosurg 2013; 119:1478-83. [DOI: 10.3171/2013.7.jns13273] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Object
Syndrome of inappropriate antidiuretic hormone secretion–induced hyponatremia is a common morbidity after pituitary surgery that can be profoundly symptomatic and cause costly readmissions. The authors calculated the frequency of postoperative hyponatremia after 1045 consecutive operations and determined the efficacy of interventions correcting hyponatremia.
Methods
The authors performed a retrospective review of 1045 consecutive pituitary surgeries in the first 946 patients treated since forming a dedicated pituitary center 5 years ago. Patients underwent preoperative and daily inpatient sodium checks, with outpatient checks as needed.
Results
Thirty-two patients presented with hyponatremia; 41% of these patients were symptomatic. Postoperative hyponatremia occurred after 165 operations (16%) a mean of 4 days after surgery (range 0–28 days); 19% of operations leading to postoperative hyponatremia were associated with postoperative symptoms (38% involved dizziness and 29% involved nausea/vomiting) and 15% involved readmission for a mean of 5 days (range 1–20 days). In a multivariate analysis including lesion size, age, sex, number of prior pituitary surgeries, surgical approach, pathology, lesion location, and preoperative hypopituitarism, only preoperative hypopituitarism predicted postoperative hyponatremia (p = 0.006). Of patients with preoperative hyponatremia, 59% underwent medical correction preoperatively and 56% had persistent postoperative hyponatremia. The mean correction rates were 0.4 mEq/L/hr (no treatment; n = 112), 0.5 mEq/L/hr (free water restriction; n = 24), 0.7 mEq/L/hr (salt tablets; n = 14), 0.3 mEq/L/hr (3% saline; n = 20), 0.7 mEq/L/hr (intravenous vasopressin receptor antagonist Vaprisol; n = 22), and 1.2 mEq/L/hr (oral vasopressin receptor antagonist tolvaptan; n = 9) (p = 0.002, ANOVA). While some patients received more than 1 treatment, correction rates were only recorded when a treatment was given alone.
Conclusions
After 1045 pituitary operations, postoperative hyponatremia was associated exclusively with preoperative hypopituitarism and was most efficiently managed with oral tolvaptan, with several interventions insignificantly different from no treatment. Promptly identifying hyponatremia in high-risk patients and management with agents like tolvaptan can improve safety and decrease readmission. For readmitted patients with severely symptomatic hyponatremia, the intravenous vasopressin receptor antagonist Vaprisol is another treatment option.
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Jahangiri A, De Lay M, Miller LM, Carbonell WS, Hu YL, Lu K, Tom MW, Paquette J, Tokuyasu TA, Tsao S, Marshall R, Perry A, Bjorgan KM, Chaumeil MM, Ronen SM, Bergers G, Aghi MK. Gene expression profile identifies tyrosine kinase c-Met as a targetable mediator of antiangiogenic therapy resistance. Clin Cancer Res 2013; 19:1773-83. [PMID: 23307858 DOI: 10.1158/1078-0432.ccr-12-1281] [Citation(s) in RCA: 159] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE To identify mediators of glioblastoma antiangiogenic therapy resistance and target these mediators in xenografts. EXPERIMENTAL DESIGN We conducted microarray analysis comparing bevacizumab-resistant glioblastomas (BRG) with pretreatment tumors from the same patients. We established novel xenograft models of antiangiogenic therapy resistance to target candidate resistance mediator(s). RESULTS BRG microarray analysis revealed upregulation versus pretreatment of receptor tyrosine kinase c-Met, which underwent further investigation because of its prior biologic plausibility as a bevacizumab resistance mediator. BRGs exhibited increased hypoxia versus pretreatment in a manner correlating with their c-Met upregulation, increased c-Met phosphorylation, and increased phosphorylation of c-Met-activated focal adhesion kinase and STAT3. We developed 2 novel xenograft models of antiangiogenic therapy resistance. In the first model, serial bevacizumab treatment of an initially responsive xenograft generated a xenograft with acquired bevacizumab resistance, which exhibited upregulated c-Met expression versus pretreatment. In the second model, a BRG-derived xenograft maintained refractoriness to the MRI tumor vasculature alterations and survival-promoting effects of bevacizumab. Growth of this BRG-derived xenograft was inhibited by a c-Met inhibitor. Transducing these xenograft cells with c-Met short hairpin RNA inhibited their invasion and survival in hypoxia, disrupted their mesenchymal morphology, and converted them from bevacizumab-resistant to bevacizumab-responsive. Engineering bevacizumab-responsive cells to express constitutively active c-Met caused these cells to form bevacizumab-resistant xenografts. CONCLUSION These findings support the role of c-Met in survival in hypoxia and invasion, features associated with antiangiogenic therapy resistance, and growth and therapeutic resistance of xenografts resistant to antiangiogenic therapy. Therapeutically targeting c-Met could prevent or overcome antiangiogenic therapy resistance.
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Affiliation(s)
- Arman Jahangiri
- Department of Neurological Surgery, University of California at San Francisco, San Francisco, CA 94158, USA
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Vileno B, Jeney S, Sienkiewicz A, Marcoux PR, Miller LM, Forró L. Evidence of lipid peroxidation and protein phosphorylation in cells upon oxidative stress photo-generated by fullerols. Biophys Chem 2010; 152:164-9. [PMID: 20970241 DOI: 10.1016/j.bpc.2010.09.004] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2010] [Revised: 09/18/2010] [Accepted: 09/18/2010] [Indexed: 10/19/2022]
Abstract
An oxidative stress (OS) state is characterized by the generation of Reactive Oxygen Species (ROS) in a biological system above its capacity to counterbalance them [1]. Exposure to OS induces the accumulation of intracellular ROS, which in turn causes cell damage in the form of protein, lipid, and/or DNA oxidations. Such conditions are believed to be linked to numerous diseases or simply to the ageing of tissues. However, the controlled generation of ROS via photosensitizing drugs or photosensitizers (PS) is now widely used to treat various tumors and other infections [2,3]. Here we present a method to track the chemical changes in a cell after exposure to oxidative stress. OS is induced via fullerols, a custom made water soluble derivative of fullerene (C(60)), under visible light illumination. Synchrotron-based Fourier Transform InfraRed Microspectroscopy (S-FTIRM) was used to assess the chemical makeup of single cells after OS exposure. Consequently, a chemical fingerprint of oxidative stress was probed in this study through an increase in the bands linked with lipid peroxidation (carbonyl ester group at 1740 cm(-1)) and protein phosphorylation (asymmetric phosphate stretching at 1240 cm(-1)).
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Affiliation(s)
- B Vileno
- NN Group, Institute of Physics of Condensed Matter, School of Basic Sciences (Station 3), Swiss Federal Institute of Technology (EPFL), CH-1015 Lausanne, Switzerland.
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Rowland TJ, Miller LM, Blaschke AJ, Doss EL, Bonham AJ, Hikita ST, Johnson LV, Clegg DO. Roles of Integrins in Human Induced Pluripotent Stem Cell Growth on Matrigel and Vitronectin. Stem Cells Dev 2010; 19:1231-40. [DOI: 10.1089/scd.2009.0328] [Citation(s) in RCA: 117] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Teisha J. Rowland
- Center for Stem Cell Biology and Engineering, University of California, Santa Barbara, California
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California
- Neuroscience Research Institute, University of California, Santa Barbara, California
| | - Liane M. Miller
- Center for Stem Cell Biology and Engineering, University of California, Santa Barbara, California
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California
| | - Alison J. Blaschke
- Center for Stem Cell Biology and Engineering, University of California, Santa Barbara, California
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California
| | - E. Lauren Doss
- Center for Stem Cell Biology and Engineering, University of California, Santa Barbara, California
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California
| | - Andrew J. Bonham
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, California
| | - Sherry T. Hikita
- Center for Stem Cell Biology and Engineering, University of California, Santa Barbara, California
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California
- Neuroscience Research Institute, University of California, Santa Barbara, California
| | - Lincoln V. Johnson
- Center for Stem Cell Biology and Engineering, University of California, Santa Barbara, California
- Neuroscience Research Institute, University of California, Santa Barbara, California
- Center for the Study of Macular Degeneration, University of California, Santa Barbara, California
| | - Dennis O. Clegg
- Center for Stem Cell Biology and Engineering, University of California, Santa Barbara, California
- Department of Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, California
- Neuroscience Research Institute, University of California, Santa Barbara, California
- Center for the Study of Macular Degeneration, University of California, Santa Barbara, California
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Illmer P, Schwarzenauer T, Malin C, Wagner AO, Miller LM, Gstraunthaler G. Process parameters within a 750,000 litre anaerobic digester during a year of disturbed fermenter performance. Waste Manag 2009; 29:1838-43. [PMID: 19282166 DOI: 10.1016/j.wasman.2009.02.003] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Revised: 01/29/2009] [Accepted: 02/01/2009] [Indexed: 05/08/2023]
Abstract
A 750,000litre fermenter was studied throughout one entire year by investigating the concentrations of volatile fatty acids (acetic, butyric, i-butyric, propionic, valeric and i-valeric acids), pH, concentrations of total C, N, S and NH(4)(+)-N, amounts of chemical and biological oxygen demand, and abundance of acetogenic microorganisms. Additionally several process parameters such as temperature, retention time, dry weight and input of substrate and liquids, and the concentrations and amounts of CH(4), H(2), CO(2) and H(2)S within the biogas were monitored continuously. Various volatile fatty acids and the ratio of acetic to propionic acid were shown to allow a rough indication on the fermentation but were not sufficiently precise to describe the fermenter performance. Nutrient compounds and special fractions, such as easily extractable carbohydrates or the concentration of total fats were more strongly correlated to the gas production of the fermenter. Results of an MPN-method for the determination of acetogenic microorganisms point to an important role of these microorganisms during the phase of restoration of the fermenter performance.
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Affiliation(s)
- P Illmer
- University of Innsbruck, Institute of Microbiology, Technikerstr. 25, A-6020 Innsbruck, Austria.
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Abstract
Bone mineral density is the gold-standard for assessing bone quantity and diagnosing osteoporosis. Although bone mineral density measurements assess the quantity of bone, the quality of the tissue is an important predictor of fragility. Understanding the macro- and nanoscale properties of bone is critical to understanding bone fragility in osteoporosis. Osteoporosis is a disease that affects more than 75 million people worldwide. The gold standard for osteoporosis prognosis, bone mineral density, primarily measures the quantity of bone in the skeleton, overlooking more subtle aspects of bone's properties. Bone quality, a measure of bone's architecture, geometry and material properties, is evaluated via mechanical, structural and chemical testing. Although decreased BMD indicates tissue fragility at the clinical level, changes in the substructure of bone can help indicate how bone quality is altered in osteoporosis. Additionally, mechanical properties which can quantify fragility, or bone's inability to resist fracture, can be changed due to alterations in bone architecture and composition. Recent studies have focused on examination of bone on the nanoscale, suggesting the importance of understanding the interactions of the mineral crystals and collagen fibrils and how they can alter bone quality. It is therefore important to understand alterations in bone that occur at the macro-, micro- and nanoscopic levels to determine what parameters contribute to decreased bone quality in diseased tissue.
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Affiliation(s)
- M E Ruppel
- Department of Biomedical Engineering, State University of New York-Stony Brook, Stony Brook, NY 11794, USA
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Fuchs RK, Allen MR, Condon KW, Reinwald S, Miller LM, McClenathan D, Keck B, Phipps RJ, Burr DB. Strontium ranelate does not stimulate bone formation in ovariectomized rats. Osteoporos Int 2008; 19:1331-41. [PMID: 18385919 DOI: 10.1007/s00198-008-0602-6] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2007] [Accepted: 12/17/2007] [Indexed: 10/22/2022]
Abstract
INTRODUCTION Strontium ranelate (SrR) is suggested to function as a dual-acting agent in the treatment of postmenopausal osteoporosis with anti-resorptive and anabolic skeletal benefits. We evaluated the effects of SrR on the skeleton in ovariectomized (OVX) rats and evaluated the influence of dietary calcium. METHODS Three-month old virgin female rats underwent ovariectomy (OVX, n = 50) or SHAM surgery (SHAM, n = 10). Four weeks post-surgery, rats were treated daily by oral gavage with distilled water (10 ml/kg/day) or SrR (25 or 150 mg/kg/day) for 90 days. Separate groups of animals for each dose of SrR were fed a low (0.1%) or normal (1.19%) calcium (Ca) diet. Static and dynamic histomorphometry, DXA, mu-CT, mechanical testing, and serum and skeletal concentrations of strontium were assessed. RESULTS SrR at doses of 25 and 150 mg/kg/day did not increase bone formation on trabecular or periosteal bone surfaces, and failed to inhibit bone resorption of trabecular bone regardless of Ca intake. There were no improvements in bone mass, volume or strength with either dose of SrR given normal Ca. CONCLUSION These findings demonstrate that SrR at dosages of 25 and 150 mg/kg/day did not stimulate an anabolic bone response, and failed to improve the bone biomechanical properties of OVX rats.
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Affiliation(s)
- R K Fuchs
- Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN, USA.
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24
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Busa B, Miller LM, Rubin CT, Qin YX, Judex S. Rapid establishment of chemical and mechanical properties during lamellar bone formation. Calcif Tissue Int 2005; 77:386-94. [PMID: 16362460 DOI: 10.1007/s00223-005-0148-y] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2005] [Accepted: 08/22/2005] [Indexed: 10/25/2022]
Abstract
The development of prophylaxes and treatments of bone diseases that can effectively increase the strength of bone as a structure necessitates a better understanding of the time course by which chemical properties define the stiffness of the material during primary and secondary mineralization. It was hypothesized that these processes would be relatively slow in the actively growing skeleton. Seven-week-old Sprague-Dawley female rats (n = 8) were injected with multiple fluorochrome labels over a time span of 3 weeks and killed. Chemical and mechanical properties of the tibial mid-diaphysis were spatially characterized between the endocortical and periosteal surface by in situ infrared microspectroscopy and nanoindentation. The phosphate-to-protein ratio of bone 2-6 days old was 20% smaller at the periosteal surface and 22% smaller at the endocortical surface (P < 0.05 each) compared to older intracortical regions. The ratios of carbonate to protein, crystallinity, type A/type B carbonate, collagen cross-linking, and bone elastic modulus did not differ significantly between bone 2-6, 10-14, and 8-22 days old and intracortical regions. Intracortical properties of 10-week-old rats, except for the carbonate-to-protein ratio which was 23% smaller (P < 0.01), were not significantly different from intracortical matrix properties of young adult rats (5 months, n = 4). Spatially, the phosphate-to-protein ratio (R(2) = 0.33) and the phosphate-to-carbonate ratio (R(2) = 0.55) were significantly correlated with bone material stiffness, while the combination of all chemical parameters raised the R(2) value to 0.83. These data indicate that lamellar bone has the ability to quickly establish its mechanical and chemical tissue properties during primary and secondary mineralization even when the skeleton experiences rapid growth.
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Affiliation(s)
- B Busa
- Department of Biomedical Engineering, State University of New York at Stony Brook, Stony Brook, NY, USA
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25
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Abstract
We have documented an early life survival advantage by naturalized populations of anadromous rainbow trout Oncorhynchus mykiss over a more recently introduced hatchery population and outbreeding depression resulting from interbreeding between the two strains. We tested the hypothesis that offspring of naturalized and hatchery trout, and reciprocal hybrid crosses, survive equally from fry to age 1+ in isolated reaches of Lake Superior tributary streams in Minnesota. Over the first summer, offspring of naturalized females had significantly greater survival than offspring of hatchery females in three of four comparisons (two streams and 2 years of stocking). Having an entire naturalized genome, not just a naturalized mother, was important for survival over the first winter. Naturalized offspring outperformed all others in survival to age 1+ and hybrids had reduced, but intermediate, survival relative to the two pure crosses. Averaging over years and streams, survival relative to naturalized offspring was 0.59 for hybrids with naturalized females, 0.37 for the reciprocal hybrids, and 0.21 for hatchery offspring. Our results indicate that naturalized rainbow trout are better adapted to the conditions of Minnesota's tributaries to Lake Superior so that they outperform the hatchery-propagated strain in the same manner that many native populations of salmonids outperform hatchery or transplanted fish. Continued stocking of the hatchery fish may conflict with a management goal of sustaining the naturalized populations.
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Affiliation(s)
- L M Miller
- Department of Fisheries, Wildlife and Conservation Biology, University of Minnesota, 1980 Folwell Avenue, St Paul, MN 55108, USA.
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26
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Kneipp J, Miller LM, Spassov S, Sokolowski F, Lasch P, Beekes M, Naumann D. Scrapie-infected cells, isolated prions, and recombinant prion protein: a comparative study. Biopolymers 2004; 74:163-7. [PMID: 15137116 DOI: 10.1002/bip.20064] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Fourier -transform infrared microscopic spectra of scrapie-infected nervous tissue measured at high spatial resolution (approximately 6 microm) were compared with those obtained from the purified, partly proteinase K digested scrapie isoform of the prion protein isolated from nervous tissue of hamsters infected with the same scrapie strain (263K) to elucidate similarities/dissimilarities between prion structure investigated in situ and ex vivo. A further comparison is drawn to the recombinant Syrian hamster prion protein SHaPrP(90-232) after in vitro conformational transition from the predominantly alpha-helical isoform to beta-sheet-rich structures. It is shown that prion protein structure can be investigated within tissue and that detectability of regions with elevated beta-sheet content as observed in microspectra of prion-infected tissue strongly depends on spatial resolution of the experiment.
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Affiliation(s)
- J Kneipp
- Robert Koch Institute, Nordufer 20, 13353 Berlin, Germany
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27
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Dumas P, Jamin N, Teillaud JL, Miller LM, Beccard B. Imaging capabilities of synchrotron infrared microspectroscopy. Faraday Discuss 2004; 126:289-302; discussion 303-11. [PMID: 14992414 DOI: 10.1039/b305065c] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
It has become increasingly clear that synchrotron infrared micro-spectroscopy is an extremely valuable analysis tool when determining the chemical composition of biological and biomedical samples, at the diffraction-limited spatial resolution. Highly resolved infrared micro-spectroscopy, together with the high signal-to-noise level of the recorded spectra, is essential in generating chemical and statistical (multivariate) images. This is illustrated in the case of individual cell and hair section studies. Unprecedented chemical images of lipid distribution and secondary structure relative concentration have been achieved using the synchrotron source. A comparison with a Focal plane Array imaging system, on the same hair section, shows that, despite the fast imaging processing and improved quality achieved with the focal plane array detectors, spectral quality is markedly superior in the case of the synchrotron source. It is clear that the two approaches could be very complementary if combined on the same sample area, in a synchrotron facility.
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Affiliation(s)
- P Dumas
- LURE-CNRS Bat 209D, centre Universitaire Paris Sud, Orsay, France.
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28
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Abstract
Infrared radiation from synchrotron storagerings serves as a high-brightness source fordiffraction-limited microspectroscopy inboth the mid- and far-infrared spectralranges. Mid-infrared absorption, due to localvibrational modes within complex molecules,is shown to be sensitive to small chemicalchanges associated with certain diseases.Farinfrared modes are believed to result from thefolding or twisting of larger, morecomplex molecules. The ability for thesynchrotron source to perform microscopy ata frequency of 1 THz is demonstrated.
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Affiliation(s)
- L M Miller
- Brookhaven National Laboratory, National Synchrotron Light Source, Upton, NY 11973 USA
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29
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Marinkovic NS, Huang R, Bromberg P, Sullivan M, Toomey J, Miller LM, Sperber E, Moshe S, Jones KW, Chouparova E, Lappi S, Franzen S, Chance MR. Center for Synchrotron Biosciences' U2B beamline: an international resource for biological infrared spectroscopy. J Synchrotron Radiat 2002; 9:189-197. [PMID: 12091724 DOI: 10.1107/s0909049502008543] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2002] [Accepted: 05/09/2002] [Indexed: 05/23/2023]
Abstract
A synchrotron infrared (IR) beamline, U2B, dedicated to the biomedical and biological sciences has been constructed and is in operation at the National Synchrotron Light Source (NSLS) of Brookhaven National Laboratory. The facility is operated by the Center for Synchrotron Biosciences of the Albert Einstein College of Medicine in cooperation with the NSLS. Owing to the broadband nature of the synchrotron beam with brightness 1000 times that of conventional sources, Fourier transform IR spectroscopy experiments are feasible on diffraction-limited sample areas at high signal-to-noise ratios and with relatively short data-acquisition times. A number of synchrotron IR microscopy experiments that have been performed in the mid-IR spectral range (500-5000 cm(-1)) are summarized, including time-resolved protein-folding studies in the microsecond time regime, IR imaging of neurons, bone and other biological tissues, as well as imaging of samples of interest in the chemical and environmental sciences. Owing to the high flux output of this beamline in the far-IR region (50-500 cm(-1)), investigations of hydrogen bonding and dynamic molecular motions of biomolecules have been carried out from 10 to 300 K using a custom-made cryostat and an evacuated box. This facility is intended as an international resource for biological IR spectroscopy fully available to outside users based on competitive proposal.
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Affiliation(s)
- N S Marinkovic
- Center for Synchrotron Biosciences, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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30
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Huang RY, Miller LM, Carlson CS, Chance MR. Characterization of bone mineral composition in the proximal tibia of cynomolgus monkeys: effect of ovariectomy and nandrolone decanoate treatment. Bone 2002; 30:492-7. [PMID: 11882463 DOI: 10.1016/s8756-3282(01)00691-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Life postmenopausal women, ovariectomized cynomolgus monkeys (Macaca fascicularis) experience accelerated loss of bone mass. Treatment of ovariectomized monkeys with nandrolone decanoate results in an increase in bone mass to levels comparable to those of intact animals. The changes in bone composition that occur with these treatments, however, are less well characterized. In the present study, we used synchrotron Fourier-transform infrared microspectroscopy (FT-IRM) and curve-fitting methods to monitor specific changes at cortical, subchondral, and trabecular bone regions in the proximal tibia. Four groups were studied: (1) sham-operated (sham); (2) ovariectomized and treated with placebo for 2 years (ovx); (3) ovx + nandrolone decanoate for 2 years (NAN); and (4) ovx + nandrolone decanoate beginning 1 year after ovx (dNAN). The results demonstrate that ovariectomy and nandrolone treatment did not affect the degree of mineralization as defined by the phosphate/protein ratio, but acid phosphate content (HPO(4)(2-)) in cortical and subchondral bone was increased by ovariectomy, suggesting this bone to be less mature due to increased remodeling that occurs after ovariectomy. In the subchondral and cortical bone regions, ovariectomized monkeys showed a lower total carbonate content (CO(3)(2-)/matrix ratio) than sham controls, specifically due to the decrease in labile carbonate content. In the trabecular region, no change of carbonate content was observed. Treatment with nandrolone decanoate was found to restore the loss in carbonate, where the resulting mineral had a larger quantity of type B carbonate. Finally, we correlated carbonate content with dual-energy X-ray absorptiometry measurements, and found a positive correlation between bone mineral density and type A carbonate in bone, which is stoichiometrically related to the amount of calcium in bone. Therefore, the results presented herein identify significant differences in bone chemistry after ovariectomy and nandrolone treatment, which may help explain previous findings that, although nandrolone decanoate treatment increased bone mass, it could not reverse the decrease in bone strength due to ovariectomy.
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Affiliation(s)
- R Y Huang
- Department of Physiology and Biophysics, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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31
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Paszek AA, Wilkie PJ, Flickinger GH, Miller LM, Louis CF, Rohrer GA, Alexander LJ, Beattie CW, Schook LB. Interval mapping of carcass and meat quality traits in a divergent swine cross. Anim Biotechnol 2001; 12:155-65. [PMID: 11808631 DOI: 10.1081/abio-100108342] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
An autosomal scan of the swine genome with 119 polymorphic microsatellite (ms) markers and data from 116 F2 barrows of the University of Illinois Meishan x Yorkshire Swine Resource Families identified genomic regions with effects on variance in carcass composition and meat quality at nominal significance (p-value <0.05). Marker intervals on chromosomes 1, 6, 7, 8 and 12 (SSC1, SSC6, SSC7, SSC8, SSC12) with phenotypic effects on carcass length, 10th rib backfat thickness, average backfat thickness, leaf fat, loin eye area and intramuscular fat content confirm QTL effects identified previously based on genome wide significance (p-value <0.05). Several marker intervals included nominally significant (p-value <0.05) dominance effects on leaf fat, 10th rib backfat thickness, loin eye area, muscle pH and intramuscular fat content.
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Affiliation(s)
- A A Paszek
- Food Animal Biotechnology Center, Department of Veterinary PathoBiology, University of Minnesota, St. Paul 55108, USA
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32
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Miller LM, Escabí MA, Schreiner CE. Feature selectivity and interneuronal cooperation in the thalamocortical system. J Neurosci 2001; 21:8136-44. [PMID: 11588186 PMCID: PMC6763836] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2001] [Revised: 07/19/2001] [Accepted: 07/20/2001] [Indexed: 02/21/2023] Open
Abstract
Action potentials are a universal currency for fast information transfer in the nervous system, yet few studies address how some spikes carry more information than others. We focused on the transformation of sensory representations in the lemniscal (high-fidelity) auditory thalamocortical network. While stimulating with a complex sound, we recorded simultaneously from functionally connected cell pairs in the ventral medial geniculate body and primary auditory cortex. Thalamic action potentials that immediately preceded or potentially caused a cortical spike were more selective than the average thalamic spike for spectrotemporal stimulus features. This net improvement of thalamic signaling indicates that for some thalamic cells, spikes are not propagated through cortex independently but interact with other inputs onto the same target cell. We then developed a method to identify the spectrotemporal nature of these interactions and found that they could be cooperative or antagonistic to the average receptive field of the thalamic cell. The degree of cooperativity with the thalamic cell determined the increase in feature selectivity for potentially causal thalamic spikes. We therefore show how some thalamic spikes carry more receptive field information than average and how other inputs cooperate to constrain the information communicated through a cortical cell.
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Affiliation(s)
- L M Miller
- W. M. Keck Center for Integrative Neuroscience and University of California San Francisco/Berkeley Bioengineering Group, San Francisco, California 94143, USA.
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33
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Abstract
One of the brain's fundamental tasks is to construct and transform representations of an animal's environment, yet few studies describe how individual neurons accomplish this. Our results from correlated pairs in the auditory thalamocortical system show that cortical excitatory receptive field regions can be directly inherited from thalamus, constructed from smaller inputs, and assembled by the cooperative activity of neuronal ensembles. The prevalence of functional thalamocortical connectivity is strictly governed by tonotopy, but connection strength is not. Finally, spectral and temporal modulation preferences in cortex may differ dramatically from the thalamic input. Our observations reveal a radical reconstruction of response properties from auditory thalamus to cortex, and illustrate how some properties are propagated with great fidelity while others are significantly transformed or generated intracortically.
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Affiliation(s)
- L M Miller
- W.M. Keck Center for Integrative Neuroscience, UCSF/UCB Bioengineering Group, University of California Medical Center, San Francisco, CA 94143, USA.
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Tetenbaum J, Miller LM. A new spectroscopic approach to examining the role of disulfide bonds in the structure and unfolding of soybean trypsin inhibitor. Biochemistry 2001; 40:12215-9. [PMID: 11580297 DOI: 10.1021/bi010796u] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Although it is well-known that disulfide bonds stabilize the secondary structure of many proteins, it is difficult to directly probe both disulfide bond formation/breakage and the resulting secondary structural changes during the course of the protein folding/unfolding process. In this work, we have used a new, real-time spectroscopic approach to examine how the reduction of two disulfide bonds affects the secondary structure of soybean trypsin inhibitor (STI). The disulfide bonds are reduced with tris(2-carboxyethyl)phosphine (TCEP) at 40 degrees C, and the reduction process is probed in real-time using sulfur X-ray absorption spectroscopy. Circular dichroism (CD) and Fourier transform infrared (FTIR) spectroscopies are used concurrently to determine the structural changes caused by reduction of the disulfide bonds. Results demonstrate a noncooperative reduction of the two disulfide bonds within 5 min, likely because they are located on the surface of the protein. The unfolding of STI lags behind; dramatic changes are not observed until 60-90 min after the reduction was initiated. The CD and FTIR spectra indicate a decrease in the amount of extended (hydrated) coil, suggesting that the STI structure slowly collapses after the disulfide bonds are reduced. Thus, although the disulfide bonds are not located near the active site of STI, they play a crucial role in stabilizing the protein structure, which is necessary to sustain enzymatic activity.
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Affiliation(s)
- J Tetenbaum
- National Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York 11973, USA
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35
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Meng F, Cargile BJ, Miller LM, Forbes AJ, Johnson JR, Kelleher NL. Informatics and multiplexing of intact protein identification in bacteria and the archaea. Nat Biotechnol 2001; 19:952-7. [PMID: 11581661 DOI: 10.1038/nbt1001-952] [Citation(s) in RCA: 181] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Although direct fragmentation of protein ions in a mass spectrometer is far more efficient than exhaustive mapping of 1-3 kDa peptides for complete characterization of primary structures predicted from sequenced genomes, the development of this approach is still in its infancy. Here we describe a statistical model (good to within approximately 5%) that shows that the database search specificity of this method requires only three of four fragment ions to match (at +/-0.1 Da) for a 99.8% probability of being correct in a database of 5,000 protein forms. Software developed for automated processing of protein ion fragmentation data and for probability-based retrieval of whole proteins is illustrated by identification of 18 archaeal and bacterial proteins with simultaneous mass-spectrometric (MS) mapping of their entire primary structures. Dissociation of two or three proteins at once for such identifications in parallel is also demonstrated, along with retention and exact localization of a phosphorylated serine residue through the fragmentation process. These conceptual and technical advances should assist future processing of whole proteins in a higher throughput format for more robust detection of co- and post-translational modifications.
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Affiliation(s)
- F Meng
- Department of Chemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
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Miller LM, Vairavamurthy V, Chance MR, Mendelsohn R, Paschalis EP, Betts F, Boskey AL. In situ analysis of mineral content and crystallinity in bone using infrared micro-spectroscopy of the nu(4) PO(4)(3-) vibration. Biochim Biophys Acta 2001; 1527:11-9. [PMID: 11420138 DOI: 10.1016/s0304-4165(01)00093-9] [Citation(s) in RCA: 179] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Measurements of bone mineral content and composition in situ provide insight into the chemistry of bone mineral deposition. Infrared (IR) micro-spectroscopy is well suited for this purpose. To date, IR microscopic (including imaging) analyses of bone apatite have centered on the nu(1),nu(3) PO(4)(3-) contour. The nu(4) PO(4)(3-) contour (500-650 cm(-1)), which has been extensively used to monitor the crystallinity of hydroxyapatite in homogenized bone samples, falls in a frequency region below the cutoff of the mercury-cadmium-telluride detectors used in commercial IR microscopes, thereby rendering this vibration inaccessible for imaging studies. The current study reports the first IR micro-spectroscopy spectra of human iliac crest cross sections in the nu(4) PO(4)(3-) spectral regions, obtained with a synchrotron radiation source and a Cu-doped Ge detector coupled to an IR microscope. The acid phosphate (HPO(4)(2-)) content and mineral crystallite perfection (crystallinity) of a human osteon were mapped. To develop spectra-structure correlations, a combination of X-ray powder diffraction data and conventional Fourier transform IR spectra have been obtained from a series of synthetic hydroxyapatite crystals and natural bone powders of various species and ages. X-ray powder diffraction data demonstrate that there is an increase in average crystal size as bone matures, which correlates with an increase in the nu(4) PO(4)(3-) FTIR absorption peak ratio of two peaks (603/563 cm(-1)) within the nu(4) PO(4)(3-) contour. Additionally, the IR results reveal that a band near 540 cm(-1) may be assigned to acid phosphate. This band is present at high concentrations in new bone, and decreases as bone matures. Correlation of the nu(4) PO(4)(3-) contour with the nu(2) CO (3)(2-) contour also reveals that when acid phosphate content is high, type A carbonate content (i.e., carbonate occupying OH(-) sites in the hydroxyapatite lattice) is high. As crystallinity increases and acid phosphate content decreases, carbonate substitution shifts toward occupation of PO(4)(3-) sites in the hydroxyapatite lattice. Thus, IR microscopic analysis of the nu(4) PO(4)(3-) contour provides a straightforward index of both relative mineral crystallinity and acid phosphate concentration that can be applied to in situ IR micro-spectroscopic analysis of bone samples, which are of interest for understanding the chemical mechanisms of bone deposition in normal and pathological states.
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Affiliation(s)
- L M Miller
- Albert Einstein Center for Synchrotron Biosciences, Upton, NY 11973-5000, USA.
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Abstract
The objective of the study was to develop a scintigraphic method for measurement of airway mucociliary clearance in small laboratory rodents such as the mouse. Previous investigations have characterized the secretory cell types present in the mouse airway, but analysis of the mucus transport system has been limited to in vitro examination of tissue explants or invasive in vivo measures of a single airway, the trachea. Three methods were used to deposit insoluble, radioisotopic colloidal particles: oropharyngeal aspiration, intratracheal instillation, and nose-only aerosol inhalation. The initial distribution of particles within the lower respiratory tract was visualized by gamma-camera, and clearance of particles was followed intermittently over 6 h and at the conclusion, 24 h postdelivery. Subsets of mice underwent lavage for evidence of tissue inflammation, and others were restudied for reproducibility of the methods. The aspiration and instillation methods of delivery led to greater distributions of deposited activity within the lungs, i.e., approximately 60--80% of the total respiratory tract radioactivity, whereas the nose-only aerosol technique attained a distribution of 32% to the lungs. However, the aerosol technique maximized the fraction of particles that cleared the airway over a 24-h period, i.e, deposited onto airway epithelial surfaces and cleared by mucociliary function such that lung retention at 24 h averaged 57% for delivery by aerosol inhalation and > or =80% for the aspiration or intratracheal instillation techniques. Particle delivery methods did not cause lung inflammation/injury with use of inflammatory cells and chemoattractant cytokines as criteria. Scintigraphy can discern particle deposition and clearance from the lower respiratory tract in the mouse, is noninvasive and reproducible, and includes the capability for restudy and lung lavage when time course or chronic treatments are being considered.
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Affiliation(s)
- W M Foster
- Department of Pulmonary and Critical Care Medicine, Duke University Medical Center, Durham, North Carolina 27710, USA
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O'Connor DT, Tyrell EA, Kailasam MT, Miller LM, Martinez JA, Henry RR, Parmer RJ, Gabbai FB. Early alteration in glomerular reserve in humans at genetic risk of essential hypertension: mechanisms and consequences. Hypertension 2001; 37:898-906. [PMID: 11244015 DOI: 10.1161/01.hyp.37.3.898] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Essential hypertension has a familial predisposition, but the phenotype of elevated blood pressure has delayed penetrance. Because the kidney is a crucial determinant of blood pressure homeostasis, we studied early glomerular alterations in still-normotensive young subjects at genetic risk of hypertension. Thirty-nine normotensive adults (mean age 29 to 31 years), stratified by genetic risk (parental family history [FH]) of hypertension (26 with positive FH [FH+], 13 with negative FH [FH-]), underwent intravenous infusion of mixed amino acids. Before and during amino acid administration, we measured glomerular filtration rate (GFR), putative second messengers of amino acids (nitric oxide [NO.] metabolites and cGMP), serum insulin and amino acid concentrations, and the FE(Li)+ as an index of renal proximal tubular reabsorption. The FH+ group had a blunted GFR rise in response to amino acids (2.43+/-8.16% versus 31.0+/-13.4% rise, P:=0.0126). The amino acid-induced change in GFR correlated (r=0.786, P:<0.01) with the change in urinary NO. metabolite excretion; a diminished rise in urinary NO. metabolite excretion in the FH+ group (P:=0.0105) suggested a biochemical mechanism for the different GFR responses between FH groups: a relative inability to convert arginine to NO. The FH+ group had a far lower initial cGMP excretion at baseline (261+/-21.1 versus 579+/-84.9 nmol. h(-1)/1.73 m(2), P:=0.001), although cGMP did not change during the amino acid infusion (P:=0.703). FH status, baseline GFR, and baseline serum insulin jointly predicted GFR response to amino acids (P:=0.0013), accounting for approximately 45% of the variance in GFR response. Decline in FE(Li)+, an inverse index of proximal tubular reabsorption, paralleled increase in GFR (r=-0.506, P:=0.01), suggesting differences in proximal tubular reabsorption during amino acids between the FH groups. GFR response to amino acid infusion was blunted in the FH+ group despite significantly higher serum concentrations of 6 amino acids (arginine, isoleucine, leucine, methionine, phenylalanine, and valine) in the FH+ group, suggesting a novel form of insulin resistance (to the amino acid-translocating action of insulin) in FH+ subjects. We conclude that blunted glomerular filtration reserve in response to amino acids is an early-penetrance phenotype seen even in still-normotensive subjects at genetic risk of hypertension and is linked to impaired formation of NO. in the kidney. Corresponding changes in GFR and fractional excretion of Li(+) suggest that altered proximal tubular reabsorption after amino acids is an early pathophysiologic mechanism. Resistance to the amino acid-translocating actions of insulin may play a role in the biological response to amino acids in this setting. This glomerular reserve phenotype may be useful in genetic studies of renal traits preceding or predisposing to hypertension.
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Affiliation(s)
- D T O'Connor
- Department of Medicine and Center for Molecular Genetics, University of California at San Diego, San Diego, CA92161, USA.
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Chen X, Shao Z, Marinkovic NS, Miller LM, Zhou P, Chance MR. Conformation transition kinetics of regenerated Bombyx mori silk fibroin membrane monitored by time-resolved FTIR spectroscopy. Biophys Chem 2001; 89:25-34. [PMID: 11246743 DOI: 10.1016/s0301-4622(00)00213-1] [Citation(s) in RCA: 195] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The ethanol-induced conformation transition of regenerated Bombyx mori silk fibroin membrane from a poorly defined to the well ordered state was monitored by time-resolved Fourier transform infrared spectroscopy (FTIR) for the first time. From the analysis of FTIR difference spectra, taken on time scales as short as 6 s and up to 1 h after addition of ethanol, intensity vs. time plots of an increasing band at 1618 cm(-1) were observed indicating formation of a beta-sheet coincident with the loss of intensity of a band at 1668 cm(-1) indicating decreases of random coil and/or silk I structure. Both infrared markers were fitted with identical biphasic exponential decay functions, however, there was a clear burst phase occurring prior to the onset of the observed transitions. The conformation transition process is indicated to either proceed sequentially through (at least) two intermediate states that contain different levels of beta-sheet structure or to have parallel pathways of initial beta-sheet formation followed by a slower 'perfection' phase. The first observed process forms in a burst phase a few seconds after mixing (or even faster), prior to the collection of the first spectrum at 6 s. The second observed process occurs with a time constant of approximately 0.5 min, the intermediate present at this stage then continues with a time constant of 5.5 min completing the observed formation of the beta-sheet. The conformation transition of this slower intermediate is not only indicated by an analysis of the kinetics of the random coil and beta-sheet-specific bands discussed above, it roughly coincides with the appearance of an additional infrared marker at 1695 cm(-1), which may be a marker for beta-sheet structure specific to the formation of the perfected structure. The conformation transition of this protein analyzed by infrared spectroscopy provides insight into a part of the fascinating process of cocoon formation in B. mori.
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Affiliation(s)
- X Chen
- Department of Macromolecular Science, Fudan University, Shanghai, PR Chlina.
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Abstract
The lin-31 gene is required for the proper specification of vulval cell fates in the nematode Caenorhabditis elegans and encodes a member of the winged-helix family of transcription factors. Members of this important family have been identified in many organisms and are known to bind specific DNA targets involved in a variety of developmental processes. DNA sequencing of 13 lin-31 alleles revealed six nonsense mutations and two missense mutations within the DNA-binding domain, plus three deletions, one transposon insertion, and one frameshift mutation that all cause large-scale disruptions in the gene. The missense mutations are amino acid substitutions in the DNA-binding domain and probably disrupt interactions of the LIN-31 transcription factor with its DNA target. In addition, detailed phenotypic analysis of all 19 alleles showed similar penetrance for several characteristics examined. From our analysis we conclude: (1) the null phenotype of lin-31 is the phenotype displayed by almost all of the existing alleles, (2) the DNA-binding domain plays a critical role in LIN-31 function, and (3) direct screens for multivulva and vulvaless mutants will probably yield only null (or strong) alleles of lin-31.
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Affiliation(s)
- L M Miller
- Department of Biology, Santa Clara University, Santa Clara, California 95053, USA.
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Miller LM, Schreiner CE. Stimulus-based state control in the thalamocortical system. J Neurosci 2000; 20:7011-6. [PMID: 10995846 PMCID: PMC6772827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2000] [Revised: 06/29/2000] [Accepted: 07/05/2000] [Indexed: 02/17/2023] Open
Abstract
Neural systems operate in various dynamic states that determine how they process information (Livingstone and Hubel, 1981; Funke and Eysel, 1992; Morrow and Casey, 1992; Abeles et al., 1995; Guido et al., 1995; Mukherjee and Kaplan, 1995; Kenmochi and Eggermont, 1997; Wörgötter et al., 1998; Kisley and Gerstein, 1999). To investigate the function of a brain area, it is therefore crucial to determine the state of that system. One grave difficulty is that even under well controlled conditions, the thalamocortical network may undergo random dynamic state fluctuations which alter the most basic spatial and temporal response properties of the neurons. These uncontrolled state changes hinder the evaluation of state-specific properties of neural processing and, consequently, the interpretation of thalamocortical function. Simultaneous extracellular recordings were made in the auditory thalamus and cortex of the ketamine-anesthetized cat under several stimulus conditions. By considering the cellular and network mechanisms that govern state changes, we develop a complex stimulus that controls the dynamic state of the thalamocortical network. Traditional auditory stimuli have ambivalent effects on thalamocortical state, sometimes eliciting an oscillatory state prevalent in sleeping animals and other times suppressing it. By contrast, our complex stimulus clamps the network in a dynamic state resembling that observed in the alert animal. It thus allows evaluation of neural information processing not confounded by uncontrolled variations. Stimulus-based state control illustrates a general and direct mechanism whereby the functional modes of the brain are influenced by structural features of the external world.
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Affiliation(s)
- L M Miller
- W. M. Keck Center for Integrative Neuroscience, and University of California San Francisco/Berkeley Bioengineering Group, University of California Medical Center, San Francisco, California 94143, USA.
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Miller LM, Tibrewala J, Carlson CS. Examination of bone chemical composition in osteoporosis using fluorescence-assisted synchrotron infrared microspectroscopy. Cell Mol Biol (Noisy-le-grand) 2000; 46:1035-44. [PMID: 10976861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Although it is clear that osteoporosis is associated with a reduction in bone mass and a fragile skeleton, it is not understood whether the chemical composition of osteoporotic bone is different from normal bone. In this study, cynomolgus monkeys (Macaca fascicularis) were administered fluorochrome labels at one and two years after ovariectomy (Ovx) or Sham ovariectomy (intact), that were taken up into newly remodeled bone. Using fluorescence-assisted synchrotron infrared microspectroscopy, the chemical composition of bone from intact versus Ovx monkeys has been compared. Results from overall composition distributions (labeled + non-labeled bone) reveal similar carbonate/protein and phosphate/protein ratios, but increased acid phosphate content and different collagen structure in the Ovx animals. Analysis of the fluorochrome-labeled bone indicates similar degrees of mineralization in bone remodeled after one year, but decreased mineralization in Ovx bone remodeled two years after surgery. Thus, bone from monkeys with osteoporosis can be characterized as having abnormal collagen structure and reduced rates of mineralization. Coupled with factors such as trabecular architecture and bone shape and size, these ultrastructural factors may play a contributing role in the increased bone fragility in osteoporosis.
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Affiliation(s)
- L M Miller
- National Synchrotron Light Source, Brookhaven National Laboratory, Upton, NY 11973-5000, USA.
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Abstract
In hybrid studies, potential for error is high when classifying genealogical origins of individuals (e.g., parental, F1, F2) based on their genotypic arrays. For codominant markers, previous researchers have considered the probability of misclassification by genotypic inspection and proposed alternative maximum-likelihood approaches to estimating genealogical class frequencies. Recently developed dominant marker systems may significantly increase the number of diagnostic loci available for hybrid studies. I examine probabilities of classification error based on the number of dominant loci. As in earlier studies, I assume that only parental and first- and second-generation hybrid crosses between two taxa potentially exist. Thirteen loci with dominant expression from each parental taxon (i.e., 26 total loci) are needed to reduce classification error below 5% for F2 individuals, compared to 13 codominant loci for the same error rate. Use of loci in similar numbers from both taxa most efficiently increases power to characterize all genealogical classes. In contrast, classification of backcrosses to one parental taxon is wholly dependent on loci from the other taxon. Use of dominant diagnostic markers may increase the power and expand the use of maximum-likelihood methods for evaluating hybrid mixtures.
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Affiliation(s)
- L M Miller
- Department of Fisheries and Wildlife, University of Minnesota, St. Paul 55108, USA.
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Affiliation(s)
- F Zhao
- Department of Biochemistry, University of Minnesota, Minneapolis 55455, USA
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Zhao F, Ambady S, Ponce de León FA, Miller LM, Lunney JK, Grimm DR, Schook LB, Louis CF. Microsatellite markers from a microdissected swine chromosome 6 genomic library. Anim Genet 1999; 30:251-5. [PMID: 10467699 DOI: 10.1046/j.1365-2052.1999.00502.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To develop additional microsatellite (MS) markers in the region of the porcine skeletal muscle ryanodine receptor gene (RYR1), a microdissected genomic library was generated from the proximal half of the q arm of swine chromosome 6. Purified DNA was restriction enzyme-digested, ligated to oligonucleotide adaptors and amplified by PCR using primers complementary to the adaptor sequences. The purity of the amplified products and boundaries of the microdissected chromosomal region were verified by fluorescence in situ hybridization. (CA)n-containing sequences were then identified in a small insert genomic library generated from the PCR-amplified microdissected DNA. Oligonucleotide primers were developed for the PCR amplification of 30 of the 46 (CA)n repeat-containing clones, which were subsequently used to amplify DNA isolated from unrelated pigs of different breeds to determine the informativeness of these MS markers. Twenty-two of these MS markers were genotyped on the University of Illinois Yorkshire x Meishan swine reference population. These 22 markers were all assigned within a 50.7-CM region of the swine chromosome 6 linkage map, indicating the specificity of the microdissected library.
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Affiliation(s)
- F Zhao
- Department of Biochemistry, University of Minnesota, Minneapolis 55455, USA
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Anderson GM, Dallaire A, Miller LM, Miller CW. Peripheral nerve sheath tumor of the diaphragm with osseous differentiation in a one-year-old dog. J Am Anim Hosp Assoc 1999; 35:319-22. [PMID: 10416777 DOI: 10.5326/15473317-35-4-319] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A 12-month-old, spayed female German shepherd dog was referred to the Veterinary Teaching Hospital for repair of a diaphragmatic hernia. Abdominal exploration revealed an intact diaphragm, but thoracic exploration revealed a large mass originating from the diaphragm. Resection of the mass was incomplete and required reconstruction of the diaphragm. On histopathology, the mass was composed mainly of spindle-shaped cells with occasional areas of osseous and chondroid tissue. The tumor was diagnosed as a peripheral nerve sheath tumor (PNST) with chondro-osseous differentiation. The dog was released four days after surgery; however, she began having difficulty breathing seven days after discharge, and the owners elected euthanasia. A necropsy was not performed. This is the first known report of a PNST originating in the diaphragm of a dog.
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Affiliation(s)
- G M Anderson
- Department of Companion Animals, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Canada
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Hayward R, Ferrington DA, Kochanowski LA, Miller LM, Jaworsky GM, Schneider CM. Effects of dietary protein on enzyme activity following exercise-induced muscle injury. Med Sci Sports Exerc 1999; 31:414-20. [PMID: 10188746 DOI: 10.1097/00005768-199903000-00010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE The objective of this investigation was to determine the effects of varying levels of dietary protein on the postexercise increase in serum and muscle enzyme activity normally observed following exercise-induced muscle injury. METHODS Serum creatine kinase (CK), serum aspartate aminotransferase (AST), and muscle glucose-6-phosphate dehydrogenase (G-6-PD) activities were measured in rats fed for 10 d on high (50%), normal (12%), or low (4%) protein diets following a single bout of eccentric exercise (treadmill running at 16 m.min(-1), -16 degrees incline, 90 min). RESULTS The exercise intervention resulted in significant increases in serum CK and AST activities in all diet groups. Serum CK demonstrated peak activity immediately postexercise with increases reaching 910+/-94, 594+/-53, and 283+/-52 IU.L(-1) for animals on high, normal, and low protein diets, respectively. Similarly, peak postexercise AST activity for high, normal, and low protein diets reached 193+/-10, 147+/-3, and 162+/-9 IU.L(-1), respectively. The exercise intervention resulted in increases in muscle G-6-PD activity for all diet groups; however, LP rats demonstrated significantly lower values than NP or HP rats. CONCLUSIONS These data show that dietary protein intake can significantly effect both serum and muscle enzyme activity following acute exercise-induced muscle injury.
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Affiliation(s)
- R Hayward
- Department of Kinesiology, University of Northern Colorado, Greeley 80639, USA
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Borer SO, Miller LM, Kapuscinski AR. Microsatellites in walleye Stizostedion vitreum. Mol Ecol 1999; 8:336-8. [PMID: 10065550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Affiliation(s)
- S O Borer
- Department of Fisheries and Wildlife, University of Minnesota, St. Paul 55108, USA
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George LA, Miller LM, Valberg SJ, Mickelson JR. Fourteen new polymorphic equine microsatellites. Anim Genet 1998; 29:469-70. [PMID: 9883525] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Affiliation(s)
- L A George
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Minnesota, St Paul 55108, USA
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Abstract
The effects of knowledge on on-line reading strategies and the relation of these effects to subsequent memory performance among young and elderly adults were investigated. Participants read passages with vague, ill-defined content word-by-word on a computer screen for immediate recall and reading times were recorded. High-knowledge (HK) readers received passage titles that clarified the content and low-knowledge (LK) readers did not. Reading strategy was found to be related to age, knowledge, and subsequent recall performance. LK readers, particularly those who produced high levels of recall, spent differentially more time at intrasentence and sentence boundaries suggesting that they allocated more processing resources to consolidate the concepts in the seemingly disjointed text. HK readers, on the other hand, showed facilitation in this organizational processing. These beneficial effects were more pronounced for elderly readers than for younger readers, suggesting that older readers take special advantage of knowledge in the on-line processing of discourse. Moreover, older LK readers who were above average in recall were differentially slowed at boundaries showing that successful older readers who lacked a situation model with which to interpret text allocated differentially more time to organize and integrate text than did their younger counterparts.
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