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Spencer B, Moreci R, Weller J, Evans J, Modi BP, Gray B, Ehrlich P, Ladd A, Lillehei C, Alaish S, Gadepalli S, Hirschl RB, Newman E, Zendejas B, Sandhu G. Defining Practice Readiness in Pediatric Surgery Fellowship: A Qualitative Analysis. J Surg Educ 2024; 81:503-513. [PMID: 38403502 DOI: 10.1016/j.jsurg.2024.01.003] [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] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 10/24/2023] [Accepted: 01/06/2024] [Indexed: 02/27/2024]
Abstract
INTRODUCTION While competency-based training is at the forefront of educational innovation in General Surgery, Pediatric Surgery training programs should not wait for downstream changes. There is currently no consensus on what it means for a pediatric surgery fellow to be "practice-ready". In this study, we aimed to provide a framework for better defining competency and practice readiness in a way that can support the Milestones system and allow for improved assessment of pediatric surgery fellows. METHODS For this exploratory qualitative study, we developed an interview guide with nine questions focused on how faculty recognize competency and advance autonomy among pediatric surgery fellows. Demographic information was collected using an anonymous online survey platform. We iteratively reviewed data from each interview to ensure adequate information power was achieved to answer the research question. We used inductive reasoning and thematic analysis to determine appropriate codes. Additionally, the Dreyfus model was used as a framework to guide interpretation and contextualize the responses. Through this method, we generated common themes. RESULTS A total of 19 pediatric surgeons were interviewed. We identified four major themes from 127 codes that practicing pediatric surgeons associate with practice-readiness of a fellow: skill-based competency, the recognition and benefits of struggle, developing expertise and facilitating autonomy, and difficulties in variability of evaluation. While variability in evaluation is not typically included in the concept of practice readiness, assessment and evaluation were described by study participants as essential aspects of how practicing pediatric surgeons perceive practice readiness and competency in pediatric surgery fellows. Competency was further divided into interpersonal versus technical skills. Sub-themes within struggle included personal and professional struggle, benefits of struggle and how to identify and assist those who are struggling. Autonomy was commonly stated as variable based on the attending. CONCLUSION Our analysis yielded several themes associated with practice readiness of pediatric surgery fellows. We aim to further refine our list of themes using the Dreyfus Model as our interpretive framework and establish consensus amongst the community of pediatric surgeons in order to define competency and key elements that make a fellow practice-ready. Further work will then focus on establishing assessment metrics and educational interventions directed at achieving such key elements.
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Affiliation(s)
- Brianna Spencer
- Section of Pediatric Surgery, Department of Surgery, University of Michigan Medical School, C.S. Mott Children's Hospital, Ann Arbor, Michigan.
| | - Rebecca Moreci
- Section of Pediatric Surgery, Department of Surgery, University of Michigan Medical School, C.S. Mott Children's Hospital, Ann Arbor, Michigan
| | - Jennine Weller
- Division of Pediatric Surgery, Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Julie Evans
- Department of Surgery, Michigan Medicine, Ann Arbor, Michigan
| | - Biren P Modi
- Department of Pediatric Surgery, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Brian Gray
- Division of Pediatric General Surgery, Department of Surgery, Indiana University School of Medicine, Riley Hospital for Children, Indianapolis, Indiana
| | - Peter Ehrlich
- Section of Pediatric Surgery, Department of Surgery, University of Michigan Medical School, C.S. Mott Children's Hospital, Ann Arbor, Michigan
| | - Alan Ladd
- Division of Pediatric General Surgery, Department of Surgery, Indiana University School of Medicine, Riley Hospital for Children, Indianapolis, Indiana
| | - Craig Lillehei
- Department of Pediatric Surgery, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Samuel Alaish
- Division of Pediatric Surgery, Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Samir Gadepalli
- Section of Pediatric Surgery, Department of Surgery, University of Michigan Medical School, C.S. Mott Children's Hospital, Ann Arbor, Michigan
| | - Ronald B Hirschl
- Section of Pediatric Surgery, Department of Surgery, University of Michigan Medical School, C.S. Mott Children's Hospital, Ann Arbor, Michigan
| | - Erika Newman
- Section of Pediatric Surgery, Department of Surgery, University of Michigan Medical School, C.S. Mott Children's Hospital, Ann Arbor, Michigan
| | - Benjamin Zendejas
- Department of Pediatric Surgery, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Gurjit Sandhu
- Department of Surgery, Michigan Medicine, Ann Arbor, Michigan
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Ladd A, Klaczkiewicz K, Gills S, Duru B. Standardization of Bulk Formula Recipes to Improve Safety in a Pediatric Hospital. J Acad Nutr Diet 2021. [DOI: 10.1016/j.jand.2021.06.126] [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: 10/20/2022]
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Rao R, Haddad F, Kaur S, Redkey J, Karcz A, Ladd A. Variable Patterns of Organisms Causing Central Line-Associated Blood Stream Infections in Patients Undergoing Gastrointestinal Surgery in the Pediatric Population. J Am Coll Surg 2019. [DOI: 10.1016/j.jamcollsurg.2019.08.475] [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: 10/25/2022]
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Mathurin S, Fay M, Archuleta S, Ladd A. Clinical Nutrition Staffing and Oversight of Formula Lab Operations Ensures Full Compliance with National Guidelines and Standards While Decreasing Formula Lab Related Errors. J Acad Nutr Diet 2018. [DOI: 10.1016/j.jand.2018.08.007] [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: 11/29/2022]
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Abstract
INTRODUCTION A hand and wrist disorder affects a patient's overall well-being and health-status. One concept serves as the foundation for all further consideration: in order to have confidence in your results when assessing patients with wrist and hand limitations, the clinician and researcher must choose standardised patient-oriented instruments that address the primary aims of the study. In this paper, we assess the quality of reviews published on patient oriented instruments in current use for assessing function of the hand and wrist joint. We highlight features of commonly used scales that improve readers' confidence in the choice and application of these outcome instruments. METHODS A literature search (1950-January 2010) was performed using the MESH terms: hand (strength, injuries, joints) and wrist (injuries, joint) combined with outcome and process assessment (questionnaires, outcome assessment, health status indicators, quality of life). Titles and abstracts (n=341) were screened by two reviewers independently. The GRADE approach was used to assess the quality of ten reviews and the inclusion of clinimetric properties were assessed using the COSMIN checklist. RESULTS We included three systematic reviews rated moderate to high (2 hand injury instrument reviews and 1 wrist fracture outcome review). Recommendations of use and an overview are provided for the disability of the arm, shoulder and hand questionnaire (DASH), QuickDASH, the Michigan hand questionnaire (MHQ), the patient-rated wrist hand evaluation outcome questionnaire (PRWHE) and the carpal tunnel questionnaire (CTQ) scales with established measurement properties. CONCLUSIONS The DASH, a region-specific 30-item questionnaire is the most widely tested instrument in patients with wrist and hand injuries. The MHQ can provide good value to patients with hand injuries. Although, the CTQ is the most sensitive to clinical change, the DASH and MHQ have shown to be sufficiently responsive to outcome studies of carpal tunnel syndrome. The PRWHE has a good construct validity and responsiveness, which is only slightly better than the DASH to assess patients with wrist injuries. As the quality of patient-oriented validation continues to increase then the instruments can be selected more carefully. We will then be able to see that the future orthopaedic care of patients with hand and wrist injuries may also improve.
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Affiliation(s)
- A Hoang-Kim
- St. Michael's Hospital, University of Toronto, Institute of Medical Science, Toronto, Canada.
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Thurgood J, Ladd A, Dierdorf SF. Presentation of an H-type tracheoesophageal fistula during general anesthesia. J Clin Anesth 2010; 22:576-7. [PMID: 21056822 DOI: 10.1016/j.jclinane.2010.02.009] [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] [Received: 11/20/2009] [Revised: 01/04/2010] [Accepted: 02/28/2010] [Indexed: 11/27/2022]
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Sizemore AW, Rabbani KZ, Ladd A, Applegate KE. Diagnostic performance of the upper gastrointestinal series in the evaluation of children with clinically suspected malrotation. Pediatr Radiol 2008; 38:518-28. [PMID: 18265969 DOI: 10.1007/s00247-008-0762-8] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2007] [Revised: 12/14/2007] [Accepted: 01/08/2008] [Indexed: 12/30/2022]
Abstract
BACKGROUND Malrotation is a congenital disorder of abnormal intestinal rotation and fixation that predisposes infants to potentially life-threatening midgut volvulus. Upper gastrointestinal tract (UGI) examination is sometimes equivocal and can lead to inaccurate diagnosis. OBJECTIVE To determine the diagnostic performance of UGI examinations in children who subsequently underwent a Ladd procedure for suspected malrotation or volvulus. MATERIALS AND METHODS We reviewed all children up to 21 years old who had undergone both a UGI examination and a Ladd procedure for possible malrotation across 9 years. Children were excluded if they had not undergone either a UGI examination or a Ladd procedure and if congenital abdominal wall defects were present. RESULTS Of 229 patients identified, 166 (59% male, median age 67 days) were included. Excluded were 47 without a UGI series, 12 with omphalocele or gastroschisis, 1 without verifiable operative data, 1 who had not undergone a Ladd procedure, and 2 older than 21 years. Of the 166 patients, 40% were neonates and 73% were <12 months old, and 31% presented with bilious vomiting and 15% with abdominal distention. Of 163 patients with surgically verified malrotation, 156 had a positive UGI examination, a sensitivity of 96%. There were two patients with a false-positive UGI examination and seven with false-negative examination. Jejunal position was normal in six of the seven with a false-negative examination and abnormal in the two with a false-positive examination. Of 38 patients with surgically verified volvulus, 30 showed volvulus on the UGI series. Five required bowel resection and three died. CONCLUSION Jejunal position can lead to inaccurate UGI series interpretation. Meticulous technique and periodic assessment of performance will help more accurately diagnose difficult or equivocal cases.
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Affiliation(s)
- Alecia W Sizemore
- Department of Radiology, Indiana University School of Medicine, Indianapolis, IN, USA
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8
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Abstract
BACKGROUND New techniques in imaging and surgery have made 3-dimensional anatomical knowledge an increasingly important goal of medical education. This study compared the efficacy of 2 supplemental, self-study methods for learning shoulder joint anatomy to determine which method provides for greater transfer of learning to the clinical setting. METHODS Two groups of medical students studied shoulder joint anatomy using either a second-generation virtual reality surgical simulator or images from a textbook. They were then asked to identify anatomical structures of the shoulder joint as they appeared in a videotape of a live arthroscopic procedure. RESULTS The mean identification scores, out of a possible score of 7, were 3.1 +/- 1.3 for the simulator group and 2.9 +/- 1.5 for the textbook group (P = 0.70). Student ratings of the 2 methods on a 5-point Likert scale were significantly different. The simulator group rated the simulator more highly as an effective learning tool than the textbook group rated the textbook (means of 3.2 +/- 0.7 and 2.6 +/- 0.5, respectively, P = 0.02). Furthermore, the simulator group indicated that they were more likely to use the simulator as a learning tool if it were available to them than the textbook group was willing to use the textbook (means of 4.0 +/- 1.2 and 3.0 +/- 0.9, respectively, P = 0.02). CONCLUSION Our results show that this surgical simulator is at least as effective as textbook images for learning anatomy and could enhance student learning through increased motivation. These findings provide insight into simulator development and strategies for learning anatomy. Possible explanations and future research directions are discussed.
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Affiliation(s)
- S Hariri
- Department of Orthopaedic Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
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Carney DE, Kokoska ER, Grosfeld JL, Engum SA, Rouse TM, West KM, Ladd A, Rescorla FJ. Predictors of successful outcome after cholecystectomy for biliary dyskinesia. J Pediatr Surg 2004; 39:813-6; discussion 813-6. [PMID: 15185202 DOI: 10.1016/j.jpedsurg.2004.02.017] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.8] [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] [Indexed: 02/08/2023]
Abstract
PURPOSE Laparoscopic cholecystectomy is accepted therapy for children with ill-defined abdominal pain and impaired gallbladder emptying (biliary dyskinesia). Follow-up shows poor clinical response in many of these patients. The purpose of this report is to identify clinical and radiographic predictors of successful outcome after cholecystectomy for biliary dyskinesia. METHODS The authors retrospectively reviewed records of 51 children after laparoscopic cholecystectomy for biliary dyskinesia (1990 to 2003). Clinical symptoms, radiographic findings, and pathology were evaluated. Subjective clinical improvement is stratified using an established patient satisfaction score. Logistic regression analysis determines statistically independent predictors of successful outcome. RESULTS Thirty-eight of 51 (75%) patients were available for follow-up. Twenty-seven of 38 (71%) patients reported complete resolution of symptoms. Nausea was the only symptom predictive of successful outcome by univariate analysis (odds ratio, 5.00). A cholecystokinin-stimulated, gallbladder ejection fraction less than 15% also predicts successful outcome (odds ratio, 8.00). Children with an ejection fraction greater than 15% did not have predictable resolution of symptoms. When present with pain and nausea, gallbladder emptying less than 15% has a positive predictive value of 93% and a negative predictive value of 81%. CONCLUSIONS Together, nausea, pain, and decreased gallbladder emptying (<15%) most reliably predict which children will benefit from cholecystectomy for biliary dyskinesia.
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Affiliation(s)
- David E Carney
- Section of Pediatric Surgery, Department of Surgery, Indiana University School of Medicine and the J.W. Riley Hospital for Children, Indianapolis, IN 46202, USA
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Mulvey M, Poppers J, Ladd A, Mohr I. A herpesvirus ribosome-associated, RNA-binding protein confers a growth advantage upon mutants deficient in a GADD34-related function. J Virol 1999; 73:3375-85. [PMID: 10074192 PMCID: PMC104102 DOI: 10.1128/jvi.73.4.3375-3385.1999] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.6] [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: 11/20/2022] Open
Abstract
The herpes simplex virus type 1 gamma34.5 gene product and the cellular GADD34 protein both contain similar domains that can regulate the activity of eukaryotic initiation factor 2 (eIF2), a critical translation initiation factor. Viral mutants that lack the GADD34-related function grow poorly on a variety of malignant human cells, as activation of the cellular PKR kinase leads to the accumulation of inactive, phosphorylated eIF2 at late times postinfection. Termination of translation prior to the completion of the viral reproductive cycle leads to impaired growth. Extragenic suppressors that regain the ability to synthesize proteins efficiently in the absence of the viral GADD34-related function have been isolated. These suppressor alleles are dominant in trans and affect the steady-state accumulation of several viral mRNA species. We demonstrate that deregulated expression of Us11, a virus-encoded RNA-binding, ribosome-associated protein is necessary and sufficient to confer a growth advantage upon viral mutants that lack a GADD34-related function. Ectopic expression of Us11 reduces the accumulation of the activated cellular PKR kinase and allows for sustained protein synthesis. Thus, an RNA-binding, ribosome-associated protein (Us11) and a GADD34-related protein (gamma34.5) both function in a signal pathway that regulates translation by modulating eIF2 phosphorylation.
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Affiliation(s)
- M Mulvey
- Department of Microbiology and Kaplan Comprehensive Cancer Center, New York University School of Medicine, New York, New York 10016, USA
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11
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Ladd A, Walfield A, Tsong YY, Thau R. Active immunization against LHRH alone or combined with LHRH-analogue treatment impedes growth of androgen-dependent prostatic carcinoma. Am J Reprod Immunol 1995; 34:200-6. [PMID: 8561879 DOI: 10.1111/j.1600-0897.1995.tb00939.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [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: 01/31/2023] Open
Abstract
PROBLEM To determine whether active immunization against LHRH can serve as treatment for androgen-dependent prostatic carcinoma. METHOD Male rats of Copenhagen X Fisher strain, implanted with Dunning R-3327 prostatic carcinoma cells were either immunized against LHRH, treated with LHRH-antagonist, or received a combined treatment of active immunization against LHRH and LHRH-antagonist. RESULTS Testicular histology was consistent with infertility in all treatment groups. The rate of tumor growth was inhibited by all three treatment regimens. Tumor size increased by 3.8 +/- 1.4 cm2 in the LHRH-antagonist group, 3.2 +/- 1.1 cm2 in the immunized group, and 1.0 +/- 0.4 cm2 in the combined treatment group, as compared to 8.2 +/- 2.6 cm2 in non-treated control group. CONCLUSION LHRH-antagonist administration combined with immunization against LHRH appeared to exert a synergistic effect. This may be due to the blockade of prostatic LHRH-like receptors by the antagonist, while androgen depletion was rapidly achieved by LHRH-antagonist, and maintained by continued gonadotropin suppression caused by active immunization against LHRH once antagonist treatment had been discontinued.
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Affiliation(s)
- A Ladd
- Population Council, Center for Biomedical Research, New York, New York, USA
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Schneider D, Patsy B, Ladd A, Prince J. Document imaging: long-term solution or stop-gap measure? Healthc Inform 1995; 12:58-60, 62. [PMID: 10141978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Just what exactly does a "paperless office" mean? To some healthcare professionals, it means just that-no use of paper documents whatsoever. But to others, "paperless" more or less means using paper documents to reach a higher level of electronic recording, in other words-document imaging. We asked four industry insiders to discuss their views and opinions on the use of document imaging in healthcare. Their comments follow.
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Ladd A, Tsong YY, Walfield AM, Thau R. Development of an antifertility vaccine for pets based on active immunization against luteinizing hormone-releasing hormone. Biol Reprod 1994; 51:1076-83. [PMID: 7888486 DOI: 10.1095/biolreprod51.6.1076] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [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: 01/27/2023] Open
Abstract
Male dogs and cats were immunized against LHRH in order to evaluate the feasibility of an immunological approach to pet contraception. In the first study, dogs were immunized with 100, 500, or 2500 micrograms of LHRH conjugated to tetanus toxoid. A significant decline in serum testosterone (T) levels was observed in all immunized dogs, reaching castration levels in some animals by Week 4 and remaining suppressed in all the immunized dogs through the course of the study. Testicular histology suggested arrest of spermatogenesis (infertility). The effects of "immunological castration" were reversible (study 2): steroidogenesis suppressed by "immunological castration" was restored as antibody titers declined. Effective antibodies were rapidly reinduced in dogs by a single injection of LHRH1-TT. In contrast, the level of antibodies induced in male cats (study 3) was not sufficient for "immunological castration." The conclusion was that active immunization against LHRH could provide a cost-effective, nonsurgical, reversible means to control the fertility of companion animals.
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Affiliation(s)
- A Ladd
- United Biomedical, Inc., Hauppauge, New York 11788
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Affiliation(s)
- A Ladd
- Population Council, Center for Biomedical Research, Hanppauge, NY
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Taylor GS, Ladd A, James J, Greene B, English D. Characterization of phosphatidic acid phosphohydrolase in neutrophil subcellular fractions. Biochim Biophys Acta 1993; 1175:219-24. [PMID: 8418897 DOI: 10.1016/0167-4889(93)90026-l] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
This investigation was designed to confirm the presence of PA phosphohydrolase in human neutrophils and to determine the distribution and characteristics of the enzyme in soluble and particulate subcellular fractions of disrupted neutrophils. Enzyme activity was detected in unseparated extracts of sonicated neutrophils. The majority of the recovered activity was recovered in a particulate fraction rich in neutrophil plasma-membrane markers; moderate levels (20%) of the total activity were recovered in the cytosol. While Mg2+ markedly potentiated the cytosolic but not the particulate activity, Ca2+ moderately inhibited both the cytosolic and particulate enzymes. The plasma-membrane-associated activity was absolutely dependent on detergent (0.5% Triton X-100) and displayed an apparent Km of 62 microM for phosphatidic acid. Enzyme activity was markedly inhibited by NaF, not influenced by excess glycerophosphate and slightly attenuated by propranolol, an inhibitor of PA phosphohydrolase in other systems. Preincubation of plasma membranes with N-ethylmaleimide at concentrations up to 25 mM had little effect on enzyme activity. However, activity in cytosolic and microsomal fractions of neutrophils were completely abolished by preincubation with N-ethylmaleimide at concentrations of less than 5 mM. We conclude that neutrophils possess a potent PA phosphohydrolase localized in their plasma membranes. Metabolism of cellular second-messengers by this enzyme may exert a profound effect on the functions of stimulated neutrophils.
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Affiliation(s)
- G S Taylor
- Bone Marrow Transplantation Laboratory, Methodist Hospital of Indiana, Indianapolis 46202
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Kumar N, Didolkar AK, Ladd A, Thau R, Monder C, Bardin CW, Sundaram K. Radioimmunoassay of 7 alpha-methyl-19-nortestosterone and investigation of its pharmacokinetics in animals. J Steroid Biochem Mol Biol 1990; 37:587-91. [PMID: 2278844 DOI: 10.1016/0960-0760(90)90405-a] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [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] [Indexed: 12/31/2022]
Abstract
A method for the measurement of 7 alpha-methyl-19-nortestosterone (7MENT) in serum/plasma by radioimmunoassay (RIA) is described. The antiserum, raised against 7 alpha-methyl-19-nortestosterone-3-O-oxime-bovine serum albumin, had a low titer (final dilution = 1:4500) and low affinity (Ka = 1.17 x 10(9) l/mol) but showed little or no cross-reactivity with several of the steroids tested. The sensitivity of the RIA was 28.2 pg/ml and the mean recovery of added cold steroid was 86 to 100%. Intra- and inter-assay coefficients of variation ranged from 4.3 to 7.3% and 7.3 to 8.4%, respectively. This RIA was used to follow plasma 7MENT levels after a single i.v. injection of the steroid in rats and rabbits. The metabolic clearance rates (MCR) of 7MENT as determined from the plasma disappearance curve for rats and rabbits were 50 l/day and 336 l/day, respectively. The MCR of 7MENT in rats and rabbits lies in the same range as for testosterone. When compared to other nortestosterone derivatives such as norethisterone, 7MENT is metabolized relatively faster.
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Affiliation(s)
- N Kumar
- Center for Biomedical Research, Population Council, New York, NY 10021
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Abstract
UNLABELLED Active immunization against LHRH is a promising method of contraception for men. In order to be acceptable, sufficient amounts of anti-LHRH antibodies must be induced rapidly after vaccination. In previously reported animal studies, we found that it took considerable time (up to 5 months) to obtain antibody titers (AT) that were sufficiently high for complete suppression of spermatogenesis. The possibility of accelerating the immune response to LHRH by increasing the dose of immunogen was investigated in the male rat. Six doses of LHRH conjugated to tetanus toxoid (TT) in the 10 position (LHRH10-TT), ranging from 2.5 to 612 micrograms, and three doses of LHRH1-TT (50 to 612 micrograms) were tested. The magnitude of the immune response did not depend on the dose of the antigen, provided a threshold dose had been surpassed. Antigenicity of LHRH conjugated to TT at either the 1-, 6-, or 10-position was compared in rats and rabbits. In both species LHRH1-TT induced sufficient antibody concentrations to suppress pituitary gonadotropins (LH and FSH) and, subsequently, serum testosterone (T) levels faster than either the 6- or 10-conjugates. Only materials permitted for use in humans were utilized in these experiments. CONCLUSION Active immunization against LHRH conjugated to TT at the 1-position has potential as a fast, convenient method of male contraception.
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Affiliation(s)
- A Ladd
- Population Council, New York, NY 10021
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Abstract
The possibility of immunological suppression of spermatogenesis while normal libido is maintained by exogenous androgen supplementation was tested in male rats. Neither short- nor long-term treatment with androgen (testosterone-17-trans-4-N-butyl-cyclohexane carboxylate) alone influenced fertility. Active immunization against LHRH administered simultaneously with exogenous androgen supplement caused infertility in 100% of the tested animals, all of which displayed normal sexual behavior. The atrophy of the testes and accessory sex organs was reversible.
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Affiliation(s)
- A Ladd
- Population Council, New York, NY 10021
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Ladd A, Prabhu G, Tsong YY, Probst T, Chung W, Thau RB. Active immunization against gonadotropin-releasing hormone combined with androgen supplementation is a promising antifertility vaccine for males. Am J Reprod Immunol Microbiol 1988; 17:121-7. [PMID: 3144190 DOI: 10.1111/j.1600-0897.1988.tb00215.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Male rats and rabbits were immunized against gonadotropin-releasing hormone (GnRH) conjugated to tetanus toxoid (GnRH10-TT) using only materials approved for humans. Testosterone (T)-releasing implants or the long-lasting T ester testosterone-17-trans-4-n-butyl-cyclohexane carboxylate (TE) was used as supplemental androgen for maintaining libido. Immunization against GnRH10-TT effectively suppressed fertility (spermatogenesis) in rats and rabbits. Neither T nor TE administration restored fertility. Both androgens were effective in maintaining normal libido in rats. TE, which is not hydrolyzed in rabbits, was less effective in maintaining normal ejaculatory behavior in this species. Active immunization against GnRH could be a convenient and cost-effective method of fertility control in males.
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Affiliation(s)
- A Ladd
- Population Council, New York, NY 10021
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