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Zoulek S, Shriver J, Kaur N, Kuznicki B, Brandt EJ. Comparison of virtual vs face-to-face medical nutrition therapy in patients with hyperlipidemia. J Clin Lipidol 2024; 18:e44-e49. [PMID: 38040539 DOI: 10.1016/j.jacl.2023.11.005] [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] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 11/06/2023] [Accepted: 11/10/2023] [Indexed: 12/03/2023]
Abstract
Since the COVID-19 pandemic, utilization of telemedicine visits has increased. The outcomes of virtual compared to face-to-face (F2F) visits for treating hyperlipidemia are uncharacterized. This observational study compared pre- to post-visit change in lipid markers between 41 virtual and 151 F2F visits with a registered dietitian nutritionist at the University of Michigan Preventive Cardiology program from 3/31/2019-9/31/2022. Total cholesterol (TC), high-density lipoprotein (HDL), and triglycerides (TG) were collected pre- and post-visit with a median 33 days between collections. Low-density lipoprotein (LDL-C) was calculated using the Sampson equation. We used paired T-tests to evaluate mean change in lipid markers for each visit type between pre and post timepoints, and linear regression to compare virtual to F2F visits. There was a significant decrease in TC, LDL-C, and non-HDL-C for both visit types. There was no significant difference in mean change in lipid markers between virtual and F2F visits. Telehealth is a promising strategy for increasing access to medical nutrition therapy.
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Affiliation(s)
- Shannon Zoulek
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States.
| | - Jackson Shriver
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States
| | - Navkiranjot Kaur
- Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan, United States
| | - Beverly Kuznicki
- Department of Cardiovascular Medicine, University of Michigan, Ann Arbor, Michigan, United States
| | - Eric J Brandt
- Department of Cardiovascular Medicine, University of Michigan, Ann Arbor, Michigan, United States; Institute for Healthcare Policy and Innovation, University of Michigan, Ann Arbor, MI, United States
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2
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Badshah M, Nadeem I, Foerster CE, Tjarks BJ, Shriver J, Ahmed M. Photo-Induced Sweet Syndrome: A Case Report. S D Med 2023; 76:56-59. [PMID: 36898069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 03/12/2023]
Abstract
Sweet syndrome is a rare dermatologic condition frequently accompanied by fever and neutrophilia. Underlying triggers and etiology of the sweet syndrome remain elusive, although infection, malignancy, medications, and more rarely, sun exposure have been associated with its development. We present a case of a 50-year-old female who developed a painful, mildly pruritic rash on sun-exposed areas of the neck, arms, and legs. She also reported chills, malaise, and nausea upon presentation. Before developing the rash, she had preceding upper respiratory infection symptoms, used ibuprofen for joint pain, and had extensive sunlight exposure on the beach. Laboratory findings were significant for leukocytosis with absolute neutrophilia, elevated C-reactive protein, and elevated erythrocyte sedimentation rate. Skin punch biopsy demonstrated papillary dermal edema with dense neutrophilic infiltration. Further evaluation for hematologic or solid organ malignancy was negative. Following the administration of steroids, the patient demonstrated significant clinical improvement. While rare, ultraviolet A and B sunlight has been shown in rare situations to be associated with the development of the Sweet syndrome. The underlying mechanism for the development of photo-induced Sweet syndrome remains unknown. However, excessive sunlight exposure should be considered a potential cause when evaluating the underlying triggers for the development of the Sweet syndrome.
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Affiliation(s)
- Mashood Badshah
- University of South Dakota Sanford School of Medicine, Sioux Falls, South Dakota
| | - Ifrah Nadeem
- University of South Dakota Sanford School of Medicine, Sioux Falls, South Dakota
| | | | - Brian Joel Tjarks
- Department of Pathology, University of South Dakota Sanford School of Medicine, Sioux Falls, South Dakota.,Physicians Laboratory, Sioux Falls, South Dakota
| | - Jackson Shriver
- University of South Dakota Sanford School of Medicine, Sioux Falls, South Dakota
| | - Mohammad Ahmed
- Avera McKennan Hospital and University Health Center, Sioux Falls, South Dakota
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3
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Singh A, Shriver J, Coy K, Stys T, Stys A. Complex Coronary Intervention - When Time Is of Essence: Ping Pong Technique. S D Med 2022; 75:444-446. [PMID: 36889257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 03/10/2023]
Abstract
Coronary artery disease (CAD) continues to be a significant cause of morbidity and mortality in the U.S. The prognosis and treatment of which is dependent on various factors including type, size, localization and extent of the coronary plaque and severity of the stenosis. Management of critical ostial left main CAD poses peculiar challenges. The present case report demonstrates a unique percutaneous coronary intervention technique helpful in the management of such complex left main coronary lesions.
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Affiliation(s)
- Aditya Singh
- University of South Dakota Sanford School of Medicine, Sioux Falls, South Dakota
| | - Jackson Shriver
- University of South Dakota Sanford School of Medicine, Sioux Falls, South Dakota
| | - Kevin Coy
- University of South Dakota Sanford School of Medicine, Sioux Falls, South Dakota
| | - Tomasz Stys
- Department of Internal Medicine, University of South Dakota Sanford School of Medicine, Sioux Falls, South Dakota
| | - Adam Stys
- Department of Internal Medicine, University of South Dakota Sanford School of Medicine, Sioux Falls, South Dakota.,Cardiovascular Disease and Interventional Cardiology Fellowship Program, University of South Dakota Sanford School of Medicine, Sioux Falls, South Dakota
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4
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Patrick R, Hegdahl D, Patrick R, Shriver J, Titus K, Ridgway T. Telemedicine in the Wake of COVID-19: A Statewide Demographic Study on Provider Utilization and Perspective In South Dakota. S D Med 2022; 75:294-299. [PMID: 36542567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
INTRODUCTION The COVID-19 pandemic has ushered in a rapid evolution of regulations surrounding telemedicine and the public's need for affordable, accessible, high-quality care at a distance. This necessity led to a rise in telemedicine demand that forced health systems to adapt, and for providers to witness the potential benefits and limitations of such services. METHODS In this analysis, Sanford Health EMR data was evaluated from Q2 of 2019 to Q2 of 2020 to compare specialty utilization of telemedicine and quantify percentage change within the midst of the COVID-19 pandemic. A survey was conducted to evaluate provider opinion within the Sanford Health system regarding demographics, usage, perceived benefits, and perceived barriers to this rapid adoption. RESULTS Results suggest that Sanford Health experienced a significant, 1,600 percent increase of telemedicine usage. Additionally, with this increased usage of telemedicine, provider opinion of telemedicine and its potential has improved. During the pandemic, a greater percentage of providers believe telemedicine is highly beneficial to their practice and a majority believe telemedicine will continue to play a vital role in their practice in the future. However, the barriers found within the survey included limited patient access, technical difficulties, reimbursement, and insurance coverage. CONCLUSIONS With the rapid increase in provider usage and the subsequent approval of providers, telemedicine has the potential to facilitate higher quality healthcare going forward. The COVID-19 pandemic has necessitated evolution and adoption of virtual media in medicine and has provided a unique glimpse into telemedicine's limitations and exceptional potential.
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Affiliation(s)
- Rebecca Patrick
- University of South Dakota Sanford School of Medicine.,Department of Surgery, Division of Plastic Surgery, University of Rochester Medical Center, Rochester, New York
| | - Dane Hegdahl
- University of South Dakota Sanford School of Medicine.,Department of Pediatrics, University of Utah, Salt Lake City, Utah
| | - Ryan Patrick
- University of South Dakota Sanford School of Medicine.,Department of Otolaryngology, Head and Neck Surgery, University of Rochester Medical Center, Rochester, New York
| | - Jackson Shriver
- University of South Dakota Sanford School of Medicine.,Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Katie Titus
- Berkeley School of Public Health, Berkeley, California
| | - Tim Ridgway
- University of South Dakota Sanford School of Medicine
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Grassel M, Yim D, Shriver J, Redlin T. Increased Incidence of Pyogenic Liver Abscess in a Midwest System With Emphasis on Rural Impact. Cureus 2022; 14:e21477. [PMID: 35223257 PMCID: PMC8858610 DOI: 10.7759/cureus.21477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/20/2022] [Indexed: 11/05/2022] Open
Abstract
Objective: To assess if hepatic abscess incidence in a Midwest cohort was higher in rural areas compared to metropolitan areas in relation to water infrastructure. Materials and methods: All cases of hepatic abscesses from Jan 1, 2016 through Dec 31, 2019 at Avera McKennan Hospital in Sioux Falls, South Dakota (SD), were retrospectively collected. Chart review was completed for each case for risk factor analysis. Microbiology cultures and patient demographic data were collected including age, gender, hometown, and ethnicity. Risk factors assessed included a history of abdominal surgery, gallbladder disease, sepsis, diverticulitis, cancer, and diabetes. The incidence of hepatic abscesses was calculated using the Poisson rate test and confidence interval equation. Averages of each risk factor were calculated. Finally, hometown was utilized to create a heatmap of disease burden and compared to the density of private wells. Results: Our data yielded 116 confirmed adult hepatic abscesses between 2016 and 2019. The corrected incidence per 100,000 hospitalized patients per year is 95.66. The Poisson exact probability P-value was <0.01. Rural areas had a higher per capita incidence of abscesses and higher density of private wells. Conclusions: The incidence of hepatic abscesses is higher than national averages in this single-center study of Avera McKennan Hospital. Demographics, especially geographic location, play an important role in abscess rates. Rural location may be affecting the incidence of hepatic abscesses, explaining the much higher than expected incidence in this study. Infrastructure could be a contributing factor as much of the rural area is reliant on untreated groundwater.
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Badshah M, Shriver J, Rynders B, Sjovold A, Shaukat MHS, Rajpurohit N. MODERNA mRNA-1273 vaccine-associated myopericarditis in a patient with a subclinical autoimmune predisposition. J Cardiol Cases 2021; 24:227-229. [PMID: 34868402 DOI: 10.1016/j.jccase.2021.09.007] [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: 06/30/2021] [Revised: 08/29/2021] [Accepted: 09/03/2021] [Indexed: 01/08/2023] Open
Abstract
We present a rare case of myopericarditis developing one day after the injection of the second dose of the MODERNA mRNA-1273 vaccine (Cambridge, MA, USA). The patient complained of typical positional chest pain with initial laboratory results significant for elevated troponin, erythrocyte sedimentation rate, and C-reactive protein. Autoimmune predisposition was suggested by elevated anti-nuclear antibodies and anti-Sjögren's-syndrome-related antigen A autoantibodies titers. Subsequent cardiac magnetic resonance imaging (cMRI) revealed mild global hypokinesis with an ejection fraction of 48%, diffuse pericardial hyperenhancement suggestive of acute pericarditis, and T2-weighted short tau inversion recovery apical septal hyperenhancement suggestive of myocardial edema. Based on clinical, laboratory, and cMRI findings, a diagnosis of acute myopericarditis was made and the patient was treated with colchicine and ibuprofen with prompt resolution of symptoms. Vaccine-associated myopericarditis is rare, however, there have been reports of myocarditis developing after smallpox vaccination. The American College of Rheumatology has expressed concern about flaring or development of autoimmune inflammatory rheumatic disease (AIIRD) after COVID vaccination. Further studies are required to quantify AIIRD flaring/development including myopericarditis after mRNA-1273 vaccination. <Learning objective: With the recent reports of myocarditis developing after COVID vaccination, our case report highlights the need for further studies to investigate a possible link between the mRNA-1273 vaccine and autoimmune inflammatory rheumatic disease development including myopericarditis. In addition to clinical findings and laboratory workup, our case also assesses the clinical utility of cardiac magnetic resonance imaging for the diagnosis of myopericarditis.>.
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Affiliation(s)
| | | | | | | | | | - Naveen Rajpurohit
- Department of Cardiology, University of South Dakota, Sioux Falls, SD, USA
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7
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Perrenoud AL, Heiberger G, Shriver J, Yim D. Endoleak and Pseudoaneurysm Formation in the Setting of Stent Graft Infection Following Endovascular Uretero-Arterial Fistula Repair: The Dreaded Complication. Cureus 2020; 12:e8830. [PMID: 32742842 PMCID: PMC7384727 DOI: 10.7759/cureus.8830] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The complication of uretero-arterial fistula after prolong ureteral stenting is well recognized. The treatment is primarily endovascular stenting across the fistulous communication accepting the potential risk of stent graft infection. Herein we present a case of a 71-year-old female who developed an uretero-arterial fistula after prolong ureteral stenting and exchanges following ileal conduit obstruction. Initial treatment with left common iliac stenting controlled the hematuria, but only temporarily. Repeat angiography revealed a type 1b endoleak requiring stent extension. Unfortunately, persistent hematuria necessitating further angiography showed the development of a saccular pseudoaneurysm around the stent graft requiring proximal stent extension. A nuclear medicine indium 111-tagged white blood cell scan with single-photon emission CT (SPECT)/CT confirmed stent graft infection. Conservative therapy with antibiotics failed, causing graft failure that ultimately required bypass surgery.
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Affiliation(s)
- Abby L Perrenoud
- Interventional Radiology, University of South Dakota Sanford School of Medicine, Sioux Falls, USA
| | - Garret Heiberger
- Interventional Radiology, University of South Dakota Sanford School of Medicine, Sioux Falls, USA
| | - Jackson Shriver
- Interventional Radiology, University of South Dakota Sanford School of Medicine, Sioux Falls, USA
| | - Douglas Yim
- Interventional Radiology, Avera McKennan Hospital and University Health Center, Sioux Falls, USA.,Medicine/Radiology, University of South Dakota Sanford School of Medicine, Sioux Falls, USA
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8
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Abstract
A simple procedure is introduced for accurately defining the precision with which the Cartesian coordinates of any macromolecular structure are determined by nuclear Overhauser data. The method utilizes an ensemble of structures obtained from an array of independent simulated data sets derived from a final structure. Using the noise-free, back-calculated NOE spectrum as the "true" NOE spectrum, simulated Monte Carlo data sets are created by superimposing onto the "true" spectrum Gaussian distributed noise with a standard deviation equal to that of the residuals. Full relaxation matrix refinements of the simulated data sets provide probability distributions of the Cartesian coordinates for each atom in the model. Molecular dynamics simulations are included to estimate the effect of sparse information on the precision. The procedure is applied here to the 22-residue peptide hormone motilin, and the results are compared to those obtained using the conventional method of analyzing multiple refinements using a single distance constraint set. The average root mean square deviation for alpha-carbon atoms in the central portion (Arg12-Arg18) of the single helix of motilin was determined to be 0.72 A by the Monte Carlo method, compared to 1.3 A determined by an analysis of the 10 best DIANA structures using the same number of constraints between the same atoms. The origin of the bias of the conventional method is discussed.
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Affiliation(s)
- J Shriver
- Department of Medical Biochemistry, School of Medicine, Southern Illinois University, Carbondale 62901
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9
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Edmondson S, Khan N, Shriver J, Zdunek J, Gräslund A. The solution structure of motilin from NMR distance constraints, distance geometry, molecular dynamics, and an iterative full relaxation matrix refinement. Biochemistry 1991; 30:11271-9. [PMID: 1958665 DOI: 10.1021/bi00111a012] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.7] [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: 12/29/2022]
Abstract
A model of the structure of the 22 amino acid residue gastrointestinal peptide hormone motilin in 30% hexafluoro-2-propanol has been obtained by using distance constraints obtained from two-dimensional nuclear Overhauser enhancements. A set of initial structures have been generated by using the distance geometry program DIANA, and 10 of these structures have been refined by using restrained molecular dynamics (AMBER). The resulting structures are virtually indistinguishable in terms of constraint violations and energies and display less than 0.5-A root mean square deviations (RMSD) of the backbone atom positions from Tyr7 to Lys20. A comparison of back-calculated and experimental NOE intensities indicates that RMSD's are not the best indicators of the goodness of fit or of the precision with which the structure is defined. The structure was further refined by fitting the experimental NOE data using an iterative full relaxation matrix analysis. The mean error between the observed and calculated backbone NOE intensities for the final refined structure was 0.23 for the full length of the molecule, 0.18 for the region from Glu9 to Lys20, and 0.29 for the region from Phe1 to Gly8. R factors for the same regions were 0.27, 0.19, and 0.43, respectively. All of the NOE-determined structures consistently display an alpha-helix which extends from Glu9 to Lys20. Considerable lack of definition of structure exists at the amino and carboxyl ends of the molecule and also in the vicinity of Thr6-Tyr7-Gly8. A tendency to form a wide turn appears to exist over the sequence Pro3-Ile4-Phe5-Thr6, but the structure in this region is not well defined by the NOE data.
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Affiliation(s)
- S Edmondson
- Department of Medical Biochemistry, School of Medicine, Southern Illinois University, Carbondale 62901
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10
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Lamm DL, DeHaven JI, Shriver J, Sarosdy MF. Prospective randomized comparison of intravesical with percutaneous bacillus Calmette-Guerin versus intravesical bacillus Calmette-Guerin in superficial bladder cancer. J Urol 1991; 145:738-40. [PMID: 2005691 DOI: 10.1016/s0022-5347(17)38439-2] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [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: 12/29/2022]
Abstract
Conflicting reports of the necessity for percutaneous bacillus Calmette-Guerin (BCG) administration with intravesical BCG prompted us to evaluate its benefit in a randomized prospective comparison of intravesical versus intravesical with percutaneous BCG therapy. Intravesical Tice BCG was given in a dose of 50 mg. with or without percutaneous BCG weekly for 6 weeks, at 8, 10 and 12 weeks, at 6 months and every 6 months thereafter. Tumor recurrence was documented in 13 of 30 patients (43%) receiving only intravesical BCG and in 15 of 36 patients (42%) receiving intravesical plus percutaneous BCG. The addition of percutaneous BCG to intravesical therapy did not increase treatment efficacy in this study.
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Affiliation(s)
- D L Lamm
- Department of Urology, West Virginia University Health Sciences Center, Morgantown
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11
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Lamm DL, DeHaven JI, Shriver J, Crispen R, Grau D, Sarosdy MF. A randomized prospective comparison of oral versus intravesical and percutaneous bacillus Calmette-Guerin for superficial bladder cancer. J Urol 1990; 144:65-7. [PMID: 2193172 DOI: 10.1016/s0022-5347(17)39367-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [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: 12/30/2022]
Abstract
Reports of a dramatic decrease in tumor recurrence and regression of muscle invasive disease with oral bacillus Calmette-Guerin prompted us to conduct a randomized prospective comparison of oral bacillus Calmette-Guerin with the standard intravesical plus percutaneous therapy. Oral therapy consisted of 200 mg. Tice bacillus Calmette-Guerin 3 times each week. Intravesical and percutaneous Tice bacillus Calmette-Guerin at a dose of 50 mg. was given weekly for 6 weeks, at 8, 10 and 12 weeks, then at 6 months and every 6 months thereafter. Minimal side effects confirmed the safety of oral bacillus Calmette-Guerin. Tumor recurrence was documented in 21 of 33 oral bacillus Calmette-Guerin patients (64%) and 18 of 55 (33%) who received intravesical plus percutaneous therapy (p less than 0.002, chi-square test). We were unable to demonstrate any antitumor activity of oral bacillus Calmette-Guerin in this study.
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Affiliation(s)
- D L Lamm
- Department of Urology, West Virginia University Health Sciences Center, Morgantown
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12
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Abstract
The solution structure of the 22-residue peptide hormone motilin has been studied by circular dichroism and two-dimensional 1H nuclear magnetic resonance spectroscopy. Circular dichroism spectra indicate the presence of alpha-helical secondary structure in aqueous solution, and the secondary structure can be stabilized with hexafluoro-2-propanol. Sequence-specific assignments of the proton NMR spectrum of porcine motilin in 30% hexafluoro-2-propanol have been made by using two-dimensional NMR techniques. All backbone proton resonances (NH and alpha CH) and most of the side-chain resonances have been assigned by using double-quantum-filtered COSY, RELAYED-COSY, and NOESY experiments. Simulations of NOESY cross-peak intensities as a function of mixing time indicate that spin diffusion has a relatively small effect in peptides the size of motilin, thereby allowing the use of long mixing times to confidently make assignments and delineate secondary structure. Sequential alpha CH-NH and NH-NH NOESY connectivities were observed over a significant portion of the length of the peptide. A number of medium-range NOESY cross-peaks indicate that the peptide is folded into alpha-helix from Glu9 to Lys20, which agrees favorably with the 50% helical content determined from CD measurements. The intensities of selected NOESY cross-peaks relative to corresponding diagonal peaks were used to estimate a rotational correlation time of approximately 2.5 ns for the peptide, indicating that the peptide exists as a monomer in solution under the conditions used here.
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Affiliation(s)
- N Khan
- Department of Medical Biochemistry, School of Medicine, Southern Illinois University, Carbondale 62901
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Abstract
Isolated rat and mouse extensor digitorum longus (EDL) and soleus muscles were studied under isometric and isotonic conditions at temperatures from approximately 8 degrees -38 degrees C. The rate constant for the exponential rise of tension during an isometric tetanus had a Q10 of approximately 2.5 for all muscles (corresponding to an enthalpy of activation, delta H = 66 kJ/mol, if the rate was determined by a single chemical reaction). The half-contraction time, contraction time, and maximum rate of rise for tension in an isometric twitch and the maximum shortening velocity in an isotonic contraction all had a similar temperature dependence (i.e., delta H approximately 66 kJ/mol). The Mg++ ATPase rates of myofibrils prepared from rat EDL and soleus muscles had a steeper temperature dependence (delta H = 130 kJ/mol), but absolute rates at 20 degrees C were lower than the rate of rise of tension. This suggests that the Mg++ ATPase cycle rate is not limiting for force generation. A substantial fraction of cross-bridges may exist in a resting state that converts to the force-producing state at a rate faster than required to complete the cycle and repopulate the resting state. The temperature dependence for the rate constant of the exponential decay of tension during an isometric twitch or short tetanus (and the half-fall time of a twitch) had a break point at approximately 20 degrees C, with apparent enthalpy values of delta H = 117 kJ/mol below 20 degrees C and delta H = 70 kJ/mol above 20 degrees C. The break point and the values of delta H at high and low temperatures agree closely with published values for the delta H of the sarcoplasmic reticulum (SR) Ca++ ATPase. Thus, the temperature dependence for the relaxation rate of a twitch or a short tetanus is consistent with that for the reabsorption rate of Ca++ into the SR.
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14
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Shriver J, Mateescu G, Fager R, Toricha D, Abrahamson EW. Unprotonated chromophore-protein bond in visual pigments from 13C-NMR spectra. Nature 1977; 270:271-4. [PMID: 563517 DOI: 10.1038/270271a0] [Citation(s) in RCA: 40] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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15
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Shriver J, Abrahamson EW, Mateescu GD. The structure of visual pigments. I. Carbon-13 nuclear magnetic resonance spectroscopy of N-all-trans-retinylidenepropylimine and its protonated species. J Am Chem Soc 1976; 98:2407-9. [PMID: 1262656 DOI: 10.1021/ja00425a006] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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