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Gao JL, Sanz J, Tan N, King DS, Modest AM, Dommasch ED. Androgenetic alopecia incidence in transgender and gender diverse populations: A retrospective comparative cohort study. J Am Acad Dermatol 2023; 89:504-510. [PMID: 36780950 DOI: 10.1016/j.jaad.2023.01.037] [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: 08/25/2022] [Revised: 12/30/2022] [Accepted: 01/23/2023] [Indexed: 02/13/2023]
Abstract
BACKGROUND Androgenetic alopecia (AGA) is a significant challenge for many transgender and gender diverse (TGD) patients, but the rate of AGA among TGD patients receiving gender-affirming hormone therapy (GAHT) compared to cisgender patients has not yet been studied on a large scale. OBJECTIVE We examined the incidence of AGA among TGD patients receiving GAHT compared to cisgender patients. METHODS Retrospective cohort study using electronic health records from 37,826 patients seen at Fenway Health between August 1, 2014, and August 1, 2020. Crude and adjusted incidence rate ratios (aIRR) for AGA were calculated using Poisson regression. RESULTS TGD patients receiving masculinizing GAHT had aIRR 2.50, 95% CI 1.71-3.65 and 1.30, 95% CI 0.91-1.86 compared to cisgender women and cisgender men, respectively. The rate of AGA for TGD patients receiving feminizing GAHT was not significantly different compared to cisgender men but was significantly increased compared to cisgender women (aIRR 1.91, 95% CI 1.25-2.92). LIMITATIONS Inability to determine causation and limited generalizability. CONCLUSION TGD patients receiving masculinizing GAHT have 2.5 times the rate of AGA compared to cisgender women, whereas TGD patients on feminizing GAHT did not have a significantly increased rate of AGA compared to cisgender men.
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Affiliation(s)
- Julia L Gao
- Fenway Institute, Fenway Health, Boston, Massachusetts; Department of Dermatology, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Department of Medicine, Dartmouth Health, Lebanon, New Hampshire; George Washington University School of Medicine and Health Sciences, Washington, DC.
| | - Jessika Sanz
- Fenway Institute, Fenway Health, Boston, Massachusetts; Department of Dermatology, Beth Israel Deaconess Medical Center, Boston, Massachusetts; New York Institute College of Osteopathic Medicine, Jonesboro, Arkansas
| | - Nicholas Tan
- Fenway Institute, Fenway Health, Boston, Massachusetts; Department of Dermatology, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Case Western University School of Medicine, Cleveland, Ohio
| | - Dana S King
- Fenway Institute, Fenway Health, Boston, Massachusetts
| | - Anna M Modest
- Department of Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Harvard Medical School, Boston, Massachusetts
| | - Erica D Dommasch
- Fenway Institute, Fenway Health, Boston, Massachusetts; Department of Dermatology, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Harvard Medical School, Boston, Massachusetts.
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McDowell MJ, King DS, Gitin S, Miller AS, Batchelder AW, Busch AB, Greenfield SF, Huskamp HA, Keuroghlian AS. Alcohol Use Disorder Treatment in Sexually and Gender Diverse Patients: A Retrospective Cohort Study. J Clin Psychiatry 2023; 84:23m14812. [PMID: 37656181 PMCID: PMC10535851 DOI: 10.4088/jcp.23m14812] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
Objective: While sexually and gender diverse (SGD) people have higher odds of alcohol use disorder (AUD) compared to heterosexual and cisgender people, AUD treatment access and use disparities are not well characterized. The purpose of this study is to assess differences in AUD treatment among SGD versus non-SGD populations. Methods: A retrospective cohort study was performed using data from a federally qualified health center electronic health record system in Boston, Massachusetts. Patients were 18 years or older with an International Classification of Diseases (ICD)-9 or ICD-10 AUD diagnosis and any clinic visit from January 2013 until June 2021 (N = 3,607). Treatment for AUD was identified using binary variables for medication prescription orders and visits for AUD. Results: Among patients identifying as lesbian/gay, 6.9% had an AUD diagnosis, as compared to 2.6% of patients identifying as straight/heterosexual (P < .001). The prevalence of AUD was higher in the gender diverse group as compared to the cisgender group (5.5% vs 4.4%, P < .001). There were no significant differences in receipt of a prescription for injectable naltrexone, acamprosate, or disulfiram between SGD and non-SGD patients. For oral naltrexone, 16.1% of sexually diverse patients received a prescription, as compared to 9.8% of straight/heterosexual patients (P < .001). For visits, both the straight/heterosexual cohort and the cisgender cohorts had the lowest proportion of AUD-related pharmacotherapy and individual psychotherapy visits, as compared to SGD cohorts. Conclusions: SGD patients had higher proportions of AUD diagnosis and AUD care utilization through behavioral health as compared to non-SGD patients.
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Affiliation(s)
- Michal J McDowell
- Department of Psychiatry, Massachusetts General Hospital, Boston
- McLean Hospital, Belmont, Massachusetts
- Department of Psychiatry, Harvard Medical School, Boston, Massachusetts
- Corresponding Author: Michal McDowell, MD, MPH, 15 Parkman St, WACC 812, Boston, MA 02114
| | - Dana S King
- The Fenway Institute, Fenway Health, Boston, Massachusetts
| | - Sy Gitin
- The Fenway Institute, Fenway Health, Boston, Massachusetts
| | - Amitai S Miller
- Department of Psychiatry, Harvard Medical School, Boston, Massachusetts
| | - Abigail W Batchelder
- Department of Psychiatry, Massachusetts General Hospital, Boston
- The Fenway Institute, Fenway Health, Boston, Massachusetts
- Department of Psychiatry, Harvard Medical School, Boston, Massachusetts
| | - Alisa B Busch
- McLean Hospital, Belmont, Massachusetts
- Department of Psychiatry, Harvard Medical School, Boston, Massachusetts
- Department of Health Care Policy, Harvard Medical School, Boston, Massachusetts
| | - Shelly F Greenfield
- McLean Hospital, Belmont, Massachusetts
- Department of Psychiatry, Harvard Medical School, Boston, Massachusetts
| | - Haiden A Huskamp
- Department of Health Care Policy, Harvard Medical School, Boston, Massachusetts
| | - Alex S Keuroghlian
- Department of Psychiatry, Massachusetts General Hospital, Boston
- The Fenway Institute, Fenway Health, Boston, Massachusetts
- Department of Psychiatry, Harvard Medical School, Boston, Massachusetts
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Sanz J, Gao JL, King DS, Modest AM, Dommasch ED. Prevalence of rosacea in transgender and gender-diverse populations: a retrospective cohort study. Br J Dermatol 2023; 188:304-306. [PMID: 36763873 DOI: 10.1093/bjd/ljac041] [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] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 09/26/2022] [Accepted: 10/24/2022] [Indexed: 01/22/2023]
Abstract
Hormones have been shown to affect the pathophysiology of rosacea, however, the prevalence of rosacea in transgender and gender diverse (TGD) patients on gender affirming hormone therapy (GAHT) has never been studied. Our retrospective cohort study showed a significantly decreased prevalence TGD patients on feminizing GAHT compared to cisgender men, women, and TGD not on GAHT. Our results suggest that estrogen and/or anti-androgenetic agents may play a protective role in the development or course of rosacea.
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Affiliation(s)
- Jessika Sanz
- The Fenway Institute, Fenway Health, Boston, MA, USA
- Department of Dermatology, Beth Israel Deaconess Medical Center, Boston, MA, USA
- New York Institute College of Osteopathic Medicine, Jonesboro, AR, USA
| | - Julia L Gao
- George Washington University School of Medicine & Health Sciences, Washington, DC, USA
| | - Dana S King
- The Fenway Institute, Fenway Health, Boston, MA, USA
| | - Anna M Modest
- Department of Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, Boston, MA, USA and
- Harvard Medical School, Boston, MA, USA
| | - Erica D Dommasch
- The Fenway Institute, Fenway Health, Boston, MA, USA
- Department of Dermatology, Beth Israel Deaconess Medical Center, Boston, MA, USA
- Harvard Medical School, Boston, MA, USA
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Gao JL, King DS, Modest AM, Dommasch ED. Acne risk in transgender and gender diverse populations: A retrospective, comparative cohort study. J Am Acad Dermatol 2022; 87:1198-1200. [PMID: 35283245 DOI: 10.1016/j.jaad.2022.03.013] [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] [Received: 09/23/2021] [Revised: 03/03/2022] [Accepted: 03/03/2022] [Indexed: 10/31/2022]
Affiliation(s)
- Julia L Gao
- Fenway Institute, Fenway Health, Boston, Massachusetts; Department of Dermatology, Beth Israel Deaconess Medical Center, Boston, Massachusetts; George Washington University School of Medicine & Health Sciences, Washington, District of Columbia.
| | - Dana S King
- Fenway Institute, Fenway Health, Boston, Massachusetts
| | - Anna M Modest
- Department of Obstetrics and Gynecology, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Department of Obstetrics, Gynecology and Reproductive Biology, Harvard Medical School, Boston, Massachusetts
| | - Erica D Dommasch
- Fenway Institute, Fenway Health, Boston, Massachusetts; Department of Dermatology, Beth Israel Deaconess Medical Center, Boston, Massachusetts; Harvard Medical School, Boston, Massachusetts
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Thoreson N, Grasso C, Potter J, King DS, Peebles JK, Dommasch ED. Incidence and Factors Associated With Androgenetic Alopecia Among Transgender and Gender-Diverse Patients Treated With Masculinizing Hormone Therapy. JAMA Dermatol 2021; 157:348-349. [PMID: 33566078 DOI: 10.1001/jamadermatol.2020.5475] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Nick Thoreson
- Boston University School of Medicine, Boston, Massachusetts.,The Fenway Institute, Fenway Health, Boston, Massachusetts.,Beth Israel Deaconess Medical Center, Department of Dermatology, Boston, Massachusetts
| | - Chris Grasso
- The Fenway Institute, Fenway Health, Boston, Massachusetts
| | - Jennifer Potter
- The Fenway Institute, Fenway Health, Boston, Massachusetts.,Beth Israel Deaconess Medical Center, Department of Medicine, Boston, Massachusetts.,Harvard Medical School, Boston, Massachusetts
| | - Dana S King
- The Fenway Institute, Fenway Health, Boston, Massachusetts
| | - J Klint Peebles
- Kaiser Permanente Mid-Atlantic Permanente Medical Group, Department of Dermatology, Rockville, Maryland
| | - Erica D Dommasch
- The Fenway Institute, Fenway Health, Boston, Massachusetts.,Beth Israel Deaconess Medical Center, Department of Dermatology, Boston, Massachusetts.,Harvard Medical School, Boston, Massachusetts
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Thoreson N, Park JA, Grasso C, Potter J, King DS, Marc LG, Shen C, Peebles JK, Dommasch ED. Incidence and Factors Associated With Acne Among Transgender Patients Receiving Masculinizing Hormone Therapy. JAMA Dermatol 2021; 157:290-295. [PMID: 33471082 DOI: 10.1001/jamadermatol.2020.5347] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Importance Acne is a common condition among transgender patients receiving masculinizing hormone therapy (MHT), but the incident risk and predictors of developing acne in this population have not yet been studied on a large scale. Objective To assess risk of acne among a large population of transgender patients receiving MHT and clinical risk factors for acne diagnosis. Design, Setting, and Participants A retrospective cohort study that included 988 patients who started MHT between January 1, 2014, and December 31, 2017, with at least 1 year of follow-up was performed. Data analysis was conducted from September 1 to 15, 2019. Data were obtained using electronic health records from a community health center serving the sexual and gender minority community. The population included every patient who began receiving MHT during the study period who was aged 18 years or older at the time of MHT initiation and whose assigned sex at birth was female. Main Outcomes and Measures The main outcome was acne defined by International Statistical Classification of Diseases, Tenth Revision, Clinical Modification codes for acne. Overall prevalence and incidence proportions over 2 years after initiation of MHT were calculated. Baseline demographic and clinical characteristics were collected at the time of MHT initiation. A series of univariate analyses for all factors was calculated to test for an association with acne diagnosis, followed by multivariate analyses to test for independent predictors. Results For 988 patients (median age, 25.8 years; interquartile range, 20.8-28.2 years), there was an overall acne prevalence of 31.1% (n = 307). The 1-year post-MHT acne incidence proportion was 19.0% and the 2-year incidence proportion was 25.1%. A younger age at MHT initiation was associated with a higher likelihood of developing acne, with a median of 22.4 years (interquartile range, 19.7-25.6 years) among patients who developed acne vs 24.7 years (interquartile range, 21.3-29.4 years) among patients who did not (P = .002). Conclusions and Relevance Acne is a common condition among transgender patients on MHT, with a prevalence increasing from 6.3% to 31.1% following MHT initiation. Patients aged 18 to 21 years appear to be the most likely to develop acne after MHT initiation.
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Affiliation(s)
- Nick Thoreson
- Medical student, Boston University School of Medicine, Boston, Massachusetts.,The Fenway Institute, Fenway Health, Boston, Massachusetts.,Department of Dermatology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
| | - Jason A Park
- Medical student, Boston University School of Medicine, Boston, Massachusetts.,The Fenway Institute, Fenway Health, Boston, Massachusetts
| | - Chris Grasso
- The Fenway Institute, Fenway Health, Boston, Massachusetts
| | - Jennifer Potter
- The Fenway Institute, Fenway Health, Boston, Massachusetts.,Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts.,Harvard Medical School, Boston, Massachusetts
| | - Dana S King
- The Fenway Institute, Fenway Health, Boston, Massachusetts
| | - Linda G Marc
- The Fenway Institute, Fenway Health, Boston, Massachusetts.,Department of Biostatistics, Harvard T. H. Chan School of Public Health, Boston, Massachusetts
| | - Changyu Shen
- Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts.,Harvard Medical School, Boston, Massachusetts
| | - J Klint Peebles
- Department of Dermatology, Kaiser-Permanente Mid-Atlantic Permanente Medical Group, Rockville, Maryland
| | - Erica D Dommasch
- The Fenway Institute, Fenway Health, Boston, Massachusetts.,Department of Dermatology, Beth Israel Deaconess Medical Center, Boston, Massachusetts.,Harvard Medical School, Boston, Massachusetts
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Thoreson N, Marks DH, Peebles JK, King DS, Dommasch E. Health Insurance Coverage of Permanent Hair Removal in Transgender and Gender-Minority Patients. JAMA Dermatol 2020; 156:561-565. [PMID: 32211825 DOI: 10.1001/jamadermatol.2020.0480] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Importance Hair removal can be an essential component of the gender affirmation process for gender-minority (GM) patients whose outward appearance does not align with their gender identity. Objective To examine the health insurance policies in the Affordable Care Act (ACA) marketplace and Medicaid policies for coverage of permanent hair removal for transgender and GM patients and to correlate the policies in each state with statewide protections of coverage for gender-affirming care. Design and Setting Private health insurance policies available on the ACA marketplace and statewide Medicaid policies were examined in a cross-sectional study from September 1 to October 31, 2019, and January 17 to 30, 2020. Policies were assessed for coverage of permanent hair removal. Language concerning hair removal was found in each policy's medical or clinical coverage guidelines and separated into general categories. Main Outcomes and Measures Logistic regression analyses were performed to compare Medicaid policies and ACA policies in states with and without transgender protections. Results A total of 174 policies were analyzed, including 123 private insurance policies and 51 statewide Medicaid policies. Of these policies, 8 (4.6%) permitted the coverage of permanent hair removal without explicit restrictions. The remaining 166 policies (95.4%) broadly excluded or did not mention gender-affirming care; prohibited coverage of hair removal or did not mention it; or only permitted coverage of hair removal preoperatively for genital surgery. The ACA marketplace policies in states without transgender care protections were less likely to cover hair removal without restrictions than ACA policies in states with protections (2 of 85 policies [2.4%] in states without transgender care protections vs 5 of 38 policies [13.2%] in states with transgender care protections), and Medicaid policies were less likely to cover preoperative or nonsurgical hair removal compared with ACA policies (6 of 51 Medicaid policies [11.8%] vs 47 of 123 ACA policies [38.2%]). Conclusions and Relevance Despite adoption of statewide restrictions on GM health care exclusions by several states, most Medicaid and ACA policies examined in this study did not cover permanent hair removal for transgender patients. Many GM patients seeking hair removal may be required to pay out-of-pocket costs, which could be a barrier for gender-affirming care.
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Affiliation(s)
- Nick Thoreson
- Medical student, Boston University School of Medicine, Boston, Massachusetts
| | - Dustin H Marks
- Medical student, The George Washington University School of Medicine and Health Sciences, Washington, DC
| | - J Klint Peebles
- Department of Dermatology, Kaiser Permanente Mid-Atlantic Permanente Medical Group, Rockville, Maryland
| | - Dana S King
- The Fenway Institute, Fenway Health, Boston, Massachusetts
| | - Erica Dommasch
- Department of Dermatology, Beth Israel Deaconess Medical Center, Boston, Massachusetts
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Fortmann SP, Bailey SR, Brooks NB, Hitsman B, Rittner SS, Gillespie SE, Hill CN, Leo MC, Crawford PM, Hu W, King DS, O'Cleirigh C, Puro J, Ann McBurnie M. Trends in smoking documentation rates in safety net clinics. Health Serv Res 2020; 55:170-177. [PMID: 31930738 DOI: 10.1111/1475-6773.13259] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [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: 02/03/2023] Open
Abstract
OBJECTIVE To assess the impact of provider incentive policy on smoking status documentation. DATA SOURCES Primary data were extracted from structured electronic medical records (EMRs) from 15 community health centers (CHCs). STUDY DESIGN This was an observational study of data from 2006 to 2013, assessing changes in documentation of smoking status over time. DATA EXTRACTION METHODS We extracted structured EMR data for patients age 18 and older with at least one primary care visit. PRINCIPAL FINDINGS Rates of documented smoking status rose from 30 percent in 2006 to 90 percent in 2013; the largest increase occurred from 2011 to 2012 following policy changes (21.3% [95% CI, 8.2%, 34.4%] from the overall trend). Rates varied by clinic and across patient subgroups. CONCLUSIONS Documentation of smoking status improved markedly after introduction of new federal standards. Further improvement in documentation is still needed, especially for males, nonwhite patients, those using opioids, and HIV + patients. More research is needed to study whether changes in documentation lead to improvements in counseling, cessation, and patient outcomes.
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Affiliation(s)
| | - Steffani R Bailey
- Department of Family Medicine, Oregon Health and Science University, Portland, Oregon
| | - Neon B Brooks
- Kaiser Permanente Center for Health Research, Portland, Oregon
| | - Brian Hitsman
- Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois
| | | | | | | | - Michael C Leo
- Kaiser Permanente Center for Health Research, Portland, Oregon
| | | | - Weiming Hu
- Kaiser Permanente Center for Health Research, Portland, Oregon
| | | | - Conall O'Cleirigh
- The Fenway Institute, Boston, Massachusetts.,Massachusetts General Hospital, Boston, Massachusetts.,Harvard Medical School, Boston, Massachusetts
| | - Jon Puro
- Research Informatics and Analytics, OCHIN, Inc., Portland, Oregon
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Valentine SE, Peitzmeier SM, King DS, O'Cleirigh C, Marquez SM, Presley C, Potter J. Disparities in Exposure to Intimate Partner Violence Among Transgender/Gender Nonconforming and Sexual Minority Primary Care Patients. LGBT Health 2017; 4:260-267. [PMID: 28719246 DOI: 10.1089/lgbt.2016.0113] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [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: 11/12/2022] Open
Abstract
PURPOSE We investigated the odds of intimate partner violence (IPV) among primary care patients across subgroups of transgender and gender nonconforming (TGNC) individuals relative to cisgender women, and cisgender sexual minority men and women relative to cisgender heterosexual men and women. METHODS Participants completed an IPV screener as part of routine primary care visits at an urban community health center (N = 7572). Electronic medical record data were pooled for all patients who received the IPV screener January 1 to December 31, 2014. RESULTS Overall, 3.6% of the sample reported experiencing physical or sexual IPV in the past year. Compared to cisgender women (past-year prevalence 2.7%), all TGNC subgroups reported elevated odds of physical or sexual IPV, including transgender women (past-year prevalence 12.1%; adjusted odds ratio [AOR] = 5.0, 95% confidence interval [CI] = 2.9-8.6), transgender men (6.6%; AOR = 2.4, 95% CI: 1.2-4.6), gender non-binary individuals (8.2%, AOR = 3.1, 95% CI = 1.7-5.4), and TGNC individuals who did not report their gender identity (9.1%; AOR = 3.7, 95% CI = 2.2-6.3). The prevalence of isolation-related IPV and controlling behaviors was also high in some TGNC groups. CONCLUSION Our findings support that IPV is prevalent across genders and sexual orientations. Clinical guidelines for IPV screening should be expanded to include TGNC individuals and not just cisgender women. Future research could explore the complex patterns by which individuals of different genders are at increased risk for different types of IPV, and investigate the best ways to screen TGNC patients and support TGNC survivors.
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Affiliation(s)
- Sarah E Valentine
- 1 Department of Psychiatry, Boston Medical Center/ Boston University School of Medicine , Boston, Massachusetts
| | - Sarah M Peitzmeier
- 2 Department of Population, Family and Reproductive Health, Johns Hopkins School of Public Health , Baltimore, Maryland
| | - Dana S King
- 3 The Fenway Institute , Fenway Health, Boston, Massachusetts
| | - Conall O'Cleirigh
- 3 The Fenway Institute , Fenway Health, Boston, Massachusetts.,4 Department of Psychiatry, Massachusetts General Hospital/Harvard Medical School , Boston, Massachusetts
| | | | - Cara Presley
- 5 Behavioral Health Department, Fenway Health , Boston, Massachusetts
| | - Jennifer Potter
- 6 Division of General Internal Medicine, Beth Israel Deaconess Medical Center , Boston, Massachusetts
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Bazzi AR, Whorms DS, King DS, Potter J. Adherence to Mammography Screening Guidelines Among Transgender Persons and Sexual Minority Women. Am J Public Health 2015; 105:2356-8. [PMID: 26378843 DOI: 10.2105/ajph.2015.302851] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
We used retrospective (2012-2013) chart review to examine breast cancer screening among transgender persons and sexual minority women (n = 1263) attending an urban community health center in Massachusetts. Transgender were less likely than cisgender patients and bisexuals were less likely than heterosexuals and lesbians to adhere to mammography screening guidelines (respectively, adjusted odds ratios = 0.53 and 0.56; 95% confidence intervals = 0.31, 0.91 and 0.34, 0.92) after adjustment for sociodemographics. Enhanced cancer prevention outreach is needed among gender and sexual minorities.
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Affiliation(s)
- Angela Robertson Bazzi
- Angela Robertson Bazzi is with the Department of Community Health Sciences, Boston University School of Public Health, Boston, MA. Debra S. Whorms, Dana S. King, and Jennifer Potter are with Fenway Health, Boston. Jennifer Potter is also with the Harvard Medical School, Boston
| | - Debra S Whorms
- Angela Robertson Bazzi is with the Department of Community Health Sciences, Boston University School of Public Health, Boston, MA. Debra S. Whorms, Dana S. King, and Jennifer Potter are with Fenway Health, Boston. Jennifer Potter is also with the Harvard Medical School, Boston
| | - Dana S King
- Angela Robertson Bazzi is with the Department of Community Health Sciences, Boston University School of Public Health, Boston, MA. Debra S. Whorms, Dana S. King, and Jennifer Potter are with Fenway Health, Boston. Jennifer Potter is also with the Harvard Medical School, Boston
| | - Jennifer Potter
- Angela Robertson Bazzi is with the Department of Community Health Sciences, Boston University School of Public Health, Boston, MA. Debra S. Whorms, Dana S. King, and Jennifer Potter are with Fenway Health, Boston. Jennifer Potter is also with the Harvard Medical School, Boston
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King DS, Baskerville R, Hellsten Y, Senchina DS, Burke LM, Stear SJ, Castell LM. A-Z of nutritional supplements: dietary supplements, sports nutrition foods and ergogenic aids for health and performance-Part 34. Br J Sports Med 2012; 46:689-90. [PMID: 22711798 DOI: 10.1136/bjsports-2012-091314] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Affiliation(s)
- D S King
- Department of Kinesiology, Iowa State University, Ames, USA
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12
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King DS, Bollenbacher WE, Borst DW, Vedeckis WV, O'connor JD, Ittycheriah PI, Gilbert LI. The Secretion of alpha-Ecdysone by the Prothoracic Glands of Manduca sexta In Vitro. Proc Natl Acad Sci U S A 2010; 71:793-6. [PMID: 16592146 PMCID: PMC388100 DOI: 10.1073/pnas.71.3.793] [Citation(s) in RCA: 91] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Prothoracic glands of tobacco hornworm larvae cultured in vitro secrete into the culture medium a substance which was active in ecdysone bioassays and determined to be ecdysone-like by radioimmunoassay. The prothoracic glands appear to be the sole source of this substance. The material was identified as alpha-ecdysone by thin-layer, gas-liquid, and high-resolution liquid chromatography and mass spectrometry. No other active moulting principles were present in the medium. It appears that the prothoracic gland secretes a prohormone, alpha-ecdysone, which is subsequently converted into the active moulting hormone, beta-ecdysone, in other insect tissues.
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Affiliation(s)
- D S King
- Biochemistry Department, Zoëcon Corporation, Palo Alto, California 94304
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Abstract
AIMS To (i) develop a protocol that would eliminate or greatly reduce sporulation within Bacillus anthracis vegetative cells, and (ii) harvest an adequate number of cells and sufficient DNA suitable for molecular methods including Riboprint analysis and pulse field gel electrophoresis (PFGE). METHODS AND RESULTS Seven strains of B. anthracis (Ames, French B2, Heluky, Kruger, Pasteur, Sterne, and Vollum) were grown at 37, 42 and 45 degrees C under normal air, enhanced CO(2), microaerophilic, and anaerobic conditions on solid media and subcultured in two broths with and without supplements. The bacterial cells were centrifuged and washed. Slides made from the cell pellets were stained with Malachite Green and observed for the presence of spores. Cell preparations were subjected to 80 degrees C for 30 min and processed for and analysed by either Riboprinte or PFGE. Multiple pellets of each strain were processed, stained, placed onto solid culture media, incubated for 7 days and observed for growth. The cell preparations yielded clear and reproducible results with both molecular methods. None of the cell preparations yielded growth on the culture media. CONCLUSIONS This method eliminated viable spores in cell preparations of B. anthracis, yet still allowed the growth of vegetative cells to provide sufficient DNA suitable for analysis by Riboprinter and PFGE. SIGNIFICANCE AND IMPACT OF THE STUDY This method will provide safe cell preparations, prevent instrument contamination, and may be useful for other aerobic and anaerobic spore-formers.
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Affiliation(s)
- D S King
- Center for Biological Defense, College of Public Health, University of South Florida, Tampa, FL 33612, USA
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Davis KM, King DS, Philips L, Lu Y, Edwards RB, Kalscheur V, Markel MD. Comparison of surgical techniques for synovectomy in New Zealand White rabbits with induced inflammatory arthritis. Am J Vet Res 2004; 65:573-7. [PMID: 15141875 DOI: 10.2460/ajvr.2004.65.573] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [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
OBJECTIVE To compare effects of synovectomy performed by use of monopolar radiofrequency energy (MRFE) versus mechanical debridement in rabbits with induced inflammatory arthritis. ANIMALS 25 mature female New Zealand White rabbits. PROCEDURE Inflammatory arthritis was induced in both femoropatellar joints of each rabbit. Joints then were treated by mechanical debridement or MRFE treatment or served as sham-operated controls. Rabbits were euthanatized 2 weeks or 3 months after surgery. Biopsy specimens of synovium were analyzed by use of light microscopy. RESULTS At 2 weeks after surgery, samples from MRFE-treated joints had fewer plasma cells and more heterophils than the other 2 groups and more lymphocytes than sham-operated controls, whereas samples from mechanically debrided joints had greater numbers of lymphocytes and heterophils than sham-operated controls. At 3 months after surgery, samples from MRFE-treated joints had fewer plasma cells than sham-operated controls, more heterophils than mechanically debrided and sham-operated controls, and more macrophages than mechanically debrided joints. There was no difference in synovial ablation, synovial proliferation, or fibrosis among the 3 groups at 2 weeks or 3 months after surgery. CONCLUSIONS AND CLINICAL RELEVANCE Analysis of results of this study documented a similar degree of synovial ablation when comparing use of MRFE to mechanical debridement. In rabbits with this method of induced inflammatory arthritis, there were no detectable benefits of MRFE or mechanical debridement on the synovium, compared with results for sham-operated control joints, at 2 weeks and 3 months after surgery for most of the synovial variables evaluated.
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Affiliation(s)
- Kechia M Davis
- Comparative Orthopaedic Research Laboratory, Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, WI 53706, USA
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15
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Brown GA, Dewey JC, Brunkhorst JA, Vukovich MD, King DS. Changes in serum testosterone and estradiol concentrations following acute androstenedione ingestion in young women. Horm Metab Res 2004; 36:62-6. [PMID: 14983409 DOI: 10.1055/s-2004-814201] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [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: 10/26/2022]
Abstract
The effect of androstenedione intake on serum hormone concentrations in women is equivocal. Therefore, we examined the hormonal response to androstenedione intake in healthy young (22.1 +/- 0.4 y) women for 4 hours. On day 3 of the follicular phase, subjects ingested placebo, 100, or 300 mg androstenedione in a random, double-blind, cross-over manner. Blood samples were collected before and every 30 min for 240 min after intake. Serum androstenedione concentrations (means +/- SE) increased above basal (6.2 +/- 0.8 nmol/l) from 60-240 min for both 100 mg (22.6 +/- 1.0 nmol/l at 240 min) and 300 mg (28.1 +/- 1.3 nmol/l at 210 min). Androstenedione intake increased serum total testosterone concentrations above basal (1.2 +/- 0.2 nmol/l) from 120-240 min (5.5 +/- 0.9 nmol/l at 210 min) with 100 mg and from 60-240 with 300 mg (10.2 +/- 1.6 nmol/l at 210 min). Androstenedione intake also increased serum estradiol concentrations (basal 191 +/- 24 pmol/l) at 150 min with 100 mg (237 +/- 35 pmol/l) and from 150-240 min with 300 mg (reaching 260 +/- 32 pmol/l at 240 min). These data indicate that, in contrast to men, androstenedione intake in women increases serum testosterone concentrations.
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Affiliation(s)
- G A Brown
- Exercise Biochemistry Laboratory, Department of Health and Human Performance, Iowa State University, Ames, IA 50011, USA
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16
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Abstract
Obesity, now recognized as an independent risk factor for cardiovascular disease, is closely associated with hypertension. Complex mechanisms link increasing body weight with increasing blood pressure. Treatment of the obese patient with hypertension requires consideration of physiologic changes related to obesity hypertension. Lifestyle modification, including weight reduction and increased physical activity, can directly influence blood pressure levels and improve blood pressure control in obese, hypertensive patients. Clinical trials are needed to determine the most effective antihypertensive drugs for the obese, hypertensive patient. Antiobesity drugs offer viable adjunctive pharmacotherapy for obesity hypertension, but additional long-term studies are needed to support their safety and efficacy.
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Affiliation(s)
- M R Wofford
- Division of Hypertension, Department of Medicine, University of Mississippi Medical Center, Jackson, MS 39216-4505, USA.
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17
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Abstract
An array of regulatory protein and multi-subunit cofactors has been identified that directs eukaryotic gene transcription. However, establishing the specific functions of various related cofactors has been difficult owing to the limitations inherent in assaying transcription in animals and cells indirectly. Here we describe, using an integrated chromatin-dependent reconstituted transcription reaction, the purification and identification of a multi-subunit cofactor (PBAF) that is necessary for ligand-dependent transactivation by nuclear hormone receptors. A highly related cofactor, human SWI/SNF, and the ISWI-containing chromatin-remodelling complex ACF both fail to potentiate transcription. We also show that transcriptional activation mediated by nuclear hormone receptors requires TATA-binding protein (TBP)-associated factors (TAFs) as well as the multi-subunit cofactors ARC/CRSP. These studies demonstrate functional selectivity amongst highly related complexes involved in gene regulation and help define a more complete set of factors and cofactors required to activate transcription.
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Affiliation(s)
- B Lemon
- Department of Molecular and Cell Biology, Howard Hughes Medical Institute, 401 Barker Hall, University of California, Berkeley, CA 94720-3204, USA
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18
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Abstract
In recent years, the technology of solid-phase peptide synthesis (SPPS) has improved to the extent that chemical synthesis of small proteins may be a viable complementary strategy to recombinant expression. We have prepared several modified and wild-type prion protein (PrP) polypeptides, of up to 112 residues, that demonstrate the flexibility of a chemical approach to protein synthesis. The principal event in prion disease is the conformational change of the normal, alpha-helical cellular protein (PrPc) into a beta-sheet-rich pathogenic isoform (PrP(Sc)). The ability to form PrP(Sc) in transgenic mice is retained by a 106 residue 'mini-prion' (PrP106), with the deletions 23-88 and 141-176. Synthetic PrP106 (sPrP106) and a His-tagged analog (sPrP106HT) have been prepared successfully using a highly optimized Fmoc chemical methodology involving DCC/HOBt activation and an efficient capping procedure with N-(2-chlorobenzyloxycarbonyloxy) succinimide. A single reversed-phase purification step gave homogeneous protein, in excellent yield. With respect to its conformational and aggregational properties and its response to proteinase digestion, sPrP106 was indistinguishable from its recombinant analog (rPrP106). Certain sequences that proved to be more difficult to synthesize using the Fmoc approach, such as bovine (Bo) PrP(90-200), were successfully prepared using a combination of the highly activated coupling reagent HATU and t-Boc chemistry. To mimic the glycosylphosphatidyl inositol (GPI) anchor and target sPrP to cholesterol-rich domains on the cell surface, where the conversion of PrPc is believed to occur, a lipophilic group or biotin, was added to an orthogonally side-chain-protected Lys residue at the C-terminus of sPrP sequences. These groups enabled sPrP to be immobilized on either the cell surface or a streptavidin-coated ELISA plate, respectively, in an orientation analogous to that of membrane-bound, GPI-anchored PrPc. The chemical manipulation of such biologically relevant forms of PrP by the introduction of point mutations or groups that mimic post-translational modifications should enhance our understanding of the processes that cause prion diseases and may lead to the chemical synthesis of an infectious agent.
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Affiliation(s)
- H L Ball
- Institute for Neurodegenerative Diseases and Department of Neurology, University of California at San Francisco, 94143-0518, USA.
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19
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Brown GA, Vukovich MD, Martini ER, Kohut ML, Franke WD, Jackson DA, King DS. Endocrine and lipid responses to chronic androstenediol-herbal supplementation in 30 to 58 year old men. J Am Coll Nutr 2001; 20:520-8. [PMID: 11601567 DOI: 10.1080/07315724.2001.10719061] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.8] [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: 10/26/2022]
Abstract
OBJECTIVE The effectiveness of an androgenic nutritional supplement designed to enhance serum testosterone concentrations and prevent the formation of dihydrotestosterone and estrogen was investigated in healthy 3 to 58 year old men. DESIGN Subjects were randomly assigned to consume a nutritional supplement (AND-HB) containing 300-mg androstenediol, 480-mg saw palmetto, 450-mg indole-3-carbinol, 300-mg chrysin, 1,500 mg gamma-linolenic acid and 1.350-mg Tribulus terrestris per day (n = 28), or placebo (n = 27) for 28 days. Subjects were stratified into age groups to represent the fourth (30 year olds, n = 20), fifth (40 year olds, n = 20) and sixth (50 year olds, n = 16) decades of life. MEASUREMENTS Serum free testosterone, total testosterone, androstenedione, dihydrotestosterone, estradiol, prostate specific antigen and lipid concentrations were measured before supplementation and weekly for four weeks. RESULTS Basal serum total testosterone, estradiol, and prostate specific antigen (PSA) concentrations were not different between age groups. Basal serum free testosterone concentrations were higher (p < 0.05) in the 30- (70.5 +/- 3.6 pmol/L) than in the 50 year olds (50.8 +/- 4.5 pmol/L). Basal serum androstenedione and dihydrotestosterone (DHT) concentrations were significantly higher in the 30- (for androstenedione and DHT, respectively, 10.4 +/- 0.6 nmol/L and 2198.2 +/- 166.5 pmol/L) than in the 40- (6.8 +/- 0.5 nmol/L and 1736.8 +/- 152.0 pmol/L) or 50 year olds (6.0 +/- 0.7 nmol/L and 1983.7 +/- 147.8 pmol/L). Basal serum hormone concentrations did not differ between the treatment groups. Serum concentrations of total testosterone and PSA were unchanged by supplementation. Ingestion of AND-HB resulted in increased (p < 0.05) serum androstenedione (174%), free testosterone (37%), DHT (57%) and estradiol (86%) throughout the four weeks. There was no relationship between the increases in serum free testosterone, androstenedione, DHT, or estradiol and age (r2 = 0.08, 0.03, 0.05 and 0.02, respectively). Serum HDL-C concentrations were reduced (p < 0.05) by 0.14 mmol/L in AND-HB. CONCLUSIONS These data indicate that ingestion of androstenediol combined with herbal products does not prevent the formation of estradiol and dihydrotestosterone.
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Affiliation(s)
- G A Brown
- Department of Health and Hunan Performance, Iowa State University, Ames 50011, USA
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20
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Abstract
Several studies have demonstrated that oral glucose tolerance is impaired in the immediate postexercise period. A double-tracer technique was used to examine glucose kinetics during a 2-h oral glucose (75 g) tolerance test (OGTT) 30 min after exercise (Ex, 55 min at 71 +/- 2% of peak O(2) uptake) and 24 h after exercise (Rest) in endurance-trained men. The area under the plasma glucose curve was 71% greater in Ex than in Rest (P = 0.01). The higher glucose response occurred even though whole body rate of glucose disappearance was 24% higher after exercise (P = 0.04, main effect). Whole body rate of glucose appearance was 25% higher after exercise (P = 0.03, main effect). There were no differences in total (2 h) endogenous glucose appearance (R(a)E) or the magnitude of suppression of R(a)E, although R(a)E was higher from 15 to 30 min during the OGTT in Ex. However, the cumulative appearance of oral glucose was 30% higher in Ex (P = 0.03, main effect). There were no differences in glucose clearance rate or plasma insulin responses between the two conditions. These results suggest that adaptations in splanchnic tissues by prior exercise facilitate greater glucose output from the splanchnic region after glucose ingestion, resulting in a greater glycemic response and, consequently, a greater rate of whole body glucose uptake.
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Affiliation(s)
- A J Rose
- School of Health Sciences, Deakin University, Burwood, 3125 Victoria, Australia
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21
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Mizoue LS, Sullivan SK, King DS, Kledal TN, Schwartz TW, Bacon KB, Handel TM. Molecular determinants of receptor binding and signaling by the CX3C chemokine fractalkine. J Biol Chem 2001; 276:33906-14. [PMID: 11432858 DOI: 10.1074/jbc.m101348200] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [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: 11/06/2022] Open
Abstract
Fractalkine/CX3CL1 is a membrane-tethered chemokine that functions as a chemoattractant and adhesion protein by interacting with the receptor CX3CR1. To understand the molecular basis for the interaction, an extensive mutagenesis study of fractalkine's chemokine domain was undertaken. The results reveal a cluster of basic residues (Lys-8, Lys-15, Lys-37, Arg-45, and Arg-48) and one aromatic (Phe-50) that are critical for binding and/or signaling. The mutant R48A could bind but not induce chemotaxis, demonstrating that Arg-48 is a signaling trigger. This result also shows that signaling residues are not confined to chemokine N termini, as generally thought. F50A showed no detectable binding, underscoring its importance to the stability of the complex. K15A displayed unique signaling characteristics, eliciting a wild-type calcium flux but minimal chemotaxis, suggesting that this mutant can activate some, but not all, pathways required for migration. Fractalkine also binds the human cytomegalovirus receptor US28, and analysis of the mutants indicates that US28 recognizes many of the same epitopes of fractalkine as CX3CR1. Comparison of the binding surfaces of fractalkine and the CC chemokine MCP-1 reveals structural details that may account for their dual recognition by US28 and their selective recognition by host receptors.
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Affiliation(s)
- L S Mizoue
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA
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22
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Brown GA, Vukovich MD, Martini ER, Kohut ML, Franke WD, Jackson DA, King DS. Effects of androstenedione-herbal supplementation on serum sex hormone concentrations in 30- to 59-year-old men. INT J VITAM NUTR RES 2001; 71:293-301. [PMID: 11725694 DOI: 10.1024/0300-9831.71.5.293] [Citation(s) in RCA: 34] [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: 11/19/2022]
Abstract
The effectiveness of a nutritional supplement designed to enhance serum testosterone concentrations and prevent the formation of dihydrotestosterone and estrogens from the ingested androgens was investigated in healthy 30- to 59-year old men. Subjects were randomly assigned to consume DION (300 mg androstenedione, 150 mg dehydroepiandrosterone, 540 mg saw palmetto, 300 mg indole-3-carbinol, 625 mg chrysin, and 750 mg Tribulus terrestris per day; n = 28) or placebo (n = 27) for 28 days. Serum free testosterone, total testosterone, androstenedione, dihydrotestosterone, estradiol, prostate-specific antigen (PSA), and lipid concentrations were measured before and throughout the 4-week supplementation period. Serum concentrations of total testosterone and PSA were unchanged by supplementation. DION increased (p < 0.05) serum androstenedione (342%), free testosterone (38%), dihydrotestosterone (71%), and estradiol (103%) concentrations. Serum HDL-C concentrations were reduced by 5.0 mg/dL in DION (p < 0.05). Increases in serum free testosterone (r2 = 0.01), androstenedione (r2 = 0.01), dihydrotestosterone (r2 = 0.03), or estradiol (r2 = 0.07) concentrations in DION were not related to age. While the ingestion of androstenedione combined with herbal products increased serum free testosterone concentrations in older men, these herbal products did not prevent the conversion of ingested androstenedione to estradiol and dihydrotestosterone.
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Affiliation(s)
- G A Brown
- Exercise Biochemistry Laboratory, Department of Health and Human Performance, Iowa State University, Ames, IA, USA
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23
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Panton LB, Franke WD, Bleil DA, Baier SM, King DS. Effects of resistance training on cardiovascular responses to lower body negative pressure in the elderly. Clin Physiol 2001; 21:605-11. [PMID: 11576162 DOI: 10.1046/j.1365-2281.2001.00357.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The purpose of the present study was to determine whether resistance training alters the cardiovascular responses to submaximal lower body negative pressure (LBNP) in the elderly. Twenty-one subjects were randomized into a control (C: n=10; 70 +/- 3 years, mean +/- SD) or a resistance training (TR: n=11; 67 +/- 7 years) group. Subjects in the TR underwent 12 weeks of training consisting of three sets of 8-12 contractions at approximately 60-80% of their initial maximal one repetition, three times per week, on 10 different machines. Before (Pre) and after (Post) training, all subjects underwent exposures of LBNP of -10, -20 and -40 Torr and muscle biopsy sampling at the vastus lateralis. TR increased (P< or =0.05) knee extension (Pre=379 +/- 140 N, Post=534 +/- 182 N) and chest press (Pre=349 +/- 137 N, Post=480 +/- 192 N) strength. Neither body weight nor percentage body fat were altered (P >0.05) by training. Resistance training increased (P< or =0.05) cross-sectional area in both Type I (4203 +/- 1196 to 5248 +/- 1728 microm2) and Type II (3375 +/- 1027 to 4286 +/- 1892 microm2) muscle fibres. Forearm blood flow, forearm vascular conductance, mean arterial pressure, and heart-rate responses to LBNP were not altered by the training. These data suggest that the cardiovascular responses of elderly to LBNP are unaffected by 12 weeks of whole-body resistance training despite increases in muscle strength and size.
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Affiliation(s)
- L B Panton
- Department of Nutrition, Food and Exercise Sciences, Florida State University, 436 Sandels Building, Tallahassee, FL 32306, USA
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24
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Jeffery DA, Springer M, King DS, O'Shea EK. Multi-site phosphorylation of Pho4 by the cyclin-CDK Pho80-Pho85 is semi-processive with site preference. J Mol Biol 2001; 306:997-1010. [PMID: 11237614 DOI: 10.1006/jmbi.2000.4417] [Citation(s) in RCA: 65] [Impact Index Per Article: 2.8] [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: 11/22/2022]
Abstract
As part of a nutrient-responsive signaling pathway, the budding yeast cyclin-CDK complex Pho80-Pho85 phosphorylates the transcription factor Pho4 on five sites and inactivates it. Here, we describe the kinetic reaction between Pho80-Pho85 and Pho4. Through experimentation and computer modeling we have determined that Pho80-Pho85 phosphorylates Pho4 in a semi-processive fashion that results from a balance between kcat and k(off). In addition, we show that Pho80-Pho85 phosphorylates certain sites preferentially. Phosphorylation of the site with the highest preference inhibits the transcriptional activity of Pho4 when it is in the nucleus, while phosphorylation of the lowest-preference sites is required for export of Pho4 from the nucleus. This method of phosphorylation may allow Pho80-Pho85 to quickly inactivate Pho4 in the nucleus and efficiently phosphorylate Pho4 to completion.
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Affiliation(s)
- D A Jeffery
- Howard Hughes Medical Institute, Department of Biochemistry and Biophysics, University of California San Francisco, San Francisco, CA 94143, USA
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25
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Abstract
OBJECTIVE To describe the clinical findings in 52 racehorses with axial deviation of the aryepiglottic folds (ADAF) and to report outcome in 33 of these horses after either rest or transendoscopic laser excision of aryepiglottic fold tissue. STUDY DESIGN Retrospective study. ANIMAL OR SAMPLE POPULATION Racehorses admitted for high-speed treadmill (HST) evaluation of poor performance. METHODS Medical records and videotapes of resting and exercising videoendoscopic examinations were reviewed. Racing performance records and owner or trainer interviews, at least 1 year after HST examination, were used to compare results after either surgical management or rest in 33 horses with ADAF and no other upper-airway abnormalities. RESULTS ADAF occurred in 6% of horses evaluated for poor performance. No breed or gender predisposition existed, but horses with ADAF were younger than the overall population evaluated on the HST. Of 52 horses with ADAF, 19 horses had at least one other upper-airway abnormality. There was no apparent association between ADAF and other causes of dynamic upper-respiratory obstruction. Surgical correction was successfully performed in standing or anesthetized horses without complications. When ADAF was the only upper-airway obstruction, 75% of horses that had surgery and 50% of rested horses had objective improvement in performance. Owners and trainers also perceived greater improvement in performance in horses that had surgery. CONCLUSIONS Whereas surgical management of ADAF is recommended, clinical experience indicated that it is not required to resolve ADAF in all horses. However, owners and trainers of horses that had surgery were more satisfied with outcome than those with horses managed conservatively. CLINICAL RELEVANCE Diagnosis of ADAF can only be made by videoendoscopic evaluation during high-speed exercise. Transendoscopic laser excision of the collapsing portion of the aryepiglottic folds can be performed safely in standing horses and results in resolution of airway obstruction and rapid return to training.
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Affiliation(s)
- D S King
- Department of Clinical Studies, New Bolton Center, University of Pennsylvania, Kennett Square, PA, USA
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26
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Beernink PT, Yang YR, Graf R, King DS, Shah SS, Schachman HK. Random circular permutation leading to chain disruption within and near alpha helices in the catalytic chains of aspartate transcarbamoylase: effects on assembly, stability, and function. Protein Sci 2001; 10:528-37. [PMID: 11344321 PMCID: PMC2374132 DOI: 10.1110/ps.39001] [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] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
A collection of circularly permuted catalytic chains of aspartate transcarbamoylase (ATCase) has been generated by random circular permutation of the pyrB gene. From the library of ATCases containing permuted polypeptide chains, we have chosen for further investigation nine ATCase variants whose catalytic chains have termini located within or close to an alpha helix. All of the variants fold and assemble into dodecameric holoenzymes with similar sedimentation coefficients and slightly reduced thermal stabilities. Those variants disrupted within three different helical regions in the wild-type structure show no detectable enzyme activity and no apparent binding of the bisubstrate analog N:-phosphonacetyl-L-aspartate. In contrast, two variants whose termini are just within or adjacent to other alpha helices are catalytically active and allosteric. As expected, helical disruptions are more destabilizing than loop disruptions. Nonetheless, some catalytic chains lacking continuity within helical regions can assemble into stable holoenzymes comprising six catalytic and six regulatory chains. For seven of the variants, continuity within the helices in the catalytic chains is important for enzyme activity but not necessary for proper folding, assembly, and stability of the holoenzyme.
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Affiliation(s)
- P T Beernink
- Department of Molecular and Cell Biology, University of California at Berkeley, Berkeley, CA 94720, USA
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27
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Trostle SS, Peavey CL, King DS, Hartmann FA. Treatment of methicillin-resistant Staphylococcus epidermidis infection following repair of an ulnar fracture and humeroradial joint luxation in a horse. J Am Vet Med Assoc 2001; 218:554-9, 527. [PMID: 11229509 DOI: 10.2460/javma.2001.218.554] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [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
A 27-month-old Rocky Mountain Horse was examined because of a fracture of the proximal portion of the ulna and luxation of the humeroradial joint (Monteggia fracture). Open reduction was performed, using a mechanical distractor, and the ulnar fracture was stabilized by application of a bone plate and screws. After surgery, the horse developed an infection of the surgical site, and bacterial culture of fluid from the surgical site yielded a pure growth of methicillin-resistant Staphylococcus epidermidis susceptible to oxytetracycline, erythromycin, rifampin, and vancomycin. Treatment with oxytetracycline did not result in a favorable clinical response. Therefore, the horse was treated systemically with vancomycin and rifampin, and vancomycin-impregnated polymethyl methacrylate beads were implanted at the surgical site. Six months after surgery, the horse was sound at a walk or trot, and bony union was evident on radiographs of the elbow joint.
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Affiliation(s)
- S S Trostle
- Department of Surgical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison 53706-1102, USA
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28
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Lee SY, Cho HS, Pelton JG, Yan D, Henderson RK, King DS, Huang L, Kustu S, Berry EA, Wemmer DE. Crystal structure of an activated response regulator bound to its target. Nat Struct Biol 2001; 8:52-6. [PMID: 11135671 DOI: 10.1038/83053] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The chemotactic regulator CheY controls the direction of flagellar rotation in Escherichia coli. We have determined the crystal structure of BeF3--activated CheY from E. coli in complex with an N-terminal peptide derived from its target, FliM. The structure reveals that the first seven residues of the peptide pack against the beta4-H4 loop and helix H4 of CheY in an extended conformation, whereas residues 8-15 form two turns of helix and pack against the H4-beta5-H5 face. The peptide binds the only region of CheY that undergoes noticeable conformational change upon activation and would most likely be sandwiched between activated CheY and the remainder of FliM to reverse the direction of flagellar rotation.
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Affiliation(s)
- S Y Lee
- Graduate Group in Biophysics, University of California, Berkeley, California 94720, USA
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29
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Brown GA, Vukovich MD, Martini ER, Kohut ML, Franke WD, Jackson DA, King DS. Endocrine responses to chronic androstenedione intake in 30- to 56-year-old men. J Clin Endocrinol Metab 2000; 85:4074-80. [PMID: 11095435 DOI: 10.1210/jcem.85.11.6940] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [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: 11/19/2022]
Abstract
In young men, chronic ingestion of 100 mg androstenedione (ASD), three times per day, does not increase serum total testosterone but does increase serum estrogen and ASD concentrations. We investigated the effects of ASD ingestion in healthy 30- to 56-yr-old men. In a double-blind, randomly assigned manner, subjects consumed 100 mg ASD three times daily (n = 28), or placebo (n = 27) for 28 days. Serum ASD, dihydrotestosterone (DHT), free and total testosterone, estradiol, prostate-specific antigen (PSA), and lipid concentrations were measured at week 0 and each week throughout the supplementation period. Serum total testosterone and PSA concentrations did not change with supplementation. Elevated serum concentrations of ASD (300%), free testosterone (45%), DHT (83%), and estradiol (68%) were observed during weeks 1-4 in ASD (P < 0.05). There was no relationship between age and changes in serum ASD (r2 = 0.024), free testosterone (r2 = 0.00), or estradiol (r2 = 0.029) concentrations with ASD, whereas the serum DHT response to ASD ingestion was related to age (r2 = 0.244; P < 0.05). Serum concentrations of high-density lipoprotein cholesterol were decreased by 10% during the supplementation period (P < 0.05). These results suggest that the ingestion of 100 mg ASD, three times per day, does not increase serum total testosterone or PSA concentrations but does elicit increases in ASD, free testosterone, estradiol, and DHT and decreases serum high-density lipoprotein cholesterol concentrations.
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Affiliation(s)
- G A Brown
- Department of Health and Human Performance, Iowa State University, Ames 50011, USA
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30
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Brown GA, Vukovich MD, Reifenrath TA, Uhl NL, Parsons KA, Sharp RL, King DS. Effects of anabolic precursors on serum testosterone concentrations and adaptations to resistance training in young men. Int J Sport Nutr Exerc Metab 2000; 10:340-59. [PMID: 10997957 DOI: 10.1123/ijsnem.10.3.340] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [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: 11/18/2022]
Abstract
The effects of androgen precursors, combined with herbal extracts designed to enhance testosterone formation and reduce conversion of androgens to estrogens was studied in young men. Subjects performed 3 days of resistance training per week for 8 weeks. Each day during Weeks 1, 2, 4, 5, 7, and 8, subjects consumed either placebo (PL; n = 10) or a supplement (ANDRO-6; n = 10), which contained daily doses of 300 mg androstenedione, 150 mg DHEA, 750 mg Tribulus terrestris, 625 mg Chrysin, 300 mg Indole-3-carbinol, and 540 mg Saw palmetto. Serum androstenedione concentrations were higher in ANDRO-6 after 2, 5, and 8 weeks (p <.05), while serum concentrations of free and total testosterone were unchanged in both groups. Serum estradiol was elevated at Weeks 2, 5, and 8 in ANDRO-6 (p <.05), and serum estrone was elevated at Weeks 5 and 8 (p <.05). Muscle strength increased (p <.05) similarly from Weeks 0 to 4, and again from Weeks 4 to 8 in both treatment groups. The acute effect of one third of the daily dose of ANDRO-6 and PL was studied in 10 men (23 +/- 4 years). Serum androstenedione concentrations were elevated (p <.05) in ANDRO-6 from 150 to 360 min after ingestion, while serum free or total testosterone concentrations were unchanged. These data provide evidence that the addition of these herbal extracts to androstenedione does not result in increased serum testosterone concentrations, reduce the estrogenic effect of androstenedione, and does not augment the adaptations to resistance training.
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Affiliation(s)
- G A Brown
- Exercise Biochemistry Laboratory, Department of Health and Human Performance, Iowa State University, Ames, IA 50011, USA
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Harrell TK, Necomb WW, Replogle WH, King DS, Noble SL. Onychomycosis: improved cure rates with itraconazole and terbinafine. J Am Board Fam Pract 2000; 13:268-73. [PMID: 10933291 DOI: 10.3122/15572625-13-4-268] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Onychomycosis is a disease that is important to our patients. Based on the current literature, recent developments of newer antifungal agents have improved cure rates of onychomycosis in the past few years (Table 3). No significant differences in safety and tolerability between itraconazole and terbinafine exist. Terbinafine does appear to have a preferable drug interaction profile. Daily therapy with either agent at standard doses has been shown to be effective when compared with placebo. When studies have directly compared daily administration of terbinafine and itraconazole, both medications have shown similar efficacy. Daily terbinafine therapy, however, appears to be more effective than pulse therapy with itraconazole. In addition, one small study showed a trend in favor of continuous rather than intermittent terbinafine therapy and similar efficacy of intermittent itraconazole and intermittent terbinafine therapy. Furthermore, terbinafine is more cost-effective than itraconazole. Finally, as quality-of-life data suggest, onychomycosis is important to our patients and affects both physical and psychosocial components of our patients' lives.
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Affiliation(s)
- T K Harrell
- Department of Family Medicine, University of Mississippi Medical Center, Jackson 39216, USA
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Noble SL, King DS, Olutade JI. Cyclooxygenase-2 enzyme inhibitors: place in therapy. Am Fam Physician 2000; 61:3669-76. [PMID: 10892637] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Nonsteroidal anti-inflammatory drugs (NSAIDs) play a major role in the management of inflammation and pain caused by arthritis. A new class of NSAIDs that selectively inhibit the cyclooxygenase-2 (COX-2) enzyme has been developed. The first COX-2 inhibitors, celecoxib and rofecoxib, are said to provide therapeutic benefit with less toxicity than traditional NSAIDs. A third COX-2-selective inhibitor, meloxicam, has recently been introduced. COX-2 inhibitors and traditional NSAIDs do not appear to differ significantly in their effectiveness in alleviating pain or inflammation. They have similar gastrointestinal side effects, including abdominal pain, dyspepsia and diarrhea. However, short-term studies show fewer gastrointestinal ulcers in patients treated with COX-2 inhibitors compared with traditional NSAIDs.
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Affiliation(s)
- S L Noble
- University of Mississippi Schools of Medicine and Pharmacy, Jackson, USA
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Abstract
TFIID is a large multiprotein complex that initiates assembly of the transcription machinery. It is unclear how TFIID recognizes promoters in vivo when templates are nucleosome-bound. Here, it is shown that TAFII250, the largest subunit of TFIID, contains two tandem bromodomain modules that bind selectively to multiply acetylated histone H4 peptides. The 2.1 angstrom crystal structure of the double bromodomain reveals two side-by-side, four-helix bundles with a highly polarized surface charge distribution. Each bundle contains an Nepsilon-acetyllysine binding pocket at its center, which results in a structure ideally suited for recognition of diacetylated histone H4 tails. Thus, TFIID may be targeted to specific chromatin-bound promoters and may play a role in chromatin recognition.
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Affiliation(s)
- R H Jacobson
- Howard Hughes Medical Institute and Department of Molecular and Cell Biology, 401 Barker Hall, University of California, Berkeley, CA 94720-3204, USA
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Brown GA, Vukovich MD, Sharp RL, Reifenrath TA, Parsons KA, King DS. Effect of oral DHEA on serum testosterone and adaptations to resistance training in young men. J Appl Physiol (1985) 1999; 87:2274-83. [PMID: 10601178 DOI: 10.1152/jappl.1999.87.6.2274] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [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: 11/22/2022] Open
Abstract
This study examined the effects of acute dehydroepiandrosterone (DHEA) ingestion on serum steroid hormones and the effect of chronic DHEA intake on the adaptations to resistance training. In 10 young men (23 +/- 4 yr old), ingestion of 50 mg of DHEA increased serum androstenedione concentrations 150% within 60 min (P < 0.05) but did not affect serum testosterone and estrogen concentrations. An additional 19 men (23 +/- 1 yr old) participated in an 8-wk whole body resistance-training program and ingested DHEA (150 mg/day, n = 9) or placebo (n = 10) during weeks 1, 2, 4, 5, 7, and 8. Serum androstenedione concentrations were significantly (P < 0.05) increased in the DHEA-treated group after 2 and 5 wk. Serum concentrations of free and total testosterone, estrone, estradiol, estriol, lipids, and liver transaminases were unaffected by supplementation and training, while strength and lean body mass increased significantly and similarly (P < 0.05) in the men treated with placebo and DHEA. These results suggest that DHEA ingestion does not enhance serum testosterone concentrations or adaptations associated with resistance training in young men.
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Affiliation(s)
- G A Brown
- Exercise Biochemistry Laboratory, Department of Health and Human Performance, Iowa State University, Ames, Iowa 50011, USA
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Winans KA, King DS, Rao VR, Bertozzi CR. A chemically synthesized version of the insect antibacterial glycopeptide, diptericin, disrupts bacterial membrane integrity. Biochemistry 1999; 38:11700-10. [PMID: 10512626 DOI: 10.1021/bi991247f] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.4] [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: 11/29/2022]
Abstract
Insects protect themselves against bacterial infection by secreting a battery of antimicrobial peptides into the hemolymph. Despite recent progress, important mechanistic questions, such as the precise bacterial targets, the nature of any cooperation that occurs between peptides, and the purpose of multiple peptide isoforms, remain largely unanswered. We report herein the chemical synthesis and preliminary mechanistic investigation of diptericin, an 82 residue glycopeptide that contains regions similar to two different types of antibacterial peptides. A revised, highly practical synthesis of the precursor N(alpha)-Fmoc-Thr(Ac(3)-alpha-D-GalNAc) allowed us to produce sufficient quantities of the glycopeptide for mechanistic assays. The synthetic, full-length polypeptide proved to be active in growth inhibition assays with an IC(50) of approximately 250 nM, a concentration similar to that found in the insect hemolymph. Biological analysis of diptericin fragments indicated that the main determinant of antibacterial activity lay in the C-terminal region that is similar to the attacin peptides, although the N-terminal segment, related to the proline-rich family of antibacterial peptides, augmented that activity by 100-fold. In all assays, activity appeared glycosylation independent. Circular dichroism of unglycosylated diptericin indicated that the peptide lacked structure both in plain buffer and in the presence of liposomes. Diptericin increased the permeability of the outer and inner membranes of Escherichia coli D22 cells, suggesting possible mechanisms of action. The ability to access glycopeptides of this type through chemical synthesis will facilitate further mechanistic studies.
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Affiliation(s)
- K A Winans
- Department of Chemistry, University of California, Berkeley, California 94720, USA
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King DS. Central nervous system infections. Basic concepts. Nurs Clin North Am 1999; 34:761-71. [PMID: 10433657] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
Central nervous system infections have the potential to be very dangerous and life-threatening. Advances in the understanding and care of patients experiencing these infections have aided in their detection and treatment. Caring for these patients requires a thorough knowledge of the diseases as well as a holistic approach which encompasses the patient and family.
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Affiliation(s)
- D S King
- Staff Nurse, Brain Aneurysm/AVM Center, Massachusetts General Hospital, Boston, Massachusetts, USA
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King DS, Sharp RL, Vukovich MD, Brown GA, Reifenrath TA, Uhl NL, Parsons KA. Effect of oral androstenedione on serum testosterone and adaptations to resistance training in young men: a randomized controlled trial. JAMA 1999; 281:2020-8. [PMID: 10359391 DOI: 10.1001/jama.281.21.2020] [Citation(s) in RCA: 153] [Impact Index Per Article: 6.1] [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: 11/14/2022]
Abstract
CONTEXT Androstenedione, a precursor to testosterone, is marketed to increase blood testosterone concentrations as a natural alternative to anabolic steroid use. However, whether androstenedione actually increases blood testosterone levels or produces anabolic androgenic effects is not known. OBJECTIVES To determine if short- and long-term oral androstenedione supplementation in men increases serum testosterone levels and skeletal muscle fiber size and strength and to examine its effect on blood lipids and markers of liver function. DESIGN AND SETTING Eight-week randomized controlled trial conducted between February and June 1998. PARTICIPANTS Thirty healthy, normotestosterogenic men (aged 19-29 years) not taking any nutritional supplements or androgenic-anabolic steroids or engaged in resistance training. INTERVENTIONS Twenty subjects performed 8 weeks of whole-body resistance training. During weeks 1, 2, 4, 5, 7, and 8, the men were randomized to either androstenedione, 300 mg/d (n = 10), or placebo (n = 10). The effect of a single 100-mg androstenedione dose on serum testosterone and estrogen concentrations was determined in 10 men. MAIN OUTCOME MEASURES Changes in serum testosterone and estrogen concentrations, muscle strength, muscle fiber cross-sectional area, body composition, blood lipids, and liver transaminase activities based on assessments before and after short- and long-term androstenedione administration. RESULTS Serum free and total testosterone concentrations were not affected by short- or long-term androstenedione administration. Serum estradiol concentration (mean [SEM]) was higher (P<.05) in the androstenedione group after 2 (310 [20] pmol/L), 5 (300 [30] pmol/L), and 8 (280 [20] pmol/L) weeks compared with presupplementation values (220 [20] pmol/L). The serum estrone concentration was significantly higher (P<.05) after 2 (153 [12] pmol/L) and 5 (142 [15] pmol/L) weeks of androstenedione supplementation compared with baseline (106 [11] pmol/L). Knee extension strength increased significantly (P<.05) and similarly in the placebo (770 [55] N vs 1095 [52] N) and androstenedione (717 [46] N vs 1024 [57] N) groups. The increase of the mean cross-sectional area of type 2 muscle fibers was also similar in androstenedione (4703 [471] vs 5307 [604] mm2; P<.05) and placebo (5271 [485] vs 5728 [451] mm2; P<.05) groups. The significant (P<.05) increases in lean body mass and decreases in fat mass were also not different in the androstenedione and placebo groups. In the androstenedione group, the serum high-density lipoprotein cholesterol concentration was reduced after 2 weeks (1.09 [0.08] mmol/L [42 (3) mg/dL] vs 0.96 [0.08] mmol/L [37 (3) mg/dL]; P<.05) and remained low after 5 and 8 weeks of training and supplementation. CONCLUSIONS Androstenedione supplementation does not increase serum testosterone concentrations or enhance skeletal muscle adaptations to resistance training in normotestosterogenic young men and may result in adverse health consequences.
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Affiliation(s)
- D S King
- Department of Health and Human Performance, Iowa State University, Ames 50011, USA.
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Abstract
Preimplantation genetic diagnosis (PID) is often seen as an improvement upon prenatal testing. I argue that PID may exacerbate the eugenic features of prenatal testing and make possible an expanded form of free-market eugenics. The current practice of prenatal testing is eugenic in that its aim is to reduce the numbers of people with genetic disorders. Due to social pressures and eugenic attitudes held by clinical geneticists in most countries, it results in eugenic outcomes even though no state coercion is involved. I argue that technological advances may soon make PID widely accessible. Because abortion is not involved, and multiple embryos are available, PID is radically more effective as a tool of genetic selection. It will also make possible selection on the basis of non-pathological characteristics, leading, potentially, to a full-blown free-market eugenics. For these reasons, I argue that PID should be strictly regulated.
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Peteranderl R, Rabenstein M, Shin YK, Liu CW, Wemmer DE, King DS, Nelson HC. Biochemical and biophysical characterization of the trimerization domain from the heat shock transcription factor. Biochemistry 1999; 38:3559-69. [PMID: 10090742 DOI: 10.1021/bi981774j] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.9] [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: 11/29/2022]
Abstract
Previously, we had characterized a 91 amino acid fragment of the heat shock transcription factor from the yeast Kluyveromyces lactis and had shown it to be highly alpha-helical and sufficient for formation of homotrimers [Peteranderl, R., and Nelson, H. C. M. (1992) Biochemistry 31, 12272-12276]. Based on those data, as well as the presence of hydrophobic heptad repeats, we postulated that the trimerization domain contains a three-stranded coiled-coil and that it might resemble the trimerization domain found in influenza hemagglutinin. Here, we further characterize the trimerization domain and show that the minimal domain needs 71 residues to remain trimeric and highly alpha-helical. 19F NMR spectroscopy suggests that the structure contains three parallel strands that are in register along the long axis of the coiled-coil. Electron paramagnetic resonance spectroscopy studies show that the C-termini of the subunits are in close proximity; this is in contrast to the topology of the hemaglutinin trimerization domain where the C-termini form buttressing helices. Analytical ultracentrifugation also confirms that the structure is elongated and unlikely to have buttressing helices. Additional experiments suggest that the trimerization domain has at least two subdomains. The first subdomain has the potential to form trimers independently, though not as stably as the complete domain. The second subdomain is quite helical, forms large oligomers, and appears to provide stability to the complete domain. Our current model for the heat shock transcription factor trimerization domain is a highly elongated coiled-coil structure, with a potential break in the coiled-coil region located between the two subdomains.
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Affiliation(s)
- R Peteranderl
- Department of Molecular and Cell Biology and Department of Chemistry, University of California, Berkeley, California 94720, USA
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Parcell AC, Ray ML, Moss KA, Ruden TM, Sharp RL, King DS. The effect of encapsulated soluble fiber on carohydrate metabolism during exercise. Int J Sport Nutr 1999; 9:13-23. [PMID: 10036338 DOI: 10.1123/ijsn.9.1.13] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Previous investigations have reported that soluble fiber reduces the plasma glucose and insulin changes after an oral glucose load. To improve the palatability of a soluble-fiber feeding, this study addressed how a combined, soluble fiber (delivered in capsule form) and a preexercise CHO feeding would affect metabolic responses during exercise. On 3 different days, participants ingested a placebo (CON), 75 g liquid CHO (GLU), or 75 g liquid CHO with 14.5 g encapsulated guar gum (FIB) 45 min before cycling for 60 min at 70% VO2 peak. Peak concentrations of plasma glucose and insulin were similar and significantly greater than CON preexercise (p < 05). Similarities in carbohydrate reliance were observed in GLU and FIB. Muscle glycogen use did not differ significantly among trials. These results demonstrate that encapsulated soluble fiber delivered with liquid CHO feeding does not affect plasma glucose, insulin, or muscle glycogen utilization during exercise.
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Affiliation(s)
- A C Parcell
- Human Performance Research Center, Department of Physical Education, Brigham Young University, 212 Richards Building, Provo, UT 84602, USA
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Abstract
Locust Ion Transport Peptide (ITP) a member of the arthropod neuropeptide family which includes hyperglycemic, vitellogenesis-inhibiting, and moult-inhibiting hormones (CHH, VIH, MIH, respectively) was synthesized as proposed by Meredith et al. (1996) with terminal amidation of amino acid residue 72 and with 3 disulphide bridges. This is the first member of this family to be synthesized. Biological activities of synthetic ITP (synITP) were very similar to those previously reported for ITP purified from Schistocerca corpora cardiaca (ScgITP) and partially sequenced by Audsley et al. (1992a, b). Dose-response curves for both synITP and ScgITP on ileal transport of Cl- (measured as increased short-circuit current, delta Isc), were similar with a EC50 of 1-2 nM. The Isc time course and maximum delta Isc across ileal epithelia at different dosages of synITP and ScgITP had similar patterns as did changes in transepithelial open-circuit potential (Vt) and resistance (Rt), reflecting changes in salt transport which drives fluid absorption. Disulphide bridges were shown to be required for biological activity of synITP, which caused the same 4-fold increase in ileal fluid transport rate (Jv) as previously reported for ScgITP. Both synITP and ScgITP caused only partial stimulation of rectal Isc and had no significant effect on rectal Jv. These results indicate that the structure of ITP predicted earlier from cDNA is correct.
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Affiliation(s)
- D S King
- Howard Hughes Medical Institute, Department of Molecular and Cell Biology, University of California Berkeley 94702, USA
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Abstract
To investigate the impact of fluid composition on rehydration effectiveness, 30 subjects (15 men and 15 women) were studied during 2 h of rehydration after a 2.5% body weight loss. In a randomized crossover design, subjects rehydrated with water (H2O), chicken broth (CB: 109.5 mmol/l Na, 25.3 mmol/l K), a carbohydrate-electrolyte drink (CE: 16.0 mmol/l Na, 3.3 mmol/l K), and chicken noodle soup (Soup: 333.8 mmol/l Na, 13.7 mmol/l K). Subjects ingested 175 ml at the start of rehydration and 20 min later; H2O was given every 20 min thereafter for a total volume equal to body weight loss during dehydration. At the end of the rehydration period, plasma volume was not significantly different from predehydration values in the CB (-1.6 +/- 1.1%) and Soup (-1.4 +/- 0.9%) trials. In contrast, plasma volume remained significantly (P < 0.01) below predehydration values in the H2O (-5.6 +/- 1.1%) and CE (-4.2 +/- 1.0%) trials after the rehydration period. Urine volume was greater in the CE (310 +/- 30 ml) than in the CB (188 +/- 20 ml) trial. Urine osmolality was higher in the CB and Soup trials than in the CE trial. Urinary sodium concentration was higher in the Soup and CB trials than in the CE and H2O trials. These results provide evidence that the inclusion of sodium in rehydration beverages, as well as consumption of a sodium-containing liquid meal, increases fluid retention and improves plasma volume restoration.
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Affiliation(s)
- M L Ray
- Exercise Biochemistry Laboratory, Department of Health and Human Performance, Iowa State University, Ames, Iowa 50011, USA
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Pedersen H, Hölder S, Sutherlin DP, Schwitter U, King DS, Schultz PG. A method for directed evolution and functional cloning of enzymes. Proc Natl Acad Sci U S A 1998; 95:10523-8. [PMID: 9724736 PMCID: PMC27927 DOI: 10.1073/pnas.95.18.10523] [Citation(s) in RCA: 104] [Impact Index Per Article: 4.0] [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: 11/18/2022] Open
Abstract
A general scheme is described for the in vitro evolution of protein catalysts in a biologically amplifiable system. Substrate is covalently and site specifically attached by a flexible tether to the pIII coat protein of a filamentous phage that also displays the catalyst. Intramolecular conversion of substrate to product provides a basis for selecting active catalysts from a library of mutants, either by release from or attachment to a solid support. This methodology has been developed with the enzyme staphylococcal nuclease as a model. An analysis of factors influencing the selection efficiency is presented, and it is shown that phage displaying staphylococcal nuclease can be enriched 100-fold in a single step from a library-like ensemble of phage displaying noncatalytic proteins. Additionally, this approach should allow one to functionally clone natural enzymes, based on their ability to catalyze specific reactions (e.g., glycosyl transfer, sequence-specific proteolysis or phosphorylation, polymerization, etc.) rather than their sequence- or structural homology to known enzymes.
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Affiliation(s)
- H Pedersen
- Howard Hughes Medical Institute, Department of Chemistry, University of California, Berkeley, CA 94720-1460, USA
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Abstract
BACKGROUND Proteins form specific associations, but predictive rules for protein pairing are generally unknown. Here, we describe amino-acid sequence patterns capable of mediating specific pairing of a widespread protein motif: the parallel, dimeric, alpha-helical coiled coil. The pairing rules were tested by designing a 54-residue peptide (anti-APCp1) that is predicted to dimerize preferentially with a coiled-coil sequence from the adenomatous polyposis coli (APC) tumor suppressor protein. RESULTS As judged by circular dichroism, ultracentrifugation and native gel electrophoresis, anti-APCp1 formed a specific, helical, dimeric complex with the target APC coiled coil. On western blots of APC fragments expressed in Escherichia coli, the designed peptide detected a pattern of bands identical to the pattern detected by an antibody directed against the APC coiled coil. Peptide-mediated precipitation experiments showed that anti-APCp1 bound and sequestered wild-type and mutant APC proteins in extracts of human colon cancer cell lines. In addition, binding of the designed peptide preserved native APC-beta-catenin complexes. CONCLUSIONS These biochemical experiments demonstrate that the anti-APC peptide preferentially forms a heterodimeric coiled coil with mutant and full-length APC proteins. The specificity of the designed peptide is sufficient to support several applications that commonly use antibodies. The observed specificity of anti-APCp1 validates the pairing rules used as the basis for the probe design, and it suggests that residues in the core positions of coiled coils help impart pairing selectivity.
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Affiliation(s)
- V A Sharma
- Department of Molecular and Cell Biology, University of California, Berkeley 94720-3206, USA
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Russell CJ, King DS, Thorgeirsson TE, Shin YK. De novo design of a peptide which partitions between water and phospholipid bilayers as a monomeric alpha-helix. Protein Eng 1998; 11:539-47. [PMID: 9740371 DOI: 10.1093/protein/11.7.539] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
To dissect the determinants of protein insertion into membranes, we designed a model peptide which partitions between water and phospholipid bilayers as an alpha-helical monomer. We used a simplex method to optimize the 'a, d hydrophobicity' and 'e, g charge' of a series of five peptides, where 'abcdefg' correspond to the positions in two turns of an alpha-helix. Circular dichroism and analytical ultra-centrifugation experiments showed that the final peptide (helix5) is monomeric and has an alpha-helix content of approximately 89% at 0 degrees C in aqueous solution. In the presence of large unilamellar vesicles (LUVs), helix5 partitions between the aqueous and membranous phases with a partition constant well suited for measurements by electron paramagnetic resonance (EPR) spectroscopy. EPR power saturation experiments with a cysteine-scanning strategy showed that the alpha-helicity of helix5 is conserved upon binding to LUVs and that the alpha-helix binds parallel to the membrane surface with the central axis approximately 5 A below the lipid phosphate groups. Helix5 should be a useful model peptide for studies aimed at dissecting the determinants of the membrane binding of alpha-helices. The simplex-based strategy may be useful in the rational design of proteins when desired structural or partitioning properties cannot be selected or screened from libraries.
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Affiliation(s)
- C J Russell
- Department of Chemistry, University of California, Berkeley 94720, USA
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Poirier MA, Hao JC, Malkus PN, Chan C, Moore MF, King DS, Bennett MK. Protease resistance of syntaxin.SNAP-25.VAMP complexes. Implications for assembly and structure. J Biol Chem 1998; 273:11370-7. [PMID: 9556632 DOI: 10.1074/jbc.273.18.11370] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.5] [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: 11/06/2022] Open
Abstract
A stable ternary complex formed with vesicle-associated membrane protein 2 (VAMP2) and plasma membrane proteins syntaxin 1A and synaptosome-associated protein of 25 kDa (SNAP-25) is proposed to function in synaptic vesicle exocytosis. To analyze the structural characteristics of this synaptic protein complex, recombinant binary (syntaxin 1A.SNAP-25), recombinant ternary, and native ternary complexes were subjected to limited trypsin proteolysis. The protected fragments, defined by amino-terminal sequencing and mass spectrometry, included a carboxyl-terminal region of syntaxin 1A, the cytoplasmic domain of VAMP2, and amino- and carboxyl-terminal regions of SNAP-25. Furthermore, separate amino- and carboxyl-terminal fragments of SNAP-25, when combined with VAMP2 and syntaxin 1A, were sufficient for stable complex assembly. Analysis of ternary complexes formed with full-length proteins revealed that the carboxyl-terminal transmembrane anchors of both syntaxin 1A and VAMP2 were protected from trypsin digestion. Moreover, the stability of ternary complexes was increased by inclusion of these transmembrane domains. These results suggest that the transmembrane domains of VAMP2 and syntaxin 1A contribute to complex assembly and stability and that amino- and carboxyl-terminal regions of SNAP-25 may function as independent domains.
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Affiliation(s)
- M A Poirier
- Department of Molecular and Cell Biology, University of California, Berkeley, California 94720, USA
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Vukovich MD, Sharp RL, Kesl LD, Schaulis DL, King DS. Effects of a low-dose amino acid supplement on adaptations to cycling training in untrained individuals. Int J Sport Nutr 1997; 7:298-309. [PMID: 9407256 DOI: 10.1123/ijsn.7.4.298] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The purpose of this study was to determine if amino acid supplementation influences blood and muscle lactate response to exercise and the time course of the metabolic adaptations to training. Two groups of untrained males (n = 7 each) were given (double-blind) a daily supplement (2.9 g.day-1) containing a mixture of leucine, isoleucine, valine, glutamine, and carnitine (EXP) or 3 g.day-1 of lactose (CON). Following 7 days of supplementation there was no significant change in VO2peak, time to exhaustion (TTX) at 120% VO2peak, or muscle and blood lactate in either EXP or CON. Subjects then initiated 6 weeks of combined aerobic and anaerobic training on a Monark cycle ergometer. It was found that amino acid supplementation had no effect on either blood or muscle lactate accumulation during exercise, while supplementation resulted in a faster adaptation in buffer capacity. Performance during intense exercise was not improved with amino acid supplementation.
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Affiliation(s)
- M D Vukovich
- Human Performance Laboratory, Wichita State University, KS 67226, USA
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Lehman CW, King DS, Botchan MR. A papillomavirus E2 phosphorylation mutant exhibits normal transient replication and transcription but is defective in transformation and plasmid retention. J Virol 1997; 71:3652-65. [PMID: 9094639 PMCID: PMC191514 DOI: 10.1128/jvi.71.5.3652-3665.1997] [Citation(s) in RCA: 29] [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: 02/04/2023] Open
Abstract
Papillomavirus DNA persists in infected cells as a nuclear plasmid, causing epithelial lesions in many hosts, including humans. The viral protein E2 is required for both replication and transcription to facilitate this persistence. Bovine papillomavirus E2 protein is phosphorylated at two predominant sites. Phosphorylation of one of these sites (serine 301) inhibits replication of the genome. Using mass spectrometry and Edman sequencing, we have mapped additional phosphorylation sites in tryptic peptides to positions which lie primarily in the putatively unstructured hinge region of E2. Mutation of the major sites facilitates transformation in the absence of viral repressors and only has a minor effect on transformation when the repressors are present. Mutation of the major phosphorylation sites combined with one additional change at a newly discovered site (serine 235) blocks transformation. Transformation can be restored by mutating this residue to aspartic acid, mimicking a phosphorylated amino acid, suggesting that phosphorylation is key to the regulation. Transformation by the mutant genome can also be rescued by ectopic expression of the E2 enhancer protein, demonstrating a loss of function by the mutant protein and not a toxic defect. In transient assays, phosphorylation site mutants of E2 protein were normal for all viral functions tested, including replication, transcriptional activation and repression (by the overlapping mutant repressors), protein accumulation, and surprisingly, viral oncogene E5 promoter activation. While the mutant genome transiently replicated to high levels, stable replication was defective, suggesting that a function of E2 required for plasmid retention is regulated by phosphorylation.
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Affiliation(s)
- C W Lehman
- Department of Molecular and Cell Biology, University of California, Berkeley 94720-3204, USA.
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Abstract
Circular dichroism (CD) and 2-dimensional NMR were used to study the solution conformation of conantokin-T (Con-T), a small peptide toxin found in the venom of fish-hunting cone snails, and its Glu-substituted analog. Con-T lacks disulfide bonds but contains many gamma-carboxyglutamic acids (Gla), a post-translationally modified residue. Our results show that Con-T adopts an alpha-helical conformation in aqueous solution even in the absence of calcium. Glu replacements diminish both helicity and function of Con-T. The helical content of Con-T is higher than most natural helical peptides of this length in aqueous solution. The sequence of this small toxin incorporates several known elements that stabilize alpha-helical structure in peptides. Gla residues form several salt bridges that stabilize helical conformation of Con-T.
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Affiliation(s)
- C H Lin
- Department of Life Sciences, National Tsing Hua University, Hsin-chu, Taiwan
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Abstract
Amino acids have distinct lipid bilayer affinities which influence the insertion and topology of membrane-bound polypeptides and proteins. To measure membrane affinities, 14 uncharged amino acids were introduced individually at a guest site in a 25-residue peptide derived from the membrane-binding presequence of yeast cytochrome c oxidase, and the peptides were labeled with a nitroxide spin-label. The free energies of transfer from phospholipid bilayers to water (delta delta Gbilayer) were determined directly by examination of partitioning into phospholipid bilayers using electron paramagnetic resonance. The delta delta Gbilayer values are in agreement with hydrophobicities assessed from 1-octanol-water partitioning of N-acetyl amino acid amides [Fauchere, J.-L., & Pliska, V. (1983) Eur. J. Med. Chem. 18, 369-375; Eisenberg, D., & McLachlan, A. (1986) Nature 319, 199-203] and quantitatively demonstrate the role of the hydrophobic effect in membrane-protein interactions.
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Affiliation(s)
- T E Thorgeirsson
- Department of Chemistry, University of California, Berkeley 94720, USA
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