1
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Dualeh SHA, Anderson MS, Abrahamse P, Kamdar N, Evans E, Suwanabol PA. Trends in End-of-Life Care and Satisfaction Among Veterans Undergoing Surgery. Ann Surg 2024:00000658-990000000-00792. [PMID: 38390769 DOI: 10.1097/sla.0000000000006253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
OBJECTIVE To examine trends in end-of-life care services and satisfaction among Veterans undergoing any inpatient surgery. SUMMARY BACKGROUND DATA The Veterans Health Administration has undergone system-wide transformations to improve end-of-life care yet the impacts on end-of-life care services use and family satisfaction are unknown. METHODS We performed a retrospective, cross-sectional analysis of Veterans who died within 90 days of undergoing inpatient surgery between 01/2010 and 12/2019. Using the Veterans Affairs (VA) Bereaved Family Survey (BFS), we calculated the rates of palliative care and hospice use and examined satisfaction with end-of-life care. After risk and reliability adjustment for each VA hospital, we then performed multivariable linear regression model to identify factors associated with the greatest change. RESULTS Our cohort consisted of 155,250 patients with a mean age of 73.6 years (standard deviation 11.6). Over the study period, rates of palliative care consultation and hospice use increased more than two-fold (28.1% to 61.1% and 18.9% to 46.9%, respectively) while the rate of BFS excellent overall care score increased from 56.1% to 64.7%. There was wide variation between hospitals in the absolute change in rates of palliative care consultation, hospice use and BFS excellent overall care scores. Rural location and ACGME accreditation were hospital-level factors associated with the greatest changes. CONCLUSIONS Among Veterans undergoing inpatient surgery, improvements in satisfaction with end-of-life care paralleled increases in end-of-life care service use. Future work is needed to identify actionable hospital-level characteristics that may reduce heterogeneity between VA hospitals and facilitate targeted interventions to improve end-of-life care.
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Affiliation(s)
- Shukri H A Dualeh
- University of Michigan, Department of Surgery, Ann Arbor, MI, USA
- University of Michigan, Center for Healthcare Outcomes and Policy, Ann Arbor, MI, USA
| | - Maia S Anderson
- University of Michigan, Department of Surgery, Ann Arbor, MI, USA
- University of Michigan, Center for Healthcare Outcomes and Policy, Ann Arbor, MI, USA
| | - Paul Abrahamse
- University of Michigan, Department of Biostatistics, School of Public Health, Ann Arbor, MI, USA
| | - Neil Kamdar
- University of Michigan, Institute for Healthcare Policy and Innovation, Ann Arbor, MI, USA
| | - Emily Evans
- University of Michigan Medical School, Ann Arbor, MI, USA
| | - Pasithorn A Suwanabol
- University of Michigan, Department of Surgery, Ann Arbor, MI, USA
- University of Michigan, Center for Healthcare Outcomes and Policy, Ann Arbor, MI, USA
- University of Michigan, Institute for Healthcare Policy and Innovation, Ann Arbor, MI, USA
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2
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Gilbert TJ, Anderson MS, Byrnes ME, Kim GY, Solano QP, Wan JH, Sack BS. The Inequitable Experiences of Left-Handed Medical Students in Surgical Education. Acad Med 2023:00001888-990000000-00726. [PMID: 38166317 DOI: 10.1097/acm.0000000000005627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/04/2024]
Abstract
PURPOSE Left-handed medical students contend with unique educational barriers within surgery, such as lack of educational resources, lack of left-handed-specific training, and widespread stigmatization of surgical left-handedness. This study aimed to highlight the surgical experiences of left-handed medical students so educators may be empowered to act with greater care and appreciation of these students' circumstances. METHOD In this qualitative study, the authors conducted semistructured interviews on surgical experiences during medical school between January 31, 2021, and June 20, 2021, on 31 current surgical residents and fellows from 15 U.S. institutions and 6 surgical specialties. Left-handed trainees were included regardless of their surgical hand dominance. RESULTS The authors identified 3 themes related to left-handed medical students' surgical experience: (1) disorienting advice from faculty or residents, (2) discouraging right-handed pressures and left-handed stigmatization, and (3) educational wishes of left-handed medical students. Trainees describe dialogues during medical school in which their handedness was directly addressed by residents and faculty with disorienting and nonbeneficial advice. Often trainees were explicitly told which hand to use, neglecting any preferences of the left-handed student. Participants also described possible changes in future surgical clerkships, including normalization of left-handedness, tangible mentorship, or granular and meaningful instruction. CONCLUSIONS Left-handed medical students encounter unique challenges during their surgical education. These students report being disoriented by the variability of advice provided by mentors, discouraged by how pressured they feel to operate right-handed, and burdened by the need to figure things out by themselves in the absence of adequate left-handed educational resources. Surgical education leadership should detail the unique problems left-handed learners face, impartially elicit the learner's current operative hand preference, take responsibility for their left-handed students, promote acceptance and accommodation strategies of left-handed surgical trainees, and endeavor to improve the breadth of left-handed surgical resources.
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Affiliation(s)
- Timothy J Gilbert
- T.J. Gilbert is a general surgery resident, Department of Surgery, University of Michigan, Ann Arbor, Michigan
| | - Maia S Anderson
- M.S. Anderson is a general surgery resident, Department of Surgery, University of Michigan, Ann Arbor, Michigan
| | - Mary E Byrnes
- M.E. Byrnes is assistant professor, Department of Surgery, University of Michigan, Ann Arbor, Michigan
| | - Gloria Y Kim
- G.Y. Kim is an integrated vascular surgery resident, Department of Surgery, University of Michigan, Ann Arbor, Michigan
| | - Quintin P Solano
- Q.P. Solano is an internal medicine resident, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - Julian H Wan
- J.H. Wan is professor, Department of Urology, University of Michigan, Ann Arbor, Michigan
| | - Bryan S Sack
- B.S. Sack is assistant professor, Department of Urology, University of Michigan, Ann Arbor, Michigan
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3
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Rivard SJ, Vitous CA, Bamdad MC, Lussiez A, Anderson MS, Varlamos C, Duby A, Suwanabol PA. "I Wish There had been Resources": A Photo-Elicitation Study of Rectal Cancer Survivorship Care Needs. Ann Surg Oncol 2023; 30:3530-3537. [PMID: 36847958 PMCID: PMC10460498 DOI: 10.1245/s10434-022-13042-6] [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] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 12/09/2022] [Indexed: 03/01/2023]
Abstract
BACKGROUND Rectal cancer survivors experience unique, prolonged posttherapy symptoms. Previous data indicate that providers are not skilled at identifying the most pertinent rectal cancer survivorship issues. Consequently, survivorship care is incomplete with the majority of rectal cancer survivors reporting at least one unmet posttherapy need. METHODS This photo-elicitation study combines participant-submitted photographs and minimally structured qualitative interviews to explore one's lived experiences. Twenty rectal cancer survivors from a single tertiary canter provided photographs representative of their life after rectal cancer therapy. The iterative steps informed by inductive thematic analysis were used to analyze the transcribed interviews. RESULTS Rectal cancer survivors had several recommendations to improve their survivorship care, which fell into three major themes: (1) informational needs (e.g., more details about posttherapy side effects); (2) continued multidisciplinary follow up care (e.g., dietary support); and (3) suggestions for support services (e.g., subsidized bowel altering medications and ostomy supplies). CONCLUSIONS Rectal cancer survivors desired more detailed and individualized information, access to longitudinal multidisciplinary follow-up care, and resources to ease the burdens of daily life. These needs may be met through the restructuring of rectal cancer survivorship care to include disease surveillance, symptom management, and support services. As screening and therapy continues to improve, providers must continue to screen and to provide services that address the physical and psychosocial needs of rectal cancer survivors.
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Affiliation(s)
| | - C Ann Vitous
- Center for Healthcare Outcomes and Policy, University of Michigan, Ann Arbor, MI, USA
| | | | - Alisha Lussiez
- Department of Surgery, University of Michigan, Ann Arbor, MI, USA
| | - Maia S Anderson
- Department of Surgery, University of Michigan, Ann Arbor, MI, USA
| | | | - Ashley Duby
- Department of Surgery, University of Michigan, Ann Arbor, MI, USA
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4
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Schaefer SL, Jabour SM, Englesbe M, Sonnenday CJ, Anderson MS. Incidence and outcomes of liver retransplantation using living donor allografts in the US. Liver Transpl 2023; 29:555-558. [PMID: 36747347 PMCID: PMC10134743 DOI: 10.1097/lvt.0000000000000085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 12/09/2022] [Indexed: 02/08/2023]
Affiliation(s)
- Sara L. Schaefer
- Section of Transplantation, Department of Surgery, Michigan Medicine, Ann Arbor, MI
| | - Sarah M. Jabour
- Department of Surgery, Johns Hopkins Medicine, Baltimore, MD
| | - Michael Englesbe
- Section of Transplantation, Department of Surgery, Michigan Medicine, Ann Arbor, MI
| | | | - Maia S. Anderson
- Section of Transplantation, Department of Surgery, Michigan Medicine, Ann Arbor, MI
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5
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Anderson MS, Taylor C, Englesbe MJ. From Survival to Survivorship in Pediatric Liver Transplantation. Pediatrics 2022; 150:189500. [PMID: 36111448 DOI: 10.1542/peds.2022-057753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/23/2022] [Indexed: 11/24/2022] Open
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6
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Jacobson CE, Heximer A, Olmeda-Barrientos R, Anderson MS, Waits SA, Englesbe MJ, Valbuena VSM. Language Accessibility of Liver Transplantation Center Websites. Liver Transpl 2022; 28:722-724. [PMID: 34704660 DOI: 10.1002/lt.26343] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 10/15/2021] [Accepted: 10/18/2021] [Indexed: 01/06/2023]
Affiliation(s)
| | | | | | - Maia S Anderson
- Department of Surgery, University of Michigan, Ann Arbor, MI.,Center for Healthcare Outcomes and Policy, University of Michigan, Ann Arbor, MI
| | - Seth A Waits
- Department of Surgery, University of Michigan, Ann Arbor, MI
| | | | - Valeria S M Valbuena
- Department of Surgery, University of Michigan, Ann Arbor, MI.,Center for Healthcare Outcomes and Policy, University of Michigan, Ann Arbor, MI.,National Clinician Scholars Program, University of Michigan, Ann Arbor, MI
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7
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Anderson MS, Taylor C, Englesbe MJ. Progress in Pediatric Transplantation. Pediatrics 2022; 149:184550. [PMID: 35079815 DOI: 10.1542/peds.2021-054099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/29/2021] [Indexed: 11/24/2022] Open
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8
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Rivard SJ, Vitous CA, Bamdad MC, Lussiez A, Anderson MS, Varlamos C, Duby A, Suwanabol PA. It's not fine: A photo-elicitation study of rectal cancer survivors' emotions and coping strategies. Surgery 2022; 171:1480-1485. [PMID: 34974916 PMCID: PMC10400270 DOI: 10.1016/j.surg.2021.10.067] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 10/05/2021] [Accepted: 10/31/2021] [Indexed: 10/19/2022]
Abstract
BACKGROUND Comprehensive cancer care includes supporting the psychological health of survivors who are at high risk of distress. However, little is known about the emotional experiences of rectal cancer survivors specifically. We sought to explore psychological well-being and coping strategies utilized by rectal cancer survivors. METHODS Twenty rectal cancer survivors shared photographs of their post-treatment experiences. In follow-up interviews, participants discussed photographs' meanings and emotional experiences during their cancer journey. Transcribed interviews were analyzed using iterative steps of inductive thematic analysis. RESULTS Emotions ranged from sadness to anxiety and fear of cancer recurrence. Coping mechanisms were grouped into 3 categories: (1) seeking support and information; (2) focus on attitudes and perspectives; and (3) distancing strategies. CONCLUSION Our results highlight the persistent psychological impact of rectal cancer and need for additional support for survivors. Providers may help temper patients' fear of recurrence by explicitly discussing prognosis and risk of recurrence. Although multidisciplinary survivorship clinics are ideal, all cancer care providers and primary care physicians should feel empowered to screen for psychological distress and refer patients to appropriate resources when needed.
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Affiliation(s)
| | - C Ann Vitous
- Center for Healthcare Outcomes and Policy, University of Michigan, Ann Arbor, MI
| | | | - Alisha Lussiez
- Department of Surgery, University of Michigan, Ann Arbor, MI
| | - Maia S Anderson
- Department of Surgery, University of Michigan, Ann Arbor, MI
| | | | - Ashley Duby
- Department of Surgery, University of Michigan, Ann Arbor, MI
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9
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Olmeda Barrientos R, Valbuena VSM, Jacobson CE, Santos-Parker KS, Anderson MS, Waits SA, Santos-Parker JR. Non-English Language Resources and Readability of Kidney Transplant Center Websites in the United States. JAMA Netw Open 2021; 4:e2134236. [PMID: 34762114 PMCID: PMC8586902 DOI: 10.1001/jamanetworkopen.2021.34236] [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] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/03/2022] Open
Abstract
This study examined US kidney transplant center websites for readability and for inclusion of languages other than English.
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Affiliation(s)
| | - Valeria S. M. Valbuena
- Department of Surgery, Section of Transplantation, Michigan Medicine, University of Michigan, Ann Arbor
| | | | | | - Maia S. Anderson
- Department of Surgery, Section of Transplantation, Michigan Medicine, University of Michigan, Ann Arbor
| | - Seth A. Waits
- Department of Surgery, Section of Transplantation, Michigan Medicine, University of Michigan, Ann Arbor
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10
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Turgeon MK, Shah SA, Delman AM, Tran BV, Agopian VG, Wedd JP, Magliocca JF, Kim A, Cameron A, Olyaei A, Orloff SL, Anderson MP, Kubal CA, Cannon RM, Locke JE, Simpson MA, Akoad ME, Wongjirad CP, Emamaullee J, Moro A, Aucejo F, Feizpour CA, Vagefi PA, Nguyen MH, Esquivel CO, Dhanireddy K, Subramanian V, Chavarriaga A, Kazimi MM, Anderson MS, Sonnenday CJ, Kim SC, Foley DP, Abdouljoud M, Salgia RJ, Moris D, Sudan DL, Ganesh SR, Humar A, Doyle M, Chapman WC, Maithel SK. Optimal Timing of Administration of Direct-acting Antivirals for Patients With Hepatitis C-associated Hepatocellular Carcinoma Undergoing Liver Transplantation. Ann Surg 2021; 274:613-620. [PMID: 34506316 PMCID: PMC8559662 DOI: 10.1097/sla.0000000000005070] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE To investigate the optimal timing of direct acting antiviral (DAA) administration in patients with hepatitis C-associated hepatocellular carcinoma (HCC) undergoing liver transplantation (LT). SUMMARY OF BACKGROUND DATA In patients with hepatitis C (HCV) associated HCC undergoing LT, the optimal timing of direct-acting antivirals (DAA) administration to achieve sustained virologic response (SVR) and improved oncologic outcomes remains a topic of much debate. METHODS The United States HCC LT Consortium (2015-2019) was reviewed for patients with primary HCV-associated HCC who underwent LT and received DAA therapy at 20 institutions. Primary outcomes were SVR and HCC recurrence-free survival (RFS). RESULTS Of 857 patients, 725 were within Milan criteria. SVR was associated with improved 5-year RFS (92% vs 77%, P < 0.01). Patients who received DAAs pre-LT, 0-3 months post-LT, and ≥3 months post-LT had SVR rates of 91%, 92%, and 82%, and 5-year RFS of 93%, 94%, and 87%, respectively. Among 427 HCV treatment-naïve patients (no previous interferon therapy), patients who achieved SVR with DAAs had improved 5-year RFS (93% vs 76%, P < 0.01). Patients who received DAAs pre-LT, 0-3 months post-LT, and ≥3 months post-LT had SVR rates of 91%, 93%, and 78% (P < 0.01) and 5-year RFS of 93%, 100%, and 83% (P = 0.01). CONCLUSIONS The optimal timing of DAA therapy appears to be 0 to 3 months after LT for HCV-associated HCC, given increased rates of SVR and improved RFS. Delayed administration after transplant should be avoided. A prospective randomized controlled trial is warranted to validate these results.
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Affiliation(s)
| | - Shimul A. Shah
- University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Aaron M. Delman
- University of Cincinnati College of Medicine, Cincinnati, Ohio
| | - Benjamin V. Tran
- David Geffen School of Medicine at UCLA, Los Angeles, California
| | | | | | | | | | | | - Ali Olyaei
- Oregon Health and Science University, Portland, Oregon
| | | | | | | | | | - Jayme E. Locke
- University of Alabama at Birmingham, Birmingham, Alabama
| | | | | | | | - Juliet Emamaullee
- Keck Hospital of University of Southern California, Los Angeles, California
| | | | | | | | | | | | | | | | | | | | | | | | | | - Steven C. Kim
- University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | - David P. Foley
- University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
| | | | | | | | | | | | - Abhinav Humar
- University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Majella Doyle
- Washington University School of Medicine at St. Louis, St. Louis, Missouri
| | - William C. Chapman
- Washington University School of Medicine at St. Louis, St. Louis, Missouri
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11
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Anderson MS, Valbuena VSM, Brown CS, Waits SA, Sonnenday CJ, Englesbe M, Mellinger JL. Association of COVID-19 With New Waiting List Registrations and Liver Transplantation for Alcoholic Hepatitis in the United States. JAMA Netw Open 2021; 4:e2131132. [PMID: 34698851 PMCID: PMC8548949 DOI: 10.1001/jamanetworkopen.2021.31132] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
This cross-sectional study examines trends in new waiting list registrations and liver transplantation for alcoholic hepatitis before and during the COVID-19 pandemic in the US.
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Affiliation(s)
- Maia S. Anderson
- Department of Surgery, University of Michigan, Ann Arbor, Michigan
- Center for Healthcare Outcomes and Policy, University of Michigan, Ann Arbor, Michigan
| | - Valeria S. M. Valbuena
- Department of Surgery, University of Michigan, Ann Arbor, Michigan
- Center for Healthcare Outcomes and Policy, University of Michigan, Ann Arbor, Michigan
- National Clinician Scholars Program, University of Michigan, Ann Arbor, Michigan
| | - Craig S. Brown
- Department of Surgery, University of Michigan, Ann Arbor, Michigan
- Center for Healthcare Outcomes and Policy, University of Michigan, Ann Arbor, Michigan
| | - Seth A. Waits
- Department of Surgery, University of Michigan, Ann Arbor, Michigan
| | - Christopher J. Sonnenday
- Department of Surgery, University of Michigan, Ann Arbor, Michigan
- Center for Healthcare Outcomes and Policy, University of Michigan, Ann Arbor, Michigan
| | - Michael Englesbe
- Department of Surgery, University of Michigan, Ann Arbor, Michigan
| | - Jessica L. Mellinger
- Center for Healthcare Outcomes and Policy, University of Michigan, Ann Arbor, Michigan
- Division of Gastroenterology and Hepatology, University of Michigan, Ann Arbor, Michigan
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12
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Kim GY, Anderson MS, Brown CS, Powell C, Corriere MA. Gender Disparities in Major Depression Among Patients With Peripheral Artery Disease and Associations With Mortality. J Vasc Surg 2021. [DOI: 10.1016/j.jvs.2021.06.309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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13
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Caro L, de Hoon J, Depré M, Cilissen C, Miller J, Gao W, Panebianco D, Guo Z, Troemel SL, Anderson MS, Uemura N, Butterton J, Wagner J, Wright DH. Single-Dose and Multiple-Dose Pharmacokinetics of Vaniprevir in Healthy Men. Clin Transl Sci 2017; 10:480-486. [PMID: 28796416 PMCID: PMC6402189 DOI: 10.1111/cts.12482] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Accepted: 05/22/2017] [Indexed: 12/26/2022] Open
Abstract
Vaniprevir is an inhibitor of the hepatitis C virus (HCV) NS3/4A protease. The aim of these double‐blind, placebo‐controlled phase I studies was to evaluate the safety and pharmacokinetics of vaniprevir in healthy male volunteers. The primary objective for both studies was the safety and tolerability of vaniprevir. Single‐dose and steady‐state pharmacokinetics were also assessed. In both studies, there was no apparent relationship between the frequency or intensity of adverse events and vaniprevir dose. At single doses >20 mg, the plasma area under the curve (AUC)0–∞ and maximum concentration (Cmax) increased in a greater‐than‐dose‐proportional manner. The geometric mean ratios (GMRs; fed/fasted) were 1.22 and 0.79 for AUC0–∞ and Cmax, respectively. Following multiple doses, GMR accumulations for AUC0–12h and Cmax (day 14/day 1) ranged from 1.53 to 1.90 and from 1.41 to 1.92, respectively. These data support the use of vaniprevir with peginterferon and ribavirin in patients with HCV infection.
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Affiliation(s)
- L Caro
- Merck & Co., Inc., Kenilworth, New Jersey, USA
| | - J de Hoon
- Center for Clinical Pharmacology, University Hospitals, Leuven, Belgium
| | - M Depré
- Center for Clinical Pharmacology, University Hospitals, Leuven, Belgium
| | - C Cilissen
- Merck Sharp & Dohme (Europe) Inc., Brussels, Belgium
| | - J Miller
- Merck & Co., Inc., Kenilworth, New Jersey, USA
| | - W Gao
- Merck & Co., Inc., Kenilworth, New Jersey, USA
| | | | - Z Guo
- Merck & Co., Inc., Kenilworth, New Jersey, USA
| | - S L Troemel
- Merck & Co., Inc., Kenilworth, New Jersey, USA
| | | | - N Uemura
- Merck & Co., Inc., Kenilworth, New Jersey, USA.,Current affiliation: Oita University, Oita, Japan
| | - J Butterton
- Merck & Co., Inc., Kenilworth, New Jersey, USA
| | - J Wagner
- Merck & Co., Inc., Kenilworth, New Jersey, USA.,Current affiliation: Takeda Pharmaceuticals U.S.A., Inc., Deerfield, Illinois, USA
| | - D H Wright
- Merck & Co., Inc., Kenilworth, New Jersey, USA
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14
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Kraft WK, Gilmartin JH, Chappell DL, Gheyas F, Walker BM, Nagalla S, Naik UP, Horrow JC, Wrishko RE, Zhang S, Anderson MS. Effect of Vorapaxar Alone and in Combination with Aspirin on Bleeding Time and Platelet Aggregation in Healthy Adult Subjects. Clin Transl Sci 2016; 9:221-7. [PMID: 27304196 PMCID: PMC5351335 DOI: 10.1111/cts.12405] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Revised: 05/17/2016] [Accepted: 05/12/2016] [Indexed: 11/25/2022] Open
Abstract
The effect of the protease‐activated receptor‐1 (PAR‐1) antagonist vorapaxar on human bleeding time is not known. This was a randomized, two‐period, open‐label trial in healthy men (n = 31) and women (n = 5). In period 1, subjects received 81 mg aspirin q.d. or a vorapaxar regimen achieving steady‐state plasma concentrations equivalent to chronic 2.5 mg q.d. doses, for 7 days. In period 2, each group added 7 days of the therapy alternate to that of period 1 without washout. Bleeding time and platelet aggregation using arachidonic acid, ADP, and TRAP agonists were assessed. Bleeding time geometric mean ratio (90% CI) for vorapaxar/baseline was 1.01 (0.88–1.15), aspirin/baseline was 1.32 (1.15–1.51), vorapaxar + aspirin/vorapaxar was 1.47 (1.26–1.70), and vorapaxar + aspirin/aspirin was 1.12 (0.96–1.30). Unlike aspirin, vorapaxar did not prolong bleeding time compared with baseline. Bleeding time following administration of vorapaxar with aspirin was similar to that following aspirin alone.
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Affiliation(s)
- W K Kraft
- Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | | | | | - F Gheyas
- Merck & Co, Kenilworth, New Jersey, USA
| | | | - S Nagalla
- Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - U P Naik
- Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | | | | | - S Zhang
- Merck & Co, Kenilworth, New Jersey, USA
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15
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Abstract
An atomic force microscope (AFM) is presented as an instrument for rapid, miniaturized chromatography. The AFM is used to inject a sample, provide shear driven liquid flow over a functionalized substrate, and detect separated components. The components are then analyzed with surface enhanced Raman spectroscopy using AFM deposition of gold nanoparticles on the separated bands. This AFM mediated chromatography (AFM-MC) is demonstrated using lipophilic dyes and normal phase chemistry. A significant reduction in both size and separation time scales is achieved with 25 μm length scale and 1 s separation times. AFM-MC has general applications to trace chemical analysis and microfluidics.
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Affiliation(s)
- M S Anderson
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA.
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16
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Anderson MS, Katz I, Petkov M, Blakkolb B, Mennella J, D'Agostino S, Crisp J, Evans J, Feldman J, Limonadi D. In situ cleaning of instruments for the sensitive detection of organics on Mars. Rev Sci Instrum 2012; 83:105109. [PMID: 23126806 DOI: 10.1063/1.4757861] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A method is presented for in situ cleaning of spacecraft instruments that analyze planetary soil and rock. We have found that vibrating hardware, used to facilitate powder transport, was also effective at removing contamination. Surfaces can be cleaned below monolayer levels using vibrating surfaces in the presence of mineral powder. Both organic and particulate contamination is efficiently removed. Fine grained regolith from the planetary surface or an organic free reference material may serve as the powder used for cleaning. We present both analytical and experimental results for the contamination transfer fraction and the conditions required to clean the hardware prior to sensitive chemical analysis.
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Affiliation(s)
- M S Anderson
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA.
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Anderson MS, Katz I, Petkov M, Blakkolb B, Mennella J, D'Agostino S, Crisp J, Evans J, Feldman J, Limonadi D. In situ cleaning of instruments for the sensitive detection of organics on Mars. Rev Sci Instrum 2012. [PMID: 23126806 DOI: 10.1063/1061.4757861] [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] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
A method is presented for in situ cleaning of spacecraft instruments that analyze planetary soil and rock. We have found that vibrating hardware, used to facilitate powder transport, was also effective at removing contamination. Surfaces can be cleaned below monolayer levels using vibrating surfaces in the presence of mineral powder. Both organic and particulate contamination is efficiently removed. Fine grained regolith from the planetary surface or an organic free reference material may serve as the powder used for cleaning. We present both analytical and experimental results for the contamination transfer fraction and the conditions required to clean the hardware prior to sensitive chemical analysis.
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Affiliation(s)
- M S Anderson
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California 91109, USA.
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Gleeson DF, Pappalardo RT, Anderson MS, Grasby SE, Mielke RE, Wright KE, Templeton AS. Biosignature detection at an Arctic analog to Europa. Astrobiology 2012; 12:135-150. [PMID: 22283368 DOI: 10.1089/ast.2010.0579] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The compelling evidence for an ocean beneath the ice shell of Europa makes it a high priority for astrobiological investigations. Future missions to the icy surface of this moon will query the plausibly sulfur-rich materials for potential indications of the presence of life carried to the surface by mobile ice or partial melt. However, the potential for generation and preservation of biosignatures under cold, sulfur-rich conditions has not previously been investigated, as there have not been suitable environments on Earth to study. Here, we describe the characterization of a range of biosignatures within potentially analogous sulfur deposits from the surface of an Arctic glacier at Borup Fiord Pass to evaluate whether evidence for microbial activities is produced and preserved within these deposits. Optical and electron microscopy revealed microorganisms and extracellular materials. Elemental sulfur (S⁰), the dominant mineralogy within field samples, is present as rhombic and needle-shaped mineral grains and spherical mineral aggregates, commonly observed in association with extracellular polymeric substances. Orthorhombic α-sulfur represents the stable form of S⁰, whereas the monoclinic (needle-shaped) γ-sulfur form rosickyite is metastable and has previously been associated with sulfide-oxidizing microbial communities. Scanning transmission electron microscopy showed mineral deposition on cellular and extracellular materials in the form of submicron-sized, needle-shaped crystals. X-ray diffraction measurements supply supporting evidence for the presence of a minor component of rosickyite. Infrared spectroscopy revealed parts-per-million level organics in the Borup sulfur deposits and organic functional groups diagnostic of biomolecules such as proteins and fatty acids. Organic components are below the detection limit for Raman spectra, which were dominated by sulfur peaks. These combined investigations indicate that sulfur mineral deposits may contain identifiable biosignatures that can be stabilized and preserved under low-temperature conditions. Borup Fiord Pass represents a useful testing ground for instruments and techniques relevant to future astrobiological exploration at Europa.
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Affiliation(s)
- Damhnait F Gleeson
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, California, USA.
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19
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Abstract
Peyronie's disease is a fibromatosis of the tunica albuginea. While trauma is believed to be the inciting event, the exact pathophysiology of this condition is unknown. In vitro analysis of cell biology can shed light on the pathogenesis of medical conditions and has been used for many decades as a research tool. We have established a cell culture model, which we have used to study the pathobiology of cells derived from Peyronie's disease plaque tissue. In 10 separate cell cultures derived from different individuals, these cells have demonstrated consistent phenotypic, genotypic and functional alterations. In neither of the control cell cultures, neonatal foreskin fibroblasts and normal tunica-derived fibroblasts have any of the above aberrations been demonstrated. The cells studied have been shown to be fibroblasts in nature with a sub-population of myofibroblasts present in culture. The Peyronie's disease plaque tissue-derived fibroblasts have demonstrated (i) consistent morphologic transformation (ii) increased S-phase on flow cytometry (iii) decreased dependence on culture medium (iv) cytogenic instability (v) excess production of fibrogenic cytokines and (vi) stabilization and dysfunctionalization of p53. Further refinement of this model and future analyses may permit an increased understanding of the pathogenesis of this condition and allow the development of therapeutic strategies.
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Affiliation(s)
- J P Mulhall
- Andrology Research Laboratory, Hines VA, Hines, Illinois, USA
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Stiffey-Wilusz J, Boice JA, Ronan J, Fletcher AM, Anderson MS. An ex vivo angiogenesis assay utilizing commercial porcine carotid artery: modification of the rat aortic ring assay. Angiogenesis 2002; 4:3-9. [PMID: 11824376 DOI: 10.1023/a:1016604327305] [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: 11/12/2022]
Abstract
The study of angiogenesis as a therapeutic target requires a reliable, physiologically relevant, and technically straightforward assay. An ex vivo assay bridges the gap between cell-based assays, which may not realistically represent the complex process of vessel sprouting, and in vivo assays, which are time consuming and expensive. Porcine carotid arteries provide an ideal tissue source for angiogenesis inhibitor screens due to their availability, physiological relevance and large size. 1.5 mm2 fragments of porcine carotid arteries were incubated in 48-well culture plates and sandwiched between two 100 microliters layers of Matrigel. Sprouting was observed from the explants and quantitated, using a digital imaging system, after two weeks of incubation. Histological analysis using Factor VIII-related antigen (von Willebrand Factor) as an endothelial cell-specific marker identified these sprouts, which were consistent with endothelial cell morphology, supporting the system as a model of angiogenesis. Accordingly, the angiogenesis inhibitors suramin, 2-methoxyestradiol, and the matrix metalloprotease inhibitor Batimastat were shown to completely inhibit sprouting at 50, 0.5, and 5.0 micrograms/ml, respectively and to have ED50 values of 23, 0.15, and 0.14 microgram/ml. This assay shows good reproducibility and eliminates animal to animal variation. The system should prove adaptable to other forms of angiogenic stimulation, ultimately making a variety of assays for angiogenesis available to laboratories of limited resources.
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Affiliation(s)
- J Stiffey-Wilusz
- Department of Endocrinology and Chemical Biology, Merck Research Laboratories, Rahway, New Jersey 07065, USA.
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Anderson MS, Flowers-Ziegler J, Das UG, Hay WW, Devaskar SU. Glucose transporter protein responses to selective hyperglycemia or hyperinsulinemia in fetal sheep. Am J Physiol Regul Integr Comp Physiol 2001; 281:R1545-52. [PMID: 11641127 DOI: 10.1152/ajpregu.2001.281.5.r1545] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [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: 11/22/2022]
Abstract
The acute effect of selective hyperglycemia or hyperinsulinemia on late gestation fetal ovine glucose transporter protein (GLUT-1, GLUT-3, and GLUT-4) concentrations was examined in insulin-insensitive (brain and liver) and insulin-sensitive (myocardium and fat) tissues at 1, 2.5, and 24 h. Hyperglycemia with euinsulinemia caused a two- to threefold increase in brain GLUT-3, liver GLUT-1, and myocardial GLUT-1 concentrations only at 1 h. There was no change in GLUT-4 protein amounts at any time during the selective hyperglycemia. In contrast, selective hyperinsulinemia with euglycemia led to an immediate and persistent twofold increase in liver GLUT-1, which lasted from 1 until 24 h with a concomitant decline in myocardial tissue GLUT-4 amounts, reaching statistical significance at 24 h. No other significant change in response to hyperinsulinemia was noted in any of the other isoforms in any of the other tissues. Simultaneous assessment of total fetal glucose utilization rate (GURf) during selective hyperglycemia demonstrated a transient 40% increase at 1 and 2.5 h, corresponding temporally with a transient increase in brain GLUT-3 and liver and myocardial GLUT-1 protein amounts. In contrast, selective hyperinsulinemia led to a sustained increase in GURf, corresponding temporally with the persistent increase in hepatic GLUT-1 concentrations. We conclude that excess substrate acutely increases GURf associated with an increase in various tissues of the transporter isoforms GLUT-1 and GLUT-3 that mediate fetal basal glucose transport without an effect on the GLUT-4 isoform that mediates insulin action. This contrasts with the tissue-specific effects of selective hyperinsulinemia with a sustained increase in GURf associated with a sustained increase in hepatic basal glucose transporter (GLUT-1) amounts and a myocardial-specific emergence of mild insulin resistance associated with a downregulation of GLUT-4.
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Affiliation(s)
- M S Anderson
- Division of Neonatology, Department of Pediatrics, University of Colorado, Denver, Colorado 80262, USA
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Anderson MS, He J, Flowers-Ziegler J, Devaskar SU, Hay WW. Effects of selective hyperglycemia and hyperinsulinemia on glucose transporters in fetal ovine skeletal muscle. Am J Physiol Regul Integr Comp Physiol 2001; 281:R1256-63. [PMID: 11557634 DOI: 10.1152/ajpregu.2001.281.4.r1256] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [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: 11/22/2022]
Abstract
We measured net fetal glucose uptake rate from the placenta, shown previously to be equal to total fetal glucose utilization rate (GUR(f)) and proportional to fetal hindlimb skeletal muscle glucose utilization, under normal conditions and after 1, 2.5, and 24 h of selective hyperglycemia increasing G or selective hyperinsulinemia increasing I. We simultaneously measured the amount of Glut 1 and Glut 4 glucose transporter proteins in fetal sheep skeletal muscle. With increasing G , GUR(f) was increased approximately 40% at 1 and 2.5 h but returned to the control rate by 24 h. This transient increasing G -specific increasing GUR(f) was associated with increased plasma membrane-associated Glut 1 (4-fold) and intracellular Glut 4 (3-fold) protein beginning at 1 h. With increasing I, GUR(f) was increased approximately 70% at 1, 2.5, and 24 h. This more sustained increasing I-specific increasing GUR(f) was associated with a significant increase in Glut 4 protein (2-fold) at 2.5 h but no change in Glut 1 protein. These results show that increasing G and increasing I have independent effects on the amount of Glut 1 and Glut 4 glucose transporter proteins in ovine fetal skeletal muscle. These effects are time dependent and isoform specific and may contribute to increased glucose utilization in fetal skeletal muscle. The lack of a sustained temporal correlation between the increase in transporter proteins and glucose utilization rates indicates that subcellular localization and activity of a transporter or tissues other than the skeletal muscle contribute to net GUR(f).
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Affiliation(s)
- M S Anderson
- Perinatal Research Center and Section of Neonatology, Department of Pediatrics, University of Colorado School of Medicine, Denver, Colorado 80262, USA.
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Wang Z, Wan H, Anderson MS, Abdel-Rehim M, Blomberg LG. Separation of lidocaine and its metabolites by capillary electrophoresis using volatile aqueous and nonaqueous electrolyte systems. Electrophoresis 2001; 22:2495-502. [PMID: 11519953 DOI: 10.1002/1522-2683(200107)22:12<2495::aid-elps2495>3.0.co;2-i] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The separation of the basic drug lidocaine and six of its metabolites has been investigated both by using volatile aqueous electrolyte system, at low pH and by employing non-aqueous electrolyte systems. In aqueous systems, the best separation of the compounds under the investigated conditions was achieved by using the electrolyte 60 mM trifluoroacetic acid (TFA)/triethylamine (TEA) at pH 2.5 containing 15% methanol. With this electrolyte, all seven compounds were well separated with high efficiency and migration time repeatability. The separations with bare fused-silica capillaries and polyacrylamide-coated capillaries were compared with higher separation efficiency with the latter. On the other hand, near baseline separation of all the seven compounds was also obtained by employing the non-aqueous electrolyte, 40 mM ammonium acetate in methanol and TFA (99:1, v/v), with comparable migration time repeatability but lower separation efficiency relative to the aqueous system.
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Affiliation(s)
- Z Wang
- Department of Chemistry, Karlstad University, Sweden
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Stephens E, Thureen PJ, Goalstone ML, Anderson MS, Leitner JW, Hay WW, Draznin B. Fetal hyperinsulinemia increases farnesylation of p21 Ras in fetal tissues. Am J Physiol Endocrinol Metab 2001; 281:E217-23. [PMID: 11440896 DOI: 10.1152/ajpendo.2001.281.2.e217] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [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: 11/22/2022]
Abstract
Even though the role of fetal hyperinsulinemia in the pathogenesis of fetal macrosomia in patients with overt diabetes and gestational diabetes mellitus seems plausible, the molecular mechanisms of action of hyperinsulinemia remain largely enigmatic. Recent indications that hyperinsulinemia "primes" various tissues to the mitogenic influence of growth factors by increasing the pool of prenylated Ras proteins prompted us to investigate the effect of fetal hyperinsulinemia on the activitiy of farnesyltransferase (FTase) and the amounts of farnesylated p21 Ras in fetal tissues in the ovine experimental model. Induction of fetal hyperinsulinemia by direct infusion of insulin into the fetus and by either fetal or maternal infusions of glucose resulted in significant increases in the activity of FTase and the amounts of farnesylated p21 Ras in fetal liver, skeletal muscle, fat, and white blood cells. An additional infusion of somatostatin into hyperglycemic fetuses blocked fetal hyperinsulinemia and completely prevented these increases, specifying insulin as the causative factor. We conclude that the ability of fetal hyperinsulinemia to increase the size of the pool of farnesylated p21 Ras may prime fetal tissues to the action of other growth factors and thereby constitute one mechanism by which fetal hyperinsulinemia could induce macrosomia in diabetic pregnancies.
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Affiliation(s)
- E Stephens
- Veterans Affairs Research Service, Department of Medicine, University of Colorado Health Sciences Center, Denver, Colorado 80220, USA
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25
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Abstract
Doctoral students receive many kinds of assistance from faculty members, but much of this support falls short of mentoring. This paper takes the perspective that it is more important to find out what kinds of help students receive from faculty than to assume that students are taken care of by mentors, as distinct from advisors or role models. The findings here are based on both survey and interview data collected through the Acadia Institute's project on Professional Values and Ethical Issues in the Graduate Education of Scientists and Engineers. The paper describes various kinds of assistance that students receive (or do not receive) from faculty members in their roles as teacher/coach, sponsor, and counselor, It concludes with a section on advisors assigned to doctoral students, notably the extent of their contact with and influence on students.
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Affiliation(s)
- M S Anderson
- 330 Wulling Hall, University of Minnesota, Minneapolis, Minnesota 55455, USA.
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26
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Abstract
OBJECTIVE To report a case of a clinically occult testicular tumor causing gynecomastia and to alert physicians to the importance of use of testicular ultrasonography in patients with progressive gynecomastia despite normal findings on testicular examination. METHODS We present a detailed case, including results of clinical, laboratory, and radiologic assessment, of a man with hyperprolactinemia and gynecomastia. RESULTS A 36-year-old man with progressive gynecomastia was referred to our clinic because of an increased serum prolactin level. Subsequent clinical investigation revealed no evidence of hypogonadism and several possible causes of the gynecomastia. Because of the patient's age and progressive symptoms, testicular ultrasonography was performed despite normal findings on testicular examination. This ultrasound study showed a right testicular mass, which proved to be a Leydig cell tumor. The patient was referred for definitive therapy with orchiectomy. Follow-up studies showed resolution of the gynecomastia and substantial decreases in prolactin and estradiol levels. CONCLUSION Although gynecomastia is a relatively common disorder with a benign cause in most cases, physicians should be aware that normal findings on testicular examination do not completely rule out the possibility of a testicular tumor as the cause. Because of the potentially high morbidity of testicular tumors and their known association with gynecomastia, early performance of testicular ultrasonography in a patient with gynecomastia of unknown cause is advised.
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Affiliation(s)
- M S Anderson
- Neuroendocrine Unit and Department of Pathology, Massachusetts General Hospital, Boston, Massachusetts, USA
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Anderson MS, Burns J, Treadwell TA, Pietra BA, Glodé MP. Erythrocyte sedimentation rate and C-reactive protein discrepancy and high prevalence of coronary artery abnormalities in Kawasaki disease. Pediatr Infect Dis J 2001; 20:698-702. [PMID: 11465843 DOI: 10.1097/00006454-200107000-00011] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND An outbreak of Kawasaki disease (KD) in Colorado between November, 1997, and June, 1998, provided the opportunity to study inflammatory indices and coronary artery abnormalities. METHODS Medical records of the 33 patients diagnosed with KD at The Children's Hospital during the outbreak were reviewed. Demographic and clinical information, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR) and echocardiogram results were recorded. Traditional abnormalities (dilatation, aneurysm, ectasia), as well as "prominence" of the coronary arteries were noted. RESULTS Twenty-five patients had CRP and ESR performed on the day of admission; 11 of 25 (44%) had a discrepancy between the height of the ESR and CRP values (high ESR and low CRP or low ESR and high CRP). The mean CRP was higher in patients who presented in <10 days than in patients who presented in > or =10 days: 13.9 mg/dl vs. 5.2 mg/dl (P = 0.01). The ESR value did not correlate with the day of illness. Age, gender or presence of coronary artery abnormalities did not correlate with the height of CRP or ESR elevation. Thirty percent of patients had at least one abnormality on their initial echocardiogram (dilatation, aneurysm, ectasia). An additional 24% of patients displayed prominence as the only finding on their initial echocardiogram. Of the 33 patients 7 (21.2%) had coronary artery aneurysms. CONCLUSIONS Many patients with KD have discrepancies in the degree of elevation of CRP and ESR. Physicians should consider obtaining both tests in patients with KD. This outbreak was associated with a high degree of coronary artery abnormalities. The finding of coronary artery prominence is an observation that deserves further study.
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Affiliation(s)
- M S Anderson
- University of Colorado Health Sciences Center, Children's Hospital, Denver, USA
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Azzolina BA, Yuan X, Anderson MS, El-Sherbeini M. The cell wall and cell division gene cluster in the Mra operon of Pseudomonas aeruginosa: cloning, production, and purification of active enzymes. Protein Expr Purif 2001; 21:393-400. [PMID: 11281713 DOI: 10.1006/prep.2001.1390] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We have cloned the Pseudomonas aeruginosa cell wall biosynthesis and cell division gene cluster that corresponds to the mra operon in the 2-min region of the Escherichia coli chromosome. The organization of the two chromosomal regions in P. aeruginosa and E. coli is remarkably similar with the following gene order: pbp3/pbpB, murE, murF, mraY, murD, ftsW, murG, murC, ddlB, ftsQ, ftsA, ftsZ, and envA/LpxC. All of the above P. aeruginosa genes are transcribed from the same strand of DNA with very small, if any, intragenic regions, indicating that these genes may constitute a single operon. All five amino acid ligases, MurC, MurD, MurE, MurF, and DdlB, in addition to MurG and MraY were cloned in expression vectors. The four recombinant P. aeruginosa Mur ligases, MurC, MurD, MurE, and MurF were overproduced in E. coli and purified as active enzymes.
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Affiliation(s)
- B A Azzolina
- Department of Biochemistry, Merck Research Laboratories, Rahway, New Jersey 07065, USA
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Yan Y, Munshi S, Leiting B, Anderson MS, Chrzas J, Chen Z. Crystal structure of Escherichia coli UDPMurNAc-tripeptide d-alanyl-d-alanine-adding enzyme (MurF) at 2.3 A resolution. J Mol Biol 2000; 304:435-45. [PMID: 11090285 DOI: 10.1006/jmbi.2000.4215] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.5] [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: 11/22/2022]
Abstract
MurF is required to catalyze the final step in the synthesis of the cytoplasmic precursor of the bacterial cell wall peptidoglycan, rendering it an attractive target for antibacterial drug development. The crystal structure of the MurF apo-enzyme has been determined using the multiwavelength anomalous dispersion method and refined to 2.3 A resolution. It contains three consecutive open alpha/beta-sheet domains. In comparison with the complex crystal structures of MurD and its substrates, The topology of the N-terminal domain of MurF is unique, while its central and C-terminal domains exhibit similar mononucleotide and dinucleotide-binding folds, respectively. The apo-enzyme of MurF crystal structure reveals an open conformation with the three domains juxtaposed in a crescent-like arrangement creating a wide-open space where substrates are expected to bind. As such, catalysis is not feasible and significant domain closure is expected upon substrate binding.
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Affiliation(s)
- Y Yan
- Department of Structural Biology, West Point, PA, 19486, USA.
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Anderson MS, Eveland SS, Price NP. Conserved cytoplasmic motifs that distinguish sub-groups of the polyprenol phosphate:N-acetylhexosamine-1-phosphate transferase family. FEMS Microbiol Lett 2000; 191:169-75. [PMID: 11024259 DOI: 10.1111/j.1574-6968.2000.tb09335.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
WecA, MraY and WbcO are conserved members of the polyprenol phosphate:N-acetylhexosamine-1-phosphate transferase family involved in the assembly of bacterial cell walls, and catalyze reactions involving a membrane-associated polyprenol phosphate acceptor substrate and a cytoplasmically located UDP-D-amino sugar donor. MraY, WbcO and WecA purportedly utilize different UDP-sugars, although the molecular basis of this specificity is largely unknown. However, domain variations involved in specificity are predicted to occur on the cytoplasmic side of the membrane, adjacent to conserved domains involved in the mechanistic activity, and with access to the cytoplasmically located sugar nucleotides. Conserved C-terminal domains have been identified that satisfy these criteria. Topological analyses indicate that they form the highly basic, fifth cytoplasmic loop between transmembrane regions IX and X. Four diverse loops are apparent, for MraY, WecA, WbcO and RgpG, that uniquely characterize these sub-groups of the transferase family, and a correlation is evident with the known or implied UDP-sugar specificity.
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Affiliation(s)
- M S Anderson
- Department of Chemistry, State University of New York College of Environmental Science and Forestry, Syracuse, NY 13210, USA.
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Abstract
Data from two national surveys of 4,000 faculty and doctoral students in chemistry, civil engineering, microbiology and sociology indicate that both faculty and students subscribe strongly to traditional norms but are more likely to see alternative counternorms enacted in their departments. They also show significant effects of departmental climate on normative orientations and suggest that many researchers express some degree of ambivalence about traditional norms.
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Affiliation(s)
- M S Anderson
- University of Minnesota, 330 Wulling Hall, Minneapolis, MN 55455, USA.
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32
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Abstract
Peyronie's disease is a fibromatosis of the tunica albuginea which affects up to 2% of men. Plaque development is believed to result, at least in part, from fibroblast proliferation and excess collagen deposition. Numerous oral and intralesional therapies have been used, including verapamil, colchicine and steroids. The purpose of this study was to investigate the in vitro effects of prostaglandin-E1 (PGE1), verapamil and colchicine on the proliferation rates of fibroblasts derived from Peyronie's disease tissue. Using tissue culture, multiple cell lines comprising fibroblasts from Peyronie's plaque, normal tunica and foreskin were established. Cells of low passage were removed from the parent culture and incubated with varying concentrations of PGE1 (0.1-10 mg/ml), verapamil (10-1000 mg/ml), and colchine (2.5 mg/ml). Proliferation was assessed at 48, 72 and 96 hours using the Vybrant MTT cell proliferation and then compared to control cells. Six plaque lines and 5 normal tunical cell lines were established. These cell lines exhibited excellent linear growth in culture media alone. Co-culture wih PGE1 resulted in no significant inhibition at 0.1 and 1 mg/ml, but a mean inhibition of 60.6+/-11.5% at a concenrtation of 10 mg/ml was noted. Similar inhibition was noted with verapamil at 100 and 1000 mg/ml with a mean inhibition of 65.2+/-10.6%. Colchicine resulted in a mean inhibition of 28% at a concentration of 2.5 mg/ml. Maximum inhibition occurred at 96 hours in all cases. There was no statisitically significant difference in proliferation rates between plaque and normal tunical cell lines. We have developed an in vitro model to assess the effects of biologically active agents on the growth of fibroblasts derived from Peyronie's disease tissue. Our data suggests that PGE1, verapamil, and colchicine inhibit in vitro proliferation of fibroblasts at specific concentrations. Refinement and application of this knowledge may allow the development of useful pharmacologic strategies for men with PD.
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Affiliation(s)
- M S Anderson
- Urology Research Laboratory, Hines VA, Hines, IL 60153, USA
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Abstract
A comparison of laboratory spectra with Galileo data indicates that hydrated sulfuric acid is present and is a major component of Europa's surface. In addition, this moon's visually dark surface material, which spatially correlates with the sulfuric acid concentration, is identified as radiolytically altered sulfur polymers. Radiolysis of the surface by magnetospheric plasma bombardment continuously cycles sulfur between three forms: sulfuric acid, sulfur dioxide, and sulfur polymers, with sulfuric acid being about 50 times as abundant as the other forms. Enhanced sulfuric acid concentrations are found in Europa's geologically young terrains, suggesting that low-temperature, liquid sulfuric acid may influence geological processes.
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Affiliation(s)
- R W Carlson
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA.
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34
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Affiliation(s)
- M S Anderson
- Department of Pediatrics, The Children's Hospital and University of Colorado Health Sciences Center, Denver, USA
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35
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Affiliation(s)
- M S Anderson
- Department of Pediatrics, Children's Hospital, University of Colorado Health Sciences Center, Denver, USA
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36
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Carlson RW, Anderson MS, Johnson RE, Smythe WD, Hendrix AR, Barth CA, Soderblom LA, Hansen GB, McCord TB, Dalton JB, Clark RN, Shirley JH, Ocampo AC, Matson DL. Hydrogen peroxide on the surface of Europa. Science 1999; 283:2062-4. [PMID: 10092224 DOI: 10.1126/science.283.5410.2062] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.2] [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] [Indexed: 11/02/2022]
Abstract
Spatially resolved infrared and ultraviolet wavelength spectra of Europa's leading, anti-jovian quadrant observed from the Galileo spacecraft show absorption features resulting from hydrogen peroxide. Comparisons with laboratory measurements indicate surface hydrogen peroxide concentrations of about 0.13 percent, by number, relative to water ice. The inferred abundance is consistent with radiolytic production of hydrogen peroxide by intense energetic particle bombardment and demonstrates that Europa's surface chemistry is dominated by radiolysis.
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Affiliation(s)
- R W Carlson
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109, USA.
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Chen MH, Steiner MG, de Laszlo SE, Patchett AA, Anderson MS, Hyland SA, Onishi HR, Silver LL, Raetz CR. Carbohydroxamido-oxazolidines: antibacterial agents that target lipid A biosynthesis. Bioorg Med Chem Lett 1999; 9:313-8. [PMID: 10091675 DOI: 10.1016/s0960-894x(98)00749-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A series of carbohydroxamido-oxazolidine inhibitors of UDP-3-O-[R-3-hydroxymyristoyl]-GlcNAc deacetylase, the enzyme responsible for the second step in lipid A biosynthesis, was identified. The most potent analog L-161,240 showed an IC50 = 30 nM in the DEACET assay and displayed an MIC of 1-3 microg/mL against wild-type E. coli.
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Affiliation(s)
- M H Chen
- Department of Medicinal Chemistry, Merck Research Laboratories, Rahway, New Jersey 07065, USA
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Taylor JR, Anderson MS, Bunton PH. High-speed tilt mirror for image stabilization. Appl Opt 1999; 38:219-223. [PMID: 18305606 DOI: 10.1364/ao.38.000219] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A magnetostrictively driven tilt-mirror mount for image stabilization of NASA's Marshall Space Flight Center's Experimental Vector Magnetograph has been designed, built, and tested. A simple improvement in the mounting technique of the actuator resulted in a factor of 3 increase in the lowest resonant frequency of the device. The tilt-mirror device was built, and the lowest structural resonant frequency was experimentally found to be 603 Hz.
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Affiliation(s)
- J R Taylor
- Department of Physics, Austin Peay State University, PO Box 4608, Clarksville, Tennessee 37044-0002, USA.
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Abstract
UDP-GlcN[1-14C]Ac was synthesized in a single enzymatic reaction from [1-14C]acetate and commercially available precursors on both a microcurie (micromole) and a millicurie (millimole) scale. The reaction was catalyzed by the action of acetyl coenzyme A synthetase, inorganic pyrophosphatase, and the bifunctional Escherichia coli GlmU protein. Within 2 h 86 to 94% reaction is attained, and it approaches 99% completion overnight. GlmU protein was prepared in the form of a fusion suitable for nickel chelate affinity chromatography. Several methods were developed for rapid purification of UDP-GlcN[1-14C]Ac: an HPLC method handled micromole (microcurie) loads. Alternatively, ion exchange chromatography over DOWEX AG1 X-2 using a batch elution procedure was compatible with millimole (millicurie) amounts of radiolabel and yielded both chemically and radiochemically homogeneous UDP-GlcN[1-14C]Ac. These methods allow laboratories to quickly produce and purify microcurie to millicurie quantities of N-acetyl-labeled UDP-GlcNAc by a choice of methods from relatively inexpensive precursors.
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Affiliation(s)
- B Leiting
- Department of Enzymology, Merck Research Laboratories, Rahway, New Jersey 07065, USA
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Eveland SS, Pompliano DL, Anderson MS. Conditionally lethal Escherichia coli murein mutants contain point defects that map to regions conserved among murein and folyl poly-gamma-glutamate ligases: identification of a ligase superfamily. Biochemistry 1997; 36:6223-9. [PMID: 9166795 DOI: 10.1021/bi9701078] [Citation(s) in RCA: 87] [Impact Index Per Article: 3.2] [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: 02/04/2023]
Abstract
Bacterial peptidoglycan biosynthesis includes four enzymatic reactions in which successive amino acid residues are ligated to uridine diphospho-N-acetylmuramic acid (UDP-MurNAc). By comparing the amino acid sequences of MurC, -D, -E, and -F proteins from various bacterial genera, four regions of homology were identified. A profile search of Swissprot for related sequences revealed that these regional similarities were present in the folyl-gamma-polyglutamate ligases. These sequence homologies appear to track with catalytic function: both enzyme families proceed through an ordered kinetic mechanism and form product via an acyl phosphate intermediate. Two highly conserved residues in region II were examined through site-directed mutagenesis of the murein D-alanyl-D-alanine-adding enzyme from Escherichia coli (murF; E158 and H188). All mutations were highly detrimental to activity with enzyme specific activity reductions of 200-4500-fold, validating the critical nature of these residues. DNA sequence analysis from three E. coli mutants harboring the murC3 (G344D), murE1 (G344K, A495S), and murF2 (A288T) mutations revealed the presence of point mutation(s) closely associated with the fourth of these aligned regions. The murF2 allele, expressed and purified as a glutathione S-transferase::MurF2 fusion, was 181-fold less catalytically active at 30 degrees C and was further reduced at the nonpermissive temperature (42 degrees C). Thus the murF2 temperature-sensitive phenotype arises from a point mutation within a highly conserved region within this protein family. These data argue that these proteins comprise a superfamily of three substrate amide ligases that share significant structural and catalytic homologies.
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Affiliation(s)
- S S Eveland
- Department of Enzymology, Merck Research Laboratories, Rahway, New Jersey 07065, USA
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Russ PD, Allen-Davis JT, Weingardt JP, Anderson MS, Koyle MA. Mayer-Rokitansky-Kuster-Hauser syndrome diagnosed by magnetic resonance imaging in a 15-year-old girl. J Pediatr Adolesc Gynecol 1997; 10:89-92. [PMID: 9179809 DOI: 10.1016/s1083-3188(97)70058-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
STUDY OBJECTIVE Mayer-Rokitansky-Kuster-Hauser syndrome diagnosed by magnetic resonance imaging (MRI) in a 15-year-old girl with primary amenorrhea is reported. DESIGN The presentation, MRI, and the subsequent evaluation and treatment of an adolescent female patient with Rokitansky syndrome are described. Correlation is made with previous clinical, pathologic, and imaging reports in the literature. SETTING An adolescent girl with primary amenorrhea was referred to our institution for completion of her diagnostic work-up. Previous limited evaluations suggested the presence of anomalies of the genitourinary tract. Further delineation of the suspected congenital defects was necessary. PARTICIPANT The 15-year-old female patient was evaluated by the gynecology service. Diagnostic radiology and pediatric urology were consulted. INTERVENTIONS MRI, physical examination under anesthesia, and cystoscopy were performed. After initial nonoperative treatment, the patient underwent hysterectomy and sigmoid vaginoplasty. MAIN OUTCOME MEASURES The patient's primary amenorrhea was explained. Mayer-Rokitansky-Kuster-Hauser syndrome was diagnosed. Vaginal agenesis and widely separated rudimentary uterine horns were well shown by the MRI. Associated skeletal anomalies were noted. A treatment plan was initiated based on a good understanding of the anatomic defects. RESULTS The MRI and physical examination firmly established the diagnosis. The patient was counseled and managed conservatively at first. Hysterectomy and vaginoplasty were subsequently performed. CONCLUSIONS Mayer-Rokitansky-Kuster-Hauser syndrome is an unusual müllerian-duct anomaly that is a cause of primary amenorrhea. It can be confidently and noninvasively diagnosed with MRI. The MRI demonstration of vaginal, cervical, and uterine morphology contributes significantly to treatment planning and patient management.
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Affiliation(s)
- P D Russ
- Department of Radiology, University of Colorado Health Sciences Center, Denver 80262, USA
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Hyland SA, Eveland SS, Anderson MS. Cloning, expression, and purification of UDP-3-O-acyl-GlcNAc deacetylase from Pseudomonas aeruginosa: a metalloamidase of the lipid A biosynthesis pathway. J Bacteriol 1997; 179:2029-37. [PMID: 9068651 PMCID: PMC178929 DOI: 10.1128/jb.179.6.2029-2037.1997] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The lpxC (envA) gene of Escherichia coli encodes UDP-3-O-acyl-GlcNAc deacetylase, the second and committed step of lipopolysaccharide biosynthesis. Although present in all gram-negative bacteria examined, the deacetylase from E. coli is the only example of this enzyme that has been expressed and purified. In order to examine other variants of this protein, we cloned the Pseudomonas aeruginosa deacetylase structural gene from a lambda library as a 5.1-kb EcoRI fragment. The LpxC reading frame encodes an inferred protein of 33,435 Da that is highly homologous to the E. coli protein and that possesses a nearly identical hydropathy profile. In order to verify function, we subcloned the P. aeruginosa lpxC gene into the T7-based expression vector pET11a. Upon induction at 30 degrees C, this construct yielded active protein to approximately 18% of the soluble fraction. We devised a novel, rapid, and reproducible assay for the deacetylase which facilitated purification of the enzyme in three steps. The purified recombinant protein was found to be highly sensitive to EDTA yet was reactivated by the addition of excess heavy metal, as was the case for crude extracts of P. aeruginosa. In contrast, deacetylase activity in crude extracts of E. coli was insensitive to EDTA, and the extracts of the envA1 mutant were sensitive in a time-dependent manner. The lpxC gene has no significant homology with amidase signature sequences. Therefore, we assign this protein to the metalloamidase family as a member with a novel structure.
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Affiliation(s)
- S A Hyland
- Department of Enzymology, Merck Research Laboratories, Rahway, New Jersey 07065, USA
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Anderson MS, Eveland SS, Onishi HR, Pompliano DL. Kinetic mechanism of the Escherichia coli UDPMurNAc-tripeptide D-alanyl-D-alanine-adding enzyme: use of a glutathione S-transferase fusion. Biochemistry 1996; 35:16264-9. [PMID: 8973200 DOI: 10.1021/bi961872+] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.4] [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: 02/03/2023]
Abstract
The D-alanyl-D-alanine-adding enzyme encoded by the murF gene catalyzes the ATP-dependent formation of UDP-N-acetylmuramyl-L-gamma-D-Glu-meso-diaminopimelyl-D-Ala-D-Ala (UDP-MurNAc-tripeptide). MurF has been cloned from Escherichia coli and expressed as a glutathione S-transferase (GST) fusion using the tac promoter-based pGEX-KT vector. From induced, broken cell preparations, highly active fusion was recovered and purified in one step by affinity chromatography. The purified fusion protein was strongly inhibited by substrate UDPMurNAc-tripeptide, a response unaltered by changes in assay pH or by cleavage from the fusion partner. However, this effect was suppressed by the addition of 0.5 M NaCl. Initial velocity and dead-end inhibitor studies with the fusion enzyme were most consistent with a sequential ordered kinetic mechanism for the forward reaction in which ATP binds to free enzyme, followed by tripeptide and D-Ala-D-Ala in sequence prior to product release. Reported homologies between the MurF protein and the three preceding steps of cytoplasmic murein biosynthesis, MurC, -D, and -E, [Ikeda et al. (1990) J. Gen. Appl. Microbiol. 36, 179-187], raise the prospect that all of these enzymes will be found to proceed via this mechanism.
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Affiliation(s)
- M S Anderson
- Department of Enzymology, Merck Research Laboratories, Rahway, New Jersey 07065, USA.
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Onishi HR, Pelak BA, Gerckens LS, Silver LL, Kahan FM, Chen MH, Patchett AA, Galloway SM, Hyland SA, Anderson MS, Raetz CR. Antibacterial agents that inhibit lipid A biosynthesis. Science 1996; 274:980-2. [PMID: 8875939 DOI: 10.1126/science.274.5289.980] [Citation(s) in RCA: 328] [Impact Index Per Article: 11.7] [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: 02/02/2023]
Abstract
Lipid A constitutes the outer monolayer of the outer membrane of Gram-negative bacteria and is essential for bacterial growth. Synthetic antibacterials were identified that inhibit the second enzyme (a unique deacetylase) of lipid A biosynthesis. The inhibitors are chiral hydroxamic acids bearing certain hydrophobic aromatic moieties. They may bind to a metal in the active site of the deacetylase. The most potent analog (with an inhibition constant of about 50 nM) displayed a minimal inhibitory concentration of about 1 microgram per milliliter against Escherichia coli, caused three logs of bacterial killing in 4 hours, and cured mice infected with a lethal intraperitoneal dose of E. coli.
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Affiliation(s)
- H R Onishi
- Department of Microbiology, Merck Research Laboratories, Rahway, NJ 07065, USA
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Anderson MS, Lopes JM. Carbon source regulation of PIS1 gene expression in Saccharomyces cerevisiae involves the MCM1 gene and the two-component regulatory gene, SLN1. J Biol Chem 1996; 271:26596-601. [PMID: 8900132 DOI: 10.1074/jbc.271.43.26596] [Citation(s) in RCA: 41] [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: 02/02/2023] Open
Abstract
The Saccharomyces cerevisiae PIS1 gene encodes phosphatidylinositol synthase. The amount of phosphatidylinositol synthase is not affected by the presence of inositol and choline in the growth medium. This is unusual because the amounts and/or activities of other phospholipid biosynthetic enzymes are affected by these precursors, and the promoter of the PIS1 gene contains a sequence resembling the regulatory element that coordinates the inositol-mediated regulation (UASINO). We found that transcription of the PIS1 gene was insensitive to inositol and choline and did not require the putative UASINO regulatory sequence or the cognate regulatory genes (INO2 and OPI1). The PIS1 promoter includes sequences (MCEs) that bind the Mcm1 protein. Because the Mcm1 protein interacts with both the Sln1 and the Gal11 regulatory proteins, we examined the effect of mutant alleles of the MCM1 and SLN1 genes and carbon source on expression of the PIS1 gene. We found that expression of the PIS1 gene was reduced when cells were grown in a medium containing glycerol and increased when grown in a medium containing galactose relative to cells grown in a glucose medium. The glycerol-mediated repression of PIS1 gene expression required both the MCM1 gene and the MCEs, whereas the SLN1 gene was required for full galactose-mediated induction of a PIS1-lacZ reporter gene. Thus, PIS1 gene expression is unique among the phospholipid biosynthetic structural genes because it is uncoupled from the inositol response and regulated in response to the carbon source. This is the first example in yeast of a complete circuit linking a stimulus (carbon source) to gene regulation (PIS1) using a two-component regulator (SLN1).
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Affiliation(s)
- M S Anderson
- Department of Molecular and Cellular Biochemistry, Loyola University of Chicago, Maywood, Illinois 60153, USA
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Sorensen PG, Lutkenhaus J, Young K, Eveland SS, Anderson MS, Raetz CR. Regulation of UDP-3-O-[R-3-hydroxymyristoyl]-N-acetylglucosamine deacetylase in Escherichia coli. The second enzymatic step of lipid a biosynthesis. J Biol Chem 1996; 271:25898-905. [PMID: 8824222 DOI: 10.1074/jbc.271.42.25898] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.3] [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: 02/02/2023] Open
Abstract
The first enzyme of lipid A assembly in Escherichia coli is an acyltransferase that attaches an R-3-hydroxymyristoyl moiety to UDP-GlcNAc at the GlcNAc 3-OH. This reaction is reversible and thermodynamically unfavorable. The subsequent deacetylation of the product, UDP-3-O-[R-3-hydroxymyristoyl]-GlcNAc, is therefore the first committed step of lipid A biosynthesis. We now demonstrate that inhibition of either the acyltransferase or the deacetylase in living cells results in a 5-10-fold increase in the specific activity of the deacetylase in extracts prepared from such cells. Five other enzymes of the lipid A pathway are not affected. The elevated specific activity of deacetylase observed in extracts of lipid A-depleted cells is not accompanied by a significant change in the Km for the substrate, but is mainly an effect on Vmax. Western blots demonstrate that more deacetylase protein is indeed made. However, deacetylase messenger RNA levels are not significantly altered. Inhibition of lipid A biosynthesis must either stimulate the translation of available mRNA or slow the turnover of pre-existing deacetylase. In contrast, inhibition of 3-deoxy-D-manno-octulosonic acid (Kdo) biosynthesis has no effect on deacetylase specific activity. The underacylated lipid A-like disaccharide precursors that accumulate during inhibition of Kdo formation may be sufficient to exert normal feedback control.
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Affiliation(s)
- P G Sorensen
- Department of Biochemistry, Duke University Medical Center, Durham, North Carolina 27710, USA
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Graczyk TK, Cranfield MR, Fayer R, Anderson MS. Viability and infectivity of Cryptosporidium parvum oocysts are retained upon intestinal passage through a refractory avian host. Appl Environ Microbiol 1996; 62:3234-7. [PMID: 8795213 PMCID: PMC168119 DOI: 10.1128/aem.62.9.3234-3237.1996] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Six Cryptosporidium-free Peking ducks (Anas platyrhynchos) were each orally inoculated with 2.0 x 10(6) Cryptosporidium parvum oocysts infectious to neonatal BALB/c mice. Histological examination of the stomachs jejunums, ilea, ceca, cloacae, larynges, tracheae, and lungs of the ducks euthanized on day 7 postinoculation (p.i.) revealed no life-cycle stages of C. parvum. However, inoculum-derived oocysts extracted from duck feces established severe infection in eight neonatal BALB/c mice (inoculum dose, 2.5 x 10(5) per mouse). On the basis of acid-fast stained direct wet smears, 73% of the oocysts in duck feces were intact (27% were oocyst shells), and their morphological features conformed to those of viable and infectious oocysts of the original inoculum. The fluorescence scores of the inoculated oocysts, obtained by use of the MERIFLUOR test, were identical to those obtained for the feces-recovered oocysts (the majority were 3+ to 4+). The dynamics of oocyst shedding showed that the birds released a significantly higher number of intact oocysts than the oocyst shells (P < 0.01). The number of intact oocysts shed (87%) during the first 2 days p.i. was significantly higher than the number shed during the remaining 5 days p.i. (P < 0.01) and significantly decreased from day 1 to day 2 p.i. (P < 0.01). The number of oocyst shells shed during 7 days p.i. did not vary significantly (P > 0.05). The retention of infectivity of C. parvum oocysts after intestinal passage through an aquatic bird has serious epidemiological and epizootiological implications. Waterfowl may serve as mechanical vectors for the waterborne oocysts and may enhance contamination of surface waters with C. parvum. As the concentration of Cryptosporidium oocysts in source waters is attributable to watershed management practices, the watershed protection program should consider waterfowl as a potential factor enhancing contamination of the source water with C. parvum.
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Affiliation(s)
- T K Graczyk
- Department of Molecular Microbiology and Immunology, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, Maryland 21205, USA.
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Beuers U, Throckmorton DC, Anderson MS, Isales CM, Thasler W, Kullak-Ublick GA, Sauter G, Koebe HG, Paumgartner G, Boyer JL. Tauroursodeoxycholic acid activates protein kinase C in isolated rat hepatocytes. Gastroenterology 1996; 110:1553-63. [PMID: 8613063 DOI: 10.1053/gast.1996.v110.pm8613063] [Citation(s) in RCA: 108] [Impact Index Per Article: 3.9] [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: 01/31/2023]
Abstract
BACKGROUND & AIMS Ursodeoxycholic acid (UDCA) improves liver function in patients with chronic cholestatic liver diseases by an unknown mechanism. UDCA is conjugated to taurine in vivo, and tauroursodeoxycholic acid (TUDCA) is a potent hepatocellular Ca2+ agonist and stimulates biliary exocytosis and hepatocellular Ca2+ influx, both of which are defective in experimental cholestasis. Protein kinase C (PKC) mediates stimulation of exocytosis in the liver. The aim of this study was to determine the effects of TUDCA on PKC in isolated hepatocytes. METHODS The effect of TUDCA on the distribution of PKC isoenzymes within the hepatocyte was studied using immunoblotting and immunofluorescence techniques. In addition, the effect of TUDCA on the accummulation of sn-1,2-diacylglycerol (DAG), the intracellular activator of PKC, and hepatocellular PKC activity was studied using radioenzymatic techniques. RESULTS Immunoblotting studies showed the presence of four isoenzymes (alpha, delta, epsilon, and zeta). The phorbol ester phorbol 12-myristate 13-acetate (1 mumol/L) induced translocation of alpha-PKC, delta-PKC, and epsilon-PKC from cytosol to a particulate membrane fraction, a key step for activation of PKC. TUDCA, but not taurocholic acid, selectively induced translocation of the alpha-PKC isoenzyme from cytosol to the membranes. In addition, TUDCA induced a significant increase in hepatocellular DAG mass and stimulated membrane-associated PKC activity. CONCLUSIONS TUDCA might stimulate Ca(2+)-dependent hepatocellular exocytosis into bile in part by activation of alpha-PKC.
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Affiliation(s)
- U Beuers
- Department of Internal Medicne, Yale University School of Medicine, New Haven Connecticut, USA
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49
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Young K, Silver LL, Bramhill D, Cameron P, Eveland SS, Raetz CR, Hyland SA, Anderson MS. The envA permeability/cell division gene of Escherichia coli encodes the second enzyme of lipid A biosynthesis. UDP-3-O-(R-3-hydroxymyristoyl)-N-acetylglucosamine deacetylase. J Biol Chem 1995; 270:30384-91. [PMID: 8530464 DOI: 10.1074/jbc.270.51.30384] [Citation(s) in RCA: 149] [Impact Index Per Article: 5.1] [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: 01/31/2023] Open
Abstract
The envA gene of Escherichia coli has been shown previously to be essential for cell viability (Beall, B. and Lutkenhaus, J. (1987) J. Bacteriol. 169, 5408-5415), yet it encodes a protein of unknown function. Extracts of strains harboring the mutant envA1 allele display 3.5-18-fold reductions in UDP-3-O-acyl-N-acetylglucosamine deacetylase specific activity. The deacetylase is the second enzymatic step of lipid A biosynthesis. The structural gene coding for the deacetylase has not been assigned. In order to determine if the envA gene encodes the deacetylase, envA was cloned into an isopropyl-1-thio-beta-D-galactopyranoside-inducible T7-based expression system. Upon induction, a protein of the size of envA was highly overproduced, as judged by SDS-PAGE. Direct deacetylase assays of cell lysates revealed a concomitant approximately 5,000-fold overproduction of activity. Assays of the purified, overproduced EnvA protein demonstrated a further approximately 5-fold increase in specific activity. N-terminal amino acid sequencing of the purified protein showed that the first 20 amino acids matched the predicted envA nucleotide sequence. Contaminating species were present at less than 1% of the level of the EnvA protein. Thus, envA is the structural gene for UDP-3-O-acyl-GlcNAc deacetylase. Based on its function in lipid A biosynthesis, we propose the new designation lpxC for this gene.
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Affiliation(s)
- K Young
- Department of Antibiotic Discovery and Development, Merck Research Laboratories, Rahway, New Jersey 07065, USA
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Leifer SD, Goodwin DG, Anderson MS, Anderson JR. Thermal decomposition of a fullerene mix. Phys Rev B Condens Matter 1995; 51:9973-9978. [PMID: 9977672 DOI: 10.1103/physrevb.51.9973] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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