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Nicholl DDM, Hanly PJ, Zalucky AA, Mann MC, MacRae JM, Poulin MJ, Handley GB, Sola DY, Ahmed SB. CPAP Therapy Delays Cardiovagal Reactivation and Decreases Arterial Renin-Angiotensin System Activity in Humans With Obstructive Sleep Apnea. J Clin Sleep Med 2018; 14:1509-1520. [PMID: 30176965 DOI: 10.5664/jcsm.7326] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2017] [Accepted: 05/18/2018] [Indexed: 12/11/2022]
Abstract
STUDY OBJECTIVES Obstructive sleep apnea (OSA) is associated with increased cardiovascular risk. The effect of OSA treatment with continuous positive airway pressure (CPAP) on the cardiovascular response to a stressor is unknown. We sought to determine the effect of CPAP therapy on heart rate variability (HRV) and arterial stiffness, at baseline, in response to, and recovery from a physiological stressor, Angiotensin II (AngII), in humans with OSA. METHODS Twenty-five incident healthy subjects (32% female; 49 ± 2 years) with moderate-severe OSA and nocturnal hypoxia were studied in high-salt balance, a state of maximal renin-angiotensin system (RAS) suppression, before CPAP, and after 4 weeks of effective CPAP therapy (usage > 4 h/night) in a second identical study day. HRV was calculated by spectral power and time domain analysis. Aortic augmentation index (AIx) and carotid-femoral pulse-wave velocity (PWVcf) were measured by applanation tonometry. HRV and arterial stiffness were measured at baseline and in response to AngII challenge (3 ng/ kg/min·30 minutes, 6 ng/kg/min·30 minutes, recovery·30 minutes). The primary outcome was the association between CPAP treatment and HRV and arterial stiffness responses to, and recovery from, AngII challenge. In an exploratory analysis subjects were stratified by sex. RESULTS CPAP corrected OSA and nocturnal hypoxemia. CPAP treatment was associated with increased sensitivity and delayed recovery from AngII (Δln HF [high frequency; recovery: -0.09 ± 0.19 versus -0.59 ± 0.17 ms2, P = .042; ΔrMSSD [root mean successive differences; recovery: -0.4 ± 2.0 versus -7.2 ± 1.9 ms, P = .001], ΔpNN50 [percentage of normal waves differing ≥ 50 ms compared to the preceding wave; AngII: 1.3 ± 2.3 versus -3.0 ± 2.4%, P = .043; recovery: -0.4 ± 1.4 versus -6.0 ± 1.9%, P = .001], all values pre-CPAP versus post-CPAP treatment). No differences were observed by sex. There was increased AIx sensitivity to AngII after CPAP among men (8.2 ± 1.7 versus 11.9 ± 2.2%, P = .046), but not women (11.4 ± 1.5 versus 11.6 ± 2.1%, P = .4). No change in PWVcf sensitivity was observed in either sex. CONCLUSIONS CPAP therapy was associated with delayed cardiovagal reactivation after a stressor and down-regulation of the arterial RAS. These findings may have important implications in mitigating cardiovascular risk in both men and women with OSA.
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Affiliation(s)
- David D M Nicholl
- Department of Medicine, University of Calgary, Calgary, Alberta, Canada.,Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada
| | - Patrick J Hanly
- Department of Medicine, University of Calgary, Calgary, Alberta, Canada.,Sleep Centre, Foothills Medical Centre, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada
| | - Ann A Zalucky
- Department of Medicine, University of Calgary, Calgary, Alberta, Canada.,Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada
| | - Michelle C Mann
- Department of Medicine, University of Calgary, Calgary, Alberta, Canada.,Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada
| | - Jennifer M MacRae
- Department of Medicine, University of Calgary, Calgary, Alberta, Canada.,Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada.,Alberta Kidney Disease Network, Canada
| | - Marc J Poulin
- Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada.,Hotchkiss Brain Institute, University of Calgary, Calgary, Alberta, Canada.,Department of Physiology and Pharmacology, University of Calgary, Calgary, Alberta, Canada.,Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada.,Faculty of Kinesiology, University of Calgary, Alberta, Canada
| | | | - Darlene Y Sola
- Department of Medicine, University of Calgary, Calgary, Alberta, Canada.,Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada
| | - Sofia B Ahmed
- Department of Medicine, University of Calgary, Calgary, Alberta, Canada.,Libin Cardiovascular Institute, University of Calgary, Calgary, Alberta, Canada.,Alberta Kidney Disease Network, Canada
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Muruve DA, Mann MC, Chapman K, Wong JF, Ravani P, Page SA, Benediktsson H. The biobank for the molecular classification of kidney disease: research translation and precision medicine in nephrology. BMC Nephrol 2017; 18:252. [PMID: 28747168 PMCID: PMC5530477 DOI: 10.1186/s12882-017-0669-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 07/18/2017] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Advances in technology and the ability to interrogate disease pathogenesis using systems biology approaches are exploding. As exemplified by the substantial progress in the personalized diagnosis and treatment of cancer, the application of systems biology to enable precision medicine in other disciplines such as Nephrology is well underway. Infrastructure that permits the integration of clinical data, patient biospecimens and advanced technologies is required for institutions to contribute to, and benefit from research in molecular disease classification and to devise specific and patient-oriented treatments. METHODS AND RESULTS We describe the establishment of the Biobank for the Molecular Classification of Kidney Disease (BMCKD) at the University of Calgary, Alberta, Canada. The BMCKD consists of a fully equipped wet laboratory, an information technology infrastructure, and a formal operational, ethical and legal framework for banking human biospecimens and storing clinical data. The BMCKD first consolidated a large retrospective cohort of kidney biopsy specimens to create a population-based renal pathology database and tissue inventory of glomerular and other kidney diseases. The BMCKD will continue to prospectively bank all kidney biopsies performed in Southern Alberta. The BMCKD is equipped to perform molecular, clinical and epidemiologic studies in renal pathology. The BMCKD also developed formal biobanking procedures for human specimens such as blood, urine and nucleic acids collected for basic and clinical research studies or for advanced diagnostic technologies in clinical care. The BMCKD is guided by standard operating procedures, an ethics framework and legal agreements with stakeholders that include researchers, data custodians and patients. The design and structure of the BMCKD permits its inclusion in a wide variety of research and clinical activities. CONCLUSION The BMCKD is a core multidisciplinary facility that will bridge basic and clinical research and integrate precision medicine into renal pathology and nephrology.
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Affiliation(s)
- Daniel A. Muruve
- Department of Medicine, Snyder Institute for Chronic Diseases, University of Calgary, 3280 Hospital Dr. NW, Calgary, AB T2N 4N1 Canada
| | - Michelle C. Mann
- Department of Medicine, Snyder Institute for Chronic Diseases, University of Calgary, 3280 Hospital Dr. NW, Calgary, AB T2N 4N1 Canada
| | - Kevin Chapman
- Department of Medicine, Snyder Institute for Chronic Diseases, University of Calgary, 3280 Hospital Dr. NW, Calgary, AB T2N 4N1 Canada
| | - Josee F. Wong
- Snyder Institute for Chronic Diseases, University of Calgary, Calgary, AB Canada
| | - Pietro Ravani
- Department of Medicine, Libin Cardiovascular Institute, University of Calgary, Calgary, AB Canada
| | - Stacey A. Page
- Department of Community Health Sciences, University of Calgary, Calgary, AB Canada
| | - Hallgrimur Benediktsson
- Department of Pathology and Laboratory Medicine, University of Calgary and Calgary Laboratory Services, Calgary, AB Canada
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Rannelli LA, MacRae JM, Mann MC, Ramesh S, Hemmelgarn BR, Rabi D, Sola DY, Ahmed SB. Sex differences in associations between insulin resistance, heart rate variability, and arterial stiffness in healthy women and men: a physiology study. Can J Physiol Pharmacol 2016; 95:349-355. [PMID: 28099042 DOI: 10.1139/cjpp-2016-0122] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Diabetes confers greater cardiovascular risk to women than to men. Whether insulin-resistance-mediated risk extends to the healthy population is unknown. Measures of insulin resistance (fasting insulin, homeostatic model assessment, hemoglobin A1c, quantitative insulin sensitivity check index, glucose) were determined in 48 (56% female) healthy subjects. Heart rate variability (HRV) was calculated by spectral power analysis and arterial stiffness was determined using noninvasive applanation tonometry. Both were measured at baseline and in response to angiotensin II infusion. In women, there was a non-statistically significant trend towards increasing insulin resistance being associated with an overall unfavourable HRV response and increased arterial stiffness to the stressor, while men demonstrated the opposite response. Significant differences in the associations between insulin resistance and cardiovascular physiological profile exist between healthy women and men. Further studies investigating the sex differences in the pathophysiology of insulin resistance in cardiovascular disease are warranted.
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Affiliation(s)
- Luke Anthony Rannelli
- a Faculty of Medicine, University of Calgary, 3330 Hospital Dr. NW, Calgary, AB T2N 4N1, Canada
| | - Jennifer M MacRae
- a Faculty of Medicine, University of Calgary, 3330 Hospital Dr. NW, Calgary, AB T2N 4N1, Canada.,b Alberta Kidney Disease Network, 1403-29th St. NW, C210, Calgary, AB T2N 2T9, Canada.,c Libin Cardiovascular Institute of Alberta, 1403-29th St. NW, Calgary, AB T2N 2T9, Canada
| | - Michelle C Mann
- a Faculty of Medicine, University of Calgary, 3330 Hospital Dr. NW, Calgary, AB T2N 4N1, Canada.,c Libin Cardiovascular Institute of Alberta, 1403-29th St. NW, Calgary, AB T2N 2T9, Canada
| | - Sharanya Ramesh
- a Faculty of Medicine, University of Calgary, 3330 Hospital Dr. NW, Calgary, AB T2N 4N1, Canada.,c Libin Cardiovascular Institute of Alberta, 1403-29th St. NW, Calgary, AB T2N 2T9, Canada
| | - Brenda R Hemmelgarn
- a Faculty of Medicine, University of Calgary, 3330 Hospital Dr. NW, Calgary, AB T2N 4N1, Canada.,b Alberta Kidney Disease Network, 1403-29th St. NW, C210, Calgary, AB T2N 2T9, Canada.,c Libin Cardiovascular Institute of Alberta, 1403-29th St. NW, Calgary, AB T2N 2T9, Canada.,d Institute for Public Health, University of Calgary, 3330 Hospital Dr. NW, Calgary, AB T2N 4N1, Canada
| | - Doreen Rabi
- a Faculty of Medicine, University of Calgary, 3330 Hospital Dr. NW, Calgary, AB T2N 4N1, Canada.,c Libin Cardiovascular Institute of Alberta, 1403-29th St. NW, Calgary, AB T2N 2T9, Canada.,d Institute for Public Health, University of Calgary, 3330 Hospital Dr. NW, Calgary, AB T2N 4N1, Canada
| | - Darlene Y Sola
- b Alberta Kidney Disease Network, 1403-29th St. NW, C210, Calgary, AB T2N 2T9, Canada.,c Libin Cardiovascular Institute of Alberta, 1403-29th St. NW, Calgary, AB T2N 2T9, Canada
| | - Sofia B Ahmed
- a Faculty of Medicine, University of Calgary, 3330 Hospital Dr. NW, Calgary, AB T2N 4N1, Canada.,b Alberta Kidney Disease Network, 1403-29th St. NW, C210, Calgary, AB T2N 2T9, Canada.,c Libin Cardiovascular Institute of Alberta, 1403-29th St. NW, Calgary, AB T2N 2T9, Canada
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Mann MC, Exner DV, Hemmelgarn BR, Hanley DA, Turin TC, MacRae JM, Wheeler DC, Sola DY, Ramesh S, Ahmed SB. The VITAH Trial-Vitamin D Supplementation and Cardiac Autonomic Tone in Patients with End-Stage Kidney Disease on Hemodialysis: A Blinded, Randomized Controlled Trial. Nutrients 2016; 8:nu8100608. [PMID: 27690095 PMCID: PMC5083996 DOI: 10.3390/nu8100608] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 08/27/2016] [Accepted: 09/20/2016] [Indexed: 12/12/2022] Open
Abstract
End-stage kidney disease (ESKD) patients are at increased cardiovascular risk. Vitamin D deficiency is associated with depressed heart rate variability (HRV), a risk factor depicting poor cardiac autonomic tone and risk of cardiovascular death. Vitamin D deficiency and depressed HRV are highly prevalent in the ESKD population. We aimed to determine the effects of oral vitamin D supplementation on HRV ((low frequency (LF) to high frequency (HF) spectral ratio (LF:HF)) in ESKD patients on hemodialysis. Fifty-six subjects with ESKD requiring hemodialysis were recruited from January 2013–March 2015 and randomized 1:1 to either conventional (0.25 mcg alfacalcidol plus placebo 3×/week) or intensive (0.25 mcg alfacalcidol 3×/week plus 50,000 international units (IU) ergocalciferol 1×/week) vitamin D for six weeks. The primary outcome was the change in LF:HF. There was no difference in LF:HF from baseline to six weeks for either vitamin D treatment (conventional: p = 0.9 vs. baseline; intensive: p = 0.07 vs. baseline). However, participants who remained vitamin D-deficient (25-hydroxyvitamin D < 20 ng/mL) after treatment demonstrated an increase in LF:HF (conventional: n = 13, ∆LF:HF: 0.20 ± 0.06, p < 0.001 vs. insufficient and sufficient vitamin D groups; intensive: n = 8: ∆LF:HF: 0.15 ± 0.06, p < 0.001 vs. sufficient vitamin D group). Overall, six weeks of conventional or intensive vitamin D only augmented LF:HF in ESKD subjects who remained vitamin D-deficient after treatment. Our findings potentially suggest that while activated vitamin D, with or without additional nutritional vitamin D, does not appear to improve cardiac autonomic tone in hemodialysis patients with insufficient or sufficient baseline vitamin D levels, supplementation in patients with severe vitamin D deficiency may improve cardiac autonomic tone in this higher risk sub-population of ESKD. Trial Registration: ClinicalTrials.gov, NCT01774812.
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Affiliation(s)
- Michelle C Mann
- Department of Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada.
- Libin Cardiovascular Institute of Alberta, Calgary, AB T2N 4Z6, Canada.
| | - Derek V Exner
- Department of Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada.
- Libin Cardiovascular Institute of Alberta, Calgary, AB T2N 4Z6, Canada.
| | - Brenda R Hemmelgarn
- Department of Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada.
- Libin Cardiovascular Institute of Alberta, Calgary, AB T2N 4Z6, Canada.
- Department of Community Health Sciences, University of Calgary, Calgary, AB T2N 4Z6, Canada.
| | - David A Hanley
- Department of Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada.
- Osteoporosis and Metabolic Bone Disease Centre, Calgary, AB T2T 5C7, Canada.
| | - Tanvir C Turin
- Department of Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada.
| | - Jennifer M MacRae
- Department of Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada.
- Libin Cardiovascular Institute of Alberta, Calgary, AB T2N 4Z6, Canada.
| | - David C Wheeler
- Department of Medicine, University College London, London NW3 2PF, UK.
| | - Darlene Y Sola
- Department of Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada.
| | - Sharanya Ramesh
- Department of Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada.
- Libin Cardiovascular Institute of Alberta, Calgary, AB T2N 4Z6, Canada.
| | - Sofia B Ahmed
- Department of Medicine, University of Calgary, Calgary, AB T2N 4Z6, Canada.
- Libin Cardiovascular Institute of Alberta, Calgary, AB T2N 4Z6, Canada.
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Mann MC, Hemmelgarn BR, Exner DV, Hanley DA, Turin TC, Wheeler DC, Sola DY, Ellis L, Ahmed SB. Vitamin D Supplementation Is Associated With Stabilization of Cardiac Autonomic Tone in IgA Nephropathy. Hypertension 2015; 66:e4-6. [DOI: 10.1161/hypertensionaha.115.05688] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Michelle C. Mann
- From the Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada (M.C.M., B.R.H., D.V.E., D.A.H, T.C.T., S.B.A.); Alberta Kidney Disease Network, Calgary, Alberta, Canada (B.R.H., S.B.A.); Libin Cardiovascular Institute of Alberta, Calgary, Alberta, Canada (B.R.H., D.E.V., D.Y.S., L.E., S.B.A. D.E.V., D.Y.D.); and Division of Medicine, University College, London, United Kingdom (D.C.W.)
| | - Brenda R. Hemmelgarn
- From the Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada (M.C.M., B.R.H., D.V.E., D.A.H, T.C.T., S.B.A.); Alberta Kidney Disease Network, Calgary, Alberta, Canada (B.R.H., S.B.A.); Libin Cardiovascular Institute of Alberta, Calgary, Alberta, Canada (B.R.H., D.E.V., D.Y.S., L.E., S.B.A. D.E.V., D.Y.D.); and Division of Medicine, University College, London, United Kingdom (D.C.W.)
| | - Derek V. Exner
- From the Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada (M.C.M., B.R.H., D.V.E., D.A.H, T.C.T., S.B.A.); Alberta Kidney Disease Network, Calgary, Alberta, Canada (B.R.H., S.B.A.); Libin Cardiovascular Institute of Alberta, Calgary, Alberta, Canada (B.R.H., D.E.V., D.Y.S., L.E., S.B.A. D.E.V., D.Y.D.); and Division of Medicine, University College, London, United Kingdom (D.C.W.)
| | - David A. Hanley
- From the Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada (M.C.M., B.R.H., D.V.E., D.A.H, T.C.T., S.B.A.); Alberta Kidney Disease Network, Calgary, Alberta, Canada (B.R.H., S.B.A.); Libin Cardiovascular Institute of Alberta, Calgary, Alberta, Canada (B.R.H., D.E.V., D.Y.S., L.E., S.B.A. D.E.V., D.Y.D.); and Division of Medicine, University College, London, United Kingdom (D.C.W.)
| | - Tanvir C. Turin
- From the Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada (M.C.M., B.R.H., D.V.E., D.A.H, T.C.T., S.B.A.); Alberta Kidney Disease Network, Calgary, Alberta, Canada (B.R.H., S.B.A.); Libin Cardiovascular Institute of Alberta, Calgary, Alberta, Canada (B.R.H., D.E.V., D.Y.S., L.E., S.B.A. D.E.V., D.Y.D.); and Division of Medicine, University College, London, United Kingdom (D.C.W.)
| | - David C. Wheeler
- From the Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada (M.C.M., B.R.H., D.V.E., D.A.H, T.C.T., S.B.A.); Alberta Kidney Disease Network, Calgary, Alberta, Canada (B.R.H., S.B.A.); Libin Cardiovascular Institute of Alberta, Calgary, Alberta, Canada (B.R.H., D.E.V., D.Y.S., L.E., S.B.A. D.E.V., D.Y.D.); and Division of Medicine, University College, London, United Kingdom (D.C.W.)
| | - Darlene Y. Sola
- From the Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada (M.C.M., B.R.H., D.V.E., D.A.H, T.C.T., S.B.A.); Alberta Kidney Disease Network, Calgary, Alberta, Canada (B.R.H., S.B.A.); Libin Cardiovascular Institute of Alberta, Calgary, Alberta, Canada (B.R.H., D.E.V., D.Y.S., L.E., S.B.A. D.E.V., D.Y.D.); and Division of Medicine, University College, London, United Kingdom (D.C.W.)
| | - Linda Ellis
- From the Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada (M.C.M., B.R.H., D.V.E., D.A.H, T.C.T., S.B.A.); Alberta Kidney Disease Network, Calgary, Alberta, Canada (B.R.H., S.B.A.); Libin Cardiovascular Institute of Alberta, Calgary, Alberta, Canada (B.R.H., D.E.V., D.Y.S., L.E., S.B.A. D.E.V., D.Y.D.); and Division of Medicine, University College, London, United Kingdom (D.C.W.)
| | - Sofia B. Ahmed
- From the Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada (M.C.M., B.R.H., D.V.E., D.A.H, T.C.T., S.B.A.); Alberta Kidney Disease Network, Calgary, Alberta, Canada (B.R.H., S.B.A.); Libin Cardiovascular Institute of Alberta, Calgary, Alberta, Canada (B.R.H., D.E.V., D.Y.S., L.E., S.B.A. D.E.V., D.Y.D.); and Division of Medicine, University College, London, United Kingdom (D.C.W.)
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Mann MC, Exner DV, Hemmelgarn BR, Hanley DA, Turin TC, Sola DY, Ellis L, Wheeler DC, Ahmed SB. SP307VITAMIN D SUPPLEMENTATION IS ASSOCIATED WITH IMPROVED MODULATION OF CARDIAC AUTONOMIC TONE IN IGA NEPHROPATHY. Nephrol Dial Transplant 2015. [DOI: 10.1093/ndt/gfv191.27] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Ramesh S, Mann MC, Holroyd-Leduc JM, Wilton SB, James MT, Seely EW, Ahmed SB. The effect of hormone therapy on all-cause and cardiovascular mortality in women with chronic kidney disease: protocol for a systematic review and meta-analysis. Syst Rev 2015; 4:44. [PMID: 25874808 PMCID: PMC4414431 DOI: 10.1186/s13643-015-0020-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 02/25/2015] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Chronic kidney disease affects approximately one in ten North Americans and is associated with a high risk of cardiovascular disease. Chronic kidney disease in women is characterized by an abnormal sex hormone profile and low estradiol levels. Since low estradiol levels are associated with an increased cardiovascular risk in healthy women, our objective is to determine the effect of hormone therapy on all-cause mortality, cardiovascular mortality, and cardiovascular morbidity in women with chronic kidney disease. METHODS/DESIGN Studies examining hormone therapy for adult women with chronic kidney disease will be included. The primary outcome is all-cause or cardiovascular mortality and morbidity. We will search electronic bibliographic databases (MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials (CENTRAL)) along with relevant conference proceedings, table of contents of journals, and review articles. Two investigators will independently screen identified abstracts and select observational cohort studies, case-control studies, and randomized controlled trials examining hormone therapy in women with chronic kidney disease. These investigators will also independently abstract data from relevant full-text journal articles and assess risk of bias. Where possible, these data will be summarized using pooled or combined estimates for the risk ratio or hazard ratio of all-cause mortality, cardiovascular mortality, and cardiovascular morbidity in women with chronic kidney disease with and without hormone therapy. A random effects model will be used, and meta-regression and subgroup analyses will be used to explore potential source of heterogeneity. DISCUSSION Given the high burden of cardiovascular disease in women with chronic kidney disease, this study will help guide clinical practice by summarizing current evidence on the use of hormone therapy for prevention of all-cause mortality, cardiovascular mortality, and cardiovascular morbidity in this population. SYSTEMATIC REVIEW REGISTRATION The final protocol was registered with PROSPERO ( CRD42014014566) .
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Affiliation(s)
- Sharanya Ramesh
- Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, T2N 4N1, Alberta, Canada. .,Libin Cardiovascular Institute of Alberta, 1403 29 Street NW, Calgary, T2N 2T9, Alberta, Canada.
| | - Michelle C Mann
- Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, T2N 4N1, Alberta, Canada. .,Libin Cardiovascular Institute of Alberta, 1403 29 Street NW, Calgary, T2N 2T9, Alberta, Canada.
| | - Jayna M Holroyd-Leduc
- Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, T2N 4N1, Alberta, Canada.
| | - Stephen B Wilton
- Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, T2N 4N1, Alberta, Canada. .,Libin Cardiovascular Institute of Alberta, 1403 29 Street NW, Calgary, T2N 2T9, Alberta, Canada.
| | - Matthew T James
- Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, T2N 4N1, Alberta, Canada. .,Libin Cardiovascular Institute of Alberta, 1403 29 Street NW, Calgary, T2N 2T9, Alberta, Canada. .,Alberta Kidney Disease Network, 1403-29th St. NW, C210, Calgary, T2N 2T9, Alberta, Canada.
| | - Ellen W Seely
- Division of Endocrinology, Diabetes and Hypertension, Department of Medicine, Brigham and Women's Hospital, 75 Francis St., Boston, MA, 02115, USA.
| | - Sofia B Ahmed
- Faculty of Medicine, University of Calgary, 3330 Hospital Drive NW, Calgary, T2N 4N1, Alberta, Canada. .,Libin Cardiovascular Institute of Alberta, 1403 29 Street NW, Calgary, T2N 2T9, Alberta, Canada. .,Alberta Kidney Disease Network, 1403-29th St. NW, C210, Calgary, T2N 2T9, Alberta, Canada.
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Mann MC, Hobbs AJ, Hemmelgarn BR, Roberts DJ, Ahmed SB, Rabi DM. Effect of oral vitamin D analogs on mortality and cardiovascular outcomes among adults with chronic kidney disease: a meta-analysis. Clin Kidney J 2014; 8:41-8. [PMID: 25713709 PMCID: PMC4310425 DOI: 10.1093/ckj/sfu122] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Accepted: 10/23/2014] [Indexed: 12/22/2022] Open
Abstract
Background Vitamin D deficiency is highly prevalent in patients with chronic kidney disease (CKD) and has been associated with all-cause and cardiovascular mortality in observational studies. However, evidence from randomized controlled trials (RCTs) supporting vitamin D supplementation is lacking. We sought to assess whether vitamin D supplementation alters the relative risk (RR) of all-cause and cardiovascular mortality, as well as serious adverse cardiovascular events, in patients with CKD, compared with placebo. Methods PubMed/MEDLINE, EMBASE, Cochrane Library, and selected nephrology journals and conference proceedings were searched in October 2013. RCTs considered for inclusion were those that assessed oral vitamin D supplementation versus placebo in adults with CKD (≤60 mL/min/1.73 m2), including end-stage CKD requiring dialysis. We calculated pooled RR of mortality (all-cause and cardiovascular) and that of cardiovascular events and stratified by CKD stage, vitamin D analog and diabetes prevalence. Results The search identified 4246 articles, of which 13 were included. No significant treatment effect of oral vitamin D on all-cause mortality (RR: 0.84; 95% CI: 0.47, 1.52), cardiovascular mortality (RR: 0.79; 95% CI: 0.26, 2.28) or serious adverse cardiovascular events (RR: 1.20; 95% CI: 0.49, 2.99) was observed. The pooled analysis demonstrated large variation in trials with respect to dosing (0.5 ug–200 000 IU/week) and duration (3–104 weeks). Conclusions Current RCTs do not provide sufficient or precise evidence that vitamin D supplementation affects mortality or cardiovascular risk in CKD. While its effect on biochemical endpoints is well documented, the results demonstrate a lack of appropriate patient-level data within the CKD literature, which warrants larger trials with clinical primary outcomes related to vitamin D supplementation.
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Affiliation(s)
- Michelle C Mann
- Department of Medical Sciences, Cumming School of Medicine , University of Calgary , Calgary, AB , Canada
| | - Amy J Hobbs
- Department of Community Health Sciences, Cumming School of Medicine , University of Calgary , Calgary, AB , Canada
| | - Brenda R Hemmelgarn
- Department of Community Health Sciences, Cumming School of Medicine , University of Calgary , Calgary, AB , Canada ; Division of Nephrology, Cumming School of Medicine , University of Calgary, Foothills Medical Centre , Calgary, AB , Canada
| | - Derek J Roberts
- Department of Community Health Sciences, Cumming School of Medicine , University of Calgary , Calgary, AB , Canada ; Department of Surgery, Cumming School of Medicine, University of Calgary, Foothills Medical Centre , Calgary, AB , Canada
| | - Sofia B Ahmed
- Department of Medical Sciences, Cumming School of Medicine , University of Calgary , Calgary, AB , Canada ; Division of Nephrology, Cumming School of Medicine , University of Calgary, Foothills Medical Centre , Calgary, AB , Canada
| | - Doreen M Rabi
- Department of Community Health Sciences, Cumming School of Medicine , University of Calgary , Calgary, AB , Canada
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Mann MC, Exner DV, Hemmelgarn BR, Hanley DA, Turin TC, MacRae JM, Ahmed SB. The VITAH trial VITamin D supplementation and cardiac Autonomic tone in Hemodialysis: a blinded, randomized controlled trial. BMC Nephrol 2014; 15:129. [PMID: 25098377 PMCID: PMC4130113 DOI: 10.1186/1471-2369-15-129] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [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: 11/19/2013] [Accepted: 07/28/2014] [Indexed: 02/07/2023] Open
Abstract
Background Patients with end-stage kidney disease (ESKD) have a high rate of mortality and specifically an increased risk of sudden cardiac death (SCD). Impaired cardiac autonomic tone is associated with elevated risk of SCD. Moreover, patients with ESKD are often vitamin D deficient, which we have shown may be linked to autonomic dysfunction in humans. To date, it is not known whether vitamin D supplementation normalizes cardiac autonomic function in the high-risk ESKD population. The VITamin D supplementation and cardiac Autonomic tone in Hemodialysis (VITAH) randomized trial will determine whether intensive vitamin D supplementation therapies improve cardiac autonomic tone to a greater extent than conventional vitamin D supplementation regimens in ESKD patients requiring chronic hemodialysis. Methods/Design A total of 60 subjects with ESKD requiring thrice weekly chronic hemodialysis will be enrolled in this 2x2 crossover, blinded, randomized controlled trial. Following a 4-week washout period from any prior vitamin D therapy, subjects are randomized 1:1 to intensive versus standard vitamin D therapy for 6 weeks, followed by a 12-week washout period, and finally the remaining treatment arm for 6 weeks. Intensive vitamin D treatment includes alfacalcidiol (activated vitamin D) 0.25mcg orally with each dialysis session combined with ergocalciferol (nutritional vitamin D) 50 000 IU orally once per week and placebo the remaining two dialysis days for 6 weeks. The standard vitamin D treatment includes alfacalcidiol 0.25mcg orally combined with placebo each dialysis session per week for 6 weeks. Cardiac autonomic tone is measured via 24 h Holter monitor assessments on the first dialysis day of the week every 6 weeks throughout the study period. The primary outcome is change in the low frequency: high frequency heart rate variability (HRV) ratio during the first 12 h of the Holter recording at 6 weeks versus baseline. Secondary outcomes include additional measures of HRV. The safety of intensive versus conventional vitamin D supplementation is also assessed. Discussion VITAH will determine whether an intensive vitamin D supplementation regimen will improve cardiac autonomic tone compared to conventional vitamin D supplementation and will assess the safety of these two supplementation regimens in ESKD patients receiving chronic hemodialysis. Trial registration ClinicalTrials.gov, NCT01774812
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Affiliation(s)
| | | | | | | | | | | | - Sofia B Ahmed
- Department of Medicine, University of Calgary, 1403-29th St, NW, Room C210D, T2N 2 T9 Calgary, Alberta, Canada.
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Zalucky AA, Nicholl DDM, Mann MC, Hemmelgarn BR, Turin TC, Macrae JM, Sola DY, Ahmed SB. Sex influences the effect of body mass index on the vascular response to angiotensin II in humans. Obesity (Silver Spring) 2014; 22:739-46. [PMID: 23963791 DOI: 10.1002/oby.20608] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2013] [Revised: 07/30/2013] [Accepted: 08/14/2013] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Sex influences the cardiorenal risk associated with body mass index (BMI). The role of the renin-angiotensin-aldosterone system in adiposity-mediated cardiorenal risk profiles in healthy, non-obese men and women was investigated. METHODS Systemic and renal hemodynamic responses to angiotensin-II (AngII) as a function of BMI, waist and hip circumference, waist-hip ratio, as well as fat and lean mass were measured in 18 men and 25 women in high-salt balance, stratified by BMI (<25 kg/m2 (ideal body weight (IBW)) vs. ≥25 kg/m2 overweight)). RESULTS In men (n = 7, BMI 23 ± 1 kg/m2) and women (n = 14, BMI 22 ± 2 kg/m2) of IBW, BMI was not associated with the systolic blood pressure (SBP) response to AngII. In contrast, overweight men (n = 11, 29 ± 2 kg/m2) demonstrated a progressively more blunted vasoconstrictor SBP response to AngII challenge as BMI increased (P = 0.007), even after adjustment for covariates. Women maintained the same relationship between BMI and the SBP response to AngII irrespective of weight status (P = 0.2, IBW vs. overweight women). Compared to BMI, other adiposity measures showed similar associations to systemic AngII responsiveness in men but not in women. Increasing BMI was associated with a blunted renovasoconstrictor response to AngII in all subjects, but was more pronounced in men. CONCLUSION Sex influences the effect of adiposity on vascular angiotensin-responsiveness.
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Affiliation(s)
- A A Zalucky
- Faculty of Medicine, University of Calgary, Calgary, Alberta, Canada; Libin Cardiovascular Institute of Alberta, Alberta, Canada
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Abdi-Ali A, Mann MC, Hemmelgarn BR, MacRae JM, Turin TC, Benediktsson H, Sola DY, Ahmed SB. IgA nephropathy with early kidney disease is associated with increased arterial stiffness and renin-angiotensin system activity. J Renin Angiotensin Aldosterone Syst 2014; 16:521-8. [PMID: 24464859 DOI: 10.1177/1470320313510586] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 09/25/2013] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND IgA nephropathy is associated with increased cardiovascular risk, though whether this is due to loss of kidney function or proteinuria is unclear. METHODS For this study 10 normotensive IgA nephropathy subjects with early kidney disease (41±5 yrs, glomerular filtration rate (GFR) 87±9 ml/min, proteinuria 720±300 mg/d) and 10 gender- and blood pressure-matched healthy controls (36±1 yrs, estimated GFR 102±5 ml/min, proteinuria 70±6 mg/d) were studied in high-salt balance. Blood pressure and arterial stiffness, expressed as pulse wave velocity and aortic augmentation index, were measured at baseline and in response to 60 min of angiotensin II (AngII) infusion. RESULTS At baseline, IgA nephropathy subjects demonstrated similar pulse wave velocity (8.6±0.7 vs. 8.0±0.4 m/s, p=0.5) but increased aortic augmentation index (12.6±3.1 vs. 1.8±4%, p=0.04) and a trend towards increased circulating renin-angiotensin system (RAS) components (plasma renin activity, 0.55±0.18 vs. 0.21±0.05 ng/l/s, p=0.08; angiotensin II, 25±5 vs. 16±1 ng/l, p=0.08) compared with controls. However, despite similar baseline blood pressure values (p=0.8), IgA nephropathy was associated with reduced arterial sensitivity to AngII challenge (Δmean arterial pressure: 19±4 vs. 29±1 mm Hg, p=0.05; Δpulse wave velocity: -0.06±0.6 vs. 1.5±0.3 m/s, p=0.07) compared with controls, even after multivariate analysis. CONCLUSION Even in the setting of early kidney disease, IgA nephropathy is associated with increased arterial stiffness and decreased angiotensin II responsiveness, a marker of increased RAS activity.
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Affiliation(s)
- A Abdi-Ali
- Department of Medicine, University of Calgary, Calgary, Canada
| | - M C Mann
- Department of Medicine, University of Calgary, Calgary, Canada Alberta Kidney Disease Network, Alberta, Canada
| | - B R Hemmelgarn
- Department of Medicine, University of Calgary, Calgary, Canada Alberta Kidney Disease Network, Alberta, Canada Libin Cardiovascular Institute of Alberta, Calgary, Canada
| | - J M MacRae
- Department of Medicine, University of Calgary, Calgary, Canada Alberta Kidney Disease Network, Alberta, Canada Libin Cardiovascular Institute of Alberta, Calgary, Canada
| | - T C Turin
- Department of Medicine, University of Calgary, Calgary, Canada Alberta Kidney Disease Network, Alberta, Canada
| | - H Benediktsson
- Department of Pathology, University of Calgary, Calgary, Canada
| | - D Y Sola
- Department of Medicine, University of Calgary, Calgary, Canada Libin Cardiovascular Institute of Alberta, Calgary, Canada
| | - S B Ahmed
- Department of Medicine, University of Calgary, Calgary, Canada Alberta Kidney Disease Network, Alberta, Canada Libin Cardiovascular Institute of Alberta, Calgary, Canada
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Mann MC, Exner DV, Hemmelgarn BR, Sola DY, Turin TC, Ellis L, Ahmed SB. Vitamin D levels are associated with cardiac autonomic activity in healthy humans. Nutrients 2013; 5:2114-27. [PMID: 23752493 PMCID: PMC3725496 DOI: 10.3390/nu5062114] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 05/29/2013] [Accepted: 06/03/2013] [Indexed: 12/19/2022] Open
Abstract
Vitamin D deficiency (≤50nmol/L 25-hydroxy vitamin D) is a cardiovascular (CV) risk factor that affects approximately one billion people worldwide, particularly those affected by chronic kidney disease (CKD). Individuals with CKD demonstrate abnormal cardiac autonomic nervous system activity, which has been linked to the significant rates of CV-related mortality in this population. Whether vitamin D deficiency has a direct association with regulation of cardiac autonomic activity has never been explored in humans. Methods: Thirty-four (34) healthy, normotensive subjects were studied and categorized based on 25-hydroxy vitamin D deficiency (deficient vs. non-deficient, n = 7 vs. 27), as well as 1,25-dihydroxy vitamin D levels (above vs. below 25th percentile, n = 8 vs. 26). Power spectral analysis of electrocardiogram recordings provided measures of cardiac autonomic activity across low frequency (LF) and high frequency (HF, representative of vagal contribution) bands, representative of the sympathetic and vagal limbs of the autonomic nervous system when transformed to normalized units (nu), respectively, as well as overall cardiosympathovagal balance (LF:HF) during graded angiotensin II (AngII) challenge (3 ng/kg/min × 30 min, 6 ng/kg/min × 30 min). Results: At baseline, significant suppression of sympathovagal balance was observed in the 25-hydroxy vitamin D-deficient participants (LF:HF, p = 0.02 vs. non-deficient), although no other differences were observed throughout AngII challenge. Participants in the lowest 1,25-dihydroxy VD quartile experienced significant withdrawal of inhibitory vagal control, as well as altered overall sympathovagal balance throughout AngII challenge (HF, mean difference = −6.98 ± 3 nu, p = 0.05; LF:HF, mean difference = 0.34 ± 0.1, p = 0.043 vs. above 25th percentile). Conclusions: Vitamin D deficiency is associated with suppression of resting cardiac autonomic activity, while low 1,25-dihydroxy vitamin D levels are associated with unfavourable cardiac autonomic activity during an acute AngII stressor, offering a potential pathophysiological mechanism that may be acting to elevate CV risk in in populations with low vitamin D status.
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Affiliation(s)
- Michelle C. Mann
- University of Calgary, 1403 29th St. NW, Calgary, AB T2N 2T9, Canada; E-Mails: (M.C.M.); (B.R.H.)
| | - Derek V. Exner
- Libin Cardiovascular Institute of Alberta, 3330 Hospital Dr. NW, Calgary, AB T2N 2T9, Canada; E-Mails: exner@ucalgary (D.V.E.); (D.Y.S.); (T.C.T.); (L.E.)
| | - Brenda R. Hemmelgarn
- University of Calgary, 1403 29th St. NW, Calgary, AB T2N 2T9, Canada; E-Mails: (M.C.M.); (B.R.H.)
| | - Darlene Y. Sola
- Libin Cardiovascular Institute of Alberta, 3330 Hospital Dr. NW, Calgary, AB T2N 2T9, Canada; E-Mails: exner@ucalgary (D.V.E.); (D.Y.S.); (T.C.T.); (L.E.)
| | - Tanvir C. Turin
- Libin Cardiovascular Institute of Alberta, 3330 Hospital Dr. NW, Calgary, AB T2N 2T9, Canada; E-Mails: exner@ucalgary (D.V.E.); (D.Y.S.); (T.C.T.); (L.E.)
| | - Linda Ellis
- Libin Cardiovascular Institute of Alberta, 3330 Hospital Dr. NW, Calgary, AB T2N 2T9, Canada; E-Mails: exner@ucalgary (D.V.E.); (D.Y.S.); (T.C.T.); (L.E.)
| | - Sofia B. Ahmed
- University of Calgary, 1403 29th St. NW, Calgary, AB T2N 2T9, Canada; E-Mails: (M.C.M.); (B.R.H.)
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-403-944-2745; Fax: +1-403-944-2876
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Mann MC, Fan LL, Moore RH, Burrows PE. An unusual cause of chest pain in a child. J Pediatr 2011; 158:1035. [PMID: 21310432 DOI: 10.1016/j.jpeds.2010.12.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2010] [Accepted: 12/20/2010] [Indexed: 11/16/2022]
Affiliation(s)
- Michelle C Mann
- Pulmonary Section, Department of Pediatrics, Texas Children's Hospital, Baylor College of Medicine, Houston, Texas, USA
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Affiliation(s)
- M C Mann
- Laboratories of Zoölogy, University of California, Berkeley, California
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Clausen RE, Mann MC. Inheritance in Nicotiana Tabacum: V. The Occurrence of Haploid Plants in Interspecific Progenies. Proc Natl Acad Sci U S A 2006; 10:121-4. [PMID: 16576797 PMCID: PMC1085570 DOI: 10.1073/pnas.10.4.121] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- R E Clausen
- Division of Genetics, Department of Agriculture, University of California
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Mann MC, Radeliffe KW, Basarab M. Knowledge of emergency contraception amongst female patients attending a department of genitourinary medicine. Br J Fam Plann 1999; 25:58-62. [PMID: 10454656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
The aim of the study was to assess the knowledge of emergency contraception amongst new female patients attending an inner-city department of genitourinary medicine. Information was also sought about use of regular contraception and demography. Three hundred and ninety nine questionnaires were suitable for analysis. Half of the sample answered that the latest a woman could take emergency contraception after unprotected sex was three days. None of the sample knew that emergency contraception could be obtained up to five days. Twenty nine per cent of the sample reported sex without contraception during the menstrual cycle preceding attendance. Women who had ever used regular contraception in the past were statistically less likely to have reported unprotected sex in the menstrual cycle preceding attendance (p=0.0000068). Professional women were statistically less likely to have reported unprotected sex in the menstrual cycle preceding the clinic visit. Fourteen per cent of the sample had genital warts at this first clinic visit, 10 per cent had Chlamydia trachomatis, seven per cent had herpes simplex infection, six per cent had gonococcal infection and five per cent had trichomonal infection. Women who reported unprotected sex during the preceding menstrual cycle were not statistically more likely to have a sexually transmitted infection at this first clinic visit. A large number of women attending departments of genitourinary medicine are at risk of both pregnancy and also sexually transmitted infection. Staff working in all areas of sexual health need to have a good knowledge of both contraception and sexually transmitted infections in order to educate the clients on both aspects of unprotected sex.
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Affiliation(s)
- M C Mann
- City Hospital NHS Trust, Dudley Road, Birmingham B18 7QH, UK
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Sallustio BC, Harkin LA, Mann MC, Krivickas SJ, Burcham PC. Genotoxicity of acyl glucuronide metabolites formed from clofibric acid and gemfibrozil: a novel role for phase-II-mediated bioactivation in the hepatocarcinogenicity of the parent aglycones? Toxicol Appl Pharmacol 1997; 147:459-64. [PMID: 9439741 DOI: 10.1006/taap.1997.8322] [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: 02/05/2023]
Abstract
Glucuronides formed from carboxylate-containing xenobiotics are more chemically reactive than most Phase II conjugates. However, while they have been shown to form protein adducts, their reactions with DNA have received little attention. We thus used the M13 forward mutational assay to assess the genotoxicity of acyl glucuronides formed from two widely used fibrate hypolipidemics, clofibric acid and gemfibrozil. Single-stranded M13mp19 bacteriophage DNA was incubated in pH 7.4 buffer for 16 h in the presence of 0, 1, 2.5, and 5 mM concentrations of each glucuronide as well as the respective aglycones. The modified DNA was then transfected into SOS-induced competent Escherichia coli JM105 cells and the transfection efficiency was determined after phage growth overnight at 37 degrees C. Significantly, both acyl glucuronides, but not the aglycones, caused a concentration-dependent decrease in the transfection efficiency of the DNA, with a greater than 80% decrease in phage survival produced by the 5 mM concentrations of the glucuronides. No increase in lacZa mutations accompanied the loss of phage survival. We propose that these genotoxic effects involve reactions with nucleophilic centers in DNA via a Schiff base mechanism that is analogous to the glycosylation of DNA by endogenous sugars. Since strand nicking is known to accompany such damage, we also analyzed glucuronide-treated pSP189 plasmids for strand breakages via agarose gel electrophoresis. Both clofibric acid and gemfibrozil glucuronides produced significant concentration-related strand nicking and exhibited over 10-fold greater reactivity than the endogenous glycosylating agent, glucose 6-phosphate. On the basis of these findings, the possibility that this novel bioactivation route participates in the carcinogenicity of the fibrate hypolipidemics deserves investigation.
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Affiliation(s)
- B C Sallustio
- Department of Clinical Pharmacology, Queen Elizabeth Hospital, Woodville, South Australia
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18
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Abstract
The purpose of this study was to assess the need for genitourinary medicine (GUM) referral in family planning clinics (FPC) and to investigate whether women were more likely to attend an appointment if the consultation took place in the FPC or in the GUM clinic. A total of 98 women were referred from the FPC for GUM testing. They were randomly referred to be tested either in a local FPC or in the local GUM clinic. Sixty-three per cent of the 49 women randomized to be tested in the GUM clinic attended the consultation compared to 83% of the 49 women who attended the consultation in the FPC. This was statistically significant (P < 0.05). Twenty-six per cent of those attending the GUM clinic for testing and 29% of those women attending the FPC had a sexually transmitted disease (STD), that is, excluding candidiasis and bacterial vaginosis. There was no statistical difference between the 2 groups. Full GUM testing was successfully carried out in the FPC setting. This study showed that women were less likely to attend for GUM testing if the consultation took place in the GUM clinic compared to the FPC. It is known that there is a need for GUM services to be accessible to FPC attenders (and vice versa). Further research is needed to determine why women are reluctant to attend GUM clinics.
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Affiliation(s)
- N Gunneberg
- Department of GUM, General Hospital, Birmingham, UK
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Scalise PJ, Mann MC, Votto JJ, McNamee MJ. Severe hypothermia in the elderly. Conn Med 1995; 59:515-7. [PMID: 7587179] [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] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Hypothermia is not an uncommon clinical problem in the geriatric population. Several factors place elderly individuals at risk, including their reduced ability to sense and react to cold and their underlying medical conditions and medications. Successful detection and treatment of these patients involve an awareness of these risk factors and the characteristic physiology of the elderly, as well as an appreciation of the often controversial aspects of hypothermia management. Elderly victims of severe hypothermia have a particularly grave prognosis. We present one of the oldest reported survivors of severe hypothermia, and discuss some unique aspects of his presentation.
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Affiliation(s)
- P J Scalise
- Section of Pulmonary and Critical Care Medicine, New Britain General Hospital, USA
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Close CF, Mann MC, Watts JF, Taylor KG. ACTH-independent Cushing's syndrome in pregnancy with spontaneous resolution after delivery: control of the hypercortisolism with metyrapone. Clin Endocrinol (Oxf) 1993; 39:375-9. [PMID: 8222300 DOI: 10.1111/j.1365-2265.1993.tb02380.x] [Citation(s) in RCA: 79] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A 25-year-old primigravid woman presented with Cushing's syndrome at 23 weeks gestation; serum cortisol was 1090 nmol/l at 0900 h, 1230 nmol/l at 2200 h; basal urinary free cortisol excretion was 3680 nmol/24 h, and 8830 nmol/24 h after dexamethasone 8 mg daily for 48 hours; plasma ACTH was < 1.1 pmol/l. CT scan of the adrenal glands showed bilateral adrenal hyperplasia. The hypercortisolism was controlled with metyrapone until elective delivery of the fetus by Caesarean section at 34 weeks gestation because of a decline in growth. No adverse fetal effects of metyrapone treatment were apparent, maternal outcome was uncomplicated and wound healing was unimpaired. Maternal adrenocortical function had returned to normal within 4 weeks of the cessation of pregnancy and biochemical remission has been maintained up to 9 months post-partum. Metyrapone therapy is effective in controlling the hypercortisolism in certain cases of Cushing's syndrome complicating pregnancy.
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Affiliation(s)
- C F Close
- Department of Diabetes and Endocrinology, Dudley Road Hospital, Birmingham, UK
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Abstract
OBJECTIVE To present the case of a Jehovah's Witness with severe anemia and to review the religious philosophy of such patients, the ethical and medicolegal aspects of their care, and the therapeutic options available to clinicians. DATA SOURCES A MEDLINE literature search (1980 to 1992) identified most studies. Other studies were selected from the bibliographies of identified articles. STUDY SELECTION Selection of articles was limited to the history, philosophy, medicolegal and ethical issues, and clinical management of anemic Jehovah's Witnesses; a recent article on recommendations for red cell transfusion was also reviewed. CONCLUSIONS A clear understanding of the philosophy of the Jehovah's Witnesses regarding blood transfusion and of the medicolegal and ethical aspects of their care is essential to clinicians who care for such patients. One must also be aware of the many alternative therapeutic options that can maximize oxygen delivery and minimize oxygen consumption. The insights gained from this review are applicable to any severely anemic patient who refuses blood transfusion.
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Affiliation(s)
- M C Mann
- University of Connecticut Health Center, Farmington
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Mendelsohn R, Mann MC. Abnormal cervical cytology. Br J Gen Pract 1992; 42:530-1. [PMID: 1297379 PMCID: PMC1372151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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Abstract
Although the asthmatic subject's compliance with a regimen of inhaled corticosteroids is often poor, it has been suggested this may improve during periods of increased severity. To test this, we measured daily peak expiratory flow rates (PEFRs), asthma symptoms, and the use of an albuterol inhaler over nine weeks period in ten patients with moderately severe asthma. The effect of changes in these severity indices on compliance with a q.i.d. regimen of inhaled beclomethasone was evaluated. The PEFR was measured in the morning before bronchodilator administration, and symptoms were graded on a scale of 4 to 16, while albuterol and beclomethasone inhalations were electronically recorded. Three measures of compliance with the beclomethasone regimen were used: (1) mean daily compliance ([number of inhalations/number of prescribed inhalations] x 100); (2) underuse, ie, the percentage of days with less than the prescribed number of inhalations; and (3) overuse, ie, the percentage of days with greater than the prescribed number of inhalations. Mean daily compliance was 67 +/- 36 percent, while underuse was observed in 69 percent and overuse in 11 percent of the days. Despite clinical exacerbations in six of the ten patients and considerable variation in the severity indices, no significant relationship was found between the change in asthma severity and compliance with the beclomethasone regimen. These findings do not support the concept of severity-modulated compliance with inhaled corticosteroids.
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Affiliation(s)
- M C Mann
- Section of Pulmonary Diseases, Saint Francis Hospital and Medical Center, Hartford, Conn
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Collins JL, Mann MC. INTERSPECIFIC HYBRIDS IN CREPIS. II. A PRELIMINARY REPORT ON THE RESULTS OF HYBRIDIZING CREPIS SETOSA HALL. WITH C. CAPILLARIS (L.) WALLR. AND WITH C. BIENNIS L. Genetics 1923; 8:212-32. [PMID: 17246009 PMCID: PMC1200745 DOI: 10.1093/genetics/8.3.212] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- J L Collins
- University of California, Berkeley, California
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