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Vasa M, Fichtlscherer S, Aicher A, Adler K, Urbich C, Martin H, Zeiher AM, Dimmeler S. Number and migratory activity of circulating endothelial progenitor cells inversely correlate with risk factors for coronary artery disease. Circ Res 2001; 89:E1-7. [PMID: 11440984 DOI: 10.1161/hh1301.093953] [Citation(s) in RCA: 1587] [Impact Index Per Article: 66.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Recent studies provide increasing evidence that postnatal neovascularization involves bone marrow-derived circulating endothelial progenitor cells (EPCs). The regulation of EPCs in patients with coronary artery disease (CAD) is unclear at present. Therefore, we determined the number and functional activity of EPCs in 45 patients with CAD and 15 healthy volunteers. The numbers of isolated EPCs and circulating CD34/kinase insert domain receptor (KDR)-positive precursor cells were significantly reduced in patients with CAD by approximately 40% and 48%, respectively. To determine the influence of atherosclerotic risk factors, a risk factor score including age, sex, hypertension, diabetes, smoking, positive family history of CAD, and LDL cholesterol levels was used. The number of risk factors was significantly correlated with a reduction of EPC levels (R=-0.394, P=0.002) and CD34-/KDR-positive cells (R=-0.537, P<0.001). Analysis of the individual risk factors demonstrated that smokers had significantly reduced levels of EPCs (P<0.001) and CD34-/KDR-positive cells (P=0.003). Moreover, a positive family history of CAD was associated with reduced CD34-/KDR-positive cells (P=0.011). Most importantly, EPCs isolated from patients with CAD also revealed an impaired migratory response, which was inversely correlated with the number of risk factors (R=-0.484, P=0.002). By multivariate analysis, hypertension was identified as a major independent predictor for impaired EPC migration (P=0.043). The present study demonstrates that patients with CAD revealed reduced levels and functional impairment of EPCs, which correlated with risk factors for CAD. Given the important role of EPCs for neovascularization of ischemic tissue, the decrease of EPC numbers and activity may contribute to impaired vascularization in patients with CAD. The full text of this article is available at http://www.circresaha.org.
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1587 |
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Vasa M, Fichtlscherer S, Adler K, Aicher A, Martin H, Zeiher AM, Dimmeler S. Increase in circulating endothelial progenitor cells by statin therapy in patients with stable coronary artery disease. Circulation 2001; 103:2885-90. [PMID: 11413075 DOI: 10.1161/hc2401.092816] [Citation(s) in RCA: 671] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
BACKGROUND Therapeutic neovascularization may constitute an important strategy to salvage tissue from critical ischemia. Circulating bone marrow-derived endothelial progenitor cells (EPCs) were shown to augment the neovascularization of ischemic tissue. In addition to lipid-lowering activity, hydroxymethyl glutaryl coenzyme A reductase inhibitors (statins) reportedly promote the neovascularization of ischemic tissue in normocholesterolemic animals. Methods and Results-Fifteen patients with angiographically documented stable coronary artery disease (CAD) were prospectively treated with 40 mg of atorvastatin per day for 4 weeks. Before and weekly after the initiation of statin therapy, EPCs were isolated from peripheral blood and counted. In addition, the number of hematopoietic precursor cells positive for CD34, CD133, and CD34/kinase insert domain receptor was analyzed. Statin treatment of patients with stable CAD was associated with an approximately 1.5-fold increase in the number of circulating EPCs by 1 week after initiation of treatment; this was followed by sustained increased levels to approximately 3-fold throughout the 4-week study period. Moreover, the number of CD34/kinase insert domain receptor-positive hematopoietic progenitor cells was significantly augmented after 4 weeks of therapy. Atorvastatin treatment increased the further functional activity of EPCs, as assessed by their migratory capacity. CONCLUSION The results of the present study define a novel mechanism of action of statin treatment in patients with stable CAD: the augmentation of circulating EPCs with enhanced functional activity. Given the well-established role of EPCs of participating in repair after ischemic injury, stimulation of EPCs by statins may contribute to the clinical benefit of statin therapy in patients with CAD.
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Clinical Trial |
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List B, Pojarliev P, Martin HJ. Efficient proline-catalyzed Michael additions of unmodified ketones to nitro olefins. Org Lett 2001; 3:2423-5. [PMID: 11483025 DOI: 10.1021/ol015799d] [Citation(s) in RCA: 475] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
[reaction: see text] Here we describe the proline-catalyzed Michael addition of unmodified ketones to nitro olefins. This novel reaction provides gamma-nitro ketones in modest enantioselectivity yet excellent yields.
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475 |
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Britten MB, Abolmaali ND, Assmus B, Lehmann R, Honold J, Schmitt J, Vogl TJ, Martin H, Schächinger V, Dimmeler S, Zeiher AM. Infarct remodeling after intracoronary progenitor cell treatment in patients with acute myocardial infarction (TOPCARE-AMI): mechanistic insights from serial contrast-enhanced magnetic resonance imaging. Circulation 2003; 108:2212-8. [PMID: 14557356 DOI: 10.1161/01.cir.0000095788.78169.af] [Citation(s) in RCA: 392] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND Experimental and initial clinical studies suggest that transplantation of circulating blood- (CPC) or bone marrow-derived (BMC) progenitor cells may beneficially affect postinfarction remodeling processes after acute myocardial infarction (AMI). To relate functional characteristics of the infused cells to quantitative measures of outcome at 4-month follow-up, we performed serial contrast-enhanced MRI and assessed the migratory capacity of the transplanted progenitor cells immediately before intracoronary infusion. METHODS AND RESULTS In 28 patients with reperfused AMI receiving either BMCs or CPCs into the infarct artery 4.7+/-1.7 days after AMI, serial contrast-enhanced MRI performed initially and after 4 months revealed a significant increase in global ejection fraction (from 44+/-10% to 49+/-10%; P=0.003), a decrease in end-systolic volume (from 69+/-26 to 60+/-28 mL; P=0.003), and unchanged end-diastolic volumes (122+/-34 versus 117+/-37 mL; P=NS). Infarct size, measured as late enhancement (LE) volume, decreased significantly, from 46+/-32 to 37+/-28 mL (P<0.05). There was a significant correlation between the reduction in LE volume and global ejection fraction improvement. The migratory capacity of transplanted cells as assessed ex vivo toward a gradient of vascular endothelial growth factor for CPCs and stromal cell derived factor-1 for BMCs was closely correlated with the reduction of LE volume. By multivariate analysis, migratory capacity remained the most important independent predictor of infarct remodeling. CONCLUSIONS Analysis of serial contrast-enhanced MRI suggests that intracoronary infusion of adult progenitor cells in patients with AMI beneficially affects postinfarction remodeling processes. The migratory capacity of the infused cells is a major determinant of infarct remodeling, disclosing a causal effect of progenitor cell therapy on regeneration enhancement.
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Research Support, Non-U.S. Gov't |
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392 |
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Sayer AA, Syddall H, Martin H, Patel H, Baylis D, Cooper C. The developmental origins of sarcopenia. J Nutr Health Aging 2008; 12:427-32. [PMID: 18615224 PMCID: PMC2652119 DOI: 10.1007/bf02982703] [Citation(s) in RCA: 294] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Review |
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294 |
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Dimmeler S, Aicher A, Vasa M, Mildner-Rihm C, Adler K, Tiemann M, Rütten H, Fichtlscherer S, Martin H, Zeiher AM. HMG-CoA reductase inhibitors (statins) increase endothelial progenitor cells via the PI 3-kinase/Akt pathway. J Clin Invest 2001; 108:391-7. [PMID: 11489932 PMCID: PMC209365 DOI: 10.1172/jci13152] [Citation(s) in RCA: 277] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
HMG-CoA reductase inhibitors (statins) have been developed as lipid-lowering drugs and are well established to reduce morbidity and mortality from coronary artery disease. Here we demonstrate that statins potently augment endothelial progenitor cell differentiation in mononuclear cells and CD34-positive hematopoietic stem cells isolated from peripheral blood. Moreover, treatment of mice with statins increased c-kit(+)/Sca-1(+)--positive hematopoietic stem cells in the bone marrow and further elevated the number of differentiated endothelial progenitor cells (EPCs). Statins induce EPC differentiation via the PI 3-kinase/Akt (PI3K/Akt) pathway as demonstrated by the inhibitory effect of pharmacological PI3K blockers or overexpression of a dominant negative Akt construct. Similarly, the potent angiogenic growth factor VEGF requires Akt to augment EPC numbers, suggesting an essential role for Akt in regulating hematopoietic progenitor cell differentiation. Given that statins are at least as potent as VEGF in increasing EPC differentiation, augmentation of circulating EPC might importantly contribute to the well-established beneficial effects of statins in patients with coronary artery disease.
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research-article |
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Martin H, Hu J, Gennser G, Norman M. Impaired endothelial function and increased carotid stiffness in 9-year-old children with low birthweight. Circulation 2000; 102:2739-44. [PMID: 11094041 DOI: 10.1161/01.cir.102.22.2739] [Citation(s) in RCA: 213] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Low birthweight (LBW) has been associated with an increased incidence of adult cardiovascular disease. Endothelial dysfunction and loss of arterial elasticity are early markers of hypertension and atherosclerosis. We studied the prevalence of these markers in 44 healthy, prepubertal (age 9+/-1.3 years) children, 22 with LBW for age. METHODS AND RESULTS Endothelial function in skin was tested with the local application of acetylcholine (inducing endothelium-dependent vasodilation) and nitroglycerin (endothelium-independent vasodilation), and local perfusion changes were measured with the laser Doppler method. The elastic properties of the abdominal aorta and common carotid artery were measured with an ultrasonic vessel-wall tracking system. Endothelium-dependent vasodilation was lower in children with LBW (88+/-33 perfusion units [PU]) than in normal-birthweight controls (133+/-34 PU, P<0.001). There was no difference in aortic or carotid elasticity between the 2 groups, but a negative correlation was found between birthweight and stiffness of the carotid artery wall (r=-0.45, P<0.01). Endothelium-independent vasodilation and blood pressure were similar in the 2 groups. CONCLUSIONS Schoolchildren with a history of LBW show impaired endothelial function and a trend toward increased carotid stiffness. These findings may be early expressions of vascular compromise, contributing to susceptibility to disease in adult life.
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Syddall HE, Aihie Sayer A, Dennison EM, Martin HJ, Barker DJP, Cooper C. Cohort profile: the Hertfordshire cohort study. Int J Epidemiol 2005; 34:1234-42. [PMID: 15964908 DOI: 10.1093/ije/dyi127] [Citation(s) in RCA: 208] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Journal Article |
20 |
208 |
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Martin HJ, Yule V, Syddall HE, Dennison EM, Cooper C, Aihie Sayer A. Is hand-held dynamometry useful for the measurement of quadriceps strength in older people? A comparison with the gold standard Bodex dynamometry. Gerontology 2006; 52:154-9. [PMID: 16645295 DOI: 10.1159/000091824] [Citation(s) in RCA: 206] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2005] [Accepted: 10/18/2005] [Indexed: 12/27/2022] Open
Abstract
BACKGROUND The lower limb muscle strength is an important determinant of physical function in older people. However, measurement in clinical and epidemiological settings has been limited because of the requirement for large-scale equipment. A protocol using a novel, versatile hand-held dynamometer (HHD) has been developed to measure the quadriceps strength in a supine position. OBJECTIVE The objective of this study was to assess the validity of this new methodology for measuring the lower limb muscle strength compared to the gold standard Biodex dynamometer. METHODS The supine quadriceps strength was measured twice with each of the Biodex and the HHD in 20 men and women, aged 61-81 years, on their non-dominant leg. The agreement between the peak torques obtained by Biodex and HHD was analyzed. RESULTS The mean peak Biodex and HHD results were 83.4 +/- (SD) 28.0 Nm and 68.9 +/- 19.6 Nm, respectively. The HHD undermeasured the quadriceps strength by an average of 14.5 Nm (95% CI 8.5, 20.6) compared to the Biodex, and this effect was most marked in the strongest participants. Nevertheless, there was a good correlation between the measures (r = 0.91, p < 0.0001). Classification of individuals into tertiles of muscle strength showed good agreement between the two methods (Kappa = 0.69, p < 0.0001). CONCLUSIONS Our findings suggest that the HHD using a supine positioning offers a feasible, inexpensive, and portable test of quadriceps muscle strength for use in healthy older people. It underestimates the absolute quadriceps strength compared to the Biodex particularly in stronger people, but is a useful tool for ranking muscle strength of older people in epidemiological studies. It may also be of value for quick and objective assessment of physical function in the clinical setting.
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Research Support, Non-U.S. Gov't |
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190 |
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Sayer AA, Syddall HE, Dennison EM, Martin HJ, Phillips DIW, Cooper C, Byrne CD. Grip strength and the metabolic syndrome: findings from the Hertfordshire Cohort Study. QJM 2007; 100:707-13. [PMID: 17951315 PMCID: PMC2292249 DOI: 10.1093/qjmed/hcm095] [Citation(s) in RCA: 168] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
INTRODUCTION Sarcopenia, the loss of muscle mass and strength with age, is significantly associated with type 2 diabetes in older people. AIM To determine whether there is a relationship between grip strength and features of the metabolic syndrome. DESIGN Cross-sectional study. METHODS Data were collected on grip strength, fasting glucose, triglycerides and HDL cholesterol, blood pressure, waist circumference and 2 h glucose after an oral glucose tolerance test, in a population-based sample of 2677 men and women aged 59-73 years. RESULTS In men and women combined, a standard deviation (SD) decrease in grip strength was significantly associated with higher: fasting triglycerides (0.05 SD unit increase, 95%CI 0.02-0.09, p = 0.006); blood pressure (OR 1.13, 95%CI 1.04-1.24, p = 0.004); waist circumference (0.08 SD unit increase, 95%CI 0.06-0.10, p < 0.001); 2 h glucose (0.07 SD unit increase, 95%CI 0.03-0.11, p = 0.001) and HOMA resistance (0.05 SD unit increase, 95%CI 0.01-0.09, p = 0.008), after adjustment for gender, weight, age, walking speed, social class, smoking habit and alcohol intake. Lower grip strength was also significantly associated with increased odds of having the metabolic syndrome according to both the ATPIII (OR 1.18, 95%CI 1.07-1.30, p < 0.001) and IDF definitions (OR 1.11, 95%CI 1.01-1.22, p = 0.03). DISCUSSION Our findings suggest that impaired grip strength is associated with the individual features, as well as with the overall summary definitions, of the metabolic syndrome. The potential for grip strength to be used in the clinical setting needs to be explored.
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Hebart H, Löffler J, Meisner C, Serey F, Schmidt D, Böhme A, Martin H, Engel A, Bunje D, Kern WV, Schumacher U, Kanz L, Einsele H. Early detection of aspergillus infection after allogeneic stem cell transplantation by polymerase chain reaction screening. J Infect Dis 2000; 181:1713-9. [PMID: 10823773 DOI: 10.1086/315435] [Citation(s) in RCA: 154] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/1999] [Revised: 02/07/2000] [Indexed: 11/03/2022] Open
Abstract
Invasive aspergillosis (IA) has become a major cause of mortality in patients after allogeneic stem cell transplantation. To assess the potential of prospective polymerase chain reaction (PCR) screening for early diagnosis of IA, 84 recipients of an allogeneic stem cell transplant were analyzed with the investigators blinded to clinical and microbiologic data. Of 1193 blood samples analyzed, 169 (14.2%) were positive by PCR. In patients with newly diagnosed IA (n=7), PCR positivity preceded the first clinical signs by a median of 2 days (range, 1-23 days) and preceded clinical diagnosis of IA by a median of 9 days (range, 2-34 days). Pretransplantation IA (relative risk [RR], 2.37), acute graft-versus-host disease (RR, 2.75), and corticosteroid treatment (RR, 6.5) were associated with PCR positivity. The PCR assay revealed a sensitivity of 100% (95% confidence interval [CI], 48%-100%) and a specificity of 65% (95% CI, 53%-75%). None of the PCR-negative patients developed IA during the study period. Thus, prospective PCR screening allows for identification of patients at high risk for subsequent onset of IA.
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Multicenter Study |
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154 |
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Buck V, Quinn J, Soto Pino T, Martin H, Saldanha J, Makino K, Morgan BA, Millar JB. Peroxide sensors for the fission yeast stress-activated mitogen-activated protein kinase pathway. Mol Biol Cell 2001; 12:407-19. [PMID: 11179424 PMCID: PMC30952 DOI: 10.1091/mbc.12.2.407] [Citation(s) in RCA: 138] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The Schizosaccharomyces pombe stress-activated Sty1p/Spc1p mitogen-activated protein (MAP) kinase regulates gene expression through the Atf1p and Pap1p transcription factors, homologs of human ATF2 and c-Jun, respectively. Mcs4p, a response regulator protein, acts upstream of Sty1p by binding the Wak1p/Wis4p MAP kinase kinase kinase. We show that phosphorylation of Mcs4p on a conserved aspartic acid residue is required for activation of Sty1p only in response to peroxide stress. Mcs4p acts in a conserved phospho-relay system initiated by two PAS/PAC domain-containing histidine kinases, Mak2p and Mak3p. In the absence of Mak2p or Mak3p, Sty1p fails to phosphorylate the Atf1p transcription factor or induce Atf1p-dependent gene expression. As a consequence, cells lacking Mak2p and Mak3p are sensitive to peroxide attack in the absence of Prr1p, a distinct response regulator protein that functions in association with Pap1p. The Mak1p histidine kinase, which also contains PAS/PAC repeats, does not regulate Sty1p or Atf1p but is partially required for Pap1p- and Prr1p-dependent transcription. We conclude that the transcriptional response to free radical attack is initiated by at least two distinct phospho-relay pathways in fission yeast.
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Journal Article |
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137 |
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Martin H. Ultrasonic disinfection of the root canal. ORAL SURGERY, ORAL MEDICINE, AND ORAL PATHOLOGY 1976; 42:92-9. [PMID: 821029 DOI: 10.1016/0030-4220(76)90035-9] [Citation(s) in RCA: 136] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The use of ultrasonics to increase the bactericidal efficiency of endodontic irrigation was tested on four microorganisms. Ultransonics alone had a reducing effect but coupling it with a biocidal agent led to a more efficient bactericidal synergism. A sonosynergistic system of cleaning and disinfecting the root canal system has been described.
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Comparative Study |
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136 |
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Syddall HE, Martin HJ, Harwood RH, Cooper C, Aihie Sayer A. The SF-36: a simple, effective measure of mobility-disability for epidemiological studies. J Nutr Health Aging 2009; 13:57-62. [PMID: 19151909 PMCID: PMC2654814 DOI: 10.1007/s12603-009-0010-4] [Citation(s) in RCA: 134] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Mobility disability is a major problem in older people. Numerous scales exist for the measurement of disability but often these do not permit comparisons between study groups. The physical functioning (PF) domain of the established and widely used Short Form-36 (SF-36) questionnaire asks about limitations on ten mobility activities. OBJECTIVES To describe prevalence of mobility disability in an elderly population, investigate the validity of the SF-36 PF score as a measure of mobility disability, and to establish age and sex specific norms for the PF score. METHODS We explored relationships between the SF-36 PF score and objectively measured physical performance variables among 349 men and 280 women, 59-72 years of age, who participated in the Hertfordshire Cohort Study (HCS). Normative data were derived from the Health Survey for England (HSE) 1996. RESULTS 32% of men and 46% of women had at least some limitation in PF scale items. Poor SF-36 PF scores (lowest fifth of the gender-specific distribution) were related to: lower grip strength; longer timed-up-and-go, 3m walk, and chair rises test times in men and women; and lower quadriceps peak torque in women but not men. HSE normative data showed that median PF scores declined with increasing age in men and women. CONCLUSION Our results are consistent with the SF-36 PF score being a valid measure of mobility disability in epidemiological studies. This approach might be a first step towards enabling simple comparisons of prevalence of mobility disability between different studies of older people. The SF-36 PF score could usefully complement existing detailed schemes for classification of disability and it now requires validation against them.
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Validation Study |
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134 |
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Martin H, Rostas J, Patel Y, Aitken A. Subcellular localisation of 14-3-3 isoforms in rat brain using specific antibodies. J Neurochem 1994; 63:2259-65. [PMID: 7964746 DOI: 10.1046/j.1471-4159.1994.63062259.x] [Citation(s) in RCA: 130] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The 14-3-3 protein family, which is present at particularly high concentrations in mammalian brain, is known to be involved in various cellular functions, including protein kinase C regulation and exocytosis. Despite the fact that most of the 14-3-3 proteins are cytosolic, a small but significant proportion of 14-3-3 in brain is tightly and selectively associated with some membranes. Using a panel of isoform-specific antisera we find that the epsilon, eta, gamma, beta, and zeta isoforms are all present in purified synaptic membranes but absent from mitochondrial and myelin membranes. In addition, the eta, epsilon, and gamma isoforms but not the beta and zeta isoforms are associated with isolated synaptic junctions. When different populations of synaptosomes were fractionated by a nonequilibrium Percoll gradient procedure, the epsilon and gamma isoforms were present and the beta and zeta isoforms were absent from the membranes of synaptosomes sedimenting in the more dense parts of the gradient. The finding that these proteins are associated with different populations of synaptic membranes suggests that they are selectively expressed in different classes of neurones and raises the possibility that some or all of them may influence neurotransmission by regulating exocytosis and/or phosphorylation.
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Cunningham WT, Martin H, Forrest WR. Evaluation of root canal débridement by the endosonic ultrasonic synergistic system. ORAL SURGERY, ORAL MEDICINE, AND ORAL PATHOLOGY 1982; 53:401-4. [PMID: 6952152 DOI: 10.1016/0030-4220(82)90442-x] [Citation(s) in RCA: 130] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The endosonic ultrasonic synergistic system was compared to conventional hand-filing and irrigating techniques for its ability to débride the root canal system. Extracted human teeth were endodontically prepared by conventional and ultrasonic techniques. The roots were cross sectioned and evaluated microscopically at the 1, 3, and 5 mm. levels from the apex for cleanliness. The endosonically prepared canals were significantly cleaner at all levels.
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Comparative Study |
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Voos W, Martin H, Krimmer T, Pfanner N. Mechanisms of protein translocation into mitochondria. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1422:235-54. [PMID: 10548718 DOI: 10.1016/s0304-4157(99)00007-6] [Citation(s) in RCA: 122] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Mitochondrial biogenesis utilizes a complex proteinaceous machinery for the import of cytosolically synthesized preproteins. At least three large multisubunit protein complexes, one in the outer membrane and two in the inner membrane, have been identified. These translocase complexes cooperate with soluble proteins from the cytosol, the intermembrane space and the matrix. The translocation of presequence-containing preproteins through the outer membrane channel includes successive electrostatic interactions of the charged mitochondrial targeting sequence with a chain of import components. Translocation across the inner mitochondrial membrane utilizes the energy of the proton motive force of the inner membrane and the hydrolysis of ATP. The matrix chaperone system of the mitochondrial heat shock protein 70 forms an ATP-dependent import motor by interaction with the polypeptide chain in transit and components of the inner membrane translocase. The precursors of integral inner membrane proteins of the metabolite carrier family interact with newly identified import components of the intermembrane space and are inserted into the inner membrane by a second translocase complex. A comparison of the full set of import components between the yeast Sacccharomyces cerevisiae and the nematode Caenorhabditis elegans demonstrates an evolutionary conservation of most components of the mitochondrial import machinery with a possible greater divergence for the import pathway of the inner membrane carrier proteins.
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Review |
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122 |
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Cunningham WT, Martin H. A scanning electron microscope evaluation of root canal débridement with the endosonic ultrasonic synergistic system. ORAL SURGERY, ORAL MEDICINE, AND ORAL PATHOLOGY 1982; 53:527-31. [PMID: 6954428 DOI: 10.1016/0030-4220(82)90471-6] [Citation(s) in RCA: 122] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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Comparative Study |
43 |
122 |
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Sayer HG, Kröger M, Beyer J, Kiehl M, Klein SA, Schaefer-Eckart K, Schwerdtfeger R, Siegert W, Runde V, Theuser C, Martin H, Schetelig J, Beelen DW, Fauser A, Kienast J, Höffken K, Ehninger G, Bornhäuser M. Reduced intensity conditioning for allogeneic hematopoietic stem cell transplantation in patients with acute myeloid leukemia: disease status by marrow blasts is the strongest prognostic factor. Bone Marrow Transplant 2003; 31:1089-95. [PMID: 12796788 DOI: 10.1038/sj.bmt.1704062] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We analyzed predictive factors for the outcome of 113 acute myeloid leukemia patients receiving reduced-intensity conditioning prior to allogeneic hematopoietic stem cell transplantation (HSCT). Patients were ineligible for conventional-intensity HSCT. Conditioning consisted of fludarabine and 50% of the conventional dose of busulfan (n=93) or total body irradiation (n=20). The source of stem cells was blood in 102 patients, marrow in 10, and both in one. In total, 50 (44.2%) donors were HLA-matched siblings, 50 (44.2%) unrelated fully matched and 13 (11.5%) partially mismatched family (n=1) or unrelated (n=12) donors. In all, 107 (94.6%) patients showed neutrophil and platelet engraftment after a median time of 13.5 and 13 days. The probabilities of event-free survival (EFS) (median follow-up: 12 months) were 49% for patients with less than 5% blasts in the marrow, 24% for patients with 5-20% blasts (P=0.002) and 14% with >20% blasts (P<or=0.001). Death occurred because of relapse in 29 patients (25.6%), infection in 12 patients (10.6%), acute graft-versus-host disease in eight patients (7.0%) and organ toxicity in nine patients (7.9%). In multivariate analysis, higher number of blasts in the marrow, alternative donors and low Karnofsky performance score were independent adverse prognostic factors for EFS.
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Multicenter Study |
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115 |
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Thiel G, Losanowa T, Kintzel D, Nisch G, Martin H, Vorpahl K, Witkowski R. Karyotypes in 90 human gliomas. CANCER GENETICS AND CYTOGENETICS 1992; 58:109-20. [PMID: 1551072 DOI: 10.1016/0165-4608(92)90095-p] [Citation(s) in RCA: 115] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cytogenetic studies were performed on 90 human gliomas including 26 astrocytomas, 12 oligodendrogliomas, three oligo-astrocytomas, seven ependymomas, eight pilocytic astrocytomas, and 33 malignant gliomas (anaplastic astrocytomas and glioblastomas). The most common abnormalities were trisomy 7 in 23 cases, monosomy 22 in 15 cases, losses of the Y chromosome in 19 of 50 male cases, and losses of the X chromosome in 10 of 39 female cases. There are evident differences between the particular subgroups of gliomas. Monosomy 10 and double minutes are typical for malignant gliomas. The 58 determined chromosomal breakpoints were located on 45 different sites. Chromosomes 1, 9, 6, 3, 10, and 17 were predominantly involved.
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Bardoux P, Martin H, Ahloulay M, Schmitt F, Bouby N, Trinh-Trang-Tan MM, Bankir L. Vasopressin contributes to hyperfiltration, albuminuria, and renal hypertrophy in diabetes mellitus: study in vasopressin-deficient Brattleboro rats. Proc Natl Acad Sci U S A 1999; 96:10397-402. [PMID: 10468619 PMCID: PMC17899 DOI: 10.1073/pnas.96.18.10397] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Diabetic nephropathy represents a major complication of diabetes mellitus (DM), and the origin of this complication is poorly understood. Vasopressin (VP), which is elevated in type I and type II DM, has been shown to increase glomerular filtration rate in normal rats and to contribute to progression of chronic renal failure in 5/6 nephrectomized rats. The present study was thus designed to evaluate whether VP contributes to the renal disorders of DM. Renal function was compared in Brattleboro rats with diabetes insipidus (DI) lacking VP and in normal Long-Evans (LE) rats, with or without streptozotocin-induced DM. Blood and urine were collected after 2 and 4 weeks of DM, and creatinine clearance, urinary glucose and albumin excretion, and kidney weight were measured. Plasma glucose increased 3-fold in DM rats of both strains, but glucose excretion was approximately 40% lower in DI-DM than in LE-DM, suggesting less intense metabolic disorders. Creatinine clearance increased significantly in LE-DM (P < 0.01) but failed to increase in DI-DM. Urinary albumin excretion more than doubled in LE-DM but rose by only 34% in DI-DM rats (P < 0.05). Kidney hypertrophy was also less intense in DI-DM than in LE-DM (P < 0.001). These results suggest that VP plays a critical role in diabetic hyperfiltration and albuminuria induced by DM. This hormone thus seems to be an additional risk factor for diabetic nephropathy and, thus, a potential target for prevention and/or therapeutic intervention.
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Jones DH, Martin H, Madrazo J, Robinson KA, Nielsen P, Roseboom PH, Patel Y, Howell SA, Aitken A. Expression and structural analysis of 14-3-3 proteins. J Mol Biol 1995; 245:375-84. [PMID: 7837270 DOI: 10.1006/jmbi.1994.0031] [Citation(s) in RCA: 103] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The 14-3-3 family of proteins plays a role in a wide variety of cellular functions including regulation of protein kinase C and exocytosis. Using antisera specific for the N termini of 14-3-3 isoforms described previously and an additional antiserum specific for the C terminus of epsilon isoform, protease digestion of intact 14-3-3 showed that the N-terminal half of 14-3-3 (a 16 kDa fragment) was an intact, dimeric domain of the protein. Two isoforms of 14-3-3, tau and epsilon, were expressed in E. coli and their secondary structure was shown by circular dichroism to be identical to wild-type protein, and expression of N-terminally-deleted epsilon 14-3-3 protein showed that the N-terminal 26 amino acids are important for dimerization. Intact 14-3-3 is a potent inhibitor of protein kinase C, but the N-terminal domain does not inhibit PKC activity. Site-specific mutagenesis of several regions in the tau isoform of 14-3-3, including the mutation of a putative pseudosubstrate site to a potential substrate sequence, did not alter its inhibitory activity. Intact 14-3-3 proteins are phosphorylated by protein kinase C with a low stoichiometry, but truncated isoforms are phosphorylated much more efficiently by this kinase. This may imply that the proteins may adopt a different structural conformation, possibly upon binding to the membrane, which could modulate their activity. 14-3-3 proteins are found at high concentration on synaptic plasma membranes and this binding is mediated through the N-terminal 12 kDa of 14-3-3.
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Warner DS, Martin H, Ludwig P, McAllister A, Keana JF, Weber E. In vivo models of cerebral ischemia: effects of parenterally administered NMDA receptor glycine site antagonists. J Cereb Blood Flow Metab 1995; 15:188-96. [PMID: 7860652 DOI: 10.1038/jcbfm.1995.24] [Citation(s) in RCA: 99] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Both in vitro and in vivo experiments have implicated extracellular glycine in the pathogenesis of ischemic brain damage. Recently, halogenated derivatives of quinoxaline-2,3-dione have been synthesized that possess bioavailability when parenterally administered and minimal psychotomimetic properties. Such compounds have allowed investigation into the efficacy of glycine receptor antagonism as a strategy for protection against cerebral ischemic insults. Rats underwent either 90 min of middle cerebral artery filament occlusion or 10 min of forebrain ischemia with recovery while receiving intraperitoneal injections of either a glycine receptor antagonist (ACEA-1021, ACEA-1031, or ACEA-1011) or vehicle (dimethyl sulfoxide). Both ACEA-1021 and ACEA-1031 reduced cerebral infarct volumes and were associated with a reduced incidence of hemiparesis resulting from MCA occlusion. ACEA-1011, administered in a smaller dose had no effect. In the forebrain ischemia model, glycine receptor antagonism had no effect on delayed neuronal necrosis in the hippocampal CA1 sector, neocortex, or caudoputamen. We conclude that pharmacologic antagonism of glycine at the strychnine-insensitive glycine receptor presents a neuroprotective profile similar to that previously observed for antagonists of glutamate at the N-methyl-D-aspartate complex with a potential for fewer side effects.
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