1
|
Thompson RR, George K, Walton JC, Orr SP, Benson J. Sex-specific influences of vasopressin on human social communication. Proc Natl Acad Sci U S A 2006; 103:7889-94. [PMID: 16682649 PMCID: PMC1472540 DOI: 10.1073/pnas.0600406103] [Citation(s) in RCA: 230] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2006] [Indexed: 11/18/2022] Open
Abstract
Arginine vasopressin (AVP) and related peptides affect social behaviors in numerous species, but AVP influences on human social functions have not yet been established. Here, we describe how intranasal AVP administration differentially affects social communication in men and women, and we propose a mechanism through which it may exert those influences. In men, AVP stimulates agonistic facial motor patterns in response to the faces of unfamiliar men and decreases perceptions of the friendliness of those faces. In contrast, in women, AVP stimulates affiliative facial motor patterns in response to the faces of unfamiliar women and increases perceptions of the friendliness of those faces. AVP also affected autonomic responsiveness to threatening faces and increased anxiety, which may underlie both communication patterns by promoting different social strategies in stressful contexts in men and women.
Collapse
|
Research Support, N.I.H., Extramural |
19 |
230 |
2
|
Wilson M, O'Hanlon R, Prasad S, Deighan A, Macmillan P, Oxborough D, Godfrey R, Smith G, Maceira A, Sharma S, George K, Whyte G. Diverse patterns of myocardial fibrosis in lifelong, veteran endurance athletes. J Appl Physiol (1985) 2011; 110:1622-6. [PMID: 21330616 DOI: 10.1152/japplphysiol.01280.2010] [Citation(s) in RCA: 200] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This study examined the cardiac structure and function of a unique cohort of documented lifelong, competitive endurance veteran athletes (>50 yr). Twelve lifelong veteran male endurance athletes [mean ± SD (range) age: 56 ± 6 yr (50-67)], 20 age-matched veteran controls [60 ± 5 yr; (52-69)], and 17 younger male endurance athletes [31 ± 5 yr (26-40)] without significant comorbidities underwent cardiac magnetic resonance (CMR) imaging to assess cardiac morphology and function, as well as CMR imaging with late gadolinium enhancement (LGE) to assess myocardial fibrosis. Lifelong veteran athletes had smaller left (LV) and right ventricular (RV) end-diastolic and end-systolic volumes (P < 0.05), but maintained LV and RV systolic function compared with young athletes. However, veteran athletes had a significantly larger absolute and indexed LV and RV end-diastolic and systolic volumes, intraventricular septum thickness during diastole, posterior wall thickness during diastole, and LV and RV stroke volumes (P < 0.05), together with significantly reduced LV and RV ejection fractions (P < 0.05), compared with veteran controls. In six (50%) of the veteran athletes, LGE of CMR indicated the presence of myocardial fibrosis (4 veteran athletes with LGE of nonspecific cause, 1 probable previous myocarditis, and 1 probable previous silent myocardial infarction). There was no LGE in the age-matched veteran controls or young athletes. The prevalence of LGE in veteran athletes was not associated with age, height, weight, or body surface area (P > 0.05), but was significantly associated with the number of years spent training (P < 0.001), number of competitive marathons (P < 0.001), and ultraendurance (>50 miles) marathons (P < 0.007) completed. An unexpectedly high prevalence of myocardial fibrosis (50%) was observed in healthy, asymptomatic, lifelong veteran male athletes, compared with zero cases in age-matched veteran controls and young athletes. These data suggest a link between lifelong endurance exercise and myocardial fibrosis that requires further investigation.
Collapse
|
Multicenter Study |
14 |
200 |
3
|
Harriss DJ, Atkinson G, Batterham A, George K, Cable NT, Reilly T, Haboubi N, Renehan AG, Colorectal Cancer, Lifestyle, Exercise And Research Group. Lifestyle factors and colorectal cancer risk (2): a systematic review and meta-analysis of associations with leisure-time physical activity. Colorectal Dis 2009; 11:689-701. [PMID: 19207713 DOI: 10.1111/j.1463-1318.2009.01767.x] [Citation(s) in RCA: 137] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Increased physical activity may decrease the risk of colorectal cancer. As a prerequisite to the determination of lifestyle attributable risks, we performed a systematic review and meta-analysis of prospective observational studies to quantify gender-specific risk associated with increased leisure-time physical activity (LT-PA). METHOD We searched MEDLINE and EMBASE (to December 2007), and other sources, selecting reports based on strict inclusion criteria. We used random-effects meta-analyses to estimate summary risk ratios (RR) and 95% confidence intervals (95% CI) for uppermost vs lowermost categories of physical activity. To investigate dose-response, we explored risks ratios as a function of cumulative percentiles of physical activity distribution. RESULTS Fifteen datasets from 14 articles, including 7873 incident cases, were identified. For colon cancer, there were inverse associations with LT-PA for men (RR: 0.80; 95% CI: 0.67-0.96) and women (0.86; 0.76-0.98). LT-PA did not influence risk of rectal cancer. The dose-response analysis was consistent with linear pattern reductions in risk of colon cancer in both genders. There was evidence of moderate between-study heterogeneity but summary estimates were broadly consistent across potential confounding factors. CONCLUSION Increased LT-PA is associated with a modest reduction in colon but not rectal cancer risk; a risk reduction, which previously may have been overstated. LT-PA only interventions in public health cancer prevention strategies are unlikely to impact substantially on colorectal cancer incidences.
Collapse
|
Meta-Analysis |
16 |
137 |
4
|
van Schaik IN, Bril V, van Geloven N, Hartung HP, Lewis RA, Sobue G, Lawo JP, Praus M, Mielke O, Durn BL, Cornblath DR, Merkies ISJ, Sabet A, George K, Roberts L, Carne R, Blum S, Henderson R, Van Damme P, Demeestere J, Larue S, D'Amour C, Bril V, Breiner A, Kunc P, Valis M, Sussova J, Kalous T, Talab R, Bednar M, Toomsoo T, Rubanovits I, Gross-Paju K, Sorro U, Saarela M, Auranen M, Pouget J, Attarian S, Le Masson G, Wielanek-Bachelet A, Desnuelle C, Delmont E, Clavelou P, Aufauvre D, Schmidt J, Zschuentssch J, Sommer C, Kramer D, Hoffmann O, Goerlitz C, Haas J, Chatzopoulos M, Yoon R, Gold R, Berlit P, Jaspert-Grehl A, Liebetanz D, Kutschenko A, Stangel M, Trebst C, Baum P, Bergh F, Klehmet J, Meisel A, Klostermann F, Oechtering J, Lehmann H, Schroeter M, Hagenacker T, Mueller D, Sperfeld A, Bethke F, Drory V, Algom A, Yarnitsky D, Murinson B, Di Muzio A, Ciccocioppo F, Sorbi S, Mata S, Schenone A, Grandis M, Lauria G, Cazzato D, Antonini G, Morino S, Cocito D, Zibetti M, Yokota T, Ohkubo T, Kanda T, Kawai M, Kaida K, Onoue H, Kuwabara S, Mori M, Iijima M, Ohyama K, Baba M, Tomiyama M, et alvan Schaik IN, Bril V, van Geloven N, Hartung HP, Lewis RA, Sobue G, Lawo JP, Praus M, Mielke O, Durn BL, Cornblath DR, Merkies ISJ, Sabet A, George K, Roberts L, Carne R, Blum S, Henderson R, Van Damme P, Demeestere J, Larue S, D'Amour C, Bril V, Breiner A, Kunc P, Valis M, Sussova J, Kalous T, Talab R, Bednar M, Toomsoo T, Rubanovits I, Gross-Paju K, Sorro U, Saarela M, Auranen M, Pouget J, Attarian S, Le Masson G, Wielanek-Bachelet A, Desnuelle C, Delmont E, Clavelou P, Aufauvre D, Schmidt J, Zschuentssch J, Sommer C, Kramer D, Hoffmann O, Goerlitz C, Haas J, Chatzopoulos M, Yoon R, Gold R, Berlit P, Jaspert-Grehl A, Liebetanz D, Kutschenko A, Stangel M, Trebst C, Baum P, Bergh F, Klehmet J, Meisel A, Klostermann F, Oechtering J, Lehmann H, Schroeter M, Hagenacker T, Mueller D, Sperfeld A, Bethke F, Drory V, Algom A, Yarnitsky D, Murinson B, Di Muzio A, Ciccocioppo F, Sorbi S, Mata S, Schenone A, Grandis M, Lauria G, Cazzato D, Antonini G, Morino S, Cocito D, Zibetti M, Yokota T, Ohkubo T, Kanda T, Kawai M, Kaida K, Onoue H, Kuwabara S, Mori M, Iijima M, Ohyama K, Baba M, Tomiyama M, Nishiyama K, Akutsu T, Yokoyama K, Kanai K, van Schaik I, Eftimov F, Notermans N, Visser N, Faber C, Hoeijmakers J, Rejdak K, Chyrchel-Paszkiewicz U, Casanovas Pons C, Alberti Aguiló M, Gamez J, Figueras M, Marquez Infante C, Benitez Rivero S, Lunn M, Morrow J, Gosal D, Lavin T, Melamed I, Testori A, Ajroud-Driss S, Menichella D, Simpson E, Chi-Ho Lai E, Dimachkie M, Barohn R, Beydoun S, Johl H, Lange D, Shtilbans A, Muley S, Ladha S, Freimer M, Kissel J, Latov N, Chin R, Ubogu E, Mumfrey S, Rao T, MacDonald P, Sharma K, Gonzalez G, Allen J, Walk D, Hobson-Webb L, Gable K. Subcutaneous immunoglobulin for maintenance treatment in chronic inflammatory demyelinating polyneuropathy (PATH): a randomised, double-blind, placebo-controlled, phase 3 trial. Lancet Neurol 2018; 17:35-46. [DOI: 10.1016/s1474-4422(17)30378-2] [Show More Authors] [Citation(s) in RCA: 130] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 09/28/2017] [Accepted: 10/02/2017] [Indexed: 10/18/2022]
|
|
7 |
130 |
5
|
Dowse GK, Zimmet PZ, Gareeboo H, George K, Alberti MM, Tuomilehto J, Finch CF, Chitson P, Tulsidas H. Abdominal obesity and physical inactivity as risk factors for NIDDM and impaired glucose tolerance in Indian, Creole, and Chinese Mauritians. Diabetes Care 1991; 14:271-82. [PMID: 2060430 DOI: 10.2337/diacare.14.4.271] [Citation(s) in RCA: 128] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE We wanted to determine whether obesity, abdominal fat distribution, and physical inactivity act similarly and independently as risk factors for noninsulin-dependent diabetes mellitus (NIDDM) and impaired glucose tolerance (IGT) in Hindu and Muslim Asian Indians, African-origin Creoles, and Chinese Mauritians. RESEARCH DESIGN AND METHODS We examined a population-based random cluster sample of 5080 adult subjects from the Indian Ocean island of Mauritius. Glucose tolerance was assessed with a 75-g oral glucose tolerance test and World Health Organization criteria. RESULTS Univariate data and multiple logistic regression models indicated that age, family history of diabetes, body mass index (BMI), waist-hip ratio (WHR), and physical inactivity conveyed similar risk for NIDDM (and IGT) in each ethnic group. After adjusting for all other factors, Hindu ethnicity conferred additional risk for NIDDM (but not IGT) in men, but in women there were no clear ethnic differences. Although BMI and WHR were independently significant risk factors, WHR conveyed relatively stronger risk for NIDDM than BMI in women, whereas the converse was true in men. For ethnic groups combined, the independent odds ratios for IGT associated with moderate and low physical activity scores (relative to high) were 1.56 and 1.71 (P less than 0.05), respectively, in men and 1.32 and 1.69 (P less than 0.05) in women. In subjects with asymptomatic NIDDM diagnosed during the survey, the independent odds ratios were 1.96 and 2.00 (P less than 0.05) in men and 1.73 and 2.70 (P less than 0.05) in women. CONCLUSIONS These data indicate that BMI, abdominally distributed fat, and physical inactivity are important independent risk factors for both IGT and NIDDM in diverse ethnic groups. Attributable risk fractions for Mauritius suggest that populationwide modification of levels of these risk factors could potentially result in substantially lower occurrence of NIDDM (and IGT). Such interventions should be attempted in high-risk populations.
Collapse
|
|
34 |
128 |
6
|
Harriss DJ, Atkinson G, George K, Cable NT, Reilly T, Haboubi N, Zwahlen M, Egger M, Renehan AG, C-CLEAR group. Lifestyle factors and colorectal cancer risk (1): systematic review and meta-analysis of associations with body mass index. Colorectal Dis 2009; 11:547-63. [PMID: 19207714 DOI: 10.1111/j.1463-1318.2009.01766.x] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
OBJECTIVE Excess body weight, defined by body mass index (BMI), may increase the risk of colorectal cancer. As a prerequisite to the determination of lifestyle attributable risks, we undertook a systematic review and meta-analysis of prospective observational studies to quantify colorectal cancer risk associated with increased BMI and explore for differences by gender, sub-site and study characteristics. METHOD We searched MEDLINE and EMBASE (to December 2007), and other sources, selecting reports based on strict inclusion criteria. Random-effects meta-analyses and meta-regressions of study-specific incremental estimates were performed to determine the risk ratio (RR) and 95% confidence intervals (CIs) associated with a 5 kg/m(2) increase in BMI. RESULTS We analysed 29 datasets from 28 articles, including 67,361 incident cases. Higher BMI was associated with colon (RR 1.24, 95% CIs: 1.20-1.28) and rectal (1.09, 1.05-1.14) cancers in men, and with colon cancer (1.09, 1.04-1.12) in women. Associations were stronger in men than in women for colon (P < 0.001) and rectal (P = 0.005) cancers. Associations were generally consistent across geographic populations. Study characteristics and adjustments accounted for only moderate variations of associations. CONCLUSION Increasing BMI is associated with a modest increased risk of developing colon and rectal cancers, but this modest risk may translate to large attributable proportions in high-prevalence obese populations. Inter-gender differences point to potentially important mechanistic differences, which merit further research.
Collapse
|
Meta-Analysis |
16 |
126 |
7
|
Whyte GP, George K, Sharma S, Lumley S, Gates P, Prasad K, McKenna WJ. Cardiac fatigue following prolonged endurance exercise of differing distances. Med Sci Sports Exerc 2000; 32:1067-72. [PMID: 10862531 DOI: 10.1097/00005768-200006000-00005] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE Recent echocardiographic studies have reported cardiac dysfunction following ultra-endurance exercise in trained individuals. The duration of exercise required to elicit cardiac dysfunction and the mechanisms underlying this phenomenon have not been fully elucidated. The aim of the present study was to examine the presence of cardiac dysfunction following a half-Ironman and Ironman triathlon in trained individuals. METHODS 14 male triathletes (age: 32 +/- 5 yr; height: 180 +/- 8 cm; body mass: 75 +/- 9 kg) completed a half-Ironman triathlon. Following a 4-wk period, 10 of the original 14 triathletes completed an Ironman triathlon. All triathletes were assessed using ECG, echocardiography, and blood analysis pre-, immediately post-, and 48 h postrace for both distances. RESULTS Echocardiographic results indicated diastolic and systolic left ventricular dysfunction, for both race distances, which were associated with altered relaxation characteristics and a reduced inotropic contractility, respectively. Following 48-h recovery, all echocardiographic measures were similar to resting values. Creatine kinase MB (CKMB) was significantly elevated immediately postrace for both distances; however, it accounted for less than 5% of the total CK value and in the presence of an elevated total CK and CKMM implied that the elevated CKMB was noncardiac in origin. Troponin-T, however, was significantly elevated immediately postrace for both distances and returned to normal following 48-h recovery indicating myocardial damage. CONCLUSIONS Ironman and half-Ironman competition resulted in reversible abnormalities in resting left ventricular diastolic and systolic function. Results suggest that myocardial damage may be, in part, responsible for cardiac dysfunction, although the mechanisms responsible for this cardiac damage remain to be fully elucidated.
Collapse
|
|
25 |
111 |
8
|
Joseph A, Abraham S, Muliyil JP, George K, Prasad J, Minz S, Abraham VJ, Jacob KS. Evaluation of suicide rates in rural India using verbal autopsies, 1994-9. BMJ 2003; 326:1121-2. [PMID: 12763983 PMCID: PMC156005 DOI: 10.1136/bmj.326.7399.1121] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
research-article |
22 |
107 |
9
|
McCabe MP, Davison TE, George K. Effectiveness of staff training programs for behavioral problems among older people with dementia. Aging Ment Health 2007; 11:505-19. [PMID: 17882588 DOI: 10.1080/13607860601086405] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
This paper reviewed studies on staff training programs to address the behavioral problems associated with dementia among older people in residential care. The papers were classified according to whether or not the studies included a control group in the research design. The results of the review demonstrate that there has been a wide range of psychosocial and educational interventions to reduce behavioral problems among older people with dementia, with inconsistent results being obtained. However, many of these studies suffer from problems in their research design that make it difficult to evaluate their effectiveness. Problems in conducting research in the nursing home setting are highlighted, and suggestions for future research in this area are discussed.
Collapse
|
Review |
18 |
93 |
10
|
Rose A, Roy S, Abraham V, Holmgren G, George K, Balraj V, Abraham S, Muliyil J, Joseph A, Kang G. Solar disinfection of water for diarrhoeal prevention in southern India. Arch Dis Child 2006; 91:139-41. [PMID: 16403847 PMCID: PMC2082686 DOI: 10.1136/adc.2005.077867] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
AIMS To evaluate the efficacy and acceptability of solar irradiation in the prevention of diarrhoeal morbidity in children under 5 years of age, in an urban slum in Vellore, Tamil Nadu. METHODS A total of 100 children were assigned to receive drinking water that had been subjected to solar disinfection in polyethylene terephthalate bottles. One hundred age and sex matched controls were also selected. Both groups were followed by weekly home visits for a period of six months for any diarrhoeal morbidity. At the end of the follow up period, the acceptability of the intervention was assessed by interviews, questionnaires, and focus group discussions. RESULTS There was significant reduction in the incidence, duration, and severity of diarrhoea in children receiving solar disinfected water, despite 86% of the children drinking water other than that treated by the intervention. The incidence of diarrhoea in the intervention group was 1.7 per child-year, and among controls 2.7 per child-year, with an incidence rate ratio of 0.64 (95% CI -0.48 to 0.86). The risk of diarrhoea was reduced by 40% by using solar disinfection. In qualitative evaluation of acceptability, most women felt that solar disinfection was a feasible and sustainable method of disinfecting water. CONCLUSIONS Solar disinfection of water is an inexpensive, effective, and acceptable method of increasing water safety in a resource limited environment, and can significantly decrease diarrhoeal morbidity in children.
Collapse
|
research-article |
19 |
90 |
11
|
Abstract
Chromosomal aberrations were analyzed using multicolor fluorescence in situ hybridization (mFISH) in human peripheral blood lymphocytes after in vitro exposure to gamma rays or accelerated (56)Fe ions (1 GeV/nucleon, 145 keV/microm) at Brookhaven National Laboratory (Upton, NY). Doses of 0.3 and 3 Gy were used for both radiation types. Chromosomes were prematurely condensed by a phosphatase inhibitor (calyculin A) to avoid the population selection bias observed at metaphase as a result of the severe cell cycle delays induced by heavy ions. A total of 1053 karyotypes (G(2) and M phases) were analyzed in irradiated lymphocytes. Results revealed different distribution patterns for chromosomal aberrations after low- and high-LET radiation exposures: Heavy ions induced a much higher fraction of cells with multiple aberrations, while the majority of the aberrant cells induced by low doses of gamma rays contained a single aberration. The high fraction of complex-type exchanges after heavy ions leads to an overestimation of simple-type asymmetrical interchanges (dicentrics) from analysis of Giemsa-stained samples. However, even after a dose of 3 Gy iron ions, about 30% of the cells presented no complex-type exchanges. The involvement of individual chromosomes in exchanges was similar for densely and sparsely ionizing radiation, and no statistically significant evidence of a nonrandom involvement of specific chromosomes was detected.
Collapse
|
|
23 |
85 |
12
|
George K, Zafiropoulos GG, Murat Y, Hubertus S, Nisengard RJ. Clinical and microbiological status of osseointegrated implants. J Periodontol 1994; 65:766-70. [PMID: 7965553 DOI: 10.1902/jop.1994.65.8.766] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Peri-implantitis, an inflammatory response around implants, has a poorly defined etiology and pathogenesis. To better understand the role of specific microorganisms in this disease process, clinical and microbiological parameters were examined in 24 patients with 98 osseointegrated implants. Sites were evaluated for probing depth (PD), plaque/calculus index (PI), gingival bleeding index (GBI), mobility, and crevicular fluid flow rate (CFFR). Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, and Prevotella intermedia in subgingival plaque were identified by latex agglutination assays. Clinically, a statistically significant correlation (P < 0.001) was observed between probing depth and the length of time an implant was present. Mobility was also significantly greater (P < 0.001) in the maxillary than in the mandibular implants. Subgingival sites harboring one of the three microorganisms had significantly greater PD, GBI, and CFFR than non-colonized sites. Implants in partially edentulous patients more frequently were colonized with P. gingivalis/P. intermedia than edentulous patients. The incidence of these microorganisms also correlated with fixture longevity. Implants present for 3 to 4 years had a significantly greater frequency of test microorganisms than implants present for 1 to 2 years. These findings suggest that microbial pathogens associated with periodontitis occur more commonly around implants exhibiting gingival inflammation (GBI) and may contribute to peri-implantitis.
Collapse
|
|
31 |
79 |
13
|
George K, Durante M, Wu H, Willingham V, Badhwar G, Cucinotta FA. Chromosome aberrations in the blood lymphocytes of astronauts after space flight. Radiat Res 2001; 156:731-8. [PMID: 11741497 DOI: 10.1667/0033-7587(2001)156[0731:caitbl]2.0.co;2] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Cytogenetic analysis of the lymphocytes of astronauts provides a direct measurement of space radiation damage in vivo, which takes into account individual radiosensitivity and considers the influence of microgravity and other stress conditions. Chromosome exchanges were measured in the blood lymphocytes of eight crew members after their respective space missions, using fluorescence in situ hybridization (FISH) with chromosome painting probes. Significant increases in aberrations were observed after the long-duration missions. The in vivo dose was derived from the frequencies of translocations and total exchanges using calibration curves determined before flight, and the RBE was estimated by comparison with individually measured physical absorbed doses. The values for average RBE were compared to the average quality factor (Q) from direct measurements of the lineal energy spectra using a tissue-equivalent proportional counter (TEPC) and radiation transport codes. The ratio of aberrations identified as complex was slightly higher after flight, which is thought to be an indication of exposure to high-LET radiation. To determine whether the frequency of complex aberrations measured in metaphase spreads after exposure to high-LET radiation was influenced by a cell cycle delay, chromosome damage was analyzed in prematurely condensed chromosome samples collected from two crew members before and after a short-duration mission. The frequency of complex exchanges after flight was higher in prematurely condensed chromosomes than in metaphase cells for one crew member.
Collapse
|
|
24 |
76 |
14
|
George K, Wu H, Willingham V, Furusawa Y, Kawata T, Cucinotta FA. High- and low-LET induced chromosome damage in human lymphocytes: a time-course of aberrations in metaphase and interphase. Int J Radiat Biol 2001; 77:175-83. [PMID: 11236924 DOI: 10.1080/0955300001003760] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
PURPOSE To investigate how cell-cycle delays in human peripheral lymphocytes affect the expression of complex chromosome damage in metaphase following high- and low-LET radiation exposure. MATERIALS AND METHODS Whole blood was irradiated in vitro with a low and a high dose of 1 GeV u(-1) iron particles, 400MeV u(-1) neon particles or y-rays. Lymphocytes were cultured and metaphase cells were collected at different time points after 48-84h in culture. Interphase chromosomes were prematurely condensed using calyculin-A, either 48 or 72 h after exposure to iron particles or gamma-rays. Cells in first division were analysed using a combination of FISH whole-chromosome painting and DAPI/ Hoechst 33258 harlequin staining. RESULTS There was a delay in expression of chromosome damage in metaphase that was LET- and dose-dependant. This delay was mostly related to the late emergence of complex-type damage into metaphase. Yields of damage in PCC collected 48 h after irradiation with iron particles were similar to values obtained from cells undergoing mitosis after prolonged incubation. CONCLUSION The yield of high-LET radiation-induced complex chromosome damage could be underestimated when analysing metaphase cells collected at one time point after irradiation. Chemically induced PCC is a more accurate technique since problems with complicated cell-cycle delays are avoided.
Collapse
|
|
24 |
75 |
15
|
Noronha V, Dikshit R, Raut N, Joshi A, Pramesh CS, George K, Agarwal JP, Munshi A, Prabhash K. Epidemiology of lung cancer in India: focus on the differences between non-smokers and smokers: a single-centre experience. Indian J Cancer 2012; 49:74-81. [PMID: 22842172 DOI: 10.4103/0019-509x.98925] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
CONTEXT Lung cancer has varied epidemiology depending on the geographic region. Globally, there have been important changes in incidence trends amongst men and women, histology, and incidence in non-smokers. Indian epidemiological data on lung cancer is scarce. AIMS We set out to study the epidemiological patterns and clinical profile of lung cancer in India. MATERIALS AND METHODS We interviewed patients discussed in the thoracic oncology multidisciplinary meetings between 2008 and 2009. Demographic data, smoking history, place of residence, histology, stage at presentation, and treatment details were collected. Data was entered and analyzed in SPSS. RESULTS There were 489 patients, with a median age of 56 years, of which 255 (52%) were non-smokers and 234 (48%) were smokers. One hundred and thirty-three patients had consumed smokeless tobacco. The male-to-female ratio was 3.5:1. Sixty-nine patients (14.1%) were incorrectly diagnosed and treated with anti-tuberculosis treatment, which delayed the diagnosis of lung cancer by four months. Eight percent of patients had small-cell carcinoma; of the 92% patients with non-small-cell carcinoma (NSCLC), the most common histology was adenocarcinoma (43.8%), followed by squamous cell (26.2%), large cell (2.1%) and other (8.3%). Eighteen percent of patients were diagnosed by cytology, therefore were diagnosed as NSCLC, without further histologic subtyping. Most patients (43%) were in Stage III at presentation. Lung followed by bone were the common sites of metastases. The majority of the patients (49%) received palliative chemotherapy. Among definitive therapy, concurrent chemo-radiation (13%) was offered more frequently than surgery (6%). CONCLUSION Considerably higher numbers of Indian patients with lung cancer are non-smokers, compared to the West. The global trend of rise in adenocarcinoma is paralleled in India. Non-tobacco-related risk factors need further investigation.
Collapse
|
Journal Article |
13 |
74 |
16
|
Yang TC, George K, Johnson AS, Durante M, Fedorenko BS. Biodosimetry Results from Space Flight Mir-18. Radiat Res 1997. [DOI: 10.2307/3579712] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
|
28 |
70 |
17
|
Shave RE, Dawson E, Whyte G, George K, Ball D, Gaze DC, Collinson PO. Evidence of exercise-induced cardiac dysfunction and elevated cTnT in separate cohorts competing in an ultra-endurance mountain marathon race. Int J Sports Med 2002; 23:489-94. [PMID: 12402180 DOI: 10.1055/s-2002-35069] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Cardiac damage has recently been implicated in the aetiology of "exercise induced cardiac dysfunction". The humoral markers of cardiac damage that have been utilised to date are not sufficiently cardio-specific to investigate this hypothesis. The aim of the present study was to examine cardiac function following prolonged exercise, and investigate the contention of cardiac damage utilising a new highly cardio-specific marker. Thirty-seven competitors in the 2-day Lowe Alpine Mountain Marathon 2000 volunteered for the study. Competitors were sub-divided into 2 groups. Group 1 (n = 11) were examined using echocardiography pre and post the event, examining left ventricular diastolic and systolic function. Group 2 (n = 26) had venous blood samples drawn prior to the event and immediately following day-1 and day-2. Blood samples were analysed for total creatine kinase activity (CK), creatine kinase isoenzyme MB(mass) (CK-MB(mass)), and cardiac troponin T. Echocardiographic results indicated left ventricular diastolic and systolic dysfunction following cessation of exercise. CK and CK-MB(mass) were both elevated following day-1, and immediately following race completion. Cardiac troponin T levels were below the 99th percentile (0.01 microg/L) in all subjects prior to the event, following day-1 cTnT was elevated above 0.01 microg/L in 13 subjects, but returned to below 0.01 microg/L following race completion on day-2. However, no individual data reached clinical cut-off levels for acute myocardial infarction (AMI) (0.1 microg/L). Two days arduous exercise over mountainous terrain resulted in cardiac dysfunction, and significant skeletal muscular degradation. The elevation of cTnT above the 99th percentile in the present study is suggestive of minimal myocardial damage. The clinical significance of and exact mechanism responsible for such damage remains to be elucidated.
Collapse
|
|
23 |
68 |
18
|
Carmel R, Vasireddy H, Aurangzeb I, George K. High serum cobalamin levels in the clinical setting--clinical associations and holo-transcobalamin changes. CLINICAL AND LABORATORY HAEMATOLOGY 2001; 23:365-71. [PMID: 11843883 DOI: 10.1046/j.1365-2257.2001.00134.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Whereas low cobalamin levels have been studied intensively, systematic information about high levels, especially in the clinical setting, is scarce. Therefore, a prospective comparison was done of 60 patients with high cobalamin levels and 75 with normal levels obtained by a hospital laboratory over a 2.5 month period. Associations with clinical disorders and laboratory test results were examined. Transcobalamin (TC) I and II were measured, especially the holoproteins (TC carrying circulating endogenous cobalamin) which were fractionated with microfine silica powder. High cobalamin levels (> 664 pmol/l; > 900 ng/l) occurred in 94 of 670 consecutive clinically requested assays (14%). The only independently significant associations with a high cobalamin level were renal failure among the clinical disorders (P=0.01), elevated serum creatinine (P=0.0001) and diminished albumin (P=0.0002) levels among laboratory tests. Both holo-TC I and holo-TC II levels were increased in renal failure (P=0.0001) but the increase was relatively greater in holo-TC II. The results indicate that high cobalamin levels are more frequent than low ones in clinical practice and appear to be associated often with renal failure. The elevation of both holo-TC II and holo-TC I suggests that several mechanisms are operative. The accumulation of holo-TC II suggests that cellular uptake of cobalamin by the abundant TC II receptors in the kidney may be impaired. The much better known association of high cobalamin levels with leucocytic disorders is rare, and no association was seen with liver disease.
Collapse
|
Comparative Study |
24 |
67 |
19
|
Durante M, Furusawa Y, George K, Gialanella G, Greco O, Grossi G, Matsufuji N, Pugliese M, Yang TC. Rejoining and misrejoining of radiation-induced chromatin breaks. IV. Charged particles. Radiat Res 1998. [PMID: 9588355 DOI: 10.2307/3579784] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
We have recently reported the kinetics of chromosome rejoining and exchange formation in human lymphocytes exposed to gamma rays using the techniques of fluorescence in situ hybridization (FISH) and premature chromosome condensation (PCC). In this paper, we have extended previous measurements to cells exposed to charged particles. Our goal was to determine differences in chromatin break rejoining and misrejoining after exposure to low- and high-linear energy transfer (LET) radiation. Cells were irradiated with hydrogen, neon, carbon or iron ions in the LET range 0.3-140 keV/microm and were incubated at 37 degrees C for various times after exposure. Little difference was observed in the yield of early prematurely condensed chromosome breaks for the different ions. The kinetics of break rejoining was exponential for all ions and had similar time constants, but the residual level of unrejoined breaks after prolonged incubation was higher for high-LET radiation. The kinetics of exchange formation was also similar for the different ions, but the yield of chromosome interchanges measured soon after exposure was higher for high-LET particles, suggesting that a higher fraction of DNA breaks are misrejoined quickly. On the other hand, the rate of formation of complete exchanges was slightly lower for densely ionizing radiation. The ratios between the yields of different types of aberrations observed at 10 h postirradiation in prematurely condensed chromosome preparations were dependent on LET. We found significant differences between the yields of aberrations measured in interphase (after repair) and metaphase for densely ionizing radiation. This difference might be caused by prolonged mitotic delay and/or interphase death. Overall, the results point out significant differences between low- and high-LET radiation for the formation of chromosome aberrations.
Collapse
|
Research Support, U.S. Gov't, Non-P.H.S. |
27 |
67 |
20
|
Prasad J, Abraham VJ, Minz S, Abraham S, Joseph A, Muliyil JP, George K, Jacob KS. Rates and factors associated with suicide in Kaniyambadi Block, Tamil Nadu, South India, 2000-2002. Int J Soc Psychiatry 2006; 52:65-71. [PMID: 16463596 DOI: 10.1177/0020764006061253] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Inefficient civil registration systems, non-report of deaths, variable standards in certifying death and the legal and social consequences of suicide are major obstacles to investigating suicide in the developing world. OBJECTIVE The aim of this study was to prospectively determine the suicide rate in Kaniyambadi Block, Tamil Nadu, South India, for the years 2000-2002 using verbal autopsies. METHOD The setting for the study was a comprehensive community health programme in a development block in rural South India. The main outcome measure was death by suicide, diagnosed by a detailed verbal autopsy and census, and birth and death data to identify the population base. RESULTS The average suicide rate was 92.1 per 100,000. The ratio of male to female suicides was 1:0.66. The age-specific suicide rate for men increased with age while that for women showed two peaks: 15-24 years and over 65 years of age. Hanging (49%) and poisoning with organo-phosphorus compounds (40.5%) were the commonest methods of committing suicide. Acute and/or chronic stress was elicited for nearly all subjects. More men suffered from chronic stress while more women had acute precipitating events (chi2 = 4.58; p < 0.04). People less than 44 years of age had more acute precipitating events before death while older subjects reported more chronic stress (chi2 = 17.38; p < 0.001). CONCLUSION The study replicates findings of an earlier study from the area. The suicide rate documented in this study is very high and is a major public health concern. There is a need for sentinel centres in India and in developing countries to monitor trends and to develop innovative strategies to reduce deaths by suicide.
Collapse
|
|
19 |
66 |
21
|
Serrano-Ostáriz E, Terreros-Blanco JL, Legaz-Arrese A, George K, Shave R, Bocos-Terraz P, Izquierdo-Álvarez S, Bancalero JL, Echavarri JM, Quilez J, Aragonés MT, Carranza-García LE. The impact of exercise duration and intensity on the release of cardiac biomarkers. Scand J Med Sci Sports 2011; 21:244-9. [DOI: 10.1111/j.1600-0838.2009.01042.x] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
|
14 |
65 |
22
|
Hopkins ND, Stratton G, Tinken TM, McWhannell N, Ridgers ND, Graves LEF, George K, Cable NT, Green DJ. Relationships between measures of fitness, physical activity, body composition and vascular function in children. Atherosclerosis 2008; 204:244-9. [PMID: 18930229 DOI: 10.1016/j.atherosclerosis.2008.09.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Revised: 09/02/2008] [Accepted: 09/03/2008] [Indexed: 11/17/2022]
Abstract
BACKGROUND The prevalence of obesity and physical inactivity in Western countries has increased rapidly. Both are modifiable risk factors for cardiovascular disease. Atherosclerosis begins in childhood and endothelial dysfunction is its earliest detectable manifestation. METHODS We assessed flow-mediated dilation (FMD) in 129 children (75 female; 10.3+0.3 yrs; 54 male; 10.4; 0.3 yrs). FMD was normalised for differences in the eliciting shear rate stimulus between subjects (SR(AUC)). Fitness was assessed as peak oxygen uptake during an incremental treadmill exercise test (V O(2)peak). Body composition was measured using a dual-energy X-ray absorptiometry (DEXA) scan. Physical activity (PA) was assessed using Actigraph accelerometers. The cohort was split into tertiles according to FMD% and also FMD% corrected for SR(AUC) to gain insight into the determinants of vascular function. RESULTS Across the cohort, significant correlations were observed between FMD%/SR(AUC) and DEXA percentage fat (r=-0.23, p=0.009) and percentage lean mass (r=0.21, p=0.008), and also with PA performed at moderate-to-high intensity (r=0.363, p=0.001). For children in the lowest FMD%/SR(AUC) tertile, a stronger relationship with all PA measures was observed, particularly with high intensity PA (r=0.572, P=0.003). Regression analysis revealed that high intensity PA was the only predictor of impaired FMD%/SR(AUC). CONCLUSIONS These data suggest that traditional risk factors for CHD in adult populations impact upon vascular function in young people. Furthermore, it appears that individuals with impaired FMD may benefit from performing high intensity PA, whereas no relationships exist between FMD and lower intensities of PA or between PA and FMD in those subjects who possess preserved vascular function a priori.
Collapse
|
Journal Article |
17 |
63 |
23
|
Nie J, Tong TK, George K, Fu FH, Lin H, Shi Q. Resting and post-exercise serum biomarkers of cardiac and skeletal muscle damage in adolescent runners. Scand J Med Sci Sports 2010; 21:625-9. [DOI: 10.1111/j.1600-0838.2010.01096.x] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
|
15 |
63 |
24
|
Whyte GP, George K, Sharma S, Firoozi S, Stephens N, Senior R, McKenna WJ. The upper limit of physiological cardiac hypertrophy in elite male and female athletes: the British experience. Eur J Appl Physiol 2004; 92:592-7. [PMID: 15054661 DOI: 10.1007/s00421-004-1052-2] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/11/2004] [Indexed: 10/26/2022]
Abstract
Establishment of upper normal limits of physiological hypertrophy in response to physical training is important in the differentiation of physiological and pathological left ventricular hypertrophy. The genetic differences that exist in the adaptive response of the heart to physical training and the causes of sudden cardiac death in young athletes indicate the need for population-specific normal values. Between September 1994 and December 2001, 442 (306 male, 136 female) elite British athletes from 13 sports were profiled. Standard two-dimensional guided M-mode and Doppler echocardiography were employed to evaluate left ventricular morphology and function. Eleven (2.5%) athletes, competing in a range of sports including judo, skiing, cycling, triathlon, rugby and tennis, presented with a wall thickness >13 mm, commensurate with a diagnosis of hypertrophic cardiomyopathy. Eighteen (5.8%) male athletes presented with a left ventricular internal diameter during diastole (LVIDd) >60 mm, with an upper limit of 65 mm. Of the 136 female athletes, none where found to have a maximum wall thickness >11 mm. Left ventricular internal diameter was <60 mm in all female athletes. Systolic and diastolic function were within normal limits for all athletes. Upper normal limits for left ventricular wall thickness and LVIDd are 14 mm and 65 mm for elite male British athletes, and 11 mm and 60 mm for elite female British athletes. Values in excess of these should be viewed with caution and should prompt further investigation to identify the underlying mechanism.
Collapse
|
|
21 |
60 |
25
|
Davison TE, McCabe MP, Mellor D, Ski C, George K, Moore KA. The prevalence and recognition of major depression among low-level aged care residents with and without cognitive impairment. Aging Ment Health 2007; 11:82-8. [PMID: 17164162 DOI: 10.1080/13607860600736109] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Previous research has demonstrated a high level of depression in nursing homes. The current study was designed to determine the prevalence of depression, using a structured diagnostic interview, among older people with and without mild-moderate cognitive impairment residing in low-level care facilities. The results demonstrated that, consistent with previous research in nursing homes, 16.9% of older people were diagnosed with major depressive disorder. Less than half of these cases had been detected or treated. Individuals with moderate cognitive impairment were more likely to be depressed, but cognitive impairment did not appear to act as a strong impediment to the detection of depression by general practitioners. A low awareness of their use of antidepressant medications was demonstrated among older people prescribed this treatment, including those with normal cognitive function. Reasons for the poor recognition of depression among older people are discussed.
Collapse
|
|
18 |
54 |