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Biomedical subjects

A Shin

Publications and source records attributed to A Shin.

At least 19 recordsLinked to original sources

Long-term exposure to particulate matter and all-cause and cause-specific mortality in an analysis of multiple Asian cohorts.

BACKGROUND: Exposure to ambient air pollution is associated with a significant number of deaths. Much of the evidence associating air pollution with adverse effects is from North American and Europe, partially due to incomplete data in other regions limiting location specific examinations. The aim of the current paper is to leverage satellite derived air quality data to examine the relationship between ambient particulate matter and all-cause and cause-specific mortality in Asia. METHODS: Six cohorts from the Asia Cohort Consortium provided residential information for participants, recruited between 1991 and 2008, across six countries (Bangladesh, India, Iran, Japan, South Korea, and Taiwan). Ambient particulate material (PM2·5) levels for the year of enrolment (or 1998 if enrolled earlier) were assigned utilizing satellite and sensor-based maps. Cox proportional models were used to examine the association between ambient air pollution and all-cause and cause-specific mortality (all cancer, lung cancer, cardiovascular and lung disease). Models were additionally adjusted for urbanicity (representing urban and built characteristics) and stratified by smoking status in secondary analyses. Country-specific findings were pooled via random-effects meta-analysis. FINDINGS: More than 300,000 participants across six cohorts were included, representing more than 4-million-person years. A positive relationship was observed between a 5 µg/m (Dockery et al., 1993) increase in PM2·5 and cardiovascular mortality (HR: 1·06, 95 % CI: 0.99, 1·13). The additional adjustment for urbanicity resulted in increased associations between PM2.5 and mortality outcomes, including all-cause mortality (1·04, 95 % CI: 0·97, 1·11). Results were generally similar regardless of whether one was a current, never, or ex-smoker. INTERPRETATION: Using satellite and remote sensing technology we showed that associations between PM2.5 and all-cause and cause-specific Hazard Ratios estimated are similar to those reported for U.S. and European cohorts. FUNDING: This project was supported by the Health Effects Institute. Grant number #4963-RFA/18-5. Specific funding support for individual cohorts is described in the Acknowledgements.

Humans↗

Genetic polymorphisms of OPG, RANK, and ESR1 and bone mineral density in Korean postmenopausal women.

To evaluate the effects of genetic polymorphisms of OPG, RANK, and ESR1, which regulate osteoclastogenesis, on bone mineral density (BMD), a cross-sectional study was conducted in 650 Korean postmenopausal women. BMDs of the distal radius and the calcaneus were measured by dual energy X-ray absorptiometry (DXA). Genetic polymorphisms of OPG 163 A > G, 1181 G > C; RANK 421 C > T, 575 T > C; and ESR1 1335 C > T, 2142 G > A were determined by matrix-assisted laser desorption/ionization-time of flight (MALDI-ToF) mass spectrometry. The differences between the BMDs of the genotypes of OPG, RANK, and ESR1 were analyzed by multiple linear regression model adjusted for age and body mass index. Women with the OPG 1181 CC genotype had higher BMDs at the distal radius (7%) and calcaneus (10%) than those with the GG genotype; and these differences were statistically significant (P = 0.001 and P = 0.007, respectively). A significant association was also observed between RANK 575 T > C and calcaneus BMD (P for trend = 0.017). No significant association was observed between BMDs and the polymorphisms of ESR1. The association between OPG 1181 G > C and BMD was profound in subjects with the RANK 575 TT or ESR1 2142 GG genotypes; women with OPG 1181 CC had higher BMDs at the distal radius (11%) and calcaneus (11%) than those with OPG 1181 GG only in women with RANK 575 TT genotype (P = 0.002 and P = 0.021, respectively). These results suggest that OPG genetic polymorphisms, especially with the RANK 575 TT or ESR1 2142 GG genotypes, are related to low BMD in postmenopausal Korean women.

Adult↗

Don't ask, don't tell: patterns of HIV disclosure among HIV positive men who have sex with men with recent STI practising high risk behaviour in Los Angeles and Seattle.

OBJECTIVES: A high incidence of HIV continues among men who have sex with men (MSM) in industrialised nations and research indicates many MSM do not disclose their HIV status to sex partners. Themes as to why MSM attending sexually transmitted infection (STI) clinics in Los Angeles and Seattle do and do not disclose their HIV status are identified. METHODS: 55 HIV positive MSM (24 in Seattle, 31 in Los Angeles) reporting recent STI or unprotected anal intercourse with a serostatus negative or unknown partner from STI clinics underwent in-depth interviews about their disclosure practices that were tape recorded, transcribed verbatim, coded, and content analysed. RESULTS: HIV disclosure themes fell into a continuum from unlikely to likely. Themes for "unlikely to disclose" were HIV is "nobody's business," being in denial, having a low viral load, fear of rejection, "it's just sex," using drugs, and sex in public places. Themes for "possible disclosure" were type of sex practised and partners asking/disclosing first. Themes for "likely to disclose" were feelings for partner, feeling responsible for partner's health, and fearing arrest. Many reported non-verbal disclosure methods. Some thought partners should ask for HIV status; many assumed if not asked then their partner must be positive. CONCLUSIONS: HIV positive MSM's decision to disclose their HIV status to sex partners is complex, and is influenced by a sense of responsibility to partners, acceptance of being HIV positive, the perceived transmission risk, and the context and meaning of sex. Efforts to promote disclosure will need to address these complex issues.

Adult↗

Genetic polymorphisms of cytochrome P450 19 and 1B1, alcohol use, and breast cancer risk in Korean women.

A case-control study was performed to assess the potential influence of CYP19 Arg(264)Cys and CYP1B1 Leu(432)Val polymorphisms on breast cancer risk in a series of Korean breast cancer patients and controls. The results suggest that the CYP19 Arg(264)Cys polymorphism modifies breast cancer risk (OR=1.5, 95% CI=1.1-2.2), especially in association with alcohol consumption (P for interaction=0.04), whereas the CYP1B1 Leu(432)Val polymorphism appears to play no role here.

Adult↗

Leukocyte activation in the peripheral blood of patients with cirrhosis of the liver and SIRS. Correlation with serum interleukin-6 levels and organ dysfunction.

OBJECTIVE: Leukocyte adhesion plays an important role in inflammation. Adhesion molecules such as CD11b on polymorphonuclear neutrophil leukocytes (PMNs) up-regulate in response to tumor necrosis factor-alpha, interleukin-8 (IL-8), and other mediators that are involved in systemic inflammatory response syndrome (SIRS). This study examined the behavior of CD11b and other membrane molecules in SIRS in relation to serum cytokines and the severity of illness. DESIGN: Survey study. SETTING: Liver transplantation intensive care unit at a tertiary care center. PATIENTS: A consecutive sample of 22 patients admitted to the liver transplantation intensive care unit for complications related to cirrhosis of the liver in the absence of other disease. Sixteen of the patients developed SIRS and multiple organ dysfunction syndrome with suspected bacterial infections. Seven control subjects were also studied. MAIN OUTCOME MEASURES: Modified Goris organ failure score and Acute Physiology and Chronic Health Evaluation II score. RESULTS: Mean serum IL-6 levels, but not IL-1 beta or tumor necrosis factor-alpha levels, correlated with organ failure (r = 0.79, P < .001). Leukocyte cell-surface markers fluctuated from day to day. The mean of several values was more stable. Mean CD11b and CD35 on PMNs correlated with serum IL-6 level (r = 0.75, P < .001, and r = 0.77, P < .005, respectively). Up-regulation of both CD11b and CD35 display on PMNs correlated with organ failure (r = 0.74, P < .001, and r = 0.71, P < .01, respectively). Polymorphonuclear neutrophil leukocyte L-selectin, CD31, and CD16 were simultaneously decreased, consistent with PMN activation. Monocytes appeared to be activated, but the pattern of surface molecule display was different. CONCLUSIONS: In human SIRS, the circulating monocyte and PMN pools undergo alterations suggestive of leukocyte activation, including up-regulation of PMN CD11b in correlation with the serum IL-6 level and severity of organ dysfunction.

Adult↗

Multiple change in E2F function and regulation occur upon muscle differentiation.

We have examined regulation of the E2F transcription factor during differentiation of muscle cells. E2F regulates many genes involved in growth control and is also the target of regulation by diverse cellular signals, including the RB family of growth suppressors (e.g., the retinoblastoma protein [RB], p107, and p130). The following aspects of E2F function and regulation during muscle differentiation were investigated: (i) protein-protein interactions, (ii) protein levels, (iii) phosphorylation of the E2F protein, and (iv) transcriptional activity. A distinct E2F complex was present in differentiated cells but not in undifferentiated cells. The p130 protein was a prominent component of the E2F complex associated with differentiation. In contrast, in undifferentiated cells, the p107 protein was the prominent component in one of three E2F complexes. In addition, use of a differentiation-defective muscle line provided genetic and biochemical evidence that quiescence and differentiation are separable events. Exclusive formation of the E2F-p130 complex did not occur in this differentiation-defective line; however, E2F complexes diagnostic of quiescence were readily apparent. Thus, sole formation of the E2F-p130 complex is a necessary event in terminal differentiation. Other changes in E2F function and regulation upon differentiation include decreased phosphorylation and increased repression by E2F. These observations suggest that the regulation of E2F function during terminal differentiation may proceed through differential interaction within the RB family and/or phosphorylation.

Carrier Proteins↗

Venous thromboembolism in patients undergoing rehabilitation for stroke.

OBJECTIVE: To determine the incidence of venous thromboembolism during rehabilitation for stroke and to identify factors that alter its risk. DESIGN: Cohort. SETTING: Tertiary care stroke rehabilitation program. PATIENTS: 102 consecutive patients undergoing rehabilitation for stroke. INTERVENTIONS: Impedance plethysmography (IPG) as routine screening and in patients with symptoms of deep venous thrombosis (DVT). MAIN OUTCOME MEASURES: DVT, pulmonary embolism (PE), death from PE. RESULTS: Venous thromboembolism was documented in 11 patients (11%) an average of 60 days after stroke onset (range 14-138 days); 2 patients (2%) died from PE. DVT was found on routine IPG screening in six patients and verified by IPG in two clinically symptomatic patients. The odds of developing venous thromboembolism was 17.6 (95% confidence interval: 2.2-143.5) in patients who were bedridden or wheelchair-bound at the time of admission. CONCLUSIONS: The incidence of venous thromboembolism is high and greatest in bedridden or wheelchair-bound patients undergoing stroke rehabilitation; randomized trials evaluating the safety and efficacy of screening and/or prophylaxis in such patients are required.

Aged↗

Detection of previous proximal venous thrombosis with Doppler ultrasonography and photoplethysmography.

To evaluate the reliability of two noninvasive tests, the photoplethysmograph (PPG) and venous Doppler ultrasound, in determining the presence or absence of previous proximal deep vein thrombosis (DVT), we performed a blinded retrospective cohort study of patients with objectively confirmed (DVT+) or refuted (DVT-) previous episodes of suspected DVT. Twenty-nine of 33 DVT+ patients had abnormal PPG and/or reflux by venous Doppler ultrasound, whereas 39 of 49 DVT- patients had normal PPG and no Doppler reflux (sensitivity, 88%; specificity, 80%). Of 33 DVT+ patients, 20 had abnormal Doppler results (sensitivity, 61%), in contrast to 46 of 49 DVT- patients with normal results (specificity, 94%). Moreover, 23 of 33 DVT+ patients showed abnormal PPG results (sensitivity, 70%), whereas 40 of 49 DVT- patients had normal PPG (specificity, 82%). Based on our findings, the presence of Doppler reflux is specific for previous proximal DVT, whereas a combination of normal PPG and Doppler ultrasound is reliable for excluding previous proximal DVT. Abnormal PPG with normal Doppler ultrasound does not reliably predict the presence or absence of previous DVT. However, this occurred in only 16 of 82 patients. Therefore, the combination of PPG and venous Doppler ultrasound can reliably predict the presence or absence of previous proximal DVT in most patients.

Female↗

Electrical coupling and pacemaker activity in colonic smooth muscle.

The effect of heptanol on electrical coupling between submucosal circular muscle cells of the dog colon and consequences for slow-wave activity were investigated. Electrotonic potentials showed exponential decay giving a length constant of 2.6 +/- 0.5 mm and a time constant of 157 +/- 48 ms. Heptanol reversibly abolished electrotonic current spread, and subsequently no slow-wave activity was recorded. The length constant decreased to less than 0.2 mm. The input resistance increased from 3 to 36 M omega, suggesting a change from tissue syncytium to electrically isolated cells. D600 (5 X 10(-6) M) also abolished slow wave activity but had opposite effects on electrotonic current spread. The data are consistent with the hypothesis that heptanol reversibly inhibits intercellular coupling, resulting in loss of spread of extracellularly applied current, uncoupling of cells, and loss of pacemaker activity. Regulation of intercellular communication may be important in the control of intestinal motility.

Alcohols↗