Exacerbation of thrombotic events by diesel exhaust particle in mouse model of hypertension

Several epidemiological studies have shown that acute exposure to particulate air pollution is associated with increases in cardiovascular morbidity and mortality, and that these effects are especially exacerbated among individuals with pre-existing compromised cardiovascular function such as hypertension. This study was undertaken to determine the cardiovascular effect of diesel exhaust on TO mice made hypertensive by implanting osmotic minipump infusing angiotensin II or vehicle (control). On day 13, the animals were intratracheally instilled with either DEP (15 μg/mouse) or saline. 24 h later, pulmonary exposure to DEP had significantly decreased the systolic blood pressure (SBP) in hypertensive (HT) mice (P<0.01), but not in normotensive (NT) mice. The number of leukocytes and red blood cells, and the plasma interleukin 6 concentration in plasma, however, were not affected in any of the animals. The PaO? was decreased, and PaCO? increased in DEP-treated HT mice compared to NT mice treated with DEP (P<0.05). The number of circulating platelets was significantly increased in DEP-treated HT versus saline-treated HT and DEP-treated NT mice. Moreover, in NT mice, DEP exposure induced a prothrombotic effect in pial arterioles compared with saline-treated NT mice (P<0.05). Interestingly, in DEP-treated HT mice, the prothrombotic events were significantly aggravated compared with saline-treated HT and DEP-treated NT mice. The direct addition of DEP (0.1-1 μg/ml) to untreated mouse blood significantly induced in vitro platelet aggregation in a dose-dependent fashion, and these effects were more pronounced in blood of HT mice. In vitro exposure to DEP (0.25-1 μg/ml) led to activated intravascular coagulation, an effect that was confirmed by a shortening of both the activated partial thromboplastin time (aPTT) and the prothrombin time (PT). The effect of DEP on aPTT was potentiated in the plasma of HT mice. It can be concluded that the thrombotic events caused by DEP are exacerbated by hypertension in mice. Our findings, therefore, provide a possible plausible explanation for the cardiovascular morbidity and mortality accompanying urban air pollution.     

Optic axis determination by fibre-based polarization-sensitive swept-source optical coherence tomography

We describe a fibre-based variable-incidence angle (VIA) polarization-sensitive swept-source optical coherence tomography (PS-SS-OCT) system to determine the 3D optical axis of birefringent biological tissues. Single-plane VIA-PS-OCT is also explored which requires measurement of the absolute fast-axis orientation. A state-of-the-art PS-SS-OCT system with some improvements both in hardware and software was used to determine the apparent optical birefringence of equine tendon for a number of different illumination directions. Polar and azimuthal angles of cut equine tendon were produced by the VIA method and compared with the nominal values. A quarter waveplate (QWP) and equine tendon were used as test targets to validate the fast-axis measurements using the system. Polar and azimuthal angles of cut equine tendon broadly agreed with the expected values within about 8% of the nominal values. A theoretical and experimental analysis of the effect of the sample arm fibre on determination of optical axis orientation using a proposed definition based on the orientation of the eigenpolarization ellipse experimentally confirms that this algorithm only works correctly for special settings of the sample arm fibre. A proposed algorithm based on the angle between Stokes vectors on the Poincaré sphere is confirmed to work for all settings of the sample arm fibre. A calibration procedure is proposed to remove the sign ambiguity of the measured orientation and was confirmed experimentally by using the QWP.     

A diabetes risk score helps identify metabolic syndrome and cardiovascular risk in Indians - the Chennai Urban Rural Epidemiology Study (CURES-38)

AIMS: The aims of the study were to compare the recently evolved Indian Diabetes Risk Score (IDRS), in subjects with different grades of glucose intolerance and to evaluate its usefulness as an indicator of cardiovascular risk in Asian Indians, a high risk group for diabetes and coronary artery disease (CAD). METHODS: The data for the present study were obtained from the Phase 3 (n = 2350, response rate: 90.4%) of the Chennai Urban Rural Epidemiology Study, a population-based study done in Chennai, the largest city in southern India. IDRS was developed based on multiple logistic regression analysis using four simple parameters namely age, abdominal obesity, family history of type 2 diabetes and physical activity. In all subjects, family history of diabetes was obtained, and details on physical activity were assessed using a validated questionnaire. Subjects with an IDRS of <30 was categorized as low risk, 30-50 as medium risk and those with > or =60 as high risk for diabetes. Biochemical and anthropometric measurements were done using standardized procedures. Minnesota coding was used to grade 12-lead electrocardiogram. RESULTS: The mean IDRS increased significantly with worsening glucose intolerance [normal glucose tolerance (NGT) subjects: 48 +/- 17, impaired glucose tolerance (IGT): 57 +/- 16, newly diagnosed diabetics (NDD): 61 +/- 15 and known diabetics (KD): 68 +/- 12; p for trend <0.001]. Among NGT group, the prevalence of cardiovascular risk factors increased progressively in low-, medium- to high-risk score groups; hypertension: 9.4, 22.1 and 38.2% (p for trend: < 0.001), hypertriglyceridemia: 8.8, 19.9 and 25.3% (p for trend: < 0.001), hypercholesterolemia: 7.2, 20.3 and 34.9% (p for trend: < 0.001) and metabolic syndrome: 1.8, 14.6 and 30.3% (p for trend: < 0.001), respectively. The prevalence of CAD was also significantly higher in individuals with high risk compared with those with low risk (p = 0.030) and the medium risk (p = 0.050) in the NGT group. CONCLUSIONS: The results suggest that in Asian Indians, (i) the diabetes risk score increases with increasing glucose intolerance, and (ii) it can serve as an effective indicator of metabolic syndrome and cardiovascular risk even among subjects with NGT.     

Oxidized low-density lipoprotein and intimal medial thickness in subjects with glucose intolerance: the Chennai Urban Rural Epidemiology Study-25

The aim of the present study was to assess the association of oxidized low-density lipoprotein (OX-LDL) with carotid intimal medial thickness (IMT) in different grades of glucose intolerance in Asian Indians. Three groups were recruited from the Chennai Urban Rural Epidemiology Study, a population-based study: group 1, normal glucose tolerance (NGT) (n = 175); group 2, impaired glucose tolerance (IGT) (n = 175); and group 3, type 2 diabetes mellitus (n = 175). Oxidized LDL (enzyme-linked immunosorbent assay) and carotid IMT (high-resolution B-mode ultrasonography) were assessed. Subjects with diabetes had higher IMT values (0.85 +/- 0.30 mm) compared with those who have IGT (0.79 +/- 0.16 mm, P < .05) and NGT (0.71 +/- 0.12 mm, P < .001). Subjects with diabetes (40.1 +/- 13.1 U/L) and IGT (34.3 +/- 12.8 U/L) had significantly higher mean OX-LDL values compared with the NGT group (26.2 +/- 16.6 U/L, P < .001). Oxidized LDL showed a correlation with IMT (total population: r = 0.294, P < .001; subjects with NGT: r = 0.444, P < .001; and subjects with IGT: r = 0.481, P < .001). In multiple linear regression analysis, OX-LDL showed a strong association with IMT (beta = .005, P < .001), even after adjusting for age, sex (beta = .003, P < .001), and glucose intolerance (beta = .002, P < .001). In conclusion, OX-LDL levels increase with increasing glucose intolerance. Oxidized LDL is associated with carotid IMT and this is independent of age, sex, and glucose intolerance status.     

Serum visfatin in relation to visceral fat, obesity, and type 2 diabetes mellitus in Asian Indians

To investigate the role of the novel adipokine visfatin in type 2 diabetes mellitus and obesity and to examine its association with visceral and subcutaneous fat in Asian Indians, who have increased susceptibility to type 2 diabetes mellitus and coronary artery disease, 150 subjects with type 2 diabetes mellitus (75 men, 75 women) and 150 age- and sex-matched subjects with normal glucose tolerance were recruited from the Chennai Urban Rural Epidemiology Study, a population-based study done in Chennai, southern India. Anthropometric and biochemical measurements were done by using standardized techniques. Fasting serum visfatin levels were measured by enzyme-linked immunosorbent assay. Visceral and subcutaneous fat were measured by computerized tomography in a subset of 130 individuals. Serum visfatin levels were significantly higher in diabetic subjects compared with nondiabetic subjects (11.4+/-5.9 vs 9.8+/-4.3 ng/mL, P=.008). However, this association was lost when adjusted for body mass index (odds ratio [OR], 1.048; 95% confidence interval [CI], 0.997-1.101; P=.067) or waist circumference (OR, 1.050; 95% CI, 0.999-1.104; P=.057). Serum visfatin showed a significant association with obesity even after adjusting for age, sex, and type 2 diabetes mellitus (OR, 1.060; 95% CI, 1.005-1.119; P=.033). Visceral fat, but not subcutaneous fat, was significantly associated with serum visfatin levels even after adjusting for age, sex, type 2 diabetes mellitus, and body mass index (P=.002). In Asian Indians, serum visfatin levels are associated with obesity and visceral fat but not with subcutaneous fat. Although visfatin levels are increased in type 2 diabetes mellitus, the association seems to be primarily through obesity.     

Infused therapy and survival in older patients diagnosed with metastatic breast cancer who received trastuzumab

We used Surveillance, Epidemiology, and End Results-Medicare data (2000-2006) to describe treatment and survival in women diagnosed with metastatic breast cancer (MBC) who received trastuzumab. There were 610 patients with a mean age of 74 years. Overall, 32% received trastuzumab alone and 47% received trastuzumab plus a taxane. In multivariate analysis, trastuzumab plus chemotherapy was associated with a lower adjusted cancer mortality rate (Hazard Ratio [HR] 0.54; 95% Confidence Interval [CI] 0.39-0.74; p < .001) than trastuzumab alone among patients who received trastuzumab as part of first-line therapy. Adding chemotherapy to first-line trastuzumab for metastatic breast cancer is associated with improved cancer survival.