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The hypothesis that addition of mental stress to physical exercise would modify the circulation response to stress and improve noninvasive detection of myocardial ischemia was tested in a randomized, crossover radionuclide angiocardiographic study. Compared with physical exercise or mental stress alone, combined stress led to higher heart rates and rate-pressure products in early stress stages, to more pronounced symptoms, and to a better discrimination of subjects with and without coronary artery disease by radionuclide angiography. [ABSTRACT FROM AUTHOR]

Background: Although myocardial perfusion imaging (MPI) is widely used in patients with coronary artery disease, few data are available concerning the relationship between myocardial scar and ischemia and arrhythmic potential.Patients and Methods: One hundred forty-four patients with chronic coronary artery disease who underwent electrophysiological studies (EPS) and MPI within 3 months constituted the study population. By history, 26% of the patients had sustained ventricular tachycardia (VT), 21% had cardiac arrest with ventricular fibrillation, and 53% had nonsustained VT. Eighty-five percent had previous myocardial infarction. Standard EPS protocol with up to three extra stimuli was used. Patients with a response of sustained monomorphic VT were defined as inducible. Quantitative MPI was used to define stress perfusion defect size and reversibility. The relations of ischemia (reversible defect) and scar (fixed defect) to inducibility on EPS were assessed by univariate analysis. Multivariate analysis was used to compare MPI results with known clinical predictors of inducibility.Results: Fifty-two percent of the patients had inducible monomorphic sustained VT. MPI showed scar alone in 33%, scar with additional ischemia in 53%, ischemia alone in 8%, and no abnormality in 6%. No relation was found between the scintigraphic presence or size of ischemia and the likelihood of inducibility or to the type of arrhythmia history. In contrast, scar size was related to the result of EPS; inducible patients had significantly larger resting defect integrals (27 +/- 23 vs 14 +/- 15) than noninducible patients (p < 0.0001). Of 37 patients with very large defects (defect integral > 30), 78% were inducible, whereas only 30% of 33 patients with defect integrals < 5 were inducible. On multivariate analysis resting defect integral was an independent predictor of inducibility. In comparison with left ventricular ejection fraction (available in 122 patients), perfusion defect size was a better independent predictor of sustained VT on EPS.Conclusion: The presence or size of potentially ischemic myocardium does not appear to be related to the inducibility during EPS. Size of scar as quantified by myocardial perfusion imaging correlates well and better than the global left ventricular function with inducibility of sustained VT on EPS. [ABSTRACT FROM AUTHOR]

Background: Many poor in developing countries have turned to artisanal small-scale gold mining (ASGM) in an attempt to improve their situation. However, the mercury used to extract gold from ore is discharged in vaporized form into the environment, where it poses a hazard for human health., Methods: As part of an environmental epidemiological study in Mongolia-to evaluate the burden of environmental mercury contamination-urine, blood and hair samples were collected from residents of areas with or without mercury contamination. A total of 200 blood, urine and hair samples were analyzed for mercury and divided into three subgroups according to mercury content: (1) occupational exposure (high/medium); (2) environmental exposure (low); and (3) no exposure. Internal mercury distributions of the subgroups were compared using the Kruskal-Wallis and Mann-Whitney U-test. The Chi-square test and likelihood ratio proportion were used to compare the findings with threshold limits., Results: The highest values and greatest differences were seen in the urine samples (p<0.001, Kruskal-Wallis). The occupational group showing the highest exposure with a median mercury level of 4.36μg/l (control group: 0.10μg/l, p<0.001), 7.18μg/g creatinine and 12 results above the threshold limit HBM I (Human Biomonitoring I). Even participants from the low-exposure subgroup showed elevated mercury levels (median 2.88μg/l urine and 2.98μg/g creatinine, p<0.001), with 10 individuals above the HBM I threshold limits., Discussion: The body burden resulting from the use of mercury in artisanal gold mining is high not only in the miners themselves, an increased mercury hazard was also found for inhabitants of mining areas who were not actively involved in mining. Public health support measures are urgently needed to alleviate the situation., (Copyright © 2010 Elsevier B.V. All rights reserved.)

Despite the ominous prognosis of severe left ventricular (LV) dysfunction from coronary artery disease, coronary artery bypass grafting (CABG) in this setting remains controversial because of concerns over high operative risk and low likelihood of functional or survival benefit. We analyzed 135 consecutive patients (113 men, 22 women; age 42 to 87 years, mean 66.5) with LV ejection fraction (EF) < or =30% undergoing isolated CABG by 1 surgeon over an 8-year period. LVEF ranged from 10% to 30% (mean 23.6%). Preoperatively, 63% of patients had angina, 61% had heart failure (23% with pulmonary edema), and 24% manifested severe ventricular arrhythmia. The mean number of grafts was 2.7 per patient. The internal mammary artery was used in 103 of the 120 grafts (86%) to the left anterior descending coronary artery. Seven patients (5.2%) died in hospital. Only 2 of 99 patients (2%) not in intensive care preoperatively died in hospital. Angina class improved by 2.0 categories and congestive heart failure class by 1.5 categories. LVEF (assessed in 104 of 128 hospital survivors) improved from 24% preoperatively to 34% postoperatively (p <0.0001). At 1, 3, and 4.5 years respectively, all-cause survival was 87%, 81%, and 71%, and freedom from cardiac death was 90%, 85%, and 80%. CABG in patients with coronary artery disease and advanced LV dysfunction: (1) can be performed relatively safely, (2) achieves good long-term survival, (3) improves LVEF, (4) improves quality of life, and (5) can safely utilize the internal mammary artery as a conduit. The use of CABG is encouraged for patients with advanced LV dysfunction and may provide a viable alternative to transplantation in selected patients.

Studies on the rate and extent of galacturonic acid and isolated pectin digestion were carried out with nine strains of rumen bacteria (Butyrivibrio fibrisolvens H10b and D16f, Bacteroides ruminicola 23 and D31d, Lachnospira multiparus D15d, Peptostreptococcus sp. D43e, B. succinogenes A3c, Ruminococcus flavefaciens B34b, and R. albus 7). Only three strains, 23, D16f, and D31d, utilized galacturonic acid as a sole energy source, whereas all strains except A3c and H10b degraded (solubilized) and utilized purified pectin. Nutrient composition of the basal medium and separate sterilization of the substrate affected the rate and extent of fermentation for both substrates. Pectin degradation and utilization were measured with two maturity stages each of intact bromegrass and alfalfa. For bromegrass I, all strains tested (B34b, 23, D16f, D31d, D15d, and D43e) degraded a considerable amount of pectin and, with the exception of B34b, utilized most of what was degraded. Similar, but lower, results were obtained with bromegrass II, except for the two strains of B. ruminicola, 23 and D31d, which were unable to degrade and utilize pectin from this forage. All strains were able to degrade and utilize pectin from both maturity stages of alfalfa; however, values were considerably lower for strains 23 and D31d. Synergism studies, in which a limited utilizing strain, B34b, was combined with the limited degrading strain, D31d, resulted in a slight increase in degradation and a very marked increase in utilization of the pectin in all four forages. Similar results were obtained on both alfalfa substrates with a combination of strains B34b and D16f; however, no increases were observed with this combination on bromegrass.