Pathological effects of particulate matter (PM2.5) on pulmonary airways and its roles in asthma pathobiology / 医用生物力学

Asthma is an important respiratory disease that endangers human health, while its complex mechanisms of pathobiology have not been fully understood. Recently, environmental factors are increasingly recognized to play important roles in the pathogenesis of asthma. In particular, the effect of PM2.5 (particulate matter with diameter smaller than 2.5 μm) on the structure and function of pulmonary airways at cell level has become a research hotspot and frontier, and led to many important findings. In this article, the main pathological features, i.e. airway inflammation and hyperresponsiveness were discussed, and recent progress and important findings in pathological effects of PM2.5 on the airway and its mechanism were reviewed, including PM2.5 transport and deposition in the airway, PM2.5 and airway inflammation and damage, PM2.5 and airway remodeling, PM2.5 and airway hyperresponsiveness, PM2.5 and airway smooth muscle cell mechanics via either indirect regulation or direct interaction. The analysis on the role of PM2.5 in airway biomechanics in relation to asthma pathobiology will provide a valuable reference for studying effects of PM2.5 on the respiratory system.

Sensitivity of different cytotoxic responses of Vero cells exposed to organic chemical pollutants and their reliability in the bio-toxicity test of trace chemical pollutants / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To find a sensitive cytotoxic response to reflect the bio-toxicity of trace organic pollutants, the sensitivity and reliability of morphological change and proliferation inhibition of Vero cells exposed to 2, 4, 6-trichlorophenol (TCP) and the leachate from products related to drinking water (PRDW) were compared, and the mechanism of the morphological change in Vero cells exposed to chemical pollutants was studied.</p><p><b>METHODS</b>Vero cells were treated by different concentration of TCP and the leachate from PRDW. Methylthiazol-2-yl-2, 5-diphenyl tetrazolium bromide (MTT) assay was carried out for proliferation inhibition. Bioluminescence method was carried out as another method to test the toxicity of TCP. Flow Cytometry assay was used to test cell Apoptosis and damage of cell-membrane.</p><p><b>RESULTS</b>0.25 mg/L TCP had an effect on cell morphology, and the proportion of morphologically changed cells increased with increasing TCP concentration. At low TCP concentrations, inhibition of cell proliferation did not seem to correlate to TCP concentration, and was negative when TCP concentration was <1.0 mg/L. After exposure to leachate from PRDW extracted at different temperatures, the percentage of morphologically changed cells increased with extracting temperature, but the inhibition of cell proliferation failed to reflect the correlation between extracting temperature and proliferation inhibition of Vero cells. Although the Sensitivity of bioluminescence method seems to be similar to morphological change in Vero cells, the bacterial in this method is not homologous enough with human body cells to reflect the toxicity to human body. These imply cell morphological change is a more sensitive and reliable method to reflect bio-toxicity of organic pollutants than proliferation inhibition. Flow cytometry analysis and cell rejuvenation experiments indicated cell membrane damage, which results in cell morphological change, was an early and sensitive cytotoxic response comparing with necrosis.</p><p><b>CONCLUSION</b>These results indicated that the cell membrane toxicity represented by morphological changes is a more sensitive and reliable method to indicate the composite bio-toxicity of trace chemicals than proliferation inhibition, inhibition on bioluminescence and necrosis. Nevertheless, the quantification of morphological change should be studied further.</p>

Preventive effects of soybean isoflavones on chronic allograft nephropathy in rats / 中华器官移植杂志

Objective To identify whether soybean isoflavones plays a role in the prevention of chronicallograft nephropathy(CAN)in rats.Methods Forty-five male Lewis rats as receptors were randomly divided into 3 groups,receiving a diet with protein from high isoflavone soy protein fraction (HIS),low isoflavone soy protein fraction(LIS)or casein(CAS)starting one week before renal transplants from fisher donors,and continuing throughout the study.Serial serum and urine samples were collected at the beginning of the study,and at 4th,12th and 24th week.All rats were killed and the grafts were harvested in the 24th week.The functional and histopathogical changes of renal grafts were evaluated.Results In HIS group,arteria caudilis systolic blood pressure(SBP)value,24 h uri- nary protein(Upro)and serum creatitine(Cr)concentrations were significantly lower than those in LIS and CAS groups(all P