Concentration‐dependent effect of (−) epicatechin in hypertensive patients

Non‐vitamin polyphenolic compounds are ubiquitous in food plants and therefore potentially present in human plasma in a diet‐dependent concentration. The aim of this study was to evaluate the concentration‐dependent effect of (?) epicatechin, a polyphenol present in green tea with antioxidant activity, on various biomarkers of oxidative stress. The current study examined the in vitro concentration‐dependent (10^?4 M to 10^?7 M) effects of (?) epicatechin on biomarkers of oxidative stress viz. malondialdehyde (MDA), reduced glutathione (GSH), membrane sulfhydryl (‐SH) group and protein carbonyl content in hypertensive patients and normal ones. This effect seems to be due to ability of (?) epicatechin to reduce MDA and protein carbonyl content while increase in GSH and membrane ‐SH group in hypertensive patients. It can be concluded that (‐) epicatechin exerts an antioxidant action inside the cell, responsible for the observed modulation of cellular response to oxidative challenges. Copyright © 2010 John Wiley & Sons, Ltd.     

Nanotechnology in ocular delivery: current and future directions

Our knowledge in the field of ocular drug delivery is rapidly expanding. An increase in the understanding of ocular drug absorption and disposition vis-à-vis developments in nanotechnology has led to the emergence of many of the nanotechnology-based ocular drug delivery systems including nanoparticles, microemulsions, liposomes, solid lipid nanoparticles, light-sensitive nanocarrier systems, etc. The need to develop effective treatments for posterior eye segment diseases is more important than surface delivery. Treatment of blinding diseases of the eye, such as proliferative retinopathy or macular degeneration, requires effective and safe delivery of drugs to posterior eye segment tissues, and recent advances in nanotechnology have demonstrated successful outcomes. Nanoscientists should focus their efforts on nano-ophthalmology. This review describes the current status and progress made so far, and the course that needs to be pursued in the future.     

Anticancer property of gallic acid in A549, a human lung adenocarcinoma cell line, and possible mechanisms

Gallic acid is widely distributed in plants, fruits and foods with a range of biological activities. In the present study the possible mechanisms of gallic acid anticancer properties were explored in A549, a human lung adenocarcinoma cell line. Our study shows that it inhibited the A549 cell growth and decreased cell viability monitored at 24 h. It also inhibited cell proliferation in dose- and time-dependent manner as measured by 3-[4,5-methylthiazol-2-yl]-2,5-diphenyl-tetrazolium bromide assay at 24 and 48 h. Morphological examination of the cells after gallic acid treatment showed the typical feature of cell death such as cell shrinkage and rounding up of the cells. Clonogenic assay indicated that gallic acid treatments inhibited the colony formation. DNA fragmentation assay indicated the disappearance of the genomic DNA in dose-dependent manner. To find out possible mechanisms, mitochondrial potential and intracellular reactive oxygen species were measured. It was observed that gallic acid treatment decreased mitochondrial membrane potential and increased intracellular reactive oxygen species. Further caspases activity was measured and it was found that gallic acid activated the caspase-3 but not caspase-8 indicating the involvement of intrinsic pathway of cell apoptosis.     

ERIC PCR and RAPD based fingerprinting of Salmonella Typhi strains isolated over a period of two decades

Salmonella enterica serotype Typhi strains (n = 113) were isolated from typhoid patients over a period of 2 decades, i.e. 1987–2006. RAPD and ERIC PCR methods were used for random whole genome typing of these strains. ERIC PCR was found to be very efficient with the discriminatory index (DI) of 0.9821 with 100% reproducibility. RAPD was satisfactory in discriminating the strains (DI = 0.8978) but with poor reproducibility (40%). However, composite genotypic analysis was still better with DI of 0.9981 but with inherent poor reproducibility due to RAPD. Two major clones were observed to be circulating in the community with few unrelated strains too. The dendrogram constructed based on ERIC PCR banding pattern by involving 89 Typhi strains revealed 71 patterns, indicating that the genome of the bacterium is capable of rapid changes and variations. Thus, the spectrum of biological manifestations of human infection by S. Typhi may be related to its capacity for genetic diversity underlined by its highly plastic hypermutable genome.     

Bioassay-Guided Fractionation and In Vitro Antiproliferative Effects of Fractions of Artemisia nilagirica on THP-1 cell line

Artemisia nilagirica (Clarke) is a widely used medicinal herb in Indian traditional system of medicine. Therefore, the present study was designed to evaluate the effects of A. nilagirica extracts/fractions on inhibition of proliferation and apoptosis in a human monocytic leukemia (THP-1) cell line. The crude extracts (A. nilagirica ethyl acetate extract [ANE] and A. nilagirica methanolic extract [ANA]) showed cytotoxic activity toward THP-1 cells with the IC₅₀ values of 38.21 ± 7.37 and 132.41 ± 7.19 µg/ml, respectively. However, the cytotoxic activity of active fractions (ANE-B and ANM-9) obtained after column chromatography was found to be much more pronounced than their parent extracts. The IC₅₀ values of ANE-B and ANM-9 were found to be 27.04 ± 2.54 µg/ml and 12.70 ± 4.79 µg/ml, respectively, suggesting greater susceptibility of the malignant cells. Cell cycle analysis and terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick-end-labeling (TUNEL) assay revealed that inhibition of cell growth by A. nilagirica fractions on THP-1 cells was mediated by apoptosis. Active fractions of A. nilagirica increased the expression levels of caspase-3, ?7, and poly-ADP-ribose polymerase (PARP), a critical member of the apoptotic pathway. These results suggested that active fractions of A. nilagirica may play a promising role in growth suppression by inducing apoptosis in human monocytic leukemic cells via mitochondria-dependent and death receptor-dependent apoptotic pathways.     

Human papillomavirus molecular biology and pathogenesis

Human papillomavirus (HPV) infection is the most common sexually transmitted disease in the world and accounts for an estimated 11% of the global cancer incidence in women. HPV-16 is the most prevalent type detected in cervical cancer and along with types 18, 31, 33 and 45 has been classified as a class I carcinogen. In addition to cervical cancer, HPVs are also associated with the malignant transformation of other mucosal and skin cancers. Thus, the combination of the malignant potential of HPV and its high prevalence of infection confers to it an importance of generalized clinical and virological significance. The natural history of HPV infection with or without treatment varies from spontaneous regression to persistence. The most important mechanism for wart regression appears to be cell-mediated immunity. Cytokines released by keratinocytes or cells of the immune system may play a part in the induction of an effective immune response against HPV infection and the subsequent regression of lesions. This review discusses the molecular biology, pathogenesis and immunology of HPV infections.     

复合自适应滤波器用于体感诱发电位信噪比的提高

本研究以可靠、快速提取体感诱发电位为目标,试图解决相干叠加方法既费时又不能反映体感诱发电位时变特征的缺点。运用以自适应噪声减法器和自适应增强器为基础构造的复合自适应滤波器提取体感诱发电位。仿真实验表明,运用复合自适应滤波器可实现从强噪声背景中快速提取体感诱发电位,能更快地识别体感诱发电位的潜伏期及幅值,并且系统性能稳定。