Antiproliferative, cytotoxic and apoptogenic activity of Indian toad (Bufo melanostictus, Schneider) skin extract on U937 and K562 cells.

The antiproliferative, cytotoxic and apoptogenic activities of Bufo melanostictus (Indian common toad) skin extract (TSE) on U937 and K562 leukemic cell line has been investigated. TSE significantly (P<0.001) reduced the time-dependent cell proliferation and decreased MTT values in U937 and K562 cells. TSE (IC50 doses) suppressed the proliferating cell nuclear antigen expression in both the cells. It was demonstrated that, TSE (IC50 doses) primarily arrested the U937 and K562 cells at G1 phase of the cell cycle. Confocal microscopy showed the altered fragmented nuclei and apoptotic bodies formation in TSE (IC50 doses) treated U937 and K562 cells. Membrane blebbing, cell surface shrinkage and perforation were observed through scanning electron microscope. TSE-induced DNA fragmentation in U937 and K562 cells was reflected in single-cell gel electrophoresis. TSE significantly (P<0.001) increase the length-width ratio of DNA mass as compared to control in comet assay. The flow cytometric analysis of annexin-V binding to the cancer cells further supported the apoptotogenic activity of TSE. The effect of TSE on normal human peripheral blood mononuclear cells viability and cytotoxicity was studied in culture and found to be less cytotoxic than on the U937 and K562 cells. The findings from the present study suggested that TSE might possess potent antineoplastic agent having antiproliferative, cytotoxic and apoptogenic activity against U937 and K562 myeloid leukemic cells.     

cDNA Sequencing of the 5′ Noncoding Region (5′ NCR) to Determine Hepatitis C Genotypes in Patients with Chronic Hepatitis C

Reports suggest that response tointerferon-alpha therapy is influenced by both hepatitisC viral genotype and titer. Our aim was to determine ifdirect, automated, cycle sequencing of the PCR productfrom an HCV RNA detection assay could be used toreliably determine HCV genotype. In addition, theapproach was used to determine the HCV genotypedistribution in our patient population and to learn ifthere was a correlation between HCV genotype and RNAtiter that could be used to predict response totreatment. In all 143 consecutive patients were testedfor both HCV RNA titer and genotype. Automated, cycle sequencing of PCR product was highly effectiveand failed to yield a genotype in only 3 (2%) patients.The distribution of HCV genotypes was: 1a (40%), 1b(39%), 2a (2%), 2b (6%), 3a (4%). There were significant differences in the median HCV RNA titersbetween genotypes 1, 2, and 3. 6 High HCV RNA titers>4.4 × 10⁶ copies/ml were only seenin genotype 1. However, the HCV RNA level should not beused as a surrogate marker of genotype because of a significantoverlap of titers within the genotypes.     

Surgical management of trismus due to Oral Submucous Fibrosis — Lysis of fibrotic bands with the KTP-532 Laser

Oral Submucous Fibrosis is an insidious, chronic disease affecting the oral cavity, sometimes the pharynx and rarely the tongue. 15 patients with Oral Submucous Fibrosis presenting with severe trismus were treated with lysis of the fibrotic bands with a KTP-532 Laser and adjunctive treatment with excellent results over a 12 month follow-up period.     

Effect of ethanol on cyclic AMP levels in intact PC12 cells

Two subclones of the rat pheochromocytoma cell line, PC12, were used to compare the effects of ethanol on adenylate cyclase activity in isolated membranes with its effects on cyclic AMP accumulation in intact cells. Consistent with previous reports, ethanol increased basal and 2-chloroadenosine-stimulated adenylate cyclase activity in isolated membrane preparations from both subclones. However, ethanol had opposite effects on agonist-stimulated cyclic AMP accumulation in intact cells of the two subclones, enhancing accumulation in one subclone, and inhibiting it in the other. The inhibition of cyclic AMP accumulation did not result from stimulation of phosphodiesterase activity, activation of the inhibitory guanyl nucleotide regulatory protein, Gi, or stimulation of protein kinase C. The results indicate that extrapolation of the effects of ethanol from one cell type to another, or from in vitro to in vivo systems, may be complicated by the interaction of ethanol with regulatory processes that influence second messenger systems, and can differ in various types of intact cells.     

Antifungal potential of disulfiram.

Disulfiram, an alcohol antagonistic drug has been on the market since 1949 with 80% bioavailability and an established safety profile. Recently it has been reported as a P-glycoprotein efflux pump modulator. Herein we report its antifungal potential. The MIC50 and MIC90 of disulfiram for yeast isolates is 4 and 8 microg/ml, respectively, and the MIC range is 1-16 micro g/ml for both fluconazole sensitive and resistant strains. Interestingly, disulfiram also showed fungicidal activity on Aspergillus spp. with MIC50 and MIC90 of 2 and 8 microg/ml, respectively.     

Induction of sister chromatid exchanges by cypermethrin and carbosulfan in bone marrow cells of mice in vivo

The public health effects of pesticides cannot be denied. However, the undesired effects of chemical pesticides have been recognized as a serious public health concern during the past decades. The present study describes the genotoxic effects of two pesticides, namely cypermethrin and carbosulfan, in a murine test system in vivo. The test parameter used was analysis of sister chromatid exchanges (SCE) in bone marrow cells. Both cypermethrin (5, 10 and 20 mg/kg) and carbosulfan (1.25, 2.5 and 5 mg/kg) induced significant increases in the frequency of SCEs (P < 0.001). However, no significant dose-response correlation could be found for either of the pesticides. Carbosulfan induced a cell cycle delay, as evidenced by an increase in average generation time accompanied by accumulation of cells in the first division cycle, but cypermethrin did not induce any such response. The present study indicates that carbosulfan has a higher potential to cause genetic alterations than cypermethrin in mice and may also pose a mutagenic risk to human beings.