A Fission Yeast Bioassay For Rapid Screening For Antiproliferative Agents From Bauhinia Variegata And Leptadenia Reticulata

The aim of the present study was to evaluate the antiproliferative activity of crude extracts from leaves of Bauhinia variegata and Leptadenia reticulata using fission yeast Schizosaccharomyces pombe as a model. The crude extracts of both plants were prepared by three experimental conditions (25°C, elevated temperature and ultrasound waves) and four solvent systems [Water, Methanol, Water: Methanol (1:1) and Chloroform: Methanol (1:1)]. MTT assay was performed for estimating the cell viability and the results were expressed as % growth inhibition. Overall based on the MTT assay performed on yeast cells, Water: Methanol, Methanol and Water extracts showed higher antiproliferative activity than the positive control (Paclitaxel) in a dose-dependent manner. For Bauhinia variegata and Leptadenia reticulata, methanol extract (25°C temperature & elevated temperature, respectively) exhibited highest inhibition which was approximately 80%. In conclusion, this study has indicated that Bauhinia variegata and Leptadenia reticulata extracts possess strong antiproliferative activity. Furthermore, it could act as a potential source for identifying new molecules with chemotherapeutic potential against cancer.

Molecular characterisation of Giardia intestinalis assemblages from human isolates at a tertiary care centre of India.

Purpose: The aim of the study was to determine the genetic heterogeneity of Giardia intestinalis isolates detected in stool samples of the study population using polymerase chain reaction assay and restriction fragment length polymorphism. We also tried to correlate the association/differences between the clinical symptomatology and infection by different assemblages (genotypes) of G. intestinalis. Materials and Methods: This cross-sectional study was conducted from April 2008 to June 2010. A total of 40 adults (n = 40) and 42 children (n = 42) below the age of 12 years with the clinical suspicion of giardiasis and with the onset of one or more of the following fi ve symptoms, i.e., loose stool, nausea, weight loss, fatigue and foul smelling faeces and confi rmed laboratory diagnosis of giardiasis at least once during the current episode of diarrhoea were included in this study. Results: Of the 82 patients (males 66) enrolled in the study, 70 (85%) presented with diarrhoea (56 males) and 12 (15%) without diarrhoea (10 males). Out of 70 diarrheic patients, 61 (87%) had chronic diarrhoea, 8 (11.5%) had acute diarrhoea and 1 (1.5%) had persistent diarrhoea. Of the total patients, 63 (77%) were clinically assessed and were apparently immunocompetent, whereas, 19 (23%) immunocompromised patients had different underlying conditions besides giardiasis. Genotyping identifi ed all 82 (100%) isolates as assemblage B. Conclusion: We found that assemblage B of G. intestinalis presents with all kinds of clinical features ranging from asymptomatic carriage to acute, persistent or chronic diarrhoea.

Biological control of Fusarium wilt of pigeonpea Cajanus cajan (L.) Millsp with chitinolytic Alcaligenes xylosoxydans.

Alcaligenes xylosoxydans protected pigeonpea from Fusarium wilt in a pot experiment and field trials. When seeds of pigeonpea (C. cajan) were treated with A. xylosoxydans and sown in soil infested with Fusarium, the incidence of wilt was reduced by 43.5% and resulted in 58% higher grain yield. The antifungal activity of A. xylosoxydans was based on chitinase production and was comparable in efficacy to commercial antifungal agents such as benlate, monitor WP, thiram and bavistin.

Characterization of carbamoyl phosphate synthetase of Streptomyces spp.

Carbamoyl phosphate synthetase (CPS) activity in Streptomyces lividans was repressed (70%) by addition of arginine and uracil in the growth medium. Enzyme activity was also inhibited by UMP and activated by ornithine and IMP. Pattern of inhibition and activation was similar irrespective of whether the cells were grown in medium supplemented with arginine or with uracil. A mutant of S. coelicolor with dual auxotrophy for arginine and uracil possessed only about 20% of CPS activity compared to the wild-type strain. An activity staining protocol has been developed for CPS enzyme. Using this method a single CPS band has been observed in the crude extracts of Escherichia coli as well as in S. lividans. Taken together, our results supported the conclusion that Streptomyces species might possess a single CPS enzyme unlike other gram-positive bacteria, which show the presence of two pathway-specific isozymes (Bacillus) or none (Lactobacillus and Leuconostoc).

Post-penetrating keratoplasty glaucoma.

To study the risk factors in the development of glaucoma following penetrating keratoplasty, we retrospectively analysed 190 eyes of 185 consecutive patients who had undergone surgery during 1990. The donor button was larger by 0.2 mm and 0.5 mm in phakia and aphakia/pseudophakia patients, respectively. Over a mean follow-up period of 14.5 months, 52 of the 190 eyes (27.4%) either developed glaucoma de novo or had worsening of preexisting glaucoma. Of these 52 eyes, 38 were managed medically and 14 required surgery. From our study, aphakia (37%), pseudophakia (24%), preexisting glaucoma (81.8%), and regrafting (43.18%) were found to be the significant risk factors in the development of glaucoma following penetrating keratoplasty.