Aspergillosis in imported penguins.

An outbreak of aspergillosis in imported penguins caused by Aspergillus fumigatus is described. The birds probably acquired the infection from the country of origin or during their transportation. Predisposing circumstances are discussed.     

Estimation of disulfide bonds using 2-nitro-5-thiosulfobenzoic acid: limitations

Recently an elegant method for the quantification of the number of disulfide bonds in proteins and peptides has been reported [T.W. Thannhauser, Y. Konishi, and H.A. Scheraga (1984) Anal. Biochem. 138, 181-188]. The method is based on the quantification of 2-nitro-5-thiobenzoate (NTB) formed from the reaction of 2-nitro-5-thiosulfobenzoate with disulfides in the presence of excess sodium sulfite. Here it is reported that the NTB anion undergoes photochemical reaction with excess sulfite in the system, which results in the rapid disappearance of absorbance at 412 nm in the presence of light. The nonchromophoric derivative of this photochemical reaction is tentatively identified as a sulfo derivative of NTB. Based on these observations it is suggested that, for the quantification of disulfide bonds using the NTSB method, the assay should be carried out in the dark.     

Influence of exogenous application of glutathione on rubisco and rubisco activase in heavy metal-stressed tobacco plant grown in vitro

The effect of glutathione on the influences of heavy metals affecting rubisco and rubisco activase was studied in tobacco plants grown in vitro where the shoot explants of the tobacco plant cultured on MS medium under aseptic conditions and two explants were placed in the control, 0.1 mM GSH, 1 mM GSH, 0.2 mM Cd, 0.2 mM Cu, 0.2 mM Zn, and a mixture of Cd and GSH, Cu and GSH, Zn and GSH, respectively. The effect of GSH on the growth of the tobacco plant was minimal, but the heavy metals clearly retarded its growth. GSH recovered the growth retarded by heavy metals, and the concentration of GSH required to recover the growth differed depending on the heavy metals. The content of chlorophyll in the plant increased through GSH and Zn, and decreased through Cd and Cu. The chlorophyll content which decreased due to Cd and Cu was recovered by GSH, and the content which increased due to Zn was decreased by 1 mM GSH. The content of rubisco decreased due to GSH and heavy metals, and the content which decreased due to heavy metals was recovered by GSH, and when GSH was treated with Zn, the increased rate was maximum compared to other heavy metals. The activity of rubisco was increased due to GSH and heavy metals, and the activity increased by Cd and Zn decreased through GSH. In the case of Cu, the activity of GSH increased even more. There was no effect of GSH on the influences of heavy metals on the content and activity of rubisco activase. The activity of rubisco decreased by thiourea among six denaturing agents, and increased by l-cysteine, and in most cases the activity level was recorded as high. The activity of rubisco activase all decreased as a result of six denaturing agents, and the effect caused by EDTA and guanidine-HCl was the greatest, while the effect caused by l-cysteine and urea was minimal.     

Depth-related patterns of meiofauna on the Indian continental shelf are conserved at reduced taxonomic resolution

Taxonomic sufficiency (TS) has been used in impact assessment studies of various pollution effects on marine benthic communities and found appropriate to identify the effects of pollution on marine communities. Cost, in terms of the expertise and time needed to identify organisms, increases with the level of taxonomic accuracy. Recently, TS has been adopted to study spatial patterns of macrobenthic community structure. In order to accept TS as a routine approach in wider benthic studies, it needs to be proved valid for various taxa and in geographically different areas. The present study investigates the value of TS in meiofaunal nematodes by analyzing an extensive data set based on samples collected from a wide geographical area covering a large depth gradient. For this study, samples were collected from every degree square of the western Indian continental shelf (7°–22°N latitudes). Our high resolution data showed that with increase in depth, nematode species richness and diversity decreased and communities showed significant variation between shallow and deeper waters. The present study tests whether lower taxonomic resolution nematode data can explain community shifts along a depth gradient in a similar way to species level data from the same data set. Meiofauna have often been neglected from benthic studies, and most attention has been given to macrofauna. This is mainly due to the difficulty in the taxonomic identification of meiofauna. The results of this study based on univariate and multivariate analyses support the use of family level data of nematodes to explain some aspects of depth variation in a similar way to species level data.     

Studies on titin PEVK peptides and their interaction

Experiments were conducted on several synthetic and expressed peptides from the PEVK region of titin, the giant muscle protein. Different secondary structure prediction methods based on amino acid sequence gave estimates ranging from over 70% alpha helical to no helix (totally disordered) for the polyE peptide corresponding to human exon 115. Circular dichroism (CD) experiments demonstrated that both the positively charged PPAK modules and the negatively charged PolyE repeats had similar spectral properties with disordered secondary structure predominating. Gel permeation chromatography showed that both PPAK and polyE peptides had 2-4 times larger Stokes radii than expected from their molecular mass. Mixtures of the oppositely charged titin peptides caused no change in apparent secondary structure as observed by circular dichroism or migration properties using native gel electrophoresis. Similarly addition of calcium did not alter the CD spectra or peptide electrophoretic mobility of the individual peptides or their mixtures. The properties of both the PPAK and polyE type peptides suggest that both had most of the characteristic properties to be classified as intrinsically disordered proteins.     

Aplysinopsin analogs: Synthesis and anti-proliferative activity of substituted (Z)-5-(N-benzylindol-3-ylmethylene)imidazolidine-2,4-diones

A series of substituted (Z)-5-(N-benzylindol-3-ylmethylene)imidazolidine-2,4-dione (3) analogs structurally related to aplysinopsin, and that incorporate a variety of substituents in both the indole and N-benzyl moieties have been synthesized under microwave irradiation and conventional heating methods These analogs were evaluated for their anti-proliferative activity against MCF-7 and MDA-231 breast cancer cell lines, and A549 and H460 lung cancer cell lines. Two analogs, 3f and 3j had IC₅₀ values of 4.4 and 5.2 μM, respectively, compared to 5-fluorouracil (IC₅₀ = 15.2 μM) against MCF-7 cells.     

Differentially expressed miR-20, miR-21, miR-100, miR-125a and miR-146a as a potential biomarker for prostate cancer

Prostate cancer is the leading cause of death among men worldwide. Deregulation of microRNAs has been reported in many cancers. Expression of microRNAs miR-20a-5p, miR-21-5p, miR-100-5p, miR-125a-5p and miR-146a-5p in tissue blocks of histologically confirmed prostate cancer patients compared with BPH patients, to identify potential microRNA biomarker for prostate cancer. MicroRNA was isolated and expression was quantified by qRT-PCR using Taqman Advanced microRNA assay kits. The interactions between the microRNA:target mRNA were predicted by using bioinformatics tools such as miRwalk and miRTargetlink. The experimentally validated targets were analysed using gprofiler to identify their molecular function, biological process and related pathways. The expression analysis revealed that miR-21 and miR-100 were significantly down-regulated whereas miR-125a was up-regulated in prostate cancer patients. Comparative analysis of the expression levels with tumor grading reveal that miR-100 was significantly down-regulated (p?<?0.05) in high grade tumor, indicating that miR-100 associated with prostate cancer. ROC analysis revealed that combined analysis of down-regulated miRNAs (miR-21 and miR-100) shown AUC of 0.72 (95% CI 0.65–0.79). The combined analysis of all five miRNAs showed AUC of 0.87 (95% CI 0.81–0.92). The targets prediction analysis revealed several validated targets including BCL2, ROCK1, EGFR, PTEN, MTOR, NAIF1 and VEGFA. Our results provide evidence that combined analysis of all the five miRNAs as a panel can significantly improve the prediction level of the presence of prostate cancer and may be used as a potential diagnostic biomarker.