Upadhyayula Suryanarayana Murty

Comparative study of genotoxicity and tissue distribution of nano and micron sized iron oxide in rats after acute oral treatment.

Though nanomaterials (NMs) are being utilized worldwide, increasing use of NMs have raised concerns over their safety to human health and environment. Iron oxide (Fe(2)O(3)) NMs have important applications. The aim of this study was to assess the genotoxicity of Fe(2)O(3)-30nm and Fe(2)O(3)-bulk in female Wistar rats. Fe(2)O(3)-30nm was characterized by using transmission electron microscopy, dynamic light scattering, laser Doppler velocimetry and surface area analysis. The rats were treated orally with the single doses of 500, 1000, 2000mg/kg bw of Fe(2)O(3)-30nm and Fe(2)O(3) -bulk. The genotoxicity was evaluated at 6, 24, 48 and 72h by the comet assay in leucocytes, 48 and 72h by micronucleus test (MNT) in peripheral blood cells, 18 and 24h by chromosomal aberration (CA) assay and 24 and 48h by MNT in bone marrow cells. The biodistribution of iron (Fe) was carried out at 6, 24, 48 and 72h after treatment in liver, spleen, kidney, heart, brain, bone marrow, urine and feces by using atomic absorption spectrophotometry. The % tail DNA, frequencies of micronuclei and CAs were statistically insignificant (p>0.05) at all doses. These results suggest that Fe(2)O(3)-30nm and Fe(2)O(3)-bulk was not genotoxic at the doses tested. Bioavailability of Fe was size and dose dependent in all the tissues from the groups exposed to Fe(2)O(3)-30nm. Fe(2)O(3) NMs were able to enter in the organs and the rats are biocompatible with much higher concentration of Fe. However, the accumulated Fe did not cause significant genotoxicity. This study provides additional knowledge about the toxicology of Fe(2)O(3) NMs.

Oxidative stress induced by aluminum oxide nanomaterials after acute oral treatment in Wistar rats.

This study investigated the oxidative stress induced after acute oral treatment with 500, 1000 and 2000 mg kg−1 doses of Al2O3‐30 and −40 nm and bulk Al2O3 in Wistar rats. Both the nanomaterials induced significant oxidative stress in a dose‐dependent manner in comparison to the bulk. There was no significant difference between the two nanomaterials. However, the effect decreased with increase with time after treatment. The histopathological examination showed lesions only in liver with Al2O3 nanomaterials at 2000 mg kg−1. Copyright

Biochemical alterations induced by acute oral doses of iron oxide nanoparticles in Wistar rats

Magnetic iron oxide nanoparticles with appropriate surface chemistry have been widely used with potential new applications in biomedical industry. Therefore, the aim of this study was to assess the size-, dose-, and time-dependent effects, after acute oral exposure to iron oxide-30 NP (Fe2O3-30), on various biochemical enzyme activities of clinical significances in a female Wistar rat model. Rats were exposed to three different doses (500, 1,000, and 2,000 mg/kg) of Fe2O3-30 and Fe2O3-Bulk along with control. Fe2O3-30 had no effect on growth, behavior, and nutritional performance of animals. Fe2O3-30 caused significant inhibition of acetylcholinestrase in red blood cells as well as in brains of treated rats. Further, more than 50% inhibition of total, Na+-K+, Mg2+, and Ca2+-ATPases activities, as observed in brains of exposed female rats, may be the result of disturbances in cellular physiology and the iono-regulatory process. Activation of the hepatotoxicity marker enzymes, aspartate aminotransferase and alanine aminotransferase, was recorded in serum and liver, whereas inhibition was observed in kidney. Similarly, enhancement of lactate dehydrogenase activity was observed in serum and liver; however, a decrease in enzyme levels was observed in kidneys of Fe2O3-30-treated rats. On the other hand, Fe2O3-Bulk did not depict any significant changes in these biochemical parameters, and alterations were near to control. Therefore, this study suggests that exposure to nanosize particles at acute doses may cause adverse changes in animal biochemical profiles. The use of the rat model signifies the correlation with the human system.

Comparative characterization of commercially important xylanase enzymes

Xylanase is an industrially important enzyme having wide range of applications especially in paper industry. It is crucial to gain an understanding about the structure and functional aspects of various xylanases produced from diverse sources. In this study, a bioinformatics and molecular modeling approach was adopted to explore properties and structure of xylanases. Physico-chemical properties were predicted and prediction of motifs, disulfide bridges and secondary structure was performed for functional characterization. Apart from these analyses, three dimensional structures were constructed and stereo-chemical quality was evaluated by different structure validation tools. Comparative catalytic site analysis and assessment was performed to extract information about the important residues. Asn72 was found to be the common residue in the active sites of the proteins P35809 and Q12603.

Mutational analysis of the FIGLA gene in women with idiopathic premature ovarian failure.

ObjectiveThe aim of our study was to identify the association of FIGLA (factor in the germ line &agr;) gene variants with premature ovarian failure (POF) in the Indian population. MethodsTwo hundred nineteen women with idiopathic POF and 230 healthy controls were recruited for this study. All exons, intron-exon boundaries, and untranslated regions of the FIGLA gene were analyzed by polymerase chain reaction and sequencing. All FIGLA variants were analyzed in silico, using PolyPhen, SIFT, MutationTaster, PMUT, I-Mutant, Mupro, Align-GVGD, PROVEAN, and HOPE software, to predict pathogenicity and changes in protein stability. ResultsSeven different FIGLA variants were detected among women with POF. Two exon 3 variants, c.427G→C and c.557C→T, showed strong association between cases and controls (P = 0.02 and P = 0.02, respectively). Significant differences in both of these variants were observed between cases and controls in genotype and dominant models. No significant difference between controls and women with POF was found on haplotype analysis. A nonsynonymous variant, p.(Arg83Cys), was found only in POF cases. Variant p.(Arg83Cys) lies in the functional domain of the FIGLA gene (basic helix-loop-helix), and protein alignments reveal that it is highly conserved among mammals. In silico analysis suggests the functional involvement of p.(Arg83Cys) and p.(Ser141Thr) variants in POF pathogenesis. ConclusionsWe have established a strong association between FIGLA gene variants and POF in Indian women, which may be a potential genetic risk factor in the development of idiopathic POF. However, further independent genetic and functional studies are necessary to confirm our findings.

Assessment of genotoxic effects of lead in occupationally exposed workers

The genotoxicological effects in 200 lead acid storage battery recycling and manufacturing industry workers in Hyderabad along with matched 200 controls were studied. The genetic damage was determined by comet, micronucleus (MN), and chromosomal aberration (CA) test in peripheral blood lymphocytes (PBL). The MN test was also carried out in buccal epithelial cells (BECs). Pb in ambient air, blood Pb (B-Pb) concentrations, and hematological parameters were measured. The superoxide dismutase (SOD), catalase (CAT), glutathione (GSH), glutathione peroxidase (GPx), and malondialdehyde (MDA) formed were also studied. The results of the present study showed that there was a statistically significant (P < 0.01) increase in mean percent tail DNA, frequency of CA, and MN in PBL as well as in BEC as compared to controls. Pb in ambient air and B-Pb concentrations were found to be significantly higher (P < 0.01). The hematocrit, hemoglobin, and red blood cell values were significantly lowered in Pb-exposed workers in comparison to controls. SOD, GPx, and CAT levels were significantly decreased while GSH and MDA levels increased in exposed group when compared to control group. The present study suggests that environmental health standards should be enforced to control Pb contamination from battery industries to reduce human health risk.

Application of Kohonen maps for solving the classification puzzle in AGC kinase protein sequences

Availability of enormous number of sequences in public domain databases warrants the need for effective tools for clustering and classification of such data. AGC protein kinase family is known to contain many enzymes involved in important cellular processes. In the present study, 21 important physicochemical parameters were calculated for 115 sequences of AGC kinase family belonging to mouse and human. Kohonen maps, also known as Self Organizing Maps (SOM) were employed for the identification of clusters of similar sequences, projection and visualization of high dimensional data spaces owing to their capability of preserving topological relationships between the features. This simplistic approach can provide a method not only for studying intricate interplay of features and minute differences even in the members of same protein family but also for recognition of certain unifying common features. Each cluster obtained using SOM in this study has a distinct characteristic that sets it apart from the other clusters.

Modeling analysis of GST (glutathione-S-transferases) from Wuchereria bancrofti and Brugia malayi

GST (glutathione S-transferases) are a family of detoxification enzymes that catalyze the conjugation of reduced GSH (glutathione) to xenobiotic (endogenous electrophilic) compounds. GST from Wb (Wuchereria bancrofti) and Bm (Brugia malayi) are significantly different from human GST in sequence and structure. Thus, Wb-GST and Bm-GST are potential chemotherapeutic targets for anti-filarial treatment. Comparison of modeled Wb and Bm GST with human GST show structural difference between them. Analysis of the active site residues for the binding of electrophilic co-substrates provides insight towards the design of parasite specific GST inhibitors.

Prioritization of malaria endemic zones using self-organizing maps in the Manipur state of India

Due to the availability of a huge amount of epidemiological and public health data that require analysis and interpretation by using appropriate mathematical tools to support the existing method to control the mosquito and mosquito-borne diseases in a more effective way, data-mining tools are used to make sense from the chaos. Using data-mining tools, one can develop predictive models, patterns, association rules, and clusters of diseases, which can help the decision-makers in controlling the diseases. This paper mainly focuses on the applications of data-mining tools that have been used for the first time to prioritize the malaria endemic regions in Manipur state by using Self Organizing Maps (SOM). The SOM results (in two-dimensional images called Kohonen maps) clearly show the visual classification of malaria endemic zones into high, medium and low in the different districts of Manipur, and will be discussed in the paper.

TOWARDS CLASSIFYING ORGANISMS BASED ON THEIR PROTEIN PHYSICOCHEMICAL PROPERTIES USING COMPARATIVE INTELLIGENT TECHNIQUES

Several supervised and unsupervised methods are presently available for classification and clustering extremely nonlinear data sets. Biological data sets are known to be complex in nature due to their greater dimension, complex attribute interactions, and dynamic behavior. In this article, we present the classification of 16 organisms based on physicochemical properties of their proteins employing comparative intelligent techniques. Considering the complexity of the present working data set, an attempt has been made to select the most important attributes using the feature selection facility available in TANAGRA (http://eric.univlyon2.fr/∼ricco/tanagra/en/tanagra.html) for better classification efficiency. Various methods available in LIB-SVM, a library for support vector machines, Waikato Environment for Knowledge Analysis (WEKA), and Konstanz Information Miner (KNIME) were utilized. Support vector machines (SVMs), radial basis function (RBF), polynomial, multiple layer perceptron (MLP), hyper-tangent, and sequential minimal optimization (SMO) were adopted to achieve maximum accuracy in the results. The best results obtained (>70%) are compared.