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Sudhir Kumar

Publications and source records attributed to Sudhir Kumar.

At least 91 records · Page 5Linked to original sources
PubMed2003

Multifocal skeletal tuberculosis in children: a retrospective study of 18 cases.

Multifocal skeletal tuberculosis is an uncommonly reported entity, Unanimity on terminology is lacking in the literature. The article presents a series of 18 such patients encountered in our institution. All the patients were below 15 y of age. Male to female ratio was 13:5. Most of the cases presented with swellings, discharging sinuses and/or ulcers. Appendicular involvement was seen in 17 of these cases. All the cases were diagnosed histopathologically as tuberculosis. All the cases were treated with multi-drug anti-tubercular therapy with additional procedures such as incision and drainage or sinus tract curettage performed in 9 of the patients. All the lesions healed. Their clinical behaviour, result and outcome are analysed with available international literature.

Adolescent↗
PubMed2003

Local or general anesthesia for open hernia repair: a randomized trial.

OBJECTIVE: To compare patient outcome following repair of a primary groin hernia under local (LA) or general anesthesia (GA) in a randomized clinical trial. SUMMARY BACKGROUND DATA: LA hernia repair is thought to be safer for patients, causes less postoperative pain, cost less, and is associated with a more rapid recovery when compared with the same operation performed under GA. METHODS: All patients presenting to three surgeons during the study period with a primary groin hernia were considered eligible. Outcome parameters measured including tests of vigilance, divided attention, sustained attention, memory, cognitive function, pain, return to normal activity, and costs. RESULTS: Two hundred seventy-nine patients were randomized to LA or GA hernia repair; 276 of these had an operation, with 138 participants in each group. At 6, 24, and 72 hours postoperatively there were no differences in vigilance or divided attention between the groups. Similarly, memory, sustained attention, and cognitive function were not impaired in either group. Although physical activity was significantly impaired at 24 hours, this and return to usual social activities were similar in both groups. While patients in the LA group had significantly less pain on moving, at 6 hours they were less likely to recommend the same operation to someone else. GA hernia repair cost 4% more than the same operation under LA. CONCLUSIONS: There are no major differences in patient recovery after LA or GA hernia repair. Patients should be offered a choice of anesthesia, LA or GA, for repair of their groin hernia.

Anesthesia, General↗
PubMed2003

Neutral substitutions occur at a faster rate in exons than in noncoding DNA in primate genomes.

Point mutation rates in exons (synonymous sites) and noncoding (introns and intergenic) regions are generally assumed to be the same. However, comparative sequence analyses of synonymous substitutions in exons (81 genes) and that of long intergenic fragments (141.3 kbp) of human and chimpanzee genomes reveal a 30%-60% higher mutation rate in exons than in noncoding DNA. We propose a differential CpG content hypothesis to explain this fundamental, and seemingly unintuitive, pattern. We find that the increased exonic rate is the result of the relative overabundance of synonymous sites involved in CpG dinucleotides, as the evolutionary divergence in non-CpG sites is similar in noncoding DNA and synonymous sites of exons. Expectations and predictions of our hypothesis are confirmed in comparisons involving more distantly related species, including human-orangutan, human-baboon, and human-macaque. Our results suggest an underlying mechanism for higher mutation rate in GC-rich genomic regions, predict nonlinear accumulation of mutations in pseudogenes over time, and provide a possible explanation for the observed higher diversity of single nucleotide polymorphisms (SNPs) in the synonymous sites of exons compared to the noncoding regions.

Animals↗
PubMed2003

Arsenic contamination in parts of Yamuna sub-basin, West Bengal.

Arsenic rarely occurs in free state and is generally found in combination with Sulphur, Oxygen and Iron. In the environment, Arsenic occurs as a result of several inputs that contain this element in organic and inorganic forms. Arsenic is present in Coal, Lead, Zinc, Gold and Copper ores in the form of several minerals viz. Arsenopyrite (FeAsS), Orpiment (As2S3), Realgar (AsS), Arsenolite (As2O3) and Lollingite (FeAs2). The commonly existing species in groundwater are in two forms viz. Arsenite [As(III)] which is the reduced state of inorganic Arsenic and Arsenate [As(V)], which is the oxidized state of inorganic Arsenic, The As(III) form is more mobile and toxic for living organisms. Recently, the symptoms of chronic arsenic poisoning have been observed in many parts of West Bengal (India) and Bangladesh. In the present study, an integrated evaluation of hydrogeology and hydrochemistry has been carried out by processing the available data of Yamuna sub-basin (Part of Nadia and North 24 Parganas district) of West Bengal in order to understand the possible reason of arsenic pollution in the ground water. Arsenic has generally been observed in higher concentration in shallow aquifer. Northwestern region of the study area has been observed to be the most effected with premonsoon periods exhibiting higher concentration. Transmissivity values have been observed to vary inversely with arsenic concentrations. Arsenic values have not indicated any well defined association with many other constituents. Arsenic buildup could also not be conclusively related to lowering of ground water table of the study area.

Arsenic↗
PubMed2002

Mutation rates in mammalian genomes.

Knowledge of the rate of point mutation is of fundamental importance, because mutations are a vital source of genetic novelty and a significant cause of human diseases. Currently, mutation rate is thought to vary many fold among genes within a genome and among lineages in mammals. We have conducted a computational analysis of 5,669 genes (17,208 sequences) from species representing major groups of placental mammals to characterize the extent of mutation rate differences among genes in a genome and among diverse mammalian lineages. We find that mutation rate is approximately constant per year and largely similar among genes. Similarity of mutation rates among lineages with vastly different generation lengths and physiological attributes points to a much greater contribution of replication-independent mutational processes to the overall mutation rate. Our results suggest that the average mammalian genome mutation rate is 2.2 x 10(-9) per base pair per year, which provides further opportunities for estimating species and population divergence times by using molecular clocks.

Animals↗
PubMed2002

Estimation of the rate of osteogenesis by tetracycline double labeling in intertrochanteric fractures of the femur in different age groups and its correlation with radiological grading of osteoporosis.

Our aim was to estimate the rate of osteogenesis by using tetracycline double labeling and to correlate it with the radiological grading of osteoporosis in patients of intertrochanteric fracture of the femur in different age groups. Thirty-two cases of intertrochanteric fracture of the femur of either sex, without any associated osteopenic conditions, who were admitted for surgery constituted the clinical material. The cases were divided into three age groups: group I, <45 years; group II, 45-60 years; and group III, >60 years. Osteoporosis was graded in all groups on plain X-rays by Singh's index (SI) and metacarpal index (MI). The patients were labeled with a single large dose (1.5 g) of tetracycline orally on day 1 and day 8. An iliac crest bone biopsy specimen was obtained from each of the patients during surgical intervention. Thin undecalcified sections were made by the hand grinding technique. The sections were studied under UV light for presence of fluorescence, and rate of osteogenesis (mineral appositional rate, MAR) was calculated for each of the groups. Only 7 patients were found to have radiological osteoporosis (by Singh's index). The average MI and MAR were found to be 46.5% and 1.48 microm/day, respectively. The single-dose labeling schedule has shown good fluorescent bands, comparable to the conventional dose schedule. No correlation was found between Singh's index and metacarpal index in group I and III, whereas in group II it was significant. There is no significant correlation between the rate of new bone formation and the radiological grading of osteoporosis.

Adult↗
PubMed2002

BEST: a novel computational approach for comparing gene expression patterns from early stages of Drosophila melanogaster development.

Embryonic gene expression patterns are an indispensable part of modern developmental biology. Currently, investigators must visually inspect numerous images containing embryonic expression patterns to identify spatially similar patterns for inferring potential genetic interactions. The lack of a computational approach to identify pattern similarities is an impediment to advancement in developmental biology research because of the rapidly increasing amount of available embryonic gene expression data. Therefore, we have developed computational approaches to automate the comparison of gene expression patterns contained in images of early stage Drosophila melanogaster embryos (prior to the beginning of germ-band elongation); similarities and differences in gene expression patterns in these early stages have extensive developmental effects. Here we describe a basic expression search tool (BEST) to retrieve best matching expression patterns for a given query expression pattern and a computational device for gene interaction inference using gene expression pattern images and information on the associated genotypes and probes. Analysis of a prototype collection of Drosophila gene expression pattern images is presented to demonstrate the utility of these methods in identifying biologically meaningful matches and inferring gene interactions by direct image content analysis. In particular, the use of BEST searches for gene expression patterns is akin to that of BLAST searches for finding similar sequences. These computational developmental biology methodologies are likely to make the great wealth of embryonic gene expression pattern data easily accessible and to accelerate the discovery of developmental networks.

Algorithms↗
PubMed2002

Evolutionary distance estimation under heterogeneous substitution pattern among lineages.

Most of the sophisticated methods to estimate evolutionary divergence between DNA sequences assume that the two sequences have evolved with the same pattern of nucleotide substitution after their divergence from their most recent common ancestor (homogeneity assumption). If this assumption is violated, the evolutionary distance estimated will be biased, which may result in biased estimates of divergence times and substitution rates, and may lead to erroneous branching patterns in the inferred phylogenies. Here we present a simple modification for existing distance estimation methods to relax the assumption of the substitution pattern homogeneity among lineages when analyzing DNA and protein sequences. Results from computer simulations and empirical data analyses for human and mouse genes are presented to demonstrate that the proposed modification reduces the estimation bias considerably and that the modified method performs much better than the LogDet methods, which do not require the homogeneity assumption in estimating the number of substitutions per site. We also discuss the relationship of the substitution and mutation rate estimates when the substitution pattern is not the same in the lineages leading to the two sequences compared.

Animals↗
PubMed2002

Measuring conservation of contiguous sets of autosomal markers on bovine and porcine genomes in relation to the map of the human genome.

Based on published information, we have identified 991 genes and gene-family clusters for cattle and 764 for pigs that have orthologues in the human genome. The relative linear locations of these genes on human sequence maps were used as "rulers" to annotate bovine and porcine genomes based on a CSAM (contiguous sets of autosomal markers) approach. A CSAM is an uninterrupted set of markers in one genome (primary genome; the human genome in this study) that is syntenic in the other genome (secondary genome; the bovine and porcine genomes in this study). The analysis revealed 81 conserved syntenies and 161 CSAMs between human and bovine autosomes and 50 conserved syntenies and 95 CSAMs between human and porcine autosomes. Using the human sequence map as a reference, these 991 and 764 markers could correlate 72 and 74% of the human genome with the bovine and porcine genomes, respectively. Based on the number of contiguous markers in each CSAM, we classified these CSAMs into five size groups as follows: singletons (one marker only), small (2-4 markers), medium (5-10 markers), large (11-20 markers), and very large (> 20 markers). Several bovine and porcine chromosomes appear to be represented as di-CSAM repeats in a tandem or dispersed way on human chromosomes. The number of potential CSAMs for which no markers are currently available were estimated to be 63 between human and bovine genomes and 18 between human and porcine genomes. These results provide basic guidelines for further gene and QTL mapping of the bovine and porcine genomes, as well as insight into the evolution of mammalian genomes.

Animals↗
PubMed2002

Need for revision of nitrates standards for drinking water: a case study of Rajasthan.

An attempt has been made to classify ground waters in various districts of Rajasthan based on distribution of nitrate in their drinking water samples. It is seen that nitrate in ground water is unevenly distributed in the state. Major parts of Churu, Alwar, Bharatpur, Jalore, Jaipur, Sikar, Tonk and Jhunjhunu, are inherited by nitrate rich ground waters while districts like Banswara, Bundi, Bikaner, Chittor, Kota and Jhalawar have low nitrates in their ground waters at many places. It is well documented internationally that water supplied containing high levels of nitrate have been responsible for cases of infantile methemoglobinemia which may ultimately lead to death. A very high infant mortality rate in Rajasthan might be a consequence of high nitrates in drinking water supply. Some recent studies have shown that nitrates in drinking water besides causing methemoglobinemia can result in various other clinical manifestations like recurrent stomatitis, recurrent respiratory tract infections (RRTI) etc. These findings have indicated that a rethinking has to be given to the existing standards for nitrates in drinking water. Based on potential nitrate toxicity studies in view of above health effects the whole region has been classified into five water quality zones, namely, safe, mild, moderately problematic, highly problematic and dangerous. For areas falling under fourth and fifth zones it is recommended that immediate measures be taken to overcome the adverse health effects.

Drinking↗
PubMed2001

Interlaminar discectomy and selective foraminotomy in lumbar disc herniation.

Our objective was to assess the clinical outcome of interlaminar discectomy in patients suffering with degenerated lumbar disc lesions. We made a prospective study of 50 consecutive patients who underwent limited lumbar discectomy. The clinico-radiological parameters, type of surgery performed and the post-operative follow up were assessed. We found that interlaminar discectomy without laminotomy was adequate in 33 cases (66%). Most patients requiring laminotomy (17 cases -34%) for discectomy had associated lumbar canal stenosis, herniation at proximal levels (L3-4) and/or sacralization of L5 vertebra. Selective foraminotomy in addition to discectomy was performed in 28 cases (56%). The post-operative results were good in 43 (86%fair in 6 (12%) and poor subjective in 1 case (2%). No patient was classified as poor objective. In conclusion, interlaminar discectomy without laminotomy is a safe, effective and reliable surgical technique for treating properly selected patients with herniated lumbar disc at L4-5 and L5-S1 levels.

Journal Article↗