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Biomedical subjects

B Sharma

Publications and source records attributed to B Sharma.

At least 37 records · Page 2Linked to original sources
PubMed1997

Examination of soils from residential garbage in Betul, India, for fungi by the keratin baiting technique.

A report on an examination of soils from residential garbage of Betul, India, for fungi by the keratin (materials) baiting technique is presented. A total of 69 fungi representing 39 species among 17 genera were isolated. In all the soil samples, only two genera, namely Aspergillus (190.9%), followed by Fusarium (118.18%), were most frequently isolated. Maximum colonisation of fungi was found on hair, followed by horn, feathers and nails. For the first time, the genus Fusoma is reported here as a keratinophilic fungus. The keratin baiting technique was found very effective in detecting a broad spectrum of fungi in biological wastes and compost.

Aspergillus↗
PubMed1997

Clinical correlates of CT abnormality in generalized childhood epilepsy in India.

The CT scan gives valuable insight into the aetiology of epilepsy. Studies done so far in India suggest that the causes are quite different from the West. CT scan has become available in larger cities in India, but is expensive. Information about clinical features that may 'predict' a CT abnormality would be useful to clinicians. The object was to determine which, if any, of 10 clinical features predict a CT abnormality in patients presenting with generalized epilepsy. Consecutive children with generalized epilepsy were enrolled prospectively and clinical features charted. Predetermined clinical variables were compared in those with and without CT abnormality. The setting was a pediatric in-patients and out-patients of a teaching hospital in northern India. One-hundred-and-sixty-two out of 178 consecutive children (age 1 month to 12 years) presenting with generalized epilepsy; ten clinical features viz seizure type, age at onset, number of seizures, duration of epilepsy, family/antecedent history, mental/neurological deficit, abnormal EEG and evidence of tuberculosis, were studied. Univariate analysis taking (1) CT abnormality/no abnormality and (2) ring/disc enhancing lesion/no such lesion on CT as outcomes. An abnormal CT scan was found in 79 (49 percent) patients. There were two high yield groups: (1) younger children with neurological/mental deficits; (2) older children without deficits. When these two groups were combined, odds ratio for CT abnormality was 3.06 (1.4-6.7). The commonest CT abnormality was a ring/disc like enhancing lesion seen in 32 patients. Higher age at onset (> 4 years), absence of mental/neurological deficits, generalized tonic-clonic type of seizures and fewer episodes of seizures at presentation were significantly associated with this finding. In addition to existing indications for CT scan, these results can guide physicians when referring patients for this investigation.

Brain↗
PubMed1997

sfi-independent filamentation in Escherichia coli Is lexA dependent and requires DNA damage for induction.

In Escherichia coli, damage to DNA induces the expression of a set of genes known collectively as the SOS response. Part of the SOS response includes genes that repair DNA damage, but another part of the response coordinates DNA replication and septation to prevent untimely cell division. The classic SOS gene product that inhibits cell division is SfiA (or SulA), which binds to FtsZ and prevents septum formation until the DNA damage has been repaired. However, another pathway acts to coordinate DNA replication and cell division when sfiA, or the sfi-dependent pathway, is inoperative. Until recently, little was known of this alternative pathway, which is called the sfi-independent pathway. We report here that sfi-independent filamentation is suppressed by lexA(Ind-) mutations, suggesting that derepression of the LexA regulon is necessary for sfi-independent induction. However, expression of LexA-controlled genes is not sufficient; DNA damage is also required to induce this secondary pathway of cell division inhibition. Furthermore, we postulate that loss of the common regulatory circuitry of the sfi-dependent and sfi-independent pathways by recA or lexA mutants uncouples cell division and DNA replication.

Bacterial Proteins↗
PubMed1997

Cardiovascular responses to treadmill exercise testing in anemia.

OBJECTIVE: To study exercise performance on a treadmill in anemic children. DESIGN: Prospective case control study. SETTING: Department of Pediatrics and Intensive Care Unit, Department of Medicine, King George's Medical College, Lucknow. SUBJECTS: The study population consisted of 41 cases of anemia (10 mild, 21 moderate and 10 severe) and 11 normal age and height matched children aged between 7-12 years. METHODS: These subjects were exercise tested on Quinton Model Q5000 treadmill using Modified Naughton Q5000 protocol. Heart rate, systolic blood pressure, double product, ECG changes, exercise duration and metabolic equivalents achieved during peak exercise were studied. Statistical analysis was performed using analysis of variance (ANOVA) test. RESULTS: No significant difference was observed in values of resting heart rate, heart rate at peak exercise, recovery heart rate, blood pressure response, resting double product, double product at peak exercise, recovery double product and ECG changes in any of the study groups (p > 0.05). However, the gain in heart rate at peak exercise compared to basal value, and double product, total exercise duration and metabolic equivalent (MET) values at peak exercise were significantly low in anemic children on comparison to normal controls (p < 0.001). CONCLUSIONS: Cardiovascular responses are blunted in anemia, mainly because of depleted cardiac reserve.

Analysis of Variance↗
PubMed1996

Epidemiology of Staphylococcus aureus during space flight.

Staphylococcus aureus was isolated over 2 years from Space Shuttle mission crewmembers to determine dissemination and retention of bacteria. Samples before and after each mission were from nasal, throat, urine, and feces and from air and surface sampling of the Space Shuttle. DNA fingerprinting of samples by digestion of DNA with SmaI restriction endonuclease followed by pulsed-field gel electrophoresis showed S. aureus from each crewmember had a unique fingerprint and usually only one strain was carried by an individual. There was only one instance of transfer between crewmembers. Strains from interior surfaces after flight matched those of crewmembers, suggesting microbial fingerprinting may have forensic application.

DNA Fingerprinting↗
PubMed1996

A peroxiredoxin antioxidant is encoded by a dormancy-related gene, Per1, expressed during late development in the aleurone and embryo of barley grains.

Antioxidants can remove damaging reactive oxygen species produced as by-products of desiccation and respiration during late embryogenesis, imbibition of dormant seeds and germination. We have expressed a protein, PER1, encoded by the Balem (barley aleurone and embryo) transcript previously called B15C, and show it to reduce oxidative damage in vitro. PER1 shares high similarity to a novel group of thiol-requiring antioxidants, named peroxiredoxins, and represents a subgroup with only one conserved cysteine residue (1-Cys). PER1 is the first antioxidant belonging to the 1-Cys subgroup shown to be functionally active, and the first peroxiredoxin of any kind to be functionally described in plants. The steady state level of the transcript, Per1, homologous to a dormancy-related transcript (pBS128) from bromegrass (Bromus secalinus), increases considerably in imbibed embryos from dormant barley (Hordeum vulgare L.) grains. Our investigations also indicate that Per1 transcript levels are dormancy-related in the aleurone layer of whole grains. In contrast to most seed-expressed antioxidants Per1 disappears in germinating embryos, and in the mature aleurone the transcript is down-regulated by the germinating embryo or by gibberellic acid (GA). Our data show that the barley seed peroxiredoxin is encoded by a single Per1 gene. Possible roles of the PER1 peroxiredoxin in barley grains during desiccation, dormancy and imbibition are discussed.

Antioxidants↗
PubMed1996

Sensitization of bacteria to danofloxacin by temperate prophages.

Danofloxacin (CP-76,136) is in a class of agents that inhibit DNA gyrase and trigger induction of the SOS response and temperate bacteriophages. Killing studies against the bovine pathogen Pasteurella haemolytica demonstrated that danofloxacin exhibits particularly rapid killing kinetics. Here, lysogenic Escherichia coli bearing lambda is found to be more sensitive to danofloxacin than nonlysogenic E. coli. Danofloxacin exposure also induced a prophage in P. haemolytica. The potency of danofloxacin against lysogens in likely enhanced by this prophage induction.

Animals↗
PubMed1996

Perinatal mortality in urban slums in Lucknow.

OBJECTIVES: To determine the perinatal mortality rate (PNMR) in the urban slums of Lucknow DESIGN: Cross-sectional survey. SETTING: Twenty five Anganwadi centres of urban Lucknow, with a population of 25,901. METHODS: Data was collected on birth and early neonatal deaths, gestational age of the neonate (determined at birth) and maternal variables like socio-economic status, maternal age, parity, and bad obstetrical history from January 1992 to March 1993. RESULTS: There were 966 births with a still-birth rate of 37.2 and PNMR of 59.0 per 1000. The relative risk of perinatal mortality with lower socio-economic status was 1.87, bad obstetrical history 2.18, and gestational age < 37 weeks 1.95. CONCLUSIONS: Further reduction in PNMR may be possible with focussed medical services to women of low socio-economic status having bad obstetrical history and those delivering before term.

Cross-Sectional Studies↗
PubMed1996

Value of CT scan in the diagnosis of meningitis.

OBJECTIVE: To study the diagnostic test characteristics of computed tomography (CT scan) in differentiating tuberculous (TBM) and pyogenic (PM) meningitis. DESIGN: Prospective diagnostic test evaluation. SETTING: Teaching hospital. METHODS: Children beyond 1 month of age admitted with meningitis were enrolled prospectively and CT scan done. Results of CT scan were compared with predefined gold standards for the diagnosis of either TBM or PM. RESULTS: CT scan was performed in 154 patients with meningitis. Of these 94 were TBM, 52 had PM and 8 were indeterminate and excluded from analysis. Basal enhancement, ventriculomegaly, tuberculoma and infarction were all significantly more common in the TBM group, while subdural collections were seen more in the PM group. The highest sensitivity (89.2%) and specificity (100%) for diagnosis of TBM were found for basal enhancement or tuberculoma or both. CONCLUSIONS: CT scan can be used to effectively distinguish TBM and PM.

Cerebral Infarction↗
PubMed1996

Isolation of poliovirus from cases of acute flaccid paralysis.

OBJECTIVE: To evaluate the frequency of isolation of polio and other viruses from fecal samples in subjects with acute flaccid paralysis in northern parts of India. SETTING: Rural and Urban Immunization Centers used for Expanded Programme on Immunization. METHODS: 219 fecal samples were collected by anal tube in 1992 from Punjab, Haryana, Himachal Pradesh and Chandigarh and processed for virus isolation. RESULTS: Of 219 fecal samples, 103 (47%) were positive for viruses in the age group of 3 mo to 5 yr. Amongst the positive samples, the predominant isolated was poliovirus type 1 (70.9%) from all the States. Non polio enteroviruses were isolated from 20.4% of fecal samples. CONCLUSION: Even though poliovirus is still the most common etiologic agent for acute flaccid paralysis in northern India, non polio enteroviruses are also emerging as important causal pathogens in this condition.

Acute Disease↗
PubMed1995

Regulation of the activity of human chymase during storage and release from mast cells: the contributions of inorganic cations, pH, heparin and histamine.

Chymase, the major chymotryptic proteinase of human mast cells, can be released in substantial quantities following mast cell activation. As this enzyme is stored in the secretory granules in its fully active form, we have investigated various factors which might regulate its activity in storage and upon release. Chymase was purified from human skin by high salt extraction, cetylpyridinium chloride precipitation, heparin agarose affinity chromatography and gel filtration. Neither the addition of Mg2+ or Ca2+ (0.3-10 mM) nor their sequestration by EDTA had any effect on the rate of cleavage of the synthetic substrate N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide. Monovalent cations (Na+,K+) enhanced enzyme activity, but only at non-physiological concentrations (0.5-3.0 M), suggesting an ionic strength effect. At constant I = 0.15, enzyme activity was strongly pH-dependent: at pH 5.5 (the approximate pH of the mast cell granule) the activity was only 10% of that at pH 7.5 (the approximate pH of the extracellular space). Heparin, which is stored with chymase in the mast cell granule, accentuated this difference by enhancing activity at pH 7.5 by 33% and depressing it a pH 5.5 by 40%. Histamine at concentrations up to 50 mM (I = 0.15) had little effect on chymase activity at either pH, although high concentrations did attenuate the actions of heparin. It is concluded that pH and the interaction with heparin are central to the regulation of chymase activity within the granule and following release.

Amino Acid Sequence↗
PubMed1995

Scintigraphic diagnosis of protein losing enteropathy using Tc-99m dextran.

The authors performed abdominal scintigraphy using intravenously administered Tc-99m dextran in a patient with protein losing enteropathy. The study revealed abnormal leakage of the radiotracer in the left lumber area that moved over time in a pattern suggestive of small intestinal transit. Besides being a nonprotein and having long stay in intravascular compartment, the macromolecule may have many advantages over Tc-99m human serum albumin, the current radiotracer of choice for imaging intestinal protein loss.

Adult↗
PubMed1995

Insertion of inverted Ter sites into the terminus region of the Escherichia coli chromosome delays completion of DNA replication and disrupts the cell cycle.

To investigate the co-ordination between DNA replication and cell division, we have disrupted the DNA-replication cycle of Escherichia coli by inserting inverted Ter sites into the terminus region to delay completion of the chromosome. The inverted Ter sites (designated InvTer::spcr) were initially inserted into the chromosome of a delta tus strain to allow unrestrained chromosomal replication. We then introduced a functional tus gene by transforming the InvTer::spcr strain with a plasmid carrying the tus gene under control of an arabinose-inducible promoter. In the presence of 0.2% arabinose, the cells formed long filaments, suggesting that activation of the inverted Ter sites by Tus arrested DNA replication and delayed the onset of cell division. Induction of sfiA, a gene in the SOS regulon, was observed following arrest of DNA replication; however, when a sfiB114 allele was introduced into InvTer::spcr strain, long filaments were still formed, suggesting that the sfi-independent pathway also caused filamentation. Either recA::camr or lexA3 alleles suppressed filamentation when introduced in the InvTer strain. Interestingly, in both the recA::camr and lexA3 mutants, virtually all cells had a nucleoid, suggesting that cell division was proceeding even though DNA replication was not complete. These results suggest that DNA replication and cell division are uncoupled when recA is inactivated or when genes repressed by LexA cannot be induced.

Bacterial Proteins↗
PubMed1995

Isolation of Pasteurella haemolytica leukotoxin mutants.

Two mutants of Pasteurella haemolytica A1 that do not produce leukotoxin were isolated. Following mutagenesis, colonies were screened with antiserum by a filter assay for absence of the secreted leukotoxin. The two mutants both appeared to produce normal amounts of other antigens, as judged by reactivity with polyclonal serum from an animal with pasteurellosis, and were not altered in beta-hemolytic activity as seen on blood agar plates. There was no evidence of either cell-associated or secreted leukotoxin protein when Western blots (immunoblots) were carried out with the polyclonal serum or with a monoclonal antibody directed against the leukotoxin. Southern blots revealed that both mutants show the wild-type restriction pattern at the leukotoxin locus, although the strain with the lktA2 mutation showed differences in other regions of the chromosome on analysis by pulsed-field gel electrophoresis. The strain with the lktA2 mutation grew more slowly than did the wild-type strain, while the strain with the lktA1 mutation was indistinguishable from the wild-type strain in its growth properties. The strain with the lktA1 mutation should be valuable in determining the role of the leukotoxin in virulence as well as in identifying other virulence factors of P. haemolytica.

Bacterial Toxins↗
PubMed1995

Cloning of 2.4 kb bovine herpesvirus-1 DNA fragment containing glycoprotein III gene into pUC18 plasmid vector.

A recombinant pBR322 plasmid containing bovine herpesvirus-1 HindIII 'I' fragment was analysed using EcoRI and BamHI restriction endonucleases. This recombinant plasmid was labelled with [alpha 32P]dATP and hybridized with southern blot of HindIII digested BHV-1 DNA fragments. A 2.4 kb double digested EcoRI-BamHI fragment of HindIII 'I' was subcloned into pUC18 plasmid to get complete gIII gene. The recombinant pUC18 plasmid was analysed for 2.4 kb BHV-1 DNA insert by restriction digestion with EcoRI and BamHI. Southern blot of restriction digested plasmid was hybridized with [alpha 32P]dATP labelled BHV-1 DNA probe.

Animals↗
PubMed1995

Cloning of HindIII digested bovine herpesvirus-1 DNA fragments from an Indian respiratory isolate.

The DNA from an Indian isolate of Bovine Herpesvirus-1 was isolated and analysed with restriction endonucleases. On shot gun cloning seven HindIII digested BHV-1 DNA fragments could be cloned in pBR322 vector. Recombinant clones with viral DNA insert was identified by insertional inactivation of the selection marker and restriction analysis of recombinant plasmids with HindIII. Further, recombinant plasmids were analysed with HindIII, EcoRI and BamHI restriction endonucleases to identify the different viral DNA inserts. The restriction site map of recombinant plasmids were correlated with the map reported earlier. The southern blot of restriction digested recombinant plasmids was hybridized with radio-labelled BHV-1 DNA as probe.

Animals↗