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Biomedical subjects

R D Kulkarni

Publications and source records attributed to R D Kulkarni.

At least 19 recordsLinked to original sources
PubMed2006

Inconsistencies between human genetic cytolocations and those derived using genomic sequence.

One result of the publishing of the human genome sequence is the ability to define objects through their position on the consensus sequence. While this has simplified the process of creating order maps for genes on a chromosome, it has created discrepancies between the published cytolocations of human genes, as presented through genetic references, and those locations derived computationally from the genomic sequence. For the 6,830 records with HUGO gene symbols shared between the online version of Mendelian Inheritance in Man and Ensembl, 18% of the records have a discrepancy of at least one cytogenetic band between the datasets. Discordance between data sets at this frequency would have a significant impact on the utility of datasets created by the amalgamation of numerous biological databases.

Base Sequence↗
PubMed2005

Modified cold Z-N staining for presumptive identification of Brucella.

Brucellosis is one of the most common zoonotic diseases in India. Growth of Brucella is slow and needs meticulous biochemical tests and antisera for confirmation of the isolates. In the present study modified cold ZN staining was tried on the broth cultures for early presumptive identification of Brucella growth. Blood cultures were attempted in 22 seropositive patients. In the five blood cultures positive for Brucella, acid-fast coccobacilli were seen in broth smears stained with modified cold ZN stain, thus providing presumptive identification of Brucella growth. Acid-fast bacteria were not seen in the broth smears of the remaining 17 broths negative for Brucella growth. The method is simple, reliable and reproducible and needs to be evaluated further on a larger sample.

Brucella↗
PubMed2003

Identification of proteins that interact with two regulators of appressorium development, adenylate cyclase and cAMP-dependent protein kinase A, in the rice blast fungus Magnaporthe grisea.

Adenylate cyclase (MAC1) and the catalytic subunit of cAMP-dependent protein kinase A (CPKA) are required for appressorium development and pathogenesis in the rice blast pathogen Magnaporthe grisea. To identify new components in the cAMP signal transduction pathway, we used the yeast two-hybrid system to screen MAC1 and CPKA against an appressorium cDNA library. The cDNA library was constructed by GATEWAY recombinational cloning, enabling transfer of the library to various alternative vectors. The protein phosphatase domain in MAC1, which is unique to fungal adenylate cyclases, interacted with a MAP kinase kinase and a Ser/Thr kinase. Interactions of MAC1 with the kinases may prove to be part of feedback loops between the corresponding signaling pathways. A predicted membrane protein, ACI1, which is highly expressed under conditions that are conducive to appressorium formation, also interacted with MAC1. ACI1 has an extracellular domain containing eight-cysteines, which is also present in other fungal proteins implicated in pathogenesis. The N-terminal half of CPKA, which includes a glutamine-rich sequence unique to a group of fungal sequences, interacted with a putative transcriptional regulator and two different glycosyl hydrolases. Phosphorylation motifs in these sequences suggest that they could be CPKA substrates. The protein interaction assay employed here can now be scaled up to identify interactions between a larger set of proteins in the M. grisea interactome.

Adenylyl Cyclases↗
PubMed2002

Relative bioavailability of two brands of ornidazole in twelve healthy volunteers.

AIM OF THE STUDY: To determine the bioequivalence of two marketed ornidazole formulations in healthy volunteers. METHODOLOGY: A single dose relative bioavailability of Ornidazole 1.5 g (3 x 500 mg tablets) of test product (Giro, Panacea Biotec Ltd.) and that of standard reference (Dazolic, Sun Pharmaceutical Industries), was investigated in healthy adult males. A total of 12 subjects wee enrolled in the study and investigations consisted of two treatment phases separated by a washout period of seven days. Both treatment phases were of 12 hours durations each. Blood samples were collected at 0, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10 and 12 hours post-administration of assigned drug product. Appropriate fasting restrictions were employed during both the treatment phases. Drug assay was done using HPTLC method. The statistical significance of difference in pharmacokinetic parameters between preparations was tested using ANOVA. RESULTS: The mean peak plasma concentration (Cmax) of 32.67 +/- 4.45 microg/ml was achieved at 1.54 +/- 0.81 hours following administration of test product as against mean Cmax of 31.55 +/- 5.04 microg/ml at 1.79 +/- 0.89 hours for reference standard. The area under time concentration curve (AUC(0-12)) hours was 261.67 +/- 77 microg/ml hours with reference standard and 265.41 +/- 30.82 microg/ml hours for test product. CONCLUSION: There was no statistically significant difference between the two formulations and the two products

Adult↗
PubMed2000

Comparative bioavailability study of clonazepam after oral administration of two tablet formulations.

OBJECTIVE: To assess the bioavailability of clonazepam from two brands of 2 mg tablet formulations--Epitril and reference brand. METHODS: A two-way randomised cross-over bioavailability study was carried out in 12 healthy male volunteers. Coded plasma samples were analysed for levels of clonazepam by high performance liquid chromatography (HPLC) method. RESULTS: The mean Cmax, Tmax t1/2 beta and AUC (0-48) for Epitril were: 16.31 +/- 3.07 ng/mL, 1.63 +/- 0.48 h, 46.97 +/- 12.26 h and 207.70 +/- 57.07 ng/ml.h; for reference brand were 19.75 +/- 5.95 ng/mL, 1.42 +/- 0.29 h, 46.88 +/- 11.29 h and 215.70 +/- 50.89 ng/ml.h respectively. These were comparable and the differences were not statistically significant. CONCLUSION: Based on above pharmacokinetic parameters, Epitril was bioequivalent to reference brand.

Administration, Oral↗
PubMed1999

MerR cross-links to the alpha, beta, and sigma 70 subunits of RNA polymerase in the preinitiation complex at the merTPCAD promoter.

MerR, the metalloregulator of the mercury resistance (mer) operon, binds the operator (merO)between -10 and -35 of the merTPCAD promoter (PT) and sequesters RNA polymerase (RNAP) in a closed complex. MerR represses PT until Hg(II) induces it to underwind merO DNA and thus facilitate open complex formation. We used cross-linking to determine if direct contacts between MerR and RNAP also occur during this process. MerR cross-linked to the alpha, beta, and sigma70 subunits of RNAP alone, indicating stable contacts which were further stabilized upon forming the preinitiation complex at PT. Hg(II) did not eliminate any of the MerR-RNAP cross-links but did increase the relative abundance of a MerR dimer conformer. Interference by MerR with self-cross-links among RNAP subunits and the formation of an electrophoretically stable association between MerR and RNAP also indicated MerR-RNAP interactions. This is the first evidence for stable physical contacts between MerR and RNAP and for a Hg(II)-induced allosteric change in MerR in the transcription-competent complex.

Bacterial Proteins↗
PubMed1997

mRNA stability is regulated by a coding-region element and the unique 5' untranslated leader sequences of the three Synechococcus psbA transcripts.

The psbAI and psbAIII transcripts in Synechococcus sp. strain PCC 7942 are subject to accelerated turnover when cells are exposed to high light intensities, but psbAII message stability is unaffected. We used a psbAI 'minigene' which has a part of the coding sequence removed as a reporter gene in order to identify the cis-acting elements of the transcript that determine stability. While engineering the minigene to optimally mimic the native gene, we identified a stabilizer element within the open reading frame, corresponding to the coding region for the first membrane span of the D1 protein, the presence of and translation through which was essential for normal psbA mRNA stability. We propose that this stabilizer is a site for ribosome pausing, and that accumulation of ribosomes on the transcript upstream of the pause site increases stability. To identify the elements that regulate the differential responses of the psbA transcripts to high-light growth, sequences from psbAII and psbAIII were substituted in the psbAI minigene reporter. The chimeric reporter transcripts established that the psbAI and psbAIII untranslated leaders determine the faster turnover of these messages. The untranslated leader regions of the psbA transcripts may regulate mRNA stability by modulating translation and thereby stability, or by recruiting RNA-binding proteins that affect mRNA turnover more directly.

Cyanobacteria↗
PubMed1995

Can chronic maternal drug therapy alter the nursing infant's hepatic drug metabolizing enzyme pattern?

This study was carried out to investigate whether minute quantities of maternal drugs ingested over an extended period of time by a breast-feeding infant can alter the activity pattern of the infant's hepatic drug metabolizing enzyme (HDME). The HDME activity patterns of 12 breast-fed infants whose mothers were not on drug therapy were compared with those of 11 infants whose mothers had been taking 30 micrograms levo-norgesterel daily for 90 to 195 days (oral contraceptives group) and of 10 infants whose mothers had been taking ethambutol and isoniazid daily since pregnancy (tuberculosis group). As 6 beta hydroxycortisol in urine is considered to be a good and acceptable reflector of HDME activity, it was estimated from the infants' urine using enzyme-linked immunosorbent assay (ELISA) technique. A comparison of the patterns between 90 days of age and 195 days of age of the infants in the control group and the two study groups indicated an increase from 36.6 ng/mL to 58.4 ng/mL at 195 days in the control group. An initial decrease from 36.6 ng/mL to 26.2 ng/mL was noted with commencement of maternal levo-norgesterel therapy, followed by a slow and steady rise to 47.8 ng/mL at 195 days of age, with a shift in the peak from 120 to 135 days of infants age in the oral contraceptive group. A suppressed pattern with decreased levels of 6 beta hydroxycortisol ranging from 19.3 ng/mL to 26.5 ng/mL at 195 days was found in the tuberculosis group. The data were analyzed by two-way analysis of variance (ANOVA) coupled with Duncan's Multiple range test. Both treatment group showed significant differences from the control group at the 0.050 level. The HDME plays an important role in determining the final outcome of any drug in humans, as it controls the metabolism of drugs. Hence, alterations in its activity caused by the transfer of maternal drugs over a prolonged period of time could pose a serious problem to nurslings when they require drugs for their own benefit.

Adult↗
PubMed1995

Is time-interval between mini-pill ingestion and breastfeeding essential?

A study was conducted on four alternate days over an eight-day period in a group of 12 healthy, 20-35 year old exclusively breast feeding women who were interested in weaning their infants. On each study day the women ingested 150 micrograms levonorgestrel. Maternal blood and milk samples were collected at 2, 4, 6, and 8 hr intervals after LNG ingestion on the 1st, 3rd, 5th, and 8th day. A time-dependent decrease in maternal serum and increase in breast milk levels of LNG were observed. Maintaining a time interval between mini-pill intake and breastfeeding results in higher levels of LNG in breast milk, thereby exposing the infant to a bolus of LNG in a "single-delayed" feed.

Administration, Oral↗
PubMed1995

Multidrug resistant non-typhoidal Salmonella infections.

Over a period of 2 years, 28 patients admitted to Government General Hospital (GGH), Sangli (which is attached to Government Medical College (GMC), Miraj) yielded multi-drug resistant non-typhoidal salmonellae from their clinical material. The pediatric age group predominated in the study, accounting for 93% of cases. Salmonella typhimurium was the main isolate (86%), the other being Salmonella newport (14%). Gastroenteritis was the commonest presentation. Septicaemia was seen with 100% mortality, in infants below 1 month of age. Two cases of meningitis were also seen.

Adolescent↗
PubMed1995

Reassessment of frequency of occurrence of typhoid fever and cost efficacy analysis of antibiotic therapy.

Typhoid fever has assumed importance due to the increased incidence of drug resistance in India. The exact magnitude of the problem is not accurately known. The objective of this study was to collect retrospectively the data on the incidence and frequency of typhoid fever among hospital admissions at St. Johns Medical College Hospital (SJMCH), Bangalore during the year 1987 to 1992 and also to study the sensitivity pattern and the use of antibiotics. The study was also aimed at comparison of immunogenicity and tolerance of conventional vaccine to the newer polysaccharide vaccine. It was found that the incidence of typhoid fever showed change from epidemic to endemic situation with outbreaks of epidemics. Sensitivity pattern also showed change during the same period and antibiotic resistance was increasingly demonstrated from 1989. Cost per patient and total cost to the hospital due to increased admissions also showed progressive increase. The polysaccharide vaccine (recently made available in India) had very low adverse reaction profile with higher immunogenicity as compared to conventional vaccine. Its single dose effect with long lasting immunity indicates it probable usefulness in the eradication of disease.

Adolescent↗
PubMed1994

At what 'infant-age' can levonorgestrel contraceptives be recommended to nursing mothers?

OBJECTIVE: Levonorgestrel (LNG), a low-dose progestin, does not affect lactation but like all drugs taken by breastfeeding mothers, it can be transferred to the infant via breast milk. How infants of various ages cope with this unwanted maternal drug would help in deciding when to recommend this method of contraception to breastfeeding mothers. METHODS: The study was conducted in 30 exclusively breastfeeding mothers and their 4-, 12- and 24-week-old infants. The mothers daily received 30 micrograms LNG over a five-week period, thus exposing their infants to maternal LNG for that period. RESULTS: Four-week-old infants could neither absorb nor metabolize LNG efficiently. Twelve-week-old infants could metabolize LNG more efficiently than absorb. Twenty-four-week-old infants could do both efficiently. CONCLUSION: It is safe to introduce LNG to breastfeeding mothers at 12 weeks postpartum.

Adult↗
PubMed1994

Adaptation to high light intensity in Synechococcus sp. strain PCC 7942: regulation of three psbA genes and two forms of the D1 protein.

The three psbA genes in the cyanobacterium Synechococcus sp. strain PCC 7942 encode two distinct forms of the D1 protein of photosystem II. The psbAI message, which encodes form I, dominates the psbA transcript pool at low to moderate light intensities; however, exposure to high light triggers a response in which the psbAI message is actively degraded while psbAII and psbAIII, which encode form II, are transcriptionally induced. We addressed whether these changes result from a generalized stress response and examined the consequence of light-responsive psbA regulation on the composition of D1 in thylakoid membranes. Heat shock and oxidative stress had some effect on levels of the three psbA transcripts but did not produce the responses generated by an increase in light intensity. Prolonged exposure to high light (24-h time course) was characterized by elevated levels of all psbA transcripts through maintenance of high levels of psbAII and psbAIII messages and a rebound of the psbAI transcript after its initial decline. Form II-encoding transcripts were enriched relative to those encoding form I at all high-light time points. Form II replaced form I in the thylakoid membrane at high light despite an abundance of psbAI transcript at later time points; this may be explained by the observed faster turnover of form I than form II in the membrane. We propose that form II is less susceptible to damage at high light and that this qualitative alteration, coupled with increased turnover of D1, protects the cells from photoinhibition.

Adaptation, Physiological↗
PubMed1994

Immunotherapeutic modification by an ayurvedic formulation Septilin.

Effect of Septilin, an ayurvedic formulation proven to be effective in the therapy of chronic infections, was investigated on the phagocytic system and humoral response in rats and mice. Septilin exhibited significant protection in E. coli-induced abdominal sepsis in normal mice and in Staphylococcus aureus-induced sepsis in neutropenic mice. It significantly reduced the viable E. coli cells when incubated with neutrophils in rats. Septilin stimulated the phagocytic function of the reticuloendothelial system in mice. In normal rats, Septilin enhanced anti-SRBC hemagglutination antibody titre by 5.7-fold and showed significant protection in cyclophosphamide-induced humoral suppression.

Animals↗
PubMed1993

Nucleotide sequence of psbB from Synechococcus sp. strain PCC 7942.

The nucleotide sequence was determined for the Synechococcus sp. strain PCC 7942 psbB gene, which encodes the CP-47 protein of Photosystem II. The derived amino-acid sequence is highly conserved with those from other cyanobacterial and chloroplast psbB sequences. Transcript mapping experiments indicated two psbB transcription start sites in Synechococcus.

Amino Acid Sequence↗
PubMed1993

Circadian rhythms in prokaryotes: luciferase as a reporter of circadian gene expression in cyanobacteria.

We have used a luciferase reporter gene and continuous automated monitoring of bioluminescence to demonstrate unequivocally that cyanobacteria exhibit circadian behaviors that are fundamentally the same as circadian rhythms of eukaryotes. We also show that these rhythms can be studied by molecular methods in Synechococcus sp. PCC7942, a strain for which genetic transformation is well established. A promoterless segment of the Vibrio harveyi luciferase structural genes (luxAB) was introduced downstream of the promoter for the Synechococcus psbAI gene, which encodes a photosystem II protein. This reporter construction was recombined into the Synechococcus chromosome, and bioluminescence was monitored under conditions of constant illumination following entrainment to light and dark cycles. The reporter strain, AMC149, expressed a rhythm of bioluminescence which satisfies the criteria of circadian rhythms: persistence in constant conditions, phase resetting by light/dark signals, and temperature compensation of the period. Rhythmic changes in levels of the native psbAI message following light/dark entrainment supported the reporter data. The behavior of this prokaryote disproves the dogma that circadian mechanisms must be based on eukaryotic cellular organization. Moreover, the cyanobacterial strain described here provides an efficient experimental system for molecular analysis of the circadian clock.

Circadian Rhythm↗
PubMed1993

Protective effect of Liv.52 on alcohol-induced fetotoxicity.

The adverse effects of maternal alcohol consumption on the development of the fetus are well known. The adverse effects of ethanol on the liver are now believed to be due to acetaldehyde formed as an intermediate metabolite of ethanol. Liv.52 has been shown to bring about faster elimination of acetaldehyde from the body and thus prevent alcoholic liver damage. Other toxic effects of alcohol may also be due to acetaldehyde and may be prevented by Liv.52. In this study, rats were given 20% (v/v) ethanol in drinking water, during the gestation period, and the effect on maternal body weight and fetal outcome was noted. The protective effect of Liv.52 administration during the gestation period was studied. The results show that ethanol ingestion caused a decrease in gestational weight gain, total fetal weight, and number of live fetuses. There were increases in resorptions. Liv.52 administration reduced the deleterious effects of ethanol. The concentration of acetaldehyde in the amniotic fluid of ethanol-consuming animals was 0.727 microgram/ml. Liv.52 administration lowered it to 0.244 microgram/ml. The protective effect of Liv.52 could be due to the rapid elimination of acetaldehyde.

Acetaldehyde↗