PubMed Health⌕ Search

Biomedical subjects

V Verma

Publications and source records attributed to V Verma.

At least 19 recordsLinked to original sources
PubMed2007

Isolation and characterization of embryonic stem cell-like cells from in vitro-produced buffalo (Bubalus bubalis) embryos.

This study was carried out to isolate and characterize buffalo embryonic stem (ES) cell-like cells from in vitro-produced embryos. Inner cell mass (ICM) cells were isolated either mechanically or by enzymatic digestion from 120 blastocysts whereas 28 morulae were used for the isolation of blastomeres mechanically. The ICM cells/ blastomeres were cultured on mitomycin-C-treated feeder layer. Primary cell colony formation was higher (P < 0.05) for hatched blastocysts (73.1%, 30/41) than that for early/expanded blastocysts (25.3%, 20/79). However, no primary cell colonies were formed when blastomeres obtained from morulae were cultured. Primary colonies were formed in 14.1% (12/85) of intact blastocyst culture, which was significantly lower (P < 0.05) than that of 41.6% for ICM culture. These colonies were separated by enzymatic or mechanical disaggregation. Using mechanical disaggregation method, the cells remained undifferentiated and two buffalo ES cell-like cell lines (bES1, bES2) continued to grow in culture up to eight passages. However, disassociation through enzymatic method resulted in differentiation. Undifferentiated cells exhibited stem cell morphological features, normal chromosomal morphology, and expressed specific markers such as alkaline phosphatase (AP) and Oct-4. Cells formed embryoid bodies (EBs) in suspension culture; extended culture of EBs resulted in formation of cystic EBs. Following prolonged in vitro culture, these cells differentiated into several types of cells including neuron-like and epithelium-like cells. Furthermore, the vitrified-thawed ES cell-like cells also exhibited typical stem cell characteristics. In conclusion, buffalo ES cell-like cells could be isolated from in vitro-produced blastocysts and maintained in vitro for prolonged periods of time.

Animals↗
PubMed2006

Effects of short-term and chronic olanzapine treatment on immediate early gene protein and tyrosine hydroxylase immunoreactivity in the rat locus coeruleus and medial prefrontal cortex.

Atypical antipsychotic drugs, such as olanzapine, have been reported to activate the locus coeruleus (LC) and lead to acute expression of the Fos-like immediate early gene (IEG) protein in the LC and medial prefrontal cortex (mPFC). Stimuli that activate the LC have been reported to increase expression of tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine synthesis. However, the effects of chronic treatment with olanzapine on IEG expression and the dose-dependence of the effects of olanzapine on IEG and TH expression are not known. Thus, we examined Fos-like, c-Jun, activating transcription factor 2 (ATF-2), early growth response 1 (Egr-1), early growth response 2 (Egr-2), and TH immunoreactivity expression in the LC and mPFC in rats receiving 2, 4, 8, or 15 mg/kg/day olanzapine by s.c. osmotic minipump for 4 h, 1 week, 2 weeks, or 4 weeks. ATF-2 expression was up-regulated at all treatment durations, while Egr-1 and Egr-2 were down-regulated in both the LC and mPFC. Fos-like expression was up-regulated through 2 weeks, but not 4 weeks, in both the LC and mPFC. C-Jun expression was up-regulated for 4 weeks in the LC and for 2 weeks, but not 4 weeks, in the mPFC. At all doses, there were rapid and sustained increases in TH immunoreactivity in the LC, but only delayed increases in the mPFC. These data indicate that olanzapine has rapid effects on IEG in the LC and mPFC, many of which are sustained through four weeks of treatment. Further, these data indicate that the delayed increase in TH expression in the mPFC parallels, and may play an important role in, the increased efficacy of olanzapine that emerges over time in humans.

Analysis of Variance↗
PubMed2006

Quantitative determination of four constituents of Tinospora sps. by a reversed-phase HPLC-UV-DAD method. Broad-based studies revealing variation in content of four secondary metabolites in the plant from different eco-geographical regions of India.

This paper describes the separation and quantitation of important markers, such as 20beta-hydroxyecdysone, tinosporaside, cordioside, and columbin, present in three species of Tinospora viz, T. cordifolia, T. malabrica, and T. crispa. A reverse-phase (RP) high-performance liquid chromatography (HPLC)-UV-diode array detection (DAD) method employing gradient elution is thus developed. The marker compounds isolated from 70% ethanolic extract of T. cordfolia by repeated column chromatography are identified on the basis of (1)H NMR, (13)C NMR, and mass spectral data. The compounds are separated on a RP (RP-18, 5 microm, 250 x 4.6-mm i.d.) column using water-acetonitrile gradient and are detected by the HPLC-UV-DAD method. The calibration curves that result from marker compounds in the concentration range of 100-2000 ng on column exhibit a good correlation (r(2) > or = 0.99978). The method is successfully applied to separate and study the content of four marker compounds in 40 different accessions of three Tinospora species collected from different regions of India. The studies reveal that the maximum amount of the marker compounds is present in Tinospora cordifolia species, especially from accessions collected from higher altitudes of the Jammu province (North India).

Calibration↗
PubMed2006

Distribution of hepatitis C virus genotypes in beta-thalassaemic patients from Northern India.

Multitransfused beta-thalassaemic patients constitute a population having a higher prevalence of hepatitis C virus (HCV) infection because of its transmission from infected blood collected during seronegative window period. HCV genotyping in thalassaemic patients is mainly useful for the clinical management of the patients and for facilitating decisions on therapy. Thus, the aim of the present study was to identify the genotypes that are prevalent in thalassaemic patients and to correlate these with gender, age, number of blood transfusions and the liver function test profiles. Reverse transcription-polymerase chain reaction (RT-PCR) was carried out in 80 beta-thalassaemic patients (58 men and 22 women) for detection of HCV RNA who were seronegative for hepatitis B virus or human immunodeficiency virus antibodies. HCV genotyping was carried out by restriction fragment length polymorphism (RFLP) method of Chinchai et al. Type-specific PCR followed by direct sequencing was also used to confirm the mixed-genotype infection. Among the 80 thalassaemic patients, 20 and eight patients were infected with genotypes 3 and 1, respectively, whereas two cases had infection with HCV genotype1c/5a. The serum levels of aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase were found to be significantly altered between the two groups of HCV-infected and noninfected thalassaemic patients. No significant correlation was observed between genotypes when compared with gender, age and number of blood transfusions, except significantly higher level of ALP in genotype 1 than in genotype 3. Genotype 3 alone was the predominant type in beta-thalassaemic patients, with approximately 45% being infected with mixed type. Hence, detection of HCV RNA would help in decreasing the transmission of HCV-infected blood collected during the seronegative window period, whereas determination of genotypes would provide help in adoption of different treatment policies for better management of thalassaemic patients.

Adolescent↗
PubMed2006

Bioreactor studies on the endophytic fungus Entrophospora infrequens for the production of an anticancer alkaloid camptothecin.

Twigs (young and old) from Nothapodytes foetida growing in the Jammu and Mahabaleshwar regions in India were used for the isolation of 52 strains of endophytic fungi and were tested for their ability to produce the anticancer alkaloid camptothecin. One of the isolates from the inner bark tissue of the N. foetida plant growing in the Jammu region of J&K state, India, was found to produce detectable quantities of camptothecin and its derivatives when grown in a semi-synthetic liquid medium. Camptothecin was identified by physicochemical analysis and further confirmed by spectroscopic studies. No camptothecin was detected in zero time cultures or in uninoculated culture broth. The maximum yield of camptothecin was 0.575 +/- 0.031 mg/100 g of dry cell mass in 96 h in shake flasks, whereas 4.96 +/- 0.73 mg/100 g of dry mass was recorded in 48 h in a bioreactor.

Alkaloids↗
PubMed2006

Molecular characterization of hepatitis A virus from a large outbreak from Kerala, India.

BACKGROUND & OBJECTIVES: Hepatitis A is highly prevalent in India and mainly presents as a sporadic disease. This study investigated an outbreak of viral hepatitis at Medical College Hospital area, Kottayam, Kerala state, India during January 2005. METHODS: Blood (133), faecal (1), sewage (4), and water samples (13) were collected. Sera were tested for IgG- and IgM-anti-HAV and IgM antibodies against hepatitis E (IgM-anti-HEV). Sewage, faeces and water samples were tested for HAV RNA in nested RT-PCR and HAV RNA positive samples were further processed for RNA quantitation using Real Time PCR. RESULTS: Of the 1180 total cases, 540 were reported from Medical college area. Two deaths were reported among doctors. Patients from the community gave a previous history of visit to medical college hospital area. The sewage treatment plant at the campus was non-functional since 1990 and the untreated sewage was constantly overflowing and getting mixed with a canal. At the time of the study, all the water sources were superchlorinated. HAV RNA was present in the faeces of hepatitis A patient (1.36 x 10(7) copies/ml), sewage tank (2.57 x 10(3) copies/ml and the canal (<100 copies/ml). None of the 13 water samples concentrated 10,000-fold and the soil sample showed presence of HAV RNA. Phylogenetic analysis based on 5'-non-coding and P2 regions showed HAV-genotype IIIA in all samples. INTERPRETATION & CONCLUSION: The aetiological agent of the present outbreak was found to be HAV. Epidemic hepatitis A (genotype-IIIA) is emerging in Indian adults, emphasizing the need for definite policy for control.

Antibodies, Viral↗
PubMed2005

Anti-HCV seropositivity among multiple transfused patients with beta thalassaemia.

Hepatitis C virus is considered to be the main aetiological agent responsible for the occurrence of post-transfusion hepatitis. Patients with thalassaemia acquire hepatitis most often from viruses contracted through blood transfusions. The present study was undertaken to evaluate the prevalence of hepatitis C virus (HCV) in thalassaemic patients with multiple blood transfusions. The association of HCV seropositivity with number of blood transfusions and liver enzyme profile was also analysed. The study group consisted of fifty patients (40 males and 10 females) attending the thalassaemic unit of Lok Nayak Hospital, a tertiary care hospital at Delhi, within the age group of 1-25 years. Thirty patients (60%) were found to be seropositive for HCV antibodies while one patient (2%) was co-infected with HCV antibodies and hepatitis B surface antigen. Study of liver enzyme profile showed aspartate aminotransferase levels to be significantly higher, although the level of serum alanine aminotransferase, alkaline phosphatase, total protein, bilirubin and albumin were not significantly altered in these patients. It is inferred from this study that 60% of the thalassaemics were infected with HCV and this was directly related to the number of blood transfusions received by them. The regularised national blood policy followed by blood banks for providing safe blood along with better screening method of donated blood in blood banks would bring down the incidence of hepatitis C in such high risk group.

Blood Transfusion↗
PubMed2005

Microplate nitrate reductase assay versus Alamar Blue assay for MIC determination of Mycobacterium tuberculosis.

A rapid colorimetric, microplate based nitrate reductase assay (NRA) method for minimum inhibitory concentration (MIC) determination of clinical isolates of Mycobacterium tuberculosis was compared with the microplate Alamar Blue assay (MABA), presently in vogue. Reproducible results were obtained in 7 days by NRA. The NRA method was found to be inexpensive, suitable for MIC determination against M. tuberculosis and can be suggested as an ideal substitute to MABA.

Biological Assay↗
PubMed2004

Cloning, sequencing and partial characterisation of sorbitol transporter (srlT) gene encoding phosphotransferase system, glucitol/sorbitol-specific IIBC components of Erwinia herbicola ATCC 21998.

A DNA fragment of approximately 1500 bp, harbouring the sorbitol transport gene (srlT), was amplified from the chromosomal DNA of Erwinia herbicola ATCC 21998 by PCR and cloned in Escherichia coli JM109. Degenerate oligonucleotide primers used were designed based on the conserved regions in the gene sequences within the gut operon of E. coli (Gene Bank accession no. J02708) and the srl operon of Erwinia amylovora (Gene Bank accession no. Y14603). The cloned DNA fragment was sequenced and found to contain an open reading frame of 1473 nucleotides coding for a protein of 491 amino acids, corresponding to a mass of 52410 Da. The nucleotide sequence of this ORF was highly homologous to that of the gutA gene of Escherichia coli gut operon, the srlE gene of Shigella flexrni and the sorbitol transporter gene sequence of Escherichia coli K12 (Gene Bank accession nos. J02708, AE016987 and D90892 respectively). The protein sequence showed significant homology to that of the phosphotransferase system i.e. the glucitol/sorbitol-specific IIBC components of Escherichia coli and Erwinia amylovora (P56580, O32522). The cloned DNA fragment was introduced into a pRA90 vector and the recombinant was used for developing srlT mutants of Erwinia herbicola, by homologous recombination. Mutants obtained were unable to grow on minimal medium with sorbitol. The insertion of the pRA90 vector inside the srlT gene sequence of the mutants was confirmed by DNA-DNA hybridisation.

Amino Acid Sequence↗
PubMed2001

Purification and characterisation of an ester hydrolase from a strain of Arthrobacter species: its application in asymmetrisation of 2-benzyl-1,3-propanediol acylates.

An ester hydrolase (ABL) has been isolated from a strain of Arthrobacter species (RRLJ-1/95) maintained in the culture collection of this laboratory. The purified enzyme has a specific activity of 1700 U/mg protein and is found to be composed of a single subunit (Mr 32,000), exhibiting both lipase and esterase activities shown by hydrolysis of triglycerides and p-nitrophenyl acetate respectively. Potential application of the enzyme concerns the asymmetrisation of prochiral 2-benzyl-1,3-propanediol esters besides enantioselective hydrolysis of alkyl esters of unsubstituted and substituted 1-phenyl ethanols.

Arthrobacter↗
PubMed2001

Portal and mesenteric venous calcification in patients with advanced cirrhosis.

OBJECTIVE: The incidence of calcification in the portal and mesenteric venous system was studied in patients with advanced cirrhosis undergoing evaluation for liver transplantation. The significance of portal and mesenteric calcification on liver transplantation was also investigated. CONCLUSION: An 11% incidence of portal and mesenteric venous calcification was found in patients with cirrhosis, which was much higher than anticipated. Two (29%) of seven patients who had calcification present on CT and underwent liver transplantation died at surgery as a result of portal venous thrombosis. Thus, venous calcification seen on CT is a significant finding in patients undergoing liver transplantation.

Adult↗
PubMed2001

Incidence of anaerobes in throat infections and their sensitivity pattern in Ludhiana.

Of 175 throat swabs processed, anaerobes were isolated from 16 (9.14%) patients. Isolation of anaerobes from healthy controls was 2 out of 25 (8%). Peptostreptococci and Bacteroides species were the commonest isolates followed by Peptococci and Propioni-bacterium. All of these isolates were sensitive to Metronidazole. Clindamycin, Erythromycin and Tetracycline also showed good response.

Anti-Bacterial Agents↗
PubMed2001

Potentiation of analgesia and reversal of tolerance to morphine by calcium channel blockers.

Effect of four calcium channel blockers (CCBs) belonging to different chemical classes, alone and in combination with morphine was investigated on two models of pain sensitivity, i.e. formalin and tail flick tests in mice. All the studied CCBs, i.e. diltiazem, flunarizine, nimodipine and verapamil inhibited formalin-induced pain responses; however, with verapamil, though there was a trend towards a reduction of paw-licking response to formalin, it was not found to be statistically significant. In contrast, none of the CCBs affected the tail flick latency at any of the doses studied. Morphine, a mu-receptor agonist exerted a significant analgesic effect in formalin as well in tail flick tests. Pretreatment with all CCBs significantly enhanced the analgesic effect of morphine in both tests of nociception. Further, concomitant administration of one of the CCBs, diltiazem with morphine prevented the development of tolerance to the latter. However, combination of diltiazem with morphine, like morphine alone was found to be ineffective in morphine tolerant animals. Results, thus, show that CCBs produced an analgesic effect of their own in formalin-induced tonic pain and potentiated the analgesic activity of morphine. They also modulated opioid-induced tolerance.

Analgesia↗
PubMed2000

The pyrroloquinoline quinone synthesis genes of Gluconobacter oxydans.

A Tn5-induced glucose dehydrogenase (GDH) deficient mutant of Gluconobacter oxydans IFO 3293 was characterised. DNA sequencing showed that the insertion site occurred in an open reading frame with homology to the pqqE gene. It was shown that acid production could be restored by addition of the coenzyme pyrroloquinoline quinone (PQQ) to the medium. The pqq cluster of G. oxydans ATCC 9937 was cloned and sequenced. It has five genes pqqA-E. The cluster could complement the Tn5-induced mutation in IFO 3293. Pulsed-field gel electrophoresis suggested that the pqq genes are not closely linked to the ribF gene that produces the riboflavin cofactor for the gluconic acid dehydrogenase.

Bacterial Proteins↗
PubMed2000

Interaction of pentazocine with calcium channel blocking drugs during chemical and thermal pain in mice.

The present study was designed to investigate the antinociceptive interaction of a clinically used opioid, pentazocine which produces its analgesic effect mainly through kappa receptors, with some calcium channel blockers (CCBs, viz. Diltiazem, flunarizine, nimodipine and verapamil--each representing one chemical class) in formalin and tail flick tests in mice. All the CCBs, except verapamil, significantly inhibited the formalin-induced pain response in a dose-dependent manner. However, none of these drugs affected tail flick latency at any of the studied doses. Pentazocine showed a significant antinociceptive response in both pain models, although a high dose was required to increase the tail flick latency. Pretreatment with all CCBs, individually enhanced the analgesic effect of pentazocine in both formalin and tail flick tests. In the latter test of nociception, a per se ineffective dose of pentazocine, showed a significant analgesic response in presence of CCB dose which itself was not effective in the test. Chronic concomitant administration of diltiazem with pentazocine did not prevent the development of tolerance to the opioid compound. However, diltiazem when given in combination with pentazocine to pentazocine-tolerant animals, it effectively reversed the tolerance. Results of the study thus suggest that concomitant treatment with CCBs, irrespective of their chemical nature, not only potentiate the antinociceptive effect of pentazocine in opioid naive animals in both tonic and acute nociceptive tests but also reverse the pentazocine tolerance.

Analgesics, Opioid↗
PubMed2000

IL-12 and IL-2 potentiate the in vitro tumor-specific activity of peripheral blood cells from cervical cancer patients.

We have carried out a detailed analysis of the cellular immune functions of cervical cancer patients in comparison with healthy controls. It has been observed that the freshly isolated peripheral blood mononuclear cells (PBMC) exhibit natural cytotoxicity (NC) against a number of targets including tumor cells, mainly delivered by NK cells, which are non-adoptive and MHC unrestricted. Upon stimulation with cytokines like IL-2, IL-7, IL-12, IL-15 and interferons, PBMC acquire lymphokine activated killer (LAK) activity which enables them to lyse a wide range of targets including fresh tumor cells and virally infected cells. We compared the effect of IL-2 and IL-12 on enhancement of NC of PBMC from cervical cancer patients. IL-12 stimulated cultures (CD3+, CD56+) exhibited significant levels of tumoricidal activity. IL-2 stimulated lytic activity sustained even after 10 days while that of IL-12 stimulated cells declined after 6 days. Activation of PBMC was marked by increase in the expression of activation marker CD45RO and adhesion molecules LFA-1alpha, ICAM-1 and CD44. Addition of IL-12 to IL-2 stimulated cultures further enhanced the degree of lytic activity. Our data, thus, provide an evidence that PBMC from cervical cancer patients can be stimulated in response to cytokines and local or systemic treatment with low doses of cytokines may help to yield a better immune response against virus infected tumor cells in cervical cancer.

Adult↗