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Biomedical subjects

M Verma

Publications and source records attributed to M Verma.

At least 19 recordsLinked to original sources
PubMed1995

Primary structure of the canine U1 snRNA.

The nucleotide (nt) sequence of the canine U1 snRNA was determined. It exhibited significant homology (90-98%) with known U1 sequences. The RNA can be folded according to the secondary structure previously proposed for the U1 snRNA. It contained the conserved sequence UUACCUG in loop A (nt 6-12), required for the recognition of the 5' splice site, and the sequence UGCACU in loop B (nt 68-73), required for recognition of the U1-70K protein. The U1 snRNA was localized in the nucleus and its transcription was sensitive to alpha-amanitin, suggesting that it is transcribed by RNA polymerase II. Southern analysis revealed that the canine genome possesses 5-10 copies of U1 snRNA-encoding genes.

Animals↗
PubMed1994

Fetal sex determination in infants in Punjab, India: correlations and implications.

OBJECTIVES: To determine the proportion of children whose sex was determined prenatally among those attending one Indian hospital and to identify factors which affect use of fetal sex determination. DESIGN: Cross sectional study using interviews with mothers. SETTING: Medical school hospital in Punjab, India. SUBJECTS: 596 children delivered or seen for inpatient or outpatient care. MAIN OUTCOME MEASURES: Fetal sex determination, sex of child, number and sex of siblings, type of care received, socioeconomic status, and maternal education. RESULTS: Sex had been determined prenatally for fewer girls (5/236, 2%) than boys (49/360, 14%). Fetal sex determination had been done for only 2% (3/154) of first born boys compared with 18% (12/66) with one older sister and no older brother and 63% (30/48) with more than one older sister and no older brother. Only four boys whose sex had been determined prenatally had older brothers. The five girls whose sex had been determined prenatally either had a male twin or were incorrectly identified as male. Prenatal sex determination had been done for 21% (26/122) of boys admitted for inpatient care compared with 11% (19/173) seen as outpatients. Use of fetal sex determination increased with increasing monthly income (chi2 for trend = 6.384, P = 0.0115). None of the mothers who had had no education had used fetal sex determination, but among mothers with some education the frequency of use did not change with increasing education. The sex ratio of children born at the hospital rose from 107 boys/100 girls in 1982 to 132 boys/100 girls in 1993. CONCLUSIONS: Fetal sex determination was common, especially if the family already had daughters. Sex determination seems to be driven by a desire to have sons, with socioeconomic status and education having little effect. The lower prevalence of fetal sex determinations for girls is likely to be due to abortion of fetuses found to be female.

Cross-Sectional Studies↗
PubMed1994

Frequency-dependent alterations in enolase activity in Escherichia coli caused by exposure to electric and magnetic fields.

Some neurochemical effects of low-intensity electric and magnetic fields have been shown to be nonlinear functions of exposure parameters. These effects occurred within narrow ranges of frequency and intensity. Previous studies on membrane-associated endpoints in cell culture preparations demonstrated changes in calcium efflux and in acetylcholinesterase activity following exposure to radiofrequency radiation, amplitude modulated (AM) at 16 and at 60 Hz, at a specific absorption rate of 0.05 W/kg. In this study, these modulation frequencies were tested for their influence on the activity of a cytoplasmic enzyme, enolase, which is being tested clinically for detection of neoplasia. Escherichia coli cultures containing a plasmid with a mammalian gene for enolase were exposed for 30 min, and cell extracts were assayed for enolase activity by measuring absorbance at 240 nm. The enolase activity in exposed cultures was compared to the activity in paired control cultures. Exposure to 147 MHz carrier waves at 0.05 W/kg, AM at 16 Hz showed enolase activity enhanced by 62%, and AM at 60 Hz showed enolase activity reduced by 28%. Similarly, exposure to 16 Hz fields alone, at 21.2 V/mrms (electric) and 97 nTrms (magnetic), showed enhancement in enolase activity by 59%, whereas exposure to 60 Hz fields alone, at 14.1 V/mrms (electric) and 65 nTrms (magnetic), showed reduction in activity by 24%. Sham exposures as well as exposure to continuous-wave 147 MHz radiation at 0.05 W/kg showed no change in enolase activity.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholinesterase↗
PubMed1994

Inhibition of neutrophil leukotriene generation by the 21-aminosteroid, U-74389F.

The 21-aminosteroids are potent inhibitors of iron-dependent lipid peroxidation and more protective than methylprednisolone in models of trauma and reperfusion, but without glucocorticosteroid side effects. Histologically, animals treated with 21-aminosteroids have decreased neutrophil (PMN) infiltrates and diminished tissue destruction associated with trauma or reperfusion. Since PMN contribute to organ failure following ischemia-reperfusion, we assessed the effect of U-74389F (U7), on normal PMN function. Neutrophils from normal volunteers were incubated for 90 min with either vehicle, 15 microM U7 or 80 microM methylprednisolone (MP), in DMSO. Lactoferrin released and generation of leukotrienes to calcium ionophore A23187, also oxygen consumed to PMA and leukotriene B4 (LTB4) and chemotaxis to FMLP and LTB4, were determined for each group of PMN. Lactoferrin released to A23187 was significantly decreased in both steroid groups (7.29 +/- 0.82 micrograms vs 3.06 +/- 0.57 micrograms U7 and 2.88 +/- 0.62 micrograms MP, P < 0.01). PMN incubated with U7 or MP generated significantly less LTB4 (60.6 +/- 4.3 ng vs 47.7 +/- 2.4 ng U7 and 43.3 +/- 5.6 ng MP, P < 0.05). There were no differences noted in the ability of PMN incubated with either compound to consume oxygen or to respond to chemotactic stimuli. We conclude that the proven protective action of the 21-aminosteroids in models of ischemia-reperfusion is related to the ability of "steroids" to inhibit leukotriene generation and degranulation and may be related to the prevention of tissue lipid peroxidation by scavenging oxygen radicals.

Antioxidants↗
PubMed1994

DNA sequences encoding enolase are remarkably conserved from yeast to mammals.

Enolase (2-phospho-D-glycerate hydrolase, EC 4.2.1.11), particularly isoform neuron-specific enolase (NSE), is primarily localized in neurons and neuroendocrine cells and is a cancer diagnostic marker for brain tumors. Homology of enolase-coding DNA sequences from human, dog, cow, rat, mouse, rabbit, chicken, and yeast cells was investigated using hybridization techniques, percent sequence divergence, and amino acid analysis. Because enolase is a significant enzyme of the glycolytic pathway, enolase-coding DNA sequences have been found in all organisms tested so far. The human enzyme was found to be more like those of monkey and dog in structure than to those of chicken and yeast. The implications of the existence of the genetic conservation of enolase-coding DNA sequences in understanding concerted evolution as well as post-transcriptional regulation during differentiation are discussed. This is the first report is which sequence divergence in the coding region for enolase has been determined in a variety of organisms.

Amino Acid Sequence↗
PubMed1994

Mucin synthesis in immortalized canine tracheal epithelial cells.

To study the regulation of mucin synthesis in canine tracheal epithelial cells, it is desirable to establish a cell line which synthesizes mucin continuously. We adopted the approach of immortalizing canine tracheal epithelial cells using a vector encoding the human papillomavirus (type 18) E6 and E7 genes. The E6 and E7 genes are essential and sufficient for the immortalization of human genital keratinocytes, as well as human tracheal epithelium. Primary epithelial cells from dog trachea were transfected with a vector containing HPV18 genes E6 and E7. The resultant cells (CT1) were cloned and maintained in selective medium supplemented with growth factors and hormones. Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis indicated the expression of the canine tracheal mucin (CTM) mRNA in these cells. The half-life of the CTM mRNA was found to be 45-60 min. Incorporation of labelled precursor (glucosamine) indicated that high-molecular-weight mucin glycoprotein was synthesized by these immortalized cells, which reacted with the antiserum to the native CTM. Equilibrium gradient centrifugation analysis showed that the buoyant density of the mucin synthesized in CT1 cells (1.486 g/ml) was similar to the reported value for native CTM (1.5 g/ml). Mucin which was isolated from immortalized cells was not a proteoglycan as chondroitinase treatment had no effect. These results suggest that CT1 cells synthesize a mucin glycoprotein which exhibits properties similar to native CTM. When characterized by immunostaining with a pool of monoclonal antibodies, these cells showed common epithelial antigens related to keratin expression. The CT1 cell line represents a unique resource for studying mucin biosynthesis and regulation.

Animals↗
PubMed1994

Effect of Escherichia coli enterotoxins on macromolecular absorption.

Macromolecular absorption of gliadin, a wheat protein and alpha lactalbumin, a milk protein was evaluated in control and Escherichia coli enterotoxin (heat-stable, heat-labile, and both heat-stable and heat-labile enterotoxin) treated mice. The peak concentration of gliadin and lactalbumin was two hours and three hours after their ingestion, respectively. There was also a significant increase (p < 0.01) in the absorption of both the proteins in all the three toxin treated groups compared with the control group. These results suggest that intestinal permeability and macromolecular absorption changes after E coli infection.

Animals↗
PubMed1994

2,3,7,8-Tetrachlorodibenzo-p-dioxin-mediated gene expression in the immature rat thymus.

To examine the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on thymic gene expression in vitro, freshly isolated rat thymocytes were incubated with 10 nM TCDD, and reverse transcriptase polymerase chain reaction experiments were performed using primers specific for prostaglandin G/H synthase (PGHS) and glyceraldehyde 3-phosphate dehydrogenase. TCDD selectively repressed PGHS gene expression, with maximal inhibition occurring within 60 min. Gel retardation assays demonstrated that dioxin transiently induced binding of the ubiquitous transcription factor NF kappa B to its cognate response element at early time points. However, TCDD had little ability to induce transformation of the Ah receptor to the xenobiotic responsive element in thymic cytosol. These results indicate that TCDD exerts changes in thymocyte gene expression prior to inducing toxicity.

Animals↗
PubMed1994

Carcinoma associated mucins: molecular biology and clinical applications.

Mucin is a viscous secretion of glycoproteins secreted by epithelial cells of normal and cancerous tissues. Excessive and abnormal mucin synthesis has been observed in a number of cancers. The conformation and configuration of the surface carbohydrates play a key role in generating multiple forms of mucins in different cancers. The epitopes on the surface of mucin are recognized by antibodies present in different cancer cells. The primary structure of some of the cancer-associated mucins has been determined by molecular cloning of their complementary DNAs. The detection methods for cancer-associated mucins and their clinical applications are discussed.

Animals↗
PubMed1994

Mucin coding sequences are remarkably conserved.

Mucins are complex glycoproteins expressed by glandular epithelia and the carcinoma which develop from these tissues. The core protein is aberrantly glycosylated in cancers, and some antibodies show specificity in their reactions with the cancer-associated mucins, which also contains epitopes recognized by T-cells from pancreatic and breast cancer patients. Based on the PCR amplification of the mucin coding sequences, hybridization analysis and determination of the sequence divergence we present the evidence that mucin coding sequences are conserved in a number of species. A broad series of organisms were examined for analogous sequences. Data show that mucin-type sequences are present in a variety of mammals, but less apparent in chicken and yeast. Divergence increased in the order human, monkey, rabbit/rat/cow, mouse; chicken and yeast exhibited minimal homology. Furthermore, nucleotide sequences not included in the tandem repeats, a common feature of mucin core structure, are more conserved than the flanking sequences which also suggests that the flanking sequences may be functionally significant while repeats are structurally important. The hybridization bands showed different restriction patterns (suggesting for the existence of the restriction fragment length polymorphism). Northern analysis indicates message polydispersity, commonly seen with this class of RNA. The major features of the protein appear broadly conserved in the different mammalian species examined. The evolutionary significance of the above studies has been discussed.

Animals↗
PubMed1994

Refractive errors in preterm babies.

Fifty preterm neonates were followed up at the age of 6 months and 1 year. In addition to developmental assessment, a complete ophthalmological examination was done on both visits. The largest (62%) gestational age group was of 34-36 weeks. At 6 months, none of the infants had normal vision. At 1 year of age, 64% of the babies had normal vision while incidence of myopia and hypermetropia was 16% and 20%, respectively. There was an inverse relationship noted between gestation and incidence of refractive errors. It was also noted that with decreasing weight, the incidence of myopia increased. Myopia was seen exclusively among infants of birth weight of 2000 g or less. Birth weight had a significant positive correlation with astigmatism. No correlation of asphyxia with refractive errors was observed. It is recommended that all preterm babies should have an ophthalmological examination at one year of age with follow up later on.

Anisometropia↗
PubMed1994

Waning of post vaccinial allergy after neonatal BCG vaccination.

Tuberculin sensitivity or post vaccinial allergy (PVA) is widely used as an indicator of successful BCG vaccination. The protection conferred by BCG vaccination, the duration of post-vaccinial allergy and the relationship between the two remain a subject of controversy. The present study was conducted with the aim of finding the duration of PVA and evaluate the need for revaccination. One thousand newborns were given BCG under controlled conditions and followed up for PVA by serial PPD (5TU) injection at 3, 6, 12, 24, 30 and 36 months. An induration of 5 mm or less was recorded as negative and no subsequent testing was done. At 3 month, all the infants were given PPD and 95.3% showed a positive response. The positivity rate declined significantly (p < 0.01) to 19% by 3 years of age. A statistically significant (p < 0.01) fall in the mean PPD induration size was also noted. At 3 months, the mean induration size was 10.68 mm but by 3 years it had decreased to 3.86 mm. The distribution of PPD size also showed that with the increase in age, there was a shift towards the smaller size. At 3 years of age, none of the children had an induration of more than 10 mm. The booster effect due to repeated PPD testing was seen in a small percentage and only at 6 and 12 months test. Subsequently no increase in PPD induration was noted. Sex of the child did not influence the PPD induration size significantly (p > 0.05). At 3, 6 and 12 months of age, significant correlation between BCG lesion and PVA was noted, the co-efficient of correlation being 6.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1994

Communication skills in clinical practice fad or necessity?

Communication skills of 40 final year medical students were assessed using Objective Structured Clinical Examination. The scores obtained were significantly less than those obtained in clinical skills. There was no significant correlation between the two sets of scores. It is suggested that emphasis should be placed on developing and evaluating communication skills during undergraduate medical curriculum.

Communication↗
PubMed1994

Safe motherhood: when to begin.

Two thousand five hundred college girls were assessed for their knowledge and attitudes regarding sex, pregnancy and child rearing with the help of a pretested questionnaire. The site of menstruation was known to only 35.3% of the girls. The knowledge about the time and site of conception was 25.3% and 58.2%, respectively. Only 16.3% of the respondents knew the normal route of delivery although the duration of normal pregnancy was known to majority (87.7%). The girls were aware of the ideal timing of abortion (67.5%) but the safe method and legality were poorly known facts. Only 5% of the girls believed in pre-marital sex. More than half (54.9%) of the girls knew about some form of contraceptive, Copper-T being the best known. Nearly one fifth of the girls were either undecided or wished family members to decide about antenatal check-ups. The need for better diet and injections during pregnancy was well known although few (15.2%) were aware of the injections being tetanus toxoid. Only about 10% wanted a home delivery but one fourth felt that a Dai or a relative was suitable for conducting the delivery. An overwhelming majority of the students stated that knowledge about above facts was important and they would like to learn about them preferably during college education. It is recommended that 'Family life education' be provided during pre-adolescent and adolescent years to ensure a safe motherhood and a healthy child.

Adolescent↗
PubMed1994

Obesity and hypertension in children.

A study was conducted on two thousand five hundred and sixty school children to evaluate the prevalence of hypertension in apparently healthy school children of a prosperous, industrialized city of Punjab. The children belonged to 5-15 years age group of both sexes. The weight (kg) was taken by a standardized weighing machine while height was measured using a calibrated bar. For diagnosing obesity, the body mass index (BMI) was calculated by the formula: [formula: see text] A value of > or = 2.26 was considered as obesity. Blood pressure (BP) measurements were taken by a a mercury sphygmomanometer as per the recommendations of American Heart Association. Hypertension was diagnosed if blood pressure was more than 95th percentile for the age. Family history of hypertension was enquired from the parents of children. The BP of the hypertensive children was reassessed after six and nine months. The prevalence of hypertension was 2.8% at the first screening but decreased to 1.3% and 1.1% by 6 and 9 months, respectively. This fall was statistically significant (p < 0.01). There was no significant difference in the prevalence of hypertension between the two sexes. At the final screening, only children of 11 years or above were hypertensive. A statistically significant correlation with positive family history of hypertension was noted; 85.7% of hypertensive children had positive family history. The prevalence of hypertension was much higher in obese as compared to non-obese children (13.7% vs 0.4%). The correlation between obesity and hypertension was statistically significant (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Canine U2 snRNA gene: nucleotide sequence, characterization and implications in RNA processing and cancer biology.

Abnormal RNA processing (splicing) may lead a cell to become cancerous. Transcription of a gene starts in the nucleus where genomic DNA is converted to precursor RNA by removing introns and joining exons. Splicing, mediated by small nuclear RNA (snRNA) and nuclear proteins, is tightly regulated during growth and development. U2 snRNAs are small, stable RNAs located in the nucleus of eukaryotic cells that recognize the branch point of the intron-exon junction. We describe here the organization of DNA sequences complementary to canine U2 snRNA. From a genomic library we isolated one recombinant containing the U2 gene. Southern analysis revealed that the canine species possesses only 3 to 5 U2 snRNA genes or very closely related sequences. The size of the U2 gene is 125 nt whereas in rat, Drosophila, trypanosome and yeast it is 189, 234, 141, and 192 nt respectively. The nucleotide sequence showed 82, 78, 72 and 95% homology with rat, Drosophila, yeast, and trypanosome U2 snRNA, respectively. The sensitivity of U2 snRNA towards alpha-amanitin suggests that it is transcribed by RNA polymerase II. The conserved nucleotide sequences which have been implicated in heterogeneous nuclear RNA splicing have been identified. The implications of the knowledge gained through above studies in cancer biology are discussed.

Animals↗
PubMed1994

Neonatal conjunctivitis: a profile.

Neonatal conjunctivitis is one of the commonest infections encountered in the newborn. A prospective study was conducted on all babies born over a period of one year. No prophylactic ocular medication was instilled routinely in newborns. Babies developing purulent eye discharge were diagnosed to have conjunctivitis. Eye Swab from the neonates and maternal vaginal/cervical swabs were sent for culture. Chloromycetin eye drops were used for treatment and in case of no response, changed as per sensitivity report or to gentamicin eye drops. Oral erthromycin was given for dacryocystitis or when there was no response to topical therapy. The incidence of conjunctivitis was 7.2%. Two seasonal peaks, namely, February and then May and June, were noted. In 91.6% of the babies, conjunctivitis developed within the first week. A prolonged rupture of membranes was associated with a significantly higher incidence of conjunctivitis (p < 0.01). The most common organism grown from conjunctival swab was Staph aureus (35.2%) followed by Enterococcus (4.3%), Klebsiella (3.5%) and E. coli (2.8%). From vaginal/cervical swabs, E. coli was the most common organism isolated. No concurrence of organisms was noted between eye swabs and vaginal/cervical swabs. A uniformly good response to chloromycetin eye drops was noted with only 3.5% requiring a change of therapy. It is concluded that neonatal conjunctivitis is commonly acquired postnatally and responds well to topical chloromycetin therapy. Oral erythromycin may be used in resistant cases which will cover the chlamydial infection also.

Anti-Bacterial Agents↗