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Biomedical subjects

R Kumar

Publications and source records attributed to R Kumar.

At least 721 records · Page 40Linked to original sources
PubMed1996

Unusual diversity of human rotavirus G and P genotypes in India.

Between April and December 1993, we determined P and G genotypes of group A rotavirus strains obtained from children admitted to diarrhea treatment centers in five Indian cities. From a total of 63 rotavirus-positive specimens, we identified 10 different strains with five different G genotypes and four distinct P types by using reverse transcription-PCR. The common worldwide strains G1P8, G2P4, G3P8, and G4P8 were underrepresented among Indian children (33%), whereas strains of P type 6 (G1P6, G2P6, G3P6, G4P6, and G9P6), which primarily infect asymptomatic newborns but are rare in children with diarrhea were common in India (43%). Of these, G9P6, a strain not previously reported to be found in children with diarrhea, was the most prevalent (22%). Eleven percent of the strains were nontypeable, and another 11% of the specimens had mixed infections. Using digoxigenin-labeled, genotype-specific hybridization probes, we confirmed all G9 strains and mixed infections tested and identified three nontypeable strains (one G9 and two P8). The epidemiological significance of G9 rotavirus strains, if confirmed in other settings, may have important implications for vaccine development.

Base Sequence↗
PubMed1996

Monitoring and evaluating cataract intervention in India.

AIM: To identify indicators to monitor and evaluate the cataract intervention programme in India. METHODS: Available data on blindness due to cataract, demography, staffing levels, and infrastructure available under the programme were reviewed. Four key elements of the programme were identified: the magnitude of blindness due to cataract and the need for surgical services; the available resources; the output, in quantity and in quality, as well as the resource utilisation; and lastly the impact this has on society and the problem of blindness due to cataract. Indicators to quantify these key elements were designed and available data were used to calculate the defined indicators. RESULTS: At least 2.5 million sight restoring cataract operations will have to be performed annually. Staffing levels and infrastructure resources at present allow for increased output. The effectiveness of cataract services can be increased with better case selection. CONCLUSION: The use of these indicators provides an insight into the dynamics of the problem of cataract blindness and its intervention. They facilitate adequate management and evaluation of the efficiency and effectiveness of the intervention programme and may ensure optimal utilisation of the available resources for cataract surgery.

Blindness↗
PubMed1996

Presence of katG gene in resistant Mycobacterium tuberculosis.

It has been reported recently that isoniazid resistant strains of Mycobacterium tuberculosis have lost the katG gene which encodes the catalase-peroxidase enzyme. A 35 mer oligonucleotide probe specific for the katG gene of M tuberculosis, 3' end-labelled with digoxigenin, was constructed and hybridised with DNA extracted from 26 clinical isolates of M tuberculosis under high stringency conditions. Twenty two of these isolates were resistant to 0.2 microgram/ml isoniazid and 20 to 1.0 microgram/ml isoniazid. Semiquantitative detection of catalase did not show any discrimination between isoniazid sensitive and resistant strains. The katG gene was present in all clinical strains of M tuberculosis. Therefore, complete deletion of the katG gene does not seem to be the mechanism of isoniazid resistance in M tuberculosis strains isolated from patients in India.

Antitubercular Agents↗
PubMed1996

Model clamp and its application to synchronization of rabbit sinoatrial node cells.

A method for coupling an isolated cardiac cell to a simulated cardiac cell, i.e., the real-time solution of a mathematical model of such cell, has been developed. With this "model clamp" technique, the real cell and the model cell are coupled by any desired value of intercellular coupling conductance, producing the effect of mutual interaction by electrical coupling through gap junctional channels. We implemented the model clamp technique with our previously published model of an isolated rabbit sinoatrial node cell. We used this model clamp system to study synchronization of sinoatrial node cells with regard to the critical value of intercellular coupling conductance required for frequency entrainment and the common interbeat interval during frequency entrainment. This common interbeat interval lay between the intrinsic intervals of the real cell and the model cell, but was closer to that of the intrinsically faster beating cell. Critical coupling conductance increased with increasing difference in intrinsic interbeat interval of the real cell and the model cell and ranged between 50 and 300 pS in 11 hybrid cell pairs.

Action Potentials↗
PubMed1996

Differential expression and autoradiographic localization of atrial natriuretic peptide receptor in spontaneously hypertensive and normotensive rat testes: diminution of testosterone in hypertension.

Previous studies have shown that the diuretic hormone atrial natriuretic peptide (ANP) also regulates the steroidogenic responsiveness in isolated Leydig cells from mouse and rat testes. In the present study, we examined the distribution of specific receptors for ANP and C-type natriuretic peptide (CNP) in the testicular compartments of 12-week-old Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). We used an in vitro autoradiographic procedure on slide-mounted frozen testicular sections to localize the receptors of the natriuretic peptide hormone family using 125I-ANP and 125I-CNP as radioligands. A high level of specific 125I-ANP binding sites was localized largely in the Leydig cells of the interstitial compartment; other testicular cells were not significantly labeled. On the other hand, no significant difference was observed in 125I-CNP binding sites in the testicular cells of SHR and WKY. Semiquantitative analysis of the binding sites indicated that the density of 125I-ANP receptor binding in Leydig cells of WKY testis was ninefold higher than in those of SHR testis. A moderate level of 125I-ANP binding was also observed in seminiferous tubules, particularly in the spermatids of both SHR and WKY. 125I-ANP binding in WKY spermatids was approximately 2.5-fold higher than in SHR spermatids. Northern blot analysis showed that mRNA specific for guanylyl cyclase type A (Npra) was expressed at approximately twofold higher levels in WKY than in SHR testis. ANP (1 x 10(-8) mol/L) stimulated fourfold to fivefold increased levels of testosterone production in isolated Leydig cells from normotensive WKY compared with those from SHR. These findings support a new physiological role of ANP in Leydig cells, in which a functional relationship seems to exist between testicular ANP receptor expression and testosterone production and the state of hypertension in SHR.

Animals↗
PubMed1996

Infanticide in Scotland.

Details from Scottish Office records of all infants under a year who were the victims of homicide in Scotland during 1978-1993 are presented and compared with results from studies of infant homicide in England and Wales. Although Scottish homicide rates in the total population are much higher than those in England and Wales, the annual Scottish infanticide rate (43/million) is remarkably similar to that of England and Wales (45/million). In addition, characteristics of victims and perpetrators are also similar between the two regions. As with England and Wales, in Scotland the younger the infant the greater the risk of becoming the victim of homicide (83% were killed within 6 months of birth); male babies were more frequently killed than female ones; a parent was the most frequent perpetrator (93% of offences); mothers tended to kill neonates but for infants older than a day more fathers than mothers were recorded as the main accused. Mothers and fathers were convicted of similar offences but fathers were less likely to receive non-custodial sentences. Differences in sentencing appeared to be related to either gender-related differences in attributions as to the motivation for the offence, or to the level of violence used against the victim. Offences of mothers were most frequently recorded as being motivated by mental illness, those by fathers as due to rage. Fathers were more likely to have killed by kicking or hitting, mothers by some form of suffocation.

Adult↗
PubMed1996

Microcytosis: guidelines for family doctors.

In our studies of microcytosis, the complete blood count (CBC) of 82,830 randomly selected patients was analysed. Of these 34.3% showed microcytosis, and 5.5% were not anaemic. Emphasis was given to study the extent, causes and patterns of non-iron deficient microcytosis. Haematological data was adequate to differentiate iron deficient (ID) from non-iron deficient (NID) patients with microcytosis in 285 subjects. Of these 21.4% were found to be NID. A majority (73.8%) had showed a form of haemoglobinopathy, the commonest being beta-thalassaemia minor (60.7%). Of non-invasive investigations, mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), red cell size distribution width (RDW), anisocytosis in blood smears, serum iron (SI) and haemoglobin electrophoresis, the parameter which separated ID from NID patients most effectively was haemoglobin electrophoresis. It showed an abnormal pattern in 82% of NID subjects and normal pattern in 96.4% ID subjects. In the 18% of the NID subjects with a normal pattern, raised serum iron levels characterized 11% additional subjects with NID.

Adult↗
PubMed1996

Development of a clinical rating scale to assess mother-infant interaction in a psychiatric mother and baby unit.

BACKGROUND: Psychiatrists are sometimes asked to express an opinion about the competence and motivation of a mentally ill mother to be a consistent, adequate and safe parent of her recently born infant. There are no reliable methods for assessing mother-infant interaction and relationship in a psychiatric context. METHOD: The Bethlem Mother-infant interaction Scale (BMIS) was developed by the staff of a specialised psychiatric mother and baby unit. Of the seven subscales, four measured different aspects of the mother's contribution to the dialogue with her baby, one measured her capacity to organise and maintain routine care, one attempted to rate the perception by staff of risk to the child, and the remaining subscale rated the baby's contribution to their interaction. In normal clinical practice the ratings were made consensually by nurses and they encompassed observations that had been made by them during the previous week. RESULTS: Despite the simple and global nature of the ratings of the BMIS, moderate to high coefficients of inter-rater reliability were obtained for weekly ratings by nurses as well as for intra-rater reliability of ratings of videotaped interactions between mothers and their infants. Ratings of mothers and babies in day-to-day activity in the unit that were based on one hour's observation only were much less reliable. The internal consistency of the BMIS was high and comparisons with other methods used in non-clinical settings showed good criterion-related validity. CONCLUSIONS: Using the BMIS facilitated attempts to reliably assess disturbances of mother-infant interaction and the scale was acceptable and clinically useful. The nurses' ratings of their perceptions of 'risk' to the infant, which are in some ways the most important, were the least reliable. Repeated weekly ratings gave a valuable impression of change or lack of it over time. The predictive validity of the scale has yet to be determined.

Adolescent↗
PubMed1996

Comparative incidence of depression in women and men, during pregnancy and after childbirth. Validation of the Edinburgh Postnatal Depression Scale in Portuguese mothers.

BACKGROUND: Comparing women's and men's emotional reactions to childbirth can clarify the impact on mental health of childbirth as a life event. METHOD: Fifty-four first-time mothers attending obstetric services in Oporto, Portugal, and 42 of their husbands or partners participated in a longitudinal study of their mental health. All subjects were given a semi-structured clinical interview (SADS) at 6 months antenatally and at 12 months postnatally and sub-samples were interviewed at 3 months postnatally. At all these times all the mothers and fathers also completed a translated version of a self-rating scale for depression, the Edinburgh Postnatal Depression Scale (EPDS). RESULTS: More women than men had past histories of depression but their rates of depression did not differ significantly during pregnancy. In the first 3 months postnatally, nearly a quarter of the women at risk were found to have become depressed (major, minor and intermittent) in contrast with less than 5% of the men. In the next nine months men were more prone to become depressed than previously and their conditions tended to follow an earlier onset of depression in their spouses. CONCLUSION: Comparisons of EPDS and SADS ratings showed that the translated EPDS was a valid instrument for women but it was less satisfactory when applied to men.

Adolescent↗
PubMed1996

Correlates of postnatal depression in mothers and fathers.

BACKGROUND: We compare and contrast some correlates of paternal and maternal depression after the live birth of a first child, as part of a longitudinal study. METHOD: Fifty-four first-time mothers attending obstetric services in Oporto, Portugal, and 42 of their husbands or partners participated in a longitudinal study of their mental health. All subjects were given a semi-structured clinical interview (SADS) at six months antenatally and at 12 months postnatally and sub-samples were interviewed at three months postnatally. At all these times all the mothers and fathers also completed a translated version of a self-rating scale for depression, the Edinburgh Postnatal Depression Scale (EPDS) and a series of other questionnaires and interviews to measure different psychosocial variables. Profiles of risk factors associated with depression in the first postnatal year were analysed by means of logistic regressions. RESULTS: In the mothers, aside from a history of depression, the only other powerful predictor of postnatal depression was the mean objective negative impact score of life events. 'Postnatal' depression in fathers was associated with a history of depression in themselves and with the presence of depression in their wives or partners during pregnancy and soon after delivery. CONCLUSION: Prevention and early treatment of depression in fathers may benefit not only themselves but also their spouses and their children.

Adolescent↗
PubMed1996

Maternal psychopathology and prediction of outcome based on mother-infant interaction ratings (BMIS).

BACKGROUND: Very little is known about the adequacy and safety of maternal parenting behaviour in the context of severe postpartum psychiatric illness, about specific difficulties in relation to different types of mental illness, or about the potential for improvement over the course of an episode of illness. The Bethlem Mother-Infant Interaction Scale (BMIS) was thus developed as an aid to assessment on a specialist psychiatric Mother and Baby Unit. METHOD: Nurses' ratings of the quality of mother-infant interaction using the BMIS were collected throughout the consecutive admissions of 78 in-patient pairs. The ratings from three points during the admissions were examined according to the mothers' RDC diagnoses and also according to the eventual outcome of the admission. RESULTS: The nature of the mother's illness was associated with the quality of her infant care-taking using the BMIS ratings. The nurses' ratings during the second week of admission together with maternal psychiatric diagnosis, were strongly predictive of the eventual outcome of the admission. The majority of women who were separated from their infants on discharge or who required formal supervision belonged to the schizophrenic group. CONCLUSIONS: The results suggest that the BMIS can be used in this in-patient setting to aid clinical decisions about the safety of parenting by individual mothers with severe mental illness in the postpartum period.

Adolescent↗
PubMed1996

Future research directions in the use of biomarkers.

Many DNA adduct studies have been carried out in occupational groups that have been at a risk of cancer based on epidemiological results relating to exposure decades ago. Even new epidemiological publications on cancer cannot accurately address the effective exposures after about 1970. This is one justification for biomarker studies. Another justification is exposures for which epidemiological studies have not been conducted or have provided inadequate results, in spite of suspicions raised by short-term or animal experiments. The modulation of environment carcinogenesis by host polymorphism in genes for xenobiotic metabolizing and DNA repair enzymes is currently under extensive investigation. The studies relating phenotype/genotype to cancer are presently extended to various end points that may be related to cancer such as DNA adducts and cytogenetic damage. Adjustment for a metabolic phenotype or genotype may also increase the precision in the measurement. Mutations in oncogenes and tumor suppressor genes may give clues to the etiology of cancer.

Alkenes↗
PubMed1996

Transplantation of immortalized, nontumorigenic parotid acinar cells into the allogeneic rat parotid gland and oral submucosa.

The recent establishment of an immortalized clonal cell line of rat parotid acinar cells (2RSG) by transfecting isoproterenol-stimulated parotid cells with a plasmid vector, pSV3neo which carries the large T-antigen gene from SV40 virus, afforded the opportunity to develop a model for parotid acinar cell transplantation. Single cell suspensions of 2RSG cells labeled with a fluorescent tracer, DiI, were injected into the parotid gland or oral submucosa of allogeneic adult rats. The grafted cells survived and were functionally viable for at least 30 days. Histological sections revealed no evidence of infiltration of leukocytes or lymphocytes. Grafted cells did not form tumors. Results suggest that allogeneic parotid acinar cell transplantation is a feasible technique in the animal model.

Animals↗
PubMed1996

1,25-dihydroxyvitamin D-mediated hypercalcemia in a renal transplant recipient.

Hypercalcemia occurs in 10 to 30% of renal transplant recipients and is most often due to persistent hyperparathyroidism. Herein we describe a patient with a history of hyperparathyroidism who sought medical assessment because of recurrence of hypercalcemia 7 years after a successful renal transplantation. The hypercalcemia was associated with a normal serum phosphate level, a low to normal parathyroid hormone level, virtually undetectable levels of parathyroid hormone-related protein, and increased 1,25-dihydroxyvitamin D levels. Further assessment led to the diagnosis of an underlying lymphoma. To our knowledge, this is the first report of 1,25-dihydroxyvitamin D-mediated hypercalcemia in a renal transplant recipient with lymphoma. The possibility of an underlying lymphoproliferative disorder should be considered in the differential diagnosis of hypercalcemia in a renal transplant recipient.

Calcitriol↗
PubMed1996

Nutritional status of children: validity of mid-upper arm circumference for screening undernutrition.

OBJECTIVES: To determine the nutritional status and validity of mid upper arm circumference (MAC) in diagnosing malnutrition among preschool children. DESIGN: Cross-sectional household survey. SETTING: 47 villages in District Ambala, Haryana. SUBJECTS: 3747 children aged less than six years. METHODOLOGY: Trained field workers recorded age, weight, length/ height and MAC of children. Prevalence of underweight, stunting, and wasting were calculated in reference to National Centre for Health Statistics (NCHS) standards. Sensitivity and specificity of MAC for detecting underweight, wasting and stunting among children aged 1 to 4 years were determined. RESULTS: At the cut-off level of < -2.00 SD of Z-scores, 48.8% children were stunted, 49.6% were underweight and 9.1% were wasted whereas 47.6% children had neither wasting nor stunting. Prevalence of severe stunting, underweight, and wasting (Z-score < -3 SD) was 18.1%, 11.5% and 0.6%, respectively. Undernutrition showed a significant rise after 12 months of age (p < 0.0001). Stunting and underweight were significantly more among girls compared to boys (p < 0.01) but wasting was not significantly different in them. Compared to the conventional MAC cut off levels of < 13.5 cm and < 12.5 cm, sensitivity and specificity in our setting were optimum at < 13.5 cm for detection of wasting and < 14.0 cm for diagnosis of underweight and stunting, and < 13.0 cm for detection of severe wasting and < 13.5 cm for diagnosis of severe underweight and severe stunting. CONCLUSIONS: Almost every second child was undernourished. Optimum cut off level of MAC in our setting were higher than the conventional cut off points for detection of undernutrition among children.

Anthropometry↗
PubMed1996

Immunolocalization of polycystin in human tissues and cultured cells.

The gene PKD I, which is mutated in type I autosomal dominant polycystic kidney disease (ADPKD 1), encodes a large protein of novel structure and unknown function and distribution that has been named polycystin. To gain better insight into polycystin function, we raised a panel of antisera against synthetic peptide antigens derived from the unique portion of the predicted polycystin sequence. Antisera were used to immunolocalize the protein in a variety of normal human fetal, childhood, and adult tissues as well as kidney and liver tissue from individuals with ADPKD 1, the genetically distinct ADPKD 2, and acquired renal cystic disease (ARCD). Subcellular localization studies were carried out on human cultured cell lines of renal epithelial origin. In normal tissues, polycystin expression was noted in renal tubular epithelial cells from 20 weeks gestation to 4 years postpartum, and in hepatocytes and biliary epithelium up to 4 years, but not in adult kidney or liver. Expression also was present in fetal and childhood pancreas, myocardium, bowel, and adrenal medulla. In cell lines of renal epithelial origin, immunofluorescence and immunoelectron-microscopical studies showed localization of polycystin epitopes to the peripheral cytoplasm. Kidney and liver from four unrelated adults with known ADPKD 1 showed strong staining, which was not seen in kidney and liver from one adult with ADPKD 2 or in kidney from three patients with ARCD. We conclude that polycystin is expressed in renal tubular epithelial cells as well as a variety of other cell types during development and growth but is absent or weakly expressed in adult kidney and liver. Overexpression of polycystin epitopes within affected tissue may be a specific feature of some or all cases of ADPKD 1.

Adult↗
PubMed1996

Association of metal tolerance with multiple antibiotic resistance of enteropathogenic organisms isolated from coastal region of deltaic Sunderbans.

A survey of microorganisms was conducted in four coastal regions of the deltaic Sunderbans. Among ten different isolates, three were enteropathogenic. They were Vibrio cholerae non-O1 (CT+), enterotoxinogenic Escherichia coli (ETEC) and Pseudomonas aeruginosa. These enteropathogens were able to grow in the presence of zinc (Zn++), cadmium (Cd++), lead (Pb++), cobalt (Co++), copper (Cu++), nickel (Ni++) and silver (Ag+) up to 10 mM concentration. They also showed resistance against 5 to 10 antibiotics. Metal tolerance and drug resistance were not determined by plasmid(s). Synthesis of outer membrane protein among the marine isolates was higher in presence of metal. Enteropathogens isolated from the deltaic Sunderbans were well adapted for growth of the saline environment with higher concentrations of toxic metals.

Drug Resistance, Microbial↗