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Biomedical subjects

R C Sharma

Publications and source records attributed to R C Sharma.

At least 55 records · Page 3Linked to original sources
PubMed1999

Linear attenuation coefficients of tissue-equivalent materials of differing compositions for low energy photons.

Total linear attenuation coefficients of three tissue equivalent materials differing in their fat contents were experimentally determined for low energy photons in the range 13-51 keV. It is found that their variations with photon energy for each of these materials are describable by two distinct power functions with the validity ranges being (13-23 keV) and (32-51 keV), respectively. Therefore, to adequately represent the variation of total linear attenuation coefficients over the full photon energy range i.e., 13-51 keV, a sum of two power functions is needed. Least squares fitted equations to the entire experimental data are thus included. For muscle, the experimental data show a reasonably good agreement with the theoretically computed values that are available in literature.

Adipose Tissue↗
PubMed1999

Erythroderma in children: a clinico-etiological study.

Although there are various published studies on erythroderma from western and Asian countries, most of them have only included patients in the adult age groups. As we have an exclusively pediatric dermatology unit, we thought it would be intriguing to study the clinical, etiological and laboratory parameters of erythroderma in children. Seventeen erythroderma patients of both sexes were inducted into the study between 1993 to 1998. The mean age of onset was 3.3 years and the male:female ratio was 0.89:1. Eight (47%) of the patients were infants; 9 (53%) others belonged to the preschool and school going age group (age range between 1 to 12 years). An acute onset of the disease was seen in 47% of the patients while 53% of the patients had a chronic onset. The main presenting complaints were itching in 41% and burning in 18% of patients. Scalp involvement (71%), nail involvement (18%), and alopecia (6%) were the main cutaneous features observed while fever (53%), tachycardia (53%), pedal edema (12%), lymphadenopathy (18%), and hepatomegaly (12%) were the main systemic features observed in this study. Etiologically, drugs (29%), showed the highest incidence, followed equally (18%) by genodermatoses, psoriasis, and staphylococcal scalded skin syndrome (SSSS). Two (12%) patients had erythroderma due to atopic dermatitis, while one was (5%) due to infantile seborrheic dermatitis coexisting with dermatophytosis. Laboratory parameters contributed little towards diagnosis of the underlying dermatological condition. Thus, though erythroderma is a striking entity, it is yet uncommon in the pediatric age group. Because the drug induced group was the largest in this study, we recommend that drugs should be suspected as important causative factors of erythroderma in children.

Age Distribution↗
PubMed1999

Clinico-bacteriological study of pyodermas in children.

One hundred cases of pyodermas in children were investigated clinically and bacteriologically. Nasal and throat swabs from all cases were subjected to bacteriological examination. Most of the children (42%) were in the 1-4 year age group. The majority (58%) belonged to lower socio-economic groups with poor standards of hygiene. A history of over-crowding was obtained from 87% of cases, 82% were undernourished. Most of the children (68%) reported during the hot and humid months of June, July, August, and September. Primary pyodermas were observed in 72% of the children, and secondary pyodermas in 28%. Impetigo was the commonest primary pyoderma (48.61%); among secondary pyodermas, infected scabies was noted predominantly (42.86%). The face and legs were more commonly involved. Bacteriological cultures from pyoderma lesions revealed a single microorganism in the majority of the patients (84%). Staphylococcus aureus was isolated in pure culture from 48% and pure beta-hemolytic streptococci from 36%. A combination of both was obtained from 16%. No other organism was isolated from any case. A similar pattern was also observed in cultures from the nose and throat. Only 46 out of the 64 strains (84.3%) of Staphylococcus aureus isolated from pyoderma were typable. The majority (39.1%) showed a mixed pattern of phages; the second commonest was the non-allocated phage type (30.4%). Nasal flora had more of the non-allocated phage type (50%); two out of the three strains (66.6%) isolated from the throat showed a mixed pattern. All the strains of beta hemolytic streptococci, isolated either from lesions of pyoderma, nose, or throat belonged to group A. Staphylococcus aureus and showed a high sensitivity to netilmycin (100%), ofloxacin (98.4%), amoxycillin/clavulanic acid (96.9%), ciprofloxacin (89.1%) and gentamycin (84.4%) but a high resistance to penicillin (85.9%). A greater correlation was noted between nasal flora and organisms causing pyodermas. A change in the pattern of organisms causing pyodermas in children and their antibiotic sensitivities in this part of the globe has been observed in this study. The role of endogenous nasal and throat flora in the causation of pyodermas has also been highlighted.

Anti-Bacterial Agents↗
PubMed1998

Familial reactive perforating collagenosis: a case report.

Reactive perforating collagenosis is characterised by trans-epidermal elimination of collagen and is hypothesized to be both autosomally dominant and recessive. We report a family in which two brothers and a sister had lesions of reactive perforating collagenosis.

Adolescent↗
PubMed1997

False indications of an actinide lung burden arising from a contaminated finger wound.

This paper presents the results of in vivo measurements on a worker from a fuel reprocessing plant who was involved in an actinide intake. The results revealed that false indications of an actinide lung burden could arise from a contaminant present elsewhere in the chest region. Consequently, it is important that lung monitoring programs for occupational workers handling actinides are conducted with this caution in mind and that due consideration is given even in cases of minor cuts/wounds in order to rule out substantial overestimation of internal radiation doses.

Adult↗
PubMed1997

Erythema nodosum leprosum in histoid leprosy: a case report.

A 28-year-old married female developed histoid papules and nodules de novo over her face, extremities, back, buttocks and thighs. She had developed erythema nodosum leprosum lesions without any antileprosy treatment. Histopathology from a histoid nodule showed well defined nodular collections of plump, spindle-shaped histiocytes. A few globi were also seen with Ziehl Neelson staining. Leucocytoclastic vasculitis was present in the ENL lesion. The CD4:CD8 ratio was 1.5:1.

Adult↗
PubMed1997

Status of Plasmodium falciparum resistance to chloroquine in Orissa.

Orissa is known for its contribution of 15-20% of malaria cases to the national total. Deaths due to malaria in the state are also not uncommon. Proportion of P. falciparum cases have reached to 85%. In the recent years over 0.3 million confirmed malaria cases have been reported each year. Annual consumption of chloroquine in the state is over 170 lakh tablets. A 17 year study on monitoring of choloroquine resistance in P. falciparum in Orissa revealed that out of a total of 1165 tests conducted in vivo, in 12% of the cases RI level of resistance was detected. And 4.4% cases were of RII and 1.9% RIII level. 51% of the sample tested in vitro showed P. falciparum resistance to chloroquine. P. falciparum resistance to chloroquine appears to have been developed by the parasite over the length and breadth of the state. Strengthening of the monitoring of drug resistance in P. falciparum in the state is indicated.

Antimalarials↗
PubMed1997

Operational research in malaria--why and how?

Research studies conducted so far have had little bearing on the National Malaria Eradication Programme implementation for want of operational component. In India there is no dearth of scientific knowledge and technical know-how but dearth of operational research of direct relevance to the programme. The rationale for research under the operational conditions of the NMEP is discussed in this paper.

Humans↗
PubMed1996

P-glycoprotein confers methotrexate resistance in 3T6 cells with deficient carrier-mediated methotrexate uptake.

P-glycoprotein (Pgp), a transmembrane efflux pump encoded by the MDR1 gene, transports various lipophilic drugs that enter the cell by passive diffusion through the lipid bilayer. Pgp-expressing multidrug-resistant cell lines are not usually cross-resistant to a hydrophilic antifolate methotrexate (MTX). MTX enters cells primarily through a folate carrier, but passive diffusion becomes the primary mode of MTX uptake in carrier-deficient cells. To test if a deficiency in MTX carrier would allow Pgp to confer resistance to MTX, a MTX carrier-deficient cell line (3T6-C26) was infected with a recombinant retrovirus expressing the human MDR1 gene. The infected 3T6-C26 cells showed increased survival in MTX relative to uninfected cells. Multistep selection of the infected cells with vinblastine led to increased Pgp expression and a concomitant increase in resistance to MTX. MTX resistance of Pgp-expressing 3T6-C26 cells was reduced by Pgp inhibitors, including a Pgp-specific monoclonal antibody UTC2. In contrast, the expression and the inhibition of Pgp had no effect on MTX resistance in 3T6 cells with normal carrier-mediated MTX uptake. Thus, a deficiency in the MTX carrier enables Pgp to confer resistance to MTX, suggesting that hydrophilic compounds may become Pgp substrates when such compounds enter cells by passive diffusion.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

Quantitation and localization of regional body fat distribution--a comparison between magnetic resonance imaging and somatometry.

UNLABELLED: The emerging concept that various fat compartments are metabolically active and play separate and decisive roles in the pathogenesis of coronary atherosclerosis, hypertension, insulin resistance, diabetes and stroke, has given obesity research a new direction. Of particular interest is the relative amount of intra-abdominal fat thought to be responsible for the metabolic complications. We studied the precise fat distribution and its correlations with the metabolic parameters in 44 non-human primates (Macaca fascicularis). Intra-abdominal, subcutaneous, and total abdominal fat (IAF, SAF, TAF) were assessed by magnetic resonance imaging (MRI) and somatometry. Quantitative computer analyses of abdominal MRI scans revealed predominant IAF distribution. Box plot analysis of IAF and SAF revealed wide diversity in the amounts of fat, especially in monkeys with body mass index (BMI) < 30 kg/m2. Primates with similar BMI in each quartile revealed an extensive heterogeneity in IAF as well as SAF. Numerous significant correlations within site-specific somatometric measurements as well as within the MRI determinants of abdominal fat were seen. However, only body weight correlated with IAF and skinfolds could predict SAF. After adjusting for body weight, partial correlation analysis showed a significant correlation (P < 0.05) between total cholesterol and IAF. CONCLUSION: MRI revealed considerable heterogeneity of IAF, SAF and TAF in cohort of primates believed to be homogeneous by somatometric definition. Male cynomolgus monkeys appear to be a valuable model for a systematic evaluation of fat. Individuals with identical body weight and height may show a diverse pattern of fat distribution.

Abdomen↗
PubMed1996

Probucol suppresses oxidant stress in hypertensive arteries. Immunohistochemical evidence.

Oxy-free radicals may be involved in the pathogenesis of accelerated atherosclerosis in hypertension. We evaluated the direct antioxidant potential of probucol in hypertensive arteries by studying the spatial immunohistochemical distribution of three primary antioxidant enzymes (AEs). Nineteen normocholesterolemic New Zealand White rabbits were divided into two groups: normotensive controls (NT; n = 6) and 13 animals rendered hypertensive by surgical coarctation of abdominal aorta. The hypertensive group was subdivided into hypertensive alone (HT; n = 8) and hypertensive treated with 1% probucol (PO) for 9 weeks (HT-P; n = 5). Blood pressure rose significantly in both hypertensive groups (P < .005). At autopsy, both hypertensive groups showed similarly significant increases in mean arterial intima-media thickness (IMT) whether or not they were treated with probucol. However, only HT rabbits revealed significant increases in the intima-media depth penetration of glutathione peroxidase, superoxide dismutase, and catalase AEs. By contrast, in HT-P animals probucol produced significant reductions of immunostaining of all three AEs compared to the HT group (P < .05). Additionally, specific macrophage immunostaining revealed that the arterial wall of HT rabbits had numerous (10 to 12 per high power field) subintimal and medial macrophages as compared to the HT-P animals (1 to 2 per high power field). The blood pressure level correlated significantly with IMT in all three groups, but with depth penetration of the three AEs only in the NT and HT groups. Probucol, therefore, appears to act in concert with the native arterial antioxidant enzymes as a potent free radical scavenger to reduce oxidative stress and thus attenuate the macrophage invasive response in hypertensive arteries.

Animals↗
PubMed1996

Cutis laxa.

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Cutis Laxa↗