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Biomedical subjects

R Kumar

Publications and source records attributed to R Kumar.

At least 37 records · Page 2Linked to original sources
PubMed1992

Prenatal growth curves corrected for certain genetic and environmental factors.

Factor analysis for non-orthogonal data was done to assess the straight and interaction effects of certain genetic and environmental factors on birth weight. While the interaction effects did not assume any significance, straight effects of gestational age, parity, mother's weight, and sex were significant in influencing the birth weight. Mother's height and socio-economic status of the family had no significant effect on birth weight. Step-up multiple regression analysis showed that contribution to the total variance explained (R2 x 100 = 29.7 per cent) in birth weight was about 15, 7, 5, and 2 per cent, respectively, from gestational age, parity, mother's weight, and sex of the baby. Correction of the mean weight curve was done by successive graphic approximation method and residuals were further minimized.

Birth Weight↗
PubMed1992

Is small bowel bacterial overgrowth of pathogenic significance in persistent diarrhea?

Bacterial overgrowth in the upper small intestine is postulated to cause persistent diarrhea. We compared the fecal and upper intestinal flora in 82 patients with persistent diarrhea aged < or = 36 months and weight-for-length < or = 90% of National Center for Health Statistics standards (NCHS) and 39 non-diarrheal children with age < or = 36 months, nutritionally matched with the patients and residing in the same environment. In the age groups < or = 12 months and > 12 months the duodenal fluid bacterial counts > or = 10(5)/ml were found with similar frequency in patients and controls for aerobic (p = 0.33; p = 0.1) and anaerobic (p = 1.0; p = 1.0) bacteria. However, the duodenal isolation rates of any aerobic bacteria (p < 0.05) without regard to counts and Enterobacteriaceae (p = 0.06) were higher in patients than in controls. Colonization with Enterobacteriaceae was directly correlated with increased stool weight over a 7-day observation period (p < 0.05; p < 0.01). One or more pathogens were isolated in the feces of 58% of the patients and 43.8% of the controls. Enteroadherent E. coli of the localized [EAEC-L] (p < 0.01) and aggregative [EAggEC] (p = 0.22) phenotypes were isolated more commonly from the feces of patients. The duodenal fluid detection rates for Klebsiella were significantly greater (p < 0.01) in patients, while Giardia lamblia was detected more commonly in the duodenal fluid of controls (p < 0.01). The presence of specific pathogens in the feces did not seem to be related to the extent of small bowel colonization.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Chondrosarcoma: MR imaging with pathologic correlation.

Magnetic resonance (MR) images of 21 surgically confirmed chondrosarcomas were retrospectively reviewed in conjunction with plain radiographs and computed tomographic scans and correlated with pathologic findings. The tumors appeared lobulated, and signal intensity, as analyzed visually (intermediate on T1-weighted, high on T2-weighted images), was similar for all lesions, regardless of pathologic type. Size of lesion was not an indicator of grade. The appearances of mesenchymal and dedifferentiated chondrosarcomas mimicked that of conventional chondrosarcoma. Extraskeletal chondrosarcoma was visualized as a lobulated soft-tissue mass. In all cases, MR imaging accurately depicted intraosseous and soft-tissue extent of tumor noted at surgery and pathologic examination. Histologic type or grade of chondrosarcoma generally cannot be characterized on the basis of visual analysis of signal intensity noted on routine MR images. However, MR imaging is excellent for exact delineation of tumor extent.

Bone Neoplasms↗
PubMed1992

Women whose mental illnesses recur after childbirth and partners' levels of expressed emotion during late pregnancy.

Expressed emotion (EE) in the partners of 25 pregnant women with a history of psychosis or severe depression and in 13 pregnant control subjects without any previous psychiatric disorder was assessed in the ninth month of pregnancy. At this time, no patient presented as a case according to RDC. Eleven subjects with a history of psychiatric disorder experienced a further episode of illness in the six months following delivery. Partners of women who became ill had made fewer critical and positive comments about their wives during the pregnancy than the partners of women who remained well. Poor self-rated social adjustment in the partners was also predictive of recurrence of illness after delivery.

Adult↗
PubMed1992

Skeletal responsiveness to endogenous parathyroid hormone in postmenopausal osteoporosis.

To test the hypothesis that increased sensitivity of bone to PTH may be a major cause of bone loss in postmenopausal osteoporosis, we induced acute calcium deprivation and measured bone responsiveness to endogenous PTH under physiological conditions. Eighteen osteoporotic and 17 normal postmenopausal women with similar dietary calcium intakes were studied before and after 4 days of calcium deprivation (dietary calcium 230 mg/day and treatment with a calcium-binding agent). Despite decreased serum PTH values, the baseline indices of bone turnover (serum osteocalcin level and 24-h urinary excretions of total deoxypyridinoline/creatinine and pyridinoline/creatinine corrected for total body bone mineral content), were higher in the osteoporotic women. During calcium deprivation, the changes in bone markers from baseline were similar in both groups, except for serum osteocalcin and serum type I procollagen carboxy-terminal propeptide. Changes in the normal and the osteoporotic women were, respectively: serum ionized calcium concentration decreased 3.3% and 2.1%; serum intact PTH increased 65% and 56%; plasma 1,25-dihydroxyvitamin D3 increased 29% and 39%; pyridinoline/creatinine increased 12% and 11%; and deoxypyridinoline/creatinine increased 27% and 12%. Serum osteocalcin increased 2.3% and serum procollagen carboxy-terminal propeptide decreased 9.4% in the normal women but did not change in the osteoporotic women. We conclude that women with postmenopausal osteoporosis do not have increased skeletal responsiveness to PTH compared with age-comparable normal postmenopausal women. Therefore, the higher bone turnover in postmenopausal osteoporosis, despite lower serum intact PTH concentration, must be due to other factors. Assessment of acute changes in bone turnover during physiological alterations in endogenous PTH secretion is a useful test in metabolic bone diseases.

Bone Density↗
PubMed1992

MR imaging of clival and paraclival lesions.

A wide spectrum of diseases involve the clivus and paraclival structures. Primary neoplasms, metastatic tumors, and inflammatory, vascular, and hematopoietic disorders are the most common abnormalities to arise from or directly involve the clivus. MR imaging exquisitely shows and helps characterize the diseases that affect this area. Sagittal and coronal MR imaging allows precise localization and evaluation of the signal characteristics of a mass, enabling a more specific diagnosis. The multiplanar capabilities of MR imaging provide superb visualization of the adjacent cranial nerves and vascular structures, aiding in surgical planning and radiation therapy. In this pictorial essay, the MR imaging, CT, and conventional radiographic findings of various clival and paraclival lesions are illustrated.

Adult↗
PubMed1992

Intestinal colonization & production of diarrhoea by enteroadherent-aggregative Escherichia coli.

The ability of HEp-2 cell adherent Esch. coli of aggregative phenotype (EA-Agg EC) to cause diarrhoea and to colonize the bowel of rabbits was studied. Thirty six rabbits were challenged with one of three EA-Agg EC strains (F23A; H766C and F17A-15, 3 and 3 rabbits respectively) or a control strain (K12-15 rabbits) in reversible ileal-tie in adult rabbit diarrhoea (RITARD) model. The animals were sacrificed 72 h post challenge. Severe diarrhoea occurred in greater number of F23A challenged rabbits than the controls (P < 0.05). Mucosal cultures from proximal and distal small intestine and colon yielded about 1000 times more Esch. coli in the test than control rabbits (P < 0.001 in each case). EA-Agg EC were consistently grown from mucosa in the test rabbits who commonly showed mild to moderate villous stunting and grade + to nuclear fragmentation (karyorrhexis) in the small and large bowel epithelium. The control animals had either normal villi or very mild villous stunting. Results comparable to F23A were obtained with the other two EA-Agg EC strains tested in a smaller number of animals.

Animals↗
PubMed1992

A 4-kilobase congo red binding plasmid DNA fragment of Shigella dysenteriae 1 suppresses the growth and cell differentiation in Escherichia coli.

A 4-kilobase congo red binding plasmid DNA fragment of pCAT 120 of Shigella dysenteriae 1 was transferred to an Escherichia coli K12 strain by transformation. Transformants were unable to grow in any liquid broth medium. Electron microscopic studies revealed that the transformants grown on tryptic soy agar were associated in clusters after cell division. Normal cell separation among the transformants in comparison with recipient E. coli K12 was only observed when the growth medium was supplemented with sterile culture filtrate of the recipient strain. An unknown factor(s) required for cell separation located on the chromosome was suppressed by a 4-kb congo red binding plasmid DNA (pCAT 120) fragment of S. dysenteriae 1.

Cell Division↗
PubMed1992

Synthesis, antiviral and cytotoxic activity of 2'-deoxyuridines, 2'-fluoro-2'-deoxyuridines and 2'-arabinouridines containing 5-(1-hydroxy-2-halo-2-ethoxycarbonylethyl)-, 5-(1-hydroxy-2-iodo-2- carboxyethyl)- and 5-[1-hydroxy (or methoxy)-2-iodoethyl] substituents.

The 5-[1-hydroxy-2-chloro-2-(ethoxycarbonyl)ethyl]-2'-deoxyuridine (7) and 5-[1-hydroxy-2-bromo-2-(ethoxycarbonyl)ethyl]-2'- fluoro-2'-deoxyuridine/uridine nucleosides (8, 9) were synthesized by the regiospecific addition of HOX (X = Br or Cl) to the vinyl substituent of the respective (E)-5-[2-(ethoxycarbonyl)-vinyl]-2'-deoxyuridines (6a-b) and uridine (6c). A related reaction of (E)-5-(2-carboxyvinyl)-2'-deoxyuridines (10a-b) and uridine (10c) with iodine and potassium iodate afforded the 5-(1-hydroxy-2-iodo-2-carboxyethyl) derivatives (11-13). 5-(1-Hydroxy-2-iodoethyl)-arabinouridine (18) was obtained by the reaction of (17) with iodine in the presence of the oxidizing agent iodic acid. Treatment of (18) with methanolic sulfuric acid afforded 5-(1-methoxy-2-iodoethyl)-arabinouridine (19) in 65% yield. Of the newly synthesized compounds, 7, 11 and 12 showed activity in vitro against HSV-1. The most active compound (12, ID50 = 0.1 microgram/ml) was 10 times less active than acyclovir (ID50 = 0.01 microgram/ml) against HSV-1. Compounds 7 and 11 were cytotoxic to L1210 cells in culture, exhibiting an ED50 of 7.2 and 4.7 micrograms/ml respectively, relative to melphalan (ED50 = 0.15 microgram/ml), but were inactive against the KB cell line.

Animals↗
PubMed1992

Incidence of mycoses in bronchopulmonary disorders.

A total of 274 samples were collected--180 sputum samples, 82 bronchial secretions and 12 pleural aspirates. Main fungus was Candida albicans from sputum (45.5 percent), from bronchial secretions (14.6 percent). Rest were Aspergillus, Alternaria and Helminthosporium. All the pleural aspirates were negative for fungus.

Adult↗
PubMed1992

Malarial placental infection and low birth weight babies.

Two-hundred fifty-six mothers and their newborns were subjected to clinical and haematological tests for the evidence of malaria. Placentae of these were examined histopathologically for malarial parasites and malarial pigment. Forty six placentae showed scanty malarial pigment ingested by monocytes. These appearances were associated with focal syncytial necrosis and proliferation of cytotrophoblastic cells. Plasmodium falciparum was found in cord blood of six cases. The mean weight of newborns born to mothers having no evidence of malarial placental infection was 2.763 kg, while mean weight of newborns belonging to infected placentae was 2.143 kg. The difference was highly significant.

Birth Weight↗
PubMed1992

Meningococcal meningitis in Ludhiana.

A retrospective study was carried out at Dayanand Medical College & Hospital, Ludhiana (Punjab) during the period from January 1985 to June 1990 to know the incidence of meningococcal meningitis. Meningococcal etiology was established in 170 (49.41%) cases out of 344 cases of bacterial meningitis. Out of 170 cases of meningococcal meningitis, 74 (43.52%) were positive only by smear examination, 90 (52.94%) were positive both by smear as well as culture and there were six (3.52%) cases which were positive only by culture. The organisms were sensitive to most of the common antibiotics including penicillin, chloramphenicol, ampicillin and sulphadiazine.

Adolescent↗
PubMed1992

Gastrin-dependent inhibitory effects of octreotide on the genesis of gastric ECLomas.

BACKGROUND: The efficacy of octreotide in the regulation of endocrine tumor secretion and symptomatology has been well documented. Its effects on neuroendocrine tumor generation and cell proliferation are less well understood. The purpose of this study was to determine if blockade of somatostatin receptors by octreotide would alter gastrin levels and influence enterochromaffin-like (ECL) cell proliferation. METHODS: The well-established gastric ECLoma model of the rodent, mastomys, was used. Animals received loxtidine (1 mg/kg/day), an irreversible H2 blocker, and subcutaneous slow release, octreotide pellet implants (150 or 300 micrograms/kg/day) or placebo pellets for a 4-month period. RESULTS: Control parameters for gastric mucosal thickness, plasma gastrin level, ECL cell density, and bromodeoxyuridine-positive cells were 517 +/- 20 microns, 46.1 +/- 11.4 pmol/L, 7.4 +/- 0.9 cells/visual field, and 13.8 +/- 2.6 cells/visual field, respectively. After loxtidine-placebo treatment all values were significantly increased (p < 0.05; 883 +/- 70 microns, 192.8 +/- 10.6 pmol/L, 97 +/- 16.2 cells/visual field, and 51.7 +/- 19.2 cells/visual field, respectively). High dose octreotide significantly inhibited all parameters (668 +/- 3.5 microns, 66.2 +/- 20.5 pmol/L, 37.0 +/- 8.0 cells/visual field, and 10.9 +/- 2.2 cells/visual field; p < 0.05). Low dose octreotide failed to significantly inhibit ECL cell density mucosal thickness, or cell proliferation. CONCLUSIONS: Irreversible H2 receptor blockade results in hypergastrinemia and ECL cell tumor generation. Hypergastrinemia, ECL cell hyperplasia, and cell proliferation are significantly inhibited by in vivo blockade of somatostatin receptors by administration of octreotide.

Animals↗
PubMed1992

Interferon-inducible gene expression in HL-60 cells: effects of the state of differentiation.

The promyelocytic leukemia line HL-60 can be terminally differentiated in vitro to either monocyte/macrophages or granulocytes. We used this cell line to test whether the state of differentiation of a cell changes its response to interferon (IFN). The characteristics of expression of several IFN-alpha- and IFN-gamma-inducible genes in undifferentiated and differentiated HL-60 cells were examined. p67, an IFN-gamma-inducible protein, was induced similarly in three cell types, whereas another IFN-gamma-inducible protein, p56, was induced strongly only in undifferentiated cells. In contrast, two isozymes of 2,5(A)-synthetase were induced better in differentiated cells in response to either IFN. Several IFN-alpha-inducible mRNAs, e.g., 561, 6-16, 1-8, and 2A, were induced much more strongly in granulocytes than in macrophages or in undifferentiated cells. Electrophoretic mobility shift assays using the IFN-stimulated response element of gene 561 and nuclear extracts of IFN-alpha-treated cells revealed the appearance of one complex and the disappearance of another one, concomitant with differentiation of the cells to granulocytes. These observations suggest that expression of IFN-inducible genes in HL-60 cells is regulated by trans-acting factors whose activity changes with the state of differentiation of the cells. Our study may have implications in the optimal clinical use of IFNs. Inducing cellular differentiation may augment the efficacy of IFNs as antitumor agents.

Base Sequence↗
PubMed1992

Participation of health workers, school teachers and pupils in the control of rheumatic fever: evaluation of a training programme.

In a rural community block of north India we initiated a programme for control of rheumatic fever and rheumatic heart disease (RF/RHD). This included a training campaign for all 74 health workers, 773 school teachers and 12,500 older pupils (class V to X) to enable them to suspect and refer cases of RF/RHD and counsel them about secondary prophylaxis. Training material was used by project staff, medical officers and teachers to convey that this serious disease with onset between 5 and 15 years can be recognized by four simple criteria: fever with joint pain or swelling; breathlessness and fatigue; involuntary face and limb movements. One year later we evaluated awareness generated by training by administering a questionnaire to random samples in the intervention area and in a noncontiguous control area. Health workers, teachers and pupils of the intervention block were significantly better aware of the nature, severity and presentation of the disease and reported having recognized cases whom they had referred for diagnosis, prophylaxis and counselled for follow up. We conclude that a training protocol incorporating simple messages can effectively create practical awareness for RF/RHD control among teachers, health workers and pupils in a rural community.

Community Health Workers↗