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Biomedical subjects

S Mehta

Publications and source records attributed to S Mehta.

At least 199 records · Page 11Linked to original sources
PubMed1994

Differential tropism of EB rotavirus (serotype 3) to small intestine of homologous murine model.

The 4-5 days-old NMRI strain infant mice were orally inoculated with EB rotavirus (serotype 3). The intestinal disaccharidases activity was studied separately in three segments of the small intestine i.e. duodenum, jejunum and ileum on day 1 to 7 post inoculation (p.i.). The severity of EB rotavirus infection correlated with a significant decrease of small intestinal lactase, maltase and sucrase on day 3 p.i. The level of maltase after the initial decline increased in all the three segments of small intestine of infected mice. However, the lactase activity remained suppressed for a relatively longer period in ileum of infected mice than in controls. These enzymes began to approach to normal value by day 5 p.i., but in ileum, lactase activity continued to be severely depressed even on day 7 p.i. Rotavirus was consistently detected in intestinal contents by ELISA on days 1 to 7 p.i. The infected mice showed a significant increase in rotavirus (serotype 3)-specific serum IgG and IgM antibody level during the declining (days 5-7 p.i.) phase of infection. Diarrhoea was noted up to day 6 p.i. The protracted suppression of the lactase activity in ileum in comparison to duodenum and jejunum showed a differential tropism of EB rotavirus (serotype 3) strain to the small intestine of homologous murine model.

Animals↗
PubMed1994

Epidemiology, subgroups and serotypes of rotavirus diarrhea in north Indian communities.

To know prevalence of rotavirus diarrhea subgroups and serotypes, a prospective study was conducted in rural, periurban and urban communities at Chandigarh. Weekly surveillance for diarrheal episodes was carried out in 110 families each from rural, periurban and urban localities constituting 584 children < 5 years of age from October, 1988 to February, 1991. Stool samples of 218 diarrheal episodes occurring in 115 children were subjected to rotavirus detection by ELISA. Rotavirus positive samples were further analyzed for subgroups and serotypes using specific monoclonal antibodies. Overall prevalence of rotavirus diarrhea was 4.3% (25/584). Rotavirus constituted 11.5% (25/218) of total diarrheal episodes and 22% (25/115) among the children affected with acute diarrhea. Among rural, periurban and urban communities, the overall prevalences of rotavirus diarrhea were 7.3%, 3.2% and 2.3% and episode related prevalences of 31.8%, 7.4% and 5%, respectively (chi 2 test for trend was highly significant from rural to periurban to urban localities). Forty per cent (10/25 of rotavirus positive samples were subgroup I and 60% (15/25) sub-group II. Of the 25 rotavirus strains, 40% (10) were serotype 2, 24% (n = 6) serotype 3 and 36% (n = 9) serotype 4. No definite temporal or seasonal pattern of rotavirus was observed; however, more of rotavirus diarrheal episodes (16%) occurred during winter season. Subgroups and serotypes were observed to cocirculate during the rotavirus episodes. Demonstration of serotypes in our field study imply that the vaccine to be used in our country must be cross protective to have an effective impact on rotavirus infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Child, Preschool↗
PubMed1994

Impact of nutrition and health education on rural pre-school children.

Pre-school children (n = 155) belonging to low socio-economic group from eight creches in villages around Chandigarh, were imparted nutrition and health education (NHE) for one year. Appropriate teaching material in the form of songs, rhymes and roleplays were scientifically developed for the purpose. For impact evaluation, objective tools in the form of checklists were formulated and used. NHE on three aspects, i.e., personal hygiene (PH), food hygiene (FH) and recognition of foods (RF) was imparted by Balsevikas (BSs) incharge of the creches, daily in a non-formal manner, for one year and evaluated periodically. On PH only, children of the lowest income group improved significantly. On FH and RF, all children registered significant improvement as these two aspects, were under the direct control of BSs who enthused and involved the children by providing an interacting and stimulating environment. The results are encouraging and indicate the pre-school children are educable in NHE provided participatory and appropriate material and methods are used.

Child Nutrition Sciences↗
PubMed1994

The use of somatosensory evoked potentials to prevent ischemic neural damage during preoperative embolization of a vascular renal metastasis.

Tumors at the spinal cord level present challenging surgical problems. Hypernephromas and other tumors may have copious bleeding at the time of resection. This bleeding can be reduced by preoperative embolization resulting in a dramatic decrease in surgical morbidity. However, embolization does carry a risk of spinal cord infarction and resultant neurologic injury. To monitor this, somatosensory evoked potentials (SSEPs) were evaluated during embolization, with a resultant termination of the procedure after significant SSEP changes and clinical symptoms indicated cord ischemia. The SSEP readings normalized 24 hours later, by the time of surgical resection. We present a relevant case history and review of the literature on this subject. Clearly, SSEPs, and in the future, motor evoked potentials (MEPs), serve as a valuable adjunct to monitoring spinal cord function during embolization and may prevent preoperative ischemic injury.

Aged↗
PubMed1994

The roles of myoglobin, MB iso-enzyme of creatine phosphokinase and aspartate aminotransferase in serum in the acute phase of myocardial infarction.

The diagnostic value of serum myoglobin as compared to MB iso-enzyme of creatine phosphokinase and aspartate aminotransferase was investigated in 25 patients admitted on suspicion of acute myocardial infarction with a duration of symptoms less than 6 hours. In group 1 (acute myocardial infarction group), the first blood sample, obtained at a mean time of 3.27 hours after onset of infarction, invariably showed increased myoglobin (mean 2.6-fold normal) whereas MB iso-enzyme of creatine phosphokinase and aspartate aminotransferase were often normal. Peak myoglobin values occurred earlier than peak serum MB iso-enzyme of creatine phosphokinase values. The highest peak values of serum myoglobin were found in patients with extensive myocardial infarction. In group 2 (non-acute myocardial infarction or control group) serial determinations of serum myoglobin, serum MB iso-enzyme of creatine phosphokinase and aspartate aminotransferase were within normal limits. Hence the importance lies with the early detection of serum myoglobin in acute myocardial infarction.

Adult↗
PubMed1994

Surgical treatment of idiopathic thoracolumbar and lumbar scoliosis in adolescent patients.

The surgical management of idiopathic thoracolumbar and lumbar scoliosis is complex because of the surgeon's desire to achieve curve correction while maintaining normal lumbar lordosis with as many distal mobile lumbar segments as possible. By doing so, the surgeon is able to maintain normal sagittal alignment and decrease the chance of degenerative lumbar spine disease below the scoliosis fusion. This article discusses the surgical treatment of the thoracolumbar and lumbar curve, and, it is hoped, provides a better understanding of this complex problem.

Adolescent↗
PubMed1993

Effect of amitriptyline on neurotransmitter levels in adult mice following infection with the avirulent strain of Semliki Forest virus.

Infection of adult mice with the avirulent strain of Semliki Forest virus (SFV) led to neurochemical abnormalities, notably depressed levels of catecholamines (CATs) such as noradrenaline (NA), adrenaline (A) and 3-methoxy-4-hydroxyphenylglycol (MHPG) (a metabolite of NA) particularly in the hypothalamus and the inferior colliculus but not in the temporal cortex. In addition, depressed levels of NA and A were also found in the cerebrospinal fluid (CSF) and the serum. Administration of a tricyclic antidepressant drug, amitriptyline, kept the levels of NA, A and MHPG similar to those of the saline-treated control mice in the hypothalamus, inferior colliculus and CSF.

Amitriptyline↗
PubMed1993

Contribution of serum inhibitory factors and immune cellular defects to the depressed cell-mediated immunity in patients with head and neck cancer.

The immune system of patients with head and neck cancer is frequently depressed. Serum inhibitory factors and immune cell dysfunction are known contributors to this depression, but their relative roles are unclear. We have examined these factors to determine whether a common pathway is involved. Is the defect an unresponding "switched-off cell" or is it a remedial defect responsive to the removal of serum inhibitory factors and/or to lymphokine restoration? Immune tests were performed in 66 patients with high-stage head and neck cancer. Serum inhibitory factors were measured by incubation of heat-inactivated serum (10%) with phytohemagglutinin (PHA)-stimulated lymphocytes or natural killer (NK) cells using the K562 assay. Lymphokine-activated killer (LAK) cell cytotoxicity was measured (in the presence/absence of serum) using chromium 51-labeled Raji tumor cells cultured 5 days with interleukin-2 (IL-2) (100 or 1,000 U/mL) and/or interferon-alpha (INF-alpha) (100 U/mL). IL-2 receptors, CD25 or p55 (low affinity) and p75 (high affinity), were measured by flow cytometry through fluorescence-activated cell sorter analysis. Serum inhibitory factors were detected in more than 50% of the patients. Head and neck cancer sera significantly inhibiting the normal lymphocyte response to PHA (11 of 22 patients), as well as significantly inhibiting the NK response of normal lymphocytes and the functional expression of the IL-2 receptor. LAK cell function at low-dose IL-2 was depressed in 45% of the patients (9 of 20) and was restored by increased IL-2 (1,000 U/mL) or a combination of IL-2 and INF-alpha. Twenty-five percent of the patients were unresponsive to maximum lymphokine stimulation. Half of the patients had depressed expression of the low-affinity IL-2 receptor (CD25). The cause of immune depression in patients with head and neck cancer is multifactorial and is related to serum inhibitory factors, as well as to inherent cellular defects. Based on these data, we would suggest a therapeutic approach in selected patients that includes the removal of serum inhibitory factors by plasmapheresis and restoration of cellular defects by combined IL-2 with or without INF-alpha.

Adult↗
PubMed1993

Neurite outgrowth and protein phosphorylation in chick embryonic sensory ganglia induced by a brief exposure to 12-O-tetradecanoylphorbol 13-acetate.

An exposure to 12-O-tetradecanoylphorbol 13-acetate (TPA) at 20 nM for as short as 30 min was sufficient to elicit neurite outgrowth from explanted chick embryonic sensory ganglia. Attachment of the ganglia to the collagen-coated substratum during exposure to TPA was essential for subsequent neurite outgrowth. Pulse-labeling with [35S]-methionine indicated no significant difference in protein synthesis between control and TPA-treated ganglia. In vitro phosphorylation assay revealed a prominent protein kinase C substrate with an apparent molecular mass of 66,000 dalton (66 kDa) in chick embryo ganglia extracts. Treatment of intact ganglia with TPA for 30 min also specifically stimulated the phosphorylation of the same protein. When staurosporine, a potent inhibitor of protein kinase C, was present during TPA treatment, both neurite outgrowth and the phosphorylation of the 66-kDa protein were blocked. Biochemical analysis of the phosphorylated 66-kDa protein indicated that (1) phosphorylation was only in serine residue, (2) the pI value was 4.5, (3) after V8 protease digestion, two phosphorylated peptide fragments, 6.0 and 7.5 kDa in size, were produced, and (4) it cross-reacted with an antiserum raised against a 66-kDa neurofilament subunit from rat spinal cord. These results suggest that early activation of protein kinase C and the phosphorylation of the 66-kDa protein may be involved in neuritogenesis.

Alkaloids↗
PubMed1993

Uses and limitations of monoclonal antibodies to Giardia lamblia-specific 66-kDa copro-antigen in copro-immunodiagnosis of giardiasis.

Antigen-capture enzyme-linked immunosorbent assay for the detection of Giardia lamblia-specific antigen in stool eluates from clinical subjects employing monoclonal antibody directed at 66-kDa G. lamblia copro-antigen has been evaluated. The G. lamblia copro-antigen was detected in 67% (31 of the 46 cases) of stool eluates from clinical cases, while none of the stool eluates from subjects with other intestinal parasites or from apparently healthy individuals, had detectable levels of G. lamblia copro-antigen. Monoclonal antibodies secreted by clones B4C5 and D3F4 recognised the periodate-sensitive and -insensitive epitopes of 66-kDa G. lamblia specific copro-antigen, respectively. Eight (73%) of the 11 symptomatic cases of giardiasis had trypsin-/periodate-sensitive epitopes of 66-kDa copro-antigen while 9 (92%) of 11 of the symptomatic cases and asymptomatic G. lamblia cyst carriers had trypsin-sensitive periodate-insensitive G. lamblia specific copro-antigen. The data tend to suggest that detection of periodate-insensitive epitopes of G. lamblia copro-antigen would indicate the presence of the parasite while the detection of periodate sensitive epitopes of G. lamblia copro-antigen would suggest symptomatic active giardial infection.

Animals↗
PubMed1993

Bone loss, contraception and lactation.

Loss of bone mass with age, is a universal phenomenon and is more pronounced in women than in men. The condition where the bone loss has proceeded to the extent that fractures occur is termed osteoporosis. As the number of elderly persons in the population increases, its magnitude is likely to increase, both in the developing and the developed countries. Bone mass increases rapidly in childhood and the adolescent years, reaching a peak in the third decade of life, and begins to decline soon thereafter. Several factors are thought to influence bone loss: these include race, diet, smoking, and physical exercise. Although the rate of bone loss accelerates in the immediate postmenopausal period, the process actually begins in the premenopausal years. By the time osteoporosis is clinically apparent and manifested by fracture, it probably cannot be reversed. The peak adult bone mass achieved, and the subsequent rate of bone loss are the major factors that determine a woman's susceptibility to postmenopausal osteoporosis. A primary cause of bone loss after menopause is the associated decline in ovarian function. Scanty information is available on the factors that affect bone mineral density or initiate bone loss before menopause, although both estrogens and progestins have been shown to prevent bone loss in postmenopausal women. Available data on the relationship between steroid hormone contraceptive use and bone mass/density is limited to combined oral contraceptives and one report related to the use of depot medroxyprogesterone acetate.(ABSTRACT TRUNCATED AT 250 WORDS)

Bone Density↗
PubMed1993

Effect of beta-blockers on ventilatory function in smokers and non smokers.

Twenty healthy nonsmokers, 20 asymptomatic mild smokers and 20 asymptomatic moderate smokers were assessed for ventilatory functions, before and after equipotent dosages of atenolol, propranolol and oxprenolol in a single blind longitudinal study. The basal spirometric values were significantly lower in smokers than non smokers. After propranolol significant reduction was seen from basal values in FEV1, FEF 75%, MMFR, FEF 200-1200 in all the three groups. After oxprenolol significant difference was seen only with MMFR in the moderate smokers. With atenolol the variation was not significant in any group. Intercomparison of values after the drugs in each group was done. The values after propranolol was significantly lower than values after atenolol or oxprenolol for FEF 75%, MMFR and FEF 200-1200 in both the smoker groups whereas values after oxprenolol and Atenolol did not differ significantly from each other. Thus, in smokers atenolol offers a safe choice. If propranolol is to be used, the possibility of significant bronchospasm should be considered.

Adrenergic beta-Antagonists↗
PubMed1993

[Radiologic determination of bone screw exit site on the femoral condyle. A method of exact imaging and length determination of internal fixation devices (screws, K-wires) in metaphyses of larger tubular bones exemplified by the distal femur].

Distal femur imaging (A-P and lateral X-rays) after internal fixation often give only poor visualization of the exact position. A model with two anteriorly positioned cortex screws was used to show that an additional oblique X-ray, or fluoroscopy of the tip of the screw, allows much more exact determination of its length, so that it can be changed if necessary. This method is considered by the authors as a simple check of screw length measurement in "foyer fermée" procedures.

Adolescent↗