Search PubMed⌕ Search

Biomedical subjects

N S Kumar

Publications and source records attributed to N S Kumar.

At least 55 records · Page 3Linked to original sources
PubMed1990

Structural studies of an arabinoxylan isolated from Litsea glutinosa (Lauraceae).

A water-soluble arabinoxylan (D-xylose and L-arabinose in the molar ratio 1.0:3.4) was isolated from the mucilaginous bark of Litsea glutinosa (Lauraceae). The results of methylation analysis, partial hydrolysis, and 1H- and 13C-n.m.r. spectroscopy indicated a backbone of (1----4)-linked beta-D-xylopranosyl residues substituted at both positions 2 and 3 with side chains composed of either single or (1----3)-linked arabinofuranosyl residues. Both alpha-L- and beta-L-arabinofuranosyl residues were present. It is possible that side chains composed of two beta-L-arabinofuranosyl residues are attached mainly at O-2 of some xylosyl residues.

Arabinose↗
PubMed1990

Management of menopause when estrogen cannot be used.

Estrogen deficiency, whether surgically induced or as a consequence of natural ovarian failure, has destructive effects on many organ systems. With current levels of life expectancy, untreated women may expect to spend a third of their lifetime in this state. Appropriate estrogen replacement therapy (ERT) can avert (if started promptly) or ameliorate these devastating consequences, some of which (osteoporotic fractures, increased cardiovascular morbidity) can be lethal. Nevertheless, from 10 to 20% of postmenopausal women may have significant contraindications to ERT. Treatment of symptoms and improving the quality of life is imperative, yet many physicians abjure intervention, for reasons which are not entirely clear. Recent studies of conventional intervention with sedatives or tranquilisers show results equivalent to placebo therapy. On the other hand, specific agents with demonstrated effectiveness are available for management of the major estrogen-deficiency effects, although none of them are truly adequate replacement for the effect of estrogen itself.

Contraindications↗
PubMed1989

Effect of breast feeding on the development of anti-idiotype antibody response to F glycoprotein of respiratory syncytial virus in infant mice after post-partum maternal immunization.

Groups of lactating BALB/c mice were immunized in the immediate postpartum period with high doses of mAb (Ab-1) to the F-glycoprotein (F-gp) of respiratory syncytial virus (RSV). This antibody possessed neutralizing activity against the whole virus. The immune response to F-gp was studied in the breast feeding infant mice of such mothers at regular intervals before and after weaning. All infant mice exhibited anti-F-gp activity in serum, which was detected until 6 wk of age. Splenic cells of such breast feeding infant mice collected after weaning exhibited in vitro synthesis of antibody against Ab-1, the antibody previously used for maternal immunization. Subsequent immunization with homologous purified RSV F-gp resulted in a booster response for IgG, IgM, and plaque-neutralizing antibody to the immunizing RSV protein and to the whole virus in the infants primed via breast feeding. The enhanced antibody response was specific for the antigenic epitopes of the virus protein recognized by the monoclonal antibody used for maternal immunization. Similar booster effect was seen in control infants of nonimmunized mothers who were immunized with a polyclonal Ab-2 prepared by repeated immunization with Ab-1 in DBA/2 mice. These data demonstrate induction of RSV-specific anti-idiotype antibody in the neonates via the process of breast feeding, secondary to maternal immunization after the delivery of the neonate. Use of idiotypic vaccines in the mother and the transfer of RSV-specific idiotypes may offer an alternate approach to the development of effective immunoprophylaxis for RSV infection in early infancy.

Animals↗
PubMed1989

An antifungal constituent from the stem bark of Butea monosperma.

The petroleum and ethyl acetate extracts of the stem bark from Butea monosperma displayed antifungal activity against Cladosporium cladosporioides. The active constituent of low polarity was isolated by bioassay-monitored chromatographic fractionation, and identified as (-)-medicarpin by comparison of physical data. The antifungal activity of (-)-medicarpin was found to be greater than that of Benlate, a standard fungicide, while (-)-medicarpin acetate also exhibited significant activity against C. cladosporiodes.

Acetates↗
PubMed1988

Structural studies of the capsular polysaccharide from Streptococcus pneumoniae type 18A.

The structure of the capsular polysaccharide (S18A) elaborated by Streptococcus pneumoniae type 18A has been investigated by using methylation analysis and n.m.r. spectroscopy. It is concluded that the polysaccharide is composed of pentasaccharide repeating-units having the following structure. (formula; see text) In this structure, the absolute configuration of the glycerol 1-phosphate moiety has not been determined but is assumed to be D from biosynthesis considerations. The structure of S18A is, as expected, closely similar to those determined for S18F and S18C.

Carbohydrate Conformation↗
PubMed1986

Structural studies of a polysaccharide (S-88) elaborated by Pseudomonas ATCC 31554.

The structure of the extracellular polysaccharide elaborated by Pseudomonas ATCC 31554 has been investigated, methylation analyses, specific degradations, and 1H-n.m.r. spectroscopy being the main methods used. It is concluded that the polysaccharide is composed of pentasaccharide repeating-units with the structure: ----3)-beta-D-Glcp-(1----4)-beta-D-GlcpA-(1----4)-beta-D-Glcp- (1----4)-alpha-L-[Rha or Man]-(1---- 3 increases 1 alpha-L-Rha. An unusual feature is that a sugar residue in the chain may be either L-rhamnose or L-mannose. The polysaccharide also contains O-acetyl groups (approximately 5%) which have not been located.

Carbohydrate Conformation↗
PubMed1983

Hematologic values and prevalence of anaemia in Libyan school children.

The hematologic values and prevalence of anemia in Libyan school children 6-19 yrs of age were investigated. The mean values of boys followed the normal pattern of rise with age. In girls, the mean values increased with age until age 15 yrs, and subsequently declined. The prevalence of low hemoglobin and of low hematocrit values was 3.2% and 11.3% respectively. The highest prevalence of low hemoglobin in boys and in girls was 4.6% (13-15 yrs) and 6.2% (16-19 yrs) respectively. The highest prevalence of low hematocrit was observed in age group 6-9 yrs in both sexes (boys 17.0%, girls 20.2%). Rates of prevalence of anaemia in Libyan school children were compared with those in Bahrain, Oman and USA.

Adolescent↗
PubMed1980

Failure of ethanol to induce dominant lethal mutations in Wistar male rats.

2 groups of Wistar male rats (6-7 weeks old) were given ethanol, 15% in drinking water, for 5 days. The level of ethanol was gradually raised to 20 and 30% resp. Both groups received ethanol between 15 and 20% or 15 and 30% continuously during 35 days. Another group was given 30% ethanol for a period of 4 days before mating started. In addition to a control group, which received no treatment, a positive control group of rats exposed to 200 R X-rays, was used. After the treatments, individual males were paired with virgin Wistar females (10-12 weeks) at weekly intervals, and 8 sequential pairings were undertaken. Females were examined for uterine contents and corpora lutea, 10-11 days after their separation from the males. The females mated with irradiated males showed a high incidence of dead implantations and reduction of live implantations. No significant differences in the number of dead, live and total implantations at pre- and/or post-implantation levels were observed among the control and the ethanolic groups, showing that ethanol did not induce any dominant lethal mutations in these Wistar male rats. In the light of studies on alcoholics and other recent data, a need to investigate, independently, the potential mutagenic effects of ethanol and alcoholic beverages is discussed.

Animals↗
PubMed1977

Evaluation of freshly irradiated wheat for dominant lethal mutations in Wistar rats.

Three independent, serially performed experiments involving acute and chronic feeding of freshly irradiated wheat (75 krad, gamma-irradiation) were carried out in Wistar rats. In the first experiment groups of 10 males were given wheat for 1 week; irradiated wheat was consumed by the animals within 24 h or irradiation. In the other two experiments feeding of males was continued for 6 (10 males per group) and 12 (13 males per group) weeks, respectively, and the irradiated wheat was fed within 7 days of irradiation. At the end of each treatment period each male was paired with 3 females for 7 days and sequentially at weekly intervals for 5 or 8 weeks. Females were killed and examined for live and dead implantations and corpora lutea. There were no differences between groups with regard to fertility nor was there any inter-group differences as regards pre- and post-implantation losses whether the rats were fed irradiated or non-irradiated wheat. This suggested that even feeding of freshly irradiated wheat does not induce any dominant lethal mutations in rats.

Animals↗
PubMedDate not supplied

A study on the health status of twin babies.

A study on twin births was conducted from May 1993 to April 1994 at S.A.T. Hospital, Thiruvananthapuram. The twinning rate in this period was found as 17.33 per 1000 births. 79.6% babies in the twin pairs were of like sex and 20.4% were of unlike sex. The incidence of low birth weight twin babies in this study was 68.9%. There was no significant difference in the physical parameters (birth weight, body length and head circumference) of twin babies in relation to sex. The incidence of twin birth was higher among primipara mothers and in the mothers of age group 21 to 25 years. The first born baby (twin A) was found to be heavier than the second born baby (twin B) in 44.78% twin pairs and their mean birth weight difference was 438 g, while the second born baby (twin B) was found to be heavier than the first born (twin A) in 38.31% twin pairs and their mean birth weight difference was 291 g. Statistical analysis showed that the difference between the mean birth weight difference in the case of twin A > B was significantly greater when compared to that of twin A < B.

Anthropometry↗
PubMedDate not supplied

Late phase response during nasal challenge: effect of astemizole on leukotriene B4 levels.

Nasal provocation (NP) in allergic rhinitis patients can elicit a late phase inflammatory response in which interleukins (IL), leukotrienes (LT), and neutrophils have been implicated. Certain antihistamines have been shown to have anti-inflammatory properties. The objective was to determine whether astemizole at 10 mgs/day has any anti-inflammatory characteristics. We clinically evaluated 20 patients with allergic rhinitis and measured nasal IL-8 and LTB4 during NP with increasing doses of grass and ragweed antigen in a double-blind placebo-controlled fashion after a 4-week course of treatment. Clinical symptom scores for sneezing, pruritus, and rhinorrhea were evaluated. Nasal fluid was examined by ELISA and RIA for IL-8 and LTB4 levels along with neutrophil assessment before NP and at 3, 6, and 8 hours. Symptom scores for nasal sneezing, pruritus, rhinorrhea, and nasal LTB4 levels at 6 and 8 hours and IL-8 at 3, 6, and 8 hours were generally lower in astemizole-treated patients compared to those on placebo. Nasal IL-8 levels corresponded to LTB4 levels at diluent and at 6 hours in the placebo group (P = 0.01). The percentage of neutrophils correlated with LTB4 levels at baseline, coefficient = 0.76, P = 0.02 and at 6 hours, coefficient = 0.62, P = 0.035 in the placebo group. This study is the first to demonstrate an effect of astemizole during NP on IL-8 and LTB4 levels with a significant correlation of neutrophil numbers in untreated patients during the nasal late phase response.

Adult↗