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Biomedical subjects

R K Chandra

Publications and source records attributed to R K Chandra.

At least 55 records · Page 3Linked to original sources
PubMed1991

Effect of two feeding formulas on immune responses and mortality in mice challenged with Listeria monocytogenes.

Cell-mediated immunity and natural killer cells play an important role against facultative intracellular organisms. The effect of two commercially available tube feeding formulas used for patients with acute or chronic debilitating and life-threatening illnesses was studied in mice challenged with Listeria monocytogenes. C57BL/6 X DBA/2 F1 hybrid mice were given ad libitum access to one of two formulas or to chow. Sixty mice in each of the feeding groups were challenged with 4.8 X 10(3) organisms intraperitoneally. Mortality was significantly less in animals fed Impact, a formula enriched with arginine, RNA and selected fatty acids. This was associated with reduced number of viable organisms in the spleen on day 7 after challenge. There was no difference in the spleen/body weight index between the different groups. Delayed cutaneous hypersensitivity was slightly higher in the Impact group but this was not statistically significant. Natural killer cell activity was significantly higher in the Impact group compared with the other two feeding regimens. These observations suggest that selective manipulation of the composition of tube feeding formulas may have a significant impact on immune responses and on morbidity and mortality following infectious challenge.

Animal Feed↗
PubMed1991

Immunocompetence is a sensitive and functional barometer of nutritional status.

Nutrition is a critical determinant of immunocompetence and risk of illness. Young children with protein-energy malnutrition exhibit increased mortality and morbidity, due largely to infectious disease. Recent work has demonstrated that undernourished individuals have impaired immune responses. The most consistent abnormalities are seen in cell-mediated immunity, complement system, phagocytes, mucosal secretory antibody response, and antibody affinity. Many of these immunologic changes occur early in the course of nutritional depletion and therefore can serve as sensitive functional indices of nutritional status.

Child↗
PubMed1991

Interactions between early nutrition and the immune system.

The ontogenetic development of the immune system is a well-defined, almost stereotyped event. The anlagen of the human thymus can be distinguished in the third and fourth branchial arches in the sixth week of gestation. Several distinct responses have been observed in the first trimester of fetal development. In addition to genetic factors, environmental influences such as nutrition play an important role in influencing the developing human immune system. Adverse factors that impair fetal growth hinder immunological maturation as well. These include maternal malnutrition, smoking, alcohol and other substance abuse, placental insufficiency and infection. The immunocompetence of low birth weight infants is compromised; those who are small for gestation show persistent immunological impairment for several months, even years. Prolonged effects on immune responses can be seen in animal models of fetal malnutrition. A second area where interactions occur between dietary factors and the immune system is the IgE-mediated allergic response. Those with a family history of atopy are at high risk of developing allergic disease in late childhood and adult life. The enormous costs of atopic disease in terms of health management and physical and emotional isolation have led to attempts at prevention. These strategies include restriction of the mother's diet during pregnancy and lactation to exclude common allergenic foods and prolonged exclusive breast feeding. Casein or whey hydrolysate formulas are advisable in those not breast fed.

Diet↗
PubMed1991

Cumulative incidence of atopic disorders in high risk infants fed whey hydrolysate, soy, and conventional cow milk formulas.

A recent increase in the prevalence of atopic disorders and the enormous costs of management of atopic patients have prompted attempts at prevention. We have examined the effect of exclusive breast feeding and of feeding different infant formulas on incidence of atopic disease in a prospective randomized controlled study. Seventy-two infants were recruited into each of the following groups: cow milk whey hydrolysate formula (NAN/HA) conventional cow milk formula (Similac), soy-based formula (Isomil), and exclusive breast feeding for greater than 4 months. The cumulative incidence of atopic eczema, recurrent wheezing, rhinitis, gastrointestinal symptoms, and colic were noted. Skin prick tests and radioallergosorbent tests for IgE antibodies to milk and soy were performed. At 12 and 18 months of age, the incidence of atopic eczema as also that of all atopic symptoms was significantly lower and similar in the breast-fed and whey hydrolysate groups, compared with the cow milk and soy formula groups. IgE antibodies were detected more often in the cow milk and soy formula groups, especially the former. Among symptomatic infants, fewer skin positive prick tests were seen in the soy group compared with the cow milk group. Our observations show that among infants at high risk of developing atopic disease because of positive family history, exclusive breast feeding or whey hydrolysate formula is associated with a lower incidence and thus a delay in the occurrence of allergic disorders compared with groups fed conventional cow milk or soy formulas.

Adult↗
PubMed1989

Influence of maternal diet during lactation and use of formula feeds on development of atopic eczema in high risk infants.

OBJECTIVE: To examine the effects of maternal diet during lactation and the use of formula feeds on the development of atopic eczema in infants at risk. DESIGN: Mothers who planned to breast feed exclusively were randomly allocated to either a restricted diet (avoiding milk and other dairy products, eggs, fish, peanuts, and soybeans) or a diet without restrictions. Mothers who did not plan to breast feed were randomly allocated to using one of three formula feeds. SETTING: Child health centre in Canada. SUBJECTS: 97 Mothers who chose to breast feed and 124 mothers who did not. INTERVENTIONS: Restricted diet for 49 mothers who breast fed. Casein hydrolysate formula, soy milk formula, or cows' milk formula for infants not breast fed. MAIN OUTCOME MEASURE: Development of eczema in babies. RESULTS: Infants were followed up over 18 months and examined for eczema. Eczema was less common and milder in babies who were breast fed and whose mothers were on a restricted diet (11/49 (22%) v 21/48 (48%)). In infants fed casein hydrolysate, soy milk, or cows' milk 9/43 (21%), 26/41 (63%), and 28/40 (70%), respectively, developed atopic eczema. CONCLUSIONS: In families with a history of atopic disease [corrected] mothers who breast feed should avoid common allergenic foods during lactation. If they choose not to breast feed a hydrolysate formula should be used.

Bottle Feeding↗
PubMed1989

A Canadian multicenter study with Zaditen (ketotifen) in the treatment of bronchial asthma in children aged 5 to 17 years.

One hundred thirty-eight children with chronic asthma, requiring daily treatment with bronchodilators, took part in a 7-month, double-blind, multicenter clinical study. Patients were randomized into two groups, and after a 1-month baseline, were administered Zaditen (ketotifen), 1.0 mg twice daily, or an identical placebo for a period of 6 months. After 10 weeks of receiving the study medication, bronchodilator use was reduced or stopped. In the Zaditen-treated group, 60% of the children taking theophylline were able to stop its use completely, compared to 34% of the patients taking placebo (p less than 0.05). Of the patients who were unable to stop taking theophylline, the Zaditen-and placebo-treated groups recorded average dosage reductions of 62% and 26%, respectively. These differences were statistically significant (p less than 0.05). Thus, a high percentage of patients in the placebo-treated group maintained asthma symptom control with theophylline, whereas most of the Zaditen-treated patients could stop using this medication. Although pulmonary function readings improved in both groups, those patients taking Zaditen demonstrated earlier improvement and greater changes from baseline. Significant differences (p less than 0.05) in favor of Zaditen were found for reduction of concomitant medications, patient's global evaluation, physician's clinical evaluations, incidence of emergency room visits for asthma, and upper respiratory tract infections. No unexpected side effects were observed. It is concluded that Zaditen is an effective medication for long-term control of asthma in children.

Adolescent↗
PubMed1989

Effect of zinc administration on cadmium-induced suppression of natural killer cell activity in mice.

Natural killer (NK) cells play an important role in immune surveillance against viral infections and neoplasms. The effect of cadmium with or without zinc on mouse spleen NK cell activity was studied. Six-week-old male C57BL/6 mice were given drinking water containing either 50 ppm cadmium, 50 ppm cadmium together with 500 ppm zinc, or 500 ppm zinc. A fourth group receiving no additional cadmium or zinc served as control. After 3 weeks of treatment, the mice were killed, splenic lymphocytes isolated and cultured with 51Cr-labelled YAC-1 target cells for 4 and 12 h in a ratio of 50:1. The percentage of target cell lysis was measured to assess NK cell activity. In the 12-h assay, cadmium-treated animals had significantly lower NK cell activity than controls. Concurrent zinc administration prevented the suppression. In the 4-h assay, a similar trend was observed. Between 4 and 12 h, NK cell activity increased significantly in control and zinc-treated groups, but not in those receiving cadmium. The results suggest that a relatively low dose of cadmium suppresses NK cell activity, which can be prevented by a moderately large dose of zinc.

Analysis of Variance↗