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Biomedical subjects

R K Chandra

Publications and source records attributed to R K Chandra.

At least 145 records · Page 8Linked to original sources

Thymus-dependent lymphocytes and delayed hypersensitivity in low birth weight infants.

The proportion of thymus-dependent (T) lymphocytes in the blood and the ability to mount cutaneous delayed hypersensitivity to a battery of antigens were evaluated in 50 low birth weight (LBW) infants when they were 3 months to 5 years old. There was a significant reduction in the number of T lymphocytes. Delayed hypersensitivity was impaired. The abnormalities were more pronounced in those with persistent growth retardation. It is suggested that continued postnatal depression of cell-mediated immunity in LBW infants may contribute to increased frequency of infections and immunopathological diseases.

Child, Preschool↗

Lymphocyte subpopulations in human malnutrition: cytotoxic and suppressor cells.

Lymphocytes in the peripheral blood of young children with protein-calorie undernutrition were evaluated for surface markers and function. Thymus-dependent lymphocytes were reduced and the immunoglobulin-bearing B lymphocytes were unchanged. The relative proportion of the remaining "null" lymphoid cells was increased. Null cells and, to a lesser extent, B lymphocytes showed cytotoxic activity against xenogeneic target cells and suppressed phytohemagglutinin-induced DNA synthesis by normal T lymphocytes. It is suggested that these alterations in lymphoid subpopulations contribute to depressed cell-mediated immunity in malnutrition.

B-Lymphocytes↗

Indian childhood cirrhosis: genealogic data, alpha-foetoprotein, hepatitis antigen and circulating immune complexes.

Indian childhood cirrhosis is a significant cause of morbidity and mortality in young children in India. One hundred patients with ICC, 66 boys and 34 girls, were studied. Pedigree analysis yielded a segregation ratio of 0-2196, suggestive of an autosomal recessive inheritance. Serum alpha1-antitrypsin level was normal. Serum alpha-foetoprotein (AFP) concentration was increased in all the patients, parents and in some siblings. Serum immunoglobulins G, A, M, and D were elevated. Haemolytic complement and C3 were low. Electrophoretically altered complement components were detected in 36% of patients. There was an inverse relationship between C3 concentration and immunoconglutinin titre. Circulatingimmune complexes were detected in the sera of six out of ten patients who had significant proteinuria. Hepatitis B surface antigen (HBsAg) was present in the serum, ascitic fluid, saliva, urine and faeces of ICC patients more frequently than in controls. HBsAb was detected less often. Lymphocyte response to HBsAg was impaired. The first-degree relatives had a higher incidence of HBsAg and HBsAb than healthy controls. It is suggested that ICC occurs in infants with an inherited hepatocyte vulnerability and that one of the precipitating causes of liver cell necrosis is infection with hepatitis virus(es). The consequent immunologic epiphenomena contribute to progressive hepatic damage ending in death.

Antigen-Antibody Complex↗

Chemotaxis, random mobility, and mobilization of polymorphonuclear leucocytes in malnutrition.

Neutrophil mobilization following administration of Pseudomonas polysaccharide was significantly reduced in malnutrition, especially during infection. The random mobility of polymorphonuclear leucocytes (PMNs) was slightly decreased in undernutrition. Chemotactic migration of PMNs was depressed and correlated more with the presence of infection than with nutritional deficiency. It is possible that these abnormalities of PMN mobilization and mobility in malnourished individuals contribute to suboptimal amount, kinetics, and pattern of tissue inflammatory response to bacteraemic challenge.

Bacterial Infections↗

Polymorphonuclear leucocyte function in hypothyroidism.

The quantitative nitroblue-tetrazolium test demonstrated that polymorphonuclear leucocytes from patients with hypothyroidism reduced the dye less well than leucocytes from euthyroid persons. The ability of these cells to ingest and kill staphylococci were unimpaired. The abnormality of the nitroblue-tetrazolium test in hypothyroid patients was corrected after their treatment with thyroxine.

Humans↗

The effect of nutritional status on immune capacity and immune responses in preschool children in a rural community in India.

Cell-mediated immune response (CMI) and several aspects of humoral immune status and response were measured and related to nutritional status in preschool children in north India. CMI was measured by means of postvaccinal (BCG) tuberculin sensitivity and leucocytic blast cell transformation. Humoral immune response was measured by means of tetanus antibody production following vaccination with diphtheria-pertussis-tetanus vaccine. Immunoglobulins A, G, and M and complement (C(3)) were also determined. CMI, serum IgA, and C(3) were found to be directly correlated with weight-for-age status.

Antibody Formation↗

Antibody formation in first and second generation offspring of nutritionally deprived rats.

Prolonged partial restriction of calorie intake in young rats results in reduced growth, involution of lymphoid organs, and lymphopenia. After immunization with sheep red blood cells, the number of antibody-forming cells in the spleen and serum hemolysin titers are markedly reduced. The effect is more pronounced on the primary response and on immunoglobulin G antibody-forming cells. Significant impairment of antibody formation is detectable in the first (F1) and second (F2) generation offspring of starved Fo mothers.

Animals↗

Reduced secretory antibody response to live attenuated measles and poliovirus vaccines in malnourished children.

Serum and nasopharyngeal IgA antibody levels were estimated in 20 malnourished children and 20 matched healthy controls after immunization with a single dose of live attenuated measles or poliovirus vaccine. Seroconversion and serum neutralizing antibody titres were comparable in the two groups. Secretory IgA antibody was detected significantly less often in undernourished children; the time of its first appearance was delayed-and its maximum level was significantly lower. Impaired secretory antibody response in malnourished children may contribute to slow inadequate recovery from viral and enterobacterial infections and predispose to lifethreatening complications.

Antibodies, Viral↗

Serum alpha - fetoprotein levels in patients with cystic fibrosis and their parents and siblings.

Patients with cystic fibrosis (C.F.) showed raised serum levels of alpha-fetoprotein (AFP). A moderate but significant increase in serum AFP was present in their parents and some siblings. There was no correlation between the clinical severity of the disease and serum AFP concentration. Samples from control groups with gluten-induced malabsorption and bronchiectasis had normal levels. Persistent synthesis of AFP may be an associated marker of C.F. genes, and estimation of serum AFP might help in detecting heterozygote carriers in families at risk.

Bronchiectasis↗