Biomedical subjects

S Arredondo

Publications and source records attributed to S Arredondo.

5 recordsLinked to original sources

PubMed1997

Effect of human newborn BCG immunization on monocyte viability and function at 3 months of age.

SETTING: Immune response induced by BCG vaccination seems to reflect the development of T-cell immunity and monocyte activation. Participants were recruited from a large prospective study in infants from a suburb in Santiago, Chile. OBJECTIVE: To determine whether newborn BCG immunization changes the innate ability of cultured monocyte-macrophages to ingest and kill virulent mycobacteria in the absence of lymphocytes. DESIGN: The study population consisted of 15 three-month-old, tuberculin-positive infants immunized with BCG (Japanese) at birth, 13 randomly-selected, age-matched tuberculin-nonreactive infants in whom BCG immunization was postponed until one year of age, and five BCG-immunized, tuberculin-reactive adults. Adherent cells were cultured for 48 h. Monocyte-macrophage viability and number and viability of intracellular Mycobacterium tuberculosis bacilli were assessed after an additional 2 h and 4 and 7 days of incubation. RESULTS: There was no difference in the mean number of adherent cells present after 48 h among the three study groups. Adherent cells from BCG-immunized infants and adults had a significantly higher viability after 7 days in culture than adherent cells from non-immunized infants. The percentage of cells ingesting M. tuberculosis and the number of bacilli per cell after 2 h and 4 days was significantly higher in immunized infants and adults than in non-immunized infants. However, there was no evidence for increased killing of mycobacteria by cells from immunized infants and adults. CONCLUSION: These results suggest that BCG vaccination increases monocyte viability and the uptake of M. tuberculosis without enhancing the ability to kill ingested M. tuberculosis in the absence of lymphocytes.

Adult↗

PubMed1993

Zinc supplementation impairs monocyte function.

Zinc has been shown to be involved in many functions of the immune system. This study was conducted to examine the effect of zinc supplementation on phagocytic, fungicidal and metabolic activity of blood monocytes of marasmic infants during nutritional rehabilitation. A controlled, double-blind design was used in which 19 infants fed a zinc-fortified formula were compared with 20 infants fed the same, unfortified formula. Evaluation of phagocytic-fungicidal capacity, growth, zinc, copper and iron status was performed in both groups on admission and after 60 and 105 days of nutritional rehabilitation. Although energy, copper and iron intakes were similar in the two groups, a decrease in the number of infants able to phagocytose one or more Candida buds was observed after 60 days of zinc supplementation compared to admission (p < 0.03). No change in phagocytic ability was detected between admission and 60 days in the control group. The number of infants with depressed fungicidal activity increased significantly after 105 days of nutritional rehabilitation in the zinc-fortified group as compared to controls (p < 0.04). The number and duration of impetigo episodes was significantly greater in the group fed the zinc-fortified formula. These results suggest that zinc supplements at the RDA level may impair monocyte function.

Candida albicans↗

PubMed1992

Effect of a zinc-fortified formula on immunocompetence and growth of malnourished infants.

This study attempted to define the possible contribution of zinc nutrition to immunocompetence and growth in severely malnourished infants. The effect of zinc supplementation was evaluated in marasmic infants during nutritional rehabilitation by using a controlled double-blind design in which 19 infants fed a zinc-fortified formula were compared with 20 infants fed the same non-supplemented formula. Evaluation of immunocompetence, growth, and zinc, copper, and iron status was performed on admission and at 30, 60, and 105 d of nutritional rehabilitation. Although energy intake was similar in both groups, the zinc-supplemented infants had significantly higher linear growth gain, and their immune function improved as demonstrated by conversion of their delayed hypersensitivity skin reactions, enhanced lymphoproliferative response to PHA, and increased salivary IgA concentrations. Thus, the use of a zinc-fortified formula during nutritional rehabilitation can prevent the development of zinc deficiency and improve growth and immune function.

Copper↗

PubMed1989

Functional capacity of colostral leukocytes from women delivering prematurely.

The phagocytic, bactericidal, and metabolic activity of colostral leukocytes from mothers delivering preterm infants was compared with that of colostral leukocytes from mothers of term infants. In addition, the proliferative capacity of colostral lymphocytes was compared. Preterm adherent colostral leukocytes had a significantly higher phagocytic index than term colostral adherent leukocytes. Mean +/- SEM values were 5.4 +/- 0.5 versus 2.7 +/- 0.2, respectively (p less than 0.001). Bactericidal capacity against Escherichia coli and nitroblue tetrazolium reduction of preterm and term colostral leukocytes were comparable. Lymphocyte proliferative response was equivalent in preterm and term milk. We conclude that colostral leukocytes from preterm mothers are at least as functional in their antimicrobial activity and possibly phagocytose even better than the colostral cells of mothers of term infants.

Adult↗

PubMed1986

Effect of iron therapy on phagocytosis and bactericidal activity in neutrophils of iron-deficient infants.

Phagocytosis and bactericidal capacity of neutrophils were measured in 10 iron-deficient infants age 6-23 mo. All infants had hemoglobins less than 11 mg/dL with low saturation of transferrin and serum ferritin but were otherwise in good health. Neutrophil function and iron status were assessed at 0, 3-5, 15, 30, and 90 days of oral iron therapy. Phagocytosis was unaffected in iron deficiency and remained unchanged during therapy. Bactericidal capacity was severely impaired prior to treatment. After 3-5 days of ferrous sulfate administration, there was no significant improvement. At day 15 it returned to normal ranges and remained so at days 30 and 90. The sequence of events suggests that iron does not have a direct effect upon circulating neutrophils but, rather, that it is required during the development of neutrophils in the bone marrow.

Anemia, Hypochromic↗