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Biomedical subjects

A Soyano

Publications and source records attributed to A Soyano.

36 records · Page 2Linked to original sources
PubMed1986

Effect of fetal and adult bovine albumins on human lymphocyte proliferation in vitro.

Fetal and adult bovine albumins were isolated and compared with the commercially obtained fraction V of Cohn, in terms of their ability to support cell proliferation, when added as a supplement to serum-free lymphocyte cultures activated with phytohemagglutinin. It was found that fetal albumin is the least efficient of the three proteins in permitting lymphoproliferation. A difference between the kinetics of proliferation of lymphocyte cultures supplemented with albumin and with serum was also observed.

Animals↗
PubMed1985

Synergistic effect of albumin and transferrin on the mitogen stimulation of human mononuclear leukocytes in serum-free medium.

It is well known that optimal lymphocyte proliferation in vitro requires the supplementation of the culture medium with serum, the usual concentration varying between 5% and 20%. In an attempt to reduce the serum requirement of lymphocytes in culture, we have found that supplementation of RPMI 1640 medium with as low as 1% human serum allows an adequate proliferation of human peripheral blood lymphocytes cultured in microtiter plates in a CO2 atmosphere and stimulated by phytohemagglutinin. In serum-free cultures, the addition of albumin (4 mg/ml) or transferrin (10 micrograms/ml) allows a significant proliferation of lymphocytes. This permissive effect was cell concentration-dependent, being maximal at 2 X 10(5) cells/well. The simultaneous addition of albumin and transferrin produced a synergistic effect, the phytohemagglutinin-induced proliferation being higher than expected from the addition of the two proteins separately. This synergistic effect was observed in 89% of the subjects studied (8 out of 9). These results suggest that albumin and transferrin are required for optimal lymphocyte proliferation and that the serum can be partially substituted by these two proteins.

Animals↗
PubMed1985

Suppressive effect of iron on in vitro lymphocyte function: formation of iron polymers as a possible explanation.

The evidence presented here indicates that ferric citrate inhibits both the phytohemagglutinin-induced lymphocyte proliferation and the formation of E rosettes by T lymphocytes. These inhibitory effects are only observed in the presence of ferric citrate with a metal to ligand molar ratio of (1:1) but not with ferric citrate (1:20) or sodium citrate. Since ferric citrate (1:1) at a physiological pH tends to hydrolyze and polymerize, we suggest that the inhibitory effect is mediated by the formation of iron polymers.

Ferric Compounds↗
PubMed1985

Interrelationships between immediate, intermediate, and delayed cutaneous reactions and their in vitro correlates.

The mutual correlations between immediate, intermediate, and delayed cutaneous reactions, IgE, IgG, or combined IgG, A, and M antibody levels, and antigen- or mitogen-induced lymphocyte transformation were evaluated in a mixed group of allergic or non-allergic individuals. As might be expected, immediate and delayed reactions correlated significantly with IgE antibody levels and lymphocyte transformation, respectively. Intermediate time-course reactions did not correlate with IgG or IgG, A, and M antibody levels, but did so with immediate reactions, thus suggesting their "late phase" nature. Of particular interest was the finding of correlations that do not conform to the classical concept of the mechanisms involved in the generation of the different cutaneous reactions. Significant correlations were found between immediate or intermediate reactions and antigen-induced lymphocyte transformation, and between immediate and delayed reactions. These results are discussed in relation to recent suggestions that factors released from sensitized T cells can mediate early time-course reactions, and that such reactions may contribute to the manifestation of delayed-type hypersensitivity.

Adolescent↗
PubMed1984

Circulating immune complexes, immunoglobulins, complement, antibodies to dietary antigens, cholesterol and lipoproteins levels in patients with occlusive coronary lesions.

The presence of circulating immune complexes, serum immunoglobulins, C3 (the third component of complement), antibodies to alpha-lactalbumin, beta-lactoglobulin and bovine serum albumin was studied in 39 patients subjected to coronary arteriography. Total serum cholesterol and triglycerides and cholesterol in VLDL, LDL and HDL were also estimated. The results obtained in the group of patients found with occlusive lesions were compared with those found in the group without lesions. With one of the five assays used for the detection of immune complexes, higher and significant levels were found in the group with lesions. A negative and significant correlation was found between the number of vessels with lesions and the levels of serum C3.

Adult↗
PubMed1984

The effect of desferrioxamine on the proliferative response of rat lymphocytes stimulated with various mitogens in vitro.

This paper reports experiments designed to evaluate the effect of desferrioxamine on lymphocytes obtained from the spleen of Sprague-Dawley rats. The results showed that desferrioxamine inhibits the proliferative response of lymphocytes stimulated by concanavalin A or pokeweed mitogen, the effect being proportional to the dose used, and being maximal at the end of the culture period. To exert its effect, desferrioxamine has to be present from the initiation of the cultures--its addition 24 h later markedly reduced its inhibitory effect. Studies of cell viability indicated that the inhibition was not due to toxicity. Lymphocytes obtained from young animals (4 to 12-week-old) were more sensitive to desferrioxamine than older animals (13 to 18-week-old). Saturation of desferrioxamine with iron abolished its effect, suggesting a direct relationship between chelating properties and inhibition, and reinforcing the hypothesis that iron plays an important role in the process of cell division.

Animals↗
PubMed1984

Destruction of IgG anti-A sensitized erythrocytes by mononuclear leucocytes from normal and ABO haemolytic disease affected infants.

Studies were undertaken to investigate the antibody-dependent cell-mediated cytotoxicity (ADCC) activity of mononuclear leucocytes (MNL) from cord and healthy adult blood and that from infants with ABO haemolytic disease. The ADCC levels of MNL from both types of newborn blood were found to be higher than that of MNL from adult blood. The extent of ADCC was positively related to the degree of antibody sensitization of the red cells and to the effector cell target cell ratio. The ADCC activity was effected mainly by the adherent cell fraction and could be inhibited by cytochalasin B, hydrocortisone and also by high concentrations (more than 0.5 mg/ml) of non-specific free human IgG. Phagocytosis was also demonstrated to be an important mechanism in the destruction of IgG anti-A coated red cells by the MNL.

ABO Blood-Group System↗
PubMed1983

Studies on the binding of IgG and F(ab) anti-A to adult and newborn group A red cells.

The values of the functional affinity constants for the binding of human IgG anti-A and its F(ab) derivative with adult and newborn group-A red cells have been determined. The values obtained for both monovalent and bivalent antibody with both types of cells were of the same order (about 1 X 10(8) M-1), indicating that IgG anti-A binds to red cells only by one of its F(ab) arms.

ABO Blood-Group System↗
PubMed1982

Effect of iron deficiency on the mitogen-induced proliferative response of rat lymphocytes.

To delineate the alterations of the immune function induced by iron deficiency male Sprague-Dawley rats were obtained at 3 weeks of age and fed an iron-deficient diet. By the end of the 3rd week on this diet the animals were anemic and ferropenic. A marked increase in the proliferative response of splenic lymphocytes at optimal doses of mitogen (PHA, Con A, and PWM) was observed. On the contrary, thymic lymphocytes showed a decreased proliferative response. Time-course experiments demonstrated significant alterations in these proliferative responses after only 1 week of iron deprivation, at a time when the level of hemoglobin was normal. Nutritional rehabilitation after 5 weeks of iron deprivation showed complete recovery of the response after 11/2 weeks on normal diet.

Anemia, Hypochromic↗
PubMed1979

Hepatitis--Bs antigen in an isolated Indian population of southern Venezuela: a family study.

A genetic analysis of the presence of HBsAg in a population of which 7.2% of the members were positive is presented. Though the ratios of carriers: non-carriers were generally in good agreement with expectation if the carrier state were determined by homozygosity for a single recessive gene, the two examples of mating most critical to a test of the hypothesis, carrier X carrier, yielded 2 normal children among 4 in one family, and one normal child, the only offspring, in the second family. Other investigators have reported similar findings. We conclude that the hypothesis of simple recessive inheritance cannot be sustained.

Adolescent↗
PubMedDate not supplied

Interaction of iron polymers with blood mononuclear cells and its detection with the Prussian Blue reaction.

An inhibitory effect of iron salts on various immune functions in vitro has been reported in several laboratories during the last few years. This study confirms and extends those observations by showing that iron citrate inhibits the mitogen-induced (PHA, Con A and PWM) lymphocyte proliferation. Such inhibition is observed in the presence of ferric citrate with a metal-to-ligand molar ratio of 1:1 but not with ferric citrate with metal-to-ligand molar ratio 1:20 in which the formation of polynuclear iron complexes is prevented. Increasing the concentration of serum in the culture medium diminished the inhibitory effect of 1:1 ferric citrate. Using the Prussian Blue reaction the presence of ferric iron was observed on the cell surface. It is proposed that the deposition of polynuclear iron complexes on the lymphocytes membrane is one of the possible factors determining the iron inhibitory effect.

Cells, Cultured↗
PubMedDate not supplied

Long-term care for the elderly in Japan.

This article, using data from the first author's research, presents selected issues in long-term care (LTC) of the elderly in Japan. A brief discussion of historical and cultural factors frame the current realities of LTC. These realities include the vast numbers of elderly people in Japan, changing definitions of the relationship of the individual to the group, and enactment of the new Care Insurance Law for the Elderly to be implemented in the year 2000. Some of the work underway for this implementation is detailed.

Aged↗
PubMedDate not supplied

Profiles of NK, NKT cell activation and cytokine production following vaccination against hepatitis B.

Human natural killer (NK) cells (CD56+ CD3-) represent crucial components of the innate immune system especially against viral infections and because their activation can modulate the outcome of the adaptive immune response. NKT cells (CD56+CD3+), a lymphocyte T population characterized by expression of surface markers of NK cells, are known to be abundant in the liver and their activation could be associated with hepatic injury. Using three-color flow cytometry to measure surface receptors and intracellular cytokines, we have explored early activation signals and cytokine production in NK and NKT cells within a group of hepatitis B vaccinated and non-vaccinated individuals. A specific increase of the CD56bright cell population, the activation receptor CD69 and IFN-gamma, was observed in NK cells following incubation with recombinant HBsAg in responders to vaccination. Comparable results were observed in NKT cells showing an increment of CD69, CD25, IL-2 and IFN-gamma expression in responder subjects. These parameters were statistically diminished in non-responder individuals (p<0.05) in both groups of cells. These results demonstrate a diminished activation of these cells in non-responders to the vaccine, suggesting that NK and NKT cells play an important role in the immune response following hepatitis B vaccination.

Adult↗