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Biomedical subjects

A Garrido

Publications and source records attributed to A Garrido.

At least 91 records · Page 5Linked to original sources
PubMed1988

Study of the secretion of pepsinogen I in cirrhotic humans with and without portacaval shunt.

Thirty-nine subjects have been studied: 14 with hepatic cirrhosis who had not been subjected to surgery, 13 cirrhotic patients in whom portacaval shunt had been performed, and 12 normal controls. In all of them, we performed serum determinations of pepsinogen I, both basal and after pentagastrin stimulation, and of basal gastrin levels, as well as analyses of basal and stimulated gastric acid secretion (basal acid output and maximal acid output). The values for pepsinogen I, basal or post-stimulation, were higher (p less than 0.001) in patients with cirrhosis who had not undergone surgical shunt than in those in the control group. However, there were no statistically significant differences when these two groups were compared with the patients who had been subjected to portacaval shunt. In this last group of patients, seven had levels similar to those of the controls, and six presented higher values. Likewise, the values for gastric acid secretion were similar in the three groups of patients, and the basal gastrin level was lower (p less than 0.001) among patients with liver cirrhosis, whether or not they had undergone surgery, than among the control population. In conclusion, the functional alterations of the gastric mucosa in patients with hepatic cirrhosis are not significantly different from those found in cirrhotic patients with portacaval shunt.

Adult↗
PubMed1987

A study of GRM1 monoclonal antibody that reacts with natural killer cells and granulocytes.

We have produced a monoclonal antibody, GRM1, against a prolymphocytic leukemia that defines an antigen present in neutrophilic granulocytes (PMN) and a lymphocyte subset with natural killer (NK) activity, which was identified as large granular lymphocytes. This monoclonal antibody recognizes FcR2 (CD16), an antigen composed of two polypeptides of 50 and 60 kilodaltons, respectively. This GRM1 monoclonal antibody was tested against normal T and B cells, neutrophilic granulocytes, monocytes, platelets, acute and chronic leukemias, and was positive only against granulocytes (95%) and cells with NK activity. GRM1 was able to deplete NK cell activity in complement-dependent lysis. However, GRM1 did not block NK activity nor peripheral blood lymphocyte- and PMN-mediated antibody-dependent cytotoxicity in healthy individuals. GRM1 also did not block Fc receptor in an erythrocyte antibody rosette assay. The immunochemical data and cell distribution patterns lead us to conclude that GRM1 recognizes and FcR2 receptor epitope which is not involved in the receptor's function.

Adult↗
PubMed1987

Differences in the lipid peroxidative status, cytochrome P-450 content and microsomal oxygen consumption between right and left lobes of the liver in fetal sheep. Comparison with maternal liver.

The existence of the ductus venosus in mammalian fetal liver determines a different blood flow in the right and left lobes. This asymmetry is associated to a decrease in oxygen delivery to the right lobe. Some stages in oxygen metabolism are related to the formation of free radicals that can induce cellular damage dependent on the tissue oxygen concentration and on the activity of the enzymatic and non enzymatic systems involved in the tissue protection. In the present study, the differences in the lipid peroxidative status and some parameters related to the protection against oxygen toxicity between both lobes in the sheep fetal liver were analyzed and compared to the same parameters in the dam liver.

Animals↗
PubMed1986

Influence of class I H-2 gene expression on local tumor growth. Description of a model obtained from clones derived from a solid BALB/c tumor.

A BALB/c methylcholanthrene-induced tumor was studied for class I and II H-2 expression. GR9 was adapted to tissue culture without any passage in vivo to avoid immunoselection mechanisms. Forty-three clones were obtained and typed for H-2 antigens. A variety of techniques were used for typing, for example, 51Cr release assay, radiobinding assay; absorption with anti H-2 monoclonal antibodies or H-2 allo-antisera and alloreacting cytotoxic T lymphocytes. A heterogeneity of H-2 expression was detected in these clones with clones H-2 K+/D+, to clones H-2K-D-. This heterogeneity was also evident when several GR9 clones were tested for in vivo growth in syngeneic BALB/c mice. Two clones, A7 and B9, were selected for further studies and injected into syngeneic animals to measure local tumor growth. A7 (K+/D+) was rather immunogenic while B9 (K-/D-) was not. These differences were probably due to an immunoresponse, since both clones grow similarly in irradiated syngeneic BALB/c mice. Immunoprecipitations of H-2 antigens and SDS-PAGE analysis confirmed the results obtained in serology. Three isoenzymes were also determined in GR9 clones and their electrophoretic mobility was always identical to that obtained in normal BALB/c tissues. These results suggest that K and D molecules are important structures for an immunoresponse against tumor-associated antigens.

Animals↗
PubMed1985

Inhibitory effect of the flavonoid silymarin on the erythrocyte hemolysis induced by phenylhydrazine.

The flavonoid silymarin, which is used as a therapeutical agent in the treatment of liver diseases, can inhibit the hemolysis and lipid peroxidation induced by phenylhydrazine on erythrocytes obtained from rats treated with the flavonoid. This effect is ascribed to the antioxidant properties as a free radical scavenger exhibited by the flavonoid. Silymarin failed to inhibit the glutathione depletion induced by phenylhydrazine on erythrocytes. It is proposed that the flavonoid acts at the membrane level of the cell avoiding the lipid peroxidative and fluidizing effect of phenylhydrazine.

Animals↗
PubMed1985

[Effect of a serum inhibitor on hematopoiesis regulation: in vitro effect on RNA synthesis in bone marrows of rats].

Hematopoiesis is regulated by several hormones and protein factors, among them, erytropoietin (Ep) and granulopoietin (CSF: Colony Stimulating Factor) play the fundamental control activities inducing the differentiation of stem cells to red and white cells series, respectively. The action of serum inhibitors and cyclic nucleotides on hematopoietic process is not well understood at present time. In this work a rat serum-inhibiting activity was detected that diminished the in vitro [3H] uridine incorporation into rat bone marrow whole RNA. The experiments show that the inhibitory may have a platelet origin.

Animals↗
PubMed1981

[Changes in the expression of H-2 antigenic determinants in several sublines proceeding from the same tumor].

Four sublines of the chemically induced BALB/c tumour MCG4 have been obtained after serial intraperitoneal transplantation in syngeneic recipients and have been named MCG4-O, MCG4-A, MCG4-B and MCG4-C. The four subline have been typed for H-2 antigens in a complement dependent microradioassay with H-2 alloantisera defining H-2 specificities as well as with two syngeneic anti tumour sera: BALB/c anti MCG4-O and BALB/c anti MCG4-A. The results obtained showed a progressive loss of the foreign H-2 antigens detected in the primitive line, MCG4-O, with a simultaneous appearance of the appropriate H-2 antigens detected in MCG4-B and MCG4-C. Furthermore the immunogenic capacity of the sublines decrease progressively with the transplantation procedures, rendering MCG4-O and MCG4-A highly immunogenic and capable of producing isoantibodies while MCG4-B and MCG4-C are poorly immunogenic. The results could suggest that the primitive subline is heterogeneous mixture of (H-2d) are immunoselected by the transplantation procedures with rejection of the most immunogenic clones, which would express the foreign H-2 antigens.

Animals↗