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Biomedical subjects

F Garrido

Publications and source records attributed to F Garrido.

At least 145 records · Page 8Linked to original sources
PubMed1988

Phenotypic and genetic analysis of HLA class I and HLA-DR antigen expression on human melanomas.

Class I and HLA-DR antigen expression were studied with histochemical techniques involving monomorphic monoclonal antibodies in 49 cases of human malignant melanomas, 20 primary and 29 metastatic. A large percentage (90%) of primary melanomas were positive for HLA class I, while those primary lesions showing lowest levels of class I antigen expression were at the upper end of the range of invasiveness and possessed a higher metastatic potential. Expression of HLA-DR molecules on primary melanomas was low (25% of all cases) and HLA-DR-positive melanomas were among the most aggressive. In metastatic melanomas, HLA class I expression was less common than in primary lesions. The lowest percentage of cases positive for HLA class I was found for cutaneous metastases. HLA-DR molecules were more frequently expressed by lymph node metastases than on primary melanomas. The comparison of the expression of HLA class I and HLA-DR molecules by primary melanomas and their autologous metastases revealed a high degree of heterogeneity. Class I genes were further studied by Southern blot assays. No differences were found in restriction fragments for class I genes among 4 melanomas and their autologous lymphocytes, 2 of which were positive and 2 negative for class I expression.

Blotting, Southern↗
PubMed1987

Incidence of abortions caused by leptospirosis in sheep and goats in Spain.

From 1970 to 1985, 973 outbreaks of abortion in sheep and 262 outbreaks of abortion in goats from southern Spain were studied. Of these, 1.7 and 2.6% respectively were caused by leptospiras, chiefly by the serovar pomona (11 flocks of sheep, 64.7%, and six herds of goats, 75.0%) and in a lower proportion the serovars sejroe (three flocks of sheep 17.6%, and one herd of goats, 12.5%), icterohaemorrhagiae (two and one outbreaks respectively) and grippotyphosa in one ovine flock (5.8%). The mean rates of attach (X + SD) of abortions by leptospirosis have been estimated as 16.9 + 6.5% in ovine outbreaks and 20.7 + 8.3% among goats.

Abortion, Veterinary↗
PubMed1987

A monoclonal antibody, GR7A4, reacting with the T10 antigen.

The monoclonal antibody GR7A4 was produced against a human lymphoblastic leukemia (ALL-B). Biochemical characterization of GR7A4 was carried out with Raji cells in SDS-PAGE studies. GR7A4 precipitated a 43 kd molecule. The tissue distribution and molecular weight were similar to the T10 antigen. Modulation and capping of GR7A4 antigen reduced its binding ability to cells with either GR7A4 or OKT10. However, the cell surface distribution pattern observed was somewhat different from other similar monoclonal antibodies. Thus GR7A4 reacted greatly with pre-B-cell lines, Burkitt cell lines, EBV cell lines and activated PHA, ConA and PWM lymphocytes, however reactivity with leukemic cells was very limited. The kinetics of appearance of GR7A4 antigen on PWM blasts show that this molecule seems to represent an intermediate stage in lymphocytic activation. The differences in comparison with other similar MAbs are discussed and correlated with the peculiar discontinous pattern of appearance of this antigen.

Antibodies, Monoclonal↗
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

Class I and II HLA antigen distribution in normal mucosa, adenoma and colon carcinoma: relation with malignancy and invasiveness.

HLA class I and II antigen expression was studied in normal mucosa, adenoma and colon carcinoma. Alkaline phosphatase anti-alkaline phosphatase (APAAP) staining techniques were used in cryostatic sections with anti-HLA-ABC and DR,DP,DQ monoclonal antibodies. All normal mucosa were intensely positive for HLA class I antigen expression, while failing to express class II molecules, except in mucosa adjacent to tumors (15/19 cases). All adenomatous polyps expressed HLA class I antigen, while the intensity of class II expression (DR greater than DQ greater than DP) was paralleled by the degree of dysplasia. In colon carcinoma, the loss of class I expression was seen in 4 out of 32 cases, and class II expression was found to be heterogeneous in 16 of these 32 cases (DR greater than DP greater than DQ). No relationship was noted between class II expression and degree of differentiation. However a correlation was seen between HLA-DR antigen expression and degree of invasiveness, mononuclear infiltrate and prognosis, according to Jass's criteria.

Adenocarcinoma↗
PubMed1987

Heterogeneity of chronic T-cell lymphocytosis: immunological and clinical aspects.

The clinical and laboratory findings as well as the immunological cell phenotype of nine patients with chronic T-cell lymphocytosis (T-CL) are presented. The clinical course was stable in most patients and only one patient died. Splenic enlargement was the main clinical finding and in contrast to B-CLL the age at presentation was lower; T-CL predominated in females and lymphadenopathy was rare. The lymphocyte count was moderate (range 4.1-23.8 X 10(9)/L). Six patients displayed neutropenia; in contrast, anaemia was only observed in one patient and thrombopenia in another. The immunological cell phenotype was heterogeneous: four cases exhibited a cytotoxic/suppressor phenotype, two a helper phenotype and in the remaining three cases mixed OKT4+ and OKT8+ lymphocytes were observed; these results suggest that T-CL may originate from different T-cell subsets. Although the question of the benign or neoplastic nature of the T-CL remains open, some of the characteristics of the immunological phenotype could provide additional evidence to demonstrate the malignant condition of the process: in contrast to normal lymphocytes (CD5+, CD7+) the lymphocytes in T-CL were generally CD5 +/-, CD7-, and one patient showed an aberrant phenotype (OKT3+, OKT6+), an occasional finding in other T lymphoproliferative disorders.

Aged↗
PubMed1986

Influence of hormones on DNA synthesis of breast tumors in culture.

Tissue culture techniques have been developed for studying the influence of hormones on human breast tissues. The present study demonstrated that estrogen induced a highly significant increase in 3H-thymidine incorporation into DNA and labelling index of ductal epithelium of fibrocystic disease; there was no effect of progesterone, either alone or in combination with ovine prolactin, on benign lesions. Estrogen stimulated certain malignant tumors derived from postmenopausal women. These studies also showed that there was an inhibitory effect of 3H-thymidine incorporation into DNA by the effect of progesterone on malignant lesions. When menopausal status was considered, it was found that DNA synthesis was significantly higher in the presence of insulin and hydrocortisone in malignant tumors derived from premenopausal women than from postmenopausal women, or than in benign lesions. Thus, the present findings may provide evidence that specific activity may be an important measurement for breast tumor DNA synthesis in response to ovarian hormones or other substances.

Adenoma↗
PubMed1986

Production of monoclonal antibodies to metacyclic trypomastigotes of Trypanosoma cruzi.

Monoclonal antibodies were produced and characterized to the metacyclic trypomastigotes stage of Trypanosoma cruzi. All the monoclonal antibodies (GR-12C/5; GR-P2B/5; GR-F2B/1; GR-J2C/6; GR-E6B/3; GR-A5B/5) also recognized antigens of epimastigotes of T. cruzi. These antigens are associated with the plasma membrane, flagellum, and an intracellular structure located by the nucleus. Immunoprecipitation using the monoclonal antibodies GR-J2C/6 and GR-E6B/3 followed by SDS-PAGE analysis has led to the following results: GR-J2C/6 precipitated two molecules with apparent molecular weights of 58 and 60 kD; the antigen recognized by GR-E6B/3 was a molecule with molecular weight of 68 kD. Only two of the monoclonal antibodies (GR-12C/5 and GR-P2B/5) recognized antigens of promastigotes of both Leishmania mexicana and L. infantum, and are associated with the plasma membrane.

Antibodies, Monoclonal↗
PubMed1986

Characterization of monoclonal antibodies directed against HLA class II molecules.

Four MAbs recognizing HLA class II antigens were produced by immunization with human leukemic cells, and were characterized through immunoprecipitation and cell distribution studies. They were tested against a panel of normal and leukemic cells, Epstein-Barr virus (EBV)-transformed homozygous typing cells (HTC)s, deletion mutant cell lines, and 11 other cell lines. The immunochemical studies revealed the presence of two bands of 34 and 28 kD, corresponding to the alpha- and beta-subunits of HLA class II antigens, respectively. The cell distribution studies led to the conclusion that GRB1, GRB2, and GRB3 MAbs recognize the HLA-DR monomorphic antigens, and that the GRB4 MAb seems to recognize basically the DR molecules but shows also a cross-reaction to DP molecules.

Antibodies, Monoclonal↗
PubMed1986

Hypercorticosteronuria and diminished pituitary responsiveness to corticotropin-releasing factor in obese Zucker rats.

Metabolic defects in obese (fa/fa) Zucker rats have previously been shown to be reversed by adrenalectomy; however, hypercorticosteronemia has not been demonstrated. We now report that the total daily excretion of corticosterone and urea nitrogen are significantly greater (P less than 0.01) in obese Zucker rats than in age-matched lean Zucker rats. This excessive excretion of corticosterone is not of autonomous adrenal origin, since dexamethasone treatment (20 micrograms/kg X day) for 2 days induced a proportionate reduction in corticosterone excretion (approximately 50%) in both obese and lean Zucker rats. Corticosterone excretion was further suppressed to levels not different from those in lean rats after 2 days of dexamethasone (40 micrograms/kg X day). Both the peak and total pituitary beta-endorphin secretion in response to an iv bolus of corticotropin-releasing factor (CRF) were diminished in obese Zuckers. The response to CRF in obese Zucker rats was dampened and superimposable on that of dexamethasone-treated lean Zucker rats, suggesting the existence of chronic hypercorticosteronemia as a component of this genetic obesity. These observations provide evidence for a compensatory alteration of the pituitary-adrenal axis. We suggest that corticosterone turnover may be increased in obese Zucker rats.

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

Plasmatic beta-endorphin levels and thalamic surgery for pain.

Plasma beta-endorphin levels were found to be significantly lower in patients suffering from chronic pain of malignant etiology than in a control group. After a bilateral stereotactic cryothalamotomy in Centrum Medianum and Parafascicularis nuclei, a good clinical result and a significant increase in plasma beta-endorphin levels were obtained.

Adult↗
PubMed1985

A monoclonal antibody GR2110 reactive with a P24 antigen present in a subgroup of acute lymphoid leukemias.

A monoclonal antibody IgG1K against a P24 antigen has been obtained. This antigen is present on a subgroup of non-T-ALL and platelets. GR2110 monoclonal antibody was produced by immunizing with a CALL (CALLA+, Ia+, IgS-, E-, T3-) This P24 antigen is absent in normal T-lymphocytes, monocytes, mitogen-activated T-cells; weakly expressed on B-cells and granulocytes and negative with several cell lines, except with KM3. GR2110 monoclonal antibody was tested with chronic and acute human leukemias. It was positive only with some CALL, NULL ALL, B-ALL and negative with B-CLL, T-CLL, T-cell lymphoma, Hairy cell leukemia, AML, T-ALL. The immunoprecipitation of 125I-labeled cell membrane with the monoclonal antibody and SDS-PAGE analysis revealed a 24 kD molecular weight polypeptide. The comparison of GR2110 and FMC 8 in capping experiments and cellular reaction patterns, showed that both antibodies react with the same molecule but probably with different epitopes.

Antibodies, Monoclonal↗