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Biomedical subjects

F Garrido

Publications and source records attributed to F Garrido.

At least 91 records · Page 5Linked to original sources
PubMed1995

Different patterns of HLA-DR antigen expression in normal epithelium, hyperplastic and neoplastic malignant lesions of the breast.

Fifteen samples of non-tumoural breast tissue, 24 cases of benign lesions, four biopsies of inflammatory carcinomas and 94 tumour samples of primitive mammary carcinomas were analysed for HLA class II expression. We found, first, that HLA class II antigens were detectable in all cases of non-neoplastic breast tissue. Secondly, HLA class II antigen expression was notably increased in benign neoplasms and hyperplastic lesions. In contrast, only 32 out of 94 carcinomas showed expression of HLA-DR antigens, 17 tumours had HLA-DP antigens and 11 carcinomas were positive for the presence of DQ molecules. The expression of class II antigen was associated with the degree of histological differentiation (P < 0.05) but was independent of stromal leucocytic infiltration. Thirdly, HLA-DR was very strongly expressed in intravascular tumoural thrombi, especially in the 'inflammatory carcinomas'. The immunophenotype of inflammatory infiltrate was analysed in benign and malignant lesions. In malignant lesions the mean number of inflammatory cells was significantly higher than in benign lesions. Interestingly, we found no differences in the amount and composition of inflammatory infiltrate between HLA-DR positive and negative tumours.

Adenocarcinoma↗
PubMed1995

Nafadotride, a potent preferential dopamine D3 receptor antagonist, activates locomotion in rodents.

Nafadotride (N[(n-butyl-2-pyrrolidinyl)methyl]-1-methoxy-4-cyano naphtalene-2-carboxamide) is a novel compound, which inhibits potently and stereoselectively [125I]iodosulpride binding at recombinant human dopamine D3 receptors. the levoisomer displays an apparent Ki value of 0.3 nM at the dopamine D3 receptor, but is 10 times less potent at the human recombinant dopamine D2 receptor. In comparison, the dextroisomer displays 20-fold less apparent affinity at the dopamine D3 receptor and reduced (2-fold) selectivity. l-Nafadotride displays iow, micromolar affinity at dopamine D1 and D4 receptors and negligible apparent affinity at various other receptors. In dopamine D3 receptor-transfected NG-108 15 cells, in which dopamine agonists increase mitogenesis, l-nafadotride has no intrinsic activity, but competitively antagonizes the quinpirole-induced mitogenetic response, monitored by [3H]thymidine incorporation with a pA2 of 9.6. In dopamine D2 receptor-transfected Chinese Hamster Ovary cells, l-nafadotride also behaves as a competitive antagonist of quinpirole-induced mitogenesis with an 11-fold lower potency. These studies establish nafadotride as a pure, extremely potent, competitive and preferential dopamine D3 receptor antagonist in vitro. l-Nafadotride displaces in vivo N-[3H]propylnorapomorphine accumulation at lower dosage and for longer periods in limbic structures, containing both dopamine D2 and D3 receptors than in the stratum, containing dopamine D2 receptor only. At low dosage (0.1-1 mg/kg), nafadotride, unlike haloperidol, a dopamine D2 receptor-preferring antagonist, increases spontaneous locomotion of habituated rats and climbing behavior of mice, at doses that do not modify striatal homovanillic acid levels. At high dosage (1-100 mg/kg), nafadotride, like haloperidol, produces catalepsy and antagonizes apomorphine-induced climbing.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

The D3 receptor and its relevance in psychiatry.

A large fraction of neurotensin neurons in the ventromedial shell subdivision of nucleus accumbens express D3 receptors. Blockade of D2/D3 receptors by antipsychotic agents paradoxically decreases neurotensin gene expression in these neurons whereas it enhances it in other striatal areas expressing the D2 receptor. This suggests that D2 and D3 receptors mediate opposite actions of dopamine. In support of this view low doses of nafadotride, a novel D3 receptor-preferring antagonist, enhances locomotor activity in rodents, a behavioral response opposite to that of current neuroleptics. The action of D3 receptor-preferring agonists was characterized by the mitogenic response they elicit in transfected NG 108-15 cells. Finally, gene expression of the D3 receptor is in opposition to that of the D2 receptor, being decreased by denervation and unaffected by chronic blockade by neuroleptics.

Antipsychotic Agents↗
PubMed1994

Upmodulation by estrogen of HLA class I expression in breast tumor cell lines.

The expression of major histocompatibility complex (MHC) class I antigens was studied in five breast carcinoma cell lines before and after treatment with 17-beta estradiol. Increased HLA class I antigen expression correlated with the presence of estrogen receptors. The modulation of expression appeared to be mediated by transcriptional mechanisms, as revealed by class I mRNA levels. To elucidate the basis of MHC class I upregulation, we examined transcriptional factor binding activity to the class I regulatory element (CRE). Our results showed that 17-beta estradiol induced increases in factor binding activity to the CRE II probe, and decreases to the CRE I probe. In addition, our results suggested that factors that bind the CRE I region may modulate the binding of CRE II. Binding to CRE II was significantly increased in extracts pretreated with a competitor that contained the CRE I sequence, and that bound NF-kB/kBF1. In addition, induction of NF-kB binding activity by the tumor necrosis factor was accompanied by a decrease in nuclear factors that bind to the CRE II region.

Base Sequence↗
PubMed1994

In vivo activation of NK cells induces inhibition of lung colonization of H-2 positive and H-2 negative fibrosarcoma tumor clones.

The role of different tilorone analogs in the abrogation of the metastatic spread of H-2 positive and H-2 negative tumor clones was studied. Pre-treatment of BALB/c mice with RMI 10,874DA compound completely abolished lung colonization of an H-2 negative (GR9.B9) MCA-induced fibrosarcoma clone in an experimental metastasis assay. This effect was also evident when clones were treated with other tilorone analogs (R11,567DA or R11,513DA). Other H-2 positive and H-2 negative chemically induced fibrosarcoma clones were also tested. The effect was not due to direct toxicity of the tilorone analog on tumor cells, but instead was dependent on NK cells; this was suggested by the finding that treatment of mice with anti-asialo GM1 abrogated the effect of the tilorone analog (RMI 10,874DA compound). Interestingly, the inhibition of lung colonization after intravenous injection was again observed regardless of the H-2 phenotype of the tumor clones, and H-2+ and H-2- clones were similarly inhibited. In vitro assays of NK sensitivity of tumor clones showed that lysis varied depending on the H-2 phenotype of tumor clones, indicating an absence of correlation between in vivo and in vitro results.

Animals↗
PubMed1994

Disruption of a recombinant yeast for the release of beta-galactosidase.

A recombinant yeast, Saccharomyces cerevisiae, expressing Escherichia coli beta-galactosidase gene under the control of CYC1 constitutive promoter of the yeast, was disrupted in a continuous flow, high speed, bead mill for the release of intracellular beta-galactosidase (EC 3.2.1.23). Release of the beta-galactosidase activity was characterized with respect to glass bead loading in the grinding chamber (70-85% of chamber volume), diameter of the beads (0.25-0.75 mm), number of passes of the cell slurry through the mill (0-6 passes), flow rate of the slurry (25-250 mL.min-1), cell concentration in the slurry (5-20 gDW.L-1), the agitation rotor speed (1000-4000 rpm) and the pH of the slurry (pH 5-10). The optimal conditions for the release of the enzyme were pH 6.0-9.0, 85% loading of 0.5 mm diameter beads and an agitation speed of 2000 rpm. The enzyme release followed first-order kinetics. For otherwise fixed conditions, the extent of cell disruption increase with increasing bead load, number of passes and agitation rotor speed. Cell concentration did not affect disruption. The release of beta-galactosidase activity declined with increasing flow rate of the cell slurry through the mill, but the disruption rate constant increased with flow rate. Under optimal condition, three passes through the grinding chamber were sufficient to release all of the enzyme. In comparison with disruption in the bead mill, chloroform-sodium dodecyl sulfate induced lysis of cells was ineffective in releasing the enzyme quantitatively.

Biotechnology↗
PubMed1994

[Frequency of molecular alterations in heterozygous beta-thalassemia in southern Spain and their relation to the hematologic phenotype].

INTRODUCTION: Heterozygous beta-thalassemia manifests hematologically with microcytosis, reduced red blood cell hemoglobin concentration and high hemoglobin A2 levels. Almost all molecular alterations are due to point mutations. We attempt to determinate the frequency of that mutations in the Oriental Andalusia Area, and its relationship with the hematological phenotype. PATIENTS AND METHODS: We have studied 45 heterozygous patients. DNA samples were amplified by PCR, using the printers CD7 and HI1. A 16 Kb fragment corresponding to beta globin gene was obtained and analyzed by Dot Blot assay and hybridized with allelic specific oligonucleotide (ASO) probes to detect the 6 more frequent mutations found in the South of Spain. RESULTS: Codon 39 nonsense mutation (31.1%) was the most frequent finding followed by IVS-1 NT 110 (26.7%). The relationship between hematological parameters and molecular mutations concluded that IVS-I NT 6 mutation developed a minimal anemia. DISCUSSION: From the practical point of view, this study indicates that we were able to detect more than 90% of heterozygous beta-tal. with 5 out of 6 ASO probes used in this work. Thus, our data also provides a further implication in prenatal diagnosis.

Base Sequence↗
PubMed1993

Generation and control of metastasis in experimental tumor systems; inhibition of experimental metastases by a tilorone analogue.

The role of the chemical compound RMI 10,874DA (3,6-bis[2-(dimethylamino)-ethoxyl]-9H-xanthene-9-one dihydrochloride) in the abrogation of the metastatic spread of tumor cells was studied. Pre-treatment of BALB/c mice with the RMI 10,874DA compound (referred to below as tilorone analogue) completely eliminated lung colonization of an H-2-negative (GR9.B9) MCA-induced fibrosarcoma clone in an experimental metastasis assay. Other murine tumors, including H-2-positive and H-2-negative chemically induced fibrosarcoma clones and B16 melanoma, were also sensitive to the treatment; orally administered tilorone analogue given one day before the i.v. injection of tumor cells markedly inhibited lung colonization. The effect was not due to direct toxicity of tilorone analogue on tumor cells, but instead it was dependent on NK cells; this was suggested by the finding that anti-asialo GM, treatment of mice abrogated the effect of tilorone analogue. Kinetic studies of splenic NK activity in tilorone-treated mice showed a rapid boosting of NK-cell activity, the greatest stimulation occurring the day before removal of splenocytes for 51Cr-release assay against YAC-I target cells. These kinetics correlated with the inhibition of in vivo lung colonization after tilorone analogue treatment. Inhibition of experimental tumor metastasis was dose-dependent and was observed when animals were treated the day before or the day after tumor-cell injection. Furthermore, repeated treatment of mice with this tilorone analogue significantly reduced lung colonization.

Animals↗
PubMed1993

CD5+ B lymphocytes in HIV infection: relationship to immunological progression of disease.

We analyzed CD5+ B cells in HIV-seropositive individuals because there is accumulating evidence of the involvement of this subset in natural immunity against virus and bacteria. There are also arguments maintaining that CD5+ B cells play a role in autoimmunity and lymphoid malignancies, both phenomena which are strongly associated with HIV infection. Seventy-two HIV-positive subjects (58 drug abusers, 7 homosexual men, 4 heterosexuals, and 3 hemophiliacs) were included in a phenotypic study of mononuclear cells. A direct immunofluorescence with doubly conjugated monoclonal antibodies was performed, and analysis was carried out in a FACScan cytometer. HIV-infected patients showed a striking increase in the percentage of CD5+ B lymphocytes (54.7 +/- 19% of circulating B cells) compared with HIV-negative drug users (35.5 + 14%) and with healthy controls (17 +/- 5%), P < 0.01 and P < 0.0001, respectively. In addition, levels of CD5+ B cells were correlated with CD4+ cell counts (r = -0.50373), WR staging (r = 0.5295), lymphocytopenia (r = 0.57356), and T4/T8 ratio (r = -0.3151) and showed a close association with the progression of immune system damage by HIV. Patients who developed hypergammaglobulinemia, thrombocytopenia, or other autoimmune manifestations associated with HIV infection showed levels of CD5+ B cells increased over those of the remaining HIV-seropositive individuals (P < 0.001, P < 0.001, and P < 0.05).

Adult↗
PubMed1993

Natural history of HLA expression during tumour development.

HLA expression is frequently altered in tumours compared to the tissue from which they originate. Given the central role of MHC products in the restriction of T-cell recognition, regulation of tumour HLA expression might be a strategy for the evasion of immune surveillance by the malignant cells. Federico Garrido, Peter Stern and colleagues present data from a variety of tumour types, suggesting that HLA class I alterations may occur at a particular step between the development of an in situ lesion and an invasive carcinoma.

Carcinoma in Situ↗
PubMed1993

HLA class I expression and HPV-16 sequences in premalignant and malignant lesions of the cervix.

A series of 10 normal cervix epithelia, 38 condylomas, 17 CIN (cervical intraepithelial neoplasm) I/II (low-grade CIN), 10 CIN III (high-grade CIN), 27 squamous cell carcinomas and 7 adenocarcinomas of the cervix were studied in paraffin-embedded sections for the expression of MHC class I antigens, using antibodies against HLA antigens and the immunoperoxidase technique. A PCR technique was also used to evaluate the presence of HPV-16 DNA. All samples from normal tissue, benign, premalignant and CIN III lesions expressed HLA class I antigens. However, 15% of the invasive carcinomas completely lacked HLA-B and HLA-C antigen expression, 20% presented a heterogeneous pattern and 2 cases lacked HLA-B and HLA-C heavy chain but retained beta 2-microglobulin. MHC class I antigen expression on tumors was compared with clinical-pathological parameters. The absence of expression of HLA class I molecules was significantly associated with the Glanz histoprognostic index of malignancy. HPV-16 sequences were detected in 60% of the condylomas, 88% of the CIN I/II, 80% of the CIN III and 82% of the cervical carcinomas. Eight-six per cent of the tumors expressing HLA class I antigen presented HPV-16, whereas only 40% of the nonexpressing tumors did. Our results lead us to the following conclusions: a) HLA class I losses occurred when the tumor became invasive, and in tumors of a more aggressive histological type; b) The presence of HPV-16 was associated with tumors expressing HLA class I antigens.

Adenocarcinoma↗
PubMed1993

Alcohol consumption, low birth weight, and preterm delivery in the National Addiction Survey (Mexico).

In 1988 the Mexican General Directorate of Epidemiology and the Mexican Institute of Psychiatry carried out the first National Addiction Survey that provided prevalence estimates at national and regional levels of alcohol consumption, tobacco smoking, and several other drugs use. In addition, a questionnaire included questions regarding alcohol consumption during pregnancy and adverse outcomes. According to the results of logistic regression, women classified as suffering from Alcohol Dependence Syndrome had a very high risk of low birth weight and/or preterm delivery: Odds ratio = 12.1 with a 95% confidence interval of (1.3, 108.9) and p = .026. After controlling for several confounding variables, the findings remained basically the same.

Adolescent↗
PubMed1992

Effect of MHC class-I transfection on local tumor growth and metastasis in an H-2-negative clone derived from a chemically induced fibrosarcoma.

GR9 is a chemically induced fibrosarcoma composed of clones with different H-2 class-I expression. These clones differ with respect to local growth and spontaneous metastasis. The B9 clone (H-2 negative) is highly tumorigenic (local growth) but of low metastatic potential (spontaneous metastasis assay). We have analyzed the effect that transfection of H-2Dd and H-2Kd genes on this clone have upon local growth, lung colonization after i.v. injection and ability to form spontaneous metastases. The results showed that the effect on local growth of transfection of the Kd-gene was stronger than that of the Dd gene. In addition, B9 co-transfected with H-2Kd and Dd genes showed the highest immunogenic properties in syngeneic BALB/c mice. Interestingly, the pSV2-neo transfected clone gave almost the same result as that obtained with Dd transfection. Lung colonization after i.v. injection of the different clones (experimental metastasis), paralleled the results obtained for local growth: the number of lung nodules followed the cadence KdDd less than Kd less than Dd less than pSV2. Survival of mice was always inversely correlated with local growth, e.g., all mice injected with 5 x 10(5) B9 H-2KdDd transfected cells survived. In contrast, no mice injected with the B9 control did. These differences were abrogated in irradiated and nude BALB/c mice. Finally, all transfected clones remained non-metastatic in a spontaneous metastasis assay, behaving as the control, non-transfected B9 cells.

Animals↗
PubMed1992

Expression of alpha-tropomyosin during cardiac development in the chick embryo.

A new monoclonal antibody (mAb) that recognizes alpha-tropomyosin in cardiac muscle cells was used in a qualitative (polyacrylamide gel electrophoresis and indirect immunofluorescence) and quantitative (fluorescence-activated cell sorting) study of the expression of this protein during heart development. alpha-Tropomyosin expression was weak in early stages of chick embryo development (Hamburger and Hamilton stage 18), and increased steadily until Hamburger Hamilton stage 40. In early stages, the protein was found mainly in cytoplasm, whereas by the final stages, it was more abundant in the cytoskeletal compartment. The mAb cross-reacted with alpha-tropomyosin in smooth and striated muscle cells from chickens, mice, and humans, but did not cross-react with nonmuscle tropomyosin.

Animals↗
PubMed1992

HLA molecules in basal cell carcinoma of the skin.

Fifty basal cell carcinomas (BCC) and 8 samples of healthy skin were studied for HLA class I and class II antigen expression and for the presence of mutations in codon 12 of the K-ras and H-ras genes. All samples of healthy skin and of epithelium near the tumor showed high levels of class I molecules, whereas 38% of the tumors showed complete absence. Sixty-two percent of the tumors presented positive class I expression with heterogeneous staining. These losses were due to the simultaneous lack of heavy chain and beta 2-microglobulin. Selective losses of HLA-A or HLA-B antigens were not detected. Class II antigens were absent in most of the tumors, only two tumors showing a few weakly positive cells with anti-HLA-DR mAb. The loss of class I expression correlated significantly with the degree of histological differentiation and aggressiveness. We were unable to correlate class I expression with clinical size, depth of invasion or the extent of leukocytic infiltrate surrounding the tumor. Analysis by PCR amplification of codon 12 of the K-ras and H-ras oncogenes detected H-ras mutations in 1 out of 50 cases, and no K-ras mutations in any of the tumors studied. Thus, a positive relationship between K-ras and H-ras mutations and BCC tumorigenesis or MHC alterations seems unlikely in this neoplasia.

Antigens, Neoplasm↗
PubMed1992

Tracking genetically engineered bacteria: monoclonal antibodies against surface determinants of the soil bacterium Pseudomonas putida 2440.

Assessment of potential risks involved in the release of genetically engineered microorganisms is facilitated by the availability of monoclonal antibodies (MAbs), a tool potentially able to monitor specific organisms. We raised a bank of MAbs against the soil bacterium Pseudomonas putida 2440, which is a host for modified TOL plasmids and other recombinant plasmids. Three MAbs, 7.3B, 7.4D, and 7.5D, were highly specific and recognized only P. putida bacteria. Furthermore, we developed a semiquantitative dot blot assay that allowed us to detect as few as 100 cells per spot. A 40-kDa cell surface protein was the target for MAbs 7.4D and 7.5D. Detection of the cell antigen depended on the bacterial growth phase and culture medium. The O antigen of lipopolysaccharide seems to be the target for MAb 7.3B, and its in vivo detection was independent of the bacterial growth phase and culture medium. MAb 7.3B was used successfully to track P. putida (pWW0) released in unsterile lake mesocosms.

Antibodies, Monoclonal↗