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Biomedical subjects

S Garcia

Publications and source records attributed to S Garcia.

At least 73 records · Page 4Linked to original sources
PubMed1998

VLA2 integrin expression in breast carcinomas evaluated by automated and quantitative immunohistochemistry.

VLA2 is thought to be involved in the metastatic process in malignant tumours, in particular in carcinomatous cell adhesion to vessel basement membrane. VLA2 expression was immunohistochemically investigated in 204 breast carcinomas. Frozen tissue sections were probed with monoclonal anti-VLA2 using automated (Ventana ES 320 System) and quantitative (SAMBA 2005 image processor) immunoperoxidase. A positive anti-VLA2 immunoreaction was observed in 48 tumours (23.5%), within epithelial carcinomatous cells. The VLA2-positive surface in tumours varied from 3% to 20% (mean 8.75, S.D. 7.17) and was correlated with histoprognostic indicators and tumour expression of various antigens detected using the same method as that for VLA2. The results show that VLA2 immunoexpression was independent of the tumour size, grade, type and aneuploidy, and of the nodal status. VLA2 significantly correlated with ELAM, VCAM, VLA3 and P-glycoprotein (P-gp) (P < 0.01) and inversely correlated with cathepsin D (P < 0.001), but was independent of Ki67/MIB1, p53, bcl-2, c-erbB-2, E cadherin, CD44v, CD31, oestrogen and progesterone receptors' (ER, PR) antigenic sites and pS2. The exact role, if any, of VLA2 in tumour cell dissemination remains to be elucidated and the clinical relevance of VLA2 immunodetection in breast carcinomas requires further investigation of the correlation between VLA2 immunocytochemical expression and patients' outcome and response to chemotherapy.

Adult↗
PubMed1998

Persistent expansion, in a human immunodeficiency virus-infected person, of V beta-restricted CD4+CD8+ T lymphocytes that express cytotoxicity-associated molecules and are committed to produce interferon-gamma and tumor necrosis factor-alpha.

The present study describes the persistent expansion of a subpopulation of circulating double-positive CD4+CD8+ T cells in a human immunodeficiency virus (HIV)-infected person over 8 years. The percentage of double-positive cells was remarkably stable with time and was not related to HIV plasma virus load. CD4+CD8+ cells exhibited phenotypic characteristics of activated memory T lymphocytes. Analysis of V beta usage by the T cell receptors of these cells indicated restricted expression to the V beta 14 and V beta 17 families. Most CD4+CD8+ cells constitutively expressed cytotoxicity-associated molecules (C1.7 and perforin) and were selectively committed to produce interferon-gamma and tumor necrosis factor-alpha, cytokines involved in cytotoxic function. The kinetics of changes in the relative proportion of single-positive CD4+ and double-positive CD4+CD8+ T cell subsets and a similar bias in V beta usage by these subsets suggest that CD4+CD8+ lymphocytes originate from peripheral expansion of mature CD4+ T cells.

CD4 Antigens↗
PubMed1998

Comparison of thyroid peroxidase expression with cellular proliferation in thyroid follicular tumors.

Thyroid cancer is associated with abnormal thyroid peroxidase (TPO) expression as shown by abolition of immunodetection by monoclonal antibody 47 (Mab 47). The purpose of this study was to determine the relation of this abnormality with differentiation and proliferative potential of follicular tumors evaluated by analyzing thyroglobulin (TG) expression and proliferative cell nuclear antigen (PCNA) index. TPO, TG, and PCNA immunostaining were performed in a series of 30 thyroid follicular tumors ranging from adenoma to invasive carcinoma. Our findings confirmed that TPO abnormalities and PCNA index were correlated with malignancy, and that PCNA as well as TPO could be used to determine the growth potential of follicular proliferations in fine-needle aspirates. The most discriminant parameter was the ratio between the percentage of Mab-47 and PCNA positive cells. Ratios under 0.6 were correlated with malignancy in 90% of the cases, with only 3 cases of atypical adenomas being misdiagnosed as carcinomas. An inverse correlation was found between TPO and PCNA expression, but TG, which persisted at high levels in several actively growing follicular carcinomas, did not appear directly linked to cellular proliferation. These findings confirm that, unlike a decrease in TG synthesis that merely reflects the progressive loss of differentiation occurring in high-grade proliferations, alteration of TPO is an early marker of thyroid follicular tumors, closely related to acceleration of tumor growth in the first stages of malignant transformation.

Adenocarcinoma, Follicular↗
PubMed1998

Reduced E-cadherin immunohistochemical expression in node-negative breast carcinomas correlates with 10-year survival.

E-cadherin immunodetection was performed on frozen sections, using an immunoperoxidase procedure and with computer-assisted analysis of digitized colored microscopic images in a series of 179 breast carcinomas. Quantitative immunocytochemical assays were correlated with follow-up (129 months). The results showed that reduced E-cadherin immunocytochemical expression in tumors (cut point, 4%) significantly correlated with shorter overall survival in node-negative patients (Kaplan Meier log rank test). But E-cadherin immunostained expression (cut point, 4%) did not correlate with metastasis-free or recurrence-free survival. In multivariate analysis (Cox proportional hazards regression model), E-cadherin prognostic significance for overall survival in node-negative patients was independent of the tumor size, grade, and histologic type. The results suggest that reduced E-cadherin expression detected in optimum technical conditions (frozen samples and quantitative immunohistochemistry) is an independent indicator of poor survival in node-negative patients and may be clinically relevant for the treatment of patients with breast carcinomas.

Adult↗
PubMed1998

Induction of in vitro heart block is not restricted to affinity purified anti-52 kDa Ro/SSA antibody from mothers of children with neonatal lupus.

The ability of affinity purified anti-52 kDa Ro/SSA antibody from patients without obstetric history of neonatal lupus to cause heart block using an experimental model was investigated. IgG-enriched fractions from sera of 20 systemic lupus erythematosus (SLE) and one Sjögren's syndrome (SS) all positives for anti-Ro/SSA antibodies as detected by CIE, were perfused on isolated whole rabbit hearts. Only six (29%) samples induced A-V block, five of them presenting low anti-Ro/SSA titre. All of them recognized the 52 kDa isoform on ELISA whereas only one had a concomitant binding to the 60 kDa protein. Moreover, affinity purified antibodies from two sera previously known to induce A-V block were obtained by affinity chromatography using a column containing the full-length 52 kDa Ro/SSA fusion protein. Paired eluate and effluent devoid of anti-52 kDa activity from the same patient were individually perfused in whole hearts. The ability to cause cardiac blockade was restricted to the affinity anti-52 kDa eluates. In addition, anti-52 kDa eluates from three IgG fractions that primarily failed to induce blockade remained ineffective. The present study has added to our knowledge that affinity anti-52 kDa Ro/SSA antibodies from mothers with healthy infants are capable of causing in vitro cardiac conduction disturbances. A prospective follow up of these patients will better delineate the clinical usefulness of this experimental model.

Antibodies, Antinuclear↗
PubMed1998

bcl-2 automated and quantitative immunocytochemical assays in breast carcinomas: correlation with 10-year follow-up.

PURPOSE: bcl-2 protein is detectable in human cancers and may be involved in the response to antineoplastic drugs or endocrine therapy in breast carcinomas. In a previous study, we had developed optimal technical conditions for bcl-2 immunodetection. The aim of the present report was to determine the prognostic significance of bcl-2 expression in breast carinomas by the use of a similar immunocytochemical procedure. METHODS: bcl-2 immunocytochemical assays were performed on frozen sections by automated immunoperoxidase technique (Ventana) and computer-assisted analysis of digitized colored microscopic images (SAMBA) in a series of 170 breast carcinomas. The results of automated quantitative immunocytochemical assays were correlated with patient follow-up (120 months). RESULTS: Intense bcl-2 immunocytochemical expression in tumors (cutpoint, 15%) significantly correlated with longer disease-free survival and longer recurrence-free survival in the entire cohort of patients (P = .028 and P = .035, respectively) and also in node-negative subgroups of patients (P = .028 and P = .01; Kaplan-Meier long-rank test; NCSS 6.0.1 software). But bcl-2 immunostained surfaces (cutpoint, 15%) did not correlate with overall survival. In multivariate analysis (proportional hazards regression, Cox model), bcl-2 prognostic significance in terms of disease-free survival was only independent of the tumor size and grade and histoprognostic index (Nottingham prognostic index [NPI]). CONCLUSION: bcl-2 immunohistochemical expression is a significant indicator of favorable outcome only in terms of disease-free and local recurrence-free survival. However, bcl-2 expression in tumors is an independent weakly prognostic indicator in breast carcinomas. bcl-2 immunodetection assessed in optimal technical conditions (frozen samples, automation, quantitative analysis, scatter diagram cutoffs) may have some limited practical clinical relevance for the management of patients with breast carcinomas.

Adult↗
PubMed1998

Immunoexpression of E-cadherin and beta-catenin correlates to survival of patients with hepatocellular carcinomas.

Expression of E-cadherin (E-cad) and -catenin ( -cat) was investigated immunohistologically in 91 cases of excised hepatocellular carcinomas. Immunodectection was altered in 56% of tumours for E-cad and in 30.8% for -cat. Downregulation of E-cad and -cat correlated with the size of tumours, and high nuclear grade, but only E-cad alteration correlated with the mitotic index. Alterations of E-cad and -cat expression correlated with survival. Although E-cad and -cat immunodetections were independent prognostic factors, their prognostic value was lower than that of current clinicopathological parameters.

Adult↗
PubMed1998

ELAM selectin expression in breast carcinomas detected by automated and quantitative immunohistochemical assays.

ELAM is an E-Selectin adhesion molecule involved in the inflammatory process but it is also thought to potentially participate in the development of blood borne metastases, by facilitating tumour cell adhesion to vessels wall. ELAM expression in tumours was immunohistochemically investigated in 203 breast carcinomas. Frozen tissue sections were probed with monoclonal anti ELAM (Clone 1.2B6) using automated and quantitative immunoperoxidase systems. A positive anti-ELAM immunoreaction was observed in 113 tumours (57%). The mean surface of positive tumours varied from 3% to 50% (mean = 11.75%, SD = 8.7) and was correlated with histoprognostic indicators and tumour expression of various antigens detected according to the same method as ELAM. The results showed that ELAM immunoexpression was independent of the tumour size, grade and type and of the nodal status but significantly increased parallel to patients' age (p<0. 01). ELAM expression was independent of Ki-67/MIB1, anti-P53 and anti-Bcl2, anti-CD44v, anti-c-erbB-2, anti-CD31, anti-RE/RP, anti-PS2, and anti-VLA3 immunoreactions. But ELAM expression correlated with that of the VCAM vascular cell adhesion molecule (p=0.0004), VLA2 (p<0.0001), P-glycoprotein (p=0.025), and of Cathepsin D to a lower degree (p=0.06) and inversely correlated with E-cadherin (p=0.03). The results suggest that endothelial cell activation is independent of tumour cell proliferative activity and of stromal angiogenesis and that the precise role and regulation of ELAM in tumours remains to be elucidated. Also the clinical relevance of ELAM immunohistochemical expression requires further investigation and correlation with patients' follow-up.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

[Polycystic disease of the salivary glands: report of an attack of the submaxillary glands].

Bilateral dysgenetic polycystic disease of parotid glands is an extremely rare pathologic condition in which salivary parenchyma is partially replaced by multiple epithelial-lined cysts arising from intercalated ducts. Review of the fourteen cases published in literature shows that it affects nearly exclusively women with an history of asymptomatic progressive enlargement of almost always both parotid glands. We report here the first case, to our knowledge, of a polycystic disease involving both submandibular salivary gland in a man.

Cysts↗
PubMed1998

[Prognostic value of E-cadherin expression in hepatocellular carcinoma].

Expression of E-cadherin (E-cad) was investigated immunohistologically in 91 cases of operated hepatocellular carcinomas. An alteration of E-cad immunodetection was found in 56% of tumours. These alterations were correlated with histopathologic features of prognostic value including tumour size (> 3 cm), high nuclear grade and mitotic index. Patients with down-regulated E-cad expression had statistically significant shorter survival than the others. Although E-cad immunodetection was an independent prognostic factor, the Cox multivariate analysis showed that its prognostic value was low when compared to other prognostic factors.

Adult↗
PubMed1997

Dietary supplementation with marine fish oil improves in vitro small artery endothelial function in hypercholesterolemic patients: a double-blind placebo-controlled study.

BACKGROUND: Marine fish oils improve vascular function, but the mechanism of benefit is unclear. We conducted a study to examine the effects of fish oils given to hypercholesterolemic patients on small artery function in vitro. METHODS AND RESULTS: In a randomized, double-blind, placebo-controlled trial, subcutaneous gluteal fat biopsies were taken from 16 hypercholesterolemic patients (serum total cholesterol, 7.97+/-0.16 mmol/L [mean+/-SEM]) and 12 age- and sex-matched control subjects (mean cholesterol, 5.11+/-0.34 mmol/L). Small arteries were mounted on a wire myograph for isometric tension experiments. Patients and control subjects were randomized to receive fish oil (Maxepa 5 capsules BID) or placebo for 3 months. A second biopsy was taken and the studies were repeated. Relaxation to acetylcholine was significantly improved in the hypercholesterolemic group given Maxepa but not in the placebo group (mean maximum relaxation before and after, 48+/-6.2% and 68.83+/-2.19%, P=.0054). The dysfunction was not restored to control values (84.3+/-5.2%, P=.0002). There was also a smaller but significant impairment in endothelium-independent relaxation provoked by sodium nitroprusside (P<.01). A good correlation between the increase in eicosapentanoic acid (n=3) in red cell membrane and improvement in relaxation in the hypercholesterolemic group given fish oils was seen (r=.781, P<.02). CONCLUSIONS: Marine fish oil significantly improved endothelial function in peripheral small arteries in hypercholesterolemia patients. This may provide a mechanism for the beneficial effects of these fatty acids in coronary heart disease.

Adult↗
PubMed1997

Thymocytes in Thy-1-/- mice show augmented TCR signaling and impaired differentiation.

Thy-1, a single variable-like immunoglobulin superfamily domain anchored in the plasma membrane by a glycosyl phosphaditylinositol tail [1], is a major surface glycoprotein in adult mammalian neurons and rodent thymocytes [2]; the function of Thy-1 has remained enigmatic since its discovery [3]. Studies in vitro have implicated Thy-1 in homotypic and heterotypic cell-cell interactions [2,4]. Ligation of Thy-1 initiates transmembrane signaling pathways that lead to diverse physiological outcomes in different cells [2,5-7]. In rodents, Thy-1 is highly expressed on the surface of CD4+CD8+ double-positive immature thymocytes and downregulated in mature T cells. Here, we report that thymocytes from Thy-1-/- mice [8] had altered cell-cell contacts, and hyperresponsiveness to T-cell receptor (TCR) triggering as demonstrated by the heightened activation of p56lck, phosphorylation of TCR subunits, Ca2+ fluxes and cell proliferation. Thy-1-/- thymocytes exhibited impaired maturation from the double positive to single positive stage of thymocyte development, possibly due to inappropriate negative selection, and were prone to T lymphomas in aged mice. These observations indicate that Thy-1 negatively regulates TCR-mediated signaling and controls activation thresholds during thymocyte differentiation.

Animals↗
PubMed1997

Automated and quantitative immunocytochemical assays of Nm23/NDPK protein in breast carcinomas.

A series for Nm23-protein immunodetection was investigated in human breast carcinomas. Frozen sections were processed by automated immunoperoxidase procedure, and immunoprecipitates in positive tumors were quantified by processing digitized microscopic images. Nm23 immunohistochemical expression in tumors was correlated with clinicopathological data and with intra-tumoral proteins also detected by automated and quantitative immunohistochemistry. A positive Nm23 immunoreaction was observed in 58% of tumors, within cell cytoplasm. Nm23 expression was independent of the patient's age, and of tumor size, type and grade, but an inverse relationship was observed between Nm23 expression and axillary-lymph-node metastasis. An inverse relationship was also observed between Nm23 and P-53, CD-31, cathepsin D, tenascin and P-gp immunohistochemical expressions. But Nm23 expression was independent of c-erb-B product, growth fraction (MIB1/Ki67), and immunohistochemical expression of hormone receptors/P-S2. The results suggest that the anti-metastatic nm23 gene may partly act upon the regulation of tumor-cell proliferation (correlation with P-53) and may have some effects on epithelial-cell/stroma interactions (regulation of extracellular-matrix protease and of angiogenesis) independently of hormone sensitivity.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1997

Potential deleterious effect of anti-viral cytotoxic lymphocyte through the CD95 (FAS/APO-1)-mediated pathway during chronic HIV infection.

The potential deleterious effect through a CD95-based pathway of anti-viral cytotoxic lymphocyte (CTL) during HIV-infection was studied. The present paper reports that a Nef specific CTL line derived from an HIV-infected person is able to kill not only Nef-expressing target cells but also CD95+ compliant Jurkat cells. The two mechanisms of cytotoxicity, i.e. perforin-vs-CD95-dependent were differentiated according to their respective Ca(2+)-dependence. The existence of the dual killing machinery in the anti-HIV CTL line was correlated with the coexpression in these cells of perforin and CD95-L molecules. A model of AIDS pathogenesis involving the deleterious effect through the CD95 pathway of the viral specific CTL response is discussed.

Antigen-Presenting Cells↗
PubMed1997

Prune-belly syndrome and other anomalies in a stillborn fetus with a ring X chromosome lacking XIST.

Ring X chromosomes that lack the X inactivation center and fail to be inactivated have been implicated as a cause of mental retardation and multiple congenital anomalies. We report on a stillborn fetus with karyotype mos45,X/46,X,r(X) and early urethral obstruction or prune-belly sequence, single umbilical artery, limb deficiency, horseshoe kidney, cardiac hypertrophy, persistent left superior vena cava, and axial skeleton abnormalities. Fluorescent in situ hydridization (FISH) studies confirmed that the ring chromosome is X-derived and demonstrated that it lacks the XIST locus. The findings in this fetus are discussed with regard to the spectrum of phenotypes associated with monosomy X and small ring X chromosomes.

Abnormalities, Multiple↗
PubMed1997

Limits of the human-PBL-SCID mice model: severe restriction of the V beta T-cell repertoire of engrafted human T cells.

A recent study in the human-peripheral blood lymphocytes severe combined immunodeficiency (hu-PBL-SCID) model, analyzing the specificity of the engrafted human T cells, showed that human T-cell lines and clones derived from engrafted cells presented a xenoreactivity toward murine host molecules. This observation raised the question of the influence of the SCID environment on the ex vivo repertoire and function on the human T cells reconstituting the murine host. We have characterized the human V beta repertoire in the spleen of hu-PBL-SCID mice 1 to 3 months after their engraftment. Fluorescence-activated cell sorting (FACS) analysis of human V beta T-cell representation showed that, for all chimeras, all tested V beta subsets were submitted to underrepresentation and/or expansion upon engraftment. Importantly, these quantitative modifications of the T-cell repertoire were associated with a severe restriction in both the CDR3 size distribution pattern of the V beta transcripts and the number of J beta segments used by these transcripts. In addition, ex vivo phenotypic characterization of engrafted cells showed that 70% to 100% expressed the activation markers HLA-DR, CD45RO, and CD38. Taken together, these results suggest that, following their engraftment, human T cells were submitted to a massive antigenic selection. Moreover, we found that these activated T cells were unresponsive to in vitro mitogenic and superantigenic activation. The consequences of the skewed repertoire and altered function of engrafted human T cells on the validity of this humanized murine model are discussed.

Animals↗
PubMed1997

E-cadherin quantitative immunocytochemical assays in breast carcinomas.

The reduction of E-cadherin expression, which is involved in the initial step of invasion and metastasis of cancer, was investigated in 218 human breast carcinomas. Quantitative immunohistochemical assays (ICAs) were performed on frozen sections. Quantitation was assessed by processing digitized microscopic images of immunoreactions using a computerized system of image analysis (SAMBA). The results were correlated with clinicopathological data and quantitative immunodetection of other molecules. E-cadherin expression was significantly (P < 0.001) stronger in ductal carcinomas than in lobular carcinomas and stronger (P < 0.01) in low grades than in high grades, but E-cadherin was independent of lymph node status and tumour size. Also an inverse significant (P < 0.01) relationship was observed between E-cadherin expression on tissue sections and positive immunoreactions with anti-P53, MIB1 (growth fraction), and anti-c-erb-B2 product. Conversely, strong positive and anti-E-cadherin immunoreactions correlated with strong positive anti-ER and anti-PR immunoreactions (P < 0.01). No relationship was observed between E-cadherin and the results of quantitative ICAs of cathepsin D, CD31, and P-glycoprotein, assessed on consecutive sections from the same frozen tissue samples. The results show that preserved E-cadherin expression correlates with high degree of tumour differentiation, low proliferative activity, and low expression of prognostic markers. The deregulation of E-cadherin is independent of other steps of tumour invasion, such as protease digestion of extracellular matrix and angiogenesis.

Adult↗