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Biomedical subjects

S Garcia

Publications and source records attributed to S Garcia.

At least 109 records · Page 6Linked to original sources
PubMed1996

Quantitative immunocytochemical assays on frozen sections of p53: correlation to the follow-up of patients with breast carcinomas.

A series of 222 tumor samples stored at -80 degrees C in the authors' tumor library were investigated with anti-p53 (PA 1801) and streptavidin-biotin-peroxidase complex. The p53 immunoprecipitates were quantified by densitometry assessed by image analysis of digitized microscopic images. Two parameters, percentage of positive surface and mean optical densities, were compared with the patient's outcome (follow-up = 96.8 months) (life table method, Mantel Cox test, BMDP statistical software). The p53 expression significantly correlated with a poor overall survival (P = .0063), metastasis-free survival (P = .024), and recurrence-free survival (P = .022) at a 20% cutoff point of positive immunoreactive tumor surface. A strong prognostic significance was observed in the node-positive subset of patients but not in the node-negative subset, except for recurrence-free survival (P = .047). The results indicate the clinical relevance p53 evaluated by quantitative immunocytochemistry.

Adult↗
PubMed1996

[Tumor markers in the cytodiagnosis of thyroid nodules. Detection of dipeptidyl aminopeptidase IV (DAP IV) activity].

Dipeptidyl-aminopeptidase IV (DAP IV), an exopeptidase involved in T-cell activation is absent from normal thyroid tissue but highly expressed by malignant thyroid cells. It has been suggested to be a useful adjunct for the diagnosis of malignant thyroid tumors on fine needle aspirates (FNA). To assess this assumption DAP IV activity was demonstrated by histochemical staining on FNA performed on 102 thyroid nodules at the time of surgery (60 macrofollicular adenomas, 15 microfollicular adenomas. 7 Hashimoto's thyroïditis, 3 Graves' disease. 13 papillary carcinomas and 4 follicular carcinomas). A staining score based on the percentage of positive epithelial cells and staining intensity was established for each case and results were compared to histological diagnosis. Most cells in malignant tumors were deeply stained except in one case of papillary carcinoma. Null or very low scores resulting from light or medium staining of less than 40% of the cells were obtained in 78/85 benign nodules. In 6 macrofollicular adenomas and in 1 case of thyroiditis staining score was as as high as in carcinomas. DAP IV staining was correlated to malignancy in all follicular tumours (4 malignant tumours were positive and 15 benign were negative). The sensitivity for diagnosis of malignancy was 94.1% and the specificity 91.7%. This study brings confirmation that DAP IV activity detection could be an useful adjunct to cytological examination for the distinction between benign and malignant thyroid nodules, especially in cases of follicular tumors.

Biomarkers, Tumor↗
PubMed1995

Relational features of acetylcholine, noradrenaline, serotonin and GABA axon terminals in the stratum radiatum of adult rat hippocampus (CA1).

In a well-defined sector of adult rat hippocampus (CA1, stratum radiatum), the ultrastructural features of acetylcholine (ACh), noradrenaline (NA), serotonin (5-HT) and GABA axon terminals (varicosities) were compared by electron microscopy after immunostaining with antibodies against choline acetyltransferase, NA, 5-HT and glutamic acid decarboxylase. Approximately 100 sectional profiles of each type were analyzed for size, presence of a synaptic membrane specialization (synaptic incidence) and composition of the microenvironment. An equivalent number of immunonegative varicosity profiles selected at random from the same micrographs were similarly examined. ACh, NA and 5-HT varicosity profiles were of comparable size, and significantly smaller than GABA profiles. They exhibited a low frequency of junctional specialization, amounting to 7%, 15% and 21%, respectively, when extrapolated to the whole volume of these terminals. In contrast, GABA varicosities appeared entirely synaptic. The ACh, NA and 5-HT varicosities also differed from their GABA counterparts in being juxtaposed to a greater number of unlabeled axonal varicosities and a lower number of dendritic branches. In addition, the microenvironment of immunostained terminals showed a much lower number of dendritic spines than that of immunonegative varicosities. This latter finding was viewed as another indication that predominantly asynaptic varicosities do not maintain particular relationships with their immediate surround. It was also concluded that volume transmission represents a major mode of transmission for ACh, NA and 5-HT in adult rat hippocampus, thus contributing to the properties and functions assigned to these transmitters in this part of brain.

Acetylcholine↗
PubMed1995

Empathic accuracy in a clinically relevant setting.

This study addressed 3 questions regarding empathic accuracy in a clinically relevant setting. First, does the empathic accuracy of a perceiver improve with increased exposure to a target individual? Second, can empathic accuracy be enhanced by providing the perceiver with feedback about the target's actual thoughts and feelings? Third, are there stable individual differences in empathic accuracy that generalize across different targets? The results indicated that although absolute performance levels varied from 1 target to another, empathic accuracy generally improved with increased exposure to the target. In addition, feedback concerning the target's actual thoughts and feelings accelerated the rate at which the perceivers' empathic accuracy improved. Finally, cross-target consistency in responding (alpha = .86) revealed stable individual differences in the perceivers' empathic ability. Implications of these findings for clinical training and practice are discussed.

Divorce↗
PubMed1995

A survey of drug treatment and outcomes in diabetic patients with acute myocardial infarcts.

Sixty-four diabetic patients suffering an acute myocardial infarct were retrospectively matched, by age, gender and smoking habit, to non-diabetic controls. The two groups were compared for cardiovascular risk factors, pre-admission and discharge drug treatment, in-hospital drug treatment, and complication and mortality rates. Hypertension was more prevalent in the diabetic (63%) than in the control (42%) group. When comparing drugs on admission to those at discharge, there was a significant increase in antiplatelet and nitrate usage in both groups (P < 0.001), in beta-blocker usage in the control group (P < 0.001) and in loop diuretic usage in the diabetic group (P < 0.001). The usage of angiotensin converting enzyme inhibitors was low: 16% of diabetic patients and 5% of controls at discharge. Thrombolytic therapy was used in 29 diabetics and 37 controls. There was a significantly higher complication rate in the diabetic group than in the control group (P < 0.006), the most common being congestive cardiac failure (59% vs 30%, P < 0.001). Four controls and 13 diabetic patients died; three of the latter had their diabetes diagnosed during the admission. This study did not clearly demonstrate any underlying risk factors or treatment variables to account for the increased morbidity or mortality in diabetic patients with acute myocardial infarct, when compared to a matched non-diabetic population. However, modest associations not detected by this relatively small study are still possible.

Adult↗
PubMed1995

Carbohydrate-deficient transferrin levels in a female population.

Female college students (n = 49) from a small southwestern United States university participated in the 9-month study. Data collected included the assessment of drinking habits and other related substance use habits and serum levels of carbohydrate-deficient transferrin (CDT). Each subject provided an interview and blood sample on three occasions at 90-day intervals. Appended to the interview were a series of questions regarding stage of menstrual cycle and the diagnoses of certain diseases. The CDT values obtained were consistent with those obtained in other studies. Moderate-drinking subjects had significantly higher CDT values than did the abstainers and light drinkers. Females using oral contraceptives had significantly higher CDT values than those who were not taking oral contraceptives. Finally, although CDT values varied over time, they did not appear to vary as a function of menstrual cycle stage.

Adolescent↗
PubMed1995

In vitro influence of Mycoplasma penetrans on activation of peripheral T lymphocytes from healthy donors or human immunodeficiency virus-infected individuals.

Mycoplasma penetrans is a mycoplasma species newly isolated from the urine of human immunodeficiency virus (HIV)-infected individuals and presents the only case in which an association has been found between antibodies against a mycoplasma and HIV infection. To further explore the effects of M. penetrans on the immune system, we studied the influence of this mycoplasma on peripheral blood mononuclear cells (PBMCs) from healthy donors and HIV-infected individuals. M. penetrans induced, in addition to blastogenesis of PBMCs, a significant proliferative response associated with the expression of some activation markers such as CD69, HLA-DR, and CD25. This M. penetrans-dependent lymphocyte activation was observed not only in healthy donors but also in HIV-infected persons at different stages of the disease. In addition, our study revealed that both CD4+ and CD8+ T lymphocytes were responsive to M. penetrans. Interestingly, the mitogenic activity of M. penetrans was associated with mycoplasma cells but not with the supernatants of mycoplasma culture. The potent stimulating activity of M. penetrans on T lymphocytes from HIV-infected individuals is of particular interest in view of the supposed contribution of immune activation to HIV replication and disease progression.

Antigens, CD↗
PubMed1995

[Morphometry by analysis of microcalcifications and histopathological diagnosis: a new approach to the diagnosis of impalpable lesions of the breast detected by mammography].

A series of 104 impalpable breast lesions detected by mammograms containing microcalcifications was studied. Intraoperative radiographs of intact and sliced specimens were assessed, followed by microscopic diagnostic on frozen sections of areas containing microcalcifications. Microcalcification detected on mammograms and on radiographs of the specimens were digitized and evaluated according morphometric parameters including the mean surface, shape factor, bend energy, the envelope surface and the total surface, the total number and the concentration of the microcalcifications. Benign disorders, atypical hyperplasia and carcinomas accounted for 47.2%, 4.8% and 48% of the tissue lesions respectively, but disorders were most often heterogeneous and mixed. Most but not all parameters were significantly correlated in the three types of radiographs, although radiographs of the sliced specimens provided for images of the best quality. Only two parameters, the mean size and the bend energy were significantly (p = 0.008, p. = 0.036) different in benign and malignant lesions. It is concluded that image analysis of digitized microcalcifications in radiographs may provide a quantitative basis helpful for mammograms interpretation.

Breast↗
PubMed1994

Selective anergy of V beta 8+ T cells in human immunodeficiency virus-infected individuals.

We have analyzed the V beta usage by CD4+ and CD8+ T cells from human immunodeficiency virus (HIV)-infected individuals in response to an in vitro stimulation with the superantigenic erythrogenic toxin A (ETA) of Streptococcus pyogenes. ETA amplifies specifically CD4+ and CD8+ T cells from control donors expressing the V beta 8 and the V beta 12 elements. When peripheral T cells from asymptomatic HIV-infected individuals were stimulated with ETA, there was a complete lack of activation of the V beta 8+ T cell subset, whereas the V beta 12+ T cell subset responded normally to the superantigen. This V beta-specific anergy, which was also observed in response to staphylococcal enterotoxin E (SEE), affected both CD4+ and CD8+ T cells and represented an intrinsic functional defect rather than a specific lack of response to bacterial superantigens since it was also observed after a stimulation with V beta 8 monoclonal antibodies. The V beta 8 anergic T cells did not express interleukin 2 receptors (IL-2Rs) and failed to proliferate in response to exogenous IL-2 or IL-4, suggesting that this anergy was not a reversible process, at least by the use of these cytokines. The unresponsiveness of the V beta 8 T cell subset is frequent since it was found in 56% of the patients studied, and comparison of the clinical status of responder vs. anergic patients indicated that the only known common factor between them was HIV infection. In addition, it is noteworthy that the anergy of the V beta 8 subset may be a very early phenomenon since it was found in a patient at Centers for Disease Control stage I of the disease. These data provide evidence that a dominant superantigen may be involved in the course of HIV infection and that the contribution of HIV has to be considered.

Adult↗
PubMed1994

Effects of a job-simulated exercise programme on employees performing manual handling operations.

This study investigated the effects of physical training on employees performing manual handling operations in three manufacturing plants. Employees from two plants were trained using progressive resistance exercise (PRE) while employees in the third plant were trained using PRE and trunk flexibility exercises (TFE). The results were: (1) a combined TFE and PRE programme significantly improved muscular endurance (124%), dynamic (86%) and static (back: 59%; arm: 25%; shoulder: 23%) muscular strength, and trunk flexibility (low back flexibility: 11%; total trunk rotation: 48%); (2) a dynamic PRE programme did not improve static strength (arm: 3%; shoulder: 8%; back: 14%; composite: 7%) as much as dynamic strength (71%); (3) endurance time at a fixed workload increased without changing job demand perception, but daily operations were performed more easily.

Adult↗
PubMed1994

A correlational study of carbohydrate-deficient transferrin values and alcohol consumption among Hispanic college students.

One hundred and forty-eight U.S. college students from a small southwestern university were asked to provide or complete the following: the Michigan Alcoholism Screening Test (MAST), a structured alcohol-use interview, and a 10-ml blood sample to be assayed for carbohydrate-deficient transferrin (CDT) levels and gamma-glutamyl-transpeptidase (GGTP) activity. Using the data obtained in the interview, only 2 females and 5 males were identified as heavy drinkers. Conclusions regarding the efficacy of the biochemical markers are therefore limited. It was found that CDT levels were significantly and positively correlated with various measures of alcohol consumption among males. There was no similar association between CDT, or GGTP, and alcohol consumption within the female sample.

Adolescent↗
PubMed1994

In vitro activities of enoxacin, enrofloxacin, sparfloxacin, and ciprofloxacin against Escherichia coli strains isolated from diarrheic lambs and kids.

The in vitro activities of four fluoroquinolone compounds were tested against 92 Escherichia coli strains of ovine and caprine origin under aerobic and anaerobic incubation conditions. The four fluoroquinolones proved to be highly effective against the E. coli isolates tested. When bacteria were cultured anaerobically, at least fourfold increases in the MICs of enoxacin for the strains occurred and no detectable changes in enrofloxacin, sparfloxacin, and ciprofloxacin MICs occurred.

Animals↗
PubMed1994

Cellular mechanism of the conduction abnormalities induced by serum from anti-Ro/SSA-positive patients in rabbit hearts.

In this study, IgG fractions from sera of SLE patients with anti-Ro/SSA or anti-Ro/SSA and anti-La/SSB activity were tested in Langendorff preparations of adult rabbit hearts, aiming to reproduce the cardiac manifestations observed in neonatal lupus in an experimental model. The hearts were perfused with normal Tyrode's solution for 30 min, followed by perfusion with Tyrode's containing 0.3 mg/ml of anti-Ro/SSA- (or anti-Ro/La-) positive IgG (nine sera), anti-ribonucleoprotein (RNP)-positive IgG (five sera), or IgG fractions from normal donors (five sera). In one third of the experiments done with anti-Ro/La-positive IgG, heart block was observed. With the remaining fractions, a decrease in heart rate of 17.1% was observed, but normal sinus rhythm was maintained. The IgG fractions with anti-RNP activity (five experiments) and from normal sera (six experiments) reduced heart rates by 12.9 and 3.3%, respectively, but heart block was not observed. To further characterize the cellular mechanisms involved in the conduction disturbances observed in the whole rabbit hearts, we conducted experiments with ventricular myocytes isolated from young rabbit hearts, studied by whole cell patch-clamp technique. In these experiments, the slow inward currents were analyzed during the superfusion of the cell with normal Tyrode's solution and 5 min after superfusion with Tyrode's solution containing 0.3 mg/ml of anti-Ro/SSA- (or anti-Ro/La-) positive IgG (five sera), anti-RNP-positive IgG (three sera), or IgG from normal donors (four sera). Resting and action potential amplitudes were not affected by any of the sera used. The anti-Ro/SSA IgG fraction induced a mean reduction in the peak slow inward current of 31.6%. IgG fractions with anti-RNP activity reduced slow inward current by 4.4%, whereas IgG fractions from normal donors increased this current by 3.3%. IgG-free fractions from sera of patients with anti-Ro/SSA activity did not alter the peak slow inward current. These results show, for the first time, that the presence of anti-Ro/SSA or anti-Ro/SSA and anti-La/SSB antibody activity in IgG fractions from lupus patients' sera can induce cardiac conduction disorders similar to those observed in neonatal lupus.

Animals↗
PubMed1994

Thyroid peroxidase immunodetection as a tool to assist diagnosis of thyroid nodules on fine-needle aspiration biopsy.

In a previous work we have reported the presence in 96.9% of malignant and 4.2% of benign thyroid tumors of an immunological abnormality of the enzyme thyroid peroxidase, impeding the fixation of the anti-thyroid peroxidase monoclonal antibody termed "MoAb47". The present study has been designed to establish the ability of thyroid peroxidase immunodetection to assist the diagnosis of malignancy in fine-needle aspiration of thyroid nodules. The fixation of anti-thyroid peroxidase monoclonal antibody was investigated by immunohistochemistry on fine-needle aspirates of 150 surgically removed thyroid nodules (20 papillary carcinomas, five follicular carcinomas, 90 colloid adenomas, nine fetal adenoma, 13 atypical adenomas, five oncocytic adenomas, six Hashimoto's thyroiditis and two Graves' disease). The percentage of positive cells has been compared to the final histological diagnosis. In samples from 113/125 benign nodules 80-100% cells presented a positive immunoreaction, whereas all samples from malignant tumors yielded less than 80% positive cells. Benign nodules exhibiting less than 80% positive cells corresponded to three degenerative colloid nodules, five atypical follicular adenomas, two oncocytomas and two thyroiditis. According to results obtained in this series, with the value of 80% as the limit for discrimination between benign and high-risk nodules, the sensitivity of thyroid peroxidase staining for diagnosis of malignancy would be 100%, its specificity 90% and its overall accuracy 92%. Thyroid peroxidase staining with monoclonal antibody MoAb47 on fine-needle aspirates is a useful adjunct to conventional cytology for the investigation of patients with thyroid nodules.

Biopsy, Needle↗