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C Vazquez

Publications and source records attributed to C Vazquez.

At least 37 records · Page 2Linked to original sources
PubMed1994

Estradiol receptors in combination with neu or myc oncogene amplifications might define new subtypes of breast cancer.

Amplifications of neu and c-myc were evaluated in 218 and 145 breast cancers (BC), respectively. Oncogene amplifications were determined for the most part by Southern blot. An association between the proportion of nodes affected and the intensity of neu amplification in estadiol receptor negative (ER-) BC was found (P = 0.028), which was confirmed by the multi-factor analysis of variance (P = 0.05). A significantly greater incidence in neu amplifications among BC with metastases was also found (P = 0.031). A strong association (P = 0.01) between the neu and myc amplification was observed. There is a strong association between myc amplification and ER- BC (P < 0.01). It is concluded that (1) the combination ER- with neu amplification might define a new group of more aggressive BC, as is suggested by their associated nodal involvement; (2) the linkage of myc amplifications with ER- BC and high grade of neu amplification might reflect a trait of tumor aggressivity.

Adult↗
PubMed1994

Experience of an intravenous therapy team at the Instituto Nacional de Cancerología (Mexico) with a long-lasting, low-cost silastic venous catheter.

Means of vascular access are fundamental in the management of cancer. However, since current intravenous devices for long-term treatment are expensive and necessitate a high degree of education among medical personnel, in developing countries they are impractical for use in most of the population. We describe the use of a nontunneled, low-cost, long-lasting Silastic catheter (LLSC), cared for by an intravenous therapy team (IVTT), in 462 patients with cancer. The rate of infectious complications was 0.66 infections per 1,000 catheter-days, which is as low as that reported in association with other catheters in developed countries. Neutropenia and skin and/or soft-tissue infections were significant risk factors associated with LLSC-related infections. We believe that use of this catheter may be an alternative for patients with cancer who need chemotherapy, as long as an IVTT is established for its care. Our experience could be useful for practitioners in countries with similar socioeconomic characteristics.

Antineoplastic Agents↗
PubMed1993

Epidermal growth factor in human breast cancer, endometrial carcinoma and lung cancer. Its relationship to epidermal growth factor receptor, estradiol receptor and tumor TNM.

Epidermal growth factor (EGF) and its receptor (EGFR) were measured in 60 breast cancers (BC), 6 benign mammary tumors (BM), 8 samples of normal breast (NB), 6 endometrial carcinomas (EC) and 30 lung cancers (LC). EGF was measured in plasma, saliva and urine from 20 patients with BC, before and after tumor excision, and in 8 patients with metastatic disease. The median EGF in BM and BC was significantly higher (P < 0.05) than in NB. No significant correlation between EGF and EGFR was found in BC. Neither tumor excision nor the spreading of the disease significantly modified the EGF concentrations in biological fluids. In LC there was an inverse relationship between EGF and EGFR (rs = -0.36; P = 0.09), which disappeared in normal lung. It is concluded that EGF may play a role in malignant transformation; however, the weak correlation between EGF and EGFR lessens the importance of EGF in either autocrine or paracrine stimulation of tumor growth.

Adult↗
PubMed1993

Clinical and molecular analysis of five inv dup(15) patients.

Five patients with inv dup(15) chromosomes were investigated with molecular probes on proximal 15q to determine the parental origin and extent of the duplicated segment. Cytogenetic investigation showed that four patients carried one and a fifth patient had two extra chromosomes derived from number 15 in all cells. In situ hybridization with a chromosome 15 library and a centromere 15 probe confirmed that the entire inv dup chromosomes were derived from chromosome 15. Molecular analysis using probes mapping in the region deleted in Prader-Willi syndrome (PWS) and Angelman syndrome (AS) patients implied that in at least two patients the extra chromosomes were asymmetric with one copy of the PWS region on the extra marker chromosome but two copies of the region centromeric to the PWS region. Three other cases had an inv dup(15) with two extra copies of the PWS region, but in one of these, heteromorphisms clearly demonstrated that the two centromeres derived from two different chromosomes. The inv dup(15) presumably resulted from an illegitimate recombination event between two different chromosomes 15 in most or all of these cases. All patients showed a maternal origin of the duplicated chromosome. The clinical severity appears to be associated with dosage of the PWS/AS region rather than with differences in the extent of the duplicated segment.

Abnormalities, Multiple↗
PubMed1992

Aromatase activity and estradiol in human breast cancer: its relationship to estradiol and epidermal growth factor receptors and to tumor-node-metastasis staging.

PURPOSE: The present report attempts to clarify whether there is a relationship between aromatase activity (ARAC) and estradiol (E2), hormonal receptors, E2 receptor (ER), and epidermal growth factor receptor (EGFR), as well as with tumor stage and histopathology in human breast cancers. MATERIALS AND METHODS: We studied 225 breast carcinomas, 67 of which were premenopausal and 158 postmenopausal. In each sample, ARAC, EGFR, ER, and E2 were quantified. ARAC was quantified by Thompson and Siiterii's method, EGFR was quantified with a two-point assay method using radioactive iodine (125I)-EGF as ligand, and ER was measured by the Scatchard method using 3H-E2. E2 was quantified by radioimmunoassay in the diethylether tumor extract. RESULTS: ARAC was found in 64% of the cancers studied. There is a strong direct association between ARAC and tumor size in postmenopausal patients (P = .001). In the postmenopausal group, the proportion of ARAC-positive (ARAC+) tumors is significantly higher among ER-positive (ER+) than ER-negative (ER-) ones (P less than .001). ER+ tumors also have significantly higher levels of E2 than do ER- ones (P less than .0001); similarly, ARAC+ tumors have significantly higher levels of E2 than do ARAC- ones (P less than .0001). There is a significant multiple linear correlation between the log of the levels of ARAC, ER, and EGFR and the log of tumor E2 (P less than .0001). The correlation coefficients obtained show that ARAC and ER have a positive effect on tumor E2. CONCLUSION: The results obtained suggest the importance of tumor ARAC in the tumoral levels of E2 and reinforce the possible biologic significance of tumor ARAC, especially in postmenopausal breast carcinoma patients.

Adult↗
PubMed1991

Cytogenetics, flow cytometry, cytophotometry and morphometry of 22 cases of primary breast carcinoma. A comparative study.

Cytogenetic, flow cytometric, cytophotometric and morphometric analyses were performed on 22 previously untreated, primary solid breast carcinomas. Although the cell nuclei as the primary object of these studies were the same in all the tumors, distinct features were evaluated in each case to determine to what degree the results obtained by these techniques are comparable. From the cytogenetic viewpoint, six tumors had a modal number in the diploid range, seven were in the triploid range, and two in the tetraploid range; seven tumors had no modal number. These data correlate with the flow cytometry and cytophotometry results obtained, with DNA values slightly higher than their respective chromosomal modes. However, no correspondence between chromosomal modes and mean nuclear area was found. Chromosomal markers have been identified that particularly affect chromosomes 1 (p11, q21-qter), 11 and 16, although no common markers existed in all cases. Cytogenetics is the most sensitive technique, but the low yield (22 out of 140 tumors assayed) considerably restricts its value in any prospective breast cancer study.

Adult↗
PubMed1990

Epidermal growth factor receptor in human breast cancer: correlation with cytosolic and nuclear ER receptors and with biological and histological tumor characteristics.

Epidermal growth factor receptor (EGFr) and cytosolic (cER) and nuclear (nER) estradiol receptors were quantified in 220 primary breast cancers. The EGFr was significantly more frequent (chi 2 = 5.9; P less than 0.025) and its concentration was significantly higher (P less than 0.001) among ER- tumors than in ER+ tumors. There was a significantly greater proportion (chi 2 = 6.4; P less than 0.05) of node involvement in EGFr+/ER+ tumors than in EFGr-/ER+. Increases in the proportion of EGFr+ in ER- tumors are parallel to Scarff-Bloom scores (chi 2 = 6.1; P less than 0.05) and there is a significant trend (Spearman rs = 0.25; P less than 0.05) towards increased EGFr concentrations with histologic dedifferentiation. In ER+ tumors the median concentrations of EGFr in the different age groups show a linear correlation (LCC = 0.89; P less than 0.05) and follow a parallel profile with the medians of nER. These findings support the hypothesis that EGFr is a bad prognosis factor and suggest that EGFr expression and concentration in ER+ tumors might be considered an estrogenic action mediated through the binding of ER to their nuclear acceptors.

Adult↗
PubMed1989

Clinical response and plasma haloperidol levels in chronic and subchronic schizophrenia.

Levels of haloperidol were determined by radioimmunoassay (RIA) in 30 schizophrenic patients (diagnosed according to the criteria of DSM-III), who were treated with fixed doses of this neuroleptic for a period of 21 days. An inverted U-shaped relationship was found between the percent improvement observed in the BPRS global score and the steady state of haloperidol. The interval of effective concentration of haloperidol was set between 12.0 and 35.5 ng/ml. However, the limits of such an interval found in the subchronic schizophrenic subgroup (SS) ranged from 7.4 to 24.9 ng/ml, whereas in the chronic schizophrenic subgroup (CS), it ranged from 14.8 to 38.5 ng/ml. This finding suggests that the interval of effective concentrations may vary as a function of the number of years of evolution of the subjects' illness. This may be compatible with the development of tolerance in the mesolimbic and/or mesocortical dopaminergic systems as a response to prolonged neuroleptic treatments.

Adolescent↗
PubMed1989

Determination of plasma haloperidol concentrations by radioreceptor assay in schizophrenia: clinical utility.

1. Haloperidol concentrations were determined by radioreceptor assay (RRA) and prolactin concentrations were measured in 20 patients diagnosed as schizophrenia (DSM-III). 2. The patients were treated with a fixed dose of haloperidol for 21 days. 3. Our results suggest the existence of a curvilinear relationship, in the form of an inverted U, between stable haloperidol levels and clinical improvement assessed by total BPRS score. 4. We also found a curvilinear relationship between the improvement observed in positive symptoms and state steady levels. 5. No relationship was seen between improvement in negative symptoms and state steady levels. 6. An interval of optimal haloperidol concentration was found: 8.1 ng/ml to 19.6 ng/ml. 7. No relation was found between the dose of haloperidol administered and plasmatic concentration, nor between haloperidol and prolactin levels. 8. Our findings suggest that haloperidol concentrations determined by RRA have clinical utility as predictors of response in schizophrenia.

Adolescent↗
PubMed1989

Beta-N-acetylglucosaminidase from Aspergillus nidulans which degrades chitin oligomers during autolysis.

A hexosaminidase from autolyzed cultures of Aspergillus nidulans was purified 196 fold and characterized as a beta-N-acetylglucosaminidase (EC 3.2.1.30). The enzyme has a MW of 190000, a pI of 4.3, and optimum pH of 5.0 and is unstable at temperatures above 50 degrees C. The enzyme is a glycoprotein with 19.5% sugars, mannose being the principal component. It binds strongly to chitin. The enzyme hydrolyzes different substrates. The Ki with the competitive inhibitor 2-acetamido-2-deoxy-D-gluconolactone was independent of the substrate used. The enzyme was inhibited by Hg2+, Ag+, acetate and other organic anions. The kinetics of hydrolysis of chitin oligosaccharides from 2 to 6 units was studied by HPLC. This enzyme is an exoenzyme which degraded chitin oligomers gradually with the production of N-acetylglucosamine. The hydrolysis of N-N'-diacetylchitobiose was inhibited non-competitively by glucosamine and N-acetylglucosamine. In mixtures of chitin oligosaccharides, the hydrolysis of chitobiose was competitively inhibited by each of the other oligomers.

Acetylglucosaminidase↗
PubMed1989

Clinical implications of determination of plasma haloperidol levels.

The aim of this study was to analyze the clinical utility of monitoring plasma levels, since the utility of monitoring is not yet well established. After a washout period, 30 schizophrenic patients were given fixed doses of haloperidol for 3 weeks. A U-shaped second-grade polynomic relationship (R = 0.69) was found between steady state of haloperidol and percentage improvement in total score on the Brief Psychiatric Rating Scale. The interval of effective concentrations was between 12 and 59 ng/ml. Fourteen of the 15 patients who had a steady state of haloperidol within that therapeutic interval were responders: only 5 out of the 15 patients below the therapeutic interval were responders. None of the 5 patients who had concentrations below 8 ng/ml was a responder. Furthermore, responder patients showed a steady-state level of haloperidol significantly higher than that of nonresponders. These data suggest that plasma levels of haloperidol are predictors of therapeutic response in schizophrenic disorders.

Adult↗
PubMed1985

Isolated atresia of the left pulmonary veins.

Four cases of congenital isolated atresia of the left pulmonary veins were observed over a 12-year period. The diagnosis was established through radionuclide pulmonary perfusion studies together with cardiac catheterization and pulmonary arteriography. Both procedures showed an elevated pulmonary pressure wedge and decreased blood flow with late poor filling of the pulmonary capillary bed on the affected side. Arteriography revealed non-visualization of the left pulmonary veins. The possibility of congenital atresia of the pulmonary veins should be borne in mind when confronted by unexplained hemoptysis, recurrent lower respiratory infections with protracted infiltrates, or pulmonary arterial hypertension. Surgical treatment, though difficult, is feasible.

Angiocardiography↗
PubMed1983

DNA/protein ratio as an index of oestrogen receptor content in human breast cancer.

The nuclear DNA/cytoplasmic protein ratio was related to the oestradiol receptor content in both cytoplasmic (ERc) and nuclear (ERn) fractions in 165 cases of breast cancer. The patients under study were divided into groups according to whether their biopsies contained functional (ERc/ERn = +/+), abnormal (+/0) or non-detectable receptor (0/0). The mean microgram DNA/mg protein ratio was significantly decreased in both the abnormal and receptor-negative groups, with means of 30.4 and 30.2 respectively, when compared to the mean of 52.8 for the receptor-positive group. When the DNA/protein ratio for each patient was related to age, a discriminant line which clearly differentiated the ER +/+ group from the other two groups was obtained. It may be concluded that an increased DNA/protein ratio is related to the presence of ERn. Furthermore, since the DNA content per cell is higher in ER-negative tumours, an increase in cellularity must exist in ER-positive tumours.

Adult↗
PubMed1983

HLA-DR phenotypes in Spanish coeliac children: their contribution to the understanding of the genetics of the disease.

The DR-locus controlled B-cell antigens were studied in 163 unrelated Spanish coeliac children and 68 families of this group, nine of them with more than one coeliac patient, to obtain more information about the association between these antigens and coeliac disease. The results show that the most common coeliac phenotypes are DR3/DR7, DR7/DR5, DR3/other DR, and DR3/DR3. The family study confirmed the segregation of the disease with the above mentioned phenotypes. In eight of the nine multiple case families, all coeliac children shared both HLA-DR antigens. These findings make it unlikely that a single dominant gene linked to HLA-DR controls the susceptibility to coeliac disease. The phenotypes in the patients were not distributed according to the Hardy-Weinberg equilibrium. Thus, a model based on one recessive susceptibility gene linked to HLA-DR is not probable either. The complexity of the genetics of coeliac disease and some of the features shared with the HLA-DR pattern in juvenile insulin-dependent diabetes are discussed.

Celiac Disease↗