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Biomedical subjects

J Prat

Publications and source records attributed to J Prat.

At least 109 records · Page 6Linked to original sources
PubMed1994

p53 expression in anaplastic carcinomas arising from thyroid papillary carcinomas.

AIM: To study the expression of p53 tumour suppressor gene in anaplastic carcinomas arising from thyroid papillary carcinomas. METHODS: Formalin fixed, paraffin wax embedded tissues from four cases of anaplastic carcinomas associated with thyroid papillary carcinomas were studied by immunohistochemistry with two different p53 monoclonal antibodies. RESULTS: The anaplastic component showed nuclear immunostaining in two cases, but not in the other two. In all cases the papillary carcinoma component was negative. CONCLUSION: The results support the hypothesis that p53 stimulates tumour progression in thyroid tumours.

Carcinoma↗
PubMed1994

Detection of steroid receptors in breast cancer: relationship between EIA and IHC methods.

The efficiency of EIA and IHC (frozen tissue) in the detection of ER and PR in 51 breast cancers were compared. ER were detected in 51% of cases by IHC and in 49% of tumours by EIA. PR were detected in 56.8% of cases by IHC and in 54.8% of tumours by EIA. Concordance of the results of IHC and EIA reached 78.4% in ER and 82.4% in PR detection. Discordance between IHC and EIA seems to be related to minor changes in sensibility of methods, but we cannot conclude that one of the two techniques is superior to the other in the detection of hormonal receptors. There is a common trend of association between low grade of histologic or nuclear malignancy and a high expression of hormonal receptors.

Breast Neoplasms↗
PubMed1994

Ploidy of 36 stromal tumors of the gastrointestinal tract. A comparative study with flow cytometry and image analysis.

DNA ploidy was investigated by flow cytometry (FC) and image analysis (IA) in paraffin-embedded tissue sections from 36 stromal tumors of the gastrointestinal tract. The results of both techniques were correlated with pathologic features of the tumors and survival. Ten (27.8%) tumors were aneuploid by FC and IA. Most of the diploid tumors were identified by both techniques, but FC appeared to be superior to tissue section IA for identification of aneuploid tumors (25% vs. 13.8%). Aneuploidy by FC correlated with pathologic grade and mitotic index (P < .05), and a trend to short survival was also detected (P < .1). No similar correlation was found by IA. Enlargement and variation of nuclei may explain the discrepancy between FC and IA.

Flow Cytometry↗
PubMed1993

Ovarian carcinomas with choriocarcinomatous differentiation.

BACKGROUND: Ovarian carcinomas may produce human chorionic gonadotropin (HCG) or HCG-like substances and may even contain syncytiotrophoblast cells, but a true choriocarcinomatous component has not been described in these tumors. METHODS: Two cases of poorly differentiated ovarian carcinoma with choriocarcinomatous components are reported. Pathologic findings were correlated with immunohistochemical stains, hormonal effects, and clinical behavior. RESULTS: Each tumor contained a circumscribed, extensively necrotic and hemorrhagic brown nodule. Microscopically, the nodules exhibited a mixture of cytotrophoblast and syncytiotrophoblast. The syncytiotrophoblast capped cytotrophoblast and was strongly positive for beta-HCG. In one of the cases, a transformation zone composed of poorly differentiated carcinoma with occasional beta-HCG-positive cells was observed between a mucinous cystadenoma and the choriocarcinomatous elements. The two cases exhibited activation of the ovarian stroma in the form of condensation and luteinization. Extra-abdominal metastases developed early in both patients and, despite multiagent chemotherapy, they died shortly postoperatively. CONCLUSIONS: Choriocarcinoma may rarely develop as a result of dedifferentiation of common epithelial ovarian tumors. Recognition of choriocarcinomatous components in ovarian carcinomas is important because of its association with aggressive behavior.

Adult↗
PubMed1993

Relationship between lipid peroxidation, fatty acid composition, and ascorbic acid in the liver during carbohydrate and caloric restriction in mice.

Growing OF1 mice were treated on a short-term basis with ad libitum, caloric-restricted, or carbohydrate-restricted diets, maintaining the same intake of vitamins and minerals in the three groups. Caloric intake was 60% of controls both in the caloric-restricted and in the carbohydrate-restricted groups. Neither global nor carbohydrate restriction changed liver superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, cytochrome oxidase, GSH, uric acid, or malondialdehyde (HPLC). Ascorbate was decreased in both restricted groups. Carbohydrate restriction, but not caloric restriction, increased unsaturation indexes of fatty acids in all lipid classes analyzed and increased sensitivity to peroxidation by one order of magnitude. It is concluded that short-term caloric restriction does not seem to increase antioxidants and decrease peroxidation in the mouse liver whereas long-term restriction can avoid decreases of antioxidants and increases of peroxidation during aging. Our experiments support the prevailing view that the caloric restriction phenomenon is due to a reduction in calories themselves instead of to a reduction in carbohydrates. This last manipulation strongly increases sensitivity to peroxidative damage in the liver. The results show that in vivo fatty acid unsaturation is a main factor in determining the sensitivity to lipid peroxidation.

Animals↗
PubMed1993

Intratesticular serous cystadenoma of borderline malignancy. A pathological, histochemical and DNA content study of a case with long-term follow-up.

A 61-year-old man presented with a painless right testicular swelling of 6 months duration. A right orchiectomy was performed and pathological examination showed an intratesticular serous borderline tumour (SBT). Immunohistochemical staining was positive for carcinoembryonic antigen, LeuM1, B72.3, S100-protein, Ca125, cytokeratins AE1/AE3 and vimentin, suggesting a Müllerian origin or differentiation. DNA image analysis revealed an aneuploid histogram. The favorable outcome of the patient confirms that testicular SBTs behave as non-aggressive tumours, even when characterized by aneuploid DNA content.

Biomarkers, Tumor↗
PubMed1993

Release of chemical mediators and inflammatory cell influx during early allergic reaction in the nose: effect of furosemide.

BACKGROUND: We evaluated the effect of furosemide on allergen-induced rhinitis in a double-blind, crossover, placebo-controlled experiment. METHODS: Fourteen patients with rhinitis who were allergic to house dust were nebulized with an intranasal dose of 20 mg of furosemide or placebo before allergen challenge with an extract of Dermatophagoides pteronyssinus (100 BU). Clinical evaluation and nasal lavages with normal saline solution were performed at baseline; after placebo-furosemide nebulization, and at 10, 30, and 60 minutes after allergen challenge. Number of sneezes and a composite symptom score were recorded to evaluate clinical response. Prostaglandin E2 (PGE2), PGD2 peptide leukotrienes and 15-hydroxy, 5,8,11,13-eicosatetraenoic acid (15-HETE) were measured by radioimmunoassay in nasal lavages. Cells were counted and classified as epithelial cells, neutrophils, eosinophils, and others. RESULTS: No differences in either clinical symptoms or cell influx after allergen challenge were found between furosemide and placebo groups. PGE2 levels did not change after provocation, and furosemide had no effect on its production. Ten minutes after antigen challenge there was a marked increase of PGD2 (p < 0.01), peptide leukotrienes (p < 0.01), and 15-HETE (not significant) on both study days. However, no significant differences in the release of eicosanoids were found between furosemide and placebo groups. CONCLUSIONS: Our observations in the nasal mucosa suggest that furosemide has no effect on the release of proinflammatory and bronchoconstrictor metabolites (PGD2, peptide leukotrienes, and 15-HETE). In contrast to bronchial asthma, allergen-induced rhinitis was not effectively prevented by furosemide.

Adult↗
PubMed1993

Mechanisms of glycation in atherogenesis.

Non-enzymatic glycation may affect the arterial wall altering its connective tissue and promoting LDL accumulation. Its recognition by specific receptors and growth factor release, as well as possible alteration of DNA, may stimulate smooth muscle cell proliferation. Free radical generation may favour non-enzymatic PUFA degradation and quench NO, which would alter vascular relaxation. All of these aspects may participate in atherogenesis.

Animals↗
PubMed1993

Immunocytologic analysis of nasal cells obtained by nasal lavage: a comparative study with a standard method of cell identification.

For evaluation of two methods of nasal cell identification, cell morphology and immunocytologic analysis, nasal lavage was performed in 16 healthy subjects and 29 patients suffering from rhinitis. Nasal lavage smears were stained with May-Grünwald-Giemsa (MGG), and cells were identified according to their structure as epithelial cells, neutrophils, lymphocytes, eosinophils, and metachromatic cells (basophils and mast cells). Immunocytologic analysis was performed with monoclonal antibodies by the immunoalkaline phosphatase method. The following monoclonal antibodies were used: CK1, EG2, and CD3, which identify epithelial cells, activated eosinophils, and T lymphocytes, respectively; CD15, which recognizes mature granulocytic cells; and CD14, which reacts with monocytes and macrophages. A significant difference was observed between the two methods in the number of identified epithelial cells, in both controls (64.6 +/- 7.8% with MGG, 14.2 +/- 3.5% with CK1 analysis) and patients with rhinitis (56.9 +/- 7.6% with MGG, 18.2 +/- 3.7% with CK1 analysis). In contrast, no significant differences were found in eosinophil and neutrophil counts when the two methods were compared. After nasal allergic provocation, a significant increase in the number of eosinophils was observed with both methods in seven patients with rhinitis. The results of this study indicate that: 1) MGG staining is a useful method to identify the cells obtained by nasal lavage, and 2) immunocytologic analysis with monoclonal antibodies accurately identifies granulocytic cells, while only a low proportion of epithelial cells are detected, probably because anticytokeratin monoclonal antibody reacts only with viable cells.

Adult↗
PubMed1993

Design and development of a new general purpose stereotaxic device.

This paper describes the design and development of a new device which allows the surgeon to locate an internal point following two X-ray views with an image intensifier. Three dimensional coordinates of the target point are directly estimated by means of two ring-and-bead sights and no computer calculations are necessary. After the location of the target point it is possible to choose any track to it by means of the rotation of an arc and the circumferential sliding of the arc. The system reduces radiation doses and it can be used for many purposes such as percutaneous discectomies and chemonucleolysis, biopsies and screw insertion of interlocking nails.

Bias↗
PubMed1993

Detection of human papillomavirus 16 and 18 DNA in epithelial lesions of the lower genital tract by in situ hybridization and polymerase chain reaction: cervical scrapes are not substitutes for biopsies.

Human papillomavirus (HPV) types 16 and 18 in 66 women with histologically documented lesions of the genital tract and 64 control cohorts were investigated. The efficacies of in situ hybridization and polymerase chain reaction (PCR) in detecting HPV 16 and 18 DNA were analyzed. In order to assess the usefulness of replacing biopsies with cervical scrapes, the two samples were compared by PCR. The prevalence rates of HPV infection by PCR were 59.1 and 10.9% in patients and controls, respectively. PCR was three times more sensitive than in situ hybridization (52.6 versus 17.8%). However, the need to improve PCR sensitivity by subsequent dot blot hybridization reduced one of the main advantages of PCR, i.e., expeditious diagnosis. Cervical scrapes were less sensitive than biopsies (13.6 versus 53%), although with four (6.1%) patients with intraepithelial neoplasias, HPV DNA was identified only by means of cervical scraping. We conclude that obtaining biopsy specimens and cervical scraping are complementary sampling procedures.

Adolescent↗
PubMed1993

Failure of frusemide to increase production of prostaglandin E2 in human nasal mucosa in vivo.

BACKGROUND: It has been suggested that inhaled frusemide protects subjects with asthma against bronchoconstriction by enhancing the synthesis of prostaglandin E2 (PGE2). To evaluate this hypothesis the effect of frusemide on PGE2 production from nasal mucosa was studied. METHODS: Two main arachidonic acid metabolites produced by epithelial cells, PGE2 and 15-hydroxy 5,8,11,13-eicosatetraenoic acid (15-HETE), were measured by radioimmunoassay in nasal secretions obtained by nasal lavages with saline. Eleven healthy volunteers were randomly assigned to two study days, one week apart, in a double blind crossover study. Nasal instillation with three increasing doses of frusemide (5, 10, and 20 mg) or placebo was carried out at intervals of 15 minutes. Nasal lavages were performed immediately before nasal instillations and 15, 30, and 60 minutes after the last instillation. RESULTS: Baseline concentrations of 15-HETE were at least six times higher than PGE2. No differences between frusemide and placebo were detected either on PGE2 or 15-HETE release. CONCLUSIONS: The findings do not support the hypothesis that the antiasthmatic effect of frusemide may be due to increased synthesis of PGE2 or release in the respiratory mucosa.

Adult↗
PubMed1993

Morphologic precursors of ovarian epithelial tumors.

OBJECTIVE: To correlate various types of hyperplastic lesions of the ovarian surface epithelium with primary disease of the female genital tract. METHODS: Using whole-organ multiple sections of the ovary, we studied 200 hysterectomy and bilateral salpingo-oophorectomy specimens distributed into four groups: cases without hyperplastic or neoplastic disease in the tube, uterus, or vagina; those with contralateral epithelial ovarian tumors; those with endometrial adenocarcinomas; and those with polycystic ovary disease. RESULTS: We found a high frequency of hyperplastic and metaplastic changes in the surface epithelium or in the inclusion cysts in ovaries with contralateral epithelial ovarian tumors (92%), endometrial adenocarcinomas (76%), and polycystic ovary disease (68%) compared to ovaries without hyperplastic or neoplastic disease (22%). These changes were frequently associated with intracystic papillae and psammoma bodies similar to those observed in epithelial tumors. The inclusion cysts were unrelated morphologically to signs of preceding ovulation, but were related to deep crypts of the ovarian epithelium and to stromal hyperplasia. CONCLUSIONS: The hyperplastic and metaplastic changes of the surface epithelium and related inclusion cysts can be considered morphologic precursors of common epithelial tumors. Similar changes are found as a response to a hormonal ovarian or extraovarian stimulus, which may play an important role in ovarian carcinogenesis.

Adenocarcinoma↗
PubMed1993

Adenocarcinoma in situ of the uterine cervix: clinicopathological study of nine cases with detection of human papillomavirus DNA by in situ hybridization and polymerase chain reaction.

The clinicopathological features of nine patients with adenocarcinoma in situ (AIS) of the uterine cervix, one of them with microinvasion, were studied. In situ hybridization (ISH) with biotinylated probes to human papillomavirus (HPV) types 6/11, 16/18, and 31/35/51 was performed in eight tumors. The presence of HPV types 16 and 18 was also investigated by the polymerase chain reaction (PCR) in seven. Four tumors were of the endocervical type, two were endometrioid, and three were mixed (endocervical-intestinal). Coexisting cervical intraepithelial squamous neoplasia (CIN) was found in eight tumors. Only one of the eight tumors studied by ISH was positive for HPV 16/18 in the dysplastic squamous epithelium, but none of them showed positivity in the adenocarcinomatous areas. In contrast, four of seven AIS studied by PCR were positive: three for HPV 16 and one (the microinvasive adenocarcinoma) for HPV 18. The results confirm the frequent association of AIS with CIN and HPV.

Adenocarcinoma↗
PubMed1993

Cell content and albumin concentration in nasal lavage from patients with rhinitis.

Influx of inflammatory cells in the nose was evaluated in 14 patients with rhinitis and 11 healthy subjects. Nasal secretions were obtained by nasal lavages. Total cell count and differential count were carried out with a Neubauer chamber and in cytospin slides, respectively. Cells were classified according to their morphology as epithelial cells without nuclei (degenerated), epithelial nucleated cells, neutrophils, eosinophils, and other. Total protein and albumin concentration were measured by the Lowry method and a nephelometric assay respectively. A statistically significant difference was found in total nucleated epithelial cells (P < .01), total neutrophils (P < .01), and total eosinophils (P < .05) between patients and healthy subjects. A significant correlation was found between albumin/total protein concentration with eosinophil numbers (r = .83, P < .001) in patients with rhinitis. These findings suggest that eosinophils participate in the inflammatory process taking place in rhinitis. Since the cellularity present in the nose of rhinitic patients is similar to that usually found in the bronchial secretions of asthmatic patients obtained by bronchoalveolar lavage, our results also suggest that nasal lavage may be used in the study of the inflammatory cells involved in airway diseases.

Adult↗
PubMed1992

Serous borderline tumors of the ovary. A clinicopathologic, immunohistochemical, and quantitative study of 44 cases.

The clinicopathologic features of 44 serous borderline tumors (SBT) of the ovary were evaluated. Nineteen were Stages II and III, and 9 had invasive peritoneal implants. All 19 patients received chemotherapy and 4, who had invasive implants, died of disease after 3, 4.3, 8, and 9 years. The other 25 patients were free of tumor 1-14 years (mean, 5.3 years) after surgery. Coexpression of low molecular weight keratins (AE1, CAM 5.2) and vimentin was found in all tumors and their implants. No significant differences were found between SBT with different volume-corrected mitotic indices (M/Vi) with respect to gross features, presence or absence of implants, stage, and survival. Cytometric DNA analysis also was performed on the primary ovarian tumors and the implants. Twenty-one primary tumors had diploid or tetraploid histograms, and 23 had aneuploid histograms. DNA ploidy of the primary ovarian tumors did not correlate with gross features, the presence or absence of implants, M/Vi, stage, and survival. The data from this study confirm that most SBT are clinically benign, but SBT with invasive implants may behave aggressively. Expression of intermediate filaments, M/Vi, and DNA ploidy evaluation of the primary ovarian tumors seem to be of no value in predicting prognosis. However, four of seven patients with aneuploid DNA implants died of tumor.

Adolescent↗