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Biomedical subjects

M T Allende

Publications and source records attributed to M T Allende.

At least 37 records · Page 2Linked to original sources
PubMed1990

Evaluation of human breast cysts according to their biochemical and hormonal composition, and cytologic examination.

Breast cyst fluids were aspirated during the mild luteal phase of the menstrual cycle from 88 patients with gross cystic disease. According to intracystic Na+/K+ ratio three categories of cyst were identified: Type I with low Na+/K+ ratio, low levels of chloride, glucose, and pH, and high concentrations of dehydroepiandrosterone-sulphate (DHAS) and apocrine epithelium; Type II with high Na+/K+ ratio presenting levels of chloride, glucose, pH, and DHAS similar to those found in plasma, and flattened epithelium; Type III with intermediate values for the above parameters. The findings suggest that the cysts could correspond to the different functional stages of the epithelium lining the cysts. Cyst classification was evaluated using a discriminant analysis, which allows breast cyst fluids to be assigned within a category defined by the Na+/K+ ratio. The apparent correct rate for each category was more than 87%. The variables that better discriminate among groups of cysts were chloride, glucose, intracystic prolactin, and pH, respectively. These discriminant functions could be used as criteria for an optimal classification of breast cysts, which might help study of the epidemiology of breast cancer and its relationship to gross cystic disease.

Adult↗
PubMed1989

[Hyperaluminemia and parathormone release].

Previous studies have shown that aluminum (Al) could inhibit parathyroid function. However, controversy still remains about the possible mechanisms implicated. Thus, the aim of this study was to evaluate the acute parathyroid hormone (PTH) response to intravenous Al infusion. Male Wistar rats were divided into two groups: Group A (n = 5): received 0.1 ml of saline. Group B (n = 5): received 0.5 mg of Cl3Al in 0.1 ml of saline. In both groups ionized calcium (Ca(+)+) decreased, but despite a similar degree of haemodilution, this change was only significant in group A. This variable Ca(+)+ decrease was followed by different responses in the PTH secretion. In group B there was a significantly (p less than 0.05) lower PTH release compared with control group. These results suggest that Al could directly inhibit the PTH secretion, and at the same time might exert an indirect effect on PTH release "blunting" the serum Ca(+)+ variations.

Aluminum↗
PubMed1985

Gastrointestinal aluminium absorption: is it modulated by the iron-absorptive mechanism?

Gastrointestinal aluminium (A1) absorption has been proved but its mechanism is still unknown. This study investigates the pattern of A1 absorption in patients with different degrees of iron stores. We studied 29 haemodialysis patients forming three groups according to their serum ferritin values. Over seven days all patients received the same dose of aluminium hydroxide after which patients with 'low-normal' and normal serum ferritin increased their serum A1 proportionally with the increased aluminium hydroxide intake. By contrast patients with high serum ferritin did not show any change in their serum A1 values. Our results therefore suggest that a 'common pathway' of metal absorption could be implicated in A1 absorption. Serum ferritin might be a valuable predictor of different behaviour.

Adult↗
PubMedDate not supplied

Tissue-type plasminogen activator (tPA) content in colorectal cancer and in surrounding mucosa: relationship with clinicopathologic parameters and prognostic significance.

The aim of this study was to evaluate the cytosolic tissue-type plasminogen activator (tPA) content in colorectal cancer, its possible relationship with the clinicopathologic parameters of tumors, and its prognostic significance. We have therefore examined by immunoenzymatic assay the cytosolic tPA content in tumors and paired surrounding normal mucosa samples from 162 colorectal cancer patients. Cytosolic tPA levels were significantly higher in surrounding normal mucosa samples than in neoplastic tissues (4.01 +/- 5.07 vs 2.63 +/- 5.82 ng/mg protein; p < 0.0001). By contrast, no significant correlation was found between tPA content and clinicopathologic tumor parameters such as location, Dukes' stage, histologic grade, and DNA content or S-phase fraction. However, the results indicated that a high cytosolic tPA content (> 0.75 ng/mg protein) in tumors predicted for a shorter relapse-free and overall survival (both p < 0.05) in 123 resectable colorectal cancer patients who were prospectively evaluated during a mean follow-up period of 32.2 months. This suggests that tPA may give additional information to that provided by other biochemical markers currently used in colorectal cancer.

Aged↗
PubMedDate not supplied

C-erbB-2 oncoprotein content in gastric cancer and in adjacent mucosa.

The aim of this study was to evaluate, by means of an immunoenzymatic assay, the membranous and cytosolic c-erbB-2 oncoprotein contents in primary tumors and in adjacent mucosa from gastric cancer patients. Fifty-two patients with primary gastric adenocarcinomas were enrolled in this prospective study. c-erbB-2 protein levels were significantly higher in membranous than in cytosolic samples, both in neoplastic tissues (median: 3602 vs 525 NHU/mg protein; p<0.0001) and in adjacent mucosa samples (median: 3174 vs 509 NHU/mg protein; p<0.0001). Nevertheless, there was a significant positive relation between membranous and cytosolic c-erbB-2 protein contents in both neoplastic tissue (p<0.001) and adjacent mucosa (p<0.001) samples. There was no significant difference in the membranous c-erbB-2 protein content between neoplastic tissues and adjacent mucosa samples. However, the cytosolic c-erbB-2 content was significantly higher in neoplastic tissues than in adjacent mucosa (p<0.05). Finally, the results did not show any significant correlations of these oncoprotein contents with patient characteristics, clinicopathologic parameters and overall survival of the study population.

Adult↗
PubMedDate not supplied

Prognostic significance of cytosolic pS2 protein content in gastric cancer.

pS2, a 60-amino-acid chain peptide which is the most widespread estrogen-induced RNA messenger in MCF-7 breast cancer cells, is normally detected in the epithelium of gastric mucosa. The aims of this work were to evaluate the cytosolic pS2 content and its clinical significance in gastric carcinomas. Cytosolic pS2 levels were examined by immunoradiometric methods in 108 patients with primary gastric adenocarcinomas. The mean follow-up period was 23.3 months. The cytosolic pS2 levels of the tumors ranged widely, i.e., from 0.1 to 3217 ng/mg protein. There were no significant differences in pS2 content between tumors (mean +/- standard error: 137.2+/-31.4 ng/mg protein) and paired adjacent mucosa samples (n=84; mean +/- standard error: 249.6+/-32.6 ng/mg protein), nor were there any significant differences in tumoral pS2 levels with respect to clinicopathologic parameters such as patient age and sex or tumor location, stage, histologic type or grade. However, the results indicated that high intratumoral pS2 levels were significantly and independently associated with an unfavorable outcome in the overall group of patients (p=0.0266) and in patients with resectable gastric cancer (p=0.003). In conclusion, pS2 may represent a useful biological marker in gastric cancer.

Adenocarcinoma↗
PubMedDate not supplied

Clinical significance of epidermal growth factor receptor content in gastric cancer.

The objective of this work was to evaluate the epidermal growth factor receptor (EGFR) content in gastric cancer, its possible relationship with clinicopathological parameters of tumors and its prognostic significance. Membranous EGFR levels were examined by radioligand binding assays in 110 patients with gastric cancer. The mean follow-up period was 30.7 months. EGFR levels of tumors ranged widely, from 0.3 to 510 fmol/mg protein. EGFR levels were significantly higher (p<0.0005) in neoplastic tissue than in paired adjacent mucosa samples (median) (n= 84; 8.7 vs. 3.9 fmol/mg protein). Intratumoral EGFR levels were significantly correlated with tumor stage (p<0.05), and were higher in patients with stage III tumors (median) (7.6, 6.4, 12.3 and 7.5 fmol/mg protein for stages I, II, III and IV, respectively). In addition, the tumor/mucosa ratios of the EGFR content were significantly higher (p<0.05) in patients with stage III tumors (1, 1.8, 3.9, and 0.92, respectively). Although there was no significant relationship between EGFR levels of tumors and overall survival, the results suggest a role for EGFR in tumor progression of gastric cancer.

Adenocarcinoma↗