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Biomedical subjects

M Valente

Publications and source records attributed to M Valente.

At least 235 records · Page 13Linked to original sources
PubMed1982

Secondary lung cancer resection with curative intent: causes of success and failure and prognostic factors.

Observed and disease-free survivals were evaluated in a consecutive series of 46 resections of pulmonary metastases, with major chance of being a unique phenomenon. Survival curves were computed both since the treatment of primary tumors and since resection of lung metastases. From the treatment of primary tumors, median disease-free interval was 33 months, and rose to 66 months after resection of lung metastases. From the treatment of secondary lung cancers the observed survivals at 1, 3 and 5 years were respectively 60%, 41% and 26%. Survival was clearly affected by development and resectability of post-thoracotomic recurrence (100% without recurrence, 50% with resectable recurrence and 4% with unresectable recurrence). Recurrence rate was related to the first disease-free interval and to the anatomical extent (particularly for nodal status) of secondary lung cancer. This fact suggests that the failure of secondary lung cancer resection may arise either from the primary cancer (poor selection) or from the secondary cancer (delay in treatment).

Adolescent↗
PubMed1982

Cusp disruption by massive lipid infiltration. A rare cause of porcine valve dysfunction.

A 68-year-old man underwent reoperation because of severe incompetence of a mitral valve xenograft, 96 months following implantation. Gross examination of the device showed yellow spots on the cusps, suggesting lipid infiltration, and a torn commissure. Plasmatic cholesterol and lipiprotein levels were normal. X-ray examination of the explants showed no calcific deposits. Histologic and electron microscopic studies disclosed massive accumulation of lipid clefts and droplets, predominantly at the level of the tear; focal loss and detachment of the endothelial lining and scanty porcine fibroblasts and collagen bundles with preserved periodicity were also noted. Primary disruption of porcine valvular bioprostheses without significant calcifications or collagen breakdown is uncommon. In the present case, lipid accumulation was the main determinant of tissue failure.

Aged↗
PubMed1981

[Evaluation of lung cancer treatment in an unselected population].

The modality of lung cancer treatment was retrospectively evaluated in an unselected population. All the lung cancer cases diagnosed among the residents in a Local Sanitary Unit of Lombardy during four years (1974-1979), were identified. The clinical records of the 235 collected patients were reviewed and on this basis the anatomical extent of disease was retrospectively classified in stages according to the TNM of UICC (1978). The relative frequency of clinical stages resulted 29% for stage I, 17% II, 20% III and 32% IV. Only 57% of all the subjects had been treated; 11% by resection, 22% by radiotherapy and 24% by chemotherapy. For the stages I and II the operability rates were 35% and 26% respectively, while the resectability rates were 29% and 17%. An objective reason of exclusion from surgery was found in no more than a quarter of stage I and II lung cancers, while the remaining (40%) had probably been excluded from exploration owing to a subjective prognostic evaluation. If compared with similar reports from other countries, these data show a striking defect in the choice of curative treatment for a high proportion of the examined cases.

Adult↗
PubMed1981

Pentasomy X: report of patient and studies of X-inactivation.

A five-year-old girl presented with mental retardation (MR), microcephaly, short stature, ptosis, malocclusion, abnormal elbows, fifth finger clinodactyly, joint hyperextensibility in hands and feet, renal hypoplasia, nonobstructive ureteral stasis, pyelonephritis, and renal failure. Five X chromosomes (49,XXXXX) were found in all peripheral blood lymphocytes and skin fibroblasts examined. Xa RBC typing, utilizing serial dilutions of antiserum, gave agglutination at a higher titer than in either Xg(a+) positive parent; the patient's serum IgM was also elevated. These immunological findings imply a lack of dosage compensation and incomplete inactivation of some X-linked loci.

Abnormalities, Multiple↗
PubMed1981

Hydrogen peroxide and hematin in microsomal lipid peroxidation.

Lipids of rat liver microsomes underwent peroxidation with production of malondialdehyde in the presence of H2O2 and hematin. Rates of peroxidation of 27-33 nmol of MDA formed/mg of microsomal protein/30 min were measured with 5 mM H2O2 and 10 microM hematin at 22 degrees C. Histidine (0.01 M) caused a 55% inhibition. Hematin could be added to the reaction mixtures either simultaneously with H2O2 or afterwards, when all H2O2 had been destroyed by catalase present in the microsomal preparation. Catalase was necessary for formation of MDA. Indeed, when heat-denatured microsomes were employed, incubation with H2O2 and the iron complex led to formation of lipid hydroperoxides; however, no production of MDA was observed, unless exogenous catalase was added together with H2O2 and hematin to the reaction mixture. The role of H2O2 in microsomal lipid peroxidation is that of promoting the formation of fatty acid hydroperoxides. These are decomposed in the presence of hematin, with formation of free radicals, bicyclic endoperoxides and MDA. Catalase is necessary to remove H2O2, which, after starting the peroxidation process, blocks the decomposition of lipid hydroperoxides, apparently by binding to the iron complex.

Animals↗