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Biomedical subjects

M Piazza

Publications and source records attributed to M Piazza.

At least 91 records · Page 5Linked to original sources
PubMed1985

Hepatitis B immunisation with a reduced number of doses in newborn babies and children.

74 healthy babies born to mothers positive for hepatitis B surface antigen (HBsAg) were randomly divided at birth to receive either HB immunoglobulin and 2 doses of HB vaccine 2 months apart, or HB immunoglobulin and 3 doses of HB vaccine 1 month apart. 80 healthy babies born to HBsAg, anti-HBs, and anti-HB core (c) negative mothers were randomly divided at birth to receive either 2 doses of vaccine 2 months apart or 3 doses 1 month apart. The seroconversion rates and the geometric means of anti-HBs titres were lower in both groups of babies given 2 doses of vaccine than in the groups given 3 doses. 60 pairs of children at risk, aged 1 to 12 years and HBsAg, anti-HBs, and anti-HBc negative, were randomly divided to receive either the 2-dose regimen or the 3-dose regimen. The seroconversion rates and the geometric means of anti-HBs titres were satisfactory in both groups.

Child↗
PubMed1984

[Unusual ultrastructural findings in a case of asymptomatic primary biliary cirrhosis].

The investigators report an ultrastructural study of a case of primary biliary cirrhosis histologically in stage II (Scheuer), a rare disease which has not been investigated extensively at the ultrastructural level. Biliary canaliculi are dilated and microvilli are scarce. Large granular formations are observed in the perisinusoidal cytoplasm. The plasma membrane between adjacent hepatocytes appears convoluted. The ultrastructural alterations of the biliary canaliculi which we observed have been described in the literature in cholestatic patients and ascribed to cholestasis. Our patients, however, has never suffered episodes of jaundice or itching and has no histological signs indicating cholestasis. We suggest that these are precocious alterations which precede the appearance of clinical and histological signs of cholestasis. It is necessary to study other cases in order to evaluate the significance of the large granular formations and the changes observed in the plasma membrane.

Adult↗
PubMed1983

Renal oncocytoma: report of two cases.

The clinico-radiologic, gross, microscopic and ultrastructural findings in 2 cases of renal oncocytoma are reported. The diagnosis of renal oncocytoma has important clinical and prognostic implications, since the neoplasia is usually benign despite its often large size. The differential diagnosis with other renal neoplasms, in particular renal cell carcinoma, is discussed. The problem of the pre-operatory diagnosis of renal oncocytoma is explored on the basis of clinico-radiologic findings and/or histologic examination of pre- or intraoperatory biopsy. In view of the tumor's benign nature, this diagnosis implies tumorectomy, but its close resemblance to renal cell carcinoma at present counsels nephrectomy. A final diagnosis of oncocytoma may be formulated only after histologic examination of several specimens and ultrastructural confirmation.

Adenoma↗
PubMed1983

Pathological anatomy of the heart in noncardiogenic shock.

The main study methods used in situations of cardiogenic shock were applied to the hearts of patients who died of noncardiogenic shock, namely, the macroscopic nitro-BT test and histological examination for waves, contraction bands and coagulation necrosis. The hearts studied were obtained at autopsy from 20 patients who had died of hemorrhage due to the rupture of esophageal varices, from 18 patients who had died of massive pulmonary embolism and 15 patients who had died of noncardiogenic shock of different origin as well as 20 Wistar albino rats subjected to hemorrhagic shock. It was seen that all the forms of shock that were examined led to severe ischemic myocardial damage, as demonstrated by a positive nitro-BT test.

Adult↗
PubMed1982

[Ultrastructural changes in hepatocytes of mice treated with morphine].

In a study of the ultrastructure of hepatocytes in mice treated with morphine a statistically significant increase in the volume density and surface density of smooth endoplasmic reticulum (SER) was observed. Morphometric measurements using the method described by Weibel (2,3) were employed to calculate volume density of smooth and rough endoplasmic reticulum mitochondria, and surface density of rough and smooth endoplasmic reticulum membranes and of the mitochondrial envelope and cristae. Statistical analysis using the t test of Student was carried out for all parameters. Both surface density and volume density of SER in mice treated with morphine increased significantly when compared to mice of control group (P less than 0.05 for surface density of smooth endoplasmic reticulum and P less than 0.01 for volume density of smooth endoplasmic reticulum). These ultrastructural changes after administration of morphine and related opiates are not accompanied by an increase of drug metabolizing enzymes and the huge tolerance observed in mice can be a phenomenon of adaptation at the receptor site (4).

Animals↗
PubMed1982

[Ultrastructural changes in hepatocytes of mice treated with heroin].

In a study of the ultrastructure of a hepatocytes in mice treated with heroin a statistically significant increase in the volume density and surface density of smooth endoplasmic reticulum (SER) was observed. Morphometric measurements using the method described by Weibel (2,3) were employed to calculate volume density of smooth and rough endoplasmic reticulum and mitochondria, and surface density of rough and smooth endoplasmic reticulum membranes and of the mitochondrial envelope and cristae. Statistical analysis using the t test of Student was carried out for all parameters. Both surface density and volume density of SER in mice treated with heroin increased significantly when compared to mice of the control group. An increase in volume density of SER is generally believed to be correlated to an increase in drug metabolizing enzymes localized in or on smooth endoplasmic reticulum membranes. We have demonstrated a statistically significant increase in SER in mice treated with heroin which is not accompanied by an increase in drug metabolizing enzymes (7). We feel that further investigation of these anomalous cases is necessary in order to clarify the role of the SER membranes and their function in the metabolism of drugs.

Animals↗