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Biomedical subjects

M Piazza

Publications and source records attributed to M Piazza.

At least 55 records · Page 3Linked to original sources
PubMed1990

Chemotherapy of invasive thymoma.

Thirty-two patients with stage III or IV invasive thymoma (14 women and 18 men; median age, 40 years) were treated at the Padua Medical Oncology Department from 1977 to 1988. All patients received the following chemotherapy in 4-day courses: 50 mg/m2 of cisplatin intravenously (IV) and 40 mg/m2 of doxorubicin IV on day 1; 0.6 mg/m2 of vincristine IV on day 3; and 700 mg/m2 of cyclophosphamide IV on day 4 (ADOC). The courses were repeated every 3 weeks, and toxic effects were tolerable. The radiologically defined overall clinical response rate (complete plus partial response) was 91% with 47% clinical complete remissions; median time to progression was 11 months (range, 0 to 96) and the median estimated (Kaplan-Meier) progression-free interval was 22 months. Five of the 15 clinical complete remissions were pathologically confirmed at thoracotomy. We believe the ADOC regimen qualifies for adjuvant and preoperative treatment of invasive thymoma due to the high complete response and overall response rates.

Adult↗
PubMed1990

Prevention of hepatitis C in partners of anti-HCV positive subjects by periodic gammaglobulin administration.

Since hepatitis C is sexually transmitted, this poses the problem of protecting the anti-HCV negative partners of anti-HCV positive subjects. Since no specific prophylaxis exists for hepatitis C, I suggest that 4 ml of normal human gammaglobulin should be given to the anti-HCV negative partners intramuscularly every two months until a vaccine against hepatitis C virus is available.

Hepatitis Antibodies↗
PubMed1990

Aetiological association of virus like particles with hepatitis C.

Isolation of virus-like particles from sera of anti-HCV positive patients and their ultrastructural characterization are reported. Particles were identified in sera of 5 out of 6 patients tested. Immunoelectron microscopy assay revealed small aggregates of viral particles. Size and morphological criteria suggest that these particles can be classified as Togaviridae.

Hepacivirus↗
PubMed1990

[Ultrastructural study of the yeast-mycelium transition in Histoplasma capsulatum. II. Changes at 34 degrees C].

The ultrastructural changes which occur during the mycelium to yeast transition in Histoplasma capsulatum induced by a temperature shift from 25 degrees C to 34 degrees C are described and compared to those observed after a temperature shift from 25 degrees C to 37 degrees C. 24 hours after the temperature shift to 34 degrees C only 8% of the cells are lysed. However, many mitochondria have lost their characteristic elongated form and have become rounded. Vesicular cristae which are no longer oriented parallel to the long axis of the mitochondria are also observed. In contrast a temperature shift from 25 degrees C to 37 degrees C induces lysis of 70% of the cells; mitochondria are rarely observed in the remaining cells. These ultrastructural changes can be correlated with the uncoupling of oxidative phosphorylation and the production of heat shock proteins.

Fungal Proteins↗
PubMed1990

[Ultrastructural study of the mycelium-yeast transition in Histoplasma capsulatum. I. Changes at 37 degrees C].

Ultrastructural changes observed during the first 24 hours of mycelium to yeast transition in the dimorphic fungus Histoplasma capsulatum are reported. During this period the plasma membrane becomes undulated and the cell wall loses its characteristic fibrous outer layer. At 8 h the ordered lamellar structure of the mitochondria is no longer apparent. 24 h after the temperature shift 70% of the cells are lysed. The remaining cells contain many cytoplasmic membrane structures; mitochondria are rarely observed. These morphological changes are probably correlated with the physiological events characteristic of mycelial to yeast transition.

Cell Wall↗
PubMed1989

Mycelium-yeast transition in Histoplasma capsulatum. Early ultrastructural changes.

The ultrastructural changes which occur during the first 24 h of mycelium to yeast transition have been studied in the dimorphic fungus Histoplasma capsulatum. A temperature shift controls mycelial to yeast transition. During the first 24 h respiratory rate, ATP and cytochrome concentration fall to very low levels. Ultrastructural observations showed that the plasma membrane became undulated and the cell wall lost its characteristic fibrous outer layer. At 8 h the ordered lamellar structure of the mitochondria was no longer apparent. 24 h after the temperature shift 70% of the cells were lysed. The remaining cells contained many cytoplasmic membrane structures; mitochondria were rarely observed. These changes are considered to be the morphological expression of the physiological events characteristic of stage one in mycelial to yeast transition.

Histoplasma↗
PubMed1989

Immunogenicity of a DNA-recombinant hepatitis B vaccine (Engerix B) given at 3, 5 and 11 months of age with a new schedule suitable for mass vaccination programmes.

Following the demonstration of a fully satisfactory immunogenic activity of a hepatitis B vaccination protocol consisting of three doses given at the 3rd and 5th months of age with a booster at 11, it was possible to administer this vaccine at the same times as the vaccinations for diphtheria, tetanus and polio which are mandatory in Italy at those ages. A field trial of this protocol in a hyperendemic area near Naples (prevalence of HBsAg about 14%) started on January 1987. The French vaccine, Hevac B, Pasteur, was used. At this time compliance is 99%, and fully satisfactory results both in terms of seroconversion rate (96.3%) and of mean anti-HBs titre (4,352 mIU/ml) two months after the booster dose have been obtained. In this paper we demonstrate that even for a new hepatitis B vaccine prepared by a DNA-recombinant technique (Engerix B, SK & F) recently introduced in Italy, the same schedule can be used. In fact two doses of this vaccine, the first given at three months of age and the second two months later, resulted in a 100% seroconversion rate and a mean anti-HBs titre of 560 mIU/ml. Two months after the booster given at 11 months of age the mean anti-HBs titre was 12,100.

Drug Evaluation↗
PubMed1989

Prevalence of intranuclear particles in liver pathologies.

An ultrastructural study of the prevalence of electron dense 23-27 nm intranuclear particles was carried out on liver biopsies from patients with NANB chronic active hepatitis (CAH), Delta + CAH, HBsAg + CAH, nonviral liver pathologies and in one healthy volunteer. The particles were classified according to aggregation pattern and were found to be correlated with NANB CAH and Delta + CAH. No particles were observed in nonviral liver pathologies. A close antigenic relationship has been shown between the cytoplasmic alterations observed in NANB and delta hepatitis in chimpanzees. Our data indicate that there is a structural similarity between the intranuclear particles seen in both Delta and NANB hepatitis, thus reinforcing the hypothesis that the NANB and Delta agents are closely related.

Adult↗