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Biomedical subjects

S Alberti

Publications and source records attributed to S Alberti.

82 records · Page 5Linked to original sources
PubMed1981

Lack of association between BK virus and ependymomas, malignant tumors of pancreatic islets, osteosarcomas and other human tumors.

BK virus (BKV) DNA sequences were not detected in 142 human tumors analyzed by DNA-DNA reassociation kinetics and blot hybridization. The investigation was focused mainly on those rare types of human tumors (ependymomas, choroid plexus papillomas, tumors of pancreatic islets and osteosarcomas) that are induced with highest frequency by BKV in experimental animals. In addition, other tumors of the urinary apparatus and of the central nervous system were analyzed. BKV tumor (T) antigen was not detected in neoplastic tissues, and BKV T antibodies were not found in sera and cerebrospinal fluids from patients with neoplasms. Sequences homologous to BKV DNA were found in normal tissue from a kidney carrying a carcinoma. The neoplastic tissue from the same organ, however, had no sequences homologous to BKV DNA. Such DNA does not belong to BKV but probably to another papovavirus related to BKV.

Antibodies, Viral↗
PubMed1981

Morphological characterization of a cell population responsible for natural killer activity.

Large granular lymphocytes (LGL) were observed in the peripheral blood, spleen, lung and, to a lesser extent, bone marrow and lymph nodes, but not in the thymus of C3H/HeN mice 8 weeks old. The organ distribution of natural-killer (NK) cytotoxicity closely followed that of LGL. Nude mice had higher LGL percentages and NK activity than normal mice. In addition, the age distribution of LGL from the peripheral blood followed that of NK activity. Employing discontinuous Percoll density gradients the percentage of LGL and the NK cytotoxicity of the low density fractions could be enriched in comparison with the original populations of lymphocytes from peripheral blood and spleen, but not from thymus. These results suggest that, as recently shown for humans and rats, in mice too LGL are associated with NK activity.

Animals↗
PubMedDate not supplied

Effect of zinc ions on apoptosis in PBMCs from healthy aged subjects.

Immunosenescence features, such as thymic involution, alteration of T-cell repertoire, autoimmunity and accumulation of memory/effector T cells, may be the result, at least in part, of a zinc deficiency, which is often observed during ageing. Zinc, as essential trace element, affects the immune system function and it is an important regulator of apoptosis of immune cells. In this study we addressed the question whether zinc supplementation in vitro at physiological doses can affect spontaneous and oxidative stress-induced apoptosis in peripheral blood mononuclear cells from subjects of three different age groups: young (mean age 28 years), old (mean age 72 years) and nonagenarians. We studied different parameters related to apoptosis (phosphatydilserine exposure, mitochondrial membrane potential, caspase 3 cleavage) and we found that zinc, while decreasing spontaneous apoptosis, can increase oxidative stress-induced apoptosis in an age-related fashion, being this effect more evident in nonagenarians than in old or young subjects. In particular, zinc can increase late apoptosis/necrosis, a phenomenon that could trigger unnecessary inflammation in vivo. We surmise that these age-associated alterations in susceptibility to apoptosis may be due to a different effect of zinc on T cell subsets, that are altered in very old people, and finally that the zinc deficiency, which is often observed in aged subjects, could be a compensatory mechanism to counteract the inflammatory status of the elderly.

Adult↗
PubMedDate not supplied

Signaling protein networks as targets of new antineoplastic drugs.

In-depth analysis of molecular regulatory networks in cancer holds the promise of improved knowledge of the pathophysiology of tumor cells so that it will become possible to design a detailed molecular tumor taxonomy. This knowledge will also offer new opportunities for the identification and validation of key molecular tumor targets to be exploited for novel therapeutic approaches. Some signaling proteins have already been identified as such, e.g. c-Myc, Cyclin D1, Bcl-XL, kinases and some nuclear receptors. This has led to the successful development of a few function-modulatory drugs (Glivec, SERM, Iressa), providing proof-of-principle of the validity of this approach. Further developments are likely to derive from "-omic" approaches, aimed at the understanding of signaling networks and of the mechanism of action of newfound lead molecules. High-throughput screening of small drug-like molecules from combinatorial chemical libraries or from microbial extracts will identify novel, "intelligent" drug candidates. An additional medicinal chemistry strategy (via 40-50 unit rosary-bead chains) has the potential to be much more effective than small molecules in interfering with protein-protein interactions. This may lead to considerably higher selectivity and effectiveness compared with historical approaches in drug discovery.

Antineoplastic Agents↗
PubMedDate not supplied

Prognostic value of mutations in TP53 and RAS genes in breast cancer.

The identification of molecular indicators of higher risk for specific subgroups of cancer patients may allow to develop more aggressive therapeutic strategies aimed at cases with the highest likelihood of response. This would avoid unnecessary toxicity to patients and alleviate the burden of cancer care for healthcare systems. Activated oncogenes and mutated tumor suppressor genes are causal determinants of the appearance and progression of tumors in man. They therefore represent potential indicators of prognosis and/or response to therapy. However, even in cases of well-studied oncogenes and tumor suppressor genes such as TP53 and RAS, their attributed prognostic and predictive value is often based on studies of insufficient statistical power that often lead to conflicting conclusions. Findings in favor or against the use of TP53 and RAS as prognostic and predictive indicators in breast cancer are reviewed and discussed here.

Animals↗