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Biomedical subjects

C Santangelo

Publications and source records attributed to C Santangelo.

13 recordsLinked to original sources
PubMed1999

Expression of p53 and retinoblastoma gene in high-grade nodal peripheral T-cell lymphomas: immunohistochemical and molecular findings suggesting different pathogenetic pathways and possible clinical implications.

The expression of p53 and the retinoblastoma gene has been investigated by immunohistochemical and molecular analysis in 45 cases of nodal peripheral T-cell lymphoma with high-grade histology. Most cases (73.3 per cent) were primary nodal lymphomas without any extra-nodal site involvement. Most of them (75.6 per cent) were histologically classified as pleomorphic, small, medium, and large cell type. Immunohistochemistry detected p53 in nine cases (20 per cent). In each of these cases, the polymerase chain reaction (PCR)/heteroduplex analysis did not show the presence of mutations, this finding being consistent with an alteration of the p53 functional pathway, in the presence of a wild-type protein. The retinoblastoma gene product was detected by immunohistochemistry in 35 cases (77.8 per cent) and not detected in ten cases (22.2 per cent). In the latter cases, the reverse transcription (RT)-PCR analysis showed the presence of a specific retinoblastoma gene transcript in six cases and was negative in the remaining four cases. The immunohistochemical and molecular findings seem to be consistent with abnormalities of retinoblastoma gene expression at either the transcriptional or the post-transcriptional level. Since all nine p53-positive cases by immunohistochemical analysis were also retinoblastoma gene product-positive, and all ten retinoblastoma gene product-negative cases were also p53-negative, two different and mutually exclusive pathways of possible pathogenetic significance may be suggested, the former involving abnormalities of the functional pathway of p53 in the absence of mutations and the latter abnormalities of retinoblastoma gene expression at the transcriptional and/or post-transcriptional level. Finally, the clinico-pathological correlations showed that p53 immunohistochemical expression is significantly associated with a poorer response to intensive chemotherapy.

Adolescent↗
PubMed1999

Nitric oxide synthases in normal and benign hyperplastic human prostate: immunohistochemistry and molecular biology.

The expression of nitric oxide synthase (NOS) isoforms has been investigated in normal (three subjects) and benign hyperplastic prostate (ten patients) by immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR). The inducible NOS (iNOS or NOS-2) is not detected in normal prostate, while it is expressed in the prostate of all benign prostatic hyperplasia (BPH) patients, even in the absence of prostatitis or systemic signs of an inflammatory condition. This suggests that sex hormones may be involved in iNOS induction and that there may be a role for NO in the pathogenesis of BPH. Constitutive NOSs (nNOS and eNOS) are expressed in both normal and hyperplastic prostate and are co-expressed in epithelial cells. eNOS, however, is present mainly in the basal layer cells; nNOS seems abundantly expressed in the more superficial cells of the affected prostate. This indicates that the switching between the two constitutive isoforms may be part of the usual process of cell differentiation from the basal to the secretory layer of the epithelium.

Aged↗
PubMed1994

"Normal" control subjects are hard to find: a model for centralized recruitment.

A central program for recruiting "normal" control subjects is examined by considering the yield of subjects who meet criteria for "healthy" as defined by their personal and family histories of mental disorders. Of the 267 applicants, 30.3% have no lifetime diagnoses, 41.2% are currently healthy with a history of mental illness, and 27.7% are currently mentally ill. Only 16.1% met Research Diagnostic Criteria for "never mentally ill" and reported no family history of mental disorders. Benefits of a central recruitment program for studies of mental disorders include increased information on a large subject pool and decreased volunteer bias.

Adult↗
PubMed1990

Plasmid resistance to ampicillin in Salmonella typhi.

A Salmonella typhi strain resistant to ampicillin, streptomycin and sulfonamides was isolated in Catania in 1988. It has been shown that these resistances were encoded by an auto-transferable R-plasmid, of molecular weight 70 Md, belonging to the incompatibility group B.

Ampicillin Resistance↗
PubMed1981

[Multicenter study on the distribution of Streptococcus pneumoniae strains in Italy].

Pneumococcal serotyping by quellung reaction has been performed in five Italian areas on 267 strains, isolated from throat swab, sputum, blood, liquor, etc. 37 serotypes have been identified. The most frequent types resulted 19, 6, 3, 20, 9, 4 (in 50% of total samples), with no difference from those detected in other European countries. The proportion of type 19 was the highest among all age group, in four out of five different areas and in bacteremic pneumonia and meningitis. 36 strains were isolated from infection sites among which type 19 resulted more frequent than in isolates from throat swab and sputum (27.7% versus 16.1%). Pneumococcal serotyping should be routinely done in the light of forthcoming use of polysaccharide vaccine.

Adult↗
PubMedDate not supplied

Effects of prolonged exposure to pancreatic glucagon on the function, antigenicity and survival of isolated human islets.

BACKGROUND: Certain clinical conditions are associated with inappropriately high levels of circulating glucagon. To date, little information is available about the direct effects of prolonged exposure of human islet cells to pancreatic glucagon. In the present study we evaluated the function, antigenicity and survival of human islets exposed for 24 h to human pancreatic glucagon. METHODS: We prepared human islets of Langerhans by collagenase digestion and density-gradient purification, incubated them for 24 h with 44 or 430 pmol/l pancreatic glucagon at physiological (5.5 mmol/l) glucose level, and evaluated their insulin release function, which was then compared with that obtained from islets kept at high (11.1 mmol/l) glucose concentration. In addition, aliquots of the islets were evaluated to assess their chemotactic properties towards human monocyte-macrophage cells, and their potency to induce cytokine release from human lymphocytes. Finally, survival of the islet cells cultured under varying conditions was evaluated, and an assessment was performed of mRNA expression of Bcl-2 and Bax proteins. RESULTS: The insulin secretion results demonstrated that, compared to the control islets, the islets previously exposed to either 44 or 430 pmol/l glucagon exhibited changes in insulin release in response to glucose, consisting of augmented secretion at low glucose challenge, and no further significant increase at high glucose stimulation, similar to the effects observed with islets pre-cultured with high glucose. These effects were reversible, as documented by the recovery of normal islet sensitivity to glucose after an additional 24-h culture in medium lacking glucagon. Compared to control islets, the culture medium from islets pre-cultured with high glucagon or high glucose showed an increased chemotactic potency towards human monocyte-macrophage cells. In addition, human lymphocytes released a greater amount of tumour necrosis factor alpha when co-cultured with the islets pre-exposed to high glucagon or high glucose, whereas no significant difference was observed (in comparison with control islets) as regards the release of gamma-interferon, interleukin-2 and interleukin-10. The TUNEL technique and RT-PCR showed, respectively, no major difference in cell survival and expression of mRNA encoding for Bcl-2 and Bax protein between control islets and islets kept for 24 h in the presence of high glucagon or high glucose. CONCLUSIONS: Our results show that in vitro exposure of human islets to pancreatic glucagon for 24 h causes changes in the function and antigenicity of isolated human islets that are similar to the changes observed after pre-culture with increased glucose levels. Under our experimental conditions, these changes were not accompanied by any evidence of cytotoxicity.

Cell Survival↗