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Biomedical subjects

G Santini

Publications and source records attributed to G Santini.

At least 199 records · Page 11Linked to original sources
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In situ and laboratory assessment of heart rate in a Mediterranean limpet using a noninvasive technique.

Heart rate of the Mediterranean limpet Patella caerulea L. was investigated on the natural shore and in the laboratory by using a technique based on infrared phototransducers. Field recording occurred in the Gulf of Trieste (northern Adriatic) during March and June 1997. A consistent dependence of heart rate on temperature was observed in limpets both when submerged and when exposed to air in the two periods, but thermal acclimation was evident. During spontaneous activity at high tide, heart rate increased 1.5-1.7 times the values observed during resting in water at corresponding temperatures. The dependence of heart rate on temperature (10 degrees, 16 degrees, and 22 degrees C) and size (wet weight <1.25 and >1.30 g) in submerged limpets from different populations (northern Adriatic and Tyrrhenian) was tested in the laboratory by adopting a factorial design. The results showed a marked effect of temperature, body weight, and their interaction, independent from the site of origin. Smaller limpets showed a linear increase of heart rate in the whole range of temperature tests, while in the larger ones the increase between 10 degrees and 16 degrees C was greater than between 16 degrees and 22 degrees C. Heart rate decreased with increasing body size at control (16 degrees C) and high (22 degrees C) temperature, while at lower temperature (10 degrees C) no effect of body size was evident. When removed from their home scar, limpets increased heart rate to about 1.5 times the reference value. Finally, correlation of oxygen consumption with heart rate of submerged limpets maintained at a different temperature (10 degrees -22 degrees C) was statistically significant.

Animals↗
PubMedDate not supplied

Infections, atherosclerosis, and coronary heart disease.

There is growing evidence that the immune response is involved in atherosclerosis. Studies done over the past several years have shown an association between markers of inflammation and coronary atherosclerosis with an exacerbation of the inflammatory process during acute myocardial ischemia. Overall, these data have greatly renewed interest in the infectious theory of atherosclerosis and coronary heart disease. Search of bibliographic databases (from January 1991 through December 1999) and manual scanning of both peer-reviewed publications and other documents were used to identify pertinent literature. Infections and coronary heart disease were indexed as key words. A large number of studies have reported an association of human coronary heart disease and certain persistent bacterial and viral infections. The association between Chlamydia pneumoniae and coronary heart disease appears quite significant although the sequence of infection and disease is uncertain. The association between Helicobacter pylori and coronary heart disease may be accounted for by residual confounding from classic risk factors. Preliminary findings indicate that this association could be due to a higher prevalence of more virulent Helicobacter strains. Infection with Cytomegalovirus appears to be associated with a greater risk of restenosis after angioplasty rather than primary atherosclerosis. Early trials of appropriate antibiotic therapy in subjects with recent acute myocardial infarction have been encouraging. A causal relationship between infections and coronary heart disease is still elusive. Improved studies involving prospective collection of data are required to demonstrate such an association with potential implications for public health worldwide.

Arteriosclerosis↗
PubMedDate not supplied

CD8 lymphocytes during Epstein Barr virus (EBV) infection: A CD29 positive population is expanded in acute infectious mononucleosis.

The expression of phenotypic markers on CD4 and CD8 lymphocytes during the acute and convalescent phases of Epstein Barr virus (EBV) induced infectious mononucleosis was examined by two colour flow cytometry. Activated CD8 cells constitute the major population increased during acute infectious mononucleosis; in this phase we observed a preferential expansion of the CD8 CD29+ compared to the CD8 CD45RA+ cells. Serum soluble CD8 levels were also raised during the acute phase and a correlation with CD8 CD38+ and CD8 CD29+ cell numbers was found. The convalescent phase of infectious mononucleosis was characterized by a progressive return of CD8 subset and of soluble CD8 to baseline normal values. These results demonstrate that acute EBV infection induces the expansion of a CD8 subset with peculiar surface antigenic profile.

Acute Disease↗
PubMedDate not supplied

Relationship of the epidermal growth factor-receptor to the growth fraction (Ki-67 antibody) and the flow cytometric S-phase as cell kinetics parameters, in human mammary carcinomas.

Epidermal growth factor (EGF) has been shown to have a mitogenic effect on some breast cancer cells lines in vitro. The growth of the subclass of human breast tumors which expresses the specific receptor for EGF seems to be mediated by autocrine mechanisms rather than steroid hormones. The expression of EGF-receptor, as detected by an immunocytochemical method, was compared with the Growth Fraction (GF) by the Ki-67 monoclonal antibody and the S-phase content as tumor proliferative activity indexes, and with DNA ploidy and some pathologic features in 86 stage I-II breast carcinomas. Overall 52 out of 86 (60%) of the tumors were EGF-receptor positive. There was no correlation between the cell kinetics parameters and the EGF-receptor status, suggesting that its expression may be unrelated to the proliferative activity of the tumor in these clinical stages and that the EGF-receptor GF and S-phase may be independent variables in breast cancer. In our series 57% of tumors were DNA aneuploid and only a trend was found towards EGF-receptor positivity (P = 0.08). There was no correlation between EGF-receptor expression and grading or node-status. The overall picture is that of an independent relationship between EGF-receptor with the cell kinetics parameters and ploidy, confirming the complex and heterogeneous biology of breast carcinoma. These results suggest the possibility of better recognition of subsets of patients with diverse tumor aggressiveness, combining together EGF-receptor status, cell kinetics and ploidy, with a better stratification for treatment options.

Antibodies, Monoclonal↗
PubMedDate not supplied

Breast cancer cell kinetics: immunocytochemical determination of growth fractions by monoclonal antibody Ki-67 and correlation with flow cytometric S-phase and with some features of tumor aggressiveness.

In operable breast cancer, cell kinetics can be utilized in the prediction of the clinical outcome of patients. The discovery of monoclonal antibodies recognizing antigens related to cell proliferation has permitted the assessment of cell kinetics by rapid and practical immunocytochemical methods. It is claimed that the Ki-67 mouse monoclonal antibody recognizes an antigen expressed in proliferating cells but not present in quiescent (G0) cells. To study the relationship between Ki-67 score and DNA flow cytometric S-Phase Fraction (SPF), the latter being one of the most widely used methods to assess cell kinetics, we compared these two techniques of measurement in 122 breast carcinomas using both for each specimen. In this series 90% of tumors were Ki-67 positive, with a median value of 7.5% (range 1% to 70%). DNA flow cytometric analysis revealed that 69 tumors (57%) were aneuploid, whereas 53 were diploid. The median SPF value was 8% for diploid and 15% for aneuploid tumors (range 2% to 32%). Ki-67 scores were significantly higher in the DNA aneuploid compared to the diploid carcinomas (p = 0.015). Overall, a good correlation was found between Ki-67 and SPF values both in diploid (r = 0.60) and in aneuploid (r = 0.38) tumors. High Ki-67 scores were associated with the presence of axillary lymph node metastases (p = 0.0023) and poor histologic differentiation (p = 0.0028). Menopausal status, tumor size and peritumoral vessel invasion were unrelated to the Ki-67 score. Over-expression of the Epidermal Growth Factor receptor (EGF-r) and the c-erbB-2 oncogene were not correlated with Ki-67 staining. In conclusion, in this study Ki-67 immunostaining correlated with other indices of cell proliferation (SPF and Grade) and with some features of tumor aggressiveness (DNA aneuploidy and lymph node metastases) but seemed to be independent of some biological markers (EGR-r and c-erbB-2). Since the major objective for assessing proliferative status in Stage I-II breast carcinoma is to determine prognosis, it will have to be evaluated whether the determination of the Growth Fraction has comparable or even greater prognostic value than other cell kinetics markers.

Aneuploidy↗
PubMedDate not supplied

Mitoxantrone alone or in combination chemotherapy (VeMP) as second-line treatment in relapsed or refractory poor-prognosis non-Hodgkin's lymphoma. A report of the Non-Hodgkin's Lymphoma Co-operative Study Group (NHLCSG).

BACKGROUND AND METHODS: From October, 1986 to July 1989, 35 consecutive patients with high- and intermediate-grade non-Hodgkin's lymphoma, relapsed or refractory to first-line-anthracycline-containing regimens, were treated with mitoxantrone alone or in combination chemotherapy (VeMP: Ve = VP-16, M = Mitoxantrone, P = Prednisolone). RESULTS: In the first 15 patients, treated with Mitoxantrone alone, complete response (CR) and partial response (PR) each occurred in 4 patients, for a total response rate of 54%. In the following 20 patients, treated with the VeMP regimen, CR occurred in 10 patients (50%), PR in 1. The overall three-year survival was 27% in the first group and 40% in the second. Acute toxicity was generally mild. No patient developed cardiac symptoms or other toxicities requiring discontinuation of therapy. Myelosuppression was the most important side effect, being more remarkable for patients treated with VeMP regimen. CONCLUSION: Mitoxantrone, alone or in combination chemotherapy, appears to be a drug with significant activity in aggressive non-Hodgkin's lymphomas.

Actuarial Analysis↗