Biomedical subjects
Publications and source records attributed to S Rizzo.
The population exposure to those living on the island of Pantelleria, Italy, was estimated by measuring the natural gamma background. Gamma spectra of natural rocks and measurements of absorbed dose in air were taken. A correlation was found between the mean gamma exposure rate and the mean values of natural radionuclide concentrations in the investigated rocks.
Recirculation and homing properties of normal lymphocytes are controlled by interactions with high endothelial venules (HEVs), specialized vessels which mediate the extravasation into lymphoid tissues. The present study was aimed at elucidating whether lymphoma-derived leukemic cell spreading and peripheral lymph node invasion ability are mediated by the recognition mechanisms which physiologically regulate normal lymphocyte trafficking. For this purpose, we tested the HEV-binding ability and the expression of the lymphocyte homing receptor (LHR) for peripheral lymph nodes as well as Pgp-1/CD44, LFA-1 and ICAM-1 adhesion molecules by the highly leukemic cell line NQ22 in comparison with a series of non-leukemic murine T-lymphoma cell lines. Our results indicate that the hematogenous spreading as well as peripheral node invasion of lymphoma-derived leukemic cells may occur independently of LHR expression. In addition, our findings seem to rule out that gross quantitative modifications in LFA-1 or ICAM-1 antigen expression are associated with differential dissemination abilities of transformed lymphoid cells.
Proto-oncogene restriction fragment length polymorphisms (RFLPs) were investigated in a group of 23 patients with squamous cell carcinomas of the larynx. The frequency of the rare 5 kb c-mos allele was significantly higher than that observed in control groups of patients with colorectal neoplasms or lymphoproliferative disorders. In addition, the 2 patients heterozygous at the c-mos locus (TC-8 and TC-10) were the only 2 of our series of develop multiple malignancies. Also, the 10 kb L-myc allele was remarkably more represented in patients with laryngeal carcinoma when compared to controls. These findings suggest that c-mos and L-myc RFLPs might be helpful in identifying those individuals who are at a higher risk of developing laryngeal carcinomas. Single allele amplification of L-myc, c-myb and c-mos proto-oncogenes, with no concomitant mRNA hyperexpression, were observed in 3 cases. The results obtained seem to rule out a direct pathogenetic role of these proto-oncogenes and suggest that the amplification of other closely linked genes, located on chromosomes 1, 6 and 8, respectively, may be causally associated with the development of these tumors. No allelic deletions at the c-myb locus were observed, whereas a loss of a c-Ha-ras-1 allele was demonstrated in one of the 11 heterozygous patients. Thus, the analysis of polymorphic proto-oncogenes in laryngeal carcinomas allowed us to identify a group of genetic abnormalities (chromosomes 1, 6 and 8 gene amplifications and c-Ha-ras-1 deletions) which may be involved in the development or progression of these tumors.
Head and neck injuries due to sports and games represent 22.7% of all injuries admitted to the E.N.T. Department of the University of Perugia between 1980 and 1988. Epidemiological and causative factors of these injuries are examined by the authors, together with their treatment: the majority of accidents occurred during soccer games as a consequence of collisions between players. In these cases the most frequently recorded lesion was a nasal fracture. Other sporting activities were responsible for more serious injuries to the maxillo-facial bony, cartilaginous and soft tissue structures. Good results were achieved both on the anatomical and functional planes, except for a few cases of facial disruption and multiple mandibular fractures. The authors stress the importance of preventive measures, consisting of periodical medical check-ups, an adequate level of umpiring and the wearing of protective equipment, such as helmets and masks.
A prospective study was carried out between 1987 and 1989 at the Pneumological Department of the IRCCS-Policlinico S. Matteo in Pavia (Italy) to evaluate the incidence of postoperative pulmonary complications in smokers and non-smokers undergoing thoracic surgery for various diseases. Non-smokers were defined as those who had never smoked tobacco, while ex-smokers who had given up for over years were included in the "low consumption" group (less than 10 cigarettes/day). Out of a total of 55 cases, 75% were smokers. Complications developed in 20/55 cases (36.4%), whereas they were observed in 60% of the smokers' group. Major atelectasis developed in 8/20 (40%): 5 smokers and 3 non-smokers. Pulmonary complications were significantly higher among heavy smokers (greater than 10 cigarettes/day) than among non-smokers (p less than 0.001). The incidence of pulmonary complications in this study was thought to be satisfactory, although it could probably be further improved, given that daily postoperative chest X-rays and physical and/or pharmacological pre- and postoperative prophylaxis--in addition to continuous clinical monitoring--were performed. This strategy enabled complications to be detected early and controlled.
Understanding of the leukemic evolution of human non-Hodgkin's lymphomas is hindered by the lack of appropriate animal models. For this purpose, a highly leukemic cell line NQ22, derived from a MCF 247 murine leukemia virus (MuLV)-induced murine T-cell lymphoma, was established, and its preliminary characterization is described. The NQ22 cell line is easily transplantable subcutaneously (s.c.) into syngeneic AKR mice exhibiting early peripheral blood invasion and widespread dissemination with a leukemic pattern of infiltration. Such peculiar in vivo behavior is a stable phenotypic feature, probably determined genetically. Biological and differentiation characteristics of the NQ22 cell line were analyzed and compared to those of other non-leukemic T-lymphoma lines. In addition, no evidence of possible involvement of plasminogen activator (PA) enzymes and of their inhibitors (PAI) in the spreading ability of NQ22 cells was observed.
An experimental study was conducted to evaluate the effect of different fractions (bile and pancreaticoduodenal secretions) on the gastric stump and esophageal mucosa. Twenty pigs underwent partial gastrectomy (two-third distal) and cardiomyotomy in order to induce free gastroesophageal reflux. Then, reconstruction of the alimentary tract was performed to assess the effects of different types of alkaline reflux. A combined (biliary and pancreaticoduodenal) reflux, an isolated biliary reflux, and an isolated pancreaticoduodenal reflux were induced, respectively, in three different groups of five pigs each. In a control group a Roux-en-Y gastrojejunostomy was performed. Nine months later, the animals were sacrificed, the esophagus and the gastric stump were removed for histologic examination. The results show that the most severe histopathological lesions are determined by combined alkaline reflux; on the other hand, separated fractions can induce only mild changes on the gastric stump and esophageal mucosa.
Proto-oncogene transcriptional activation was analyzed in a group of MCF 247 MuLv-induced T-cell lymphomas to identify transformation-specific gene activations and determine whether the proviral insertion near a myc gene could promote a peculiar mechanism of transformation through a differential proto-oncogene expression pattern. Of the six lymphomas analyzed, three showed the MCF 247 provirus integrated within the N-myc locus, one carried the provirus integrated near c-myc, whereas for the remaining two, no evidence of proviral integrations in any of the known myc loci was obtained. Independently of the integrative events, the pattern of proto-oncogene expression was almost identical in all six lymphomas. These findings seem to rule out the existence of a peculiar pathway of transformation associated with the proviral insertion near a myc locus. Moreover, the transcription pattern observed was qualitatively identical to that displayed by normal thymocytes; only quantitative differences in c- or N-myc, c-myb and Ha-ras were observed. These results suggest that the T-cell proto-oncogene activation program is not qualitatively affected by the transforming event(s).
Seven cases of colorectal adenocarcinomas were investigated for the presence of oestrogen receptors and progesterone receptors. The tumours specifically bound oestradiol. This binding almost exclusively resulted from the presence of high numbers of type II oestrogen binding sites. Oestrogen receptors were absent or present at very low concentrations. Immunohistochemical investigation of nuclear oestrogen receptors gave negative results. This indicates that antioestrogen receptor antibodies recognise oestrogen receptors but not type II oestrogen binding sites. The presence of specific type II oestrogen binding sites and progesterone binding offers further evidence for a potential role for these steroids and their receptors in colorectal carcinoma.
The clinical and histological aspects of gingival hypertrophy due to cyclosporine-A in 10 heart-transplanted patients are studied. The behaviour to avoid or to limit gingival overgrowth is suggested.
Problems binded with dental treatment of handicapped patients and analysis of data obtained in ten years of experiences have been pointed out. The preventive role of oral hygiene, the role of narcosis in treatments and structural lacks come out from this analysis.
The prognostic role of some clinical and pathologic variables in patients with carcinoma of the stomach was evaluated. While for some of these (invasion of the gastric wall, nodal status) the prognostic value is widely accepted, for the others (age, sex, size and site of tumors, histologic type, surgical procedure) the prognostic significance has not been fully defined. Using univariate analysis, the best predictors of survival after curative resection were nodal status, histologic type and serosal involvement. As related to the last three, using a multivariate analysis, the serosal involvement was the most important prognostic variable.
N-myc proto-oncogene rearrangement was found in three out of six AKR murine T-cell lymphomas induced by the highly oncogenic MCF 247 MuLV. Molecular analyses showed that structural modification of the proto-oncogene in all three lymphomas was in the consequence of MCF 247 proviral integration within the gene III exon. All integrated proviruses have the same transcriptional orientation as the N-myc gene. As a consequence of proviral insertion, the N-myc gene becomes transcriptionally active, producing an abnormal mRNA. These findings suggest a possible causative role of such an integrative event in murine T-cell lymphomagenesis.
Instrumental neutron activation analysis has been used to determine quantitatively the content of certain trace elements forming the healthy tooth in a sample of 31 teeth extracted for orthodontic or periodontal reasons.
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Familial sarcoidosis is a quite unusual occurrence. We describe two affected sisters, in which the clinical features of the disease were fairly similar. Interestingly, the two patients and two unaffected siblings share an HLA haplotype [A10 (26); CW7; B16 (38); DRW6; DQW1] rare in Caucasians.