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T Valente

Publications and source records attributed to T Valente.

At least 19 recordsLinked to original sources
PubMed2004

Zac1 is up-regulated in neural cells of the limbic system of mouse brain following seizures that provoke strong cell activation.

Zac1, a new zinc-finger protein that regulates both apoptosis and cell cycle arrest, is abundantly expressed in many proliferative/differentiation areas during brain development. In the present work, we studied Zac1 gene expression and protein in experimental seizure models following i.p. injection of pentylenetetrazole (PTZ) or kainic acid (KA). Following KA treatment, an early and intense up-regulation of Zac1 is detected in the limbic areas, such as the hippocampus, cortex and amygdaloid and hypothalamic nuclei. Pre-treatment with MK-801, an antagonist of the NMDA receptors, fully blocks the effect of KA in the hippocampus, whereas it only attenuates KA-induced Zac1 up-regulation in the other areas of the limbic system. A reduced induction is obtained with PTZ-treated animals, specifically in the entorhinal and piriform cortices as well as in amygdaloid and hypothalamic nuclei. Thus, Zac1 is highly induced in the seizure models that generate strong neuronal stimulation and/or extensive cell damage (cell death), reinforcing its putative role in the control of the cell cycle and/or apoptosis. Moreover, strong induction is observed in the granular cells of the dentate gyrus (which are resistant to neurodegeneration) and in some glial cells of the dentate gyrus and subventricular zone, suggesting that Zac1 may be implicated in the mechanisms of neural plasticity following injury.

Animals↗
PubMed2003

Pure ductal carcinoma in situ and in situ component of ductal invasive carcinoma of the breast. A preliminary morphometric study.

Nuclear pleomorphism is a fundamental feature in evaluating the aggressiveness of ductal carcinoma in situ (DCIS) of the breast. In this study, pure DCIS and the in situ component (IS-comp) of invasive duct carcinoma (IDC) are compared in order to verify if these are two different entities or the same process observed at different times during its evolution. Five cases of pure DCIS and nine of IDC with extensive in situ component were selected. They were moderately and poorly differentiated. 30 nuclei for each DCIS, and 30 nuclei for both the in situ and invasive component of each IDC were studied; thus, a total of 720 nuclei were submitted to the SAM (Shape Analytical Morphometry) analysis, which enables a numerical expression not only of dimensions (area, perimeter, diameter) but also of nuclear contour irregularities and nuclear shape distortions. Univariate statistical comparisons were carried out between the nuclei of: (1) DCIS and in situ component of invasive duct carcinoma, (2) DCIS and the invasive component of infiltrating carcinoma and (3) between the in situ and invasive component of infiltrating carcinoma. Multivariate analysis was utilized to compare nuclei of DCIS with the in situ component of IDC. The in situ features of each tumor were also evaluated with the mitotic index (MI). Nuclei of pure DCIS resulted significantly larger (p < 0.001) and with a more regular shape (p < 0.001) than those of the in situ component of IDC. No differences were observed between the nuclei of the in situ and the invasive component of infiltrating carcinomas. Multivariate statistical analysis discriminated 77% of nuclei of in situ proliferation when both G2 and G3 tumors were considered, and 80% when only G3 tumors were considered. In conclusions morphological differences exist between pure DCIS and the in situ component of IDC, which may be an expression of their biological behavior; moreover, these morphological differences seem to have a better discriminating power within the same histological grade.

Adult↗
PubMed2002

Assessment of reference values for mercury in urine: the results of an Italian polycentric study.

The results of a polycentric study to assess the reference values of urinary mercury (U-Hg) in four Italian cities are presented. A total of 383 subjects were selected on the basis of standardised criteria by a questionnaire on personal habits, lifestyle, occupational or non-occupational exposure to Hg, medical history, number and area of dental amalgams. U-Hg was determined by hydride generation atomic absorption method (HG-AAS), with a detection limit of 0.5 microg/l and by flow injection (FI) inductively coupled plasma mass spectrometry (ICP-MS), with a detection limit of 0.03 microg/l. The median value of U-Hg, determined by HG-AAS, was 0.78 microg/g creatinine (0.75 for males and 0.83 for females), with 5 degrees and 95 degrees percentiles, respectively, of 0.17 and 3.66 microg/g creatinine. When determined by FI ICP-MS, the median value was 0.79 microg/g creatinine (0.77 for males and 0.79 for females) with 5 degrees and 95 degrees percentiles of, respectively, 0.12 and 5.02 microg/g creatinine. Among the independent variables, city of origin, area of dental amalgams, fish intake and tobacco smoking significantly influenced the U-Hg levels. The U-Hg reference values from this survey are lower than those from other recent investigations, probably due to characteristics and selection of the examined individuals and to the strict control of pre-analytical and analytical factors of variability.

Adult↗
PubMed2002

Blood lead reference values: the results of an Italian polycentric study.

This paper presents the results of a polycentric study carried out in seven different areas, organized by the Italian Society of Reference Values (SIVR) for assessing reference values of lead in blood (B-Pb) at the current doses of the metal to general population. The estimated arithmetic mean for B-Pb in males was of 45.1 microg/l and 30.6 microg/l in females; the 95th centile was 100 and 60 for males and females, respectively. The main variables influencing B-Pb levels were gender, age, BMI, outside sport practice, alcohol consumption and smoking habits, while the geographic area and the urban residence did not affect the metal concentration in blood.

Adolescent↗
PubMed2002

[The Ljubljana classification of epithelial hyperplastic laryngeal lesions: a morphometric evaluation of nuclear pleomorphism].

Epithelial hyperplastic laryngeal lesions (EHLL) are associated, with a varying degree of "epithelial risk"- to develop invasive carcinoma. Several classifications have been proposed but none has received a total agreement. The 1999 Ljubljana classification distinguished four grades: simple, abnormal and atypical hyperplasia and in situ carcinoma (ISC). The first two grades are considered benign lesions; the ISC is the malignant lesion, while the atypical hyperplasia is considered a "risky lesion". This is characterized by alterations of epithelial cells towards malignancy, but not to the extent to be found in carcinoma cells. Such characteristics refer to cytomorphological (e.g., nuclear hyperchromatism, nucleoli, increased nuclear/cytoplasmic ratio) and architectural (e.g. stratification, orientation, maturation) features. In the Ljubljana scheme, nuclear pleomorphism is one of the most important features. We wanted to improve the importance of nuclear pleomorphism in the basal cells layer in different classes of EHLL using morphometrical analysis. We studied 8 cases of simple hyperplasia, 10 of abnormal hyperplasia, 10 of atypical hyperplasia and 8 of ISC using the software SAM (Shape Analytical Morphometry). The results were submitted to univariate statistical analysis. Nuclear dimensions (maximum diameter, perimeter and area) showed a progressive increase from simple to atypical hyperplasias to ISC, while abnormal hyperplasia showed the lowest values. On the contrary, analytical parameters related to nuclear contour irregularities and asymmetries showed their highest values in abnormal hyperplasia nuclei. There were no significant differences between atypical hyperplasia and ISC, while it was possible to differentiate abnormal hyperplasia from the others. In conclusion basal nuclei of atypical hyperplasia and ISC are similar so that other cytological and morphological architectural parameters are necessary to distinguish the two lesions. Abnormal hyperplasia seems to be the biological category of 'proliferative " benign laryngeal epithelium; simple hyperplasia refers to "stable" - irritative epithelium.

Biopsy↗
PubMed2002

Malignant deciduoid mesothelioma of the pleura: report of two cases with long survival.

AIMS: To present two rare cases of malignant mesotheliomas with deciduoid features arising in the pleura, both with long survival. METHODS AND RESULTS: These two cases of deciduoid mesotheliomas were observed in adult patients (one 73-year-old male and one 23-year-old female). Only the male had a history of occupational asbestos exposure, whereas the woman had a history of familial mesothelioma. A deciduoid morphology was predominant and focal areas with tubular-papillary features were noted. The tumour cells were positive for cytokeratins, HMBE-1, calretinin, EMA and mitochondrion antibodies. The follow-up data did not suggest a particularly poor prognosis; the mean survival observed was 23 months (17 and 39 months, respectively). CONCLUSIONS: This deciduoid mesothelioma histological subtype does not appear to represent an unfavourable prognostic category.

Adult↗
PubMed2002

Quantitative morphometrical investigation of basal cell layer in laryngeal premalignant lesions.

Histological diagnosis of laryngeal dysplasia is quite subjective. Since morphometry is highly reproducible, this method was applied to compare shape and size variations of the basal nuclei of the laryngeal epithelium in normal, laryngeal intraepithelium neoplasia (LIN) and invasive carcinoma to assess the reliability of light microscopic criteria used in grading dysplasia according to Friedman classification. Morphometrical analysis was carried out by Shape Analytical Morphometry (S.A.M) system. The logical architecture assumes that each irregular shape contains elements of two distinct logical domains: gross distortions that interest the contour and its local perturbations. These features were investigated separately by analytical procedures to acquire independent parameters both on the logical level and the numerical one. The nuclear area significantly increased from normal to carcinoma (p<.001). The increasing of the nuclear area was evident also in LIN I. Nuclear distortions were present in LIN II and LIN III. The highest nuclear contour irregularities were found in LIN III. Multivariate analysis showed a difficulty in discriminating various grades of dysplasia, especially between LIN I and LIN II (31% of error). In conclusion, our results indicate that nuclear pleomorphism of the basal cells layer, using a unique evaluator, is an unsatisfying criterion to distinguish moderate dysplasia.

Analysis of Variance↗
PubMed2001

Expression pattern of Zac1 mouse gene, a new zinc-finger protein that regulates apoptosis and cellular cycle arrest, in both adult brain and along development.

Using in situ hybridization, we analyzed the expression pattern of the Zac1 gene in mouse brain during the embryonic and postnatal development. Zac1 is a new gene that regulates extensive apoptosis and cell cycle arrest through unrelated pathways. At embryonic stages, strong expression was observed in brain areas with active proliferation (ventricular zone and numerous neuroepithelius) and in nervous system (neural retina and neural tube). In addition, some areas with differentiation activity were noticeably labeled such as arcuate nucleus and amygdaloid region of the brain together with other embryonic sites (hindlimb, forelimb and somites). From P0 onwards, the expression appeared in some proliferative areas, such as subventricular zone and cerebellum (external granular layer and Purkinje cells) and in some synaptic plasticity areas, such as the dorso and ventromedial hypothalamic nuclei, arcuate nucleus, ventral thalamic nucleus.

Animals↗
PubMed2001

Peers, schools, and adolescent cigarette smoking.

PURPOSE: To investigate the effects of popularity, best friend smoking, and cigarette smoking within the peer networks on current smoking of seventh- through 12th-grade students. These factors were examined for adolescents attending schools with varying rates of student cigarette smoking. METHODS: This study used data from the saturated school sample of National Longitudinal Study of Adolescent Health (Add Health), a nationally representative school-based sample. The sample for the present study was 2525 adolescents in Grades 7-12 who completed an in-school questionnaire and an in-home interview. Information from the in-school questionnaire was used to construct measures of school smoking prevalence and popularity. Using peer nominations from the in-home interview, best friend smoking, and peer network smoking exposure were constructed using the peers' own reports of their cigarette smoking. Multiple regression techniques were used to estimate the risk of current cigarette smoking as a function of popularity, best friend smoking, peer network smoking, and school smoking prevalence, and all first-order interactions between measures of peer and school smoking prevalence. RESULTS: Adjusting for age, gender, race/ethnicity, parent education, school, and availability of cigarettes in the home, the risk of current smoking was significantly associated with peer networks in which at least half of the members smoked [odds ratio (OR) = 1.91], one or two best friends smoked (OR = 2.00), and with increasing rates of school smoking prevalence (OR = 1.73). In addition, there was a significant interaction of popularity and school smoking prevalence such that risk of current smoking was somewhat greater among popular students in schools with high smoking prevalence than among popular students in schools with low smoking prevalence. CONCLUSION: Findings suggest that school environments are important contexts for understanding peer group influences on adolescent cigarette smoking.

Adolescent↗
PubMed2001

Morphometric discrimination between syndromic (Gorlin) and nonsyndromic keratocysts.

OBJECTIVE: To search for morphologic nuclear features in the epithelial lining of odontogenic keratocysts to differentiate simple from Gorlin syndrome cysts. STUDY DESIGN: Five cases of syndrome-associated keratocysts and five of simple ones were studied. Thirty nuclei from the epithelial basal layer for each case were analyzed by the shape analytical morphometry (SAM) software system to quantitatively evaluate nuclear dimensions (area, perimeter, diameter), contour irregularities and nuclear shape asymmetries. Results were subjected to Student's t test and cluster analysis. RESULTS: Values of nuclear dimensions were very close in both groups of keratocysts, without any significant statistical differences. The variables related to nuclear profile irregularities, as well as those describing nuclear asymmetry, showed significantly higher values (P < .001) in syndromic cysts. Cluster analysis produced two different clusters by using variables related to nuclear contour irregularities. CONCLUSION: Preliminary results indicate the existence of nuclear morphologic differences between simple and syndromic cysts.

Adult↗
PubMed2000

Syringe exchange not associated with social network formation: results from Baltimore.

OBJECTIVE: To examine possible formation of new social contacts at the Baltimore Syringe Exchange Program (SEP). DESIGN: Systematic sub-sample of new SEP participants recruited into evaluation cohort for biannual interviews. This analysis used 6-month interview data. METHODS: Participants were interviewed for behavioral and network characteristics, and number of new social contacts formed at the SEP. Variables were cross-tabulated using chi2 statistics. RESULTS: Of 413 participants interviewed, 32 (8%) said they had made at least one social contact at the SEP. These 32 individuals were more likely to have engaged in commercial sex (16 versus 3%, P = 0.005) and, among active injectors, were more likely to have used syringes obtained from other drug users (22 versus 8%, P = 0.026). CONCLUSIONS: Findings argue against the formation of new social networks (and therefore new disease transmission networks) in the context of syringe exchange participation.

Adult↗
PubMed1997

Massive enterolithiasis associated with ileal dysgenesis.

A 20-year-old man with massive ileal enterolithiasis was investigated with plain radiography, ultrasound, computed tomography, barium follow through and double contrast barium enema. Ileocecal valve agenesis was found at surgery. The enteroliths were located in the distal ileum, which communicated with the large intestine via an ileotransverse fistula.

Adult↗
PubMed1996

[The echographic anatomy of the larynx and the perilaryngeal structures].

The normal laryngeal and perilaryngeal structures (neither nodal nor vascular) of 120 healthy and informed volunteers and of 46 patients with extralaryngeal neck conditions were studied with ultrasonography (US). The study was performed with a high-frequency linear probe on the transverse and sagittal planes; the patients were examined supine, with neck hyperextension, during quiet breathing, in inspiratory and expiratory breath-holding, during Valsalva maneuver or phonation. Axial scans clearly depict, in cranio-caudal direction, the base of the tongue, the hyoid and adjacent muscular structures. At the laryngeal vestibule epiglottis is always clearly demonstrated as a thin hypoechoic curvilinear rim and the pre-epiglottic space as a fat-filled and markedly echogenic structure. Pyriform sinuses are more difficult to study with US and should therefore be always distended by air during Valsalva because no suitable US contrast agent is available for their exploration yet. The ossification of thyroid laminae prevents or hinders the exploration of endolaryngeal structures because of consequent posterior acoustic shadow. In case of partial ossification or cartilaginous thyroid laminae, paraglottic spaces are easily demonstrated with US, as well as the false cords and, partially, arytenoids and posterior laryngeal wall muscles. The muscular structure of the true cords, their mobility in the M-mode and, in half of the cases, the thin vocal plicae joining anteriorly in the anterior commissure, are easily depicted with US. To conclude, US permits to demonstrate normal laryngeal anatomy by a quick and harmless examination in several breathing and phonation phases, which is an essential premise to the correct interpretation of abnormal US findings.

Adolescent↗
PubMed1994

[Cholangiocarcinoma of the main biliary tract. Judging its resectability by imaging procedures].

Eighteen patients with main biliary tract cholangiocarcinomas and no spread to the gallbladder and to the papilla of Vater underwent a combined US, ERCP/PTC and CT study. Angiography was performed on a selected group of 12 patients. We divided the infiltrating, polypoid or stenosing lesions in three groups: upper portion tumors, involving the confluence and the common hepatic duct (8 patients); middle portion tumors, originating from the common bile duct between the confluence of the cystic duct and the upper duodenal profile (6 patients); and finally lower third tumors, originating from the common bile duct between the upper rim of the duodenum and the papilla of Vater (4 patients). According to ERCP and/or PTC, US, CT and angiographic findings, only 9 of 18 cholangiocarcinomas were judged as resectable. The authors stress the need to optimize the use of imaging methods: US can locate the biliary obstruction; ERCP and/or PTC can show the tumor and its spread out of the duct, and finally angiography can exclude or confirm the vascular involvement of the hepatic hilum.

Aged↗
PubMed1989

[Percent composition of fatty acids in Tigriopus fulvus from rocky pools on the Ligurian coast (Copepoda harpacticoida)].

The study concerns the Tigriopus fulvus specimens fatty acid composition, sampled in Ligurian coast rockpools from September 1980 to June 1981. By the study of frequency distribution it was observed that the fatty acid found in greater quantity was the palmitic one, followed by the palmitoleic, the oleic and stearic acids. Short and long chain fatty acids are less frequent. Investigation about each fatty acid concentration shows that the seasonal trends between males and females are different and the trend of some fatty acids (e.g. linolenic and stearic acid) is characteristic.

Animals↗
PubMed1987

[Celiac disease as a risk factor for digestive neoplasms].

Coeliac disease is a primary malabsorption syndrome, whose gastrointestinal symptomatology regresses following a gluten-free diet. Several authors report an increased incidence of intestinal lymphoma in patients with longstanding coeliac disease; on the other hand the association of this malabsorption syndrome with malignant tumors of the esophagus, stomach or large bowel is not very common. The authors describe three cases of coeliac disease complicated after 5, 12 and 18 years by neoplasms of the esophagus, stomach and small bowel. It is stressed that in this disease patients must be monitored with periodic radiologic examinations, in the hope of detecting any malignancy at an early and perhaps treatable stage.

Adenocarcinoma↗