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Biomedical subjects

V Fano

Publications and source records attributed to V Fano.

At least 19 recordsLinked to original sources
PubMed2005

Adhesiveness of dental resin-based restorative materials investigated with atomic force microscopy.

This study aimed to show that the polymerization contraction of dental methacrylate-based materials, when used as adhesives on hard substrate, produces voids at the material-substrate interface. This phenomenology is closely related with the nanoleakage and the sealing ability of these materials. One prime/bond system, three restorative composite resins, and one orthodontic bonding system were cured by using mirror-like glass slides as a compliance-free reference substrate. The adhesive surface was analyzed by atomic force microscopy, and the polymerization contraction of bulk material was tested by laser beam-scanning method. Nanoperiodic structure of three-dimensional (3D) images, section analysis, and roughness characteristics (R(a) and R(z)) indicated that polymerization contraction produced voids at the interface. When the adhesive surface was exposed to oral simulating fluids (water, ethanol, and lactic acid solutions), hydrolytic degradation involved some hundreds of nanometers in depth. In visible light-cured (VLC) materials, the interface porosity decreased when an irradiation pause ( approximately 2 min) was carried out during gelation.

Adhesiveness↗
PubMed2004

Occupational and environmental exposures and lung cancer in an industrialised area in Italy.

AIMS: To investigate the effects of occupational exposures and residence near to industrial sites on lung cancer mortality in an area in Italy. METHODS: 234 cases of lung cancer and 729 controls matched by sex, age, and date of death were enrolled. Environmental exposure was evaluated using historical residence data. A geographical information system was used to compute distances from residence to pollution source (cement factory, power plants, harbour) and an average distance was computed for each subject. Odds ratios (OR) and 95% confidence intervals (CI) in a logistic regression model were used to estimate the relative risk of lung cancer associated with the risk factors (smoking habits and occupational exposure) collected by questionnaire; ORs for distances from pollution sources and from city centre were computed, adjusting for smoking habits, education, and occupation. RESULTS: Smoking habits (< or =10 cigarettes/day, OR = 2.28; 11-20, OR = 4.64; >20, OR = 6.61) and occupational exposure to asbestos (OR = 3.50) were significantly associated with lung cancer risk. Reported traffic level of area of residence and residence near the four sources were not associated with increased risk of lung cancer. There was a significantly increased risk for those residing outside the city centre, in the southern outskirts (OR = 1.51). CONCLUSIONS: The increased lung cancer risk observed in the area can partly be explained by occupational exposures. The increased risk in the outskirts of the city is consistent with the results of dispersion models that indicate high levels of pollutant deposition in the same area.

Adult↗
PubMed2002

Polymerization of dental composite resins using plasma light.

Five visible light-cured composite resins used as restoration or adhesive materials in dentistry, were irradiated with high energy plasma light (1300 mW/cm2), and contraction, rate of contraction, irradiation-induced temperature were analysed. A comparison was carried out with the same materials irradiated with a conventional halogen light (400 mW/cm2). The exposure to the photoactivating lights was either continuously or sequentially in three or more intervals with 10 min between intervals. Comparing the lengths of exposure of both lights, which induced the same contraction in a given material, it was found that the exposure length to the plasma light was greatly reduced, when compared with the exposure length of the halogen light (1:10). Frequently, the final contraction of plasma-irradiated materials was lower, whereas the rate of contraction, as indicated by the linear dimensional variation curves obtained by laser beam scanning method, did not show significant differences between the two lights. The temperature increase induced by plasma light on the material did not exceed the temperature induced by conventional light.

Composite Resins↗
PubMed2001

Factors associated with hepatitis B virus immunization coverage at the beginning of a population campaign in the Lazio region, Italy.

BACKGROUND: The hepatitis B virus (HBV) vaccination was introduced in Italy in 1991 as compulsory among newborns and among 11-year-old children. METHODS: We conducted a retrospective study to evaluate the HBV immunization coverage of the two target populations by the public health services in the Lazio region and to analyze factors associated with starting and completing HBV immunization in the initial period of the campaign. We used data registered in the public health services of 7/51 Health Districts. As a proxy indicator of services' performance we used the "expected immunization period," that is, the 6-month period in which each child should have been started on immunization, according to the calendar. RESULTS: HBV vaccine coverage rates were 63% in the younger cohort and 50% in the older one. The results of univariate and multivariate regression analysis showed that starting HBV immunization was associated with being newborn (crude OR = 3.30; 95%CI 2.17-2.44), with living in a small city (crude OR = 6.81; 95%CI 6.12-7.58), and with being assigned to the second (crude OR = 1.77; 95%CI 1.65-1.90) or to the third 6-month period of the expected immunization period (crude OR = 2.58; 95%CI 2.42-2.76). The probability of completing HBV immunization was higher among children who had had the first dose "age-appropriately" or with "acceptable delay" and among those living in small cities. It was lower among children in the second or the third 6-month period. Size of urban area of residence was associated with both outcomes: the city of Rome showed the lowest probabilities of starting and completing HBV immunization, while the small cities showed the highest ones. CONCLUSIONS: The performance of public health services was the most important determinant of recourse to public health services for vaccinations; it varied according to size of urban area; in towns organization difficulties contributed to the delay of starting vaccination, for at least a year. The expected immunization period was a good proxy indicator of services' performance. The timing of the first dose was the strongest predictor of completing vaccination also at the beginning of the campaign.

Child↗
PubMed2001

Spondylo-meta-epiphyseal dysplasia, short limbs, abnormal calcification type: a new case with severe neurological involvement.

A case of an affected girl with spondylo-meta-epiphyseal dysplasia (SMED) is reported. The disease was detected at birth as a congenital dysplasia with generalized lesions. At 10 months of age, abnormal calcifications appeared in both wrists. The patient evolved with severe growth retardation and multiple neurological and respiratory complications, followed by death at 21 months of age.

Calcinosis↗
PubMed2001

Structure of dental glass-ionomer cements by confocal fluorescence microscopy and stereomicroscopy.

The microstructure of four cements, setting by different mechanisms (acid-base, dual cure, triple cure), was studied. The porosity of unpolymerized materials was detected by stereomicroscopy. After polymerization and storage in water or lactic acid solution, the porosity, filler distribution and gel layer, which was formed at the filler/matrix interface of polymerized materials, were examined by confocal laser microscopy. For this purpose, the specimens were treated with fluorescent dye solution before the test. The results showed that hydrolytic degradation (pH 7) mainly involved the resin matrix, and the acid erosion (pH 3.5) involved the gel layer too. As regards the filler, materials with different setting mechanism released the glass particles in different times. The loss of the filler particles occurred quicker in acid-base setting cements, and slower in triple-cured material.

Fluorescent Dyes↗
PubMed2000

Estimating incidence of bacterial meningitis with capture-recapture method, Lazio Region, Italy.

To estimate the incidence of bacterial meningitis in the Lazio Region, including the city of Rome, and to assess the quality of the surveillance systems, we adopted a multiple-capture model by merging cases from three sources available in 1995-1996: the Notifiable Disease Surveillance (NDS) system, the Special Hospital Surveillance (SHS) system and the Hospital Discharge (HD) registry. A medical record revision was carried out to confirm the cases of bacterial meningitis. A total of 199 individuals was classified as probable or confirmed cases of bacterial meningitis in 1995-1996. In this period, the incidence of reported meningitis was 3.8/100,000 (population = 5,209,633). The log-linear model yielded a total estimated number of 236 cases (95% confidence interval (CI): 206-306), the estimate of incidence reaching the value of 4.5/100,000. Hospital Discharge registry showed the highest sensitivity (77%), the SHS system the highest positive predictive value (83%). In 1997-1998, the meningitis surveillance was integrated with an additional laboratory-based source and yielded 326 cases, with an incidence of reported cases of 6.3/100,000. Laboratory surveillance, involving 115 (92%) public hospitals and 84 (57%) private clinics, contributed 35 (27%) cases in addition to those notified to NDS (n = 130). Multiple-capture models, in our experience could estimate the bacterial meningitis incidence with a very good approximation. In order to improve both sensitivity and positive predictive value of surveillance, hospital and public health sources should be integrated with laboratory-based system.

Case-Control Studies↗
PubMed1998

Study of dental materials by laser beam scanning.

Several properties of dental materials are characterized by dimensional variation induced by different parameters. In this work a non-contact method used for measurement of linear dimensional variation is shown. The accuracy is +/- 1 micron for sample length ranging from 1 to 70 mm.

Chemical Phenomena↗
PubMed1998

The effect of zinc and vitamin A supplementation on immune response in an older population.

OBJECTIVE: To determine if either supplemental vitamin A, zinc, or both increases cell-mediated immune response in an older population. DESIGN: A double-blind, randomized, controlled trial of supplementation with vitamin A and zinc. SETTING: Casa Di Riposo Roma III, a public home for older people in Rome, Italy. SUBJECTS: The health and nutritional status of 178 residents were evaluated. One hundred thirty-six residents agreed to participate in the trial and were randomized into four treatment groups, and 118 of these residents completed the trial. INTERVENTION: The four treatments consisted of: (1) Vitamin A (800 micrograms retinol palmitate); (2) Zinc (25 mg as zinc sulfate); (3) Vitamin A and Zinc (800 micrograms retinol palmitate and 25 mg as zinc sulfate); (4) Placebo capsules containing starch. MAIN OUTCOME MEASUREMENTS: Immune tests-counts of leucocytes, lymphocytes, T-cell subsets, and lymphocyte proliferative response to mitogens-were measured before and after supplementation. RESULTS: Zinc increased the number of CD4 + DR + T-cells (P = .016) and cytotoxic T-lymphocytes (P = .005). Subjects treated with vitamin A experienced a reduction in the number of CD3 + T-cells (P = .012) and CD4 + T-cells (P = .012). CONCLUSIONS: These data indicate that zinc supplementation improved cell-mediated immune response, whereas vitamin A had a deleterious effect in this older population. Further research is needed to clarify the clinical significance of these findings.

Aged↗
PubMed1998

Determinants of tuberculosis in an immigrant population in Rome: a case-control study.

SETTING: An out-patient clinic for immigrants in Rome, Italy. OBJECTIVE: To determine risk factors for tuberculosis among immigrants in Italy. DESIGN: Case-control study. Cases comprised 44 individuals aged 15-55 years who had a first diagnosis of tuberculosis between 1989 and 1994 at the clinic. Controls comprised 264 individuals randomly recruited among immigrants who attended the clinic for other reasons within seven days before or after the case was diagnosed. Subject information included country of origin, date of first arrival in Italy, level of education, knowledge of the Italian language, and legal resident status. RESULTS: An increase of tuberculosis risk was observed with increasing tuberculosis incidence in the country of origin. Multivariate analysis showed an increased risk for those coming from Central and South America (odds ratio [OR] 5.5; 95% confidence interval [CI] 1.6-18.7). The adjusted odds ratio by time since entry in Italy increased during the second year of residence (OR 2.8; 95% CI 1.1-7.0), but decreased after that period. A trend toward increasing risk with decreasing educational level was observed. CONCLUSIONS: These results demonstrate the need for a public health policy in Italy for tuberculosis control among immigrants which includes screening, prophylaxis and treatment.

Adolescent↗
PubMed1997

Mortality among workers at municipal waste incinerators in Rome: a retrospective cohort study.

A retrospective mortality study of a cohort of 532 male subjects employed at two municipal plants for garbage recycling and incinerating has been conducted. All workers ever employed at the plants since 1962 were enrolled and followed up from January 1, 1965 to December 31, 1992. Standardized Mortality Ratios (SMRs) and 90% confidence intervals (90%CI) were calculated using regional population mortality rates. The study yielded a total of 8,585 person-years of observation. Mortality from all causes was significantly lower than expected (observed [obs] = 31; SMR = 0.71; 90%CI = 0.51-0.95). All cancer mortality was comparable with that of the general population (obs = 15; SMR = 0.95; 90%CI = 0.58-1.46). Mortality from lung cancer was reduced (obs = 3; SMR = 0.55; 90%CI = 0.15-1.42). Increased risk was found for gastric cancer (obs = 4; SMR = 2.79; 90%CI = 0.94-6.35). Analysis by latency indicated that the excess risk of gastric cancer was confined in the category with more than 10 years since first exposure. Our results for gastric and lung cancers indicate the need to further investigate the role on cancer of occupational exposure to organic dust and bacterial endotoxins in the waste management.

Adult↗
PubMed1997

Polymerization shrinkage of microfilled composites determined by laser beam scanning.

An He-Ne scanning laser beam was used to measure for the first time the linear shrinkage of light-cured microfilled composites. A low-power beam, which has a wavelength (632.8 nm) different from the polymerization wavelength (approximately 450 nm), was used. In these conditions no shrinkage is induced by the laser light. This method of measurement makes it possible to analyse small samples with a very low error (1.1 microns). Five different materials were tested using 10-20 mg specimens, and the shrinkage process was examined in detail over 2 days. All these materials showed shrinkage of more than 50% of their original length after 1 min of irradiation and approximately 99% of the total shrinkage occurred 4 h after irradiation.

Acrylic Resins↗
PubMed1997

Cancer mortality among chemical workers in an Italian plant.

Objective of this study was to assess the mortality experience of a cohort of chemical workers at a plant located in central Italy. Subjects employed for any time between 1954 and 1970 at the chemical plant were included in the cohort and followed up to June 1991. The workers were classified as having ever/never worked in one of the following work processes: organic chemicals, acid mixtures, cleansing agents and insecticides. Mortality experience of the cohort was compared with that of the regional population by computing SMRs (standardized mortality ratios) and 90% CI (confidence intervals). Vital status was ascertained for 96% of the 505 cohort members. All causes of mortality for the entire cohort were lower than expected (Obs: 176; SMR: 0.90; 90% CI: 0.79-1.03). Analysis by work process revealed an increased mortality for lymphatic and hematopoietic tissue neoplasm in the cleansing agents department (Obs: 3; SMR: 5.00; 90% CI: 1.36-12.9); peritoneum and retropertioneum neoplasm in the organic compounds production (Obs: 2; SMR: 13.33; 90% CI: 2.37-42.0), and bladder cancer in the insecticides process (Obs: 3; SMR: 3.53; 90% CI: 0.96-9.12). Although the study had a low statistical power, the increased cancer risks detected are consistent with previous observations and may be of etiologic interest.

Adult↗
PubMed1997

Zinc supplementation and plasma lipid peroxides in an elderly population.

OBJECTIVE: To determine the effect of vitamin A, zinc or both on plasma lipid peroxides in a healthy elderly population. DESIGN: Double-blind randomized controlled trial supplementation of vitamin A and zinc. SETTING: Public home for elderly people, in Rome, Italy. SUBJECTS: A total of 178 residents of a Public home for elderly people were evaluated regarding health and nutritional status. 136 gave a written consensus to participate in the trial and were randomized in four groups of treatment. 118 elderly completed the trial. INTERVENTIONS: Three months supplementation of the following treatments: (1) vitamin A (800 micrograms retinol palmitate); (2) zinc (25 mg zinc as sulphate); (3) vitamin A and zinc (800 micrograms retinol palmitate and 25 mg zinc as sulphate); (4) placebo (starch containing capsules). MAIN OUTCOME MEASURES: Plasma lipid peroxides (TBA-RS) were measured before and after supplementation. RESULTS: Zinc supplementation was associated with a decrease in plasma lipid peroxides (beta = -0.19; 95% confidence levels: -0.37, -0.002; p-value = 0.05) after adjusting for sex, smoking habits, baseline plasma lipid peroxides and vitamin A plasma levels. CONCLUSIONS: Zinc supplementation decreased plasma lipid peroxides while vitamin A had no effect in this elderly population. Adequate zinc intake or supplementation could play an important role in the prevention and/ or modulation of diseases in the elderly people.

Aged↗
PubMed1996

Immunological changes among farmers exposed to phenoxy herbicides: preliminary observations.

OBJECTIVES: To evaluate short term immunological changes after agricultural exposure to commercial formulations of chlorophenoxy herbicides. METHODS: Blood samples were collected from 10 farmers within seven days before exposure, one to 12 days after exposure, and again 50 to 70 days after exposure. Whole blood was used to count lymphocyte subsets with monoclonal antibodies. Peripheral blood mononuclear (PBM) cells were used to measure natural killer (NK) cell activity and lymphocyte response to mitogenic stimulations. Values before exposure were used as reference. RESULTS: In comparison with concentrations before exposure, a significant reduction was found one to 12 days after exposure in the following variables (P < 0.05): circulating helper (CD4) and suppressor T cells (CD8), CD8 dim, cytotoxic T lymphocytes (CTL), natural killer cells (NK), and CD8 cells expressing the surface antigens HLA-DR (CD8-DR), and lymphoproliferative response to mitogen stimulations. All immunological values found 50-70 days after exposure were comparable with concentrations before exposure, but mitogenic proliferative responses of lymphocytes were still significantly decreased. CONCLUSIONS: According to our data agricultural exposure to commercial 2,4-dichlorophenoxyacetic acid (2,4-D) and 4-chloro-2-methylphenoxyacetic acid (MCPA) formulations may exert short term immunosuppressive effects. Further studies should clarify whether the immunological changes found may have health implications and can specifically contribute to cancer aetiology.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1995

Porosity in composite resins.

Porosity in the pastes of composite resins before and after polymerization has been measured. The influence of the diameter of the extrusion orifices and the spatulation of the chemically-activated pastes has been evaluated. Considering that thin layers of these materials are transparent, the investigation has been carried out mainly by analysis of approximately 300 microns or lower thickness layers, that are still transparent under the microscope. Generally, there was a significant dependence of the porosity on the orifice diameter. However, this rule showed some exceptions. As far as the chemically-activated pastes were concerned, in all examined cases the number of small size (10-40 microns) porosities increased after spatulation.

Biocompatible Materials↗
PubMed1992

Dimensional stability of silicone-based impression materials.

This study attempts to demonstrate that the polymerization reaction is not the only factor that affects the shrinkage of silicone-based impression materials because evaporation of the constituents also contributes to the shrinkage. These factors can be evaluated by the study of time-dependent dimensional changes. This is shown both by chemical kinetics and by experimental testing of condensation and addition polymerizing impression materials with different viscosities. Comparison of the different materials shows that the two contributions, polymerization shrinkage, and evaporation shrinkage, can be assessed separately by analysis of the time-dependent shrinkage diagrams. The instability due to the polymerization reaction is complete after a few hours, but the contribution of the constituent evaporation, if present, can have a significant long-term role.

Dental Impression Materials↗