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V Fontana

Publications and source records attributed to V Fontana.

At least 37 records · Page 2Linked to original sources
PubMed1997

Sister chromatid exchange induction in peripheral blood lymphocytes of traffic police workers.

Traffic police workers, as a population exposed to urban atmosphere, were compared with a control population exposed to indoor air pollution levels. Sister chromatid exchanges (SCEs) as a biomarker of effect were measured in peripheral blood lymphocytes of 54 exposed subjects and 35 controls, and environmental concentration of polynuclear aromatic hydrocarbon (PAH) tracer compounds was detected by personal air samplers. The mean exposure level to benzo[a]pyrene in our group of traffic policemen (3.4 mg/m3) was in the range that has been estimated in urban areas in Europe during the last 10 years. No difference in SCE levels was found between exposed workers (7.36, SD 1.35) and controls (7.47, SD 1.28). No correlation was observed between SCE/cell and airborne PAH concentration in the traffic worker population. A positive regression of SCE on exposure estimate was found only in the non-smoking group of police workers. Our findings suggest that exposure to urban air pollution does not induce relevant cytogenetic effects.

Adult↗
PubMed1997

Long-term effects of fenretinide on retinal function.

The long-term effects of the synthetic retinoid fenretinide (4-HPR) on retinal function were studied by electroretinogram (ERG) in 24 women treated for a median of 30.5 months and in 18 untreated controls belonging to a phase III intervention trial. The six outcome measures were: a wave implicit time, peak-to-peak amplitude and implicit time of b wave following both cone stimulation and maximal cone-rod stimulation in the dark-adapted eye. Multivariate analysis of covariance was applied to evaluate the joint effect on the whole set of ERG measures taking into account their inter-relationship. Predictive factors with a significant effect on ERG measures were: (1) a qualitative interaction between age and treatment duration and (2) the squared (parabolic) function of plasma retinol. Individually, the b wave implicit time following cone stimulation was the only ERG measure significantly influenced by the predictors, indicating a primary effect of 4-HPR on retinal photoreceptor sensitivity without significant alterations of the inner nuclear layer. Thus, in contrast to previous reports at higher dose, administration of 4-HPR at 200 mg/day seems to exert subtle alterations of retinal function as measured by ERG.

Age Factors↗
PubMed1996

Effect of tamoxifen on endometrial proliferation.

PURPOSE: An increase in the incidence of endometrial cancer and a potential increase in related mortality has been associated with the administration of 20 mg tamoxifen, the dose adopted in breast cancer chemoprevention trials, thus urging studies on intermediate markers of risk. PATIENTS AND METHODS: Thirty-three women who received 20 mg tamoxifen as adjuvant breast cancer treatment underwent endometrial biopsy. Samples were divided for histologic examination, including a quantitative analysis of stromal:epithelial ratio, and an assessment of DNA ploidy and proliferation by flow cytometry. Results were compared with 37 symptomatic subjects. RESULTS: All histograms were DNA diploid. Compared with controls, a significant increase in the risk of proliferation as measured by the hyperdiploid fraction was associated with tamoxifen duration (< or = 36 months: cumulative odds ratio = 16.5, 95% confidence interval, 1.85 to 146.5; > 36 months: cumulative odds ratio = 28.2, 95% confidence interval, 2.56 to 310.6, P for trend < .05). Tamoxifen-induced risk was significantly reduced by the extent of menopausal status. No cases of cancer or epithelial hyperplasia were observed in the tamoxifen group, whereas seven cases of epithelial hyperplasia without atypia were observed in the control group. The effect of tamoxifen on proliferation was associated with an increase in the stromal component. CONCLUSION: Tamoxifen at 20 mg/d exerts a time-dependent proliferative effect on the endometrium, particularly in premenopausal and early postmenopausal women. This effect appears to be mediated by the stromal component, which accounts for the discrepancy between flow cytometry and histology. Our study provides preliminary evidence that the DNA flow cytometric hyperdiploid fraction may be a useful tool for monitoring endometrial cell proliferation in women exposed to tamoxifen.

Adult↗
PubMed1996

Exposure to styrene and mortality from nonmalignant diseases of the genitourinary system.

OBJECTIVES: A historical cohort study was carried out to investigate mortality from nonmalignant diseases of the genitourinary system among workers in the reinforced plastics industry, where high workroom concentrations of styrene are encountered. METHODS: The external comparisons in this report were based on an average of 12.6 years of retrospective follow-up of 35 443 workers who were first employed in the reinforced plastics industry during 1945-1991 and were known to have been exposed to styrene in their work. For the internal comparisons, 2641 subjects with incomplete occupational histories were excluded, leaving 32 802 subjects. Previous individual exposure histories to styrene were reconstructed through job histories and environmental and biological monitoring data. RESULTS: Mortality from nonmalignant diseases of the genitourinary system (N = 20) was associated with average exposure to styrene (P for trend 0.05). Weaker increasing trends in risk were seen for time since first exposure and cumulative exposure, while no increase was identified for duration of exposure. There was a significant increasing trend in mortality from nephritis and nephrosis (N = 5), associated with an increasing average level of exposure to styrene (P for trend 0.03). No clear trend was observed for time since first exposure, duration of exposure, or cumulative exposure. CONCLUSIONS: In this large cohort study of workers exposed to styrene, mortality from nonmalignant diseases of the genitourinary system increased as the average intensity of exposure increased. This finding indicates that other data should be scrutinized.

Air Pollutants, Occupational↗
PubMed1994

Multiple regression analysis of cytogenetic human data.

Biomonitoring studies on cytogenetic outcomes in humans should be considered as epidemiological studies, rather than randomized trials. Under this light the emphasis given to the achievement of a significant p-value should be reduced, since this measure suffers from major limitations. The use of a point estimate (and its corresponding confidence interval) to measure the association between exposure and effect offers several advantages, including the adjustment for confounding, and the evaluation of possible interaction between factors. In most instances the use of multivariate statistical methods allows an efficient analysis of these studies, even in presence of a small sample size and several covariates. In this paper we re-analyzed four biomonitoring studies by using multivariate methods to estimate relative risks through statistical modeling. The use of multiple regression techniques allowed the computation of point estimates of association and their confidence intervals for each covariate evaluated by the studies considered; the estimate of the effect of confounding variables such as smoking habits, age and gender; and the presence of interaction between covariates. Measures of association estimated through univariate and multivariate statistical approaches are compared. The advantages of the latter technique are discussed.

Adult↗
PubMed1994

Stimulation of erythropoiesis by the non-steroidal anti-androgen nilutamide in men with prostate cancer: evidence for an agonistic effect?

The effects of steroid hormones are pleiotropic. Similarly, non-steroidal oestrogen receptor antagonists such as tamoxifen exert partial agonistic effects with a species- and tissue-specific pattern. Conversely, little is known of the biological effects of non-steroidal anti-androgens, whose role has been investigated in the palliative treatment of prostate cancer. We studied the effects of the non-steroidal anti-androgen nilutamide on parameters of red blood cells, an androgen-dependent cell compartment, in 24 men with prostate cancer and compared the results with those obtained in 38 historical control patients treated with D-tryptophan-6-LHRH. Administration of the anti-androgen induced a limited rise in testosterone concentrations (from 14.1 +/- 1.8 up to a maximum of 19.6 +/- 2.3 nmol l-1) and a significant increase with time in haemoglobin and haematocrit (y = 12.6 g dl-1 + 0.15 months and y = 37.3% + 0.46 months respectively, P = 0.008 for both), while no change occurred in red blood cell count (y = 4.19 x 10(6) mm-3 + 0.02 months, P = 0.2). Conversely, no variation in erythroid parameters was observed in the patients treated with the LHRH analogue (haemoglobin = 12.7 + 0.02 months, P = 0.59; haematocrit = 38.1 + 0.02 months, P = 0.9; red blood cells = 4.34 x 10(6) mm-3 + 0.15 months, P = 0.4). The difference between the linear regression slopes of haemoglobin in the two treatment groups was significant (F-ratio = 3.39, P = 0.03). While the stimulation of erythropoiesis induced by the anti-androgen might be due to incomplete neutralisation of endogenous androgens at the bone marrow level, a cell-specific agonistic effect of the drug cannot be excluded, thus calling into question the designation of pure antagonists which has been attributed to this class of compounds. Ongoing randomised trials should address this issue.

Aged↗
PubMed1994

Pleural mesothelioma and asbestos exposure among Italian oil refinery workers.

OBJECTIVES: The association between asbestos exposure and risk of mesothelioma was studied among workers from two oil refineries located in the northern Italian cities of Genoa and La Spezia, given that previous cohort analyses revealed two clusters of mesotheliomas and that international cohort studies have so far not reported an excess of this neoplasm among oil refinery workers. METHODS: Men (N = 2300) who had been employed between 1914 and 1988 in two oil refineries located in northern Italy were studied. The follow-up covered the mortality of 639 white-collar and 1661 blue-collar from 1950 to 1991. RESULTS: Among the cases, the median duration of employment was 14.5 years, and the median time since first employment was 27.5 years. The job titles of the 10 men with pleural mesothelioma were maintenance worker (seven men), electrician (one man) and unspecified blue-collar worker (two men). Blue-collar workers experienced a significantly increased risk of pleural neoplasms, five deaths in each plant, in respect to both the provincial [standardized mortality ratio (SMR) 266] and national (SMR 1663) reference populations. The SMR, based on eight deaths, was 320 for workers with more than 10 years of employment and 20 years since first exposure. CONCLUSIONS: The results uphold the notion that exposure to asbestos in oil refineries causes pleural mesotheliomas. This is the first study to find an excess of pleural mesotheliomas among oil refinery workers exposed to asbestos.

Adult↗
PubMed1994

[Percutaneous transluminal coronary angioplasty for postinfarction residual ischemia: mid- and long-term results].

Aim of this study was to assess the long-term results of PTCA in patients with a recent myocardial infarction. The study population consisted of 244 consecutive patients who underwent a PTCA < or = 30 days after myocardial infarction either because of angina (116 patients), or because of provoked ischemia (62 patients), or in the absence of both (66 patients). "Simple" balloon angioplasty, without adjunctive devices, was performed. Most of the patients were seen at 1 year intervals at the outpatient clinic; otherwise information was gathered either from the family physician or by telephone. The following events were noted during a follow-up of 6-102 months (median 39 months): death, myocardial infarction, need for re-PTCA or surgical revascularization, recurrence of angina. Survival and event-free curves were calculated according to the method of Kaplan and Meier; statistical comparisons between the curves were obtained by the log-rank test. Periprocedural deaths, infarctions and surgical revascularizations are included in the actuarial curves. Differences were examined between patients with Q and non-Q wave infarctions, single vessel versus multivessel disease, left ventricular ejection fraction > or 50% versus < 50%. A clinical success was achieved in 85% of the procedures. Sixteen patients were lost at follow-up. Overall, within the first 30 days and during follow-up, 12 (4.9%) patients died, 19 (7.7%) suffered from myocardial infarction, 34 (13.9%) required re-PTCA or surgical revascularization, and 63 (25.8%) experienced angina again.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1994

Factors affecting plasma retinol decline during long-term administration of the synthetic retinoid fenretinide in breast cancer patients.

Administration of the synthetic retinoid Fenretinide lowers circulating retinol and may thus affect night vision. We have recently shown that plasma retinol levels below 100 ng/ml are associated with moderate alterations of the dark adaptometry test. To identify which patients are more likely to experience a decrease of plasma retinol under this threshold, we measured plasma levels of retinol, Fenretinide, and its metabolite 4-MPR in a cohort of 28 women receiving Fenretinide at the daily dose of 200 mg and studied their relationship with clinical characteristics such as age, menstrual status, body mass index, and time on treatment. Our results show that patients aged over 55 years with a higher percentage of adipose tissue had higher plasma concentrations of 4-MPR, which turned out to be the major determinant of the retinol decrease. This subgroup may thus deserve careful ophthalmological surveillance.

Adipose Tissue↗
PubMed1993

Long-term endocrine effects of administration of either a non-steroidal antiandrogen or a luteinizing hormone-releasing hormone agonist in men with prostate cancer.

The claimed ability of non-steroidal antiandrogens to preserve libido and sexual potency is sought as a potential improvement in the palliative management of prostate cancer. A critical issue for the clinical use of these compounds is, however, the reported evidence in the rat of an excessive increase in testosterone concentrations as a consequence of the androgen negative feedback interruption. On the other hand, the recovery of testicular function after long-term inhibition by luteinizing hormone-releasing hormone (LHRH) analogs is also an important concern in view of the proposed use of these compounds for the treatment of several non-malignant conditions. We addressed these issues by studying the long-term endocrine effects induced by the administration of either the non-steroidal antiandrogen nilutamide or the depot preparation of D-Trp6-LHRH in men with prostate cancer. Treatment with the antiandrogen induced a marked increase in gonadotropin levels, LH concentrations rising from a mean (SEM) of 17.5 +/- 1.6 to a maximum of 56.6 +/- 6.9 kU/l (p < 0.001), while mean testosterone and 17 beta estradiol-concentrations rose only by about 50% and 70% over pretreatment values, testosterone levels reaching a plateau after 1 month of treatment. In the subjects treated with the LHRH agonist, 6 months after discontinuation of long-term administration the mean (+/- SEM) LH had risen to 36.9 +/- 6.8 IU/l while mean testosterone levels were still as low as 1.7 +/- 0.7 and rose only to a maximum of 4.2 +/- 1 nmol/l after high-dose human chorionic gonadotropin loadings.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1993

[Functional maneuvers for the diagnosis of hypertrophic cardiomyopathies with and without left ventricular outflow obstruction].

PURPOSE OF THE STUDY: to assess the diagnostic value of the commonly adopted haemodynamic criteria for the diagnosis of obstructive and non-obstructive hypertrophic cardiomyopathy. PATIENTS: 16 cases of hypertrophic cardiomyopathy, 7 cases of the non-obstructive form, 16 fixed subaortic stenosis, 8 valvular aortic stenosis, and 7 cases of hypertensive heart disease. METHODS: left and right heart catheterisation, with particular attention to the pressure gradient and to the aortic pulse pressure by means of simultaneous pressure recording from the left ventricle and aorta under basal conditions, after a ventricular premature beat, during the Valsalva manoeuvre, during amyl nitrite inhalation, and isoproterenol administration. RESULTS AND CONCLUSION: the Valsalva manoeuvre increases significantly (p < 0.001) the pressure gradient, and the aortic pulse pressure in the post-extrasystolic beat decreases significantly (p < 0.001) in patients with hypertrophic obstructive cardiomyopathy. This response is significantly different from that of the other 3 disease groups. If the non-obstructive form is defined by strict criteria (i.e. no gradient above 30 mmHg even after provocative manoeuvres), then it cannot be separated from other forms of secondary left ventricular hypertrophy.

Adult↗
PubMed1991

A quality control method in cardiac surgical outcome: experience in 462 patients.

The aim of our study is to verify the reliability, reproductiveness and simplicity of a method to control cardiac surgical results. We divided 462 adult patients, operated on for acquired heart disease from October 1989 to January 1991, into five classes according to an individual score which was predictive for their operative mortality risk. The score resulted from 15 different risk factors tested with univariate and multivariate analysis against one event: operative death. The total number of deaths was 12: 2, 2, 1, 2, 5 for each class respectively. When comparing the predicted versus our observed mortality, we found no statistically significant difference, using the chi-squared test. The method we used is highly predictive for surgical mortality risk: it makes the results objectively comparable among different institutions; it is useful as a self-controlled quality method for cardiac surgical activity in any single institution.

Adolescent↗
PubMed1991

Intracoronary streptokinase in unstable angina: a prospective randomised study.

Results of our prospective, randomised pilot trial to evaluate the clinical effects and the angiographic correlates of early thrombolysis in patients with unstable angina are reported. Sixty-seven patients had coronary angiography 10 +/- 8 (median 7) hours after an episode of transient chest pain at rest with reversible ischaemic changes on the electrocardiogram. Patients with left main disease (4), or diffuse coronary disease and unidentified ischemia-producing lesions (13) were excluded, as were those without severe (greater than or equal to 70%) stenosis (10). Intracoronary thrombus was identified at angiography in 7 patients (17%) and complex coronary lesions in 5 (12%) of the remaining 40 patients who were randomised to either intracoronary streptokinase 250,000 IU followed by intravenous heparin along with conventional treatment (20 patients), or to conventional treatment alone (20 patients). All patients received Aspirin. No differences between the streptokinase and the conventional treatment groups were observed with respect to demographic and clinical characteristics at admission to the study. During observation in the intensive care unit for 3 +/- 1 days, 8 patients (40%) with streptokinase and 10 (50%) with conventional treatment were free from angina and infarction (p = 0.75; 95% confidence interval for the difference in response rates = -20 to 40%). There were no bleeding complications and no patient died. Patients enrolled in our study had fewer coronary thrombi at angiography than currently reported. Our data did not show that adjunct treatment with streptokinase and heparin is superior to conventional treatment alone in these patients.

Aged↗
PubMed1991

[Rapid onset aortic stenosis and clinical course in adults. Clinico-hemodynamic correlations].

In 8 patients aged 41-66 years, a second left heart catheterisation done 27-98 months after the first study, demonstrated a pressure gradient across the aortic valve, that had not previously existed, or had been trivial. No significant change of the cardiac output had occurred. All but 1 patient were hypertensive. The etiology was rheumatic in 4, degenerative in 4. Electrocardiographic, radiographic, and echocardiographic evolution could not separate the patients with a gradient greater than or equal to 70 mmHg from those whose gradient was less than or equal to 40 mmHg. The intensity of the aortic component of the second heart sound, however, decreased in all former patients, and in only 1 of the latter. Aortic valvular stenosis can arise and rapidly develop in adult patients. Concomitant rheumatic mitral valve disease, coronary artery disease and hypertension can mask and/or modify symptoms, signs and laboratory findings. Changes of the aortic component of the second sound may suggest its occurrence.

Adult↗
PubMed1990

[Use of a balloon-tipped guidewire to pre-dilate coronary stenosis].

Two cases of coronary angioplasty of very tight stenoses are reported in which, after failure of conventional low-profile catheters, a balloon-tipped guidewire was used to predilate the lesion, with subsequent advancement of a larger balloon catheter over the wire itself to complete the dilatation. It is suggested that this balloon-tipped guidewire can be helpful for safe predilatation of very tight coronary stenoses with no need for complex catheter exchanges.

Aged↗