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Biomedical subjects

G Pastore

Publications and source records attributed to G Pastore.

At least 19 recordsLinked to original sources

Risk factors and outcome among a large patient cohort with community-acquired acute hepatitis C in Italy.

BACKGROUND: The epidemiology of acute hepatitis C has changed during the past decade in Western countries. Acute HCV infection has a high rate of chronicity, but it is unclear when patients with acute infection should be treated. METHODS: To evaluate current sources of hepatitis C virus (HCV) transmission in Italy and to assess the rate of and factors associated with chronic infection, we enrolled 214 consecutive patients with newly acquired hepatitis C during 1999-2004. The patients were from 12 health care centers throughout the country, and they were followed up for a mean (+/- SD) period of 14+/-15.8 months. Biochemical liver tests were performed, and HCV RNA levels were monitored. RESULTS: A total of 146 patients (68%) had symptomatic disease. The most common risk factors for acquiring hepatitis C that were reported were intravenous drug use and medical procedures. The proportion of subjects with spontaneous resolution of infection was 36%. The average timespan from disease onset to HCV RNA clearance was 71 days (range, 27-173 days). In fact, 58 (80%) of 73 patients with self-limiting hepatitis experienced HCV RNA clearance within 3 months of disease onset. Multiple logistic regression analyses showed that none of the variables considered (including asymptomatic disease) were associated with increased risk of developing chronic hepatitis C. CONCLUSIONS: These findings underscore the importance of medical procedures as risk factors in the current spread of HCV infection in Italy. Because nearly all patients with acute, self-limiting hepatitis C--both symptomatic and asymptomatic--have spontaneous viral clearance within 3 months of disease onset, it seems reasonable to start treatment after this time period ends to avoid costly and useless treatment.

Acute Disease↗

Mortality from second tumour among long-term survivors of retinoblastoma: a retrospective analysis of the Italian retinoblastoma registry.

Survivors of retinoblastoma (Rb) are at high risk of dying from second malignant tumour. The occurrence of second malignant neoplasm (SMN) and related mortality in a cohort of 1111 cases from the Italian Retinoblastoma Registry was analysed, considering the possible role of both genetic and iatrogenic causes. Rb patients had a greater than 10-fold excess in overall mortality compared with the general population (standardized mortality ratio (SMR) 10.73, 95% CI 9.00-12.80). Their excess risk attributable to cancers other than Rb was 14.93 95% CI 10.38-21.49). Survivors of hereditary Rb had an SMR for all causes of 16.25 (95% CI 13.20-20.00), whereas their SMR for all cancers was 25.72 (95% CI 17.38-38.07). Survivors of unilateral sporadic Rb had an SMR of 4.12 from all cancers (95% CI 1.55-10.98) and a much higher excess for overall mortality (SMR 13.34, 95% CI 10.74-16.56). As expected, survivors of hereditary Rb had higher mortality from cancers of the bone (SMR 391.90, 95% CI 203.90-753.20) and soft tissue (SMR 453.00, 95% CI 203.50-1008.40), small intestine (SMR 1375.50, 95% CI 344.00-5499.70), nasal cavity (SMR 13.71, 95% CI 1.93-97.35) and cancers of the brain and central nervous system (SMR 41.14, 95% CI 13.2-127.55).

Cohort Studies↗

Thermal response of contrast agent microbubbles: preliminary results from physico-chemical and US-imaging characterization.

Hyperthermia (HT) is a therapeutic strategy based on the selective damaging of tumoral cells when heated at temperatures in the range 41-45 degrees C. We are currently investigating the feasibility of Ultrasound (US) imaging to perform a non-invasive, efficient and cost effective temperature monitoring of heated tissues. Commercial US contrast agents (Sonovue, Bracco), consisting in microbubbles of SF(6) coated with a phospholipidic shell, greatly improve the US echo signal from tissues. Further investigations have been performed, consisting in physico-chemical and US-imaging characterization. In conclusion, we demonstrate that Sonovue microbubbles reach their maximal diameter at 40 degrees C, and then a sharp decrease is observed, possible due to the occurrence of gel-sol transition of the phospholipidic shell. At the same temperature the maximal backscattering intensity is predicted and actually experimentally observed. Sonovue, as well as other contrast agents based only on phospholipids, are, therefore, not suitable for use as non-invasive temperature monitoring medium since it is sensitive to temperatures below the hyperthermic range. Although microbubbles are in principle thermally effective, other coating materials should be investigated in order to increase their operative thermal range.

Contrast Media↗

Life expectancy as an indicator of outcome in follow-up of population-based cancer registries: the example of childhood leukemia.

BACKGROUND: Survival analysis is a standard methodology to assess progress in oncology disease treatment. However, survival analysis commonly only measures survival during the treatment period (and the period immediately afterwards), and does not provide an estimate of life expectancy, which is often of more interest to patients and to health policy makers. In this paper we propose a method to estimate childhood acute lymphoblastic leukemia (ALL) life expectancy through the integration of traditional survival analysis and life expectancy tables. PATIENTS AND METHODS: The study included 305 incident cases registered by the Childhood Cancer Registry of Piedmont in 1979-1991. Vital status on 30 June 2004 was known for 304 cases. Survival analyses were carried out using the Kaplan-Meier method and the Gompertz model, according to the time period of diagnosis and gender. RESULTS: Cumulative survival at 5 years increased from 58.6% (95% CI 48.9-68.3) for cases diagnosed in March 1979-July 1982 to 79.1% (95% CI 70.8-87.5) in March 1987-February 1991 (P = 0.002). Average life expectancy increased from 46.1 years for boys and 42.6 years for girls diagnosed in March 1979-July 1982 to 58.3 and 69.1, respectively, in March 1987-February 1991. CONCLUSIONS: These analyses show an improvement over the time period of diagnosis of life expectancy for children with ALL.

Adolescent↗

Genitourinary anomalies in Mowat-Wilson syndrome with deletion/mutation in the zinc finger homeo box 1B gene (ZFHX1B). Report of three Italian cases with hypospadias and review.

Hypospadias, when the urethra opens on the ventral side of the penis, is a common malformation seen in about 3 per 1,000 male births. It is a complex disorder associated with genetic and environmental factors and can be part of genetic syndromes. Mowat-Wilson syndrome (MWS) is a multiple congenital anomaly syndrome characterized by a distinct facial phenotype, Hirschsprung disease, microcephaly and mental retardation. It is caused by mutations in the zinc finger homeo box 1B gene, ZFHX1B (SIP1). To date, 68 deletion/mutation-positive cases have been reported. Genitourinary anomalies are common in MWS. Here we report that hypospadias is common in males with this syndrome. In 39 patients where this information was available, hypospadias was present in 46% of patients (18/39). In the 3 Italian male cases reported here, hypospadias was always present. MWS should be considered by endocrinologists in patients with hypospadias associated with developmental delays/mental retardation, in particular in the presence of a distinct facial phenotype.

Child, Preschool↗

Fluid-phase diagrams of binary mixtures from constant pressure integral equations.

A new algorithm for solving integral equations of the theory of liquids at fixed pressure is introduced. Combining this technique with the Lee's star function approximation for the chemical potentials, we obtain an efficient method to investigate fluid-phase diagrams of binary mixtures. We have tested the capabilities of such technique to study symmetric and asymmetric phase diagrams in nonadditive hard spheres and Lennard-Jones mixtures. We find that the integral equation theories, although approximate, can provide a flexible tool to determine the fluid-phase diagrams whose accuracy is critically dependent on the quality of the closure and of the resulting chemical potentials.

Journal Article↗

Correlates of Mycobacterium tuberculosis infection in a prison population.

Prisons represent a crucial setting for tuberculosis control. Currently, there is scarce information concerning Mycobacterium tuberculosis (MT) infection in European prisons, and no data are available for Italy. This study aims to describe the prevalence and correlates of MT infection in an Italian prison population. In this multicentre cross-sectional study, 1,247 inmates from nine prisons were recruited and asked to undergo questioning regarding socio-economic and demographic variables, tuberculin skin testing (TST), chest radiographs and testing for HIV, hepatitis B and hepatitis C virus infection. TST was positive in 17.9% of the 448 evaluable subjects. With multivariate logistic regression (performed among male inmates), MT infection was correlated with age (adjusted odds ratio (OR) 4.12 for inmates aged 31-40 yrs; 3.78 for those aged >40 yrs), being foreign-born (OR = 4.9), education < or =5 yrs (OR = 1.88) and length of detention (increased risk per yr: 11%). As with elsewhere in the world, the prison system in Italy features a population with an increased rate of Mycobacterium tuberculosis infection and at-risk rate for Mycobacterium tuberculosis transmission. Improved tuberculosis surveillance and control measures are deemed necessary in correctional facilities nationwide, especially for subjects with the above risk factors and those who are HIV infected, in whom the tuberculin skin testing can be misleading. The screening of entrants is particularly important to avoid undiagnosed smear-positive tuberculosis cases.

Adult↗

Computer simulation study of the closure relations in hard sphere fluids.

We study, using Monte Carlo simulations, the cavity and the bridge functions of various hard sphere fluids: one component system, equimolar additive, and nonadditive binary mixtures. In particular, we numerically check the assumption of local dependency of the bridge functions from the indirect correlation functions, on which most of the existing integral equation theories hinge. We find that this condition can be violated either in the region around the first and second neighbors shell, or inside the hard core, for the systems here considered. The violations manifest themselves clearly in the so-called Duh-Haymet plots of the bridge functions versus the indirect correlation functions and become amplified as the coupling of the system increases.

Journal Article↗

In vitro productive infection of non polarised cervical and rectal biopsies by syncytium-inducing and non syncytium inducing primary HIV-1 isolates.

An in vitro model was used to study the transmission of HIV-1 primary isolates with different biological phenotype to cervical and rectal non polarised bioptic fragments. The method described allowed the productive infection of both cervical and rectal tissues and the virus produced could be propagated onto peripheral blood mononuclear cell cultures. Syncytium-inducing and non-syncytium inducing viral isolates were equally able to produce infection and replication.

Biopsy↗

Re-treatment of patients with anti-HBe-positive chronic hepatitis B who relapsed after an initial course of lamivudine.

AIM: To evaluate the efficacy of a long-term course of lamivudine monotherapy in patients with anti-HBe-positive chronic hepatitis B who relapsed after the first course of either lamivudine/interferon (n = 16; Group 1) or lamivudine (n = 20; Group 2). METHODS: Biochemical and virological tests were performed every 3 months. At baseline and breakthrough, the region coding for the YMDD amino acid motif was sequenced. RESULTS: The length of re-treatment averaged 24 months. The virological response peaked at 6 months (94.4%), and declined to 66.7% and 50% at 12 and 24 months, respectively. The rates of breakthrough were 2.9%, 31.4% and 48.6% at 6, 12 and 24 months, respectively. By the second year, responders amounted to 62.5% and 40% in Groups 1 and 2, respectively (P = 0.10). The 18 responders at month 24 are still on therapy after 25-51 months of treatment: 14 still maintain a response, nine from Group 1 and five from Group 2. CONCLUSIONS: Re-treatment with lamivudine can control viral replication. This effect is maintained for the initial 12 months in two-thirds of patients, but afterwards the duration of response lessens due to the development of viral resistance.

Adult↗

Stability of the iterative solutions of integral equations as one phase freezing criterion.

A recently proposed connection between the threshold for the stability of the iterative solution of integral equations for the pair correlation functions of a classical fluid and the structural instability of the corresponding real fluid is carefully analyzed. Direct calculation of the Lyapunov exponent of the standard iterative solution of hypernetted chain and Percus-Yevick integral equations for the one-dimensional (1D) hard rods fluid shows the same behavior observed in 3D systems. Since no phase transition is allowed in such 1D system, our analysis shows that the proposed one phase criterion, at least in this case, fails. We argue that the observed proximity between the numerical and the structural instability in 3D originates from the enhanced structure present in the fluid but, in view of the arbitrary dependence on the iteration scheme, it seems uneasy to relate the numerical stability analysis to a robust one-phase criterion for predicting a thermodynamic phase transition.

Journal Article↗

Population-based survival after childhood lymphoblastic leukaemia in time periods corresponding to specific clinical trials from 1979 to 1998--a report from the Childhood Cancer Registry of Piedmont (Italy).

This study evaluated the outcome after childhood acute lymphoblastic leukaemia (ALL) in a population aged 0-14 years served by the Childhood Cancer Registry of Piedmont (CCRP) during the accrual periods to nationwide clinical studies run by the Italian Association for Paediatric Haematology and Oncology (AIEOP). In the time period considered (March 1979-December 1998) the CCRP recorded 498 incident cases of ALL. The living status on 31 December 2000 was known for 497 cases. Overall survival at 5 years was 74.1% standard error (S.E.) 2.0%). It increased from 58.6% (S.E. 4.9%) for cases diagnosed in March 1979-July 1982 to 87.3 (S.E. 3.6) in May 1995-December 1998. Results observed from data in our population-based study in Piedmont were similar to those presented in the nationwide clinical trials. Survival was better (statistically significant) for children aged 1-4 years, with a white blood cell (WBC) count lower than 10 000 x 10(3) cells/litre and for B-precursor ALL. Differences by immunophenotype were statistically significant only in the univariate analyses. Girls showed a non-statistically significant survival advantage over boys. Results of the present study show the impact on the population of recent clinical trials and emphasise the role of population-based cancer registries in evaluating childhood cancer care delivery in a given population.

Adolescent↗

Natural course of acute hepatitis C: a long-term prospective study.

BACKGROUND: Acute hepatitis C has a high chronicity rate which appears to be significantly reduced by early antiviral treatment. However, it is unclear if all acutely infected patients should be treated, and when. In this prospective study, patients with a well-documented diagnosis of acute hepatitis C were evaluated to define the natural course, the rate of chronicity, and host and virus-related factors which might predict a self-limiting or chronic evolution requiring early antiviral treatment. METHODS: From 1995 to 2000, 40 consecutive patients with a community-acquired AHC were enrolled. Liver tests, anti-hepatitis C virus antibodies and hepatitis C virus RNA levels were monitored. Median follow-up was 35 months (range 12-68). RESULTS: A total of 24/40 patients had symptomatic disease including 20 with jaundice; 13/40 patients had prompt serum hepatitis C virus RNA clearance and ALT normalisation within 12 weeks; in 12/13 patients this pattern remained unchanged during follow-up. Overall, 27/40 patients remained hepatitis C virus RNA positive with fluctuating ALT levels. Older age and jaundice were predictive of resolution whereas there was no correlation with other host factors, viral genotype or viral load. CONCLUSIONS: Our data demonstrate that spontaneous resolution can occur in about 30% of AHC patients. This favourable outcome rarely occurs in patients with anicteric AHC or in those with jaundice but with persistent viremia for more than 12 weeks from onset; early antiviral treatment for these patients may avoid or reduce chronicity.

Acute Disease↗