Biomedical subjects

E Spada

Publications and source records attributed to E Spada.

At least 19 recordsLinked to original sources

PubMed2006

Postnatal weight increase and growth velocity of very low birthweight infants.

BACKGROUND: Only a few studies have dealt with postnatal growth velocity of very low birthweight (VLBW) infants. OBJECTIVE: To analyse weight growth kinetics of VLBW infants from birth to over 2 years of age. PATIENTS: A total of 262 VLBW infants were selected; inaccurate estimate of gestational age, major congenital anomalies, necrotising enterocolitis, death, and loss to follow up within the first year were the exclusion criteria. METHODS: Body weight was recorded daily up to 28 days or up to discontinuation of parenteral nutrition, weekly up to discharge, then at 1, 3, 6, 9, 12, 18, and 24 months of corrected age. Individual growth profiles were fitted with a seven constant, exponential-logistic function suitable for modelling weight loss and weight recovery, two peaks, and the subsequent slow decrease in growth velocity. RESULTS: After a postnatal weight loss, all infants showed a late neonatal peak of growth velocity between the 7th and 21st weeks; most also experienced an early neonatal peak between the 2nd and 6th week. VLBW infants who were small for gestational age and those with major morbidities grew less than reference VLBW infants who were the appropriate size for gestational age without major morbidities: at 2 years of age, the difference in weight was about 860 g. The more severe growth impairment seen in VLBW infants with major morbidities is almost entirely due to the reduced height of the late neonatal peak of velocity. CONCLUSIONS: The growth model presented here should be a useful tool for evaluating to what extent different pathological conditions or nutritional and medical care protocols affect growth kinetics.

Aging↗

PubMed2006

Early impairment of hepatitis C virus specific T cell proliferation during acute infection leads to failure of viral clearance.

BACKGROUND AND AIMS: Cellular mediated immunity (CMI) is thought to play a key role in resolution of primary hepatitis C virus (HCV) infection. However, CD4+ and CD8+ T cell responses are also generated during acute infection in individuals who become chronic, suggesting that they developed a defective CMI. The aim of this study was to verify if and when such immune dysfunction is established by measuring the breadth, magnitude, function, and duration of CMI in a large cohort of subjects during the natural course of acute HCV infection. METHODS: CMI was comprehensively studied by prospective sampling of 31 HCV acutely infected subjects enrolled at the onset of infection and followed for a median period of one year. RESULTS: Our results indicated that while at the onset of acute HCV infection a measurable CMI with effector function was detected in the majority of subjects, after approximately six months less than 10% of chronically infected individuals displayed significant CMI compared with 70% of subjects who cleared the virus. We showed that progressive disappearance of HCV specific T cells from the peripheral blood of chronic patients was due to an impaired ability to proliferate that could be rescued in vitro by concomitant exposure to interleukin 2 and the antigen. CONCLUSION: Our data provide evidence of strong and multispecific T cell responses with a sustained ability to proliferate in response to antigen stimulation as reliable pharmacodynamic measures of a protective CMI during acute infection, and suggest that early impairment of proliferation may contribute to loss of T cell response and chronic HCV persistence.

Acute Disease↗

PubMed2005

Self-regulation of E x B flow shear via plasma turbulence.

The momentum balance has been applied to the ExB flow in the edge region of a reversed field pinch (RFP) configuration. All terms, including those involving fluctuations, have been measured in stationary condition in the edge region of the Extrap-T2R RFP experiment. It is found that the component of the Reynolds stress driven by electrostatic fluctuations is the term playing the major role in driving the shear of the ExB flow to a value marginal for turbulent suppression, so that the results are in favor of a turbulence self-regulating mechanism underlying the momentum balance at the edge. Balancing the sheared flow driving and damping terms, the plasma viscosity is found anomalous and consistent with the diffusivity due to electrostatic turbulence.

Journal Article↗

PubMed2005

[Autofluorescence bronchoscopy in early diagnosis of pulmonary carcinoma].

AIM: Autofluorescence bronchoscopy (AFB) has been proposed to widen traditional white light bronchoscopy (WLB) possibilities of early diagnosis of neoplastic and preneoplastic lesions of the tracheo-bronchial mucosa in high risk groups. The authors report their study on AFB with the aim of establishing its role in the early diagnosis of bronchogenic carcinoma and its positive predictive value (PPV) compared and associated to WLB. METHODS: From May 2002 to May 2004 we performed WLB and AFB in 213 patients (177 males, 36 females), mean age 63.7 years (range 18-84 years), who were divided into 2 main groups (group A: patients at risk for bronchogenic carcinoma, n=82; group B: patients to be operated on for bronchogenic carcinoma, n=131). In total, 237 WLB-AFB were performed (101 in group A, 136 in group B) and 77 biopsies for pathological examination. RESULTS: The 2 tools (WLB and AFB) were concordant in 156 (66%) and discordant in 81 (34%) cases. Considering the biopsies performed, we obtained a PPV of 26% for lesions visible with WLB, of 40% for those visible with AFB, of 38% for those visible with the association of both. In group A, in 56 patients of the follow-up subgroup, we found 2 dysplastic areas and 1 carcinoma in situ. In group B there was a discordant extension of the pathologic area visible with WLB and with AFB in 30 cases which was positive in 18 of them at histological examination. CONCLUSIONS: In our experience, AFB has revealed to be a valid tool for both early diagnosis of neoplastic recurrences or a second primary lung neoplasia in patients in follow-up after resection and preoperative evaluation of resection margins in patients candidate to surgery. More studies are needed to widen its indications in the early diagnosis in high risk groups, to improve its potentialities and optimize its learning curve in order to establish the procedural guide lines.

Adult↗

PubMed2004

Vortex-induced diffusivity in reversed field pinch plasmas.

Coherent structures identified in two reversed field pinch experiments are interpreted as a dynamic balance of dipolar and monopolar vortices growing and evolving under the effect of the ExB flow shear. For the first time their contribution to the anomalous transport has been estimated in fusion related plasmas, showing that they can account for up to 50% of the total plasma diffusivity. The experimental findings indicate that the diffusion coefficient associated with the coherent structures depends on the relative population of the two types of vortices and is minimum when the two populations are equal. An interpretative model is proposed to explain this feature.

Journal Article↗

PubMed2004

Multispecific T cell response and negative HCV RNA tests during acute HCV infection are early prognostic factors of spontaneous clearance.

BACKGROUND/AIMS: Hepatitis C virus (HCV) infection results in a high frequency of chronic disease. The aim of this study was to identify early prognostic markers of disease resolution by performing a comprehensive analysis of viral and host factors during the natural course of acute HCV infection. METHODS: The clinical course of acute hepatitis C was determined in 34 consecutive patients. Epidemiological and virological parameters, as well as cell mediated immunity (CMI) and distribution of human leukocyte antigens (HLA) alleles were analysed. RESULTS: Ten out of 34 patients experienced self-limiting infection, with most resolving patients showing fast kinetics of viral clearance: at least one negative HCV RNA test during this phase predicted a favourable outcome. Among other clinical epidemiological parameters measured, the self-limiting course was significantly associated with higher median peak bilirubin levels at the onset of disease, and with the female sex, but only the latter parameter was independently associated after multivariate analysis. No significant differences between self-limiting or chronic course were observed for the distribution of DRB1 and DQB1 alleles. HCV specific T cell response was more frequently detected during acute HCV infection, than in patients with chronic HCV disease. A significantly broader T cell response was found in patients with self-limiting infection than in those with chronic evolving acute hepatitis C. CONCLUSION: The results suggest that host related factors, in particular sex and CMI, play a crucial role in the spontaneous clearance of this virus. Most importantly, a negative HCV RNA test and broad CMI within the first month after onset of the symptoms represent very efficacious predictors of viral clearance and could thus be used as criteria in selecting candidates for early antiviral treatment.

Adult↗

PubMed2003

Case fatality rate of acute viral hepatitis in Italy: 1995-2000. An update.

BACKGROUND: Fulminant hepatic failure is the most serious complication of viral hepatitis. Although this event occurs rarely, it may be fatal. AIMS: To evaluate the case fatality rate (several deaths divided by number of cases x 100) for each viral hepatitis type in Italy from 1995 to 2000. PATIENTS: Acute hepatitis cases identified by the surveillance system for acute viral hepatitis, which covers approximately 58% of the Italian population. RESULTS: Twenty-five deaths (0.1%) occurred among the 18 460 acute viral hepatitis cases observed from 1995 to 2000, a rate threefold lower than the 0.3% reported during the period 1985-1994. The highest case fatality rate (0.4%) was seen for acute hepatitis B (18 deaths among 4257 cases). Only one death (0.01%) occurred among the 11 063 acute hepatitis A cases and two deaths (0.1%) among the 1536 acute hepatitis C cases. No deaths were observed among the 309 acute hepatitis A cases superimposed on chronic HBsAg carriers and the 166 superimposed on chronic HCV carriers. Intravenous drug use (22.2% of cases) and other parenteral exposures (22.2% of cases) were the most frequent non-mutually exclusive sources of infection reported by subjects who died of acute hepatitis B. CONCLUSIONS: Analysis of surveillance system data from 1995 to 2000 indicates that, in Italy, deaths due to acute viral hepatitis are rare, but most commonly observed with acute hepatitis B. There is no evidence that acute hepatitis A may be fatal in chronic HBsAg or HCV carriers. The overall better survival rate may probably reflect improvements in the treatment of fulminant hepatitis in the last few years in Italy.

Acute Disease↗

PubMed2001

Transport processes in reversed-field-pinch plasmas: inconsistency with the self-organized-criticality paradigm.

A statistical analysis of the anomalous particle flux in the edge region of the RFX experiment has revealed that laminar times between bursts, which account for more than 50% of the losses, have a power law distribution and that flux fluctuations are not self-similar. These properties are found in contrast with a wide class of self-organized-criticality models so that it is concluded that there is no experimental evidence of avalanchelike process occurrence in the plasma of RFX.

Journal Article↗

PubMed2001

Search of self-organized criticality processes in magnetically confined plasmas: hints from the reversed field pinch configuration.

In order to test the self-organized criticality (SOC) paradigm in transport processes, a novel technique has been applied for the first time to plasmas confined in reversed field pinch configuration. This technique consists of an analysis of the probability distribution function of the times between bursts in density fluctuations measured by microwave reflectometry and electrostatic probes. The same analysis has also been applied to intermittent events sorted out from the Gaussian background. In both cases, the experimental results disagree with the predictions for a SOC system.

Journal Article↗

PubMed2001

Risk of parenterally transmitted hepatitis following exposure to surgery or other invasive procedures: results from the hepatitis surveillance system in Italy.

BACKGROUND/AIMS: To evaluate the strength of association between parenterally transmitted viral hepatitis and specific types of invasive procedures. METHODS: Data from the surveillance system for type-specific acute viral hepatitis (SEIEVA) during the period 1994-1999 were used. The association of acute hepatitis B virus (HBV) and hepatitis C virus (HCV) infection with the potential risk factors (odds ratios (OR)) was estimated comparing 3120 hepatitis B and 1023 hepatitis C cases with 7158 hepatitis A cases, used as controls, by multiple logistic regression analysis. RESULTS: Most procedures resulted in being associated with the risk of acquiring acute HBV or HCV. The strongest associations were: for HBV infection, abdominal surgery (adjusted OR = 3.9; 95% confidence intervals (CI) = 2.0-7.5), oral surgery (OR = 2.7; 95% CI = 1.6-4.5) and gynaecological surgery (OR = 2.6; 95% CI = 1.2-5.5); for HCV infection, obstetric/gynaecological interventions (OR = 12.1; 95% CI = 5.6-26.3), abdominal surgery (OR = 7.0; 95% CI = 3.2-14.9) and ophthalmological surgery (OR = 5.2; 95% CI = 1.1-23.2). Biopsy and/or endoscopy were associated with HCV, but not with HBV infection. CONCLUSIONS: Invasive procedures represent an important mode of HBV and HCV transmission. Since a large proportion of the adult general population is exposed to these procedures and an effective HCV vaccine is not yet available, non-immunological means of controlling iatrogenic modes of transmission are extremely important.

Adolescent↗

PubMed2001

Changing epidemiology of parenterally transmitted viral hepatitis: results from the hepatitis surveillance system in Italy.

BACKGROUND: In 1991, compulsory hepatitis B virus vaccination and screening for anti-hepatitis C virus of blood banks were introduced in Italy. AIM: To evaluate the impact of preventive measures on the incidence and risk factors for parenterally transmitted viral hepatitis. METHODS: Data from the surveillance system for acute viral hepatitis for the period 1985-99 were used. Temporal trends in distribution of reported risk factors were analysed by comparing three-year periods: 1987-89 and 1997-99. RESULTS: The incidence (no. cases per 100,000 population) of hepatitis B was 12 in 1985 and 3 in 1999; the incidence of hepatitis non-A, non-B decreased from 5 to 1 in the same period. These decreases were more evident among young adults and before rather than after 1991. Multiple sexual partners, other parenteral exposures and dental treatment remain the most common risk factors for parenterally transmitted viral hepatitis. An increase in frequency over time was observed for other parenteral exposures, whereas a marked decrease was evident for blood transfusion and household contact with an HB-sAg carrier. Invasive medical procedures continue to represent an important source of infection. Intravenous drug use was reported particularly by young adults with non-A, non-B hepatitis, with increased frequency over time. CONCLUSIONS: Non-immunologic measures for preventing hepatitis B and non-A, non B due to iatrogenic and other parenteral exposures, combined with hepatitis B virus vaccination, could further reduce parenteral transmission.

Acute Disease↗

PubMed2000

Molecular evolution of HCV genotype 2c persistent infection following mother-to-infant transmission.

The molecular evolution of HCV 2c in a case of vertical transmission was studied by comparing the virus quasispecies in the sera from the mother and from the child in a two-year follow-up. The positivity of HCV-RNA since the delivery accounted for an in-utero infection. The Core-E1 genome region (nt 928-1225) was amplified by polymerase chain reaction (PCR) from serum samples collected at delivery and at 3, 9, 18 and 24 months after birth. The RIBA pattern was characterised by isolated anti-c22 positivity in the serum from mother and in sera from the child during the first 9 months. Additional presence of anti-c33 was observed afterwards. Genetic relatedness among isolates and with a mother minor variant serum (Mo1. 13) was found (mean variability ranged between 0.79% and 1.20%). From phylogenetic analysis this variant was identified as the origin of one of the two main lineages that included all isolates from child sera at 9, 18 and 24 months. The variability analysis has shown that high viral heterogeneity is present in the child serum collected at birth (3.16%). In this phase the dn/ds index (1.26%) indicates the presence of strong selective pressures. The development of child specific immune response at 9th month was concurrent with the disappearance of two mutants at positions 11 and 104 of E1. This rare case of in-utero mother-to-infant transmission can be considered as a model to elucidate the HCV quasispecies diversification during the first stage of infection.

Adult↗

PubMed1998

Correlation between virus genotype and chronicity rate in acute hepatitis C.

BACKGROUND/AIMS: Forty-two patients with the diagnosis of acute hepatitis C virus hepatitis were studied to investigate the relationship between hepatitis C virus genotype and progression to chronic infection. METHODS: The patients were followed for more than 1 year (mean age 29 years, male/female ratio 2.5). Intravenous drug use was documented in 15 cases, blood transfusion in four, surgical intervention, dental therapy or other parenteral exposure in 15, and unknown factors in the remaining eight. The evolution to chronicity was diagnosed on the basis of a persistent increase in transaminase levels, the presence of HCV-RNA and the histological pattern of chronic hepatitis. RESULTS: The majority of cases presented hepatitis C virus infection of subtype 1a (38.1%) or 1b (33.9%). Six cases showed the presence of genotype 3a (14.3%). Subtype 2c was observed in three out of four cases infected with genotype 2. No significant association was demonstrated with documented risk factors. The overall chronicity rate was 59.5%. This value increased to 92% in individuals infected with genotype 1b. By multivariate analysis the age-adjusted odds ratio for infection with genotype 1b as compared with all other genotypes was 14.4 (95% confidence interval; 1.52-137). Moreover, significant differences (p= 0.0002) were present in this group for histological activity index (8.7 as compared with 5-7). CONCLUSIONS: The results of this prospective study are consistent with an independent association between hepatitis C virus genotype 1b and a poor prognosis.

Acute Disease↗

PubMed1997

High dosage alpha-interferon for treatment of children and young adults with chronic hepatitis C disease.

BACKGROUND: There are limited data on the use of high interferon (IFN) dosage for treatment of children and young adults with hepatitis C virus infection and in those affected by thalassemia major (TM). OBJECTIVES: To assess the response of children and young adults with chronic hepatitis C disease, including those affected by TM, to high dose natural alpha-interferon (IFN-alpha). To evaluate the effect of iron overload in response to high dose IFN-alpha in young chronic hepatitis C virus thalassemia patients. METHODS: We conducted a therapeutic trial of natural IFN-alpha, using 10 million units/m2 three times a week for 6 months in 14 chronic hepatitis C patients ages 5 to 28 years; 7 also had TM. The follow-up period lasted 12 months. RESULTS: Ten patients (73%) showed normal or nearly normal alanine aminotransferase values at the end of follow-up (biochemical response), but only five (35%) were negative for serum hepatitis C virus-RNA (complete responders). Four of the patients (57%) with TM were sustained complete responders. No correlation was found between the initial serum concentration of ferritin and response to IFN therapy. Patients infected with genotype 1b showed a poor response although high dose of natural IFN was used. CONCLUSIONS: These results indicate that IFN-alpha can be used in children and young patients with chronic hepatitis C disease as well as in those affected by TM. Treatment with high dosage natural IFN-alpha in children and young adults with hepatitis C infection does not appear to be more effective than dosages previously used.

Adolescent↗

PubMed1996

Heterogeneity of hepatitis C virus genotype 2 variants in West Central Africa (Guinea Conakry).

An overall anti-hepatitis C virus (HCV) prevalence of 6.7% was found in a sero-epidemiological study carried out in the town of Conakry (Guinea Conakry, West Central Africa) on 1421 subjects who were either blood donors, pregnant women or in- and outpatients receiving treatment for conditions other than liver disease. Seven HCV isolates from a subsample of 73 sterile sera from this population were studied for genetic characterization and classification. The 5'NCR was analysed by the Line Probe Assay. This method assigned the isolates to genotype 2. Analysis of the 5'NCR sequences alone was unable to give a more accurate classification. Comparison of NS5b region sequences (nucleotides 7575-8196), from Guinea isolates and genotype 2 database sequences, showed evolutionary distances in the range 0.15-0.26. There was a high level of subtype heterogeneity among the genotype 2 Guinea HCV isolates. Four of the subtypes were possibly new.

Base Sequence↗

PubMed1996

Partitioning of inspiratory muscle workload and pressure assistance in ventilator-dependent COPD patients.

To investigate the mechanisms underlying ventilator-dependence in patients with chronic obstructive pulmonary disease (COPD), and to assess the effects of the combination of positive end-expiratory pressure (PEEP) and pressure-support ventilation (PSV) on inspiratory muscle effort, we investigated respiratory mechanics in eight ventilator-dependent COPD patients. The patients' breathing pattern, lung mechanics, diaphragmatic effort (PTPdi), diaphragmatic tension-time index (TTdi), and arterial blood gases were measured during both spontaneous breathing (SB) and ventilatory assistance consisting of PSV alone (15, 20, and 25 cm H2O) and PSV combined with a PEEP of 5 cm H2O (reducing PSV to 10, 15, and 20 cm H2O, respectively, to maintain equivalent inspiratory pressure). The different levels of ventilatory support were delivered in a randomized sequence. Maximal inspiratory (MIP), esophageal (PpImax) and transdiaphragmatic (Pdi(max)) pressures and respiratory drive (P(0.1)) were measured at the beginning of the procedure during SB. We found a high P(0.1) (6.1 +/- 1.7 cm H2O), which seemed to rule out an impairment of respiratory-center output. Apparently, inspiratory muscle strength was compatible with successful weaning (38.5 +/- 8.8, 50.9 +/- 9.7, and 51.8 +/- 9.5 cm H2O for MIP, PPImax and Pdi(max), respectively). However, abnormal respiratory mechanics (particularly an intrinsic positive end-expiratory pressure (PEEPi) of 8.3 +/- 1.9 cm H2O and pulmonary resistance 24.7 +/- 9.5 cm H2O/L/s imposed an excessive load on the inspiratory muscles, as indicated by a high PTPdi (499 +/- 122 cm H2O x s). Increasing levels of PSV progressively and significantly unloaded the patients' inspiratory muscles, although at pressures above 20 cm H2O uncoupling occurred between patient and ventilator respiratory frequency. Application of PEEP during PSV improved ventilatory assistance by further reducing the inspiratory effort (by 17% on average) and by ameliorating patient-ventilator interaction. We conclude that the excessive mechanical load, and in particular the high PEEPi, is the major determinant of ventilator-dependence in COPD patients. Application of PEEP improves the efficiency of PSV in unloading these patients' inspiratory muscles, and can sometimes improve patient-ventilator interaction.

Aged↗

PubMed1995

Recombinant interferon-alpha and ursodeoxycholic acid versus interferon-alpha alone in the treatment of chronic hepatitis C: a randomized clinical trial with long-term follow-up.

OBJECTIVES: The purpose of this study was to compare, within a randomized controlled trial, the efficacy of recombinant interferon-alpha in combination with ursodeoxycholic acid versus interferon-alpha alone in the treatment of chronic HCV hepatitis. METHODS: Forty anti-HCV positive chronic hepatitis patients with ALT levels persistently greater than 3 times the upper normal level were randomized to receive either interferon-alpha (6 million units three times/wk for 6 months) plus ursodeoxycholic acid (10 mg/kg/day for 9 months) (n = 20) or interferon-alpha (6 million units three times/wk for 6 months) alone (n = 20). Disease activity was monitored monthly by ALT measurement until 18 months after interferon-alpha cessation. Serum HCV-RNA was measured at baseline and after 6, 9, and 24 months. Liver biopsies (basal and at the 9th month) were evaluated blindly and scored by Knodell's criteria. RESULTS: The probability of full or partial response during interferon-alpha treatment was similar in the two groups. The probability of biochemical relapse (i.e, any persistent return of ALT above normal) after 18-month of posttreatment follow-up was 75% in both the combination and the monotherapy group. Relapse, however, occurred significantly later in the combination than in the monotherapy group (6.6 +/- 5.4 [SD] months and 1.8 +/- 1.6 months after IFN-alpha cessation, respectively, p < 0.02). Severe biochemical relapse (i.e., a persistent ALT elevation greater than 3 times normal) occurred more frequently and earlier (p = 0.05) in patients treated with interferon-alpha (58.3%) than in those receiving the combination therapy (27.3%). The cumulative duration of normalized ALT periods during and after treatment was significantly greater (p = 0.005, chi 2) in patients treated with IFN-alpha + UDCA than with monotherapy (189/354 months vs 136/323 months. Lobular necrosis improved in both groups (p = 0.056 and p = 0.001, respectively), whereas portal inflammation improved (p = 0.009) only in the combination therapy group. Among the 30 patients who were viremic at entry, plasma HCV-RNA was no longer detectable after 6 months in four from the combination group and in five from the monotherapy group, yet all patients but one returned HCV-RNA positive 3 months after interferon-alpha cessation and were still viremic after 18 months. Cox's multiple regression identified the histological degree of posttreatment portal inflammation as the sole positive indicator of relapse. CONCLUSIONS: The combination of interferon-alpha and ursodeoxycholic acid prolongs the efficacy of interferon-alpha alone in chronic hepatitic C by delaying the probability of biochemical relapse and/or by reducing its severity, without affecting HCV viremia.

Adult↗

PubMed1994

Incidence of hepatitis B virus infection among an Italian military population: evidence of low infection spread.

In 1990, a prospective serological survey to estimate the rate of clinical and inapparent infection with hepatitis B virus was performed in a cohort of 1324 soldiers, 18-24 years old, during an eight-month period in Italy. At the time of enrollment the prevalence of hepatitis B markers was 4.6% (0.7% subjects positive for hepatitis B surface antigen [HBsAg], 3.0% positive for antibody to hepatitis B surface antigen [anti-HBs], and 0.9% positive for antibody to hepatitis B core antigen [anti-HBc] alone. Among the 1263 susceptible subjects who were followed-up, only 2 (0.24/100 person-years of exposure) had seroconversion for HBV markers, none of which was associated with clinical illness. Among the 9 subjects HBsAg-positive at the time of enrollment, 1 (11.2%) had lost HBsAg at the end of follow-up. These data show a low spread of HBV infection among Italian young generations.

Adolescent↗