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Biomedical subjects

F Leone

Publications and source records attributed to F Leone.

At least 19 recordsLinked to original sources
PubMed2003

Magnetization transfer changes of grey and white matter in Parkinson's disease.

Since the attempt to evidence structural brain damage in Parkinson's disease (PD) by conventional magnetic resonance imaging (MRI) is usually disappointing, we have investigated whether the magnetization transfer ratio (MTR) can reflect changes in grey and white matter of PD patients. MTR was quantified in 44 regions of interest (ROIs) in both grey and white matter of 11 non-demented PD patients, ranging from 2 to 4 on the Hoehn and Yahr Scale, and eight age-matched healthy subjects. MTR differences between patients and controls were found in the supratentorial white matter and in the brainstem. In particular, lower MTR values were found in the paraventricular white matter of PD patients (p<0.05) while no differences were observed in corpus callosum, frontal, parietal, occipital lobes or centrum semiovalis. Lower MTR values were found in substantia nigra (p<0.001), red nucleus (p<0.05) and pons (p<0.05) of the patient group. No differences were discovered in basal ganglia and thalamus. These findings suggest that MTR measurements in the paraventricular white matter and brainstem may help to recognize a marker for probable PD.

Aged↗
PubMed2003

Efficacy of granulocyte transfusions for neutropenia-related infections: retrospective analysis of predictive factors.

BACKGROUND: The transfusion of G-CSf-primed granulocytes (GTX) might represent an important treatment option for neutropenia-related infections unresponsive to conventional antimicrobial therapies and to recombinant hematopoietic growth factors. However, few studies to date have identified the factors that can predict clinical outcome and the patient populations who are likely to benefit most from GTX. The primary endpoint of the present retrospective study was to evaluate the efficacy of GTX in 22 patients with hematological malignancies who developed neutropenia-related bacterial and fungal infections that were unresponsive to appropriate antimicrobial therapies. METHODS: Peripheral blood granulocytes were collected by continuous-flow leukapheresis from HLA-identical siblings after priming with G-CSF. The response to GTX was classified as 'favorable' if clinical symptoms and signs of infection resolved or 'unfavorable' if clinical symptoms and signs of infection were unchanged or worsened. Control of infection at Day 30 after the enrollment in the GTX program was considered as the outcome variable in multiple regression analysis. RESULTS: Two patients died of infection before receiving the granulocyte concentrates. Bacterial infections (monomicrobial or mixed bacteremias) were documented in 11 patients, whereas fungal infections (fungemia or focal fungal infections) were diagnosed in seven patients. In two patients, no infecting agent could be isolated (clinical infection). Control of infection at Day 30 after the first GTX was achieved in 10 of 20 assemble patients. Overall, 54% of patients with bacterial infections had a favorable response, compared with 57% of patients with fungal infections. No differences in terms of survival were found when comparing patients with bacterial and those with fungal infections at a median follow-up 90 days from the first GTX. In univariate analysis, disease status before GTX, e.g., complete or partial remission, and spontaneous recovery of the neutrophil count were significantly associated with control of infection. when multivariate regression models were formed, the recovery 0.5 x 10 (9)/L PMN was the only parameter that significantly and independently correlated with a favorable response to GTX. DISCUSSION: GTX can be used to successfully treat bacterial as well as fungal infections in severely neutropenic patients when administered early after the onset of febrile neutropenia in patients with remission of the underlying disease and who are likely to recover marrow function.

Adult↗
PubMed2001

Glycopeptide resistance among coagulase-negative staphylococci that cause bacteremia: epidemiological and clinical findings from a case-control study.

A 1-year prospective case-control study (ratio of control patients to case patients, 3:1) was performed to assess the incidence, risk factors, and genotypic patterns of bacteremia caused by glycopeptide-resistant coagulase-negative staphylococci (CoNS) and their correlation with hospital glycopeptide use. Among 535 subjects with CoNS bacteremia, 20 subjects had a glycopeptide-resistant strain (19 strains were resistant to teicoplanin and 1 was resistant to both teicoplanin and vancomycin). The percentage of resistant isolates recovered in 1 year was 8% in intensive care units and 3% and 2% in medical and surgical wards, respectively. Genotypic analysis of resistant strains showed different patterns with a high degree of polymorphism. Use of glycopeptides in individual wards was not statistically associated with the percentage of resistance. Previous exposure to beta-lactams and glycopeptides, multiple hospitalization in the previous year, and concomitant pneumonia were significantly associated with the onset of glycopeptide-resistant CoNS bacteremia. Mortality rates were 25% among case patients and 18% among control patients, and they were significantly higher among patients who presented with concomitant pneumonia and a high Acute Physiology and Chronic Health Evaluation III score.

Aged↗
PubMed2001

Detection of breast cancer cell contamination in leukapheresis product by real-time quantitative polymerase chain reaction.

Identification of sensitive techniques for breast cancer cell detection might be relevant for high-dose chemotherapy programs with autologous stem cell transplantation. We investigated the feasibility of Maspin, Mammaglobin and c-ErbB-2 amplification by real-time quantitative polymerase chain reaction (RQ-PCR) for the detection of breast cancer cells in leukaphereses. Expression of the three markers was determined in primary breast cancers and cell lines. Peripheral blood (PB), bone marrow (BM), and leukapheresis samples from patients with malignancies other than breast cancer were used as controls. Sensitivity was evaluated by dilution of primary tumors and cell lines with mononuclear blood cells. We found expression of the three markers in all primary tumors and most cell lines. No blood specimen from control patients had the Maspin transcript, while only one was positive for Mammaglobin. Weak c-ErbB-2 expression was detectable in most PB, all BM and all leukapheresis samples from controls. We observed a low sensitivity of Maspin RQ-PCR and a sensitivity of Mammaglobin RQ-PCR up to one tumor cell in 10(6) mononuclear cells. One out of 18 leukaphereses from breast cancer patients screened for the presence of Mammaglobin mRNA was positive. We conclude that Mammaglobin RQ-PCR might be a useful tool for detection of leukapheresis contamination.

Blood↗
PubMed2001

Efficacy of nonwoven fabric bioreactor immobilized with porcine hepatocytes for ex vivo xenogeneic perfusion treatment of liver failure in dogs.

We have developed a new bioartificial liver bioreactor filled with porcine hepatocytes immobilized on polyester nonwoven fabric (NWF). In this study, we investigated the efficacy of our hybrid bioartificial liver system incorporating the NWF bioreactors and an immunoglobulin adsorbent column for perfusion treatment in a canine liver failure model. Xenogeneic perfusion treatment for operative canine liver failure models were performed for 3 h, and survival time, intracranial pressure, and blood and cerebrospinal fluid data were documented. Treatment was carried out without obstruction by immunological rejection when immunoglobulin adsorbent columns were used with the NWF bioreactors in combination. Dogs treated with this system exhibited a restricted increase of intracranial pressure and significant compensatory effects on blood and cerebrospinal amino acid imbalances as shown by a significant improvement of Fischer's ratio. On the other hand, relatively low capacity for ammonia elimination was shown as compared with homologous direct hemoperfusion.

Animals↗
PubMed2000

HIV-associated bacteremia: how it has changed in the highly active antiretroviral therapy (HAART) era.

To evaluate the changing characteristics of HIV-associated bacteremia in the highly active antiretroviral therapy (HAART) era, we conducted a prospective case control study, comparing two periods of time, before (period A) and after (period B) the introduction of HAART. In total, 174 patients with bacteremia and 348 controls were studied. By comparing incidence in periods A and B, a statistically significant reduction of bacteremia, from 11.8 to 6.3/100 person-years (PY), was observed (p = .0001). Incidence of hospital-acquired bacteremia decreased from 5.8 episodes/100 PY in period A to 2.4/100 PY in period B (p = .0005). A similar trend was also observed for community-acquired episodes of bacteremia, with a value close to statistical significance. Logistic regression analysis indicated that intravenous drug abuse, central venous catheter (CVC) use, high value on APACHE III score, and neutropenia were independent risk factors for bacteremia in both the study periods. Interestingly, comparing the prevalence of bacteremia risk factors in the two study periods, we observed a significant reduction in the use of CVC (p = .04, period A versus period B) and in neutropenia (p = .04). The crude mortality rate was 31% in period A and 23% in period B (p = not significant [ns]). Logistic regression analysis indicated that an high value of Acute Physiology and Chronic Health Evaluation III (APACHE III) score (p < .001) predicted an increased risk of death. Analysis of prognostic factors of bacteremia did not significantly differ in both the study periods. We conclude that HAART has determined a significant reduction of the incidence and a modification of the characteristics of bacteremia. This reduced incidence may produce a substantial impact on future morbidity and health care costs of patients with HIV.

AIDS-Related Opportunistic Infections↗
PubMed2000

Morbidity associated with central venous catheter-use in a cohort of 212 hospitalized subjects with HIV infection.

Technical complications and nosocomial bloodstream infections associated with short-term central venous catheterization remain a heavy burden in terms of morbidity, mortality and cost in HIV-positive subjects. Between 1994 and 1997, 327 central venous catheters (CVCs) inserted in 212 patients for a total of 5005 catheter days were investigated. Forty-two technical complications (13%) occurred in 40 patients. Logistic regression analysis revealed that a high APACHE III score was associated with development of CVC-related complications (P = 0.01). One hundred and eight of 327 CVCs (33%) were suspected as being infected. However only 61 episodes (61/327, 19%) were finally diagnosed as CVC-related sepsis. Three variables affecting the rate of CVC-related sepsis were identified: 1) administration of TPN (P = 0.01); 2) low number of circulating CD4+ cells (P = 0.04); 3) high APACHE III score (P = 0. 04). Doctors responsible for AIDS patients should carefully consider the relative risks and benefits of CVC insertion in an individual patient.

AIDS-Related Opportunistic Infections↗
PubMed1999

RANTES and MCP-1 chemokine plasma levels in chronic renal transplant dysfunction and chronic renal failure.

OBJECTIVES: Procedures to diagnose renal allograft rejection depend on detection of graft dysfunction due to the presence of mononuclear leukocytic infiltrates. DESIGN AND METHODS: In our study, we pursued an immunodiagnostic approach utilizing an ELISA method on plasma samples to monitor patients waiting to undergo transplantation in order to evidence prognostic developments in renal transplantation and, at least, to diagnose renal chronic transplant dysfunction. We analyzed blood levels of two chemokines, RANTES and MCP-1, which are normally overexpressed locally in renal chronic rejection. RESULTS: Our results showed that patients affected by chronic renal failure (and waiting for kidney transplant), as well as kidney-grafted patients affected by chronic transplant dysfunction, had plasma levels of RANTES significantly higher than those of controls (patients without acute or chronic pathologies). CONCLUSIONS: Our data suggest a simple method to evaluate the plasmatic presence of RANTES, which could be involved in longterm kidney graft failure.

Adolescent↗
PubMed1999

Epidemiological and virological analysis of couples infected with hepatitis C virus.

BACKGROUND: If transmission of hepatitis C virus (HCV) infection through parenteral exposure is well documented, sexual transmission of HCV is still debated. AIMS: To perform extensive epidemiological and virological analysis in 24 couples in which each spouse was anti-HCV positive in order to delineate more precisely potential sexual transmission of HCV. PATIENTS: Twenty four couples in which each partner was anti-HCV positive. These 48 spouses were recruited in a liver unit by regular screening of spouses of index patients. METHODS: All 48 spouses completed an epidemiological questionnaire on risk factors for HCV. Qualitative detection of serum HCV RNA and determination of HCV type by genotyping and serotyping were performed. Sequence analysis of HCV strains by phylogenetic analysis was carried out in seven couples with concordant genotypes. RESULTS: The mean (SD) partnership duration was 12 (10) years. Serum HCV RNA was detected in both partners in 18 of the couples (75%) and in only one partner in six of the couples (25%). HCV typing showed concordant genotypes in 12 couples (50%), discordant genotypes in seven (29%), and in the other five couples (21%) only one spouse could be genotyped. Of the 48 spouses, 33 had a major risk factor for HCV transmission such as transfusion (n = 6) and intravenous drug use (n = 27). Eleven of the 12 couples infected with the same HCV genotype had at least one parenteral risk factor for viral transmission in both spouses. Whatever the genotype concordance, in most couples (75%), both spouses showed parenteral risk factors for viral transmission. Sequence analysis of HCV strains was possible in seven of 12 couples with identical genotype and showed different and identical isolates in four and three couples respectively. CONCLUSION: The study emphasises the risk of overestimating the importance of a very low sexual HCV transmission risk as against other, mainly parenteral, risk factors.

Adult↗
PubMed1999

Immunohistochemical study of collagens of the extracellular matrix in cartilage of Sepia officinalis.

We used various anti-collagen antibodies to perform indirect immunofluorescent staining of cartilage sections from cuttlefish (S. officinalis). On ultrathin sections and collagen fibril preparations from the same tissue, we performed immunostaining with colloidal gold. The extracellular matrix (ECM) of S. officinalis cartilage reacted intensely and homogeneously with an antibody directed against type I-like collagen isolated from the cartilage of cuttlefish and with anti-rat type V collagen antibody. A weak reaction was observed with anti-fish and anti-chicken type I collagen antibodies, while no reaction was observed with anti-rat type I and anti calf type II collagen antibodies. Anti-chicken type II, anti calf type IX and type XI collagen antibodies reacted weakly with ECM, while stained cell bodies and cell processes reacted more intensely. A similar pattern of reaction was observed on cartilage section and isolated collagen fibrils prepared for electron microscopy. These findings suggest that ECM of cuttlefish cartilage may be composed of molecules similar to the type I, type V, type IX and type XI collagen molecules of vertebrates. Cephalopods have evolved a cartilage of structure and macromolecular organisation similar to that of vertebrate cartilage. However, the main molecular components of S. officinalis cartilage--type I-like and type V collagens--differ from those of vertebrate cartilage. We suggest that this type I-like collagen can be considered an initial step toward the evolution of type II collagen typical of vertebrates.

Animals↗
PubMed1998

Nosocomial bloodstream infections in HIV-infected patients: attributable mortality and extension of hospital stay.

A 3-year prospective matched case-control study was performed to investigate the potential risk factors, prognostic indicators, extension of hospital stay, and attributable mortality of nosocomial bloodstream infections in HIV-infected patients. Matching variables were: age, gender, number of circulating CD4+ T lymphocytes, cause of hospital admission, hospitalization in the same ward within the 6 weeks of diagnosis of the case, and length of stay before the day of infection in the case. Eighty-four cases and 168 matched controls were studied. Nosocomial bloodstream infections complicated about 3 of 1000 hospital days per patient in the study period. With step-wise logistic regression analysis, the most important predictors for developing nosocomial bloodstream infections were: increasing value of Acute Physiology and Chronic Health Evaluation (APACHE II) score (p = .001) and use of central venous catheter (CVC) (p = .002). The excess of hospital stay attributable to nosocomial bloodstream infections was 17 days. The crude mortality rate was 43%. The attributable mortality rate was estimated to be 27% (95% confidence interval [CI] = 13%-48%). The estimated risk ratio for death was 3.91 (95% CI = 2.06-7.44). Multivariate analysis identified two prognostic indicators that were significantly associated with unfavorable outcome of bloodstream infections: number of circulating CD4+ T cells <100/mm3 (p = .002) and APACHE II score >15 (p = .01). Nosocomial bloodstream infections are more common in patients with advanced HIV disease. Important cofactors are high APACHE II score and use of CVC. These infections can cause an excess mortality and significantly prolong the hospital stay of HIV-infected patients.

Adult↗
PubMed1998

Hepatitis C virus (HCV) hypervariable region 1 complexity does not correlate with severity of liver disease, HCV type, viral load or duration of infection.

BACKGROUND/AIMS: Several studies have suggested that infection with a highly heterogeneous population of hepatitis C virus correlates with a low response rate to interferon. It is still debated, however, whether or not this heterogeneity might be associated with liver disease severity. The aim of this study was to analyse hepatitis C virus genome complexity in patients with various stages of liver disease. METHODS: We used polymerase chain reaction-single strand conformation polymorphism (SSCP) analysis to estimate the degree of complexity of the hypervariable region (HVR1) in 95 anti-HCV and serum HCV-RNA positive patients. They were divided into two groups according to Knodell's histological activity index (HAI) grading: 22 with HAI <4 and 73 with HAI> or =4, including 19 with cirrhosis. RESULTS: The number of visible SSCP bands ranged from 1 to 7. There was no significant difference in the number of SSCP bands between patients with HAI <4 and patients with HAI> or =4 (median number of bands was 4 in both groups). The number of SSCP bands was not correlated to the biochemical activity, the genotype, the HCV-RNA titre or the duration of hepatitis C virus infection. CONCLUSIONS: The HCV-HVR1 complexity profile alone does not correlate with the severity of liver disease, whatever the biological and virological profile of the viral infection.

Female↗
PubMed1998

Hypothesis: interleukin-5 production impairment can be a key point in the pathogenesis of the MHC-linked selective IgA deficiency.

Selective IgA deficiency (IgA-D) is associated with the expression of some human leukocyte antigens (HLA) haplotypes and Major Hystocompatibility Complex (MHC) gene products have been suggested to be involved in the regulation of IgA synthesis. Recently, we have obtained evidences indicating that MHC influences the production of IgA and interleukin-5 (IL-5) both in humans and in mice. Lymphnode cells from pychril chloride (PC1) immunised BALB/c mice (bearing the H-2d haplotype) fail to produce IL-5 when stimulated in vitro with PC1 and this correlates with low antigen specific IgA production in vivo. In contrast using congenic BALB/k mice (bearing the H-2k haplotype) an high production both of IL-5 and of PC1-specific IgA is observed. Moreover, in vivo or in vitro administration of IL-5 to BALB/c mice was able to increase the production of antigen specific IgA. Similar evidences have been obtained by evaluation of the HLA influence on circulating immunoglobulin levels and interleukin production in normal HLA typed subjects. In fact HLA-B8, DR3 positive subjects show reduced level of serum IgA and their peripheral blood mononuclear cells stimulated with mitogen produce significantly reduced amounts of IL-5, IL-12, IL-2 and Interferon-gamma. We hypothesise that HLA-B8, DR3 associated IgA deficiency, known to be asymptomatic, can be due to a lack of subsequent signals, in particular of IL-5, involved in the late regulation of B cell differentiation. Preliminary evidences demonstrating that low amounts of human recombinant IL-5 are able to reconstitute IgA production by cells from HLA-B8, DR3 IgA-D subjects, seem to confirm this hypothesis.

Animals↗