Interferon (IFN) monotherapy significantly reduces the chronicity rate of acute hepatitis C (AHC) but optimal regimen and treatment timing remain undefined. The aim of this study was to assess the ...efficacy of a 6-month course of pegylated IFN (PEG-IFN) α-2b monotherapy in AHC patients and to investigate if IFN treatment initiated after 12 weeks from clinical presentation, still achieved a high response rate.
Sixteen AHC patients still viremic after 12 weeks from the onset were treated with PEG-IFN α-2b (1.5
mcg/kg once weekly) for 6 months and followed for at least 12 months. Response to therapy was defined as normal ALT values and undetectable HCV RNA (<50
IU/ml) at the end of therapy, after 6 (sustained response) and 12 months follow-up (long-term response).
At the end of treatment, HCV RNA was undetectable in 15/16 patients while ALT normalized in 14/16 patients. After 6 and 12 months follow-up, 15/16 patients (94%) showed virological and biochemical response.
A 6-month course of PEG-IFN α-2b is effective in inducing resolution of AHC in 94% of patients. Our results provide a rationale for delaying treatment for 12 weeks, targeting only patients who fail to clear the virus spontaneously and truly requiring therapy without loss of efficacy.
Interferon (IFN) monotherapy significantly reduces the chronicity rate of acute hepatitis C (AHC) but optimal regimen and treatment timing remain undefined. The aim of this study was to assess the ...efficacy of a 6-month course of pegylated IFN (PEG-IFN) alpha-2b monotherapy in AHC patients and to investigate if IFN treatment initiated after 12 weeks from clinical presentation, still achieved a high response rate.
Sixteen AHC patients still viremic after 12 weeks from the onset were treated with PEG-IFN alpha-2b (1.5 mcg/kg once weekly) for 6 months and followed for at least 12 months. Response to therapy was defined as normal ALT values and undetectable HCV RNA (<50 IU/ml) at the end of therapy, after 6 (sustained response) and 12 months follow-up (long-term response).
At the end of treatment, HCV RNA was undetectable in 15/16 patients while ALT normalized in 14/16 patients. After 6 and 12 months follow-up, 15/16 patients (94%) showed virological and biochemical response.
A 6-month course of PEG-IFN alpha-2b is effective in inducing resolution of AHC in 94% of patients. Our results provide a rationale for delaying treatment for 12 weeks, targeting only patients who fail to clear the virus spontaneously and truly requiring therapy without loss of efficacy.
To assess hepatitis C virus (HCV) incidence rates and identify determinants of infection among hemodialysis patients, a multicenter study was conducted in 58 units in Italy. An initial seroprevalence ...survey was conducted among 3,492 patients already on hemodialysis therapy as of January 1997 and among an additional 434 patients who began dialysis up to January 1998. HCV antibodies were assessed by third-generation enzyme Immunoassays. Patients testing seronegative at baseline were enrolled Into a 1-year incidence study with serological follow-up at 6 and 12 months. For patients who seroconverted, an HCV RNA assay was performed on stored baseline samples to confirm new infection. A nested case-control study was subsequently performed to Investigate potential risk factors. For each incident case, three controls negative for both HCV antibodies and HCV RNA were randomly selected. At enrollment, HCV seroprevalence was 30.0%. During follow-up, 23 new HCV cases were documented, with a cumulative incidence of 9.5 cases/1,000 patient-years. By logistic regression analysis, an increased risk for HCV infection emerged for patients attending the dialysis units with a high prevalence of HCV-infected patients at baseline (odds ratio OR, 4.6) and for those attending units with a low personnel-patient ratio (OR, 5.4). Among extradialysis factors, a history of surgical Intervention in the previous 6 months (OR, 16.7) significantly Increased HCV risk. These findings suggest that the combination of understaffing and a high level of Infected patients in the dialysis setting increases the risk for HCV nosocomial transmission. This is likely related to an increased likelihood for breaks in infection control measures.
Supported in part by the Progetto Epatite Vrale-ISS(D.L.vo 30/12/1992 n. 502), and Ricerca Corrente-IRCCS Spallanzani.
To assess hepatitis C virus (HCV) incidence rates and identify determinants of infection among hemodialysis patients, a multicenter study was conducted in 58 units in ITALY: An initial seroprevalence ...survey was conducted among 3,492 patients already on hemodialysis therapy as of January 1997 and among an additional 434 patients who began dialysis up to January 1998. HCV antibodies were assessed by third-generation enzyme immunoassays. Patients testing seronegative at baseline were enrolled into a 1-year incidence study with serological follow-up at 6 and 12 months. For patients who seroconverted, an HCV RNA assay was performed on stored baseline samples to confirm new infection. A nested case-control study was subsequently performed to investigate potential risk factors. For each incident case, three controls negative for both HCV antibodies and HCV RNA were randomly selected. At enrollment, HCV seroprevalence was 30.0%. During follow-up, 23 new HCV cases were documented, with a cumulative incidence of 9.5 cases/1,000 patient-years. By logistic regression analysis, an increased risk for HCV infection emerged for patients attending the dialysis units with a high prevalence of HCV-infected patients at baseline (odds ratio OR, 4.6) and for those attending units with a low personnel-patient ratio (OR, 5.4). Among extradialysis factors, a history of surgical intervention in the previous 6 months (OR, 16.7) significantly increased HCV risk. These findings suggest that the combination of understaffing and a high level of infected patients in the dialysis setting increases the risk for HCV nosocomial transmission. This is likely related to an increased likelihood for breaks in infection control measures.
Hepatitis C Virus Serotypes in Haemodialysis Patients in South-East Italy Pietro Dentico, Rodolfo Sacco, Anna Volpe, Cristina Ranieri, Saverio Carabellese, Michele Carbone, Caterina Casalino, Rosalba Buongiorno
Scandinavian journal of infectious diseases,
2000, Letnik:
32, Številka:
2
Journal Article
Hepatitis C virus (HCV) infection is highly prevalent in haemodialysis patients. To date, only a few studies involving a small number of subjects have characterized HCV-infected dialysis patients by ...serotyping. The spread of HCV serotypes in 114 HCV-positive dialysis patients from the same geographical area was evaluated by Murex HCV serotyping assay. Serotypes were detected in 102 subjects (89.5%), with type 1 being the most frequent (37.7%), followed by types 2 (19.3%), 4 (8.8%) and 3 (7.9%). Types 5 and 6 were the least prevalent (3.5%). Ten samples (8.8%) revealed mixed infections: type 1 was detectable in all and the co-infecting HCV types were types 2, 3 and 4 in 3, 4 and 3 cases, respectively. These results suggest that the serotyping assay as an alternative method of distinguishing the major types of HCV, also for particular risk groups and especially in laboratories that lack the specific expertise to perform genotyping methods. Age-related differences in patients with type 5 compared with those with types 3 and 6 may provide evidence of a more recent spread of these latter types.
Friction Stir Welding (FSW) is a solid-state joining process;
, no melting occurs. The welding process is promoted by the rotation and translation of an axis-symmetric non-consumable tool along the ...weld centerline. Thus, the FSW process is performed at much lower temperatures than conventional fusion welding, nevertheless it has some disadvantages. Laser Assisted Friction Stir Welding (LAFSW) is a combination in which the FSW is the dominant welding process and the laser pre-heats the weld. In this work FSW and LAFSW tests were conducted on 6 mm thick 5754H111 aluminum alloy plates in butt joint configuration. LAFSW is studied firstly to demonstrate the weldability of aluminum alloy using that technique. Secondly, process parameters, such as laser power and temperature gradient are investigated in order to evaluate changes in microstructure, micro-hardness, residual stress, and tensile properties. Once the possibility to achieve sound weld using LAFSW is demonstrated, it will be possible to explore the benefits for tool wear, higher welding speeds, and lower clamping force.
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•AISI 410 HAZ showed a continuous layer of martensite.•FZ showed a peak of the longitudinal residual stress.•Line energy influenced the amount of martensite in HAZ.•Stress was high on ...AISI 304 surface and AISI 410 bottom side.•High laser line energy improved weld penetration.
In this study, AISI 304 and AISI 410 stainless steels were welded together by a fiber laser-TIG hybrid welding system. Weldability was evaluated through the characterization of the microstructure and mechanical properties. The effects of welding parameters, such as laser line energy (ratio between laser power and feed rate) and arc current, were analyzed. Welds microstructure and defects were assessed and related to the tensile test, type of fracture and residual stress. The latter was measured in the normal and longitudinal directions respect to the weld line. The difference observed in the two sides of the weld were highlighted and commented. FZ microstructure resulted predominantly martensitic, which increased the micro-hardness up to an average value of about 350 HV. Porosity reached a minimum, about 0.2%, when the maximum values were used for laser line energy and arc current. Maximum elongation was as far as 4.87% and the tensile strength as big as 391 MPa. Residual stresses were much lower than the ultimate tensile and yield stresses. Eventually, the paper demonstrated the good and easy weldability of dissimilar austenitic and martensitic stainless steels in annealed condition by fiber laser coupled with an electric arc.
In last years, the introduction of 2-dimensional materials such as graphene has revolutionized the world of silicon photonics. In this work, we demonstrate a new approach for integrating graphene ...into silicon-based photodetectors. We leverage a thin film of hydrogenated amorphous silicon to embed the graphene within two different photonic structures, an optical Fabry-Pérot microcavity, and a waveguide, achieving a stronger light-matter interaction. The investigated devices have shown promising performance resulting in responsivities as high as 27 mA/W and 0.15 A/W around 1550 nm, respectively.
In this work, we investigate a vertically illuminated near-infrared photodetector based on a graphene layer physically embedded between a crystalline and a hydrogenated silicon layer. Under ...near-infrared illumination, our devices show an unforeseen increase in the thermionic current. This effect has been ascribed to the lowering of the graphene/crystalline silicon Schottky barrier as the result of an upward shift in the graphene Fermi level induced by the charge carriers released from traps localized at the graphene/amorphous silicon interface under illumination. A complex model reproducing the experimental observations has been presented and discussed. Responsivity of our devices exhibits a maximum value of 27 mA/W at 1543 nm under an optical power of 8.7 μW, which could be further improved at lower optical power. Our findings offer new insights, highlighting at the same time a new detection mechanism which could be exploited for developing near-infrared silicon photodetectors suitable for power monitoring applications.
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