Development of a HGV FEM for road safety analysis

In the last years roadside safety design, in particular for passive systems, was greatly improved with the possibility to use computational mechanics. Computational mechanics is based on the use of complex finite element codes, that allows the virtual reproduction of real world problems. Regarding roadside safety, the design phase was, until now, based on the use of simplified analysis, unable to describe accurately the complexity of vehicle impacts against safety hardware. To build a FE model for an impact problem many elements are necessary: • Model geometry. • Constitutive laws of the materials. • Links (rigid, cinematic, etc.) between bodies or part of them. • Definition and characterization of contact surfaces. This set of information is needed for each different body involved in the event; making the development of a complete model very much demanding, but once a part (subset) of the entire model has been accurately validated by the comparison with real experimental data, it can be used again and again in other analogous models. Our goal was to build and validate a FE model of a Heavy Goods Vehicle (HGV). We chose this kind of vehicle because it wasn't available and because it was useful to test the containment of the barriers, and to study the dynamic interactions between vehicle and road pavement. In particular, this vehicle can be used to test the safety barriers according to EN 1317 standard, for the H4a class of containment. It reproduces a FIAT-IVECO F180 truck, a vehicle with 4 axles and a mass of 10.5 ton (30 with the full load). The model (12337 elements and 11470 nodes) was built for and is ready to use with LS Dyna FE code from Livermore Software Technology Corporation

Prevalência e incidência da hepatite C em pacientes submetidos a transplante renal

OBJECTIVE: To detect the prevalence and the seroconversion of the anti-HCV in renal transplants, while evaluating the presence of this antibody at the time of thetransplant, and during a 1-year follow-up, as well as the possibility of transmitting the disease to the recipient of the contaminated organ.PATIENTS AND METHODS: We investigated the prevalence of anti-HCV infection in 48 kidney transplant recipients, and also in their respective donors. Serumspecimens were collected from the organ recipients right before kidney transplant, and 6 and 12 months after transplant; serum specimens were collected from donors at the time of nephroctomy. The 192 samples were stored at -20º C. The anti-HCV tests used were commercial kits based on synthetic HCV peptides (UBI), enzygnost anti-HCV (Boehringer), and Abbot HCV EIA 2nd generation. In patients with a positive anti-hepatitis C UBI test, the presence of HCV-RNA was verified by polymerase chain reaction .RESULTS: Eleven of 40 patients had positive UBI results, and 12 of 48 had positive EIA anti-HCV results before the transplant. Sixteen patients were anti-HCV positive during the 1-year follow-up. Two patients became positive after 6 months, and one after 12 months. One of these patients was also HCV-RNA positive. No transplant recipient patient with positive anti-HCV before transplant seroconverted after 1 year. Fifty percent of the patients who received a kidney were HCV-RNA positive. Three of 40 donors indicated a positive anti-HCV antibody in the UBI test, and 4 of 48 donors indicated a positive anti-HCV antibody in the Boehringer and EIA tests. Two donors were HCV-RNA positive.CONCLUSIONS: The prevalence of anti-HCV before transplant was high, and the serconversion to positive was low during the follow-up; none of the anti-HCV positive patients seroconverted; the HCV-RNA positive patients did not change to negative after transplant, which indicates the persistence of viral replication even after immunosupression; anti-HCV positive donors, even in the presence of HCV-RNA, did not transmit the infection during 1 year after transplant.OBJETIVO: Investigar a prevalência do anti-VHC em 48 receptores renais e seusrespectivos doadores.PACIENTES E MÉTODOS: Foi coletado sangue dos receptores pré-transplante, 6meses e 1 ano pós-transplante; e dos doadores, no momento da nefrectomia. As192 amostras foram conservadas a -20 °C. Os testes anti-VHC utilizados forampeptídeos sintéticos (UBI) e ELISA de segunda geração (Abbott). Nos pacientescom positividade ao anti-VHC pelo teste UBI, foi pesquisado o VHC-ARN por reaçãoem cadeia da polimerase.RESULTADOS: Onze de 40 receptores foram anti-VHC positivos pelo teste da UBIe 12 de 48 pelo teste da Abbott pré-transplante. Dezesseis pacientes apresentarampositividade ao anti-VHC no período de 1 ano pós-operatório. Dois positivaram aos6 meses e um em 1 ano. Um deles apresentou positividade também ao VHC-ARN.Nenhum paciente anti-VHC positivo seroconverteu com 1 ano de seguimento.Verificou-se a presença do VHC-ARN em 50% dos receptores renais. Três de 40doadores foram anti-VHC positivos pelo teste UBI e 4 de 48 pelo teste Abbott. Doisdoadores apresentaram positividade ao VHC-ARN.CONCLUSÕES: 1) A prevalência do anti-VHC pré-transplante foi alta, porém aseroconversão para anti-VHC positivo no seguimento de 1 ano foi baixa; 2) nenhumpaciente anti-VHC positivo seroconverteu; 3) houve manutenção da positividadeao VHC-ARN demonstrando persistência da replicação viral apesar daimunossupressão; 4) os doadores anti-VHC positivos, mesmo com a presença doVHC-ARN não transmitiram a infecção através do enxerto renal no seguimento de1 ano pós-operatório

Hepatits C incidence and prevalence in kidney transplant patients

OBJETIVO: Investigar a prevalência do anti-VHC em 48 receptores renais e seus respectivos doadores. PACIENTES E MÉTODOS: Foi coletado sangue dos receptores pré-transplante, 6 meses e 1 ano pós-transplante; e dos doadores, no momento da nefrectomia. As 192 amostras foram conservadas a -20 °C. Os testes anti-VHC utilizados foram peptídeos sintéticos (UBI) e ELISA de segunda geração (Abbott). Nos pacientes com positividade ao anti-VHC pelo teste UBI, foi pesquisado o VHC-ARN por reação em cadeia da polimerase. RESULTADOS: Onze de 40 receptores foram anti-VHC positivos pelo teste da UBI e 12 de 48 pelo teste da Abbott pré-transplante. Dezesseis pacientes apresentaram positividade ao anti-VHC no período de 1 ano pós-operatório. Dois positivaram aos 6 meses e um em 1 ano. Um deles apresentou positividade também ao VHC-ARN. Nenhum paciente anti-VHC positivo seroconverteu com 1 ano de seguimento. Verificou-se a presença do VHC-ARN em 50% dos receptores renais. Três de 40 doadores foram anti-VHC positivos pelo teste UBI e 4 de 48 pelo teste Abbott. Dois doadores apresentaram positividade ao VHC-ARN. CONCLUSÕES: 1) A prevalência do anti-VHC pré-transplante foi alta, porém a seroconversão para anti-VHC positivo no seguimento de 1 ano foi baixa; 2) nenhum paciente anti-VHC positivo seroconverteu; 3) houve manutenção da positividade ao VHC-ARN demonstrando persistência da replicação viral apesar da imunossupressão; 4) os doadores anti-VHC positivos, mesmo com a presença do VHC-ARN não transmitiram a infecção através do enxerto renal no seguimento de 1 ano pós-operatório.OBJECTIVE: To detect the prevalence and the seroconversion of the anti-HCV in renal transplants, while evaluating the presence of this antibody at the time of the transplant, and during a 1-year follow-up, as well as the possibility of transmitting the disease to the recipient of the contaminated organ. PATIENTS AND METHODS: We investigated the prevalence of anti-HCV infection in 48 kidney transplant recipients, and also in their respective donors. Serum specimens were collected from the organ recipients right before kidney transplant, and 6 and 12 months after transplant; serum specimens were collected from donors at the time of nephroctomy. The 192 samples were stored at -20º C. The anti-HCV tests used were commercial kits based on synthetic HCV peptides (UBI), enzygnost anti-HCV (Boehringer), and Abbot HCV EIA 2nd generation. In patients with a positive anti-hepatitis C UBI test, the presence of HCV-RNA was verified by polymerase chain reaction RESULTS: Eleven of 40 patients had positive UBI results, and 12 of 48 had positive EIA anti-HCV results before the transplant. Sixteen patients were anti-HCV positive during the 1-year follow-up. Two patients became positive after 6 months, and one after 12 months. One of these patients was also HCV-RNA positive. No transplant recipient patient with positive anti-HCV before transplant seroconverted after 1 year. Fifty percent of the patients who received a kidney were HCV-RNA positive. Three of 40 donors indicated a positive anti-HCV antibody in the UBI test, and 4 of 48 donors indicated a positive anti-HCV antibody in the Boehringer and EIA tests. Two donors were HCV-RNA positive. CONCLUSIONS: The prevalence of anti-HCV before transplant was high, and the serconversion to positive was low during the follow-up; none of the anti-HCV positive patients seroconverted; the HCV-RNA positive patients did not change to negative after transplant, which indicates the persistence of viral replication even after immunosupression; anti-HCV positive donors, even in the presence of HCV-RNA, did not transmit the infection during 1 year after transplant

Real-world effectiveness and safety of direct-acting antivirals for the treatment of hepatitis C virus in kidney and liver transplant recipients: experience of a large transplant center in Brazil

Direct-acting antivirals are the gold-standard treatment for chronic HCV infections, but few studies have investigated their use on kidney and liver transplant recipients. We conducted a real-world study to evaluate the rates of sustained virological response with direct-acting antivirals in kidney and liver transplant recipients. Moreover, it also aimed to evaluate direct-acting antivirals (DAAs) interference with immunosuppressant levels and to describe the frequency of adverse events. As part of this retrospective observational cohort, we included adult patients that had undergone a kidney transplant (KT) or liver transplant (LT) at our center, had a chronic HCV infection, and were treated with DAAs from June 2016 to December 2021. A total of 165 patients were included in the analysis, divided in 108 KT and 57 LT recipients. HCV genotype 1 was more frequent in KT (58.4%), and genotype 3 was more prevalent in LT (57.9%) patients. Sustained virological response was achieved in 89.6% of patients. Adverse effects were reported by 36% of patients. There were significant interactions with immunosuppressants requiring dose adjustments. A total of three episodes of rejection were reported in KT recipients. In conclusion, DAA treatment resulted in high rates of SVR and was well tolerated in both kidney and liver transplant patients. Adverse events were frequent but not severe in most patients, with low treatment drop-out rates. Interactions with immunosuppressants need monitoring since dose adjustments may be required. Reporting real-life experiences is important to help build evidence for patient management in non-controlled environments

Sofosbuvir, ribavirin and pegylated interferon for a daclatasvir-resistent genotype 3 hepatitis C virus: case report and review

Chronic Hepatitis C relapse after liver transplantation can lead to graft failure within a short time period. The high efficacy and good safety profile of direct-acting antivirals has led to consensual recommendations for using interferon-free treatment after liver transplantation. However, pegylated interferon may still be required for genotype 3 non-responders. We treated a liver graft recipient with grade 1 fibrosis in the biopsy with daclatasvir and sofosbuvir for 12 weeks. He did not respond and progressed to grade 3 fibrosis. Lacking other options, we obtained a sustained virological response with pegylated interferon, ribavirin and sofosbuvir for 12 weeks. The combination of pegylated interferon, ribavirin and sofosbuvir is a viable option after the failure of direct acting antivirals in economically disadvantaged countries

Infecções em pacientes pediátricos submetidos a transplante hepático

OBJECTIVE: To identify bacterial, viral, and fungal infections in the first 20 pediatric patients submitted to liver transplant at Hospital de Clínicas de Porto Alegre.PATIENTS AND METHODS: Twenty-one liver transplants were performed in 20  infant and adolescent patients from March 1995 to September 1997, at Hospital deClínicas de Porto Alegre. All transplanted organs were taken from deceased donors with the same ABO blood type as the organ transplant recipient. Nine patientsreceived a whole liver transplant, and 11 patients received a reduced liver transplant. Bacterial infection was diagnosed by the existence of clinical and laboratory evidence;and/or by hemoculture; and/or by positive  cultures. For the diagnosis of viral infections, patients were examined for Epstein Barr virus and for cytomegalovirus. For the diagnosis of fungal infection, hemocultures and secretion cultures were taken, and patients were also submitted to draining and sample collections, such as urine samples using a catheter.RESULTS: Of the 20 organ transplant recipient patients, two died within the first 24- 48 hours, and only four of the patients did not present any infections and/or positive cultures that were clinically significant. Fourteen patients had bacterial infection, and nine patients had more than one case of infection. The most frequently found organisms were Staphylococus aureus and epidermidis, and Xanthomonas maltophilia. Five transplant recipients were positive for cytomegalovirus antigenemia, and only one of these recipients was seronegative before the transplant. Fungal infection was diagnosed in two patients, and a third patient presented a positive culture of the biliary drain.CONCLUSIONS: Of the 20 liver transplant recipients, four died due to infection complications. By exerting a careful control, and establishing appropriate prophylacticand therapeutic measures, infection and its consequences may be reduced.OBJETIVO: Identificar infecções bacterianas, virais e fúngicas nos primeiros 20pacientes pediátricos submetidos a transplante de fígado no HCPA.PACIENTES E MÉTODOS: 21 transplantes foram realizados em 20 crianças eadolescentes, no período de março de 1995 a setembro de 1997, no HCPA. Todosos transplantes foram de doador cadavérico, do mesmo grupo sangüíneo ABO.Nove transplantes foram de fígado inteiro e 11, de fígado reduzido. O diagnósticode infecção bacteriana foi feito quando havia evidências clínico-laboratoriais e/ouhemocultura e/ou outros culturais positivos. Os vírus pesquisados foram citomegaloe Epstein Barr. Fungos eram pesquisados através de hemoculturas e culturas desecreções, drenos e coleções, cateteres e urina.RESULTADOS: Dos 20 pacientes transplantados, dois morreram nas primeiras24-48 horas e apenas quatro não apresentaram infecção e/ou culturais positivos,clinicamente significativos. Quatorze pacientes apresentaram infecção bacteriana,sendo que nove pacientes apresentaram mais do que um episódio infeccioso. Osorganismos mais freqüentes foram Staphylococus aureus e epidermidis eXantomonas maltophilia. Cinco receptores positivaram antigenemia para CMV, sendoque apenas um apresentava sorologia negativa no pré-transplante. Infecção fúngicafoi diagnosticada em dois pacientes e um terceiro paciente apresentou cultura dodreno biliar positiva.CONCLUSÕES: Dos 20 pacientes transplantados, quatro foram ao óbito porcomplicações infecciosas. Um controle cuidadoso e medidas profiláticas eterapêuticas adequadas podem diminuir infecções e suas conseqüências apóstransplante hepático

Infections in pediatric patients submitted to hepatic transplant

OBJETIVO: Identificar infecções bacterianas, virais e fúngicas nos primeiros 20 pacientes pediátricos submetidos a transplante de fígado no HCPA. PACIENTES E MÉTODOS: 21 transplantes foram realizados em 20 crianças e adolescentes, no período de março de 1995 a setembro de 1997, no HCPA. Todos os transplantes foram de doador cadavérico, do mesmo grupo sangüíneo ABO. Nove transplantes foram de fígado inteiro e 11, de fígado reduzido. O diagnóstico de infecção bacteriana foi feito quando havia evidências clínico-laboratoriais e/ou hemocultura e/ou outros culturais positivos. Os vírus pesquisados foram citomegalo e Epstein Barr. Fungos eram pesquisados através de hemoculturas e culturas de secreções, drenos e coleções, cateteres e urina. RESULTADOS: Dos 20 pacientes transplantados, dois morreram nas primeiras 24-48 horas e apenas quatro não apresentaram infecção e/ou culturais positivos, clinicamente significativos. Quatorze pacientes apresentaram infecção bacteriana, sendo que nove pacientes apresentaram mais do que um episódio infeccioso. Os organismos mais freqüentes foram Staphylococus aureus e epidermidis e Xantomonas maltophilia. Cinco receptores positivaram antigenemia para CMV, sendo que apenas um apresentava sorologia negativa no pré-transplante. Infecção fúngica foi diagnosticada em dois pacientes e um terceiro paciente apresentou cultura do dreno biliar positiva. CONCLUSÕES: Dos 20 pacientes transplantados, quatro foram ao óbito por complicações infecciosas. Um controle cuidadoso e medidas profiláticas e terapêuticas adequadas podem diminuir infecções e suas conseqüências após transplante hepático.OBJECTIVE: To identify bacterial, viral, and fungal infections in the first 20 pediatric patients submitted to liver transplant at Hospital de Clínicas de Porto Alegre. PATIENTS AND METHODS: Twenty-one liver transplants were performed in 20 infant and adolescent patients from March 1995 to September 1997, at Hospital de Clínicas de Porto Alegre. All transplanted organs were taken from deceased donors with the same ABO blood type as the organ transplant recipient. Nine patients received a whole liver transplant, and 11 patients received a reduced liver transplant. Bacterial infection was diagnosed by the existence of clinical and laboratory evidence; and/or by hemoculture; and/or by positive cultures. For the diagnosis of viral infections, patients were examined for Epstein Barr virus and for cytomegalovirus. For the diagnosis of fungal infection, hemocultures and secretion cultures were taken, and patients were also submitted to draining and sample collections, such as urine samples using a catheter. RESULTS: Of the 20 organ transplant recipient patients, two died within the first 24- 48 hours, and only four of the patients did not present any infections and/or positive cultures that were clinically significant. Fourteen patients had bacterial infection, and nine patients had more than one case of infection. The most frequently found organisms were Staphylococus aureus and epidermidis, and Xanthomonas maltophilia. Five transplant recipients were positive for cytomegalovirus antigenemia, and only one of these recipients was seronegative before the transplant. Fungal infection was diagnosed in two patients, and a third patient presented a positive culture of the biliary drain. CONCLUSIONS: Of the 20 liver transplant recipients, four died due to infection complications. By exerting a careful control, and establishing appropriate prophylactic and therapeutic measures, infection and its consequences may be reduced