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1.
Transpl Infect Dis ; 20(5): e12934, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29809312

RESUMO

INTRODUCTION: Although antiviral prophylaxis is effective in preventing early cytomegalovirus (CMV) reactivation following liver transplantation (OLT), it predisposes patients to late CMV after prophylaxis has ceased. QuantiFERON-CMV (QFN-CMV, Qiagen, The Netherlands) measures an individual's viral-specific immune response. METHODS: Fifty-nine OLT recipients were prospectively monitored post-OLT in an observational cohort study. QFN-CMV was performed at regular time-points. An absolute QFN-CMV <0.1 IU/mL was considered non-reactive. RESULTS: 50/59 (84.7%) had a reactive QFN-CMV by M6. 38/59 (64.4%) had antiviral prophylaxis or treatment before M6, with 31/38 (81.6%) developing a reactive QFN-CMV by 6 months. Over 90% already had a reactive result as early as 3 months post transplant, 3 patients (5.08%) developed late CMV between 6-12 months (median 251 days)-all had a non-reactive M6 QFN-CMV. And 2/3 experienced CMV disease. Non-reactive M6 QFN-CMV was significantly associated with late CMV (OR = 54.4, PPV = 0.33, NPV = 1.00, P = .003). CONCLUSION: Although only 5% of recipients developed late CMV, 2/3 suffered CMV disease. M6 QFN-CMV has an excellent NPV for late CMV, suggesting patients who exhibit a robust ex vivo immune response at M6 can safely cease CMV monitoring. Furthermore, >90% already express viral-specific immunity as early as 3 months. Conceivably, antiviral prophylaxis could be discontinued early in these patients.


Assuntos
Infecções por Citomegalovirus/sangue , Citomegalovirus/fisiologia , Transplante de Fígado/efeitos adversos , Linfócitos T/imunologia , Ativação Viral , Antibioticoprofilaxia/métodos , Antivirais/uso terapêutico , Infecções por Citomegalovirus/diagnóstico , Infecções por Citomegalovirus/imunologia , Infecções por Citomegalovirus/prevenção & controle , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Testes Sorológicos/instrumentação , Testes Sorológicos/métodos , Resultado do Tratamento , Carga Viral/imunologia
2.
Aliment Pharmacol Ther ; 47(3): 401-411, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29205432

RESUMO

BACKGROUND: Antiviral therapy for hepatitis C has the potential to improve liver function in patients with decompensated cirrhosis. AIMS: To examine the virological response and effect of viral clearance in patients with decompensated hepatitis C cirrhosis all with MELD scores ≥15 following sofosbuvir/daclatasvir ± ribavirin. METHODS: We prospectively collected data on patients who commenced sofosbuvir/daclatasvir for 24-weeks under the Australian patient supply program (TOSCAR) and analysed outcomes including sustained viral response at 12 weeks (SVR12), death and transplant. RESULTS: 108 patients (M/F, 79/29; median age 56years; Child-Pugh 10; MELD 16; genotype 1/3, 55/47) received sofosbuvir/daclatasvir and two also received ribavirin. On intention-to-treat, the SVR12 rate was 70% (76/108). Seventy-eight patients completed 24-weeks therapy. SVR12 was achieved in 56 of these patients on per-protocol-analysis (76%). SVR12 was 80% in genotype 1 compared to 69% in genotype 3. Thirty patients failed to complete therapy. In patients achieving SVR12, median MELD and Child-Pugh fell from 16(IQR15-17) to 14(12-17) and 10(9-11) to 8(7-9), respectively (P<.001). In those who died, MELD increased from 16 to 23 at death (P=.036). Patients who required transplantation had a significantly higher baseline MELD (20) compared to those patients completing treatment (16) (P=.0010). The odds ratio for transplant in patients with baseline MELD ≥20 was 13.8(95%CI 2.78-69.04). CONCLUSIONS: SVR12 rates with sofosbuvir/daclatasvir in advanced liver disease are lower than in compensated disease. Although treatment improves MELD and Child-Pugh in most patients, a significant proportion will die or require transplantation. In those with MELD ≥20, it may be better to delay treatment until post-transplant.


Assuntos
Antivirais/administração & dosagem , Hepatite C Crônica/tratamento farmacológico , Imidazóis/administração & dosagem , Cirrose Hepática/tratamento farmacológico , Sofosbuvir/administração & dosagem , Austrália/epidemiologia , Carbamatos , Ensaios de Uso Compassivo , Progressão da Doença , Quimioterapia Combinada , Feminino , Hepatite C Crônica/complicações , Hepatite C Crônica/epidemiologia , Hepatite C Crônica/patologia , Humanos , Cirrose Hepática/epidemiologia , Cirrose Hepática/patologia , Cirrose Hepática/virologia , Transplante de Fígado/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Pirrolidinas , Estudos Retrospectivos , Ribavirina/administração & dosagem , Análise de Sobrevida , Resultado do Tratamento , Valina/análogos & derivados
3.
J Viral Hepat ; 23(9): 730-43, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27167351

RESUMO

In recurrent hepatitis C (HCV) post-liver transplantation (OLT), the combination of immunosuppressants and HCV is postulated to increase hepatocyte apoptosis and liver fibrosis. We evaluated hepatocyte apoptosis within the liver tissue of patients with postOLT HCV recurrence compared to HCV-negative individuals and correlated these findings with the effects of immunosuppressants on HCV-induced cell death and its inhibition in primary mouse hepatocytes (PMoH). Liver biopsies from patients with and without HCV were evaluated by immunohistochemistry for markers of apoptosis M30 CytoDEATH (M30) and cleaved PARP (clPARP). PMoH from C57BL/6 mice were infected with recombinant adenoviruses (rAdHCV) that expressed HCV proteins in hepatocytes. Infected cells were treated with cyclosporine, tacrolimus, sirolimus and/or MMF with or without pan-caspase inhibitor Q-VD-Oph. Cell viability and apoptosis were evaluated using crystal violet assays and Western immunoblots probed for cleaved caspase-3 (clCas3) and clPARP. Both M30 and clPARP were increased in the liver biopsies of patients with postOLT HCV recurrence compared to HCV-negative individuals. Treatment of rAdHCV-infected PMoH with cyclosporine, tacrolimus or sirolimus reduced cell viability and increased clCas3 and clPARP compared to rAdHCV infection alone. Addition of MMF to cyclosporine, tacrolimus or sirolimus further reduced cell viability and increased clCas3 and clPARP. Q-VD-Oph improved cell viability in HCV-infected PMoH treated with immunosuppressants alone and in combination and reduced clCas3 and clPARP by approximately 90%. Immunosuppressive agents, especially in combination, enhanced apoptosis in HCV-infected hepatocytes. The finding that Q-VD-Oph reversed hepatocyte death suggests that treatments utilizing apoptosis inhibition might reduce liver injury in postOLT HCV recurrence.


Assuntos
Apoptose , Hepatite C/patologia , Hepatócitos/fisiologia , Hepatócitos/virologia , Imunossupressores/uso terapêutico , Transplante de Fígado , Animais , Biópsia , Sobrevivência Celular , Células Cultivadas , Humanos , Imuno-Histoquímica , Fígado/patologia , Camundongos Endogâmicos C57BL
4.
Aliment Pharmacol Ther ; 43(7): 765-77, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26847265

RESUMO

BACKGROUND: Sarcopenia (loss of muscle mass) is common in cirrhosis and is associated with poor outcomes. Current teaching recommends the use of protein supplementation and exercise, however, this fails to address many other factors which contribute to muscle loss in this setting. AIMS: To summarise existing knowledge regarding the aetiology of sarcopenia in cirrhosis, diagnostic modalities and the clinical significance of this condition. In addition to discuss recent research findings that may allow the development of more effective treatments. METHODS: We conducted a Medline and PubMed search using the search terms 'sarcopenia', 'muscle', 'body composition', 'cirrhosis', 'liver' and 'malnutrition' from inception to October 2015. RESULTS: Cirrhotic patients with sarcopenia have reduced survival, experience increased rates of infection and have worse outcomes following liver transplantation. The aetiology of this condition is more complex than simple protein and calorie malnutrition. Cirrhosis also results in depleted glycogen stores and metabolic alterations that cause excessive protein catabolism, increased activation of the ubiquitin-proteasome pathway and inappropriate muscle autophagy. Satellite cell differentiation and proliferation is also reduced due to a combination of elevated myostatin levels, reduced IGF-1 and hypogonadism. Although there is some evidence supporting the use of late evening snacks, branched chain amino acid supplementation and high protein/high calorie diets, well designed clinical trials addressing the effects of treatment on body composition in cirrhosis are lacking. CONCLUSION: Sarcopenia in cirrhosis has a complex pathogenesis and simple dietary interventions are insufficient. Improved understanding of the multiple mechanisms involved should allow the development of more effective therapies, which target the specific underlying metabolic derangements.


Assuntos
Cirrose Hepática/complicações , Cirrose Hepática/diagnóstico , Sarcopenia/diagnóstico , Sarcopenia/etiologia , Adulto , Composição Corporal , Feminino , Humanos , Cirrose Hepática/terapia , Transplante de Fígado/efeitos adversos , Transplante de Fígado/tendências , Síndromes de Malabsorção/complicações , Síndromes de Malabsorção/diagnóstico , Síndromes de Malabsorção/terapia , Pessoa de Meia-Idade , Proteólise , Sarcopenia/terapia , Resultado do Tratamento
5.
Am J Transplant ; 15(2): 555-9, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25582147

RESUMO

Unexpected donor-to-recipient infectious disease transmission is an important, albeit rare, complication of solid organ transplantation. Greater work and understanding about the epidemiology of these donor-derived transmissions is continually required to further mitigate this risk. Herein we present the first reported case of proven donor-derived transmission of coxsackievirus serogroup-3, an enterovirus, following solid organ transplant. Swift and effective communication between the organ donation agency, treating physicians, laboratory testing and notification ensured a coordinated approach. The resulting clinical syndromes in the organ recipients were mild. This case highlights the requirement for ongoing surveillance over a broad range of infecting pathogens that may present as a donor-derived infection.


Assuntos
Infecções por Coxsackievirus/transmissão , Enterovirus Humano B/patogenicidade , Transplante de Rim , Transplante de Fígado , Transplante de Pulmão , Transplante de Pâncreas , Doadores de Tecidos , Adulto , Biópsia , Enterovirus Humano B/isolamento & purificação , Humanos , Rim/patologia , Rim/virologia , Fígado/patologia , Fígado/virologia , Pulmão/patologia , Pulmão/virologia , Pâncreas/patologia , Pâncreas/virologia , Transplantados
6.
Intern Med J ; 44(6): 601-4, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24946816

RESUMO

Homozygous familial hypercholesterolaemia (FH) causes severe premature coronary artery disease because of very high levels of low density lipoprotein (LDL)-cholesterol. Standard lipid-lowering drugs and LDL-apheresis may not be sufficiently effective. Liver transplantation replaces defective LDL receptors and vastly improves the lipid profile, and we present the first report of an Australian adult to receive this treatment. Emerging drug treatments for FH may be alternatives to LDL-apheresis and transplantation, but long-term safety and efficacy data are lacking for all of these options.


Assuntos
Hiperlipoproteinemia Tipo II/tratamento farmacológico , Hiperlipoproteinemia Tipo II/cirurgia , Hipolipemiantes/uso terapêutico , Transplante de Fígado , Adulto , Atorvastatina , Azetidinas/administração & dosagem , Azetidinas/uso terapêutico , Remoção de Componentes Sanguíneos , LDL-Colesterol/sangue , Terapia Combinada , Consanguinidade , Ponte de Artéria Coronária , Doença das Coronárias/genética , Doença das Coronárias/cirurgia , Quimioterapia Combinada , Ezetimiba , Fenofibrato/administração & dosagem , Fenofibrato/uso terapêutico , Doenças das Valvas Cardíacas/genética , Doenças das Valvas Cardíacas/cirurgia , Implante de Prótese de Valva Cardíaca , Ácidos Heptanoicos/administração & dosagem , Ácidos Heptanoicos/uso terapêutico , Homozigoto , Humanos , Hiperlipoproteinemia Tipo II/sangue , Hiperlipoproteinemia Tipo II/dietoterapia , Hiperlipoproteinemia Tipo II/terapia , Hipolipemiantes/administração & dosagem , Lipoproteínas LDL/sangue , Masculino , Pirróis/administração & dosagem , Pirróis/uso terapêutico , Receptores de LDL/deficiência , Receptores de LDL/genética
7.
Neurogastroenterol Motil ; 26(8): 1188-99, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24952996

RESUMO

BACKGROUND: Disorders of gastrointestinal functions that are controlled by enteric neurons commonly accompany fatty liver disease. Established fatty liver disease is associated with diabetes, which itself induces enteric neuron damage. Here, we investigate the relationship between fatty liver disease and enteric neuropathy, in animals fed a high-fat, high-cholesterol diet in the absence of diabetes. METHODS: Mice were fed a high-fat, high-cholesterol diet (21% fat, 2% cholesterol) or normal chow for 33 weeks. Liver injury was assessed by hematoxylin and eosin, picrosirius red staining, and measurement of plasma alanine aminotransaminase (ALT). Quantitative immunohistochemistry was performed for different types of enteric neurons. KEY RESULTS: The mice developed steatosis, steatohepatitis, fibrosis, and a 10-fold increase in plasma ALT, indicative of liver disease. Oral glucose tolerance was unchanged. Loss and damage to enteric neurons occurred in the myenteric plexus of ileum, cecum, and colon. Total numbers of neurons were reduced by 15-30% and neurons expressing nitric oxide synthase were reduced by 20-40%. The RNA regulating protein, Hu, became more concentrated in the nuclei of enteric neurons after high-fat feeding, which is an indication of stress on the enteric nervous system. There was also disruption of the neuronal cytoskeletal protein, neurofilament medium. CONCLUSIONS & INFERENCES: Enteric neuron loss and damage occurs in animals with fatty liver disease in the absence of glucose intolerance. The enteric neuron damage may contribute to the gastrointestinal complications of fatty liver disease.


Assuntos
Diabetes Mellitus/etiologia , Dieta Hiperlipídica/efeitos adversos , Sistema Nervoso Entérico/patologia , Neurônios/patologia , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/patologia , Animais , Resistência à Insulina , Intestinos/patologia , Camundongos , Camundongos Endogâmicos C57BL
8.
Am J Transplant ; 13(11): 3031-4, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24007548

RESUMO

We describe the first case of a patient undergoing orthoptic liver transplantation for acquired generalized lipodystrophy-related nonalcoholic steatohepatitis who developed severe recurrence of nonalcoholic fatty liver disease in the first few months posttransplant but responded rapidly to the administration of exogenous leptin. The beneficial effects of therapy were supported by histology along with magnetic resonance spectroscopy studies, which demonstrated that leptin therapy greatly reduced fat deposition in the liver. Leptin therapy may have a role to play in preventing patients with lipodystrophy developing end-stage liver disease or in rescuing such patients who develop disease recurrence postliver transplantation.


Assuntos
Fígado Gorduroso/complicações , Leptina/farmacologia , Lipodistrofia/complicações , Transplante de Fígado/efeitos adversos , Complicações Pós-Operatórias/prevenção & controle , Prevenção Secundária , Adulto , Fígado Gorduroso/patologia , Fígado Gorduroso/cirurgia , Feminino , Humanos , Lipodistrofia/patologia , Lipodistrofia/cirurgia , Espectroscopia de Ressonância Magnética , Hepatopatia Gordurosa não Alcoólica , Resultado do Tratamento
9.
Aliment Pharmacol Ther ; 35(4): 414-28, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22221317

RESUMO

BACKGROUND: The renin-angiotensin system (RAS) is a homeostatic pathway widely known to regulate cardiovascular and renal physiology; however, little is known about its influence in gastrointestinal tissues. AIM: To elicit the anatomical distribution and physiological significance of the components of the RAS in the gastrointestinal tract. METHODS: An extensive online literature review including Pubmed and Medline. RESULTS: There is evidence for RAS involvement in gastrointestinal physiology and pathophysiology, with all the components required for autonomous regulation identified throughout the gastrointestinal tract. The RAS is implicated in the regulation of glucose, amino acid, fluid and electrolyte absorption and secretion, motility, inflammation, blood flow and possibly malignant disease within the gastrointestinal tract. Animal studies investigating the effects of RAS blockade in a range of conditions including inflammatory bowel disease, functional gut disorders, gastrointestinal malignancy and even intestinal ischaemia have been encouraging to date. Given the ready availability of drugs that modify the RAS and their excellent safety profile, an opportunity exists for investigation of their possible therapeutic role in a variety of human gastrointestinal diseases. CONCLUSIONS: The gastrointestinal renin-angiotensin system appears to be intricately involved in a number of physiological processes, and provides a possible target for novel investigative and therapeutic approaches.


Assuntos
Gastroenteropatias/fisiopatologia , Trato Gastrointestinal/fisiologia , Sistema Renina-Angiotensina/fisiologia , Animais , Ensaios Clínicos como Assunto , Homeostase/fisiologia , Humanos
10.
Transplant Proc ; 43(10): 3802-6, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22172850

RESUMO

BACKGROUND: It has become common practice to withdraw or reduce calcineurin inhibitors (CNI) in patients with renal dysfunction after liver transplantation; however, little is known about the long-term outcome of this strategy. This study investigates the long-term results of CNI withdrawal for post-liver transplant renal dysfunction and examines for factors that predict a significant improvement in renal function. METHODS: A retrospective database review was performed to examine outcomes in patients with CNI withdrawn for chronic renal impairment. Univariate analyses were used to identify predictors of an improvement in creatinine clearance (CrC). RESULTS: Sixty patients (44 males) were included. Of these, 82% of patients were switched to mycophenolate mofetil and 18% azathioprine. Median follow-up after CNI withdrawal was 48 (range 3-72) months. Postwithdrawal, there was an initial improvement in CrCl (mean 5.5 mL), which remained above baseline levels at 6 years. Acute cellular rejection developed in six patients (10%), but there was no rejection-associated graft loss. A shorter time from transplantation to conversion was associated with greatest improvement in CrCI. CONCLUSIONS: CNI withdrawal is associated with a significant initial improvement and then arrest in long-term decline of renal function. Rejection in this setting is uncommon. The greatest benefit is seen in patients switched within the early years after transplantation.


Assuntos
Inibidores de Calcineurina , Rejeição de Enxerto/prevenção & controle , Imunossupressores/efeitos adversos , Nefropatias/etiologia , Rim/efeitos dos fármacos , Transplante de Fígado/efeitos adversos , Idoso , Biomarcadores/metabolismo , Doença Crônica , Creatinina/metabolismo , Substituição de Medicamentos , Feminino , Rejeição de Enxerto/imunologia , Humanos , Rim/metabolismo , Rim/fisiopatologia , Nefropatias/diagnóstico , Nefropatias/metabolismo , Nefropatias/fisiopatologia , Transplante de Fígado/imunologia , Masculino , Pessoa de Meia-Idade , Medição de Risco , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento , Vitória
13.
Am J Transplant ; 11(1): 169-72, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21199357

RESUMO

Multicentric Castleman disease is a lymphoproliferative disorder which when seen in the setting of HIV/AIDS is often associated with human herpes virus 8 (HHV-8) infection. We describe the case of a HIV-negative man who developed HHV-8-associated multicentric Castleman disease 11 years after liver transplantation. The patient presented with fevers and weight loss. Physical examination revealed enlarged cervical, axillary and inguinal lymph nodes. Widespread lymphadenopathy was confirmed on computed tomography (CT) scanning. Histology of an enlarged lymph node showed a polymorphous infiltrate with mature plasma cells, plasmacytoid lymphocytes and occasional blasts within the cortex and paracortex. The diagnosis of Castleman disease was confirmed by the finding of numerous HHV-8-immunopositive cells around the regressed lymph node follicles and the detection of HHV-8 on plasma PCR. Although the conventional treatment for this condition has been combination chemotherapy, in the post-transplant context it was decided to treat the patient with valganciclovir and cessation of immunosuppression. His symptoms resolved rapidly and repeat plasma PCR done 3 months after starting treatment was negative for HHV-8. A follow-up CT scan showed a dramatic reduction in the size and amount of lymphadenopathy. After 15 months of treatment, he remains well with no evidence of graft dysfunction or rejection.


Assuntos
Ganciclovir/análogos & derivados , Hiperplasia do Linfonodo Gigante/tratamento farmacológico , Hiperplasia do Linfonodo Gigante/etiologia , Hiperplasia do Linfonodo Gigante/patologia , Ganciclovir/uso terapêutico , Humanos , Transplante de Fígado , Masculino , Pessoa de Meia-Idade , Valganciclovir
14.
Gut ; 60(2): 247-54, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21036792

RESUMO

OBJECTIVE: To determine the efficacy of tenofovir disoproxil fumarate (TDF) in adults with chronic hepatitis B virus (HBV) infection who had previously failed lamivudine (LAM) and had significant viral replication (HBV DNA >105 copies/ml if HBeAg positive, > 104 copies/ml if HBeAg negative) despite at least 24 weeks of treatment with adefovir dipivoxil (ADV). DESIGN: A prospective open-label study of TDF 300 mg daily. Patients receiving combination ADV/LAM prior to baseline were switched to TDF/LAM. SETTING: Multiple tertiary referral centres. METHODS: Sixty patients were enrolled. The median age was 48.5 years (range 21e80), 46 (77%) were male and 40 (67%) were HBeAg positive. Thirty-eight patients (63%) were switched from ADV to TDF, the remainder from ADV/LAM to TDF/LAM. At baseline, substitutions conferring resistance to LAM or ADV were present in 20 patients (33%) and 17 patients (28%), respectively. The median baseline viral load was 5.33 log10 IU/ml (range 2.81-8.04). Patients initially treated with TDF monotherapy with persistent viral replication at or after 24 weeks were switched to TDF/LAM. The main outcome measures were change in HBV viral load from baseline and percentage of patients achieving an undetectable viral load (<15 IU/ml). RESULTS: Results are reported at 96 weeks of treatment. One patient discontinued TDF at 10 days due to rash. The time-weighted change in viral load from baseline to week 12 was -2.19 log10 IU/ml overall. The median change in HBV DNA from baseline to weeks 12, 24, 48 and 96 was -2.86, -3.23, -3.75 and -4.03 log10 IU/ml, respectively. At 48 and 96 weeks, 27/59 (46%) and 38/59 (64%) patients achieved a HBV DNA <15 IU/ml. The response was independent of baseline LAM therapy or mutations conferring ADV resistance. CONCLUSIONS: In heavily pretreated patients with a high rate of genotypic resistance, TDF retains significant activity against HBV although this appears diminished in comparison with studies of naïve patients.


Assuntos
Adenina/análogos & derivados , Hepatite B Crônica/tratamento farmacológico , Organofosfonatos/uso terapêutico , Inibidores da Transcriptase Reversa/uso terapêutico , Terapia de Salvação/métodos , Adenina/efeitos adversos , Adenina/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , DNA Viral/sangue , Farmacorresistência Viral/genética , Métodos Epidemiológicos , Feminino , Vírus da Hepatite B/efeitos dos fármacos , Vírus da Hepatite B/genética , Vírus da Hepatite B/isolamento & purificação , Hepatite B Crônica/virologia , Humanos , Lamivudina/uso terapêutico , Masculino , Pessoa de Meia-Idade , Mutação , Organofosfonatos/efeitos adversos , Inibidores da Transcriptase Reversa/efeitos adversos , Tenofovir , Falha de Tratamento , Resultado do Tratamento , Carga Viral , Adulto Jovem
15.
Cytotechnology ; 58(3): 119-26, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19224387

RESUMO

Cell culture experiments often employ the use of culture media that contain fetal calf serum (FCS). The angiotensin peptides angiotensin II and angiotensin 1-7 have opposing effects with angiotensin converting enzyme 2 (ACE2) being the enzyme predominantly responsible for generating angiotensin 1-7 from angiotensin II. The effect of FCS on angiotensin peptides has not previously been described. We have shown that FCS has ACE2 enzyme activity capable of degrading angiotensin II and generating angiotensin 1-7. Researchers should be aware that FCS possesses ACE2 activity and that heat-treating FCS to 56 degrees C only partially inhibits this enzyme activity, whereas heat-treating to 70 degrees C completely abolishes ACE2 activity.

16.
Intern Med J ; 37(10): 705-12, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17894766

RESUMO

It is well known that immunosuppressive drugs or cancer chemotherapy can stimulate replication of hepatitis B virus (HBV) and precipitate severe flares of HBV infection. The risk of this syndrome of 'reactivation hepatitis B' is highest in haematopoietic stem cell or solid organ transplant recipients and in those undergoing chemotherapy for haematological malignancies; however, it has been described following almost any form of immunosuppressive treatment. Fortunately, it can be largely prevented by prophylactic therapy with oral anti-HBV nucleoside/nucleotide analogues. Importantly, chronic HBV infection is usually asymptomatic, and most patients at risk are likely to be unaware that they carry the infection. Thus, the key to avoiding this potentially fatal complication of immunosuppressive treatment is to ensure that all patients at risk of chronic HBV infection are screened for the disease before commencing immunosuppressive treatment or chemotherapy.


Assuntos
Vírus da Hepatite B/fisiologia , Hepatite B/prevenção & controle , Hepatite B/terapia , Imunossupressores/efeitos adversos , Guias de Prática Clínica como Assunto , Ativação Viral/efeitos dos fármacos , Animais , Gerenciamento Clínico , Hepatite B/imunologia , Humanos , Guias de Prática Clínica como Assunto/normas , Ativação Viral/fisiologia
18.
Gut ; 54(12): 1790-6, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16166274

RESUMO

BACKGROUND: Angiotensin converting enzyme (ACE) 2 is a recently identified homologue of ACE that may counterregulate the actions of angiotensin (Ang) II by facilitating its breakdown to Ang 1-7. The renin-angiotensin system (RAS) has been implicated in the pathogenesis of cirrhosis but the role of ACE2 in liver disease is not known. AIMS: This study examined the effects of liver injury on ACE2 expression and activity in experimental hepatic fibrosis and human cirrhosis, and the effects of Ang 1-7 on vascular tone in cirrhotic rat aorta. METHODS: In sham operated and bile duct ligated (BDL) rats, quantitative reverse transcriptase-polymerase chain reaction was used to assess hepatic ACE2 mRNA, and western blotting and immunohistochemistry to quantify and localise ACE2 protein. ACE2 activity was quantified by quenched fluorescent substrate assay. Similar studies were performed in normal human liver and in hepatitis C cirrhosis. RESULTS: ACE2 mRNA was detectable at low levels in rat liver and increased following BDL (363-fold; p < 0.01). ACE2 protein increased after BDL (23.5-fold; p < 0.05) as did ACE2 activity (fourfold; p < 0.05). In human cirrhotic liver, gene (>30-fold), protein expression (97-fold), and activity of ACE2 (2.4 fold) were increased compared with controls (all p < 0.01). In healthy livers, ACE2 was confined to endothelial cells, occasional bile ducts, and perivenular hepatocytes but in both BDL and human cirrhosis there was widespread parenchymal expression of ACE2 protein. Exposure of cultured human hepatocytes to hypoxia led to increased ACE2 expression. In preconstricted rat aorta, Ang 1-7 alone did not affect vascular tone but it significantly enhanced acetylcholine mediated vasodilatation in cirrhotic vessels. CONCLUSIONS: ACE2 expression is significantly increased in liver injury in both humans and rat, possibly in response to increasing hepatocellular hypoxia, and may modulate RAS activity in cirrhosis.


Assuntos
Carboxipeptidases/metabolismo , Cirrose Hepática/enzimologia , Regulação para Cima , Angiotensina I/farmacologia , Enzima de Conversão de Angiotensina 2 , Animais , Aorta Torácica/efeitos dos fármacos , Aorta Torácica/fisiologia , Hipóxia Celular , Células Cultivadas , Doença Crônica , Modelos Animais de Doenças , Feminino , Hepatite C Crônica/complicações , Hepatite C Crônica/enzimologia , Hepatócitos/enzimologia , Humanos , Técnicas Imunoenzimáticas , Fígado/enzimologia , Cirrose Hepática/virologia , Masculino , Nitroimidazóis/metabolismo , Fragmentos de Peptídeos/farmacologia , Peptidil Dipeptidase A , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Vasodilatação/efeitos dos fármacos
19.
Intern Med J ; 35(1): 45-9, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15667468

RESUMO

The development of portal hypertension plays a major role in the pathogenesis of many of the complications of chronic liver disease. In developed countries, most patients with portal hypertension have cirrhosis, and, in this condition, portal pressure is elevated as a result of both an increase in hepatic resistance to portal perfusion and increased mesenteric blood flow. Bleeding from oesophageal varices is a major cause of mortality in patients with significant portal hypertension. This review concentrates on the recognition, prevention and acute management of this life threatening complication of cirrhosis.


Assuntos
Hipertensão Portal/terapia , Varizes Esofágicas e Gástricas/complicações , Hemorragia Gastrointestinal/complicações , Humanos , Hipertensão Portal/diagnóstico , Hipertensão Portal/etiologia , Hipertensão Portal/fisiopatologia , Fígado/fisiopatologia , Derivação Portossistêmica Transjugular Intra-Hepática
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