RESUMO
BACKGROUND/AIM: We aimed to evaluate safety and efficacy of granulocyte-colony stimulating factor treatment in patients with acute on chronic liver failure and the effect of granulocyte-colony stimulating factor on the expression level of CXCR4, vascular endothelial growth factor receptor and very late activation antigen 4. METHODS: Twenty-four patients with acute on chronic liver failure were randomised to receive standard therapy, standard therapy+granulocyte-colony stimulating factor (5 microg/kg/day for 6 days) and standard therapy+granulocyte-colony stimulating factor (15 microg/kg/day s.c. for 6 days). Data on CD34+cell mobilisation were compared to age-matched peripheral blood haematopoietic stem cell donors treated with granulocyte-colony stimulating factor. On day third of treatment, the expression level of CXCR4, vascular endothelial growth factor receptor and very late activation antigen 4 was analysed in mobilised CD34+ cells. RESULTS: CD34 cell count increased after the second day of granulocyte-colony stimulating factor injection in both treatment groups compared to the linear increase observed in control. After the fifth day the increase was significantly higher in healthy donors versus patients with acute on chronic liver failure. A decrease in the expression of CXCR4, very late activation antigen 4 and vascular endothelial growth factor receptor compared to premobilisation values was observed. No major side effects were observed. CONCLUSIONS: Granulocyte-colony stimulating factor treatment is able to induce CD34 mobilisation in patients with acute on chronic liver failure. The expression pattern of CXCR4, very late activation antigen 4 and vascular endothelial growth factor receptor suggests that these molecules are involved in the granulocyte-colony stimulating factor-induced stem cell mobilisation.
Assuntos
Doença Crônica/tratamento farmacológico , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Falência Hepática Aguda/tratamento farmacológico , Antígenos CD34/metabolismo , Feminino , Expressão Gênica/efeitos dos fármacos , Mobilização de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/efeitos dos fármacos , Células-Tronco Hematopoéticas/metabolismo , Humanos , Integrina alfa4beta1/genética , Integrina alfa4beta1/metabolismo , Falência Hepática Aguda/metabolismo , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/metabolismo , Receptores CXCR4/genética , Receptores CXCR4/metabolismo , Resultado do Tratamento , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/genética , Receptor 1 de Fatores de Crescimento do Endotélio Vascular/metabolismoRESUMO
Recent efforts have been directed toward new therapeutic options to approach drug-induced hepatitis. We report a case of acute liver failure associated with Nimesulide in a 67-year-old man, with a medical history of chronic alcohol abuse. The biopsy was compatible with chronic alcoholic liver disease and acute drug-induced injury. The patient was enrolled to receive G-CSF followed by apheresis and selection of peripheral-blood stem cells. After ultrasound-guided injection of CD34+cells in the portal vein, we observed a rapid improvement of synthetic liver function, with particular reference to coagulation parameters. Liver biopsy performed 20 days after, showed wide areas of regeneration. In the next 30 days the laboratory signs of acute decompensation progressively improved. Unfortunately he died of multiple-organ failure related to bacterial infection. Intrahepatic injection of peripheral-blood stem cells seemed safe and produced good periprocedural results with improvement of synthetic profile, suggesting a possible role of stem cells in the regeneration process.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas/terapia , Falência Hepática/induzido quimicamente , Falência Hepática/terapia , Regeneração Hepática , Transplante de Células-Tronco de Sangue Periférico/métodos , Idoso , Anti-Inflamatórios não Esteroides/efeitos adversos , Humanos , Masculino , Sulfonamidas/efeitos adversos , Transplante Autólogo , Resultado do TratamentoRESUMO
Nonalcoholic fatty liver disease (NAFLD) refers to a wide picture of liver damage, ranging from steatosis to steatohepatitis, fibrosis and cirrhosis. The epidemiological studies demonstrated an association of NAFLD with obesity, type 2 diabetes and hyperlipidemia. Under this light the metabolic syndrome (MS), including NAFLD, obesity, central fat distribution, diabetes, dyslipidemia, hypertension and atherosclerotic cardiovascular disease (CVD) can be considered the link to explain the presence of vascular diseases in patients with NAFLD. In NHANES III, the authors demonstrated that the presence of MS was associated with increased risk of myocardial infarction, stroke or both. In a prospective study on 1209 Finnish middle-aged men without CVD or diabetes at baseline, Lakka showed that MS per se is associated with an increased risk of CVD and all-cause mortality. Finally the Atherosclerosis Risk in Communities (ARIC) confirmed that subjects with MS were 2 times more likely to have prevalent coronary heart disease. From a pathophysiological point of view, growing evidences implicate the oxidative stress as the unifying mechanism for many CVD risk factors. Under this light there is emerging evidence suggesting that there is a significant increase in vascular oxidative stress in patients with MS, with the presence of endothelial dysfunction in the early stage of the syndrome. Indeed, the inflammation process evidentiated in these patients is initiated at the endothelial level, stressing the key role of this active and dynamic tissue in the pathophysiological pathways. Under this light the endothelium can be considered as the last effector of a multi-syndrome and the main target of all the future studies focused on the underlying mechamisms of this complex network. Because of the potential serious public health impact, the comprehension of these patophysiological pathways will be crucial to design new preventive measures and therapeutic strategies.
Assuntos
Doenças Cardiovasculares/complicações , Fígado Gorduroso/complicações , Síndrome Metabólica/complicações , Animais , Humanos , Resistência à Insulina , Estresse OxidativoRESUMO
BACKGROUND: Patients with inflammatory bowel disease have an increased risk of thrombotic complications; moreover, mesenteric microvascular thrombosis has been hypothesized as a contributing factor in the pathogenesis of inflammatory bowel disease. AIM: To assess the extent of subclinical atherosclerosis in inflammatory bowel disease by measuring the intima-media thickness of the common carotid artery. METHODS: Fifty-two patients were enrolled in the study. Patients aged >45 years, with a history of cardiovascular disease and known risk factors for atherosclerosis were excluded from the study. Twenty healthy subjects were studied as controls. Carotid ultrasonography was performed in all patients and controls. intima-media thickness was measured proximal to the carotid bifurcation over both right and left common carotid arteries. The clinical characteristics and the laboratory parameters relevant to disease activity were recorded for all inflammatory bowel disease patients. In particular, plasma homocysteine, a well-known risk factor for thrombosis, was assessed. RESULTS: Common carotid artery intima-media thickness was significantly higher in inflammatory bowel disease patients (0.63 +/- 0.15 mm) compared with controls (0.53 +/- 0.08 mm). Multiple regression analysis revealed a significant association of carotid intima-media thickness with homocysteine levels and age. CONCLUSIONS: Inflammatory bowel disease patients have an increased risk of early atherosclerosis than healthy controls as showed by greater values of carotid intima-media thickness. Homocysteine levels and age resulted independently associated with the increased arterial wall thickness.
Assuntos
Artéria Carótida Primitiva/diagnóstico por imagem , Doenças Inflamatórias Intestinais/diagnóstico por imagem , Túnica Íntima/diagnóstico por imagem , Adulto , Anticorpos Monoclonais/uso terapêutico , Pressão Sanguínea/fisiologia , Sedimentação Sanguínea , Proteína C-Reativa/análise , Doenças das Artérias Carótidas/sangue , Doenças das Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/etiologia , Artéria Carótida Primitiva/patologia , Colesterol/sangue , Feminino , Fármacos Gastrointestinais/uso terapêutico , Homocisteína/sangue , Humanos , Doenças Inflamatórias Intestinais/sangue , Doenças Inflamatórias Intestinais/tratamento farmacológico , Infliximab , Masculino , Fatores de Risco , Túnica Íntima/patologia , UltrassonografiaRESUMO
BACKGROUND: Tissue homeostasis is guaranteed by stem proliferating reserve, depending on dynamic changes in gene expression. A high plasticity is shown by the haematopoietic stem cells, potential source for liver regeneration. AIM: We aimed to evaluate the gene expression modifications induced by human haematopoietic stem cell therapy after liver injury in rats. SUBJECTS: Rats were sorted as follows: (A) human-haematopoietic stem cell injection after allyl alcohol liver damage; (B) only haematopoietic stem cell injection; (C) only allyl alcohol injection; and (D) sacrifice without any treatment. METHODS: Livers, spleens and bone marrows were analysed with flow-cytometry. Livers were also studied by reverse-transcription PCR, histology, immunohistochemistry and microarray analysis; selected genes were confirmed by real-time PCR. RESULTS: In subset A, haematopoietic stem cells were selectively recruited by liver, with respect to the group B, and they improved the liver regeneration process compared to group C. As regards microarrays, haematopoietic stem cell infusion upregulates 265 genes and downregulates 149 genes. Differentially regulated genes belong to a broad range of functional pathways, including proliferation, differentiation, adhesion/migration and transcripts related to oval-cell activation. Real-time PCR validated array results. CONCLUSIONS: Our study confirmed the capacity of haematopoietic stem cells to contribute to liver regeneration. Moreover, microarray analysis led to the identification of genes whose regulation strongly correlates with a more efficient process of liver repair after haematopoietic stem cell injection.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas/terapia , Transplante de Células-Tronco de Sangue do Cordão Umbilical , Expressão Gênica , Regeneração Hepática , Animais , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Humanos , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Ratos , Ratos WistarRESUMO
BACKGROUND AND AIM: Molecular adsorbent recycling system (MARS) treatment is able to remove both hydrosoluble and small- and medium-sized lipophilic toxins. MARS plays an important role in modifying liver failure complications, such as hepatorenal syndrome and hepatic encephalopathy. We sought to evaluate the clinical efficacy and safety of a MARS device in a consecutive series of hepatic failure patients. MATERIALS: Twenty patients with acute liver failure, transplantation failure, or acute on chronic liver failure fulfilled the inclusion criteria of total bilirubin > or =10 mg/dL and at least one of the following: hepatic encephalopathy (HE) > or =II grade, hepatorenal syndrome (HRS) for chronic patients or total bilirubin > or =5 mg/dL and HE > or =I grade for acute patients. RESULTS: MARS was able to reduce cholestatic parameters and improve neurologic status and renal function parameters in all treated patients. We also observed an improvement in the 3-month survival rate compared to the expected outcome in patients with MELD scores between 20 and 29, as well as 30 and 39. CONCLUSIONS: Based on these results, we confirm the safety and clinical efficacy of MARS treatment, with the best results in patients with MELD score of 20 to 29. Further studies are necessary to confirm whether this treatment is able to modify patient outcomes and prognosis.
Assuntos
Hemodiafiltração/métodos , Falência Hepática/terapia , Fígado Artificial , Bilirrubina/sangue , Doença Crônica , Feminino , Encefalopatia Hepática/terapia , Síndrome Hepatorrenal/terapia , Humanos , Falência Hepática/etiologia , Falência Hepática/mortalidade , Falência Hepática Aguda/etiologia , Falência Hepática Aguda/mortalidade , Falência Hepática Aguda/terapia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Desintoxicação por Sorção/métodos , Análise de SobrevidaRESUMO
BACKGROUND AND AIM: The clearance of plasma cytokines by means of albumin dialysis (MARS) has been demonstrated in various studies involving patients affected by either acute liver failure (ALF) or acute on chronic liver failure. The aim of the study was to measure the plasma levels of TNF-alpha, IL-6, and IL-1beta in patients with ALF after each MARS treatment to evaluate the relationship between variations in cytokines levels and patient prognosis. MATERIALS AND METHODS: Ten patients with ALF undergoing several MARS treatments were enrolled (group 1). Blood samples were collected before and after each MARS treatment to measure TNF-alpha, IL-6, and IL-1beta, and other hematochemical parameters. We also enrolled 10 patients with ALF who underwent standard therapy (group 2) as well as a control group of 10 healthy subjects matched for sex and age (group 3). RESULTS: MARS reduced total bilirubin levels, biliary acids, BUN, ammonia, TNF-alpha, IL-6, and IL-1beta (P < .05). Moreover, the reduction in inflammatory cytokines levels and improved prognosis were related. CONCLUSIONS: We confirmed the therapeutic efficacy of MARS treatment for ALF, which appeared to be related to removal of toxins and inflammatory cytokines determine that which patients prognosis.
Assuntos
Bilirrubina/sangue , Citocinas/sangue , Falência Hepática Aguda/terapia , Falência Hepática/terapia , Diálise Renal/métodos , Desintoxicação por Sorção/métodos , Adulto , Amônia/sangue , Pré-Escolar , Doença Crônica , Feminino , Humanos , Interleucinas/sangue , Masculino , Pessoa de Meia-Idade , Fator de Necrose Tumoral alfa/análiseRESUMO
BACKGROUND AND AIM: Oxidative injury occurs as a direct result of hepatitis C virus (HCV) core protein expression both in vitro and in vivo, and may be due to a direct effect on mitochondria. The ketoisocaproic acid (KICA) breath test is a simple, reliable, and noninvasive test to evaluate hepatic mitochondrial function. Albumin dialysis (MARS) is an effective bridge treatment for patients with acute failure superimposed on chronic liver disease. The aim of our study was to evaluate the improvement of mitochondrial function measured by KICA in patients undergoing MARS for acute-on-chronic HCV liver failure. MATERIALS AND METHODS: Five patients with HCV chronic infection undergoing MARS treatment for acute decompensation were enrolled. Before and after each MARS treatment, patients underwent blood testing for the main hematochemical parameters as well as for mitochondrial function by the KICA breath test and the arterial ketone bodies ratio (AKBR). RESULTS: MARS treatment effectively decreased the serum level of total bilirubin, bile acids, urea, and ammonium. Moreover, MARS treatment produced an increase in AKBR and in the cumulative percentage of (13)CO(2) recovered in exhaled air 2 hours after KICA ingestion. CONCLUSION: Liver mitochondrial function appears to be beneficially affected by MARS treatment.
Assuntos
Caproatos/análise , Hemodiafiltração , Hepatite C/terapia , Cetoácidos/análise , Adulto , Idoso , Ácidos e Sais Biliares/sangue , Bilirrubina/sangue , Nitrogênio da Ureia Sanguínea , Testes Respiratórios , Creatinina/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Liver regeneration is a heterogeneous phenomenon involving the proliferation of different cell lineages in response to injury. Under a strong positive selection pressure bone marrow derived stem cells may be involved in this process, by making a contribution to both parenchymal restoration and endothelial cell replacement. We investigate bone marrow stem cell migration to the liver in patients undergoing hepatectomy or with acute on chronic liver failure. METHODS: We enrolled 6 patients submitted to hepatectomy, 6 patients to cholecystectomy and 8 patients with acute decompensation of liver cirrhosis. Mobilization of CD34+ cells was evaluated by cytofluorimetry on peripheral blood samples at different time points; baseline, 1, 3, 7, 15 and 30 days after surgery and at admission, 1, 7 and discharge among patients with acute on chronic liver failure. 10 healthy subjects undergoing blood donation were also enrolled to evaluated the basal value of CD34+ cells. RESULTS: White blood cell counts remained in the normal range (4.1-9.8 x 10(9)/L) in all groups throughout the follow-up. In all patients of Groups 1, 2 and 3, circulating CD34+ failed to show statistically significant differences both as the absolute number and as the percentage at any time point compared to healthy controls. CONCLUSIONS: Bone marrow derived cell mobilization can not be detected after hepatectomy or during an acute decompensation on a cirrhotic liver. Under these circumstances liver regeneration can probably call upon mature hepatocytes and endogenous progenitor cells. The involvement of extrahepatic progenitors if any, is a rare and limited phenomenon.
Assuntos
Mobilização de Células-Tronco Hematopoéticas , Hepatectomia , Falência Hepática Aguda/fisiopatologia , Falência Hepática/fisiopatologia , Regeneração Hepática/fisiologia , Adulto , Antígenos CD/sangue , Antígenos CD34/sangue , Contagem de Células Sanguíneas , Colecistectomia , Doença Crônica , Feminino , Humanos , Falência Hepática/sangue , Falência Hepática/etiologia , Falência Hepática Aguda/sangue , Falência Hepática Aguda/etiologia , Masculino , Pessoa de Meia-IdadeRESUMO
Among the different approaches for diabetes mellitus-pancreas and pancreatic islet transplantation-the use of stem cells represent a renewable alternative source of insulin-producing cells. Stem cells capable of differentiating into beta-like cells can be isolated namely from embryonic cells, bone marrow, and umbilical cord blood, but also from adult organs such as pancreas, liver, and spleen. Several studies have demonstrated that by manipulating culture conditions and using growth and transcription factors of beta-cell lineage (in particular pdx-1 and pax4), embryonic stem cells can differentiate in vitro after formation of embryoid bodies. Bone marrow stem cells can give rise to mesenchymal; endodermal-, and ectodermal-derived cells. In vivo it has been shown that after bone marrow transplantation, using a murine sex-mismatched model, insulin-producing cells expressing the Y chromosome can be detected in the donor pancreas, although not in a significantly number. Cells characterized by a group of markers (Nestin, CK-8, CK-18) and transcription factors (Isl-1, Pdx-1, Pax-4, Ngn-3) important for beta-cell differentiation have been detected in umbilical cord blood. The recent evidence of the possibility to transdifferentiate stem cells to beta cells encourages further studies in animal models to exhaustively determine the differentiation pathways of stem cells to insulin producing cells. These findings might open the way to a successful human investigation.
Assuntos
Pâncreas/citologia , Células-Tronco/citologia , Adulto , Diferenciação Celular , Diabetes Mellitus Tipo 1/cirurgia , Humanos , Transplante das Ilhotas Pancreáticas , Segurança , Transplante de Células-TroncoRESUMO
BACKGROUND AND AIMS: Because of their plasticity potential local and systemic application of cord blood stem cells may represent excellent candidates for cell-based therapeutic strategies in toxic liver injuries. It is already known that intraperitoneal administration of hematopoietic stem cells provides rapid liver homing in animal models of hepatic injury. We sought to assess the efficacy of a hematopoietic stem cell infusion to decrease the histologic damage and the mortality rate of animals previously damaged by allyl alcohol. MATERIAL AND METHODS: NOD/SCID mice were divided into two groups. (1) animals treated by intraperitoneal administration of allyl alcohol and (2) animals treated with allyl alcohol and 24 hours later with an intraperitoneal infusion of human cord blood cells. Flow cytometry, histology, immunohistochemistry, and RT-PCR were performed to monitor human cell engraftment by evidences of human hepatic markers. RESULTS: Human stem cells were able to transdifferentiate into hepatocytes, improve liver regeneration after damage, and reduce the mortality rate even when requiring qualitative and quantitative differences in the transdifferentiation processes. The mortality rate decreased from 70% to 20%, with a significant improvement in the histologic findings. CONCLUSION: We demonstrated that the infusion of hematopoietic stem cells into the liver in the early stage of damage might initiate endogenous hepatic tissue regeneration that oppose the injury inflicted by toxicants.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Transplante de Células-Tronco de Sangue do Cordão Umbilical/métodos , Hepatócitos/transplante , Hepatopatias/terapia , Transplante Heterólogo/patologia , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Propanóis/toxicidadeRESUMO
BACKGROUND AND AIM: Tissue homeostasis and turnover require reserve stem proliferating cells. Several studies performed on immunodeficient animals have suggested a degree of plasticity by the hematopoietic stem cell compartment that may represent source for liver regeneration. We sought to explore the hepatic differentiation potential of hematopoietic stem cells from human cord blood, after toxic liver damage induced by allyl-alcohol in immunocompetent rats. MATERIALS AND METHODS: Wistar rats were divided into groups (A) allyl-alcohol intraperitoneal injection with hematopoietic stem cell intraperitoneal infusion at 1 day and sacrifice 3 days later; (B) stem cell injection and sacrifice 3 days later; (C) allyl-alcohol infusion and sacrifice 4 days later; and (D) sacrifice without any treatment. Livers, spleens, and bone marrows were analysed for human stem cells using flow-cytometry; livers were also tested by histology and immunohistochemistry to study the pattern of hepatic regeneration after damage and human stem cell conversion into hepatocyte-like cells, respectively. RESULTS: Flow-cytometry revealed selective recruitment of human hematopoietic stem cells by damaged livers (group A) compared with control group B. In addition, liver damage was reduced in animals treated with stem cells. Immunohistochemistry demonstrated that human stem cells could convert hepatic cells. CONCLUSIONS: Our study demonstrated that hematopoietic stem cells selectively recruited by injured livers can contribute to hepatic regeneration after acute toxic damage in immunocompetent recipients.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas , Transplante de Células-Tronco de Sangue do Cordão Umbilical/métodos , Hepatopatias/terapia , Propanóis/toxicidade , Transplante Heterólogo/métodos , Animais , Modelos Animais de Doenças , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Células de Kupffer/efeitos dos fármacos , Células de Kupffer/patologia , Hepatopatias/patologia , Ratos , Ratos WistarRESUMO
Adult stem cells (ASC) have becoming a great domain of research by their promising interest for the regenerative medicine. For some years, the number of publications has been increasing, displaying the potential of ASC to differentiate in all tissue-lineages, challenging the previous dogma that ASC were restricted to give rise only to specific cells from their tissue of origin. Among the diversity of ASC, hematopoietic stem cells (HSC) have been the most studied and their use in the clinical setting is largely documented. Commonly, HSC have been harvested from the bone marrow, but for some years, two others sources, the peripheral blood and the umbilical cord blood have been introduced. All these HSC posses their own molecular characteristics and degree of maturity and represent a more or less good candidate to participate in the cellular-based tissue regeneration. We have reviewed the different parameters allowing to define which subset could be the more favorable such as the accessibility to the pool of HSC; the quantity of available cells; the tolerability of host-engraftment and the capacity of the cells to home correctly to the required site of damaged. Besides, recently, the molecular profiling of HSC has allowed identifying which subset posses the more promising characteristics.
Assuntos
Transplante de Células-Tronco/métodos , Células-Tronco/citologia , Animais , Células da Medula Óssea/citologia , Sangue Fetal/citologia , Células-Tronco Hematopoéticas/citologia , Humanos , Medicina Regenerativa/métodos , Transplante de Células-Tronco/classificação , Transplante de Células-Tronco/normasRESUMO
BACKGROUND: Several studies have demonstrated that bone marrow contains a subpopulation of stem cells capable of participating in the hepatic regenerative process, even if some reports indicate quite a low level of liver repopulation by human stem cells in the normal and transiently injured liver. AIMS: In order to overcome the low engraftment levels seen in previous models, we tried the direct intraperitoneal administration of human cord blood stem cells, using a model of hepatic damage induced by allyl alcohol in NOD/SCID mice. METHODS: We designed a protocol based on stem cell infusion following liver damage in the absence of irradiation. Flow cytometry, histology, immunohistochemistry and RT-PCR for human hepatic markers were performed to monitor human cell engraftment. RESULTS: Human stem cells were able to transdifferentiate into hepatocytes, to improve liver regeneration after damage and to reduce the mortality rate both in both protocols, even if with qualitative and quantitative differences in the transdifferentiation process. CONCLUSIONS: We demonstrated for the first time that the intraperitoneal administration of stem cells can guarantee a rapid liver engraftment. Moreover, the new protocol based on stem cell infusion following liver damage in the absence of irradiation may represent a step forward for the clinical application of stem cell transplantation.
Assuntos
Doença Hepática Induzida por Substâncias e Drogas/terapia , Transplante de Células-Tronco de Sangue do Cordão Umbilical , Animais , Doença Hepática Induzida por Substâncias e Drogas/etiologia , Doença Hepática Induzida por Substâncias e Drogas/mortalidade , Modelos Animais de Doenças , Citometria de Fluxo , Gliceraldeído-3-Fosfato Desidrogenases/genética , Humanos , Imuno-Histoquímica , Queratina-7 , Queratinas/análise , Fígado/metabolismo , Fígado/patologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Propanóis/toxicidade , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Taxa de Sobrevida , Transplante Heterólogo , Resultado do TratamentoRESUMO
BACKGROUND: Several epidemiological studies have shown a statistically significant association between standing work and chronic venous insufficiency of lower limbs. This condition has been associated with an enhanced oxidative stress that, according to the literature, could represent a risk factor for cardiovascular and other systemic diseases. AIMS AND METHODS: To evaluate venous pressure of the lower limbs and reactive oxygen species (ROS) before and after work in 62 workers with a standing occupation (surgery room nurses) and 65 outpatient department nurses who can walk during their working time. RESULTS: After work, a statistically significant increase of venous pressure of the lower limbs levels was observed in both the study group and controls. Standing workers showed significantly higher mean levels of ROS after work.
Assuntos
Doenças Profissionais/epidemiologia , Estresse Oxidativo , Espécies Reativas de Oxigênio/análise , Insuficiência Venosa/epidemiologia , Adulto , Doença Crônica , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Enfermeiras e Enfermeiros/estatística & dados numéricos , Postura , Espécies Reativas de Oxigênio/sangue , Fatores de Risco , Insuficiência Venosa/sangue , Pressão Venosa/fisiologiaRESUMO
Cell-based therapies, comprising isolated hepatocyte transplantation, ex vivo gene therapy and bioartificial liver devices, may actually design a new scenario in the treatment of patients with liver failure. Recent advances in the liver repopulation field and the considerable excitement surrounding the use of haematopoietic stem cells for a 'regenerative medicine', allow us to see under a new light the alternative cell sources actually under investigation. In particular, the major drawbacks and the most important advantages of xenogenic primary cells, tumour-derived cell lines, immortalised hepatocytes and stem cells in the wide range of experimental and clinical applications are presented. Even if up to now none of them represent a 'gold standard' in the clinical practice, the intersecting advances in the development of mechanical components of artificial devices and in the liver biology and bioengineering will open tantalising possibilities to treat patients with liver failure, by tailoring the therapeutic choice on the basis of the aetiology and the stage of liver disease.
Assuntos
Hepatócitos/transplante , Falência Hepática/terapia , Transplante de Células-Tronco/métodos , Órgãos Artificiais , HumanosRESUMO
Although liver transplantation has become standard therapy in the treatment of patients with liver failure, several problems should be considered in the management of these patients. Other approaches have been proposed, in particular cellular-based procedures. Isolated hepatocytes may be used instead of whole organ transplantation or integrated within the bioartificial devices, in order to replace the missing synthetic and metabolic liver functions. Moreover patient's own hepatocytes may be ex vivo genetically modified to provide the function of a mutant gene. However, new cell sources alternative to adult hepatocytes are actually under investigation, on the basis of recent advances in the field of liver repopulation. Xenogenic primary cells, human hepatoma cells, immortalized hepatocytes and stem cells have been testing in several experiments, even if up to now none of them represent a "gold-standard" for cell-based treatment of liver diseases. In the next future, it is possible that different clinical situations will require different therapeutic approaches, that will be finally defined from the concomitant advances in the development of artificial devices and liver cell biology.
Assuntos
Transplante de Células , Hepatócitos/transplante , Falência Hepática Aguda/terapia , Humanos , Fígado ArtificialRESUMO
Stem cells play a key role in tissue homeostasis and renewal after damage, so learning more about them may become a sort of 'Pandora's box', which when opened will make it possible to clarify the nature and the pathophysiology of several human diseases and to find new treatments for pathologies, such as cancers, degenerative, autoimmune and genetic disorders, that are currently untreatable. The characteristics of the gastrointestinal tract and of the liver, in terms of genesis and regeneration and their special relationship with the haemolymphopoietic system, allow stem cell research to outline interesting therapeutic perspectives in these fields. We aim to summarize the knowledge acquired on gastrointestinal and hepatic stem cell biology, focusing attention on the issues that remain to be addressed, and to present the main perspectives of treatment offered by these 'new tools' in gastroenterology and hepatology.
Assuntos
Sistema Digestório/citologia , Células-Tronco Hematopoéticas/fisiologia , Fígado/citologia , Células da Medula Óssea/fisiologia , Fenômenos Fisiológicos do Sistema Digestório , Homeostase/fisiologia , Humanos , Fígado/fisiologiaRESUMO
BACKGROUND: Oxygen-free radicals generation is considered to be a major cause of gastric injury during reperfusion. Chemiluminescence has been used to assess real-time free radical release on the surface of isolated organs. AIMS: To evaluate the combined use of chemiluminescence and gastroendoscopy techniques and to assess the real-time production of free radicals during ischemic damage of the gastric wall in an animal model. PATIENTS AND METHODS: For the experiment, an optical junction was set up between a fibroendoscope and a luminograph apparatus. Three pigs were submitted to gastrofibroendoscopy before, during and after 30 min of clamping of the coeliac artery. Under basal conditions, at the end of the ischemic phase and at the beginning of reperfusion, 1 mM of lucigenin, a specific superoxide enhancer, was injected in the left gastric artery of the animal. The endoscopic live images and chemiluminescence emission were recorded and successively superimposed to measure rate and spatial distribution of photon emission (photons/s). RESULTS: Free radical production was not observed under basal conditions or during the ischemic phase, but significantly increased during reperfusion reaching a maximum peak after 15 min (0.6+/-0.2 photons x 10(5)/s) and decreased progressively thereafter. The superimposition of live and chemiluminescence images allowed the determination of the regional production rate and distribution of photons. CONCLUSIONS: Preliminary observations, in an animal model, on an innovative imaging system which allows the visualization of rate and spatial distribution of reactive oxygen species formation are presented. This new endoscopic technique could be useful for the assessment of oxidative gastric mucosal injury in several gastric diseases; however, further studies remain necessary to determine the applicability of this technique in humans.
Assuntos
Mucosa Gástrica/metabolismo , Gastroscopia , Isquemia/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Estômago/irrigação sanguínea , Animais , Medições Luminescentes , Masculino , Modelos Animais , Estômago/patologia , SuínosRESUMO
Although liver transplantation has become standard procedure for patients with liver failure, a number of issues in the management of these patients remains to be addressed. Alternative approaches have been tested, such as hepatocytes containing liver-support systems and filtration devices. However, the replacement of detoxification has been difficult, as the majority of toxins accumulating in liver failure is albumin-bound. Albumin dialysis (MARS system) is characterized by the specific removal of albumin-bound toxins through an innovative membrane transport. In particular, the albumin acts as a specific molecular adsorbent that is regenerated on line in a recycling system. Nowadays MARS represents the most frequently used liver support system. This treatment has been shown to remove albumin-bound molecules, such as bilirubin, bile acids, aromatic amino acids and copper. The removal of these toxins is clinically accompanied with an improvement of liver, cardiovascular and renal functions and hepatic encephalopathy. In several trials MARS was found to improve the clinical situation in patients with acute exacerbation of chronic liver failure and acute hepatic failure, but also in hepatorenal syndrome and primary graft non function or chronic rejection after liver transplantation. In summary, a critical analysis of the literature confirms that MARS device can be a safe therapeutic choice to achieve a better clinical outcome, and, sometimes, a survival advantage in patients with liver failure, even if a multi-center randomized trial is the only reliable way to enforce today's results. Further advances in the MARS components will definitively state whether albumin dialysis may represent the future in the field of artificial liver devices.