Spontaneous apoptosis of cells in therapeutic stem cell preparation exert immunomodulatory effects through release of phosphatidylserine.

Mesenchymal stem cell (MSC)-mediated immunomodulation has been harnessed for the treatment of human diseases, but its underlying mechanism has not been fully understood. Dead cells, including apoptotic cells have immunomodulatory properties. It has been repeatedly reported that the proportion of nonviable MSCs in a MSC therapeutic preparation varied from 5~50% in the ongoing clinical trials. It is conceivable that the nonviable cells in a MSC therapeutic preparation may play a role in the therapeutic effects of MSCs. We found that the MSC therapeutic preparation in the present study had about 5% dead MSCs (DMSCs), characterized by apoptotic cells. Namely, 1 × 106 MSCs in the preparation contained about 5 × 104 DMSCs. We found that the treatment with even 5 × 104 DMSCs alone had the equal therapeutic effects as with 1 × 106 MSCs. This protective effect of the dead MSCs alone was confirmed in four mouse models, including concanavalin A (ConA)- and carbon tetrachloride (CCl4)-induced acute liver injury, LPS-induced lung injury and spinal cord injury. We also found that the infused MSCs died by apoptosis in vivo. Furthermore, the therapeutic effect was attributed to the elevated level of phosphatidylserine (PS) upon the injection of MSCs or DMSCs. The direct administration of PS liposomes (PSLs) mimic apoptotic cell fragments also exerted the protective effects as MSCs and DMSCs. The Mer tyrosine kinase (MerTK) deficiency or the knockout of chemokine receptor C-C motif chemokine receptor 2 (CCR2) reversed these protective effects of MSCs or DMSCs. These results revealed that DMSCs alone in the therapeutic stem cell preparation or the apoptotic cells induced in vivo may exert the same immunomodulatory property as the "living MSCs preparation" through releasing PS, which was further recognized by MerTK and participated in modulating immune cells.

Bidens pilosa L. (Asteraceae) cultivated in Brazil on acute liver disease in dogs / [Bidens pilosa L. (Asteraceae) cultivada no Brasil na doença hepática aguda em cães]

Bidens pilosa L. is a medicinal plant popularly used for treatment of liver diseases. In this study, the dry extract of aerial parts of Bidens pilosa and Silymarin, a phytocomplex obtained from the Silybum marianum fruits and marketed as hepatoprotective, were tested in dogs experimentally acutely intoxicated with carbon tetrachloride. The liver activity was evaluated by hematological and biochemical profiles, and histological and ultrasound analyzes. It was observed that the lowest serum activities of ALT and serum concentrations of total bilirubin occurred in the groups treated with the dry extract of Bidens pilosa, while only decreased serum concentrations of total bilirubin occurred in the group treated with Silymarin. Best liver recovery was also observed for the dry extract of B. pilosa at a 400mg/Kg dose by ultrasonography. This study showed that the dry extract of Bidens pilosa acted more efficiently in the treatment of acute toxic hepatitis induced in dogs than Silymarin.(AU)

Bidens pilosa L. é uma planta medicinal utilizada popularmente para tratamento de doenças hepáticas. Neste trabalho, o extrato seco das partes aéreas da Bidens pilosa e a silimarina, um fitocomplexo obtido dos frutos da Silybum marianum e comercializado como hepatoprotetor, foram testados em cães intoxicados experimentalmente de forma aguda com tetracloreto de carbono. A atividade hepática foi avaliada por meio dos perfis hematológico e bioquímico, análises histológica e ultrassonográfica. Observou-se que, nos grupos tratados com o extrato seco da Bidens pilosa, ocorreram as menores atividades séricas da ALT e de concentrações séricas de bilirrubina total, enquanto no grupo tratado com silimarina, ocorreu apenas diminuição de concentrações séricas de bilirrubina total. Melhor recuperação hepática também foi verificada para o extrato seco de B. pilosa na dose de 400mg/kg por ultrassonografia. Este estudo evidenciou que o extrato seco da Bidens pilosa atuou de forma mais eficiente no tratamento da hepatite aguda tóxica induzida em cães do que a silimarina.(AU)

Oct4 and Hnf4α-induced hepatic stem cells ameliorate chronic liver injury in liver fibrosis model.

Direct conversion from fibroblasts to generate hepatocyte like-cells (iHeps) bypassing the pluripotent state has been described in previous reports as an attractive method acquiring hepatocytes for cell-based therapy. The limited proliferation of iHeps, however, has hampered it uses in cell-based therapy. Since hepatic stem cells (HepSCs) possess self-renewal and bipotency with the capacity to differentiate into both hepatocytes and cholangiocytes, they have therapeutic potential for treating liver disease. Here, we investigated the therapeutic effects of induced HepSCs (iHepSCs) on a carbon tetrachloride (CCl4)-induced liver fibrosis model. We demonstrate that Oct4 and Hnf4a are sufficient to convert fibroblasts into expandable iHepSCs. Hepatocyte-like cells derived from iHepSCs (iHepSC-HEPs) exhibit the typical morphology of hepatocytes and hepatic functions, including glycogen storage, low-density lipoprotein (LDL) uptake, Indocyanine green (ICG) detoxification, drug metabolism, urea production, and albumin secretion. iHepSCs-derived cholangiocyte-like cells (iHepSC-CLCs) expressed cholangiocyte-specific markers and formed cysts and tubule-like structures with apical-basal polarity and secretory function in three-dimensional culture condition. Furthermore, iHepSCs showed anti-inflammatory and anti-fibrotic effects in CCl4-induced liver fibrosis. This study demonstrates that Oct4 and Hnf4α-induced HepSCs show typical hepatic and biliary functionality in vitro. It also presents the therapeutic effect of iHepSCs in liver fibrosis. Therefore, directly converting iHepSCs from somatic cells may facilitate the development of patient-specific cell-based therapy for chronic liver damage.

Human bone marrow mesenchymal stem cells-derived exosomes alleviate liver fibrosis through the Wnt/ß-catenin pathway.

BACKGROUND: Mesenchymal stem cells (MSCs) are increasingly being applied as a therapy for liver fibrosis. Exosomes possess similar functions to their parent cells; however, they are safe and effective cell-free reagents with controllable and predictable outcomes. In this study, we investigated the therapeutic potential and underlying molecular mechanism for human bone mesenchymal stem cells-derived exosomes (hBM-MSCs-Ex) in the treatment of liver fibrosis. METHODS: We established an 8-week CCl4-induced rat liver fibrosis model, after which, we administered hBM-MSCs-Ex in vivo for 4 weeks. The resulting histopathology, liver function, and inflammatory cytokines were analyzed. In addition, we investigated the anti-fibrotic mechanism of hBM-MSCs-Ex in hepatic stellate cells (HSCs) and liver fibrosis tissue, by western blotting for the expression of Wnt/ß-catenin signaling pathway-related genes. RESULTS: In vivo administration of hBM-MSCs-Ex effectively alleviated liver fibrosis, including a reduction in collagen accumulation, enhanced liver functionality, inhibition of inflammation, and increased hepatocyte regeneration. Moreover, based on measurement of the collagen area, Ishak fibrosis score, MDA levels, IL-1, and IL-6, the therapeutic effect of hBM-MSCs-Ex against liver fibrosis was significantly greater than that of hBM-MSCs. In addition, we found that hBM-MSCs-Ex inhibited the expression of Wnt/ß-catenin pathway components (PPARγ, Wnt3a, Wnt10b, ß-catenin, WISP1, Cyclin D1), α-SMA, and Collagen I, in both HSCs and liver fibrosis tissue. CONCLUSIONS: These results suggest that hBM-MSCs-Ex treatment could ameliorate CCl4-induced liver fibrosis via inhibition of HSC activation through the Wnt/ß-catenin pathway.

Hepatogenic differentiation from human adipose-derived stem cells and application for mouse acute liver injury.

Adipose-derived stem cells (ADSCs) derived from adipose tissue have the capacity to differentiate into endodermal, mesoderm, and ectodermal cell lineages in vitro, which are an ideal engraft in tissue-engineered repair. In this study, human ADSCs were isolated from subcutaneous fat. The markers of ADSCs, CD13, CD71, CD73, CD90, CD105, CD166, CYP3A4, and ALB were detected by immunofluorescence assays. Human ADSCs were cultured in a specific hepatogenesis differentiation medium containing HGF, bFGF, nicotinamide, ITS, and oncostatin M for hepatogenic differentiation. The hepatocyte markers were analyzed using immunofluorescence and real-time PCR after dramatic changes in morphology. Hepatocytes derived from ADSCs or ADSCs were transplanted into the mice of liver injury for observation cells colonization and therapy in liver tissue. The result demonstrated that human ADSCs were positive for the CD13, CD71, CD73, CD90, CD105, and CD166 but negative for hepatocyte markers, ALB and CYP3A4. After hepatogenic differentiation, the hepatocytes were positive for liver special markers, gene expression level showed a time-lapse increase with induction time. Human ADSCs or ADSCs-derived hepatocyte injected into the vein could improve liver function repair and functionally rescue the CCl4-treated mice with liver injury, but the ADSCs transplantation was better than ADSCs-derived hepatocyte transplantation. In conclusion, our research shows that a population of hepatocyte can be specifically generated from human ADSCs and that cells may allow for participation in tissue-repair.

Influences of keratinocyte growth factor - mesenchymal stem cells on chronic liver injury in rats.

To study the effects of keratinocyte growth factor (KGF) modified umbilical cord mesenchymal stem cells (MSC) on chronic liver injury in rats, adenovirus carrying human KGF gene (Ad-KGF) was used. Rat liver injury model was established by subcutaneous injection of CCl4 - olive oil solution; 56 male Wistar rats were randomly divided into normal control, model, MSC, KGF, and KGF/MSC groups. Of all three treatments, KGF/MSC had the most obvious therapeutic effects on liver injury, and cell injections did not cause adverse reaction. The experiment provides new data for clinical research of KGF/MSC and possible methods for liver injury treatment.

Resetting the transcription factor network reverses terminal chronic hepatic failure.

The cause of organ failure is enigmatic for many degenerative diseases, including end-stage liver disease. Here, using a CCl4-induced rat model of irreversible and fatal hepatic failure, which also exhibits terminal changes in the extracellular matrix, we demonstrated that chronic injury stably reprograms the critical balance of transcription factors and that diseased and dedifferentiated cells can be returned to normal function by re-expression of critical transcription factors, a process similar to the type of reprogramming that induces somatic cells to become pluripotent or to change their cell lineage. Forced re-expression of the transcription factor HNF4α induced expression of the other hepatocyte-expressed transcription factors; restored functionality in terminally diseased hepatocytes isolated from CCl4-treated rats; and rapidly reversed fatal liver failure in CCl4-treated animals by restoring diseased hepatocytes rather than replacing them with new hepatocytes or stem cells. Together, the results of our study indicate that disruption of the transcription factor network and cellular dedifferentiation likely mediate terminal liver failure and suggest reinstatement of this network has therapeutic potential for correcting organ failure without cell replacement.

Melatonin promotes hepatic differentiation of human dental pulp stem cells: clinical implications for the prevention of liver fibrosis.

Melatonin's effect on hepatic differentiation of stem cells remains unclear. The aim of this study was to investigate the action of melatonin on hepatic differentiation as well as its related signaling pathways of human dental pulp stem cells (hDPSCs) and to examine the therapeutic effects of a combination of melatonin and hDPSC transplantation on carbon tetrachloride (CCl4 )-induced liver fibrosis in mice. In vitro hepatic differentiation was assessed by periodic acid-Schiff (PAS) staining and mRNA expression for hepatocyte markers. Liver fibrosis model was established by injecting 0.5 mL/kg CCl4 followed by treatment with melatonin (5 mg/kg, twice a week) and hDPSCs. In vivo therapeutic effects were evaluated by histopathology and by means of liver function tests including measurement of alanine transaminase (ALT), aspartate transaminase (AST), and ammonia levels. Melatonin promoted hepatic differentiation based on mRNA expression of differentiation markers and PAS-stained glycogen-laden cells. In addition, melatonin increased bone morphogenic protein (BMP)-2 expression and Smad1/5/8 phosphorylation, which was blocked by the BMP antagonist noggin. Furthermore, melatonin activated p38, extracellular signal-regulated kinase (ERK), and nuclear factor-κB (NF-κB) in hDPSCs. Melatonin-induced hepatic differentiation was attenuated by inhibitors of BMP, p38, ERK, and NF-κB. Compared to treatment of CCl4 -injured mice with either melatonin or hDPSC transplantation alone, the combination of melatonin and hDPSC significantly suppressed liver fibrosis and restored ALT, AST, and ammonia levels. For the first time, this study demonstrates that melatonin promotes hepatic differentiation of hDPSCs by modulating the BMP, p38, ERK, and NF-κB pathway. Combined treatment of grafted hDPSCs and melatonin could be a viable approach for the treatment of liver cirrhosis.

Chronic restraint stress decreases the repair potential from mesenchymal stem cells on liver injury by inhibiting TGF-ß1 generation.

Chronic psychological stress has been demonstrated to play an important role in several severe diseases, but whether it affects disease therapy or not remains unclear. Mesenchymal stem cells (MSCs) have been demonstrated to have therapeutic potentials in treating tissue injury based on their multidifferentiation potential toward various cell types. We investigated the effect of chronic restraint stress on therapeutic potential of MSCs on carbon tetrachloride (CCl4)-induced liver injury in mice. CCl4-induced mice were injected with enhanced green fluorescent protein-MSCs, which was followed by chronic restraint stress administration. Corticosterone and RU486, a glucocorticoid receptor (GR) antagonist, were employed in vivo and in vitro, too. In the present study, we illustrated that MSCs could repair liver injury by differentiating into myofibroblasts (MFs) which contribute to fibrosis, whereas stress repressed differentiation of MSCs into MFs displayed by reducing α-smooth muscle actin (α-SMA, a solid marker of MFs) expression. Whereas RU486 could maintain the liver injury reduction and liver fibrosis increases induced by MSCs in stressed mice and block the decrease of α-SMA expression induced by stress. Furthermore, chronic stress inhibited MFs differentiation from MSCs by inhibiting transforming growth factor-ß1 (TGF-ß1)/Smads signaling pathway which is essential for MFs differentiation. Chronic stress reduced autocrine TGF-ß1 of MSCs, but not blunted activation of Smads. All these data suggested that corticosterone triggered by chronic stress impaired liver injury repair by MSCs through inhibiting TGF-ß1 expression which results in reduced MFs differentiation of MSCs.

Transplanted human amniotic membrane-derived mesenchymal stem cells ameliorate carbon tetrachloride-induced liver cirrhosis in mouse.

BACKGROUND: Human amniotic membrane-derived mesenchymal stem cells (hAMCs) have the potential to reduce heart and lung fibrosis, but whether could reduce liver fibrosis remains largely unknown. METHODOLOGY/PRINCIPAL FINDINGS: Hepatic cirrhosis model was established by infusion of CCl4 (1 ml/kg body weight twice a week for 8 weeks) in immunocompetent C57Bl/6J mice. hAMCs, isolated from term delivered placenta, were infused into the spleen at 4 weeks after mice were challenged with CCl4. Control mice received only saline infusion. Animals were sacrificed at 4 weeks post-transplantation. Blood analysis was performed to evaluate alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Histological analysis of the livers for fibrosis, hepatic stellate cells activation, hepatocyte apoptosis, proliferation and senescence were performed. The donor cell engraftment was assessed using immunofluorescence and polymerase chain reaction. The areas of hepatic fibrosis were reduced (6.2%±2.1 vs. control 9.6%±1.7, p<0.05) and liver function parameters (ALT 539.6±545.1 U/dl, AST 589.7±342.8 U/dl,vs. control ALT 139.1±138.3 U/dl, p<0.05 and AST 212.3±110.7 U/dl, p<0.01) were markedly ameliorated in the hAMCs group compared to control group. The transplantation of hAMCs into liver-fibrotic mice suppressed activation of hepatic stellate cells, decreased hepatocyte apoptosis and promoted liver regeneration. More interesting, hepatocyte senescence was depressed significantly in hAMCs group compared to control group. Immunofluorescence and polymerase chain reaction revealed that hAMCs engraftment into host livers and expressed the hepatocyte-specific markers, human albumin and α-fetoproteinran. CONCLUSIONS/SIGNIFICANCE: The transplantation of hAMCs significantly decreased the fibrosis formation and progression of CCl4-induced cirrhosis, providing a new approach for the treatment of fibrotic liver disease.

Novel findings for the development of drug therapy for various liver diseases: Current state and future prospects for our liver regeneration therapy using autologous bone marrow cells for decompensated liver cirrhosis patients.

We have developed an in vivo mouse model [the green fluorescent protein (GFP) / carbon tetrachloride (CCl(4)) model] and reported that infused GFP-positive bone marrow cells administered via a tail vein efficiently repopulated cirrhotic liver tissue under conditions of persistent liver damage induced by CCl(4). Moreover, bone marrow cells infused into the liver improved liver function and ameliorated liver fibrosis with higher expression of matrix metalloproteinase 9 (MMP-9), consistent with improved survival rate. Based on these findings, we started a multicenter clinical trial of autologous bone marrow cell infusion (ABMi) therapy for decompensated liver cirrhosis patients and demonstrated the efficacy of this approach without unexpected complications. However, this therapy involves bone marrow aspiration under general anesthesia and is not indicated for patients for whom general anesthesia is difficult. We therefore aimed to develop a new liver regeneration therapy in which cells having a curative effect on liver cirrhosis are isolated and cultured from a small amount of autologous bone marrow aspirated under local anesthesia and infused back into the same subject. Herein, we present results for the GFP/CCl(4) model and ABMi therapy and future prospects for a new liver regeneration therapy.

Differential anti-inflammatory and anti-fibrotic activity of transplanted mesenchymal vs. hematopoietic stem cells in carbon tetrachloride-induced liver injury in mice.

Bone marrow stem cells nullify acquired and non-acquired diseases of liver through multiple strategies including antiinflammation. However, little is known about the in vivo mechanism of immunomodulation by stem cells in mediating liver cirrhosis. Mesenchymal stem cells (MSC) or hematopoietic stem cells (HSC) isolated from bone marrow of male mice were transplanted into female mice with acute liver inflammation. Serum levels of liver proteins and aminotransferase as well as hepatic antioxidant enzymes were estimated. Immunostaining for the expression of tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), alpha smooth muscle actin (alpha-SMA) and type I collagen proteins was carried out and the expression of these mRNAs was also studied. After post-transplantation, the levels of serum albumin and aminotransferases became normal and the levels of antioxidants were significantly high in the MSC treated mice compared to HSC and control mice. Necrotic cells and invasion of neutrophils were not observed in histological sections of liver of MSC treated mice. Immunostaining showed that IL-6 and TNF-alpha were not expressed in the MSC treated mice when compared to the control and HSC treated mice. alpha-SMA representing activated myofibroblasts and type I collagen were not expressed in MSC treated group. These inflammatory and fibrogenic results were further confirmed by reverse transcription-polymerase chain reaction (RT-PCR). The acute inflammation ended with the formation of fibrosis in the HSC and control groups by the uncontrolled immunoreactions. Protection mechanism of MSC therapy against injury and fibrosis in the liver occurs by the suppression of inflammation. Our findings suggest that bone marrow MSC are capable of alleviating the immunoreactions leading to the fibrosis in the liver.

Suppression of carbon tetrachloride-induced liver fibrosis by transplantation of a clonal mesenchymal stem cell line derived from rat bone marrow.

Transplantation of hepatocytes or bone marrow-derived cells has been shown to ameliorate liver fibrosis in animal models, but no direct comparison of relative efficiency has been made. The aim of this study was to compare the efficiency of a bone marrow-derived clonal mesenchymal stem cell line established by us (rBM25/S3) with that of its adipogenic or hepatogenic differentiation derivative for suppression of rat liver fibrosis. After induction of differentiation of rBM25/S3 cells into adipogenic or hepatogenic cells in culture, we intrasplenically transplanted the three types of cells into rats (3 x 10(7) cells/rat) before and 4 weeks after initiation of carbon tetrachloride treatment (1 ml/kg body weight twice a week for 8 weeks) to induce liver fibrosis. Undifferentiated rBM25/S3 cells were the most effective for suppression of liver fibrosis, followed by the adipogenic cells and hepatogenic cells. Expression levels of MMP-2 and MMP-9 were also highest in undifferentiated rBM25/S3 cells. These results indicate that bone marrow-derived clonal mesenchymal stem cell lines are useful for further mechanistic studies on cell-mediated suppression of liver fibrosis and that such cell lines will provide information on an appropriate cell source for transplantation therapy for cirrhosis.

No contribution of multipotent mesenchymal stromal cells to liver regeneration in a rat model of prolonged hepatic injury.

Multipotent mesenchymal stromal (MS) cells from adult bone marrow are a cell population that can be expanded to large numbers in culture. MS cells might be differentiated toward hepatocytes in vitro and thus are promising candidates for therapeutic applications in vivo. The efficacy of bone marrow-derived MS cells versus hepatocytes to contribute to liver regeneration was compared in a rat model of prolonged toxic hepatic injury. Liver damage was induced by injection of carbon tetrachloride (CCl(4)) or allyl alcohol (AA) with and without retrorsine (R) pretreatment. MS cells or hepatocytes of wild-type F344 rats were injected into dipeptidyl peptidase IV (DPPIV)-deficient syngeneic rats. Hepatocyte chimerism was higher after intraportal hepatocyte transplantation in the R/AA group (mean maximal cluster size [MCS] = 21 cells) compared with the R/CCl(4) treatment group (MCS = 18). No hepatocyte engraftment was outlined following post-transplant CCl(4) injection only, whereas mere AA injection resulted in small clusters of donor-derived hepatocytes (MCS = 2). Intraparenchymal injection of hepatocytes was associated with a MCS = 11 after R/AA treatment and a MCS = 6 after AA administration alone. Redistribution of MS cells to the liver was shown after intraportal and intraparenchymal injection. In contrast to hepatocyte transplantation, however, donor-derived DPPIV-positive cells could not be demonstrated in any recipient after MS cell transplantation. Data from the present study indicate that a well-defined population of MS cells obtained according to established standard protocols does not differentiate into hepatocytes in vivo when transplanted under regenerative conditions, in which the application of hepatocytes results in stable hepatic engraftment.

Differentiation of hematopoietic stem cells into hepatocytes in liver fibrosis in rats.

It has been reported that hematopoietic stem cells (HSC) can differentiate into hepatocytes in the normal liver and in some pathologic environments. The aim of this study was to investigate whether HSC can differentiate into hepatocytes in cases of established liver fibrosis. Rat liver fibrosis was induced by subcutaneous injection of tetrachloride (CCl4). Thy+ CD3- CD45RA- HSC in bone marrow cells, which had been enriched by fluorescence-activated cell sorting (FACS), were labeled with PKH26-GL, and autologously transplanted into CCl4-treated rats. The expressions of albumin (Alb), cytokeratin 8 (CK8), and alpha-smooth muscle actin (SMA) were determined by immunofluorescence methods. The PKH26-GL labeled Thy+ CD3- CD45RA- HSC expressed the hepatocyte-specific markers Alb and CK8, but did not express alpha-SMA in liver fibrosis. Thy+ CD3- CD45RA- HSC differentiated into hepatocytes, but not into hepatic stellate cells. In conclusion, autologous stem cell transplantation may be helpful to treat hepatic fibrosis.

New model of liver regeneration induced through use of vascular endothelial growth factor.

INTRODUCTION: Vascular endothelial growth factor (VEGF) is an endothelial cell mitogen. The objective of this study was to verify the proregenerative effects of VEGF in an experimental model of acute liver failure. MATERIALS AND METHODS: Sixty four rats that underwent intraperitoneal injection of carbon tetrachloride (CCl(4)) were randomly divided into two groups: group B animals received intravenous injection of VEGF(164) 1 hour following CCl(4) poisoning. Group A hosts were untreated. To obtain daily liver function tests (LFTs) and histological samples, on each day up to 8 days we sacrificed four rats in each group. RESULTS: The laboratory examinations showed notable alteration of LFTs in group A, while group B revealed only slight changes. The histological examination showed greater liver damage in group A compared with group B. CONCLUSION: Our results suggest that administration of exogenous VEGF protects the liver from CCl(4)-induced acute hepatic failure. Further studies are underway to assess whether exogenous VEGF is effective in other liver injuries.

[Impact of seasons on efficacy of physiotherapeutic correction of hepatic function in toxic hepatitis in experiment].

Experiments on 172 Wistar rats modeled CCl4-hepatitis in transitory phases of about-annual cycle. In the autumn phase the animals with toxic hepatitis demonstrated poor normalization of biochemical parameters while the efficacy of physiotherapy (sapropel combined with magnetic field) was very high. In spring, normalization of the biochemical parameters was very high while the above physiotherapeutic complex was low effective.

Intrasplenic transplantation of syngenic hepatocytes modified by IFN-gamma gene ameliorates hepatic fibrosis in rats.

Transplanted hepatocytes are ideal carriers for exogenous genes in liver gene therapy. The present study investigated the anti-fibrogenic effects of intrasplenically transplanted hepatocytes modified with interferon gamma (IFN-gamma) gene on cirrhotic rats. Hepatocytes isolated from normal Sprague-Dawley (SD) rats were transfected with an adenoviral vector encoding human IFN-gamma gene (AdCMVhIFN-gamma) and transplanted into the spleens of syngenic recipients with ongoing liver fibrosis induced by carbon tetrachloride (CCl(4)). Histology was assessed, and liver hydroxyproline was detected. Additionally, serum procollagen type III (PIIINP) levels and hepatic collagenase activity were measured to determine hepatic collagen synthesis and degradation. Transplantation with AdCMVhIFN-gamma transfected hepatocytes ameliorated the histological outcome of liver fibrosis by reducing liver collagen content and decreasing hepatic hydroxyproline. Additionally, IFN-gamma transfected hepatocytes reduced serum PIIINP levels and increased hepatic collagenase activity. Our data suggest that transplantation of IFN-gamma transfected hepatocytes may reduce the pace of liver fibrosis by inhibiting the synthesis and enhancing the degradation of hepatic collagen.

[Carbon tetrachloride poisoning]. / Intoxicación por tetracloruro de carbono.

Cases of severe acute carbon tetrachloride poisoning are sporadically described in Spain. We report the cases of three patients that inhaled toxic vapour of carbon tetrachloride that they used as a solvent during their working activity. They developed hepatic disfunction and one of them acute renal failure. The interval between the labour exposure and the medical care was higher than 24 hours. All the patients received N-acetylcysteine treatment (300 mg/kg) and oxygen. The patient ith renal failure recurred hemodialysis. The basic aspects of diagnosis and treatment are commented.

Carbon tetrachloride toxicity. Agency for Toxic Substances and Disease Registry.

Industrial carbon tetrachloride is used in the synthesis of chlorofluorocarbons and chlorinated solvents. Although both production and use of carbon tetrachloride are declining, industrial and hazardous waste sites remain as sources of exposure. Workers using carbon tetrachloride or products that contain it are at highest risk of exposure. Diabetics and persons who drink alcohol may have an increased risk of adverse effects following exposure to carbon tetrachloride. Acute exposure may result in rapid central nervous system depression. Symptoms of hepatic and renal toxicity may arise one to four days later. Carbon tetrachloride is considered a possible carcinogenic agent. Administration of N-acetylcysteine may reduce complications of severe carbon tetrachloride exposure. Removal of the source of exposure and avoidance of other hepatotoxicants is the only treatment for chronic carbon tetrachloride toxicity.