Mice containing livers repopulated with human hepatocytes would provide excellent in vivo models for studies on human liver diseases and hepatotropic viruses, for which no permissive cell lines exist. Here, we report partial repopulation of the liver of immunodeficient urokinase-type plasminogen activator (uPA)/recombinant activation gene-2 (RAG-2) mice with normal human hepatocytes isolated from the adult liver. In the transplanted mice, the production of human albumin was demonstrated, indicating that human hepatocytes remained functional in the mouse liver for at least 2 months after transplantation. Inoculation of transplanted mice with human hepatitis B virus (HBV) led to the establishment of productive HBV infection. According to human-specific genomic DNA analysis and immunostaining of cryostat liver sections, human hepatocytes were estimated to constitute up to 15% of the uPA/RAG-2 mouse liver. This is proof that normal human hepatocytes can integrate into the mouse hepatic parenchyma, undergo multiple cell divisions, and remain permissive for a human hepatotropic virus in a xenogenic liver. This system will provide new opportunities for studies on etiology and therapy of viral and nonviral human liver diseases, as well as on hepatocyte biology and hepatocellular transplantation. Persistent infection with hepatitis B virus (HBV) is a major worldwide health problem, and chronically infected individuals are at high risk for developing cirrhosis and hepatocellular carcinoma. 1,2 Despite the availability of an HBV vaccine, there are still more than 350 million chronically infected people worldwide, and the few antiviral treatments currently available have a limited rate of efficacy. The narrow host range of HBV and the lack of both in vitro systems and of convenient animal models have greatly hampered our understanding of the complete virus life cycle, as well as the development of more effective antiviral drugs aimed at eradicating the virus from chronic carriers. 3 Chimpanzees are the only animal species infectable with HBV, 4,5 but studies with these animals and evaluation of antiviral therapies are severely restricted because of their limited availability and high costs. Animal models based on HBV-related hepadnaviruses, such as woodchuck and Pekin duck hepatitis B viruses, are often used for assessment of antiviral drugs 6-8 and have provided important information about factors involved in establishment of virus infection, viral persistence, and hepatocarcinogenesis. 9-14 However, woodchucks are relatively large animals of outbred origins that are difficult to handle in many laboratories, and chronic hepadnavirus infection in birds does not lead to cancer. The development of HBV-expressing transgenic mice has also provided important insights regarding viral pathobiology and the role of HBV gene products in hepatocellular injury. 12,[15][16][17][18][19] Although infectious virus can be produced in transgenic mice, their hepatocytes are not permissive for infection. Therefore, the still-unknown early step...

SUMMARY Fifty seven children with dermatitis herpetiformis, 18 from Finland and 39 from Hungary, were studied. Diagnostic criteria included the finding of granular IgA deposits in the skin of all patients. The mean age at onset of the rash was 7-2 years and favoured sites were the elbows, knees, and buttocks. Symptoms suggesting small intestinal disease were rare but in 35 (61%) of the children subtotal villous atrophy and in 16 (28%) partial villous atrophy were found on jejunal biopsy.Eighteen children underwent a second biopsy after a mean of 21 months on a gluten free diet; villous height was found to be increased and the intraepithelial lymphocyte count decreased in all these patients. Gluten challenge caused a reversal in the two children who underwent a third biopsy. The effect of the gluten free diet on the rash was examined in Finnish children by observing the daily requirements of dapsone, a drug used to control the rash at the beginning of the diet. Eight (67%) of the 12 children were able to stop taking dapsone after a mean of 11 months on the diet and all three patients treated with diet alone became asymptomatic after three to 6 months on the diet.These results confirm that most children with dermatitis herpetiformis have jejunal villous atrophy, though they rarely have gastrointestinal symptoms. The central role of gluten in childhood dermatitis herpetiformis is evidenced by the fact that a gluten free diet helps the damaged jejunal mucosa to recover and controls the rash even in those children who do not have an abnormal jejunal biopsy.Dermatitis herpetiformis in adults is characterised by a pruritic, blistering rash and is associated with coeliac disease which is mostly subclinical in these patients.' Gluten plays an important role in adult dermatitis herpetiformis; both the enteropathy and rash respond to gluten withdrawal and relapse on gluten challenge.2-4 Dermatitis herpetiformis in

Liver transplantation is an established treatment for acute and chronic liver disease. However, because of the shortage of donor organs, it does not fulfill the needs of all patients. Hepatocyte transplantation is promising as an alternative method for the treatment of end-stage liver disease and as bridging therapy until liver transplantation. Our group has been working on the optimization of matrix-based hepatocyte transplantation. In order to increase cell survival after transplantation, freshly isolated human hepatocytes were seeded onto biodegradable poly(l-lactic acid) (PLLA) polymer scaffolds and were cultured in a flow bioreactor. PLLA discs were seeded with human hepatocytes and exposed to a recirculated medium flow for 6 days. Human hepatocytes formed spheroidal aggregates with a liver-like morphology and active metabolic function. Phase contrast microscopy showed increasing numbers of spheroids of increasing diameter during the culture period. Hematoxylin and eosin histology showed viable and intact hepatocytes inside the spheroids. Immunohistochemistry confirmed sustained hepatocyte function and a preserved hepatocyte-specific cytoskeleton. Albumin, alpha-1-antitrypsin, and urea assays showed continued production during the culture period. Northern blot analysis demonstrated increasing albumin signals. Scanning electron micrographs showed hepatocyte spheroids with relatively smooth undulating surfaces and numerous microvilli. Transmission electron micrographs revealed intact hepatocytes and junctional complexes with coated pits and vesicles inside the spheroids. Therefore, we conclude that primary human hepatocytes, precultured in a flow bioreactor on a PLLA scaffold, reorganize to form morphologically intact liver neotissue, and this might offer an optimized method for hepatocyte transplantation because of the expected reduction of the initial cell loss, the high regenerative potential in vivo, and the preformed functional integrity.

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A 25-year-old woman with Hallopeau-Siemens recessive dystrophic epidermolysis bullosa had generalized blistering, scarring and milia since birth. In the course of the disease, acral pseudosyndactyly developed, and the patient suffered from corneal erosions, oesophageal strictures, malabsorption, recurrent severe pneumonias and nephrotic syndrome. In addition, she had severe anaemia, sideropaenia, hypocalcaemia, heavy proteinuria and hypoalbuminaemia. A rapidly growing skin squamous cell carcinoma developed on the neck that spread to axillary and cervical lymph nodes. Recurrent hypocalcaemic tetanic convulsions and dyspnoea and a pneumonia refractory to antibiotics led to the premature demise of the patient. Autopsy revealed extensive amyloidosis of the renal, hepatic and splenic tissues. AA type amyloid deposits were detected in the renal glomeruli and in the lung, explaining the patient's unusually severe pulmonary infections. In essence, the patient had severe recessive dystrophic epidermolysis bullosa, complicated by squamous cell carcinoma, recurrent pneumonias and nephrotic syndrome due to secondary amyloidosis of the kidney and lung. The possibility of secondary pulmonary amyloidosis should be considered in severe dystrophic epidermolysis bullosa patients with recurrent pulmonary infections.

Isolated hepatocytes represent a relevant model of the liver and are highly required both for research and therapeutic applications. However, sources of primary liver cells from human beings and from some animal species are limited. Therefore, cryopreservation of hepatocytes could greatly facilitate advances in various research areas. The aim of this study was to evaluate whether cryopreserved primary woodchuck hepatocytes could be used for woodchuck hepatitis B virus (WHV) infection studies, and whether they could maintain their regenerative potential in vivo after thawing. Critical steps for good quality of cryopreserved hepatocytes included the use of University of Wisconsin (UW) solution as a main component of the freezing medium, stepwise reduction of dimethylsulfoxide (DMSO) to avoid osmotic shock, and maintenance of low concentrations of DMSO in the culture medium. After cryopreservation, cell viability was still high (70% to 80%), and 50% to Liver transplantation is a successful and well-established treatment for end-stage liver disease and liver failure. However, donor-organ scarcity is a fundamental limitation of this therapy. The availability of highly differentiated primary liver cells to be used for cell-based therapies, such as hepatocyte transplantation, tissue-engineered organs, or for extracorporeal liver support systems, represents an attractive alternative to whole-organ transplantation. 1,2 Freshly isolated normal adult hepatocytes are already widely used in various research areas of hepatology, pharmacology, and toxicology, and initial clinical trials have also shown their potential for therapeutic applications. 3 Essential prerequisites for therapeutic use of hepatocyte transplantation in humans is that primary liver cells must be promptly available, remain highly differentiated, and maintain their proliferative capabilities within the host liver, because only a limited number of cells can be infused into a patient. 4 In past years, numerous research laboratories established procedures for the isolation of primary hepatocytes from commonly used laboratory animals, rat hepatocytes being the most studied. However, only a few laboratories have the possibility to procure livers and perform the isolation of highly viable hepatocytes from humans and animal species that are scarcely available. Therefore, efficient cryopreservation and banking of hepatocytes would greatly expand and facilitate the use of primary liver cells both for research and therapeutic applications, while decreasing the need of freshly procured livers for the preparation of hepatocytes both from animal species and humans.Persistent infection with hepatitis B virus (HBV) is one of the major causes of liver disease in humans, being associated with various degrees of chronic hepatitis, cirrhosis, and the development of hepatocellular carcinoma. 5,6 Replication of HBV can be successfully achieved by transfecting hepatoma cell lines with cloned HBV-DNA genomes. These systems have significantly contributed to elucidating various asp...

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The current results show that mild hypothermia (33 degrees C) exhibits sustained neuroprotection if applied up to 3 hours after SAH. Overall, mild hypothermia seems to be an effective neuroprotective strategy after SAH and should therefore be evaluated as a treatment option for SAH in patients.