Biomedical subjects

D Kluth

Publications and source records attributed to D Kluth.

At least 19 recordsLinked to original sources

PubMed2006

Submucosal plexus of dilatated gut disappears after ligation in chicken embryos: preliminary results.

INTRODUCTION: Dilatation and impaired function of the gut is a condition often seen in newborns with bowel obstruction caused by intestinal atresia. In a previous experimental study in chicken embryos, we established a model to study ultrastructural changes during the development of the enteric nervous system after small bowel ligation. The aim of this study is to investigate the changes of the enteric nervous system (ENS) after gut ligation. METHODS: 56 chicken embryos were investigated. In the operation group fertilized eggs and the allantoic membrane were opened and the small bowel was ligated on embryonal day (ED) 11. The controls were sham-operated. The gut was prepared and harvested for analysis on ED 11, 12, 13, 14, 15, 16, 17 and 18. Silver staining or staining of the specimens for acetylcholinesterase (AchE) was performed. RESULTS: A marked dilatation of the bowel was observed three days after operation (ED 14). The submucosal (PSM) and myenteric plexus (PM) appeared normal at this time, however silver staining showed rarification of the neuronal axonal network between the myenteric and submucosal plexus. Later, on ED 16 an additional rarification of the submucosal plexus was also seen in the operation group using AchE staining, compared to the controls. DISCUSSION: The data suggest that distension of the gut hinders normal development of the ENS in the gut ligation model of chicken embryos. The changes were observed sequentially, starting with rarification of the axonal network between the PM and PSM. Future studies will be required to show whether the changes of the ENS are reversible.

Animals↗

PubMed2003

The embryology of gut rotation.

Until today, the puzzling spectrum of midgut "malrotations" is commonly explained by an "impaired" process of rotation of the midgut. However, a closer look at the literature reveals that the description of this "process of rotation" is rather schematic and is aimed more at explaining pathological findings, while detailed proper embryological investigations are still rare. Despite recent trials, good animals models that would allow the comparison of normal and abnormal midgut development are still missing. In the first part of this article, the "normal process of rotation," as it is described in the literature, is presented and critically analyzed. In general, it is a shortcoming that reliable illustrations of these crucial embryological processes are missing in most of these papers. Therefore, in the second part of this review scanning electron microscopy pictures of the developing midgut are presented in a series of rat embryos. In these pictures clear signs of a process of rotation are missing.

Animals↗

PubMed2002

Effect of prenatal glucocorticoids and postnatal nitric oxide inhalation on survival of newborn rats with nitrofen-induced congenital diaphragmatic hernia.

BACKGROUND/PURPOSE: Pulmonary hypertension and pulmonary hypoplasia account for the high mortality rate associated with congenital diaphragmatic hernia (CDH). In animal models of CDH, postnatal nitric oxide (NO) inhalation resulted in significantly better survival rates and antenatal glucocorticoid administration in improved lung compliance. The objective of this study was to evaluate the combined effect of prenatal glucocorticoid administration and postnatal NO inhalation on the survival rate of newborn rats with nitrofen-induced CDH. METHODS: Right-sided CDH was induced by maternal administration of a single oral dose (100 mg, intraperitoneally) of nitrofen on day 11.5 of pregnancy. Dexamethasone (DEX, 0.25 mg/kg) was given in groups III and IV by maternal intraperitoneal injection on day 18.5 and 19.5 of pregnancy. Control animals (groups I and II) received vehicle alone. After spontaneous delivery, the newborn animals were exposed to either NO (80 ppm; groups II and IV) or room air (groups I and III). Vitality (Rat-Score), sO(2) and survival were monitored continuously for 12 hours until animals were killed. Hernia size was estimated as percentage of total thoracic content. RESULTS: Right-sided CDH was observed in 392 of 491 newborn rats (81%). Animals with large hernias (>50%) died within 4 hours after birth, irrespective of treatment. Hernias with less than 50% of the thoracic volume were considered clinically relevant hernias. In this category, 12.5% of animals without treatment (group I) survived compared with 63.6% after NO treatment alone (group II; P <.01). Survival rate after DEX treatment alone (group III) was 69.4% (group III v I; P <.01). In group IV (DEX and NO) 95.2% of the animals survived (group IV v I; P <.001). In contrast to DEX alone, NO administration resulted in significantly better sO(2)(group II and IV) compared with group I (P <.05). CONCLUSION: Combination of prenatal maternal glucocorticoids and postnatal NO inhalation significantly improved survival rate of newborn rats with nitrofen-induced CDH.

Administration, Inhalation↗

PubMed2001

Hepatocyte transplantation using biodegradable matrices in ascorbic acid-deficient rats: comparison with heterotopically transplanted liver grafts.

BACKGROUND: Hepatocyte transplantation using polymeric matrices is under investigation as an alternative therapy for metabolic liver diseases. Long-term engraftment of hepatocytes in polymers has been demonstrated. However, the metabolic activity of hepatocytes in such devices has never been assessed in direct comparison with liver grafts. METHODS: Hepatocyte and partial liver transplantation were evaluated in the scurvy-prone osteogenic disorder Shionogi rat model. Biodegradable poly glycolic acid matrices seeded with hepatocytes equivalent to 20% of the recipient's liver mass, or 20% liver grafts were heterotopically transplanted into ascorbic acid- (AsA) deficient recipients. Recipients of cell-free matrices or AsA-deficient liver grafts served as controls. Recipients were set on AsA-free diet after transplantation. Plasma AsA levels, AsA concentrations in liver and adrenal gland tissue, and body weight ratios were assessed and H&E histology was performed. RESULTS: Recipients from the control groups showed symptoms of scurvy at 1 month after cessation of AsA supply. Hepatocyte transplantation and auxiliary liver transplantation prevented symptoms of scurvy and increased plasma and tissue AsA levels and body weight ratios. AsA levels in recipients of 20% liver grafts were comparable to normal control animals. CONCLUSIONS: Hepatocytes transplanted in polymeric matrices are able to compensate for liver-based metabolic deficiencies. Hepatocyte transplantation improves plasma AsA levels in AsA-deficient recipients. However, auxiliary liver grafts are superior to hepatocyte grafts in improving metabolic parameters. Further research work is needed to increase the efficiency of liver cell transplantation with regard to a clinical application.

Animals↗

PubMed2001

Optimization of hepatocyte spheroid formation for hepatic tissue engineering on three-dimensional biodegradable polymer within a flow bioreactor prior to implantation.

We hypothesize that in vitro conditioning of hepatocytes within biodegradable poly-L-lactic acid (PLLA) polymer matrices prior to implantation may increase hepatocyte survival and function after transplantation. The purpose of this study was to optimize the culture conditions of hepatocytes in a pulsatile flow bioreactor. PLLA discs were seeded with rat hepatocytes in a concentration of 2.5, 5, 10, 20 and 40 x 10(6) cells/ml. Seeded discs were exposed to recirculated perpendicular flow of 0, 7, 15, 24, 32, 52 ml/min of supplemented Williams' Medium E and harvested after 6 days in flow culture. Only under flow conditions the hepatocytes formed spheroidal aggregates (SphA) of 50-260 microm in diameter with a liver-like morphology and active metabolic function. The number of SphA was examined by phase contrast microscopy and the reductive enzyme function of the hepatocytes was tested using MTT. Hematoxylin and eosin histology showed vital hepatocytes within the SphA less than 200 microm in diameter but central necrosis in the SphA exceeding this size. Immunohistochemical staining confirmed albumin production of hepatocytes within the SphA. The optimal cell seeding concentration was 10 x 10(6) cells/ml with a flow speed of 24 ml/min. SphA of hepatocytes cultured with this flow bioreactor method may prove useful as a functional unit for tissue engineering of an in vivo liver substitute.

Albumins↗

PubMed2001

Hepatic tissue engineering on 3-dimensional biodegradable polymers within a pulsatile flow bioreactor.

BACKGROUND: An optimal method for hepatocyte transplantation is not yet determined. With the principles of tissue engineering in vitro conditioning of hepatocytes on biodegradable polymer in a flow bioreactor before implantation forming spheroids may achieve increased cell mass and function to replace lost organ function in vivo. METHODS: Biodegradable poly-L-lactic (PLLA) polymer discs were seeded with rat hepatocytes in a concentration of 10 x 10(6) cells per ml and exposed to a medium flow of 24 ml/min for 1, 2, 4 and 6 days. The number and diameter of spheroidal aggregates was measured by phase-contrast microscopy. H&E histology was performed. Albumin production as hepatocyte specific function was determined by ELISA. RESULTS: Spheroids of viable hepatocytes of 50-200 microm in diameter were formed. Both the number and diameter of the spheroids increased during the first 2 days and then remained constant until day 6. Albumin production was maintained throughout the culture period. CONCLUSION: Short (2- 3 days) pre-transplant conditioning of hepatocytes in a flow bioreactor on biodegradable PLLA resulted in formation of spheroids with a liver-like morphology and preserved specific metabolic function. Tissue engineered hepatocyte spheroids on polymer may represent a functionally active and easy transplantable neotissue and may serve as an in vivo substitute for lost liver function.

Albumins↗

PubMed2001

In vitro function of islets of Langerhans encapsulated with a membrane of porcine chondrocytes for immunoisolation.

BACKGROUND/AIMS: Widespread clinical application of islet transplantation remains restricted, because of insufficient methods to prevent rejection and autoimmune destruction of islet grafts. In this study we demonstrate long-term function of islets of Langerhans within a capsule of porcine chondrocytes which may serve as an immunoisolation barrier utilizing the immunoprivileged properties of the chondrocyte matrix. METHODS: Islets of Langerhans were isolated from Lewis rats, seeded on biodegradable polyglycolic acid polymer, and encapsulated with a monolayer of porcine chondrocytes. The encapsulated constructs and controls were kept in culture for 5 weeks. One group was exposed to a glucose challenge every 5th day. The insulin concentration of the culture medium was measured. Histological and insulin-immunohistochemical studies were performed. RESULTS: Hematoxylin and eosin histology demonstrated viability of the islets of Langerhans. The intact morphology was demonstrated by Heidenhain staining. Toluidine blue showed viability of surrounding chondrocyte layers. Immunohistochemistry was positive for insulin within the beta cells of the islets. Both encapsulated constructs and nonencapsulated controls showed increasing insulin levels after glucose challenge. CONCLUSIONS: We can tissue engineer a chondrocyte encapsulation membrane which permits diffusion of glucose and insulin. Islets of Langerhans survive within the chondrocyte capsule, and the glucose/insulin feedback mechanism remains intact.

Animals↗

PubMed2000

Hydrophilic bile salts protect bile duct epithelium during cold preservation: a scanning electron microscopy study.

Prolonged graft preservation is associated with postoperative bile duct strictures after liver transplantation. We previously showed that hydrophilic bile salts mitigate bile duct preservation injury in a pig model. Because this injury occurs at the epithelial level, scanning electron microscopy was performed to further characterize this effect in vitro. Swine livers were harvested after the intravenous infusion of 1 of 3 solutions: saline (n = 7), tauroursodeoxycholate ([TUDC] hydrophilic; n = 4), or taurodeoxycholate ([TDC] hydrophobic; n = 4). Livers were perfused with University of Wisconsin solution. The bile ducts were flushed retrograde, and the liver was stored at 0 degrees C to 1 degrees C for 20 hours. Bile duct samples were obtained at the time of harvest and 8, 12, 16, and 20 hours thereafter. In saline-infused controls at time 0, the epithelium was intact and composed of uniform cuboidal cells covered with fine regular microvilli. There were no spaces between individual cells. After 8 to 12 hours of preservation, cells were more irregular in shape, with loss of cell-cell contact. The cell surfaces showed fewer microvilli. Surface erosions suggested loss of cell-wall integrity. TUDC was protective, evidenced by normal-appearing cells with uniform microvilli after 16 hours. In contrast, TDC accelerated the injury process, causing cell-surface erosions, blebs, and loss of microvilli as early as time 0. Scanning electron microscopy is an excellent tool to study injury to bile duct epithelium. This study supports the hypothesis that hydrophilic bile salts protect bile ducts during preservation. To determine whether treatment with hydrophilic bile salts can prevent postoperative stricture, in vivo transplantation studies are needed.

Animals↗

PubMed2000

Effect of CGS 26303, an endothelin-converting enzyme-neutral endopeptidase inhibitor, on nitrofen-induced congenital diaphragmatic hernia in the rat.

BACKGROUND/PURPOSE: The pathophysiology of congenital diaphragmatic hernia (CDH) associated with lung hypoplasia and pulmonary hypertension is not understood fully. Endothelins (ETs) are the most potent vasoconstrictors that also act as promitogenic agents. They may play a role during pregnancy in leading to the condition found at birth and ongoing mortality in CDH. Therefore, the authors studied the effect of CGS 26303, a nonselective endothelin-converting enzyme and neutral endopeptidase inhibitor, in the rat model of CDH. METHODS: Pregnant Sprague-Dawley rats were divided into 3 groups: group 1 (n = 4) received CGS 26303 (50 mg/kg, subcutaneously, twice a day), from gestational day 12 until term (21 to 23 days); group 2 (n = 8) received nitrofen (100 mg/kg, orally) at gestational day 11.5; group 3 (n = 8) received both nitrofen and CGS 26303. The survival of the newborn rats was monitored up to 240 minutes. After natural death or euthanasia, they were weighed and microdissected. The degree of hernia was quantified as small, moderate, or severe, and lungs and liver were harvested and weighed. RESULTS: Newborn rats from mothers of group 3 (n = 81) survived 196 +/- 8 minutes compared with 173 +/- 9 minutes of those of group 2 (n = 97). Severe CDH from group 3 (n = 20) had a mean survival time of 66 +/- 13 minutes compared with 26 +/- 4 minutes for those of group 2 (n = 27). Lung index in severe CDH pups of group 3 was increased by 13% compared with those from group 2 (P < .0001), whereas their liver index went down by 8% (P < .05). CONCLUSIONS: These results suggest that CGS 26303 might have a beneficial effect when given during pregnancy in increasing survival at birth and reducing the severity of the pulmonary hypoplasia in newborn rats with nitrofen-induced CDH.

Animals↗

PubMed2000

Priming of hepatocytes for cell culture by partial hepatectomy prior to cell isolation.

The combination of ex vivo gene transfer and a sufficient transplant model for hepatocytes may permit treatment of single enzyme-based metabolic liver diseases. Induction of replicative potential (priming) in hepatocyte cultures may enhance the efficiency of gene transfer under stable in vitro conditions. It is known that hepatocyte replication is increased in vivo after partial hepatectomy. We investigated the effect of partial hepatectomy prior to cell isolation on hepatocytes in vitro. Male Lewis rats served as donors. Hepatocytes were isolated by collagenase digestion from either intact livers or from livers 48 h after 70% hepatectomy (PH). Cells were seeded on collagen-coated culture dishes with hormone-supplemented culture media. Hepatocyte morphology, number, albumin secretion rate, and mono-ethyl-glycin-xylidid (MEGX)-biotransformation capacity were assessed on days 1, 3, and 5 in culture. PH significantly increased hepatocyte number and albumin secretion of cultured hepatocytes over the whole observation period. In contrast, MEGX-biotransformation capacity was significantly decreased. Morphology of cultured hepatocytes was not affected by PH prior to hepatocyte isolation. These results suggest a prolonged and complex response of hepatocytes to PH in vitro. Hepatocyte priming by PH is a promising approach toward stable cultures of proliferating hepatocytes and may provide a model for in vitro studies of hepatic regeneration mechanisms. Further research on hepatocyte priming toward an application in ex vivo gene transfer and hepatic tissue engineering seems justified.

Animals↗

PubMed2000

[Tube obstruction in operation of esophageal atresia. Brief review of intraoperative complications based on a case report].

In this case report we discuss the anaesthetic management of newborns with esophageal atresia classified as Vogt III b. This type is characterised by an upper esophageal pouch which ends blindly and a distal tracheoesophageal fistula. Commonly associated diseases are cardiac, renal, vertebral and anal anomalies. The most important intraoperative anaesthesiological complications are acidosis, hypoxaemia, gastric distension, endotracheal tube obstruction, tracheal compression, cardiac arrhythmias and atelectasis. In the presented case an endotracheal tube obstruction with hypercapnia occurred which required a change of the airway. After changing the endotracheal tube the newborn could be ventilated sufficiently. Further postoperative course was uneventful.

Anesthesia, Endotracheal↗

PubMed1999

Long-term differentiated function of heterotopically transplanted hepatocytes on three-dimensional polymer matrices.

Hepatocyte transplantation using porous matrices is under investigation as an alternative therapy for certain liver diseases. For this purpose, long-term function of transplanted hepatocytes is mandatory. This problem has not been sufficiently investigated yet. In this study Lewis rats were used as donors and recipients. Stimulated (group A, portocaval shunt) or unstimulated (group B) hepatocytes were transplanted into prevascularized polyvinyl-alcohol matrices. Cell-free matrices served as controls (group C). Matrices were harvested between 1 h and 1 year after implantation and analyzed by morphometry; albumin RNA in situ hybridization; and cytokeratin-, actin-, desmin-, and macrophage-specific antigen immunohistology. The hepatocyte number significantly decreased within the first week following implantation. Between 1 month and 1 year after transplantation a significant increase in hepatocyte number was noted in groups A and B. Albumin transcripts of transplanted hepatocytes were at normal levels at all times except for group B after 1 year. The immunohistology suggested engraftment of nonparenchymal liver cells. We conclude that 3-dimensional matrices provide a sufficient environment for long-term engraftment of transplanted liver cells. The hepatocytes are able, despite suboptimal initial engraftment, to repopulate the scaffold for at least half of the recipient's life span and maintain cell-specific function after sufficient stimulation.

Animals↗

PubMed1999

Is there an optimal concentration of cotransplanted islets of Langerhans for stimulation of hepatocytes in three dimensional matrices?

BACKGROUND: Hepatocyte transplantation using three-dimensional matrices is under investigation as an alternative therapy for several liver diseases. For sufficient transplantation results hepatotrophic stimulation is necessary. We investigated the stimulatory effect of cotransplanted pancreatic islets in different ratios. METHODS: Lewis rats were used as donors and recipients. A portocaval shunt (group A) or sham operation (groups B-G) was performed 1 week before hepatocyte transplantation. Four polyvinyl-alcohol matrices each containing 1.25 x 10(7) hepatocytes (groups A and B) or 1.25 x 10(7) hepatocytes and 125 (C), 250 (D), 500 (E), or 750 (F) islets were implanted between small bowel mesenteric leaves. In group G, medium soaked matrices were implanted. One month after implantation, specimens were harvested and investigated using albumin-RNA in situ hybridization, and insulin, glucagon, and bromodesoxy uridine immunohistochemistry. The hepatocyte area was assessed using image analysis. RESULTS: Hepatocyte area and proliferation ratio increased depending on the number of cotransplanted islets with a peak at 40 islets per 1 million hepatocytes (group E). Cotransplantation of islets in higher concentrations did not further increase hepatocyte area or proliferation ratio. Hepatocytes in all groups expressed albumin RNA at normal transcription levels as compared to standard liver sections. Islets displayed insulin and glucagon in physiological distribution. DISCUSSION: Three-dimensional matrices provide a sufficient environment for transplanted hepatocytes and islets. The hepatotrophic effect of cotransplanted islets is comparable to portocaval shunting and has a saturation limit at 40 islets per 1 million hepatocytes. For further application of islet cotransplantation, this ratio seems to be preferable.

Albumins↗

PubMed1999

Pulmonary echinococcosis (hydatidosis) in children: results of surgical treatment.

From 1986-1996, 33 children with 49 pulmonary hydatid cysts underwent surgical treatment in Vienna and Istanbul. Cysts were unilateral in 28 and bilateral in 5 cases; unruptured cysts (URC) were diagnosed in 19 patients, and 14 children presented with ruptured cysts (RC). Ten patients had cysts in other organs (liver, spleen, central nervous system) in addition to pulmonary cysts. Diagnosis was primarily based on chest X-ray and computed tomography scan. In Austrian children, a new combination of serological tests was used successfully (71% positive). The standard surgical procedure was cystotomy followed by capitonnage. The main postoperative complications were fever and wound infection. There were two recurrences after a mean follow-up of 4.8 years, and one patient died because of multiple organ involvement. We conclude that the therapy of choice in pediatric pulmonary hydatidosis is complete surgical elimination of the cyst by cystotomy and capitonnage, whereas more extended resections should be avoided. Ideally, benzimidazole treatment should be combined with surgery. New serological tests can improve diagnostic accuracy.

Adolescent↗

PubMed1999

Tauroursodeoxycholate ameliorates reperfusion injury after pig liver transplantation.

Reperfusion injury is a serious problem after clinical liver transplantation, often leading to dys- or even non-function of grafts. The present study was designed to determine whether the hydrophilic bile salt tauroursodeoxycholate (TUDC), known to be hepatoprotective in cholestatic liver disease, mitigates reperfusion injury in an in vivo pig liver transplantation model. Liver transplantation was performed in 12 pigs after a preservation time of 8 h. TUDC was administered to donor and recipient animals, and saline to controls. Blood was drawn at different time points for determination of liver enzymes. Bile samples were collected, and bile flow (BF), and bile salt secretion rate (BSSR) determined. Samples of liver tissue and bile ducts were taken for assessment by light and electron microscopy. Liver enzymes were significantly lower in the TUDC group. BF and BSSR were significantly higher. Microscopy revealed better preservation of bile duct architecture of the TUDC-infused animals. We can conclude that infusions of TUDC in pig livers ameliorate reperfusion injury in vivo. The molecular basis for this finding may be the membrane stabilizing effect of TUDC. Further studies are warranted to clarify its effect.

Animals↗

PubMed1999

Long-term insulin-secretory function of islets of Langerhans encapsulated with a layer of confluent chondrocytes for immunoisolation.

Islet transplantation is a potential cure for diabetes mellitus. The major problem for broad clinical application remains the prevention of transplant rejection without major side effects. Immunoisolation is an experimental strategy to prevent rejection by separating the transplanted cells from the host immune system using a barrier device. Current methods use artificial, not completely inert materials as barrier devices and induce an unwanted foreign-body (FB) reaction. Using the recipients of own cells for encapsulation, the FB reaction could be prevented. This study describes a new method of encapsulation of islets of Langerhans within a capsule of chondrocytes, which may serve as an immunoisolation barrier utilizing the immunoprivileged properties of the chrondrocyte matrix, and demonstrates the functional survival of the encapsulated islets in vitro.

Animals↗

PubMed1999

Heterotopic hepatocyte transplantation utilizing pancreatic islet cotransplantation for hepatotrophic stimulation: morphologic and morphometric evaluation.

Hepatocyte transplantation using three-dimensional (3D) matrices is under evaluation as an alternative therapy for liver diseases. It is known that hepatotropic stimulation optimizes hepatocyte engraftment. We investigated hepatotrophic stimulation by portocaval shunt operation (PCS) or pancreatic islet cotransplantation (ICT) over a period of 6 months. Lewis rats served as donors and recipients, respectively. One week prior to hepatocyte implantation PCS (group A) or a sham operation (groups B-D) was performed. Four polyvinyl-alcohol matrices, each containing 1.25 x 10(7) hepatocytes (groups A and C), 1.25 x 10(7) hepatocytes and 500 islets (group B), or cell-free culture medium (group D, control) were implanted between recipients' small-bowel mesenteric leaves. One, 3, and 6 months after implantation eight polymers from each group were harvested and analyzed by morphometry, PAS reaction, and immunohistochemistry for insulin, glucagon, and bromodesoxyuridine. Morphologically healthy-appearing hepatocytes were found in all cell transplantation groups at all times. Stimulation by either PCS or ICT significantly increased hepatocyte area at 1 and 6 months compared to unstimulated specimens (group C). Over time, an increase in hepatocyte area was noted in all groups. There were no significant differences in proliferation ratios between the three experimental groups. The initially reduced PAS reaction became normal after 3 months. 3D matrices provided a sufficient environment for transplanted hepatocytes and islets. Hepatocytes proliferated and maintained differentiation independent of hepatotrophic stimulation for at least 6 months when 3D matrices were utilized. ICT efficiently stimulated transplanted hepatocytes by means of hepatocyte area. These results justify further research on hepatocyte transplantation and ICT with regard to clinical application.

Animals↗

PubMed1999

Interaction of hepatocytes and pancreatic islets cotransplanted in polymeric matrices.

Heterotopic hepatocyte transplantation (HcTx) in polymeric matrices may become an alternative to liver transplantation for metabolic disorders. Hepatotrophic stimulation by means of a portocaval shunt operation is an established, but invasive, procedure used to optimize hepatocyte engraftment in matrices. We evaluated hepatocyte and pancreatic islet cotransplantation (ICT) as an alternative noninvasive approach to hepatotrophic stimulation. Lewis rats served as donors and recipients. Hepatocytes and islets were isolated using collagenase digestion and seeded into polyvinylalcohol matrices. HcTx and ICT were compared with HcTx plus portocaval shunt and HcTx without stimulation. Matrices were investigated at 1, 3, and 6 months after implantation: the test methods applied were trichrome staining, PAS, immunohistochemistry for insulin, glucagon and incorporated BrdU, and in situ hybridization for albumin RNA. Hepatocytes expressed albumin RNA and formed conglomerates without atypias in all animals. ICT and portocaval shunting increased the number of hepatocytes and BrdU uptake. Alpha cells migrated into the islet-surrounding hepatocytes, whereas beta cells remained immobile. It is concluded that ICT and portocaval shunting supported engraftment of hepatocytes in polymeric matrices equally well. ICT did not interfere with recipient glucose metabolism and did not induce hyperproliferative premalignant foci within the transplanted hepatocytes. The technique is an attractive approach to hepatotrophic stimulation of bioartificial liver equivalents.

Animals↗