Mariana Barbich

Effect of the embolization of completely unpurified islets on portal vein pressure and hepatic biochemistry in clinical practice.

Here we report on the impact of completely unpurified islet transplantation on the portal vein pressure (PVP) and the hepatic biochemistry in the peritransplant period and on follow-up. Type I diabetic patients underwent simultaneous kidney and islet transplantation. Islets were not purified from the acinar tissue to prevent loss of endocrine mass. Each patient received a mean 521,846 ± 201,539.4 islet equivalents (7812.1 islet equivalents/kg/recipient). Immunosuppression and peritransplant medication were given according to the Giessen protocol. The islets were injected into the left hepatic lobe through the umbilical vein. PVP was recorded at time 0 and every 5 min throughout cell infusion. Liver function was assessed daily for the first 10 days, and on follow-up. Basal, peak, and final PVP were 12 ± 3.8, 25.1 ± 7.9, and 19.5 ± 6.2 mmHg, respectively (basal vs. final, p < 0.05). Bilirubin, alkaline phosphatase, prothrombin time, and APTT stayed within normal range. Peak aspartate aminotransferase (AST), alanine aminotransferase (ALT), and serum amylase were 109.4 ± 61.2 IU/L (basal vs. peak, not significant), 79.5 ± 56.9 IU/L (basal vs. peak, not significant), and 887.5 ± 153.6 IU/L (basal vs. peak, p = 0.02), respectively. In all cases AST, ALT, and amylase normalized within 6 days posttransplant and remained so on follow-up (longest control, 33 months posttransplant). Although the intrahepatic infusion of unpurified pancreatic islets affects both the portal vein pressure and the hepatic biochemical profile, this effect is transient and does not compromise the safety of the procedure.

Histologic Changes After Urethroplasty Using Small Intestinal Submucosa Unseeded With Cells in Rabbits With Injured Urethra

OBJECTIVE To determine whether small intestine submucosa has the same regenerative capacity when urethroplasty is performed in injured urethras. METHODS Our experiment was conducted in 30 New Zealand male rabbits, all of which had urethral injury. One month after the injury, the animals were randomized into a control group or a group with onlay urethroplasty with small intestine submucosa. The animals were euthanized at 2, 4, 12, 24, and 36 weeks after urethroplasty, and their urethras were removed for histologic and immunohistochemical examination. Before the scheduled euthanasia, urethrography and cystoscopy were performed. RESULTS After 2 weeks, there was evidence of a continuous monolayer of stratified epithelial cells and absence of smooth muscle fibers. One month later, the epithelium showed no changes from the previously observed features, but some smooth muscle fibers (representing newly formed vessels) became apparent. After 3 months, the graft showed increased concentration of smooth muscle fibers. After 6 and 9 months, the density of smooth muscle cells remained unchanged. Fiber arrangement was irregular, particularly at the anastomosis site. Epithelial and smooth muscle phenotypes were confirmed by immunohistochemistry using anti-pan-citokeratin (AE1/AE3) antibodies and anti-α-smooth muscle actin, respectively. CONCLUSION Small intestine submucosa promotes regeneration in traumatized urethras, with slightly delayed epithelialization and abnormal distribution of smooth muscle. Urethral damage caused by trauma interferes with the normal healing process.

Initial experience with clinical islet transplantation in Argentina.

WHOLE pancreas transplantation may be the best therapeutic option for type I diabetic patients in advanced stages of their disease. However, those patients who are not eligible for whole pancreas transplantation may still benefit from pancreatic cell transplantation, which in spite of its lower rate of insulin independence, involves a minor surgical procedure and a lower posttransplant risk. We herein report our initial experience on pancreatic islet transplantation at a kidney and pancreas transplantation program based in Argentina since 1995.

Hepatic cell transplantation in childhood. State of the art

To date, children who suffer from a certain type of illness such as hepatic failure, could benefit with a non conventional functional replacement as an alternative to liver transplantation. Deterioration and death of patients on waiting list encourage the search for alternatives methods within transplantation. Liver cell transplantation has become a potential alternative treatment whose validation as an alternative or as a bridge until the donor appears, will probably contribute to improve the quality of life and survival of the patients. The aim of this review is to describe the state of the art of hepatocyte transplantation in pediatric patients.

CULTURE AND CHARACTERIZATION OF HUMAN HEPATOCYTES OBTAINED AFTER GRAFT REDUCTION FOR LIVER TRANSPLANTATION: A RELIABLE SOURCE OF CELLS FOR A BIOARTIFICIAL LIVER

This article describes results obtained when human liver cells obtained from reduced grafts are cultured in a chemically defined medium. Remnants of livers after reduction for pediatric transplantation were processed by a multiple cannulation system through the existing vasculature, which allowed the homogeneous perfusion of collagenase. The graft weight ranged between 55 and 1000 g (median value: 145.6 g). The yield ranged between 0.13 x 10(6) and 38 x 10(6) cells/g of tissue (median value 14.73 x 10(6) cells/g), and the viability was 61.17 +/- 27.43%. The total number of cells ranged between 57.6 x 10(6) and 12 150 x 10(6) cells (median value: 740 x 10(6) cells). Cells were cultured for 30 days. Albumin synthesis was observed during the first 2 weeks, with a peak value at day 6 (27.85 +/- 1.77 micro g/mL). Urea production was detected during the first week (peak value at day 6: 17.12 +/- 2.11 mg/dL). Light microscopy showed the presence of cells in a monolayer. Biliary pigments were observed at day 20. By immunohistochemistry, positive cells for albumin, for hepatocyte marker, cytokeratin 19, CD 34, CD 68, and for alpha actin for smooth muscle, were observed. Our results showed that hepatocytes obtained from reduced liver grafts are easily cultured and are able to maintain viability and functionality in vitro. This alternative source of human cells maintained under controlled culture conditions may play an important role in the development of a bioartificial liver.

The perenal retroperitoneum as an alternative site for pancreatic islets tansplantation

I SLETS OF Langerhans are currently being used to treat type I diabetic patients as an alternative to the vascularized pancreas transplant.” Islet functionality may depend on a variety of factors such as the host’s immunologic response, the quality and number of islets, and the implant site. The latter should provide the adequate milieu (eg, vascularization and nutrition) to maximize the chances for cell engraftment.4,s The aim of this work was to evaluate the prerenal peritoneum as a receptor site for pancreatic islets in a pancreatectomized pig.