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A D Moscioni

Publications and source records attributed to A D Moscioni.

At least 37 records · Page 2Linked to original sources
PubMed1993

Use of a novel bioartificial liver in a patient with acute liver insufficiency.

We have developed a bioartificial liver support system (BAL) using porcine hepatocytes attached to microcarriers and placed on the outer surface of hollow fibers. The BAL system was attached to a plasmapheresis device that was then used to treat the plasma of a patient with acute liver failure. Our aim was to test the efficacy and safety of this system after a single short treatment period. A patient with alcohol-induced, severe, acute liver failure manifested by coagulopathy, rising plasma ammonia level, and deteriorating mental status was studied. The procedure was well tolerated by the patient, who remained hemodynamically stable throughout the treatment period. A marked increase in coagulation factor V, VII, VIII, and IX activities, a decrease in serum ammonia level (120 to 32 mumol/L), a twofold increase in all serum amino acids except for aminobutyric acid, and an improvement in mental status were noted after a 6-hour treatment period. This preliminary report of the first use of this novel BAL system in conjunction with plasmapheresis appears promising. A clinical study is now in progress to prove its efficacy.

Adult↗
PubMed1992

A model for directed foreign gene delivery to rat liver cells in vivo.

A novel technique for directed delivery of retroviral genes to rat liver cells in vivo is described. Vascular isolation of the liver was achieved in situ and perfusate containing retrovirus expressing the bacterial gene conferring resistance to Hygromycin-B was delivered selectively to the posterior liver lobes. After 15 min, normal blood flow to the liver was restored. The portal venous branch supplying the two anterior liver lobes was ligated either at the same time (Group I, n = 4) or 20 hr prior to perfusion (Group II, n = 4) to stimulate DNA synthesis in the posterior lobes. Controls (Group III, n = 4) were perfused with retrovirus without portal branch ligation. Hepatocyte transduction was assessed 7 days later by isolating the cells and assessing their viability in a selection medium. In Group I and II rats, 9.2 +/- 0.5 and 16.0 +/- 1.0%, respectively, of harvested hepatocytes, expressed the Hygromycin-B gene. In contrast, a significantly smaller number of hepatocytes (2.8 +/- 0.9%, P less than 0.003) expressed the gene in the absence of stimulation of DNA synthesis.

Animals↗
PubMed1991

Hepatocyte transplantation. A potential treatment for liver disease.

The purpose of this report is to summarize data collected over the past several years in the field of hepatocyte transplantation. Herein, a novel method of intraperitoneal transplantation of hepatocytes attached to collagen-coated microcarriers (or a totally biodegradable collagen sponge) is described, resulting in correction of specific genetic liver defects in rats and improved survival in rats undergoing 90% partial hepatectomy. Transplanted cells/matrix form well-vascularized aggregates in the peritoneal cavity; transplanted hepatocytes can be identified by light microscopy using immunohistochemical methods. Prolongation of transplanted hepatocyte survival and function was demonstrated by pretreatment of cells with ultraviolet irradiation. The ability of transplanted cells to proliferate was examined using both biochemical and morphologic criteria. Finally, a method of harvesting, cryopreserving, and in vivo functional testing of human hepatocytes is described.

Animals↗
PubMed1991

Bilirubin conjugates produced by human, dog, and rat hepatocytes transplanted into athymic Gunn rats.

We developed a new hybrid mutant rat (athymic Gunn hybrid strain) that does not form and excrete conjugated bilirubin into bile and accepts xenografts because of T-lymphocyte deficiency. Cryopreserved isolated normal human, dog, or rat liver cells attached to collagen-coated microcarriers were transplanted into the athymic Gunn hybrid rats. Transplantation of human or rat liver cells resulted in biliary excretion of bilirubin conjugates predominantly as glucuronides, whereas isolated dog liver cells likewise transplanted resulted in the excretion of 40% to 50% of the conjugates as a glucoside-glucuronide diconjugate. The biliary bilirubin conjugates of the transplanted athymic Gunn hybrid rats paralleled those of the donor species. The data indicate that the types of bilirubin conjugates excreted by each species are determined by intrinsic properties of the respective hepatocytes rather than nutritional or other environmental factors. The findings also show that conjugation of bilirubin after liver cell transplantation results from functioning of the engrafted cells rather than activation of endogenous uridine diphosphatelucuronosyltransferase activity of the host.

Animals↗
PubMed1990

Development of bioartificial liver: bilirubin conjugation in Gunn rats.

We developed a novel bioartificial liver using microcarrier-attached hepatocytes and a bioreactor. The bioreactor consists of an intracapillary chamber made up of porous (0.2 micron) cellulose acetate hollow fibers enclosed in a polycarbonate module forming an extracapillary chamber. Cryopreserved (-80 degrees C, 3 weeks) microcarrier-attached hepatocytes (3-4 X 10(7] were inoculated into the extracapillary chamber. The bioartificial liver, containing either microcarrier hepatocytes (n = 6) or microcarriers alone (n = 5); was attached to adult Gunn rats via cannulas in the aorta and inferior vena cava. Bile samples were collected before and at hourly intervals after attachment to the bioartificial liver. The same animal model was used to demonstrate de novo conjugation of free bilirubin by the bioartificial liver (n = 3) following systemic administration of unconjugated [3H]bilirubin. Bile was analyzed for bilirubin mono- and diglucuronides by high-performance liquid chromatography and confirmed by digestion with beta-glucuronidase and cochromatography with normal rat bile. A progressive increase in the concentration of bilirubin monoglucuronide and bilirubin diglucuronide in bile was seen as early as 30 min and lasted up to 4 hr following attachment to a bioartificial liver containing microcarrier hepatocytes (3.53 +/- 0.68 to 8.07 +/- 0.85 microM; P less than 0.01). Approximately 22% of the radiolabeled bilirubin excreted in bile was seen in the form of bilirubin conjugates, no radioactivity was seen in the free bilirubin fraction. In conclusion, we developed a bioartificial liver using microcarrier hepatocytes which carry out an important differentiated liver function which results in partial correction of a specific metabolic liver defect, i.e., conjugation of bilirubin.

Animals↗
PubMed1989

Intraperitoneal transplantation of microcarrier-attached enterocytes in rats.

The purpose of this study was to determine whether enterocyte transplantation could be used to correct a specific genetic metabolic defect. Bilirubin uridine diphosphoglucuronyl transferase (UDPGT) activity has been demonstrated in normal rat intestinal mucosa. We hypothesized that normal rat enterocyte transplantation may restore the ability of Gunn rats, which lack bilirubin UDPGT, to conjugate bilirubin. Small intestine was resected from normal Wistar rat donors. Enterocytes were harvested and suspended in Dulbecco's modified Eagle's medium with 10 percent fetal calf serum. Isolated enterocytes were attached to collagen-coated dextran microcarriers and transplanted into congeneic Gunn rat recipients. Recipient rats underwent bile duct cannulation after transplantation, and bile was analyzed for bilirubin glucuronides by high-pressure liquid chromatography. Fifty percent of the transplanted rats showed a significant increase in the concentration of bilirubin monoglucuronide and diglucuronide in their bile 4 and 7 days posttransplantation. Recipient rats had well vascularized microcarrier-enterocyte aggregates in the peritoneal cavity. Our method for intraperitoneal transplantation of isolated enterocytes in rats could potentially be used to correct specific enzymatic and metabolic defects.

Animals↗
PubMed1989

Impaired liver regeneration in the analbuminemic rat.

Albumin has been implicated as both an inhibitor and a stimulator of liver regeneration. We examined the rate of liver regeneration following partial hepatectomy in rats which are genetically analbuminemic. Adult male analbuminemic and Sprague-Dawley control rats underwent either a 70% partial hepatectomy or a sham operation. Twenty-four hours postoperatively, rats were injected iv with tritiated thymidine and the liver remnants were resected 1 hr later. Liver weight, protein and DNA contents, and the rate of tritiated thymidine incorporation into DNA were determined. The rate of DNA synthesis in control sham-operated rats was greater (P less than 0.05) than that of analbuminemic rats. Following partial hepatectomy, there was a statistically significant (P less than 0.01) increase in DNA synthesis in control rats; no significant increase was noted in the analbuminemic rats. No significant differences in liver remnant weight or protein and DNA contents were noted between control and analbuminemic sham-operated or partially hepatectomized rats. Our data suggest that albumin plays a role in the regulation of DNA synthesis in both the resting and the regenerating liver and it may be essential in maintaining a normal rate of liver regeneration.

Albumins↗
PubMed1989

Human liver cell transplantation. Prolonged function in athymic-Gunn and athymic-analbuminemic hybrid rats.

Isolated cryopreserved human liver cells, attached to collagen-coated microcarriers, were injected intraperitoneally into mutant rat recipients genetically deficient in either bilirubin uridine diphosphoglucuronosyltransferase activity (Gunn rats) or albumin synthesis (Nagase analbuminemic rats). One group of the recipient Gunn and analbuminemic rats were made genetically immunodeficient by interbreeding with athymic rats with inherited T-cell deficiency. Injected microcarriers and cells formed aggregates on the surface of the pancreas. There was no morphologic evidence of rejection in athymic recipients, whereas immunocompetent recipients demonstrated rejection within 5 days of transplantation. Athymic-Gunn rat recipients demonstrated excretion of bilirubin glucuronides in bile for 30 days and reduction in their serum bilirubin levels. In recipient athymic-analbuminemic rats, plasma albumin levels increased from pretransplantation levels of 0.025-0.05 mg/ml to 3.9-4.8 mg/ml 8 days posttransplantation and remained nearly at that level throughout the 30 days of the study. A method of harvesting, attaching to microcarriers, cryopreserving, and in vivo testing of human hepatocytes with prolonged survival and function in athymic-Gunn and athymic-analbuminemic hybrid rats is reported. These rats are excellent animal models for testing xenograft function.

Animals↗
PubMed1987

Isolation of multiple normal and functionally defective forms of uridine diphosphate-glucuronosyltransferase from inbred Gunn rats.

Gunn rats are a mutant strain of Wistar rats that have unconjugated hyperbilirubinemia due to absence of hepatic uridine diphosphate-glucuronosyltransferase (UDPGT; EC. 2.4.1.17) activity toward bilirubin. We isolated five UDPGT isoforms from solubilized microsomal fractions from liver of inbred Wistar (RHA) rats and congeneic Gunn rats. UDPGT isoform V (elution pH 7.5) from Wistar (RHA) rats is active toward bilirubin and 4'-hydroxydimethylaminoazobenzene. The corresponding isoform from Gunn rat liver was enzymically inactive but exhibited normal elution pH and mobility on NaDodSO4/polyacrylamide gel electrophoresis (Mr 53,000), and was recognized by a UDPGT-specific antiserum. UDPGT isoform I (elution pH 8.7) from Wistar (RHA) and Gunn rats was active toward 4-nitrophenol. The isoform from Gunn rat liver had only 10% of normal UDPGT activity, however UDPGT activity increased to normal upon addition of 15 mM diethylnitrosamine in vitro. Isoforms II (elution pH 8.4), III (elution pH 8.0), and IV (elution pH 7.8) from Gunn rats had normal UDPGT activities, except that Isoform IV was inactive toward bilirubin.

Animals↗
PubMed1987

The effect of tin (IV)-protoporphyrin-IX on bilirubin production and excretion in the rat.

Tin (IV)-protoporphyrin-IX alpha (tin-heme) may have use in treating neonatal jaundice. To evaluate its effect on bilirubin metabolism, we measured bile-bilirubin excretion in adult, male Sprague-Dawley rats (350-500 g). After a 4-h baseline period, tin-heme (100 mumol/kg) or buffer was injected subcutaneously, and bile was collected for 19 h. Bile flow, bile salt excretion, and bile-bilirubin excretion (averaging 600 +/- 60 ng/100 g/min for all animals) remained stable in the control period. Tin-heme treatment did not alter bile flow or bile salt excretion, but within 2 h bilirubin output was significantly reduced. The nadir of output was 5 h after injection when it was 380 +/- 40 ng/100 g/min (p less than 0.001). Cumulative excretion over 19 h was reduced 30.8% (p less than 0.01). To determine if tin-heme interfered with hepatic uptake or excretion of bilirubin, additional animals were administered intravenous bilirubin at 30 mg/kg/h for 3 h after tin-heme injection. Neither peak bile-bilirubin (37.4 +/- 4.68, control; 38.19 +/- 3.81 micrograms/100 g/min, treated) nor cumulative excretion (87.8 +/- 4.7, control; 88.9 +/- 4.2%, treated) were altered. Biliary excretion of tin-heme was measured under various experimental conditions. When administered alone, maximal excretion was 4 h after injection (4.41 +/- 1.58 micrograms/100 g/min); by 15 h, it fell to 0.024 +/- 0.011 microgram/100 g/min; 20-h cumulative tin-heme excretion in bile was 21.8 +/- 3.1% of the administered dose. Intravenous coadministration of albumin or albumin and bilirubin reduced the peak output but did not alter cumulative excretion of tin-heme. These data indicate that tin-heme reduces endogenous bilirubin formation but does not impair hepatic uptake and excretion. Bile is a major excretory route for tin-heme.

Animals↗
PubMed1986

Replacement of liver function in rats by transplantation of microcarrier-attached hepatocytes.

Isolated hepatocytes, harvested from normal rat livers by portal vein collagenase perfusion, can be attached to collagen-coated dextran microcarriers and transplanted by intraperitoneal injection into rats. Survival and function of the transplanted hepatocytes have been demonstrated in mutant rats lacking bilirubin-uridine diphosphate glucuronosyltransferase activity (Gunn strain) and rats with inherited lack of plasma albumin (Nagase analbuminemia rat strain). This simple technique promises to be useful in the treatment of acute liver failure in humans.

Animals↗
PubMed1983

Differential regulation by triiodothyronine of substrate-specific uridinediphosphoglucuronate glucuronosyl transferases in rat liver.

Hepatic uridinediphosphoglucuronate glucuronosyl transferase (UDPglucuronyltransferase, EC 2.4.1.17) is functionally heterogeneous; 4-nitrophenol and bilirubin are representative substrates for two functional forms of the enzyme. UDPglucuronyltransferase activity for bilirubin and 4-nitrophenol was separated from solubilized rat liver microsomes by DEAE-cellulose chromatography and corresponding enzymes were purified. A radioimmunoassay was developed using a rabbit antiserum against purified rat 4-nitrophenol-specific UDPglucuronyltransferase, which precipitated enzyme activities toward both 4-nitrophenol and bilirubin. After treatment with triiodothyronine (T3) (0.55 mg/kg body weight), hepatic microsomal UDPglucuronyltransferase activity for 4-nitrophenol was increased 400% as compared to controls; the enzyme activity for bilirubin was decreased by 80%; the changes in the substrate-specific enzyme activities were reflected in the enzymatically active fractions separated after DEAE-cellulose chromatography. The changes in enzyme activities paralleled changes in the concentrations of the two corresponding UDP glucuronyltransferase proteins in the chromatographic fractions, as measured by radioimmunoassay. The results indicate that the opposite effects of T3 on the two forms of UDPglucuronyltransferase activity is due to its differential effect on corresponding enzyme proteins.

Animals↗
PubMed1983

Effect of milk feeding on intestinal bilirubin absorption in the rat.

The hypothesis that the etiologic mechanism of the late-onset, prolonged, unconjugated hyperbilirubinemia of the breast-fed infant, known as the breast milk jaundice syndrome, results from exaggeration of intestinal bilirubin absorption has been investigated in an adult rat model, which permits quantitative measurement of the enterohepatic circulation of bilirubin. After instillation of unconjugated bilirubin in buffer into the duodenum, 25% of the dose was absorbed and appeared in bile. Administration of bilirubin in human milk or cow milk formula resulted in a marked reduction in absorption to 2%. Administration of bilirubin in milk from mothers of infants with breast milk jaundice syndrome not only failed entirely to prevent the absorption of bilirubin, but enhanced late absorption, to produce a total absorption of 60% of the bilirubin dose. Thus, although normal milk significantly retarded intestinal bilirubin absorption and diminished the bilirubin load to the liver, milk from mothers of infants with breast milk jaundice syndrome appeared to enhance the enterohepatic circulation of bilirubin and to increase the total hepatic bilirubin load. This exaggeration of the enterohepatic circulation of bilirubin may be related to the increased concentrations in these milks of long-chain nonesterified fatty acids.

Animals↗
PubMed1983

Thyroid hormone and hepatic UDP-glucuronosyl transferase activity: contrary effects in rat and mouse.

The administration of tri-iodothyronine (T3) to female Sprague-Dawley (SD) rats lowered the basal activity of uridine diphosphoglucuronate glucuronosyl transferase (UDPGT:EC 2.4.1.17) for bilirubin (Bili) by 75 percent, but dramatically increased the level of UDP-glucuronosyl transferase for p-nitrophenol (UDPGT-PNP) by more than 100 percent. Similar experiments performed in four strains of female mice produced results contrary to those observed in the rat. T3 administered to C57BL/6J, DBA/2J, Swiss-Webster (SW) and CD-1 mice significantly increased hepatic UDPGT-Bili by 28, 69, 79 and 94%, respectively. The increase of UDPGT-Bili in the selected strains was observed to be inversely and linearly proportional to the basal level of enzyme measured in each strain (r = -0.99215; p less than 0.001). Only in the DBA/2J strain was UDPGT-PNP significantly diminished to 66% of control levels, producing a result exactly opposite to that observed in the SD rat; in the other three strains, UDPGT-PNP was not significantly altered.

Animals↗
PubMedDate not supplied

Transplantation of microcarrier-attached hepatocytes into 90% partially hepatectomized rats.

We previously reported a method of intraperitoneal transplantation of liver cells attached to collagen-coated microcarriers, which resulted in prolonged survival and function of the transplanted cells. In the present study, we evaluated the efficacy of liver cell transplantation in providing metabolic support during acute liver insufficiency induced by 90% partial hepatectomy in rats. Ninety per cent of the liver mass (all lobes except the caudate lobe) was resected, and the rats were provided with 5% dextrose orally ad libitum upon regaining consciousness. This regimen results in severe hypoglycemia and death within 48 hr. When microcarrier-attached liver cells were transplanted into syngeneic and allogeneic recipients 3 days prior to 90% partial hepatectomy, significantly higher blood glucose levels were observed (p less than 0.01), compared to the levels in control rats which received injections of microcarriers, liver cells or medium alone. There was a marked improvement in long-term survival (40% survived longer than 28 days; p less than 0.001) in rats transplanted with microcarriers-attached cells. None of the rats given injections of microcarriers, liver cells or medium alone survived beyond 5 days. When liver cells alone or attached to microcarriers were injected intraperitoneally immediately after 90% partial hepatectomy, all rats became hypoglycemic and died within 48 hr, suggesting that vascularization of the transplant is required for function of the transplanted hepatocytes. The results indicate that intraperitoneal transplantation of microcarrier-attached hepatocytes prior to 90% partial hepatectomy in rats provides acute metabolic support resulting in improved survival.

Acute Disease↗