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M Hagihara

Publications and source records attributed to M Hagihara.

119 records · Page 7Linked to original sources

Xenogeneic (pig to rat) fetal liver fragment transplantation using macrocapsules for immunoisolation.

Acute liver failure caused by viral infection, surgical resection of a large part of the liver or by drug use has a high mortality. For its treatment, hepatocyte or liver tissue transplantation is useful. We report here the beneficial effects of xenogeneic fetal liver fragment (FLF) transplantation with an immunoisolation macrocapsule. The macrocapsules were made of a microporous polypropylene membrane. Pig FLFs (1 mL) was inserted into each capsule to serve as a graft in LEW rats. Acute liver failure was induced by 90% liver resection on day 0. Group 1: transplantation of encapsulated FLF into the omentum 2 days before liver resection (n = 17). Group 2: FLF transplantation into the omentum on day -2 (n = 11). Group 3: liver resection (control) (n = 19). The survival rate, the histology of the grafts and the biochemical parameters [blood sugar (BS), GPT, and GOT] were evaluated. The survival rates of groups 1, 2, and 3 on day 7 were 70.6, 0, and 11.1%, respectively. There were significant differences in BS, GPT, and GOT levels between groups 1 and 3 on day 1 (p < 0.05). On day 28, the histological analyses of the grafts of encapsulated FLFs revealed that the hepatocytes appeared viable, but that the haematopoietic cells had degenerated. Xenogeneic FLFs with macrocapsules survived more than 1 mo, and supported the host's liver function.

Animals↗

Effects of iso and xeno fetal liver fragments transplantation on acute and chronic liver failure in rats.

Isogeneic (rat) and xenogeneic (swine) fetal liver fragments (FLF) transplantation into the omentum was performed for D-galactosamine (D-Gal)-induced acute and carbon tetrachloride (CCl4)-induced chronic hepatic failure in rats. The recipients that had iso or xeno FLF showed higher survival rates than the nontransplanted controls on a lethal dose (2.6 g/kg body weight) of D-Gal (survival rates: Iso 70%, Xeno 80%, and control 9.1%). On a sublethal dose (1.0 or 1.2 g/kg) of D-Gal, iso, or xeno FLF caused marked improvement of the values of GPT, GOT, and total bilirubin (T.Bil); at 72 h after D-Gal injection they went significantly lower than those of controls (Iso vs. control; p < 0.01, Xeno vs. control; p < 0.05). Histological examination of the livers revealed severe damage in controls, however, only a slight damage was found in iso or xeno FLF transplanted rats. Iso grafts were fairly well preserved in the omentum at 72 h posttransplants, however, xeno graft had almost changed into a necrotic tissue. CCl4 was administered subcutaneously for 14 wk to induce chronic hepatic failure and then iso FLF were transplanted 3 days after the last CCl4 injection. Iso FLF transplanted rats showed higher improvement of GPT and GOT values at 12 days posttransplants compared with controls (GPT p < 0.01, GOT p < 0.05), although histological improvement was not so remarkable in both group. Iso grafts formed nodules with many hepatocytes in the omentum 12 days posttransplant. The results indicate that iso or xeno FLF transplantation could be an alternative approach for incurable liver insufficiencies.

Animals↗

In vitro and in vivo grafting of xeno pig fetal liver fragments using ultrafiltration membrane.

Transplantation of xeno fetal liver fragments (FLF) could be an alternative or supplementary therapy for acute and chronic liver failure not resolved by routine medical therapies. However, the xenografts themselves are rejected by the host immune system. To overcome these problems, immunoisolate capsules with various cutoff points, from 50,000 (YM30) to 500,000 (ZM500) were tested for their protective effects on FLF graft survival. In an in vitro study, the capsule with the smallest cutoff size (YM30) had an excellent protective effect on the grafts it contained, and showed the lowest GOT values in the culture supernatant and the normal histological structure. In an in vivo study using rats, the same capsule enabled a FLF graft to survive as long as 21 days, even with severe IgG deposition on and within the graft. In another in vivo study, which used beagle dog, however, it did not improve the natural course of survival of the graft, which had totally degenerated by day 7. In conclusion, 1) Immunocapsules, especially those with the smallest cutoff values, impeded the infiltration of the (xeno) humoral attacking factor, but the blocking effect was not complete, as shown by the immunoglobulin (IgG) deposit on the grafts they contained. 2) The FLFs with capsules survived longer than those without capsules--only in rats, not in beagles. This difference may be attributable to the difference of the extent of humoral or nutritional response to the xenografts.

Alanine Transaminase↗

Beneficial effects of immunoisolated fetal and neonatal pig liver fragments on acute liver failure in a large animal.

Xenogeneic cell (fragment) transplantation may be used as an interim therapy until the organ allotransplanation. Immunologic rejection, however, constitutes the major hurdle. To overcome this problem, "xeno" fetal and neonatal liver fragments (FLF, NLF) were encapsulated into separate micropore devices that protect them from immunological attack by the recipient. The FLF or NLF were then transplanted into beagles with hepatic failure to observe their biological effects. In Experiment 1 (n = 5) beagles were injected IV with D-galactosamine (D-gal, 1.0 g/kg) on day 0 and then received FLF grafts (0, 0.3, 0.8, 1.0, 2.0 g/kg). In Experiment 2 (n = 6) beagles received NLF grafts (1.8 g/kg) and on the following day were injected with D-gal (1.0 g/kg). In Experiment 1 only the high dose of xeno-FLF (2.0 g/kg) decreased the elevated ALT (GPT) and T. Bil. levels. Histologic examination showed that some of the hepatocytes of the host liver survived only in the high-dose graft. In Experiment 2, at 36 and 48 h after D-gal injection, the transplanted group had a significantly lower AST (GOT) level than the control. The grafted NLF survived for 14 days, according to histologic examinations. Thus, encapsulated FLF and NLF xenotransplantation can prevent liver dysfunction in a large animal hepatic failure model.

Age Factors↗

Immunological analysis in xenogeneic fetal porcine liver transplantation into a beagle.

BACKGROUND/AIMS: While allogeneic organ transplantation has been performed safely, a major barrier in xenogeneic transplantation is how to inhibit hyperacute rejection. METHODOLOGY: We challenged xenogeneic fetal liver transplantation from pig to dog. The graft was investigated by immunohistochemical analysis on recipient's IgG, IgM and C3. RESULTS: In 1 of 4 cases, the graft escaped hyperacute rejection for about 4 hours after transplantation, however, the recipient died next day due to hemorrhage from the torn capsule of the liver due to the arterial blood pressure of the recipient. Histologically, the parenchyma showed good countenance and no congestion nor hemorrhage was shown in the vessels. On immunohistochemical analysis, canine IgG, IgM and C3 were deposited on the sinusoidal epithelium of the fetal liver more moderately than that of adult control. Fetal porcine liver showed less expression of major histocompatability complex class I antigen than that of the adult one. CONCLUSIONS: We consider that the hyperacute rejection occurred more slowly in xenogeneic fetal liver transplantation than in the adult one due to not only less expression of major histocompatability complex class I, but also lower expression of the epitope recognized by a natural antibody of the recipient.

Animals↗