Liver allograft rejection: an overview of morphologic findings.

Recent improvements in patient survival has resulted in widespread use of liver transplantation as therapy for end stage liver disease. The pathologist plays a critical role in the pre- and post-operative care of these patients, and the core needle biopsy of the allograft has become a fairly reliable method of diagnosing acute cellular rejection. Most of the non-rejection related causes of graft dysfunction produce morphologic manifestations similar to those seen in nontransplanted livers (e.g., duct obstruction resembles duct obstruction). Many pathologists are, however, unfamiliar with the histologic changes of the various types of rejection. The following article is an attempt to acquaint pathologists with the morphologic features of liver allograft rejection. As a backdrop to understanding the events in humans, observations in untreated experimental animals are presented and reviewed briefly.

Platelet-activating factor and hyperacute rejection. The effect of a platelet-activating factor antagonist, SRI 63-441, on rejection of xenografts and allografts in sensitized hosts.

The pathogenesis of hyperacute transplantation reactions includes the activation of a cascade of nonspecific inflammatory reactions that precipitates the destruction of the target organ. Platelet-activating factor (PAF) represents an important component of these inflammatory cascades, and we have examined the influence of a specific PAF receptor antagonist (SRI 63-441) on the inhibition of hyperacute rejection in two experimental models, the rejection of rat cardiac allografts by presensitized recipients and guinea pig-to-rat and mouse-to-rat cardiac xenografts. Our results demonstrate that inhibition of PAF function by SRI 63-441 has a variable effect on the survival of cardiac allografts in presensitized rat recipients. In the ACI to sensitized BN cardiac allograft model, the use of SRI 63-441 alone, or in combination with CsA, FK506, or prostaglandin E2 (PGE2), does not prolong graft survival. As we have previously reported, SRI 63-441 does act as a single agent to prolong the survival of ACI to sensitized LEW grafts, and this survival effect is synergistic when combined with CsA. Here we extend these results to demonstrate that this survival is also extended when FK506 is used in the ACI-to-LEW model. Concordant mouse-to-rat cardiac xenografts are also relatively resistant to prolongation of graft survival following treatment with SRI 63-441 alone or in combination with CsA or FK506. Discordant xenografts appear to be more susceptible to inhibition of the rejection reaction with SRI 63-441. When either donor or recipient animals were treated with SRI 63-441 alone, or in combination with CsA or FK506, there was significant prolongation of guinea pig-to-rat cardiac xenograft survival. These results are consistent with our earlier description of the effectiveness of SRI 63-441 in preventing the rejection of cat-to-rabbit kidney xenografts. We believe that these results demonstrate that the use of the SRI 63-441 to specifically interfere with the function of PAF has the effect of prolonging graft survival in those systems in which performed antibody and/or complement activation are important components of the hyperacute reaction. This synthetic drug is representative of a family of compounds whose structure can be modified to balance their therapeutic and toxicity activities, and may prove to be important components of a polytherapeutic approach to the control of graft rejection in sensitized patients or following discordant xenografting.

[The clinical observation of early neonatal pure breast-feeding].

Through observation on the rate of physiological body weight loss, the percentage of body weight regaining and the incidence of infection in hospital of 160 newborns with rooming in and pure breast-feeding after uneventful delivery or caesarean section. The average rates of physiological body weight loss were 6.70% and 6.47% in pure breast-feeding group with normal delivery and caesarean section respectively, whereas 5.03% and 5.57% in mix feeding group. The percentage of body weight regaining at discharge were 34.00% and 53.33% in pure breast-feeding group compared with 11.46% and 40.00% in mix feeding group. The incidence of neonatal infection in hospital were 2.00% and 13.33% in pure breast-feeding group, instead 14.00% and 13.33% in mix feeding group. The results showed advantages and feasible of pure breast-feeding.

Long-term efficacy of active postexposure immunization of infants for prevention of hepatitis B virus infection. United States-People's Republic of China Study Group on Hepatitis B.

Perinatal transmission of hepatitis B virus (HBV) contributes to the high prevalence of chronic infection in China and many other countries. In a placebo-controlled trial among 166 infants, the 12-month efficacy of active postexposure prophylaxis to prevent chronic perinatal HBV infection varied by vaccine (range, 45%-89%). In a 5-year follow-up study, 2 additional infants became chronically infected with HBV, and the efficacy of active prophylaxis was estimated to be 38% and 72% for the two vaccines at 5 years. In addition, 80% of immunized infants continued to have protective levels of antibody at the end of 5 years. However, among 27 infants who received passive-active immunoprophylaxis with high-dose hepatitis B immune globulin, only 60% (11/19) had protective antibody levels. These data indicate that active postexposure immunization initiated soon after birth continues to provide protection during early childhood when there is a high risk of chronic HBV infection.