Parvimico materdei gen. et sp. nov.: A new platyrrhine from the Early Miocene of the Amazon Basin, Peru.

Three field seasons of exploration along the Río Alto Madre de Dios in Peruvian Amazonia have yielded a fauna of micromammals from a new locality AMD-45, at ∼12.8°S. So far we have identified the new primate described here as well as small caviomorph rodents, cenolestoid marsupials, interatheriid notoungulates, xenarthrans, fish, lizards and invertebrates.

A semiquantitative PCR technique for detecting chimerism in hamster-to-rat bone marrow xenotransplantation.

Although bone marrow transplantation has been used to induce donor-specific tolerance in many allogeneic models, similar effort in xenogeneic transplantation is met with obstacles like more severe graft versus host disease (GVHD). We are currently engaged in developing a GVHD-free hamster-to-rat xenotransplantation model using splenectomy, total body irradiation, and donor bone marrow transplantation. To test donor cell chimerism, particularly in the solid tissues, we developed a semiquantitative polymerase chain reaction (PCR) method using primers specific for hamster beta-actin and mitochondrial cytochrome C oxidase I and II (MCO I and II) genes and rat sex determination region on the Y chromosome (SRY) gene.

Some morphological, growth, and genomic properties of human cells chronically infected with porcine endogenous retrovirus (PERV).

A major concern in using porcine organs for transplantation is the potential of transmission of porcine endogenous retrovirus (PERV). To investigate the long-term effects of PERV infection on human cells, human embryonic kidney cell line HEK-293 infected with PERV PK-15 was maintained for up to 72 passages and samples were harvested at intervals for use in morphological, growth, and genomic analyses. Morphology, DNA content/cell, and doubling time of uninfected and infected cells were similar.

Correction of congenital hyperbilirubinemia in homozygous Gunn rats by xenotransplantation of hamster livers.

The homozygous Gunn(j/j) rat is an animal model for Crigler-Najjarsyndrome in which the lack of the enzyme uridine diphosphoglucoronate-glucuronosyltransferase (UDP-GT) results in congenital unconjugated nonhemolytic hyperbilirubinemia. Because the binding of bilirubin to albumin in plasma varies from species to species, xenotransplantation (XTx) of liver afforded in this model the opportunity to study the interactions between xenoproteins of the donor and bilirubin of the recipient. For this purpose, orthotopic liver transplantation (OLTx) was performed from hamster to adult Gunn(j/j) rats.