Joshua M. Osborne

Learn More
To evaluate the potential role of human placental endothelial cells in the transport of IgG from maternal to fetal circulation, we studied Fc gamma receptor (Fc gamma R) expression by immunohistology and immunoblotting. Several pan-Fc gamma RII Abs that label the placental endothelium displayed a distribution pattern that correlated well with transport(More)
The spectrum of protein tyrosine phosphatases (PTPs) expressed in bone marrow-derived murine macrophages (BMMs) was examined using reverse transcriptase-polymerase chain reaction. Ten different PTP cDNAs were isolated and in this study we focus on mDEP-1, a type III receptor PTP. Three mDEP-1 transcripts were expressed in primary macrophages and macrophage(More)
The IgG transporter responsible for ferrying maternal IgG across the human placenta to fetal circulation has not been identified, although the human homologue of the neonatal rat Fc receptor (FcRn), a heterodimer with pH-dependent IgG affinity, structurally similar to MHC Class I molecules, was recently proposed as a candidate. Affirming this hypothesis, we(More)
We have genotyped 53 individuals from three ethnic groups (Japanese, Chinese, Asian Indian) for an allotypic polymorphism of a widely expressed low affinity Fc receptor for IgG (Fc gamma RIIA). The method, requiring PCR amplification of genomic DNA and Southern analysis with allele specific oligonucleotide probes, detects a single nucleotide difference (G(More)
Heparin induced thrombocytopenia (HIT) is characterized by the formation of antibodies that activate normal donor platelets in vitro in the presence of heparin. We asked whether the commonly observed donor-specific variation in the platelet aggregation response to HIT antibodies is influenced by the density of Fc gamma RII on platelets or by the Arg/His 131(More)
The enzyme 20-alpha-hydroxysteroid dehydrogenase (20 alpha SDH) has been proposed as a T lymphocyte marker that is specifically induced by interleukin 3. We have examined the expression of 20 alpha SDH and its relationship to interleukin 3 responsiveness in other hemopoietic lineages. The enzyme is expressed at high levels in the bone marrow of athymic(More)
1. Diabetes had no significant effect on IGFBP-3 message and serum levels however, subsequent insulin treatment caused more than a two-fold increase in both hepatic IGFBP-3 mRNA and serum levels above controls (P < 0.05). 2. The induction of diabetes in pigs significantly increased the steady state levels of IGFBP-2 mRNA in the liver of young swine (P <(More)
'Dysmorphic lung' is introduced as a term to describe any complex congenital malformation which involves both abnormal vascular morphology and disordered growth of a whole lung. The major group within this definition is the scimitar syndrome, which we choose to mean a hypoplastic lung with anomalous venous drainage and various degrees of collateral arterial(More)
Madin-Darby canine kidney (MDCK) cells exhibit many of the characteristics of cells of the cortical collecting tubule. Since hypotheses concerning the development of gouty and uric acid nephropathy involve a reaction between such cells and crystals, either of monosodium urate monohydrate (MSUM) or uric acid, the reaction between MDCK cells in culture and(More)
The Fc receptor for IgG in platelets was identified as the integral membrane isoform encoded by the Fc gamma RIIA gene. Functional analysis of this molecule determined that activated Fc gamma RIIA is tyrosine phosphorylated and that activation induced the physical association with the protein tyrosine kinase p72syk. Other tyrosine-phosphorylated molecules(More)