Echoencephalographic findings of Apert syndrome.

Although Apert syndrome has been characterized in the prenatal period and clinically described in the literature, postnatal echoencephalographic findings have not been reported. We present a case of Apert syndrome that shows bilateral periventricular cysts, unusual posterior downward curving of the lateral ventricles without evidence of hydrocephalus, along with a decreased anterior-posterior diameter of the cranial vault. Given that Apert syndrome, characterized by acrocephalosyndactyly, can give rise to numerous CNS abnormalities, echoencephalography could be used to further characterize Apert syndrome in the postnatal period.

How H13 histocompatibility peptides differing by a single methyl group and lacking conventional MHC binding anchor motifs determine self-nonself discrimination.

The mouse H13 minor histocompatibility (H) Ag, originally detected as a barrier to allograft transplants, is remarkable in that rejection is a consequence of an extremely subtle interchange, P4(Val/Ile), in a nonamer H2-D(b)-bound peptide. Moreover, H13 peptides lack the canonical P5(Asn) central anchor residue normally considered important for forming a peptide/MHC complex. To understand how these noncanonical peptide pMHC complexes form physiologically active TCR ligands, crystal structures of allelic H13 pD(b) complexes and a P5(Asn) anchored pD(b) analog were solved to high resolution.

Expression of phosphodiesterase 4D (PDE4D) is regulated by both the cyclic AMP-dependent protein kinase and mitogen-activated protein kinase signaling pathways. A potential mechanism allowing for the coordinated regulation of PDE4D activity and expression in cells.

Multiple families of cyclic nucleotide phosphodiesterases (PDE) have been described, and the regulated expression of these genes in cells is complex. Although cAMP is known to control the expression of certain PDE in cells, presumably reflecting a system of feedback on cAMP signaling, relatively little is known about the influence of non-cAMP signaling systems on PDE expression. In this study, we describe a novel mechanism by which activators of the protein kinase C (PKC)-Raf-MEK-ERK cascade regulate phosphodiesterase 4D (PDE4D) expression in vascular smooth muscle cells (VSMC) and assess the functional consequences of this effect.

Fetal hepatosplenomegaly associated with transient myeloproliferative disorder in trisomy 21.

The in utero diagnosis of fetal myeloproliferative disease was made by cordocentesis following the ultrasound appearance of fetal hepatosplenomegaly and mild hydrops. The 2 fetuses reported both had leukocyte counts greater than 75,000/mm3 with a predominance of blast forms. In both cases the karyotype revealed trisomy 21.

Computer simulation of counterlungs.

We have developed a computer model of chest-mounted counterlungs, which accounts for counterlung shape, effective volume, and pressure centroid. The model has been validated and the principles are applicable to other counterlung systems. The highly non-linear and discontinuous behavior of a counterlung is predicted by use of a sophisticated numerical integration method that computes variables such as pressure and volume in the time domain.