Comparison of chloral hydrate and pentobarbital sedation for pediatric echocardiography.

BACKGROUND: In 2013, outpatient use of chloral hydrate (CH) was limited and other alternatives such as oral pentobarbital (PB) were explored to achieve conscious sedation in young children for transthoracic echocardiography (TTE). We aimed to assess efficacy and safety of the two medications. METHODS: Clinical information, from a computerized database, about children who received sedation with either CH or PB for TTE at our center (2008-2015) was reviewed, and the two groups were compared for sedation effectiveness and complications. RESULTS: Three thousand eight hundred fifty one pediatric patients (median age 8 months) underwent conscious sedation during TTE (mean doses CH 50 mg/kg, PB 4 mg/kg). Demographic characteristics of the two groups were similar. Sedation failure rate (CH 2.4%, PB 2.9%, P = NS), need for supplemental doses (CH 17.9%, PB 16.2%, P = NS), and overall adverse event rate (PB 1.4%, CH 1.9%; P = NS) were similar in the two groups. There were fewer episodes of respiratory depression with PB (0.3% vs 1.6%, P < 0.05). The rate of paradoxical reactions was higher with PB (1% vs 0.03%, P < 0.05). Increasing age predicted the need for supplemental doses and for sedation failure in both groups. Neonates (7.5% vs 0%) and infants (2% vs 0.6%) given CH were more likely to develop adverse reactions. CONCLUSION: Chloral hydrate and PB are equally effective. However, CH is associated with an increased incidence of transient desaturation, while PB is associated with an increased incidence of a paradoxical reaction. Increasing age is predictive of the need for supplemental doses and for failure of sedation in both groups.

Genetic deletion of JAM-C reveals a role in myeloid progenitor generation.

Hematopoietic stem cells (HSCs) have the capacity to self-renew and continuously differentiate into all blood cell lineages throughout life. At each branching point during differentiation, interactions with the environment are key in the generation of daughter cells with distinct fates. Here, we examined the role of the cell adhesion molecule JAM-C, a protein known to mediate cellular polarity during spermatogenesis, in hematopoiesis. We show that murine JAM-C is highly expressed on HSCs in the bone marrow (BM). Expression correlates with self-renewal, the highest being on long-term repopulating HSCs, and decreases with differentiation, which is maintained longest among myeloid committed progenitors. Inclusion of JAM-C as a sole marker on lineage-negative BM cells yields HSC enrichments and long-term multilineage reconstitution when transferred to lethally irradiated mice. Analysis of Jam-C-deficient mice showed that two-thirds die within 48 hours after birth. In the surviving animals, loss of Jam-C leads to an increase in myeloid progenitors and granulocytes in the BM. Stem cells and myeloid cells from fetal liver are normal in number and homing to the BM. These results provide evidence that JAM-C defines HSCs in the BM and that JAM-C plays a role in controlling myeloid progenitor generation in the BM.

Solid-phase synthesis of dual alpha4beta1/alpha4beta7 integrin antagonists: two scaffolds with overlapping pharmacophores.

Two structural classes of dual alpha4beta1/alpha4beta7 integrin antagonists were investigated via solid-phase parallel synthesis. Using an acylated amino acid backbone, lead compounds containing biphenylalanine or tyrosine carbamate scaffolds were optimized for inhibition of alpha4beta1/VCAM and alpha4beta7/MAdCAM. A comparison of the structure-activity relationships in the inhibition of the alpha4beta7/MAdCAM interaction for substituted amines employed in both scaffolds suggests a similar binding mode for the compounds.

Selective alpha4beta7 integrin antagonists and their potential as antiinflammatory agents.

The accumulation of leukocytes in various tissues contributes to the pathogenesis of numerous human autoimmune diseases. The integrin alpha4beta7, expressed on the surface of B and T lymphocytes, plays an essential role in lymphocyte trafficking throughout the gastrointestinal (GI) tract via interaction with its primary ligand, mucosal addressin cell adhesion molecule (MAdCAM). Elevated MAdCAM expression in the intestines and liver has been linked to GI-associated autoimmune disorders, including Crohn's disease, ulcerative colitis, and hepatitis C. Monoclonal antibodies that block the interaction of alpha4beta7 with MAdCAM inhibit lymphocyte homing to murine intestines without effecting migration to peripheral organs; this suggests that alpha4beta7-selective antagonists might be useful as GI specific antiinflammatory agents. Here, we report the discovery of highly potent and selective alpha4beta7 antagonists affinity selected from a random peptide-phage library. Subsequent optimization of initial peptide leads afforded alpha4beta7-selective heptapeptide inhibitors that competitively inhibit binding to MAdCAM in vitro and inhibit lymphocyte homing to murine intestines in vivo. Substitution of a single carboxylate moiety alters selectivity for alpha4beta7 by more than 500-fold to afford a potent and selective alpha4beta1 antagonist. The antagonists described here are the first peptides to demonstrate potency and selectivity for alpha4beta7 compared to other integrins.

Vascular endothelial-junctional adhesion molecule (VE-JAM)/JAM 2 interacts with T, NK, and dendritic cells through JAM 3.

Screening expressed sequence tag databases for endothelial-specific homologs to human junctional adhesion molecule (JAM) and A33-Ag, we identified a protein of 298 aa that represents the recently described vascular endothelial-JAM (VE-JAM)/JAM 2. We confirmed VE-JAM/JAM 2 expression to be restricted to the high endothelial venule of tonsil and lymph nodes, and we further expanded the localization to the endothelium of arterioles in and around inflammatory and tumor foci. In our functional characterizations of VE-JAM/JAM 2, we discovered that it can function as an adhesive ligand for the T cell line J45 and can interact with GM-CSF/IL-4-derived peripheral blood dendritic cells, circulating CD56(+) NK cells, circulating CD56(+)CD3(+) NK/T cells, and circulating CD56(+)CD3(+)CD8(+) cytolytic T cells. In the course of our studies, we also isolated and characterized the functional VE-JAM/JAM 2 receptor, which, upon cloning, turned out to be a submitted sequence representing JAM 3 (accession number NP 113658). With these understandings, we have characterized a protein-interacting pair that can be important in the role of T, NK, and dendritic cell trafficking and inflammation.