When should we send in our rads to bat alone?

The families of 26 patients with Ebstein's anomaly were examined. There were 120 first-degree relatives, 100 of whom were living, and 93 of these were examined. Information was available on 14 of the 20 who had died. No case of Ebstein's anomaly was found among the first-degree relatives, but 2 had ventricular septal defects and another, who died at 7 months, was said to have had congenital heart disease. In more distant relatives there were 6 with congenital heart disease, including 2 with ventricular septal defects and 2 with Fallot's tetralogy.     

Response of plasma fibronectin to major body burn

The ability of macrophages of phagocytize particulate matter is largely dependent on fibronectin, a nonspecific opsonin found in plasma. Fibronectin depletion, resulting in reticuloendothelial system (RES) depression, occurs following a variety of physical insults. RES depression may contribute to postinjury sequelae such as respiratory distress syndrome and septicemia. Fibronectin concentration was measured in the plasma of sheep with chronic lung lymph fistulas subjected to controlled thermal injury. Fibronectin levels were significantly (p < 0.05) decreased at 4, 24, 48, and 72 hours following burning. Fibronectin concentration decreased in parallel with serum albumin concentration; serum globulin concentrations did not decrease. Fibronectin concentration had an inverse relationship to lung lymph flow, a reflection of pulmonary transvascular fluid filtration rate. The role of fibronectin in the pathogenesis of postinjury respiratory distress syndrome deserves further exploration.     

Liposarcoma of the hypopharynx

The effects of chemico-physical growth conditions such as pH, temperature and water activity (aw) on lethal high homogenization pressure effects on Listeria monocytogenes, Staphylococcus aureus, Escherichia coli and Yarrowia lipolytica were investigated. The results, though based on standard media, emphasize the importance of food system composition and its thermal history on the high pressure tolerance of the microbial population.     

A single side chain prevents Escherichia coli DNA polymerase I (Klenow fragment) from incorporating ribonucleotides

Although nucleic acid polymerases from different families show striking similarities in structure, they maintain stringent specificity for the sugar structure of the incoming nucleoside triphosphate. The Klenow fragment of E. coli DNA polymerase I selects its natural substrates, deoxynucleotides, over ribonucleotides by several thousand fold. Analysis of mutant Klenow fragment derivatives indicates that discrimination is provided by the Glu-710 side chain which sterically blocks the 2'-OH of an incoming rNTP. A nearby aromatic side chain, at position 762, plays an important role in constraining the nucleotide so that the Glu-710 "steric gate" can be fully effective. Even with the E710A mutation, which is extremely permissive for addition of a single ribonucleotide to a DNA primer, Klenow fragment does not efficiently synthesize pure RNA, indicating that additional barriers prevent the incorporation of successive ribonucleotides.     

Activation of p38 mitogen-activated protein kinase by lipopolysaccharide in human neutrophils requires nitric oxide-dependent cGMP accumulation

This study examined the signal transduction pathway(s) leading to phosphorylation of p38 in human neutrophils stimulated with lipopolysaccharide and formyl peptides. Blockade of the nitric oxide (NO) pathway in neutrophils with the NO synthase inhibitor N-nitro-L-arginine methyl ester or by treatment with the NO scavenger 2-phenyl-tetramethylimidazoline-1-oxyl-3-oxide attenuated phosphorylation of the mitogen-activated protein kinase p38 in response to lipopolysaccharide but not fMet-Leu-Phe. Using the NO releasing agents S-nitroso-N-acetylpenicillamine and sodium nitroprusside it was determined that nitric oxide is sufficient to cause an increase in phosphorylation of p38. Increasing cellular cGMP with phosphodiesterase inhibitors, by stimulation of soluble guanylyl cyclase with YC-1 or with exogenous dibutyryl cGMP resulted in mitogen-activated protein kinase/extracellular signal-regulated kinase kinase 3,6 (MEK3,6) activation and phosphorylation of p38. This phenomenon was specific for MEK3,6, because these agents had no effect on the phosphorylation state of MEK1,2. A role for protein kinase G but not protein kinase A downstream of lipopolysaccharide but not formylmethionylleucylphenylalanine was shown using the specific inhibitors KT5823 and H89, respectively. These data indicate that activation of p38 by fMet-Leu-Phe and lipopolysaccharide involve different mechanisms, and that activation of protein kinase G by NO-dependent stimulation of guanylyl cyclase is necessary and sufficient for phosphorylation of p38 downstream of lipopolysaccharide.     

Variation in clinical disease and species susceptibility to psittacine beak and feather disease in Zimbabwean lovebirds

While psittacine beak and feather disease has caused 100% mortality in captive flocks of 2 species of native Zimbabwean lovebirds (Agapornis nigrigensis and A. lilianae), other lovebird species in close contact with the sick birds have been only transiently affected or not at all. The clinical course of the disease in affected lovebirds may differ from that reported elsewhere, with recovery in some cases. These differences, along with ultrastructural differences may suggest a different virus or different strain of virus underlying disease in Zimbabwe.