Multimeric cytokine receptors.

Cytokines are pleiotropic regulators that control proliferation, differentiation, and other cellular functions. They play a pivotal role in the immune and hematopoietic systems, and subsets of cytokines often exhibit similar biologic activities in common target cells. Recent cloning of genes for the cytokine receptors has provided new insights into the understanding of how the cytokines control the immune and hematopoietic systems.

Monoclonal antibodies specific for low-affinity interleukin-3 (IL-3) binding protein AIC2A: evidence that AIC2A is a component of a high-affinity IL-3 receptor.

Mouse interleukin-3 (IL-3) binds to its receptor with high and low affinities. Using anti-Aic2 antibody, two distinct cDNAs (AIC2A and AIC2B) were isolated. The AIC2A gene encodes a protein of 120 Kd that binds IL-3 with low affinity, whereas the AIC2B gene encodes a protein that is 91% identical to AIC2A at the amino acid level, but which does not bind IL-3.

Structure of mouse interleukin 3 (IL-3) binding protein (AIC2A). Amino acid residues critical for IL-3 binding.

Despite the high degree of sequence homology between two mouse proteins AIC2A and AIC2B (91% at the amino acid level), only the AIC2A protein binds interleukin 3 (IL-3). Soluble AIC2A protein bound IL-3 with affinity similar to the membrane-bound AIC2A protein, indicating that binding of IL-3 to AIC2A was mediated by the external domain alone. The extracellular domain of the AIC2A protein has two repeats of the common motif shared by members of the cytokine receptor family.

cDNA cloning of Gb, the substrate for botulinum ADP-ribosyltransferase from bovine adrenal gland and its identification as a rho gene product.

A 1.5 kilobase cDNA coding for the complete amino acid sequence of Gb, the substrate for ADP-ribosyltransferase in C1 and D botulinum toxins from bovine adrenal gland, has been isolated from a cDNA library of bovine adrenal gland. This cDNA encodes a polypeptide of 21,770 Da consisting of 193 amino acid residues, and the deduced amino acid sequence contains all the partial amino acid sequences reported previously (Narumiya, S.

Intrauterine depressed skull fracture. A report of two cases.

Two cases of intrauterine depressed fracture are presented. In each case, the mother had no history of abdominal trauma during pregnancy, the children were delivered normally without the use of forceps, but a round depression was present in the left frontal bone at time of delivery. CT scans demonstrated a depressed fracture of the left frontal bone and stagnation of cerebrospinal fluid around the fracture.

Stimulated arachidonate metabolism during foam cell transformation of mouse peritoneal macrophages with oxidized low density lipoprotein.

Changes in arachidonate metabolism were examined in mouse peritoneal macrophages incubated with various types of lipoproteins. Oxidized low density lipoprotein (LDL) was incorporated by macrophages and stimulated macrophage prostaglandin E2 (PGE2) and leukotriene C4 syntheses, respectively, 10.8- and 10.

Hemorrhagic thrombocytopathy with platelet thromboxane A2 receptor abnormality: defective signal transduction with normal binding activity.

Subnormal platelet responses to thromboxane A2 (TXA2) were found in a patient with polycythemia vera, and the mechanism of this dysfunction was analyzed. The patient's platelets showed defective aggregation and release reaction to arachidonic acid, enzymatically generated TXA2 and synthetic TXA2 mimetics (STA2, U-46619). In contrast, they showed normal responses to thrombin.

Purification and properties of prostaglandin H-E isomerase from the cytosol of human brain: identification as anionic forms of glutathione S-transferase.

Prostaglandin H-E isomerase (EC 5.3.99.

Regional distribution of prostaglandins D2, E2, and F2 alpha and related enzymes in postmortem human brain.

The presence of prostaglandins D2, E2, and F2 alpha was demonstrated and their contents measured in various regions of postmortem human brain, pineal body, and pituitary by using specific radioimmunoassays and gas chromatography-mass spectrometry. The three prostaglandins were widely distributed in similar concentrations ranging from several hundred pg/g wet weight to about 40 ng/g wet weight. Prostaglandins D2 and E2 showed consistent and similar regional distributions in all six brains tested; amounts were high in pineal body, pituitary, olfactory bulb, and hypothalamus.

Prostaglandin D2 and prostaglandin D synthetase in mast cell deficient mice.

The content of prostaglandin D2 (PGD2) and the activity of PGD synthetase were measured in various tissues of mutant mice deficient in tissue mast cells (W/Wv) and congenic normal mice (+/+). The amounts of PGD2 were determined by the radioimmunoassay specific for PGD2. PGD2 was found in all tested tissues including brain, lung, stomach, spleen and skin of both genotypes in concentrations of a few to about thirty ng/g wet weight tissue, and in spite of the absence of tissue mast cells and the very low content of tissue histamine in W/Wv mice, there was no difference in tissue PGD2 amounts between W/Wv and +/+ mice.

Role of prostaglandin D2 in the hypothermia of rats caused by bacterial lipopolysaccharide.

The intraperitoneal administration of lipopolysaccharide from Salmonella typhimurium (1 mg/kg) caused a fall in the rat colonic temperature of about 2 degrees C at an ambient temperature of 22 +/- 3 degrees C. The hypothermia induced by the lipopolysaccharide was abated in a dose-dependent manner by the administration of indomethacin. Other inhibitors of prostaglandin synthetase such as aspirin, flufenamic acid, and phenylbutazone had effects similar to those of indomethacin.