Progesterone-induced blocking factor blockade causes hypertension in pregnant rats.

Preeclampsia (PE) is a multisystem disorder characterized by new onset hypertension in mid-late gestation and can include multi-organ dysfunction with or without proteinuria. It affects 5%-7% of all pregnancies in the U.S.

Implications of COVID-19 On A Rapidly Growing Thymoma Case.

Introduction: Thymomas are a rare form of slow-growing malignancy that originate from thymic epithelial cells presenting as an anterior mediastinal mass. Although most are asymptomatic, they can have a variety of presentations, such as local thoracic symptoms, superior vena cava syndrome, or paraneoplastic syndromes. Local compressive thoracic symptoms include shortness of breath, chest pain, and cough.

Vagotonic effects of enkephalin are not mediated by sympatholytic mechanisms.

This study examined the hypothesis that vagotonic and sympatholytic effects of cardiac enkephalins are independently mediated by different receptors. A dose-response was constructed by administering the delta-receptor opioid methionine-enkephalin-arginine-phenylalanine (MEAP) by microdialysis into the interstitium of the canine sinoatrial node during vagal and sympathetic stimulation. The right cardiac sympathetic nerves were stimulated as they exited the stellate ganglion at frequencies selected to increase heart rate approximately 35 bpm.

Influence of subunit configuration on the interaction of picrotoxin-site ligands with recombinant GABA(A) receptors.

We have assessed the interaction of picrotoxin and a putative picrotoxin-site ligand [4-dimethyl-3-t-butylcarboxyl-4,5-dihydro (1, 5-a) quinoxaline] (U-93631) with varying configurations of recombinant GABA(A) receptors, using the whole-cell patch clamp technique. In alpha2beta2gamma2 GABA(A) receptors, coapplication of picrotoxin with GABA had minimal effects on initial GABA-activated Cl(-) current amplitude, and subsequently enhanced decay of GABA-activated Cl(-) currents. The half-maximal inhibitory concentration (IC(50)) for picrotoxin in alpha2beta2gamma2 receptors was 10.

Kinetic and chemical mechanisms of the sheep liver 6-phosphogluconate dehydrogenase.

A complete kinetic characterization of sheep liver 6-phosphogluconate dehydrogenase including product and dead-end inhibition patterns, primary deuterium isotope effects, and the pH dependence of kinetic parameters has been completed in order to determine the kinetic mechanism and obtain information on the chemical mechanism of the enzyme. A rapid equilibrium random kinetic mechanism has been proposed, with product and dead-end inhibition patterns both being symmetric. Ribulose 5-phosphate and 6-sulfogluconate are both competitive with 6-phosphogluconate (6-PG) and noncompetitive with NADP, and NADPH and ATP-ribose are both competitive with NADP and noncompetitive with 6-phosphogluconate.

Biochemical characterization of ADP-ribose polymer metabolism in SLE.

The metabolism of poly(ADP-ribose) in peripheral blood mononuclear (PBM) cells was studied in 13 patients with systemic lupus erythematosus (SLE) and in 12 age and sex matched controls. Poly(ADP-ribose) polymerase activity was measured as the net accumulation of ADP-ribose polymers during the conversion of 32P-NAD to poly(ADP-ribose) in PBM cells in vitro. The control population showed a mean activity of 418 +/- 91(s.

Clenbuterol: a substitute for anabolic steroids?

Clenbuterol is a recently popular drug used by athletes in many sports for its purported anabolic effects and reduction of subcutaneous fat. It is a beta-2 (beta 2) agonist prescribed overseas as a bronchodilator, but not approved for use in this country. It is on the banned substance list of the United States Olympic Committee.

Kinetic mechanism of serine transacetylase from Salmonella typhimurium.

Serine transacetylase from Salmonella typhimurium was purified to near homogeneity. A complete initial velocity study in both reaction directions suggests that the enzyme catalyzes the conversion of acetyl CoA and L-serine to O-acetyl-L-serine (OAS) and coenzyme A (CoASH) by a ping pong bi bi kinetic mechanism. Initial velocity patterns in the absence of added inhibitors in both directions are best described by a series of parallel lines.