Mapping of the multiple regulatory sites for putP and putA expression in the putC region of Escherichia coli

Summary The effects of regulatory proteins on the expression of putP and putA were studied using put-lacZ fusion genes. The expression of the putP-lacZ gene was activated by the glnG gene product and the catabolite gene activator protein (CAP). The putA gene product inhibited activation of putP-lacZ gene expression by CAP or the glnG gene product and its inhibition was greater in the absence of proline. The expression of the putA-lacZ gene was activated by CAP and repressed by the glnG gene product. The putA gene product acted as a repressor in the absence of proline, but not in its presence. Studies using put-lacZ fusion genes with upstream deletions showed that the region required for the activation of putP by CAP was within 234 bp upstream of the translational initiation site and that that for the activation of putP was within 107 bp upstream of the translational initiation site of the putA gene. This supported the suggested locations of CAP binding sites. The region required for induction of putP and putA expression by proline was located at the Hpal site 182 bp upstream of the translational starting site of putA, suggesting that a sequence of dyad symmetry located 1 bp to the left of the HpaI site is a candidate for the binding site of the putA gene product.Abbreviations AC L-azetidine-2-carboxylic acid - Ap ampicillin - CAP catabolite gene activator protein - NR_I nitrogen regulator I - RF DNA DNA replicative form - Str streptomycin - Tc tetracycline - TTC 2,3,5-triphenyl tetrazolium chloride - UV ultraviolet     

Atrial natriuretic polypeptide (ANP) in human ventricle. Increased gene expression of ANP in dilated cardiomyopathy

Tissue levels of atrial natriuretic polypeptide (ANP) messenger RNA (ANPmRNA) and ANP in the human atrium and ventricle were measured simultaneously by the blot hybridization technique and the specific radioimmunoassay for ANP. Hearts were obtained from two patients without cardiac complications and from a patient with dilated cardiomyopathy (DCM) at autopsy. Total RNA extracted from ventricles contained a hybridizing RNA band of the same size as atrial ANPmRNA in both control and DCM hearts. The ANPmRNA level in the control ventricle was 0.2% of that in the atrium. The ANPmRNA level in the DCM ventricle increased to about 7% of that in the corresponding atrium and was approximately 40 times higher than that in the control ventricle, although the ANPmRNA level in the DCM atrium was comparable to that in the control atrium. The total content of ANPmRNA in the DCM ventricle reached about 30% of that in the corresponding atrium and was much the same as that in the control atrium. The ANP level in the DCM ventricle was approximately 1.0 microgram/g and much higher than that in the control ventricle (0.02 microgram/g).     

SC-39026, a specific human neutrophil elastase inhibitor

SC-39026, (+/-) 2-chloro-4-(1-hydroxyoctadecyl)benzoic acid, inhibits human neutrophil elastase with an IC50 of 0.5 microM (KI of 1.5 microM). Its inhibition of elastase is reversible and noncompetitive at low concentrations (0.5-1.25 microM). Inhibition is "mixed" at higher inhibitor concentrations. SC-39026 is inactive against hog pancreatic elastase, bovine alpha-chymotrypsin and Pseudomonas aeruginosa elastase, but does inhibit human neutrophil cathepsin G with an IC50 of approximately 2.5 microM. Neutrophil elastases isolated from rat, hamster, rabbit and hog are also inhibited by SC-39026.     

Dynamic association of band 3 with triton shells in human erythrocyte ghosts

To test a possibility that free band 3 and ankyrin-linked band 3 are exchanged in situ, band 3 was labeled with 125I, using intact red blood cells and lactoperoxidase. The cytoplasmic surface of this labeled band 3 was considered to be intact. When Triton shells were incubated with Triton supernatants prepared from 125I-labeled intact erythrocytes at 37 degrees C in the presence of Mg-ATP under isotonic conditions, the incorporation of free 125I-labeled band 3 to shells was observed. This incorporation was affected by the presence of Triton X-100 in the incubation mixture, and significantly decreased when the content of Triton X-100 was less than 0.04% (v/v). On the other hand, ankyrin-linked 125I-labeled band 3 was released when shells prepared from 125I-labeled intact erythrocytes were incubated with the Triton supernatants at 37 degrees C under the same condition as when free 125I-labeled band 3 incorporation was observed. These results strongly suggest that free and ankyrin-linked band 3 exchanged with each other in the presence of Triton X-100. A water-soluble 43 kDa fragment of band 3 inhibited the incorporation of free 125I-labeled band 3 to the shells and also inhibited the Mg-ATP-dependent shape change of ghosts in the absence of Triton X-100. Both of these inhibitory effects remained, even after 10 min of heat treatment at 100 degrees C, but drastically decreased by treatment with trypsin. Our results strongly suggest that a dynamic exchange of the free band 3 for ankyrin-linked band 3 may occur in intact erythrocytes, and it may even contribute to the shape change of erythrocytes.     

甘草酸单钕盐对猪肾脏微粒体钠、钾三磷酸腺苷酶活性的影响

 <正> 甘草有补脾益气、止咳祛痰、清热解毒、缓急止痛、调和药性的功能。伤寒论113方剂中有74方剂含有甘草。欧洲从古代开始亦将甘草作为药物应用于临床。荷兰医师Revers氏指出,甘草提取液具有盐皮质类固醇样作用,治疗消化性溃疡病时,20％的患者发生浮肿,心脏喘息样发作。其后,Molhuysen氏指出,甘草浸膏具有脱氧皮质酮(DOC)样作用,健康人服用时,钠、氯排出减少,钾排出增加。Louis和Conn二氏经实验表明,每日     

Effect of 1-desamino-8-D-arginine vasopressin (DDAVP) on vasopressin release and blood pressure during hemorrhage.

Whether or not 1-desamino-8-D-arginine-vasopressin (DDAVP) reduces blood pressure or affects the release of arginine vasopressin (AVP) and renin is controversial, although evidence suggests AVP and renin are important in maintaining blood pressure during hemorrhage. We therefore investigated the effect of DDAVP on endogenous release of AVP and renin and on blood pressure during hemorrhage in dogs. In the control group the hemorrhage was performed at a rate of 0.4 ml.kg-1.min-1 for 40 min from the femoral artery. The plasma AVP concentration and renin activity (PRA) increased progressively in response to the hemorrhage, from 7.5 +/- 0.5 to 40.3 +/- 7.3 pg.ml-1, and from 11.8 +/- 1.5 to 20.5 +/- 4.2 ng.ml-1.h-1, respectively, while blood pressure decreased slightly. In the DDAVP group, intravenous infusion of DDAVP (2.5 ng.kg-1.min-1 for 40 min) and hemorrhage were simultaneously performed. The plasma DDAVP concentration increased progressively to 218 +/- 21.0 pg.ml-1. There was no significant difference, however, between the control and DDAVP groups in the response of AVP, PRA and blood pressure. The results suggested that DDAVP may not affect the release of AVP and renin or blood pressure during hemorrhage.     

Identification and endothelin-induced activation of multiple extracellular signal-regulated kinases in aortic smooth muscle cells.

In order to explore intracellular signaling pathways of the mitogenic action of endothelin (ET), we examined the effect of ET on activities of extracellular signal-regulated kinases (ERKs) in rat aortic smooth muscle cells (SMCs). Treatment of rat aortic SMCs with ET-1 increased kinase activities toward myelin basic protein (MBP). Both 43- and 41-kDa proteins were activated when kinase assays were done in MBP-containing polyacrylamide gels after SDS-PAGE. These proteins were identified as ERK1 and ERK2 with immunoprecipitation and immunoblotting using antipeptide antibodies, respectively. These results indicate that ERKs mediate signal transduction by ET.     

Augmented secretion of brain natriuretic peptide in acute myocardial infarction.

In order to elucidate biosynthesis and secretion of natriuretic peptides in the early phase of acute myocardial infarction (AMI), we measured the plasma level of brain natriuretic peptide (BNP), a novel cardiac hormone secreted from the ventricle, in patients with AMI and compared with that of atrial natriuretic peptide (ANP). The plasma level of BNP increased rapidly (within hours from the onset of AMI) and markedly (greater than 100 times the normal level) as compared to that of ANP. The plasma ANP level correlated with pulmonary capillary wedge pressure (PCWP), whereas the plasma BNP level did not correlate with PCWP but highly correlated inversely with cardiac index. These results indicate that BNP is secreted from the heart much more acutely and prominently than ANP in the early phase of AMI, in association with left ventricular dysfunction.     

Fertirelin and buserelin compared by LH release, milk progesterone and subsequent reproductive performance in dairy cows treated for follicular cysts

This field study compared the efficacy of a single injection of 200 microg fertirelin with that of 20 microg buserelin in shortening the recovery period of 68 laotating Holstein-Friesian cows with ovarian follicular cysts 65 d post partum or later. Differential diagnosis was based not only on palpation per rectum but also on skim milk progesterone profiles (or= 1.0 ng/ml) 1 wk after treatment, was evidenced in 75% of the fertirelin group and 72% of the buserelin group. A 74% conception rate was achieved in fertirelin-treated cows, with a mean interval of 71 d from treatment to conception. In the buserelin-treated cows, 65% conceived and the treatment-to-conception interval was 63 d. Differences were insignificant. At the doses used the two GnRH analogs were deemed equally effective in managing particularly stubborn follicular cysts.