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161.
Schistosoma mansoni: serotonin uptake and its drug inhibition 总被引:2,自引:0,他引:2
5-Hydroxytryptamine (serotonin) uptake by male and female Schistosoma mansoni was studied in vitro. Initial uptake was determined during the first 2 min of incubation with the indoleamine. There were two types of uptake: a saturable component that is apparent at low concentrations of serotonin, and a passive component that predominates at high concentrations. Female S. mansoni take up more 5-hydroxytryptamine per milligram protein than do the males. Studies on the distribution of 5-hydroxytryptamine taken up by the parasites show that a large proportion of the indoleamine is in the tegument. The female tegument had a greater proportion of the 5-hydroxytryptamine taken up than did the male tegument. The evidence indicated that 5-hydroxytryptamine associated with tegument represented the passive uptake while uptake in the main parasite body was both active and passive. Compounds that were shown to inhibit 5-hydroxytryptamine uptake include methylclonazepam, metergoline, imipramine, and ouabain. Maximal inhibition by these compounds ranged from 50 to 60%. Inhibition appeared to be confined to the saturable uptake component of the body fraction. 相似文献
162.
163.
Detection of Escherichia coli in blood using flow cytometry 总被引:3,自引:0,他引:3
A rapid method for the detection of Escherichia coli in blood has been developed. The method employs blood cell lysis, staining of bacteria with ethidium bromide, and detection of stained bacteria using flow cytometry. The detection protocol requires less than 2 h sample handling time and is not dependent on bacterial growth. This method has been applied to human donor blood specimens seeded with various E. coli concentrations and to two rabbit model systems. Bacterial detection is evident from the in vitro human blood studies at levels of 10 E. coli/ml and from in vivo rabbit model studies at less than 100 E. coli/ml. 相似文献
164.
Genetic differences in response to pulmonary cytochrome P-450 inducers and oxygen toxicity 总被引:1,自引:0,他引:1
Mansour H.; Levacher M.; Azoulay-Dupuis E.; Moreau J.; Marquetty C.; Gougerot-Pocidalo M. A. 《Journal of applied physiology》1988,64(4):1376-1381
The effects of cytochrome P-450 inducers on O2 toxicity were studied in mice. We first examined three cytochrome P-450 inducers, which differ by their specific tissue affinity: phenobarbital sodium (PB), essentially active in the liver, and 3-methylcholanthrene (3-MC) and beta-naphthoflavone (BNF), which are also active in the lung. Both BNF and 3-MC increased the survival rate and significantly decreased pulmonary edema (pulmonary water and wet-to-dry weight ratio) in C57BL/6J mice exposed to hyperoxia (O2 greater than or equal to 95%), whereas PB had no protective effect. In the second part of this study, we compared the action of BNF in two strains of mice. In one (C57BL/6J), cytochrome P-450 can be induced by aromatic hydrocarbons, whereas in the other (DBA/2J) cytochrome P-450 is not inducible by these compounds. Protection against O2 toxicity was assessed in terms of lethality and pulmonary edema and of lung lipid peroxidation (assessed by measuring malondialdehyde). BNF only protected against O2 toxicity in the inducible strain. This protective effect of BNF on O2 toxicity in C57BL/6J mice was associated mainly with a large increase in the components of the cytochrome P-450 system (cytochrome P-450 and cytochrome b5) in the lung. The activity of pulmonary superoxide dismutase was also slightly increased, but the enhancement was not statistically significant. In contrast, in DBA/2J mice neither the components of the cytochrome P-450 system nor the activity of superoxide dismutase showed any increase.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
165.
166.
Phylogeography of Walton’s Mudskipper,Periophthalmus waltoni Koumans, 1941 (Perciformes: Gobiidae), from the Persian Gulf and Gulf of Oman 总被引:1,自引:0,他引:1
Mehdi Ghanbarifardi Mansour Aliabadian Hamid Reza Esmaeili 《Zoology in the Middle East.》2018,64(3):207-218
Mudskippers are amphibious air breathing fish with terrestrial adaptations in contrast to entirely aquatic fish. They are adapted to living on mudflats and show morphological, physiological, and behavioural features that could affect their phylogeny and phylogeography. A comparative genetic analysis was carried out on 100 specimens of the mudskipper Periophthalmus waltoni Koumans, 1941 from eight different sites along the coast of the Persian Gulf and Gulf of Oman. Phylogeographic inference based on two mitochondrial markers (Cyt b and D-loop) suggests that P. waltoni populations are divided into two well-divergent clades western and eastern. This is likely related to the geohydrological history of the area during the last Pleistocene glaciations. The regional phylogeographies are apparently also influenced by ecological and geographical barriers such as salinity, water current, and the geographic position of the Strait of Hormuz. 相似文献
167.
Inhibition of a signaling pathway in cardiac muscle cells by active mitogen-activated protein kinase kinase. 总被引:4,自引:0,他引:4
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J Thorburn M Carlson S J Mansour K R Chien N G Ahn A Thorburn 《Molecular biology of the cell》1995,6(11):1479-1490
Signaling via the Ras pathway involves sequential activation of Ras, Raf-1, mitogen-activated protein kinase kinase (MKK), and the extracellular signal-regulated (ERK) group of mitogen-activated protein (MAP) kinases. Expression from the c-Fos, atrial natriuretic factor (ANF), and myosin light chain-2 (MLC-2) promoters during phenylephrine-induced cardiac muscle cell hypertrophy requires activation of this pathway. Furthermore, constitutively active Ras or Raf-1 can mimic the action of phenylephrine in inducing expression from these promoters. In this study, we tested whether constitutively active MKK, the molecule immediately downstream of Raf, was sufficient to induce expression. Expression of constitutively active MKK induce ERK2 kinase activity and caused expression from the c-Fos promoter, but did not significantly activate expression of reporter genes under the control of either the ANF or MLC-2 promoters. Expression of CL100, a phosphatase that inactivates ERKs, prevented expression from all of the promoters. Taken together, these data suggest that ERK activation is required for expression from the Fos, ANF, and MLC-2 promoters but MKK and ERK activation is sufficient for expression only from the Fos promoter. Constitutively active MKK synergized with phenylephrine to increase expression from a c-Fos- or an AP1-driven reporter. However, active MKK inhibited phenylephrine- and Raf-1-induced expression from the ANF and MLC-2 promoters. A DNA sequence in the MLC-2 promoter that is a target for inhibition by active MKK, but not CL100, was mapped to a previously characterized DNA element (HF1) that is responsible for cardiac specificity. Thus, activation of cardiac gene expression during phenylephrine-induced hypertrophy requires ERK activation but constitutive activation by MKK can inhibit expression by targeting a DNA element that controls the cardiac specificity of gene expression. 相似文献
168.
Alfred Mansour Larry P. Taylor Jeffrey L. Fine Robert C. Thompson Mary T. Hoversten Henry I. Mosberg Stanley J. Watson Huda Akil 《Journal of neurochemistry》1997,68(1):344-353
Abstract: Structural elements of the rat μ-opioid receptor important in ligand receptor binding and selectivity were examined using a site-directed mutagenesis approach. Five single amino acid mutations were made, three that altered conserved residues in the μ, δ, and κ receptors (Asn150 to Ala, His297 to Ala, and Tyr326 to Phe) and two designed to test for μ/δ selectivity (Ile198 to Val and Val202 to Ile). Mutation of His297 in transmembrane domain 6 (TM6) resulted in no detectable binding with [3 H]DAMGO (3 H-labeled d -Ala2 , N -Me-Phe4 ,Gly-ol5 -enkephalin), [3 H]bremazocine, or [3 H]ethylketocyclazocine. Mutation of Asn150 in TM3 produces a three- to 20-fold increase in affinity for the opioid agonists morphine, DAMGO, fentanyl, β-endorphin1–31 , JOM-13, deltorphin II, dynorphin1–13 , and U50,488, with no change in the binding of antagonists such as naloxone, naltrexone, naltrindole, and nor-binaltorphamine. In contrast, the Tyr326 mutation in TM7 resulted in a decreased affinity for a wide spectrum of μ, δ, and κ agonists and antagonists. Altering Val202 to Ile in TM4 produced no change on ligand affinity, but Ile198 to Val resulted in a four- to fivefold decreased affinity for the μ agonists morphine and DAMGO, with no change in the binding affinities of κ and δ ligands. 相似文献
169.
Toxicity of crude extracellular products of Aeromonas hydrophila in tilapia, Tilapianilotica 总被引:1,自引:0,他引:1
Extracellular products (ECP) secreted from Aeromonas hydrophila with haemolytic andproteolytic activity were studied with respect to temperature and time of incubation as well as thelethal toxicity on tilapia, Tilapia nilotica . The highest production of the haemolysin productwas achieved when Aer. hydrophila was grown at 35°C for 30 h. Tilapia erythrocytewas found to be more susceptible than sheep erythrocyte for determining the haemolytic activity.The haemolytic activity against tilapia erythrocyte was completely inactivated after heating theECP at 60°C for 10 min or 55°C for 15 min. The proteolytic activity was maximized whenthe bacterium was grown at 30°C for 36 h. Complete inactivation of the protease enzyme wasperformed after heating the ECP at 80°C for 10 min or 70°C for 15 min. Aeromonashydrophila was found to produce haemolytic and proteolytic exotoxin lethal to tilapia (LD50 2·1 × 104 cell/fish), as well as heat stable unknown virulent factors thatwere responsible for 20% mortality. The lethality of ECP was decreased by heating andcompletely inactivated by boiling at 100°C for 10 min. 相似文献
170.
Mohamed A. Metwally Jasmin Jakupovic Mansour I. Youns Ferdinand Bohlmann 《Phytochemistry》1985,24(5):1103-1104
The aerial parts of Artemisia judaica afforded in addition to known compounds a hydroperoxide corresponding to vulgarin as well as an isomer of the latter. The configurations of these lactones have been established by NOE difference spectroscopy. 相似文献