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631.
New P element plasmids containing the organophosphate-degrading gene opd as a dominant selectable marker were tested as transformation vectors in Drosophila melanogaster. One of these vectors was modified by the addition of the D. melanogaster mini-white gene as a comarker. When transformed individuals were identified using paraoxon selection for opd alone, results were similar to those obtained with mini-white. No false positives were recovered, however one strain contained the mini-white gene but inadequate resistance to survive our screening regimen due to a defective Hsp70-opd gene. Results suggest that Hsp70-opd is similar to mini-white for distinguishing transformed individuals but does not require time-consuming individual examination. Due to the mode of action of organophosphorus nerve agents, Hsp70-opd has potential as a selectable marker in numerous animals beside fruit flies. 相似文献
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JD Ramamoorthy S Ramamoorthy VB Mahesh FH Leibach V Ganapathy 《Canadian Metallurgical Quarterly》1995,136(3):924-932
The expression and ligand binding characteristics of sigma-receptors in human placental syncytiotrophoblast and choriocarcinoma cells were investigated using haloperidol as a ligand. Haloperidol bound to purified placental brush border membranes with high affinity; the apparent dissociation constant for the process was about 3 nM. These binding sites were not related to dopamine (D2) and serotonin (5-HT2) receptors nor to serotonin and norepinephrine transporters. The ligands of sigma-receptors [3.g. (+)-3-(3-hydroxyphenyl)N-(1-propyl)piperidine, 1,3-di-(2-tolyl)guanidine, clorgyline, rimcazole, and dexromethorphan] were very potent in competing with haloperidol for the binding sites. The binding sites were detected not only in the brush border membrane, but also in intracellular membranes. The rank order of potency of various sigma-receptor ligands to inhibit haloperidol binding indicated that placental sigma-receptors belong to the sigma 1 subtype. Cocaine and its analog RTI-55 [2 beta-carbomethoxy-3 beta-(4-iodophenyl-) tropane] inhibited the binding of haloperidol to placental membranes with appreciable potency. The steroid hormones, progesterone and testosterone, were also potent inhibitors, and the inhibition constant for progesterone was 0.3 microM, a concentration much smaller than that found in plasma during pregnancy. The inhibition was competitive. beta-Estradiol and a number of other steroids were relatively much weaker inhibitors than progesterone and testosterone. Phenytoin and neuropeptide-Y did not interact with sigma-receptors in placenta. The choriocarcinoma cell line JAR was also found to express sigma-receptors in the plasma membrane as well as in intracellular membranes. The characteristics of the receptors in this cell were qualitatively similar to those of the receptors in normal placenta, including subtype identity and interaction with cocaine and progesterone. Interestingly, however, all sigma-receptor ligands interacted with the receptors in the JAR cell with much higher affinity than with the receptors in normal placenta. It is concluded that the placental syncytiotrophoblast and choriocarcinoma cells express cocaine-sensitive sigma-receptors and that progesterone is most likely an endogenous ligand for these receptors. 相似文献
635.
SC Park FH Weiss RD Siewers WH Neches JR Zuberbuhler CC Lenox 《Canadian Metallurgical Quarterly》1976,54(4):684-688
Three patients developed severe pulmonary venous obstruction following Mustard operation for transposition of the great arteries. Each patient had a soft continuous murmur with distinct diastolic accentuation at the low left sternal border or xiphoid area. Simultaneous recording of intracardiac sound and pressure in one patient showed that the murmur originated at the site of obstruction in the surgically-constructed pulmonary venous atrium. Selective cineangiograms demonstrated the baffle to be the cause of the obstruction. A continuous murmur in a patient following Mustard operation may suggest significant pulmonary venous obstruction. 相似文献
636.
Among 351 patients undergoing pneumonectomy, the mortality was 6%, and when the operation was performed for malignant disease, the mortality was 8.5%. Much of the risk of the operation is associated with the age, physiologic state, and associated diseases which are prevalent in patients who require pneumonectomy. The conduct of the operative procedure itself is of paramount importance since complications clearly increase the mortality. Operative mishaps predispose to postoperative complications, and the addition of postoperative problems to the operative complications combine to bring the mortality to 24%. Careful hemostasis, meticulous technique, fluid and blood replacement, as well as careful preoperative and postoperative management combine to produce an acceptable mortality in this serious procedure. 相似文献
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Uptake of 22Na and 42K into ejaculated boar spermatozoa was measured in vitro. Cells were suspended either in seminal plasma or in a biological salt solution of essentially the same composition as boar seminal plasma. Samples were incubated at 30 degrees C. Correction was made for extracellular space in the centrifuged sperm pellet. This was determined as 22Na-space, which was less (P less than 0.001) than [14C] carboxyinulin space. Large differences were observed among individual ejaculates. The half-time for potassium uptake into the spermatozoa averaged 11.5 min, which is much faster than that for leukocytes or erythrocytes. When the spermatozoa were suspended in the biological salt solution, the initial rate of 42K uptake was significantly decreased. This may be due to disturbances of the protein components of the sperm membrane. The uptake of 22Na into the spermatozoa was slow. Sodium and potassium transport appeared not to be coupled in the 3/2 ratio which has been reported for erythrocyte membranes. The average concentration of sodium was 108 mM in seminal plasma and 26 mM in the spermatozoa (112 mmol/kg water and 38 mmol/kg water, respectively). The corresponding figures for potassium were 26 mM and 51 mM (27 mmol/kg water and 74 mmol/kg water). The random error for a single determination for the various methods used varied between 2.4 and 13.3% of the mean. 相似文献
639.
Epidemiologic data revealed that a low sodium intake might have a favorable influence on blood pressure throughout an individual's lifetime. Sodium restriction was reported to lead to a modest fall in blood pressure in some studies, although a few groups of hypertensive patients experienced a rise in blood pressure. Left ventricular hypertrophy has been demonstrated to be related to cardiovascular morbidity and mortality independent of other risk factors. Dietary salt intake participates in the hypertrophic process independent of other determinants. Thus, 24-hour urinary sodium excretion has been reported to correlate with left ventricular mass independent of levels of arterial pressure. Three different mechanisms may link dietary salt intake to myocardial hypertrophy: the renin-angiotensin-aldosterone system, the sympathetic nervous system, and fluid volume homeostasis. Whether salt restriction reduces cardiovascular structural damage independent of arterial pressure has not been determined. 相似文献
640.
Adult rat hippocampus-derived neural progenitor cells (AHPC) show considerable adaptability following grafting to several brain regions. To evaluate the plasticity of AHPCs within the optic retina, retrovirally engineered AHPCs were grafted into the vitreous cavity of the adult and newborn rat eye. Within the adult eye, AHPCs formed a uniform nondisruptive lamina in intimate contact with the inner limiting membrane. Within 4 weeks of grafting to the developing eye, the AHPCs were well integrated into the retina and adopted the morphologies and positions of Müller, amacrine, bipolar, horizontal, photoreceptor, and astroglial cells. Although the cells expressed neuronal or glial markers, none acquired end-stage markers unique to retinal neurons. This suggests that the adult-derived stem cells can adapt to a wide variety of heterologous environments and express some but not all features of retinal cells when exposed to the cues present late in retinal development. 相似文献