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131.
The ratio of the lengths of the second and fourth finger (2D∶4D) has been described as reflecting the degree of prenatal androgen exposure in humans. 2D∶4D is smaller for males than females and is associated with traits such as left-handedness, physical aggression, attention-deficit-hyperactivity disorder and a genetic polymorphism of the androgen receptor. All of these traits are known to be correlated to the vulnerability for alcohol dependency. We therefore hypothesized low 2D∶4D in patients with alcohol dependency. In the present study on 131 patients suffering from alcohol dependency and 185 healthy volunteers, we found that alcohol dependent patients had smaller 2D∶4D ratios compared to controls with preserved sexual dimorphism but with reduced right-left differences. The detection of alcohol dependency based on 2D∶4D ratios was most accurate using the right hand of males (ROC-analysis: AUC 0.725, sensitivity 0.667, specificity 0.723). These findings provide novel insights into the role of prenatal androgen exposure in the development of alcohol dependency and for the use of 2D∶4D as a possible trait marker in identifying patients with alcohol dependency.  相似文献   
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Abstract. 1. Adult males of the two-spot ladybird beetle, Adalia bipunctata , did not show a functional response to increase in aphid abundance and consumed markedly fewer aphids than do the females.
2. At high densities of prey, females spent more time in area-restricted search than when prey was scarce. Males were always less active than females and they did not respond to an increase in prey abundance by a change in searching behaviour.
3. After a brief encounter with a female, a male showed area-restricted searching behaviour. This behaviour occurred in response to encountering a female's elytra and in particular to a chloroform-soluble component (sex pheromone) present on or in the elytra.
4. Males needed to encounter a female in order to respond to her presence, which indicated the pheromone is a contact pheromone.
5. The searching behaviour of males appeared to be mainly directed towards locating females; that of females towards locating aphids. This difference between the sexes should be taken into account when quantifying the predatory response of ladybirds to aphid abundance in the field.  相似文献   
135.
The effect of microiontophoretically administered beta-endorphin on the activity of 62 cortical and hippocampal neurones was studied in acute experiments on 14 rats. The effectiveness of beta-endorphin was first of all verified in the isolated guinea pig ileum, the mouse was deferens and in a study if its analgetic and catatonic effect in rats. Beta-endorphin only mildly depressed the spontaneous activity of cortical neurones, but markedly inhibited the activity stimulated by the microiontophoretic administration of glutamate. In the hippocampus, beta-endorphin stimulated the activity of all the studied neurones when only low ejection currents were used and activation persisted for 1-4 min after terminating administration. With higher ejection currents, the discharge frequency rose enormously and not even GABA blocked this effect. The excitatory effect of beta-endorphin on the hippocampal neurones may possibly be the basis of the epileptogenic action of this substance.  相似文献   
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A procedure is described for the trapping and identification of hydrogen selenide and methyl selenol ( CH3SeH ). The volatile selenols were generated by reducing selenious acid or dimethyldiselenide with Zn dust and hydrochloric acid under a stream of nitrogen and passing into a trapping solution composed of 50 mM 1-fluoro-2,4-dinitrobenzene plus 83 mM sodium bicarbonate in 67% dimethylformamide:33% water. The selenols react rapidly to form stable dinitrophenyl (DNP) selenoethers that can be extracted into benzene; these are easily identified by TLC, HPLC, or mass spectrometry. Hydrogen selenide is trapped in 90-99% yield, primarily as the di-DNP- monoselenide with a trace of di-DNP- diselenide .  相似文献   
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SphK (sphingosine kinase) is the major source of the bioactive lipid and GPCR (G-protein-coupled receptor) agonist S1P (sphingosine 1-phosphate). S1P promotes cell growth, survival and migration, and is a key regulator of lymphocyte trafficking. Inhibition of S1P signalling has been proposed as a strategy for treatment of inflammatory diseases and cancer. In the present paper we describe the discovery and characterization of PF-543, a novel cell-permeant inhibitor of SphK1. PF-543 inhibits SphK1 with a K(i) of 3.6 nM, is sphingosine-competitive and is more than 100-fold selective for SphK1 over the SphK2 isoform. In 1483 head and neck carcinoma cells, which are characterized by high levels of SphK1 expression and an unusually high rate of S1P production, PF-543 decreased the level of endogenous S1P 10-fold with a proportional increase in the level of sphingosine. In contrast with past reports that show that the growth of many cancer cell lines is SphK1-dependent, specific inhibition of SphK1 had no effect on the proliferation and survival of 1483 cells, despite a dramatic change in the cellular S1P/sphingosine ratio. PF-543 was effective as a potent inhibitor of S1P formation in whole blood, indicating that the SphK1 isoform of sphingosine kinase is the major source of S1P in human blood. PF-543 is the most potent inhibitor of SphK1 described to date and it will be useful for dissecting specific roles of SphK1-driven S1P signalling.  相似文献   
138.
We report an optical and EPR spectral study of three hemoglobins, Hb I, II, and III, from the gill of the clam Lucina pectinata. Hemoglobin I reacts much more avidly with hydrogen sulfide than do Hbs II and III. The proximal ligand to the heme iron of each hemoglobin is histidyl imidazole. The acid/alkaline transition of ferric Hb I occurs with pK 9.6; those of ferric Hbs II and III with pK 6.6 and 5.9, respectively. At their acid limits each ferric hemoglobin exists as aquoferric hemoglobin. Broadening of the g = 6 resonance suggests that the bound water enjoys great positional freedom. Ferric Hb I, at the alkaline limit (pH 11), exists as ferric hemoglobin hydroxide. Ferric Hbs II and III, at their alkaline limit (pH 7.5), each exist as equal mixtures of two species. The low spin species with optical maxima near 541 and 576 nm and g values of 2.61, 2.20, and 1.82, are identified as ferric hemoglobin hydroxide. The high spin species, with optical maxima near 486 and 603 nm and g values of 6.71, 5.87, and 5.06, resemble Dicrocoelium hemoglobin and hemoglobin MSaskatoon. Here we show that Hbs II and III resemble hemoglobin MSaskatoon in which a distal tyrosinate oxygen ligated to the ferric heme iron at alkaline pH is displaced by water at acid pH. The H2S product of ferric Hb I is identified as ferric hemoglobin sulfide.  相似文献   
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Human chromosome 21 has been analyzed by pulsed-field gel electrophoresis using somatic cell hybrids containing limited regions of the chromosome and greater than 60 unique sequence probes. Thirty-three independent NotI fragments have been identified, totalling 43 million bp. This must account for essentially the entire long arm, and therefore gaps remaining in the map must be small. The extent of the pulsed-field map has allowed the direct correlation of the physical map with the cytogenetic map: translocation breakpoints can be unambiguously positioned along the long arm and the distances between them measured in base pairs. Three breakpoints have been identified, providing physical confirmation of cytogenetic landmarks. Information on sequence organization has been obtained: (i) 60% of the unique sequence probes are located within 11 physical linkage groups which can be contained in only 20% of the long arm; (ii) 9/21 genes are clustered within 4%; (iii) translocation breakpoints appear to occur within CpG island regions, making their identification difficult by pulsed-field techniques. This analysis contributes to the human genome mapping effort, and provides information to guide the rapid investigation of the biology of chromosome 21.  相似文献   
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