Brain mapping in animals and humans

The discovery of the Mothers against dpp (Mad) gene in Drosophila has opened a window on an entirely unique signalling pathway that functions to mediate responses to the tumour growth factor beta (TGF beta) superfamily. This pathway, which is comprised of a family of proteins related to Mad, acts to convey signals directly from TGF beta receptors to the nucleus and is implicated in the pathogenesis of human diseases.     

Geographic distribution and clinical description of leishmaniasis cases in Peru

Asymmetric acetylcholinesterase (AChE) is anchored to the basal lamina (BL) of cholinergic synapses via its collagenic tail, yet the complement of matrix receptors involved in its attachment remains unknown. The development of a novel overlay technique has allowed us to identify two Torpedo BL components that bind asymmetric AChE: a polypeptide of approximately 140 kDa and a doublet of 195-215 kDa. These were found to stain metachromatically with Coomassie blue R-250, were solubilized by acetic acid, and were sensitive to collagenase treatment. Upon sequence analysis, the 140 kDa polypeptide yielded a characteristic collagenous motif. Another AChE-binding BL constituent, identified by overlay, corresponded to a heparan sulfate proteoglycan. Lastly, we established that this proteoglycan, but not the collagenous proteins, interacted with at least one heparin binding domain of the collagenic tail of AChE. Our results indicate that at least two BL receptors are likely to exist for asymmetric AChE in Torpedo electric organ.     

Patterns of expression for the mRNA corresponding to the four isoforms of phospholipase Cbeta in mouse brain

Ligand binding to neurotransmitter and hormone receptors which couple to the Gq subclass of GTP-binding protein leads to the activation of phospholipase Cbeta (PLCbeta) which hydrolyses phosphatidyl-inositol 4,5-bisphosphate, yielding a pair of second messengers, diacylglycerol and inositol 1,4,5-trisphosphate (IP3). The expression of PLCbeta1-4 mRNAs was comparatively examined by in situ hybridization in the mouse brain. In adults, PLCbeta1 mRNA was expressed predominantly in the telencephalon, including the cerebral cortex, hippocampus, amygdala, lateral septum and olfactory bulb, with little expression in most thalamic nuclei. PLCbeta2 mRNA was distributed in the white matter, suggesting its expression in non-neuronal cells, most likely oligodendrocytes. PLCbeta3 mRNA was specifically expressed in cerebellar Purkinje cells. The highest levels of PLCbeta4 mRNA were detected in Purkinje cells. High levels of PLCbeta4 mRNA were also found in the thalamus and medial septum, whereas weak signals were detected in most telencephalic regions, thus showing an expression pattern almost reciprocal to that of PLCbeta1 mRNA. During development, such characteristic regional expression of PLCbeta1 and PLCbeta4 were observed starting in late foetal stages, while specific expression of PLCbeta2 and PLCbeta3 appeared in early postnatal stages. We conclude that despite the existence of four PLCbeta isoforms, only one or two of them is expressed in individual neurons and glial cells. The distinct expression of PLCbetas provides a molecular basis for analysing the nature of the specific signal transduction pathway leading to the production of diacylglycerol and IP3 in distinct cell types and in different regions of the brain.     

RP-HPLC binding domains of proteins

Procedures have been developed to identify the chromatographic binding domains of horse heart cytochrome c (Cyt c) and bovine growth hormone (bGH) during their interaction with reversed-phase sorbent materials. The procedure involves adsorption of the protein solute to the chromatographic sorbent, followed by proteolytic cleavage. Comparison of the proteolytic map obtained for Cyt c and bGH in free solution with the corresponding map obtained when these proteins are adsorbed to the chromatographic sorbent revealed significant differences in the digestion pattern. Following characterization of the peptides generated in both maps, the results indicated that specific regions on the surface of both Cyt c and bGH are inaccessible to tryptic cleavage when adsorbed to the hydrophobic surface of both a C-4 and a C-18 sorbent. Based on the assumption that the region of the protein surface that is in contact with the sorbent remains intact and bound to the sorbent during the digestion step, while the protein surface that is exposed to the solvent is accessible to proteolysis, the regions that were inaccessible to tryptic digestion were found to correspond to hydrophobic domains on the protein surface. These results also suggest that the three-dimensional structures of these proteins remain largely intact upon adsorption to the hydrophobic surface.     

Non-transferrin iron uptake by trophoblast cells in culture. Significance of a NADH-dependent ferrireductase

BACKGROUND: Glucocorticoids have been linked to self-administration of a wide range of drugs in animals and are increased endogenously by chronic nicotine intake. Corticosteroids have also been shown to regulate nicotine receptor sensitivity and to be involved in behavioral sensitization to nicotine. METHODS: Cortisol levels and cortisol suppression in response to dexamethasone were measured in a sample of smokers participating in a smoking cessation treatment trial. RESULTS: Cortisol levels dropped significantly during the early quitting process (2 weeks post-quit) and returned to a level below baseline 1 month post-quit. The magnitude of the initial drop in cortisol was strongly related to post-quit distress and marginally predictive of abstinence. Neither baseline nor post-quit changes in percent cortisol suppression after dexamethasone were related to abstinence success or withdrawal distress. CONCLUSIONS: Withdrawal from cigarette smoking is marked by a reduction in cortisol levels that appears to be related to the degree of distress experienced during the early quitting period. Further work is needed to determine whether withdrawal-related cortisol changes or distress are predictive of abstinence success.     

Radiation doses in the population of the coastal area of the Kakhovsk Water Reservoir

Central and cerebral hemodynamics was studied using echocardiography and transcranial dopplerography in 200 poststroke patients over 60 in the course of 5-year follow-up. It was established that cardiac hypodynamic syndrome, i.e. continuous or paroxysmal fall of minute blood volume below 3 l, is the most significant contributing factor in the onset of cerebral ischemia. Drugs are recommended for prevention of ischemic stroke. Those lowering cardiac hemodynamic reserve should be excluded in patients at high risk of acute failure of cerebral circulation.     

钛合金叶片隔热烘漆的研制

以双酚A型环氧树脂为主要成膜物质,以氮化硼为功能填料,以丁醇醚化脲醛树脂为固化剂,并添加己二酸聚酯弹性体树脂改善其柔韧性、提高涂膜的机械性能,最终得到附着力强、耐热性好、隔热作用明显的飞机发动机叶片用防护涂料.     

遗传算法理论及其应用研究进展

首先阐述遗传算法的原理和求解问题的一般过程;然后讨论了近年来从遗传算子、控制参数等方面对遗传算法的改进,并对遗传算法在计算机科学与人工智能、自动控制以及组合优化等领域的应用进行陈述;最后评述了遗传算法未来的研究方向和主要研究内容。     

Progress and recent trend in MILD combustion

Moderate or intense low oxygen dilution(MILD)combustion plays a significant role in the mitigation of combustion-generated pollutants and greenhouse gases whilst meeting thermal efficiency needs.However,due to the lack of the fundamental knowledge on this combustion,there is a misconception that MILD combustion should be established by high preheating of the air,which has limited its application.Our research and development on this combustion has been performed for several years. We have found that the requ...