Single nephron glomerular filtration rate ratios of superficial,intercortical and juxtamedullary nephrons in rats during development

Summary In 20, 40 and 60-day-old rats the filtration rate was studied, using Baines modification of Hanssen's Na₄Fe(¹⁴CN)₆ method enabeling the determination of single nephron glomerular filtration rate (SNGFR) ratio between superficial (S), intercortical (I) and juxtamedullary (J) nephrons. The proximal tubule lengths were determined as well. A close correlation was obtained between age and S/I, I/J and S/J of proximal tubule lengths and between age and I/J, S/J¹⁴C-activities of ferrocyanide. Presented findings confirm the data on the increasing role of superficial nephrons in the course of postnatal development of rat.     

我院基于XML异构数据集成的开发应用及研究

基于XML的数据集成，Web Services中间件能够较容易地实现对各数据源的描述以及数据源之间的数据转换，它在应用程序和数据库之间起着接口的作用．本文结合实际医院信息工作，运用VFP9 COM模型，作了有效性的研究及应用，并对标准数据集的二次开发进行了讨论。结果表明，该方法用于医院跨网络平台、跨应用系统、异构信息集成是有效的和易于操作的。     

Functional AMPA/kainate receptors in human embryonic and foetal central nervous system

Here, functional AMPA/kainate receptors in human embryonic (5.5–7.5 gestational weeks) and foetal (8–10 gestational weeks) central nervous system tissue, shown by the cobalt labeling method, are reported. Specific agonist-induced cobalt incorporation was detected in brainstem and spinal cord cells, even in the youngest embryo studied. T-AMPA or kainate, but also vegetal toxins such as L-BOAA or acromelate, induced accumulation of cobalt. In contrast, no labeling was observed after exposure to KCl or NMDA. Cobalt labeled cells were particularly prominent in motor regions of brainstem and spinal cord. Co-application of the diuretic agent cyclothiazide, a desensitization blocker at AMPA receptors, dramatically increased the number of stained cells, which was particularly obvious in sensory regions, suggesting different receptor properties in motor versus sensory regions. This is the first study providing evidence for functional AMPA/kainate receptors, permeable to divalent cations, in brainstem and spinal cord at an early stage of human central nervous system development. Since many developmental processes are influenced by the modulation of cytosolic calcium, exposure at critical stages of embryogenesis to food or drug substances modifying the activity of AMPA/kainate receptors may alter brain development.     

Development of feminine sexual behavior in the rat: Androgenic and temporal influences

The contributions of prenatal and postnatal androgen exposure upon the development of sexual behavior in rats were examined by prenatal treatment of pups with an androgen antagonist (flutamide) and postnatal androgenization or castration. Male and female rats were exposed to the androgen receptor-blocker flutamide (FLU) in utero via prenatal injections to the mother on Days 10 through 22 of gestation. At birth (Day 1) males were castrated. Both males and females were injected with either 100 μg testosterone propionate (TP) or oil on Day 1. In adulthood all gonadectomized animals were tested for the display of feminine sexual behavior (lordosis) in response to a range of estrogen dosages. Prenatal exposure to FLU enhanced lordosis in both sexes when compared to vehicle-treated controls. Postnatal TP treatment decreased lordotic potential as expected. However, in animals given TP postnatally, those receiving prenatal flutamide had higher lordosis quotients than animals receiving vehicle treatment. These data confirm (1) that the development of feminine sexual behavior is inhibited by androgen exposure, (2) that such exposure occurs prenatally, (3) that the potential for feminine behavioral differentiation occurs prenatally as well as postnatally, and (4) that androgen acts perinatally to affect estrogen sensitivity in adulthood.     

Prenatal development of transient receptor potential vanilloid 1-expressing primary sensory projections to sacral autonomic preganglionic neurons

The visceral reflexes of the pelvic organs are mediated by connections between primary afferents innervating the pelvic organs and parasympathetic preganglionic neurons in the intermediolateral column of the sacral spinal cord. The present immunohistochemical study revealed many varicosities expressing transient receptor potential vanilloid 1 (TRPV1) that were closely apposed to the preganglionic neuronal perikarya at embryonic day 16 in mice. Many, but not all, varicosities expressing TRPV1 in the intermediolateral column were also immunopositive for calcitonin gene-related peptide. In contrast, no nerve fibers expressing TRPV1 projected to the sympathetic preganglionic cell column in the lumbar spinal cord in prenatal stages. The results of the present study raised the possibility that the primary afferents transmit signals elicited by the activation of TRPV1 receptors to the sacral parasympathetic preganglionic neurons. Thus, the functional circuit for pelvic spinal reflexes, such as micturition induced by urine influx, might develop in the prenatal stages in mice.     

血浆内皮素与降钙素基因相关肽改变在高血压病中的意义

用特异性放射免疫分析法测定50例原发性高血压（EH）患者和32名正常人的血浆内皮素（ET）和降钙素基因相关肽（CGRP）水平，结果显示：EH患者ET的水平明显高于对照组，且有左室重塑组明显高于无左室重塑组。EH患者的CGRP水平明显低于对照组，有左室重塑组明显低于无左室重塑组。ET／ＣＧＲP比值越大，病情越重，预后越差。提示：循环血中ET增高，CGRP含量不足可能是EH发病及导致左室重塑的重要因素之一。     

Restriction of visual experience to a single orientation affects the organization of orientation columns in cat visual cortex

Summary and Conclusions In six dark reared, 4-weak-old kittens visual experience was restricted to contours of a single orientation, horizontal or vertical, using cylindrical lenses. Subsequently, the deoxyglucose method was used to determine whether these artificial raising conditions had affected the development of orientation columns in the visual cortex. After application of the deoxyglucose pulse one hemifield was stimulated with vertical, the other with horizontal contours. Thus, from interhemispheric comparison, changes in columnar systems corresponding to experienced and inexperienced orientations could be determined. The following results were obtained: (1) Irrespective of the restrictions in visual experience, orientation columns develop in areas 17, 18, 19 and in the visual areas of the posterior suprasylvian sulcus. (2) Within area 17, spacing between columns encoding the same orientations is remarkably regular (1 mm), is not influenced by selective experience and shows only slight interindividual variation. (3) In non-striate areas the spacing of columns is less regular and the spatial frequency of the periodicity is lower. (4) The modifiability of this columnar pattern by selective experience is small within the granular layer of striate cortex but substantial in non-granular layers: Within layer IV columns whose preference corresponds to the experienced orientation are wider and more active than those encoding the orthogonal orientation but the columnar grid remains basically unaltered. Outside layer IV the columnar system is maintained only for columns encoding the experienced orientations. The deprived columns by contrast frequently fail to extend into non-granular layers and remain confined to the vicinity of layer IV. (5) These modifications in the columnar arrangement are more pronounced in striate cortex than in non-striate visual areas and, within the former, more conspicuous in the central than in the peripheral representation of the visual field. It is concluded that within layer IV the blue print for the system of orientation columns is determined by genetic instructions: first order cells in layer IV develop orientation selectivity irrespective of experience whereby the preference for a particular orientation is predetermined by the position in the columnar grid. Dependent on experience is, however, the expansion of the columnar system from layer IV into non-granular layers. It is argued that all distortions following selective rearing can be accounted for by competitive interactions between intracortical pathways, the mechanisms being identical to those established for competitive processes in the domain of ocular dominance columns. It is proposed that such experience dependent modifiability of connections between first and second order cells is a necessary prerequisite for the development of orientation selectivity in cells with large and complex receptive fields.This work has partially been supported by a grant from the Deutsche Forschungsgemeinschaft, SFB 50, A14Dedicated to Prof. D. Ploog on the occasion of his 60th anniversaryResearch Fellow of the Alexander-von Humboldt-Stiftung     

旋转叶轮血泵的发展与展望

主要从结构设计、轴承密封设计、控制系统设计三个方面介绍了旋转叶轮血泵技术的最新发展 ,并对其发展趋势做出了展望。     

职业过劳测验的编制

目的:编制职业过劳测验.方法:将职业过劳测验、艾森克人格问卷简式量表中国版、明尼苏达工作满意度问卷-短式修订版、一般自我效能感量表对162名销售人员进行测量.结果:职业过劳测验包含精疲力竭和焦虑两个因素,它们与人格、工作满意度、自我效能感和销售业绩排名之间存在复杂的关系.结论:职业过劳测验信度、效度较好,适用于实际测量.     

Immunocytochemical localization of cell adhesion molecule L1 in developing rat pyramidal tract

L1 is a representative of a family of carbohydrate neural cell adhesion molecules. The expression of L1 was studied during postnatal development of the rat pyramidal tract by immunohistology using polyclonal antibodies to L1 in spinal cord cervical intumescences. On postnatal day 1 (P1), L1 immunoreactivity was present in the entire dorsal funiculus, consisting of the ascending fasciculus gracilis and fasciculus cuneatus and the descending pyramidal tract. At that time the cervical pyramidal tract contains the first outgrowing corticospinal axons. At P4 both the fasciculus gracilis and the pyramidal tract are immunoreactive whereas the fasciculus cuneatus is negative. At P10 the pyramidal tract is intensely labelled whereas both ascending bundles are negatively stained. In the period between P4 and P10 the pyramidal tract is characterized by a massive outgrowth of corticospinal axons. During pyramidal tract myelination, between P10 and the end of the third postnatal week (P21), L1 immunoreactivity is progressively reduced. These observations suggest that L1 may play a prominent role in outgrowth, fasciculation and the onset of myelination of rat pyramidal tract axons. The differential L1 immunoreactivity of the pyramidal tract and the earlier developing ascending systems in rat dorsal funiculus indicate that this polyclonal antiserum is a useful differentiating marker for outgrowing fibre tracts.