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71.
Mutations in PAX6/Pax6 lead to a variety of ocular anomalies in humans and mice. The aim of the study was to characterise the ocular abnormalities caused by the missense Pax6Leca4 mutation and compare them to published observations on Pax6 alleles that are functionally equivalent to Pax6 null alleles (such as Pax6Sey and Pax6Sey-Neu) and human inherited eye diseases. Ocular features of homozygous Pax6Leca4/Leca4 and heterozygous Pax6Leca4/+ embryos at E12.5-E18.5, heterozygous Pax6Leca4/+ young mice at P18 and heterozygous Pax6Leca4/+ adults at 12 weeks were analysed histologically with their wild-type Pax6+/+ littermates. Homozygous Pax6Leca4/Leca4 fetuses died perinatally with no eyes although an optic cup rudiment with pigmented cells developed. Pax6Leca4/+ mice were microphthalmic and a range of other severe ocular phenotypes affected both the anterior and the posterior segments. In contrast to Pax6+/−, the Pax6Leca4/+ eyes had no goblet cells in the corneal epithelium, the iris was not hypoplastic and there was no lens-corneal epithelial plug. However, microphthalmia was more severe, corneal vascularisation occurred earlier (during fetal stages), pigmented cells were present in the vitreous and corneal stroma and the ciliary body was malformed or abnormal. These results show that, although Pax6Leca4/+ lacked some eye abnormalities commonly seen in Pax6Sey/+ and Pax6Sey-Neu/+ eyes, in most respects their eyes were more severely affected. These differences probably reflect both differences between the Pax6Leca4 and the Pax6Sey-Neu mutations and differences in modifier gene expression in different genetic backgrounds. The presence of pigmented cells in the cornea is a novel observation. Some Pax6Leca4/+ ocular abnormalities were similar to those present in human Peters' anomaly and persistent hyperplastic primary vitreous (PHPV) so Pax6Leca4/+ mice provide a useful model for some inherited eye diseases.  相似文献   
72.
目的 观察经祛瘀解毒颗粒治疗后子宫内膜异位症(endometriosis,EM)患者卵泡液对小鼠胚胎发育的影响。 方法 在常规培养液中分别加入治疗组EM患者卵泡液(祛瘀解毒颗粒)、对照组EM患者卵泡液及空白组(因输卵管因素行体外受精-胚胎移植)患者卵泡液,20只小鼠超排卵共收集189枚2 细胞鼠胚分别放入各组培养液进行培养,其中治疗组培养液70枚,对照组培养液60枚,空白组培养液59枚,观察和检测2 细胞鼠胚在体外发育至8细胞期、桑葚胚期和囊胚期的比率,及早期鼠胚优质胚胎数目和优质胚胎率。 结果 治疗组培养液有53枚鼠胚(75.71%,53/70)发育到8细胞期,48枚(68.57%,48/70)发育到桑葚胚期,45枚(64.28%,45/70)发育到囊胚期,与对照组培养液(56.67%,34/60、48.33%,29/60、35.00%,21/60)比较差异有统计学意义(P<0.05)。治疗组有61枚优质胚胎(87.14%),对照组为44枚(73.33%),两组比较差异有统计学意义(P<0.05)。 结论 EM患者卵泡液对早期鼠胚存在毒性作用,经祛瘀解毒颗粒治疗后EM患者卵泡液可提高早期鼠胚培养质量。  相似文献   
73.
通过对口腔崩解片的特点及主要制备工艺的分析,结合当前中成药工业的现状及具体实际,认为口腔崩解片可以应用于中成药制剂的开发。  相似文献   
74.
Over the past several years, increased interest in preventing youth problems and promoting healthy youth development has led youth and family practitioners, policy makers, and researchers to develop a wide range of approaches based on various theoretical frameworks. Although the growth in guiding frameworks has led to more complex models and a greater diversity in the options available to scholars and practitioners, the lack of an integrative conceptual scheme and consistent terminology has led to some confusion in the field. Here, we provide an overview of three approaches to youth development and problem prevention, critically examine their strengths and weaknesses, and offer some elaborations to help clarify, extend, and integrate the models. We conclude by discussing some general implications for researchers, practitioners, and policy makers.  相似文献   
75.
优化结构提高效率实现医院可持续发展   总被引:1,自引:0,他引:1  
随着我国医疗保险的大范围实施,医院只有优化结构、提高效率,才能实现可持续发展。以财务管理为出发点,分析了目前大型医院所面临的现行国家医疗政策、外部环境以及内部约束等条件,提出强化医疗业务管理.建立科学合理的医疗业绩考核指标体系:平均住院天数、出院人数、手术量、门诊预约率,促进医疗业绩的提高:强化财务管理,建立现代医院财务考核指标体系:结余率、人均结余、病人人均费用,对各个科室的经济效益进行考核,促进医院经济效益的提高。  相似文献   
76.
Metabolism is one of the major determinants for age-related changes in susceptibility to chemicals. Aldehydes are highly reactive molecules present in the environment that also can be produced during biotransformation of xenobiotics and endogenous metabolism. Although the lung is a major target for aldehyde toxicity, early development of aldehyde dehydrogenases (ALDHs) in lung has been poorly studied. The expression of ALDH in liver and lung across ages (postnatal day 1, 8, 22, and 60) was investigated in Wistar-Han rats. In adult, the majority of hepatic ALDH activity was found in mitochondria, while cytosolic ALDH activity was the highest contributor in lung. Total aldehyde oxidation capability in liver increases with age, but stays constant in lung. These overall developmental profiles of ALDH expression in a tissue appear to be determined by the different composition of ALDH isoforms within the tissue and their independent temporal and tissue-specific development. ALDH2 showed the most notable tissue-specific development. Hepatic ALDH2 was increased with age, while the pulmonary form did not. ALDH1 was at its maximum value at postnatal day 1 (PND1) and decreased thereafter both in liver and lung. ALDH3 increased with age in liver and lung, although ALDH3A1 was only detectible in lung. Collectively, the present study indicates that, in the case of aldehyde exposure, the in vivo responses would be tissue and age dependent.  相似文献   
77.
Abstract Over the past 15–20 years, research has progressively focused on the mucosal T cell as the central factor in the initiation of physiological or pathological changes, first in the growth and maturation of the early (postnatal) intestine, and second in adult-type enteropathies resulting from sensitivity to either food or pathogen-derived antigens. T cell-mediated events may be measured, for example, in terms of specific immunopathologic patterns of change and injury, such as type 1 (lymphocyte infiltration), type 2 (crypt hyperplasia) and type 3 (flat-destructive), which can be recognized and quantitated microscopically; by determination of lymphocyte reactivity through secretion of interleukin-2 receptors (IL-2R) into plasma or expression by mucosal lymphocytes; by quantitation of lymphocyte subsets emigrating into inflamed tissues by immunoperoxidase-labelled monoclonal antibodies; or by the determination of T cell receptor polymorphisms. Alterations in intestinal growth, structure and function at weaning are likely to be T cell-mediated as they are analogous to the same type 1/2 lesions that reflect modulation of adult mucosal architecture in food and parasite-induced hypersensitivity reactions. Enteropathies associated with HIV infection and T cell deficiency display a milder degree of villous flattening and impaired crypt hyperplasia than that typical of gluten-sensitivity, suggesting a reversion to lesser degrees of mucosal pathology (type 1/2). Clearly more information will accrue; meanwhile the remarks in this brief survey should provide a firm basis whereby clinician and scientist can meet, and together recognize and further dissect the modulatory effect of T lymphocytes on mucosal structure and function.  相似文献   
78.
通过半年对35名7~12岁轻度碘缺乏病儿童进行补碘,并与同龄、同地的正常儿童和缺碘未补碘儿童进行比较,以观察补碘对儿童脑功能及生长发育的影响。结果发现:①补碘可使儿童碘营养状况恢复正常,尿碘值由(83.2±3.5)μg/L上升到(162.2±1.6)μg/L,血清T4、FT4I和rT3:也与正常儿童一致而与未补碘儿童有显著性差异(P<0.05).②轻度碘缺乏病儿童智商低于正常儿童(P<0.01),补碘在一定程度上改善其智商水平。③轻度碘缺乏病及补碘未能明显影响儿童的生长发育,可能与儿童总营养水平较差有关。  相似文献   
79.
Anatomical and physiological segregation of neurons into ON (brightening detector) and OFF (darkening detector) channels in the retina and subsequent visual system ensure the high sensitivity required for contrast detection and spatial discrimination. This segregation is finest at the visual axis. Neurochemically, ON and OFF ganglion cells at the visual axis seem to be distinguished by different inhibitory transmitters but not excitatory transmitters. Microiontophoretic studies of inhibitory transmitters on the retinal ganglion cells in kittens and adult cats suggest that this neurochemical distinction is poor in immature ganglion cells at the visual axis. Initially both ON and OFF cells seem to be supplied by GABAergic, glycinergic, and catecholaminergic amacrine cells, but in adults, ON cells remain supplied only by GABAergic amacrines, while OFF cells are supplied by glycinergic amacrines. Postnatal elimination of multiple inputs and strengthening of the appropriate inputs, as seen in the central nervous system, also seem to occur at the retinal neurotransmitter synapses during development.  相似文献   
80.
The development of intrinsic, N-methyl-D-aspartate (NMDA) receptor-mediated voltage oscillations and their dependence on co-activation of 5-hydroxytryptamine (5HT) receptors was explored in motor neurons of late embryonic and early larval Xenopus laevis. Under tetrodotoxin, 100 μM NMDA elicited a membrane depolarization of around 20 mV, but did not lead to voltage oscillations. However, following the addition of 2–5 μM 5HT, oscillations were observed in 12% of embryonic and 70% of larval motor neurons. The voltage oscillations depended upon co-activation of NMDA and 5HT receptors since they were curtailed by selectively blocking NMDA receptors with D-2-amino-5-phosphonovaleric acid (APV) or by excluding Mg2+ from the experimental saline. 5HT applied in the absence of NMDA also failed to elicit oscillations. Oscillations could be induced by the non-selective 5HT1a receptor agonist, 5-carboxamidotryptamine (5CT) and both 5HT- and 5CT-induced oscillations were abolished by pindobind-5HT1, a selective 5HT1a receptor antagonist. To test whether 5HT enables voltage oscillations by modulating the voltage-dependent block of NMDA channels by Mg2+, membrane conductance was monitored under tetrodotoxin. Although 5HT caused membrane hyperpolarization of 4–8 mV, there was little detectable change in conductance. NMDA application caused an approximate 20 mV depolarization and an ‘apparent’ decrease in conductance, presumably due to the conductance pulse bringing the membrane into a voltage region where Mg2+ blocks the NMDA ionophore. 5HT further decreased conductance, which we propose is due to its enhancement of the voltage-dependent Mg2+ block. When the membrane potential was depolarized by ~20 mV via depolarizing current injection (to mimic the NMDA-induced depolarization), 5HT increased rather than decreased membrane conductance. Furthermore, 5HT did not affect the increase in membrane conductance following NMDA applications in zero Mg2+ saline. The results suggest that intrinsic, NMDA receptor-mediated voltage oscillations develop in a brief period after hatching, and that they depend upon the co-activation of 5HT and NMDA receptors. The enabling function of 5HT may involve the facilitation of the voltage-dependent block of the NMDA ionophore by Mg2+ through activation of receptors with 5HT1a-like pharmacology.  相似文献   
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