两种系膜增殖性肾炎大鼠模型的建立比较

目的　探讨快速建立系膜增殖性肾炎大鼠模型的方法。方法　 30只SD大鼠随机分 3组。正常对照组 ;葡萄球菌内毒素 (SEB)静脉注射 ,牛血清白蛋白 (BSA)隔日口服及免疫佐剂皮下注射组 ;在第二组基础上加作肝左叶切除组。 14周后分别作尿蛋白 ,IGA免疫荧光及病理组织检查。结果　肝左叶切除组蛋白尿出现的时间早于非肝切除组 ,但两组在 14周后蛋白尿定量无明显统计学差异 (P >0 0 5 ) ,对照组尿蛋白定性始终均为阴性。光镜检测轻至中度系膜扩张 ,伴系膜细胞少量增生 但两组比较无明显统计学意义 (P >0 0 5 ) ,肝左叶切除组IgA免疫荧光强于非肝切除组。结论　葡萄球菌肠内毒素静脉注射、BSA隔日口服、免疫增强剂或在上述基础上加肝左叶切除的方法都能诱发SD大鼠系膜增殖性肾炎模型。肝左叶切除组蛋白尿出现时间早 ;但于 14周后尿蛋白量无显著差异。     

Partitioning Coefficients in Plant Models with Turn-over

Reynolds and Thornley have presented a model for the partitioningof newly synthesized dry matter between shoots and roots invegetative plants, which combines a whole-plant functional balancewith an adaptive partitioning pattern. It turns out, however,that the derived partitioning coefficients are only applicableto models with equal turn-over rates for shoot and roots. Itis shown in this paper that the method used for the derivationof these coefficients does not always provide a partitioningpattern that is well-behaved, and a more general derivationis presented which includes the Reynolds and Thornley modelas a special case. Partitioning, growth, models, functional balance, turn-over rates     

Comparison of Two Mathematical Models of Cellularity Calculation

OBJECT: Nowadays, there is increasing evidence that functional magnetic resonance imaging (MRI) modalities, namely, diffusion-weighted imaging (DWI) and dynamic-contrast enhanced MRI (DCE MRI), can characterize tumor architecture like cellularity and vascularity. Previously, two formulas based on a logistic tumor growth model were proposed to predict tumor cellularity with DWI and DCE. The purpose of this study was to proof these formulas. METHODS: 16 patients with head and neck squamous cell carcinomas were included into the study. There were 2 women and 14 men with a mean age of 57.0 ± 7.5 years. In every case, tumor cellularity was calculated using the proposed formulas by Atuegwu et al. In every case, also tumor cell count was estimated on histopathological specimens as an average cell count per 2 to 5 high-power fields. RESULTS: There was no significant correlation between the calculated cellularity and histopathologically estimated cell count by using the formula based on apparent diffusion coefficient (ADC) values. A moderate positive correlation (r=0.515, P=.041) could be identified by using the formula including ADC and V_e values. CONCLUSIONS: The formula including ADC and V_e values is more sensitive to predict tumor cellularity than the formula including ADC values only.     

Comparison of Three Inbred Mouse Strains with Respect to General and Genetic Radiosensitivity

The radiosensitivities of three mouse strains (BALB/cLacY, C3H/SnY, and 101/HY) have been compared using the following parameters: survival after irradiation at a dose of 6–7 Gy, chromosome aberration frequency in bone marrow cells after irradiation at a dose of 1.5 Gy, and the change in testis weight and frequency of abnormal sperm heads (ASHs) after irradiation at doses from 0.5 to 4 Gy. Strain BALB/c is the most radiosensitive with respect to the survival and chromosome aberration frequency in the bone marrow but the most resistant with respect to the change in testis weight and the frequency of abnormal sperm heads. Strain 101/HY was the most resistant with respect to survival and chromosome aberration frequency in bone marrow after irradiation but the most radiosensitive with respect to testis damage.     

两种吗啡依赖大鼠模型脑内单胺神经递质水平的比较

目的通过对吗啡诱导的躯体依赖与精神依赖两种大鼠模型脑内单胺类递质水平的比较,探讨其在吗啡依赖形成中的作用。方法采用剂量递增法复制吗啡依赖大鼠模型,然后用纳洛酮催促,引起躯体戒断症状。连续给予吗啡（5mg／kg,ip）6d,引起大鼠产生显著的条件性位置偏爱效应。脑组织去甲肾上腺素（NE）、5-羟色胺（5-HT）和多巴胺（DA）含量采用荧光分光光度法测定。结果吗啡依赖大鼠催促戒断后脑内NE和5-HT水平明显升高,DA水平下降。吗啡在引起大鼠明显位置偏爱的同时,使大鼠脑内DA和5-HT水平显著升高,NE无明显改变。结论吗啡依赖的形成和戒断与脑内单胺神经递质有密切关系,吗啡依赖的躯体戒断症状与NE升高有关,而吗啡诱导的精神依赖则与脑内DA水平升高有关。     

Comparison of Chuvashes,Maris, and Russians with Respect to Vital Statistics and Crow's Index

Genetic demographic characteristics were calculated for Chuvash and Russian inhabitants of the Republic of Chuvashia. The generation lengths were 27.09 and 26.4 years and the sibship sizes were 2.54 and 1.82 for Chuvashes and Russians, respectively. Crow's indices and their components were as follows: I_m = 0.05, I_f = 0.31, and I_tot = 0.37 for Chuvashes and I_m = 0.03, I_f = 0.43, and I_tot = 0.46 for Russians. The genetic demographic characteristics obtained were compared with those for Highland and Meadow Maris.     

Densities of Two Frugivorous Primates with Respect to Forest and Fragment Tree Species Composition and Fruit Availability

Conservation of wildlife populations requires extensive knowledge of their habitat requirements, efficient methods to evaluate habitat quality, and an understanding of the value of fragments and edges. Kibale National Park, Uganda has areas that differ in the densities of 2 species of frugivorous monkeys—Cercopithecus mitis and Lophocebus albigena—including one on an edge and forest fragments outside the park that lack both species. We compared the basal area densities of important food trees with primate densities. The density of Cercopithecus mitis correlates most strongly with the basal area density of all types of food trees combined. The density of Lophocebus albigena does not correlate with the basal area densities of any category of food trees or with fruit availability. An index of their density—number of groups seen per km walked—correlates to fruit availability but with marginal significance. Lack of a relationship between the basal area densities of food trees and density of Lophocebus albigena may be the result of a mismatch in scale between the forest area measured and their large home ranges. We compared the unused area of forest to the other areas of the forest and the fragments and found it had higher basal area densities in all food tree categories for both species than the fragments and lower basal area densities of most categories than the other parts of the forest, indicating that the fragments are poor quality and would probably be unused even if dispersal were likely.     

Passive Immunization with Phospho-Tau Antibodies Reduces Tau Pathology and Functional Deficits in Two Distinct Mouse Tauopathy Models

In Alzheimer’s disease (AD), an extensive accumulation of extracellular amyloid plaques and intraneuronal tau tangles, along with neuronal loss, is evident in distinct brain regions. Staging of tau pathology by postmortem analysis of AD subjects suggests a sequence of initiation and subsequent spread of neurofibrillary tau tangles along defined brain anatomical pathways. Further, the severity of cognitive deficits correlates with the degree and extent of tau pathology. In this study, we demonstrate that phospho-tau (p-tau) antibodies, PHF6 and PHF13, can prevent the induction of tau pathology in primary neuron cultures. The impact of passive immunotherapy on the formation and spread of tau pathology, as well as functional deficits, was subsequently evaluated with these antibodies in two distinct transgenic mouse tauopathy models. The rTg4510 transgenic mouse is characterized by inducible over-expression of P301L mutant tau, and exhibits robust age-dependent brain tau pathology. Systemic treatment with PHF6 and PHF13 from 3 to 6 months of age led to a significant decline in brain and CSF p-tau levels. In a second model, injection of preformed tau fibrils (PFFs) comprised of recombinant tau protein encompassing the microtubule-repeat domains into the cortex and hippocampus of young P301S mutant tau over-expressing mice (PS19) led to robust tau pathology on the ipsilateral side with evidence of spread to distant sites, including the contralateral hippocampus and bilateral entorhinal cortex 4 weeks post-injection. Systemic treatment with PHF13 led to a significant decline in the spread of tau pathology in this model. The reduction in tau species after p-tau antibody treatment was associated with an improvement in novel-object recognition memory test in both models. These studies provide evidence supporting the use of tau immunotherapy as a potential treatment option for AD and other tauopathies.     

大鼠慢性肾功能不全模型两种制作方式的比较

目的比较大鼠肾大部切除与肾结扎两种方法制备的5／6肾切除慢性肾功能不全模型的异同。方法雄性SD大鼠随机分为三组。A组行左肾2／3切除加右肾切除,B组行结扎左肾动脉2／3分支加右肾切除,C组为假手术组。分别于第二次手术后5周、9周及13周测血压,处死大鼠,留取24h尿及肾组织。检测尿蛋白,肾组织切片染色。用半定量法评价肾小球硬化指数。结果第5周时,B组大鼠的收缩压显著升高,而A组与C组相比无显著差异,第9周和13周A组和B组与C组大鼠相比,收缩压均显著升高。肾部分切除术后,尿蛋白随时间进行性增加。B组与A组相比,尿蛋白增加更为显著。A组和B组在各观察点均有不同程度肾小球硬化,B组较A组肾小球硬化程度重。结论肾大部切除和肾结扎两种方法制备的大鼠5／6肾切除模型表现有所不同。     

舒必利与垂体移植诱发小鼠子宫腺肌病的比较

目的比较舒必利诱导和垂体移植诱导两种造模方法的效果,评价适用于子宫腺肌病研究的小鼠模型。方法 45只7周龄未曾受孕的雌性BALB/c小鼠,随机分为对照组、舒必利组和垂体移植组,每组15只。舒必利组每日皮下注射舒必利,每20 g体重注射800μg,垂体移植组则将同种同龄雄鼠的垂体放入雌鼠右侧子宫内,对照组不予任何处理。5个月后以子宫湿重、终末体重、子宫湿重/终末体重的比值、卵巢湿重、子宫HE染色评分及模型成功率等指标评价造模效果。结果 5个月后舒必利组和垂体移植组小鼠的子宫湿重、子宫湿重/终末体重的比值、子宫HE染色评分及成功率均显著高于对照组,但两模型组各项指标比较差别无统计学意义,三组小鼠终末体重和卵巢湿重比较差别均无统计学意义。结论对照组无一例形成子宫腺肌病,舒必利诱导和垂体移植诱导两种造模方法均可引起小鼠子宫腺肌病,造模的各项评价指标均无显著差异,都可用于子宫腺肌病的研究。     

江苏海涂两种水生利用模式的能值分析

自然资源的开发利用模式是多种多样的 ,要明确哪一种模式更优化 ,就必须对其生态经济效益作比较全面的分析评价。传统经济学的劳动价值论或市场价值论只表现了人对生态经济系统的贡献 ,没有体现自然对生态经济系统的贡献 ;传统的能量分析方法 ,把所有的可利用能量看成是等同的 ,没能体现能级和能质的差异[10 ]。能值分析方法克服了以上各方法的缺陷 ,从自然进化和系统演化的角度指出真正财富的共同价值基础能值 ,使得生态经济系统中各种能量、信息和物质能以同一标准进行比较和估算1) 。最大能值流原理提供了几条明确标准 ,反映系统自组织的…     

两种异位心脏移植小鼠模型的建立和比较

目的比较腹部和颈部小鼠心脏移植模型的优缺点,探讨二次器官移植或双心脏移植研究的可行性和实用性动物模型。方法参照Ono法和Chen法并加以改进,建立了同系或者同种小鼠腹部和颈部异位心脏移植模型,同时对两种手术方式的成功率、手术时间、移植心脏存活时间和病理组织学进行了比较。结果腹部和颈部异位心脏移植手术成功率分别为86.7%和83.3%,两种手术方式在总手术时间、移植心脏存活时间和病理组织形态学检查上均无明显差异(P0.05)。结论在熟练掌握显微外科技术的基础上,两种异位心脏移植模型都能顺利建立,两者既可分开选用,又可结合运用,以适应不同实验需求。     

Experimental Subarachnoid Hemorrhage in Rats: Comparison of Two Endovascular Perforation Techniques with Respect to Success Rate,Confounding Pathologies and Early Hippocampal Tissue Lesion Pattern

Recently aside from the “classic” endovascular monofilament perforation technique to induce experimental subarachnoid hemorrhage (SAH) a modification using a tungsten wire advanced through a guide tube has been described. We aim to assess both techniques for their success rate (induction of SAH without confounding pathologies) as primary endpoint. Further, the early tissue lesion pattern as evidence for early brain injury will be analyzed as secondary endpoint. Sprague Dawley rats (n=39) were randomly assigned to receive either Sham surgery (n=4), SAH using the “classic” technique (n=18) or using a modified technique (n=17). Course of intracranial pressure (ICP) and regional cerebral blood flow (rCBF) was analyzed; subsequent pathologies were documented either 6 or 24 h after SAH. Hippocampal tissue samples were analyzed via immunohistochemistry and western blotting. SAH-induction, regardless of confounding pathologies, was independent from type of technique (p=0.679). There was no significant difference concerning case fatality rate (classic: 40%; modified: 20%; p=0.213). Successful induction of SAH without collateral ICH or SDH was possible in 40% with the classic and in 86.7% with the modified technique (p=0.008). Peak ICP levels differed significantly between the two groups (classic: 94 +/- 23 mmHg; modified: 68 +/- 19 mmHg; p=0.003). Evidence of early cellular stress response and activation of apoptotic pathways 6 h after SAH was demonstrated. The extent of stress response is not dependent on type of technique. Both tested techniques successfully produce SAH including activation of an early stress response and apoptotic pathways in the hippocampal tissue. However, the induction of SAH with less confounding pathologies was more frequently achieved with the modified tungsten wire technique.     

Partitioning and Utilization of Net Photosynthate in a Nodulated Annual Legume

The economy of carbon in nodulated white lupin (Lupinus albusL.) was studied in terms of consumption of net photosynthatein nitrogen fixation, in maintenance of respiration, and inthe production of dry matter and protein. Net photosynthesisrose to a maximum in early fruiting and then fell abruptly dueto shedding of leaves. Nodulated roots acquired translocateequivalent to 51% of the plant's net photosynthate, 78% of thecarbon of this translocate being respired, 10% entering drymatter, and 12% returning to the shoot attached to productsof nitrogen fixation. Nodules utilized 4?0–6?5 g C infixing 1 g nitrogen. Photosynthate was utilized most effectivelyfor nitrogen fixation in late vegetative growth. Fruits sequestered16% of the plant's net photosynthate, shoot night respiration17%, and dry matter formation in shoot vegetative parts 22%.Averaged over growth, 9?9 g net photosynthate was required toproduce 1 g seed dry matter and 31 g net photosynthate to produce1 g seed protein. Budgets for utilization of the carbon of netphotosynthate were constructed for 10 d intervals of the plant'sgrowth cycle. Feeding of shoots with ¹⁴CO₂ resulted in radiocarbonbecoming partitioned approximately as predicted by these budgets.The dependence of root respiration on recent photosynthate wasassessed by following the time course of release of ¹⁴CO₂ tothe rooting medium of the ¹⁴CO-labelled plants.     

Relationship of C5L2 Receptor to Skeletal Muscle Substrate Utilization

Objective

To investigate the role of Acylation Stimulating Protein (ASP) receptor C5L2 in skeletal muscle fatty acid accumulation and metabolism as well as insulin sensitivity in both mice and human models of diet-induced insulin resistance.

Design and Methods

Male wildtype (WT) and C5L2 knockout (KO) mice were fed a low (LFD) or a high (HFD) fat diet for 10 weeks. Intramyocellular lipid (IMCL) accumulation (by oil red O staining) and beta-oxidation HADH enzyme activity were determined in skeletal muscle. Mitochondria were isolated from hindleg muscles for high-resolution respirometry. Muscle C5L2 protein content was also determined in obese type 2 diabetics and age- and BMI matched men.

Results

IMCL levels were increased by six-fold in C5L2KO-HFD compared to WT-HFD mice (p<0.05) and plasma insulin levels were markedly increased in C5L2KO-HFD mice (twofold, p<0.05). Muscle HADH activity was elevated in C5L2KO-LFD mice (+75%, p<0.001 vs. WT-LFD) and C5L2KO-HFD displayed increased mitochondrial fatty acid oxidative capacity compared to WT-HFD mice (+23%, p<0.05). In human subjects, C5L2 protein content was reduced (−48%, p<0.01) in type 2 diabetic patients when compared to obese controls. Further, exercise training increased C5L2 (+45%, p = 0.0019) and ASP (+80%, p<0.001) in obese insulin-resistant men.

Conclusion

The results suggest that insulin sensitivity may be permissive for coupling of C5L2 levels to lipid storage and utilization.     

Dynamical Models Explaining Social Balance and Evolution of Cooperation

Social networks with positive and negative links often split into two antagonistic factions. Examples of such a split abound: revolutionaries versus an old regime, Republicans versus Democrats, Axis versus Allies during the second world war, or the Western versus the Eastern bloc during the Cold War. Although this structure, known as social balance, is well understood, it is not clear how such factions emerge. An earlier model could explain the formation of such factions if reputations were assumed to be symmetric. We show this is not the case for non-symmetric reputations, and propose an alternative model which (almost) always leads to social balance, thereby explaining the tendency of social networks to split into two factions. In addition, the alternative model may lead to cooperation when faced with defectors, contrary to the earlier model. The difference between the two models may be understood in terms of the underlying gossiping mechanism: whereas the earlier model assumed that an individual adjusts his opinion about somebody by gossiping about that person with everybody in the network, we assume instead that the individual gossips with that person about everybody. It turns out that the alternative model is able to lead to cooperative behaviour, unlike the previous model.     

Partitioning and Utilization of Carbon and Nitrogen in Nodulated Roots and Nodules of Chickpea (Cicer arietinum) Grown at Two Moisture Levels

The partitioning and utilization of carbon (C) and nitrogen(N) in nodulated roots and nodules of chickpea (Cicer arietinumL.) was studied at two moisture levels at 10-d intervals 40–140d after sowing (DAS). More C was used in respiration and lessin growth of nodulated roots and nodules under water stresscompared to controls during all growth stages except at theearly vegetative stage. Similarly, less nitrogen was investedin dry matter of both nodules and nodulated roots under stress,except during the vegetative stage where more nitrogen was used.Calculated over the entire growth period, as much as 14 and20% of the total nitrogen and 3 and 4% of the total carbon fixedby the plant was lost to the rooting medium under controlledand stressed conditions, respectively. The efficiency of nitrogen fixation with respect to net C utilizationwas maximal during seed filling under both control and stressconditions However, the efficiency of nitrogen fixation wasalways greater under drier conditions. Carbon, chickpea (Cicer arietinum L.), nitrogen, nitrogen fixation, partitioning