病理浓度甲醛的累积导致小鼠神经母瘤细胞活力及黏附能力下降

Formaldehyde (FA) plays a role in age-related cognitive impairment. An increase in endogenous FA induced by long-term oral administration of methanol, which triggers Tau hyperphosphorylation in the brain of Macaca mulatta and deteriorates the animal’s working memory. Short-term, high-dose FA treatment induces Tau hyperphosphorylation in the cytoplasm and nucleus of murine neural cells in vivo and in vitro. However, the pathological FA level is lower than that used in those experiments. The long-term effect on neural cells of FA at pathological doses has not yet been investigated. Here, based on the pathological level of endogenous FA in Alzheimer’s disease (AD) patients, we added 10 mmol/l (mM) FA to the medium and incubated murine neuroblastoma (N2a) cells for six days by using a serial passage strategy. FA-induced significant decreases in cell number and viability as well as increased lactate dehydrogenase (LDH) release were observed during the culture. Holographic microscopy showed that cells exposed to FA were thicker and smaller, exhibiting a weakened adhesive morphology. Immunofluorescence staining demonstrated that the pathological dose of FA increases Tau phosphorylation at Threonine (T181) and Serine (S396) epitopes over time. These results indicate that long-term exposure to a pathological concentration of FA causes the cell viability decline and even cell death under the experimental conditions     

半干旱黄土区坡面尺度柠条生长状况及影响要素分析

以半干旱黄土丘陵区典型小流域坡面大规模人工种植柠条林为例,基于坡面不同部位柠条生长状况和生境条件调查,定量分析了地形变化、土壤水分及灌木密度对柠条生长的直接、间接影响及其贡献率。结果表明:(1)东坡大株柠条生长明显好于南坡,下坡位柠条生长状况略好于中上坡位,其他各坡位之间柠条生长状况差异较小;(2)大株柠条生长与浅层土壤水分有正相关关系,而与灌木密度和深层土壤水分则呈负相关关系;大株柠条灌木高度、灌木纵截面积和冠幅体积对浅层土壤水分的响应敏感,冠幅长度对坡向和坡位的响应较为敏感,冠幅宽度对灌木密度的响应较为敏感;(3)地形和土壤水分变化解释了59.9%的大株柠条生长变异,其中坡向、坡位和浅层土壤水分是影响大株柠条生长的主导环境因子,它们分别解释了21.1%、16.0%和13.1%的柠条生长变化。研究认为半干旱黄土区人工植被恢复既要重视空间布局,也要在后期实施必要的管理措施以维持人工林地的稳定性。     

贵州布依族体质人类学研究

本文对773名(男379人,女394人)生活在贵州的布依族进行活体观察和测量(观察项目28个,测量项目64个)。调查对象年龄20—55岁三代均为布依族。分析结果表明:布依族中头型多见;男性多为中面型,女性以阔面型为主;属阔鼻型;亚中等偏矮型身材。布依族与我国南方其他29个民族群体10项头面部体部测量数据聚类分析,结果显示布依族的体质特征与广西壮族、海南黎族最为接近,与湖南土家族、瑶族、贵州苗族、广西彝族次之,与湖南侗族、贵州毛南族、白裤瑶较远。布依族属蒙古人种南亚类型,具有现代黄种人的容貌特征。     

鼎湖山森林土壤渗透水酸度和无机氮含量对模拟氮沉降增加的早期响应

在林地分别喷加0、50、100和150kg N hm^-1a^-1,研究鼎湖山马尾松林、马尾松针阔混交林和季风常绿阔叶林中土壤20cm深渗透水酸度和无机氮含量在开始9个月的变化。结果表明,3种森林对照样方土壤渗透水pH值为3．82—4．24,外加氮处理使其平均降低了0．08—0．18。3个森林对照样方土壤渗透水无机氮平均含量分别为6．14、6．66和11．64mg L^-1,铵态氮占15．0％、11．9％和3．0％。外加氮处理使3种森林土壤渗透水铵态氮和硝态氮含量均有不同程度的提高,这表明外加氮处理不但增加了无机氮从森林土壤流失的潜力,而且使土壤进一步酸化。     

miR-375靶向MMP13抑制骨肉瘤细胞的迁移和侵袭

目的 为了探究miR-375是否通过影响基质金属蛋白酶13（MMP13）的表达来调控骨肉瘤（osteosarcoma,OS）恶性特征。方法 用Lipofectamine 3000试剂盒将质粒、miRNA转染至骨肉瘤细胞和HEK293细胞中。实时定量聚合酶链反应（real-time quantitative PCR,RT-qPCR）检测OS患者和OS细胞中miR-375和MMP13的表达。蛋白质印迹法（Western blot）分析OS患者和OS细胞中MMP13蛋白的表达。双荧光素酶法分析miR-375与MMP13的靶向关系。伤口愈合和transwell实验分别分析OS细胞的迁移和侵袭。结果 OS组织中miR-375的表达低于正常组织。MMP13在OS组织中表达上调。在OS患者中,MMP13的表达与miR-375呈负相关。与转染miRNA对照的OS细胞相比,转染miR-375模拟物OS细胞的迁移和侵袭明显被抑制。MMP13能部分逆转miR-375对OS细胞迁移和侵袭的抑制作用。结论 在OS细胞中,过表达miR-375通过调控MMP13的表达抑制细胞的迁移和侵袭。     

鼎湖山主要森林土壤CO2排放和CH4吸收特征

研究了鼎湖山生物圈保护区马尾松林、混交林和季风常绿阔叶林(季风林)在2000~2001年期间土壤CO2排放和CH4吸收特征。季风林、混交林和马尾松林土壤CO2排放速率在研究期间的平均值分别为(kgCO2-C·hm-2·d-1):18.6±2.6,20.5±3.7和17.8±3.8,土壤CH4吸收速率则分别为(gCH4-C·hm-2·d-1):-5.5±1.8,-3.3±1.6和-7.7±1.8。土壤CO2排放速率和土壤CH4吸收速率在三种森林类型中均表现明显的季节性变化,且其季节性变化根据森林类型和年份不同而异。总的来说,土壤CO2排放速率在所有森林中均呈现夏季最高而冬季最低的变化,土壤CH4吸收速率的季节性变化则相反,基本上表现为冬季最高而夏季最低的变化。三种森林土壤的CO2排放速率和CH4吸收速率在两观测年间的差异均不显著。土壤CO2排放速率在不同森林类型间的差异也不显著,但土壤CH4吸收速率在马尾松林显著高于混交林。在两观测年中,土壤CO2排放速率与土壤CH4吸收速率之间在季风林呈现显著的负相关关系,在混交林和马尾松林中它们之间也趋向呈负相关关系,但未达显著水平。土壤CO2排放速率与土壤温度之间在季风林呈现显著的指数正相关关系,但在其余森林(混交林和马尾松林)中它们之间的关系则不明显。     

中国瘿蚊一新种记述(双翅目,瘿蚊科)

记述采自浙江省的端突瘿蚊属Epidiplosis 1新种:指状端突瘿蚊Epidiplosis dactylina sp.nov,.模式标本存放于山东农业大学昆虫标本室.     

Comparison of Endocrine Response to Stress Between Captive-Raised and Wild-Caught Bighorn Sheep

ABSTRACT Stress hormones in Rocky Mountain bighorn sheep (Ovis canadensis canadensis), produced in response to environmental changes, road development, or high population density, may impact their immune systems to a threshold level that predisposes them to periodic, large-scale mortality. We compared the stress response to a novel environmental situation and repeated handling between bighorn sheep born and raised in captivity (CR) and bighorn sheep born in the wild (WC) and brought into captivity. We measured plasma epinephrine, norepinephrine, cortisol, and fecal glucocorticoid metabolites (FGM). Three weeks after each group's arrival we used a one-time drop-net event to elicit an acute stress response, and we collected blood samples from each sheep over 35 minutes, as well as one fecal sample. We collected blood and fecal samples from both groups on 7 other occasions over the subsequent 6 months. We also collected fecal samples from the pen at approximately 24-hour intervals for 3 days following every handling event to monitor the stress response to handling. We found that CR sheep had a stronger autonomic nervous system response than WC sheep, as measured by epinephrine and norepinephrine levels, but we found a very similar hypothalamic-pituitary–adrenal axis (HPA) response, measured by cortisol levels, to the acute stress event of a drop-net restraint. We also found that once the WC sheep had acclimated, as indicated by the return to the initial baseline FGM levels within 12 weeks, the CR and WC groups' HPA responses to sampling events were not significantly different from one another. Fecal samples can provide a noninvasive mechanism for managers to monitor baseline FGM for a given herd. Using long-term monitoring of FGM rather than values from a single point in time may allow managers to correlate these levels to outside influences on the herd and better understand the impacts of management changes, population density, or increased human developments on the health of the sheep population.     

Fluorescent vital staining of plant sexual cell nuclei with DNA—specific fluorochromes and its application in gametoplast fusion

DNA－binding fluorochromes are often used for vital staining of plant cell nuclei.However,it is not always sure whether the cells after staining still remain in living state.We chose several criteria to estimate the validity of real vital staining for sexual cell nuclei.These were:the cytoplasmic streaming in pollen tubes whose nuclei were stined,the simultaneous visualization of fluorochromatic reaction and nucleus staining in isolated generative cells,and the capability of isolated.prestained generative or sperm cells to fuse with other protoplasts.The results confirmed that 4,6-diamidino-2-phenylindole(DAPI),Hoechst 33258 and mithramycin could be used as real vital stains,though their efficiency varied from case to case;among them DAPI showed best effect.The fluo rescent vital staining technique offered a useful means foridentification and selection of heterokaryons in gametoplast manipulation studies.