高重力加速度及其模拟条件下脑电变化研究综述

高重力加速度及其模拟条件下脑电变化的相关研究在航空医学领域具有重要意义。本文综合介绍了飞行中＋Gz和离心机＋Gz作用、下体负压作用、不同程度缺氧、短暂意识丧失下的脑电变化特点及其相互之间的关系。国内外学者围绕＋Gz及其模拟条件下的脑电变化规律已取得一定研究成果,但在脑电的定量分析,以及利用脑电对＋Gz加速度引起的短暂意识丧失进行前驱预警等方面的研究尚待深入。本文为高重力加速度环境下的脑电变化特征研究提供重要参考依据,对探寻利用脑电预警高重力加速度引起的意识丧失具有现实意义。     

A somatostatin analogue decreases embryonic loss following superovulation in rats by normalizing insulin-like growth factor-I action in the uterus

This study was designed to determine whether the somatostatin analogue, octreotide, could prevent embryonic loss by normalizing increased uterine insulin-like growth factor-I (IGF-I) action related to hyperoestrogenaemia following superovulation. Superovulated immature and oestradiol-17beta-treated adult rats were infused with 100 or 300 microg/ml of octreotide respectively, or injected daily with 1 or 10 microg of octreotide from day 1 to day 3 of pregnancy. On day 3, embryos were collected from the oviducts and uteri. Uterine luminal fluid was subjected to embryo culture. The amounts of uterine IGF-I and IGF binding proteins (IGFBP) were determined by radioimmunoassay and ligand binding assay respectively. Octreotide infusion normalized uterine IGF-I action following superovulatory and oestradiol-17beta treatment, by reducing IGF-I concentrations and increasing IGFBP concentrations. Octreotide infusion increased the number of normal embryos by 2.7-fold and 1.7-fold in superovulated and oestradiol-17beta- treated rats respectively, and reversed the detrimental effects of uterine luminal fluid on embryonic development caused by superovulatory and oestradiol-17beta treatment. Daily injections with octreotide had similar but reduced effects in all parameters examined in both treatment groups. In conclusion, octreotide may reduce embryonic loss, at least in part, by normalizing IGF-I action following superovulation.      

Microtubules are required for cytokeratin aggresome (Mallory body) formation in hepatocytes: an in vitro study

Mallory bodies are cytokeratin-ubiquitin aggresomes that form in hepatocytes in many different chronic liver diseases. One of the key components in aggresome formation, not yet investigated in Mallory body formation, is the role of microtubules. An in vitro tissue culture assay is required to test for microtubule involvement in Mallory body formation so that Mallory body formation can be observed in the presence or absence of microtubule-disrupting agents. In this report, a new model of in vitro Mallory body formation was developed, which uses cultured hepatocytes isolated from drug-primed mice. When hepatocytes were incubated in the presence of antimicrotubule agents, they failed to form Mallory bodies. It is concluded that intact microtubules are required for Mallory body formation.     

P2X3-mediated peripheral sensitization of neuropathic pain in resiniferatoxin-induced neuropathy

Patients suffering from sensory neuropathy due to skin denervation frequently have paradoxical manifestations of reduced nociception and neuropathic pain. However, there is a lack of satisfactory animal models to investigate these phenomena and underlying mechanisms. We developed a mouse system of neuropathy induced by resiniferatoxin (RTX), a capsaicin analog, and examined the functional significance of P2X3 receptor in neuropathic pain. From day 7 of RTX neuropathy, mice displayed mechanical allodynia (p<0.0001) and thermal hypoalgesia (p<0.0001). After RTX treatment, dorsal root ganglion (DRG) neurons of the peripherin type were depleted (p=0.012), while neurofilament (+) DRG neurons were not affected (p=0.62). In addition, RTX caused a shift in neuronal profiles of DRG: (1) increased in P2X3 receptor (p=0.0002) and ATF3 (p=0.0006) but (2) reduced TRPV1 (p=0.036) and CGRP (p=0.015). The number of P2X3(+)/ATF3(+) neurons was linearly correlated with mechanical thresholds (p=0.0017). The peripheral expression of P2X3 receptor in dermal nerves was accordingly increased (p=0.016), and an intraplantar injection of the P2X3 antagonists, A-317491 and TNP-ATP, relieved mechanical allodynia in a dose-dependent manner. In conclusion, RTX-induced sensory neuropathy with upregulation of P2X3 receptor for peripheral sensitization of mechanical allodynia, which provides a new therapeutic target for neuropathic pain after skin denervation.     

军事飞行人员腰椎峡部裂影像学诊断和医学鉴定的专家建议

笔者通过文献综述、前期研究经验以及医学鉴定专家组的经验,对腰椎峡部裂影像学检查技术、影像学诊断标准、分型、运动生物力学分析和飞行安全风险评估等方面进行全面深入的分析,针对飞行人员峡部裂患者的影像诊断和医学鉴定标准进行探讨和修订,并提出建议案,旨在对腰椎峡部裂进行更精准的医学鉴定和保证飞行安全.     

高性能载人离心机推拉效应模拟方法研究

目的开发利用高性能载人离心机的功能,进行推拉效应(PPE)模拟方法的研究。方法推拉动作(PPM)加速度曲线的参数设为:Gmin为-1Gz持续5s,Gmax范围为从+2.5Gz持续10s开始按0.25Gz的幅度递增,对编制的模拟PPM加速度曲线进行试运行后,以12名战斗机飞行员和6名志愿者为受试者,分别测定了在预先有和无-1Gz5s作用情况下受试者的基础+Gz耐力。结果 -1Gz的产生会附带产生+1Gx和+0.5Gy,能够为人体所耐受。预先暴露于-1Gz5s后所有受试者的基础+Gz耐力均显著下降,志愿者组平均下降(0.87±0.13)G(P0.01),飞行员组平均下降(0.95±0.25)G(P0.01)。1名志愿者和1名飞行员受试者在PPM暴露的"拉"阶段发生加速度导致的意识丧失(G-LOC)结论在高性能载人离心机上初步建立推拉效应模拟方法,为后续的推拉效应研究奠定基础。     

New universal precaution aspiration tray

A new tray has been designed for use during procedures involving needles and other sharp objects. The tray includes a foam adhesive pad, marked into 10 sections, into which the sharp objects can be placed point first. After the procedure, the objects can be safely withdrawn by their handles and then discarded. The tray has been used in more than 250 procedures.     

Reduced striatal tyrosine hydroxylase in incidental Lewy body disease

Incidental Lewy body disease (ILBD) is the term used when Lewy bodies are found in the nervous system of subjects without clinically documented parkinsonism or dementia. The prevalence of ILBD in the elderly population has been estimated at between 3.8 and 30%, depending on subject age and anatomical site of sampling. It has been speculated that ILBD represents the preclinical stage of Parkinson’s disease (PD) and/or dementia with Lewy bodies (DLB). Studies of ILBD could potentially identify early diagnostic signs of these disorders. At present, however, it is impossible to know whether ILBD is a precursor to PD or DLB or is just a benign finding of normal aging. We hypothesized that, if ILBD represents an early stage of PD or DLB, it should be associated with depletion of striatal dopaminergic markers. Eleven subjects with ILBD and 27 control subjects were studied. The ILBD subjects ranged in age from 74 to 96 years (mean 86.5) while the control subjects’ age ranged from 75 to 102 years (mean 86.7). Controls and subjects did not differ in terms of age, postmortem interval, gender distribution, medical history conditions, brain weight, neuritic plaque density or Braak neurofibrillary stage. Quantitative ELISA measurement of striatal tyrosine hydroxylase (TH), the principal enzyme for dopamine synthesis, showed a 49.8% (P = 0.01) reduction in ILBD cases, as compared with control cases. The finding suggests that ILBD is not a benign condition but is likely a precursor to PD and/or DLB.     

Who is the 40-Year-Old Virgin and Where Did He/She Come From? Data from the National Survey of Family Growth

IntroductionLittle is known about young and middle aged adults who have never engaged in sexual intercourse. Individuals who have not engaged in sexual activity may theoretically have diminished overall quality of life, as recent evidence suggests that sexual activity may be related to overall health status in adults.AimWe sought to identify factors related to sexual abstinence in young and middle-aged adults.MethodsWe analyzed data from the male and female sample of the 2002 National Survey of Family Growth to examine sexual abstinence among unmarried participants aged 25–45 (men: N = 2,469; women: N = 5,120).Main Outcome MeasuresMultivariable logistic regression modeling was used to test for independent associations between demographic, medical, and anthropometric variables and abstinence while adjusting for confounding and mediating variables.ResultsA total of 122 (13.9%) men aged 25–45 reported never having had sex, representing approximately 1.1 million American men in this age cohort. Among female participants, a total of 104 (8.9%) women aged 25–45 reported never having sex, representing approximately 800,000 American women in this age cohort. Both men and women who reported that they attend religious services one or more times per week were more likely to be sexually abstinent, independent of their specific religious beliefs. Virgin status was also significantly associated with drinking alcohol within the past year. While a college degree in women predicted virginity, education was not associated with virginity in men. Men showed lower rates of sexual abstinence if they reported having spent time in prison or serving in the military.ConclusionsAmongst young adults, sexual abstinence does not appear to be mediated by health status, anthropometric measures, or age. Attending religious services and avoidance of alcohol consumption are associated with virginity in adults. Other factors associated with abstinence differ between genders and merit further study. Eisenberg ML, Shindel AW, Smith JF, Lue TF, and Walsh TJ. Who is the 40 year old virgin and where did he/she come from? Data from the National Survey of Family Growth. J Sex Med 2009;6:2154–2161.     

小肺癌SCT漏／误诊5例CT征像分析

目的：确定初次SCT漏／误诊而后CT扫描检测到的小肺癌CT征象。材料与方法：复习2490例初次SCT普查中漏／误诊患者的CT征象，回顾性评价其CT征象、检测时间、细胞类型及病理分期。结果：初次SCT扫描漏误诊小肺癌5例，其中4例病检肺癌为1期，1例为Ⅱ期。结论：SCT普查可漏／误诊接近检测阈的小肺癌结节，慎用双窗观察，推荐随访检查。