Brain Cytochrome Oxidase in Alzheimer''s Disease

A recent demonstration of markedly reduced (-50%) activity of cytochrome oxidase (CO; complex 4), the terminal enzyme of the mitochondrial enzyme transport chain, in platelets of patients with Alzheimer's disease (AD) suggested the possibility of a systemic and etiologically fundamental CO defect in AD. To determine whether a CO deficiency occurs in AD brain, we measured the activity of CO in homogenates of autopsied brain regions of 19 patients with AD and 30 controls matched with respect to age, postmortem time, sex, and, as indices of agonal status, brain pH and lactic acid concentration. Mean CO activity in AD brain was reduced in frontal (-26%: p less than 0.01), temporal (-17%; p less than 0.05), and parietal (-16%; not significant, p = 0.055) cortices. In occipital cortex and putamen, mean CO levels were normal, whereas in hippocampus, CO activity, on average, was nonsignificantly elevated (20%). The reduction of CO activity, which is tightly coupled to neuronal metabolic activity, could be explained by hypofunction of neurons, neuronal or mitochondrial loss, or possibly by a more primary, but region-specific, defect in the enzyme itself. The absence of a CO activity reduction in all of the examined brain areas does not support the notion of a generalized brain CO abnormality. Although the functional significance of a 16-26% cerebral cortical CO deficit in human brain is not known, a deficiency of this key energy-metabolizing enzyme could reduce energy stores and thereby contribute to the brain dysfunction and neurodegenerative processes in AD.     

圈养獐分娩的初步观察

2004年的5~7月,在浙江省嵊州市河麂种源繁育基地对34只獐(Hydropotes inermis)的分娩活动进行了观察。结果表明,母獐通常选择安全的地点进行分娩。獐集中分娩的时间为6月3日到6月19日,占分娩母獐总数的73.53%(n=34),并且分娩多在白天进行。产程(从胎膜露出到胎盘娩出)平均为(302.20±15.27)min(n=15)。胎儿娩出的姿势多为前躯前置(前足、头先露出),占83.78%;少数为后躯前置(后足先露出),占16.22%。幼仔首次吮乳时间在单胎和多胎间无显著差异,平均为出生后(44.97±2.73)min(n=35)。幼仔出生后首次平均站立时间在双胞胎、三胞胎和四胞胎分别为(32.25±2.49)min(n=16)(、29.42±2.52)min(n=12)和(65.00±7.39)min(n=6)。每胎幼仔数越多,初生幼仔的平均体重越轻。     

Spontaneous activation of circulating granulocytes in patients with acute myocardial and cerebral diseases.

Recent animal studies have suggested that there exists an activated subpopulation of circulating granulocytes which plays an important part in microvascular sequestration and tissue injury during shock and ischemia. In this respect, spontaneous granulocyte activation in form of pseudopod formation, a manifestation of actin polymerization, is a high risk for microvascular entrapment. The present investigation was carried out to determine if there is a significant difference in pseudopod formation in vitro between granulocytes obtained from healthy volunteers without symptoms and patients with acute cardiovascular illnesses. Blood samples from 25 healthy volunteers, 12 patients with acute myocardial infarction (AMI) and 12 patients with acute cerebral infarction (ACI) to determine spontaneous pseudopod formation in granulocytes with a high resolution light microscope over a period of several hours. The results revealed that the mean percentage of cells with pseudopod formation in the control group was below 10% in the first 3 hours, and increased to about 50% at 12 hours. In AMI patients, the level of activation within the first hour was not significantly different from the controls, but it rose rapidly to 90% in 4 to 5 hours. Patients with cerebral infarction, however, showed no significant difference from the control group. When the granulocytes of healthy subjects were incubated in plasma of AMI, the cells were activated similar to AMI granulocytes in their own plasma. When AMI plasma was serially diluted with Ringer's solution, the activation curve fell successively. These results indicate that AMI patients' blood contains plasma factor(s) which can activate granulocytes at a more rapid rate than controls.     

细胞质膜在罗非鱼和叉尾斗鱼低温驯化过程中的功能

研究通过一系列科学的指标,比如死亡温度、累计温度处理时间和存活率曲线,检测并比较了吉富罗非鱼和叉尾斗鱼的低温耐受能力,然后系统地检测了在两种鱼中,低温对一系列与细胞膜相关的生理指标的影响,包括细胞膜流动性、内吞作用和膜蛋白Na+, K+ -ATPase的活性。实验结果显示叉尾斗鱼比吉富罗非鱼有着明显优良的耐寒力。两种鱼内与细胞膜相关的生理指标都对温度敏感,但是具体的敏感程度却在耐寒种(叉尾斗鱼)和不耐寒种(吉富罗非鱼)之间存在显著差异。在具体每个物种内部,与细胞膜相关的一系列生理功能对温度的敏感程度是一致的。所有这些种间差异性和种内一致性都使得细胞膜流动性在物种耐寒过程中的重要性凸显出来。结果揭示细胞质膜,尤其是质膜流动性可能在这两种鱼对低温适应过程中扮演重要的角色。       

A DNA Vaccine Encoding a Codon-Optimized Human Papillomavirus Type 16 E6 Gene Enhances CTL Response and Anti-tumor Activity

Summary The HPV oncoproteins E6 and E7 are consistently expressed in HPV-associated cancer cells and are responsible for their malignant transformation. Therefore, HPV E6 and E7 are ideal target antigens for developing vaccines and immunotherapeutic strategies against HPV-associated neoplasms. Recently, it has been demonstrated that codon optimization of the HPV-16 E7 gene resulted in highly efficient translation of E7 and increased the immunogenicity of E7-specific DNA vaccines. Since vaccines targeting E6 also represent an important strategy for controlling HPV-associated lesions, we developed a codon-optimized HPV-16 E6 DNA vaccine (pNGVL4a-E6/opt) and characterized the E6-specific CD8⁺ T cell immune responses as well as the protective and therapeutic anti-tumor effects in vaccinated C57BL/6 mice. Our data indicated that transfection of human embryonic kidney cells (293 cells) with pNGVL4a-E6/opt resulted in highly efficient translation of E6. In addition, vaccination with pNGVL4a-E6/opt significantly enhanced E6-specific CD8⁺ T cell immune responses in C57BL/6 mice. Mice vaccinated with pNGVL4a-E6/opt are able to generate potent protective and therapeutic antitumor effects against challenge with E6-expressing tumor cell line, TC-1. Thus, DNA vaccines encoding a codon-optimized HPV-16 E6 may be a promising strategy for improving the potency of prophylactic and therapeutic HPV vaccines with potential clinical implications.     

温度对中型指环虫产卵和孵化的影响

指环虫病是严重影响鱼类养殖的寄生虫病.为了有效控制指环虫病,实验研究了寄生在金鱼(Carassius auratus)鳃部的中型指环虫(Dactylogyrus intermedius)卵、纤毛幼虫的形态,以及在离体条件下温度对其产卵和孵化的影响.成熟的中型指环虫虫卵大部分为梨形,长30 μm左右,后端有一个卵柄.纤毛幼虫呈圆筒状,两端稍尖,眼点两对;后吸盘具有若干对小锚钩;在前部、中部和尾部分别具有一圈纤毛.实验研究了4℃、10℃、22℃、30℃和35℃条件下中型指环虫的产卵和孵化情况,在4℃条件下,中型指环虫基本不产卵也不孵化;在其他4个温度条件下,产卵量随着温度的升高而增加,其平均产卵量分别为3.30、4.10、4.13和4.24枚/虫.统计结果显示:在35℃条件下的产卵量明显高于10℃(P＜0.05),其他温度条件下的平均产卵量没有显著性差异.中型指环虫的产卵速率随着温度的升高而加快,产卵维持的时间分别为4d、23h、15h和llh.孵化率在22℃时最高,为72.7％,在30℃和35℃的孵化率为50％左右,卡方检验显示:4种温度下的孵化率之间没有显著性差异p＞0.05);随着温度的升高,孵化速率逐渐加快,而孵化时间和纤毛幼虫的存活时间则缩短,平均孵化时间分别为24d、3d、42h和26h,纤毛幼虫的最长存活时间分别为4d、3d、56h和34h.结果显示,当水温为22℃时,中型指环虫的产卵数量和纤毛幼虫的存活时间都比较高,且孵化率最高,表明该温度条件较适合中型指环虫的种群增长.     

麋鹿幼仔的活动同步性与同性聚群倾向

哺乳动物幼体从出生到性成熟这段时间存在生理和行为上的巨大变化.麋鹿幼仔出生1周内,与成鹿和其它仔鹿呈隔离状态,且藏卧于隐蔽处,母鹿哺乳是引起幼仔活动的主要因素.     

家蚕核型多角体病毒同源重复区hr5的结构和功能

家蚕核型多角体病毒(BmNPV)和首蓿尺蠖核型多角体病毒(AcMNPV)是宿主不同的同类昆虫杆状病毒.AcMNPV有5个同源重复区,hr5具较强增强子功能,最近被发现可能参与病毒DNA复制.Maeda等曾将BmNPV hrs图谱定位,最近又报道了BmNPV hr s的结构,但功能研究至今未见报道.与Maeda等同时,从野生型BmNPV基因组中克隆了hr 5区,进行了全序列测定,与Maeda等的报道有一定差别.功能分析证实,含BmNPV hr 5的质粒在辅助病毒存在下,不仅在宿主细胞(BmN)中能进行复制,而且在非宿主细胞 Sf 21中亦能进行复制.此外,不仅完整的BmNPV hr 5(含 8个重复单位),而且部分序列(含6个重复单位)亦显示上述功能.以上研究结果,并对hr 5在病毒 DNA复制过程中可能有的功能进行了探讨.     

Molecular epidemiology of scrub typhus in Taiwan during 2006–2016

Scrub typhus is the most common endemic vector-borne disease in Taiwan. We identified a total of 4,857 laboratory-confirmed cases during 2006–2016 with hyperendemic foci on offshore islands, including Penghu (778 cases, 16.0%) and Kinmen (716 cases, 14.7%), and eastern Taiwan, including Taitung (628 cases, 12.9%) and Hualien (508 cases, 10.5%). Scrub typhus cases occur year-round throughout Taiwan, with a summer peak in June and July. A total of 545 O. tsutsugamushi isolates were successfully obtained from patients infected in diverse geographic areas, including Taiwan and three offshore islands, and the complete open reading frame of the 56 kDa type-specific antigen gene (tsa56) sequence of these isolates was examined. High phylogenetic diversity was found in these isolates, which could be grouped into 36 distinct sequence types. Most isolates belonged to the Karp (49.9%; 272/545), followed by the TW-22 (17.8%; 97/454) and Kawasaki (14.7%; 80/545) genotypes. In conclusion, our data indicate the widespread presence of tsa56 genotypes closely related to Thailand and Korean strains and the presence of the unique endemic strains TW-12, TW-22, TW-29, and TW-36 in Taiwan.