Effects of mutagenized X chromosomes of Drosophila melanogaster on viability and fitness in males

Drosophila melanogaster males were treated with different doses of X-rays or ethyl methanesulfonate (EMS) and mated so that mutagenized X chromosomes could be recovered and tested for lethal mutations and for less drastic mutations affecting viability and other aspects of fitness. The lethals were detected in standard X-linked lethal tests. The less drastic mutations were detected in one generation tests for effects on viability and in multigeneration tests for effects on overall fitness. The Poisson-corrected frequencies of the lethal mutations increased linearly with dose for both X-rays and EMS. Based on the data, 1 Krad X-rays given acutely induces the same number of lethals as 0.55 mM EMS administered by feeding. For some of the X-ray and EMS doses, the mutagenized chromosomes that were nonlethal reduced the viability of their carriers by a small amount, but there was no discernable dose-effect relationship. However in every case where a viability effect was seen, the percentage reduction was less than the corresponding frequency of lethals. All the groups of mutagenized nonlethal chromosomes reduced overall fitness by a significant percentage. Wherever a meaningful comparison was possible, this reduction was 2-3 times the reduction in viability, but, as in the viability data, no dose-effect relationship was discernable.     

Specific absorbed fractions from the image-based VIP-Man body model and EGS4-VLSI Monte Carlo code: internal electron emitters

VIP-Man is a whole-body anatomical model newly developed at Rensselaer from the high-resolution colour images of the National Library of Medicine's Visible Human Project. This paper summarizes the use of VIP-Man and the Monte Carlo method to calculate specific absorbed fractions from internal electron emitters. A specially designed EGS4 user code, named EGS4-VLSI, was developed to use the extremely large number of image data contained in the VIP-Man. Monoenergetic and isotropic electron emitters with energies from 100 keV to 4 MeV are considered to be uniformly distributed in 26 organs. This paper presents, for the first time, results of internal electron exposures based on a realistic whole-body tomographic model. Because VIP-Man has many organs and tissues that were previously not well defined (or not available) in other models, the efforts at Rensselaer and elsewhere bring an unprecedented opportunity to significantly improve the internal dosimetry.     

Decreased accumulation of endogenous brain-derived neurotrophic factor against constricting sciatic nerve ligatures in streptozotocin-diabetic and galactose-fed rats

Anterograde and retrograde trafficking of brain-derived neurotrophic factor (BDNF) was examined in streptozotocin-diabetic and galactose-fed rats by measuring accumulation of endogenous neurotrophin proximal and distal to two constricting sciatic nerve ligatures and by direct injection of radiolabeled neurotrophin into the sciatic nerve. Compared to controls, accumulation of endogenous BDNF proximal and distal to the ligatures as well as basal levels in non-ligated nerve segments were decreased in streptozotocin-diabetic and galactose-fed rats. Neither streptozotocin diabetes nor galactose intoxication affected the amount of 125I-labeled BDNF retrogradely transported to the DRG after injection into the sciatic nerve. These results suggest that reduced anterograde and retrograde accumulations of BDNF in experimental diabetes are not a result of impaired capacity for receptor-mediated transport.     

Effects of voluntary exercise on synaptic plasticity and gene expression in the dentate gyrus of adult male Sprague-Dawley rats in vivo

We have previously shown that voluntary exercise produces enhanced neurogenesis and long-term potentiation (LTP) in the dentate gyrus (DG) of mice in vitro. In the present experiments we show that rats given access to a running wheel (Runners) exhibit significantly more short-term potentiation and LTP with theta-patterned conditioning stimulation in vivo than do age-matched litter mates (Controls). This increase in LTP appears to reflect an alteration in the induction threshold for synaptic plasticity that accompanies voluntary exercise. Weak theta-patterned stimulation, which did not produce LTP in control subjects, produced a robust and long-lasting LTP in Runners. LTP induction in both groups was dependent upon the activation of N-methyl-D-aspartate (NMDA) receptors, and could be blocked by the competitive antagonist [+/-]-3-[2-carboxypiperazin-4-yl] propanephosphonic acid. Consistent with these findings, we found that mRNA levels for NR2B subtype of NMDA receptor were increased specifically in the DG of Runners. In addition to changes in NR2B mRNA levels, quantitative polymerase chain reaction analysis revealed that brain-derived neurotrophic factor (BDNF) and glutamate receptor 5 mRNA levels were also significantly elevated in the DG of Runners, but not in other areas of the hippocampus. Thus, alterations in the expression of BDNF, and specific glutamate receptor subtypes, may underlie the ability of exercise to enhance neurogenesis and reduce the threshold for LTP in the DG.     

胃肠道肿瘤中纤维粘连蛋白的分布及其与肿瘤生物学特性的关系

Through immunohistochemical technique, distribution of FN in normal mucosa, benign and malignant tumors of human gastrointestinal tract were studied. In normal and adenoma tissues, FN was found in both basement membrane (BN) and interstitial tissue. While in cancer tissue, there was a consistent decrease of BM FN content around the tumor nests particularly more apparently in cases of invading carcinoma. Statistical analysis showed that the reduction of BM FN was correlated with the degree of tumor dedifferentiation but not with the incidence of regional metastases. No association was noticed between the stroma FN and tumor behaviors. Since small blood vessels were usually delineated clearly by the staining for FN, FN might be considered as a marker in identifying the invasion of blood vessel wall by tumor cells. It is suggested that lack of BM FN in tumor tissues might be mainly due to decrease of FN synthesis by the tumor cells.     

Seroprevalence studies using a recombinant norwalk virus protein enzyme immunoassay

A recombinant Norwalk virus (NV) protein enzyme immunoassay was used to study the age of acquisition of NV IgG in various populations. In London, England, there was little evidence of infection during the first 2 years of life. However, the prevalence of NV IgG rose steadily throughout the period that children attend school, reaching a peak of 70% in the group aged 11–16 years. High levels of maternal antibody were detected in infants aged <3 months. Comparison of the acquisition of antibodies to three strains of human calicivirus in Japanese children in northern Japan indicated that although the majority had experienced infection with strains Japan and UK1 by the age of 12 years, only 22% possessed antibodies to NV. In Australian aborigines NV infection occurs early in life; by the age of 6 years over 90% of children were seropositive. © 1994 Wiley-Liss, Inc.     

中医药多途径介入低预后再次IVF-ET拮抗剂方案患者卵巢功能、中医证候及自孕的临床疗效评估

目的 分析中医药多途径介入对体外受精-胚胎移植（IVF-ET）失败后拟再次接受IVF-ET拮抗剂方案低预后（肾阴虚肝郁血瘀证）患者卵巢功能、中医证候及自然受孕情况的影响。方法 选取2020年8月至2023年2月在四川大学华西第二医院、成都中医药大学附属医院就诊拟再次接受IVF-ET拮抗剂方案助孕且符合纳入标准的肾阴虚肝郁血瘀证低预后患者128例,按随机对照表分为观察组和对照组,每组各有患者64例。对照组采用口服脱氢表雄酮（DHEA）治疗,观察组采用多途径中医药（口服中药汤剂+耳穴贴压+补肾活血方导法）治疗。经过3个月经周期的治疗后,收集两组患者的卵巢功能评估相关指标,中医证候评分和自然受孕情况。结果 与本组治疗前比较,观察组患者基础卵泡刺激素（bFSH）、基础卵泡刺激素/基础黄体生成激素（bFSH/bLH）值、基础雌二醇（bE₂）、窦卵泡数（AFC）、获卵数、正常受精数、优胚数、中医证候评分在治疗后均有明显改善（P<0.05,P<0.01）,对照组患者bFSH/bLH、中医证候评分均较治疗前升高（P<0.05）,而bFSH、bE₂、AFC值、获卵数、正常受精数、优胚数差异无统计学意义。治疗后观察组患者bFSH、bFSH/bLH、bE₂、AFC、正常受精数、优胚数、中医证候评分改善情况均优于对照组（P<0.05,P<0.01）,而获卵数差异无统计学意义。治疗后,观察组自然受孕3人,而对照组无自然受孕者。结论 对于IVF-ET失败后,拟再次接受IVF-ET拮抗剂方案的肾阴虚肝郁血瘀证低预后患者,通过多途径的中医药干预,可以降低bFSH、bFSH/bLH值、改善bE₂水平,增加AFC、获卵数、正常受精数和优胚数,改善卵巢功能、月经状况和中医证候,提高生活质量,使部分患者在再次进周前自然受孕,改善妊娠结局。     

不同机制大动脉粥样硬化型脑卒中基线特征和血管内治疗后结局比较

目的 本研究旨在比较颅内大血管伴/不伴同侧颈内动脉闭塞的大动脉粥样硬化型脑卒中患者基线特征以及行血管内治疗后结局的差异。方法 对DIRECT-MT亚组进行回顾性分析,以比较前循环大动脉粥样硬化（large-artery atherosclerosis,LAA）型卒中串联闭塞和颅内闭塞接受血管内治疗（endovascular treatment,EVT）的患者的基线特征和预后,分析不同机制学特征（动脉粥样硬化或动脉-动脉栓塞）对临床结局的影响。结果 LAA型卒中患者共108例,其中串联闭塞63例,颅内闭塞45例。颅内闭塞组患者高血压史率高于串联闭塞组（77.8% vs. 52.4%, P=0.007）。颅内闭塞组闭塞部位最常见于大脑中动脉M1段（88.6%）,而串联闭塞组颅内闭塞主要位于颈内动脉颅内段（49.2%）和大脑中动脉M1段（49.2%）（P＜0.001）。两组患者在年龄、性别、术前抗栓、他汀类药物的使用,卒中、房颤、吸烟史,基线mRS、NIHSS评分,是否静脉溶栓,侧枝循环,以及救治流程时间差异均无统计学意义（P均＞0.05）。90天mRS 0-2分的患者比例两组差异无统计学意义（53.3% vs. 41.9%, P=0.243）。颅内闭塞组术后成功再灌注率高于串联闭塞组（93.3% vs. 77.4%, P=0.026）,但术后24-72小时血管再通的比例前组低于后组（57.1% vs. 77.2%, P=0.034）。最终梗死体积,颅内闭塞组小于串联闭塞组（20.1 vs. 34.5, P=0.025）。术后NIHSS评分,90天EQ-5D-5L评分和BI指数等其他次要结局,两组间差异无统计学意义（P均＞0.05）。两组在90天内的死亡率,发生的无症状性和症状性颅内出血率,5-7天时在另外的血管区域新发脑梗死,以及新流域栓塞的患者百分比相似,差异无统计学意义（P均＞0.05）。结论 动脉粥样硬化导致的串联闭塞相较于孤立颅内闭塞,末次造影成功再灌注率较低,梗死体积更大,但术后24-72小时再通率更高,且神经功能良好预后率以及不良事件发生率均与颅内闭塞相仿。     

Homer 1b/c通过内质网功能调节由谷氨酸诱发的HT22细胞自噬

目的　研究Homer1b/c蛋白在谷氨酸诱发的细胞自噬中的作用及机制。方法　选用小鼠海马细胞系HT22细胞,通过500 ?mol/L谷氨酸处理建立细胞损伤模型。用siRNA慢病毒转染方式下调Homer1b/c表达和10 ?mol/LBAPTA-AM（1,2-双(2-氨基苯氧基)乙烷-N,N,N`,N`-四乙酸四乙酸甲酯,钙离子螯合剂）、10 mmol/L4-PBA（4-苯基丁酸,内质网应激抑制剂）分别抑制细胞内钙离子释放和内质网应激后,使用蛋白质印迹法检测Homer1b/c,自噬蛋白Beclin-1、微管相关蛋白轻链3（LC3）,以及内质网应激标志蛋白CHOP（人内质网应激相关蛋白）、GRP-78(葡萄糖调节蛋白78)的表达水平。每组实验均进行3次,采用独立样本t检验和单因素方差分析进行统计学分析。结果　谷氨酸处理HT22细胞12 h后,Beclin-1表达和LC3-Ⅱ/LC3-Ⅰ比值均升高（P<0.05）,下调Homer1b/c表达可降低Beclin-1表达和LC3-Ⅱ/LC3-Ⅰ比值的升高程度（P<0.05）。抑制细胞内钙离子释放和抑制内质网应激均能降低Beclin-1表达和LC3-Ⅱ/LC3-Ⅰ比值的升高程度（P<0.05）。然而在下调Homer1b/c表达后,抑制细胞内钙离子释放和抑制内质网应激未能进一步降低Beclin-1表达和LC3-Ⅱ/LC3-Ⅰ比值的升高程度（P<0.05）。结论　Homer1b/c能够调节谷氨酸诱导的自噬,其调节作用可能与内质网功能有关。