伊文氏蓝染色对大鼠脑内肿瘤生物学标记方法的研究

目的研究在大鼠脑内肿瘤模型中生物学染色标记脑内肿瘤的方法。方法选择F344大鼠,移植体外培养的RG2胶质瘤细胞制作脑内肿瘤模型,移植18d后经大腿静脉注射伊文氏蓝(Evans blue,EB)染色肿瘤组织,探讨生物学染色对脑内肿瘤的标示作用和手术中对肿瘤和周围正常脑组织鉴别的意义。结果EB浓度在100mg/kg时,肿瘤组织染色成鲜明蓝色,同时大鼠的皮肤和所有器官都被染色成蓝色;当浓度低于10mg/kg时,仅染色肿瘤组织而皮肤和其他器官不被染色;肉眼可鉴别的最低静注浓度为1.25mg/kg。肿瘤组织的染色效果持续到静注后96h。血清中EB浓度在静注后3h内迅速减少,之后呈缓慢代谢过程,静注后24h减少到静注浓度的38%,静注后24h EB在血清和肿瘤组织中的浓度差达到最大值。染色后在手术显微镜下进行肿瘤切除手术操作较未染色对照组明显容易,手术后切片组织学观察肿瘤被完全切除。结论EB生物学染色标记脑内肿瘤效果可靠,手术中作为肿瘤的标示鉴别肿瘤和周围正常脑组织的界限有效。     

文拉法辛缓释剂治疗伴或不伴高血压的老年期抑郁症对照研究

目的:探讨文拉法辛缓释剂对伴有高血压的老年期抑郁症的疗效和安全性。方法:使用文拉法辛缓释剂对30例伴有高血压的老年期抑郁症和30例无高血压的老年期抑郁症患者进行为期6周的对照治疗,在治疗前及治疗后第1、2、4、6周末评定汉密尔顿抑郁量表(HAMD 17项),并进行临床疗效评定, 监测血压,记录不良反应。结果:高血压组和非高血压组患者的HAMD评分均从第1周末起明显下降(P< 0．05或P<0．01),且一直持续至治疗第6周末。两组6周末的有效率和临床治愈率差异无显著性(P> 0．05)。高血压组患者使用文拉法辛缓释剂治疗后第2周末收缩压变化值显著高于非高血压患者(0．9±0．4, 0．6±0．5,P=0．01)。两组间的不良反应发生率差异无统计学意义(P>0．05)。结论:文拉法辛缓释剂治疗老年期抑郁症疗效肯定,不良反应少,对血压无明显影响。     

Assessing the Effectiveness of Front of Pack Labels: Findings from an Online Randomised-Controlled Experiment in a Representative British Sample

Front of pack food labels (FOPLs) provide accessible nutritional information to guide consumer choice. Using an online experiment with a large representative British sample, we aimed to examine whether FOPLs improve participants’ ability to identify the healthiness of foods and drinks. The primary aim was to compare ability to rank between FOPL groups and a no label control. Adults (≥18 years), recruited from the NatCen panel, were randomised to one of five experimental groups (Multiple Traffic Light, MTL; Nutri-Score, N-S; Warning Label, WL; Positive Choice tick, PC; no label control). Stratification variables were year of recruitment to panel, sex, age, government office region, and household income. Packaging images were created for three versions, varying in healthiness, of six food and drink products (pizza, drinks, cakes, crisps, yoghurts, breakfast cereals). Participants were asked to rank the three product images in order of healthiness. Ranking was completed on a single occasion and comprised a baseline measure (with no FOPL), and a follow-up measure including the FOPL as per each participant’s experimental group. The primary outcome was the ability to accurately rank product healthiness (all products ranked correctly vs. any incorrect). In 2020, 4504 participants had complete data and were included in the analysis. The probability of correct ranking at follow-up, and improving between baseline and follow-up, was significantly greater across all products for the N-S, MTL and WL groups, compared to control. This was seen for only some of the products for the PC group. The largest effects were seen for N-S, followed by MTL. These analyses were adjusted for stratification variables, ethnicity, education, household composition, food shopping responsibility, and current FOPL use. Exploratory analyses showed a tendency for participants with higher compared to lower education to rank products more accurately. Conclusions: All FOPLs were effective at improving participants’ ability to correctly rank products according to healthiness in this large representative British sample, with the largest effects seen for N-S, followed by MTL.     

Less Is Better: How Nutrition and Low-Carbon Labels Jointly Backfire on the Evaluation of Food Products

(1) Background: Labeling is one of the significant strategies to guide sustainable consumption behaviors. Nowadays, multi labels being displayed on the front-of-pack of food products is a common phenomenon. However, labels seldom operate solo, and competition or complement effects may be exerted on different labels. Therefore, the research objective is to explore the interaction effect when nutrition and low-carbon labels appear simultaneously; (2) Methods: Across four scenario-based experiments, including ice cream, yogurt, steak, and toast, this study manipulated the separate and joint occurrences of low-carbon and nutrition labels, the interaction effect of joint labels was tested, and the serial mediation model, which includes resource allocation and anticipated enjoyment of food consumption, was verified; (3) Results: Results show that people have a positive preference for the nutrition label and the carbon label, respectively, while these two labels working simultaneously attenuate the positive effect of the single label. When facing nutrition and carbon labels simultaneously, people would infer partial resources are allocated to healthy and environmental aspects so they have a lower anticipated enjoyment from food consumption. Thus, these two labels working simultaneously attenuate the positive effect of the single label, and consumers have a lower evaluation of food products. In addition, the joint backfire on the effect is only exerted on people with a higher level of zero-sum bias and only when joint labels have a high consistency of labels; (4) Conclusions: This study solved the contradictory problem of the joint effect of positive labels. The findings in this research contribute to promote sustainable food consumption. We suggest that similar labels should be avoided in the same front-of-pack of food, and manufacturers need to use ads to bring down consumers’ zero-sum bias.     

荧光标记mRNA差异显示技术在分离食管癌相关基因片段中的应用

目的 :以荧光标记的mRNA差异显示技术分离食管癌及其正常食管粘膜组织相关的差异基因片段。方法 :结合GenomyxLRTM DNA测序 /差异显示系统及GenomyxSCTM 荧光图象扫描系统 ,以及配套的FluoroDD和HI EROGLYPHmRNAProfileKit,采用荧光标记的mRNA差异显示技术进行检测。结果 :从人食管癌及正常食管粘膜组织间 ,同时直接分离出了相关的癌基因或抑癌基因片段 74条。结论 :该技术方便、快捷 ,值得推广应用     

基于集成神经网络的类风湿关节炎中医证候分类研究

目的 针对基于AI技术的类风湿关节炎（RA）中医证候多标签分类中存在标签关联性差、泛化性能低等问题,提出构建一种集成神经网络模型来实现RA中医证候分类,并探究其中的特征重要性和风险因素,为RA的诊断和治疗提供参考。方法 本文提出一种集成神经网络模型实现RA中医证候分类。该模型采用一种基于多层神经网络的基分类器提取临床RA多标签样本的深层特征,增强RA特征区分度,根据协方差理论衡量标签相关性,调节分类器链的输入空间,减少RA错误信息传播和冗余度,采用集成学习方法减小分类器链中不合理标签序列对RA特征分类的影响。结果 该模型在10折交叉验证性能参数中表现出优秀的性能,其中汉明损失、1-错误率、准确率和F1值分别为0.0036、0.0248、97.52%、99.18%。与其他常用多标签分类器相比,该模型的性能更为优秀具有更好的分类性能。此外,本文分析了RA中医证候特征重要性,并挖掘了潜在的风险因素。结论 基于集成神经网络模型的RA中医证候分类器具有较高的分类精度和效率,对于RA的临床诊断和治疗具有重要参考价值。     

The structure of human S-phase chromosome fibres

Recentin situ hybridization studies suggested that within the range of 0.1–1.0 Mb, human interphase chromosomes follow a random walk model (i.e. they behave as flexible polymers without major constraints). However, chromosome structure may differ in the G1, S, and G2 phases, and phase-specific constraints may be masked if the chromosome analysis does not discriminate between the phases. Therefore, using confocal microscopy, we examined the structure of S-phase chromosomes labelled with 5-iododeoxyuridine after prolonged treatment with 5-fluorodeoxyuridine. In the S-phase, labelled 0.32 µ chromosome fibres mostly appear as semi-circles with an average diameter of 0.83 ±0.03 µ. These semi-circles are joined together to form different 3D structures, and two semicircles frequently adopt s- or-like conformations involving about 2.5 µ of the chromosome contour length (L). Morphometric analysis of the S-phase fibres suggests that our data fit both the random flexible polymer model and also a model in which two constrained semi-circles are attached to each other by a flexible joint, thus eliminating constraints at long distances (L more than 2 µ).     

Pharmacokinetics of methyldopa in healthy man

Summary The pharmacokinetics of 2-¹⁴C-L--methyldopa have been investigated in five healthy volunteers following intravenous and oral administration. In the intravenous study a bi-phasic plasma concentration curve was found both for chemically determined -methyldopa and for radioactivity. The plasma level of radioactivity differed significantly from chemically determined drug, a pattern which was also found in urine. This suggests the presence of unidentified metabolite(s). The difference between plasma disappearance and urine recovery of -methyldopa and radioactivity during the first 4 h after injection suggests distribution to an extravascular compartment. Plasma half-lives of total radioactivity and of unchanged drug were calculated. In three subjects, pharmacokinetic parameters for a two-compartment open body model were calculated from urine and plasma data. Urinary recovery of radioactivity was almost complete within 48 h after intravenous administration. After oral administration, however, only about 40 per cent of the radioactive dose was recovered in the urine, and it contained approximately equal amounts of unconjugated methyldopa, acid-labile conjugated methyldopa and unidentified metabolite(s). The acid-labile conjugate was found only after oral administration, which supports the theory of a mucosal conjugation process. The lack of acid-labile conjugated drug either in the plasma or urine after intravenous injection indicates that there is no enterohepatic circulation of this drug.