Recombinant Sendai viruses with L1618V mutation in their L polymerase protein establish persistent infection, but not temperature sensitivity

The Sendai virus pi strain (SeVpi) isolated from cells persistently infected with SeV shows mainly two phenotypes: (1) temperature sensitivity and (2) an ability of establishing persistent infection (steady state). Three amino acid substitutions are found in the Lpi protein and are located at aa 1088, 1618, and 1664. Recombinant SeV(Lpi) (rSeV(Lpi)) having all these substitutions is temperature sensitive and is capable of establishing persistent infection (steady state). rSeVs carrying the fragment containing L1618V show both phenotypes. rSeV(L1618V), in which leucine at aa 1618 is replaced with valine, has the ability of establishing persistent infection, but is not a temperature-sensitive mutant, indicating that the ability of a virus to establish persistent infection can be separated from temperature sensitivity. The amino acid change at 1618(L-->V) coexisting with aa 1169 threonine is required for acquirement of a temperature-sensitive phenotype. Three amino acid substitutions are also found in the Ppi protein, but rSeV(Ppi) does not show these phenotypes.     

RPI卡环受力分析与临床应用

本文讨论了常规设计的游离端义齿存在的问题,并对Kratochvil提出的RPI卡环,结合力学知识,提出了RPI卡环在游离端义齿应用中的优缺点,并通过典型病例介绍和对20名病例随访分析表明,用RPI卡环修复游离端牙齿缺失,可获得较好的临床效果。     

国产全热解碳双叶瓣的动物实验

目的 :探讨人造瓣膜动物实验的方法 ,并对国产瓣的性能作动物体内评价。方法 :体外循环下行羊的二尖瓣替换术 ,先作预实验以确定实验方法 ,后作正式实验。用心导管和超声 ,并用多巴酚丁胺负荷法模拟运动条件 ,分别测定人造瓣的血流动力学参数 ;根据动物存活情况及有无血栓形成和血栓栓塞等评价其生物相容性。结果 :预实验 10只羊均死亡 ,主要与瓣环撕裂有关 ;正式实验 5只羊均存活。术中和术后 2 .5年用导管法测得平均跨瓣压差分别为 0 .69± 0 .2 3k Pa、0 .81± 0 .0 4k Pa;动物尸检未见血栓形成和血栓栓塞。结论 :瓣环撕裂是本组手术主要死亡原因 ,选择适当体重的动物和保留瓣叶的折叠缝补 ,及术后合理的呼吸支持等是实验的关键 ;该国产瓣在动物体内血流动力学和抗血栓性能优良     

银康颗粒剂治疗银屑病252例疗效观察

目的:观察纯中药制剂银康颗粒剂治疗银屑病的,临床疗效及治疗前后患者血粘度的变化。方法:将382例患者随机分为2组,治疗组252例应用银康颗粒剂治疗,对照组130例应用复方青黛胶囊治疗;对治疗组部分病例(212例)治疗前后血粘度指标进行观察。结果:治疗组治愈148例,好转82例,未愈22例,总有效率为91.12％;对照组治愈51例,好转46例,未愈33例,总有效率为74.62％,2组总有效率比较,差异有非常显著性意义(P<0.01)。治疗组患者治疗前后全血粘度差异无显著性意义(P>0.05),血浆粘度差异有显著性意义(P<0.05)。结论:风邪外袭、血虚生风、气滞血瘀是致病的主要原因。治疗应以清热祛风与养血活血并举。     

"树皮年轮"质疑

目的：评述“树皮年轮”的概念及其应用于判断树龄的科学性。方法：在广泛查阅相关文献资料的基础上，对“树皮年轮”的概念及其在判断树龄方面应用的科学性问题进行了综合分析。结果：虽然韧皮部纤维存在分层排列的现象，但是不能称其为“年轮”。因为呈带状排列的纤维束的数目，在每个生长季节不总是固定的，有的甚至缺乏韧皮部纤维；并且次生韧皮部在次生生长过程中的数量有限，还会随着树皮逐渐剥落。结论：因此，认为“树皮年轮”的提法缺乏科学性，也不能作为判断树龄的依据。     

银翘解毒丸中金银花药材HPLC-UV鉴定及绿原酸含量测定

目的:建立银翘解毒丸(金银花,连翘,甘草,薄荷等)中金银花药材的鉴别和绿原酸含量测定的方法.方法:采用YWG C18色谱柱;甲醇-10%的磷酸氢二钠(冰醋酸调pH值为2.7)为流动相进行梯度洗脱;检测波长为326nm;流速为1.0mL·min-1;柱温为室温.结果:HPLC-UV法定性鉴别制剂中金银花药材;绿原酸在5.0～60μg·mL-1的范围内呈良好线性关系(r=0.9999),平均回收率为98.71%(RSD=1.57%).结论:本法操作简单,准确,重现性好,可用于银翘解毒丸的质量控制.     

Reduction of oocyte lipid droplets and meiotic failure due to biotin deficiency was not rescued by restoring the biotin nutritional status

BACKGROUND/OBJECTIVESOocyte lipid droplets play a crucial role in meiosis and embryo development. Biotin is associated with fatty acid synthesis and is the coenzyme for acetyl-CoA carboxylase (ACC). The effects of a biotin deficiency on the oocyte lipid metabolism remain unknown. This study examined the effects of a biotin deficiency and its replenishment on murine 1) oocyte lipid droplet levels, 2) ovary lipid metabolism, and 3) oocyte meiosis.MATERIALS/METHODSMice were divided into 3 groups: control, biotin deficient (BD), and recovery groups. The control and BD groups were fed a control diet or BD diet (0.004 or 0 g biotin/kg), respectively. The recovery group mice were fed a BD diet until day 21, and were then fed the control diet from days 22 to 64. This study then quantified the oocyte lipid droplet levels, assessed the oocyte mitochondrial function, and examined the ability of oocytes to undergo meiosis. Ovarian phosphorylated ACC (p-ACC), lipogenesis, β-oxidation, and ATP production-related genes were evaluated.RESULTSThe BD group showed a decrease in lipid droplets and mitochondrial membrane potential and increased p-ACC levels. In the recovery group, the hepatic biotin concentration, ovarian p-ACC levels, and mitochondrial membrane potential were restored to the control group levels. On the other hand, the quantity of lipid droplets in the recovery group was not restored to the control levels. Furthermore, the percentage of oocytes with meiotic abnormalities was higher in the recovery group than in the control group.CONCLUSIONSA biotin deficiency reduced the oocyte lipid droplet levels by downregulating lipogenesis. The decreased lipid droplets and increased oocyte meiosis failure were not fully restored, even though the biotin nutrition status and gene expression of lipid metabolism was resumed. These results suggest that a biotin deficiency remains robust and can be long-lasting. Biotin might play a crucial role in maintaining the oocyte quality.     

多参数MRI联合临床危险因素术前预测直肠癌淋巴血管间隙侵犯的应用价值

目的 探讨多参数 MRI 联合临床危险因素术前预测直肠癌淋巴血管间隙侵犯（LSVI）的价值。 方法 回顾性分析池州市人民医院 2022 年 4 月至 2023 年 11 月经术后病理证实的 38 例直肠癌患者的临床及影像学资料,所有患者均行常规 MRI、合成 MRI及 IVIM-DWI 序列扫描。依据术后病理结果分为 LVSI 阳性组（n=14）和 LVSI 阴性组（n=24）。采用单因素和多因素 logistic 回归分析LVSI 阳性组和 LVSI 阴性组的临床资料,分析 LVSI 的临床危险因素;比较两组患者合成 MRI （T1 值、T₂ 值、PD 值）及 IVIM-DWI 参数（D值、D*值、f 值）,采用受试者工作特征（ROC）曲线评价各定量参数预测模型及联合临床危险因素预测模型的诊断效能。 结果 合成MRI 的 T₂ 值及 IVIM-DWI 的 D 值、f 值在直肠癌 LVSI 阳性组和阴性组中比较差异具有统计学意义（P＜0.05）。术前 CEA（OR=10.818,95%CI：1.391~84.124）及临床 N 分期（OR=11.852,95%CI：1.534~91.552）是直肠癌 LVSI 的独立危险因素（P＜0.05）。单独的 T₂ 值、D 值、f 值及三者联合的曲线下面积（AUC）分别为 0.801、0.747、0.766、0.807,联合临床危险因素的预测模型效能最高（AUC=0.845）,灵敏度为 78.58%,特异度为 100%。 结论 多参数 MRI 术前可有效预测直肠癌 LVSI 的状态,结合临床危险因素的联合预测模型可进一步提升预测效能,有助于临床医师制定个性化直肠癌治疗方案。