壳寡聚糖抑制变形链球菌的致龋能力

目的研究壳寡聚糖(chitooligosaccharide,COS)对变形链球菌生长、产酸及粘附能力的影响。方法选用变形链球菌标准株ATCC 25175,采用对倍稀释法测定COS对变形链球菌的最低抑菌浓度(minimum inhibitory concentration,MIC)和最低杀菌浓度(minimum bactericidal concentration,MBC);采用菌落计数法,通过时间—杀菌曲线的变化,分析COS对细菌生长速度的影响;将COS及变形链球菌菌悬液各1 m L接种于无菌试管内厌氧培养,使COS的终浓度分别达到1/2 MIC、1/4 MIC、1/8MIC,测定上清液p H变化并绘制p H曲线;采用液体闪烁计数法测定壳寡聚糖对变形链球菌粘附羟磷灰石能力的影响。结果 COS对变形链球菌的MIC和MBC分别为2.00 g/L和4.00 g/L;COS能有效抑制变形链球菌的生长,较高浓度时对细菌还具有杀菌作用。亚抑菌浓度的COS可显著影响变形链球菌的产酸性和粘附能力,并且这种抑制作用呈浓度依赖性。结论 COS对变形链球菌的生长、产酸和粘附能力均有抑制作用。     

乙型肝炎病毒基因组S区编码产物的检测及临床意义

为了进一步明确 ＨＢＶ基因组 Ｓ区编码产物对乙型病毒性肝炎诊断的临床价值，用双抗体夹心 ＥＬＩＳＡ法检测 ９０份乙型病毒性肝炎患者血清标本ＨＢｓＡｇ·ＰＨＳＡ－Ｒｅ、Ｐｒｅ－Ｓ１和 Ｐｒｅ－Ｓ２，并与 ＨＢＶＭ及 ＨＢＶＤＮＡ ＰＣＲ进行对比分析。结果以抗 ＨＢｃ、ＨＢｓＡｇ·ＰＨＳＡ－Ｒｅ、ＨＢＶＤＮＡ（ＰＣＲ）及 Ｐｒｅ－Ｓ２的阳性检出率为最高，分别为８７．８％、７３．３％、７２．２％和６４．４％，以ＨＢＶＤＮＡ作为ＨＢＶ感染的金标准，无显著性差异（Ｐ＞０．０５）；其中ＨＢｓＡｇ·ＰＨＳＡ－Ｒｅ与 ＨＢＶＤＮＡ和ＨＢｅＡｇ的符合率最高，分别为 ７６．７ ％和 ７４．７ ％；ＭＢｓＡｇ·ＰＨＳＡ－Ｒｅ与 ＨＢＶＤＮＡ具有高度相关性。ＨＢｓＡｇ·ＰＨＳＡ－Ｒｅ做为早期诊断ＨＢＶ感染及判断是否具有传染性方面，是一项非常重要的血清学指标，Ｐｒｅ－Ｓ２也可作为ＨＢＶ复制活跃的标志之一，用于急慢性肝炎的预后判断．     

Mitochondrial dysfunctions,endothelial progenitor cells and diabetic retinopathy

Aim

Diabetic retinopathy (DR) is the leading cause of vision loss in the working age population. Endothelial progenitor cells (EPC) play a vital role in vascular damage repair. This article will review recent progress regarding mitochondrial and EPC dysfunction associated with DR.

Insulin resistance in non-diabetic patients with non-alcoholic fatty liver disease: sites and mechanisms

Aims/Hypothesis Non-alcoholic fatty liver disease (NAFLD) has been associated with the metabolic syndrome. However, it is not clear whether insulin resistance is an independent feature of NAFLD, and it remains to be determined which of the in vivo actions of insulin are impaired in this condition.Methods We performed a two-step (1.5 and 6 pmol min^–1 kg^–1) euglycaemic insulin clamp coupled with tracer infusion ([6,6-²H₂]glucose and [²H₅]glycerol) and indirect calorimetry in 12 non-obese, normolipidaemic, normotensive, non-diabetic patients with biopsy-proven NAFLD and six control subjects.Results In NAFLD patients, endogenous glucose production (basal and during the clamp) was normal; however, peripheral glucose disposal was markedly decreased (by 30% and 45% at the low and high insulin doses, respectively, p<0.0001) at higher plasma insulin levels (p=0.05), due to impaired glucose oxidation (p=0.003) and glycogen synthesis (p<0.001). Compared with control subjects, glycerol appearance and lipid oxidation were significantly increased in NAFLD patients in the basal state, and were suppressed by insulin to a lesser extent (p<0.05–0.001). The lag phase of the in vitro copper-catalysed peroxidation of LDL particles was significantly shorter in the patients than in the control subjects (48±12 vs 63±13 min, p<0.04). Lipid oxidation was significantly related to endogenous glucose production, glucose disposal, the degree of hepatic steatosis, and LDL oxidisability.Conclusions/interpretation Insulin resistance appears to be an intrinsic defect in NAFLD, with the metabolic pattern observed indicating that adipose tissue is an important site.     

Exploring consequences of short- and long-term deafness on speech production: A lip-tube perturbation study

Studies have reported strong links between speech production and perception. We aimed to evaluate the role of long- and short-term auditory feedback alteration on speech production. Eleven adults with normal hearing (controls) and 17 cochlear implant (CI) users (7 pre-lingually deaf and 10 post-lingually deaf adults) were recruited. Short-term auditory feedback deprivation was induced by turning off the CI or by providing masking noise. Acoustic and articulatory measures were obtained during the production of /u/, with and without a tube inserted between the lips (perturbation), and with and without auditory feedback. F1 values were significantly different between the implant OFF and ON conditions for the pre-lingually deaf participants. In the absence of auditory feedback, the pre-lingually deaf participants moved the tongue more forward. Thus, a lack of normal auditory experience of speech may affect the internal representation of a vowel.     

Preclinical Testing Oncolytic Vaccinia Virus Strain GLV-5b451 Expressing an Anti-VEGF Single-Chain Antibody for Canine Cancer Therapy

Virotherapy on the basis of oncolytic vaccinia virus (VACV) strains is a novel approach for canine cancer therapy. Here we describe, for the first time, the characterization and the use of VACV strain GLV-5b451 expressing the anti-vascular endothelial growth factor (VEGF) single-chain antibody (scAb) GLAF-2 as therapeutic agent against different canine cancers. Cell culture data demonstrated that GLV-5b451 efficiently infected and destroyed all four tested canine cancer cell lines including: mammary carcinoma (MTH52c), mammary adenoma (ZMTH3), prostate carcinoma (CT1258), and soft tissue sarcoma (STSA-1). The GLV-5b451 virus-mediated production of GLAF-2 antibody was observed in all four cancer cell lines. In addition, this antibody specifically recognized canine VEGF. Finally, in canine soft tissue sarcoma (CSTS) xenografted mice, a single systemic administration of GLV-5b451 was found to be safe and led to anti-tumor effects resulting in the significant reduction and substantial long-term inhibition of tumor growth. A CD31-based immuno-staining showed significantly decreased neo-angiogenesis in GLV-5b451-treated tumors compared to the controls. In summary, these findings indicate that GLV-5b451 has potential for use as a therapeutic agent in the treatment of CSTS.     

锥形单腔多侧孔加长肌肉注射针头的研制及临床应用

目的探讨减轻肌肉注射时针头对局部组织的损伤方法。方法采用研制锥形单腔多侧孔加长肌肉注射针头与传统注射针头,单盲法试验比较,选择注射药物参数完全相同。操作护士相对固定,实验组每日8:00用锥形单腔多侧孔加长针头进行肌肉注射;对照组选择右侧臀部,每日16:00用传统针头进行肌肉注射,在同一病人的左、右侧臀部进行注射对照试验。观察患者的疼痛程度和硬结出现率。所获数据采用X2检验。结果 60例患者624次肌肉注射配效果比较:应用锥形单腔多侧孔加长针头行肌肉注射后局部疼痛、硬结发生率明显减少,两组比较P<0.005,有非常显著性差异。结论锥形单腔多侧孔加长肌肉注射针头疼痛感减轻,硬结发生率低。     

慢性心力衰竭动物模型的制作进展

建立合适的慢性心力衰竭(CHF)动物模型是研究其发病机制及治疗措施的首要条件.稳定可靠的动物模型不仅对新药的开发具有促进作用,也为CHF的发病机制和病理生理改变提供重要资料.目前常用的制作方法主要有药物腹腔注射损伤心肌、结扎冠状动脉左前降支造成心肌梗死、快速起搏致心动过速心肌病、通过手术建立瓣膜关闭不全或动静脉分流造成容量超负荷及通过缩窄腹主动脉造成压力超负荷等.