Systematic comparison of adeno‐associated virus and biotinylated dextran amine reveals equivalent sensitivity between tracers and novel projection targets in the mouse brain

As an anterograde neuronal tracer, recombinant adeno‐associated virus (AAV) has distinct advantages over the widely used biotinylated dextran amine (BDA). However, the sensitivity and selectivity of AAV remain uncharacterized for many brain regions and species. To validate this tracing method further, AAV (serotype 1) was systematically compared with BDA as an anterograde tracer by injecting both tracers into three cortical and 15 subcortical regions in C57BL/6J mice. Identical parameters were used for our sequential iontophoretic injections, producing injections of AAV that were more robust in size and in density of neurons infected compared with those of BDA. However, these differences did not preclude further comparison between the tracers, because the pairs of injections were suitably colocalized and contained some percentage of double‐labeled neurons. A qualitative analysis of projection patterns showed that the two tracers behave very similarly when injection sites are well matched. Additionally, a quantitative analysis of relative projection intensity for cases targeting primary motor cortex (MOp), primary somatosensory cortex (SSp), and caudoputamen (CP) showed strong agreement in the ranked order of projection intensities between the two tracers. A detailed analysis of the projections of two brain regions (SSp and MOp) revealed many targets that have not previously been described in the mouse or rat. Minor retrograde labeling of neurons was observed in all cases examined, for both AAV and BDA. Our results show that AAV has actions equivalent to those of BDA as an anterograde tracer and is suitable for analysis of neural circuitry throughout the mouse brain. J. Comp. Neurol. 522:1989–2012, 2014. © 2014 Wiley Periodicals, Inc.     

Lower prediagnostic serum 25-hydroxyvitamin D concentration is associated with higher risk of insulin-requiring diabetes: a nested case–control study

Aims/hypothesis

Low serum 25-hydroxyvitamin D [25(OH)D] concentration may increase risk of insulin-requiring diabetes.

Methods

A nested case–control study was performed using serum collected during 2002–2008 from military service members. One thousand subjects subsequently developed insulin-requiring diabetes. A healthy control was individually matched to each case on blood-draw date (±2?days), age (±3?months), length of service (±30?days) and sex. The median elapsed time between serum collection and first diagnosis of diabetes was 1?year (range 1?month to 10?years). Statistical analysis used matched pairs and conditional logistic regression.

Results

ORs for insulin-requiring diabetes by quintile of serum 25(OH)D, from lowest to highest, were 3.5 (95% CI 2.0, 6.0), 2.5 (1.5, 4.2), 0.8 (0.4, 1.4), 1.1 (0.6, 2.8) and 1.0 (reference) (p _trend <0.001). The quintiles (based on fifths using serum 25(OH)D concentration in the controls) of serum 25(OH)D in nmol/l, were <43 (median 28), 43–59 (median 52), 60–77 (median 70), 78–99 (median 88) and ≥100 (median 128).

Conclusions/interpretation

Individuals with lower serum 25(OH)D concentrations had higher risk of insulin-requiring diabetes than those with higher concentrations. A 3.5-fold lower risk was associated with a serum 25(OH)D concentration ≥60?nmol/l.     

RNA干扰酪氨酸激酶受体2对人脐静脉内皮细胞增殖的影响

目的研究抑制酪氨酸激酶受体2（Tie2）对内皮细胞凋亡和增殖活性的影响。方法采用RNA干扰技术,将含有Tie2基因的特异性短发夹状RNA（shRNA）片段的质粒转染入人脐静脉内皮细胞（HUVECs）,采用实时定量逆转录聚合酶链反应和免疫印迹法检测细胞中Tie2 mRNA和蛋白表达的改变;噻唑蓝比色分析（MTT）法检测细胞的生
长情况;显微镜下观察细胞凋亡情况。以转染了pGenesil-hk质粒组为阴性对照,未转染质粒组为空白对照。结果质粒转染入HUVECs后,实验组细胞中Tie2 mRNA和蛋白表达水平较阴性对照组和空白对照组下调,尤以转染后48 h Tie2的mRNA和蛋白表达水平下调更为明显（P<0.05）。MTT检测结果显示：实验组细胞的增殖活性受到明显抑制（P<0.05）。转染48 h后,实验组的细胞凋亡率明显高于两个对照组（P<0.05）。结论RNA干扰技术沉默Tie2基因可致Tie2基因表达下调后诱导HUVECs凋亡,并抑制HUVECs的增殖。     

本科口腔医学生牙科色彩学教学效果评价

目的:探讨本科口腔医学生牙科色彩学教学的效果。方法:对43名口腔医学专业五年级本科生进行牙科色彩学教学培训,包括色彩学基础知识及VITA3D-MASTER比色板的比色技巧和应用方法,比较教学前后学生的比色成绩差异及男、女生比色结果差异。结果:色彩学教学后学生的比色成绩有明显提高(P<0.05),男生和女生比色成绩差异无统计学意义(P>0.05)。结论:牙科色彩学教学可以明显提高本科口腔医学生的色彩识别能力。     

OSAHS诊断:AG与PSG、头影测量比较研究

目的:比较AG监测与多导睡眠监测(PSG)和头颅侧位片头影测量结果,评价几种检查方法对于睡眠呼吸障碍疾病性质、严重程度及阻塞定位诊断的准确性。方法:利用美国杰西AG200系统对36名成年男性阻塞性睡眠呼吸暂停低通气综合征(OSAHS)患者行上气道-食道压力监测,将AG结果与PSG结果和头颅侧位片头影测量结果进行对比分析。结果:AG和PSG测得的AHI、最低血氧、阻塞性暂停低通气次数/h无差异;测得的平均血氧、阻塞性暂停次数/h有差异。头颅侧位片头影测量和AG对于主要阻塞平面的判定结果间有差异;头颅侧位片显示的某平面气道最小前后径与AG测得的平均每小时该平面阻塞次数在腭后区呈线性相关,在舌后区无线性相关关系。结论:AG系统具备了便携PSG的功能,能对睡眠呼吸疾病作出准确的初步定性诊断,且能较准确地进行上气道阻塞定性定位。