Methuselah‐like genes affect development,stress resistance,lifespan and reproduction in Tribolium castaneum

Methuselah (Mth) is associated with lifespan, stress resistance and reproduction in Drosophila melanogaster, but Mth is not present in nondrosophiline insects. A number of methuselah‐likes (mthls) have been identified in nondrosophiline insects, but it is unknown whether the functions of mth are shared by mthls or are divergent from them. Five mthls have been identified in Tribolium castaneum. Although they have different developmental expression patterns, they all enhance resistance to starvation. Only mthl1 and mthl2 enhance resistance to high temperature, whereas mthl4 and mthl5 negatively regulate oxidative stress in T. castaneum. Unlike in the fly with mth mutation, knockdown of mthls, except mthl3, shortens the lifespan of T. castaneum. Moreover, mthl1 and mthl2 are critical for Tribolium development. mthl1 plays important roles in larval and pupal development and adult eclosion, while mthl2 is required for eclosion. Moreover, mthl1 and mthl2 silencing reduces the fertility of T. castaneum, and mthl1 and mthl4 are also essential for embryo development. In conclusion, mthls have a significant effect on insect development, lifespan, stress resistance and reproduction. These results provide experimental evidence for functional divergence among mthls/mth and clues for the signal transduction of Mthls.     

淋巴瘤病理诊断基础方法

文章主要介绍淋巴瘤病理诊断的基础方法,强调要做好以下三项,以提高淋巴瘤病理诊断的准确率.(1)正确观察淋巴结HE切片;(2)确定各类型不同体积细胞的参照细胞;(3)正确评估淋巴组织良恶性增生病变病理诊断的四要素.     

Comparing Humoral and Cellular Immune Response Against HBV Vaccine in Kidney Transplant Patients

Host protection upon vaccination usually results from the complex interplay of humoral and cellular components of the immune system. Exploring hepatitis B surface antigen (HBsAg)‐specific T cell responses and their correlation with humoral responses under immunosuppression, we analyzed 51 renal transplant recipients, differing in HBV vaccine–specific antibody titers (non [NRs]‐, low [LRs]‐, and high responders [HRs]) and in 22 healthy controls (HCs) in a cross‐sectional study. HBsAg‐specific T cells were analyzed by flow cytometry according to expression of activation markers CD40L and/or CD69, and the cytokines IFNγ, IL‐2, TNFα, and IL‐17. No significant differences in responder rate and magnitude of HBsAg‐specific T cell responses were found between HCs and HRs. Interestingly, HBsAg‐specific Th‐cells were also observed in 50% of humoral NRs. Frequencies of HBsAg‐specific CD40L+ Th‐cells were significantly higher in HRs compared to LRs (p = 0.009) and in LRs in comparison to NRs (p = 0.043). All but NRs showed a predominance of multi‐potent HBsAg‐specific TNFα+IL‐2+ Th‐cells. As expected, HBsAg‐specific CD8⁺ T cells were rarely found. In conclusion, mounting of hepatitis B vaccine‐specific T cell responses is possible in kidney transplant recipients despite immunosuppression. Detection of HBV‐specific Th‐cells in a significant proportion of humoral NRs contributes to the current discussion on conferring immune protection by cellular memory in such patients.     

丙泊酚通过上调纤维细胞生长因子的表达激活磷酸肌醇3激酶-蛋白激酶B和磷酸化细胞外信号调节激酶1/2信号通路抑制体外培养神经元缺血/再灌注损伤

目的 探讨丙泊酚在脑缺血/再灌注损伤(ischemia/reperfusion injury,I/RI)中发挥的作用及其具体机制. 方法 采用氧糖剥夺再灌注(oxygen-glucose deprivation/reperfusion,OGD/RP)法体外构建缺血/再灌注细胞模型,将细胞分为对照组、OGD/RP组、丙泊酚+OGD/RP组.采用甲基噻唑基四唑(methyl thiazolyl tetrazolium,MTT)法检测皮质神经细胞存活率,Annexin V-PI检测细胞凋亡情况,即时聚合酶链式反应(real-time polymerase chain reaction,RT-PCR)方法检测碱性成纤维细胞生长因子(basic fibroblast growth factor,bFGF)的mRNA表达情况,免疫印迹法(Western blot)检测丙泊酚对皮质神经细胞内bFGF,磷酸化蛋白激酶B(phosphorylated protein kinase B,pAkt)以及磷酸化细胞外信号调节激酶1/2 (phosphorylated extr acellular signal-regulated kinase 1/2,pERK 1/2)蛋白表达的影响;采用小干扰RNA构建bFGF沉默的细胞. 结果 OGD/RP处理组神经细胞凋亡率为43.2％,经10 mg/L的丙泊酚预处理后,细胞的凋亡率降为19.5％.与对照组比较,OGD处理后,细胞中bFGF的含量显著下调(P＜0.05),丙泊酚处理的皮质神经元中bFGF含量显著高于OGD处理组(P＜0.05).丙泊酚能够上调pAKT以及pERK1/2的表达,激活这两条信号通路.沉默bFGF或者施加磷酸肌醇3激酶-蛋白激酶B(phosphotylinosital 3 kinase-protein kinase B,PI3K-Akt)以及pERK1/2信号通路抑制剂都会导致细胞存活率显著下降(P＜0.05),抑制PI3K-Akt以及pERK1/2的激活. 结论 丙白酚可以通过上调bFGF的表达,激活PI3K-Akt和ERK 1/2信号通路,增加皮质神经元的存活.     

大鼠胸段脊髓损伤后后肢神经肌肉的自然变化

目的:观察大鼠完全性脊髓损伤后损伤平面以下周围神经和骨骼肌的自然变化,为脊髓损伤治疗与康复相关基础研究提供科学依据。方法:将50只健康成年雌性SD大鼠随机分为对照组(A组)5只、假手术组(B组)10只和脊髓损伤组(C组)35只,B组行单纯椎板切除术;C组在椎板切除基础上用横断法制成T10完全脊髓损伤模型。分别对3组大鼠术前,B组术后1、2周,C组术后1、2、4、12、24周进行BBB评分,并检测腓肠肌的运动单位计数(motor unit number estimation,MUNE);再于各时间点处死大鼠,取坐骨神经和腓肠肌内侧头,应用光镜和透射电镜观察坐骨神经-运动终板-腓肠肌的形态变化。对3组所有结果进行对比分析。结果:C组术后各时间点的BBB评分与术前及A组、B组比较差异均有统计学意义(P0.05),C组术后4周时的BBB评分与其他时间点比较差异均有统计学意义(P0.05)。C组术前MUNE数值与A组、B组比较差异无统计学意义(P0.05);C组术后各时间点与术前比较差异均有统计学意义(P0.05),术后4周与24周比较差异无统计学意义,其余各时间点比较差异均有统计学意义(P0.05)。A组和B组术后1、2周时坐骨神经有髓神经纤维髓鞘外形正常。C组术后1、2周时与A组、B组无明显差异;4周时部分有髓神经纤维髓鞘崩解、板层分离;12周时髓鞘崩解明显增多,高倍电镜观察见崩解的髓鞘板层清晰;24周时有髓神经纤维髓鞘崩解、融合,新生神经纤维管细壁薄,无髓神经纤维增多,高倍电镜观察见崩解的髓鞘板层模糊。A组肌细胞肌束膜及肌内膜边界清晰,肌细胞核位于肌膜下方。B组术后1、2周时与对照组无明显区别。C组术后1、2周时,除肌细胞截面积轻度缩小外,与对照组无明显不同;4周时肌细胞截面积缩小,局部肌细胞破坏;12周时多数肌细胞边界模糊,细胞核相对聚集,结缔组织增生明显;24周时肌细胞融合,细胞核密集,融合细胞间可见大小不一空隙,结缔组织增生更加明显。A组和B组术后1、2周运动终板结构清晰完整。C组术后1、2、4周时运动终板结构较A组、B组无明显差别;术后12周时相对完好运动终板与破坏运动终板并存,高倍电镜下观察见突触前膜、突触间隙、突触后膜层次分明,各层结构内可见细小颗粒,突触间隙内可见多个类圆形突触小泡,肌板清晰,同时也可见突触皱褶及突触前、后膜不可辨,肌板结构不清晰;术后24周时找不到运动终板。结论:大鼠完全横断性脊髓损伤后损伤平面以下周围神经和骨骼肌形态结构随时间退变程度逐步加重甚至消失;损伤后12周时已有明显变化,24周时出现显著的结构损害和功能丧失。     

Effects of low power red laser on induced-dental caries in rats

OBJECTIVE: The purpose of this study was to investigate the effects of low power red laser associated with acidulated phosphate fluoride on the development of induced-dental caries in rats. DESIGN: Dental caries were induced in molars of 40 rats divided into five groups: control group (CG), the teeth were not submitted to any treatment; laser group (LG), teeth were irradiated with a low power red laser (LPRL), power of 30 mW and dose of 5 J/cm(2); fluoride group (FG), teeth were treated with topical acidulated phosphate fluoride (APF) 1.23% applied for 4 min; laser+fluoride group (LFG), teeth were irradiated with LPRL followed by APF; fluoride+laser group (FLG), teeth were treated with APF followed by LPRL. The animals were killed after 48 days, and the first and second molars were extracted to analyze the caries lesion area, microhardness, and calcium and phosphorus ratio. RESULTS: There were no statistical differences among FG, LFG, and FLG regarding to caries area and microhardness, although the caries area were smaller in LFG. Ca/P ratio did not show significant differences among all groups. CONCLUSIONS: Although LPRL before APF application appeared to diminish the caries progression, LPRL did not present any additional benefit compared with acidulated phosphate fluoride on the prevention of induced-dental caries in rats.     

定量缓释基因重组碱性成纤维细胞生长因子／聚乳酸-聚羟基乙酸植入片的制备及体外释药研究

目的制备基因重组碱性成纤维细胞生长因子／聚乳酸-聚羟基乙酸（rbFGF／PLGA）定量缓释植入片，观察其一般性质、体外释药特性和rbFGF生物活性维持情况。方法溶剂挥发法制备rbFGF／PLGA植入片，用ELISA双抗体夹心法测定植入片中rbFGF含量，进行体外释药试验，检测rbFGF释放速度和含量，并将植入片植入兔下颌牵张成骨区局部缓慢释放观察rbFGF活性。结果rbFGF／PLGA植入片表面光滑平整，质地均匀，rbFGF含量为3.613μg／片。标准曲线方程为C=1280，54A-99.21（n=7，r^2=0.9952），线性范围15.6，1000pg／ml。植入片体外第1天释放rbFGF 10.70％，第9天累积释放51％，第20天释放达到80％以上。兔下颌牵张成骨实验结果显示植入组新骨形成速度和质量均优于对照组。结论rbFGF／PLGA植入片制备工艺良好，植入片中rbFGF生物活性保存良好，具有定量缓释作用并能促进牵张成骨中新骨形成的速度和质量。