低碘膳食对大鼠脑组织中同源盒基因NKX－2.2表达的影响

目的：探讨低碘膳食对大鼠脑组织同源盒基因Nkx－2.2表达的影响,揭示低碘导致脑发育迟滞的可能分子作用机制。方法：雌性Wistar大鼠随机分为2组：低碘组和正常对照组,均饲以低碘饲料,分别饮用去离子水和碘酸钾溶液,3个月后分别取材于孕16天、新生及20日鼠龄低碘及正常仔鼠,实时荧光定量PCR检测其脑组织中Nkx－2.2 mRNA含量。结果：低碘组血清甲状腺激素水平明显低于对照组(P＜0.05或P＜0.01）,建立缺碘Wistar大鼠动物模型。低碘及正常各年龄组的表达水平随着年龄增加表达趋势不一致,但均有明显差别（F=573.68、120.82, P<0.01)。各年龄组低碘及正常大鼠比较,孕16天正常鼠Nkx－2.2表达水平明显高于低碘鼠(t=6.86, P<0.01),而新生及20日龄低碘鼠Nkx－2.2表达水平明显高于正常鼠(t=15.85、10.61, P<0.01)。结论：同源盒基因Nkx－2.2表达差异与低碘导致脑发育迟滞密切相关。     

Anisotropism of the Non-Smooth Surface of Butterfly Wing

Twenty-nine species of butterflies were collected for observation and determination of the wing surfaces using a ScanningElectron Microscope(SEM).Butterfly wing surface displays structural anisotropism in micro-,submicro- and nano-scales.Thescales on butterfly wing surface arrange like overlapping roof tiles.There are submicrometric vertical gibbosities,horizontallinks,and nano-protuberances on the scales.First-incline-then-drip method and first-drip-then-incline method were used tomeasure the Sliding Angle(SA)of droplet on butterfly wing surface by an optical Contact Angle(CA)measuring system.Relatively smaller sliding angles indicate that the butterfly wing surface has fine self-cleaning property.Significantly differentSAs in various directions indicate the anisotropic self-cleaning property of butterfly wing surface.The SAs on the butterfly wingsurface without scales are remarkably larger than those with scales,which proves the crucial role of scales in determining theself-cleaning property.Butterfly wing surface is a template for design and fabrication ofbiomimetic materials and self-cleaningsubstrates.This work may offer insights into how to design directional self-cleaning coatings and anisotropic wetting surface.     

抑郁症模型大鼠学习记忆能力变化研究

为探讨抑郁症发生发展过程中学习记忆能力的变化模式及其可能机制．分别采用21天慢性非预见性刺激法和嗅球切除法建立的抑郁症模型大鼠．运用旷场行为实验（open—field behavior）检测大鼠主动性活动能力,用Morris水迷宫法检测大鼠空间学习记忆能力,HPLC—UV法测定大鼠血清皮质醇含量。电生理法记录海马CA1区LTP与LTD,观察海马神经元的突触可塑性。结果显示：与对照组相比,两种模型的自主活动性、空间探索兴趣和学习能力都明显降低,而记忆的反馈功能没有明显的变化。同时．两种模型大鼠海马神经细胞的突触可塑性显著下降,血清皮质醇的含量则明显上升。提示两种建模方法均导致大鼠产生抑郁症状和学习能力障碍．但对记忆反馈功能无明显影响。     

2型糖尿病患者血清RANTES与下肢大血管病变的相关性

目的:探讨2型糖尿病(T2DM)患者血清RANTES与下肢大血管病变的相关性.方法:(1)T2DM 61例,根据是否合并下肢大血管病变,分为非下肢大血管病变组(30例)和下肢大血管病变组(31例),与正常对照组20例比较,采用双抗体夹心ELISA法测定血清RANTES,比较三组间血清RANTES水平的差异.(2)测定各组TG、TC、LDL、Hd1-ch、、FPG、HbA1c、FIB等水平,分析其与2型糖尿病大血管病变的相关性.结果:(1)2型糖尿病组血清RANTES水平明显高于正常对照组(P<0.05),下肢大血管病变组血清RANTES水平明显高于非下肢大血管病变组和正常对照组(P<0.05),(2)以T2DM组为整体,有无下肢大血管病变为因变量Y(有=1,无=0),以RANTES等其它危险因素为自变量,进行Logstic回归分析,SBP、病程和RANTES入回归方程.结论:RANTES可能是T2DM下肢大血管病变的一个重要的独立危险因素.     

Mesenchymal stem cells as a gene therapy carrier for treatment of fibrosarcoma

Background aimsCell-based gene therapy is an alternative to viral and non-viral gene therapy. Emerging evidence suggests that mesenchymal stem cells (MSC) are able to migrate to sites of tissue injury and have immunosuppressive properties that may be useful in targeted gene therapy for sustained specific tissue engraftment.MethodsIn this study, we injected intravenously (i.v.) 1 × 10⁶ MSC, isolated from green fluorescent protein (GFP) transgenic rats, into Rif-1 fibrosarcoma-bearing C3H/HeN mice. The MSC had been infected using a lentiviral vector to express stably the luciferase reporter gene (MSC-GFP-luci). An in vivo imaging system (IVIS 200) and Western blotting techniques were used to detect the distribution of MSC-GFP-luci in tumor-bearing animals.ResultsWe observed that xenogenic MSC selectively migrated to the tumor site, proliferated and expressed the exogenous gene in subcutaneous fibrosarcoma transplants. No MSC distribution was detected in other organs, such as the liver, spleen, colon and kidney. We further showed that the FGF2/FGFR pathways may play a role in the directional movement of MSC to the Rif-1 fibrosarcoma. We performed in vitro co-culture and in vivo tumor growth analysis, showing that MSC did not affect the proliferation of Rif-1 cells and fibrosarcoma growth compared with an untreated control group. Finally, we demonstrated that the xenogenic MSC stably expressing inducible nitric oxide synthase (iNOS) protein transferred by a lentivirus-based system had a significant inhibitory effect on the growth of Rif-1 tumors compared with MSC alone and the non-treatment control group.ConclusionsiNOS delivered by genetically modified iNOS-MSC showed a significant anti-tumor effect both in vitro and in vivo. MSC may be used as a target gene delivery vehicle for the treatment of fibrosarcoma and other tumors.     

Differential stepwise evolution of SARS coronavirus functional proteins in different host species

Background  

SARS coronavirus (SARS-CoV) was identified as the etiological agent of SARS, and extensive investigations indicated that it originated from an animal source (probably bats) and was recently introduced into the human population via wildlife animals from wet markets in southern China. Previous studies revealed that the spike (S) protein of SARS had experienced adaptive evolution, but whether other functional proteins of SARS have undergone adaptive evolution is not known.     

In vitro drug release behavior from a novel thermosensitive composite hydrogel based on Pluronic f127 and poly(ethylene glycol)-poly(ε-caprolactone)-poly(ethylene glycol) copolymer

Background  

Most conventional methods for delivering chemotherapeutic agents fail to achieve therapeutic concentrations of drugs, despite reaching toxic systemic levels. Novel controlled drug delivery systems are designed to deliver drugs at predetermined rates for predefined periods at the target organ and overcome the shortcomings of conventional drug formulations therefore could diminish the side effects and improve the life quality of the patients. Thus, a suitable controlled drug delivery system is extremely important for chemotherapy.