The bridging function of hepatic lipase clears plasma cholesterol in LDL receptor-deficient "apoB-48-only" and "apoB-100-only" mice

Hepatic lipase clears plasma cholesterol by lipolytic and nonlipolytic processing of lipoproteins. We hypothesized that the nonlipolytic processing (known as the bridging function) clears cholesterol by removing apoB-48- and apoB-100-containing lipoproteins by whole particle uptake. To test our hypotheses, we expressed catalytically inactive human HL (ciHL) in LDL receptor deficient "apoB-48-only" and "apoB-100-only" mice. Expression of ciHL in "apoB-48-only" mice reduced cholesterol by reducing LDL-C (by 54%, 46 +/- 6 vs. 19 +/- 8 mg/dl, P < 0.001). ApoB-48 was similarly reduced (by 60%). The similar reductions in LDL-C and apoB-48 indicate cholesterol removal by whole particle uptake. Expression of ciHL in "apoB-100-only" mice reduced cholesterol by reducing IDL-C (by 37%, 61 +/- 19 vs. 38 +/- 12 mg/dl, P < 0.003). Apo-B100 was also reduced (by 27%). The contribution of nutritional influences was examined with a high-fat diet challenge in the "apoB-100-only" background. On the high fat diet, ciHL reduced IDL-C (by 30%, 355 +/- 72 vs. 257 +/- 64 mg/dl, P < 0.04) but did not reduce apoB-100. The reduction in IDL-C in excess of apoB-100 suggests removal either by selective cholesteryl ester uptake, or by selective removal of larger, cholesteryl ester-enriched particles. Our results demonstrate that the bridging function removes apoB-48- and apoB-100-containing lipoproteins by whole particle uptake and other mechanisms.     

The outer membrane usher forms a twin-pore secretion complex

The PapC usher is an outer membrane protein required for assembly and secretion of P pili in uropathogenic Escherichia coli. P pilus biogenesis occurs by the chaperone/usher pathway, a terminal branch of the general secretory pathway. Periplasmic chaperone-subunit complexes target to the PapC usher for fiber assembly and secretion through the usher to the cell surface. The molecular details of pilus biogenesis at the usher, and protein secretion across the outer membrane in general, are unclear. We studied the structure and oligomeric state of PapC by gel filtration, dynamic light scattering, and electron microscopy and image analysis. Two-dimensional crystals of wild-type PapC and a C-terminal deletion mutant of PapC were produced by reconstituting detergent purified usher into E.coli lipids. PapC formed a dimer both in detergent solution and in the phospholipid bilayer. Cryo-electron microscopy revealed that the usher forms a twin-pore complex. Removal of the C-terminal domain did not change the basic shape of the PapC molecule, but altered the dimeric association of the usher, suggesting that the C terminus forms part of the dimerization interface. The overall molecular size (11 nm), pore size (2 nm), and twin-pore configuration of PapC resemble that of the Tom40 complex, a mitochondrial outer membrane protein translocase.     

门诊妇女阴道乳酸菌对临床常用抗生素耐药性的初步研究

目的研究临床常用抗生素类药物对妇女生殖道正常菌群乳酸菌的影响,为临床医生选用抗生素治疗妇科疾病提供初步参考,并为微生态学治疗和预防相关疾病提供理论依据。方法采用K-B法（纸片扩散法）,以临床采集到的12株阴道乳酸菌为试验菌,研究其对临床常用9大类13种抗生素的耐药性。结果在所测试的抗生索中,试验菌对甲硝唑形成的耐药环直径最小,对头孢噻肟形成的耐药直径最大。除甲硝唑外不同菌株对不同抗生索形成的耐药环直径差异较大。结论在该试验的条件下,乳酸菌对甲硝唑耐药性最强,可作为治疗阴道感染的首选药物;乳酸菌对头孢噻肟最敏感,因而在治疗阴道感染时,应尽量避免使用该药物。     

仙台病毒核衣壳蛋白基因的克隆与原核表达

目的利用原核表达系统表达仙台病毒(Sendai Virus,SV)核衣壳蛋白。方法根据GenBank上发表的仙台病毒(Sendai Virus,SV)核衣壳蛋白基因序列,设计并合成一对引物,通过RT-PCR扩增出核衣壳蛋白全长cDNA序列,将其克隆至原核表达载体pET-30a,转化大肠杆菌BL21(DE3)PlysS,于37℃1mmol/LIPTG条件下诱导表达,大肠杆菌裂解物经SDS-PAGE分析,在相对分子质量约60×103处出现一新蛋白带,与预期目的蛋白分子量相符。结果Western blot检测表明,表达产物能与兔抗SV阳性血清发生特异性反应,出现单一反应带,表明其具有免疫原性。结论为建立以重组NP蛋白为诊断抗原检测SV奠定基础。     

罗布麻的形态解剖研究--兼论中花罗布麻的分类问题

详细描述了3种罗布麻的形态解剖特征,指出它们的主要区别。对中花罗布麻的分类地位作了讨论,可将它作为罗布白麻的一个变型或变种,归纳入罗布白麻(Apocynum hendersonii Hook.f.)之中,暂可称为:中花罗布麻(Apocynum hendersonii Hook.f.var.salsuginodum Rus.)。但不应将它作为Apocynum pictum Schrenk或Poacynum pictum(Schrenk)Baill.看待。     

罗布麻资源利用与罗布麻植物分类问题

叙述了有关罗布麻分类的简要历史,讨论了我国罗布麻的植物分类问题,从植物分类学的依据和生产实践的需要考虑,应将我国罗布麻植物划分为1属2种,即罗布麻属（Apocynum L．）和罗布红麻（A．venetum L．）及罗布白麻（A．hendersonii Hook．f．）2种。     

A new inducible adenoviral expression system that responds to inflammatory stimuli in vivo

BACKGROUND: Gene transfer using inducible promoters, which control expression of transgenic proteins in response to physiological conditions, may have significant advantages. In this study, we tried to achieve an inducible adenoviral expression system for physiologically responsive gene therapy of autoimmune or inflammatory diseases. METHODS: A luciferase reporter vector with a hybrid promoter containing the human IL-1beta enhancer region (-3690 to - 2720) and the human CIITA promoter IV (-399 to + 2) was constructed. A replication-deficient adenovirus was engineered with luciferase controlled by the IL1beta/CIITApIV promoter (Ad-IL1beta/CIITApIV-Luc). The reporter vector or adenovirus was transfected to C57Bl/6 myeloid dendritic cells (DCs), RAW264.7, and Hep G2 to study the in vitro characteristics of this hybrid promoter. An inflammation model was prepared by injecting lipopolysaccharide (LPS) into Balb/c mice intraperitoneally (i.p.), and infected with Ad-IL1beta/CIITApIV-Luc or Ad-CMV-Luc to study the in vivo characteristics of the IL1beta/CIITApIV promoter. RESULTS: The IL1beta/CIITApIV hybrid promoter has pronounced promoter activity, broad-range responsiveness to cytokines or LPS, and can be rechallenged after first induction. In the inflammation model, IL1beta/CIITApIV could drive hepatic luciferase expression increasedly rapidly after LPS challenge and in a LPS dose-dependent manner. CONCLUSIONS: Using the IL1beta/CIITApIV hybrid promoter in gene transfer vectors may make it possible to produce transgenic proteins in vivo in direct relationship with the intensity and duration of an individual's status. By providing endogenously controlled production of transgenic proteins, this approach might limit the severity of autoimmune or inflammatory response without interfering with the beneficial components of host defense and immunity.     

中国苔类新记录种——疣茎类钱袋苔

报道产于西藏和云南的中国苔类植物缺萼苔科类钱袋苔属1 个新记录种: 疣茎类钱袋苔Ap omarsup ella
crystallocaulon ( Grolle) Vana。该种主要特征为茎皮部细胞角质层具透明疣, 有别于本科其他种类。     

缺失型Duchenne/Becker 肌营养不良家系女性携带者及新发突变的确认

应用多重PCR（multiple polymerase reaction／mPCR）技术,联合DMD基因内部及附近11个短串连重复序列（short tandem repeats,STRs）位点连锁分析,对缺失型Duchenne／Beeker肌营养不良（Duchenne／Becker Muscular Dystrophy,DMD／BMD）家系成员进行DMD基因分型,确定家系中女性成员是否携带者,并进行产前诊断。3个家系中的4名缺失型患者,其中2例为新发突变：4位女性成员中,1名为携带者。应用mPCR和11个STRs的连锁分析,能快速、准确、客观判断家系中女性成员是否携带者身份,适于DMD／BMD临床研究机构遗传咨询、基因诊断和产前诊断常规应用。但在mPCR分析过程中,发现45号外显子扩增产物在不同凝胶中电泳迁移率不同。聚丙烯酰胺凝胶电泳（Polyacrylamide Gels Electrophoresis／PAGE）对mPCR产物分析快速、清晰,但需要注意片段迁移率,以防止分析错误。     

糖尿病视网膜病变的基因治疗

糖尿病视网膜病变（diabetic retinopathy,DR）是糖尿病的主要并发症之一,大量的研究表明DR早期表现为视网膜神经细胞退化性改变,晚期出现新生血管及增殖膜,目前尚没有有效的治疗方法,严重危害患者视力。基因治疗为探索DR的治疗方法提供了新的手段,本文就目前DR的基因治疗研究现状和进展作一综述。