Chain Growth Polycondensation as a Polymer Generating Reaction in the Synthesis of Oligo(p‐phenyleneethynylene)s with Low Polydispersity

Summary: The polycondensation of 1‐ethynyl‐2,5‐dihexyl‐4‐iodobenzene in the presence of 1‐ethynyl‐2,5‐dihexyl‐4‐(2‐phenylethynyl)benzene proceeds according to the mechanism of initiated chain growth polycondensation. It has allowed the synthesis of oligomers with a desired molecular weight and a narrow molecular weight distribution. The reasons for the side reaction leading to the formation of diyne compounds are revealed and the presumed mechanism is given. This opens prospects for the preparation of defectless poly(p‐phenyleneethynylene)s with required molecular weights and narrow molecular weight distributions.

     

Conjugation of DNA fragments to protein carriers by glutaraldehyde: immunogenicity of oligonucleotide-hemocyanin conjugates

The practical realization of the concept of specific immunotherapy for systemic lupus erythematosus (SLE) has been hampered, thus far, by an inability to link DNA fragments to carrier protein. In this paper, a novel technique is described, in which glutaraldehyde is the linking agent. A 2-stage method was used to link oligonucleotides to a soluble protein carrier, such as keyhole limpet hemocyanin (KLH) or human gamma globulin (HGG), whereas a 1-stage technique was sufficient to link oligonucleotides to sheep red cells. Both the ultraviolet absorbance spectrum and diphenylamine assay demonstrated that oligonucleotides were coupled to soluble protein. The conjugate of oligonucleotide to protein carrier appears to be recognized by anti-DNA antibody since oligonucleotide linked to either KLH or HGG inhibited the binding of anti-DNA antibody in vitro, and oligonucleotide-coupled sheep cells are agglutinating by seropositve sera from lupus patients. In addition, oligonucleotide-KLH raised hemagglutinating antibody to denatured DNA in C57BL/6, DBA/2 or NZB mice, as well as IgG antibody as detected by SPRIA in C57BL/6 and DBA/2 mice. The significance of this new method for the development of an antigen specific therapy of SLE is discussed.     

高F值寡肽混合物对四氯化碳损伤大鼠血液生化指标的影响

利用CCl4对肝脏损伤的大鼠来检测高F值寡肽混合物对肝脏功能的保护作用和修复作用 .试验表明 ,高F值寡肽混和物能有效地保护大鼠肝细胞 ,减轻由CCl4导致的肝损伤 .     

Characterisation of a novel conjugate of ibuprofen with 3‐hydroxybutyric acid oligomers

Objectives A conjugate of ibuprofen with 3‐hydroxybutyric acid oligomers has been evaluated as a novel drug delivery model system. Methods This paper focuses on the synthesis and the characterisation of the physicochemical properties of this conjugate, and on hydrolysis studies in aqueous buffers and simulated intestinal fluid. We also describe the development of an analytical method (HPLC) for hydrolysis studies of this compound. Key findings The conjugate had high stability in aqueous solutions of pH 6–8 and underwent slow enzymatic hydrolysis. Conclusions This conjugate is not well suited for oral administration but might be considered a candidate for development of prodrug preparations for parenteral or topical sustained release.     

Soluble proteins produced by probiotic bacteria regulate intestinal epithelial cell survival and growth

BACKGROUND & AIMS: Increased inflammatory cytokine levels and intestinal epithelial cell apoptosis leading to disruption of epithelial integrity are major pathologic factors in inflammatory bowel diseases. The probiotic bacterium Lactobacillus rhamnosus GG (LGG) and factors recovered from LGG broth culture supernatant (LGG-s) prevent cytokine-induced apoptosis in human and mouse intestinal epithelial cells by regulating signaling pathways. Here, we purify and characterize 2 secreted LGG proteins that regulate intestinal epithelial cell antiapoptotic and proliferation responses. METHODS: LGG proteins were purified from LGG-s, analyzed, and used to generate polyclonal antibodies for immunodepletion of respective proteins from LGG-conditioned cell culture media (CM). Mouse colon epithelial cells and cultured colon explants were treated with purified proteins in the absence or presence of tumor necrosis factor (TNF). Akt activation, proliferation, tissue injury, apoptosis, and caspase-3 activation were determined. RESULTS: We purified 2 novel proteins, p75 (75 kilodaltons) and p40 (40 kilodaltons), from LGG-s. Each of these purified protein preparations activated Akt, inhibited cytokine-induced epithelial cell apoptosis, and promoted cell growth in human and mouse colon epithelial cells and cultured mouse colon explants. TNF-induced colon epithelial damage was significantly reduced by p75 and p40. Immunodepletion of p75 and p40 from LGG-CM reversed LGG-CM activation of Akt and its inhibitory effects on cytokine-induced apoptosis and loss of intestinal epithelial cells. CONCLUSIONS: p75 and p40 are the first probiotic bacterial proteins demonstrated to promote intestinal epithelial homeostasis through specific signaling pathways. These findings suggest that probiotic bacterial components may be useful for preventing cytokine-mediated gastrointestinal diseases.     

他莫西芬联合十一酸睾酮治疗特发性少精及弱精子症的临床观察

目的探讨他莫西芬和十一酸睾酮联合应用对男性特发性少精、弱精症精液参数及生殖激素水平的影响。方法将60例特发性少弱精症患者随机分成Tc组、Tu组及TT组,各20例。分别接受他莫西芬、十一酸睾酮、他莫西芬和十一酸睾酮联合应用,于1个月、3个月取患者精液分别进行精子形态学分析,检测精子数量（密度）、精子活力（a＋b百分率）及血清中FSH、LH、T水平。结果治疗1个月后,他莫西芬和十一酸睾酮联合应用组（TT组）精子的数量、活力及功能明显改善,血清中FSH、LH水平升高,T水平变化不大;3个月后,精子的数量,活力及功能等显著提高,血清中FSH、LH、T水平明显升高,均显著优于Tc组及Tu组（P〈0.01或P〈0.05）。结论他莫西芬与十一酸睾酮联合应用能够显著提高特发性少弱精症患者精液主要参数,改善生殖激素水平。     

单分散PPE齐聚物的合成及其荧光性质

合成了PPE的齐聚物{1，4-二[3，5-二（3-甲基-3-羟基-1-丁炔基）苯炔基]苯）（4），通过^1H—NMR对其结构进行表征，并对其荧光性质做了研究。研究结果表明引入四个2-甲基-2-羟基-丁炔基作为取代基团后，溶解性提高。取代基的引入导致齐聚物4旋转阻力增大，溶液荧光有明显的精细结构。而4具有较好的荧光单色性，因而是一种潜在的新型荧光发射材料。     

The reaction of glial progenitor cells in remyelination following ethidium bromide‐induced demyelination in the mouse spinal cord

The present study investigated how glial progenitor cells participated in the process of remyelination following ethidium bromide (EBr)‐induced demyelination in the adult mouse spinal cord. In situ hybridization techniques for detecting mRNA for platelet‐derived growth factor α receptor (PDGFαR) and proteolipid protein (PLP) were employed to identify glial progenitor cells and mature oligodendrocytes, respectively. During the demyelination stage and early stage of remyelination, large cells strongly expressing PDGFαR mRNA were observed in the border of the demyelinating lesion, and with immunohistochemistry they exhibited positive labeling of the astrocytic marker glial fibrillary acidic protein (GFAP). Other glial progenitor cells expressing PDGFαR mRNA proliferated around the lesion during the demyelination stage. During the remyelination stage, some PDGFαR mRNA‐positive cells partly expressed mRNA for PLP in the periphery of the demyelinating lesion. These results suggest that PDGFαR mRNA‐positive glial progenitor cells may give rise to both astrocytes and oligodendrocytes, which participate in remyelination following demyelination.