检测体内异种II型胶原异体移植引起的细胞毒反应

检测用猪II型胶原免疫新西兰大白兔的异种异体细胞免疫反应。用II型胶原免疫新西兰大白兔60 d,定期抽取血浆检测抗II型胶原抗体;第60 d取兔的外周血淋巴细胞、兔脾细胞、淋巴结分别分离淋巴细胞,进行体外二次II型胶原刺激,检测由此引起的反应性的细胞增殖规律。实验分为二组,第一组加入不同浓度植物血凝素(PHA)作阳性对照,并测定非特异性免疫;第二组加入不同浓度II型胶原,检测特异性免疫。正常兔的淋巴细胞在PHA剌激下发生增殖,但对II型胶原的第一次剌激不发生增殖,而免疫兔对PHA和II型胶原的剌激均能发生显著的增殖。表明异种II型胶原在一定浓度下,可以引起免疫兔的抗II型胶原抗体的升高,并可引起兔脾、外周血淋巴细胞增殖,异种II型胶原能在体内引起细胞免疫反应。     

健脾补肾药对脾虚大鼠细胞因子水平的影响

目的 :观察健脾补肾方药对实验性脾虚证大鼠细胞因子的影响 ,探讨脾虚证与细胞因子的关系及脏腑相关的意义。方法 :选用SD雄性大鼠 ,随机分为 :正常对照组 ,脾虚模型组 ,健脾补肾方高、低剂量组 ,通过大黄复制脾虚证动物模型 ,并用健脾补肾方药进行防治。采用放射免疫分析观察各组动物血清肿瘤坏死因子(TNF)、白细胞介素 - 6 (IL - 6 )、白细胞介素 - 2 (IL - 2 )水平的变化。结果 :脾虚模型组大鼠血清TNF、IL - 6、IL - 2含量均比正常对照组显著降低 (p <0 0 1) ,而健脾补肾方药能明显升高TNF、IL - 6、IL - 2含量 ,使体重增加 ,脾脏和胸腺组织的重量增加。结论 :脾虚证的发生与细胞因子网络调节系统的失衡有关 ,而健脾补肾中药对实验性脾虚证有较好的防治作用 ,脾肾相关理论对实践有指导意义。     

PENA方法的建立及与ELISA IgM检测CMV的比较

目的　介绍一种敏感、稳定、快速、简便的实验室检测CMV的方法 ,同时探讨该种新方法与ELISA检测CMV方法的优、缺点。方法　对 5 5 2例病人应用间接荧光免疫法测定细胞核中的特异病毒早期抗体 (PENA)和ELISA法测定IgM抗体。结果　PENA方法 :强阳性 88例 ,阳性率 15 4 9% ,弱阳性 2 73例 ,阳性率 5 9 4 6 % ;ELISA -IgM方法 :阳性 34例 ,阳性率6 16 %。结论　PENA方法操作简便 ,与ELISA方法相比较 ,可对CMV感染进行早期测定及诊断 ,并可区分既往感染和即时感染 ,具有敏感性和稳定性 ,是测定小儿CMV感染的一种较好的方法     

GDF-8 propeptide binds to GDF-8 and antagonizes biological activity by inhibiting GDF-8 receptor binding

GDF-8 is a new member of the TGF-beta superfamily which appears to be a negative regulator of skeletal muscle mass. Factors which regulate the biological activity of GDF-8 have not yet been identified. However, the biological activities of TGF-beta superfamily members, TGF-beta1, -beta2 and -beta3, can be inhibited by noncovalent association with TGF-beta1, -beta2 and beta3 propeptides cleaved from the amino-termini of the TGF-beta precursor proteins. In contrast, the propeptides of other TGF-beta superfamily members do not appear to be inhibitory. In this investigation, we demonstrate that purified recombinant GDF-8 propeptide associates with purified recombinant GDF-8 to form a noncovalent complex, as evidenced by size exclusion chromatography and chemical crosslinking analysis. Furthermore, we show that GDF-8 propeptide inhibits the biological activity of GDF-8 assayed on A204 rhabdomyosarcoma cells transfected with a (CAGA)12 reporter construct. Finally, we demonstrate that GDF-8 propeptide inhibits specific GDF-8 binding to L6 myoblast cells. Collectively, these data identify the GDF-8 propeptide as an inhibitor of GDF-8 biological activity.     

Frequent allelic loss of 21q11.1 approximately q21.1 region in advanced stage oral squamous cell carcinoma

A fine mapping of loss of heterozygosity (LOH) was performed in oral squamous cell carcinoma (OSCC), using 12 markers on 21q11.1 approximately q21.1. We studied 43 resected primary invasive tumors and their paired normal tissues, concurrent dysplasia or carcinoma in situ in separate areas from 8 of the specimens, and 6 local recurrent carcinomas. LOH status was compared between lesions of different phases of progression within the same patient. A high frequency of LOH was observed for D21S1410, D21S120, and D21S1433 (60% each) in the primary lesions, constituting two interstitial deleted regions encompassing eight known genes. Cases showing LOH of D21S120 were significantly associated with advanced clinical stages (III and IV; P=0.02). Consistent allelic loss was observed in 64.2% of the informative cases between the precursor lesions and their corresponding invasive tumors, and in 59.5% of those between the primary lesions and their recurrent counterparts. Fewer than half of the different lesions within a given patient showed discordant allelic loss for tested markers. Our results suggest that 21q11.1 approximately q21.1 harbors tumor suppressor genes in OSCC. Genetic divergence may develop during tumor clone evolution.     

Acrylic‐Based Polyurethane/Silica Hybrids Prepared by Acid‐Catalyzed Sol–Gel Process: Structure and Mechanical Properties

Summary: Silica sols were first prepared based on different ratios of tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) by an acid‐catalyzed sol–gel process, and then incorporated into acrylic‐based polyurethanes. The structures and morphologies of silicone‐oxo clusters were studied by ²⁹Si NMR, SAXS, and scanning electron microscopy (SEM), whereas the mechanical properties of polyurethane/silica hybrids were characterized by DMA and tensile tests. The silicone‐oxo clusters in both silica sol and polyurethane hybrids became denser and larger at a higher molar ratio of TEOS/MTES and higher silica content, and the silica‐oxo clusters of polyurethane/silica hybrids even became more compact and larger than those of silica sols, increasing the elastic modulus and tensile strength of polyurethane/silica hybrids.

Typical structure of silica sol prepared from the hydrolysis and condensation of TEOS and MTES with acid as the catalyst.     

Rapid Identification of Yeasts Commonly Found in Positive Blood Cultures by Amplification of the Internal Transcribed Spacer Regions 1 and 2

A multiplex PCR method using one universal and eight species-specific primers was developed to rapidly identify eight yeast species found in positive blood cultures. The species-specific primers were designed from the internal transcribed spacer regions 1 and 2 of the rRNA gene, whereas the universal primer was located at the 26S rRNA gene. The eight species were Candida albicans, Candida glabrata, Candida guilliermondii, Candida krusei, Candida lusitaniae, Candida parapsilosis, Candida tropicalis, and Cryptococcus neoformans. The PCR products (116 to 630 bp) were different in length and could be effectively separated and recognized by polyacrylamide gel electrophoresis. By testing 234 positive blood cultures (237 isolates), 234 (98.7%) isolates of the above eight species were correctly identified by the multiplex PCR. The present method is simple to perform and can be completed within 6 h.     

Ovarian serous cystadenoma with mural nodules of genital rhabdomyoma

We present an extremely rare case of ovarian serous cystadenoma with mural nodules of rhabdomyoma. The patient, a 48-year-old woman, was admitted to our hospital with left lower abdominal pain and vaginal bleeding. A unilocular cystic tumor, measuring 13 x 10 x 10 cm, was found in her left ovary and was removed. The tumor contained clear serous fluid, approximately 600 mL, and 2 mural nodules, up to 7.5 x 5.5 x 4.5 cm. The internal cystic wall was thin for the most part and lined with ciliated cuboidal epithelium without any malignant feature. The mural part was composed of mainly more mature muscle fibers with easily discernible cross-striations, set in abundant myxoid to fibromyxoid stroma, similar to clinical and microscopic manifestations of genital rhabdomyomas reported in other sites. Because extracardiac rhabdomyoma has never been described occurring in the ovary, especially arising in serous cystadenoma, to our knowledge, this is the first case reported in the English literature.     

Characterization of cortical neuron outgrowth in two- and three-dimensional culture systems

To improve the ability of regeneration by grafting living cells or by adding growth factor to a lesion site, it is important to find good biomaterials for neuron survival and regeneration. This study focused on two- and three-dimensional cultures in a matrix using biomaterials such as agarose, collagen, fibrin, and their mixtures, because these are considered to be suitable biomaterials for neuron outgrowth. Cortical neurons were dissected from E17 rat embryos and cultured in agarose gel, collagen gel, fibrin glue, and mixtures of collagen and fibrin. Results showed that neurons cultured in collagen gel and fibrin glue had longer periods of survival (more than 3 weeks) and better neurite extension than those observed in agarose gels. As to the survival rate according to the MTT and lactate dehydrogenase assays, fibrin glue was the most suitable biomaterial for neuron survival among the biomaterials examined. With two-dimensional fibrin plating, neuron cells exhibited cell aggregation and stress fibers, but the same results were not observed with collagen gel. There were no differences in neurite extension and survival in the mixtures of collagen and fibrin. The results suggest that collagen and fibrin can provide a suitable substrate for a three-dimensional culture matrix for neuronal survival and differentiation.     

Protective efficacy in chickens, geese and ducks of an H5N1-inactivated vaccine developed by reverse genetics

We generated a high-growth H5N1/PR8 virus by plasmid-based reverse genetics. The virulence associated multiple basic amino acids of the HA gene were removed, and the resulting virus is attenuated for chickens and chicken eggs. A formalin-inactivated oil-emulsion vaccine was prepared from this virus. When SPF chickens were inoculated with 0.3 ml of the vaccine, the hemagglutinin-inhibition (HI) antibody became detectable at 1 week post-vaccination (p.v.) and reached a peak of 10log2 at 6 weeks p.v. then slowly declined to 4log2 at 43 weeks p.v. Challenge studies performed at 2, 3 and 43 weeks p.v. indicated that all of the chickens were completely protected from disease signs and death. Ducks and geese were completely protected from highly pathogenic H5N1 virus challenge 3 weeks p.v. The duration of protective immunity in ducks and geese was investigated by detecting the HI antibody of the field vaccinated birds, and the results indicated that 3 doses of the vaccine inoculation in geese could induce a 34 weeks protection, while 2 doses induced more than 52 weeks protection in ducks. We first reported that an oil-emulsion inactivated vaccine derived from a high-growth H5N1 vaccine induced approximately 10 months of protective immunity in chickens and demonstrated that the oil-emulsion inactivated avian influenza vaccine is immunogenic for geese and ducks. These results provide useful information for the application of vaccines to the control of H5N1 avian influenza in poultry, including chickens and domestic waterfowl.