Short-term enzyme replacement in the murine model of Sanfilippo syndrome type B

The Sanfilippo syndrome type B (MPS III B) is an autosomal recessive disease caused by deficiency of alpha-N-acetylglucosaminidase (EC 3. 2.1.50), one of the lysosomal enzymes required for the degradation of heparan sulfate. The disease is characterized by profound neurodegeneration but relatively mild somatic manifestations, and is usually fatal in the second decade. A mouse model had been generated by disruption of the Naglu gene in order to facilitate the study of pathogenesis and the development of therapy for this currently untreatable disease. Recombinant human alpha-N-acetylglucosaminidase (rhNAGLU) was prepared from secretions of Lec1 mutant Chinese hamster ovary cells. The enzyme, which has only unphosphorylated high-mannose carbohydrate chains, was endocytosed by mouse peritoneal macrophages via mannose receptors, with half-maximal uptake at ca. 10(-7) M. When administered intravenously to 3 month-old mice, rhNAGLU was taken up avidly by liver and spleen but marginally if at all by thymus, lung, kidney, heart, and brain (in order of diminishing uptake). The half-life of the enzyme was 2.5 days in liver and spleen. Immunohistochemistry and electron microscopy showed that only macrophages were involved in enzyme uptake and correction in these two organs, yet the storage of glycosaminoglycan was reduced to almost normal levels. The results show that the macrophage-targeted rhNAGLU can substantially reduce the body burden of glycosaminoglycan storage in the mouse model of Sanfilippo syndrome III B.     

Clinical utility of an enhanced human immunodeficiency virus type 1 p24 antigen capture assay

The presence of p24 core antigen in the serum of individuals with human acquired immunodeficiency syndrome has been used as one of the important prognostic markers of HIV-1 infection and also as an end point in evaluating antiviral drugs and vaccines. Unfortunately the majority of p24 antigen present in serum exists as an antigenantibody complex and is not detected with the commercial kits currently available to measure p24 antigen. In this study, we report a simple procedure utilizing treatment of serum samples with glycine buffer (pH 1.85) to dissociate antigen-antibody complexes prior to assaying for p24 antigen. A 300% increase in the number of p24-reactive samples and a 3- to 12-fold increase in the quantity of antigen detected were observed when samples were pretreated with 1.5M glycine buffer (pH 1.85) for 1 hr. Glycine treatment of samples did not result in nonspecific positive tests and samples previously shown to be reactive remained positive. In reconstruction experiments the release of antigen was found to be inversely proportional to the amount of p24 antibody present in the serum. The percentage of HIV-1-infected patients positive for p24 antigen was clearly a function of CD4 count. Forty-nine percent of patients with more than 500 CD4 cells and 100% of patients with less than 200 CD4 were p24 positive. The improved sensitivity for detection of p24 provided by this procedure enhances our understanding of the pathogenesis of AIDS by showing that the majority of patients with HIV-1 infection is p24 positive and facilitates the analysis of data obtained in clinical trials involving anti-HIV compounds.     

Solid phase C1q microassay for the rapid detection of circulating immune complexes

A C1q solid phase microassay was designed for the rapid detection of circulating immune complexes. Its level of sensitivity is comparable to that of the Raji cell and greater than the C1q binding assay; furthermore, it is faster and low in cost. These conditions make it more practical and applicable in the clinical setting.     

Airway responses to antigen challenge in allergic rhinitis and allergic asthma

The density dependence of the maximum expiratory flow-volume curve, functional residual capacity (FRC), and specific airway conductance (SGaw) were determined before and during bronchial provocation with ragweed extract in 27 subjects with ragweed hypersensitivity and a history of either bronchial asthma (16 subjects) or allergic rhinitis (11 subjects). Mean baseline SGaw was significantly lower while mean volume of isoflow (Visov) and FrC were significantly higher in subjects with bronchial asthma. During antigen challenge, 10 of 16 subjects with bronchial asthma (63%) and five of 11 subjects with allergic rhinitis (45%) showed a greater than 35% decrease in SGaw ("reactors"): mean relative decreases in SGaw from baseline were 46% and 53%, respectively. The remaining subjects showed a less than 35% decrease in SGaw ("nonreactors") with mean relative decreases of 9% (allergic asthma) and 6% (allergic rhinitis). Mean Visov increased in all subjects with bronchial asthma and in eight of 11 subjects with allergic rhinitis. A significant increase in FRC (6%) was seen only in the "reactors" with bronchial asthma. Following antigen challenge, the beta adrenergic agonist, isoetharine, increased SGaw and decreased Visov. We conclude that in asymptomatic subjects with ragweed hypersensitivity, (1) central and peripheral airway function is more abnormal in subjects with bronchial asthma than in subjects with allergic rhinitis, (2) subjects of both groups show quantitatively and qualitatively comparable airway responses during antigen challenge with a decrease in SGaw or an increase in Visov, possibly representing increase in central and/or peripheral airflow resistance, respectively, (3) Visov may be a more sensitive indicator of airway response to antigen challenge than SGaw, and (4) the bronchodilator effects of a beta adrenergic agonist on antigen-induced bronchospasm are similar in both groups.     

Are transforming properties of the bovine papillomavirus E5 protein shared by E5 from high-risk human papillomavirus type 16?

The E5 proteins of bovine papillomavirus type 1 (BPV-1) and human papillomavirus type 16 (HPV-16) are small (44-83 amino acids), hydrophobic polypeptides that localize to membranes of the Golgi apparatus and endoplasmic reticulum, respectively. While the oncogenic properties of BPV-1 E5 have been characterized in detail, less is known about HPV-16 E5 due to its low expression in mammalian cells. Using codon-optimized HPV-16 E5 DNA, we have generated stable fibroblast cell lines that express equivalent levels of epitope-tagged BPV-1 and HPV-16 E5 proteins. In contrast to BPV-1 E5, HPV-16 E5 does not activate growth factor receptors, phosphoinositide 3-kinase or c-Src, and fails to induce focus formation, although it does promote anchorage-independent growth in soft agar. These variant activities are apparently unrelated to differences in intracellular localization of the E5 proteins since retargeting HPV-16 E5 to the Golgi apparatus does not induce focus formation.     

Overexpression of Ets-1 proto-oncogene in latent and clinical prostatic carcinomas

AIMS: The high incidence of clinically diagnosed prostatic cancer is exceeded by the frequency of tumours detected at autopsy. The Ets-1 proto-oncogene is expressed by a variety of malignant and normal tissues. Therefore, in this study, expression of Ets-1 protein was investigated in 'latent' prostatic cancer detected at autopsy, compared with benign prostatic hyperplasia, normal prostatic tissues and clinical prostatic cancer. METHODS AND RESULTS: Using immunohistochemistry, we analysed Ets-1 expression in 95 prostatic specimens including 19 cases of latent prostatic carcinoma (LPC) and 55 cases of clinical prostatic carcinoma (CPC), 11 cases of benign prostatic hyperplasia (BPH) and 10 cases of normal prostate (NP). Differences in the incidence of LPC and CPC suggest different courses for the biological progression of prostatic cancer. There was a significant difference in the degree of Ets-1 expression in CPC and LPC (P < 0.05). Ets-1 was not expressed in BPH and NP, but in malignant cases (57 of 74; 77.0%) commonly demonstrated immunoreactivity in the tumour cells. In our study the expression of Ets-1 between benign and malignant, and well, moderately and poorly differentiated adenocarcinomas of prostatic cancer showed significant differences. The presence of Ets-1 mRNA was confirmed by in-situ hybridization in human prostatic tissues. CONCLUSION: Our results suggest that Ets-1 might play an important role in carcinogenesis and/or the progression of human prostatic carcinomas.     

肺炎衣原体对血管内皮细胞的感染及其对ICAM-1表达的影响

目的:观察肺炎衣原体对人脐静脉内皮细胞(HUVECs)的感染及其对细胞分泌和表达细胞间粘附分子1(ICAM-1)的影响,探讨C.pneumoniae感染在动脉粥样硬化形成中的作用及其可能机制。方法:用人喉表皮癌(HEP-2)细胞培养C.pneumoniae,以C.pneumoniae感染HUVE细胞,经透射电镜及PCR检测有无感染。用流式细胞仪检测感染前后HUVE细胞表面ICAM-1蛋白的表达的变化,用荧光定量RT-PCR检测ICAM-1mRNA的变化。结果:C.pneumoniae能感染体外培养的HUVE细胞;感染后12h,细胞表面ICAM-1蛋白的表达即增加,其峰值约在感染后24h;荧光定量RT-PCR结果显示其增加在mRNA水平。结论:C.pneumoniae能感染体外培养的人脐静脉内皮细胞并增加ICAM-1的表达,提示C.pneumoniae感染可能是动脉粥样硬化的始动因子之一,其致动脉粥样硬化机制可能与感染后血管内皮细胞粘附分子表达的增加有关。     

HIV-1协同受体CXCR4、CCR5及相关趋化因子SDF-1在胎盘的表达

目的：研究HIV-1协同受体CXCR4、CCR5及CXCR4的特异性配体SDF-1在人胎盘组织的表达，探索HIV-1子宫内垂直传播的分子机制。方法：半定量RT-PCR检测早、中、晚孕期胎盘及早孕滋养细胞CXCR4、CCR5 mRNA水平；免疫组化和免疫细胞化学检测早孕胎盘及原代培养滋养细胞CXCR4、CCR5蛋白表达；原位杂交及免疫组化分析SDF-1在早孕胎盘的表达；ELISA测定滋养细胞SDF-1的动态分泌水平。结果：各孕期胎盘表达CXCR4及CCR5 mRNA；CXCR4蛋白定位于滋养细胞，而CCR5蛋白定位于绒毛基质中。滋养细胞可转录并翻译SDF-1，且能分泌可溶性SDF-1。结论：滋养细胞同时表达CXCR4及SDF-1，SDF-1可能通过降调CXCR4而拮抗X4-HIV-1感染胎儿细胞；R5-HIV-1或许能通过滋养层裂隙感染CCR5^#基质细胞和/或Hotbauer细胞，从而发生子宫内垂直传播。     

白细胞介素-1基因多态性与高血压易感性的研究

目的　观察白细胞介素 - 1(interleukin- 1,IL- 1)基因多态性在中国汉族人群中的分布及其与原发性高血压 (essential hypertension,EH)的关系 ,初步分析其基因型与 EH易感性的相关性。方法　应用聚合酶链反应和限制性片段长度多态性的方法 ,检测湖北省汉族 15 2例 EH患者和 16 8名正常对照者的IL- 1基因多态性 ,包括 IL- 1α(- 889C/ T)位点、IL- 1β(- 5 11C/ T)位点、IL- 1β( 395 3C/ T)位点、IL- 1Ra( 80 0 6 T/ C)位点多态性以及 IL- 1Ra第 2内含子可变数串联重复序列多态性。结果　IL- 1α(- 889C/ T)位点、IL- 1β( 395 3C/ T)位点、IL- 1Ra( 80 0 6 T/ C)位点多态性和 IL- 1Ra可变重复序列多态性在 EH组和正常人群中的分布差异无显著性 (P>0 .0 5 ) ,而 IL- 1β(- 5 11C/ T)位点多态性在两组人群中的分布差异存在显著性 (P<0 .0 5 ) ,携带 CT基因型罹患 EH的危险性可增加 2 .5 4倍。结论　 IL- 1β基因启动子区 - 5 11位点 C/ T多态性可能与 EH易感性存在相关关系。     

马凡综合征两种新的原纤维蛋白-1基因突变

目的对9例马凡综合征(Marfansyndrome,MFS)患者的原纤维蛋白-1(fibrillin-1,FBN1)基因进行突变筛查,以发现新的FBN1基因突变。方法应用变性高效液相色谱法对MFS患者FBN1基因65个外显子中的35个进行突变筛查,对变性高效液相色谱图形异常的PCR扩增片段用DNA测序鉴定突变位置及性质,并用等位基因特异性PCR以及限制性片段长度多态性分析等方法进一步证实突变。结果在两例MFS患者中发现两种新的FBN1基因突变。其中一种为第34外显子4307～4308位4个碱基TCGT的插入突变(4307insTCGT),另一种为第43外显子5309位的点突变5309G>A。结论FBN1基因移码突变(4307insTCGT)与点突变(5309G>A)分别是这两例MFS患者的发病原因。