阳离子交换色谱柱上聚合血红蛋白研究

采用柱上聚合的方法制备血红蛋白溶液，解决传统血红蛋白聚合过程中由于戊二醛的活性过高导致平均分子量大、产物分子量分布宽的问题。该方法利用阳离子交换剂对修饰度（聚合度）小的血红蛋白吸附能力大的原理，使其在柱上富积，同时加入戊二醛进行聚合反应。结果表明该方法能比较有效地缩小聚合血红蛋白的分子量分布。     

Lipoblastoma and lipoblastomatosis in infancy and childhood: histopathologic, ultrastructural, and cytogenetic features

Lipoblastoma is a relatively rare tumor that occurs in infancy and early childhood and arises from embryonic white fat. Although a benign tumor, lipoblastomas tend to recur and may resemble myxoid liposarcoma. The authors report 26 cases over a 15-year period at Texas Children's Hospital. There was a slight female predilection (14F:12M). The most common symptom was a painless mass with or without increasing size. The trunk, extremities, head and neck, retroperitoneum, inguinal canal, peritoneal cavity, and lung were the tumor sites. Most tumors were circumscribed lipoblastomas and the minority were diffuse infiltrative lipoblastomatosis. Reexcision for residual or recurrent tumor was necessary more frequently in patients with lipoblastomatosis. Histopathologic examination and ultrastructural examination revealed cellular neoplasms composed of immature adipocytes with relatively well-defined septa, frequent lipoblasts, a fine vascular network, and often a myxoid appearance resembling myxoid liposarcoma. Cytogenetics was performed in 4 cases with chromosome 8q abnormality being most common. The major concern with lipoblastoma in children is to completely excise the tumor to avoid leaving residual tumor and to prevent recurrences. Confusion with myxoid liposarcoma, well-differentiated liposarcoma, and typical lipomas may occur. Although asymptomatic, lipoblastomas may cause dysfunction of other organ systems due to mass effect. Complete surgical excision with at least 2 years of follow-up is the preferred therapy.     

Induction of female sexual behavior by GTP in ovariectomized estrogen primed rats

The effect of both intrahypothalamic and systemic administration of guanosine triphosphate (GTP) on lordosis behavior was studied in ovariectomized and ovariectomized-adrenalectomized, estrogen-primed rats (estradiol benzoate, 4 μg). This estrogen dose per se induced only weak or no lordosis behavior. Injection of GTP into the medial hypothalamic area (100 μg in 2.5 μl) elicited lordosis behavior with relatively short latency in 6 out of 7 rats. Systemic administration of GTP in a dose range of 0.8 mg to 5.0 mg to ovariectomized estrogen-primed rats, stimulated intense lordosis behavior in all subjects. Weak lordosis responses were displayed within the first 12 hr after GTP injection, but at 48 hr all rats were highly estrous. Lordosis behavior remained for up to eight days, its duration being related to the dose of GTP administered. GTP (2 mg) induced lordosis behavior in ovariectomized, adrenalectomized estrogen-primed rats, thus excluding the participation of adrenal steroids in this effect. The results are interpreted in terms of the stimulation of adenyl cyclase-cAMP systems by GTP.     

Evidence for cell surface association of CD2 and LFA-1 (CD11a/CD18) on T lymphocytes

Previous studies have reported an association of the cell surface adhesion molecule CD2 with the T cell receptor and with CD45 on mouse and human T lymphocytes. In this study the association of CD2 with cell surface molecules was investigated using cell surface biotinylation of T lymphocytes, coupled with immunoprecipitation using two CD2-specific monoclonal antibodies (mAb) (RM2–5 and 12–15) and analysis by SDS-PAGE. Although both CD2 mAb immunoprecipitated CD2 from lysates of murine lymphocytes, it was found that mAb 12–15, but not RM2–5, co-precipitated two other molecules of 95 and 180 kDa. Subsequent studies revealed that the 95- and 180-kDa molecules were associated with a subspecies of CD2 (? 5%) on thymocytes, the antigen-specific T cell line D10, and splenic T cells but not B cells. Two lines of evidence were obtained consistent with the 95- and 180-kDa molecules being the β and α chains of LFA-1. Firstly, an analysis of 12–15 mAb immunoprecipitates on 4–12% gels under reducing and nonreducing conditions shows that the 95- and 180-kDa molecules have a molecular weight and migration pattern identical to LFA-1. Secondly, depletion of LFA-1 from lysates with LFA-1 mAb abolished the ability of CD2 mAb 12–15 to co-precipitate the 95- and 180-kDa molecules, thereby identifying these as the β and α chains of mouse LFA-1, respectively. These results provide evidence for the first time for an association of LFA-1 and CD2 on mouse T lymphocytes, and suggest that the association occurs with an immunologically distinct subspecies of CD2 molecules.     

哮喘患儿IL-4近侧启动子区克隆和多态性分析

目的：对哮喘症患儿白细胞介素-4(IL-4)近侧启动子区进行克隆并分析其DNA序列的多态性。方法：对40名有明显家族及过敏史哮喘患儿和１０名正常儿童，以多聚酶链式反应（PCR）结合单链构象多态性（SSCP）扩增、筛选IL-4近侧启动子片段，进一步构建正常对照和异常条带PCR产物的重组质粒pIL-4-Jx2，并用双脱氧链终止法对重组质粒进行序列测定。结果：在对40名患儿SSCP分析中发现了7组异常条带。DNA测序结果显示有４外变异位点于已知的调控元件之内或毗邻位点，１名病人-229位C被A所替代，该变异恰好位于IL-4正性调节元件-I(PRE-I)之内；２名病人负性调节元件-Ⅱ（NRE-Ⅱ）毗邻C被T所替代，TATA框前增加1个G；1名病人STAT-6元件附近缺少了ATTTT五碱基核苷酸。结论：过敏性哮喘患儿IL-4近侧启动子区DNA序列存在多态性，这可能与IL-4基因异常表达及哮喘的发病有关。     

系统性红斑狼疮的分子遗传学研究

系统性红斑狼疮（systemiclupuserythematosus,SLE）是一种复合性多基因的自身免疫性疾病。遗传因素在SLE易感性方面起重要的作用。该文介绍目前已知几个与SLE的易感性有关的遗传基因。通过对这些基因研究,有利于阐明SLE的发病机制,进一步为SLE的预防、诊断和治疗提供重要的依据。     

Molecular weights of individual proteins correlate with molecular volumes measured by atomic force microscopy

 Proteins are usually identified by their molecular weights, and atomic force microscopy (AFM) produces images of single molecules in three dimensions. We have used AFM to measure the molecular volumes of a number of proteins and to determine any correlation with their known molecular weights. We used native proteins (the TATA-binding protein Tbp, a fusion protein of glutathione-S-transferase and the renal potassium channel protein ROMK1, the immunoglobulins IgG and IgM, and the vasodilator-stimulated phosphoprotein VASP) and also denatured proteins (the red blood cell proteins actin, Band 3 and spectrin separated by SDS-gel electrophoresis and isolated from nitrocellulose). Proteins studied had molecular weights between 38 and 900 kDa and were imaged attached to a mica substrate. We found that molecular weight increased with an increasing molecular volume (correlation coefficient = 0.994). Thus, the molecular volumes measured with AFM compare well with the calculated volumes of the individual proteins. The degree of resolution achieved (lateral 5 nm, vertical 0.2 nm) depended upon the firm attachment of the proteins to the mica. This was aided by coating the mica with suitable detergent and by imaging using the AFM tapping mode which minimizes any lateral force applied to the protein. We conclude that single (native and denatured) proteins can be imaged by AFM in three dimensions and identified by their specific molecular volumes. This new approach permits detection of the number of monomers of a homomultimeric protein and study of single proteins under physiological conditions at the molecular level. Received: 14 February 1997 / Received after revision: 8 September 1997 / Accepted: 8 September 1997     

Molecular abnormality and cDNA cloning of human aldehyde dehydrogenases

Usual human livers contain two major ALDH isozymes, i.e., cytosolic ALDH1 and mitochondrial ALDH2, while approximately 50% of Orientals are "atypical" and have only the ALDH1 and are missing the ALDH2. Instead, the atypical livers contain an enzymatically inactive but immunologically cross-reactive material (CRM) corresponding to the ALDH2 component. Some Orientals are found to be atypical also in the ALDH1 locus, i.e., they are missing the enzymatically active ALDH1 but contain a large amount of CRM corresponding to the ALDH1 component. cDNA for ALDH1 and that for ALDH2 were cloned and their nucleotide sequences were determined. The amino acid sequences of ALDH1 and ALDH2 were deduced from their cDNA sequences. The molecular abnormality of the inactive ALDH2(2) is found to be the substitution of Glu at the 14th position from the COOH-terminal of the protein by Lys which resulted from G----A transition in the gene.     

2019年广东省部分地区感染性腹泻病原学及人轮状病毒分子流行病学特征

目的 对感染性腹泻样本进行检测鉴定,并对轮状病毒A组进行病毒分离,研究2019年广东省部分地区感染性腹泻病原学及轮状病毒分子流行病学特征。方法 2019年1月1日至2020年1月12日,采集广东省广州市、东莞市和江门市临床感染性腹泻患者粪便样本,进行多重RT-PCR扩增和微球杂交技术检测鉴定,并对轮状病毒A组阳性样本进行分离后,采用半巢式PCR试验对阳性细胞培养物进行G/P基因分型。结果 共纳入706例合格病例,病原体总检出率43.06%,病毒检出率18.13%高于细菌检出率8.36%高于寄生虫检出率1.27%。病毒病原谱以轮状病毒A组G9P[8]和诺如病毒GII型感染为主,细菌病原谱以沙门菌和艰难梭菌为主,寄生虫以蓝氏贾第鞭毛虫为首。不同季度、不同年龄组病原谱构成各不相同。轮状病毒A组主要受累群体为≤5岁儿童,主要时间分布于1—4月,基因型呈现多样性,包括G2P[4]、G3P[8]和G9P[8]。结论 2019年广东省部分地区感染性腹泻病毒类病原体高于细菌类高于寄生虫类,轮状病毒A组G9P[8]、诺如GII型、沙门菌和蓝氏贾第鞭毛虫是最主要的病原体,且G9P[8]型A组轮状病毒毒株在轮状病毒感染中占主导趋势。在防控病毒性和细菌性腹泻的同时,应警惕寄生虫所致腹泻并重视混合感染的病原学监测。     

FAM19A4基因启动子甲基化检测在宫颈癌及其癌前病变筛查的研究

宫颈癌是最常见的妇科恶性肿瘤之一。目前人乳头瘤病毒(HPV)检测及细胞学检查是宫颈癌及其癌前病变(CCPL)的主要筛查手段。由于上述传统筛查方法,仍然存在对CCPL漏诊的风险,因此寻找有效识别CCPL的特异性分子标志物,具有重要临床意义。对具有序列相似性家族19成员A4(FAM19A4)基因启动子甲基化定量检测,可有效检出CCPL组织,较传统筛查方法有较高特异度,有望成为CCPL筛查的特异性分子标志物。笔者拟就FAM19A4基因启动子甲基化定量检测,在CCPL筛查中应用的最新研究现状进行阐述,旨在为进一步推进CCPL筛查方法的开发,提供思路。