肝素酶与肿瘤转移

肿瘤细胞实现扩散、转移 ,与免疫细胞趋向炎症反应区一样 ,必须首先穿越由细胞外基质和基底膜组成的屏障。该屏障主要由两种成分构成 :一是结构蛋白 ,包括胶原、层粘素、纤维结合素和玻璃体结合素等 ;二是糖氨聚糖 ,其主要成分是硫酸乙酰肝素蛋白多糖 (ｈｅｐａｒａｎｓｕｌｆａｔｅｐｒｏｔｏｇｌｙｃａｎ ,ＨＳＰＧ)。ＨＳＰＧ主要由一个蛋白核心和数个与之共价连接的线性硫酸乙酰肝素 (ｈｅｐａｒａｎｓｕｌｆａｔｅ ,ＨＳ)侧链组成[1] 。起初认为 ,结构蛋白的破坏是肿瘤细胞转移的决定性步骤 ,因此 ,在过去的 10多年中 ,研究兴趣大多集…     

Multicenter analytical evaluation of an automated immunoassay for total plasma homocysteine

A fully automated immunoassay for total plasma homocysteine assay was evaluated at four centers. To measure total homocysteine, oxidized forms of homocysteine in serum and plasma were reduced by dithiothreitol and assayed by a competitive fluorescence polarization technique. The assay had within-run precision from 0.9 to 3.0% and total precision from 2.8 to 4.1% for control materials with homocysteine concentrations of approximately 7, 12.5, and 25 micromol/L, a sensitivity of 0.35 micromol/L, good parallelism upon dilution, and analytical recovery ranging from 97.4 to 103.8%. The immunoassay correlated with four different HPLC assays for homocysteine, yielding a slope of 0.98, an intercept of -0.19 micromol/L, and a correlation coefficient of 0.966 for 440 paired samples. The reference range, determined with plasma samples from 609 males and 600 females, yielded a mean of 9.17+/-2.86 micromol/L, with a central 95% range of 4.78-15.43 micromol/L. The immunoassay is a suitable alternative to HPLC and may be useful in screening persons with high risk of coronary artery disease.     

The selachian terminal nerve]

In order to clarify morphology and function(s) of the terminal nerve, gross examinations of the nerve were carried out in 9 species of selachians. The terminal ganglion was observed light- and electron-microscopically. FMRF-amide immunoreactivity of the terminal nerve was also examined in some species. The results were as follows: 1) The terminal nerve was divided into peripheral and central branches by interposed ganglion(s). Macroscopically, the peripheral branch appeared from an area between the nasal sac and the olfactory bulb. The central branch entered the telencephalon from either the rostral, dorsal, or ventral surface. The position seemed to differ from species to species. 2) The terminal nerve showed great species differences and individual variations in the macroscopic morphology, such as number and course of the peripheral branch, position, size and number of ganglia, and telencephalic areas where the central branch entered. Even in the same individual, there was a difference in left and right sides. 3) According to general histology, the ganglion was encapsulated and had no direct connection with the telencephalon through the capsule, even when the ganglion was situated on the telencephalon. The Bodian preparations showed that most ganglion cells were unipolar, and a few were bipolar or pseudounipolar. 4) All ganglion cells and the processes were FMRF-amide immunoreactive. Immunoreactive fibers of the central branch terminated in the septal and preoptic areas. FMRF-amide immunoreactive cells were also found in the olfactory nerves or the septal area of the telencephalon in some species. These neurons were thought to be ectopic ganglion cells. 5) Neuronal somata and the axons in the ganglion contained large dense cored vesicles.(ABSTRACT TRUNCATED AT 250 WORDS)     

Recessive inheritance of a high number of sodium pump sites

The number of sodium pump sites on erythrocytes was measured on 1,847 individuals in 80 Utah kindreds ascertained through probands with cardiovascular disease. Likelihood analysis supported recessive inheritance of high pump number. The major locus explained 14.0% of the variance in pump number; polygenic inheritance explained another 63.4%. Homozygotes for the recessive allele occurred with a frequency of 1.74% and had a mean pump number estimated as 566.0 sites/red blood cell (RBC) versus a mean of 312.2 sites/RBC for the other genotypes. Young individuals with the high pump number genotype were leaner, and older adults with the high pump number genotype were heavier. Diabetes and early hypertension were more prevalent in women with the high pump number genotype. Although not significant, obesity in adults of both sexes and early coronary heart disease in men were more prevalent in individuals with the high pump number genotype.     

Syndiotactic polymerization of styrene with cyclopentadienyltribenzyloxytitanium/methylaluminoxane catalyst

Syndiotactic polystyrene was efficiently prepared in the presence of a homogeneous catalyst composed of (η⁵-cyclopentadienyl)tribenzyloxytitanium and methylaluminoxane (MAO) as a cocatalyst. Influences of various polymerization conditions, e.g., [Ti]. [MAO], [St], temperature and the content of retained trimethylaluminium (TMA) in MAO on the catalytic activity, syndiotacticity and molecular weight of the polymer were studied. It was found that the retained TMA plays an important role in the polymerization. Lowering the retained TMA content in MAO decreases the activity of the catalyst remarkably. Addition of external alkylaluminium (TMA or triisobutylaluminium) into the catalyst system with MAO containing low amounts of retained TMA promotes styrene polymerization.     

植物血凝素(PHA)对小鼠骨髓粒—单祖细胞增殖的影响

用体外琼脂培养法研究了PHA对小鼠骨髓CFU-GM的影响,结果表明,小鼠经腹腔注射PHA后,对小鼠CFU-GM产率和自杀率的影响随PHA的剂量不同而异,20～40mg/kg的PHA能明显提高CFU-GM的产率,其作用时间维持3天,剂量大于50mg/kg,可抑制CFU-GM产率。PHA组自杀率较对照组明显提高,提示适量的PHA在体内可促进小鼠CFU-GM的增殖,使更多的CFU-GM由Go期进入S期。将PHA直接加入无CSF的培养体系中,未见集落生长。此项结果提示PHA可能通过间接机制而非直接作用于CFU-GM。     

Low-grade squamous intraepithelial lesions: Cytologic predictors of biopsy Confirmation

One hundred and seven smears demonstrating a low-grade squamous intraepithelial lesion (LSIL) were analyzed for features predicting subsequent biopsy confirmation. Twelve (29%) of 41 smears showing few LSIL cells were biopsy confirmed compared to 33 (60%) of 55 containing an intermediate number of LSIL cells and 9 (82%) of 11 displaying many LSIL cells (P < 0.002). Thirty-seven (47%) of 78 smears showing mainly condylomatous atypia (CA), 7 (54%) of 13 revealing predominantly cervical intraepithelial neoplasia 1 (CIN 1), and 10 (63%) of 16 displaying both CA and CIN 1 were histologically confirmed (N.S.). Biopsy confirmation was obtained in 35 (65%) of 54 women whose repeat smears obtained at colposcopy demonstrated SIL compared to four (15%) of 26 patients whose repeat smears were normal or contained atypical squamous cells of undetermined significance (P < 0.001). These results suggest that the number of diagnostic cells in an LSIL smear predicts biopsy confirmation and affirm the validity of combining CA and CIN 1 under the category of LSIL in the Bethesda System. © 1994 Wiley-Liss, Inc.     

Nucleolar localization of non-structural protein 3b, a protein specifically encoded by the severe acute respiratory syndrome coronavirus

The open reading frame 3 (ORF3) of the severe acute respiratory syndrome coronavirus (SARS-CoV) genome encodes a predicted 154-amino acid protein, which lacks similarities to any known protein, and is named 3b. In this study, it was shown that 3b protein was predominately localized to nucleus with EGFP tag at its N- or C-terminus. The localization patterns were similar in different transfected cells. Immuno-fluorescence assay revealed that 3b protein was co-localized well with C23 in nucleolus. C23, B23 and fibrillarin all are important nucleolar proteins, which localize in the region of the nucleolus. Co-transfection of p3b-EGFP with pC23-DsRed, pB23-DsRed and pfibrillarin-DsRed further confirmed 3b's nucleolus localization. With construction of serial truncated mutants of 3b, a region (residues 134-154 aa) responsible for nucleolar localization was determinated in 3b protein. These results provide a new insight for further functional studies of SARS-CoV 3b protein.     

磁性阿霉素纳米微球的制备及在高频磁场中的发热研究

制备一种在高频磁场中能感应发热的用于治疗肿瘤的阿霉素纳米微球，研究其在磁场中的热效应。用超声搅拌冷冻干燥的方法制备药物微球，平均粒径200nm左右。电镜观察其形态为球囊状。将其置于不同介质中于高频磁场中测其温度变化值，实验表明该微球在交变磁场中使介质升温。升温速度与平稳时的温度和微球的量及磁场强度成正比，介质流动性好，升温快。     

Current trends and new approaches in the management of diabetes mellitus

Current trends in the management of type 2 diabetes mellitus, based on the 20-year United Kingdom Prospective Diabetic Study, include intensive treatment to control the blood glucose level and blood pressure in order to prevent or delay microvascular and cardiovascular complications. In the new millennium, type 2 diabetes will become epidemic in developing countries. If diabetes were to develop in 10% of the 1.2 billion population of China, the expense of intensive treatment would be immense. Laboratory tests are useful for detecting risk factors before the onset of the disease and convincing the general public to take preventive measures. Glucose tolerance testing is one of these tests. When glucose tolerance is impaired, 25% of beta-cell function is lost. Determining the plasma proinsulin level is another useful evaluation; impaired glucose tolerance accompanied by increased plasma proinsulin level is indicative of an enhanced risk that type 2 diabetes will develop within 5 years. Educating the public about eating a healthy diet and exercising may prevent the development of diabetes and thereby reduce the global prevalence of type 2 diabetes.