轻稀土与联吡啶和菲罗啉三元配合物的合成与表征

合成了稀土（Ｌｎ）与２，２－联吡啶（Ｌ１）、１，１０－菲罗啉（Ｌ２）的三元固态配合物。通过元素分析、ＩＲ谱、ＴＧＡ谱和摩尔电导等对该系列配合物进行了表征，实测结果与通式ＬｎＬ１Ｌ２Ｃｌ３·３Ｈ２Ｏ符合较好。抗菌试验表明，该系列配合物有较强的广谱抗菌作用。     

结构蛋白及血管形成因子在体表海绵状静脉畸形中的表达及意义

目的：研究结构蛋白及血管形成因子（VEGF）在体表海绵状静脉畸形（cavernous venous malformation,CVM）中的表达及意义。方法：1996－2000年CVM病理样本25例，取正常中、小型静脉各12例。采用Envision法免疫组化染色观察Ⅳ型胶原、纤维连接蛋白（Fn）、层粘连蛋白（Ln）及VEGF、血管生成素－1（Ang-1）等血管形成因子的表达，半定量分析结果。结果：Ⅳ型胶原、Fn和Ln在海绵状静脉畸形与中、小静脉中的分类似，但表达量明显较少。畸形组织和小静脉VEGF表达明显强于中型静脉，小静脉Ang-1表达明显强于静脉畸形和中型静脉。结论：Ln及VEGF表达变化可能是海绵状静脉畸形形成发展的重要因素。Ang-1表达减少可能参与海绵状静脉畸形的血管塑形障碍的发生。     

Identification of functional GRP-preferring bombesin receptors on human melanoma cells

Bombesin was originally isolated from amphibian skin, wherease its mammalian counterpart, gastrin-releasing peptide (GRP), was first identified in the nervous system of the gastrointestinal tract. Whether GRP is present in the human skin is not known. Bombesin-like peptides are also known to modulate growth. We therefore investigated whether human melanoma cell lines express functional GRP-preferring bombesin receptors and whether they alter growth or other specific cellular functions of these tumour cells. GRP receptor mRNA was found in HBL, D-10, Me-28 and A375-6 cell lines, but only A375-6 cells express a large number of high-affinity binding sites for [¹²⁵I]-[Tyr⁴] bombesin ( K _d 0.31 ± 0.04 nmol L⁻¹, 3880 ± 429 binding sites per cell). Bombesin dose-dependently increased cytosolic calcium, but did not alter interleukin (IL) 1β-induced reduction of cell viability or IL-6 secretion, both A375-6-specific cell functions. Growth of A375-6 cells was not altered by bombesin or the specific GRP receptor antagonist BIM26226 as measured by [³H]-thymidine incorporation or methylene blue assay, whereas insulin alone or in combination with other potential growth factors dose-dependently stimulated growth of these cells. The newly characterized GRP-preferring bombesin receptors on highly malignant human melanoma cells could initiate studies of growth effects on solid tumours or in vivo scanning using radiolabelled tracers.     

Acoustic transmission in normal human hips: structural testing of joint symmetry

An acoustical technique has been developed for the measurement of structural symmetry of the hip joints. A mild vibratory force was applied to the sacrum and sound signals were picked up at both hips by a pair of microphones installed in two stethoscopes. These stethoscope–microphone assembles were calibrated to achieve a difference in relative sensitivity of less than 0.2 dB. The relative transmission of sound signals was analysed and compared between both hips by a dual-channel signal analyser. Twenty-seven healthy adults, 20 healthy pre-school children and 19 normal neonates were tested. Results from these three groups showed high coherence of the sound signals and that the discrepancy between both hips was smallest in the frequency range of 200–315 Hz. For normal neonates, the sound signals maintained a high coherence (γ²>0.97) and small discrepancy (D<1.25 dB) between both hips. This study has shown that the acoustical technique provides a practical structural testing for bony symmetry of the hips and the results offer a baseline for further investigation into developmental dysplasia of the hip (DDH) in neonates. Clinical screening for DDH is still problematic in developing countries.     

Comparative structural analysis of calmodulins from Trypanosoma brucei, T. congolense, T. vivax, Tetrahymena thermophila and bovine brain

Calmodulin is an intracellular calcium receptor protein utilized extensively by eukaryotic cells to mediate responsiveness to calcium signals. The present study evaluates the effects on protein structure of amino acid substitutions in trypanosome calmodulin. Calmodulin conformation, hydrophobicity and antigenic determinants are compared among Trypanosoma brucei, Trypanosoma congolense, Trypanosoma vivax, Tetrahymena thermophila and bovine brain. Trypanosome calmodulin differs from brain and Tetrahymena calmodulins based upon isoelectric point, retention time on a C-2/C-18 reverse phase column and interaction with polyclonal antibodies against trypanosome calmodulin by radioimmunoassay or Western procedures. These same analyses do not distinguish trypanosome calmodulins from each other. Polyclonal antibodies against Tetrahymena calmodulin are equally specific and do not recognize the trypanosome or brain calmodulins. Calcium-induced exposure of hydrophobic binding sites are quantitated using the fluorescent probe, N-phenyl-1-naphthylamine. All calmodulins, regardless of source, enhance the fluorescence of N-phenyl-1-naphthylamine 3-4 fold in the presence of calcium. These data demonstrate the extent to which functional calmodulins vary in their structures. We conclude that African trypanosomes share a common calmodulin that is structurally distinct from calmodulin of vertebrates or Tetrahymena.     

冠状病毒的分子生物学研究进展

冠状病毒是所有RNA病毒中基因组最大的病毒，具有胃肠道、呼吸道或神经系统嗜性，常引起人普通感冒或动物胃肠道、呼吸系统疾病，而SARS-CoV则引起人的严重急性呼吸道综合征。研究冠状病毒分子生物学特征对阐明其病毒粒子的发生、感染和致病机制有重要意义。本文就冠状病毒的分子生物学特征包括冠状病毒基因组特征，编码蛋白的结构及功能等方面的研究进展作一综述。     

恒河猴骨髓间充质干细胞分离培养及其生长特性

采用密度梯度离心和贴壁筛选方法分离纯化了恒河猴骨髓间充质干细胞(mesenchymal stem cells from bone marrow of Rhesus monkey,RhBMSCs);通过表面抗原检测和核型分析对细胞进行了初步鉴定;通过生长曲线的绘制和细胞凋亡的检测探讨了细胞的生长特点。本实验获得的RhBMSCs形态以梭型为主,核型正常,CD29表达率为99.2%,CD34、CD45、HLA-DR表达率均低于3.2%,RhBMSCs表型符合间充质干细胞的特点,且纯度较高,细胞生长旺盛,但倍增时间有随传代数的增加而逐渐延长的趋势。本实验探讨了RhBMSCs的体外分离、扩增培养及鉴定的方法,并对其生长特点进行了初步观察,这不仅有助于进一步了解与之近似的人的骨髓间充质干细胞的相关特性,而且为以猕猴为对象的BMSC定向分化和组织修复等动物体内实验打下了基础。     

A组轮状病毒广州地方株VP7基因序列的比较分析

目的 了解我国轮状病毒G1型广州地方株与标准株及北京G1型地方株VP7基因序列的差异，为我国轮状病毒疫苗的研制提供资料。方法 通过逆转录—聚合酶链反应(RT—PCR)获得了轮状病毒广州地方株R97—196 VP7全基因的cDNA片段，将其克隆入T—A克隆质粒pUCm—T中，构建成重组质粒pUCmT—VP7，对克隆的VP7基因进行序列测定。结果 该地方株的基因核苷酸全长为1062nt，读码框架和以往的研究一致，和北京G1型地方株173的VP7氨基酸序列具有高度同源性(98％)，而与不同血清型标准株间则变异较大(73％—81％)，氨基酸序列中存在的一些高变区和保守功能区与已报道的研究结果一致。从进化角度分析，与轮状病毒标准株Wa株，相距较远。结论 轮状病毒广州地方株R97—196 VP7基因片段属G1型，轮状病毒VP7基因的变异与地域有一定关系。     

FISH characterization of a supernumerary r(1)(::cen→q22::q22→sq21::) chromosome associated with multiple anomalies and bilateral cataracts

We describe the case of a 15‐year‐old girl with multiple congenital anomalies, dysmorphic features, severe kyphoscoliosis, growth and mental retardation, and the absence of speech, in whom 35% of the cells carried a supernumerary ring chromosome 1. Fluorescence in situ hybridization (FISH) analysis using YAC/BAC clones spanning the region from 1p13 to 1q21 made it possible to determine the genomic content and structure of the ring(1), which was found to consist of the cytogenetic bands 1q21–22. A complex structure was delineated in the ring chromosome with a partial inverted duplication delimited by markers WI‐7732 and WI‐607, with WI‐7396 and WI‐8386 being the boundaries of the single copy segment. Comparison of the clinical signs of other patients with mosaic r(1) reported in the literature allowed the identification of a patient sharing a number of clinical signs including cataracts. Given that mutations of the GJA8 gene encoding connexin 50 (Cx50) and mapping to 1q21 have been associated with the presence of cataracts, it is possible that a gain in copy number or a rearrangement of GJA8 may contribute to cataractogenesis.     

In Vitro and In Vivo Characterization of MEMS Microneedles

Transdermal drug delivery TDD systems have many advantages but are conventionally limited by the low permeability of skin. The idea of using microneedles to painlessly penetrate the topmost impermeable stratum corneum has previously been put forward. In this paper, the fabrication of solid and hollow silicon microneedles with straight side-walls and with the following dimensions: 20–100 m in diameter and 100–150 m in length is described. In vitro tests demonstrate that with prior solid microneedle application, transdermal drug transport is significantly increased by 10–20 times, with the degree of enhancement being related to needle diameter. In vivo tests in diabetic animals, however, were unable to demonstrate any delivery of insulin through the hollow microneedles. It is proposed that two factors, microneedle length and tip sharpness, have to be improved for systemic drug delivery to be seen in vivo.