人胚雪旺细胞组织工程神经修复坐骨神经缺损的实验研究

目的：探索人胚雪旺细胞作为组织工程的种子细胞修复周围神经缺损的可行性。方法：通过组织工程方法用PLGA导管和polyglactin 910纤维负载人胚雪旺细胞预先构置好人工神经，然后用于修复大鼠20mm的坐骨神经缺损，并与神经切断后原位缝合以及用单纯的PLGA导管进行修复的实验组进行对照。通过活体肢体功能观察、靶器官肌肉测量、电生理检测、辣根过氧化物酶示踪、连续组织切片图像分析以及透射电镜等检查神经再生情况。结果：人工神经修复组神经再生良好，效果接近于神经原位缝合组，明显优于单纯的PLGA导管修复组。结论：人胚雪旺细胞构建的人工神经可以修复20mm的周围神经缺损。     

Membrane-seeded autologous chondrocytes: cell viability and characterization at surgery

The implantation of chondrocytes, seeded on matrices such as hyaluronic acid or collagen membranes, is a method that is being widely used for the treatment of chondral defects. The aim of the present study was to evaluate the distribution, viability and phenotype expression of the cells seeded on a collagen membrane just at the time of the implantation. Twelve patients who were suffering from articular cartilage lesions were treated by the MACI^® procedure. The residual part of each membrane was tested by colorimetric assay (MTT) and histochemical and ultrastructural analyses were carried out. In all of the samples a large number of viable cells, quite homogenously distributed, was detected. The cells expressed the markers of the differentiated hyaline chondrocytes. These data reassure in that the MACI procedure provides a suitable engineered tissue for cartilage repair, in line with the clinical evidences emerging in the literature.     

HPCE法测定蛹虫草及其培养物中核苷类化合物的含量

目的　建立蛹虫草中核苷类化合物的高效毛细管电泳测定法 ,比较天然蛹虫草及其培养物中核苷类化合物的含量。方法　在HV - 30 1高效毛细管电泳仪上进行定量分析 ,采用石英毛细管柱 ,以pH9.0的 4 0mmol·L-1 硼砂溶液作为电极缓冲液 ;分离电压为 1 6KV ;检测波长为 2 5 4nm。结果　天然蛹虫草中核苷类化合物主要集中在子座部分。人工培养蛹虫草子座和菌丝中虫草素的含量分别是天然蛹虫草子座中的 5 .0 4倍和 1 0 .85倍 ;液体培养蛹虫草菌丝中腺嘌呤、腺苷、尿苷、鸟苷含量均高于固体培养蛹虫草子座。结论　天然蛹虫草及其培养物中核苷类化合物的种类和含量具有较大的差异。高效毛细管电泳法可以用于蛹虫草的定量分析 ,具有分离度高、简便、准确 ,样品消耗少等特点     

Cell-killing Activity and Kinetic Analysis of a Novel Antitumor Compound NC-190, a Benzo[a]phenazine Derivative

A novel antitumor compound, N-β-dimethylaminoethyl 9-carboxy-5-hydroxy-10-methoxybenzo[a]-phenazine-6-carboxamide sodium salt (NC-190), was evaluated for antitumor activity in vitro against cultured tumor cell lines, and the kinetics of cell killing was elucidated. NC-190 strongly inhibited the growth of all of 3 murine tumor cell lines, 7 human tumor cell lines and 2 normal cell lines. With continuous exposure, the 50% inhibition concentrations were in the range of 0.005–0.06 μg/ml, except for KATO-III (2.15 μ g/ml). By colony-forming assay, concentrations of NC-190 giving 90% cell kill (IC₉₀) at various exposure times were obtained with HeLa S3 cells. The plot of IC₉₀exposure time on a log-log scale was linear for NC-190 with a slope of -1, which is typical for cell cycle phase-nonspecific agents. A 2 h treatment with NC-190 induced a rapid reduction in cell viability at doses of more than 3 μ g/ml. At the dose where colony formation was completely inhibited, cell viability was persistently reduced to below 20% during the cell culture period. NC-190 cauced a dose- and time-dependent reduction in DNA synthesis. The inhibitions of RNA and protein synthesis were less than that of DNA synthesis. Spectroscopic studies of NC-190 mixed with calf thymus DNA demonstrated that NC-190 was capable of interacting with DNA. However, DNA thermal denaturation studies suggested that intercalation of NC-190 was weak in comparison with those of classical intercalating drugs.     

大豆总皂甙对培养心肌细胞自发性搏动与动作电位的影响

培养Wistar大鼠乳鼠的心室肌细胞,向培养基中分别加入浓度为1.56μg/ml至50μg/ml的大豆皂甙,可使心肌细胞群落的自发性搏动呈剂量依赖性抑制。洗脱大豆皂甙或向培养基中再加入10μg/ml肾上腺素均能使自发性搏动恢复。向培养基中加入大豆皂甙5μg/ml使心肌细胞动作电位的波幅、波宽、超射、最大舒张电位、阈电位、最大除极速度等各电参数立即减小。Ca~(2+)80μg/ml能使动作电位的抑制逆转。上述结果表明大豆皂甙对培养的鼠心肌细胞具有钙通道阻滞用。     

New synthetic analogs of lipid A as lipopolysaccharide agonists or antagonists of B lymphocyte activation.

We have studied the ability of synthetic analogs of lipid A to mimic lipopolysaccharide (LPS) for activation of 70Z/3 pre-B cells (expression of surface Igs) or to antagonize this effect. The results indicate that the presence of glucosamine (mono- or disaccharide) as a 'backbone' for the attachment of fatty acids is not necessary for activation of cells of the B lineage. Phosphate groups are not necessary either. Other structural features such as the configuration of particular asymmetric carbons, and the distance between an anionic group and an N-acyl chain, seem to be much more critical parameters for activation of B cells. Among the synthetic lipids which were unable to activate 70Z/3 cells, one compound, consisting of N,N-acylated and bisphosphorylated 2,3-dideoxy-2,3-diamino-D-glucose, behaved as a specific LPS antagonist and blocked also the activation triggered by the other synthetic inducers. The influence of the synthetic lipids on the entry of mature mouse B lymphocytes into the G1A phase of the cell cycle (cell enlargement) was also investigated. A high correlation was observed between the potency to activate pre-B cells and the ability to induce blast formation in mature B cells.     

Pharmacological properties of the norepinephrine-induced depolarization of astrocytes in primary culture: evidence for the involvement of an α1-adrenergic receptor

The membrane potentials of astrocytes in primary cultures prepared from neonatal rat cerebral cortices were depolarized by (−)-norepinephrine. The average first response to 10⁻⁵ M (−)-norepinephrine was 24 mV from an average resting potential of −68 mV, and the average for the second response was 14 mV. Thus this process showed marked desensitization. The response was attributed to an activation of an α₁-receptor since it was about 1000 times more sensitive to inhibition by prazosin than to yohimbine or idazoxan. In addition, depolarization was seen to the application of 10⁻⁵ M phenylephrine.     

异丙酚对布比卡因诱导的PC12细胞毒性的作用

目的 探讨异丙酚对布比卡因诱导的PC12细胞毒性的作用及其可能机制。方法PCI2细胞接种于96孔培养板中培养，随机分为4组：对照组、布比卡因组、异丙酚组和布比卡因＋异丙酚组，分别加入Hanks液、布比卡因（终浓度为0．03、0．06、0．09、0．12、0．15mmol／L）、异丙酚（终浓度为1、2,4、8mmol／L）以及同时加入布比卡因（终浓度为0．09mmol／L）和异丙酚（终浓度为1、2,4、8mmol／L）。培养24h时，采用二甲基噻唑二甲基四唑溴盐比色微量分析法测定各孔的细胞活力和上清液乳酸脱氢酶（LDH）的活性，应用流式细胞仪检测硫氧还蛋白-1（Trx-1）和硫氧还蛋白还原酶-1（TrxR-1）表达率。结果 与对照组比较，布比卡因组PC12细胞活力降低（P〈0．01），且呈浓度依赖性；异丙酚组PC12细胞活力差异无统计学意义（P〉0．05）。与布比卡因组的0．09mmol／L亚组比较，布比卡因＋异丙酚组的2—8mmol／L亚组PC12细胞活力增加（P〈0．05）。与对照组比较，布比卡因组和布比卡因＋异丙酚组LDH活性升高，Trx-1和TrxR-1表达率降低（P〈0．01）；与布比卡因组比较，异丙酚组和布比卡因＋异丙酚组LDH活性降低，Trx-1和TrxR-1表达率升高（P〈0．01）。结论 布比卡因对PC12细胞具有浓度依赖性的细胞毒性作用。异丙酚可通过保护内源性硫氧还蛋白系统减轻布比卡因诱导的PCI2细胞的毒性。     

Metabolism of methyl-branched iodo palmitic acids in cultured hepatocytes

The metabolic fate of methyl-branched iodo fatty acids was studied in primary culture of rat hepatocytes. We compared 16-iodo-2-R,S-methyl palmitic acid (2-Me), which can be oxidized, with 16-iodo-3-R,S-methyl palmitic acid (3-Me) which can be oxidized only after an initial oxydation and with 16-iodo-2,2-dimethyl palmitic acid (2,2-Me₂) and 16-iodo-3,3-dimethyl palmitic acid (3,3-Me₂) which cannot be oxidized at all. The normal fate of natural fatty acids was given by comparative experiments with [1-¹⁴C] palmitic acid. Monomethyl-branched iodo fatty acids were taken up in the same range as palmitic acid but more than dimethyl-branched iodo fatty acids. After a 15-h incubation, acido-soluble products (ASP) accounted for 75% of the radioactivity taken up as 16-iodo-2-methyl palmitic acid, 50% as other methyl-branched iodo fatty acids and only 30% as palmitic acid, which indicated that all the methyl-branched iodo fatty acids underwent a strong deiodination process. Fatty acids were esterified in the following order: palmitic acid >16-iodo-3-R,S-methyl palmitic acid>16-iodo-2-R,S-methyl palmitic acid>16-iodo-2,2-dimethyl palmitic acid>16-iodo-3,3-dimethyl palmitic acid. Cultured hepatocytes, labelled for 3 h with the various fatty acids and reincubated for 12 h without fatty acid, secreted large amounts of free dimethylbranched iodo fatty acids as compared to the monomethyl ones and palmitic acid. Only hepatocytes prelabelled with 16-[¹²⁵I]iodo-2,2-dimethyl palmitic acid exhibited an appreciable secretion of labeled triglycerides, but at a lower rate than with [1-¹⁴C] palmitic acid. Conversely, the 16-iodo-monomethyl palmitic acids remained chiefly in hepatocyte triglycerides. Minute amounts of 16-iodo-methyl-branched-palmitic acids were found in hepatocyte or secred phospholipids as compared with palmitic acid. This metabolic fate of methyl-branched iodo palmitic acids argues against their utilization as imaging probes to monitor in vivo the synthesis and the secretion of triglycerides by the liver.     

Down-regulation of 3H-lofentanil binding to opiate receptors in different cultured neuronal cells

Summary There was stereospecific binding of ³H-lofentanil (K _D value = 1.53 nM) to membranes of neuroblastoma-glioma NG 108-15 cells which are known to bear high affinity binding sites for enkephalin derivatives (-opiate receptor subtype). There was no high affinity specific binding of the -opiate specific ligand ³H-sufentanil. The specific binding of ³H-lofentanil to -opiate receptor subtype was down-regulated (decrease in B _max value without change in the K _D value) after prolonged incubation of the cells in the presence of leu- and met- enkephalin (0.1 M). There was no down-regulation of the opiate receptors (³H-lofentanil and ³H-d-ala-d-leu-enkephalin specific binding) after incubation of NG 108-15 cells with drugs from the fentanyl series (alfentanil or sufentanil).In cultured neurones from rat forebrain (15 day old embryos), the ³H-lofentanil binding was specific with high affinity (K _D: 0.048 nM) and a slow dissociation rate similar to that in adult rat cortex. Drugs of the fentanyl series (4-anilino-piperidines) were potent displacers whereas agonists of the - (enkephalin derivatives), (phencyclidine, haloperidol, 3-hydroxyphenyl-propylpiperidine) or K- (U 50488) opiate sites had a low affinity (K _i > 0.5 M) for ³H-lofentanil specific binding sites. Since there was also specific binding of ³H-sufentanil, the opiate receptors in cultured neurones seem to be mainly of the -subtype and this is consistent with the ontogeny of opiate receptors subtypes. These receptors were down-regulated after incubation in the presence of etorphine, sufentanil and alfentanil but not enkephalin derivatives.These results strongly suggest specific binding of ³H-sufentanil and ³H-lofentanil mainly to the so-called -opiate receptors in cultured neurones and a specific binding of ³H-lofentanil to lower affinity -opiate receptors in neuroblastoma-glioma cells. The down-regulation of the -opiate binding sites in cultured neurones and that of the -site in neuroblastoma × glioma hybrid cells were dose-and temperature-dependent, induced by the corresponding high affinity agonists and prevented by naloxone. Morphine did not induce down-regulation of or receptor sites, possibly because of a partial antagonist effect on both receptor subtypes. Send offprint requests to J. M. Maloteaux at the above address