豚鼠耳蜗单离Deiters细胞的钾电流

目的 研究豚鼠耳蜗单离Deiters细胞的钾电流及其特性。方法 运用膜片钳技术 ,在全细胞模式下记录正常细胞外液中钾电流 ,不同K+浓度的细胞外液对细胞反转电位和外向钾电流的影响 ,四氨基吡啶 (4 aminopyridine ,4 AP)和四乙基胺 (tetraethylammonium ,TEA)对钾电流成分的阻滞作用 ,探讨外向钾电流通道的激活和失活动力学。结果 单离Deiters细胞具有电压依赖的外向整流离子选择性通道 ;钾通道阻滞剂 4 AP和TEA可使峰电流和迟电流幅度下降 ,表明存在两种类型的钾通道 ,或者这种通道有两种不同的状态 ;通道的激活和失活符合Boltzmann方程。未记录到Deiters细胞的内向钙电流。

坛紫菜雌雄叶状体的细胞分化比较

以室内培养20-90d的坛紫菜雌雄叶状体为研究材料,用酶解法分别获取单离细胞进行再生培养。在雌雄叶状体的体细胞再生体中,都出现9种不同发育类型。再生体发育类型的数目和比例与种藻日龄密切相关等结果,证实了离体培养的单离细胞发育成不同形态的再生体是基于其离体前处于不同分化时期所致;由壳孢子分化成性母细胞大致可划分成8个不同阶段。雌雄叶状体的细胞分化途经大致相同,但也有一定差异,雌性叶状体的细胞最终分化成雌性性母细胞,并产生大量的丝状体;而雄性叶状体的细胞最终分化成雄性性母细胞,绝大部分生成精子,但极少数产生丝状体。在雌雄叶状体的细胞再生体中,均产生“类单孢子”并长成正常叶状体。雄性叶状体成熟较雌性早,与其细胞分化速度较快有关。成熟期不同的雌性品系观察结果表明,叶状体成熟越早、生长期越短,其体细胞分化速度也越快。

坛紫菜人工色素突变体的诱变与分离

坛紫菜叶状体经一定剂量的60Co-γ射线辐射再培养一段时间后,出现了少量色素体颜色发生变异的细胞,它们呈点状无规则地镶嵌在野生型细胞中。培养3周后,色素变异细胞分裂并形成了不同颜色的细胞块, 其颜色呈桔红、桔黄、浅黄褐、浅红、紫红、紫褐、黄绿、绿色等。在辐射剂量0-1 100 Gy范围内,叶状体上色素变异细胞块的出现频率随着辐射剂量的增加而增加;但辐射剂量增至1400 Gy时,色素变异细胞块出现的频率反而下降,说明1 100 Gy是合适的辐射剂量。在同一个叶状体的不同部位上色素变异细胞块出现的频率是不同的,从基部到稍部,随着部位的上移而逐渐增加。用酶解法把含色素变异细胞的叶状体细胞单个分离出来并进行离体培养,在它们的再生体中,出现了多种单色的色素突变叶状体,从中分离到tan(红褐色)、bor(深结红色)、ceb(紫红色)、hon(枯草色)、cac(深黄绿色)等不同颜色的纯色突变体。从各单色突变体中分离出来的丝状体,其颜色与各自的叶状体相同。各突变体的丝状体成熟后,放散的壳孢子长成单色的F1叶状体,其颜色与各自最初的母体叶状体相同,说明所得到的上述突变体是稳定的色素突变体。

小鸡单离听毛细胞的分离及其形态学观察

用胶原酶孵育后机械分离15只小鸡的听毛细胞，平均每侧可分离428个。对其中5只鸡的215个活性良好的单离毛细胞进行了形态学测量，其中高毛细胞164个，长20．22±3．32μm，宽9．93±2．01μm，矮毛细胞30个，长10．97±2．29μm，宽14．8±2．29μm，中间型毛细胞21个，长宽相等，均为11.93±1.74μm。用双醋酸荧光素-碘化丙啶对另外5只鸡单离毛细胞进行染色，在荧光显微镜下观察细胞的变性过程。鸡断头3h内，活性良好的细胞着非常明亮的绿色荧光，到5h，活性细胞呈现不清晰的绿影。实验结果表明，判断单离毛细胞的活性，应将形态学观察标准与细胞染色结合起来。

Control of In Vitro Regeneration of Individual Reproductive and Vegetative Organs in Dracaena fragrans cv. massangeana Hort. Regularities of the Direct Regenerationof Individual Organs In Vitro

Various individual organs (tepal, flower bud, inflorescence branch, inflorescence, adult vegetative bud and juvenile vegetative bud) were directly regenerated respectively by callus in Dracaena fragrans cv. massangeana Hort. During the regeneration of these individual organs some regularity phenomena were observed. Firstly, the kind range of the individual organs, which are directly regenerated in vitro, is in close relationship to the differentiated stages of the organs used for explant excision during plant ontogeny. The explants excised from the epigeous organ that is differentiated at some stage (stage A) during plant ontogeny must be able to separately regenerate all of those individual epigeous organs: ones differentiated slightly later than the stage A, ones differentiated at the stage A and all ones differentiated earlier than the stage A. Secondly, within this range which kind of organ is regenerated depends on the exogenous auxin concentrations in medium. With the gradual increase of 2,4-D concentration from 0.005 mg/L to 0.5 mg/L, the kinds of regenerated organs will change by the order as follows: vegetative bud, inflorescence, inflorescence branch, flower bud, tepal. These regularities will be able to be used for inducing the direct regeneration of a given epigeous organ in angiosperms.

Adherent properties of Helicobacter pylori to human epithelial cells *

AIM To study the properties and factors of Helicobacter pylori adherence to human epithelial cells. METHODS The adherent properties of human epithelial cells were studied by using a group of isolated H. pylori strains, anti H. pylori monoclonal antibodies and varied pH environment in in vitro adherence model with HEp 2 cell.

THE ROLE OF CALCIUM ION IN THE PATHOGENESIS OF HUMAN PITUITARY GH－SECRETING ADENOMAS

To study the role of Ca2+ in the pathogenesis of pituitary growth hormone secreting adenomas, the function of Ca2+ in 23 cases of human Prturtary GH-secreting adenoma was investigated in monolayer cell culture. It was found that Ca2+ channel blockers nicardipin and nifedipin inhibrted basal and growth hormone releasing hormone (GRH)stimulated GH secretion in 87. 5 % and 100. 0 % of the GH adenomas . respectively, demonstrating that in most human pituitary GH adenomas, the basal and GRH regulated GH secretion is Ca2+ dependent. The GRH and sometostatin (SRIF) agonist octreotide regulated the processes of GH secretion via Ca2+ had defects in different steps including receptor ,postreceptor Ca2+ channel and Ca2+GH secreting coupling in 6 (66. 6%) and 5 (55. 5 % ) cases of 9 GH adenomas respectively. Among them,the defects in GRH receptor and SRIF regulated Ca2+ channel are the main causes of the dysfunction of GH adenomas. These defects may be related to GH hypersecretion in GH adenomas. Our data provides advance evidences for intrinsic defects of GH adenomas.

P48-Triggered transmembrane signaling transduction of human monocytes:mobilization of calcium ion and activation of protein kinase C(PKC)

P48 is a cytokine which induces monocyte differentia-tion and the induction of cytotoxic activity. In this study,the signal transduction events involved in the stimulation of monocytes with the membrane form of P48 (mP48) were investigated. Monocyte stimulation with mP48 was found to involve the mobilization of intracellular calcium (Ca2+)and the activation and translocation of PKC from the cy-tosol to the membrane. Membane P48 induced a rapid rise of intracellular Ca2+ in a dose dependent maner. Simi-larly the stimulation of monocytes with P48 was found to involve the activation and translocation of PKC. The translocation of PKC was rapid (within 0-5 min) yet tran-sient with PKC activity returning to control levels by 8 min. The functional role of protein kineses in P48 induced TNF secretion was studied using various kinese inhibitors. The PKC inhibitors, H-7 and sphingosine, were found to inhibit P48 induced TNF secretion with 50% inhibition at 5μM HA1004, which inhibts cyclic nucleotide-dependent kinase (PKA, Ki 1.2μM), did not inhibit TNF secretion. H-8 (PKA inhibitor) was found to be an effective inhibitor of TNF secretion only at high concentrations(30μp. The Calmodulin-dependent kinase inhibitor, W7 (Ki 12μM)was found to be effective at concentration above 5μM.These findings suggest that P48-triggered TNF secretion involves transmembrane Ca2+ signaling and the subse-quent activation of at least two protein kineses, PKC and CaMK.

Stimulation of staphylococcal enterotoxin A combined with PML-RARα peptide on the specifical T-cells against NB4 cell line

Objective： To investigate the effects of staphyococcal enterotoxin A （SEA） on the cytotoxicity of T cells stimulated by PML-RARa peptide in vitro. Methods： Peripheral blood mononuclear cells （MNC） from healthy donor were obtained by density gradient centrifugation on Ficoll-Hypaque, MNC were cultured with PML-RARa peptide and SEA for 20 days. After induction, the cytotoxicity of T cells induced against NB4 and K562 cell lines were examined by Cell Counting Kit-8 （CCK-8）. The CD4 and CD8 surface markers on the harvested CD3^＋ T cells were detected by flow cytometry （FCM）. Results： The cytotoxicity of T cells induced by PML-RARa peptide with SEA was higher than that of T cells induced only by PML-RARa peptide against NB4 cells. The FCM assay showed that the ratio of CD4^＋/CD8^＋ T cells were gradually decreased in both groups of PML-RARα peptide whether with SEA or not at the intervals of day 5,10 and 20 day after induction, but the most significantly decreased by PML-RARe peptide with SEA. Conclusion： The specific cytotoxicity of T cells induced by PML-RARa peptide against NB4 cells could be enhanced with superantigen SEA.

Mitochondrial superoxide anions induced by exogenous oxidative stress determine tumor cell fate: an individual cell-based study

Objective: Reactive oxygen species(ROS) are involved in a variety of biological phenomena and serve both deleterious and beneficial roles. ROS quantification and assessment of reaction networks are desirable but difficult because of their short half-life and high reactivity. Here, we describe a pro-oxidative model in a single human lung carcinoma SPC-A-1 cell that was created by application of extracellular H2O2 stimuli. Methods: Modified microfluidics and imaging techniques were used to determine O2·- levels and construct an O2^·- reaction network. To elucidate the consequences of increased O2^·- input, the mitochondria were given a central role in the oxidative stress mode, by manipulating mitochondria-interrelated cytosolic Ca2+ levels, mitochondrial Ca^2+ uptake, auto-amplification of intracellular ROS and the intrinsic apoptotic pathway. Results and conclusions: Results from a modified microchip demonstrated that 1 mmol/L H·-2 O2 induced a rapid increase in cellular O2 levels(>27 vs.>406 amol in 20 min), leading to increased cellular oxidizing power(evaluated by ROS levels) and decreased reducing power(evaluated by glutathione(GSH) levels). In addition, we examined the dynamics of cytosolic Ca^2+ and mitochondrial Ca^2+ by confocal laser scanning microscopy and confirmed that Ca^2+ stores in the endoplasmic reticulum were the primary source of H2O2-induced cytosolic Ca^2+ bursts. It is clear that mitochondria have pivotal roles in determining how exogenous oxidative stress affects cell fate. The stress response involves the transfer of Ca^2+ signals between organelles,ROS auto-amplification, mitochondrial dysfunction, and a caspase-dependent apoptotic pathway.

听力学

921375 豚鼠耳蜗毛细胞分离法/苏振伦…中华耳鼻咽唤科杂志,1992,27(2.)、133~135 用木瓜蛋白酶孵育后机械法分离豚鼠耳蜗毛细胞,4只豚鼠,平均每侧耳可分离出毛细胞7。士27个,其中含内毛细胞。0~4个。;分离后室温下短期培养,2小时内90纬单离毛细胞保持良好活性,到5小时仍有近40环保持良好活性。

Fluvastatin protects against puromycin aminonucleoside-induced podocyte injury by inhibiting TRPC6

In the present study,we aimed to investigate the effect of puromycin aminonucleoside(PAN)on the expression and distribution of transient receptor potential canonical 6(TRPC6)of murine podocytes and further study the protective mechanism of fluvastatin on podocyte injury by TRPC6 in vitro.Podocytes were treated by PAN at different doses and at different time points.The expressions of TRPC6 at mRNA and protein levels were assessed.An immunofluorescent assay was used to observe the distribution of TRPC6.Cultured podocytes were then divided into four groups.The expressions of TRPC6 at mRNA and protein levels were measured.The intracellular calcium concentration of podocytes was measured with a laser-scanning confocal microscope.The paracellular permeability to BSA was evaluated using Millicell-PCF Inserts.The expressions of TRPC6 at mRNA and protein levels were increased in a dose and time-dependent manner after exposure to PAN.Immunofluorescence showed that the expression intensity of TRPC6 was significantly increased,and the distribution of TRPC6 was changed after PAN was applied to podocytes.With fluvastatin intervention,PAN-induced up-regulation of TRPC6 was significantly reversed.The ratio of the peak value of intracellular calcium to the basic calcium value in the PAN group was significantly higher after TRPC6 was activated by OAG,while it is obviously reversed under the action of fluvastatin.The podocyte permeability was significantly increased after 48 h of PAN treatment,while the above situation was effectively improved after fluvastatin intervention.The changes of distribution and expression of TRPC6 were related to podocyte injury induced by PAN.Fluvastatin could exert its protective effects on podocytes by down-regulating TRPC6.