造血生长因子对长期培养中骨髓造血细胞增殖和分化的影响

应用骨髓长期培养法研究了ＨＧＦｓ联合应用对ＬＴＢＭＣ中造血干／祖细胞的增殖、分化的影响，结果显示，在ＬＴＢＭＣ中，含有ＨＧＦｓ（ＩＬ－２＋ＩＬ－６＋Ｇ－ＣＳＦ＋ＧＭ－ＣＳＦ＋Ｅｐｏ）的扩增组与对照组相比，ＨＧＦｓ能显著地扩增ＨＳＣｓ，在第一周，ＣＦＵ－ＧＭ，ＣＦＵ－Ｅ和ＢＦＵ－Ｅ总数分别扩增１８．０９－１６．５９倍、１０．２６－８．４８和１４．９９－１２．７８倍，而累积扩增倍数分别达３６．１９－６     

Cellular mechanism of action of resiniferatoxin: a potent sensory neuron excitotoxin

The mechanism of activation of sensory neurons by the potent irritant resiniferatoxin (RTX) was compared with that of the pungent compound, capsaicin. RTX and capsaicin evoked an inward, depolarising current associated with an increase in membrane conductance in a subpopulation of dissociated cultured neurons from rat dorsal root ganglia. RTX also evoked an uptake of⁴⁵Ca into and an efflux of [¹⁴C]guanidinium and of⁸⁶Rb from these cells but was at least 100-fold potent than capsaicin. The levels of cGMP, but not cAMP were elevated by RTX. Prolonged exposure to RTX damaged DRG neurons by a predominantly osmotic process. RTX-sensitive cells were identified by a cobalt-staining method; neurofilament-containing DRG neurons were RTX-insensitive as were all sympathetic neurons and non-neuronal cells. Cultured DRG neurons from chick embryos were also unaffected by RTX. In a neonatal rat spinal cord-tail preparation in vitro, RTX activated capsaicin-sensitive peripheral noiciceptive fibres and caused a subsequent spinal cord depolarization measured in the ventral spinal roots. Neither prolonged exposure to a phorbol ester, to desensitize/down-regulate protein kinase C, nor inhibition of protein kinase C by staurosporine affected responses produced by RTX or capsaicin. The effects of capsaicin were abolished when preparations were exposed to desensitizing concentrations of RTX. RTX therefore acts as a highly potent capsaicin analogue to activate a subpopulation of rat sensory neurons.     

缺血性脑血管病患者骨髓间充质干细胞的实验研究

目的：观察缺血性脑血管病患者骨髓间充质干细胞形态学特征。方法：将缺血性脑血管病患者自体骨髓中的阃充质干细胞（bone marrow mesenchymal stem cells，BM—MSCs）经密度梯度离心法分离、纯化和培养，观察原代和传代细胞的形态。结果：原代培养的BM—MSCs最佳贴壁时间为3d，生长性状不一，呈散在圆形细胞群、散在梭形细胞群、克隆圆形细胞群、花带状细胞群、漩涡状细胞群，而传代培养的细胞，增殖速度较快，性状一致，排列规则，呈饱满的梭行。结论：通过体外非诱导培养获得的自体BM—MSCs，有较强的增殖能力和多向分化潜能，为缺血性脑血管病的临床治疗提供了实验依据。     

肿瘤坏死因子对人甲状腺细胞分泌功能的影响

将正常人甲状腺组织行单层细胞培养后分为两组，Ａ组内加定量ｂＴＳＨ（１ｍＵ／Ｌ）和不同浓度肿瘤坏死因子，Ｂ级内仅加ＴＮＦ。培养２４和４８小时，分别测定上清液甲状腺球蛋白含量。结果：Ａ组ＴＧ含量随ＴＮＦ浓度增加而明显减少，提示ＴＮＦ可阻断ＴＳＨ对甲状腺细胞的刺激作用；Ｂ组ＴＧ含量则不受ＴＮＦ影响，说明ＴＮＦ对甲状腺细胞无直接杀作用。正常甲状腺功能的病态综合征患者血ＴＮＦ浓度明显高，可能是导致Ｔ３和Ｔ４     

Endoplasmic reticulum stress induces myostatin precursor protein and NF-kappaB in cultured human muscle fibers: relevance to inclusion body myositis

Sporadic-inclusion body myositis (s-IBM) is the most common progressive muscle disease of older persons. It leads to pronounced muscle fiber atrophy and weakness, and there is no successful treatment. We have previously shown that myostatin precursor protein (MstnPP) and myostatin (Mstn) dimer are increased in biopsied s-IBM muscle fibers, and proposed that MstnPP/Mstn increase may contribute to muscle fiber atrophy and weakness in s-IBM patients. Mstn is known to be a negative regulator of muscle fiber mass. It is synthesized as MstnPP, which undergoes posttranslational processing in the muscle fiber to produce mature, active Mstn. To explore possible mechanisms involved in Mstn abnormalities in s-IBM, in the present study we utilized primary cultures of normal human muscle fibers and experimentally modified the intracellular micro-environment to induce endoplasmic-reticulum (ER)-stress, thereby mimicking an important aspect of the s-IBM muscle fiber milieu. ER stress was induced by treating well-differentiated cultured muscle fibers with either tunicamycin or thapsigargin, both well-established ER stress inducers. Our results indicate for the first time that the ER stress significantly increased MstnPP mRNA and protein. The results also suggest that in our system ER stress activates NF-kappaB, and we suggest that MstnPP increase occurred through the ER-stress-activated NF-kappaB. We therefore propose a novel mechanism leading to the Mstn increase in s-IBM. Accordingly, interfering with pathways inducing ER stress, NF-kappaB activation or its action on the MstnPP gene promoter might prevent Mstn increase and provide a new therapeutic approach for s-IBM and, possibly, for muscle atrophy in other neuromuscular diseases.     

New role of IKK alpha/beta phosphorylated I kappa B alpha in axon outgrowth and axon initial segment development

Neuronal polarity development begins by the outgrowth of the axon and the formation of the axon initial segment which acts as a diffusion barrier and it is the place of action potential generation. The mechanisms controlling this development are largely unknown. We describe a role for IκBα, the NFκB inhibitor, in the initial stages of axon outgrowth and the development of the axon initial segment. In cultured hippocampal neurons, inhibition of IκBα phosphorylation by IκB kinases (IKKs) impedes axon outgrowth. Moreover, the absence of IκBα phosphorylation, in the next stages of axon development, impairs the localization of structural and functional proteins at the axon initial segment, such as ankyrin G and voltage gated sodium channels. These results demonstrate a new role for proteins of the NFκB pathway in the acquisition of neuronal polarity and its involvement in the development of the axon initial segment.     

Morphological,biochemical, ultrastructural,tissue culture and clinical observations of typical and aggressive craniopharyngiomas

Summary Craniopharyngiomas are tumors of the suprasellar area, which are often cystic, encapsulated and slow-growing. Certain of these tumors can behave in an aggressive manner and either invade surrounding structures or recur.In order to determine characteristics which may aid in distinguishing typical from atypical lesions, a study of biopsy and tissue culture specimens from 25 human craniopharyngiomas was undertaken. Tissue culture observations reveal two distinct cell populations.Typical lesions grew in culture in an orderly epithelial pattern and had desmosome-tonofibril aggregates and smooth surface topography demonstrable by electron microscopy.In the atypical tumors the cell growth was irregular, with mitotic activity, cholesterol crystals and features characteristic of neoplastic transformation, such as surface microvilli, an increase of cytoplasmic basophilia, size and number of nucleoli and retraction of cytoplasm.Correlation with the clinical status of the patients suggests that tumors of the four patients which exhibited atypical features in culture behaved more aggressively.     

Effects of organochlorine pesticides on DNA synthesis of cultured oviductal and uterine cells and on estrogen receptor of uterine tissue from heifers

 The pesticides DDT, MXC and γHCH at concentrations between 41 and 200 μM inhibited DNA synthesis (measured by [³H]thymidine incorporation) of cultured bovine oviductal endosalpingeal and uterine cells in the order DDT>MXC>γHCH, in comparison to nonexposed controls. Sensitivity to the toxicants was greater in uterine epithelial and stromal cells than in uterine smooth muscle or oviductal endosalpingeal cells. Besides the inhibitory effect, there was a stimulatory effect on DNA synthesis in epithelial cells in the range of 28 nM to 2.8 μM DDT and in stromal cells at 2.8 and 28 nM for MXC. An explanation for this reaction could be that both toxicants have an estrogen-like effect. In the present study, it is shown that the o,p’ isomer of DDT can bind to the cytoplasmatic estrogen receptor and DDT or MXC were able to inhibit the binding of radiolabelled estradiol to the uterine endometrial explants in bovine, whereas γHCH did not change the binding. These findings represent an estrogenic effect of DDT and MXC in two complete in vitro systems. Received: 10 October 1995/Accepted: 19 December 1995     

The secrets of human stem cell-derived transfusable RBC for targeted large-scale production and clinical applications: A fresh look into what we need most and lessons to be learned

Blood transfusion, using the safest conventional blood bioproducts, is an irreplaceable part of substitution therapy. It is considered the most essential supportive clinical intervention aimed to restore the health of patients in need. Nevertheless, numerous unresolved problems are still associated with current blood substitution therapy. To alleviate our dependency on blood donors, many investigators have been focusing on the quest for stem cell-derived blood cells in line with major developments in the field of regenerative medicine. The main objective is to provide a safe and highly standardized universal cultured red cell concentrate [CRBC] for all clinical applications, regardless of blood groups. Currently, we are close to overcoming some of the main obstacles in culturing cells. This concise report is a prelude to the immortalized cell lines that are ready for in vivo clinical trials. It is only through the sharing of experimental ideas and knowledge-based strategies that we will be able to achieve such an enormous task and better understand ‘’the one for all concept’’ of CRBCs and their universal usage in all clinical settings.