外源钙调素对粟酒裂殖酵母细胞增殖的影响

外源钙调素（CaM）对粟酒裂殖酵母（Schizosaccharomycespombe）细胞增殖的影响。实验结果表明外源CaM能明显抑制粟酒裂殖酵母细胞的增殖,其作用方式是延长了粟酒裂殖酵母细胞生长的延滞期。抗粟酒裂殖酵母CaM抗体、TFP及Phenyl-SepharoseCL－4B能降低CaM对细胞生长的抑制作用,而Ca2+及Ca2+螫合剂EGTA对CaM的抑制作用均无影响。以上结果提示,外源CaM对粟酒裂殖酵母细胞增殖的抑制作用可能是由于胞外CaM激活了细胞膜上的Ca2+泵,使胞内Ca2+浓度降低所致。     

小鼠造血干细胞增殖与分化性能的研究

本文选择Ｙ染色体特异的性别决定基因作为新的细胞遗传标志,采用ＰＣＲ技术研究了小鼠造血干细胞的增殖与分化性能。将雄鼠骨髓细胞输注给经致死剂量射线照射的雌性受体小鼠、ＰＣＲ测试结果表明,所有ＣＦＵ－Ｓ均为供体起源。供体来源的ＣＦＵ－Ｓ在其输入体内后,可通过增殖,分化形成各系造血细胞,但ＣＦＵ－Ｓ中的纤维母细胞和ＣＦＵ－Ｓ重建造血后受体小鼠骨髓中的纤维母细胞均为受体起源。由此可见,小鼠骨髓中的ＣＦＣ－Ｓ     

THE INFLUENCE OF ADRENORECEPTOR ACTIVITY ON CRYPT CELL PROLIFERATION IN THE RAT JEJUNUM

The influence of adrenergic stimulation, adrenergic blockade and sympathectomy on crypt cell cycle time and mitotic time in rat jejunum was studied. Alpha adrenergic stimulation by noradrenaline was found to shorten both cell cycle and mitotic times, whereas beta adrenergic stimulation by adrenaline or isoprenaline was found to prolong both cell cycle and mitotic times. Conversely, alpha adrenergic blockade by phentolamine prolonged cell cycle time and beta adrenergic blockade by propranolol or practolol shortened cell cycle time but not mitotic time. Both chemical and surgical sympathectomy inhibited crypt cell proliferation. Chemically sympathectomized animals manifested supersensitivity to exogenous noradrenaline.     

THE EFFECT OF E TYPE PROSTAGLANDINS ON THE PROLIFERATION OF HAEMOPOIETIC STEM CELLS IN VIVO

The ability of protaglandins E₁ and E₂ to stimulate the proliferation of haemopoietic stem cells (CFU_s) was studied in vivo. PGE₂, in a dose range of 10^-4 to 10^-1μg/g body weight and PGE₁ in a dose range of 10^-5 to 10^-1μg/g body weight, produced a rapid cycling wave of CFU_s. The increase in the number of CFU_s in S phase was not followed by a rise in the femoral CFU_s content, and except for a transient increase in femoral CFU_c level, no increase in differentiation was found either. Therefore, it is proposed that haemopoiesis after PG-induced CFU stimulation is ineffective. PGE₂ did not stimulate regeneration of CFU_s in a perturbed state (after sublethal irradiation). All these findings support the idea that PGEs might represent potent stimulators of the haemopoietic stem cells acting in physiological doses. However, if acting concurrently with physiological control systems PGs lead to ineffective haemopoiesis (under normal conditions) or do not exert any measurable effect (after sublethal irradiation).     

THE EFFECT OF PARTIAL BODY IRRADIATION ON HAEMOPOIETIC STEM CELL MIGRATION

Data obtained after various types of partial body irradiation support the concept of a small rapidly exchangeable pool of CFUs, which seems to be exhausted rapidly after irradiation. The depletion of this pool is the most plausible explanation for the decrease in stem cell migration observed 3 hr after exposure in C₃H mice. After partial body irradiation the size of the rapidly mobilizable pool is reduced in proportion to the areas of bone marrow irradiated. When only one marrow area is shielded, the recovery of this pool does not occur during the first 24 hr after exposure.     

SOME FACTORS WHICH INFLUENCE THE OXIDATION OF SULFHYDRYL GROUPS

1. Cyanide inhibits the oxidation of the SH groups of cysteine and denatured egg albumin by the uric acid reagent. 2. At pH 4.8 cysteine is oxidized by the uric acid reagent and by ferricyanide in the presence but not in the absence of added copper sulfate. 3. In neutral solution, the uric acid reagent oxidizes the SH groups of denatured egg albumin in the presence of urea but not in the presence of alkyl sulfate or in the absence of denaturing agents. 4. Ferricyanide oxidizes the SH groups of neutral denatured egg albumin even in the presence of alkyl sulfate or, if precautions are taken to avoid aggregation, in the absence of denaturing agents. 5. In acid solution, ferricyanide does not oxidize the SH groups of denatured egg albumin completely. The oxidation is more complete, however, in the presence of urea than in the presence of alkyl sulfate, and more complete in the presence of guanidine hydrochloride than in the presence of urea. 6. The uric acid reagent which does not oxidize the SH groups of neutral denatured but unhydrolyzed egg albumin in the absence of denaturing agents does, under the same conditions, oxidize the SH groups of egg albumin partially hydrolyzed by pepsin. 7. At pH 4.8 in alkyl sulfate solution ferricyanide oxidizes the SH groups of digested egg albumin more completely than the SH groups of denatured but undigested egg albumin.     

赖诺普利对血管成形术后平滑肌细胞增殖影响的研究

为研究赖诺普利对血管成形术后平滑肌细胞（ＳＭＣ）增殖的影响,用体外血管平滑肌细胞培养及氚标记胸腺嘧啶核苷（３Ｈ－ＴｄＲ）掺入技术,观察了不同浓度赖诺普利（１～２０μｇ／ｍｌ）对培养的球囊血管成形术后的兔髂动脉ＳＭＣ增殖情况的影响。结果表明：加入赖诺普利后ＳＭＣ对３Ｈ－ＴｄＲ的摄取及细胞计数明显比对照组低（Ｐ＜０．０１或Ｐ＜０．０５）,各浓度组均有作用,浓度越高作用越明显。提示赖诺普利可抑制血管成形术后平滑肌细胞的增殖,有预防血管成形术后再狭窄的作用。     

ELF磁场对3T3细胞生长的影响及其机理的探讨

用细胞分析成像光盘记录系统测量了3T3细胞在某些ELF磁场和温度条件下生长周期的变化.实验结果表明,只有某些频率的ELF磁场才对细胞生长产生影响,磁场对细胞生长的影响还与培养细胞的生化环境有关.温度和ELF磁场都能影响细胞的生长.但二者的机理是不一样的,当撤除ELF磁场后,细胞在短时间内(2天以上)继续保持着ELF场对其生长的影响.而细胞生长周期能在短时间内(2天以内)随着温度的变化而变化.温度引起的细胞生长的变化可能与细胞内的各种生长因子、生物离子的活性有关.ELF磁场引起的细胞生长的变化可能与ELF磁场对细胞膜的影响有关,与细胞内细胞生长必不可少的生物离子(如Ca~(2+))的浓度有关.     

THE EFFECT OF CONTINUOUS IRRADIATION ON CELL PROLIFERATION AND MATURATION IN SMALL INTESTINAL EPITHELIUM

Autoradiographic studies and scintillation counting of crypt material after pulse labelling with ³H-thymidine showed that during continuous irradiation with 290 rads/day a reduced proliferative activity is present in the crypts of rat small intestine after 1 day of irradiation and of normal activity during the remaining period (5 days) irradiation. After cessation of irradiation an increase in proliferative activity can be observed after 1 day of recovery. From the time (36–48 hr after starting of the irradiation) that the number of villus cells is reduced an expansion of the proliferation zone in the crypt was observed. Both effects last until 1 day of recovery after cessation of irradiation. The process of crypt cell maturation and of villus cell function has also been studied during and after continuous irradiation by micro-chemical enzyme analyses in isolated crypts and villi. It was found that the expansion of the proliferation zone in the crypt is accompanied by a decrease in activity of only those enzymes (i.e. non-specific esterases) which normally become active during crypt cell maturation. The activity of enzymes normally present mainly in the functional villus cells remained relatively unaffected by changes in crypt cell kinetics. A hypothesis of different regulation mechanisms of the proliferative activity in the intestinal crypt and a possible explanation of the different behaviour of various enzyme activities as a result of changes in crypt cell proliferation is discussed.     

THE ENHANCEMENT OF HAEMOPOIETIC STEM CELL RECOVERY IN IRRADIATED MICE BY PRIOR TREATMENT WITH CYCLOPHOSPHAMIDE

Studies are reported of the enhancement of stem cell recovery following whole body irradiation as a result of prior administration of cyclophosphamide. It is shown that the much larger enhancement of regeneration observed for the hosts own surviving stem cells, compared to the regeneration of injected bone marrow stem cells, is due to the different numbers of stem cells initiating the regeneration in conjunction with the time course of stem cell regeneration. The results show that the environmental changes produced by cyclophosphamide greatly enhance haemopoietic recovery even though at the dose used this agent is relatively toxic to stem cells. Furthermore it has been shown that the level of stem cell regeneration is nearly independent of the γ-ray dose in the range 3–8 gray (300–800 rad). If human bone marrow should respond similarly it follows that regeneration produced by cytotoxic drugs administered prior to radiation embodies a considerable safety factor as far as recovery of the haemopoietic system is concerned.     

问充质干细胞体外调控骨髓造血前体细胞向单核系分化

研究间充质干细胞(MSC)能否在体外调控造血.体外分离培养人骨髓来源的MSC,RT-PCR检测其造血生长因子的表达,并以其为饲养层细胞,接种骨髓单个核细胞(MNC),观察生长情况,并通过形态学观察和流式细胞术分析,鉴定细胞来源和分化方向.结果显示,MSC构成性表达SCF、Flt3L和M-CSF,不表达G-CSF和GM-CSF,在骨髓MNC和MSC共培养体系中,大约2周左右可以看到大量的圆形细胞粘附在梭型MSC上生长,细胞胞体为圆形,胞浆较丰富,胞核为圆形、半月型或肾型,部分细胞呈典型的单核细胞形态,流式细胞术分析该类细胞表达CD14,不表达CD15、CD41、glycophorin A、CD5和CD19.表明不需要添加外源性造血生长因子,间充质干细胞能在体外调控骨髓造血前体细胞向单核系分化,其定向分化可能与MSC分泌造血生长因子及MSC与造血细胞间相互作用有关.     

EFFECT OF MECHANICAL STIMULATION ON CELL PROLIFERATION IN MOUSE EPIDERMIS AND ON GROWTH REGULATION BY ENDOGENOUS FACTORS (CHALONES)

Mechanical stimulation of dorsal mouse skin by skin massage or removal of the horny layer results in a mutually comparable increase in DNA-labelling and mitotic activity. However, only after injury such as removal of the horny layer hyperplasia develops. This phenomenon, called ‘hyperplastic transformation’ is characterized by a transient abolition of the epidermal G₁ chalone responsiveness. There is some indication that the susceptibility to a heat labile factor, probably the epidermal G₂ chalone, is not affected. Skin massage neither interferes with the responsiveness to epidermal G₁ chalone nor induces ‘hyperplastic transformation’. Mouse tail epidermis shows a ‘functional hyperplasia’ and responds to the G₁ chalone. To explain these observations, it is assumed that the epidermal stem cell population is heterogeneous consisting of G₁ chalone-sensitive and G₁ chalone-insensitive cells.     

EFFECT OF ADENOSINE 3''-5''-CYCLIC MONOPHOSPHATE ON CELL PROLIFERATION

Secondary cultures of human diploid fibroblasts, which demonstrate density-dependent inhibition of cell growth, were used to study the effect of adenosine 3'-5'-cyclic monophosphate (cAMP) on cell proliferation. DNA synthesis in nonconfluent cultures and in contact-inhibited cultures stimulated to grow by refeeding with fresh medium was found to be inhibited by exogenous cAMP. The properties of this inhibition of DNA synthesis, together with the alterations in cAMP metabolism observed in confluent cultures of cells stimulated with fresh medium to resume growth, strongly suggest that cAMP is involved in contact-inhibition of cell proliferation.     

环磷酰胺对大鼠神经上皮细胞向神经元方向分化的影响

目的研究环磷酰胺对大鼠神经上皮细胞向神经元方向分化的影响,进一步探讨其致畸作用的分子机制,为预防人类NTDs的发生提供理论依据。方法将孕鼠随机分实验组和对照组,实验组在妊娠第13天上午8-9时腹腔注射环磷酰胺(15mg/kg体重),对照组注射等量生理盐水。分别于给药后4、8、12、24、48h处死孕鼠,剖腹取出胎鼠,于10%中性福尔马林中固定,常规石蜡包埋、连续切片。应用免疫组织化学和免疫荧光技术检测β-tubulin和NeuN在NTDs发生中的表达变化。结果(1)β-tubulin免疫荧光染色结果:给药后4、8h,实验组β-tubulin阳性率与对照组相比,差异无统计学意义;给药后12、24、48h,β-tubulin阳性细胞与对照组相比减少,差异均有统计学意义。(2)NeuN免疫组织化学结果:给药后4、8、12h,实验组和对照组均未检测到NeuN阳性细胞;给药后24、48h,实验组与对照组相比,NeuN阳性细胞减少,差异均有统计学意义。结论环磷酰胺可使β-tubulin、NeuN的表达降低,干扰神经上皮细胞向神经元方向分化。     

Survivin靶向siRNA抑制大肠癌细胞增殖的作用

目的 构建survivin靶向siRNA重组表达载体,研究其对人大肠癌细胞生长的抑制作用。方法构建Stirvivin靶向siRNA并转染结肠癌细胞,通过RT-PCR和Westernblot方法检测survivin的表达,采用MTT法检测siRNA对细胞增殖的抑制作用。结果经酶切鉴定和测序结果证实survivin靶向siRNA重组表达载体构建成功,它对大肠癌细胞survivinmRNA和蛋白的表达抑制率分别为36．33％和44．65％,肿瘤细胞的生长受到明显抑制。结论survivin靶向siRNA构建成功并能显著抑制survivin基因的表达。     

重组人血小板生成素对巨核细胞系-Dami细胞增殖的影响

为了探讨重组人血小板生成素（ｒｅｃｏｍ ｂｉｎａｎｔｈｕｍ ａｎ ｔｈｒｏｍ ｂｏｐｏｉｅｔｉｎ,简称ｒｈＴＰＯ）的生物学活性,采用了血浆凝块培养法,５－溴－２′－脱氧尿核苷（５－ＢｒｄＵ）掺入Ｄａｍ ｉ细胞ＤＮＡ－酶联免疫吸附法,研究了ｒｈＴＰＯ对巨核细胞系－Ｄａｍ ｉ细胞增殖的作用。结果发现, 在加有ｒｈＴＰＯ的培养基中, Ｄａｍ ｉ细胞迅速增殖, 集落数量和吸光度值高于对照组。实验组ｒｈＴＰＯ浓度为２５, ５０, １００, ２００ｎｇ／ｍ ｌ, Ｄａｍ ｉ细胞集落增殖率分别为２１．０５％ ,５７．８９％ ,１０５．２６％ ,１２１．０５％ ,吸光度增加率分别为１９．３５％ ,６１．２９％ ,１０３．２３％ ,１１９．３５％ ,ｒｈＴＰＯ促进Ｄａｍ ｉ细胞增殖的作用在一定范围内存在浓度依赖性。研究结果表明, ｒｈＴＰＯ对Ｄａｍ ｉ细胞具有促进增殖的作用。