Amitotic neuroblastoma cells used for neural implants in monkeys

The potential utility of cultured neuroblastoma cells as donor tissue for neutral implants into the mammalian brain has been examined. Cells from a human neuroblastoma cell line, IMR-32, were labeled with [3H]thymidine and chemically rendered amitotic. These differentiated IMR-32 cells were grafted into the hippocampi of five adult African Green monkeys, and graft survival was evaluated for up to 270 days after transplantation. Autoradiographically labeled grafted cells were identified in four animals. Processes from grafted cells could be followed for distances of up to 150 micrometers into the host brain. No evidence for neoplastic growth of the transplant was found. Thus, grafted neuroblastoma cells can survive for prolonged periods in the primate brain and may serve as a practical source of donor tissue for neural implants.     

Donor-derived cells in the central nervous system of twitcher mice after bone marrow transplantation

The twitcher mouse is an animal model of galactosylceramidase deficiency, comparable to Krabbe's disease, a lysosomal storage disease in humans. As in most lysosomal storage diseases, neurological deterioration is a prominent feature of the disease in these mice. Transplantation of enzymatically normal congenic bone marrow was earlier found to result in prolonged survival and increased levels of galactosylceramidase in the visceral organs of twitcher mice. It is now reported that bone marrow transplantation results in increased galactosylceramidase levels in the central nervous system (CNS). Concomitantly, the levels of psychosine, a highly toxic lipid that progressively accumulates in the CNS of untreated twitcher mice, stabilized at much lower levels in the CNS of treated twitcher mice. Histologically, a gradual disappearance of globoid cells, the histological hallmark of Krabbe's disease, and the appearance of foamy macrophages capable of metabolizing the storage product were seen in the CNS. By immunohistochemical labeling it was demonstrated that these foamy macrophages were of donor origin. The infiltration of enzymatically competent, donor-derived macrophages was accompanied by extensive remyelination in the CNS. It is concluded that after bone marrow transplantation, donor-derived macrophages infiltrate the affected brain tissue and are capable of inducing a partial reversal of the enzyme deficiency.     

骨髓间充质干细胞移植治疗脑缺血的动物实验研究

    探讨骨髓间充质干细胞(MSCs)移植对大鼠脑缺血的修复和治疗.体外分离培养大鼠MSCs,以Hoeschst33342标记,移植到大脑中动脉梗塞(MCAO)模型的大鼠体内,分别设立缺血1 d和缺血7 dMSCs移植组与缺血对照组,对各组大鼠进行神经功能损害严重程度评分(NSS)及大脑组织切片观察比较.结果发现,缺血1 d MSCs移植组大鼠NSS评分低于另外两组,差异显著(P＜0.05),大脑组织结构清晰、完整,胶质瘢痕少;缺血7 d MSCs移植组与对照组无明显差异(P＞0.05).故缺血早期进行MSCs移植,大鼠神经功能恢复情况明显.MSCs在损伤后的脑组织内能够存活并且分化为神经元、胶质细胞等,对动物神经损伤后组织重建及功能恢复有一定的治疗作用.     

Brain grafts reduce motor abnormalities produced by destruction of nigrostriatal dopamine system

In order to determine if brain tissue grafts can provide functional input to recipient central nervous system tissue, fetal rat dopamine-containg neurons were implanted adjacent to the caudate nucleus of adult recipients whose endogenous dopaminergic input had been destroyed. The grafts showed good survival and axonal outgrowth. Motor abnormalities, which had been induced by the destruction of the endogenous dopaminergic input to the caudate, were significantly reduced after grafting of the fetal brain tissue. These data suggest that such implants may be potentially useful in reversing deficits after circumscribed destruction of brain tissue.     

杏花粉活力测定培养基筛选及耐贮性研究

[目的]以固体琼脂培养基离体培养‘大黄杏’品种花粉,比较不同浓度蔗糖、硼酸对花粉离体萌发的影响.[方法]用筛选出的最适培养基测定三种贮藏温度条件下花粉活力变化.[结果]‘大黄杏’品种最适萌发培养基为:l5;蔗糖+0.01;硼酸+1;琼脂;干燥密闭条件下,为期1年贮藏于三种温度条件下花粉活力大小依次均为:-18℃＞4～5℃＞室温,活力下降幅度由大到小则依次均为:室温＞4 ～5℃＞- 18℃.[结论]花粉于-18℃贮藏后1年活力仍达30.00;,4～5℃在贮后第11个月丧失活力,而在室温下贮藏3个月花粉即失去活力.     

Neocortical transplants in the mammalian brain lack a blood-brain barrier to macromolecules

In order to determine whether the blood-brain barrier was present in transplants of central nervous tissue, fetal neocortex, which already possesses blood-brain and blood-cerebrospinal fluid barriers to protein, was grafted into the undamaged fourth ventricle or directly into the neocortex of recipient rats. Horseradish peroxidase or a conjugated human immunoglobulin G-peroxidase molecule was systemically administered into the host. These proteins were detected within the cortical transplants within 2 minutes regardless of the age of the donor or postoperative time. At later times these compounds, which normally do not cross the blood-brain barrier, inundated the grafts and adjacent host brain and also entered the cerebrospinal fluid. Endogenous serum albumin detected immunocytochemically in untreated hosts had a comparable although less extensive distribution. Thus, transplants of fetal central nervous tissue have permanent barrier dysfunction, probably due to microvascular changes, and are not integrated physiologically within the host. Blood-borne compounds, either systemically administered or naturally occurring, which should never contact normal brain tissue, have direct access to these transplants and might affect neuronal function.     

Transmission of experimental kuru to the spider monkey (Ateles geoffreyi)

Clinical signs and pathological changes characteristic of kuru in man and experimental kuru in chimpanzees were observed in two spider monkeys, Ateles geoffreyi, after inoculation with brain tissue from a kuru-affected chimpanzee. The incubation period for one of the monkeys was 23 months, and 26 months for the other.     

哺乳动物胚胎干细胞研究进展

胚胎干细胞(embryonic stem cells, ES)是指从桑椹胚或附植前囊胚内细胞团分离的多潜能细胞,它具有体外培养无限增殖、自我更新和多向分化的特性。无论在体外还是体内环境,ES细胞都能被诱导分化为机体几乎所有的细胞类型。自1981年Evans和Kaufman首次成功分离小鼠ES细胞,国内外研究人员已在仓鼠、大鼠、兔、猪、牛、绵羊、山羊、水貂、恒河猴、美洲长尾猴以及人类都分离获得了ES细胞,而且已经证明小鼠ES细胞可以分化为心肌细胞、造血细胞、卵黄囊细胞、骨髓细胞、平滑肌细胞、脂肪细胞、软骨细胞、成骨细胞、内皮细胞、黑素细胞、神经细胞、神经胶质细胞、少突胶质细胞、淋巴细胞、胰岛细胞、滋养层细胞等。人类ES细胞也可以分化为滋养层细胞、神经细胞、神经胶质细胞、造血细胞、心肌细胞等。ES细胞不仅可以作为体外研究细胞分化和发育调控机制的模型,而且还可以作为一种载体,将通过同源重组产生的基因组的定点突变导入个体,更重要的是,ES细胞将会给人类移植医学带来一场革命。     

贮藏时间对栀子种子生活力和发芽率的影响

对自然条件下贮藏1、4、8个月的栀子(Gardenia jasminoides Ellis)种子的发芽率、生活力和含水量进行了测定。结果表明,采集后短时间贮藏栀子种子能保持较高的生活力和发芽率,但栀子种子寿命较短,随着贮藏时间的延长,种子的生活力、发芽率呈明显下降的趋势,种子对环境的耐受性也大大降低。生活力与贮藏时间的相关系数r=0.958,种子的生活力(Y)与贮藏时间(X)回归方程Y=102.794-3.736 X;发芽率与贮藏时间的相关系数r=0.881,种子的发芽率(W)与贮藏时间(X)回归方程W=95.740-6.368 X,均显著相关。长时间贮藏后栀子种子的含水量明显下降。     

ROS诱导的氧化应激和细胞程序性死亡对超低温保存后花粉生活力的影响

[目的]超低温保存后花粉生活力呈多种变化情况,已有研究表明活性氧(ROS)是超低温保存后花粉生活力变化的主要原因之一.因此,本研究探讨液氮冻存后花粉生活力与ROS诱导的氧化应激和细胞程序性死亡间的关系,以进一步揭示ROS在超低温保存后花粉生活力变化中的作用机制.[方法]以芍药'粉玉奴'的花粉为材料,对比分析超低温保存不...     

Transplantation of fetal hematopoietic stem cells in utero: the creation of hematopoietic chimeras

Transplantation of normal, immature, fetal hematopoietic cells into a preimmune fetal recipient with a congenital hemoglobinopathy may allow partial reconstitution of normal hemoglobin production without the complications associated with postnatal bone marrow transplantation (immunosuppression and the occurrence of graft versus host disease). In order to test this hypothesis the naturally occurring polymorphism at the beta-hemoglobin locus of the sheep was used as a marker for engraftment and hematopoietic chimerism. Intraperitoneal injection of allogeneic fetal stem cells into normal fetal lambs resulted in hematopoietic chimerism in three of four surviving recipients. This chimerism has been sustained for 6 months after birth and 9 months after engraftment, without evidence of graft versus host disease, and without the use of immunosuppressive therapy.     

Intrahippocampal septal grafts ameliorate learning impairments in aged rats

Grafts of fetal septal tissue rich in cholinergic neurons were implanted as a dissociated cell suspension into the depth of the hippocampal formation in aged rats with severe impairments in spatial learning abilities. After 2 1/2 to 3 months, the rats with grafts, but not the controls, had improved their performance in a spatial learning test. Their improvement was due, at least in part, to an increased ability to use spatial cues in the task. In all animals the grafts had produced an extensive acetylcholinesterase-positive terminal network in the surrounding host hippocampal formation. Thus, the action of cholinergic neurons in the graft onto elements in the host hippocampal circuitry may be a necessary, but perhaps not sufficient, prerequisite for the observed functional recovery.     

Copper on intrauterine devices stimulates leukocyte exudation

Metallic copper in the uterine or abdominal cavities of rats or monkeys stimulates an impressive local exudation of polymorphonuclear leukocytes. This cellular response to copper persists for at least 7 months, without significant local tissue damage or detectable systemic effects on the test animal. This finding provides a possible explanation for the capacity of copper to increase impressively the antifertility effect of polyethylene intrauterine contraceptive devices.     

Specific endocrine tissue marker defined by a monoclonal antibody

One of two mouse monoclonal antibodies (LK2H10) produced by hybridoma technology against a human endocrine tumor (pheochromocytoma) demonstrated specific immunoreactivity for 69 normal and neoplastic endocrine and tissues known to contain secretory granules. This immunoreactivity was specific, since other normal tissues, tumors from endocrine cells without granules, and tumors from other nonendocrine tissues were negative when tested with antibody LK2H10. The antibody reacted with human fetal adrenal medulla and human pancreatic endocrine cells and with adrenal medullary cells from monkeys and pigs. The antigen detected by antibody LK2H10 is associated with cytoplasmic secretory granules, has an estimated molecular weight of 68,000, and may be related to human chromogranin.     

采种温度及贮藏年限对籽瓜种子生活力的影响

在人工控制的温度条件下研究了采种温度对籽瓜种子生活力的影响，结果表明４５～５５℃的干燥温度不影响籽瓜种子的生活力；但２℃的低温会显著降低籽瓜种子的生活力，而遭遇０℃及其以下低温２ｈ以上就会使籽瓜种子失去种用价值。对不同年份采收的种子进行的发芽试验表明，籽瓜种子的生活力随贮藏年限的延长而降低，黑籽籽瓜种子的有效贮藏期限约为２～３ａ，红籽籽瓜种子的有效贮藏期限为４～５ａ。     

Transplanted suprachiasmatic nucleus determines circadian period

The pacemaker role of the suprachiasmatic nucleus in a mammalian circadian system was tested by neural transplantation by using a mutant strain of hamster that shows a short circadian period. Small neural grafts from the suprachiasmatic region restored circadian rhythms to arrhythmic animals whose own nucleus had been ablated. The restored rhythms always exhibited the period of the donor genotype regardless of the direction of the transplant or genotype of the host. The basic period of the overt circadian rhythm therefore is determined by cells of the suprachiasmatic region.     

Effects of brief separation from mother on rhesus monkeys

To summarize, data on the course of development of mother-infant relations in rhesus monkeys have been presented; a method for teasing apart the relative roles of mother and infant in causing changes or differences in the interaction described; and the complexity of the social nexus, within which the relationship is set, stressed. When the mother is removed for a few days, the infant calls a great deal at first and then shows depressed locomotor and play activity. These symptoms may last for a month after the mother's return. Simple tests given 6 months and even 2 years later strongly suggest that the differences (between infants that have had such a separation experience and infants that have not) are persistent. Are these data relevant to the human case? The rhesus monkey has no verbal language and a much less complex social development than man. Furthermore, its social environment is quite different from that found in any human culture. Parallels between monkey and man must therefore be scrutinized carefully before being used as a basis for generalization. But the facts show that a brief separation experience produces in rhesus monkey infants symptoms that are very similar (except for the apparent absence of a "phase of detachment" on reunion) to those in human infants (25). While age of separation, within the rather narrow limits used here, was a variable of minor importance, the effects of the separation varied, as in the human case, with the length of the separation experience and the sex of the infant. Differences in the techniques of experimenters, as well as differences in the species, prevent precise comparisons of the roles of the mother-infant relationships; nevertheless, the nature of the relationship appears to be an important variable in both monkey and man. There would seem, therefore, to be strong reasons for thinking that we are dealing with comparable phenomena. If that is the case, the fact that monkeys function at a simpler conceptual level than man limits the complexity of the explanatory hypotheses necessary in the human case. In addition, the finding that such a brief separation experience, involving removal of the mother but no exposure to a strange environment, can produce effects lasting for months or years in rhesus monkeys strengthens the evidence that long-term effects may occur also in man. Finally, this analysis provides bases for attempts to predict individual differences in the effects of a period of separation on rhesus infants, and the parallels with man suggest that examination of the same variables in the human case would be worthwhile.     

根瘤菌菌剂研究

以豌豆根瘤茵三叶草生物型(Rhizobium leguminosarum bv.trifolii)TA1和华癸中生根瘤菌(Mesorhizobium huakuii)7653R为供试菌,在测定生长曲线的基础上制备了固体茵剂和浓缩液体菌剂.固体茵剂分别以草炭、蛭石和珍珠岩为载体,比较测定了3种茵剂在室温条件下的保存情况.结果表明在武汉3～9月测定时间内,3种茵剂中以草炭菌剂保存效果最好,成活茵数最多,珍珠岩茵剂次之,蛭石菌剂稍差.同时还比较了保存温度、抑菌剂和保护剂等因素对浓缩液体菌剂根瘤菌存活率的影响,筛选并确定了抑茵剂和保护剂的应用浓度.     

体外培养枫径猪胚胎成纤维细胞系方法的建立

选取枫径猪胚胎,采用胶原酶消化培养法制备猪胚胎成纤维细胞,经数次传代培养及冷冻复苏试验表明胚胎成纤维细胞仍具有正常的传代能力。在体外培养至15代后成纤维细胞核型正常,符合体细胞克隆转基因的要求。用PCR方法建立了枫径猪胚胎成纤维细胞性别鉴定的反应体系,对其中6株细胞进行了性别鉴定。     

采粉期及贮藏条件对猕猴桃花粉生活力的影响

【目的】研究不同采粉期及贮藏条件对猕猴桃花粉生活力的影响,为猕猴桃生产中人工辅助授粉和杂交育种提供依据。【方法】以猕猴桃品种“中华系401”为试材,分别于开花前3,2,1 d及大蕾期和开花后6,12,24 h采集花粉,比较不同采粉期对猕猴桃花粉生活力的影响;以“软枣猕猴桃”、“秦雄201”、“中华系401”和“毛花猕猴桃”雄株为试材,采集大蕾期花粉,分别进行常温贮藏（18～26 ℃）、低温(4和-15 ℃)贮藏,比较不同贮藏条件下猕猴桃的花粉生活力。【结果】开花前3 d,猕猴桃花粉生活力仅为1.92%;开花前2和1 d,猕猴桃花粉生活力分别达到48.07%和69.11%;大蕾期猕猴桃花粉生活力最高,达82.31%;开花后6,12和24 h的花粉生活力分别为66.89%,46.03%和31.40%,均不及大蕾期高。4种猕猴桃新鲜花粉的生活力均较高,达70%以上。常温条件下,猕猴桃花粉仅可贮藏6～9 d;4 ℃冷藏条件下,花粉生活力可维持60～150 d,平均达90 d;而-15 ℃冷冻条件下花粉生活力更长,可达360 d。【结论】以采用大蕾期花粉进行人工授粉为宜;贮藏温度是影响猕猴桃花粉生活力的重要因素之一,温度越低,花粉的贮藏效果越好。