Gametogony of Sarcocystis sp. in cell culture

Sexual stages and cystlike bodies of Sarcocystis sp., a protozoan parasite found in muscles of reptiles, birds, and mammals, including man, developed in cell culture. Motile organisms, obtained from leg muscles of wild grackles, were inoculated into cell line cultures of embryonic bovine kidney. Mature micro-and macrogametes and the cystlike forms were found 30 and 42 hours after inoculation respectively. These observations indicate that the parasite is probably a coccidium.     

Acetoxycycloheximide enhances audiogenic seizures in DBA-2J mice

Inborn errors of metabolism often cause epilepsy, as with certain strains of mice. Aggravating the metabolic defect with a protein synthesis inhibitor increases the symptoms. Mature animals that have "outgrown" their genetic susceptibility to audiogenic seizures are made susceptible again by acetoxycycloheximide. After a single small dose the incidence and severity of audiogenic seizures increases at 16 hours, reaches a maximum of 40 hours, and then declines gradually.     

Cyclic changes in enzyme activity in synchronized mammalian cell cultures

Activity of the enzymes glucose-6-phosphate dehydrogenase and lactate dehydrogenase increases intermittently in synchronized cultures of Chinese hamster cells. During G(1) phase (3 hours after mitosis), midway through S phase (7 hours after mitosis) and again in late S phase (10 hours after mitosis), rapid increases in activity were observed and correlated with a net increase in cell size and total protein. The evidence suggests that this is a general phenomenon which affects a whole population of proteins and may be the expression of an endogenous cellular rhythm.     

Actinomycin D; renewed RNA synthesis after removal from mammalian cells

Suppressed RNA synthesis exceeded control rates 2 hours after removal of actinomycin from serial lines of green monkey kidney cells in exponentially dividing monolayer cultures. Enhanced synthesis was directly related to the dose of actinomycin, and release from inhibition was temperature dependent. A broad range of RNA sizes was made after removal of drug, but cytoplasmic and nucleolar sedimentation profiles were abnormal for at least 20 hours.     

不同贮藏条件下成熟椰子水品质变化规律研究

以成熟椰子水为试验材料,以吸光度、pH、白利糖度和电导率为指标,结合感官评价对4个贮藏温度下的椰子水品质变化特点进行分析。结果表明,各处理随贮藏时间延长,吸光值均逐渐增大,pH值均逐渐减小,电导率呈增大趋势;温度越低,吸光值增大越缓慢和pH维持稳定的时间段越长,说明低温更有利于椰子水的贮藏;相同贮藏温度,密封和非密封保存时间无差别,37℃可保存5 h,24℃可保存8 h,14℃可保存22 h,4℃可保存7 d。椰子水的吸光值和p H值剧变时间点与椰子水变质时间节点最接近,其中吸光值变化最为显著,吸光值和pH变化可作为反映椰子水变质的主要指标;椰子水收集后迅速降至4℃可满足工业生产要求。     

Sulfatide synthesis: inhibition by experimental allergic encephalomyelitis serum

The rate of (35)S incorporation into cerebroside sulfate in cultures of embryo mouse spinal cord shows a rapid acceleration at the time of myelin formation. Exposure of cultures to dilute serum from rabbits with experimental allergic encephalomyelitis results in almost complete inhibition of sulfatide synthesis. Within 24 hours after replacement of inhibiting medium with normal medium there is an increase in sulfatide synthesis followed by myelination.     

Eosinophilic response in glioblastoma tissue culture after addition of autologous lymphocytes

In experiments designed for the study of interactions in vitro between the cells of glioblastoma multiforme and lymphocytes from the same donor, a marked eosinophilic response was noted in three out of six cases. This was an entirely unexpected finding since few, if any, eosinophils survive in tissue cultures. These cells incorporated (3)H-cytidine and (3)H-leucine 72 hours after the cultures had been established, an indication that they were metabolically active.     

卡氏住白虫裂殖子和配子体的超微结构

卡氏住白虫(Leueocytozoon caulleryi的裂殖子和配子体是从天然感染鸡的外周血液、肝、脾及其他内脏组织采取。通过透视电镜观察其超微结构,裂殖子呈圆形或卵圆形,外包有两层膜,外膜较薄,内膜比较厚,内含有一个圆形或卵圆形的核,在核中央有一核仁、核酸糖小体、食物空泡,具有一个管状嵴的线粒体和1～2个脂类包含体。 卡氏住白虫雄性和雌性配子体都具有三层明显的膜,但成熟的配子体仅见到两层膜。雌雄配子体含有细胞核、核仁、核酸糖小体、食物空泡、管状嵴的线粒体、内质网、雄配子体较小而细胞核较大。雌配子体染色较雄配子体深,并含有较发达的内质网。     

Inhibition of endothelial regeneration by type-beta transforming growth factor from platelets

Damage to the vessel wall is a signal for endothelial migration and replication and for platelet release at the site of injury. Addition of transforming growth factor-beta (TGF-beta) purified from platelets to growing aortic endothelial cells inhibited [3H]thymidine incorporation in a concentration-dependent manner. A transient inhibition of DNA synthesis was also observed in response to wounding; cell migration and replication are inhibited during the first 24 hours after wounding. By 48 hours after wounding both TGF-beta-treated and -untreated cultures showed similar responses. Flow microfluorimetric analysis of cell cycle distribution indicated that after 24 hours of exposure to TGF-beta the cells were blocked from entering S phase, and the fraction of cells in G1 was increased. The inhibition of the initiation of regeneration by TGF-beta could allow time for recruitment of smooth muscle cells into the site of injury by other platelet components.     

Virus: mixed infection with herpes simplex and simian virus 40

Mixed infection, the infection of a single cell by two distinguishable viruses, has been demonstrated by electron microscopy in cultures of African green monkey kidney cells after inoculation with simian virus 40 and herpes simplex. Mixed infection occurs rarely when the two viruses are inoculated simultaneously, but if herpes is inoculated 24 hours after SV40 both viruses are found in the same nucleus in about 5 percent of intact cells.     

Induction of collagenolytic and proteolytic activities in rat and human fibroblasts by anti-inflammatory drugs

Confluent monolayers of either mouse or diploid human fibroblasts contained no measurable amounts of either collagenolytic (pH 5.5) or proteolytic (pH 7.5) activities. Within a few hours after exposure of these cells to antiinflammatory drugs, significant amounts of these enzymatic activities were demonstrable extracellularly. These activities were profoundly decreased in cultures simultaneously treated with the anti-inflammatory drugs and cycloheximide or actinomycin D.     

Somatomedin-C mediates growth hormone negative feedback by effects on both the hypothalamus and the pituitary

Somatomedin-C stimulates somatostatin release to a maximum of 390 percent of basal release during short-term (20-minute) incubation of rat hypothalamus. It has no effect on basal or stimulated growth hormone release from primary cultures of rat adenohypophyseal cells during a 4-hour incubation, but inhibits stimulated release by more that 90 percent after 24 hours. These findings suggest that somatomedin-C participates in the growth hormone negative feedback loop with an immediate effect on hypothalamic somatostatin and a delayed effect on the anterior pituitary.     

Euglena gracilis: formation of giant mitochondria

The addition of antimycin A (0.5 microgram per milliliter) to cultures of a bleached strain of Euglena gracilis in the logarithmic phase of growth on succinate as a carbon source results in (i) an interruption of growth for 24 hours and (ii) an increase in whole-cell respiration and the emergence of a novel succinoxidase activity within 2 to 4 hours. After 3 to 5 hours, the mitochondria enlarge, fuse, and form a sheathlike structure situated close to the periphery of the cell.     

堆型艾美耳球虫早熟减毒株细胞培养卵囊最佳收获时间的测定

堆型艾美耳球虫早熟减毒株在鸡胚小肠上皮细胞上培育,卵囊最佳收获时间为120小时。     

条件培养基对昆虫细胞BTI-Tn5B1-4及克隆株特性的影响

研究了条件培养基对细胞BTI-Tn5B1-4及其克隆株特性的影响。用含20%条件培养基以2×105cells/ml浓度测定细胞生长曲线,并与新鲜培养基作比较。结果显示,含条件培养基的细胞培养中的最大浓度比对照培养基的浓度高,同时细胞群体倍增时间比对照培养基中缩短3～5小时。当用野生型病毒AcMNPV感染时,两种培养基中细胞敏感性均在93%以上,OB产量差异不显著。重组蛋白半乳糖苷酶和碱性磷酸酶表达量测定比较,结果显示条件培养基中两种重组蛋白表达量均比对照培养基中高大约10%。     

日本晴水稻悬浮细胞系的建立和保存

本研究旨在建立日本晴水稻悬浮细胞系和保存悬浮细胞。在添加2 mg.L-1 2,4-D的NB培养基之后日本晴的成熟胚被诱导愈伤组织形成,2个月的继代后,愈伤组织在2 mg.L-1 2,4-D的NB液体培养基上用于悬浮细胞的培养。3个月的继代后,得到理想的悬浮细胞。关于培养的植物细胞的超低温保存程序大多数报道是两步保存法,采用含有脱落酸激素的预培养溶液培养,同时利用化学冷冻保护剂处理,并在-30℃下放置2 h后投入液氮保存,复苏后细胞的存活率(氯化三苯四氮唑还原法)为80%以上。     

外源激素对桃儿七愈伤组织诱导的影响

为了探讨外源激素对桃儿七愈伤组织诱导的影响,以桃儿七的胚及无菌苗的子叶和胚轴为材料,以MS为基本培养基,研究了3种不同激素配比对不同外植体愈伤组织诱导的影响。结果表明,以胚为外植体,在3.0 mg/L 2,4-D、0.5 mg/L KT和0.5 mg/L IAA组合处理的培养基中,诱导率达到39.5%;诱导子叶和胚轴形成愈伤组织的最佳激素配比为4.0 mg/L 2,4-D+0.5 mg/L KT+0.2 mg/L IAA;成熟胚比子叶和胚轴更易诱导愈伤组织的形成,诱导率分别提高了43.64%和315.79%,诱导效果最显著(P0.001);在接种前,用5mg/L 2,4-D溶液浸蘸子叶和胚轴可有效提高其出愈率。     

绿菇子实体菌株的原生质体分离及再生菌株的获得

收集30℃下，暗培养36～48hr的菌体，放入酶液中并把菌丝分散，经过3～8hr的酶解，菌体产生的分生孢子95%以上成为原生质体。经过滤、离心纯化，原生质体的产量在0.1×10     

甘草离体培养物中总黄酮提取工艺的优化

【研究目的】对甘草离体培养物中总黄酮提取和测定工艺进行优化,以建立在室内筛选高产细胞系和试管苗株系的方法;【方法】采用超声波提取技术,对提取液、浸泡时间、提取温度等进行优化;【结果】将样品以75%甲醇浸泡6h后在32℃下超声提取两次,比色法测定总黄酮含量,加样回收率为95.3%～101.4%,相对标准偏差为1.61%。测得甘草初代愈伤组织中总黄酮含量为0.0012%～0.05%,子叶愈伤组织调控后含量高达0.08%,试管苗中总黄酮含量为1.04%～1.31%,移栽后高达4.5%。【结论】此工艺准确度较高、稳定性好、简便可行,为优良细胞系的筛选和试管苗的早期鉴定奠定了技术基础。