烟草花粉管亚原生质体的分离和培养行为

应用酶法从烟草花粉管分离出大量亚原生质体。具核的和无核的亚原生质体之比约为1:1。这种亚原生质体在D_2培养基中培养后,不论有核的或是无核的都能生长管状结构和再生厚的壁。管状结构的生长有节律性,常呈结节状。随着管状结构的生长,细胞内含物逐渐流入生长中的管状结构内,有时会从薄的管状结构的顶端排出到培养液中。已生长管状结构的亚原生质体,具核的和无核的比例约为1:1.7,表明管状结构的生长和壁的再生与是否有核的存在无关。对酶液处理后花粉管亚原生质体从花粉管的释放和从单独的花粉管亚原生质体生长管状结构的过程,进行了活体连续观察和照相记录。实验结果说明,结节状的管状结构确实是从单独的一个亚原生质体形成的。管状结构的生长和壁的再生似乎与细胞质进入新生的管状结构有关。讨论了花粉管亚原生质体在植物遗传操作中应用的可能性。     

土壤中含EB病毒诱导物的检测

从广西壮族自治区梧州市、苍梧县、罗城县和北京市收集的土壤标本中发现有EB病毒诱导物。梧州市和苍梧县沿公路和江河两旁桐油树下的土壤标本,对EB病毒早期抗原诱导的阳性率为40～58％。在其他大戟科植物下的土壤标本中,也发现有EB病毒诱导物。对桐油树下土壤中EB病毒诱导物与鼻咽癌发生的可能关系进行了讨论。     

从广州市散发性脑炎病人血清中查出雪鞋野兔病毒抗体升高

近几年来夏季,在我国南方一些省市发现一些散发性病毒性脑炎病例,主要是儿童。他们的流行性乙型脑炎抗体阴性。病因不明。 为了研究本病的病因,于1983年4月至10月,我们在广州市儿童医院收集了34例散发性脑炎病人的双份血清,15例其它病种(如百日咳、心肌炎、钩端螺旋体脑炎、多发性神经根     

抗胃癌细胞系单克隆抗体PD4的初步研究

以胃癌细胞系MGC803免疫Balb/c小鼠,取其脾细胞与小鼠骨髓瘤细胞NS-1融合。经选择培养、筛选及克隆化,获得恒定地分泌抗胃癌细胞系单克隆抗体(MoAb)的杂交瘤细胞系PD4。MoAb PD4与3/4胃癌细胞系有强结合反应,与4/4肺癌细胞系有弱结合反应,但与淋巴细胞、ABO红细胞、骨髓细胞、二倍体成纤维细胞及经检测的其他肿瘤细胞均无反应。PD4抗原主要表达于靶细胞的膜上,不耐热,为分子量40kD的蛋白性抗原。该抗原与HLA抗原系统,血型抗原系统无关,亦不同于其他作者所报告的其他胃癌相关抗原。     

甲型肝炎病毒对理化因子的稳定性

用放射免疫成斑法研究了甲型肝炎病毒FM-175株的理化稳定性和灭活条件,证明甲型肝炎病毒理化稳定性与其它肠道病毒相似,具有广范围的pH(2～10)稳定性;Mg~(++)和Ca可增强其热稳定性,不能抵抗冷冻干燥,但对热的抵抗力明显高于普通肠道病毒,可被紫外线迅速杀灭,也可被多种消毒剂如3～8％的甲醛液,50～90％的乙醇,2％的石炭酸及400ppm的有效氯等杀灭,但可抵抗0.1％甲醛液,2～5％的来苏儿及200ppm的有效氯1小时以上,本研究工作为甲型肝炎病毒的理化性状、保存及消毒条件等提供了实验数据。     

黄素氧还蛋白参与的固氮链电子传递

棕色固氮菌中电子载体Fld直接向固氮酶铁蛋白传递电子。Fld_(ox)至Fld_R是双电子二步还原反应,极谱半波电位分别为-210、-550 mV。Fld_(ox)至Fld_(SR)的中点电位为-280 mV,Fld_(SR)至Fld_R为-500mV。铁蛋白中点电位为-256mV,加MgATP后为-390 mV。Fld_R与铁蛋白ox组成的电池电动势为244mV,电子传递可自发进行,反应的J△G~o为-23KJ/摩尔,铁蛋白被Fld_R还原的K_a=1.3×120~4,加入MgATP后△G~o为-10.6KJ/摩尔,K_a=72。因此,未加入MgATP时电子传递反应更易进行。     

Lectin binding sites in Paramecium tetraurelia cells. I. Labeling analysis predominantly of secretory components

Though all three lectins tested (ConA, RCA II, WGA) bound to the entire cell membrane, none bound selectively to the docking site of secretory organelles (trichocysts); the same results were achieved with FITC-conjugates, or, on the EM level, with peroxidase- or gold-labeling. Only WGA triggered the release of trichocysts and none of the lectins tested inhibited AED-induced synchronous exocytosis. When exocytosis was triggered synchronously in the presence of any of these three lectins (FITC-conjugates), the resulting ghosts trapped the FITC-lectins and the cell surface was immediately afterwards studded with regularly spaced dots (corresponding to the ghosts located on the regularly spaced exocytosis sites). These disappeared within about 10 min from the cell surface (thus reflecting ghost internalization with a half life of 3 min) and fluorescent label was then found in approximately 6-10 vacuoles, which are several microns in diameter, stain for acid phosphatase and, on the EM level, contain numerous membrane fragments (otherwise not found in this form in digesting vacuoles). We conclude that synchronous massive exocytosis involves lysosomal breakdown rather than reutilization of internalized trichocyst membranes and that these contain lectin binding sites (given the fact free fluorescent probes did not efficiently stain ghosts). Trichocyst contents were analyzed for their lectin binding capacity in situ and on polyacrylamide gels. RCA II yielded intense staining (particularly of "tips"), while ConA (fluorescence concentrated over "bodies") and WGA yielded less staining of trichocyst contents on the light and electron microscopic level. Only ConA- and WGA-staining was inhibitable by an excess of specific sugars, while RCA II binding was not. ConA binding was also confirmed on polyacrylamide gels which also allowed us to assess the rather low degree of glycosylation (approximately 1% by comparison with known glycoprotein standards) of the main trichocyst proteins contained in their expandable "matrix". Since RCA II binding could be due to its own glycosylation residues we looked for an endogenous lectin. The conjecture was substantiated by the binding of FITC-lactose-albumin (inhibitable by a mixture of glucose-galactose). This preliminary new finding may be important for the elucidation of trichocyst function.     

Intrapleural and intravenous Corynebacterium parvum in patients with resected stage I and II non-small cell carcinoma of the lung

Summary A prospective randomized trial compared the administration of intrapleural plus intravenous Corynebacterium parvum (C. parvum) versus placebo in patients with resected Stage I and Stage II non-small cell bronchogenic carcinoma. Treatment consisted of 7 mg C. parvum injected into the pleural space and 7 mg C. parvum intravenously once between days 6 and 12 postoperatively and 7 mg intravenously every 3rd month during the 1st year. Intrapleural administration of 35 cc of saline served as the placebo and the flush after intrapleural C. parvum.Of the 303 patients entered into this study, 286 were evaluable, with an average follow-up time of 3.5 years. More complications, especially fever, were observed in patients receiving C. parvum. A fever greater than 38 °C was observed in 9% of the patients assigned to placebo and 76% of the patients assigned to C. parvum. There was no significant difference between the treatments with respect to disease-free interval or survival.M. Kaufmann, J. Stjernswärd**, A. Zimmermann (Ludwig Institute for Cancer Research, Bern Branch); K. Stanley**, M. Isley, M. Zelen (Frontier Science & Tech. Research Foundation, Brookline, MA, USA); C. Mouritzen, P. Paulsen, U. Henriques (Dept. of Thoracic and Cardiovascular Surgery and Institute of Pathology, Kommunehospital, Aarhus, Denmark); N. Konietzko, W. Maassen, W. Hartung, W. Wierich (Ruhrland Clinic, Essen-Heidhausen, and Pathology Institute, Ruhr-University, Bochum, FRG); P. Oehl (Innere Klinik und Poliklinik Tumorforschung, Essen, FRG); J. Vogt-Moykopf, H. Toomes, W. Hofmann (Rohrbach Hospital, Clinic for Thoracic Medicine and Pathology Institute, Heidelberg, FRG); F. Krause, R. Rios, R. Spanel (Klinik Löwenstein, Löwenstein, and Pathology Institute, Ulm, FRG); J. Orel, B. Hrabar, D. Ferluga, T. Rott (University Medical Center, Thoracic Surgery and Pathology, Ljubljana, Yugoslavia); H. A. Rostad, J. R. Vale, P. Lexow (Rikshospital, Oslo, Norway); S. Hagen, S. Birkeland (Ulleval Hospital, Oslo, Norway); T. Harbitz, R. Nissen-Meyer (Aker Hospital, Oslo, Norway); E. Aspevik, H. Engedal, A. Mykin (Haukeland Hospital, Bergen, Norway); V. O. Björk, L. Rodriguez, K. Böök, J. Willems (Karolinska Sjukhuset, Thoracic Surgical Clinic and Pathology Department, Stockholm, Sweden); E. Grädel, J. Hasse, P. Dalquen (Kantonsspital, Dept of Surgery, Div. of Cardiac & Thoracic Surgery & Pathology Institute, Basel, Switzerland); L. Eckmann, K. Hänni, K. Zimmermann (Tiefenauspital Surg. Clinic, Univ. of Bern, Switzerland); B. Nachbur, H. U. Würsten, H. Cottier, A. Zimmermann (Inselspital Dept. of Thoracic and Cardiovascular Surg. and Pathology Institute, Bern, Switzerland); W. Maurer, M. Kaufmann (Bürgerspital, Surgical Department, Solothurn, Switzerland); H. Denck, E. Zwintz, St. Wuketich (Krankenhaus der Stadt Wien-Lainz, I. Chir. Dept., and Path. Inst., Vienna, Austria); N. Pridun, H. Hackl (Pulmonologisches Zentrum der Stadt Wien, and Path. Inst., Vienna, Austria); E. Moritz, W. Schlick, H. Holzner (II. Chir. University Clinic and Path. Inst., Vienna, Austria); K. Karrer (Institute for Cancer Research, Vienna, Austria); R. G. Crispen (ITR-Biomedical Research, University of Illinois, Chicago, USA); D. S. Freestone, R. Bomford, M. T. Scott, T. Priestman, L. Toy (The Wellcome Research Laboratories, Beckenham, England)** Present address: Cancer Unit, World Health Organization, Geneva, Switzerland Offprint requests to: K. Stanley, Ludwig Institute for Cancer Research, Inselspital, CH-3010 Bern, SwitzerlandLudwig Lung Cancer Study Group:     

Effect of Temperature on the Potential and Current Thresholds of Axon Membrane

The effect of temperature on the potential and current thresholds of the squid giant axon membrane was measured with gross external electrodes. A central segment of the axon, 0.8 mm long and in sea water, was isolated by flowing low conductance, isoosmotic sucrose solution on each side; both ends were depolarized in isoosmotic KCl. Measured biphasic square wave currents at five cycles per second were applied between one end of the nerve and the membrane of the central segment. The membrane potential was recorded between the central sea water and the other depolarized end. The recorded potentials are developed only across the membrane impedance. Threshold current values ranged from 3.2 µa at 267deg;C to 1 µa at 7.5°C. Threshold potential values ranged from 50 mv at 26°C to 6 mv at 7.5°C. The mean Q₁₀ of threshold current was 2.3 (SD = 0.2), while the Q₁₀ for threshold potentials was 2.0 (SD = 0.1).