METABOLIC AND MORPHOLOGICAL OBSERVATIONS ON THE EFFECT OF SURFACE-ACTIVE AGENTS ON LEUKOCYTES

Morphological and metabolic observations have been made on the effects of endotoxin, deoxycholate, and digitonin (at less than 50 µg/ml) on polymorphonuclear leukocytes and mononuclear cells. The agents stimulate the respiration and glucose oxidation of these cells in a manner similar to that seen during phagocytosis. Electron microscopy revealed no morphological changes with the first two agents, but dramatic membrane changes were seen in the case of digitonin. Here tubular projections of characteristic size and shape formed on and split off the membrane. All the agents stimulated uptake of inulin, but efforts to demonstrate increased pinocytosis by electron microscopy have not so far succeeded, probably due to limitations in present experimental techniques.     

凝固剂对水稻花药培养愈伤组织诱导的影响

本文初步研究了不同类型的凝固剂对水稻花药培养愈伤组织形成的影响。结果发现,用Gelrite、马铃薯淀粉、甘薯淀粉、可溶性淀粉代替琼脂可明显促进水稻花药培养愈伤组织的产生而尤以5.0%马铃薯淀粉为最佳。出愈率比琼脂增加5.2倍,达液体培养水平。以8个不同基因型,为材料研究发现,5.0%马铃薯淀粉作凝固剂,有7个材料出愈率高于对照,最高的BC 163比对照增加7.75倍,平均增加1.15倍。另外,以5.0%马铃薯淀粉作凝固剂代替0.8%琼脂可降低成本30%。因此,用马铃薯淀粉作凝固剂在水稻花药培养中可能具有潜在的应用价值。     

THE THERAPEUTIC INDEX OF CHEMOTHERAPEUTIC AGENTS: THE EFFECT OF NUCLEIC ACID ON DIMIDIUM BROMIDE

SUMMARY: The complexes of dimidium bromide with nucleic acids are less toxic and bactericidal than dimidium bromide itself, but the toxicity is reduced more than the antibacterial activity. The therapeutic activity is, therefore, raised.     

THE EFFECT OF ENVIRONMENTAL ANEUPLOIDY-INDUCING AGENTS ON THE MICROTUBULE ARCHITECTURE OF MITOTIC MERISTEMATIC ROOT CELLS INHORDEUM VULGARE

Microtubules are the prime components involved in chromosomal segregation, their functional accuracy ensuring maintenance of the normal karyotype in the progeny. Chemically-induced disruption of microtubules during mitosis can lead to aneuploidy. In this study, seven environmental chemicals, i.e. cadmium chloride (CD), econazole nitrate (EZ), benomyl (BM), thiabendazole (TB), griseofulvin (GF), thimerosal (TM) and hydroquinone (HQ), were tested for their ability to induce microtubule disruption in mitotic meristematic root cells of the higher plantHordeum vulgarewith the use of anti-tubulin indirect immunofluorescence microscopy. All chemicals tested in this study, with the exception of TB and HQ, produced modifications in the morphology of microtubule organization and reduced the fidelity of the spindle apparatus inHordeum vulgare     

A QUANTITATIVE METHOD FOR ASSESSING THE EFFECT OF DISINFECTANTS AND CLEANING AGENTS ON BACTERIA DEPOSITED ON SURFACES

SUMMARY: A test has been developed for evaluating disinfectant action on surfaces, which relies on the pH response of Strep. faecalis , since with this organism the pH of a buffered broth at the end of incubation depends on the weight of the inoculum, i.e. the numbers of organisms which survive.
The organisms are deposited as a wet film on the surface of small strips of tinned mild steel, which are dried and treated with the disinfectant. The strips are finally placed in tubes of media and, after incubation, the pH is measured.
The standardization of the different variables of the test are described. The condition of the test organism is particularly important: at the time the films are dried it must be in its stationary phase of growth, when the cells are homogeneous and more resistant to disinfectant action than during the logarithmic phase.
Incubation is terminated when the control tubes containing strips which had no disinfectant treatment have pH values averaging 5.50. Under these conditions, with hypochlorite a linear response over the range of 0–6 p/m available chlorine is generally obtained. Chlorine may therefore be used as a standard for comparison with other disinfectants.
As an example, the testing of a quaternary ammonium compound is described.     

鱼类细胞融合中助融剂效应和特异性

在鱼类细胞融合中,微量的甘油可使PEG作用显著下降。DMSO可以极大提高PEG诱导鱼类细胞融合的能力。在低分子量和较低浓度的PEG中,DMSO的作用更加突出。但PEG浓度不能低于40%的临界,否则,细胞融合就失去了DMSO浓度依赖效应。在三组鱼类细胞交叉融合中,我们发现同核体数目远远超过异核体数目(P<0.05)。这表明,PEG诱导的鱼类细胞融合具有物种和组织特异性。       

THE EFFECT OF SWELLING ON THE RESPIRATION OF ERYTHROCYTES

1. Oxygen consumption measurements made while a chicken erythrocyte swells show no increase over the control value. 2. There is no change in the rate of anaerobic glycolysis in beef erythrocytes when they swell. 3. The above statements are true whether the cells swell from a shrunken condition back to the normal volume, or swell from the normal to the hemolytic volume. 4. These data add a further test of the hypothesis that a relationship exists between the cell membrane and its respiratory activity.     

THE EFFECT OF KINETIN ON THE DEVELOPMENT OF ROOTS

The well-known fact that kinetin, when applied to leaves, inhibitsor completely prevents the regeneration and growth of rootsespecially of leaf-cuttings is attributed to the capacity ofkinetin to inhibit the migration of amino acids and other substances from the leaf-blades. This effect of kinetin manifestsitself also in relation to auxin. It was thus inferred thatkinetin plays an important role in those systems which decisivelyinfluence the correlations between the organs. (Received March 15, 1961; )     

THE EFFECT OF PHOSPHATES ON RESPIRATION

Phosphate accelerates both aerobic and anaerobic respiration. The acceleration almost disappears when the plant dies (in phosphate solution) but subsequently becomes greater than in life.