Immunotargeting of daunomycin to localized and metastatic human colon adenocarcinoma in athymic mice

Summary A monoclonal antibody (designated SF25), which recognizes a protein antigen expressed on a large number of human colon carcinomas, was used for drug targeting. Daunomycin-antibody conjugates were prepared by two previously described procedures. In one, the drug was bound to the antibody through a spacer of small molecular mass (cis-aconitic acid), while in the other a dextran bridge served as the link between drug and antibody. High substitution rates of drug to antibody were obtained using the latter binding procedure. Both conjugates were tested in vitro against two human colon carcinoma cell lines, LS180 and KM-12. The efficacy of a daunomycin-dextran-SF25 antibody conjugate was tested against colon carcinoma LS180 tumors transplanted at different sites into athymic mice. The specific conjugate was significantly more inhibitory to a subcutaneous tumor growth than its components or their mixture. SF25 antibody alone showed antitumoral effects against all three forms of transplanted tumor tested, namely, local, metastatic or intrahepatic, whereas daunomycin, on its own, was effective only against the subcutaneous tumor. Binding of daunomycin to dextran partially improved its inhibitory activity against the metastatic tumor. The conjugate, daunomycin-dextran-SF25 antibody reduced the number of metastatic foci, increased the survival rate and delayed death. Yet against lymph node metastases it was not significantly better than a mixture of both constituents. However, results obtained with an intrahepatic tumor, a model that mimics the natural progression of the disease, resembled those described with the subcutaneous tumor. Daunomycin-dextran-SF25 antibody was significantly more effective than all components separately and than a mixture of drug and antibody, provided a highly drug-substituted conjugate was used.     

Serum IgE levels in rats infected with Paragonimus westermani]

Paragonimus westermani is a common fluke in Korea. The present study aimed to determine serum total IgE and specific IgG levels in experimental paragonimiasis of rats. Each Wistar rat was inoculated orally with 20-25 metacercariae of P. westermani from Cambaroides similis. Before and after infection (1, 2, 3, 4, 6, 8 weeks) of P. westermani, the blood was collected from the retro-orbital venous plexus of rats and kept serum at -70 degrees C. Serum total IgE and specific IgG levels were determined by the capture and conventional enzyme-linked immunosorbent assay, respectively. The results were as follows; 1. Serum IgE values were increased to 0.18 +/- 0.042 at 2 weeks, 0.28 +/- 0.151 at 4 weeks and 0.43 +/- 0.055 at 8 weeks after infection. The absorbances of non-infected rats ranged 0.07 +/- 0.021-0.12 +/- 0.025. 2. Specific IgG values were slightly increased at 3 weeks (0.20 +/- 0.032) and gradually increased up to 8 weeks (0.31 +/- 0.067) after infection. The absorbances of non-infected rats ranged 0.11 +/- 0.035-0.18 +/- 0.019. The present results suggested that P. westermani could elevate serum IgE and specific IgG antibodies in Wistar rats which were not a good definitive host.     

Artificial Induction and Evaluation of a Mild Isolate of Tomato Spotted Wilt Virus

A severe isolate (BL) of tomato spotted wilt virus (TSWV) that originated from Hawaii was treated with nitrous acid in an effort to obtain mild mutants. The standardized procedure used in mutation experiments was: extracting infected Gomphrena globosa L. leaf tissue in 0.01 M Na₂SO₃, 0.125 M sodium acetate and 0.4 M sodium nitrite at pH 5.5 and incubating the extract for 20 min at room temperature. The extract was inoculated to tobacco (Nicotiana tabacum L. cv. Havana 423) and local lesions were subsequently transferred to lettuce (Lactuca sativa L. cv. Minetto). One isolate (R27G) that incited mild symptoms in lettuce was obtained out of 868 local-lesion-transfers. Under greenhouse conditions, the isolate induced mild symptoms on tomato (Lycopersicon esculentum Mill.) but was severe on peppers (Capsicum annuum L.). The effect of the R27G isolate on growth of potted tomatoes kept outdoors was variable. In one trial, only 15 % of the fruit had symptoms versus 67 % in another trial. R27G fully protected Datura stramonium L. plants that were challenge inoculated with the severe parent BL isolate. Less effective cross protection was observed against a severe isolate from Oklahoma.     

记真盔甲鱼类两新属——兼论真盔甲鱼类系统发育关系

本文记述了早泥盆世真盔甲鱼类两新属:憨鱼属(Nochelaspis)和翼角鱼属(Pterogonaspis).真盔甲鱼类是盔甲鱼类的一个单系类群,现有七属十二种,文中运用分支系统学原理对其系统发育关系进行了初步探讨.     

γ-氨基丁酸、荷包牡丹碱和L-谷氨酸钠对猫和家兔同侧和对侧图形视觉诱发电位的影响

在猫和家兔大脑半球一侧视区17/18交界处施加γ—氨基丁酸(GABA)、荷包牡丹碱和L—谷氨酸钠,以及用氯化钾和冷冻阻遏的方法,记录对侧和同侧皮层相应处图形视觉诱发电位(PVEP)的变化。讨论了GABA、荷包牡丹碱和L—谷氨酸钠对猫和兔的对侧和同侧PVEP的影响。     

Optimization of Banana Juice Fermentation for the Production of Microbial Oil

Apiotrichum curvatum ATCC 20509 (formerly Candida curvata D), a lipid-accumulating yeast, was grown in banana juice. The optimum conditions for biomass production in shake flasks were 30°C growth temperature, efficient aeration, a juice concentration of 25%, and preliminary heat treatment at less than sterilization conditions. Under controlled conditions in a fermentor, 20% banana juice was optimum. High concentrations of yeast extract (0.3%) increased biomass production by 40% but decreased oil production by 30%. A lower yeast extract concentration (0.05%) increased biomass production by 2% and oil production by 25%. The best growth and oil production were observed when asparagine (1.4 g/liter) and mineral salts were added to the banana juice. The addition of minerals seemed to improve the utilization of carbon. Growth inhibition was observed when the fermentor was aerated with pure oxygen, even when additional nutrients were present. A fed-batch process permitted the juice concentration to be increased from 15 to 82%; biomass accumulation was three times higher than in batch fermentations. However, the cellular lipid content was only 30% of dry weight, and chemical oxygen demand reduction was slow and inefficient.     

Synthesis of a nonacosapeptide (beta-fragment) corresponding to the N-terminal sequence 1-29 of human liver metallothionein II and its heavy metal-binding properties

A nonacosapeptide (beta-fragment) corresponding to the N-terminal sequence 1-29 of human liver metallothionein II was synthesized by the fragment condensation method. The Cd-binding ability of the beta-fragment was much stronger than that of cysteine as thionein and synthetic alpha-fragment corresponding to the C-terminal sequence 30-61 of human liver metallothionein II. Both the alpha- and beta-fragments bound preferentially to Cu ions rather than Cd ions.     

Clastogen-induced chromosomal breakage as a marker for first trimester prenatal diagnosis of Fanconi anemia

Summary Using cultured trophoblast cells obtained by chorionic villus biopsy, we diagnosed Fanconi anemia (FA) in two pregnancies and excluded it in eight pregnancies at risk for the syndrome. Baseline chromosomal breakage and breakage induced by diepoxybutane (DEB) were analyzed. Increased breakage was used as a marker for the syndrome. Our results were unambiguous and provide a reliable method for prenatal detection of FA in the first trimester of pregnancy.     

NUTRITION OF PANDORINA MORUM1,2

A defined medium was developed for 3 strains of Pandorina morum. The strains tested required no vitamins or other organic compounds. The optimal initial pH was between 7.0 and 8.0. Various carbon sources were tested, and only glycolate and acetate appreciably stimulated growth. Mixotrophic growth in the light was stimulated by glycolate in all 3 strains, and by acetate in strains 880 and N76-6. Only strain N76-6 utilized acetate for heterotrophic growth in the dark. Thirty strains of P. morum of world-wide distribution were surveyed for mixotrophic and heterotrophic growth with acetate. All were found to fit 1 of 3 classes with respect to acetate metabolism: (1) no effect in light or dark; (2) stimulation of growth in light only; (3) stimulation of growth in light and dark.     

Release of Inorganic Phosphate from Irradiated Yeast: Radiation Biodosimetry and Evaluation of Radioprotective Compounds

When cells of bakers' yeast, Saccharomyces cerevisiae, were irradiated with ionizing radiation, inorganic phosphate, ninhydrin-reactive material, and substances absorbing at 260 mmu were released into the suspending medium. The amount of inorganic phosphate released depended on the radiation dose and on the temperature and pH during irradiation. The concentration of yeast cells did not affect the phosphate yield per milligram of yeast. It is suggested that the release of phosphate may serve as an index of the total radiation environment (i.e., as a biodosimeter) where radiation inactivation of microrganisms is of primary importance, e.g., in radiation preservation of foods. The somewhat limited range of the yeast biodosimeter (ca. 0.5 to 1.75 Mrad) may be extended by use of other more resistant microorganisms, such as bacterial spores. Compounds which have been reported as protecting microorganisms and mammals against the lethal effect of ionizing radiation also inhibited the radiation-induced release of inorganic phosphate from yeast. This phosphate release system is proposed as the basis for an economical, rapid supplement to screening procedures in the evaluation of radioprotective compounds.