Showing papers by "Kettering University published in 1984"

Considerations in the use of nude mice for cancer research.

Abstract: Transplants of human tumors in nude mice have shown a progressive increase during the past 15 years as an experimental model for cancer research. A variety of factors, including relatively fragile health, have been identified that require appropriate experimental controls if the investigator is obtain consistent results. Not all tumors grow in nude mice. The frequency of tumor 'take' varies according to tumor origin, tumor type, inoculation site, age and conditioning of the mouse host, and a variety of other factors. Manipulation of these variables has led to successful propagation of almost every known variety of human malignancy. Following transplant, changes in characteristics have been documented, but the frequency and degree of such changes remains uncertain. Tumor growth rate probably increases after transplantation, requiring great care in the interpretation of chemotherapy experiments, but biochemical characteristics may be more stable. The nude mouse offers great interest as a model for the in vivo study of metastasis, as a number of experimental variables, mainly immunological, have been shown to affect this process. Spontaneous tumors have been shown to arise in these animals, but the controversy over their frequency relative to the thymus-bearing background strain is unresolved. We conclude that the nude mouse/tumor xenograft model, while requiring meticulous experimental controls, is nevertheless an extremely useful tool for cancer research.

A modified sucrose fractionation procedure for the isolation of frankiae from actinorhizal root nodules and soil samples

Abstract: The isolation and pure culture of the symbiotic nitrogen-fixing frankiae has always been difficult. In the past the isolation of these actinomycetes directly from soil samples has proven impossible and isolations from root nodules of many genera has been only poorly successful. We report here a modified sucrose fractionation procedure which increased the success of isolations from root nodules and which permitted the isolation of Frankia directly from soil samples. Crushed nodule suspensions or soil suspensions were incubated briefly in 0.7% phenol (carbolic acid) just before application to a sucrose density gradient. This phenol incubation decreased the number of contaminating eubacteria and fungi but more importantly increased the number of Frankia developing on the isolation plates. If the phenol incubation was used solely without sucrose fractionation no Frankia were isolated, suggesting the death of the organisms due to phenol toxicity. The use of selective nitrogen-deficient media proved important for the isolation of frankiae from soils.

Liquid chromatographic-fluorescence determination of ammonia from nitrogenase reactions: a 2-min assay.

Abstract: The analytical potential of the reaction of ammonia with o-phthalaldehyde mercaptoethanol reagent at pH 7 (an atypical fluorescence) has already been demonstrated. This, coupled with additional findings reported here, has led to an ammonia determination well suited to nitrogenase studies. As a result, large numbers of samples can be rapidly analyzed by high-pressure liquid chromatrography methods under mild conditions and without prior microdiffusion. Neither sodium dithionite (or other components of the usual nitrogenase assay), nor alternative substrates (cyanide, azide, methyl isonitrile), nor their products (methylamine, dimethylamine, hydrazine) interfere. High-pressure liquid chromatography showed that the fluorescent “product” of the o-phthalaldehyde mercaptoethanol reagent-ammonia reaction was, in fact, more than just a single compound. Despite this, once the proper solvent composition was found, high-pressure liquid chromatography with a small inexpensive C18 “guard” column proved quite fast and reproducible for this measurement. Fluorescence response to ammonia was linear to at least 40 nmol/ml. A previous problem, long-term stability of the fluorescence, was solved by running the reactions in the dark. Background ammonia in the buffer could be substantially reduced by an analogous o-phthalaldehyde mercaptoethanol reagent reaction, using t-butyl mercaptan, and solvent extraction.

On the role of fibronectin during the compaction stage of somitogenesis in the chick embryo

Abstract: During the early stages of somitogenesis in the chick embryo the presomitic cells in the segmental plate undergo compaction. The aggregation of segmental plate cells is stimulated by fibronectin. The stimulation of segmental plate cells to aggregate and undergo compaction can be effected in isolated segmental plate cells, in isolated segmental plates, and in intact embryos removed from the yolk. The fact that the segmental plate cells react with greater vigor to cellular fibronectin than to plasma fibronectin suggests a specific molecular mechanism in the initiation of somitogenesis.

Structure and Reactivity of Nitrogenase — An Overview

Abstract: Nitrogenase is composed of two separately purified proteins called the molybdenum-iron protein (MoFe protein) and the iron protein (Fe protein).1. N2 fixation and all other reductions catalyzed by nitrogenase require both component proteins, a source of reducing equivalents, MgATP, protons and an anaerobic environment. This overview covers what has been learned recently about the composition, structure and redox properties of the two component proteins and the events that occur during nitrogenase turnover. Fortunately, diffraction quality crystals have recently been obtained for both the MoFe protein (Cp1 and Av1; Weiniger, Mortenson, 1982) and the Fe protein (Av2; Rees, Howard, 1983). Thus, many of the questions raised below may soon have definitive answers.

Diagnostic imaging of herpes simplex virus encephalitis using a radiolabeled antiviral drug: autoradiographic assessment in an animal model.

Abstract: To develop a new approach to the diagnosis of herpes simplex encephalitis, we used a radiolabeled antiviral drug, 2'-fluoro-5-methyl-1-beta-D-arabinosyluracil labeled with carbon 14 ([14C]FMAU), as a probe for selectively imaging brain infection in a rat model by quantitative autoradiography. A high correlation was found between focal infection, as defined by immunoperoxidase viral antigen staining, and increased regional [14C]FMAU uptake in brain sections. Two potential sources of false-positive imaging were defined: high concentrations of drug in the choroid plexus because of its higher permeability compared with brain, and drug sequestration by proliferating uninfected cell populations. Our results support the soundness of the proposed strategy of using a labeled antiviral drug that is selectively phosphorylated by herpes simplex virus type 1 thymidine kinase in conjunction with scanning methods for human diagnosis, and also define some of the factors that must be taken into account when planning clinical application.

Use of gallium salts to treat disorders of calcium homeostasis

Abstract: The present invention comprises a method of preventing or treating a disorder associated with accelerated loss of calcium from bone in a human individual comprising administering to the individual a pharmaceutically acceptable gallium compound. Of especial importance among the disorders which may be thus prevented or treated are hypercalcemia, accelerated bone loss associated with osteopenia, osteoporosis, bone metastasis due to malignant tumors, and hyperparathyroidism. In the method of the present invention gallium compounds may be administered by any and all routes. Although all biocompatible, soluble compounds of gallium may be used in the present invention, gallium nitrate is preferred, most preferably in a pharmaceutically acceptable carrier.

Interferon receptor interaction

Abstract: Studies reported earlier [ Joshi et al. (1982) J. Biol. Chem. 257, 13884-13887] have indicated that human interferon-alpha 2 (HuIFN-alpha 2) binds to a specific macromolecular receptor on human cells as identified by cross-linking with bifunctional cross-linking reagents and analysis by polyacrylamide gel electrophoresis. We have carried out experiments to investigate the fate of the interferon-receptor complex on the cell surface under conditions which lead to cellular response. As analyzed by cross-linking and gel electrophoresis, the interferon-receptor complex, formed on incubation with 125I-IFN-alpha 2 at 4 degrees C, persisted at the cell surface for several hours at 4 degrees C; however, if the cells were switched to 37 degrees C, there was a rapid decline in the complex, apparently due to a loss of the interferon receptors from the cell surface. This was associated with an internalization of the 125I-interferon as indicated by the fact that, on incubation at 37 degrees C, an appreciable fraction of the cell-associated interferon (approximately equal to 50%) became resistant to trypsin digestion, or dissociation on incubation in growth medium or low-pH buffer. A large fraction of the trypsin-resistant (internalized) 125I-labeled material migrated as intact interferon in polyacrylamide gels, and it was immunoprecipitated by anti-(HuIFN-alpha)antibodies but not by anti-(HuIFN-beta)antibodies. The bulk of the internalized 125I-interferon was recovered in a particulate fraction and, on cross-linking with disuccinimidyl suberate, a 150000-Mr complex could be detected. The results suggest that interferon may be internalized as a complex with the receptor, which may account for the loss of the interferon-receptors on the cell surface. This modulation of the IFN-alpha/beta receptors was induced by HuIFN-alpha and HuIFN-beta but not by HuIFN-gamma. The recovery of the IFN-alpha/beta receptors, lost upon incubation with HuIFN-alpha, took several hours and required protein synthesis. The significance of the results is discussed.

Armature winding method and apparatus

Abstract: A double flier armature winding machine is provided with two wire trimming assemblies, one for each flier, each having a trimming head with a sharp edge against which a lead wire is severed by abruptly moving a wire clamp gripped to the lead wire in a direction to cause the wire to be stretched over the sharp edge.

Highly purified human interleukin 2 and method

Abstract: Interleukin 2 (IL 2; T-cell growth factor), produced with and without costimulation by Burkitt's lymphoma line Daudi, is highly purified approximately over 37,000-fold to apparent homogeneity from lymphocyte-conditioned medium derived from normal human blood cells by (NH4)2 SO4 -precipitation, ion-exchange chromatography, gel filtration and hydrophobic chromatography. hp IL-2 is free of pyrogens, B cell inducing factor, B cell growth factor, interferon, CSF, and thymocyte differentiating factor. Nature IL 2 produced in the absence of Daudi cells has a molecular weight of about 26,000 daltons as measured by gel filtration and yields IL 2 having two molecular weights of about 16,000 and 17,000 daltons after denaturation as measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. IL 2 produced in the presence of Daudi cells shows a molecular weight of approximately 14,500 daltons as measured by both gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This highly purified IL 2 is shown to correct immunodeficiency states in vitro and in vivo, especially in human patients. It shows value in the treatment of AIDS and immunodeficiency resulting from chemotherpy of cancer, as well as transplantation disorders such as graft versus host disease.

Potentiation of methylglyoxal-bis-guanylhydrazone by alpha-difluoromethylornithine in rat prostate cancer.

Abstract: The polyamines, putrescine, spermidine, and spermine, are fundamentally related to both normal and neoplastic cell proliferation. The prostate gland and prostatic tumors in man and rodents contain large amounts of polyamines. This suggests that inhibition of polyamine biosynthetic enzymes, ornithine decarboxylase (ODC) and S-adenosyl-methionine decarboxylase (SAMDC) may retard the growth of prostatic cancer. Since alpha-difluoromethylornithine (DFMO) and methylglyoxal-bis-guanylhydrazone (MGBG) are irreversible and competitive inhibitors of ODC and SAMDC, respectively, they were tested as single agents and in combination on a transplantable rapidly growing and hormone-resistant G subline of the Dunning R-3327 rat prostatic adenocarcinoma. Groups of rats bearing tumors were treated with various regimens of DFMO, MGBG, and DFMO plus MGBG, daily for 21 days. Analysis of differences in tumor growth between treatment groups and controls showed DFMO had no antitumor effect but was well tolerated, MGBG retarded growth rate significantly but resulted in drug deaths in over 50% of the animals, and the combination of DFMO and MGBG resulted in rapid decline in tumor growth rates after 5 to 9 days of treatment with reduced toxicity. At 21 days, or death, 38 of 60 (63%) rats had no viable tumor on histologic study, whereas tumor was present in each of the animals in the other groups. Alpha-difluoromethylornithine increased the intracellular uptake of MGBG and potentiated the antigrowth activity of MGBG on a hormone refractory rat prostatic tumor with less toxicity than MGBG alone.

Human monoclonal antibodies to cancer cells

Abstract: of the Disclosure Hybridomas which produce human monoclonal anti-bodies are disclosed. The hybridomas are formed by fusing lymphocytes from individuals with various cancers to an immortal cell line, such as a myeloma, from e.g., a human cell line, or a mouse cell line. The human monoclonal antibodies produced by these hybridomas recognize certain cell surface and intracellular antigens on normal and malig-nant cells. These human monoclonal antibodies are used in the diagnosis of cancer.

Human monoclonal antibodies from lymphocytes of patients with malignant melanoma

Abstract: Human monoclonal antibodies which specifically bind to antigens found on cell surfaces of renal, lung, and breast cancer cells, intracellular cytoskeletal antigens, nuclear antigens, and cytoplasmic reticular antigens are disclosed. The antibodies are the product of hybridoma cell lines, where the immortal cell line may be, e.g., a human cell line, or a murine cell line.

Anti-herpes virus compositions containing 5-substituted 1-2'(deoxy-2-'-substituted-β-d-arabinofuranosyl)pyrimedene nucleosides

Abstract: Veterinarian composition for the treatment of herpes virus in animals comprising a pyrimidine nucleoside, or veterinarianically acceptable acid addition salte thereof, of the formula ##STR1## wherein A is OR3, SR3, NR3 R4 or NHacyl wherein R3 and R4 are the same or different and are hydrogen, lower alkyl of 1 to 7 carbon atoms, aralkyl, or aryl; NHacyl is alkanoyl or aroyl amide; B is oxygen or sulfur; X is halogen, alkylsulfonyl or arylsulfonyl; Y is halogen, amino, monoalkyl- or monoaralkylamino, dialkylamino, aminomethyl, hydroxymethyl, lower alkyl, aryl, aralkyl, vinyl and substituted vinyl or ethynyl and substituted ethynyl; Z is methyne or nitrogen; R1 and R2 are the same or different and are hydrogen acyl or aroyl, in a veterinarianically acceptable carrier

Immunoglobulin Heavy Chain Switching in Cultured I.29 Murine B Lymphoma Cells: Commitment to an IgA or IgE Switch

Abstract: A clone of B cells bearing IgM can be induced to switch to the expression of other isotypes, i.e. to other CH genes, while maintaining expression of the identical heavy chain variable region (VH) gene. Studies of the structure of Ig genes in myelomas (Davis et al., 1980), in hybridomas (Hurwitz et al., 1980), and in a B cell lymphoma (Stavnezer et al., 1982) which have undergone isotype switching, and also in normal splenic B cells treated with 1ipopolysaccharide (LPS) (Hurwitz and Cebra, 1982) indicate that DNA recombinations between tandemly repeated switch (S) sequences located 5’ to each CH gene except δ result in the deletion of the µ gene and the other CH genes located 5′ to the CH gene to be expressed, and effect the isotype switch. The production of δ is an exception, as cloned cell lines which produce µ and δ simultaneously contain δ genes in the same context as in µ — producing cells and must produce µ and δ by alternative RNA processing. Other investigators have questioned whether alternative RNA processing may be used to express other H chains simultaneously with µ (Yaoita et al., 1982) in order to explain the surprisingly large number of cells in the spleen which express two isotypes simultaneously (~5% of spleen cells). But because H chain switching can occur rapidly and frequently, partly because the target for switch recombination is large, it is entirely possible that the double-producing cells are cells which have recently deleted their µ genes but still have y mRNA and protein.

Anti-leukemic beta-glycosyl C-nucleosides

Abstract: Beta-glycosyl C-nucleoside compounds showing growth inhibitory activity against leukemic cells, of the following formula, are provided: ##STR1## wherein X is NR 10 , S or O R 10 is H or alkyl with 1 to 6 carbon atoms. ##STR2## wherein R 6 , R 7 and R 8 are independently selected from H or alkyl of 1 to 6 carbon atoms; or ##STR3## wherein R 16 , R 11 and R 12 are independently selected from H or alkyl of 1-6 carbon atoms; R 3 is OH, SR 13 , or OR 9 ; R 4 is OH, SR 14 , or OR 15 ; R 9 , R 13 , R 14 and R 15 are individually selected from C 1 -C 6 alkyl and C 1 to C 6 acyl; R 5 is OH or H, R' 5 is OH or H with the provison that at least one of R 5 or R' 5 is H; excluding 2-deazoxoformycin; and HCl salts thereof.

Liquid dispensing tap

Abstract: A liquid dispensing tap for dispensing liquid from a vessel. The tap has a body adapted to fit an outlet from the vessel. The body has a dispensing mouth and a seat for a valve housed in the body. The valve comprises a valve head and stem and is spring-loaded to close against the seat and manually displaceable to open. The stem extends downstream of the seat and passes as a sliding seal fit through a guide in the body wall. A closing spring, outside the path of the dispensed liquid, is formed integrally with the body and is engaged with the outer end of the valve stem.

Composition comprising purified human tumour necrosis factor in conjunction with human interferon and its use

Abstract: A method for the production and purification of human tumor necrosis factor (hTNF) is described. This purified mater­ ial, shows growth inhibitory, hemorrhagic necrosis, cytotoxic­ ity, and cytostasis effects on a variety of human tumors and cancers. The hTNF is free of exogeneous endotoxin, bacteria, and serum factors, hTNF has a molecular weight of about 70,000 hTNF and human interferon used together have a far greater growth inhibitory or cytotoxic effect on human tumors than the sum of their separate effects. The effect is synergistic and is seen with alpha-, beta- or gamma-IFN and with natural and recombinant IFN.

Rhizobium infection and nodule development in soybean are affected by exposure of the cotyledons to light.

Abstract: The initiation of Rhizobium infections and the development of nodules on the primary root of soybean Glycine max L. Merr cv Williams seedlings are strongly affected by exposure of the cotyledons/hypocotyls to light. Seedlings in plastic growth pouches were inoculated with R. japonicum in dim light and the position of the root tip of each seedling was marked on the face of the pouch. The pouches were covered and kept in the dark for various times before exposing the upper portions of the plants (cotyledons and hypocotyls) to light. Maximum nodulation occurred if the plants were kept in the dark until 1 day after inoculation. The exposure of plants to light 2 days before inoculation reduced the number of nodules by 50% while the number of nodules was reduced by 70% if the plants were kept in the dark until 7 days after inoculation. Anatomical studies revealed that exposure to light prior to inoculation reduced both the number of infection centers with visible infection threads and the number of infections which developed nodule meristems. Plants kept in the dark for 7 days after inoculation formed a normal number of infection threads above the root tip mark, but very few of these infections developed a nodule meristem. It appears that light stimulates soybean to produce substances which can both inhibit the formation of infection threads and enhance the development of nodules from established infection threads. The effects of light on nodulation appear to be expressed independently of the Rhizobium-induced suppression of nodule formation in younger regions of the root.