Showing papers by "Kettering University published in 1986"

Major reorganization of immunoglobulin VH segmental elements during vertebrate evolution.

Abstract: In mammals, the immunoglobulin heavy-chain variable region (VH) locus is organized in a linear fashion; individual VH, diversity (DH), joining (JH) and constant (CH) region segments are linked in separate regions1. During somatic development, coding segments flanked by characteristic short recombination signal sequences, separated by intervening sequence regions that may exceed 2,000 kilobases (kb), are recombined. Combinatorial joining of different segments as well as imprecision in this process contribute to the diversity of the primary antibody response; subsequent mutation further alters functionally rearranged genes. This basic somatic reorganization mechanism is shared by six major families of genes encoding antigen receptors2. Previously, we have shown that multiple germline genes and mammalian-like recombination signal sequences are associated with the VH gene family of Heterodontus francisci (horned shark), a primitive elasmobranch3. Studies presented here demonstrate that segmental reorganization involving mammalian-like DH and JH segments occurs in the lymphoid tissues of this species. In marked contrast to the mammalian system, we find multiple instances of close linkage (∼10 kb) between individual VH, DH, JH and CH segments. This unique organization may limit combinatorial joining and be a factor in the restricted antibody response of this lower vertebrate4,5.

Changes in accessibility of DNA to various fluorochromes during spermatogenesis

Abstract: Accessibility of mouse testicular and vas deferens (vas) sperm cell DNA to acridine orange, propidium iodide, ellipticine, Hoechst 33342, mithramycin, chromomycin A3, 4'6-diamidino-2-phenylindole (DAPI), and 7-amino-actinomycin D (7-amino-AMD) was determined by flow cytometry. Permeabilized cells were either stained directly or after pretreatment with 0.06 N HCl. For histone-containing tetraploid, diploid, and round spermatid cells, HCl extraction of nuclear proteins caused an approximately sixfold increase of 7-amino-AMD stainability but had no significant effect on DAPI stainability. For these same cell types, the stainability with other intercalating (acridine orange, propidium iodide, ellipticine) and externally binding (Hoechst 33342, mithramycin, chromomycin A3) dyes was increased by 1.6- to 4.0-fold after HCl treatment. In sharp contrast, HCl treatment of vas sperm did not increase the staining level of 7-amino-AMD, DAPI, or propidium iodide but did increase the staining level for the other intercalating dyes (1.3- to 1.5-fold) and external dyes (1.3- to 1.9-fold). Elongated spermatids that contain a mixture of protein types including histones, transition proteins, and protamines demonstrated the greatest variability of staining with respect to type of stain and effect of acid extraction of proteins. In general, for nearly all dyes, the round spermatids had an increased level and tetraploid cells had a decreased level of stainability relative to the same unit DNA content of diploid cells. The observed differential staining is discussed in the context of chromatin alterations related to the unique events of meiosis and protein displacement and replacement during sperm differentiation.

The nifH, nifM and nifN genes of Azotobacter vinelandii: Characterisation by Tn5 mutagenesis and isolation from pLAFR1 gene banks

Abstract: Tn5 was introduced into Azotobacter vinelandii on a suicide vector, pGS9. Three Nif- mutants were found to carry Tn5 in nifH (MV6), in nifN (MV22), and in or near nifM (MV21), from the results of hybridisation experiments. For MV21 and MV22 this was also shown by complementation with the nif genes of Klebsiella pneumoniae on pRD1. MV6 failed to synthesis the nifH, D and K gene products. MV6 and MV22 fixed nitrogen in the absence of supplied molybdenum while mutant MV21 did not, suggesting that the nifM gene product may be required for the alternative nitrogenase system synthesised in azotobacteria under conditions of molybdenum deprivation. Reconstitution experiments with mutant extracts showed that MV22 (nifN -) lacked the FeMo cofactor and that MV21 (NifM-) synthesised inactive Fe protein. These biochemical phenotypes are identical to those of the K. pneumoniae nifN and nifM mutants, respectively, demonstrating that these genes have the same function in both K. pneumoniae and A. vinelandii. Complementation of the A. vinelandii mutants with pLAFR1 gene banks of A. vinelandii or a. chroococcum yielded three cosmids of interest. pLV10 complemented UW91, a nifH mutant, and corrected the defect in MV6 after recombination with the mutant genome. It also carried nifD (but not nifK) and about 18 kb of DNA upstream from nifH. pLV1 from the A. vinelandii gene bank complemented both MV21 and MV22 as did pLC11, isolated from the A. chroococcum gene bank. Both pLV1 and pLC11 carried part of the nif cluster downstream of nifHDK which also includes nifEN and nifMVS on about 22 kb of DNA.

Role of Pili (Fimbriae) in Attachment of Bradyrhizobium japonicum to Soybean Roots.

Abstract: Pili (fimbriae) were observed on cells of each of the five strains of Bradyrhizobium japonicum and the one strain of Rhizobium trifolii examined. Pili on B. japonicum were about 4 nm in diameter and polarly expressed. Piliated cells were estimated by transmission electron microscopy and hydrophobic attachment to polystyrene to constitute only a small percentage of the total population. The proportion of piliated cells in these populations was dependent on culture age in some strains. Piliated B. japonicum cells were selectively and quantitatively removed from suspension when cultures were incubated with either soybean roots or hydrophobic plastic surfaces, indicating that pili were involved in the attachment of the bacteria to these surfaces. Pili from B. japonicum 110 ARS were purified and found to have a subunit molecular weight of approximately 21,000. Treatment of B. japonicum suspensions with antiserum against the isolated pili reduced attachment to soybean roots by about 90% and nodulation by about 80%. Pili appear to be important mediators of attachment of B. japonicum to soybean roots under the conditions examined.

Nodulation of actinorhizal plants by Frankia strains capable of both root hair infection and intercellular penetration

Abstract: A morphological analysis of the initiation and development of root nodules ofElaeagnus angustifolia andMyrica cerifera inoculated with pure-culturedFrankia strains DDB 011610 or DDB 020110 was undertaken. From ultrastructural observations it was determined that both of theseFrankia strains can infectElaeagnus by an intercellular penetration mechanism andMyrica by the root hair infection mechanism. This indicates that both of these strains have the ability to infect host plant roots by either of two mechanisms. The reverse, thatElaeagnus orMyrica could be infected by both mechanisms, was not observed. The infection and nodule development processes of these two plants in combination with these strains were similar to observations made in previous studies (Miller andBaker 1985,Torrey andCallaham 1979). However, one exception was identified in the development of the prenodule ofMyrica when infected with strain 011610, in that endophytic hyphae developed vesicles within the cells of the prenodule. This event has not been described before for any of the actinorhizal genera and may be an indication of less than optimal compatibility between the host plant and the symbiont.

2'-fluoro-arabinofuranosyl purine nucleosides

Abstract: 2'-Deoxy-2'-fluoro-β-D-arabinofuranosyl nucleosides of the following structure are disclosed: ##STR1## wherein X and Y are the same or different and are hydrogen, OR 3 , SR 3 , NR 3 R 4 or NHacyl wherein R 3 and R 4 are the same or different and are hydrogen, lower alkyl of 1 to 7 carbon atoms, aralky, or aryl; NHacyl is alkanoyl or aroylamide; R 1 and R 2 are the same or different and are hydrogen, acyl or aroyl.

Choriocarcinoma monoclonal antibodies and antibody panels

Abstract: Monoclonal antibodies to specific cell surface antigens of human choriocarcinoma, teratocarcinoma, and normal trophoblasts are disclosed. Additionally, panels of monoclonal antibodies which may be used in phenotyping cell and tissue samples are disclosed as well.

Method and composition for hepatitis treatment with pyrimidine nucleoside compounds

Abstract: The invention relates to 5-substituted-1-(2'-deoxy-2'-substituted-beta-D-Arabinofuranoysyl) pyrimidine compounds and their use in a method for the treatment of hepatitis B viruses.

Methods of treating bone disorders

Abstract: Metal containing compounds have been found which increase bone growth, decrease hydroxyapatite solubility, increase the size and/or the perfection of hydroxyapatite crystals in bone, and increase the tensile strength of bone. These compounds, when administered to patients who are suffering from diseases characterized by bone resorption impede the flow of bone calcium into the blood, and encourage the growth of new, normal bone tissue.

Lichens to Gunnera — with emphasis on Azolla

Abstract: N2-fixing cyanobacteria occur in symbiotic associations with fungi (ascomycetes) as lichens and with a few green plants. The associated cyanobacterium is always a species of Nostoc or Anabaena. Only a small number of plant genera are involved but there is a remarkable range of host diversity. Associations occur with several bryophytes (e.g. Anthoceros, Blasia, Cavicularia), a pteridophyte (Azolla), cycads (nine genera including Macrozamia and Encephalartos) and an angiosperm (Gunnera). Except for Gunnera, where the cyanobacterium penetrates the plant cells, the cyanobacteria are extracellular with specialized morphological modifications and/or structures of the host plant organs providing an environment which facilitates interaction with the prokaryote.

The Azolla-Anabaena azollae Relationship : XII. Nitrogenase Activity and Phycobiliproteins of the Endophyte as a Function of Leaf Age and Cell Type

Abstract: Nitrogenase activity was measured in leaves along the main stem axes of Azolla pinnata R. Br. The activity was negligible in leaves of the apical region, rapidly increased to a maximum as leaves matured, and declined in aging leaves. In situ absorption and fluorescence emission spectra were obtained for individual vegetative cells and heterocysts in filaments of the A. pinnata and Azolla caroliniana endophytes removed from the cavities of progressively older leaves. These spectra unequivocally demonstrate the occurrence of phycobiliproteins in the two cell types of both endophytes at the onset of heterocyst differentiation in filaments from young leaves, during the period of maximal nitrogenase activity in filaments from mature leaves, and in filaments from leaves entering senescence. Phycobiliproteins of the A. caroliniana endophyte were purified and extinction coefficients determined for the phycoerythrocyanin, phycocyanin, and allophycocyanin. The phycobiliprotein content and complement of sequential leaf segments from main stem axes and of vegetative cell and heterocyst preparations were measured in crude extracts. There was no obvious alteration of the phycobiliprotein complement associated with increasing heterocyst frequency of the endophyte in sequential leaf segments and the phycobiliprotein complement of heterocysts was not appreciably different from that of vegetative cells. These findings indicate that the phycobiliprotein complement of the vegetative cell precursor is retained in the heterocysts of the endophyte.

Human tumor lines for cancer research.

Abstract: (1986). Human Tumor Lines for Cancer Research. Cancer Investigation: Vol. 4, No. 2, pp. 157-184.

Monoclonal antibodies to mucin-like human differentiation antigens

Abstract: Three new monoclonal antibodies, MU78, MT334, and MQ49, and the hybridoma cell lines producing these, are disclosed. The antibodies specifically bind to mucin-like antigens with distribution over various carcinomas.

Stimulation of ATPase activity in barley (Hordeum vulgare) root plasma membrane after treatment of intact tissues and cell free extracts with triacontanol

Abstract: Ca2+- and Mg2+-dependent ATPase activity (EC 3.6.1.3) in a plasma membrane-enriched fraction increased rapidly after in vivo application of physiologically active concentrations of triacontanol (TRIA) to the roots of barley (Hordeum vulgare L. cv. Conquest) seedlings. Ca2+- and Mg2+-dependent ATPase activity was 64 and 85% higher, respectively, in the roots of seedlings germinated in the presence of growth-promoting concentrations of TRIA compared to controls. The increase in vivo was concentration dependent, with the greatest increase obtained at 2.3 nM TRIA. Maximal stimulation of ATPase activity of excised tissue treated with TRIA coincided with the temperature at which the barley was grown. At this temperature the plasma membrane is primarily in a mixed gel/liquid crystalline state. Pretreatment of barley roots with cyclohexamide did not alter ATPase stimulation by TRIA. Two to three times more [14C]-TRIA (mg membrane protein)−1 was found associated with plasma membrane-enriched vesicles treated with TRIA than with vesicles enriched for mitochondrial membranes or for vesicles enriched for tonoplast, Golgi and rough endoplasmic reticulum. Both Ca2+- and Mg2+-dependent ATPase activity increased by 40–60% within 30 min of the addition of 2.3 nM TRIA to cell-free extracts of barley roots. The addition of octacosanol, the C28 analogue of TRIA, to cell-free extracts did not affect metal-dependent ATPase activity. Consistent with many studies in the green-house, simultaneous additions of equimolar amounts of TRIA and octacosanol to cell-free extracts resulted in inhibition of ATPase stimulation by TRIA. TRIA may directly affect plasma membrane function in barley roots.

Lichens toGunnera — with emphasis onAzolla

Abstract: N2-fixing cyanobacteria occur in symbiotic associations with fungi (ascomycetes) as lichens and with a few green plants. The associated cyanobacterium is always a species ofNostoc orAnabaena. Only a small number of plant genera are involved but there is a remarkable range of host diversity. Associations occur with several bryophytes (e.g.Anthoceros, Blasia, Cavicularia), a pteridophyte (Azolla), cycads (nine genera includingMacrozamia andEncephalartos) and an angiosperm (Gunnera). Except forGunnera, where the cyanobacterium penetrates the plant cells, the cyanobacteria are extracellular with specialized morphological modifications and/or structures of the host plant organs providing an environment which facilitates interaction with the prokaryote.

Nucleosides of 5-monofluoromethyluracil and 5-difluoromethyluracil

Abstract: A method for synthesizing monofluoromethyl- and difluoromethyluracil nucleosides from the corresponding thymine nucleosides is developed. These compounds which contain a partially fluorinated methyl group at the C-5 position (a new class of nucleosides) are potential antiviral and/or anticancer agents. The major features of the preparative route involve bromination of suitably protected thymine nucleosides followed by fluoride treatment.

Intracellular accumulation of T-cell receptor complex molecules in a human T-cell line.

Abstract: This work was aimed at understanding the mechanisms of T-lymphocyte function by studying the cellular distribution and traffic of molecules of the T-cell receptor complex. The accumulation of specific molecules in intracytoplasmic vesicles is related to the activation of T lymphocytes. Some of these molecules include acid hydrolases, the transferrin receptor, and class I antigens of the major histocompatibility complex. Molecules of the T-cell receptor complex have now also been found in intracytoplasmic vesicles in a human T-cell line derived from a lymphoblastic leukemia. Such vesicles were tightly associated with the cytoplasmic microtubule network. One functional aspect of this association is a cellular pathway by which vesicles traveling to and from the cell surface converge in an area of the cells that is rich in processing enzymes.

Monoclonal antibodies selective for prostate cancer

Abstract: Four monoclonal antibodies are found which selectively identify prostate cancer. These monoclonals are therefore useful in diagnosis, differential diagnosis and treatment of prostate cancer.

Monoclonal antibodies to human gastrointestinal cancer

Abstract: Diagnostic panels for human gastrointestinal abnormali­ ties such as cancer using mouse monoclonal antibodies are disclosed. These panels can be used in diagnosis and in therapeutic applications such as colon cancer.

Method for treatment of neuroectodermal malignancies and epithelial carcinomas in humans

Abstract: This invention provides a use of monoclonal antibody R-24 linked to a chemotherapeutic agent for the treatment of cancer of neuroectodermal origin, epithelial cancer of pigmentation disorder and wherein the chemotherapeutic agent is at least one agent from the group dacarbazine, adriamycin, pimozide, dibromodulcitol, bleomycin, actinomycin D, purine analog, pyrimidine analog, nitrosoureas, cis-platin, radiation-emitting reagent, tumor necrosis factor, interferon, lymphotoxins, interleukin, BCG, and autologous tumor cell vaccine

Monoclonal antibody specific for a pigmentation associated antigen

Abstract: Monoclonal antibody TA99, which specifically binds to a pigmentation associated antigen present on melanoma cells is described. Additionally, the hybridoma cell line deposited with the ATCC under Accession Number HB 8704 from which the antibody is derived, as well as methods for using the antibody are described.

Isolation of a gene encoding human thyrotropin beta subunit

Abstract: The gene expressing the beta subunit of human thyroid stimulating hormone has been isolated. The gene has been incorporated into plasmid pBR322. Vectors can be used to transform cells which in turn produce pure beta subunits. The beta subunits can then be combined with the alpha subunit of human glycoprotein hormones to produce pure thyroid stimulating hormone.