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111.
Brian G. Lawhorn Tritin Tran Victor S. Hong Lisa A. Morgan BaoChau T. Le Mark R. Harpel Larry Jolivette Elsie Diaz Benjamin Schwartz Jeffrey W. Gross Thaddeus Tomaszek Simon Semus Nestor Concha Angela Smallwood Dennis A. Holt Lara S. Kallander 《Bioorganic & medicinal chemistry letters》2017,27(21):4838-4843
Discovery of potent renin inhibitors which contain a simplified alkylamino Asp-binding group and exhibit improved selectivity for renin over Cyp3A4 is described. Structure-function results in this series are rationalized based on analysis of selected compounds bound to renin, and the contribution of each molecular feature leading to the reduced P450 inhibition is quantified. 相似文献
112.
Cryptosporidium parvum and Giardia lamblia Recovered from Flies on a Cattle Farm and in a Landfill 下载免费PDF全文
Beata Szostakowska Wieslawa Kruminis-Lozowska Maria Racewicz Ronald Knight Leena Tamang Przemyslaw Myjak Thaddeus K. Graczyk 《Applied microbiology》2004,70(6):3742-3744
Filth flies associated with a cattle barn and a municipal landfill were tested positive by combined immunofluorescent antibody and fluorescent in situ hybridization for Cryptosporidium parvum and Giardia lamblia on their exoskeletons and in their guts. More pathogens were carried by flies from the cattle barn than from the landfill; 81% of C. parvum and 84% of G. lamblia pathogens were presumptively viable. 相似文献
113.
Thaddeus S. Nowak Elizabeth B. Albright Hamish N. Munro 《Archives of biochemistry and biophysics》1983,225(2):722-730
p-Chloroamphetamine inhibited to some degree all amino acid-dependent pyrophosphate-exchange activities which could be detected in a rabbit reticulocyte extract. A detailed kinetic analysis of the reaction catalyzed by reticulocyte leucyl-tRNA synthetase demonstrated that the inhibitor affected only amino acid binding. Less rigorous studies of other synthetases from both rabbit reticulocyte and Escherichia coli could be similarly interpreted, suggesting that this compound interacts in a common manner with these several enzymes. The contribution of such effects to the inhibition of protein synthesis by the drug was investigated using cell-free translation systems in which rates of amino acid incorporation were limited to varying degrees by the synthesis and availability of aminoacyl-tRNA. In a wheat germ system programmed with globin mRNA, in which levels of amino acids and aminoacyl-tRNAs were shown to limit the rate of protein synthesis, the inhibition produced by p-chloroamphetamine could be partially reversed by increasing the concentration of the limiting amino acid. In a reticulocyte lysate, in which amino acid concentrations were not limiting, inhibition failed to show an amino acid-reversible component. Thus, while the inhibition of aminoacyl-tRNA synthetases by amphetamines can be shown in some cases to play a role in the effects of these compounds on in vitro protein synthesis, other sites of interference with initiation and/ or elongation reactions may predominate, depending on the construction of the system under study. 相似文献
114.
Giardia sp. Cysts and Infectious Cryptosporidium parvum Oocysts in the Feces of Migratory Canada Geese (Branta canadensis) 下载免费PDF全文
Thaddeus K. Graczyk Ronald Fayer James M. Trout Earl J. Lewis C. Austin Farley Irshad Sulaiman Altaf A. Lal 《Applied microbiology》1998,64(7):2736-2738
Fecal droppings of migratory Canada geese, Branta canadensis, collected from nine sites near the Chesapeake Bay (Maryland), were examined for the presence of Cryptosporidium parvum and Giardia spp. Cryptosporidium sp. oocysts were found in feces at seven of nine sites, and Giardia cysts were found at all nine sites. The oocysts from three sites were infectious for mice and molecularly identified as the zoonotic genotype of Cryptosporidium parvum. Waterfowl can disseminate infectious C. parvum oocysts in the environment. 相似文献
115.
EFFECT OF METABOLIC INHIBITORS ON NUCLEAR PORE FORMATION DURING THE HELA S3 CELL CYCLE 总被引:3,自引:3,他引:0 下载免费PDF全文
Helmut M. Maul Betty Yee Li Hsu Thaddeus M. Borun Gerd G. Maul 《The Journal of cell biology》1973,59(3):669-676
The effect of various antimetabolites on nuclear pore formation was studied in synchronized HeLa S3 cells. The nuclear size was determined by light microscopy and the pore number per unit area of nuclear surface by the freeze-etching technique and electron microscopy. It was found that the inhibition of DNA replication or ribosomal RNA synthesis has no effect on nuclear size increase or pore formation. However, the inhibition of ATP synthesis effectively stops nuclear pore formation. Cycloheximide blocks nuclear pore formation at the same time during G1 phase of the cell cycle when nuclear size increase is blocked by high concentrations of actinomycin D. This suggests that certain proteins or other factors leading to pore formation and nuclear size increase are transcribed and synthesized at about 3–4 h after mitosis, i.e., about 1–2 h before S phase begins. 相似文献
116.
Z. Thaddeus Mankowski M. D. 《Mycopathologia》1972,47(1-2):167-182
Occurrence of four lymphomas was seen following injection of 1.4×103
Candida albicans cells to the spleen of eighty non - inbred albine mice. These neoplastic changes occurred in three to seven months of the duration of the experiment. Extensive invasion of the subcutaneous tissue by the tumor was found in one animal. Two of the animals with lymphoma also had changes in the kidneys compatible with lupus erythematosus and presence of LE cells in the blood. In other animals most frequent and extensive pathological changes were found in the kidneys and in order of frequency were as follows: thickening of the basement membrane, fibrinoid degeneration, presence of hematoxylin bodies, wireloop formation. In total, the presence of positive LE cells in blood was found in seven instances and suggestive LE cells was observed in eight animals. Finding of perisplenitis, exudative pleuritis and pericarditis gave additional support to the resemblance of observed pathological changes with human lupus erythematosus. The fact that occurrence of lymphomas and lupus erythematosus together has been reported in humans provides additional interest to the results reported.Results presented here and previously suggest that there may be more extensive interrelationship among variety of pathological changes observed than is accepted until now. Better understanding of host — parasite relationship ofCandida albicans, and possible other fungi, could advance out knowledge of pathogenesis of these diseases.This work was supported partially byDora Kaplan, Joan Sloan, Memorial Funds and the Roon Foundation. 相似文献
117.
TIME SEQUENCE OF NUCLEAR PORE FORMATION IN PHYTOHEMAGGLUTININ-STIMULATED LYMPHOCYTES AND IN HELA CELLS DURING THE CELL CYCLE 总被引:23,自引:17,他引:6 下载免费PDF全文
Gerd G. Maul Helmut M. Maul Joseph E. Scogna Michael W. Lieberman Gary S. Stein Betty Yee-Li Hsu Thaddeus W. Borun 《The Journal of cell biology》1972,55(2):433-447
The time sequence of nuclear pore frequency changes was determined for phytohemagglutinin (PHA)-stimulated human lymphocytes and for HeLa S-3 cells during the cell cycle. The number of nuclear pores/nucleus was calculated from the experimentally determined values of nuclear pores/µ2 and the nuclear surface. In the lymphocyte system the number of pores/nucleus approximately doubles during the 48 hr after PHA stimulation. The increase in pore frequency is biphasic and the first increase seems to be related to an increase in the rate of protein synthesis. The second increase in pores/nucleus appears to be correlated with the onset of DNA synthesis. In the HeLa cell system, we could also observe a biphasic change in pore formation. Nuclear pores are formed at the highest rate during the first hour after mitosis. A second increase in the rate of pore formation corresponds in time with an increase in the rate of nuclear acidic protein synthesis shortly before S phase. The total number of nuclear pores in HeLa cells doubles from ~2000 in G1 to ~4000 at the end of the cell cycle. The doubling of the nuclear volume and the number of nuclear pores might be correlated to the doubling of DNA content. Another correspondence with the nuclear pore number in S phase is found in the number of simultaneously replicating replication sites. This number may be fortuitous but leads to the rather speculative possibility that the nuclear pore might be the site of initiation and/or replication of DNA as well as the site of nucleocytoplasmic exchange. That is, the nuclear pore complex may have multiple functions. 相似文献
118.
Thaddeus A. Bargiello Joseph Grossfield R. W. Steele Fred Cooke 《Biochemical genetics》1977,15(7-8):741-763
A maximum of 22 bands comprising four esterase subgroups—acetylesterase, carboxylesterase, cholinesterase, and acetylcholinesterase—were detected following electrophoresis of lesser snow goose sera on polyacrylamide gels. A minimum of seven structural genes was surmised to be involved in the biosynthesis of these enzymes following physiochemical characterizations. The genetic variability of these loci was calculated to be 1.25% average heterozygosity, while 14.3% of the loci were polymorphic. These estimates of genetic variability were substantially lower than those reported for other vertebrate species. The low degree of genetic variability found in snow goose serum esterases coupled with the extensive protein multiplicity observed may possibly reflect an adaptive strategy based on biochemical plasticity rather than genic heterozygosity for this species. The nature of evolutionary forces acting upon multiple enzyme systems such as esterases is discussed. The concept of conditional neutrality is introduced and defined within this context.This research was carried out under grants from the National Research Council of Canada and the Canadian Wildlife Service to F. Cooke. J. Grossfield was supported by grants from the National Institutes of Health, GM 21630 and FRAP 10576. 相似文献
119.
Graczyk TK 《Trends in parasitology》2005,21(3):104-107
Despite enormous efforts, the patterns of the rise of eukaryotic life on Earth are not clearly defined. The ability of eukaryotes to produce energy using oxygen and sugars was a key factor in advancing life on Earth towards complex multicellular organisms. However, this was not the only way to produce energy and survive. Mitochondria probably appeared soon after the oxygen increase in the Earth's atmosphere but many microaerophilic protists require little or no oxygen to survive. New ultrastructural, biochemical and molecular phylogeny data about structures and processes involved in the generation of energy by currently known protists have forced the revision of understanding of the "tree of life". 相似文献
120.
Thermophilic and amylolytic aerobic bacteria were isolated from soil through a selective enrichment procedure at 60 degrees C with starch as the carbon source. One of the isolates designated as HRO10 produced glucose aside from limit dextrin as the only hydrolysis product from starch and was characterized in detail. The starch-degrading enzymes produced by strain HRO10 were determined to be alpha-amylase and alpha-glucosidase. Whereas the alpha-amylase activity was detected exclusively in the culture supernatant, alpha-glucosidase occurred intracellular, extracellular, or on the surface of the bacteria depending on the growth phase. The optimum temperature and pH required for the growth of strain HRO10 were about 50 degrees C and pH 6.5 to 7.5. The strain used different carbohydrates as the carbon source, but the maximum production of alpha-amylase occurred when 1.0% (w/v) starch or dextrin was used. The use of organic vs. inorganic nitrogen favored the production of alpha-amylase in strain HRO10. The metal ions Li+, Mg2+, and Mn2+ stimulated the production of both enzymes. Identification of strain HRO10 by physiological and molecular methods including sequencing of the 16S rDNA showed that this strain belongs to the species Geobacillus thermodenitrificans. Biochemically, strain HRO10 differs from the type strain DSM 465 only in its ability to hydrolyze starch. 相似文献