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1.
Human cytomegalovirus. III. Virus-induced DNA polymerase.   总被引:47,自引:25,他引:22       下载免费PDF全文
Infection of WI-38 human fibroblasts with human cytomegalovirus (CMV) led to the stimulation of host cell DNA polymerase synthesis and induction of a novel virus-specific DNA polymerase. This cytomegalovirus-induced DNA polymerase was purified and separated from host cell enzymes by DEAE-cellulose and phosphocellulose column chromatographies. It can be distinguished from host cell enzymes by chromatographic behavior, template primer specificity, sedimentation property, and the requirement of salt for maximal activity. This virus-induced enzyme has a sedimentation coefficient of 9.2S and is found in both the nuclei and cytoplasm of virus-infected cells, but not in uninfected cells. This enzyme could efficiently use activated calf-thymus DNA, oly(dA)-oligo(dT)12-18, and poly(dC)-oligo(dG)12-18 as template primers, especially poly(dA)-oligo(dT)12-18, but it could not use poly(rA)-oligo(dT)12-18, poly(rC)-oligo(dG)12-18, or oligo(dT)12-18. The enzyme requires Mg2+ for maximal activity, is sensitive to p-hydroxymercuribenzoate, and is not a zinc metalloenzyme. In addition, the cytomegalovirus-induced DNA polymerase activity can be enhanced by adding 0.06 to 0.12 M NaCl or 0.03 to 0.06 M (NH4)2SO4 to the reaction mixture.  相似文献   

2.
Comparative investigation of 92 cases of V.A.T.E.R. syndrome (4 personal cases) and 62 cases of caudal regression (Duhamel syndrome) (2 personal cases) are performed. There is much analogy between these two entities. Initial impairment would be an early dysfunction of mesoderm setting up located on esophagus in V.A.T.E.R. syndrome and on kidneys in Duhamel syndrome. Etiopathogenic factors remain unknown. Genetic counseling is good. Detection of only one mesodermal malformation leads to inquire other unnoticed anomalies (kidneys, heart, spine, alimentary duct).  相似文献   

3.
The glycolipids of Lactobacillus casei A.T.C.C. 7469   总被引:1,自引:0,他引:1  
1. The lipids were extracted from Lactobacillus casei A.T.C.C. 7469 with chloroform-methanol mixtures. The glycolipids were obtained by chromatography on silicic acid and DEAE-cellulose (acetate form). 2. Hydrolysis of the glycolipids with alkali gave two glycerol glycosides and a mixture of fatty acids. 3. The glycosides were separated and their structures elucidated. The major component was O-alpha-d-galactopyranosyl-(1-->2)-O-alpha-d-glucopyranosyl-(1-->1)-glycerol and the minor component O-alpha-d-glucopyranosyl-(1-->6)-O-alpha-d-galactopyranosyl-(1-->2)-O-alpha-d-glucopyranosyl-(1-->1)-glycerol. 4. Analysis of the fatty acids by gas-liquid chromatography showed that they were predominantly palmitic acid, octadecenoic acid and lactobacillic acid.  相似文献   

4.
《Ibis》1930,72(S1):532-543
An easily recognized little bird in both of its very different seasonal dresses: one with no very near relative among the other species, but thoroughly Cirticoline from every point of view, alive or on the table: about the size of the Wood-Warbler (P. sibilatrix) , but with a shorter tail and much shorter wings, (totally different coloration), and in behaviour more like a bush-loving Sylvia , the Whitethroat (S. communis) for instance, only without any of that bird's aerial love-dances.  相似文献   

5.
Identification of new psychoactive substances (NPS) in biological and non-biological samples represents a hard challenge for forensic toxicologists. Their great chemical variety and the speed with which new NPS are synthesised and spread make stringent the need of advanced tools for their detection based on multidisciplinary approaches. For this reason, in August 2016, the “Unit of Research and Innovation in Forensic Toxicology and Neuroscience of Addiction” (U.R.I.To.N.) was founded by the Forensic Toxicology Division of the University of Florence. In this Research Unit, various professionals (i.e. forensic toxicologists, chemists, physicians) collaborate to study all the aspects of drugs of abuse, especially NPS. Herein, we describe the multidisciplinary approach comprising liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS), gas chromatography hyphenated to mass spectrometry (GC–MS) and solution nuclear magnetic resonance analysis that allowed the identification of three NPS such as 1-(benzofuran-5-yl)-N-methylpropan-2-amine, 2-amino-1-(4-bromo-2,5-dimethoxyphenyl)ethan-1-one (bk-2C-B), and 3-(2-aminopropyl)indole (α-methyltryptamine) in seized materials.  相似文献   

6.
Rats were exposed under aerobic or hypoxic conditions to 200-1200 rads of 60Co gamma-rays or extended-Bragg-peak helium ions on the eighth day of gestation. Uterine contents were examined on the twentieth day of gestation. At the 50 per cent embryonic survival level, helium ion r.b.e. was 1(.0) (aerobic) and 1(.2) (hypoxic). Maximum attainable gamma-ray and helium-ion o.e.r.s. were 2(.2) and 1(.7) respectively, indicating an oxygen-effect gain (o.e.g.) of 1(.2). At the 10 per cent survival level helium ion r.b.e. was 1(.1) (aerobic) and 1(.4) (hypoxic). Gamma-ray and helium-ion 0.e.r.s. were 2(.0) and 1(.5) respectively, indicating a helium ion o.e.g. of 1(.3). These data demonstrate that the small fraction of high-LET radiation present in this helium ion beam has a neglible effect on the aerobic r.b.e., but lowers the effective o.e.r. of the beam approximately 25 per cent relative to that of gamma-rays. Helium ions were significantly more effective than gamma-rays in killing embryos under hypoxic conditions, in producing congenital abnormalities under aerobic conditions, and in stunting foetal growth under both conditions.  相似文献   

7.
The spectrum of inositol phosphate isomers present in avian erythrocytes was investigated in qualitative and quantitative terms. Inositol phosphates were isolated in micromolar quantities from turkey blood by anion-exchange chromatography on Q-Sepharose and subjected to proton n.m.r. and h.p.l.c. analysis. We employed a h.p.l.c. technique with a novel, recently described complexometric post-column detection system, called 'metal-dye detection' [Mayr (1988) Biochem. J. 254, 585-591], which enabled us to identify non-radioactively labelled inositol phosphate isomers and to determine their masses. The results indicate that avian erythrocytes contain the same inositol phosphate isomers as mammalian cells. Denoted by the 'lowest-locant rule' [NC-IUB Recommendations (1988) Biochem. J. 258, 1-2] irrespective of true enantiomerism, these are Ins(1,4)P2, Ins(1,6)P2, Ins(1,3,4)P3, Ins(1,4,5)P3, Ins(1,3,4,5)P4, Ins(1,3,4,6)P4, Ins(1,4,5,6)P4, Ins(1,3,4,5,6)P5, and InsP6. Furthermore, we identified two inositol trisphosphate isomers hitherto not described for mammalian cells, namely Ins(1,5,6)P3 and Ins(2,4,5)P3. The possible position of these two isomers in inositol phosphate metabolism and implications resulting from absolute abundances of inositol phosphates are discussed.  相似文献   

8.
J Murray  B Clarke 《Heredity》1976,37(2):253-269
The general colour of the shell in Partula taeniata is controlled by at least two loci. One of these (C) has a series of six alleles which determine the yellow (Y) and neutral brown (N) series of colours. Alleles for darker colours are dominant to those for lighter colours, but dominance is not always complete. The pink (P) colours are determined by a second locus (P) which modified the expression of the lighter alleles of the C locus. Orangeshell colour segregates with yellow but its allelic relationship is unknown. Colour of the lip is controlled by a locus (L) with pink lip dominant to white lip. The colour of the spire is determined by a locus (S) with dark (N4) spire dominant to light spire. An intermediate spire colour shows the same pattern of inheritance and may represent the effect of another allele. Banding of the shell is dominant to absence of bands, with two loci (B1 and B2) determining the type of banding. An allele at B1 produces the frenata pattern; an allele at B2 produces zonata; together they produce lyra. All the loci for which linkage data are available are linked so strongly that the whole array may be considered a supergene. Self-fertilisation takes place primarily during early reproductive life. About 20 per cent of the young of the first mating of an individual are produced by selfing, but over the whole reproductive span the frequency is only about 2-5 per cent. There is inconclusive evidence for heterozygote advantage of banded individuals.  相似文献   

9.
A spore-forming bacterium strain 4J5(T) was isolated from rice field mud. When co-cultured with Methanobacterium formicicum DSM 1535(T), strain 4J5(T) could syntrophically degrade saturated fatty acids with 4-8 carbon atoms, including 2-methylbutyrate. Phylogenetic analysis based on 16S rRNA gene similarity showed that strain 4J5(T) was most closely related to Syntrophomonas wolfei subsp. wolfei DSM 2245(T) (98.9% sequence similarity); however, it differed from the latter in the substrates utilized and its genetic characteristics. Therefore, a new subspecies Syntrophomonas wolfei subsp. methylbutyratica is proposed. The type strain is 4J5(T) (=CGMCC 1.5051(T)=JCM 14075(T)). Furthermore, based on 16S rRNA sequence divergence and substrate utilization, we propose the assignment of Syntrophomonas wolfei subsp. saponavida DSM 4212(T) to Syntrophomonas saponavida sp. nov. comb. nov.  相似文献   

10.
The vacuum UV CD spectra of G.G.C triplexes.   总被引:1,自引:1,他引:0       下载免费PDF全文
Vacuum UV circular dichroism (CD) spectra were measured down to 175 nm for d(C)10, d(G)10, the d(G)10.d(C)10 duplex, and the d(G)10.d(G)10.d(C)10 triplex. A CD difference spectrum was calculated for d(G)10.d(C)10 giving the change in CD induced by forming the duplex from d(G)10 and d(C)10. The d(G)10.d(G)10.d(C)10 CD difference spectrum gave the CD induced by triplex formation from binding of d(G)10 to the d(G)10.d(C)10 duplex. In the near-UV, the d(G)10.d(C)10 and d(G)10.d(G)10.d(C)10 difference spectra resembled the difference spectrum for poly[r(G).r(C)] (Biopolymers 29, 325-333). This similarity may be an indication of similar purine base stacking. The d(G)10.d(G)10.d(C)10 vacuum UV difference spectrum had a negative band at 195 nm and a positive band at 180 nm, making it similar to difference spectra for homopolymer triplexes containing T.A.T and U.A.U triplets (Nucl. Acids Res. 19, 2275-2280). The appearance of these bands in difference spectra should be good indicators of triplex formation. The complementary oligonucleotides c-mycI d(CCCCACCCTCCC) and c-mycII d(GGGAGGGTGGGG) are part of the regulatory sequences of the human c-myc gene. G.G.C rich triplexes formed by binding c-mycII or c-mycIII d(GGGGTGGGTGGG) to the c-mycI.c-mycII duplex had CD difference spectra similar to that of d(G)10.d(G)10.d(C)10 in both the vacuum UV and near UV regions, indicating similar triplet structures.  相似文献   

11.
Reactions of OH radicals with methyl and ethyl derivatives of uracil, cytosine and thymine in aqueous solutions have been investigated. Photolysis of H2O2 was used to generate OH radicals and the radicals on the base derivatives were spin-trapped using t-nitrosobutane and identified with the help of e.s.r. spectroscopy. Addition of OH radicals was found to take place predominantly to the C(5)--C(6) double bond of the bases. H-abstraction from the methyl group occurred in the N(1) methyl derivatives of uracil, cytosine and thymine. Radicals formed by H-abstraction from the methyl group were also detected for 3-methyluracil, thymine, 1-methylthymine and 1-ethylthymine. Introduction of a methyl or ethyl group at the N(1) position of uracil, cytosine and thymine causes an increase in the C(6) proton coupling and a decrease in the N(1) splitting for radicals formed by OH addition at the C(5) position.  相似文献   

12.
A problematical, axial-symmetrical microfossil is described from Upper Ordovician Öjlemyrflint erratic boulders of the Isle of Gotland (Baltic Sea) and of the Kaolinsand (Plio-/Pleistocene) of the Isle of Sylt (North Sea).  相似文献   

13.
The teichuronic acid of Bacillus licheniformis A.T.C.C. 9945 grown under phosphate limitation was isolated from the cell walls and purified by ion-exchange and Sephadex chromatography. The detailed structure of the polysaccharide was established by methylation analysis, periodate oxidation and partial acid hydrolysis. The polymer is composed of tetrasaccharide repeating units with the structure [GlcA beta(1 leads to 4)GlcA beta(1 leads to 3)GalNAc beta(1 leads to 6)GalNAc alpha(1 leads to 4)n. 13C n.m.r. analysis has confirmed most of the structural features of the polysaccharide and, in particular, the anomeric configurations and linkage positions of substituents. The teichuronic acid from glucose-limited cells was identical with that from cells grown under phosphate limitation.  相似文献   

14.
Sulfate-reducing bacteria with oval to rod-shaped cells (strains AcRS1, AcRS2) and vibrio-shaped cells (strains AcRM3, AcRM4, AcRM5) differing by size were isolated from anaerobic marine sediment with acetate as the only electron donor. A vibrio-shaped type (strain AcKo) was also isolated from freshwater sediment. Two strains (AcRS1, AcRM3) used ethanol and pyruvate in addition to acetate, and one strain (AcRS1) grew autotrophically with H2, sulfate and CO2. Higher fatty acids or lactate were never utilized. All isolates were able to grow in ammonia-free medium in the presence of N2. Nitrogenase activity under such conditions was demonstrated by the acetylene reduction test. The facultatively lithoautotrophic strain (AcRS1), a strain (AcRS2) with unusually large cells (2×5 m), and a vibrio-shaped strain (AcRM3) are described as new Desulfobacter species, D. hydrogenophilus, D. latus, and D. curvatus, respectively.  相似文献   

15.
GTP-AMP phosphotransferase has been purified 116-fold with a yield of 24% from beef heart mitochondria using freeze-thawing, alkali and acid treatment and successive column chromatography on phosphocellulose, Sephadex G-100 and blue-dextran--Sepharose. It has crystallized from poly-(ethylene glycol) and is essential homogeneous by sodium dodecylsulfate electrophoresis and isoelectrofocusing. The specific activity of the crystalline preparation was 290 U/mg. The molecular weight was found to be 26000 and the isoelectric point to be 9.8. Amino acid analysis showed 21 aspartic acid or asparagine, 19 threonine, 12 serine, 26 glutamic acid or glutamine, 15 proline, 16 glycine, 14 alanine, 15 valine, 4 methionine, 12 isoleucine, 28 leucine, 7 tyrosine, 7 phenylalanine, 5 histidine, 14 lysine, 16 arginine, 2 tryptophan, no --SS-- bonds or free --SH. Guanosine(5')pentaphospho(5')adenosine is a very strong inhibitor similar to adenosine(5')pentaphospho(5')adenosine as an inhibitor of cytosolic adenylate kinase.  相似文献   

16.
Varve chronologies are of several kinds but glacial varves respond to summer temperature and fluvial varves to summer rainfall.Tree-ring chronologies near the timberline respond to summer temperature but European oak chronologies respond to summer rainfall.Certain global features of the weather of the summer season, notably the Biennial Index, are therefore parameters that can be used for cross-dating both varves and tree-rings in different continents.Characteristic curves for different parameters in the Late Glacial (Zones Ia, Ib and II) and in the past thousand years are presented. A moisture curve is given for the North European Plain (200 B.C.–A.D. 1100). A conversion chart for tree-rings and radiocarbon dates is extended back into the Late Glacial on the tentative assumption that the radiocarbon error was about 950 years at the beginning of the Holocene (III/IV), i.e. that 10300 b.p. should be 11250 B.P. or 9300 B.C.Supplementary sources of information useful in obtaining approximate dates include: (a) palaeomagnetism; (b) tephrochronology and X-ray analysis; (c) cycle analysis; (d) climatic peculiarities associated with specific radiocarbon centuries; (e) X-ray analysis of specific varves; and (f) new methods of varve-analysis.The varve-series used for the Late Glacial, if the author's cross-dating between North America and Scandinavia is acceptable, constitute a floating chronology of about 4000 years. Given approximate 14C dates for any long series of varves or tree-rings in one part of the world, it is now possible to obtain cross-dating with any other long series in another part of the world, and it will be easy to replace the tentative ‘950-year’ error by a precise figure determined from a combined varve and tree-ring scale extending back from the present day to (say) the zero of Sauramo's scale for varves in Finland. In the meantime the ‘950’ is mnemonically convenient, as this would make the year on the B.C. scale one thousand less than the year on the b.p. scale.  相似文献   

17.
Lipopolysaccharide-activated murine peritoneal macrophages elaborate lymphocyte-activating factor (LAF) which is mitogenic for murine thymocytes. A method of LAF production is presented that permits the generation of a relatively homogeneous molecular species. LAF has an isoelectric point of 4.8 (range 4.7-4.9). The m.w. was determined by using several physical techniques. The apparent sedimentation coefficient (S20,w) was determined to be 2.0S by sucrose gradient ultracentrifugation. The Stokes (molecular) radius was determined by gel filtration on Sephadex G-75 to be 22 A (range 21.5 to 22.5); the calculated diffusion coefficient (D20,w) was 9.7 X 10(-7) cm2/sec (range 9.5 X 10(-7) to 9.9 X 10(-7). The buoyant density of LAF is 1.30 g/cm3 (range 1.27 to 1.33) as determined by CsCl isopycnic ultracentrifugation; the partial specific volume was estimated to be 0.72 (range 0.70 to 0.74). From these data, the m.w. was calculated to be 18,000 daltons (range 16,400 to 19,600) with the Svedberg equation. The frictional ratio was calculated to be 1.25.  相似文献   

18.
T S Li  Y L Li  X T Liang 《Steroids》1992,57(2):67-71
13,17-Secodiacholestanes (6) were synthesized from cholesterol (1) in six steps. The key intermediates, (20R)- and (20S)-diacholest-13(17)-enes (3a and 3b), underwent ozonization and reduction to provide (20R)- and (20S)-13,17-secodiacholesta-13,17-dione (5a and 5b), respectively. On Clemmensen reduction, the diones (5a and 5b) yielded the target molecule 6. The structure of an unknown biomarker was shown to be different from the proposed 6 by gas chromatographic/mass spectrometric comparison.  相似文献   

19.
Radical production during the photolysis of deaerated aqueous alkaline solutions (pH 11) of some water-soluble porphyrins was investigated. Metal-free and metallo complexes of tetrakis (4-N-methylpyridyl)porphyrin (TMPyP) and tetra (4-sulphonatophenyl)porphyrin (TPPS4) were studied. Evidence for the formation of OH radicals during photolysis at 615, 545, 435, 408 and 335 nm of Fe(III) TPPS4 is presented. Fe(III) TMPyP, Mn(III) TPPS4 and Mn(III) TMPyP also gave OH radicals but only during photolysis at 335 nm. The method of spin trapping with 5,5-dimethyl-1-pyrroline-1-oxide (DMPO) and 4-pyridyl-1-oxide-N-tert-butylnitrone (POBN) combined with e.s.r. was used for the detection of OH, H and hydrated electrons. With the spin trap DMPO, photolysis generated DMPO-OH adducts under certain conditions but no DMPO-H adducts could be observed. With POBN, no POBN-H adducts were found. The formation of OH was confirmed by studying competition reactions for OH between the spin traps and OH scavengers (formate, isopropanol) and the concomitant formation of the CO-2 adduct and the (CH3)2COH adduct with both DMPO and POBN. The photochemical generation of OH radicals was pH dependent; at pH 7.5 no OH radicals could be detected. Photolysis (615-335 nm) of dicyanocomplexes of the Fe(III) porphyrins did not produce OH radicals. When corresponding Cu(II), Ni(II), Zn(II) and metal-free porphyrins were photolysed at 615 and 335 nm, no OH radicals could be spin trapped. These results tend to associate the well-known phenomenon of photoreduction of Fe(III) and Mn(III) porphyrins with the formation of OH radicals. This process is described mainly as the photoreduction of the metal ion by the ligand-bound hydroxyl ion via an intramolecular process.  相似文献   

20.
Hearts, diaphragms, esophagi, and spinal cords from 266 horses were obtained at slaughter in Creston, Ohio. Tissues were examined microscopically for Sarcocystis in sections, digested in trypsin to obtain bradyzoites, and fed to 10 dogs and 10 cats. Intramuscular cysts were found in selections of two hearts from 57 horses and four esophagi from 107 horses. The cysts were up to 900 micron long and up to 70 micron wide. The cyst wall was 1 to 2 micron thick and cross-striated. The enclosed bradyzoites were banana-shaped, 15 to 20 by 20 to 3 micron, and contained several PAS-positive granules. Bradyzoites were found in trypsin digests of seven of 57 (13%) equine tissues (heart, diaphragm, esophagus but not spinal cord) in one experiment and 10 of 47 (21%) esophagi, eight of 47 (17%) diaphragms but none of 47 hearts and spinal cords in another experiment. All of 10 dogs shed sporulated sporocysts or oocysts in feces 12 to 15 days (12 in one, 13 in eight, and 15 days in one) after digesting tissues from 169 horses. The sporocysts were 11 to 13 (12.0 +/- 0.5) by 7 to 8.5 (7.9 +/- 0.5) micron. In histologic sections of canine small intestine the sporocysts were located in the lamina propria near the tips of the villi. The 10 cats fed tissues from 266 horses did not shed Sarcocystis. A new name, S. fayeri, is proposed for this organism. Sarcocystis fayeri sporocysts (12 by 8 micron) are shorter than those of S. betrami (15 by 10 micron), the other species of Sarcocystis from the horse. The prepatent period is 12 to 15 days for S. fayeri and 8 days for S. bertrami (synonym S. equicanis Rommel and Geisel 1975).  相似文献   

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