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41.
Introduction and expression of foreign DNA in isolated spinach chloroplasts by electroporation 总被引:3,自引:1,他引:2
Kin-Ying To Ming-Chih Cheng Long-Fang Oliver Chen Shu-Chen Grace Chen 《The Plant journal : for cell and molecular biology》1996,10(4):737-743
An electroporation-mediated method for the study of foreign gene expression within chloroplasts has been developed. The chloroplast expression vector pHD203-GUS, which consists of coding regions for β-glucuronidase (GUS) and chloramphenicol acetyltransferase (CAT) separated by a double psbA promoter fragment from pea (in opposite orientation) was electroporated into spinach chloroplasts and the transient gene expression was examined. Conditions for the expression of the reporter genes have been optimized. Both CAT and GUS activities were detected in chloroplasts electroporated with pHD203-GUS, but not with nuclear expression vector pBI221 or negative control pUC18. No GUS activity was detected when pHD203-GUS was electroporated into spinach protoplasts. Dot immunoblot analysis using anti-GUS antibody confirmed the existence of GUS protein in chloroplasts electroporated with chloroplast-specific vector but not the negative controls, excluding the possibilities of endogenous GUS or bacterial contamination. The expression of GUS protein in treated chloroplasts was further confirmed by Western blot analysis. 相似文献
42.
T. Hishinuma Grace S. P. Yu M. Takabatake Y. Nakagawa K. Ito M. Nishikawa M. Ishibashi K. Suzuki M. Matsumoto T. Toyoda M. Mizugaki 《Prostaglandins, leukotrienes, and essential fatty acids》1996,54(6):445-449
We microanalyzed 2,3-dinor-6-keto-prostaglandin F1α (2,3-dinor-6-keto-PGF1α 1) and 11-dehydrothromboxane B2 (11-dehydro-TXB2, 2) in human urine. Samples containing a [2H4]-analogue as an internal standard were extracted by chromatography using Sep Pak tC18 and silica gel. The compounds were then analysed by means of the lactone ring opening reaction and dimethylisopropylsilylation. The conversion of 1 to 1-methyl ester (ME)-propylamide (PA)-9,12,15-dimethylisopropylsilyl (DMIPS) ether derivative and of 2 to 1-ME-6-methoxime (MO)-9,12,15-tris-DMIPS ether derivative was followed by gas chromatography/selected ion monitoring (GC/SIM). Interfering substances from the urine matrix were eliminated during GC/SIM analysis using a DB-5 column. We were able to detect 1 (222–1031 pg/mg creatinine) and 2 (18–155 pg/mg creatinine) in human urine. Furthermore, the thromboxane/prostacyclin (IX/PGI) ratio in the urine of diabetics was higher than that of healthy volunteers. This method can be used to determine the TX/PGI balance in human urine. 相似文献
43.
Clinical and Molecular Characterization of Patients with Distal 11q Deletions 总被引:10,自引:0,他引:10 下载免费PDF全文
Laura A. Penny Marie Dell'Aquila Marilyn C. Jones JoAnn Bergoffen Christopher Cunniff Jean-Pierre Fryns Elizabeth Grace John M. Graham Boris Kousseff Teresa Mattina James Syme Lucille Voullaire Leopoldo Zelante Julie Zenger-Hain Oliver W. Jones Glen A. Evans 《American journal of human genetics》1995,56(3):676-683
Jacobsen syndrome is caused by segmental aneusomy for the distal end of the long arm of chromosome 11. Typical features include mild to moderate psychomotor retardation, trigonocephaly, facial dysmorphism, cardiac defects, and thrombocytopenia, though none of these features are invariably present. To define the critical regions responsible for these abnormalities, we studied 17 individuals with de novo terminal deletions of 11q. The patients were characterized in a loss-of-heterozygosity analysis using polymorphic dinucleotide repeats. The breakpoints in the complete two-generation families were localized with an average resolution of 3.9 cM. Eight patients with the largest deletions extending from 11q23.3 to 11qter have breakpoints, between D11S924 and D11S1341. This cytogenetic region accounts for the majority of 11q− patients and may be related to the FRA11B fragile site in 11q23.3. One patient with a small terminal deletion distal to D11S1351 had facial dysmorphism, cardiac defects, and thrombocytopenia, suggesting that the genes responsible for these features may lie distal to D11S1351. Twelve of 15 patients with deletion breakpoints as far distal as D11S1345 had trigonocephaly, while patients with deletions distal to D11S912 did not, suggesting that, if hemizygosity for a single gene is responsible for this dysmorphic feature, the gene may lie distal to D11S1345 and proximal to D11S912. 相似文献
44.
David E. Lacy Anthony W. Smith David E. Stableforth Grace Smith Peter H. Weller Michael R.W. Brown 《FEMS immunology and medical microbiology》1995,10(3-4):253-262
Abstract Burkholderia cepacia (Pseudomonas cepacia) is now recognised as an important pathogen in cystic fibrosis patients, and several reports have suggested that sputum-culture-proven colonisation occurs despite the presence of specific antibody. In an attempt to establish the use of antibody studies as diagnostic and prognostic indicators of B. cepacia infection, we have examined the IgG response to B. cepacia outer membrane proteins and lipopolysaccharide in patients also colonised with P. aeruginosa . The B. cepacia strains were grown in a modified iron-depleted chemically defined medium and outer membrane components examined by SDS-PAGE and immunoblotting. IgG antibodies were detected against B. cepacia outer membrane antigens, which were not diminished by extensive preadsorption with P. aeruginosa . The response to B. cepacia O-antigen could be readily removed by adsorption of serum either with B. cepacia whole cells or purified LPS, whereas we were unable to adsorb anti-outer membrane protein antibodies using B. cepacia whole cells. The inability to adsorb anti-outer membrane protein antibodies using B. cepacia whole cells maybe due to non-exposed surface epitopes. Several B. cepacia sputum-culture negative patients colonised with P. aeruginosa had antibodies directed against B. cepacia outer membrane protein. This study suggests that there is a specific anti- B. cepacia LPS IgG response, which is not due to antibodies cross-reactive with P. aeruginosa . Our studies indicate that much of the B. cepacia anti-outer membrane protein response is specific and not attributable to reactivity against co-migrating LPS. 相似文献
45.
46.
Norman W.H. Cheetham Grace Teng 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1984,336(1)
Oligosaccharide separation on reversed-phase high-performance liquid chormatographic columns have been examined using a range of aqueous solvents. Addition of anionic, cationic and non-ionic surfactants, tetramethyl urea and organic solvents to the mobile phase cause faster elution of oligosaccharides, and allow the separation of the larger oligomers in an acceptable time. Addition of neutral, inorganic salts increase the retention factors considerably, and allows good resolution of some compounds poorly resolved in water alone.The mechanism operating in the separations approximates to that invoked in the solvophobic theory of reversed-phase chromatography. There is some evidence also of hydrogen bond effects. The improvements described should prove useful in the isolation and analysis of neutral oligosaccharides in general, and in structural analyses of polysaccharides in paritcular. 相似文献
47.
Grace A. Maresh Ellen A.G. Chernoff Lloyd A. Culp 《Archives of biochemistry and biophysics》1984,233(2):428-437
Human neuroblastoma cells (Platt) were detached from tissue culture substrata with a Ca2+ chelating agent, and then the suspended cells were extracted with a sodium dodecyl sulfate (SDS)-containing buffer to maximally solubilize their sulfate-radiolabeled proteoglycans. The majority of the high-molecular-weight material in these dissociative extracts was heparan sulfate proteoglycan, which resolves into two heterodisperse size classes upon gel filtration on columns of Sepharose CL4B. After removal of SDS from these extracts by hydrophobic chromatography on Sep-Pak C18 cartridges, extracts were further fractionated on various affinity matrices. All of the sulfate-radiolabeled material eluted as one peak from DEAE-Sephadex ion-exchange columns. In contrast, affinity fractionation on Sepharose columns derivatized with the heparan sulfate-binding protein, platelet factor-4, resolved three major and one minor subsets of these components. The nonbinding fraction contained some heparan sulfate proteoglycan and some chondroitin sulfate. The weak-binding fraction contained principally heparan sulfate proteoglycan, as well as a small amount of chondroitin sulfate proteoglycan; the gel-filtration properties of these proteoglycans before or after alkaline borohydride treatment indicated that they were small in size, containing perhaps 2 to 4 glycosaminoglycan chains. The high-affinity fraction eluted from platelet factor 4-Sepharose was composed entirely of “singlechain” heparan sulfate. A portion of the heparan sulfate proteoglycan of the original extract bound to the hydrophobic affinity matrix, octyl-Sepharose, and this hydrophobic proteoglycan partitioned into the nonbinding and weak-binding fractions of the platelet factor 4-Sepharose affinity columns. These studies reveal that the majority of the proteoglycan made by these neuronal cells in culture is of the heparan sulfate class, is small in size when compared to other characterized proteoglycans, and can be resolved into several overlapping subsets when fractionated on affinity matrices. 相似文献
48.
Summary A family is presented in which there were three different chromosome abnormalities in the children although the parents were cytogenetically normal. The proband had the karyotype 46,XX,r(18)(p11q23), a phenotypically normal brother was 47,XY,+mar, and another brother was a typical case of Down's syndrome, karyotype 47,XY,+21. There is nothing in the parents' history that provides grounds for a hypothesis to explain the coincidence of the abnormalities. 相似文献
49.
Robert W. Egan Paul H. Gale George C. Beveridge Grace B. Phillips Lawrence J. Marnett 《Prostaglandins & other lipid mediators》1978,16(6):861-869
Certain radical-trapping reducing agents have been shown to stimulate prostaglandin biosynthesis
(1–6) and to depress phorbol myristate acetate-induced mouse ear edema (16). The increased prostaglandin synthesis resulted from influences on the cyclooxygenase. To ascertain whether these alterations were due to direct interaction with the enzyme or to indirect scavenging of the oxidant released during PGG2 reduction, we report the effects of lipoic acid and sodium iodide.Both of these agents stimulated the enzymatic oxygenation of arachidonic acid, increased the reduction of PGG2 to PGH2, quenched the EPR signal induced by arachidonic acid and depressed mouse ear edema. In addition to discovering two unusual antiinflammatory agents, we have confirmed that materials with entirely different structures can have identical effects on the cyclooxygenase, suggesting indirect stimulation of this enzyme due to trapping of the oxidant. 相似文献
50.
John M. DeBoy Grace M. Thorne Carl F. Deneke I. Kaye Wachsmuth 《Current microbiology》1981,6(1):49-53
Hemagglutination (HA) tests using human and bovine erythrocytes and microagglutination tests using pili-specific antisera (PSA) were performed to examine 168 strains ofEscherichia coli belonging to enterotoxin-associated serotypes for colonization factors (CFs). Seventy-one (42%) of these 168 strains possessed at CF, but only 10 (6%) were found positive by both HA and PSA tests. Groups of test strains from different sources (feces, urine, blood, and wounds) were not found to contain statistically different percentages of CF-positive strains. Strains producing heat-stable enterotoxin alone were less frequently associated with a CF than were other enterotoxigenic and nonenterotoxigenic strains. Strains showing heat-labile hemolytic activity and belonging to serotype O6: H—were less likely (P=0.014, Fisher's exact probability) to contain a CF than were similarly hemolytic strains belonging to other serotypes. 相似文献