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Biomedical subjects

K Mang

Publications and source records attributed to K Mang.

At least 19 recordsLinked to original sources
PubMed1999

Preparation of GFLV CP-gene cDNA probe labeled by photosensitive biotin and its application in detection of GFLV.

The cDNA of the GFLV CP gene amplified from clone pGAB5 by PCR was labeled by photosensitive biotin. The probe sensitivity is 5 pg, and the detectable amount of unlabeled GFLV cDNA was 10 pg by Dot-blot hybridization when the biotin-labeled cDNA was used as a probe. The results of detection for GFLV by probe have positive correlation with those of ELISA. The minimum amount of grapevine tissue for detection by probe was 100 times lower than that by ELISA. The seasons and the position of grapevine leaves do not limit application of this method.

Biotinylation↗
PubMed1998

Cloning of 1-aminocyclopropane-1-carboxylate (ACC) synthetase cDNA and the inhibition of fruit ripening by its antisense RNA in transgenic tomato plants.

A 1.7 kb fragment of ACC synthetase cDNA, one member of the ACC synthetase multigene family, was amplified from total tomato cDNA through a polymerase chain reaction (PCR) and cloned in E. coli. Restriction mapping and sequencing analysis confirmed its fidelity and correctness. The cloned ACC synthetase gene was then inserted into a binary vector pBin437, in an inverted orientation between the CaMV 35S promoter with duplicated enhancers and the Nos 3' transcriptional termination sequence, to construct an expression vector pBACC. Transgenic tomato plants were obtained by A. tumefaciens-mediated transformation of cotyledons. PCR detection and Southern blot analysis confirmed the integration of the antisense ACC synthetase gene in the transformed tomato genome. The results from RT-PCR of RNAs isolated from transgenic tomato leaves confirmed that antisense ACC synthetase RNA was synthesized in these transgenic plants. The amount of ethylene released from transgenic tomato fruits was reduced significantly to about 30% of that released by non-transformed controls. The inhibition effect of antisense RNA on fruit ripening was observed in transgenic plants and their progeny (T1). The shelf life of transgenic tomato fruits was at least 60 days at room temperature without significant change in hardness and color. After 15-20 days of treatment of the transgenic fruits with ethylene, most of them reached the ripe stage. The antisense ACC synthetase gene was inherited as a single gene in the progenies of transgenic tomatoes determined by T1 progeny analysis, consistent with the results of Southern blot analysis. Transgenic homozygotes expressing antisense ACC synthetase RNA showed prolonged shelf life in the T2 progeny.

Cloning, Molecular↗
PubMed1998

Inhibition effect of transgenic tobacco plants expressing snowdrop lectin on the population development of Myzus persicae.

The cDNAs of snowdrop lectin mature protein and its precursor protein, GNA12 and GNA34, were inserted downstream of a 35S promoter with a double enhancer and a "omega" fragment of TMV-RNA cDNA in the binary vector pBin438, or the phloem-specific CoYMV promoter in the vector pBcop1, respectively, resulting in the construction of four plant expression vectors pBGna12, pBGna34, pBCGna12, and pBCGna34. Leaf stripes of Nicotiana tabacum var. K326 were transformed with A. tumefaciens LBA4404 harboring the above expression vectors, respectively. PCR and Southern blot analysis showed that foreign GNA genes were inserted into the genome of transformed tobacco plants. Western blot analysis indicated that GNA could be expressed efficiently up to 0.08-0.15% of total soluble proteins in transgenic tobacco plants with pBGna34 or pBCGna34, while in those with pBGna12 and pBCGna12 GNA were hardly detected by immunoassay. The results from insect bioassay with a peach aphid (Myzus persicae) demonstrated that the transgenic plants of pBGna34 and pBCGna34 were aphid-resistant as shown by a 45-60% reduction in insect population density, with some individual transgenic lines being reduced by over 90%. In addition, it was evident that the 35S promoter with a double enhancer and CoYMV promoter had similar abilities to direct the GNA gene to express in transgenic tobacco plants, but because the CoYMV promoter drives the foreign gene in a phloem-specific expression manner, the transgenic plants of pBCGna34 showed higher aphid resistance.

Animals↗
PubMed1997

[Purification, serology and detection of grapevine leaf roll virus].

Closterovirus-like particles associated with grapevine leaf roll disease were purified from stem phloem tissue by differential centrifugation and cesium sulphate-sucrose density gradient centrifugation. The particles were between 660-2000 nm long. Most of them were about 1400 nm long and also decorated by the antiserum against GLRV NY-1 isolate. The purified preparation was tested for their serological relatedness in indirect ELISA. The results indicated that these closterovirus-like particles reacted with serotype II, III and IV of GLRV. The antiserum to NY-1 (type III) reacted more strongly than type IV (to VA-4) and type II. (to 1800 nm). In sodium dodecyl sulfate immunodiffusion test, the extract of diseased petiole reacted with serotype III, IV and II. It is possible to be infected by 2 or 3 closterovirus-like particles in China. We have made antiserum to the purified closterovirus-like GLRV and set up a PAS-ELISA to detect GLRV-free grapevine plantelets. We have obtaimed 21 varieties of GLRV-free and GFLV-free grapevine. They shown high quality and quantity in field test.

English Abstract↗
PubMed1997

Application of biotechnology in plant agriculture in China.

Early in 1984, when biotechnology was implemented as one of the eight priority projects of the "Seventh Five-Year Plan," it was fully realized that China, a large crop consumer, must pay much attention to the development of agrobiotechnology. Later, in 1986, it was again listed as one of the priority projects in the "863" program, the long-term, high-technology program of China. At that time, the strongest field of biotechnology in China was the field of plant tissue culture which had been developing for over a decade. Several new cultivars of rice, wheat, and tobacco were created using anther cultures; virus-free meristem micropropagation had been applied in the control of potato degeneration and of some viral diseases of ornamental plants; regeneration of whole plants from plant protoplasts or calli has succeeded with tobacco, carrot, and canola. By contrast, the field of transgenic plants was just at its beginning, whether it could be a successfully applied technology still remained to be answered, while applications in transgenic animal research were unknown [1].

Agriculture↗
PubMed1996

[Transgenic Brassica napus resistant to turnip mosaic virus].

A system for obtaining regenerated plantlets of "double low" Brassica napus by using cotyledonary petioles as material was established. The turnip mosaic virus coat protein (TuMV-CP) gene inserted in the binary vector pBTu in the Agrobacterium tumefaciens LBA 4404 was integrated into Brassica napus through co-culture of cotyledonary petioles with LBA4404, and the material in co-culture was selected under the stress of Kanamycin. Regenerated plantlets were obtained, and the specific TuMV-CP gene was proved to be integrated into the genomic DNA of the regenerated plants by the specific PCR amplification, dot hybridization and Southern blot. All these transgenic plants were proved to be resistant to virulent TuMV by virus challenge in different degree.

Brassica↗
PubMed1996

[Construction of shuttle vector containing delta-endotoxin gene of Bacillus thuringiensis].

The Bacillus thuringiensis toxin gene CryIA(c) was inserted into the shuttle vector pBE-2 to construct pAMY for expressing the B.t. gene in both Gram-negative and -positive bacterial systems. pAMY was introduced into wild type Bacillus cereus, B.brevis and B.subtilis by electroporation. Transformants containing delta-endotoxin gene produced proteins reacted with B.t. crystal protein antibody. Upon biological toxicity tests, the transformants gave a mortality of 100% against Ostrinia furnacilis, 58.8% against Heliothis armigera and 100% against Heliothis assulta. The ability of promoting plant growth of the original strains is retained.

Bacillus cereus↗
PubMed1996

The cloning, sequence analysis, and expression in E. coli of coat protein gene of grapevine fanleaf virus Gh.

Fragments of 5' end and 3' end of the coat protein gene of a Chinese strain grapevine fanleaf virus (GFLV-Gh) were separately amplified through RT-PCR. The two products were cloned and ligated into a complete full-length coat protein gene via an inherent BgIII restriction site. The entire gene contains 1512 nucleotides which encode a 504 amino acids coat protein, molecular weight approximately 56 kDa. Comparison with GFLV F-13 shows 88.4% homology in nucleotides and 95.8% similarity in deduced amino acid residues. Also this coat protein gene was expressed in E. coli DH 5 alpha.

Amino Acid Sequence↗
PubMed1995

Firearm injury prevention counseling by pediatricians and family physicians. Practices and beliefs.

OBJECTIVES: To ascertain and compare beliefs, attitudes, and counseling practices of primary care physicians of children and adolescents regarding firearm injury prevention counseling. DESIGN: Cross-sectional survey. SETTING: State of Washington. SUBJECTS: All active members of the state chapters of the American Academy of Pediatrics and American Academy of Family Physicians. A total of 979 pediatricians and family physicians (53%) responded to the survey after two mailings. MAIN OUTCOME MEASURES: Attitudes, beliefs, and current practices with regard to firearm safety counseling among families of child and adolescent patients. RESULTS: Only 25% of pediatricians and 12% of family physicians currently counsel more than 5% of their patients. Pediatricians were more likely than family physicians (70% vs 46%, P < .001, chi 2 test) to believe that physicians have a responsibility to counsel families about firearm safety. Pediatricians recommended removing guns from the home more frequently than family physicians (32% vs 19%, P < .001, chi 2 test), but most physicians of both specialties perceived that parents are rarely receptive to this advice. However, 97% of physicians from both specialties agreed that firearms should be stored locked separately from ammunition, and a substantial majority believed that parents would be receptive to this advice. Compared with physicians who owned guns (32%), non-owners were 15 times more likely (odds ratio, 15; 95% confidence interval, 10 to 23) to agree that families with children should not keep firearms in the home. CONCLUSIONS: Few primary care physicians who see children and adolescents currently counsel families about firearm safety, although many agree that they have such a responsibility. At least half of these physicians would potentially benefit from an intervention to improve their knowledge of and counseling skills on this topic.

Accident Prevention↗
PubMed1995

cDNA cloning and sequence analysis of NIb gene of soybean mosaic virus.

cDNA of soybean mosaic virus (Beijing isolate, SMV-BJ) has been synthesized, using viral genomic RNA as a template and random hexanucleotides as primers. Based on the sequences of SMV-BJ coat protein (CP) gene as well as SMV- and WMV-II-related regions, oligonucleotides were made as primers for polymerase chain reaction (PCR). NIb gene of SMV-BJ was amplified by PCR, and cloned into pBluescript SK. The complete sequence was determined. The comparison of NIb genes between SMV-BJ and WMV-II (USA) shows that similarities for nucleotide sequence reach 80.3%; and the deduced amino acid sequence, 91.3%. In consideration of the high identities in between the CP gene and the 3'-non-coding region between them, WMV-II might be considered as a watermelon strain of SMV. Besides, some unexpected sequences were found in the 3'-region of 2 NIb gene clones. Following modification and splicing, a binary vector of NIb gene has been constructed for its expression in higher plant for the purpose of studying the possible replicase-mediated resistance in polyviruses.

Amino Acid Sequence↗
PubMed1994

Cloning of polygalacturonase (PG) cDNA and inhibition effects of its antisense RNA on the expression of PG gene in transgenic tomato plants.

We have amplified a 1.5-kb PG cDNA including its complete open reading frame, using two primers specific to PG gene and PCR technique. Its fidelity and correctness were confirmed by restriction mapping and partial DNA sequencing. The PG gene was then inserted into a binary vector, pBin437, in an inverted orientation between the 35S promoter with duplicated enhancers and the Nos3' transcriptional termination sequence, and the resulting plasmid pBPG was introduced into LBA 4404. The A. tumefaciens harboring pBPG was used to transform tomato plants. Sixty kanamycin-resistant transformants were selected. PCR detection showed two-third of the transformed plants tested (30 plants) contain the exogenous PG gene. The PG activity assay and SDS-PAGE analysis of proteins from ripening fruit cell wall showed that the PG activity in transgenic tomato plants were inhibited in different extent. One of them, plant 3, gave only 7% PG activity compared with the control (100%). These results suggest that the expression of the anti-PG gene has effectively inhibited the expression of endogenous PG gene. The effect of low-level PG activity on tomato fruit ripening and storage is being investigated.

Base Sequence↗
PubMed1994

Study on replicase (subunit) gene of papaya ringspot virus cloning, sequencing and construction of higher plant expression vector.

The ds-cDNA was synthesized using genomic RNA of papaya ringspot virus (PRSV) as template. The blunt-ended cDNA was cloned into the EcoRV site of vector pBluescript SK. From the recombinants, the NIb gene of PRSV was obtained, and its complete sequence was also determined. After the NIb gene was modified through PCR, a binary vector of PRSV-NIb gene was constructed for its expression in higher plants.

Amino Acid Sequence↗
PubMed1994

Transfer of shuttle vectors containing Bacillus thuringiensis toxin gene into wild-type B. cereus, B. brevis and B. subtilis by electroporation.

Gram positive and negative bacterial shuttle vectors carrying Bacillus thuringiensis (B.t.) toxin gene were introduced by electroporation into wild-type Bacillus cereus, B. brevis and B. subtilis. The transformation efficiencies for these bacteria were around 10(1)-10(4) transformants per micrograms DNA based on the numbers of neomycin- and ampicillin-resistant colonies produced. The structure of the transferred plasmids proved identical with the original ones both in size and restriction pattern. Toxicity assays showed that the transformants gave a mortality of 90-100% against caterpillar of Heliothis assulta, indicating that the gene function was not changed by electroporation.

Bacillus↗
PubMed1993

Cloning of coat protein gene of soybean mosaic virus and its expression in Escherichia coli.

The 3'-terminal genomic region of the Beijing isolate of soybean mosaic virus (SMV-BJ) has been cloned through technique of polymerase chain reaction (PCR). We have analyzed the nucleotide sequence of 3' region of SMV-BJ genome. Comparisons of the nucleotide and deduced amino acid sequence of SMV-BJ coat protein gene with those of SMV-N strain show 93.4% and 98.5% identity between them, respectively. Alignments of the 3' non-coding sequence in pairs with that of SMV-N strain show homology of 88.8%. It has been found that the SMV coat protein gene is expressed in E. coli by western blot analysis. The coat protein produced in E. coli has the same electrophoretic mobility as the authentic coat protein.

Amino Acid Sequence↗
PubMed1993

Insect tolerance of transgenic Populus nigra plants transformed with Bacillus thuringiensis toxin gene.

Leaves and stem segments of Populus nigra were transformed with A. tumefaciens LBA4404 harboring a binary vector containing chimeric genes of NPT and 35S-omega-B.t. toxin-Nos. Nineteen regenerated kanamycin resistant plants were analyzed by DNA hybridization, out of which 10 were shown to be the candidates of transgenic plants. Insect tolerance tests showed that the transgenic plants were toxic to two lepidopteran pests, Lymantria dispar L. and Apocheimia cinerarius Erschoff. Based on the results of Southern blot of PCR products and the cluster analysis of their growth and insect resistance, three independent transgenic plants were selected, which were then propagated in the nursery field. This field test is currently in progress.

Agrobacterium tumefaciens↗
PubMed1993

[Nucleotide sequence of the toxic domain of an insecticidal protein gene from B. thuringiensis subsp. kurstaki HD-1].

Two crystal protein genes, the 5.3kb and 6.6kb class respectively, from Bacillus thuringiensis subsp. kurstaki HD-1 (B. t HD-1) had been cloned previously. Based on the classification system of Hofte and Whiteley, these two genes should belong to Cry I A (b) and Cry I A (c) gene type respectively. The nucleotide sequence of the toxic domain of this Cry I A (c) gene from B. t kurstaki HD-1 is firstly reported here and compared with that of Cry I A (c) gene from B. t HD-73 and Cry I A (b) gene from B. t HD-1.

Amino Acid Sequence↗
PubMed1990

Nitroglycerin has more favourable effects on left ventricular afterload than apparent from measurement of pressure in a peripheral artery.

Nitroglycerin (0.3 mg) was administered sublingually to 14 patients undergoing cardiac catheterization, and pressure waves compared in the ascending aorta and brachial artery. After nitroglycerin, ascending aortic systolic pressure fell in all cases (by 6-44, average 22 mmHg) whereas brachial systolic pressure remained unchanged (in three) or fell to a lesser degree (4-33, average 12 mmHg). Diastolic pressure did not change significantly. Alterations in pressure and in wave contour were explained on the basis of arterial dilation, with reduction in wave reflection. Nitroglycerin reduces left ventricular afterload through arterial dilation as well as preload through venous dilation. This effect on afterload is not apparent from measurement of pressure in the brachial artery.

Administration, Sublingual↗