Biomedical subjects
Publications and source records attributed to Y Fan.
Two recombinant plasmid pFZ1 and pFZ2 containing Bti 130kDa mosquitocidal protein gene in opposite insertion orientation were constructed. The expression of 130kDa mosquitocidal protein of Bti in Bacillus subtilis was confirmed by western blotting. The mosquito-larvicidal activity against the larvae of Aedes albopictus was shown by the bioassay.
Field experiments on integrated control of pests injuring Chinese hawthorn by some nonpollution techniques including agricultural biological and physical methods, were carried out in Xinglong County, Hebei Province during 1989-1991. Satisfactory results were obtained. Compared with synthetic pesticides, the new techniques improve the control effect by 30%-60% generally, increase the number of natural enemies by 51.26%-68.51%, and enhance the yield by 47.58%. The test shows that the hawthorns from the field treated by the new techniques are either free of pesticide residual or with a residual 500-1000 times less than the residual standard fixed by FAO/WHO or the state.
The recombinant plasmid pBHGA was constructed by ligating plasmid pHTA1030 from B. thuringiensis to plasmid pJH101 from E. coli. The recombinant plasmid pBHGA was digested and deleted by various restriction enzymes, generating 14 derived recombinant plasmids differing in molecular weight. The expressible analysis for the plasmid pBHG1 from among the derived plasmids in E. coli HB101 and B. subtilis 168, the results proved the recombinant plasmid pBHG1 is carring promotive region, original region and segregational stability region of B. thuringiensis plasmid pHTA1030. The recombinant plasmid pBHG1 can be high frequency transformation in to B. thuringiensis HD-1 Cry- B and high-expression in B. thuringiensis. HD-1 Cry- B. The plasmid pBHG1 is segregational stability in B. subtilis 168 at 45 degrees C. These plasmids may be useful tools for study of plasmid replication and expression in B. thuringiensis once a reproducible transformation system is available for this organism.
The regulative region (181bp) and the fifth toxic active domain (217bp) were removed from the insecticidal protein gene of Bacillus thuringiensis var. aizawai 7-29. After the synthesis of the adaptor (15bp) that contains initiation codon (ATG) and the PCR synthesis of the fifth toxic active domain (229bp) that contains stop codon (TAA), were inserted into on 5' truncated and 3' truncated of the coding fod N-terminal peptid's DNA fragment, that to become a modified structural gene. The modified structural gene can be play initiatic translation-function and stop translation-function during translation of insecticidal protein. The insecticidal protein was determined by western blotting, showed the expression of modified structural gene in Escherichia coli JM 103. The bioassay of insecticidal proteins showed the 3' truncated and 5' truncated of insecticidal gene was higher toxic active than the 3' truncated of insecticidal gene in Escherichia coli JM 103.
The location of 130kd mosquitocidal protein gene of Bti 4Q5 strain on its 75Md plasmid was confirmed by southern hybridization using a 18-base oligonucleotide probe. The crystal protein containing the component of 130kd toxic protein was purified. The crystal protein exhibiting the mosquitocidal activity against larvae of Aedes aegypti was shown by bioassay. The purified 75Md plasmid DNA of Bti 4Q5 strain was completely digested with HindIII restriction enzyme, ligated with the vector pUC18 and transformed into the recipient cells of E. coli TG1. From Apr transformants, four clones with HindIII restriction fragment inserts highly homologous to the 18-base oligonucleotide probe were obtained by in situ hybridization and southern hybridization. The 5.2kb HindIII restriction fragment insert was obtained in clone pFH2 and clone pFH4, and 2.3kb HindIII restriction fragment insert in clone pFH1 and pFH3. For pFH2 and pFH4, the 5.2kb fragment was inserted in pUC18 in opposite orientation. It contained 130kd mosquitocidal protein gene (type I) identified by restriction enzyme map analysis. The 2.3kb HindIII fragment insert in other two clones (pFH1 and pFH3) harbored a part of the type II mosquitocidal protein gene which can be used as a probe for cloning of the type II mosquitocidal protein gene.
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The nature of the first year of postgraduate medical education has gone through many changes over the years. Relatively recent changes have made this first year into a specialty-specific experience. Medical students are increasingly experiencing a narrowed and less broad-based clinical education. Many students, residents, and attending physicians complain that they wish they had had a "rotating" or "flexible" internship. Graduate medical education authorities have recently recommended that the internship year return to a broad-based general medical education experience. In 1989, the authors surveyed the entire physician faculty and housestaff at a large academic health sciences center, asking them what type of first postgraduate year (PGY-1) the physicians had experienced themselves and what type of PGY-1 they recommended for future graduating medical students. Over one-third strongly recommended that the PGY-1 should be broad-based and not specialty-specific.
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The authors report the establishment of a human myeloma cell line--KM-2R--and its preliminary use in human-human hybridoma research. KM-2R cells are resistant to both 6-TG and ouabain. Their doubling time is about 30 h. They have a modal chromosome number of 81-85. Using ELISA and immunodiffusion techniques, gamma-heavy and kappa-light chains were detected in the concentrated cell culture supernatant. KM-2R cells are sensitive to HAT medium. When fusing with normal human spleen cells, tonsil cells, and B lymphoblasts transformed by EB virus, fusion frequencies of 20-60% resulted.
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The result of our experiment has shown that by root-zone application of carbofuran in admixture with fertilizers to Areca in spring the serious pest Tirathaba rufivena can be controlled for 4 months during flowering and young fruiting stage and the yield can increase by 50%. The final residual amount of carbofuran in fruits is below 0.1-0.01 ppm or too low to be examined, and there is no decrease in total alkaloid content in fruits.
It is effective for acute and chronic laryngopharyngitis clinically. Houjianxi can raise the pain thresholds during hot-plate test in mice, tail flick test in rats, and writhing test in mice with single dose ig 0.125 to 2.0 g/kg. Houjianxi can also inhibit the swelling of hind paw induced by sc 1% carrageenin 0.1 ml in rats as well as the increased vascular permeability induced by ip 0.7% HAC in mice. Toxic side effects were not observed for Houjianxi ig 48 g/kg x 3 within a day in mice and 1.8 g/kg daily for 90 d in rats.
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