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1.
2.
A novel ompC mutation of Escherichia coli K-12 that reduces OmpC and OmpF levels in the outer membrane 总被引:1,自引:0,他引:1
Rajeev Misra 《Molecular microbiology》1993,10(5):1029-1035
3.
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Heinz W. Kunz Andrea L. Cortese Hassett Tetsuo Inomata D. N. Misra Thomas J. Gill III 《Immunogenetics》1989,30(3):181-187
A new antigenic system in the rat homologous to theQa/TL antigen system in the mouse has been characterized. It was detected by antibodies raised in donor-recipient combinations
that were matched for theRT1. A, B, D, E loci in the major histocompatibility complex (MHC): (R11×BN)F1 anti-BN.1L(LEW), (R18×BN)F1 anti-BN.1L, and BN.1LV1(F344) anti-BN.1L. Absorption analyses using these antisera and a variety of inbred, congenic and
recombinant strains identified three alleles,RT1.G
a
,G
b
,G
c
, of whichG
c
is a null allele. The strain distribution of these alleles was determined, using 37 strains of rats representative of all
of the prototypic haplotypes and a number of congenic and recombinant strains. The use of the congenic and recombinant strains
showed that theRT1.G locus was linked to the MHC and that the most probable gene order wasA-E-G. Testcross analysis showed that the map distance betweenA andG was 1.4 cM(4/285 recombinants). The RT1.G antigen has a heavy chain ofM
r 46 000 and is present on both T and B cells. 相似文献
5.
Effect of anti-mosquito antibodies on the infectivity of the rodent malaria parasite Plasmodium berghei to Anopheles farauti 总被引:3,自引:0,他引:3
The effect of mouse anti-mosquito antibodies, present in the bloodmeal, on the infectivity of Plasmodium berghei Vincke to Anopheles farauti Laveran was investigated. Significantly fewer oocysts developed in mosquitoes feeding on mice immunized with sugar-fed mosquito midgut antigens than in mosquitoes feeding on control mice. Mosquitoes feeding on mice immunized with the midgut antigens derived from sugar-fed mosquitoes also showed reduced mortality and had lower infection rates than those fed on unimmunized mice. Blood-fed midgut antigen was less effective in producing these effects than sugar-fed midgut antigen. 相似文献
6.
Sujata Misra Kshudiram Naskar Dwijen Sarkar Dilip Kumar Ghosh 《Molecular and cellular biochemistry》1991,102(1):13-18
Summary
Leishmania donovani, the etiological agent for the disease visceral leishmaniasis, attach themselves to the macrophages for initiation of the disease. The attachment process has been found to be regulated by Ca2+ ions. Verapamil, a Ca2+-channel blocker inhibits Leishmania-macrophage attachment. The inhibitory effect is increased with time. Nifedipine, another Ca2+-channel blocker exhibits the same effect. The attachment process is stimulated by Ca2+-ionophore alone. The inhibitory effects of the calcium channel blockers are reversed by the ionophore. 相似文献
7.
Cloning and DNA sequence of a plasmid-determined citrate utilization system in Escherichia coli. 总被引:13,自引:5,他引:8 下载免费PDF全文
The citrate utilization determinant from a large 200-kilobase (kb) naturally occurring plasmid was previously cloned into the PstI site of plasmid vector pBR325 creating the Cit+ tetracycline resistance plasmid pWR61 (15 kb). Tn5 insertion mutagenesis analysis of plasmid pWR61 limited the segment responsible for citrate utilization to a 4.8-kb region bordered by EcoRI and PstI restriction nuclease sites. The 4.8-kb fragment was cloned into phage M13, and the DNA sequence was determined by the dideoxyribonucleotide method. Within this sequence was a 1,296-base-pair open reading frame with a preceding ribosomal binding site. The 431-amino-acid polypeptide that could be translated from this open reading frame would be highly hydrophobic. A second long open reading frame with the potential of encoding a 379-amino-acid polypeptide preceded the larger open reading frame. Portions of the 4.8-kb fragment were further subcloned with restriction endonucleases BglII and BamHI, reducing the minimum size needed for a citrate-positive phenotype to a 1.9-kb BamHI-BglII fragment (which includes the coding region for the 431-amino-acid polypeptide, but only the distal 2/3 of the reading frame for the 379-amino-acid polypeptide). Citrate utilization results from a citrate transport activity encoded by the plasmid. With the 4.8-kb fragment (as with larger fragments) the citrate transport activity was inducible by growth on citrate. On transfer from glucose, succinate, malate, or glycerol medium to citrate medium, the Cit+ Escherichia coli strains showed a delay of 36 to 48 h before growth. 相似文献
8.
Ferdinand Bohlmann Cornelius Scheidges Laxmi N. Misra Jasmin Jakupovic 《Phytochemistry》1984,23(8):1795-1798
The investigation of three South African Vernonia species afforded minute amounts of five new glaucolides, two monoepoxides and three diepoxides. The structures were elucidated by 1H NMR spectroscopy. The roots of Vernonia sutherlandii contain, in addition to vernonataloide, bergamotene and santalene, minute amounts of the corresponding acetoxy derivatives. 相似文献
9.
Improved synthesis of oligodeoxyribonucleotide using 3-methoxy-4-phenoxybenzoyl group for amino protection. 总被引:1,自引:1,他引:0 下载免费PDF全文
3-Methoxy-4-phenoxybenzoyl group has been used for the protection of exocyclic amino group of nucleosides. In case of 2'-deoxycytidine it has been found to be highly selective under controlled conditions. The N-protected derivatives of 2'-deoxyadenosine and 2'-deoxyguanosine have been found to be sufficiently stable towards acids minimising depurination under conditions of synthesis of oligodeoxyribonucleotide on solid support via phosphotriester approach. The high lipophilicity of the group and milder deprotection conditions are additional advantages. 相似文献
10.