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81.
Serum samples of Meishan (13 animals) and Meishan x Wild Boar crosses (361 animals) were analysed by means of two-dimensional electrophoresis. Some new variants in protease inhibitor systems PO1A, PO1B and PI2 are reported. 相似文献
82.
S. Kleinle U. Wiesmann A. Superti-Furga S. Krähenbühl E. Boltshauser J. Reichen S. Liechti-Gallati 《Human genetics》1997,100(5-6):643-650
We used a strategy based on long PCR (polymerase chain reaction) for detection and characterization of mitochondrial DNA (mtDNA)
rearrangements in two patients with clinical signs suggesting Pearson syndrome and Kearns-Sayre syndrome (KSS), respectively,
and one patient with myopathic symptoms of unidentified origin. Mitochondrial DNA rearrangements were detected by amplification
of the complete mitochondrial genome (16.6 kb) using long PCR with primers located in essential regions of the mitochondrial
genome and quantified by three-primer PCR. Long PCR with deletion-specific primers was used for identification and quantitative
estimation of the different forms of rearranged molecules, such as deletions and duplications. We detected significant amounts
of a common 7.4-kb deletion flanked by a 12-bp direct repeat in all tissues tested from the patient with Pearson syndrome.
In skeletal muscle from the patient with clinical signs of KSS we found significant amounts of a novel 3.7-kb rearrangement
flanked by a 4-bp inverted repeat that was present in the form of deletions as well as duplications. In the patient suffering
from myopathic symptoms of unidentified origin we did not detect rearranged mtDNA in blood but found low levels of two rearranged
mtDNA populations in skeletal muscle, a previously described 7-kb deletion flanked by a 7-bp direct repeat and a novel 6.6-kb
deletion with no repeat. These two populations, however, were unlikely to be the cause of the myopathic symptoms as they were
present at low levels (10–40 ppm). Using a strategy based on screening with long PCR we were able to detect and characterize
high as well as low levels of mtDNA rearrangements in three patients.
Received: 10 March 1997 / Accepted: 20 May 1997 相似文献
83.
J.-Y. Roh H.-W. Park Y.-H. Je D.-W. Lee B.-R. Jin H.-W. Oh S. S. Gill & S.-K. Kang 《Letters in applied microbiology》1997,24(6):451-454
Bacillus thuringiensis NTB-1 isolated from soil samples in Korea produces ovoidal parasporal inclusions with proteins of approximately 24–40 kDa in size. Although serological study indicated that the isolate has a flagella (H) antigen identical with subsp. israelensis , it seemed to be non-insecticidal against Lepidoptera and Coleoptera as well as Diptera. To investigate the activity of non-insecticidal B. thuringiensis transformed with insecticidal crystal protein genes, cryIVD and cytA genes of B. thuringiensis subsp. morrisoni PG-14, highly toxic to mosquito larvae, were introduced into the isolate NTB-1. The expression of mosquitocidal crystal protein genes in NTB-1 was characterized by SDS–PAGE analysis and electron microscopy. The results showed that crystalline inclusions of host, CryIVD and CytA were stably expressed in the transformant. However, the mosquitocidal activity of transformant was similar to that of B. thuringiensis subsp. kurstaki Cry− B harbouring cryIVD and cytA genes, demonstrating that a synergistic effect by an interaction of both introduced insecticidal and resident non-insecticidal crystal proteins was not observed. 相似文献
84.
A. Ugolini B. Tiribilli C. Castellini 《Journal of comparative physiology. A, Neuroethology, sensory, neural, and behavioral physiology》1997,182(1):43-50
Experiments on compass orientation under artificial light were conducted with adult individuals of Talitrus saltator. The aim was to reproduce in the laboratory an orientation based on the sun compass corresponding to that recorded in conditions
of the true sun and sky. This was obtained by the creation within an opaque Plexiglas dome of a scenario that permitted variation
of the brightness of the artificial sky and sun. The results show that it is possible to obtain sun compass orientation corresponding
to the natural situation even in an artificial environment. It can be concluded that sandhoppers identify an artificial light
source as the sun if the artificial sky is also illuminated and if the intensities of the artificial sun and sky exceed certain
threshold values (1.13 and 10 μW cm−2, respectively). The results of other experiments under the natural blue sky with an artificial sun and with the real sun
attenuated are discussed.
Accepted: 23 May 1997 相似文献
85.
A dot-ELISA technique for the detection of Pseudomonas protease was developedusing IgG of anti- Pseudomonas AFT-36 protease as capture antibody. The detection limitof protease in buffer or milk was 1·01 ng ml−1 . The procedure was performedat room temperature, took about 2·5 h and was economical. Protease AFT-36 isimmunologically related to five out of seven Pseudomonas spp. The results suggest thatthe assay could be used to detect proteases in dairy products. 相似文献
86.
Eighty-five catalase- and oxidase-positive Gram-negative rods and cocci susceptible to penicillin G were isolated from a variety of food sources. The phenotypic relationships of these isolates with reference cultures of Bergeyella -like, Chryseobacterium, Empedobacter, Myroides , Moraxella , Sphingobacterium and Weeksella -like strains were examined by numerical taxonomy. Seventy-three isolates were recovered in five groups; 80% of the isolates clustered in groups 1, 2 and 3 and produced indole, bearing a strong resemblance to Weeksella and Bergeyella . They could not, however, be regarded as belonging to the known species of W. virosa and B. zoohelcum . It is suggested that three species may be necessary to accommodate the environmental Weeksella - or Bergeyella -like bacteria. The isolates in groups 4 and 5 had white colonies and were unable to produce indole, in this way resembling the Moraxella genus. 相似文献
87.
Spectrophotometric quantification of lactic bacteria in alginate and control of cell release with chitosan coating 总被引:3,自引:0,他引:3
Y. Zhou E. Martins A. Groboillot C. P. Champagne & R. J. Neufeld 《Journal of applied microbiology》1998,84(3):342-348
Lactococcus lactis ssp. cremoris was entrapped within a Ca-alginate matrix, and an in situ spectrophotometric method for monitoring cell population in calcium alginate beads described. The intracapsular cell population can be estimated by measuring the optical density of beads containing cells, using cell-free beads as reference, or by measuring absorbance of a liquified bead suspension. Alginate beads, and beads coated with chitosan type I, II, and I and II mixtures, were examined for cell release. Lower viscosity chitosan (type I) coatings reduced cell release by a factor of 100 from105 cfu ml−1 to 103 cfu ml−1 after 6 h of fermentation. Reuse of chitosan I coated alginate beads also showed a reduction in cell release by a factor of 100. Cell loading and initial cell growth within the beads greatly affected cell release. Reducing the initial cell release would lower the overall levels of cell release throughout the fermentation. Compared to non-immobilized cultures, a 20–40% reduction in the lactic acid production rate was observed for alginate beads and chitosan I coated alginate beads, respectively. This reduction can be compensated for by increasing the intracapsular cell loading during immobilization, or before the onset of fermentation. 相似文献
88.
89.
90.
Metmyoglobin promotes arachidonic acid peroxidation at acid pH 总被引:1,自引:0,他引:1
The ability of metmyoglobin and other heme proteins to promote peroxidation of arachidonic acid under acidic conditions was investigated. Incubation of metmyoglobin with arachidonic acid resulted in a pH-dependent increase in lipid peroxidation as measured by the formation of thiobarbituric acid reactive products and oxygen consumption. Increased peroxidation was observed at pH levels below 6.0, reaching a plateau between pH 5.5 and 5.0. At comparable heme concentrations, metmyoglobin was more efficient than oxymyoglobin, methemoglobin, or ferricytochrome c in promoting arachidonic acid peroxidation. Metmyoglobin also promoted peroxidation of 1-palmityl-2-arachidonyl phosphatidylcholine and methylarachidonate but at significantly lower rates than arachidonic acid. Addition of fatty acid-free albumin inhibited arachidonic acid peroxidation in a molar ratio of 6 to 1 (arachidonic acid:albumin). Both ionic and non-ionic detergents inhibited metmyoglobin-dependent arachidonic acid peroxidation under acidic conditions. The anti-oxidants butylated hydroxytoluene and nordihydroguaiaretic acid and low molecular weight compounds with reduced sulfhydryl groups inhibited the reaction. However, mannitol, benzoic acid, and deferoxamine were without significant effect. Visible absorption spectra of metmyoglobin following reaction with arachidonic acid showed minimal changes consistent with a low level of degradation of the heme protein during the reaction. These observations support the hypothesis that metmyoglobin and other heme proteins can promote significant peroxidation of unsaturated fatty acids under conditions of mildly acidic pH such as may occur at sites of inflammation and during myocardial ischemia and reperfusion. This may be the result of enhanced aggregation of the fatty acid and/or interaction of the fatty acid with heme under acidic conditions. 相似文献