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1.
A cDNA fragment encoding cystatin, a cysteine protease inhibitor, was obtained from maturing sesame seeds. The clone was constructed in a nonfusion or fusion vector and then overexpressed in Escherichia coli. The recombinant cystatins were found in the soluble fraction of cell extract and were demonstrated to be functionally active in a reverse zymographic assay. The corresponding endogenous 22 kDa cystatin of low abundance in mature seeds was purified to homogeneity via a papain-coupling affinity column and confirmed by western blotting with antibodies against the recombinant cystatin. Both endogenous and recombinant cystatin proteins showed effective inhibitory activities against papain with K(i) values of 7.89 x 10(-8) M and 2.77 x 10(-8) M, respectively. Immunodetection indicated that cystatin was specifically expressed in maturing seeds and rapidly degraded in germination. Accordingly, zymographic and inhibition analyses showed that sesame cystatin could not inhibit the de novo synthesized proteases in germinating seeds. It is suggested that sesame cystatin may play a role in the regulation of endogenous cysteine proteases during seed maturation and germination.  相似文献   
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 水稻病毒病抗性育种工作在国外已进行了十余年,取得了显著成效,但对病毒致病力的分化问题却研究得不多。  相似文献   
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The objective of this study was to improve the reproductive efficiency of dairy cows with puerperal metritis (PM) subsequent to retained placenta (RP) using a two-step treatment strategy. A total of 188 postpartum cows, aged from 2 to 8 years, were utilised for 2 experiments. In Experiment 1, cows affected with RP/PM were randomly assigned to two treatment groups. Cows in Group A (n = 17) were treated with 600 mg of ceftiofur intramuscularly for 3 days followed by intrauterine lavage with 0.1% chlorhexidine and infusion with 0.5% povidoneiodine, while cows in Group B (n = 16) received two intrauterine infusions, first with 5 g of oxytetracycline and then with 0.5% povidone-iodine. Cows with normal postpartum findings were regarded as the healthy control group (n = 26). Ultrasonographic examination revealed that the ovarian activities including the appearance of a dominant follicle and days to first ovulation of the cows in Group A during the early postpartum period differed from those of Group B (P < 0.05), which coincided with the results of uterine swabbing for bacteriology. In Experiment 2, cows with normal postpartum findings were allocated to Group D (n = 78), which received an ovulation protocol (GnRH - 7 d PGF2α - 48 h hCG - 24 h AI) on day 50 ± 2 postpartum. Cows affected with PM were randomly divided into two groups, Group E (n = 25) combined the treatments applied in Groups A and D, while Group F (n = 26) repeated the treatment administered in Group E except for uterine lavage. The results indicated that the pregnancy rate within 150 days postpartum and the mean days open in Group E (76.0% and 106.3 ± 4.6 days, respectively) were significantly different from those in Group F (38.5% and 137.9 ± 10.9 days, respectively) (P < 0.05). This study suggests that reproductive efficiency could be improved by using the two-step treatment to regulate uterine involution and an early resumption of ovarian function in cows with RP/PM.  相似文献   
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An ocular Thelazia callipaeda infestation was found in a male domestic dog in Taiwan during regular examination. This is the first report of the parasite from pet animal in Taiwan. The infested dog showed normal bodily condition but slight conjunctival congestion. This parasite has been reported in humans in southeast Asia, China and Korea. In 1998, first human case was reported in the central area of Taiwan. The dogs infected with T. callipaeda may have important implication in the infestation of this parasite to humans as reservoir hosts.  相似文献   
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OBJECTIVE: To determine the antibacterial activity of bovine lactoferrin hydrolysate (bLf-lysate) alone or in combination with other antimicrobials against antimicrobial-resistant Escherichia coli strains isolated from baby pigs. SAMPLE POPULATION: 3 clinical strains of E coli were isolated from baby pigs with severe diarrhea and designated as strains 9061, 9062, and 9065. PROCEDURE: The broth microdilution checkerboard and fractional inhibitory (or bactericidal) concentration index were used to evaluate the antibacterial effect elicited by bLf-lysate in combination with kanamycin, gentamicin, cephalothin, cefamandole, penicillin G, ampicillin, tetracycline, erythromycin, or rifampicin against the 3 strains of E coli. RESULTS: The 3 strains of E coli were susceptible to gentamicin and rifampicin but highly resistant to most of the other antimicrobials tested, except for strain 9061 that was also susceptible to cephalothin but intermediately inhibited by kanamycin and cefamandole. Synergistic growth-inhibitory activity was observed between bLf-lysate and gentamicin against 1 strain of E coli (strain 9062); synergistic bactericidal activity was found between bLf-lysate and rifampicin against all 3 strains of E coli. Moreover, partial synergy was observed between bLf-lysate and kanamycin, gentamicin, cephalothin, or cefamandole against the strains of E coli, but this partial synergistic activity was mostly seen against only 1 of the strains. Little interaction between bLf-lysate and tetracycline, ampicillin, penicillin G, or erythromycin was observed against the clinical strains of E coli. CONCLUSIONS AND CLINICAL RELEVANCE: A combination of bLf-lysate and certain antimicrobials may prove clinically effective against antimicrobial-resistant strains of E coli.  相似文献   
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Antibacterial activity of short hydrophobic and basic-rich peptides   总被引:2,自引:0,他引:2  
OBJECTIVE-To design short and potent analogs of bovine lactoferricin by use of the concepts of lipophilic bulk and cationic charge. SAMPLE POPULATION-5 synthetic peptides of bovine lactoferricin. PROCEDURE: Antibacterial peptides were constructed by synthesizing several decapeptides rich in arginine and tryptophan. Basic residues of bovine lactoferricin (bLf 20-29; residues 20 to 29) were modified by substitution with arginine or lysine and nonbasic residues were modified by substitution with tryptophan, phenylalanine, or isoleucine. Synthetic peptides of bovine lactoferrin (LFB) were designated as LFB-RW (RRWWWRWRRW), LFB-KW (KKWWWKWKKW), LFB-RWa (RRWWRRWRRW), LFB-RF (RRFFFRFRRF), and LFB-RI (RRIIIRWRRI), where R, K, W, F, and I stand for arginine, lysine, tryptophan, phenylalanine, and isoleucine, respectively. Peptides were evaluated by determining their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against Escherichia coli, Staphylococcus aureus, and Enterococcus faecalis. RESULTS: LFB-RW, LFB-KW, and LFB-RWa possessed equivalent potency as bLf 20-29 against E coli. LFB-RW and LFB-RWa had a 2-fold increase in growth-inhibitory and bactericidal activity against S aureus, compared with bLf 20-29. LFB-RI had the lowest MIC value against E coli among the peptides but lost bactericidal activity. LFB-RW and LFB-KW had stronger bactericidal activities against S aureus or E faecalis, respectively, as well as E coli than the other synthetic peptides. LFB-RF also had antibacterial activity, but this was 2-fold less than that of LFB-RW, as determined by MIC and MBC values. CONCLUSIONS AND CLINICAL RELEVANCE: In construction of potent antibacterial peptides, inclusion of arginine, lysine, tryptophan, or isoleucine residues enhances effectiveness against certain bacteria, as measured by MIC or MBC values.  相似文献   
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Bioactive benefits of resveratrol in the diets have attracted extensive interests of the public. Peanut is one of the potent natural sources of resveratrol. In this study, germination of peanut kernels to enhance resveratrol biosynthesis and preparation of sprouts as a functional vegetable was conducted. When the rehydrated kernels of three peanut cultivars were germinated at 25 degrees C and relative humidity 95% in dark for 9 days, resveratrol contents increased significantly from the range of 2.3 to 4.5 microg/g up to the range of 11.7 to 25.7 mug/g depending upon peanut cultivar. In comparison with the sprout components, resveratrol contents were highest in the cotyledons, slightly lower in the roots, and not detected in the stems. When the sprouts were heated in boiling water for 2 min, resveratrol contents varied in a limited range. Methanol extracts of the freeze-dried sprouts exhibited potent 1,1-diphenyl-2-picryl-hydrazyl scavenging activity and antioxidative potency against linoleic acid oxidation. These activities increased with an increase of germination time. After 9 days of germination, total free amino acid, sucrose, and glucose contents increased significantly while crude protein contents decreased and the large sodium dodecyl sulfate polyacrylamide gel electrophoresis protein molecules of the kernels were extensively degraded. From a practical viewpoint, it is of potency to prepare peanut sprouts as a functional vegetable.  相似文献   
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Early differential diagnosis and timely follow‐up are advantageous in the management of Angiostrongylus cantonensis infection. This study aimed to characterize angiostrongyliasis in the rat brain for an 8‐week period using magnetic resonance imaging (MRI) with contrast‐enhanced T1‐weighted images (T1WI), T2‐weighted imaging (T2WI), fluid attenuation inversion recovery (FLAIR) and R2 mapping sequences. The data were analysed with Mathematica and Matlab software programs for weekly changes in each brain following the infection of 20, 50, 100 and 300 third‐stage larvae (L3), respectively. The results showed that the average subarachnoid space detected by T2WI technique was peaked up to 10% increase of original size on day 35 after 100 or 300 larvae infection, while those infected with 20 or 50 larvae showed less than 4% increase during the entire course of observation. This increase was relevant to the mortality of the infected rats, because those with 100 or 300 larvae infections showed a sharp decrease in survival rate before day 40. After day 40, the average subarachnoid space was decreased, but the average ventricle size was persistently increased, with the highest increase observed in the group infected with 300 larvae on day 56. Furthermore, the R2 mapping mean and R2 mapping size were significantly different between the brains with severe infection (100 and 300 larvae groups together) and those with mild infection (20 and 50 larvae groups together) on day 49, but not on day 35. Our results showed that diagnosis for different quantity of larvae infection using MRI is possible and follow‐up characterization is informative in revealing the effects of angiostrongyliasis on different brain areas. In conclusion, our results support the use of MRI as a non‐invasive diagnostic technique for eosinophilic meningitis caused by A. cantonensis infection.  相似文献   
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