1. The effects of dietary penicillin on the urease activities of small intestine, large intestine, caecum and their contents, liver and kidney in chickens fed a diet containing 5 g/kg protein plus urea were examined.
2. About 0.88 of the total urease activity determined was observed in intestinal contents, of which 0.95 of the activity was accounted for by caecal contents, 0.05 by colo‐rectal contents and none by small intestinal contents. Intestinal tissues (caecum included), liver and kidney accounted for 0.03, 0.06 and 0.02, respectively, of the total urease activity.
3. Dietary penicillin decreased urease activity to 0.17 in caecal contents and to 0.05 in colo‐rectal contents of the corresponding control values (P< 0.01). The urease activity of caecal tissue was lowered by penicillin to half that of control activity (P < 0.05) but none of the activities of other tissues were affected.
4. It is concluded that, even when the urease activity is stimulated by dietary urea, 20 mg/kg dietary penicillin can strikingly lower it in the caecum, where most of the urease activity in the chicken body is to be found. 相似文献
A 6-month-old barrow presented with lethargy, inappetence and dysstasia. At necropsy, multiple coalescing hemorrhagic foci were detected in the margins of the spleen. Gram-positive bacilli were isolated from the spleen, kidney, muscle and liver. Comparative 16S rDNA gene sequencing analysis of the isolates (TO16177) revealed that they would be the same species of unpublished Arcanobacterium species strain HJ57-14E (accession no. gi 18873551) (99.7% similarity based on a comparison of 675 bp). Histologic examination of the splenic tissue sections revealed extensive necrosis and inflammation, and gram-positive bacilli were discernible. Multifocal necrosis was also detected in the liver. Immunohistochemically, the isolates were cross-reacted with polyclonal antibodies against Arcanobacterium pyogenes and Actinomyces naeslundii, and the reaction was strong for the latter. Similar reactions were found in the suppurative lesions of the tonsil, and occasionally in the spleen and lymph nodes. The present results indicate that the unpublished Arcanobacterium species induced multiple organ failure accompanied by acute hemorrhagic necrotizing splenitis in this growing-finishing pig. 相似文献
Trials over two years were conducted using 1389 sweetpotato (Ipomoea batatas L.) genotypes collected from all over the world to characterize the polyphenolic composition in sweetpotato leaves. Wide variation was observed in relation to their total and individual leaf polyphenolic constituents. In all genotypes studied, the total polyphenol contents of sweetpotato leaf ranged from 1.42 to 17.1 g/100 g dry weight. The six different polyphenolic compounds were identified and quantified by NMR, FABMS, and RPHPLC analysis procedures. This is the first report of polyphenolic compositions in sweetpotato leaves. The relative levels of polyphenolic acids in sweetpotato leaves were as follows: 3,5-di-O-caffeoylquinic acid > 4,5-di-O-caffeoylquinic acid > chlorogenic acid (3-O-caffeoylquinic acid) > 3,4-di-O-caffeoylquinic acid > 3,4,5-tri-O-caffeoylquinic acid > caffeic acid. The highest 3,4,5-tri-O-caffeoylquinic acid and 4,5-di-O-caffeoylquinic acid occurred at 221 and 1183.30 mg/100 g dry weight, respectively. 相似文献
We examined morphological modifications among oribatid species in five microhabitats in mangrove forests in the Ryukyu Islands of Japan. A total of 89 oribatid species were recorded from canopy (leaves and branches), bark of flooded trunks (trunks of 0–50 cm high and knee roots), bark of other trunks higher than 50 cm, and littoral algae in mangrove forests, and the forest-floor soil in an adjacent bank forest. There were no significant differences in the body length, body width, and notogastral length among oribatid species from the five microhabitats. The mean sensillus length of the oribatid species from the forest-floor soil was about twice as long as that from the other microhabitats. Claw morphology was characterized by two attributes: number (monodactyly and tridactyly) and length. In the canopy and trunks, the proportion of tridactyl species was higher than that of monodactyl species. On the other hand, the proportion of tridactyl species in the forest-floor soil accounted for only about 20%, and that in the flooded trunks and littoral algae approximated to zero. The mean claw length was larger in the oribatid species from the flooded trunks and littoral algae than in both monodactyl and tridactyl species from every other microhabitat. Trydactyl species with short claws in the arboreal environments might have been selected by a compromise between grip and mobility for unpredictable environmental changes such as wind and rain. The dominance of monodactyl species with a longer claw in the littoral environments implies a consequence of selection for regular tidal flooding, which requires oribatids to grip tighter on the substrate. The modifications in claw morphology of oribatid mites in mangrove forest might be interpreted as adaptations to a difference in the predictability of the environmental conditions of microhabitats. 相似文献
The effects of the preceding crops, sunflower (mycorrhizal host) and mustard (nonhost), on arbuscular mycorrhizal (AM) colonization and growth of succeeding maize were examined in 17 soils in an attempt to clarify the influence of soil characteristics on the effects of preceding crops. Shoot weight and P uptake of maize planted after sunflower were much higher than those after mustard in 14 soils, although the preceding crop had little effect on soil-P availability. AM colonization of maize after sunflower was much higher than that after mustard. The effect of the preceding crop was eliminated by soil sterilization. These results suggested that the differences in maize growth were caused by differences in the AM colonization. Correlation analysis of the effect of the preceding crop and soil properties showed that the difference in the effects on maize growth could not be explained by soil chemical properties, but only by the AM colonization of the preceding sunflower crop. In one of the 17 soils, however, the effect was not evident despite the higher AM colonization of sunflower. This soil was sterilized, and the effect of inoculation by AM fungi (AMF) on maize was examined. However, it was found that the inoculation increased AM colonization but did not improve maize growth at any P level, suggesting that the effect of AMF was unusually inhibited in this soil by unknown soil physicochemical properties. In most soils, however, the preceding mycorrhizal host crop, sunflower, improved the growth and AM colonization of maize depending on the AM colonization of sunflower. 相似文献
(+)-Catechin derivatives with different alkyl chain lengths were synthesized from (+)-catechin and various straight chain alkylaldehydes in the presence of methyl mercaptan, and their antibacterial activities against Gram-positive bacteria were evaluated. The antibacterial activity increased markedly with elongation of the alkyl chain lengths of the derivatives and reached a maximum at a chain of four to seven carbons. Subsequently, interaction of the (+)-catechin derivatives with a model membrane using liposome was investigated. The derivatives with a chain of three carbons or more were found to have very strong affinity for the membrane. The injury action of the derivatives against the membrane was examined with liposome in which calcein was enclosed as a fluorescent indicator. The leakage was observed in the derivatives with chain lengths of four carbons or more. Particularly the derivatives with chains longer than five carbons are considered to destroy the liposome membrane judging from the degree of the fluorescent leakage. These results implied that the lipophilicity and disrupting ability of the (+)-catechin derivatives to the liposome membrane participate in their antibacterial activity. 相似文献
1. Measurements were made in situ to determine the occurrence of intraportally infused urea-15N in ureteral urine of the fowl. 2. Of the total amount of infused urea-15N, 15% was excreted intact into the urine (90% of urinary total 15N) whereas 9% remained unchanged in the blood (78% of blood non-protein-15N). 3. The proportions of non-protein-15N in the blood, liver and kidney were 12, 3 and 1%, respectively of the infused 15N. Protein-15N was 3% of that infused in blood and much less in liver and kidney. 4. About 1% of the infused 15N was observed in the urinary uric acid, and 3% of the infused 15N in non-protein N, other than urea, ammonia and glutamine amide N, of blood and liver. 5. No appreciable amounts of 15N were present in ammonia and glutamine amide N of blood, liver or kidney and in uric acid of liver or kidney. 6. The caecal contents contained about 1% of the infused 15N with 15% of this as ammonia-15N. 7. It is concluded that intraportal urea is mostly excreted unchanged into ureteral urine of the fowl. 相似文献
As the first step in investigating the possiblity of applying ribozyme technology to artificial control of the sex ratios at birth in farm animals, where the demand for females exceeds that for males, we designed a hammerhead ribozyme (HHRz) and 2 tRNA(val)-hammerhead ribozyme complexes (tRNARz3 and tRNARz4), and examined their effects upon murine Sry mRNA in vitro and in cells. We demonstrated that HHRz and tRNARz3 could effectively cleave the target Sry mRNA in vitro. For the purpose of experiments in vivo, HHRz was cloned into the highly efficient pUC-CAGGS mammalian expression vector (pCAG/HHRz), and the tRNA ribozyme complexes were cloned into the pol III promoter-driven pPUR-KE vector (pPUR/tRNARz3 and pPUR/tRNARz4); the ribozyme vectors were co-transfected with the target vector (pCAG/Sry). A suppressive action (up to approx. 60%) was confirmed for pCAG/HHRz and pPUR/tRNARz3 upon the transiently expressed exogenously introduced Sry in M15 cultured cells. 相似文献
The anthocyanin composition and antioxidant activity of the crowberry ( Empetrum nigrum) were studied. High-performance liquid chromatography (HPLC) combined with a diode array detector and electrospray ionization mass spectrometry were used for identification and quantification of individual anthocyanins. Freeze-dried crowberry powder was extracted with 80% methanol containing 0.5% acetic acid and subjected to HPLC. Thirteen kinds of anthocyanins were identified. The major anthocyanins were cyanidin-3-galactoside and delphinidin-3-galactoside, at 8.04 and 8.62 mg/g extract, respectively. The HPLC profile of crowberry extract was similar to bilberry and blueberry. The total content of anthocyanins in crowberry was 41.8 mg/g extract, higher than the other nine major berry species (2.5-38.8 mg/g extract). The antioxidant activity was also evaluated using the 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azinobis(3-ethybenzothiazoline-6-sulfonic acid) radical quenching assays and the ferric reducing activity power assy. Crowberry extract exerted the strongest antioxidant activity. In conclusion, individual anthocyanins in crowberry were identified and then quantified in this study. Additionally, crowberry is suggested to be associated with a reduction in the risk of developing chronic diseases because of its strong antioxidant activity. 相似文献