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钟淑梅 《中国兽医寄生虫病》2000,8(3):53-56
锥虫谷胱甘酰亚精胺还原酶属黄素氧化还原酶类，特异存在于锥体目生物却不存在于宿主体内。锥虫谷胱甘酰亚精胺还原酶在锥虫体内位于线粒体的动基体附近，起着抵抗氧化压力的作用，并成为治疗锥虫病药物设计的重要靶标。 相似文献
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1硒 硒存在于所有体细胞内，其中以肌肉、皮毛、骨骼和肝脏中的含量较多，肌肉占50%左右，皮毛14%~15%，骨骼10%，肝脏8%，其他15%~18%。硒是谷脱甘肽过氧化物酶的组成成分。这种酶能够催化还原型谷脱甘肽的氧化，以及由于维生素E缺乏而产生的过氧化酶类之间的氧化还原反应。谷脱甘肽是一种由谷氨酸、半胱氨酸及甘氨酸3种氨基酸组成的重要营养物质，其可以将过氧化酯类还原，防止这类毒素在体内的积累及细胞线粒体的脂类氧化，保护细胞膜不受脂类代谢副产物的破坏。含硒谷脱甘肽过氧化物酶和维生素E都有抗氧化作月，但二者具有协同作用。在一定条件下，维生素E可代替部分含硒谷肮甘肽过氧化物酶的作用，但含硒谷脱甘肽过氧化物酶不能代替维生素E。谷脱甘肽过氧化物酶能促进维生素E的吸收而减少机体对维生素E的需要量，并减轻由维生素E缺乏而导致的症状。 相似文献
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锥虫抗药性机制的研究进展 总被引：1，自引：0，他引：1
为了较全面地了解锥虫抗药性机制的研究进展,综述了国内外有关报道。锥虫抗药性形成的机制主要表现在三方面,即锥虫体内酶的活性（或含量）发生变化,抗药株虫体的苹果酸酶、锥虫硫酮还原酶或鸟氨酸脱羧酶等酶的活性明显升高;锥虫细胞膜上的特异载体,即细胞膜上转运腺苷酸和腺苷的Ｐ２载体发生改变,药物进入虫体受阻;虫体的抗药基因被激活或基因发生重组、突变或扩增。本文还总结了锥虫抗药性机制研究中存在的问题及今后的研究 相似文献
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锥虫是单细胞的真核生物,种类很多.寄生于哺乳动物的锥虫,从地域上讲有非洲锥虫、亚洲锥虫和美洲锥虫;从传播方式上讲有唾液传播锥虫(含机械传播锥虫)和粪便传播锥虫.非洲和亚洲锥虫多为唾液传播锥虫,美洲锥虫主要是粪便传播锥虫.能够在哺乳动物体内进行抗原变异的是唾液传播锥虫.唾液锥虫寄生于宿主血液之中,也存在于宿主其他部位,如马媾疫锥虫寄生于马、驴的生殖系统.大部分种类的唾液锥虫能够在昆虫体内发 相似文献
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硒的原子序数为34，具有非金属性和金属性。单质硒有三种同素异性体：无定性硒、晶体硒和金属硒。化合态的硒有低分子量化合物和高分子量化合物存在于生物体内。低分子量化合物如硒代半胱氨酸、硒代胱氨酸、胆汁硒、硒代牛黄酸、硒代辅酶A,此外还有亚硒酸钠(含硒45.7％)、硒酸钠(含硒41.8％)、硒化钠(含硒63．2％)、亚硒酸钙(含硒47．3％)。高分子量化合物有谷胱甘肽过氧化物酶(GSH-PX)、甲酸脱氢酶、甘氨酸还原酶、烟酸羟化酶、黄嘌呤脱氢酶、硫解酶以及各种含硒的蛋白质，例如硒蛋白P。 相似文献
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肉色不仅是鲜肉质量的一个重要指标,而且直接影响着消费者的购买行为。通过延迟肌红蛋白的自动氧化和加速高铁肌红蛋白的还原来维持新鲜肉色,对肉品工业极为重要。在体内,高铁肌红蛋白还原酶是高铁肌红蛋白还原反应的关键酶,在它的作用下,高铁肌红蛋白可以重新转变为有生理活性形式的肌红蛋白和氧合肌红蛋白。本文综述了肉色的形成原理,高铁肌红蛋白还原酶的部分性质以及它与肉色稳定性的关系。 相似文献
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新型饲料添加剂亚硒酸钙及其生产方法西南民族学院化学系黎星树西南民族畜牧兽医研究所邝光荣硒是人和动物体内所需的重要微量元素之一，它在生物体内可参与谷肮甘肽过氧化酶使机体免于自由基和辐射的破坏，刺激免疫反应，保护肝脏，维持细胞呼吸及对环境致癌物的解毒作用... 相似文献
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The aim of the study was to determine the selenium (Se) requirement of guinea pigs as a species unable to synthesize ascorbic acid. Forty-nine male guinea pigs (average weight 208 ± 3.5 g) were divided into an initial status group and six experimental groups. The animals received a Se deficient Torula yeast based basal diet (<0.02 mg Se and 26 mg α-tocopherol/kg) or a Se addition of 0.05, 0.10, 0.15, 0.20 and 0.25 mg/kg diet as sodium selenate for 10 weeks. There was no significant difference in weight gain (final weight 643 ± 21 g) between the groups and no clinical symptoms of Se deficiency occurred. With the exception of the testes, there was an increasing Se concentration in liver, plasma and haemolysate dependent on supplementation level. Glutathione peroxidase was determined in the plasma and Se dependent glutathione peroxidase (GPx1) in haemolysate, liver, kidney, heart and lung. Thioredoxin reductase (TR) activity was measured in liver, kidney and heart and deiodinase activity in the liver. A phospholipid hydroperoxide reducing activity with Se influence was determined in liver, kidney, heart, testes and brain. With the exception of GPx1 activity in heart and haemolysate and TR activity in the kidney, all enzymes already reached their maximal activity at 0.05 mg Se/kg diet. The activities of GPx1 and TR were used as parameters for broken line analysis and a Se requirement of 0.080 mg Se/kg diet was derived as sufficient for growing guinea pigs adequately supplied with vitamin E. 相似文献
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It has been suggested that tooth resorption (TR) in cats is associated with vitamin D3 status. The purpose of this study was to evaluate any correlation between serum 25-OH-D concentrations and the prevalence of TR. The healthy adult domestic cats (n=64) of this study had been fed similar premium dry-expanded foods throughout their lives. Serum 25-OH-D was measured, and cats received a single, complete periodontal examination, with periodontal probing of each tooth and exploration of the tooth surface using a dental explorer A complete set of 10 dental radiographs was taken for each cat. There were 168 TRs diagnosed in 40 of 64 cats (85 were Type 1 TR and 83 were Type 2). The mean serum 25-OH-D concentration was 187.7 +/- 87.3 nmol/L. The mean serum 25-OH-D in cats with one or more TR was 164.2 +/- 78.8 nmol/L, compared with 226.8 +/- 88.2 nmol/L for those without TR (p = 0.14). The mean serum 25-OH-D in the 13 cats with >5 TR was 131.2 +/- 49.5 nmol/L, which was significantly less than in cats with no TR (p < 0.05). There was no relationship between TR type and serum 25-OH-D. There was no effect of age or sex on serum 25-OH-D. On the contrary, variations in serum 25-OH-D were observed according to the studied breeds. There was no relationship between TR type and serum 25-OH-D. TR prevalence was greater in cats with lower serum 25-OH-D concentrations. In conclusion, the hypothesis that higher serum 25-OH-D concentrations are associated with a higher prevalence of TR is not supported by this study. 相似文献
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枯萎病严重影响香蕉产业的可持续发展。评估香蕉种质资源对云南枯萎病菌株TR4的抗性,遴选和储备抗病种质资源,为香蕉种质资源多样性在云南地区的利用、抗病种质资源和抗病基因的应用提供依据。本研究以国际生物多样性中心引进的11份香蕉种质资源为材料,在温室内接种不同浓度的云南枯萎病菌野生型菌株TR4（15-1）,球茎解剖调查和病情指数分析,将香蕉种质资源分为免疫,高抗,抗病,中抗,感病和高感六个等级。结合已报道香蕉种质资源对其他TR4菌株的抗病性评估,遴选对云南菌株TR4（15-1）抗性较好的香蕉种质资源。在接种常规浓度（1×106孢子数/mL）TR4（15-1）条件下,Kazirakwe,Igitsiri,Mbwazirume,Inkira,Akpakpak,Pahang是云南菌株TR4（15-1）的抗病种质资源,接种20天的病情指数范围是20.31-29.27;GCTCV-119和Gros Michel为中抗种质资源;Baxi Jiao,Banksii和Ibwi是感病种质资源。在高浓度（1×108孢子数/mL）TR4（15-1）侵染下,常规浓度筛选到的6份抗病种质资源仍然表现为抗病,但GCTCV-119,Gros Michel,Baxi Jiao,Banksii和Ibwi均划分为感病种质资源。结合不同浓度病原菌侵染的病害调查分析,11份香蕉种质资源对云南菌株TR4（15-1）的抗性存在明显的差异,抗TR4（15-1）的强度依次为：Kazirakwe> Inkira>Pahang> Akpakpak> Igitsiri> Mbwazirume。本研究遴选到6份香蕉种质资源（Kazirakwe,Inkira,Pahang,Akpakpak,Igitsiri,Mbwazirume）对云南菌株TR4（15-1）具有较好的抗病性,为广谱性抗病资源。研究结果为云南产区香蕉抗病资源的储备、抗病种质的利用、保障云南香蕉产业的稳定发展奠定基础。 相似文献
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Booij-Vrieling HE de Vries TJ Schoenmaker T Tryfonidou MA Penning LC Hazewinkel HA Everts V 《Research in veterinary science》2012,92(2):311-316
Both vitamin D and inflammatory cytokines can stimulate osteoclast formation and activity. We studied the effect of 1,25-dihydroxycholecalciferol (1,25(OH)(2)D), and interleukin-6 (IL-6), on the formation and activity of feline osteoclasts, using peripheral blood mononuclear cells (PBMCs) from cats with and without tooth resorption (TR(+) and TR(-)) as a source of osteoclast precursors. The formation of osteoclast-like cells (defined as multinucleated, tartrate-resistant acid phosphatase-positive cells) was assessed at 7 and 14 days. In the presence of M-CSF and RANKL, with and without IL-6, more osteoclasts were formed from TR(-) PBMCs than from TR(+) PBMCs on plastic. More osteoclasts were formed from TR(+) PBMCs on bone slices in the presence of M-CSF/RANKL with 1,25(OH)(2)D. This opposite effect may be due to a higher expression of the vitamin D receptor (VDR) in TR(+) osteoclasts and precursors on bone. Formation of resorption pits was analyzed and confirmed with scanning electron microscopy. In conclusion, we propose that TR(+) PBMCs when cultured on bone are sensitive to 1,25(OH)(2)D, whereas the differentiation of TR(-) PMBCs on bone seem more sensitive to IL-6, suggesting that osteoclast precursors from cats with and without tooth resorption respond differently to osteoclast stimulating factors. 相似文献
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To confirm the taxonomic identification of a trypanosomatid found in the hindgut, rectum and Malpighian tubules of dog fleas captured in Belo Horizonte, Minas Gerais, Brazil, between April and November of 2005, 910 specimens of Ctenocephalides felis felis were removed from street dogs and dissected, and isolates from their digestive tracts were cultivated in NNN-alpha-MEM medium. Four different morphological forms were observed in culture: long, slender, twisted promastigotes with a long flagellum; short, stubby, non-twisted promastigotes; rounded amastigotes; and cyst-like bodies. Twisted and non-twisted promastigotes were frequently seen forming rosettes, and these two forms presented significant differences (P<0.01) in terms of their morphological characteristics. Unlike the promastigote forms observed throughout the culture period, rounded amastigotes were seen only in the lag phase, and the cyst-like bodies were only seen in the decline phase. The trypanosomatid DNA obtained from the culture was analyzed by the polymerase chain reaction (PCR) method and found to be negative for Leishmania infantum chagasi. Based on the growth pattern, morphological parameters and molecular analysis, the flagellates were confirmed to be Leptomonas ctenocephali. The significance of this infection for animals is also commented. 相似文献
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Lewis JR Okuda A Shofer FS Pachtinger G Harvey CE Reiter AM 《Journal of veterinary dentistry》2008,25(2):86-95
Abnormal extrusion of canine teeth is often noted in middle-aged and geriatric domestic cats. The same age group of cats also is commonly affected by tooth resorption (TR). This study explored the relationship between these two phenomena of unknown etiology. Using digital radiography, the distance between the alveolar margin (AM) and cementoenamel junction (CEJ), referred to as the AM-CEJ distance, was measured in clinically and radiographically healthy maxillary canine teeth of 24 TR-affected and 29 TR-free cats. The mean AM-CEJ distance of maxillary canine teeth of cats with and cats without TR was 2.68-mm and 2.22-mm, respectively. An analysis of covariance adjusting for age revealed a significant correlation (p = 0.02) between tooth extrusion and TR. Extrusion of the maxillary canine teeth became clinically apparent when an AM-CEJ distance of 2.5-mm or greater was evident in the absence of horizontal or vertical alveolar bone loss. Based on this criterion, 15 of 24 cats with TR (63.0 %) exhibited extrusion of maxillary canine teeth, compared to 9 of 29 cats without TR (31.0 %). Four extruded and five non-extruded maxillary canine teeth were evaluated histologically. Cementum of extruded teeth was significantly thicker compared to that of non-extruded teeth. Four of 4 canine teeth with extrusion (100 %) showed histological evidence of resorption, compared to 1 of 5 canine teeth without extrusion (20.0 %). These results suggest that tooth extrusion is linked to or may be caused by similar factors responsible for the development of TR. 相似文献
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研究新发现的甲状腺激素受体(TR)TRβΔ的P-box氨基酸序列能否结合甲状腺激素反应元件(TRE)后增强靶基因转录,揭示P-box序列的保守性与TRβΔ转录激活作用的关系,验证TRβΔ的功能性和活性。构建pcDNA3.1-TRβΔ真核表达载体质粒和含有回文序列TRE的pGL3-Promoter/TRE报告基因载体。突变TRβΔ的P-box氨基酸序列对应的DNA序列,分别构建pcDNA3.1-TRβΔmut1、pcDNA3.1-TRβΔmut2突变质粒。以上质粒分组瞬时共转染至COS-7细胞中,分别用含有T3和不含T3的培养基处理后,检测各组荧光素酶的活性。以上载体经PCR、双酶切和质粒测序证实均构建成功。与TRβ1相比,TRβΔ的P-box序列仅在最后一位不同,但基本保证了完整性。在加入T3后,TRβΔ正常与TRE结合,激活报告基因表达,荧光素酶活性显著增加(P0.01)。将P-box序列突变为与TRβ1一致的pcDNA3.1-TRβΔmut1,在T3调节下也能显著提高荧光素酶的表达(P0.01)。但完全破坏P-box序列的pcDNA3.1-TRβΔmut2与TRβΔ相比,其荧光素酶的表达显著降低(P0.01)。结果证明,TRβΔ只有通过完整保守的P-box氨基酸序列,在T3的调节下才能与TRE正常结合,产生转录激活作用。TRβΔ是有转录因子性质的功能性TR。 相似文献
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C. Sánchez‐Collado J. M. Vázquez M. A. Rivero F. Martínez G. Ramírez F. Gil 《Anatomia, histologia, embryologia》2014,43(1):56-63
Distribution pattern of fibre types was studied in the muscles of the soft palate (palatinus, levator veli palatini and tensor veli palatini muscles) in the dog. The fibrillar classification was based on using histochemistry and immunohistochemistry methods: myofibrillar adenosine thriphosphatase (mATPase) to different pH of pre‐incubation; nicotine adenine dinucleotide (reduced) tetrazolium reductase (NADH‐TR) and finally, application of specific monoclonal antibodies against myosin heavy chain isoforms I, IIa and IIx. In the palatinus and levator veli palatini muscles, pure type I fibres and the hybrid type IIax and IIc were shown, with a checkerboard distribution in the first and a clear predominance of hybrid fibre types (about 98% of the total population) in levator veli palatini muscle. On the other hand, in the tensor veli palatini muscle, type IIx and IIm fibres were identified (fast‐twitch fibres related to fast‐moving muscles and the powerful jaw muscles of carnivores). The tensor veli palatini muscle had a different distribution and fibrillar composition with predominantly type IIm fibres in its central zone, whilst the peripheral zone was primarily type I and IIx fibres. 相似文献