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91.
Objective: To describe successful treatment of third-degree atrioventricular (AV) block using temporary noninvasive transthoracic pacing and placement of a permanent transvenous pacemaker in a case of suspected lily-of-the-valley ( Convallaria majalis ) intoxication in a dog.
Case summary: A 2-year-old neutered male Beagle weighing 17.8 kg was presented to the emergency service for treatment of bradycardia, vomiting, and lethargy. An electrocardiogram revealed third-degree AV block that was nonresponsive to atropine. Ten hours after admission, the dog became obtunded. Treatment initially consisted of temporary noninvasive transthoracic pacing and eventually placement of a permanent transvenous pacemaker. The initial history did not suggest that the dog had access to any known cardiotoxins. However, C. majalis , which contains cardiac glycosides, was identified within the dog's environment and the dog's serum did contain digoxin or an immunologically cross-reactive compound.
New or unique information provided: This is the first reported successful management of C. majalis toxicosis in a dog. Temporary noninvasive transthoracic pacing was used in the management of this case as a safe and effective bridge to permanent pacemaker implantation.  相似文献   
92.
A new tetramic acid glycoside, aurantoside K, was isolated from a marine sponge belonging to the genus Melophlus. The structure of the compound was elucidated on the basis of spectroscopic analysis (1H NMR, 1H-1H COSY, HSQC, and HMBC, as well as high-resolution ESILCMS). Aurantoside K did not show any significant activity in antimalarial, antibacterial, or HCT-116 cytotoxicity assays, but exhibited a wide spectrum of antifungal activity against wild type Candida albicans, amphotericin-resistant C. albicans, Cryptococcus neoformans, Aspergillus niger, Penicillium sp., Rhizopus sporangia and Sordaria sp.  相似文献   
93.
白蚁自身及其后肠共生微生物可以分泌多种糖基水解酶用于分解木质纤维素。本研究选用1%木质素、1%羧甲基纤维素钠、1%山梨糖、1%果糖、1%葡萄糖及1%半乳糖6种糖基化合物溶液,诱导台湾乳白蚁Coptotermes formosanus糖基水解酶的分泌,进行了酶活测定。结果显示,FPA活力、内切葡聚糖酶EG、β-葡萄糖苷酶BG、纤维二糖水解酶CBH和内切木聚糖酶EX的最佳诱导物分别为1%木质素(149%,0.750U/mg),1%山梨糖(126%,1.538U/mg),1%木质素(178%,5.170U/mg),1%木质素(265%,1.201U/mg),1%果糖(341%,5.146U/mg)。整头白蚁4种酶的诱导最大值顺序为:EX(6d,9.356U/mg)>BG(2d,3.313U/mg)>EG(2d,1.541U/mg)>CBH(6d,1.476U/mg)。研究表明,木质素、果糖和山梨糖对其内源性糖基水解酶诱导作用明显,而6种化合物对台湾乳白蚁后肠微生物来源的糖基水解基本为抑制作用。  相似文献   
94.
目的 探讨二苯乙烯苷(TSG)和三七总皂苷(PNS)配伍对Aβ25-35诱导的PC12细胞损伤的影响。方法 PC12细胞采用Aβ25-35诱导建立阿尔茨海默病的损伤模型,被随机分成空白组、模型组、多奈哌齐组(10 μmol/L)、TSG(100 mmol/L)组、PNS组(50 mg/L)、TSG-PNS配伍组(TSG100 mmol/L+PNS50 mg/L)。取细胞上清液测各组的乙酰胆碱酯酶(AchE)及超氧化物歧化酶(SOD)活力、丙二醛(MDA)含量。结果 与模型组比较,TSG组、PNS组、TSG-PNS配伍组可降低AchE活力、MDA含量及提高SOD活力(P<0.05)。且TSG-PNS配伍组的效应比TSG或PNS单用组效应更好(P<0.01)。结论 TSG和PNS配伍对Aβ25-35诱导的PC12细胞损伤具有明显的保护作用,其作用机制可能与胆碱能系统及氧化应激有关。  相似文献   
95.
植物几丁酶的分子生物学研究进展   总被引:6,自引:0,他引:6  
综合评述了近年来植物几丁酶的结构与功能、基因表达和调节、录译后加工及分类研究方面所取得的进展.植物几丁酶前体均含N-端信号肽和催化区,有的还有几丁质结合区和C-端液泡导向区;植物几丁酶绝大多数可由病原物等生物因素或乙烯等非生物因素诱导,并有组织专化性,有些受发育调节;译后几丁酶前体切除N-端信号肽→脯氨酸羟基化→切除C-端信号肽而成为成熟蛋白;几丁酶的分类目前存在两个系统,分别将几丁酶分为5类(class)或将几丁酶基因分4组(group).  相似文献   
96.
A field experiment was conducted during 2008 and 2009 at the Council of Scientific and Industrial Research-Institute of Himalayan Bioresource Technology, Palampur, India, to study the effect of organic sources of nutrient on yield, nutrient uptake, fertility status of soil, and quality of stevia crop in the western Himalayan region. The experiment comprised eight different combinations of organic manure [farmyard manure (FYM), vermicompost (VC), and apple pomace manure (AP)]. Total leaf dry biomass increased by 149% over the control with application of VC 1.5 t ha?1 + AP 5 t ha?1. Application of organic manures enhanced organic carbon and available nutrient status of soil more than the control. Nitrogen (N) and phosphorus (P) content in stem were significantly affected by the application of organic manures over the control. Stevia plants supplied with FYM 10 t ha?1 + AP 2.5 t ha?1 recorded more total glycoside than other treatments. Stevioside yield (kg ha?1) was greater with application of FYM 10 t ha?1 + AP 2.5 t ha?1.  相似文献   
97.
烟草中糖苷类物质研究进展   总被引:2,自引:0,他引:2  
糖苷类物质是烟草潜在香味物质,对卷烟加香具有重要作用。从糖苷的种类、性质和作用出发,综述了烟草品种、部位、调制、加工工艺和生态环境对糖苷类物质的影响,并阐述了糖苷类物质的分析测定方法及其生物合成途径。认为今后应加强研究各因素对烟草中糖苷类物质的影响,着力探寻糖苷类物质在烟草中的应用,为提高卷烟香气品质提供理论依据。  相似文献   
98.
Three new polyhydroxysteroidal glycosides, hesperuside A (1), B (2), and C (3), as well as a known novaeguinoside A (4), were isolated from the ethanol extract of starfish Craspidaster hesperus collected from the South China Sea. Their structures were elucidated by extensive spectroscopic methods and chemical evidence. The compounds 1–3 present unprecedented carbohydrate chain 3-O-methyl-β-d-galactopyranose, which differ from each other in the side chains. These compounds exhibited cytotoxicity against human tumor cells BEL-7402, MOLT-4, and A-549 in vitro.  相似文献   
99.
为了深入认识细胞壁重构酶木葡聚糖内转糖苷酶/水解酶(XTH)在植物生长发育中作用,总结了XTH酶的结构特征和作用机制,XTH在植物细胞壁重构,植株的叶、根、茎、花和果实发育的生理作用以及在响应植物激素和环境信号等方面的研究进展;并认为XTH是植物细胞壁重构过程中的关键酶,能够松弛和强化细胞壁,且参与细胞壁的降解和合成;XTH在植物生长调控过程中具有重要的作用,最后指出XTH基因研究领域潜在的问题,并对未来的研究方向进行了展望。  相似文献   
100.
Organisms specialized to thrive in cold environments (so-called psychrophiles) produce enzymes with the remarkable ability to catalyze chemical reactions at low temperature. Cold activity relies on adaptive changes in the proteins’ sequence and structural organization that result in high conformational flexibility. As a consequence of flexibility, several such enzymes are inherently heat sensitive. Cold-active enzymes are of interest for application in a number of bioprocesses, where cold activity coupled with easy thermal inactivation can be of advantage. We describe the biochemical and functional properties of two glycosyl hydrolases (named LYS177 and LYS188) of family 19 (GH19), identified in the genome of an Antarctic marine Pseudomonas. Molecular evolutionary analysis placed them in a group of characterized GH19 endolysins active on lysozyme substrates, such as peptidoglycan. Enzyme activity peaks at about 25–35 °C and 40% residual activity is retained at 5 °C. LYS177 and LYS188 are thermolabile, with Tm of 52 and 45 °C and half-lives of 48 and 12 h at 37 °C, respectively. Bioinformatics analyses suggest that low heat stability may be associated to temperature-driven increases in local flexibility occurring mainly in a specific region of the polypeptide that is predicted to contain hot spots for aggregation.  相似文献   
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