Alternaria alternata NADP-dependent mannitol dehydrogenase is an important fungal allergen.

BACKGROUND: Alternaria alternata is one of the most important allergenic fungi worldwide. Mannitol dehydrogenase (MtDH) has previously been shown to be a major allergen of Cladosporium herbarum and cross-reactivity has been demonstrated for several fungal allergens. OBJECTIVE: The present study's objective was to clone the MtDH from an A. alternata cDNA library, express and purify the recombinant non-fusion protein and test its IgE-binding properties. Methods A cDNA library prepared from A. alternata hyphae and spores was screened for mannitol dehydrogenase by DNA hybridization with the radioactively labelled C. herbarum homologue as a probe. The resulting clone was sequenced and heterologously expressed in Escherichia coli as a recombinant non-fusion protein, which was purified to homogeneity and analysed for its IgE-binding capacity. RESULTS: The coding sequence of the full-length cDNA clone comprises 798 bp encoding a protein with a molecular mass of 28.6 kDa and a predicted pI of 5.88. Protein sequence analysis revealed an identity of 75% and a homology of 86% between the MtDHs of A. alternata and C. herbarum. The functional mannitol dehydrogenase was expressed in the E. coli strain BL21(DE3) transformed with the vector pMW172 and purified to homogeneity. The enzyme catalyses the NADPH-dependent conversion of d-fructose to d-mannitol. In IgE-ELISA and immunoblots, MtDH is recognized by 41% of A. alternata-allergic patients. In vivo immunoreactivity of the recombinant MtDH was verified by skin prick testing. Finally, inhibition-ELISA experiments confirmed cross-reactivity between the MtDHs of A. alternata and C. herbarum. CONCLUSION: Mannitol dehydrogenase (Alt a 8) represents an important new allergen of the ascomycete A. alternata that might be suitable for improving diagnostic and therapeutic procedures.     

大承气颗粒剂对胃肠动力影响的影像观察

目的 :探讨大承气颗粒剂对健康人群胃肠道动力的影响。 方法 :利用加入大承气颗粒剂钡餐造影技术 ,通过监视器、录像和摄片观察记录造影剂由胃排入十二指肠、十二指肠排入空肠、空肠排入空回肠、空回肠排入回肠、回肠排入回盲部的时间 ,结肠排出时间以及造影全过程总时间。受试者分三组各 3 0人。一组大承气颗粒剂组 (大承气组 ) ;二组为甘露醇组 ;三组为常规钡餐组。 结果 :大承气组除胃排入十二指肠、十二指肠排入空肠的时间与常规钡餐组比较无明显差别外 ,余各组小肠的排入时间、结肠排出时间以及造影全过程总时间与常规钡餐组比较P <0 0 5,与甘露醇组比较无明显差异。 结论 :大承气汤颗粒剂具有提高肠道张力、促进其推进作用     

甘露醇和低温对兔骨骼肌缺血再灌流损伤的保护作用

通过兔后肢缺血模型，观察了甘露醇和低温对骨骼肌缺血再灌流损伤的保护作用。结果：甘露醇和低温可以不同程度地降低再灌流后患肢静脉回流血中细胞内酶（ＣＰＫ、ＬＤＨ、ＡＳＴ）的活性和脂质过氧化反应终末代谢产物丙二醛（ＭＤＡ）的含量，减轻骨骼肌细胞超微结构的破坏。两者单独应用效果不明显（Ｐ＞０．０５），联合应用效果非常明显（Ｐ＜０．０１）。提示自由基介导的脂质过氧化反应参与骨骼肌缺血再灌流损伤，甘露醇和低温对其具有协同保护作用。     

2-Mercapto-ethanol enhancement of agglutination reaction--a possible in vitro serological correlate for assessment of functional immunity in simian malaria

Conventional indirect haemagglutination test was performed in rhesus monkey sera (collected from Plasmodium knowlesi infected animals) with and without prior treatment of sera with 2-mercapto-ethanol (2-ME). Surprisingly, many sera samples showed significant enhancement of final titre with 2-ME. The 2-ME enhancement effect was more pronounced in the sera of hyperimmune monkeys on further injection of antigen or parasites. It was also noticeable in the sera during primary drug-suppressed P. knowlesi infection and appeared to have a bearing on the immune status of the animals to rechallenge. The use of a soluble antigen prepared from P. knowlesi infected erythrocytes was found to be essential in IHA test to demonstrate the 2-ME enhancement effect. Antigen prepared from freed parasites (commonly used) failed to show a similar effect in IHA. The possible role of certain T-lymphocyte products - antigen binding, non-agglutinating, 2-ME sensitive molecules - in malarial immunology has been proposed.     

Dependency of renal potassium excretion on Na,K-ATPase transport rate

Potassium secretion may depend on the transport rate of Na, K-ATPase in basolateral cell membranes of distal tubular cells. To examine this hypothesis experiments were performed in anaesthetized dogs during inhibition of proximal potassium reabsorption by acetazolamide or mannitol (fractional potassium excretion 1.2-1.4) or additional stimulation of potassium secretion by ethacrynic acid (fractional potassium excretion 2.1). Ouabain in a dose which inhibits 70–80% of the Na, K-ATPase activity reduced fractional potassium excretion to 0.8-0.9 by an effect on distal tubular secretion since potassium transport in the proximal tubules was not affected. Ouabain-sensitive potassium excretion varied in proportion to ouabain-sensitive sodium reabsorption during variation in glomerular nitration rate, even at urinary sodium concentrations exceeding 80 mmol 1^-1. In experiments without ouabain, saline infusion raised potassium excretion and sodium reabsorption until maximal Na, K-ATPase transport rate was reached, as judged from heat production measurements, but not during further increments in urine flow. After inhibition of Na, K-ATPase activity by hypokalaemia, potassium excretion and cortical heat production remained constant over a wide range of urine flow and sodium excretion. We conclude that potassium secretion is dependent on intact Na, K-ATPase activity and is stimulated by sodium delivery to the distal nephron until maximal transport rate of the enzyme is reached.     

脑卒中患者甘露醇性肾功能衰竭的预防

目的 :探讨预防脑卒中患者甘露醇性肾功能衰竭的方法。方法 :对照组脑卒中患者 6 0例 ,常规使用甘露醇 ,治疗组脑卒中患者 5 5例 ,改进补液方法 ,尽量从消化道补液 ,适量使用甘露醇 ,配合速尿及多巴胺等药物 ,早期诊断急性肾功能衰竭 (ARF) ,早期治疗。结果与结论 :治疗组无ARF发生 ,对照组ARF发生率 6 7%。脑卒中患者甘露醇性ARF可以预防。     

比色法测定复方虫草颗粒中甘露醇的含量

目的 研究比色法测定复方虫草颗粒中甘露醇的含量,建立一种准确、可行的含量测定方法。方法 在供试品中依次分别加入氧化剂高碘酸钾、L－鼠李糖与Nash试剂,53℃水浴加热15min使呈色,在412nm处测定吸光度,用比法测定其中甘露醇的含量。结果 在10－50μg/mL范围内对3种不同批号样品在实验条件下测定,其平均含量为1．27％,本法平均回收率为100．3％,RSD为0．83％（n＝5）结论 可作为复方虫草颗粒中甘露醇含量测定有有关质量控制的一种简便、准确和快速的方法。     

颈动脉推注甘露醇对兔脑缺血所致脑水肿的作用

目的：研究缺血性中风脑水肿时,颈动脉推注２０％甘露醇对减轻脑水的机理及效果,方法：建立兔急性不完全性脑缺血模型,随机分为对照组,非推注组及推注组（颈动脉推注２０％甘露醇）,通过测定脑含水量及观察脑组织病理变化,评价脑水肿程度,结果：推注组脑组织含水量显著低于非推注组,其脑组织病理变化亦明显轻于非推注组。结论：颈动脉推注甘露醇可明显减轻缺血性脑水肿。     

β-七叶皂苷钠在筋膜间隙综合征中的应用

目的 :观察 β-七叶皂苷钠治疗筋膜间隙综合征的疗效。方法 :将 61例筋膜间隙综合征患者随机分为治疗组 (A组 )和对照组 (B组 ) ,分别观察 A、B组患者肿胀消除起效时间及药物的不良反应。结果 :治疗组的平均消肿时间较对照组提前 2 .2 d,治疗组未出现肾功能损害。结论 :β-七叶皂苷钠具有显著的抗渗出、消水肿的作用 ,治疗筋膜间隙综合征明显优于甘露醇