Nitrogen starvation of cyanobacteria results in the production of β-N-methylamino-L-alanine

β-N-methylamino-L-alanine, an unusual amino acid implicated in neurodegenerative disease, has been detected in cultures of nearly all genera of environmentally ubiquitous cyanobacteria tested. The compound is present within cyanobacterial cells in free and protein-associated forms, with large variations occurring in the concentration of these pools between species as well as within single strains. With a lack of knowledge and supporting data on the regulation of BMAA production and the role of this compound in cyanobacteria, the association between BMAA and cyanobacteria is still subject to debate. In this study we investigated the biosynthesis of BMAA in axenic non-diazotrophic cyanobacterial cultures using the stable isotope ¹⁵N. Nitrogen starvation of nutritionally replete cells resulted in an increase in free cellular ¹⁵N BMAA suggesting that BMAA may be the result of catabolism to provide nitrogen or that BMAA is synthesised to serve a functional role in the cell in response to nitrogen deprivation. The addition of NO₃⁻ and NH₄⁺ to the culture medium following starvation resulted in a decrease of free cellular BMAA without a corresponding increase in the protein-associated fraction. The use of ammonia as a nitrogen source resulted in a more rapid reduction of BMAA when compared to nitrate. This study provides the first data regarding the regulation of intracellular BMAA concentrations in cyanobacteria with results conclusively showing the production of ¹⁵N BMAA by an axenic cyanobacterial culture.     

中药外洗为主治疗上肢感染创面的临床观察

目的探讨中药外洗为主治疗上肢感染创面的临床疗效。方法 77例患者,随机分为治疗组41例和对照组36例。对照组外科常规换药,呋喃西林纱布湿敷创面,治疗组在对照组处理基础上,在感染急性期过后,换药前用中药外洗,再用中药液浸湿无菌纱布覆盖创面。两组均于3个疗程后统计疗效。结果治疗组痊愈22例,显效16例,总有效率92.7%,与对照组比较,差异有统计学意义(P0.05)。结论应用中药外洗为主治疗上肢感染创面,是一种行之有效的方法 。     

On the ancestral recruitment of metalloproteinases into the venom of snakes

Tracing the evolutionary history of proteins can reveal insights into gene alterations responsible for changes in structure and function. Here, the origin of snake venom metalloproteinases was rigorously reassessed using phylogenetics and the reconstruction of ancestral sequences. Basal SVMPs are most closely related to ADAM 7, 28 and decysin-1 proteins. Reconstructing the evolutionary history of these proteins and their hypothetical ancestors reveals progressive alterations in the amino acid composition and structural characteristics of ADAMs/SVMPs through evolutionary time.     

Cutaneous loxoscelism caused by Loxosceles similis venom and neutralization capacity of its specific antivenom

Members of the spider genus Loxosceles pose a marked health risk to humans because of the seriousness of the necrotic and systemic effects of their bite, known as loxoscelism. The recent confirmation of Loxosceles similis in residences of Belo Horizonte in Minas Gerais Province, Brazil increases the local potential risk of loxoscelism at higher levels. The first characterization of the venom from this species showed that its main biological effects had a similar intensity as other species (e.g. Loxosceles intermedia, Loxosceles laeta, and Loxosceles gaucho). Therefore, we wished to further analyse the biological activity of the L. similis venom as well as the capacity of anti-L. similis-venom serum to reduce dermonecrotic effects to rabbit skin. Histological analysis of rabbit skin 2, 4 and 8 h after intradermal injection of L. similis venom demonstrated a dense inflammatory infiltrate, edema, degeneration and necrosis of the skin muscle, dissociation of collagen fibers, and disruption of reticular fibers. Importantly, pre-incubation of the venom with anti-L. similis-venom serum significantly decreased all of these effects. Anti-L. similis antivenom generated antibodies that were strongly reactive to L. similis venom and capable of neutralizing the dermonecrotic effects in rabbits caused by this venom. Moreover, the antivenom significantly reduced the sphingomyelinase activity of L. similis crude venom. Venoms produced by male and female spiders were equally reactive towards anti-L. similis and anti-L. intermedia antivenoms, but female venom induced larger lesions on rabbits. In contrast, female venom acted as an immunization enhancer and protected animals from L. similis envenomation to a greater degree than male venom. In conclusion, the results shown in this study for L. similis antivenom merits a more in depth study of its properties, which may become a valuable tool against loxoscelism.     

《诸病源候论》中有关“毒”的病因研究

本研究运用文献计量学、分类学等研究方法,通过对我国现存的第一部病因病机证候学专著《诸病源候论》中有关病因"毒"的内容进行归纳整理和系统研究,结果发现书中提到"风毒"、"寒毒"、"热毒"等40种毒邪,涉及患斑毒病候、脚气痹弱候、夏日沸烂疮候等共186条,其中热毒、毒气、虫兽毒、风毒、食毒的出现频率较高,从而进一步完善、发展中医病因范畴"毒"之学说。     

食品与儿童肾损害

毒蕈类毒素和鱼胆类毒素是最典型的食物天然毒素。毒蕈类毒素对肾脏的损害,按照临床表现分为早发型、迟发型和缓发型;鱼胆类毒素主要是导致急性肾小管坏死。食物污染性肾损害包括化学性污染和生物性污染。“毒奶粉”导致的泌尿系结石、肾衰竭是典型的食物化学性污染事件;“毒黄瓜”事件的罪魁祸首为出血性大肠杆菌,造成3 493人患溶血尿毒综合征。目前食物链的污染正从陆地到海洋到天空,要阻止人类食物链的污染需要全社会的努力。     

Intracutaneous botulinum toxin A versus ablative therapy of Hailey-Hailey disease - a case report

BACKGROUND: Hailey-Hailey disease is an autosomal-dominant blistering disease affecting the intertriginous skin. Dermabrasion and ablative laser treatment are known to be curative. Sweating is a common aggravating factor. Botulinum toxin A (BTXA) has been shown to inhibit sudoriferic nerves. OBJECTIVE: To evaluate whether a treatment with BTXA induces remissions and can compete with ablative therapy. To compare dermabrasion with erbium:YAG laser therapy. METHOD: Case report with side-by-side comparison. We used intracutaneous BTXA on both sides of the submammary region. Four days later a limited area of 25 cm 2 on each side was treated with either dermabrasion or erbium:YAG laser. The follow-up was 12 months. RESULTS: Wound healing was complete within 7 days after erbium:YAG laser and two weeks after dermabrasion. Areas treated with BTXA alone also showed complete remission within two weeks. During a follow-up, no relapse occurred with either treatment. CONCLUSION: BTXA is capable of inducing remissions of Hailey-Hailey disease without abrasion for at least 12 months. Among ablative treatments, erbium: YAG laser therapy leads to a more rapid wound closure than dermabrasion, with both causing complete remissions.     

基于数据挖掘探讨吴寿善治疗慢性乙型病毒性肝炎用药规律

目的：基于中医医疗与临床科研信息共享系统,运用数据挖掘技术探讨湖北中医大师吴寿善教授 中医药治疗慢性乙型病毒性肝炎的用药规律。方法：应用结构化电子病历采集767例吴寿善接诊慢性乙型病 毒性肝炎门诊患者的临床资料,通过数据集成、汇交、整合后,利用数据分类、关联、聚类规则方法对临床资料进 行分析。结果：①确定259个处方中药物的使用频次前五位药物分别是茯苓、茵陈、陈皮、丹参、连翘;②药物配 伍方面,关联度最高的配对分别为茯苓-甘草-白术、茯苓-丹参-白术、茵陈-茯苓-甘草等;③挖掘核心处方时, 发现蒿芩清胆汤、大安丸、半夏白术天麻汤等经典方加减使用频次最高。结论：通过数据挖掘方法,我们发现吴 寿善教授以中医药治疗慢性乙型病毒性肝炎在治则治法上,主要从毒痰瘀虚进行辨证施治。     

Toxin synergism in snake venoms

Synergism between venom toxins exists for a range of snake species. Synergism can be derived from both intermolecular interactions and supramolecular interactions between venom components, and can be the result of toxins targeting the same protein, biochemical pathway or physiological process. Few simple systematic tools and methods for determining the presence of synergism exist, but include co-administration of venom components and assessment of Accumulated Toxicity Scores. A better understanding of how to investigate synergism in snake venoms may help unravel strategies for developing novel therapies against snakebite envenoming by elucidating mechanisms for toxicity and interactions between venom components.     

青黄散加解毒化瘀方治疗骨髓增生异常综合征疗效及对患者血清可溶性细胞间黏附分子-1、转化生长因子-β1的影响

目的: 探究青黄散加解毒化瘀方对毒瘀阻滞证骨髓增生异常综合征(MDS)的疗效及血清可溶性细胞间黏附分子(sICAM-1)、转化生长因子β₁(TGF-β₁)水平的影响。方法:选取76例MDS患者作为研究对象,随机分为试验组和对照组,各38例,对照组予以西医基础治疗,试验组在对照组基础上联合青黄散加解毒化瘀方治疗。两组患者均于给药4个月后评估临床疗效、中医证候积分、血常规指标水平、血清学免疫因子水平,并记录两组患者不良反应发生率。结果:治疗后两组患者的主症及次症评分均低于治疗前,且试验组均低于对照组(P<0.05)。试验组临床疗效优于对照组(P<0.05)。两组不良反应发生率比较差异无统计学意义(P>0.05)。治疗后,两组患者的血清sICAM-1水平均低于治疗前,且试验组低于对照组(P<0.05); 两组治疗后TGF-β₁水平较治疗前升高,试验组高于对照组(P<0.05)。治疗后,两组PLT、Hb、WBC水平较治疗前升高,试验组PLT、Hb水平均高于对照组(P<0.05)。结论:青黄散加解毒化瘀方应用于毒瘀阻滞证MDS患者治疗中,有助于促进患者症状恢复,改善血常规指标水平,调节血清免疫因子水平,且安全性良好。