Scorpion Toxin,BmP01, Induces Pain by Targeting TRPV1 Channel

The intense pain induced by scorpion sting is a frequent clinical manifestation. To date, there is no established protocol with significant efficacy to alleviate the pain induced by scorpion envenomation. One of the important reasons is that, little information on pain-inducing compound from scorpion venoms is available. Here, a pain-inducing peptide (BmP01) has been identified and characterized from the venoms of scorpion (Mesobuthus martensii). In an animal model, intraplantar injection of BmP01 in mouse hind paw showed significant acute pain in wild type (WT) mice but not in TRPV1 knock-out (TRPV1 KO) mice during 30 min recording. BmP01 evoked currents in WT dorsal root ganglion (DRG) neurons but had no effect on DRG neurons of TRPV1 KO mice. Furthermore, BmP01 evoked currents on TRPV1-expressed HEK293T cells, but not on HEK293T cells without TRPV1. These results suggest that (1) BmP01 is one of the pain-inducing agents in scorpion venoms; and (2) BmP01 induces pain by acting on TRPV1. To our knowledge, this is the first report about a scorpion toxin that produces pain by targeting TRPV1. Identification of a pain-inducing compound may facilitate treating pain induced by scorpion envenomation.     

SARS-CoV-2 Variant of Concern 202012/01 Has about Twofold Replicative Advantage and Acquires Concerning Mutations

The novel SARS-CoV-2 Variant of Concern (VOC)-202012/01 (also known as B.1.1.7), first collected in United Kingdom on 20 September 2020, is a rapidly growing lineage that in January 2021 constituted 86% of all SARS-CoV-2 genomes sequenced in England. The VOC has been detected in 40 out of 46 countries that reported at least 50 genomes in January 2021. We have estimated that the replicative advantage of the VOC is in the range 1.83–2.18 [95% CI: 1.71–2.40] with respect to the 20A.EU1 variant that dominated in England in November 2020, and in range 1.65–1.72 [95% CI: 1.46–2.04] in Wales, Scotland, Denmark, and USA. As the VOC strain will likely spread globally towards fixation, it is important to monitor its molecular evolution. We have estimated growth rates of expanding mutations acquired by the VOC lineage to find that the L18F substitution in spike has initiated a fast growing VOC substrain. The L18F substitution is of significance because it has been found to compromise binding of neutralizing antibodies. Of concern are immune escape mutations acquired by the VOC: E484K, F490S, S494P (in the receptor binding motif of spike) and Q677H, Q675H (in the proximity of the polybasic cleavage site at the S1/S2 boundary). These mutants may hinder efficiency of existing vaccines and expand in response to the increasing after-infection or vaccine-induced seroprevalence.     

Atrioventricular block with lidocaine therapy

A case is presented of complete atrioventricular (A-V) block occurring after a 50 mg bolus injection of lidocaine. Base-line studies before administration of lidocaine showed evidence of trifascicular block manifested by complete right bundle branch block, left anterior hemiblock and a markedly prolonged H-V interval. Advanced A-V block and then complete A-V block distal to the His bundle developed after administration of lidocaine. Lidocaine should be used with caution in patients with trifascicular disease; if it is administered to such patients, insertion of a temporary pacemaker catheter should be considered.     

The frequency of HLA-B57:01 and the risk of abacavir hypersensitivity reactions in the majority population of Costa Rica

HLA-B^∗57:01 is a well-known and cost-effective pharmacogenetic marker for abacavir hypersensitivity. As with other HLA alleles, there is widespread variation in its frequency across populations. The Costa Rica Central Valley Population (CCVP) is the major population in this country. The frequency of HLA-B^∗57:01 in this population has not been described yet. Thus, our aim was to determine the frequency of this allele in the CCVP. 200 unrelated healthy volunteer donors born in the CCVP were typed. HLA-B^∗57-positive samples identified by HLA intermediate resolution typing methods were further typed by SBT to high resolution. An HLA-B^∗57:01 carrier frequency of 5.00% was determined in this sample. This frequency is relatively high in comparison to reports from other populations in Latin America. These results suggest that there is a considerable frequency of HLA-B^∗57:01 in the CCVP and that pharmacogenetic testing for HIV+ patients who are going to receive abacavir-based treatment should be considered in this country.     

消斑肽对C57BL/6J小鼠动脉粥样硬化斑块的影响

恨现从中华眼镜蛇毒素中提取一种多肽能抑制血管平滑肌细胞地殖,并在一定范围内杀伤快速增殖的平滑肌细胞。为验证消斑肽是否具有消除动脉粥样硬化斑块和预防再狭窄的药物效应,选用动脉粥样硬化敏感株近交系Ｃ５７ＢＬ／６Ｊ小鼠,经致动脉粥样硬化饮食饲喂１７周。使用消斑肽腹腔注射３．２μｇ／ｇ治疗４周,在主动脉窦部连续切片,油经Ｏ染色并在显微镜下观察,使用Ｒｏｂｅｒｔｓ ＆ Ｔｈｏｍｐｓｏｎ评分判定斑块消退情况。     

荧光标记引物miniCTTA复合扩增系统的建立

目的建立扩增片段<130bp,包括CSF1PO、TH01和TPOX及性染色体amelogenin基因座的miniCTTA扩增系统。方法采用不同荧光染料标记引物,通过PCR扩增,利用ABI3100遗传分析仪进行片段长度分析,对100份无关个体血样,10个家系样本以及30份高度降解检材进行检测。结果miniCTTA系统DNA分型结果与AmpFLSTRIden-tifiler试剂盒完全一致。结论miniCTTA系统可以应用于个人识别和亲权鉴定,为降解DNA样本分型提供了新的方法。RR     

日本血吸虫pcDNA3/SjCWL01核酸疫苗的构建及其对小鼠免疫效果观察

目的构建日本血吸虫pcDNA3/SjCWL01核酸疫苗并进行免疫保护效果观察,评价其作为疫苗的潜能。方法将日本血吸虫基因SjCWL01亚克隆入真核表达载体pcDNA3,构建目的基因真核表达质粒,将pcDNA3/SjCWL01质粒转化大肠杆菌DH5α,大量制备DNA疫苗并免疫小鼠3次,间隔2w,末次免疫后2w,用ELISA法检测免疫鼠血清特异性抗体效价,日本血吸虫尾蚴进行腹部皮肤攻击感染,感染后45d剖杀冲虫,分别计算减虫率,每克肝、粪卵减少率。结果重组DNA疫苗(pcDNA3/SjCWL01)与对照组比较,虫荷、每克肝卵、每克粪卵数分别下降了27.6%,39.5%,45.9%。结论表明pcD-NA3/SjCWL01疫苗可诱导小鼠产生部分抗血吸虫感染的保护力。