The in vitro effects of two chirodropid (Chironex fleckeri and Chiropsalmus sp.) venoms: efficacy of box jellyfish antivenom.

The pharmacological and biochemical isolation of cnidarian venoms has been hindered by difficulties with both extracting pure venom from nematocysts and venom stability. The development of a new technique to extract active, pure venom of Chironex fleckeri and Chiropsalmus sp. has enabled identify both neurotoxic and myotoxic activity in their venoms. These activities are similar, but not identical in each species. Venom (50 micro g/ml) from both species significantly inhibited indirect and direct twitches of the chick biventer nerve-muscle preparation. Pre-incubation with 1U/ml box jellyfish antivenom did not have any significant effect on venom-induced reductions of indirect twitches. However, this activity was markedly attenuated by prior addition of 5U/ml antivenom, albeit to a lesser degree for Chiropsalmus sp. In contrast, prior addition of 5U/ml box jellyfish antivenom did not neutralise the myotoxic activity of C. fleckeri venom (50 micro g/ml), although it did inhibit the myotoxicity produced by Chiropsalmus sp. venom (50 micro g/ml). Antivenom (5U/ml) added 1h after the addition of C. fleckeri venom (50 micro g/ml) had no effect on the indirect or direct twitches of the skeletal muscle preparation. However, it partially restored the reduction in indirect twitch height caused by Chiropsalmus sp. venom (50 micro g/ml). Myotoxicity was confirmed in muscle preparations stained with hematoxylin and eosin.Therefore, although antivenom was able to neutralize the neurotoxic effects of both species, and the myotoxic effects of Chiropsalmus sp., when added prior to venom, it was unable to reverse the effects after venom addition. This suggests that antivenom is unlikely to be useful in the treatment of neurotoxic or myotoxic effects in patients, although these effects are rarely seen clinically.     

海蜇皮炎86例分析

[目的]探讨海蛰皮炎的特点及有效治疗方法。[方法]对86例门诊及住院的海蛰皮炎患者的临床资料进行分析。[结果]近年来海蛰皮炎的发病率增加,皮肤损伤重,临床症状多样。[结论]海蛰皮炎的发生及症状轻重与海上活动增多、皮损面积大小、海蜇种类及就诊时间等有关。     

微波消解-电感耦合等离子体原子发射光谱法测定全血中的镧

目的评估多效防护乳中镧(La)的透皮安全性,建立微波消解-电感耦合等离子体发射光谱(ICP-OES)法测定大鼠全血中镧的分析方法。方法全血样品经微波消解后,采用电感耦合等离子发射光谱仪分析,以333.749 nm为分析谱线,对大鼠全血中的La进行含量测定。结果该方法的标准曲线相关性良好(r>0.9994),方法检出限为0.0025μg/ml,定量限为0.0077μg/ml,精密度<3%,回收率在94.9%~102.0%之间。结论基于微波消解的ICP-OES方法稳定可靠,可为镧元素的含量测定和给药安全性研究提供重要依据。     

Cardiovascular actions of the venom from the Irukandji (Carukia barnesi) jellyfish: effects in human, rat and guinea-pig tissues in vitro and in pigs in vitro

1. We have investigated the cardiovascular pharmacology of the crude venom extract (CVE) from the potentially lethal, very small carybdeid jellyfish Carukia barnesi, in rat, guinea-pig and human isolated tissues and anaesthetized piglets. 2. In rat and guinea-pig isolated right atria, CVE (0.1-10 microg/mL) caused tachycardia in the presence of atropine (1 micromol/L), a response almost completely abolished by pretreatment with tetrodotoxin (TTX; 0.1 micromol/L). In paced left atria from guinea-pig or rat, CVE (0.1-3 microg/mL) caused a positive inotropic response in the presence of atropine (1 micromol/L). 3. In rat mesenteric small arteries, CVE (0.1-30 microg/mL) caused concentration-dependent contractions that were unaffected by 0.1 micromol/L TTX, 0.3 micromol/L prazosin or 0.1 micromol/L omega-conotoxin GVIA. 4. Neither the rat right atria tachycardic response nor the contraction of rat mesenteric arteries to CVE were affected by the presence of box jellyfish (Chironex fleckeri) antivenom (92.6 units/mL). 5. In human isolated driven right atrial trabeculae muscle strips, CVE (10 microg/mL) tended to cause an initial fall, followed by a more sustained increase, in contractile force. In the presence of atropine (1 micromol/L), CVE only caused a positive inotropic response. In separate experiments in the presence of propranolol (0.2 micromol/L), the negative inotropic effect of CVE was enhanced, whereas the positive inotropic response was markedly decreased. 6. In anaesthetized piglets, CVE (67 microg/kg, i.v.) caused sustained tachycardia and systemic and pulmonary hypertension. Venous blood samples demonstrated a marked elevation in circulating levels of noradrenaline and adrenaline. 7. We conclude that C. barnesi venom may contain a neural sodium channel activator (blocked by TTX) that, in isolated atrial tissue (and in vivo), causes the release of transmitter (and circulating) catecholamines. The venom may also contain a 'direct' vasoconstrictor component. These observations explain, at least in part, the clinical features of the potentially deadly Irukandji syndrome.     

Partial purification of cytolytic venom proteins from the box jellyfish, Chironex fleckeri

Venom proteins from the nematocysts of Chironex fleckeri were fractionated by size-exclusion and cation-exchange chromatography. Using sheep erythrocyte haemolysis as an indicator of cytolytic activity, two major cytolysins, with native molecular masses of approximately 370 and 145kDa, and one minor cytolysin ( approximately 70kDa) were isolated. SDS-PAGE and western blot protein profiles revealed that the 370kDa haemolysin is composed of CfTX-1 and CfTX-2 subunits ( approximately 43 and 45kDa, respectively); the most abundant proteins found in C. fleckeri nematocyst extracts. The 145kDa haemolysin predominately contains two other major proteins ( approximately 39 and 41kDa), which are not antigenic towards commercially available box jellyfish antivenom or rabbit polyclonal antibodies raised against whole C. fleckeri nematocyst extracts or CfTX-1 and -2. The kinetics of CfTX-1 and -2 haemolytic activities are temperature dependent and characterised by a pre-lytic lag phase ( approximately 6-7min) prior to initiation of haemolysis. Significant amino acid sequence homology between the CfTX proteins and other box jellyfish toxins suggest that CfTX-1 and -2 may also be lethal and dermonecrotic. Therefore, further in vivo and in vitro studies are required to investigate the potential roles of CfTX-1 and -2 in the lethal effects of C. fleckeri venom.     

Severe delayed cutaneous reaction due to Mediterranean jellyfish (Rhopilema nomadica) envenomation

During summer, Mediterranean Sea waters are invaded by a species of jellyfish designated as Rhopilema nomadica . Their tentacles contain numerous nematocysts loaded with a toxin that causes envenomation, usually expressed as immediate appearance of redness, burning sensation and papulovesicular eruption in the affected skin. We report a lady with a severe delayed reaction due to jellyfish envenomation that developed 2 days after contact with jellyfish tentacles.     

2014 - 2017年宁夏319份市售食品中铝含量监测结果分析

目的 了解2014 - 2017年宁夏食品中铝污染的现状,为市场监管和食品安全风险分析提供参考,减少铝超标对人群的危害。方法 对宁夏地区2014 - 2017年的谷物及其制品、淀粉及淀粉类制品、即食海蜇、膨化食品、焙烤食品共5大类食品进行随机抽样,按GB/T5009.182 - 2003方法对样品进行检测。按GB2760 - 2014评价标准对检测结果进行分析评价。结果 不同类别食品中铝含量的检出情况不同。共检测食品319份,超标40份,超标率为12.54%。除焙烤食品中铝含量无超标外,即食海蜇中铝含量超标率最高,为90%（9/10）;谷物及其制品中油条的铝含量超标率次之,为33.96%（18/53）;淀粉及淀粉类制品、膨化食品的铝含量超标率依次为13.33%（6/45）、8.62%（5/58）。结论 宁夏地区市售食品中铝含量超标水平总体不高,但即食海蜇、油条中铝含量超标情况相对比较突出,建议加大监管力度和强度,保障食品安全。