临床疑似TTP-HUS患者血浆置换治疗引起的并发症

由于采用血浆置换(PE)治疗血栓性血小板减少性紫癜溶血性尿毒综合征(TTP HUS)频率的增加,PE引起的并发症也成为制定治疗方案时需要考虑的因素。由于TTP HUS的诊断常常是不确定的,掌握PE治疗利弊之间的平衡已成为制定适当治疗方案的焦点。之前,我们于1996年～2002年间曾两次报道     

Strategies of obligate intracellular parasites for evading host defences

During the course of establishing infection in a susceptible host, obligate intracellular parasites evade host defence mechanisms before, during and after entry into host cells. Before entry they circumvent the lytic activity of the complement cascade, during cell entry they avoid being killed by toxic oxygen metabolites and after entry they escape nonoxidative killing mechanisms such as degradation by lysosomal hydrolases. Different intracellular parasites, exemplified here by Leishmania spp, Trypanosoma cruzi and Toxoplasma gondii, undermine host defences at each step by various strategies that ultimately ensure their targeting to, and survival in, an appropriate intracellular compartment.     

Eosin B as a novel antimalarial agent for drug-resistant Plasmodium falciparum

4',5'-Dibromo-2',7'-dinitrofluorescein, a red dye commonly referred to as eosin B, inhibits Toxoplasma gondii in both enzymatic and cell culture studies with a 50% inhibitory concentration (IC(50)) of 180 microM. As a non-active-site inhibitor of the bifunctional T. gondii dihydrofolate reductase-thymidylate synthase (DHFR-TS), eosin B offers a novel mechanism for inhibition of the parasitic folate biosynthesis pathway. In the present study, eosin B was further evaluated as a potential antiparasitic compound through in vitro and cell culture testing of its effects on Plasmodium falciparum. Our data revealed that eosin B is a highly selective, potent inhibitor of a variety of drug-resistant malarial strains, with an average IC(50) of 124 nM. Furthermore, there is no indication of cross-resistance with other clinically utilized compounds, suggesting that eosin B is acting via a novel mechanism. The antimalarial mode of action appears to be multifaceted and includes extensive damage to membranes, the alteration of intracellular organelles, and enzymatic inhibition not only of DHFR-TS but also of glutathione reductase and thioredoxin reductase. In addition, preliminary studies suggest that eosin B is also acting as a redox cycling compound. Overall, our data suggest that eosin B is an effective lead compound for the development of new, more effective antimalarial drugs.     

A systematic review of risk of HIV transmission through biting or spitting: implications for policy

Objectives

The perceived threat of HIV transmission through spitting and biting is evidenced by the increasing use of “spit hoods” by Police Forces in the UK. In addition, a draft parliamentary bill has called for increased penalties for assaults on emergency workers, citing the risk of communicable disease transmission as one justification. We aimed to review literature relating to the risk of HIV transmission through biting or spitting.

Methods

A systematic literature search was conducted using Medline, Embase and Northern Lights databases and conference websites using search terms relating to HIV, AIDS, bite, spit and saliva. Inclusion and exclusion criteria were applied to identified citations. We classified plausibility of HIV transmission as low, medium, high or confirmed based on pre‐specified criteria.

Results

A total of 742 abstracts were reviewed, yielding 32 articles for full‐text review and 13 case reports/series after inclusion and exclusion criteria had been applied. There were no reported cases of HIV transmission related to spitting and nine cases identified following a bite, in which the majority occurred between family (six of nine), in fights involving serious wounds (three of nine), or to untrained first‐aiders placing fingers in the mouth of someone having a seizure (two of nine). Only four cases were classified as highly plausible or confirmed transmission. None related to emergency workers and none were in the UK.

Conclusions

There is no risk of transmitting HIV through spitting, and the risk through biting is negligible. Post‐exposure prophylaxis is not indicated after a bite in all but exceptional circumstances. Policies to protect emergency workers should be developed with this evidence in mind.