144 research outputs found

    Fulminant neuroleptic malignant syndrome after perioperative withdrawal of antiParkinsonian medication

    Get PDF
    Neuroleptic malignant syndrome is a rare complication when using neuroleptic drugs. We report the case of a patient with severe Parkinson's disease who developed neuroleptic malignant syndrome after withdrawal of his antiParkinsonian medication for elective coronary artery bypass grafting. Sodium dantrolene may be a therapeutic option in severe case

    A Homogeneous Actor-Based Monitor Language for Adaptive Behaviour

    Get PDF
    This paper describes a structured approach to encoding monitors in an actor language. Within a configuration of actors, each of which publishes a history, a monitor is an independent actor that triggers an action based on patterns occurring in the histories. We define a monitor language based on linear temporal logic and show how it can be homogeneously embedded within an actor language. The approach is demonstrated through a number of examples and evaluated in terms of a real-world actor-based simulation

    Short-term antigen presentation and single clonal burst limit the magnitude of the CD8(+) T cell responses to malaria liver stages.

    No full text
    Malaria sporozoites induce swift activation of antigen-specific CD8(+) T cells that inhibit the intracellular development of liver-stage parasites. The length of time of functional in vivo antigen presentation, estimated by monitoring the activation of antigen-specific CD8(+) T cells, is of short duration, with maximum T cell activation occurring within the first 8 h after immunization and lasting approximately 48 h. Although the magnitude of the CD8(+) T cell response closely correlates with the number of parasites used for immunization, increasing the time of antigen presentation by daily immunizations does not enhance the magnitude of this response. Thus, once a primary clonal burst is established, the CD8(+) T cell response becomes refractory or unresponsive to further antigenic stimulation. These findings strongly suggest that the most efficient strategy for the induction of primary CD8(+) T cell responses is the delivery of a maximal amount of antigen in a single dose, thereby ensuring a clonal burst that involves the largest number of precursors to become memory cells

    Using a New Odour-Baited Device to Explore Options for Luring and Killing Outdoor-Biting Malaria Vectors: A Report on Design and Field Evaluation of the Mosquito Landing Box.

    Get PDF
    Mosquitoes that bite people outdoors can sustain malaria transmission even where effective indoor interventions such as bednets or indoor residual spraying are already widely used. Outdoor tools may therefore complement current indoor measures and improve control. We developed and evaluated a prototype mosquito control device, the 'Mosquito Landing Box' (MLB), which is baited with human odours and treated with mosquitocidal agents. The findings are used to explore technical options and challenges relevant to luring and killing outdoor-biting malaria vectors in endemic settings. Field experiments were conducted in Tanzania to assess if wild host-seeking mosquitoes 1) visited the MLBs, 2) stayed long or left shortly after arrival at the device, 3) visited the devices at times when humans were also outdoors, and 4) could be killed by contaminants applied on the devices. Odours suctioned from volunteer-occupied tents were also evaluated as a potential low-cost bait, by comparing baited and unbaited MLBs. There were significantly more Anopheles arabiensis, An. funestus, Culex and Mansonia mosquitoes visiting baited MLB than unbaited controls (P<=0.028). Increasing sampling frequency from every 120 min to 60 and 30 min led to an increase in vector catches of up to 3.6 fold (P<=0.002), indicating that many mosquitoes visited the device but left shortly afterwards. Outdoor host-seeking activity of malaria vectors peaked between 7:30 and 10:30pm, and between 4:30 and 6:00am, matching durations when locals were also outdoors. Maximum mortality of mosquitoes visiting MLBs sprayed or painted with formulations of candidate mosquitocidal agent (pirimiphos-methyl) was 51%. Odours from volunteer occupied tents attracted significantly more mosquitoes to MLBs than controls (P<0.001). While odour-baited devices such as the MLBs clearly have potential against outdoor-biting mosquitoes in communities where LLINs are used, candidate contaminants must be those that are effective at ultra-low doses even after short contact periods, since important vector species such as An. arabiensis make only brief visits to such devices. Natural human odours suctioned from occupied dwellings could constitute affordable sources of attractants to supplement odour baits for the devices. The killing agents used should be environmentally safe, long lasting, and have different modes of action (other than pyrethroids as used on LLINs), to curb the risk of physiological insecticide resistance

    Comparative genomics of drug resistance in <i>Trypanosoma brucei rhodesiense</i>

    Get PDF
    Trypanosoma brucei rhodesiense is one of the causative agents of human sleeping sickness, a fatal disease that is transmitted by tsetse flies and restricted to Sub-Saharan Africa. Here we investigate two independent lines of T. b. rhodesiense that have been selected with the drugs melarsoprol and pentamidine over the course of 2 years, until they exhibited stable cross-resistance to an unprecedented degree. We apply comparative genomics and transcriptomics to identify the underlying mutations. Only few mutations have become fixed during selection. Three genes were affected by mutations in both lines: the aminopurine transporter AT1, the aquaporin AQP2, and the RNA-binding protein UBP1. The melarsoprol-selected line carried a large deletion including the adenosine transporter gene AT1, whereas the pentamidine-selected line carried a heterozygous point mutation in AT1, G430R, which rendered the transporter non-functional. Both resistant lines had lost AQP2, and both lines carried the same point mutation, R131L, in the RNA-binding motif of UBP1. The finding that concomitant deletion of the known resistance genes AT1 and AQP2 in T. b. brucei failed to phenocopy the high levels of resistance of the T. b. rhodesiense mutants indicated a possible role of UBP1 in melarsoprol-pentamidine cross-resistance. However, homozygous in situ expression of UBP1-Leu(131) in T. b. brucei did not affect the sensitivity to melarsoprol or pentamidine

    PSSA-2, a Membrane-Spanning Phosphoprotein of Trypanosoma brucei, Is Required for Efficient Maturation of Infection

    Get PDF
    The coat of Trypanosoma brucei consists mainly of glycosylphosphatidylinositol-anchored proteins that are present in several million copies and are characteristic of defined stages of the life cycle. While these major components of the coats of bloodstream forms and procyclic (insect midgut) forms are well characterised, very little is known about less abundant stage-regulated surface proteins and their roles in infection and transmission. By creating epitope-tagged versions of procyclic-specific surface antigen 2 (PSSA-2) we demonstrated that it is a membrane-spanning protein that is expressed by several different life cycle stages in tsetse flies, but not by parasites in the mammalian bloodstream. In common with other membrane-spanning proteins in T. brucei, PSSA-2 requires its cytoplasmic domain in order to exit the endoplasmic reticulum. Correct localisation of PSSA-2 requires phosphorylation of a cytoplasmic threonine residue (T305), a modification that depends on the presence of TbMAPK4. Mutation of T305 to alanine (T305A) has no effect on the localisation of the protein in cells that express wild type PSSA-2. In contrast, this protein is largely intracellular when expressed in a null mutant background. A variant with a T305D mutation gives strong surface expression in both the wild type and null mutant, but slows growth of the cells, suggesting that it may function as a dominant negative mutant. The PSSA-2 null mutant exhibits no perceptible phenotype in culture and is fully competent at establishing midgut infections in tsetse, but is defective in colonising the salivary glands and the production of infectious metacyclic forms. Given the protein's structure and the effects of mutation of T305 on proliferation and localisation, we postulate that PSSA-2 might sense and transmit signals that contribute to the parasite's decision to divide, differentiate or migrate
    • …
    corecore