37 research outputs found

    PIMMS43 is required for malaria parasite immune evasion and sporogonic development in the mosquito vector.

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    After being ingested by a female Anopheles mosquito during a bloodmeal on an infected host, and before they can reach the mosquito salivary glands to be transmitted to a new host, Plasmodium parasites must establish an infection of the mosquito midgut in the form of oocysts. To achieve this, they must first survive a series of robust innate immune responses that take place prior to, during, and immediately after ookinete traversal of the midgut epithelium. Understanding how parasites may evade these responses could highlight new ways to block malaria transmission. We show that an ookinete and sporozoite surface protein designated as PIMMS43 (Plasmodium Infection of the Mosquito Midgut Screen 43) is required for parasite evasion of the Anopheles coluzzii complement-like response. Disruption of PIMMS43 in the rodent malaria parasite Plasmodium berghei triggers robust complement activation and ookinete elimination upon mosquito midgut traversal. Silencing components of the complement-like system through RNAi largely restores ookinete-to-oocyst transition but oocysts remain small in size and produce a very small number of sporozoites that additionally are not infectious, indicating that PIMMS43 is also essential for sporogonic development in the oocyst. Antibodies that bind PIMMS43 interfere with parasite immune evasion when ingested with the infectious blood meal and significantly reduce the prevalence and intensity of infection. PIMMS43 genetic structure across African Plasmodium falciparum populations indicates allelic adaptation to sympatric vector populations. These data add to our understanding of mosquito-parasite interactions and identify PIMMS43 as a target of malaria transmission blocking

    Effects of Azadirachta indica seed kernel extracts on early erythrocytic schizogony of Plasmodium berghei and pro-inflammatory response in inbred mice

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    Background: Medicinal plant research may contribute to develop new pharmacological control tools for vector borne diseases, such as malaria. Methods: The effects of methanol extracts (ME) obtained from seed kernel of ripe and unripe Azadirachta indica fruits were studied on erythrocytic proliferation of the rodent malaria parasite Plasmodium berghei strain ANKA and on mice pro-inflammatory response, as evaluated by measuring the matrix-metalloproteinase-9 (MMP-9) and tumour necrosis factor (TNF) plasma levels, in two mouse strains (C57BL/6 and BALB/c) which are considered as prototypical of Th1 and Th2 immune response, respectively. Results: ME obtained from seed kernel of unripe Azadirachta indica fruits decreased by about 30% the proportion of erythrocytes infected with the malaria parasite in C57BL/6 mice in the 4 days suppressive test. In this treatment group, MMP-9 and TNF levels were notably higher than those measured in the same mouse strain treated with the anti-malarial drug artesunate, Azadirachta indica kernel extracts from ripe fruits or solvent. In BALB/c mice, treatment with kernel extracts did not influence parasitaemia. MMP-9 and TNF levels measured in this mouse strain were notably lower than those recorded in C57BL/6 mice and did not vary among treatment groups. Conclusions: The effects of the ME on the parasite-host interactions appeared to be mouse strain-dependent, but also related to the ripening stage of the neem fruits, as only the unripe fruit seed kernel extracts displayed appreciable bioactivity

    Male-Specific Protein Disulphide Isomerase Function is Essential for Plasmodium Transmission and a Vulnerable Target for Intervention

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    Abstract: Inhibiting transmission of Plasmodium is an essential strategy in malaria eradication, and the biological process of gamete fusion during fertilization is a proven target for this approach. Lack of knowledge of the mechanisms underlying fertilization have been a hindrance in the development of transmission-blocking interventions. Here we describe a protein disulphide isomerase essential for malarial transmission (PDI-Trans/PBANKA_0820300) to the mosquito. We show that PDI-Trans activity is male-specific, surface-expressed, essential for fertilization/transmission, and exhibits disulphide isomerase activity which is up-regulated post-gamete activation. We demonstrate that PDI-Trans is a viable anti-malarial drug and vaccine target blocking malarial transmission with the use of PDI inhibitor bacitracin (98.21%/92.48% reduction in intensity/prevalence), and anti-PDI-Trans antibodies (66.22%/33.16% reduction in intensity/prevalence). To our knowledge, these results provide the first evidence that PDI function is essential for malarial transmission, and emphasize the potential of anti-PDI agents to act as anti-malarials, facilitating the future development of novel transmission-blocking interventions

    An overview of Neem (Azadirachta indica) and its potential impact on health

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    Global health and medical practice seek to merge alternative medicine with evidence-based medicine for a better understanding of the metabolic process and its effects in the human body. An example is the use of complementary medicine like phytotherapy. Azadirachta indica (Neem), a tree originally from India and Myanmar, called by many “The village pharmacy” or “Divine tree” because of its many health properties. In recent times, Neem-derived extracts have been shown to work from anywhere from insect repellent, to supplements to lower inflammation, diabetic control, and even to combat cancer. Herein, we state the health benefits found in diverse compounds and extracts derived from Neem, highlighting the mechanisms and pathways in which Neem compounds produce their effects, while warning that the improper and unstandardized conditions to produce extracts can lead to health issues, particularly certain compounds might have damaging effects on the liver and kidneys

    Policy makers and performance management in e-government domain

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    This article examines the current and future development of (e)government policy making, and the critical role that measurement and impact analysis has in this. There is a clear movement from an almost exclusive focus on the efficiency impacts of e-Government for government itself to more attention being paid to effectiveness impacts, as well as to wider governance impacts. This is going hand-in-hand with a change away from measuring only the inputs and outputs of e- Government initiatives towards much greater emphasis on analyzing and measuring the outcomes for constituents and the impacts for society as a whole, for example through increased public value. In addition, the article considers likely future e-Government measurement trends which involve moving both policy target setting and measurement from central government to local government, from the back-office to the front-office, and to front- line professional staff, whether care or medical professionals, police, community workers, teachers, etc. Taking this further, it also seems likely that in future constituents themselves will also be involved in policy target setting and measurement when directly related to their own use of public sector services and facilities

    RFID Privacy and Security Risks: Italian Case Study

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    Radio Frequency Identification (RFID) technology can be used in different areas such as in occupational safety and health. This article discusses the development of the RFID technology and its legal implications in the context of the Italian law. This is one of the most advanced European Union law when legal framework for RFID systems is considered. The paper will also face the important problem of the workplaces security. When implementing certain when legal framework for RFID systems is considered. The paper will also face the important problem of the workplaces security. When implementing certain types of systems the workplaces security can be a critical issue to be addressed
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