Malaria is a pernicious public health problem in many areas of the world. Sub-Saharan Africa, where cases recorded represent over 90% of the world total, is particularly badly hit. Modelling by IRD scientists has revealed a core feature in the life-cycle of Plasmodium falciparum, the parasite responsible for the disease. Its gametocytes, the pre-gamete sexual forms, aggregate in clusters in human blood capillaries and, once ingested, keep this form until they reach the ideal breeding ground the mosquitos stomach provides. Conditions there favour encounters, and hence binding, between male and female gametocytes, thereby enhancing the parasites fertilization and reproduction capacity. Investigation of this behaviour should yield important information on both the parasites transmission to humans and on the way the disease develops.
Malaria, which infects 600 million people in the world and leads annually to 2 million deaths, is the most widespread of infectious diseases. The pathological agent is a microscopic parasite of the Plasmodium genus which develops inside the hosts erythrocytes. Plasmodia go through a series of asexual reproduction cycles before a transition takes place from asexual stages to production of sexual cells, the gametocytes or pre-gametes, in the host blood. The females of Anopheles, the mosquito vector, ingest blood and gametocytes during a nocturnal feed on human skin. The meal reaches the mosquitos stomach where Plasmodium sexual reproduction takes place. An encounter and subsequent binding between a male and a female gametocyte produces a zygote which will give rise to infectious forms. These migrate up to the mosquito salivary glands. From there they are transmitted to humans during a second blood meal.
Experimental gametocyte counts in the blood ingested by mosquitoes that had bitten volunteers naturally infected with Plasmodium falciparum showed that these sexual forms are overdispersed, in other words they have a heterogeneous distribution in the mosquito stomach. Their numbers vary between the different blood meals taken on the same volunteer, a feature previously observed in the case of large parasites (macroparasites), such as microfilariae (250 microns).
Bénédicte Robert | EurekAlert!
GLUT5 fluorescent probe fingerprints cancer cells
20.04.2018 | Michigan Technological University
Scientists re-create brain neurons to study obesity and personalize treatment
20.04.2018 | Cedars-Sinai Medical Center
Physicists at the Laboratory for Attosecond Physics, which is jointly run by Ludwig-Maximilians-Universität and the Max Planck Institute of Quantum Optics, have developed a high-power laser system that generates ultrashort pulses of light covering a large share of the mid-infrared spectrum. The researchers envisage a wide range of applications for the technology – in the early diagnosis of cancer, for instance.
Molecules are the building blocks of life. Like all other organisms, we are made of them. They control our biorhythm, and they can also reflect our state of...
University of Connecticut researchers have created a biodegradable composite made of silk fibers that can be used to repair broken load-bearing bones without the complications sometimes presented by other materials.
Repairing major load-bearing bones such as those in the leg can be a long and uncomfortable process.
Study published in the journal ACS Applied Materials & Interfaces is the outcome of an international effort that included teams from Dresden and Berlin in Germany, and the US.
Scientists at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) together with colleagues from the Helmholtz-Zentrum Berlin (HZB) and the University of Virginia...
Novel highly efficient and brilliant gamma-ray source: Based on model calculations, physicists of the Max PIanck Institute for Nuclear Physics in Heidelberg propose a novel method for an efficient high-brilliance gamma-ray source. A giant collimated gamma-ray pulse is generated from the interaction of a dense ultra-relativistic electron beam with a thin solid conductor. Energetic gamma-rays are copiously produced as the electron beam splits into filaments while propagating across the conductor. The resulting gamma-ray energy and flux enable novel experiments in nuclear and fundamental physics.
The typical wavelength of light interacting with an object of the microcosm scales with the size of this object. For atoms, this ranges from visible light to...
Stable joint cartilage can be produced from adult stem cells originating from bone marrow. This is made possible by inducing specific molecular processes occurring during embryonic cartilage formation, as researchers from the University and University Hospital of Basel report in the scientific journal PNAS.
Certain mesenchymal stem/stromal cells from the bone marrow of adults are considered extremely promising for skeletal tissue regeneration. These adult stem...
13.04.2018 | Event News
12.04.2018 | Event News
09.04.2018 | Event News
23.04.2018 | Physics and Astronomy
23.04.2018 | Physics and Astronomy
23.04.2018 | Trade Fair News