Excess polymorphisms in genes for membrane proteins in Plasmodium falciparum     

Volkman SK  Hartl DL  Wirth DF  Nielsen KM  Choi M  Batalov S  Zhou Y  Plouffe D  Le Roch KG  Abagyan R  Winzeler EA 《Science (New York, N.Y.)》2002,298(5591):216-218

The detection of single-nucleotide polymorphisms in pathogenic microorganisms has normally been carried out by trial and error. Here we show that DNA hybridization with high-density oligonucleotide arrays provides rapid and convenient detection of single-nucleotide polymorphisms in Plasmodium falciparum, despite its exceptionally high adenine-thymine (AT) content (82%). A disproportionate number of polymorphisms are found in genes encoding proteins associated with the cell membrane. These genes are targets for only 22% of the oligonucleotide probes but account for 69% of the polymorphisms. Genetic variation is also enriched in subtelomeric regions, which account for 22% of the chromosome but 76% of the polymorphisms.  相似文献   

Discovery of gene function by expression profiling of the malaria parasite life cycle     

Le Roch KG  Zhou Y  Blair PL  Grainger M  Moch JK  Haynes JD  De La Vega P  Holder AA  Batalov S  Carucci DJ  Winzeler EA 《Science (New York, N.Y.)》2003,301(5639):1503-1508

The completion of the genome sequence for Plasmodium falciparum, the species responsible for most malaria human deaths, has the potential to reveal hundreds of new drug targets and proteins involved in pathogenesis. However, only approximately 35% of the genes code for proteins with an identifiable function. The absence of routine genetic tools for studying Plasmodium parasites suggests that this number is unlikely to change quickly if conventional serial methods are used to characterize encoded proteins. Here, we use a high-density oligonucleotide array to generate expression profiles of human and mosquito stages of the malaria parasite's life cycle. Genes with highly correlated levels and temporal patterns of expression were often involved in similar functions or cellular processes.  相似文献   

A comparison of tissue oxygen saturation measurements by 2 different near‐infrared spectroscopy monitors in 21 healthy dogs     

Sarah Engbers BSc  Søren R. Boysen DVM  DACVECC  Jordan Engbers PhD  Serge Chalhoub DVM  DACVIM 《Journal of Veterinary Emergency and Critical Care》2014,24(5):536-544

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A polyetic modelling framework for plant disease emergence     

Laetitia Willocquet  Serge Savary  Bruce A. McDonald  Alexey Mikaberidze 《Plant pathology》2020,69(9):1630-1643

Plant disease emergences have dramatically increased recently as a result of global changes, especially with respect to trade, host genetic uniformity, and climate change. A better understanding of the conditions and processes determining epidemic outbreaks caused by the emergence of a new pathogen, or pathogen strain, is needed to develop strategies and inform decisions to manage emerging diseases. A polyetic process-based model is developed to analyse conditions of disease emergence. This model simulates polycyclic epidemics during successive growing seasons, the yield losses they cause, and the pathogen survival between growing seasons. This framework considers one immigrant strain coming in a single event into a system where a resident strain is already established. Outcomes are formulated as probability of emergence, time to emergence, and yield loss, resulting from deterministic and stochastic simulations. An analytical solution to determine a threshold for emergence is also derived. Analyses focus on the effects of two fitness parameters on emergence: the relative rate of reproduction (epidemic speed), and the relative rate of mortality (decay of population between seasons). Analyses revealed that stochasticity is a critical feature of disease emergence. The simulations suggest that: (a) emergence may require a series of independent immigration events before a successful invasion takes place; (b) an explosion in the population size of the new pathogen (or strain) may be preceded by many successive growing seasons of cryptic presence following an immigration event; and (c) survival between growing seasons is as important as reproduction during the growing season in determining disease emergence.  相似文献   

Cellular-resolution in vivo imaging of the feline retina using adaptive optics: preliminary results     

Rosolen SG  Lamory B  Harms F  Sahel JA  Picaud S  LeGargasson JF 《Veterinary ophthalmology》2010,13(6):369-376

Purpose To perform cellular‐level in vivo imaging of the feline retina using an adaptive optics flood illumination fundus camera (AO FIFC) designed for the human eye. Materials and methods Cellular‐level images were obtained from three eyes of two normal sedated cats. Ocular aberrations were corrected using an AO system based on a 52‐acuator electromagnetic deformable mirror and a 1024 lenslet Hartmann–Shack sensor (both Imagine Eyes, Orsay, France). A square 3°×3° area of the ocular fundus was flood‐illuminated by a pulsed LED emitting at 850 nm and imaged onto a low‐noise, high‐resolution CCD camera. The animal’s pupils were dilated and the effective pupil size was set to 7.5 mm. Conjunctival atraumatic clips were used to avoid eyeball movements and eyelid closure. The cornea was artificially hydrated throughout the experiments. Each acquisition consisted of 20 consecutive images, out of which 10 were numerically averaged to produce an enhanced final image. Results The total amount of ocular aberrations was greatly reduced by the AO correction, from 2.4 to 0.21 microns root mean square on average. The resulting images presented white dots distributed at a density similar to that of cone photoreceptors and they allowed us to visualize small blood vessels and nerve fiber bundles at a higher resolution than classically obtained with conventional fundus photography. Conclusion Retinal imaging with cellular resolution was feasible in cats under sedation using an AO FIFC designed for human eyes without any optical modification. The AO FIFC technology could find new applications in clinical, pharmacological, and toxicological investigations.  相似文献   

Update on Methodologies Available for Ciguatoxin Determination: Perspectives to Confront the Onset of Ciguatera Fish Poisoning in Europe []     

Amandine Caillaud  Pablo de la Iglesia  H. Taiana Darius  Serge Pauillac  Katerina Aligizaki  Santiago Fraga  Mireille Chinain  Jorge Diogène 《Marine drugs》2010,8(6):1838-1907

Ciguatera fish poisoning (CFP) occurs mainly when humans ingest finfish contaminated with ciguatoxins (CTXs). The complexity and variability of such toxins have made it difficult to develop reliable methods to routinely monitor CFP with specificity and sensitivity. This review aims to describe the methodologies available for CTX detection, including those based on the toxicological, biochemical, chemical, and pharmaceutical properties of CTXs. Selecting any of these methodological approaches for routine monitoring of ciguatera may be dependent upon the applicability of the method. However, identifying a reference validation method for CTXs is a critical and urgent issue, and is dependent upon the availability of certified CTX standards and the coordinated action of laboratories. Reports of CFP cases in European hospitals have been described in several countries, and are mostly due to travel to CFP endemic areas. Additionally, the recent detection of the CTX-producing tropical genus Gambierdiscus in the eastern Atlantic Ocean of the northern hemisphere and in the Mediterranean Sea, as well as the confirmation of CFP in the Canary Islands and possibly in Madeira, constitute other reasons to study the onset of CFP in Europe [1]. The question of the possible contribution of climate change to the distribution of toxin-producing microalgae and ciguateric fish is raised. The impact of ciguatera onset on European Union (EU) policies will be discussed with respect to EU regulations on marine toxins in seafood. Critical analysis and availability of methodologies for CTX determination is required for a rapid response to suspected CFP cases and to conduct sound CFP risk analysis.  相似文献   

Modelling and mapping potential epidemics of wheat diseases—examples on leaf rust and Septoria tritici blotch using EPIWHEAT     

Serge Savary  Stacia Stetkiewicz  François Brun  Laetitia Willocquet 《European journal of plant pathology / European Foundation for Plant Pathology》2015,142(4):771-790

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Effect of cow colostrum on the performance and survival rate of local newborn piglets in Benin Republic     

Aristide Mahoutin Agbokounou  Gbênangnon Serge Ahounou  Issaka Youssao Abdou Karim  Guy Apollinaire Mensah  Bénoît Koutinhouin  Jean-Luc Hornick 《Tropical animal health and production》2017,49(2):287-294

The effect of bovine colostrum, including its thermally labile compounds, on the survival and growth performance of local breed piglets reared by their mother, in Benin, was evaluated over a 49-day trial. Three groups of 16 piglets, stemming from two primiparous sows belonging to a unique traditional farm, were respectively fed for the first 48 h of life with either bovine colostrum heated to 85 °C for 30 min, or thawed bovine colostrum, or colostrum from the mother. Thereafter, the animals that received bovine colostrum turned back to their mother. At day 21, almost all piglets from the group that received heated colostrum died. The highest total weight gain was obtained in the group that received thawed bovine colostrum (P???0.01), followed by the group left with the mother. Corresponding average daily gains (ADGs) were 56, 34 and 2 g/day, respectively (P???0.05). At the end of the trial, the treatment effect was highly significant on the survival of piglets (100% in the thawed colostrum group vs. 00 and 50%, respectively, in the heated colostrum group and in the group left with the mother). At day 49, numerically higher weight and ADGs were obtained in the group that received thawed cow colostrum. Thawed bovine colostrum improved the growth performance and piglet survival in the local pig breed in Benin, probably owing to thermally labile components. Bovine colostrum may be used in our farms in order to reduce pre-weaning mortality, improve the profitability of livestock farmers, and ensure survival of traditional farms. The use of bovine colostrum on farms could be facilitated by collaboration between pig farmers and bovine farmers. It could also be facilitated by the creation of a colostrum bank.  相似文献   

Relevance of the positron emission tomography in the diagnosis of vascular graft infection with Coxiella burnetii     

Merhej V  Cammilleri S  Piquet P  Casalta JP  Raoult D 《Comparative immunology, microbiology and infectious diseases》2012,35(1):45-49

Coxiella burnetii, the causative agent of Q fever, may cause culture-negative vascular graft infections that can be diagnosed by serology and molecular biology. We present a case of vascular graft infection detected by positron emission tomography (PET) scanner. The presence of C. burnetii was confirmed by high antibody titers and positive polymerase chain reaction specific for C. burnetii. This report emphasizes the relevance of the PET scanner in the diagnosis of infection when used in association with Q fever serology and molecular biology for the etiological identification of C. burnetii.  相似文献   

Risk factors for stunting among under-fives in Libya     

El Taguri A  Betilmal I  Mahmud SM  Monem Ahmed A  Goulet O  Galan P  Hercberg S 《Public health nutrition》2009,12(8):1141-1149

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