The ctools open-source software package was developed for the scientific analysis of astronomical data from Imaging Air Cherenkov Telescopes (IACTs), such as H.E.S.S., VERITAS, MAGIC, and the future ...Cherenkov Telescope Array (CTA). To date, the software has been mainly tested using simulated CTA data; however, upon the public release of a small set of H.E.S.S. observations of the Crab nebula, MSH 15–52, RX J1713.7–3946, and PKS 2155–304 validation using real data is now possible. We analysed the data of the H.E.S.S. public data release using ctools version 1.6 and compared our results to those published by the H.E.S.S. Collaboration for the respective sources. We developed a parametric background model that satisfactorily describes the expected background rate as a function of reconstructed energy and direction for each observation. We used that model, and tested all analysis methods that are supported by ctools, including novel unbinned and joint or stacked binned analyses of the measured event energies and reconstructed directions, and classical On-Off analysis methods that are comparable to those used by the H.E.S.S. Collaboration. For all analysis methods, we found a good agreement between the ctools results and the H.E.S.S. Collaboration publications considering that they are not always directly comparable due to differences in the datatsets and event processing software. We also performed a joint analysis of H.E.S.S. and Fermi-LAT data of the Crab nebula, illustrating the multi-wavelength capacity of ctools. The joint Crab nebula spectrum is compatible with published literature values within the systematic uncertainties. We conclude that the ctools software is mature for the analysis of data from existing IACTs, as well as from the upcoming CTA.
During intraerythrocytic development, Plasmodium falciparum exports proteins that interact with the host cell plasma membrane and subplasma membrane-associated spectrin network. Parasite-exported ...proteins modify mechanical properties of host RBCs, resulting in altered cell circulation. In this work, optical tweezers experiments of cell mechanical properties at normal physiological and febrile temperatures are coupled, for the first time, with targeted gene disruption techniques to measure the effect of a single parasite-exported protein on host RBC deformability. We investigate Pf155/Ring-infected erythrocyte surface antigen (RESA), a parasite protein transported to the host spectrin network, on deformability of ring-stage parasite-harboring human RBCs. Using a set of parental, gene-disrupted, and revertant isogenic clones, we found that RESA plays a major role in reducing deformability of host cells at the early ring stage of parasite development, but not at more advanced stage. We also show that the effect of RESA on deformability is more pronounced at febrile temperature, which ring-stage parasite-harboring RBCs can be exposed to during a malaria attack, than at normal body temperature.
Toxoplasma gondii is a common human pathogen causing serious, even fatal, disease in the developing fetus and in immunocompromised patients. Despite its ability to reproduce sexually and its broad ...geographic and host range, Toxoplasma has a clonal population structure comprised principally of three lines. We have analyzed 15 polymorphic loci in the archetypal type I, II, and III strains and found that polymorphism was limited to, at most, two rather than three allelic classes and no polymorphism was detected between alleles in strains of a given type. Multilocus analysis of 10 nonarchetypal isolates likewise clustered the vast majority of alleles into the same two distinct ancestries. These data strongly suggest that the currently predominant genotypes exist as a pandemic outbreak from a genetic mixing of two discrete ancestral lines. To determine if such mixing could lead to the extreme virulence observed for some strains, we examined the F1progeny of a cross between a type II and III strain, both of which are relatively avirulent in mice. Among the progeny were recombinants that were at least 3 logs more virulent than either parent. Thus, sexual recombination, by combining polymorphisms in two distinct and competing clonal lines, can be a powerful force driving the natural evolution of virulence in this highly successful pathogen.
Campylobacter fetus is a rare Gram-negative bacteria affecting especially elderly and immunocompromised patients, and that is responsible of vascular and cutaneous involvement.
We report two cases of ...C. fetus infection in two diabetic male patients, aged 75 and 85 years. The first patient was admitted for chronic fever. First-line examinations were inconclusive. Combined positron emission tomography and computed imaging tomography (PET-CT) diagnosed an infection of a previously operated popliteal aneurysm. The patient underwent surgery, and per-operative samples were positive for C. fetus. The second patient was admitted for a leg cellulitis. Blood cultures were positive for C. fetus. PET-CT found a septic superficial thrombophlebitis. The outcome was favorable for both patients with prolonged antibiotic therapy.
Vascular involvement should be suspected in the presence of C. fetus infections. PET-CT may be useful, as other imaging modalities are not always contributive.
Genetic diversity of the merozoite surface antigen-2 gene of the human malaria parasite Plasmodium falciparum has been analyzed in a Senegalese village where malaria is holoendemic. A cross-sectional ...survey of 65 residents was performed in 1992 during the high transmission season. Plasmodium falciparum was detected both by microscopy (77% positive samples) and DNA amplification using a single (29% or 38% positive samples, depending on the primers used) or nested polymerase chain reaction (PCR) (78% positive samples). The overlap between the positive nested PCR and microscopic examination was not complete. The PCR fragments were analyzed for size polymorphism on agarose gels, and were subsequently assigned to the major allelic families 3D7 or FC27 by hybridization with family-specific probes. Both allelic families were found, with a slightly higher prevalence for FC27. Chimeric alleles that failed to hybridize under stringent conditions to the reference probes were also observed. Some were typed using a novel PCR approach, using hybrid pairs of primers, consisting of a family-specific sense oligonucleotide combined with an antisense oligonucleotide specific for the other family. Combining typing techniques, 82% of the positive PCR results yielded more than one band. Both the overall number of fragments and the number of allelic types per carrier were markedly reduced around the age of 15 years. The number of DNA fragments decreased abruptly from an average of four per carrier before the age of 15 years to an average of two in individuals more than 15 years of age.
Sprue tropicale chez un expatrié Bonnefoy, S.; Chauvin, A.; Galéano-Cassaz, C. ...
La revue de medecine interne,
20/May , Letnik:
33, Številka:
5
Journal Article
Recenzirano
La sprue tropicale est un syndrome de malabsorption d’origine postinfectieuse contractée dans certaines zones tropicales endémiques.
Un patient âgé de 65 ans, sans antécédent particulier, caucasien, ...vivant au Cambodge depuis dix ans, consultait pour un amaigrissement de 23 kg et diarrhée chronique. L’examen clinique était sans particularité. Les examens biologiques montraient un syndrome carentiel modéré. La fibroscopie œso-gastro-duodénale décrivait un aspect d’atrophie villositaire et l’examen anatomopathologique confirmait une atrophie villositaire subtotale avec lymphocytose intra-épithéliale importante. Le diagnostic de sprue tropicale était retenu sur le contexte épidémiologique, le tableau clinique, biologique et l’absence d’autre cause d’atrophie villositaire. Un traitement d’épreuve était proposé par antibiothérapie, acide folique et vitamine B12 pour une durée de trois mois. L’évolution clinique était favorable avec disparition de la diarrhée en 15 jours. Un an plus tard, le patient avait repris 20 kg, les examens biologiques et les biopsies duodénales étaient normaux.
Le diagnostic de sprue tropicale doit être systématiquement discuté devant tout syndrome de malabsorption avec atrophie villositaire chez un sujet vivant ou ayant vécu de manière prolongée en zone intertropicale.
Tropical sprue is a postinfective malabsorption syndrome that occurs in some tropical endemic areas.
A 65-year-old Caucasian patient, with no significant past medical history, living in Cambodia for 10 years, presented with a 23 kg weight loss and chronic diarrhea. Clinical examination was unremarkable. Laboratory tests showed a moderate nutritional deficiency syndrome. The upper gastrointestinal endoscopy showed duodenal villous atrophy and histological analysis confirmed subtotal villous atrophy with important intraepithelial lymphocytosis. The diagnosis of tropical sprue was considered on the epidemiological, clinical and biological context, and the absence of other cause of villous atrophy. A three-month duration treatment with antibiotics, folic acid and vitamin B12 was initiated. The clinical course was favorable with disappearance of diarrhea in 15 days. One year later, the patient had resumed his usual weight, and laboratory tests and duodenal biopsies were normal.
The diagnosis of tropical sprue should be systematically discussed in any malabsorption syndrome with villous atrophy in a patient living or having lived in the tropics.
Tropical sprue in an expatriate Bonnefoy, S; Chauvin, A; Galéano-Cassaz, C ...
La revue de medecine interne
33, Številka:
5
Journal Article
Recenzirano
Tropical sprue is a postinfective malabsorption syndrome that occurs in some tropical endemic areas.
A 65-year-old Caucasian patient, with no significant past medical history, living in Cambodia for ...10 years, presented with a 23 kg weight loss and chronic diarrhea. Clinical examination was unremarkable. Laboratory tests showed a moderate nutritional deficiency syndrome. The upper gastrointestinal endoscopy showed duodenal villous atrophy and histological analysis confirmed subtotal villous atrophy with important intraepithelial lymphocytosis. The diagnosis of tropical sprue was considered on the epidemiological, clinical and biological context, and the absence of other cause of villous atrophy. A three-month duration treatment with antibiotics, folic acid and vitamin B12 was initiated. The clinical course was favorable with disappearance of diarrhea in 15 days. One year later, the patient had resumed his usual weight, and laboratory tests and duodenal biopsies were normal.
The diagnosis of tropical sprue should be systematically discussed in any malabsorption syndrome with villous atrophy in a patient living or having lived in the tropics.
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