47 research outputs found
Histopathological patterns of the liver involvement in visceral leishmaniasis
The hepatic changes observed in liver specimen from either biopsy or necropsy of 47 patients with visceral leishmaniasis permited us to define three different histopathological patterns of involvement: typical, nodular, and fibrogenic. These patterns seem to be representative of different evolutive stages of the hepatic involvement in the disease either towards a more benign evolution or to more chronic stage with fibrosis and "cirrhosis". These histopathological evolutive stages are related to the prognosis of the disease
Why Functional Pre-Erythrocytic and Bloodstage Malaria Vaccines Fail: A Meta-Analysis of Fully Protective Immunizations and Novel Immunological Model
Background: Clinically protective malaria vaccines consistently fail to protect adults and children in endemic settings, and at best only partially protect infants. Methodology/Principal Findings: We identify and evaluate 1916 immunization studies between 1965-February 2010, and exclude partially or nonprotective results to find 177 completely protective immunization experiments. Detailed reexamination reveals an unexpectedly mundane basis for selective vaccine failure: live malaria parasites in the skin inhibit vaccine function. We next show published molecular and cellular data support a testable, novel model where parasite-host interactions in the skin induce malaria-specific regulatory T cells, and subvert early antigen-specific immunity to parasite-specific immunotolerance. This ensures infection and tolerance to reinfection. Exposure to Plasmodium-infected mosquito bites therefore systematically triggers immunosuppression of endemic vaccine-elicited responses. The extensive vaccine trial data solidly substantiate this model experimentally. Conclusions/Significance: We conclude skinstage-initiated immunosuppression, unassociated with bloodstage parasites, systematically blocks vaccine function in the field. Our model exposes novel molecular and procedural strategies to significantly and quickly increase protective efficacy in both pipeline and currently ineffective malaria vaccines, and forces fundamental reassessment of central precepts determining vaccine development. This has major implications fo
A tridimensional study using cuts at a low temperature of the infratemporal region
Although the infratemporal region is well defined anatomically, its complex topography has been the subject of numerous, and sometimes, opposite works. That is the reason why it appeared necessary for the authors to re-evaluate this topic using the original method of Combelles and Boyer, allowing to define three referential planes, and thereby, a tridimensional shape and the volume of this region. This study allows to conclude that the infratemporal region is a triangular prism with an horizontal main axis 47 mm long. Its anterior base has a mean area of 733 mm2. The posterior top consists of the Juvara slot and has a mean area of 490 mm2. This infratemporal prism contains another one, the pterygomandibular space, prismatic too. It widens out from coronoid plane (93 mm2) to mandibular foramen plane (169 mm2) before ending as a narrow groove between the neck of the mandibular condyle and the interpterygoid fascia. The volume of the pterygomandibular space is quite superior to the value usually reported in the dental literature. It is of 4.8 ml to 5.8 ml according to denture. These results point out the opportunity to accomodate more important volumes of anesthesic solutions, than the 1.8 ml usually performed, without any leak out of the infratemporal region