Evolution of the pfcrt T76 and pfmdr1 Y86 markers and chloroquine susceptibility 8 years after cessation of chloroquine use in Pikine, Senegal

The goal of the present study was to assess the evolution of the in vitro chloroquine resistance and also the prevalence of pfcrt T76 and pfmdr1 Y86 mutations in Pikine from 2000 while chloroquine (CQ) was the first-line treatment of malaria to 2009 when artemisinin-based combination therapies (ACTs) are in use. We genotyped pfcrt K76T and pfmdr1 N86Y polymorphisms by PCR-RFLP and assessed in vitro CQ susceptibility by double-site enzyme-linked pLDH immunodetection (DELI) assay in Plasmodium falciparum isolates collected in Pikine, Senegal. The proportions of the pfcrt T76 allele in the light of the three different treatment policies were 72.4?% before CQ withdrawal (2000 to 2003), 47.2?% while amodiaquine plus Fansidar was the first-line treatment (2004 to 2005), and 59.5?% since the ACT use was implemented (2006 to 2009). The prevalence of pfcrt T76 decreased significantly after CQ was stopped [X (2)?=?6.54, P?=?0.01 (2000-2003 versus 2004-2005)] and then slightly since ACTs have been implemented [X (2)?=?1.12, P?=?0.28 (2000-2003 versus 2006-2009)]. There were no significant differences on the prevalence of pfmdr1 Y86 throughout the three treatment policies. The DELI assay was carried out episodically in 2000 (n?=?36), 2001 (n?=?47), and 2009 (n?=?37). The mean IC(50)s of the isolates to CQ in 2000 versus 2009 and 2001 versus 2009 are significantly different (P?相似文献   

CD4+ T cells rely on a cytokine gradient to control intracellular pathogens beyond sites of antigen presentation

Effector T?cells are critical for clearance of pathogens from sites of infection. Like cytotoxic CD8(+) T?cells, CD4(+) helper T?cells have been shown to deliver effector molecules directionally toward the immunological synapse, suggesting that infected cells need to be engaged individually to receive effector signals. In contrast, we show here that CD4(+) T?cells stably contacted a minority of infected cells, yet these interactions triggered intracellular defense mechanisms in bystander cells in?vivo. By using a functional read-out, we provide evidence that this effector bystander activity extends via a gradient of IFN-γ more than 80?μm beyond the site of antigen presentation, promoting pathogen clearance in the absence of immunological synapse formation. Our results thus demonstrate that CD4(+) T?cells can exert their protective activity by engaging a minority of infected cells.     

Insecticidal cyclodepsipeptides from Beauveria felina

A novel cyclodepsipeptide, iso-isariin B (1), and the known isaridin E (2) were isolated from the entomopathogenic fungus Beauveria felina. Their structures were elucidated using MS/MS fragmentation and extensive 2D-heteronuclear NMR. The X-ray structure of isaridin E was obtained, showing two potent intramolecular H bonds and a type-VI turn with the HyLeu(1)-Pro(2) amide bond in a cis conformation. Iso-isariin B (1) was active against the pest-insect Sitophilus spp. with an LD(50) value of 10 μg/mL. This observation also gives some clues for ecological interpretation of cyclodepsipeptide production by B. felina.     

Rickettsia felis�Cassociated Uneruptive Fever, Senegal

During November 2008–July 2009, we investigated the origin of unknown fever in Senegalese patients with a negative malaria test result, focusing on potential rickettsial infection. Using molecular tools, we found evidence for Rickettsia felis–associated illness in the initial days of infection in febrile Senegalese patients without malaria.     

Prediction of Plasmodium falciparum placental infection according to the time of infection during pregnancy

Malarial infection during pregnancy leads to placental infection, a known risk factor for low birth weight. Whether the stage of pregnancy at infection has a differential influence on these effects is not clearly known, but may be of importance for prevention strategies, including intermittent preventive treatment of pregnant women. Malaria infection during early (before 20 weeks), middle (20-28 weeks), or late (after 28 weeks) pregnancy was evaluated by logistic regression and receiver operating characteristics analysis in relation to placental infection in pregnant Senegalese women. Plasmodium falciparum infections during late pregnancy are strongly related to placental infection, as well as those that occur in middle pregnancy. Knowledge of parasitological events over the entire duration of pregnancy permits a highly accurate prediction of placental infection. Not only malaria infections during late pregnancy increase the likelihood of placental infection. The current policy of intermittent preventive treatment of pregnant women, which implies an initial antimalarial cure after 20 weeks of pregnancy, will not avoid early infections. An earlier initiation of malaria prevention might improve its efficacy.     

La néphrite de Lyme chez l’homme : bases physiopathologiques et spectre lésionnel rénal

Known in less than half a century, borreliosis, or Lyme disease, is a zoonosis caused by the tick bite. It is the most common vector disease in Europe and the United States. Borrelia burgdorferi sensu lato, the bacterium in question, is fitted with a “cunning device” that allows it to trick the immune system and implant the infection chronically. It causes multi-system tissue damage mediated by the inflammatory response of the host. Renal involvement is rarely reported and is better known in dogs as Lyme nephritis. The first case of kidney impairment in the human being was described in 1999, and since then eight other cases have been reported. The involvement is preferentially glomerular; the histological forms vary between immune complex nephropathy and podocytopathy. The pathophysiological mechanisms appear to be triple: immune complex deposits, podocytic hyper-expression of the B7-1 membrane protein, and renal infiltration of inflammatory cells. On the basis of the accumulated knowledge of the disease in just over 40 years, this review aims at establishing the physio-pathological hypotheses of renal involvement in order to better define the histological lesions.     

Hepatitis B, C seroprevalence and delta viruses in HIV-1 Senegalese patients at HAART initiation (retrospective study)

The aim of this study was to determine hepatitis co-infection in a cohort of HIV infected patients at their inclusion in the Senegalese Initiative of ART Access. B, C, and D Hepatitis viruses serological markers were checked retrospectively on 363 stored plasma. For HBV, the Abbott laboratories equipment IMx was used to detect HBs Ag and anti Core Ab on negative HBs Ag samples. For HDV, anti Delta Ab was performed using the Abbott Murex Kit on all HBs Ag positive samples. For HCV, anti HCV Ab was detected by IMx as double screening test and confirmed by INNO-LIA(TM) HCV Core of Innogenetics laboratories. The statistical analysis was done with STATA V8. The study population was composed of 164 men and 199 women aged between 16 and 66 years. The immune and virological markers averages at their enrollment were 154 cell/mm(3) for TLCD4+ (n = 355 patients) and 4.9 log for viral load (n = 277 patients). HBs Ag was found in 61 patients or 16.8% and the prevalence of anti-HBc Ab was 83.2% (252/295). 2 patients or 3% on HBs Ag positive sample presents HBV/HDV co-infection Ab anti HCV was detects in 6 patients or 1.6% after confirmation and 2 patients had triple infection with HBV. These results showed that the prevalence of HBV and HCV in the population of persons living with HIV/AIDS in Senegal is similar to that found in the general population. Our data indicated that hepatitis pathology in the PLwHIV was essentially due to HBV. Further studies are needed to diagnose occult hepatitis in order to set up therapeutic strategies taking into account co-infections by hepatitis viruses in the ART programmes.     

Epidermoid cyst of the cerebellar vermis: Case report of a rare medial topography

Intracranial epidermoid cysts are very rare benign tumors representing less than 2% of intracranial tumors. They are located preferentially in the cerebellopontine angles, parasellar, and temporal regions. We report here the case of an epidermoid cyst of very uncommon medial location in the cerebellar vermis, in a 61-year-old female patient complicated with tumor protrusion into the foramen magnum and active hydrocephalus.     

Study of oro-dental injuries during seizures in Senegalese children with epilepsy]

The objectives of this study were to study the prevalence of oral traumatisms and their relationship to epileptic seizures in Senegalese children. This study was undertaken in the Children's National Hospital of Dakar and deal with children with epilepsy. Sotf tissues and the teeth traumatisms that have occurred during epileptic seizures were recorded. We have also studied the relationship between the frequency of the seizures and the oral soft and hard tissues traumatisms. One hundred and eight children aged from 5 to 15 years with 67 boys and 41 girls with an average age of 8.16+/-2.86 years were enrolled. Several types of epileptic seizures were observed during which 44.5% of the children presented oral traumatisms of soft tissues (27.8%) and the teeth (16.7%). There is no significant relationship between the number of seizures and the frequency of the dental traumatisms (p = 0.352). The tooth fractures are the lesions most frequently noticed and are observed in 24.4% of the children. The traumatisms of the maxillary central incisors account for 38% of the traumatisms, followed by the canines (2.7%) and the molars (1.9%). The lower central incisors are the least affected. The traumatisms of soft tissues were observed in 27.8% of the children: the lips are more often affected (44%), followed by the tongue (30%), the association between lip and tongue (18%) and the cheeks (8%). There is no significant relationship between the number of seizures and the frequency of the traumatisms of soft tissues (p = 0.35).