Facteurs associés aux perdus de vue des patients sous traitement antirétroviral dans un centre de traitement ambulatoire du VIH à Conakry,Guinée

Background

Late or inadequate therapeutic management increases the risk of mortality associated with HIV/AIDS. The aim of this study was to analyze the proportion and factors associated with loss of follow-up in HIV patients who receiving antiretroviral therapy at Conakry.

On the use of denaturing gradient gel electrophoresis approach for bacterial identification in endodontic infections

Bacteria in infected root canals of teeth evincing chronic apical periodontitis lesions were identified by a polymerase chain reaction–denaturing gradient gel electrophoresis (PCR-DGGE) approach. DNA was extracted from root canal samples, and part of the 16S rRNA gene of all bacteria was amplified by PCR and separated by DGGE, generating banding patterns representative of the community structure. Twenty visible bands were cut out of the gel, re-amplified, and sequenced to provide identification. Sequencing analysis revealed the presence of both cultivable and as-yet-uncultivated species in the samples analyzed, including representatives of the genera Fusobacterium, Bacteroides, Dialister, Synergistes, Prevotella, Eubacterium and Peptostreptococcus. Unambiguous identification was not always possible and the method’s limitations are discussed. In general, the findings showed that PCR-DGGE can be useful for the identification of both cultivable and as-yet-uncultivated bacteria in endodontic infections.     

Bacterial community profiles of endodontic abscesses from Brazilian and USA subjects as compared by denaturing gradient gel electrophoresis analysis

This study compared the bacterial community profiles of the microbiota associated with acute apical abscesses from Brazilian and USA patients using denaturing gradient gel electrophoresis (DGGE). DNA was extracted from purulent exudate aspirates and part of the 16S rRNA gene was amplified by polymerase chain reaction and separated by DGGE. The resulting banding patterns, which were representative of the bacterial community structures in samples from the two locations, were then compared. Distinct DGGE banding patterns were observed from different samples. Ninety-nine bands with distinct positions in the gels were detected, of which 27 were found only in the USA samples and 13 were exclusive to Brazilian samples. Four of the 59 shared bands showed very discrepant findings with regard to prevalence in the two locations. Cluster analysis of DGGE banding profiles showed a great variability in the bacterial populations associated with teeth with abscesses regardless of the geographical location. Two big clusters, one for each location, were observed. Other clusters contained a mixture of samples from the two locations. The results of the present study demonstrated a great variability in the bacterial community profiles among samples. This indicates that the bacterial communities of abscesses are unique for each individual in terms of diversity. The composition of the microbiota in some samples showed a geography-related pattern. Furthermore, several bands were exclusive for each location and others were shared by the two locations and showed great differences in prevalence.     

Donor‐specific chimeric antigen receptor Tregs limit rejection in naive but not sensitized allograft recipients

Cell therapy with autologous donor‐specific regulatory T cells (Tregs) is a promising strategy to minimize immunosuppression in transplant recipients. Chimeric antigen receptor (CAR) technology has recently been used successfully to generate donor‐specific Tregs and overcome the limitations of enrichment protocols based on repetitive stimulations with alloantigens. However, the ability of CAR‐Treg therapy to control alloreactivity in immunocompetent recipients is unknown. We first analyzed the effect of donor‐specific CAR Tregs on alloreactivity in naive, immunocompetent mice receiving skin allografts. Tregs expressing an irrelevant or anti‐HLA‐A2‐specific CAR were administered to Bl/6 mice at the time of transplanting an HLA‐A2⁺ Bl/6 skin graft. Donor‐specific CAR‐Tregs, but not irrelevant‐CAR Tregs, significantly delayed skin rejection and diminished donor‐specific antibodies (DSAs) and frequencies of DSA‐secreting B cells. Donor‐specific CAR‐Treg–treated mice also had a weaker recall DSA response, but normal responses to an irrelevant antigen, demonstrating antigen‐specific suppression. When donor‐specific CAR Tregs were tested in HLA‐A2‐sensitized mice, they were unable to delay allograft rejection or diminish DSAs. The finding that donor‐specific CAR‐Tregs restrain de novo but not memory alloreactivity has important implications for their use as an adoptive cell therapy in transplantation.     

Adverse Tumor Biology Associated with Mesenterico-Portal Vein Resection Influences Survival in Patients with Pancreatic Ductal Adenocarcinoma

Background

Although pancreatoduodenectomy (PD) with mesenterico-portal vein resection (VR) can be performed safely in patients with resectable pancreatic ductal adenocarcinoma (PDAC), the impact of this approach on long-term survival is controversial.

Patients and Methods

Analyses of a prospectively collected database revealed 122 consecutive patients with PDAC who underwent PD with (PD+VR) or without (PD?VR) VR between January 2004 and May 2012. Clinical data, operative results, and survival outcomes were analysed.

Results

Sixty-four (53 %) patients underwent PD+VR. The majority (84 %) of the venous reconstructions were performed with a primary end-to-end anastomosis. Demographic and postoperative outcomes were similar between the two groups. American Society of Anesthesiologists (ASA) score, duration of operation, intraoperative blood loss, and blood transfusion requirement were significantly greater in the PD+VR group compared with the PD?VR group. Furthermore, the tumor size was larger, and the rates of periuncinate neural invasion and positive resection margin were higher in the PD+VR group compared with the PD?VR group. Histological venous involvement occurred in 47 of 62 (76 %) patients in the PD+VR group. At a median follow-up of 29 months, the median overall survival (OS) was 18 months for the PD+VR group, and 31 months for the PD?VR group (p = 0.016). ASA score, lymph node metastasis, neurovascular invasion, and tumor differentiation were predictive of survival. The need for VR in itself was not prognostic of survival.

Conclusions

PD with VR has similar morbidity but worse OS compared with a PD?VR. Although VR is not predictive of survival, tumors requiring a PD+VR have more adverse biological features.