The Phage Therapy Paradigm: Prêt-à-Porter or Sur-mesure?

Pharmaceutical Research -     

IL6 and TNF expression in vessels and surrounding tissues after embolization with ibuprofen-loaded beads confirms diffusion of ibuprofen

PurposeIn the treatment of uterine fibroid embolization related pain, the use of embolics loaded with non-steroidal anti-inflammatory drugs (NSAID) relies on an efficient delivery and impregnation of the embolized tissue. Immuno-labelling and spectroscopic techniques have demonstrated the release of ibuprofen from drug eluting beads (Wassef et al., 2008, Namur et al., 2009) but failed to demonstrate diffusion of the drug beyond the vascular wall (VW). We investigated whether ibuprofen diffused beyond the VW in surrounding tissues (ST), by tracking its biological effects through the modulation of expression of two main inflammatory cytokines.Materials and methodsUterine arteries of 6 sheep were embolized with ibuprofen loaded beads (IBU-BB) or non-loaded beads (BB) and sacrificed at one week. On frozen tissue slices, VWs of occluded arteries were isolated from ST using laser capture microdissection. RNA was extracted from VW and ST samples. Gene expression of IL6 and TNFα genes was measured by quantitative real-time PCR (qPCR).ResultsIL6 expression was significantly increased in IBU-BB compared to BB group both in VW (VW: fold-change (FC) = 4.9, p = 0.0009) and ST (ST: FC = 8.7, p = 0.0003). In IBU-BB, IL6 was significantly more expressed in VW than in ST (FC = 4.4; p = 0.0009). TNFα expression was not significantly different between IBU-BB and BB groups.ConclusionUsing qPCR + microdissection was useful to evaluate the spread of the biological effects of drug-loaded systems which attest of the tissular release. This approach can be considered when other drug detection techniques are unsuccessful or difficult to achieve. IL6 can be used as a marker of ibuprofen released by drug eluting beads in uterus. Gradient of expression of IL6 suggests diffusion of ibuprofen across the VW into the ST.     

Short-term uptake of microcystin-LR by Coregonus lavaretus: GST activity and genotoxicity

In the present study, juvenile whitefish weighing 2?g were exposed by force-feeding to two ecologically relevant doses (0.05 and 0.5?μg per fish) of microcystin-LR (MC-LR). Then over 96?h the MC uptake in fish liver and muscle was measured, as the activity of the detoxification enzyme glutathione S-transferase (GST) in the liver, and the genotoxicity impact on red blood cells. Results show that (1) the MC-LR equivalent concentrations increased for both doses and in both organs of whitefish with approximately threefold lower concentrations for the low dose compared to the high dose in both organs and threefold lower concentrations in the muscle compared to the liver for each dose (2) the liver GST activity increased during the first 48?h of exposure with fivefold higher GST activity for the highest dose at 48?h compared to control and (3) MC-LR leads to deoxyribonucleic acid strand breaks that were detected by the comet assay and shown to be partially repaired. This work demonstrates that European whitefish could be impacted by cyanobacteria toxins due to rapid microcystin uptake, especially in the context of chronic contamination, which can occur during long bloom episodes.     

Actinobaculum schaalii causing Fournier's gangrene

Actinobaculum schaalii, which belongs to the group of Gram-positive rods, is difficult to culture. Using molecular genetics, Actinobaculum schaalii could be identified as a causing microorganism in a case of Fournier's gangrene.     

A phosphorylcholine-modified chitosan polymer as an endothelial progenitor cell supporting matrix

The aim of the present study was to develop a new biopolymer to increase endothelial progenitor cells (EPC) survival and amplification. As a cell culture platform, bone marrow-derived cells (BMDC) were used to investigate the biocompatibility of chitosan-phosphorylcholine (CH-PC). On CH-PC, BMDC were found in colonies with a mortality rate similar to that of fibronectin (FN), the control matrix. Adhesion/proliferation assays demonstrated a greater number of BMDC on CH-PC after 7 days with an amplification phase occurring during the second week. Difference in adhesion mechanisms between (CH-PC) and the control FN matrix suggest distinctive cell retention ability. Confocal microscopy analyses confirmed that (CH-PC) supported the survival/differentiation of endothelial cells. Moreover, flow cytometry analyses demonstrated that, (CH-PC) increased the percentage of progenitor cells (CD117(+)CD34(+)) (7.1 ± 0.8%, FN: 4.1 ± 0.8%) and EPC (CD117(+)CD34(+)VEGFR-2(+)CD31(+)) (2.33 ± 0.6%, FN: 0.25 ± 0.1%), while the mesenchymal stem cell fraction (CD44(+)CD106(+)CD90(+)) was decreased (0.07 ± 0.01%, FN: 0.55 ± 0.22%). Polymeric substrate CH-PC might provide a suitable surface to promote the amplification of EPC for future vascular therapeutic applications.     

Hepatitis E virus infection in patients infected with the human immunodeficiency virus

Hepatitis E virus (HEV) is a newly-identified causative agent of acute and chronic hepatitis in severely immunocompromized patients. The present study sought to assess the prevalences of past, recent, on-going, and chronic HEV infections in patients infected with human immunodeficiency virus (HIV) in Marseille, South-eastern France, and to determine if they were correlated with the patients' immunological status or with cirrhosis. Anti-HEV IgG and IgM and HEV RNA testing were concurrently performed on the plasma from 184 patients infected with HIV, including 81 with a CD4+ T-lymphocyte count (CD4 count) <50 cells/mm(3) and 32 with a cirrhosis. Prevalence of anti-HEV IgG and IgM was 4.4% (8/184) and 1.6% (3/184), respectively. Past, recent, and on-going infections were observed in 3.3% (6/184), 1.6% (3/184), and 0.5% (1/184) of the patients, respectively. Anti-HEV antibodies prevalence did not differ significantly according to CD4 count, cirrhosis, sex, age, mode of HIV transmission, and infection with hepatitis B or C virus. Anti-HEV IgG seroreversion was observed in two patients. The patient whose plasma tested positive for HEV RNA had a CD4 count <50 cells/mm(3) ; HEV genotype was 3f. In this patient, longitudinal testing showed HEV RNA positivity during a 10-month period, indicating chronic HEV infection; in contrast, anti-HEV IgG never tested positive. Further studies are needed to evaluate the performance of commercial HEV serological assays in patients infected with HIV and to assess the actual incidence, prevalence, and outcome of HEV infection in this special group of patients. HEV RNA testing is necessary for such purposes.