Irradiation corporelle totale : présent et avenir [Total body irradiation: present and future]

Total body irradiation (TBI) has an established role as preparative regimen for bone-marrow transplantation in the treatment of hematological malignancies. Many randomized trials demonstrated that the clinical outcomes obtained from the association of TBI and cyclophosphamide are equivalent, or, sometimes, better than those based on chemotherapeutic agents. Despite the therapeutic progress of the last years, and the consequent improvement in the overall survival, this preparative regimen remains always associated with a relatively high rate of acute and late toxicity. In this article, we review the actual indications of TBI in clinical practice, and analyze the technological progress in this domain. We focus on the hypothesis that a selective irradiation of the hematopoietic or lymphoid organs is actually possible with intensity-modulated radiotherapy. Technical limits and preliminary results in terms of acute and late toxicities of intensity-modulated TBI are analyzed. With these new technologies, treatment-related toxicity is not anymore a major limiting factor in the preparative regimens for bone-marrow transplantation, allowing for a larger spectrum of TBI indications, a possible extension to patients older than 50 years, or a dose escalation. Preliminary results warrant, however, further evaluation in clinical trials to better assess the impact of this new approach on disease control and the long-term toxicity.

Optical spectroscopy of the bladder washout fluid to optimize fluorescence cystoscopy with Hexvix®.

Fluorescence cystoscopy enhances detection of early bladder cancer. Water used to inflate the bladder during the procedure rapidly contains urine, which may contain fluorochromes. This frequently degradesfluorescence images. Samples of bladder washout fluid (BWF) or urine were collected (15 subjects). We studiedtheir fluorescence properties and assessed changes induced by pH (4 to 9) and temperature (15°C to 41°C).A typical fluorescence spectrum of BWF features a main peak (excitation/emission: 320∕420 nm, FWHM =50∕100 nm) and a weaker (5% to 20% of main peak intensity), secondary peak (excitation/emission: 455∕525 nm, FWHM = 80∕50 nm). Interpatient fluctuations of fluorescence intensity are observed. Fluorescence intensity decreases when temperature increases (max 30%) or pH values vary (max 25%). Neither approach is compatible with clinical settings. Fluorescence lifetime measurements suggest that 4-pyridoxic acid/riboflavin is the most likely molecule responsible for urine's main/secondary fluorescence peak. Our measurements give an insight into the spectroscopy of the detrimental background fluorescence. This should be included in the optical design of fluorescence cystoscopes. We estimate that restricting the excitation range from 370-430 nm to 395-415 nm would reduce the BWF background by a factor 2.

Protection from HIV-1 infection of primary CD4 T cells by CCR5 silencing is effective for the full spectrum of CCR5 expression.

Stable gene silencing by RNA interference (RNAi) can be achieved by expression of small hairpin RNAs (shRNAs) from RNA polymerase III promoters. We have tested lentiviral vectors expressing shRNAs targetting CCR5 in primary CD4 T cells from donors representing various CCR5 and CCR2 genetic backgrounds covering the full spectrum of CCR5 expression levels and permissiveness for HIV-1 infection. A linear decrease in CCR5 expression resulted in a logarithmic decrease in cellular infection, giving up to three logs protection from HIV-1 infection in vitro. Protection was maintained at very high multiplicity of infection. This and other recent reports on RNAi should open a debate about the use of RNAi gene therapy for HIV infection.

Differential effects of selective HDAC inhibitors on macrophage inflammatory responses to the Toll-like receptor 4 agonist LPS.

Broad-spectrum inhibitors of HDACs are therapeutic in many inflammatory disease models but exacerbated disease in a mouse model of atherosclerosis. HDAC inhibitors have anti- and proinflammatory effects on macrophages in vitro. We report here that several broad-spectrum HDAC inhibitors, including TSA and SAHA, suppressed the LPS-induced mRNA expression of the proinflammatory mediators Edn-1, Ccl-7/MCP-3, and Il-12p40 but amplified the expression of the proatherogenic factors Cox-2 and Pai-1/serpine1 in primary mouse BMM. Similar effects were also apparent in LPS-stimulated TEPM and HMDM. The pro- and anti-inflammatory effects of TSA were separable over a concentration range, implying that individual HDACs have differential effects on macrophage inflammatory responses. The HDAC1-selective inhibitor, MS-275, retained proinflammatory effects (amplification of LPS-induced expression of Cox-2 and Pai-1 in BMM) but suppressed only some inflammatory responses. In contrast, 17a (a reportedly HDAC6-selective inhibitor) retained anti-inflammatory but not proinflammatory properties. Despite this, HDAC6(-/-) macrophages showed normal LPS-induced expression of HDAC-dependent inflammatory genes, arguing that the anti-inflammatory effects of 17a are not a result of inhibition of HDAC6 alone. Thus, 17a provides a tool to identify individual HDACs with proinflammatory properties.

Increased epidermal expression and absence of mutations in CARD14 in a series of patients with sporadic pityriasis rubra pilaris.

Pityriasis rubra pilaris (PRP; MIM 173200) encompasses a spectrum of rare chronic papulosquamous inflammatory disorders, which have been classified into 6 subtypes(1) . Clinical features include palmoplantar keratoderma and follicular hyperkeratotic papules which coalesce into large, scaly, erythematous plaques, with frequent progression to exfoliative erythroderma. This article is protected by copyright. All rights reserved.

TBC1D7 mutations are associated with intellectual disability, macrocrania, patellar dislocation, and celiac disease.

TBC1D7 forms a complex with TSC1 and TSC2 that inhibits mTORC1 signaling and limits cell growth. Mutations in TBC1D7 were reported in a family with intellectual disability (ID) and macrocrania. Using exome sequencing, we identified two sisters homozygote for the novel c.17_20delAGAG, p.R7TfsX21 TBC1D7 truncating mutation. In addition to the already described macrocephaly and mild ID, they share osteoarticular defects, patella dislocation, behavioral abnormalities, psychosis, learning difficulties, celiac disease, prognathism, myopia, and astigmatism. Consistent with a loss-of-function of TBC1D7, the patient's cell lines show an increase in the phosphorylation of 4EBP1, a direct downstream target of mTORC1 and a delay in the initiation of the autophagy process. This second family allows enlarging the phenotypic spectrum associated with TBC1D7 mutations and defining a TBC1D7 syndrome. Our work reinforces the involvement of TBC1D7 in the regulation of mTORC1 pathways and suggests an altered control of autophagy as possible cause of this disease.

Fosfomycin versus meropenem in bacteraemic urinary tract infections caused by extended-spectrum β-lactamase-producing Escherichia coli (FOREST): study protocol for an investigator-driven randomised controlled trial.

INTRODUCTION Finding therapeutic alternatives to carbapenems in infections caused by extended-spectrum β-lactamase-producing Escherichia coli (ESBL-EC) is imperative. Although fosfomycin was discovered more than 40 years ago, it was not investigated in accordance with current standards and so is not used in clinical practice except in desperate situations. It is one of the so-called neglected antibiotics of high potential interest for the future. METHODS AND ANALYSIS The main objective of this project is to demonstrate the clinical non-inferiority of intravenous fosfomycin with regard to meropenem for treating bacteraemic urinary tract infections (UTI) caused by ESBL-EC. This is a 'real practice' multicentre, open-label, phase III randomised controlled trial, designed to compare the clinical and microbiological efficacy, and safety of intravenous fosfomycin (4 g/6 h) and meropenem (1 g/8 h) as targeted therapy for this infection; a change to oral therapy is permitted after 5 days in both arms, in accordance with predetermined options. The study design follows the latest recommendations for designing trials investigating new options for multidrug-resistant bacteria. Secondary objectives include the study of fosfomycin concentrations in plasma and the impact of both drugs on intestinal colonisation by multidrug-resistant Gram-negative bacilli. ETHICS AND DISSEMINATION Ethical approval was obtained from the Andalusian Coordinating Institutional Review Board (IRB) for Biomedical Research (Referral Ethics Committee), which obtained approval from the local ethics committees at all participating sites in Spain (22 sites). Data will be presented at international conferences and published in peer-reviewed journals. DISCUSSION This project is proposed as an initial step in the investigation of an orphan antimicrobial of low cost with high potential as a therapeutic alternative in common infections such as UTI in selected patients. These results may have a major impact on the use of antibiotics and the development of new projects with this drug, whether as monotherapy or combination therapy. TRIAL REGISTRATION NUMBER NCT02142751. EudraCT no: 2013-002922-21. Protocol V.1.1 dated 14 March 2014.

The Times They Are a-Changin': Carbapenems for Extended-Spectrum-β-Lactamase-Producing Bacteria.

Several antimicrobial agents are being investigated as alternatives to carbapenems in the treatment of infections caused by ESBL-producing Enterobacteriaceae, which may be useful in avoiding overuse of carbapenems in the context of recent global spread of carbapenem-resistant Enterobacteriaceae. The most promising candidates for invasive infections so far are β-lactam/β-lactamase inhibitor combinations and cephamycins.

Klebsiella pneumoniae strains producing extended-spectrum beta-lactamases in Spain: microbiological and clinical features.

Extended-spectrum β-lactamases (ESBL) of the CTX-M, SHV, and TEM families were recognized in 76 (67%), 31 (27%), and 6 (5%) isolates, respectively, among 162 ESBL-producing Klebsiella pneumoniae (ESBL-Kp) strains obtained in a multicenter study in Spain. Predisposing factors for ESBL-Kp acquisition included invasive procedures, mechanical ventilation, and previous antimicrobial use.

Four main virotypes among extended-spectrum-β-lactamase-producing isolates of Escherichia coli O25b:H4-B2-ST131: bacterial, epidemiological, and clinical characteristics.

A total of 1,021 extended-spectrum-β-lactamase-producing Escherichia coli (ESBLEC) isolates obtained in 2006 during a Spanish national survey conducted in 44 hospitals were analyzed for the presence of the O25b:H4-B2-ST131 (sequence type 131) clonal group. Overall, 195 (19%) O25b-ST131 isolates were detected, with prevalence rates ranging from 0% to 52% per hospital. Molecular characterization of 130 representative O25b-ST131 isolates showed that 96 (74%) were positive for CTX-M-15, 15 (12%) for CTX-M-14, 9 (7%) for SHV-12, 6 (5%) for CTX-M-9, 5 (4%) for CTX-M-32, and 1 (0.7%) each for CTX-M-3 and the new ESBL enzyme CTX-M-103. The 130 O25b-ST131 isolates exhibited relatively high virulence scores (mean, 14.4 virulence genes). Although the virulence profiles of the O25b-ST131 isolates were fairly homogeneous, they could be classified into four main virotypes based on the presence or absence of four distinctive virulence genes: virotypes A (22%) (afa FM955459 positive, iroN negative, ibeA negative, sat positive or negative), B (31%) (afa FM955459 negative, iroN positive, ibeA negative, sat positive or negative), C (32%) (afa FM955459 negative, iroN negative, ibeA negative, sat positive), and D (13%) (afa FM955459 negative, iroN positive or negative, ibeA positive, sat positive or negative). The four virotypes were also identified in other countries, with virotype C being overrepresented internationally. Correspondingly, an analysis of XbaI macrorestriction profiles revealed four major clusters, which were largely virotype specific. Certain epidemiological and clinical features corresponded with the virotype. Statistically significant virotype-specific associations included, for virotype B, older age and a lower frequency of infection (versus colonization), for virotype C, a higher frequency of infection, and for virotype D, younger age and community-acquired infections. In isolates of the O25b:H4-B2-ST131 clonal group, these findings uniquely define four main virotypes, which are internationally distributed, correspond with pulsed-field gel electrophoresis (PFGE) profiles, and exhibit distinctive clinical-epidemiological associations.

Impact of the MIC of piperacillin-tazobactam on the outcome of patients with bacteremia due to extended-spectrum-β-lactamase-producing Escherichia coli.

We investigated the impact of the piperacillin-tazobactam MIC in the outcome of 39 bloodstream infections due to extended-spectrum-β-lactamase-producing Escherichia coli. All 11 patients with urinary tract infections survived, irrespective of the MIC. For other sources, 30-day mortality was lower for isolates with a MIC of ≤ 2 mg/liter than for isolates with a higher MIC (0% versus 41.1%; P = 0.02).

An electronic portfolio for quantitative assessment of surgical skills in undergraduate medical education.

BACKGROUND We evaluated a newly designed electronic portfolio (e-Portfolio) that provided quantitative evaluation of surgical skills. Medical students at the University of Seville used the e-Portfolio on a voluntary basis for evaluation of their performance in undergraduate surgical subjects. METHODS Our new web-based e-Portfolio was designed to evaluate surgical practical knowledge and skills targets. Students recorded each activity on a form, attached evidence, and added their reflections. Students self-assessed their practical knowledge using qualitative criteria (yes/no), and graded their skills according to complexity (basic/advanced) and participation (observer/assistant/independent). A numerical value was assigned to each activity, and the values of all activities were summated to obtain the total score. The application automatically displayed quantitative feedback. We performed qualitative evaluation of the perceived usefulness of the e-Portfolio and quantitative evaluation of the targets achieved. RESULTS Thirty-seven of 112 students (33%) used the e-Portfolio, of which 87% reported that they understood the methodology of the portfolio. All students reported an improved understanding of their learning objectives resulting from the numerical visualization of progress, all students reported that the quantitative feedback encouraged their learning, and 79% of students felt that their teachers were more available because they were using the e-Portfolio. Only 51.3% of students reported that the reflective aspects of learning were useful. Individual students achieved a maximum of 65% of the total targets and 87% of the skills targets. The mean total score was 345 ± 38 points. For basic skills, 92% of students achieved the maximum score for participation as an independent operator, and all achieved the maximum scores for participation as an observer and assistant. For complex skills, 62% of students achieved the maximum score for participation as an independent operator, and 98% achieved the maximum scores for participation as an observer or assistant. CONCLUSIONS Medical students reported that use of an electronic portfolio that provided quantitative feedback on their progress was useful when the number and complexity of targets were appropriate, but not when the portfolio offered only formative evaluations based on reflection. Students felt that use of the e-Portfolio guided their learning process by indicating knowledge gaps to themselves and teachers.

Diffusion spectrum magnetic resonance imaging (DSI) tractography of crossing fibers.

MRI tractography is the mapping of neural fiber pathways based on diffusion MRI of tissue diffusion anisotropy. Tractography based on diffusion tensor imaging (DTI) cannot directly image multiple fiber orientations within a single voxel. To address this limitation, diffusion spectrum MRI (DSI) and related methods were developed to image complex distributions of intravoxel fiber orientation. Here we demonstrate that tractography based on DSI has the capacity to image crossing fibers in neural tissue. DSI was performed in formalin-fixed brains of adult macaque and in the brains of healthy human subjects. Fiber tract solutions were constructed by a streamline procedure, following directions of maximum diffusion at every point, and analyzed in an interactive visualization environment (TrackVis). We report that DSI tractography accurately shows the known anatomic fiber crossings in optic chiasm, centrum semiovale, and brainstem; fiber intersections in gray matter, including cerebellar folia and the caudate nucleus; and radial fiber architecture in cerebral cortex. In contrast, none of these examples of fiber crossing and complex structure was identified by DTI analysis of the same data sets. These findings indicate that DSI tractography is able to image crossing fibers in neural tissue, an essential step toward non-invasive imaging of connectional neuroanatomy.

Combined pulmonary fibrosis and emphysema syndrome in connective tissue disease.

OBJECTIVE: Connective tissue diseases (CTDs) are associated with several interstitial lung diseases. The aim of this study was to describe the recently individualized syndrome of combined pulmonary fibrosis and emphysema (CPFE) in a population of patients with CTD. METHODS: In this multicenter study, we retrospectively investigated data from patients with CTD who also have CPFE. The demographic characteristics of the patients, the results of pulmonary function testing, high-resolution computed tomography, lung biopsy, and treatment, and the outcomes of the patients were analyzed. RESULTS: Data from 34 patients with CTD who were followed up for a mean±SD duration of 8.3±7.0 years were analyzed. Eighteen of the patients had rheumatoid arthritis (RA), 10 had systemic sclerosis (SSc), 4 had mixed or overlap CTD, and 2 had other CTDs. The mean±SD age of the patients was 57±11 years, 23 were men, and 30 were current or former smokers. High-resolution computed tomography revealed emphysema of the upper lung zones and pulmonary fibrosis of the lower zones in all patients, and all patients exhibited dyspnea during exercise. Moderately impaired pulmonary function test results and markedly reduced carbon monoxide transfer capacity were observed. Five patients with SSc exhibited pulmonary hypertension. Four patients died during followup. Patients with CTD and CPFE were significantly younger than an historical control group of patients with idiopathic CPFE and more frequently were female. In addition, patients with CTD and CPFE had higher lung volumes, lower diffusion capacity, higher pulmonary pressures, and more frequently were male than those with CTD and lung fibrosis without emphysema. CONCLUSION: CPFE warrants inclusion as a novel, distinct pulmonary manifestation within the spectrum of CTD-associated lung diseases in smokers or former smokers, especially in patients with RA or SSc.