Le roman épistolaire et l’expérience de la hauteur: à propos d’Oberman de Senancour (II. Expérimentations et déclin au XIXe siècle)

Special Issue/Dossier spécial: Les belles lettres dangereuses: Le destin de l’épistolarité littéraire du XVIIe au XIXe siècle/ Textes réunis par Atsuo MoriMot

The Clinical Aspects of β-Lactam-Resistant Stenotrophomonas maltophilia

Recent papers argue that major increases in the isolation of multidrug-resistant Gram-negative bacteria have been of some concern in clinical practice. Among these bacteria, Stenotrophomonas maltophilia is an intrinsic producer of β-lactamases, and has been recognized as a nosocomial pathogen. But few reports are available on the impact of the potential risk of mixed infections. The goal of this review is to explore that impact. S. maltophilia is often isolated from the respiratory tract together with other Gram-negative species, and yields at least two β-lactamases. The enzymes show the capacity to hydrolyze a large amount of imipenem and ceftazidime, and exhibit a susceptibility to aztreonam in combination with cefozopran. The last section elaborates on the idea that S. maltophilia can assist in the survival of other imipenem-susceptible bacteria such as Serratia marcescens and Pseudomonas aeruginosa. This theory is also valid for ceftazidime-susceptible P. aeruginosa. The present review confirms the potential threat of S. maltophilia as an indirect pathogen, and brings an often ignored fact to light: even originally fragile bacteria can live through a strong antimicrobial attack in the presence of a helper bacteria such as S. maltophilia. Although it is sometimes difficult to attribute a causative role to this bacterium, in fact, the existence of S. maltophilia is worthy of attention

The Clinical Aspects of β-Lactam-Resistant Stenotrophomonas maltophilia

Recent papers argue that major increases in the isolation of multidrug-resistant Gram-negative bacteria have been of some concern in clinical practice. Among these bacteria, Stenotrophomonas maltophilia is an intrinsic producer of β-lactamases, and has been recognized as a nosocomial pathogen. But few reports are available on the impact of the potential risk of mixed infections. The goal of this review is to explore that impact. S. maltophilia is often isolated from the respiratory tract together with other Gram-negative species, and yields at least two β-lactamases. The enzymes show the capacity to hydrolyze a large amount of imipenem and ceftazidime, and exhibit a susceptibility to aztreonam in combination with cefozopran. The last section elaborates on the idea that S. maltophilia can assist in the survival of other imipenem-susceptible bacteria such as Serratia marcescens and Pseudomonas aeruginosa. This theory is also valid for ceftazidime-susceptible P. aeruginosa. The present review confirms the potential threat of S. maltophilia as an indirect pathogen, and brings an often ignored fact to light: even originally fragile bacteria can live through a strong antimicrobial attack in the presence of a helper bacteria such as S. maltophilia. Although it is sometimes difficult to attribute a causative role to this bacterium, in fact, the existence of S. maltophilia is worthy of attention

Unusual oral mucosal microbiota after hematopoietic cell transplantation with glycopeptide antibiotics: potential association with pathophysiology of oral mucositis

Severe oral mucositis occurs frequently in patients receiving hematopoietic stem cell transplantation (HCT). Oral mucosal bacteria can be associated with progression of oral mucositis, and systemic infection may occur via ulcerative oral mucositis. However, little information is available regarding the oral microbiota after HCT. Here, PCR-denaturing gradient gel electrophoresis (DGGE) was performed to characterize the oral mucosal microbiota, which can be affected by antibiotics, before and after HCT. Sixty reduced-intensity HCT patients were enrolled. Three patients with the least antibiotic use (quinolone prophylaxis and/or β-lactam monotherapy group) and three patients with the most antibiotic use (β-lactam-glycopeptide combination therapy group) were selected. Bacterial DNA samples obtained from the oral mucosa before and after HCT were subjected to PCR-DGGE. The trajectory of oral mucositis was evaluated. The oral mucosal microbiota in the β-lactam-glycopeptide combination therapy group was different from that in the quinolone prophylaxis and/or β-lactam monotherapy group, and Staphylococcus spp. and Enterococcus spp. were identified. Lautropia mirabilis was dominant in one patient. Ulcerative oral mucositis was observed only in the β-lactam-glycopeptide combination therapy group. In conclusion, especially with the use of strong antibiotics, such as glycopeptides, the oral mucosal microbiota differed completely from that under normal conditions, and consisted of Staphylococcus spp., Enterococcus spp., and unexpectedly L. mirabilis. The normal oral microbiota consists not only of bacteria, but these unexpected bacteria could be involved in the pathophysiology as well as systemic infection via oral mucositis. Our results can be used as the basis for future studies in larger patient populations

Follow-up with serum IgG4-monitoring in 8 patients with IgG4-related disease diagnosed by a lacrimal gland mass

The diagnostic criteria for IgG4-related disease were previously published and serum IgG4 measurement has been reimbursed by national health insurance in Japan since 2012. Eight patients diagnosed with IgG4-related disease based on lacrimal gland masses were retrospectively reviewed. The 8 patients were 3 men and 5 women ranging in age from 52 to 77 (median, 63) years at the initial visit and their follow-up period ranged from 0.25 to 11 (median, 7) years. Bilateral and unilateral involvement were noted in 4 patients each; 2 on the right side and 2 on the left side in those with unilateral involvement. Serum IgG4 was high in 5 of 8 patients at the initial visit. Five patients with no systemic signs were followed without treatment, whereas oral steroids were administered and tapered in the other 3 patients who exhibited systemic signs. One patient with a history of radiation for MALT lymphoma in bilateral lacrimal glands developed IgG4-related disease in the left lacrimal gland 10 years later and was followed without treatment. Nine years later, her serum IgG4 level increased to 1500 mg/dL and paracardiac lesions, found on positron emission tomography, were confirmed to be MALT lymphoma by needle biopsy, leading to systemic chemotherapy. The other 7 patients had neither local recurrence nor additional systemic signs. Serum IgG4 monitoring may be useful to detect systemic complications in IgG4-related ophthalmic disease and markedly high serum IgG4 levels may indicate new lymphoma at other sites

Study on dioxygen reduction by mutational modifications of the hydrogen bond network leading from bulk water to the trinuclear copper center in bilirubin oxidase

The hydrogen bond network leading from bulk water to the trinuclear copper center in bilirubin oxidase is constructed with Glu463 and water molecules to transport protons for the four-electron reduction of dioxygen. Substitutions of Glu463 with Gln or Ala were attributed to virtually complete loss or significant reduction in enzymatic activities due to an inhibition of the proton transfer steps to dioxygen. The single turnover reaction of the Glu463Gln mutant afforded the highly magnetically interacted intermediate II (native intermediate) with a broad g = 1.96 electron paramagnetic resonance signal detectable at cryogenic temperatures. Reactions of the double mutants, Cys457Ser/Glu463Gln and Cys457Ser/Glu463Ala afforded the intermediate I (peroxide intermediate) because the type I copper center to donate the fourth electron to dioxygen was vacant in addition to the interference of proton transport due to the mutation at Glu463. The intermediate I gave no electron paramagnetic resonance signal, but the type II copper signal became detectable with the decay of the intermediate I. Structural and functional similarities between multicopper oxidases are discussed based on the present mutation at Glu463 in bilirubin oxidase. © 2014 Elsevier Inc. All rights reserved

Mohawk promotes the maintenance and regeneration of the outer annulus fibrosus of intervertebral discs.

The main pathogenesis of intervertebral disc (IVD) herniation involves disruption of the annulus fibrosus (AF) caused by ageing or excessive mechanical stress and the resulting prolapse of the nucleus pulposus. Owing to the avascular nature of the IVD and lack of understanding the mechanisms that maintain the IVD, current therapies do not lead to tissue regeneration. Here we show that homeobox protein Mohawk (Mkx) is a key transcription factor that regulates AF development, maintenance and regeneration. Mkx is mainly expressed in the outer AF (OAF) of humans and mice. In Mkx(-/-) mice, the OAF displays a deficiency of multiple tendon/ligament-related genes, a smaller OAF collagen fibril diameter and a more rapid progression of IVD degeneration compared with the wild type. Mesenchymal stem cells overexpressing Mkx promote functional AF regeneration in a mouse AF defect model, with abundant collagen fibril formation. Our results indicate a therapeutic strategy for AF regeneration

Development of a preoperative prediction model for new-onset diabetes mellitus after partial pancreatectomy

ABSTRACT: Pancreatectomy is an invasive surgery that is sometimes associated with complications. New-onset diabetes mellitus sometimes develops after partial pancreatectomy and severely affects the patient's quality of life. This study aimed to develop a preoperative prediction model of new-onset diabetes mellitus after partial pancreatectomy, which will help patients and surgeons to achieve more easily better common decisions on regarding whether to perform partial pancreatectomy. This retrospective cohort study analyzed medical records of patients who underwent partial pancreatectomy (total pancreatectomy excluded) from April 1, 2008, to February 28, 2016, which were available in the database provided by Medical Data Vision Co., Ltd. (Tokyo, Japan). The predictors were preoperative age, body mass index, hemoglobin A1c level, blood glucose level, and indication for partial pancreatectomy. The outcome was the development of new-onset diabetes mellitus at 1 to 12 months after partial pancreatectomy. We used a logistic regression model and calculated the scores of each predictor. To determine test performance, we assessed discrimination ability using the receiver operating characteristic curve and calibration with a calibration plot and the Hosmer-Lemeshow test. We also performed internal validation using the bootstrap method. Of 681 patients, 125 (18.4%) had new-onset diabetes mellitus after partial pancreatectomy. The developed prediction model had a possible range of 0 to 46 points. The median score was 13, and the interquartile range was 9 to 22. The C-statistics of the receiver operating characteristic curve on the score to predict the outcome was .70 (95% confidence interval [CI], .65-.75). Regarding the test performance, the Hosmer-Lemeshow test was not significant (P = .17), and calibration was good. In the bootstrapped cohorts, the C-statistics was .69 (95% CI, .62-.76). We developed a preoperative prediction model for new-onset diabetes mellitus after partial pancreatectomy. This would provide important information for surgeons and patients when deciding whether to perform partial pancreatectomy