[Severe pneumonia and acute respiratory distress syndrome: Implication of unconventional T cells]. / Pneumonies sévères et syndrome de détresse respiratoire aiguë : implication des lymphocytes T non conventionnels.

Pneumonia is frequently complicated by occurrence of acute respiratory distress syndrome (ARDS), consequently to dysregulated inflammatory response. However, mechanisms driving this dysregulation are poorly understood. To address this, "unconventional T-cells (UTC)" -γδT, NKT and MAIT cells- appear to be relevant targets due to their key role in orchestrating anti-microbial immune response in the lung. Thus, using an experimental and translational approach, we test the hypothesis that a tight regulation of UTC is mandatory to fine-tune host response, and, subsequently to prevent emergence of an aberrant response leading to excessive tissue damages, and eventually, ARDS.

Lyme neuroborreliosis in children: Report of nine cases and a review of the literature.

Lyme neuroborreliosis is a bacterial infection caused by the dissemination and proliferation of a Borrelia species in the central nervous system. Neuroborreliosis occurs after transmission of the pathogen from an infected tick to a human host during a tick bite. We report nine cases of pediatric neuroborreliosis collected by the National Observatory of Pediatric Bacterial Meningitis in France between 2001 and 2012. The nine children, aged 4-13 years, were identified in northern and eastern France and had the following clinical features: meningeal irritation alone or with facial palsy, or isolated facial palsy. All cases showed anti-Borrelia antibodies in cerebrospinal fluid or serum, or with a positive Borrelia PCR in the CSF. The outcome was favorable in all cases after a 2- to 3-week course of third-generation cephalosporin. On the basis of these nine pediatric cases, this study provides an update on the epidemiology, pathophysiology, diagnostic strategy, and treatment of neuroborreliosis, with insight into the specific features of pediatric neuroborreliosis and the difficulties encountered in the diagnosis of this infection.

Neutrophilic NLRP3 inflammasome-dependent IL-1ß secretion regulates the γδT17 cell response in respiratory bacterial infections.

Traditionally regarded as simple foot soldiers of the innate immune response limited to the eradication of pathogens, neutrophils recently emerged as more complex cells endowed with a set of immunoregulatory functions. Using a model of invasive pneumococcal disease, we highlighted an unexpected key role for neutrophils as accessory cells in innate interleukin (IL)-17A production by lung resident Vγ6Vδ1+ T cells via nucleotide-binding oligomerization domain receptor, pyrin-containing 3 (NLRP3) inflammasome-dependent IL-1ß secretion. In vivo activation of the NLRP3 inflammasome in neutrophils required both host-derived and bacterial-derived signals. Elaborately, it relies on (i) alveolar macrophage-secreted TNF-α for priming and (ii) subsequent exposure to bacterial pneumolysin for activation. Interestingly, this mechanism can be translated to human neutrophils. Our work revealed the cellular and molecular dynamic events leading to γδT17 cell activation, and highlighted for the first time the existence of a fully functional NLRP3 inflammasome in lung neutrophils. This immune axis thus regulates the development of a protective host response to respiratory bacterial infections.

Influenza A virus-induced release of interleukin-10 inhibits the anti-microbial activities of invariant natural killer T cells during invasive pneumococcal superinfection.

During influenza A virus (IAV) infection, changes in the lung's physical and immunological defenses predispose the host to bacterial superinfections. Invariant natural killer T (iNKT) cells are innate-like T lymphocytes that have beneficial or harmful functions during infection. We investigated the iNKT cells' role in a model of invasive pneumococcal superinfection. The use of Jα18-/- mice indicated that iNKT cells limited susceptibility to influenza-pneumococcal infection and reduced the lethal synergism. This role did not depend on immune-based anti-bacterial mechanisms. At the time of bacterial exposure, iNKT cells from IAV-experienced mice failed to produce antipneumococcal interferon-γ and adoptive transfer of fresh iNKT cells before Streptococcus pneumoniae challenge did not restore anti-bacterial host defenses. Impaired iNKT cell activation in superinfected animals was related to the IAV-induced immunosuppressive cytokine interleukin-10 (IL-10), rather than to an intrinsic functional defect. IL-10 dampened the activation of iNKT cells in response to pneumococci by inhibiting the production of IL-12 by pulmonary monocyte-derived dendritic cells. Neutralization of IL-10 restored iNKT cell activation and tends to increase resistance to secondary bacterial infection. Overall, iNKT cells have a beneficial role (upstream of bacterial colonization) in controlling influenza-pneumococcal superinfection, although they represent novel targets of immunosuppression at the time of bacterial challenge.

How to introduce a program of Enhanced Recovery after Surgery? The experience of the CAPIO group.

The traditional model of hospital care has been challenged by the development of a care-management process that allows early patient autonomy (outpatient surgery, Enhanced Recovery after Surgery). Hospitalization has been transformed in response to this development, based on innovative medical and organizational strategies. Within a surgical service, the deployment of these processes requires the creation of a support structure, with re-organization of existing structures, analysis of potential obstacles, implementation of management tools, and ongoing follow-up of organizational function, clinical results, organizational and patient satisfaction. These will ultimately assess adaptation of structures within these new organizations. In this article, we share our insights based on experience gained over the past six years by surgical teams of the CAPIO group.

Chronic low back pain among French healthcare workers and prognostic factors of return to work (RTW): a non-randomized controlled trial.

BACKGROUND: Many factors influence the return to work of workers with chronic low back pain (CLBP). They have been said to vary according to socio-professional group. This study first aimed to compare prognostic factors influencing the return to work of CLBP healthcare workers (HCWs) and other workers (non-HCWs) after rehabilitation coupled with an occupational intervention. The second objective was to improve the evolution of indicators such as clinical examination, psychosocial impact and pain impact. METHODS: Between 2007 and 2012, a cohort of 217 CLBP workers (54.8 %-women; mean age = 41.3 ± 9.5 years, 118 non-HCWs; 99 HCWs mainly from the public sector) was included in an ambulatory rehabilitation program (standard physiotherapy or intensive network physiotherapy) coupled with an occupational intervention. Workers completed a questionnaire and had a clinical examination at baseline and after 24 months' follow up. Physical, social and occupational data was collected at the same time. Statistical analyses were performed to evaluate prognostic factors for return to work and compare the two worker populations. RESULTS: There was no difference between groups for the rate of OP (occupational physician) intervention or type of physiotherapy. 77.3 % of workers returned to work after 2 years following inclusion. To be an HCW (OR 0.1; 95 % CI [0.03-0.34]), to have less than 112 sick- leave days (OR 1.00; 95 % CI [0.93-1.00]), a small fingertip-floor distance (OR 0.96; 95 % CI [0.93-0.99]), a low anxiety/depression score (OR 0.97; 95 % CI [0.95-1.00]), a low impact of CLBP on daily life (OR 0.96; 95 % CI [0.93-1.00]), and on quality of life (OR 0.98; 95 % CI [0.95-1.00]) at baseline were statistically associated with return to work after 2 years of follow up. Only the profession (workplace) was statistically associated with return to work after 2 years of follow up using multivariate analysis. CONCLUSION: To our knowledge, this is the first cohort study concerning predictive factors of RTW among CLBP workers after 2 years of follow up. Interventions in the work environment did not seem to predict job retention significantly. But only 50 % of the employees in both groups (HCW and non-HCW) had one intervention at their workplace after 2 years. This study underlined the fact that the type of physiotherapy with a well-trained physiotherapist used to take care of CLBP could not impact on the RTW forecast. To develop these initial results, it might be interesting to study the comparison between private and public sectors and to randomize the physiotherapeutic intervention.

CD3bright signals on γδ T cells identify IL-17A-producing Vγ6Vδ1+ T cells.

Interleukin-17A (IL-17A) is a pro-inflammatory cytokine that has an important role at mucosal sites in a wide range of immune responses including infection, allergy and auto-immunity. γδ T cells are recognized as IL-17 producers, but based on the level of CD3 expression, we now define the remarkable ability of a CD3(bright) γδ T-cell subset with an effector memory phenotype to rapidly produce IL-17A, but not interferon-γ. CD3(bright) γδ T cells uniformly express the canonical germline encoded Vγ6/Vδ1(+) T-cell receptor. They are widely distributed with a preferential representation in the lungs and skin are negatively impacted in the absence of retinoic acid receptor-related orphan receptor gammat expression or endogenous flora. This population responded rapidly to various stimuli in a mechanism involving IL-23 and NOD-like receptor family, pyrin domain containing 3 (NLRP3)-inflammasome-dependent IL-1ß. Finally, we demonstrated that IL-17-producing CD3(bright) γδ T cells responded promptly and strongly to pneumococcal infection and during skin inflammation. Here, we propose a new way to specifically analyze IL-17-producing Vγ6/Vδ1(+) T cells based on the level of CD3 signals. Using this gating strategy, our data reinforce the crucial role of this γδ T-cell subset in respiratory and skin disorders.

Role of type 1 natural killer T cells in pulmonary immunity.

Mucosal sites are populated by a multitude of innate lymphoid cells and "innate-like" T lymphocytes expressing semiconserved T-cell receptors. Among the latter group, interest in type I natural killer T (NKT) cells has gained considerable momentum over the last decade. Exposure to NKT cell antigens is likely to occur continuously at mucosal sites. For this reason, and as they rapidly respond to stress-induced environmental cytokines, NKT cells are important contributors to immune and inflammatory responses. Here, we review the dual role of mucosal NKT cells during immune responses and pathologies with a particular focus on the lungs. Their role during pulmonary acute and chronic inflammation and respiratory infections is outlined. Whether NKT cells might provide a future attractive therapeutic target for treating human respiratory diseases is discussed.

A novel ABCC8 mutation illustrates the variability of the diabetes phenotypes associated with a single mutation.

AIM: ATP-sensitive potassium channels are important regulators of insulin secretion. They consist of four sulphonylurea receptor (encoded by ABCC8) and four inwardly rectifying protein (encoded by KCNJ11) subunits. Activating ABCC8 mutations lead to decreased insulin secretion and to diabetes. Wide phenotype variability is associated with single ABCC8 mutations, ranging from transient or permanent neonatal diabetes (ND) with or without developmental delay (DEND syndrome) to very mild phenotypes. This report describes the case of a Caucasian infant diagnosed with ND at the age of 2 months due to a novel ABCC8 missense mutation. METHODS: ABCC8 was analyzed by sequence analysis. The mutation was present in the patient and her family and was found to be associated with phenotypes ranging from ND to asymptomatic impaired fasting glucose (IFG). RESULTS: A novel His863Tyr ABCC8 mutation was identified in a 2-month-old girl diagnosed with ND. After an initial insulin treatment, treatment with glibenclamide was initiated and the treatment with insulin discontinued. The same mutation was found in her father, who had been fortuitously diagnosed with diabetes and had an HbA(1c) level of 9% (74.8 mmol/mol). The patient's brother and mother both had normal fasting glucose, and were not found to be carriers of the mutation. However, the same mutation was found in her grandmother, who had been asymptomatic and discovered IFG (6.9 mmol/L) with an HbA(1c) of 6.8% (50.8 mmol/mol). CONCLUSION: This case describes a novel ABCC8 mutation and offers a further illustration of the highly variable phenotypes associated with an identical mutation present across three generations.

Reduction in antibiotic use through procalcitonin testing in patients in the medical admission unit or intensive care unit with suspicion of infection.

We report an evaluation of the utility of serum procalcitonin (PCT) measurement as an additional diagnostic tool to support initiating or withholding antibiotics in clinical situations where there is a clinical suspicion of infection but the diagnosis is uncertain. During a six-month period, 99 patients on the medical admission unit (MAU) with suspected infection, and 42 patients on the intensive care unit (ICU) with clinical signs or physiological parameters suggesting possible new infection, had serum PCT concentration measured with the result available within 90min of the request. The test was initiated by the microbiology/infection team during clinical consultations to support the antibiotic decision. On the basis of low PCT values, antibiotics were withheld in MAU on 52 occasions and in ICU on 42 occasions. Patients were followed up prospectively for a week. There was neither progression of bacterial infection requiring antibiotics, nor complications or infection-related mortality in any patients who were denied antibiotics on either MAU or ICU. Without the PCT value it is likely that all of these patients would have received empirical antibiotics. Reduction in unnecessary antibiotic usage was made without any adverse effects on these patients and there was a clear reduction in antibiotic prescribing with cost reduction implications. PCT has the potential to become a valuable tool in antibiotic management.

Comparing microsphere deposition and flow modeling in 3D vascular trees.

Blood perfusion in organs has been shown to be heterogeneous in a number of cases. At the same time, a number of models of vascular structure and flow have been proposed that also generate heterogeneous perfusion. Although a relationship between local perfusion and vascular structure has to exist, no model has yet been validated as an accurate description of this relationship. A study of perfusion and three-dimensional (3D) arterial structure in individual rat kidneys is presented, which allows comparison between local measurements of perfusion and model-based predictions. High-resolution computed tomography is used to obtain images of both deposited microspheres and of an arterial cast in the same organ. Microsphere deposition is used as an estimate of local perfusion. A 3D cylindrical pipe model of the arterial tree is generated based on an image of the arterial cast. Results of a flow model are compared with local microsphere deposition. High correlation (r(2) > 0.94) was observed between measured and modeled flows through the vascular tree segments. However, the relative dispersion of the microsphere perfusion measurement was two- to threefold higher than perfusion heterogeneity calculated in the flow model. Also, there was no correlation in the residual deviations between the methods. This study illustrates the importance of comparing models of local perfusion with in vivo measurements of perfusion in the same biologically realistic vascular tree.

Estimating perfusion using microCT to locate microspheres.

The injection of microspheres into the blood stream has been a common method to measure the spatial distribution of blood flow (perfusion). A technique to conduct this kind of measurement in small animal organs is presented using silver-coated microspheres with a diameter of 16 microm and high-resolution computed tomography (microCT) to detect individual microspheres. Phantom experiments demonstrate the detectability of individual spheres. The distribution of microspheres within a rat heart is given as an example. Using non-destructive, three-dimensional imaging for microsphere detection avoids the cumbersome dissection of the organ into samples or slices and their subsequent registration. The detection of individual spheres allows high-resolution measurements of perfusion and arbitrary definition of regions of interest. These, in turn, allow for accurate statistical analysis of perfusion such as relative dispersion curves.

[Acute organophosphate intoxication after using a anti-lice insecticide shampoo]. / Intoxication aiguë par organophosphorés à la suite de l'utilisation d'un insecticide comme shampooing anti-poux.

CASE REPORT: Two children were admitted for poisoning by organophosphate pesticides applied as hair rinses against lice. These chemical agents inhibit the acetylcholinesterase enzyme at various sites. The resultant accumulation of the transmitter acetylcholine causes abnormal signs and symptoms. The diagnosis is based on a reduction in the blood cholinesterase activity. The specific treatment comprises the administration of atropine and pralidoxime. CONCLUSION: Accidental poisoning by organophosphate insecticides may occur, due to the misuse of such substances as shampoo against lice. An accurate information for users is necessary.

[Hypertensive manifestation of an acute intestinal intussusception]. / Forme hypertensive d'une invagination intestinale aiguë.

BACKGROUND: Hypertension may be associated with intussusception. CASE REPORT: An 8-month-old infant showed the following symptoms: lethargy, vomiting and hypertension. Abdominal ultrasound suggested the diagnosis of intussusception, which was confirmed by barium enema. The hypertension resolved after the intussusception was reduced. CONCLUSION: Intussusception should be considered a diagnostic possibility in infants who show a history of vomiting and in whom lethargy and systematic hypertension are noted. This case re-affirms the diagnostic usefulness of abdominal ultrasonography.

Modification of enzymatic antioxidants in retinal microvascular cells by glucose or advanced glycation end products.

Oxidative stress is one possible pathogenic mechanism to explain diabetic microangiopathy. In the present study, we determined the antioxidant enzyme activities in bovine retinal microvessels and cultured retinal microvascular cells: endothelial cells (BREC) and pericytes (BRP). We further investigated the effects of high glucose and advanced glycation end products (AGE) on these enzyme activities in BREC and BRP. Antioxidant enzyme activities in native retinal microvessels and BREC were quite similar but differed markedly from the BRP ones. High glucose decreased Se-GPx activity (about 20%) in BREC compared to mannitol. High concentrations of mannitol or NaCl increased Se-GPx activity (up to 40%) compared to control medium, suggesting that hyperosmolarity could regulate Se-GPx in BREC. No changes in antioxidant enzyme activities were observed when BRP were cultured with glucose or mannitol at high concentrations. AGE-BSA had no effect on enzyme activities in BREC, whereas 20 microM AGE-BSA increased catalase (40%) and superoxide dismutase (60%) activities in BRP. Differences in antioxidant enzyme activities observed between BREC and BRP, cultured with high concentrations of glucose or AGE, might help to explain their different behavior during the pathogenesis of diabetic retinopathy, i.e., early pericyte drop-out and late endothelial cell proliferation.

Synthesis and antiviral activity of prodrugs of the nucleoside 1-[2',3'-dideoxy-3'-C-(hydroxymethyl)-beta-D-erythropentofuranosyl] cytosine.

The synthesis and antiviral evaluation of 21 prodrugs of 1-[2',3'-dideoxy-3'-C-(hydroxymethyl)-beta-D-erythropentofuranosyl ] cytosine 1 is reported. Cytosine N4-imine analogues were prepared by condensation of 1 with selected formamide dimethyl acetals. Amino acid substituted prodrugs were prepared from 1 or imine prodrug 2 by coupling with either N-tert-butoxycarbonyl (t-Boc)-L-valine or N-t-Boc-L- phenylalanine in the presence of dicyclohexycarbodiimide (DCC) and 4-dimethylaminopyridine (4-DMAP). Deprotection of the t-Boc protecting group was achieved with trifluoroacetic acid (TFAA) in methylene chloride. Cytosine N4-amide analogues were prepared by reaction of 1 with appropriate anhydrides in aqueous dioxane. Triacylated analogue 22 was prepared by reaction of 1 with four equivalents of benzoyl chloride in pyridine. Prodrugs were evaluated for activity against duck hepatitis B virus, herpes simplex virus types 1 and 2, human cytomegalovirus, and human immunodeficiency virus. A number of analogues were found comparable in activity to 1 with the cytosine N4-imine series more active than the amino acid substituted and cytosine N4-amide prodrugs. Slight to moderate cellular toxicity was observed with some analogues.

Incidence and pathophysiologic significance of infected carotid artery plaque.

It is unknown whether an association exists between infectious microorganisms and atherosclerosis. Eighty consecutive patients undergoing carotid endarterectomy were studied to detect for bacterial or virus infections in removed carotid atherosclerotic plaques. Twenty-one patients (25%) were found to have positive cultures for bacteria of the carotid plaques. Three patients (4%) did not have bacterial contamination of controlled cultures of the skin. Of these three patients, two grew diptheroids and one grew staphylococcus. The control cultures of the skin demonstrated that 25 patients (31%) grew diphtheroids and 29 (36%) grew staphylococcus. Five patients grew both organisms. There was no evidence of colonization within the atheromatous plaque material in histologic studies of the three patients that had positive cultures of their plaque. All viral cultures were negative. The positive carotid cultures found were most likely due to contamination from the skin. This study demonstrates the unlikelihood of bacterial or virus infections as either an etiologic or a pathogenetic factor in carotid artery atherogenesis.

Docosahexaenoic acid is a major n-3 polyunsaturated fatty acid in bovine retinal microvessels.

The aim of this study was to purify microvessels from bovine retina and also to cultivate bovine retinal endothelial cells (BRECs) or intramural pericytes, to determine their fatty acid composition. Microvessels were obtained after Dounce homogenization of the retina followed by centrifugation on albumin cushion and finally microvessels in the pellet were trapped on a 100-microns nylon filter. Contamination of microvessel preparations by neuronal tissue, assessed after both microscopic examination and western blotting with a monoclonal antibody raised against rhodopsin, was minor. In the entire bovine retina, docosahexaenoic acid (DHA) represented 23.3% of the total fatty acids and there was about three times less arachidonic acid (AA) (8.2%) than DHA. In contrast, DHA and AA levels were almost equivalent in the retinal microvessels with approximately 10% of total fatty acids. When compared with intact microvessels, the DHA proportion of confluent monolayers of both BRECs or pericytes in primary cultures dropped to approximately 2% of the total fatty acids, whereas AA was unchanged. Culture medium supplementation with unesterified DHA (10 microM) restored the DHA proportion of BRECs close to the microvascular value at the expense of linoleic acid without affecting AA very much. In contrast, DHA supplementation in pericytes increased the DHA proportion of these cells at the expense of AA. In conclusion, DHA of intact microvessels represented 10% of the total fatty acids, which was close to the AA proportion. Mild DHA supplementation of BRECs or pericytes in primary cultures restored their DHA proportion to the original microvessel value. This high percentage of polyunsaturated fatty acids in retinal microvessels should allow us to test the hypothesis that oxidation products derived from these fatty acids may be involved in the pathogenic process leading to diabetic retinopathy.

Pharmacological characterization of LY293284: A 5-HT1A receptor agonist with high potency and selectivity.

(-)-LY293284, (-)-4R-6-acetyl-4-(di-n-propylamino)1,3,4,5- tetrahydrobenz[c,d]indole, is a conformationally restricted tryptamine derivative with an acetyl group serving as a protophilic substitution for the hydroxyl in serotonin (5-HT). In ligand displacement studies, LY293284 had a Ki of 0.07 nM for the 5-HT1A receptor but no affinity for other monoaminergic receptors within 3 orders of magnitude. LY293284 was evaluated in in vivo models, which have been used as markers for presynaptic and postsynaptic 5-HT1A receptor activity. LY293284 decreased hypothalamic 5-hydroxyindoleacetic acid levels (ED50, 2.9 micrograms/kg s.c.) and dorsal raphe serotonergic neuron firing rate (ED50, 0.08 micrograms/kg s.c.), which are accepted indices of presynaptic activity. LY293284 also induced a reduction in body temperature in rats (ED50, 3.6 micrograms/kg s.c.), which was blocked by pretreatment with (+/-)-pindolol. Hypothermic responses of rats to 5-HT1A agonists have had both pre- and postsynaptic characteristics in previous studies. The ED50 values for 8-hydroxy-2-(di-n-propylamino)-tetralin (8-OH-DPAT) in these tests were 15 to 45 times higher than those observed for LY293284. In models for postsynaptic activity, the ED50 for LY293284 for elevating serum corticosterone levels was 9.7 micrograms/kg s.c. and the minimum effective doses to induce lower lip retraction and flat posture were 3 micrograms/kg s.c. For comparison, the same indices obtained for 8-OH-DPAT were 222.4 and 100 micrograms/kg, respectively. The 5-HT syndrome responses induced by LY293284 were also attenuated by pretreatment with (+/-)-pindolol. LY293284 was 10 times more potent than 8-OH-DPAT in a drug discrimination test that used pigeons trained to identify 8-OH-DPAT. In sexual behavior tests with male rats, LY293284 induced a maximal reduction in ejaculatory latency at 0.01 micrograms/kg s.c., which was approximately 10 times higher potency than 8-OH-DPAT. In the pigeon conflict model for anxiolytic activity, LY293284 was 100 times more potent than 8-OH-DPAT in increasing punished responding. In the rat forced swim model for antidepressant-like activity, LY293284 was 30 and 35 times more potent than 8-OH-DPAT in decreasing immobility time and defecation rate. These studies have demonstrated that LY293284 is a highly selective and extremely potent 5-HT1A receptor agonist and represents a useful pharmacological tool for studying 5-HT1A receptor-mediated effects.

Evaluation of a novel antihypertensive agent, LY127210, in anesthetized and conscious spontaneously hypertensive rats.

LY127210 (7,8-dimethoxy-1H-3-benzazepin-2-amine, hydrochloride) is a novel peripheral arterial vasodilator that reduces mean arterial blood pressure in anesthetized and conscious spontaneously hypertensive rats by all conventional routes of administration. The antihypertensive activity of LY127210 results predominantly from a decrease in total peripheral vascular resistance, and the degree of reflex tachycardia produced by LY127210 in conscious spontaneously hypertensive rats is significantly less than that produced by hydralazine at equivalent antihypertensive doses. The relative lack of reflex tachycardia produced by LY127210 appears to result from a direct bradycardic effect of the compound that occurs at the level of the myocardium at doses similar to those required to produce peripheral arteriolar vasodilation. It is proposed that the direct bradycardic effect of LY127210 serves to offset, at least in part, the tachycardia resulting from reflex stimulation of sympathetic outflow that occurs upon activation of the baroreflex loop as blood pressure is lowered. The results indicate that LY127210 may provide adequate control of blood pressure and may not require the concomitant administration of a beta-adrenoceptor antagonist to control reflex tachycardia, as is commonly necessary with hydralazine.