Erythropoietin to treat anaemia in critical care patients: a multicentre feasibility study

Anaemia is common and associated with poor outcomes during and after critical illness. The use of erythropoietin to treat such anaemia is controversial with older studies showing mixed results. In this study, we aimed to evaluate the feasibility of performing a large multicentre randomised controlled trial of erythropoietin in this setting. We randomly allocated patients staying in the ICU for ≥ 72 h with haemoglobin ≤ 120 g.l-1 to either a weekly injection of erythropoietin (40,000 iu, maximum of five injections) or placebo (saline). The primary endpoint was feasibility (as measured by recruitment, randomisation and follow-up rates, and protocol compliance). Secondary endpoints included biological efficacy and clinical outcomes. Forty-two participants were recruited and randomly allocated, all participants received the allocated intervention, but one withdrew their consent and refused the use of their data, leaving 20 in the erythropoietin group and 21 in placebo group. Follow-up was completed for all patients who survived. The overall recruitment rate was 73.7% with 8.4 participants recruited on average per month. The last haemoglobin measured before hospital discharge (or death) was similar between the groups with a mean (SD) haemoglobin of 107 (21) vs. 95 (25) g.l-1 , mean difference (95%CI) 11 (-4-26), g.l-1 , p = 0.154. A large, multicentre randomised controlled trial of erythropoietin to treat anaemia in ICU patients is feasible and necessary to determine effects of erythropoietin on mortality in ICU anaemic patients.

Spin Dynamics and Unconventional Coulomb Phase in Nd_{2}Zr_{2}O_{7}

We investigate the temperature dependence of the spin dynamics in the pyrochlore magnet Nd_{2}Zr_{2}O_{7} by neutron scattering experiments. At low temperature, this material undergoes a transition towards an "all-in-all-out" antiferromagnetic phase and the spin dynamics encompass a dispersionless mode, characterized by a dynamical spin ice structure factor. Unexpectedly, this mode is found to survive above T_{N}≈300  mK. Concomitantly, elastic correlations of the spin ice type develop. These are the signatures of a peculiar correlated paramagnetic phase which can be considered as a new example of Coulomb phase. Our observations near T_{N} do not reproduce the signatures expected for a Higgs transition, but show reminiscent features of the "all-in-all-out" order superimposed on a Coulomb phase.

A new 3-hit mouse model of schizophrenia built on genetic, early and late factors

Whether the etiology of schizophrenia remains unknown, its multifactorial aspect is conversely now well admitted. However, most preclinical models of the disease still rely on a mono-factorial construction and do not allow discover unequivocal treatments, particularly for negative and cognitive symptoms. The main interaction factors that have been implicated in schizophrenia are a genetic predisposition and unfavorable environmental factors. Here we propose a new animal model combining a genetic predisposition (1st hit: partial deletion of MAP-6 (microtubule-associated protein)) with an early postnatal stress (2nd hit: 24 h maternal separation at post-natal day 9), and a late cannabinoid exposure during adolescence (3rd hit: tetrahydrocannabinol THC from post-natal day 32 to 52; 8 mg/kg/day). The 2-hit mice displayed spatial memory deficits, decreased cortical thickness and fractional anisotropy of callosal fibers. The 3-hit mice were more severely affected as attested by supplementary deficits such a decrease in spontaneous activity, sociability-related behavior, working memory performances, an increase in anxiety-like behavior, a decrease in hippocampus volume together with impaired integrity of corpus callosum fibers (less axons, less myelin). Taken together, these results show that the new 3-hit model displays several landmarks mimicking negative and cognitive symptoms of schizophrenia, conferring a high relevance for research of new treatments. Moreover, this 3-hit model possesses a strong construct validity, which fits with gene x environment interactions hypothesis of schizophrenia. The 2-hit model, which associates maternal separation with THC exposure in wild-type mice gives a less severe phenotype, and could be useful for research on other forms of psychiatric diseases.

[Observation and comparison of social abilities in Attention-Deficit/Hyperactivity Disorder and Autism Spectrum Disorder children]

OBJECTIVES

Different studies centered on social relationship issues among ADHD children struggled to provide a unicist explanation between primary social cognition process alteration on the one hand and a mere symptomatic outcome of the disorder triad on the other. Some authors support the idea of a potential "social phenotype" shared at a different intensity by Attention Deficit/Hyperactivity Disorder (ADHD) and Autism Spectrum Disorder (ASD). The point of the study is to characterize this possible social disability in a French ADHD population and compare it to control subjects and subjects with Autism Spectrum Disorder (ASD).

METHODS

Three groups, composed of 319 subjects aged 6 to 12 years, were recruited in Bordeaux: 88 untreated ADHD subjects, 24 ASD subjects and 207 control subjects. The main measure was the social skill disruption through the rating of the Social Responsiveness Scale (SRS). The ADHD-RS-IV, WFIRS-P and CBCL scales were also used.

RESULTS

Asignificant alteration in social abilities in ADHD children in comparison with controls was noted, with an average raw total SRS score intermediary between the control group and the ASD group (respectively 65.31±20.99, 37.15±16.37 and 95 75±30.83, P<0.05). When the 5 sub-scores of the SRS were taken into account, if the ASD subjects showed the highest average scores, the alteration pattern appeared qualitatively similar between the ADHD and TSA groups, with also an intermediate dispersion for the ADHD group between the control group and the group with ASD. Finally, more severe impairment of social skills in children with ADHD was associated with increased severity of the disorder (on ADHD-RS-IV scale cotation), higher daily functional impact (WFIRS-P scale), and more frequent behavioral issues (according to CBCL).

CONCLUSIONS

Our results suggest the presence of social disturbances in ADHD and characterize a symptomatic profile qualitatively similar to that of ASD, but of less intensity. Overall results promote a need for a systematic dimensional assessment of social disability in ADHD.

Pratique de l’échographie clinique au sein d’un réseau territorial d’urgence

Objectif : L’échographie clinique en médecine d’urgence (ECMU) est un outil essentiel de notre pratique. L’objectif principal de notre étude était d’évaluer les caractéristiques des médecins pratiquant l’ECMU au sein de notre territoire. L’objectif secondaire était d’analyser les facteurs influençant une pratique régulière.

Matériel et méthodes : Étude descriptive multicentrique et déclarative, réalisée auprès de médecins urgentistes travaillant au sein d’un réseau territorial de médecine d’urgence à l’aide d’un questionnaire en ligne.

Résultats : Cent onze questionnaires sur 120 envoyés ont été renseignés (92 %). Onze services (92 %) étaient dotés en échographe dont neuf (82 %) en dotation propre. Soixantesix médecins (59 %) déclaraient pratiquer l’échographie régulièrement. La FAST (focused assessment with sonography for traumas) était la plus pratiquée (80 médecins, 72 %), suivie de l’exploration hémodynamique (50 médecins, 45 %) et pleurale (44 médecins, 40 %). Dans le groupe des médecins ne pratiquant pas l’ECMU, 17 médecins sur 22 (77 %) l’expliquaient par un manque de formation. Dans le même temps, l’intérêt porté à l’ECMU par les urgentistes était coté à 7 ± 2 sur une échelle de 0 à 9. Les facteurs associés à la fréquence de la pratique de l’ECMU étaient le sexe (p < 0,001), le type d’activité (p = 0,005), le type de formation à l’échographie (p < 0,001) et l’ancienneté d’équipement de son service en échographe (p < 0,001).

Conclusion : Cette enquête a montré que la pratique régulière était majoritaire avec un intérêt porté par les praticiens à l’ECMU élevé. Cependant, le frein principal à son développement était un niveau de formation jugé insuffisant par certains praticiens.

Biocompatibility evaluation of dura mater substitutes in an animal model

Dura-Guard Dural Repair Patch, PRECLUDE Dura Substitute, and Codman ETHISORB Dura Patch were evaluated in a six-month dural tissue reaction study in rabbits. Bilateral craniotomy was followed by subdural implantation for each dura mater substitute. The surgical procedure for the sham control group was the same except that no material was implanted. Implantation of all of these dura mater substitutes for 28, 91, or 182 days post-implantation did not result in any deaths or clinical neurobehavioral abnormalities, changes in cerebrospinal fluid, or significant macroscopic changes at necropsy. However, histomorphologic evaluation of the implantation sites revealed some differences in the tissue response to these materials. For Dura-Guard Dural Repair Patch, a nonabsorbable material derived from bovine pericardium, the implantation site was characterized by fibrosis of the overlying area with islands of osseous metaplasia and adhesions to the brain surface. Over time, infiltrative fibrosis of the implant resulted in separation of the collagenous layers of the implant and compression of the underlying brain. Fibrosis of the overlying area that incorporated this material formed a 'replacement' dura mater. Adhesions to the brain surface observed initially were still present at six months post-implantation. Implantation of PRECLUDE Dura Substitute, a nonabsorbable material comprised of expanded polytetrafluoroethylene, resulted in virtually no early reaction, and few adhesions to the brain surface at any time period. Although this material was eventually incorporated by fibrosis, islands of osseous metaplasia were also observed in this 'replacement' dura mater. The tissue reaction to Codman ETHISORB Dura Patch, an absorbable material comprised of polyglactin 910 and polydioxanone, was generally characterized by low-grade granulomatous inflammation and initial adhesions to the brain surface. The three-dimensional structure of this implant acted as a scaffold to guide the development and integration of a 'replacement' dura mater. The absorption of the material was associated with complete resolution of the inflammatory reaction, a lack of cerebral adhesions, and restoration of the normal architecture of this region. In conclusion, subdural implantation of Dura-Guard Dural Repair Patch, PRECLUDE Dura Substitute, or Codman ETHISORB Dura Patch in rabbits for up to six months resulted in the eventual restoration of the dura mater without significant adverse effects. However, osseous metaplasia associated with nonabsorbable Dura-Guard Dural Repair Patch and PRECLUDE Dura Substitute, and the infiltration of Dura-Guard Dural Repair Patch by fibrosis suggests that long-term follow-up may be needed after the use of these materials in patients. An advantage of Codman ETHISORB Dura Patch was that it was completely absorbed after guiding the restoration of the dura mater without any morphological sequelae.

Pre-clinical subdural tissue reaction and absorption study of absorbable hemostatic devices

SURGIFOAM (Absorbable Gelatin Sponge, USP), a new absorbable hemostatic sponge, GELFOAM (Absorbable Gelatin Sponge, USP) or Avitene (microfibrillar collagen hemostat) were evaluated in a three-month tissue reaction and absorption study in rabbits. Bilateral craniotomy was followed by subdural implantation of each hemostatic device. A sham control group was treated in a similar way except that no material was implanted. Implantation of these hemostatic devices for 15, 43, or 92 days did not result in any deaths or clinical neurobehavioral abnormalities, changes in cerebrospinal fluid, or significant macroscopic observations at necropsy. The tissue reaction to SURGIFOAM sponge was characterized by transient granulomatous inflammation that was slightly less intense than that observed for GELFOAM sponge which correlated to slightly longer absorption. In contrast, the tissue reaction to Avitene hemostat was characterized by moderate to marked granulomatous inflammation with an acute inflammatory component indicating a greater degree of tissue irritancy. Sequelae of this reaction were still observed at 92 days post-implantation. The tissue reaction in humans to SURGIFOAM sponge used as a hemostatic agent for neurologic surgical procedures is expected to be comparable to that observed with GELFOAM sponge, resulting in no significant adverse reactions for patients. This animal model was useful to assess the tissue reaction and absorption of biomaterials implanted in contact with the central nervous system, and it was able to differentiate between materials of biologic origin.