Métabolisme énergétique et traumatisme crâniocérébral [Energy metabolism and craniocerebral injury]

Severe head injury induces major hormonal, humoral and metabolic changes, characterized by increases in stress hormone secretion, lymphokines production, associated with high lipid and protein catabolism as well as changes in energy expenditure (EE). Numerous factors influence EE in head-injured patients, particularly anthropometric data, body temperature, nutritional support, level of consciousness, muscular tone and activity. Resting EE is usually increased following brain trauma; however, normal or decreased metabolic rates can be observed in curarized patients on mechanical ventilation or in patients receiving high doses of barbiturates.

The radiation of the clownfishes has two geographical replicates

AimThe study of adaptive radiations provides an evolutionary perspective on the interactions between organisms and their environment, and is necessary to understand global biodiversity. Adaptive radiations can sometimes be replicated over several disjunct geographical entities, but most examples are found on island or in lakes. Here, we investigated the biogeographical history of the clownfishes, a clade of coral reef fish with ranges that now span most of the Indo-Pacific Ocean, in order to explore the geographical structure of an unusual adaptive radiation. LocationIndian Ocean, Indo-Australian Archipelago (IAA) and Central Pacific Ocean. MethodsWe generated DNA sequence data comprising seven nuclear markers for 27 of the 30 clownfish species. We then inferred a Bayesian phylogeny and reconstructed the biogeographical history of the group using three different methods. Finally, we applied a biogeographical model of diversification to assess whether diversification patterns differ between the Indian and Pacific Oceans. ResultsThe phylogenetic tree is highly supported and allows reconstruction of the biogeographical history of the clade. While most species arose in the IAA, one clade colonized the eastern shores of Africa and diversified there. We found that the diversification rate of clownfishes does not differ between the main radiation and the African clade. Main conclusionsThe clownfishes first appeared and diversified in the IAA. Following a colonization event, a geographically independent radiation occurred in the Indian Ocean off East Africa. This rare example of replicated adaptive radiation in the marine realm provides intriguing possibilities for further research on ecological speciation in the sea.

Délire religieux treize ans après traumatisme crânien [Religious delusion 13 years after brain injury].

We report here with a case of religious delusion in a 39 years old woman. She had suffered a head injury with right temporal concussion 13 years before but had no earlier history of psychiatric disorder. In view of the fact that this acute psychiatric state lasted for a short duration of time and that personality and affects were preserved, this incident is compared to the schizophreniform disorder of the type DSM-III-R. The hypothesis of an acquired predisposition due to head injury has been put forward as an explanation.

Changes in patterns of practice for prostate cancer radiotherapy in Italy 1995-2003. A survey of the Prostate Cancer Study Group of the Italian Radiation Oncology Society.

Aims and background. In 2002, a survey including 1759 patients treated from 1980 to 1998 established a "benchmark" Italian data source for prostate cancer radiotherapy. This report updates the previous one. Methods. Data on clinical management and outcomes of 3001 patients treated in 15 centers from 1999 through 2003 were analyzed and compared with those of the previous survey. Results. Significant differences in clinical management (-10% had abdominal ma-gnetic resonance imaging; +26% received ≥70 Gy, +48% conformal radiotherapy, -20% pelvic radiotherapy) and in G3-4 toxicity rates (-3.8%) were recorded. Actuarial 5-year overall, disease-specific, clinical relapse-free, and biochemical relapse-free survival rates were 88%, 96%, 96% and 88%, respectively. At multivariate analysis, D'Amico risk categories significantly impacted on all the outcomes; higher radiotherapy doses were significantly related with better overall survival rates, and a similar trend was evident for disease-specific and biochemical relapse-free survival; cumulative probability of 5-year late G1-4 toxicity was 24.8% and was significantly related to higher radiotherapy doses (P <0.001). Conclusions. The changing patterns of practice described seem related to an improvement in efficacy and safety of radiotherapy for prostate cancer. However, the impact of the new radiotherapy techniques should be prospectively evaluated.

Bitumens in the late Variscan hydrothermal vein-type uranium deposit of Pribram, Czech Republic: Sources, radiation-induced alteration, and relation to mineralization

The late Variscan (275-278 Ma) Pribram uranium deposit is one of the largest known accumulations of uraniferous bitumens in hydrothermal veins. The deposit extends along the northwestern boundary of the Central Bohemian pluton (345-335 Ma) with low-grade metamorphosed Late Proterozoic and unmetamorphosed Cambrian rocks. From a net uranium production of 41,742 metric tons (t), more than 6,000 t were extracted from bitumen-uraninite ores during 43 years of exploration and mining. Three morphological varieties of solid bitumen are recognized: globular, asphaltlike, and cokelike. While the globular bitumen is uranium free, the other two types are uraniferous. The amount of bitumen in ore veins gradually decreases toward the contact with the plutonic body and increases with depth. Two types of bitumen microtextures are recognized using high-resolution transmission electron microscopy: amorphous and microporous, the former being less common in uraniferous samples. A lower Raman peak area ratio (1,360/1,575 cm(-1)) in mineralized bitumens (0.9) compared with uranium-free samples (2.0) indicates a lower degree of microtextural organization in the latter The H/C and O/C atomic ratios in uranium-free bitumens (0.9-1.1 and 0.09, respectively) are higher than those in mineralized samples (H/C = 0.3-0.8, O/C = 0.03-0.09). The chloroform extractable matter yield is Very low in uranium-free bitumens (0.30-0.35% of the total organic carbon,TOC) and decreases with uranium content increase. The extracted solid uraniferous bitumen infrared spectra show depletion in aliphatic CH2 and CH3 groups compared to uranium-free samples. The concentration of oxygen-bearing functional groups relative to aromatic bonds in the IR spectra of uranium-free and mineralized bitumen, however, do not differ significantly. C-13 NMR confirmed than the aromaticity of a uraniferous sample is higher (F-ar = 0.61) than in the uranium-free bitumen (F-ar = 0.51). Pyrolysates from uraniferous and nonuraniferous bitumens do not differ significantly, being predominantly cresol, alkylphenols, alkylbenzenes, and alkylnaphthalenes. The liquid pyrolysate yield decreases significantly with increasing uranium content. The delta(13)C Values of bulk uranium-free bitumens and low-grade uraniferous, asphaltlike bitumens range from -43.6 to 52.3 per mil. High-grade, cokelike, uraniferous bitumens are more C-13 depleted (54.5 to -58.4 parts per thousand). In contrast to the very light isotopic ratios of the high-grade uraniferous cokelike bitumen bulk carbon, the individual n-alkanes and isoprenoids (pristane and phytane) extracted from the same sample are significantly C-13 enriched. The isotopic composition of the C13-24 n-alkanes extracted from the high-grade uraniferous sample (delta(13)C = -28.0 to 32.6 parts per thousand) are heavier compared with the same compounds in a uranium-free sample (delta(13)C = 31.9 to 33.8 parts per thousand). It is proposed that the bitumen source was the isotopically light (delta(13)C = 35.8 to 30.2 parts per thousand) organic matter of the Upper Proterozoic host rocks that were pyrolyzed during intrusion of the Central Bohemian pluton. The C-13- depleted pyrolysates were mobilized from the innermost part of the contact-metamorphic aureole, accumulated in structural traps in less thermally influenced parts of the sedimentary complex and were later extracted by hydrothermal fluids. Bitumens at the Pribram deposit are younger than the main part of the uranium mineralization and were formed through water-washing and radiation-induced polymerization of both the gaseous and liquid pyrolysates. Direct evidence for pyrolysate reduction of uranium in the hydrothermal system is difficult to obtain as the chemical composition of the original organic fluid phase was modified during water-washing and radiolytic alteration. However, indirect evidence-e.g., higher O/C atomic ratios in uranium-free bitumens (0.1) relative to the Upper Proterozoic source rocks (0.02-0.05), isotopically very light carbon in associated whewellite (delta(13)C = 31.7 to -28.4 parts per thousand), and the striking absence of bitumens in the pre-uranium, hematite stage of the mineralization-indicates that oxidation of organic fluids may have contributed to lowering of aO(2) and uraninite precipitation.

Severe traumatic brain injury in a high-income country: an epidemiological study.

This adult cohort determined the incidence and patients' short-term outcomes of severe traumatic brain injury (sTBI) in Switzerland and age-related differences. A prospective cohort study with a follow-up at 14 days was performed. Patients ≥16 years of age sustaining sTBI and admitted to 1 of 11 trauma centers were included. sTBI was defined by an Abbreviated Injury Scale of the head (HAIS) score >3. The centers participated from 6 months to 3 years. The results are presented as percentages, medians, and interquartile ranges (IQRs). Subgroup analyses were performed for patients ≤65 years (younger) and >65 (elderly). sTBI was observed in 921 patients (median age, 55 years; IQR, 33-71); 683 (74.2%) were male. Females were older (median age, 67 years; IQR, 42-80) than males (52; IQR, 31-67; p<0.00001). The estimated incidence was 10.58 per 100,000 inhabitants per year. Blunt trauma was observed in 879 patients (95.4%) and multiple trauma in 283 (30.7%). Median Glasgow Coma Score (GCS) on the scene was 9 (IQR 4-14; 8 in younger, 12 in elderly) and in emergency departments 5 (IQR, 3-14; 3 in younger, 8 in elderly). Trauma mechanisms included the following: 484 patients with falls (52.6%; younger, 242 patients [50.0%]; elderly, 242 [50.0%]), 291 with road traffic accidents (31.6%; younger, 237 patients [81.4%]; elderly, 54 [18.6%]), and 146 with others (15.8%). Mortality was 30.2% (24.5% in younger, 40.9% in elderly). Median GCS at 14 days was 15 (IQR, 14-15) without differences among subgroups. Estimated incidence of sTBI in Switzerland was low, age was high, and mortality considerable. The elderly had higher initial GCS and a higher death rate, but high GCS at 14 days.

Effects of propranolol on resting metabolic rate after severe head injury.

Postabsorptive resting metabolic rate (RMR), measured by indirect calorimetry, and the effect of iv propranolol administration were studied in 12 nonseptic patients with severe head injury by means of indirect calorimetry. Before propranolol RMR was moderately increased (126 +/- 10.4% of predicted values) whereas urinary excretion of catecholamines was markedly elevated (p less than .01 vs. normal values). RMR was significantly correlated with both resting heart rate (HR) (r = .72, p less than .01) and 24-h urinary N excretion (r = .85, p less than .001). The administration of iv propranolol (0.1 mg/kg) produced a rapid decrease in HR (-10 +/- 4%, p less than .001) and in RMR (-6.1 +/- 2.3%, p less than .001). Further administration of propranolol produced no additional reduction in either HR or RMR. We conclude that severely head-injured patients are moderately hypermetabolic in resting and postabsorptive conditions, and that acute iv propranolol administration induces a reduction of about one quarter of the resting hypermetabolism.

Plasmacytoid dendritic cells sense skin injury and promote wound healing through type I interferons.

Plasmacytoid dendritic cells (pDCs) are specialized type I interferon (IFN-α/β)-producing cells that express intracellular toll-like receptor (TLR) 7 and TLR9 and recognize viral nucleic acids in the context of infections. We show that pDCs also have the ability to sense host-derived nucleic acids released in common skin wounds. pDCs were found to rapidly infiltrate both murine and human skin wounds and to transiently produce type I IFNs via TLR7- and TLR9-dependent recognition of nucleic acids. This process was critical for the induction of early inflammatory responses and reepithelization of injured skin. Cathelicidin peptides, which facilitate immune recognition of released nucleic acids by promoting their access to intracellular TLR compartments, were rapidly induced in skin wounds and were sufficient but not necessary to stimulate pDC activation and type I IFN production. These data uncover a new role of pDCs in sensing tissue damage and promoting wound repair at skin surfaces.

Differential proteoglycan expression in two spinal cord regions after dorsal root injury.

Dorsal root injury leads to reactive gliosis in the spinal cord dorsal root entry zone and dorsal column, two regions that undergo Wallerian degeneration, but have distinct growth-inhibitory properties. This disparity could in part be due to differences in the number of degenerating sensory fibers, differences in glial cell activation, and/or to differential expression of growth-inhibitory molecules such as chondroitin sulfate proteoglycans. Laser capture microdissection of these two spinal cord white matter regions, followed by quantitative analysis of mRNA expression by real-time PCR, revealed that glial marker transcripts were differentially expressed post-injury and that the chondroitin sulfate proteoglycans Brevican and Versican V1 and V2 were preferentially up-regulated in the dorsal root entry zone, but not the dorsal column. These results indicate that reactive gliosis differs between these two regions and that Brevican and Versican are potential key molecules participating in the highly inhibitory properties of the dorsal root entry zone.

The expressions of GABA and glutannate transporters are altered in the spared nerve injury model of neuropathic pain in the rat

Neuropathic pain is a common form of chronic pain, and is unsuccessfully alleviated by usual medications. Mounting evidence strongly point at non-neuronal glial cells in the spinal cord as key actors behind the persistence of pain. In particular, a change in the astrocytic capacity to regulate extracellular concentrations of neurotransmitters might account for the strengthened spinal nociceptive neurotransmission. Therefore, we investigated whether spinal expressions of GABA (GAT) and glutamate (EAAT) transporters were affected in the spared nerve injury (SNI) rat model of neuropathic pain. SNI was induced in male Sprague-Dawley rats by a unilateral section of tibial and common peroneal branches of the sciatic nerve, leaving the sural branch untouched. Western-blot analysis was performed to study the expression of GAT-1 and GAT-3 as well as EAAT-1 and EAAT-2, the main astrocytic GABA and glutamate transporters respectively. Seven days post-surgery, a significant increase in GAT-1, GAT-3 and EAAT-1 expressions is detected in both ipsilateral and contralateral sides of lumbar spinal cord in comparison to sham animals. No change in EAAT-2 signal could be detected. Furthermore, the astrocytic reaction parallels the glutamate and GABA transporters changes as we found an increased GFAP expression compared to the sham condition, in both spinal sides. Together, our results indicate that modifications in GABA and glutamate transport may occur along with SNI-associated painful neuropathy and identify spinal neurotransmitter reuptake machinery as a putative pharmacological target in neuropathic pain.

Status of eye lens radiation dose monitoring in European hospitals.

A questionnaire was developed by the members of WG12 of EURADOS in order to establish an overview of the current status of eye lens radiation dose monitoring in hospitals. The questionnaire was sent to medical physicists and radiation protection officers in hospitals across Europe. Specific topics were addressed in the questionnaire such as: knowledge of the proposed eye lens dose limit; monitoring and dosimetry issues; training and radiation protection measures. The results of the survey highlighted that the new eye lens dose limit can be exceeded in interventional radiology procedures and that eye lens protection is crucial. Personnel should be properly trained in how to use protective equipment in order to keep eye lens doses as low as reasonably achievable. Finally, the results also highlighted the need to improve the design of eye dosemeters in order to ensure satisfactory use by workers.

Src is activated by the nuclear receptor peroxisome proliferator-activated receptor β/δ in ultraviolet radiation-induced skin cancer.

Although non-melanoma skin cancer (NMSC) is the most common human cancer and its incidence continues to rise worldwide, the mechanisms underlying its development remain incompletely understood. Here, we unveil a cascade of events involving peroxisome proliferator-activated receptor (PPAR) β/δ and the oncogene Src, which promotes the development of ultraviolet (UV)-induced skin cancer in mice. UV-induced PPARβ/δ activity, which directly stimulated Src expression, increased Src kinase activity and enhanced the EGFR/Erk1/2 signalling pathway, resulting in increased epithelial-to-mesenchymal transition (EMT) marker expression. Consistent with these observations, PPARβ/δ-null mice developed fewer and smaller skin tumours, and a PPARβ/δ antagonist prevented UV-dependent Src stimulation. Furthermore, the expression of PPARβ/δ positively correlated with the expression of SRC and EMT markers in human skin squamous cell carcinoma (SCC), and critically, linear models applied to several human epithelial cancers revealed an interaction between PPARβ/δ and SRC and TGFβ1 transcriptional levels. Taken together, these observations motivate the future evaluation of PPARβ/δ modulators to attenuate the development of several epithelial cancers.

Mutism and Amnesia following High-Voltage Electrical Injury: Psychogenic Symptomatology Triggered by Organic Dysfunction?

Background: Mutism and dense retrograde amnesia are found both in organic and dissociative contexts. Moreover, dissociative symptoms may be modulated by right prefrontal activity. A single case, M.R., developed left hemiparesis, mutism and retrograde amnesia after a high-voltage electric shock without evidence of lasting brain lesions. M.R. suddenly recovered from his mutism following a mild brain trauma 2 years later. Methods: M.R.'s neuropsychological pattern and anatomoclinical correlations were studied through (i) language and memory assessment to characterize his deficits, (ii) functional neuroimaging during a standard language paradigm, and (iii) assessment of frontal and left insular connectivity through diffusion tractography imaging and transcranial magnetic stimulation. A control evaluation was repeated after recovery. Findings: M.R. recovered from the left hemiparesis within 90 days of the accident, which indicated a transient right brain impairment. One year later, neurobehavioral, language and memory evaluations strongly suggested a dissociative component in the mutism and retrograde amnesia. Investigations (including MRI, fMRI, diffusion tensor imaging, EEG and r-TMS) were normal. Twenty-seven months after the electrical injury, M.R. had a very mild head injury which was followed by a rapid recovery of speech. However, the retrograde amnesia persisted. Discussion: This case indicates an interaction of both organic and dissociative mechanisms in order to explain the patient's symptoms. The study also illustrates dissociation in the time course of the two different dissociative symptoms in the same patient.