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The common neurotrophin receptor, p75NTR , has been proposed to be an inhibitor of axon regeneration after peripheral nerve injury, but whether this effect is on the regenerating axons, immune cells migrating into the injury site, or cells in the pathway surrounding the axons is not clear. Cut nerves in mice expressing fluorescent proteins in axons were repaired with grafts from non-fluorescent hosts to study axon elongation when p75NTR was eliminated separately from axons and immune cells in the proximal stump of cut nerves, from cells in the regeneration pathway, or both. Two weeks later, axons from wild type mice regenerating into grafts devoid of p75NTR had elongated more than twice as far as axons in grafts from wild type mice. No enhancement of regeneration of axons in p75NTR knockout mice was observed, whether nerves were repaired with grafts from wild type mice or from p75NTR knockout mice. To evaluate whether inhibition of p75NTR could be used to improve regeneration, nerves in wild type mice repaired without grafts were exposed to a specific inhibitor of the p75NTR receptor, LM11A-31, at the time of nerve repair. This local blockade of p75NTR resulted in successful regeneration of axons of nearly three times as many motoneurons and reinnervation of twice as many muscle fibers by regenerating motor axons as untreated controls. Expression of p75NTR surrounding regenerating axons contributes to poor regeneration during the first 2 weeks after peripheral nerve injury. Inhibition of p75NTR might be a therapeutic target for treatments of peripheral nerve injuries.

BACKGROUND Downslope walking (DSW) is an eccentric-based exercise intervention that promotes neuroplasticity of spinal reflex circuitry by inducing depression of Soleus Hoffman (H)-reflexes in young, neurologically unimpaired adults. OBJECTIVE The objective of the study was to evaluate the effects of DSW on spinal excitability (SE) and walking function (WF) in people with multiple sclerosis (PwMS). METHODS Our study comprised two experiments on 12 PwMS (11 women; 45.3±11.8 years). Experiment 1 evaluated acute effects of a single 20-minute session of treadmill walking at three different walking grades on SE, 0% or level walking (LW), - 7.5% DSW, and - 15% DSW. Experiment 2 evaluated the effects of 6 sessions of DSW, at - 7.5% DSW (with second session being - 15% DSW) on SE and WF. RESULTS Experiment 1 showed significantly greater acute % H-reflex depression following - 15% DSW compared to LW (p = 0.02) and - 7.5% DSW (p = 0.05). Experiment 2 demonstrated significant improvements in WF. PwMS who showed greater acute H-reflex depression during the - 15% DSW session also demonstrated greater physical activity, long-distance WF, and the ability to have greater H-reflex depression after DSW training. Significant changes were not observed in regards to SE. CONCLUSIONS Though significant changes were not observed in SE after DSW training, we observed an improvement in WF which merits further investigation of DSW in PwMS.

Background During the past decades, stereotactic radiosurgery, and Gamma Knife in particular, has proved its safety and efficacy for drug-resistant classic trigeminal neuralgia. However, few large series exist using linear accelerator (LINAC) reporting long-term follow-up. Methods Between 2006 and 2015, 301 patients were treated by LINAC at our institution. The prescribed radiation dose was 90 Gy at the far anterior target. Clinical response was defined using the Barrow Neurological Institute scale. We considered grades I and IIIa as a successful response. Mean duration of follow-up was 54.6 months (range, 12–132 months). Results Two hundred and seventy-three patients (90.7%) were initially pain free, and 28 patients (9.3%) were unchanged. The actuarial probabilities of maintaining pain relief with or without medication (Barrow Neurological Institute grade I and IIIa) at 0.5, 1, 2, 4, 5, and 10 years were 88.7%, 85.0%, 76.1%, 68.8%, 65.8%, and 48.1%, respectively. Hypesthesia was present in only 26.2% of patients (very bothersome, 0.3%). No anesthesia dolorosa was reported. The actuarial probabilities of maintaining pain relief without further surgery at 0.5, 1, 2, 4, and 5 years were 99.3%, 98.3%, 95.8%, 91.0%, and 89.7%, respectively. Among all treated patients, 86.5% were satisfied by the procedure and would undergo stereotactic radiosurgery again. Conclusions Stereotactic radiosurgery with dedicated LINAC is associated with high rates of long-term pain relief, with minimal invasiveness and rare complications. LINAC is a possible therapeutic alternative for drug-resistant trigeminal neuralgia and could be proposed to selected patients as the first intention therapy, among other surgical solutions.

Transcranial magnetic stimulation (TMS) of the primary motor cortex (M1) can be used to evaluate descending corticomotor influences on spinal reflex excitability through modulation of the Hoffman reflex (H-reflex). The purpose of this study was to characterize between-session reliability of cortical, spinal, and cortical-conditioned spinal excitability measures collected from the soleus muscle. Thirteen able-bodied young adult participants were tested over four sessions. Intraclass correlation coefficients were calculated to quantify between-session reliability of active motor threshold (AMT), unconditioned H-reflexes (expressed as a percentage of Mmax), and conditioned H-reflexes using short-latency facilitation (SLF) and long-latency facilitation (LLF). Pearson correlation coefficients were calculated to assess associations between H-reflex facilitation and unconditioned H-reflex amplitude. Between-session reliability for SLF (ICC = 0.71) was higher than for LLF (ICC = 0.45), was excellent for AMT (ICC = 0.95), and was moderate for unconditioned H-reflexes (ICC = 0.63). Our results suggest moderate-to-good reliability of SLF and LLF to evaluate cortical influences on spinal reflex excitability across multiple testing sessions in able-bodied individuals.

This article outlines the novel hypothesis that exercise promotes axon regeneration after peripheral nerve injury through neuronal brain-derived neurotrophic factor (BDNF), and there are three required means of promoting BDNF expression: 1) increased signaling through androgen receptors, 2) increased cAMP-responsive element-binding protein expression, and 3) increased expression of the transcription factor SRY-box containing gene 11.

Downslope walking (DSW) causes H-reflex depression in healthy adults, and thus may hold promise for inducing spinal reflex plasticity in people with Multiple Sclerosis (PwMS). The study purpose was to test the hypothesis that DSW will cause acute depression of spinal excitability in PwMS. Soleus H-reflexes were measured in PwMS (n = 18) before and after 20 min of treadmill walking during three visits. Participants walked on a different slope each visit [level: 0% level walking (LW), upslope: +7.5% treadmill walking with an upslope (USW) or downslope: −7.5% (DSW)]. The soleus Hmax/Mmax ratio was used to measure spinal excitability. Heart rate and ratings of perceived exertion (RPE) were measured during walking. DSW induced the largest change in spinal excitability (a 26.7% reduction in soleus Hmax/Mmax (p = 0.001)), although LW also reduced Hmax/Mmax (-5.3%, p = 0.05). Heart rate (p

Meningiomas are the most common non-malignant tumours of the brain. Gross-total resection remains the preferred treatment, if achievable without morbidity. Radiation therapy is advocated for inoperable, incompletely resected, or recurrent grade 1 tumours, if there is a progressive, symptomatic lesion, or in case of functional impairment. Postoperative radiation therapy is recommended for grade 2 or 3 lesions. Fractionated stereotactic radiotherapy and stereotactic radiosurgery are high precision techniques, allowing good sparing of surrounding tissues. Fractionated stereotactic radiotherapy and stereotactic radiosurgery give comparable results, with excellent 5-year tumour control rates of more than 90% for benign meningiomas. Toxicity is low and seems equivalent, despite a biased use of fractionated stereotactic radiotherapy for larger meningiomas, close to critical structures. Fractionated stereotactic radiotherapy seems to be of special interest in the treatment of cavernous sinus or optic pathways meningiomas. The different therapeutic modalities should be discussed by a multidisciplinary team.

Radiosurgery as treatment for arteriovenous malformations has shown a good efficacy in reducing intracranial bleeding due to rupture. The choice of therapeutic modalities is based on evolutive risk and arteriovenous malformations volume, patient profile and risks stratification following therapeutic techniques (microsurgery, radiosurgery, embolization). Nidus size, arteriovenous malformations anatomical localization, prior embolization or bleeding, distributed dose are predictive factors for radiosurgery's good results and tolerance. This review article will highlight arteriovenous malformations radiosurgery indications and discuss recent irradiation alternatives for large arteriovenous malformation volumes.

The pathological complications of atherosclerosis, namely heart attacks and strokes, remain the leading cause of mortality in the Western world. Preceding atherosclerosis is endothelial dysfunction. There is therefore interest in the application of non-invasive clinical tools to assess endothelial function. The flow-mediated dilation (FMD) test is the standard tool used to assess endothelial function. Reduced FMD is an early marker of atherosclerosis and has been noted for its capacity to predict future cardiovascular disease events. This review discusses the measurement of endothelial function using ultrasound, with a focus on the FMD technique.

Full functional recovery after traumatic peripheral nerve injury is rare. We postulate three reasons for the poor functional outcome measures observed. Axon regeneration is slow and not all axons participate. Significant misdirection of regenerating axons to reinnervate inappropriate targets occurs. Seemingly permanent changes in neural circuitry in the central nervous system are found to accompany axotomy of peripheral axons. Exercise in the form of modest daily treadmill training impacts all three of these areas. Compared to untrained controls, regenerating axons elongate considerably farther in treadmill trained animals and do so via an autocrine/paracrine neurotrophin signaling pathway. This enhancement of axon regeneration takes place without an increase in the amount of misdirection of regenerating axons found without training. The enhancement also occurs in a sex-dependent manner. Slow continuous training is effective only in males, while more intense interval training is effective only in females. In treadmill trained, but not untrained mice the extent of coverage of axotomized motoneurons is maintained, thus preserving important elements of the spinal circuitry.

The validity of the flow-mediated dilation (FMD) test has been doubted due to the lack of normalization to the primary stimulus, shear stress. Shear stress can be calculated using a simplified mathematical model based on Poiseuille’s law. Poiseuille’s law assumes that the blood velocity profile is parabolic. The presence of turbulence will violate this assumption. The Reynolds number (RE) is used to define critical values for the transition from laminar to turbulent flow. Between RE values of 2000 and 4000, flow enters a transitional phase where turbulence is possible. Purpose: To determine whether brachial artery blood flow becomes turbulent during reactive hyperemia following forearm ischemia. Methods: Eleven healthy male subjects (25 ± 5 years) were tested. Brachial artery diameters and blood velocities were measured continuously following 2, 4, 6 and 10 minutes ischemia. The peak post-ischemic RE (REpeak) and RE integrated over 40 seconds (RE40) post-ischemia were calculated. Results: There was a significant change in REpeak (F4,7 = 98.573, p = ≤ 0.001) and RE40) (F4,7) = 50.613, p = ≤ 0.001) in response to ischemia. Within-subjects contrasts revealed a significant increase in REpeak and RE40 for each duration of ischemia versus baseline (p = ≤ 0.001). Following 4 minutes of ischemia there was approximately 12 seconds of potentially turbulent flow. Conclusion: Blood flow transitions between laminar and turbulent flow during ischemia-induced reactive hyperemia. This may limit the efficacy of estimating shear stress when using the standard FMD test protocol.

The aim of this study was to define the optimal pH for (1)H nuclear magnetic resonance (NMR) spectroscopy analysis of perchloric acid or methanol-chloroform-water extracts from brain tumor cells and tissues. The systematic study of the proton chemical shift variations as a function of pH of 13 brain metabolites in model solutions demonstrated that recording (1)H NMR spectra at pH 10 allowed resolving resonances that are overlapped at pH 7, especially in the 3.2-3.3 ppm choline-containing-compounds region. (1)H NMR analysis of extracts at pH 7 or 10 showed that quantitative measurements of lactate, alanine, glutamate, glutamine (Gln), creatine + phosphocreatine and myo-inositol (m-Ino) can be readily performed at both pHs. The concentrations of glycerophosphocholine, phosphocholine and choline that are crucial metabolites for tumor brain malignancy grading were accurately measured at pH 10 only. Indeed, the resonances of their trimethylammonium moieties are cleared of any overlapping signal, especially those of taurine (Tau) and phosphoethanolamine. The four non-ionizable Tau protons resonating as a singlet in a non-congested spectral region permits an easier and more accurate quantitation of this apoptosis marker at pH 10 than at pH 7 where the triplet at 3.43 ppm can be overlapped with the signals of glucose or have an intensity too low to be measured. Glycine concentration was determined indirectly at both pHs after subtracting the contribution of the overlapped signals of m-Ino at pH 7 or Gln at pH 10.

The consequences of a dosimetric radiosurgery accident are not the same as a conventional radiotherapy accident. The objective of this study was to estimate the clinical and radiological outcome of patients treated by radiosurgery for metastasis during the period of the overexposure accident that occurred in the Toulouse Radiosurgery Unit. Between April 2006 and March 2007, 33 patients with 57 metastases were treated in the Toulouse Radiosurgery Unit (Novalis®, BrainLab). An initial error in the estimation of the scatter factors led to an overexposure to radiation. The median age was 55 years [range, 35–85]. Twenty-one patients (64%) harbored a single metastasis. The primary tumor location was lung (16 cases), kidney (nine cases), breast (four cases), and others (four cases). The mean tumoral volume was 3.2 cm3 [0.04–14.07]. The mean prescribed dose at the isocenter was 20 Gy [range, 10–23], the mean delivered dose was 31.5 Gy [range, 13–52], and the mean overdose was 61.2% [range, 5.6–226.8]. In order to evaluate the consequences of the overdose, three parameters were analyzed: a risk index using dose and volume, the volume of parenchyma that received more than 12 Gy, and the mean dose in a sphere of 20 cm3 surrounding the target volume. Median actuarial survival was 14.1 months, the survival rate was 79.4 % at six months, 59.1% at 12 months, and 27.2% at 24 months. The rate of tumor control was 80.7%. No morbidity was observed. There was no correlation between death and the parameters studied. The survival rates and times observed in our study of the patients treated for brain metastases by radiosurgery and overexposed were among the good results of the international literature. Deaths were not related to the overdose and no side effect was noted. This dosimetric accident has not had worse consequences in this population.

We investigated the extent of misdirection of regenerating axons when that regeneration was enhanced using treadmill training. Retrograde fluorescent tracers were applied to the cut proximal stumps of the tibial and common fibular nerves two or four weeks after transection and surgical repair of the mouse sciatic nerve. The spatial locations of retrogradely labeled motoneurons were studied in untreated control mice and in mice receiving two weeks of treadmill training, either according to a continuous protocol (10 m/min, one hour/day, five day/week) or an interval protocol (20 m/min for two minutes, followed by a five minute rest, repeated 4 times, five days/week). More retrogradely labeled motoneurons were found in both treadmill trained groups. The magnitude of this increase was as great as or greater than that found after using other enhancement strategies. In both treadmill trained groups, the proportions of motoneurons labeled from tracer applied to the common fibular nerve that were found in spinal cord locations reserved for tibial motoneurons in intact mice was no greater than in untreated control mice and significantly less than found after electrical stimulation or chondroitinase treatment. Treadmill training in the first two weeks following peripheral nerve injury produces a marked enhancement of motor axon regeneration without increasing the propensity of those axons to choose pathways leading to functionally inappropriate targets.

Animal studies have identified monocyte chemoattractive protein-1 (MCP-1) and vascular endothelial growth factor (VEGF) as critical mediators of arterial diameter enlargement in response to chronic increases in blood flow (arteriogenesis). Furthermore, cellular studies have shown that the shear stresses resulting from increased blood flow stimulate synthesis of MCP-1, which in turn stimulates synthesis of VEGF. The purpose of this study was to determine if these mechanisms are evident in healthy women. Resting femoral artery diameter and blood flow, lean leg mass, MCP-1 and VEGF concentrations, and aerobic capacity were measured in 34 healthy women along with plasma concentrations of lipids associated with cardiovascular disease risk. Femoral artery diameter was independently related to metabolically active (lean) leg mass (b=0.41, P=0.008) and aerobic capacity (b=0.45, P=0.004). Plasma MCP-1 correlated negatively with the ratio of femoral artery diameter to lean leg mass (b=-0.42, P=0.009) and positively with serum triglycerides (b=0.46, P=0.005). Plasma VEGF exhibited similar correlations and strongly correlated with MCP-1 (R=0.92, P

Physical activity after spinal cord injury promotes improvements in motor function, but its effects following peripheral nerve injury are less clear. Although axons in peripheral nerves are known to regenerate better than those in the CNS, methods of accelerating regeneration are needed due to the slow overall rate of growth. Therefore we studied the effect of two weeks of treadmill locomotion on the growth of regenerating axons in peripheral nerves following injury. The common fibular nerves of thy-1-YFP-H mice, in which a subset of axons in peripheral nerves express yellow fluorescent protein (YFP), were cut and repaired with allografts from non-fluorescent littermates, and then harvested two weeks later. Mice were divided into groups of low-intensity continuous training (CT, 60 minutes), low-intensity interval training (IT; one group, 10 reps, 20 minutes total), and high-intensity IT (three groups, 2, 4, and 10 reps). One repetition consisted of two minutes of running and five minutes of rest. Sixty minutes of CT resulted in the highest exercise volume, whereas two reps of IT resulted in the lowest volume of exercise. The lengths of regenerating YFP+ axons were measured in images of longitudinal optical sections of nerves. Axon profiles were significantly longer than control in all exercise groups except the low-intensity IT group. In the CT group and the high-intensity IT groups that trained with four or 10 repetitions axons were more than twice as long as unexercised controls. The number of intervals did not impact axon elongation. Axon sprouting was enhanced in IT groups but not the CT group. Thus exercise, even in very small quantities, increases axon elongation in injured peripheral nerves whereas continuous exercise resulting in higher volume (total steps) may have no net impact on axon sprouting.

We described a case of chronic spinal cystic arachnoiditis after subarachnoid haemorrhage in a 54-year-old woman with a ruptured vertebral artery aneurysm treated by coils. At three months she complained of lumbar pain. At twelve months she presented lower limbs paresthesia then a rapidly bilateral motor deficit. MR showed a spinal arachnoiditis with two compressive cysts. Surgical decompression was inefficient and after three months spinal compression symptoms worsened and MR signs were unchanged.

Electrical stimulation of cut peripheral nerves at the time of their surgical repair results in an enhancement of axon regeneration. Regeneration of axons through nerve allografts was used to evaluate whether this effect is due to an augmentation of cell autonomous neurotrophin signaling in the axons or signaling from neurotrophins produced in the surrounding environment. In the thy-1-YFP-H mouse, a single one hour application of electrical stimulation at the time of surgical repair of the cut common fibular nerve results in a significant increase in the proportion of YFP+ dorsal root ganglion neurons that were also immunoreactive for BDNF or trkB as well as an increase in the length of regenerating axons through allografts from wild type litter mates, both one and two weeks later. Axon growth through allografts from neurotrophin-4/5 knockout mice or grafts made acellular by repeated cycles of freezing and thawing is normally very poor, but electrical stimulation results in a growth of axons through these grafts which is similar to that observed through grafts from wild type mice after electrical stimulation. When cut nerves in NT-4/5 knockout mice were electrically stimulated, no enhancement of axon regeneration was found. Electrical stimulation thus produces a potent enhancement of the regeneration of axons in cut peripheral nerves which is independent of neurotrophin production by cells in their surrounding environment but is dependent on stimulation of trkB and its ligands in the regenerating axons themselves.

The purpose of this study was to test the hypothesis that downslope treadmill walking decreases spinal excitability. Soleus H-reflexes were measured in sixteen adults on 3 days. Measurements were taken before and twice after 20 min of treadmill walking at 2.5 mph (starting at 10 and 45 min post). Participants walked on a different slope each day [level (Lv), upslope (Us) or downslope (Ds)]. The tibial nerve was electrically stimulated with a range of intensities to construct the M-response and H-reflex curves. Maximum evoked responses (Hmax and Mmax) and slopes of the ascending limbs (Hslp and Mslp) of the curves were evaluated. Rate-dependent depression (RDD) was measured as the % depression of the H-reflex when measured at a rate of 1.0 Hz versus 0.1 Hz. Heart rate (HR), blood pressure (BP), and ratings of perceived exertion (RPE) were measured during walking. Ds and Lv walking reduced the Hmax/Mmax ratio (P = 0.001 & P = 0.02), although the reduction was larger for Ds walking (29.3 ± 6.2% vs. 6.8 ± 5.2%, P = 0.02). The reduction associated with Ds walking was correlated with physical activity level as measured via questionnaire (r = −0.52, P = 0.04). Us walking caused an increase in the Hslp/Mslp ratio (P = 0.03) and a decrease in RDD (P = 0.04). These changes recovered by 45 min. Exercise HR and BP were highest during Us walking. RPE was greater during Ds and Us walking compared to Lv walking, but did not exceed “Fairly light” for Ds walking. In conclusion, in healthy adults treadmill walking has a short-term effect on soleus H-reflex excitability that is determined by the slope of the treadmill surface.

The purpose of the study was to determine whether arterial diameter, flow-mediated dilatation (FMD), and arterial range are affected by spinal cord injury (SCI). We assessed arm (radial) and leg (posterior-tibial) arteries that are comparable in size and function to determine whether (a) arterial function is reduced in individuals with SCI vs nondisabled subjects and (b) decrements to SCI arterial function are greater in the legs vs arms.Eighteen men with chronic (9.8 +/- 6.3 years) SCI (T2 to T11; American Spinal Injury Association A) and 13 nondisabled subjects matched for age (33.1 +/- 4.8 vs 29.8 +/- 8.2 years old, respectively), height, and weight (BMI = 25.3 +/- 5.8 vs 26.6 +/- 5.5 kg/m2, respectively).Radial and posterior tibial artery B-mode ultrasound images were continuously captured to measure resting diameter, occluded diameter, and postischemic diameters. Hierarchical linear modeling accounted for the nested experimental design.Individuals with SCI have lower systemic (arm + leg) FMD than nondisabled subjects (9.3% vs 12.3%, respectively; P= 0.035), primarily because of reduced leg FMD (11.5 +/- 3.1% vs 7.0 +/- 2.8% for SCI arms vs legs, respectively; P = 0.010). Persons with SCI also had lower arterial range than nondisabled subjects (0.79 vs 1.00 mm, respectively; P = 0.043), primarily because of the legs (0.81 +/- 0.09 vs 0.56 +/- 0.11 mm for SCI arms vs legs, respectively; P = 0.030).Leg arterial function seems to deteriorate at greater rates compared to the arms for individuals with SCI. Interventions to improve cardiovascular health should include measurements taken in the legs.

Longitudinal. The purpose of this study was to evaluate the effect of lower extremity resistance training on quadriceps fatigability, femoral artery diameter, and femoral artery blood flow. Academic Institution. Five male chronic spinal cord injury (SCI) individuals (American Spinal Injury Association (ASIA): A complete; C5–T10; 36±5 years old) completed 18 weeks of home-based neuromuscular electrical stimulation (NMES) resistance training. Subjects trained the quadriceps muscle group twice a week with four sets of 10 dynamic knee extensions against resistance while in a seated position. All measurements were made before training and after 8, 12, and 18 weeks of training. Ultrasound was used to measure femoral artery diameter and blood flow. Blood flow was measured before and after 5 and 10 min of distal cuff occlusion, and during a 4-min isometric electrical stimulation fatigue protocol. Training resulted in significant increases in weight lifted and muscle mass, as well as a 60% reduction in muscle fatigue (P=0.001). However, femoral arterial diameter did not increase. The range was 0.44±0.03 to 0.46±0.05 cm over the four time points (P=0.70). Resting, reactive hyperemic, and exercise blood flow did not appear to change with training. NMES resistance training improved muscle size and fatigue despite an absence of response in the supplying vasculature. These results suggest that the decreases in arterial caliber and blood flow seen with SCI are not tightly linked to muscle mass and fatigue resistance. In addition, muscle fatigue in SCI patients can be improved without increases in arterial diameter or blood flow capacity. Grants HL65179, HD39676, and HD39676S2.

Human cytomegalovirus (HCMV) genome and related proteins have been reported in a great proportion of malignant gliomas. However, these results are unexpected since HCMV is not known as an oncogenic virus. By immunohistochemistry (with an anti-IE1 monoclonal antibody) and in situ hybridisation (with biotinylated DNA probes) on tissue microarrays and frozen sections, we investigated a French series of central nervous system (CNS) tumours, including 97 glioblastomas. In 10 cases of glioblastoma, rare astrocyte-like cells, admixed with tumour cells, stained positively for HCMV and in one case a doubtful staining of rare cells was noticed. This may indicate a reactivation of the virus under local immunosuppression but none of the cases of CNS tumours (n=132) contained HCMV genomes and/or proteins in a significant proportion of tumour cells. Our results strongly suggest that HCMV is unlikely to be implicated in the development of human malignant gliomas, at least in French cases.

Pathological diagnosis of brain tumors provides an index of brain disease severity and guides clinical practice in their treatment. Diagnoses are often made from biopsy material obtained using stereotactic techniques with the difficulty of making a histological diagnosis in small samples. In our experience, the estimation of the degree of malignancy on the basis of in vitro1H magnetic resonance spectroscopy (1H MRS) appears to well correlate with histology and clinical evolution. We report two cases with a discordance between the diagnoses on the basis of histology examination and in vitro 1H MRS whose evolution seems to correlate better with the data of1H MRS.

Resume Objectif Le but du travail est de resumer le Plan Cancer et ses applications potentielles a la Neuro-Oncologie, et d’exposer les resultats de la premiere partie de l’enquete nationale « Neurochirurgie et Neuro-Oncologie : etats des lieux ». Methode Le Club de Neuro-Oncologie de la Societe Francaise de Neurochirurgie a etabli un questionnaire qui a ete adresse a tous les services de Neurochirurgie francais. Resultats Le taux de reponse a ete de 96,5 % pour les centres hospitaliers, et 7 centres liberaux ont repondu a l’enquete. L’integralite des resultats est presentee dans le texte. Conclusion Il ressort de cette enquete, d’une part, l’interet important des neurochirurgiens pour la Neuro-Oncologie et, d’autre part, la necessite pour construire une medecine de qualite conforme aux bonnes pratiques, de developper la construction de reseaux de Neuro-Oncologie formalises permettant d’exploiter les donnees cliniques et fondamentales afin d’optimiser la prise en charge medicale. La creation du Club de Neuro-Oncologie, la publication du Plan Cancer, et les resultats de cette enquete confirment les modifications entreprises dans la prise en charge des patients. La mise en place des Unites de Concertation Pluridisciplinaire, le developpement de l’information, de la transparence, d’une prise en charge adaptee au cas par cas representent, meme si celles-ci ne sont pas encore generalisees, les principales avancees de notre medecine moderne. En pratique, les neurochirurgiens doivent poursuivre les efforts entrepris et convaincre les pouvoirs publics de la necessite de moyens complementaires pour harmoniser et optimiser la prise en charge globale des patients.

The isolation and purification of alginates from seaweeds -decoloring with hypochlorite- has been discussed by different authors, but a study about the influence of hypochlorite treatment on alginate properties was not found. The aim of this work has been the research of hypochlorite decoloration in order to obtain highly decolored alginates that have suffered minimal degradation during isolation. Preliminary experiments were carried out varying the hypochlorite dose from 1, 5 to 25,0 percentage on dry weight alga basis. Alginate yield was determined, while hypochlorite consumption and pH changes in time were measured. Infrared and UV-Visible spectra of alginates were recorded. Hypochlorite consumption was complete from the very beginning of the reaction for all experiments where an hypochlorite dose of 10% or less was applied, meanwhile low yields were obtained when the dosage was 15% or higher. Alginate absortivity (g m 1 Lcm m 1 ) in UV-Visible spectra decreases when hypochlorite dose increases, but no...

The aim of this study is to evaluate microMOSFET as in-vivo dosimeter in 6 MV shaped-beam radiosurgery for field sizes down to 6 × 6 mm2. A homemade build-up cap was developed and its use with microMOSFET was evaluated down to 6 × 6 mm2. The study with the homemade build-up cap was performed considering its influence on field size over-cover occurring at surface, achievement of the overall process of electronic equilibrium, dose deposition along beam axis and dose attenuation. An optimized calibration method has been validated using MOSFET in shaped-beam radiosurgery for field sizes from 98 × 98 down to 18 × 18 mm2. The method was detailed in a previous study and validated in irregular field shapes series measurements performed on a head phantom. The optimized calibration method was applied to microMOSFET equipped with homemade build-up cap down to 6 × 6 mm2. Using the same irregular field shapes, dose measurements were performed on head phantom. MicroMOSFET results were compared to previous MOSFET ones. Additional irregular field shapes down to 8.8 × 8.8 mm2 were studied with microMOSFET. Isocenter dose attenuation due to the homemade build-up cap over the microMOSFET was near 2% irrespective of field size. Our results suggested that microMOSFET equipped with homemade build-up cap is suitable for in-vivo dosimetry in shaped-beam radiosurgery for field sizes down to 6 × 6 mm2 and therefore that the required build-up cap dimensions to perform entrance in-vivo dosimetry in small-fields have to ensure only partial charge particle equilibrium.

The purpose of this prospective, double-blind study was to correlate motor functional MRI (fMRI) with cortical brain mapping by intraoperative stimulation using 3D reconstructed images of the surface of the brain, and to validate the spatial data of fMRI in patients with brain tumors.Fourteen patients with tumors of the rolandic region underwent functional MR mapping of the hand region and subsequently cortical mapping before tumor resection. Data obtained with fMRI and brain mapping were not known previously by the neurosurgeon and by the neuroradiologist, respectively (double-blind study).In each case, the results of direct cortical mapping matched those obtained with fMRI, both positively and negatively, although the extent of the functional activations was larger than the area required to elicit the corresponding movement during intraoperative brain mapping.fMRI can be used before surgery to assess motor functional area in patients with rolandic tumors. More studies are needed to validate during surgery the real extent of fMRI activations.

This paper describes a region-based subband coding scheme intended for efficient representation of the visual information contained in image regions of arbitrary shape. QMF filters are separately applied inside each region for the analysis and synthesis stages, using a signal-adaptive symmetric extension technique at region borders. The frequency coefficients corresponding to each region are identified over the various subbands of the decomposition, so that the coding steps — namely, bit-allocation, quantization and entropy coding — can be performed independently for each region. Region-based subband coding exploits the possible homogeneity of the region contents by distributing the available bitrate not only in the frequency domain but also in the spatial domain, i.e. among the considered regions. The number of bits assigned to the subbands is optimized region by region for the whole image, by means of a rate-distortion optimization algorithm. Improved compression efficiency is obtained thanks to the local adaptativity of the bit allocation to the spectral contents of the different regions. This compensates for the overhead data spent in the coding of contour information. As the subband coefficients obtained for each region are coded as separate data units, the content-based functionalities required for the future MPEG4 video coding standard can be readily handled. For instance, content-based scalability is possible by simply imposing user-defined constraints to the bit-assignment in some regions.

Background/Aims: DNA sequences from Simian virus 40 (SV40) have been previously isolated from various human tumours of the central nervous system (CNS). This study aimed to investigate a series of tumours of the CNS for the expression of the SV40 large T antigen (Tag), which is an oncogenic protein of the virus. Methods: A French series of 82 CNS tumours was investigated for Tag expression using a monoclonal antibody and immunohistochemistry. A Tag positive hepatocellular carcinoma cell line from transgenic mice and a kidney biopsy from a patient infected by SV40 were used as positive controls. Results: None of the tumours (20 ependymomas, 20 glioblastomas, 12 oligodendrogliomas, three plexus choroid adenomas, two plexus choroid carcinomas, 15 meningiomas, and 10 medulloblastomas) contained SV40 Tag positive cells. Conclusions: The lack of SV40 Tag in 82 CNS tumours of various types is at variance with previous studies from different countries, and suggests that the virus may not be an important factor in CNS tumorigenesis, at least in French cases.

The design of neuro-stimulators must include a realistic model of electrode-tissue interface. Complex electrochemical phenomena associated to high levels of stimulation current give fractional and non linear behavior to this interface that simple linearized models fail to fit. This paper describes both a measurement protocol based on biphasic current-controlled solicitations and a modeling procedure relying on an original approach of multi-model, taking into account the non-linear and fractional effects. This model fits correctly the measurement results with current levels varying from 50μA to 1mA. Furthermore the whole characterization protocol can be safely transposed to in vivo measurements.

In-vivo dosimetry is still a challenge in stereotactic radiosurgery since most of treatments are delivered using rotational technique with small fields. A realistic and practical solution for these treatments delivered in conformal radiotherapy is proposed to control the absorbed dose at isocentre, using multiple surface MOSFET measurements over an arc. On the one hand, a forward method was developed to optimize the location of the detectors at the patient surface, taking into account arc length, prescribed isocentre dose, collimator and field size. On the other hand, an inverse method was used to compute the dose at isocentre for conformal arc therapy in stereotactic radiosurgery, using MOSFET measurements. Finally, the reconstructed dose at isocentre was compared to real measurement, obtained for several detectors positioned at a phantom surface. Results show that the inverse method gives good results with five MOSFET equi-spaced positioned within the arc beam course: deviation between prescribed and computed average total dose at isocentre was below 2% both for 30×30 mm2 and 18×18 mm2 field size

Nowadays MOSFET dosimeters are widely used for dose verification in radiotherapy procedures. Although their sensitive area satisfies size requirements for small field dosimetry, their use in radiosurgery has rarely been reported. The aim of this study is to propose and optimize a calibration method to perform surface measurements in 6 MV shaped-beam radiosurgery for field sizes down to 18 × 18 mm(2). The effect of different parameters such as recovery time between 2 readings, batch uniformity and build-up cap attenuation was studied. Batch uniformity was found to be within 2% and isocenter dose attenuation due to the build-up cap over the MOSFET was near 2% irrespective of field size. Two sets of sensitivity coefficients (SC) were determined for TN-502RD MOSFET dosimeters using experimental and calculated calibration; the latter being developed using an inverse square law model. Validation measurements were performed on a realistic head phantom in irregular fields. MOSFET dose values obtained by applying either measured or calculated SC were compared. For calibration, optimal results were obtained for an inter-measurement time lapse of 5 min. We also found that fitting the SC values with the inverse square law reduced the number of measurements required for calibration. The study demonstrated that combining inverse square law and Sterling-Worthley formula resulted in an underestimation of up to 4% of the dose measured by MOSFETs for complex beam geometries. With the inverse square law, it is possible to reduce the number of measurements required for calibration for multiple field-SSD combinations. Our results suggested that MOSFETs are suitable sensors for dosimetry when used at the surface in shaped-beam radiosurgery down to 18 × 18 mm(2).

The pathological complications of atherosclerosis, namely heart attacks and strokes, remain the leading cause of mortality in the Western world (Lloyd-Jones & Adams et al. 2010). Preceding atherosclerosis is endothelial dysfunction (Ross 1993; Cohn 1999; Quyyumi 2003). The endothelium comprises a continuous monolayer of cells which separate the vascular wall from the circulation (Lerman & Zeiher 2005). Disruption of this essential monolayer is thought to occur early in the pathogenesis of cardiovascular disease (CVD). There is, therefore, interest in the application of non-invasive clinical tools to assess the function and health of this essential monolayer.

Flow-mediated dilation (FMD) is the standard tool used to assess endothelial function. The premise behind the standard FMD test is that it serves as an endothelial-dependant nitric oxide bioassay; however, the endothelium may release additional dilatory molecules which contribute to FMD, most notably prostacyclin and endothelial-derived hyperpolarizing factor. The relative importance of these molecules to the dilatory response may vary substantially among individuals, particularly in response to a number of diseased states. This review discusses how each of these molecules may contribute to vasodilation, and considers the circumstances in which they may vary.

The validity of the flow-mediated dilation test has been questioned due to the lack of normalization to the primary stimulus, shear stress. Shear stress can be calculated using Poiseuille's law. However, little attention has been given to the most appropriate blood velocity parameter(s) for calculating shear stress. The pulsatile nature of blood flow exposes the endothelial cells to two distinct shear stimuli during the cardiac cycle: a large rate of change in shear at the onset of flow (velocity acceleration), followed by a steady component. The parameter typically entered into the Poiseuille's law equation to determine shear stress is time-averaged blood velocity, with no regard for flow pulsatility. This paper will discuss (1) the limitations of using Posieuille's law to estimate shear stress and (2) the importance of the velocity profile—with emphasis on velocity acceleration—to endothelial function and vascular tone.

Application of chondroitinase ABC (ChABC) to injured peripheral nerves improves axon regeneration, but it is not known whether functional recovery is also improved. Recordings of EMG activity [soleus (Sol) M response and H reflexes] evoked by nerve stimulation and of Sol and tibialis anterior (TA) EMG activity and hindlimb and foot kinematics during slope walking were made to determine whether ChABC treatment of the sciatic nerve at the time of transection improves functional recovery. Recovery of evoked EMG responses began as multiple small responses with a wide range of latencies that eventually coalesced into one or two more distinctive and consistent responses (the putative M response and the putative H reflex) in both groups. Both the initial evoked responses and the time course of their maturation returned sooner in the ChABC group than in the untreated (UT) group. The reinnervated Sol and TA were coactivated during treadmill locomotion during downslope, level, and upslope walking throughout the study period in both UT and ChABC-treated rats. By 10 wk after nerve transection and repair, locomotor activity in Sol, but not TA, had returned to its pretransection pattern. There was an increased reliance on central control of Sol activation across slopes for both groups as interpreted from elevated prestance Sol EMG activity that was no longer modulated with slope. Limb length and orientation during locomotion were similar to those observed prior to nerve injury during upslope walking only in the ChABC-treated rats. Thus treatment of cut nerves with ChABC leads to improvements in functional recovery.

Exercise in the form of daily treadmill training results in significant enhancement of axon regeneration following peripheral nerve injury. Because androgens are also linked to enhanced axon regeneration, we wanted to investigate whether sex differences in the effect of treadmill training might exist. The common fibular nerves of thy-1-YFP-H mice were cut and repaired with a graft of the same nerve from a strain-matched wild type donor mouse. Animals were treated with one of two daily treadmill training paradigms: slow continuous walking for one hour or four higher intensity intervals of two minutes duration separated by five minute rest periods. Training was begun on the third day following nerve injury and continued five days per week for two weeks. Effects on regeneration were evaluated by measuring regenerating axon profile lengths in optical sections through the repair sites and grafts at the end of the training period. No sex differences were found in untrained control mice. Continuous training resulted in significant enhancement of axon regeneration only in males. No effect was found in females or in castrated males. Interval training was effective in enhancing axon regeneration only in females and not in intact males or castrated males. Untrained females treated with the aromatase inhibitor, anastrozole, had significant enhancement of axon regeneration without increasing serum testosterone levels. Two different mechanisms exist to promote axon regeneration in a sex-dependent manner. In males treadmill training utilizes testicular androgens. In females a different cellular mechanism for the effect of treadmill training must exist.

Meningiomas are the most common non-malignant tumours of the brain. Gross-total resection remains the preferred treatment, if achievable without morbidity. Radiation therapy is advocated for inoperable, incompletely resected, or recurrent grade 1 tumours, if there is a progressive, symptomatic lesion, or in case of functional impairment. Postoperative radiation therapy is recommended for grade 2 or 3 lesions. Fractionated stereotactic radiotherapy and stereotactic radiosurgery are high precision techniques, allowing good sparing of surrounding tissues. Fractionated stereotactic radiotherapy and stereotactic radiosurgery give comparable results, with excellent 5-year tumour control rates of more than 90% for benign meningiomas. Toxicity is low and seems equivalent, despite a biased use of fractionated stereotactic radiotherapy for larger meningiomas, close to critical structures. Fractionated stereotactic radiotherapy seems to be of special interest in the treatment of cavernous sinus or optic pathways meningiomas. The different therapeutic modalities should be discussed by a multidisciplinary team.