Anatomo-radiological correlation between diffusion tensor imaging and histologic analyses of glial tumors: a preliminary study.

BACKGROUND AND PURPOSE: The challenge of the neurosurgical management of gliomas lies in achieving a maximal resection without persistent functional deficit. Diffusion tensor imaging (DTI) allows non-invasive identification of white matter tracts and their interactions with the tumor. Previous DTI validation studies were compared with intraoperative cortical stimulation, but none was performed based on the tumor anatomopathological analysis. This preliminary study evaluates the correlation between the preoperative subcortical DTI tractography and histology in terms of fiber direction as well as potential tumor-related fiber disruption. METHODS: Eleven patients harboring glial tumors underwent preoperative DTI images. Correlations were performed between the visual color-coded anisotropy (FA) map analysis and the tumor histology after "en bloc" resection. Thirty-one tumor areas were classified according to the degree of tumor infiltration, the destruction of myelin fibers and neurofilaments, the presence of organized white matter fibers, and their orientation in space. RESULTS: After histologic comparison, the DTI sensitivity and specificity to predict disrupted fiber tracts were respectively of 89% and 90%. The positive and negative predicted values of DTI were 80% and 95%. The DTI data were in line with the histologic myelin fiber orientation in 90% of patients. In our series, the prevalence of destructed fiber was 31%. Glioblastoma WHO grade IV harbored a higher proportion of destructed white matter tracts. Lower WHO grades were associated with higher preservation of subcortical fiber tracts. CONCLUSION: This DTI/histology study of "en bloc"-resected gliomas reported a high and reproducible concordance of the visual color-coded FA map with the histologic examination to predict subcortical fiber tract disruption. Our series brought consistency to the DTI data that could be performed routinely for glioma surgery to predict the tumor grade and the postoperative clinical outcomes.

Guidance for the Prevention of the COVID-19 Epidemic in Long-Term Care Facilities: A Short-Term Prospective Study.

BACKGROUND: Guidance aiming at limiting the entry and spread of the COVID-19 have been widely communicated to Long-term Care Facilities (LTCFs). However, no clinical research has investigated their relevance. OBJECTIVE: Our objective was to compare the guidance applied for the prevention of the COVID-19 epidemic between the LTCFs having been contaminated by COVID-19 and LTCFs having not been contaminated. METHODS: A questionnaire was sent and systematically accompanied by phone call to the 132 LTCFs of Haute-Garonne (Occitania region, South-West of France). The questionnaire focused on the preventive measures implemented before March 23, 2020 (first LTCFs contaminated in this area). The questionnaire focused on physician support, implementation of usual guidance (eg, masks, hydro-alcoholic solute used), training on hygiene, containment in residents' rooms and other distancing measures, use of temporary workers, compartmentalization within zones of residents and staff and a self-assessment analogic scale on the quality of the application of the preventive measures. We compared implementation of the guidance between the LTCFs with at least one case of COVID-19 among residents and/or health care professionals and LTCFs without COVID-19 case (between March 23rd and May 6th). RESULTS: 124 LTCFs participated (93.9%). 30 LTCFs (24.19%) were contaminated with COVID-19. Large heterogeneity of the application of the guidance was observed. Public LTCFs (OR= 0.39 (0.20-0.73), LTCFs which organized staff compartmentalization within zones (OR= 0.19 (0.07-0.48)), and LTCF with a staff who self-assessed a higher quality implementation of the preventive measures (OR= 0.65 (0.43-0.98)) were significantly more likely to avoid contamination by the COVID-19 outbreak. CONCLUSION: Our study supports the relevance of guidance to prevent the entry of COVID-19, in particular the staff compartmentalization within zones, as well as the perception of the staff regarding the quality of implementation of those measures in LTCFs.

A viral phospholipase A2 is required for parvovirus infectivity.

Sequence analysis revealed phospholipase A2 (PLA2) motifs in capsid proteins of parvoviruses. Although PLA2 activity is not known to exist in viruses, putative PLA2s from divergent parvoviruses, human B19, porcine parvovirus, and insect GmDNV (densovirus from Galleria mellonella), can emulate catalytic properties of secreted PLA2. Mutations of critical amino acids strongly reduce both PLA2 activity and, proportionally, viral infectivity, but cell surface attachment, entry, and endocytosis by PLA2-deficient virions are not affected. PLA2 activity is critical for efficient transfer of the viral genome from late endosomes/lysosomes to the nucleus to initiate replication. These findings offer the prospect of developing PLA2 inhibitors as a new class of antiviral drugs against parvovirus infections and associated diseases.

[Comparison of quality of life in multiple system atrophy and Parkinson's disease]. / Comparaison de la qualité de vie de patients atteints d'atrophie multisystématisée et de maladie de Parkinson.

PURPOSE: Quality of life (QoL) in multiple system atrophy (MSA) is thought to be poorer than in Parkinson's disease (PD), primarily because of motor impairment, autonomic dysfunction and depression. The aim of the study was to investigate QoL in 10 patients with probable MSA (parkinsonian subtype) compared with 10 PD patients matched for motor disability on UPDRS III motor score. METHODS: All patients were ambulatory and non-demented. Mean durations of disease in MSA and PD patients were respectively 3.6 and 9.0 years. QoL was assessed using the SF-36 health-related questionnaire and a life satisfaction visual analogue scale. Patients were also evaluated for cognitive function (Mattis Dementia Rating Scale [Mattis DRS], Wisconsin Card Sorting Test [WCST], Stroop, Fluencies), depression (Beck Depression Inventory-II [BDI-II]), apathy (Modified Apathy Evaluation Scale) and were screened for non-motor symptoms (NMS Quest). RESULTS: The only difference in QoL between MSA and PD patients matched for motor disability was that the SF-36 vitality subscore was more impaired in MSA and negatively correlated with interference index on Stroop word colour testing. Depression and non-motor symptoms were associated with poorer QoL in both groups. Among MSA patients, cognitive impairment (Stroop interference index) and apathy also had a negative impact. CONCLUSION: There was no major difference in QoL between MSA and PD patients matched for motor disability with a disease duration about 5 years longer. The SF-36 vitality subscore was more impaired in MSA and associated with interference sensitivity.

Preoperative assessment of idiopathic scoliosis in adolescent and young adult with three-dimensional T2-weighted spin-echo MRI.

PURPOSE: To compare tridimensional (3D) T2-weighted spin-echo MRI and CT for minimal pedicle width measurements in the preoperative assessment of adolescent idiopathic scoliosis (AIS) in adolescent and young patients. MATERIALS AND METHODS: A total of 22 adolescents/young patients suffering from AIS were retrospectively included. There were 18 females and 4 males with a mean age of 15.3±2.3 (SD) years (range: 11-21years). Preoperative lumbar spine MRI and CT examinations of the 22 patients were reviewed by two independent readers who measured the minimal width of 259 pedicles. Inter-reader agreement for CT and MRI was assessed using intra-class correlation coefficient (ICC). Intra-reader agreement and relative differences in measurements between MRI and CT were also assessed for each reader. RESULTS: Inter-reader agreement was excellent (ICC≥0.8) for both CT and MRI. Relative differences in measurements between CT and MRI was 10.3% for reader 1 and 9.4% for reader 2. CONCLUSION: 3D T2-weighted spin-echo MRI underestimates minimal pedicle width by only 9.4 - 10.3% compared to CT. 3D T2-weighted MRI appears as a valuable alternative to CT for preoperative measurements of vertebral pedicles in AIS.

Dynamic mechanical properties of a biomimetic hydroxyapatite/polyamide 6,9 nanocomposite.

A biomimetic composite of nanohydroxyapatite (nHap) and semicrystalline polyamide 6,9 (PA 6,9) was synthesized by thermally induced phase separation. The nHap powder was dispersed in a polymer matrix with a low ratio ranging 1-10 wt %. The mean size of the nHap, determined by scanning electron microscopy (SEM) was approximately 100-200 nm (length), 40-60 nm (width). Physicochemical analyses were performed in order to characterize the PA 6,9 and nHap separately on the one hand, and the PA 6,9/nHap composites on the other hand. Differential scanning calorimetry (DSC) and dynamic mechanical analyses (DMA) have pointed out an optimization of the composite physical properties as a function of nHap content till a limit value of 5 wt %. Above this value, the mechanical properties decreased. Four main parameters have been found to influence the composite physical properties improvement: the fillers content, the physical structure of the polymeric matrix, the particles dispersion and the physical interaction strength between organic and inorganic phases. The dynamic mechanical properties of this biomimetic nanocomposite were compared with human cortical bone.

[Exogenous risk factors in sporadic ALS: a review of the literature]. / Facteurs de risque exogènes de la sclérose latérale amyotrophique sporadique.

The latest reviews of the literature devoted to the epidemiology of ALS all agree that exogenic risk factors play a role in sporadic ALS. Nevertheless, there is no convincing evidence demonstrating in a reproducible manner an association between an environmental risk factor and ALS. This discordance is mainly explained by methodological skews. Over the last ten years, exogenic factors have been analyzed within the framework of specific lifestyle factors such as place of residence, smoking or not, or certain eating practices. The most recent work suggests that interactions between genetic and environmental factors depend on the age at exposure and the duration of exposure. The objectives of this general review is: to analyze the principal case-control studies, historical cohort studies or mortality studies which looked at the associations between an environmental factor and ALS, to present main results of studies having analyzed lifestyles in relation to one or more exogenic factors, and to discuss the limitations of epidemiologic studies on ALS.

[Functional rating scales for amyotrophic lateral sclerosis]. / Echelles fonctionnelles de la sclérose latérale amyotrophique.

Amyotrophic lateral sclerosis (ALS) is a progressive degeneration of the peripheral and central motor neurons. The principal consequence is a loss of motor functions. Evaluation of motor deficit implies an assessment of the resulting deficiency or incapacity and final disability. Many evaluation are proposed for patient follow-up in order to analyze the state of motor function and their consequences on activities of everyday life. Few recommendations can be formulated. Scales must be validated and relatively simple to use and generate ordinate results allowing statistical analysis. The choice of which scale to use depends on the clinical objective. Global scales (ALS Functional rating Scale, ALS Severity Scale, Appel scale, Norris scale and Honda scale) can be used to evaluate progression of the disability. Some of these scales are strongly correlated with patient survival. Other scales (ALS Health State Scale, global clinical impression) are used to classify patients by homogeneous stage of gravity. Still other scales, such as the Sadoul and Borg scales and the Epworth score are designed for more specific evaluation of a given function. The clinician should be aware of these different scales and their relative utility. Knowledge of these scales, their validity, their sensitivity to modification, and their specificity and interpretation pitfalls is a prerequisite to good evaluation in daily practice and clinical research.

[Announcement of amyotrophic lateral sclerosis diagnosis]. / Modalités et contenu de l'annonce du diagnostic de sclérose latérale amyotrophique sporadique.

Breaking the news of amyotrophic lateral sclerosis (ALS) is considered as a daunting task in most cases and is not a standardizable procedure. However, proven techniques exist to reduce the trauma to the patient. Announcing ALS falls upen the neurologist who must respect the ethical principle of the patient's independence. After the diagnosis is firmly established, the patient should be informed that he or she has a progressive disease of the motor nerves, for which no curative therapy is available. The name of the disease must be stated and explained. If the family history is negative, it is reassuring for the patient and family to know that their children are unlikely to be at risk. Positive aspects (no pain, no disturbances in sensation, cognition, memory and continence) should be stressed as well as the availability of efficient palliative measures for practically all symptoms. Current research efforts, and when available, the possibility of taking part in clinical studies of new drugs should be pointed out as a means of hope. The answer to the question of prognosis should include the information that there are no sudden worsenings to be expected, that the course of ALS may vary between months and decades, that making a firm statement on prognosis all but impossible for any single patient and that respiratory function may worsen during the disease course. It is therefore mandatory to inform patients and families about the existence of ALS patients'associations. The way the patient is told the diagnosis is of great importance and is considered as a multiple-step procedure. Discussion should take place in a private and quiet room and respect some fundamental objectives such as finding out what the patient already knows or suspects and how much more the patient wants to know, observing and responding to the patient's reactions, reinforcing the information and planning the future. It is proven that communicating the diagnosis of ALS in an empathetic fashion is an important and sensitive step to disease management.

[Analysis of reasons for the late diagnosis of amyotrophic lateral sclerosis]. / Etude des causes du retard au diagnostic de la sclérose latérale amyotrophique.

INTRODUCTION: The mean diagnostic delay of amyotrophic lateral sclerosis (ALS) is greater than one year. Its causes are multiple, related to the affection, the patient, or medical practices. METHODS: An investigation was carried out in 77 consecutive patients, to describe their medical course since the date of the first symptoms until the diagnosis. Interrogation of the private practitioners potentially implied in the diagnostic procedure enabled an evaluation of the degree and origin of their knowledge of the disease. RESULTS: In the majority of patients, the first consultation was conducted by a general practitioner. Referral to a neurologist occurred on average 7 months after this consultation. A first-intention electrophysiological examination was prescribed in one-third of patients. Practitioners were unknowledgeable about certain clinical signs. Their knowledge on the disease came primarily from medical school training and for two-thirds, their satisfaction concerning their degree of training was low. CONCLUSION: This observational study shows that medical practices contribute to delayed diagnosis of ALS, particularly delayed referral to a neurologist. To enable earlier diagnosis, general practitioners should be informed of the usefulness of early referral for multidisciplinary care of patients.

GlobalSoilMap France: High-resolution spatial modelling the soils of France up to two meter depth.

This work presents the first GlobalSoilMap (GSM) products for France. We developed an automatic procedure for mapping the primary soil properties (clay, silt, sand, coarse elements, pH, soil organic carbon (SOC), cation exchange capacity (CEC) and soil depth). The procedure employed a data-mining technique and a straightforward method for estimating the 90% confidence intervals (CIs). The most accurate models were obtained for pH, sand and silt. Next, CEC, clay and SOC were found reasonably accurate predicted. Coarse elements and soil depth were the least accurate of all models. Overall, all models were considered robust; important indicators for this were 1) the small difference in model diagnostics between the calibration and cross-validation set, 2) the unbiased mean predictions, 3) the smaller spatial structure of the prediction residuals in comparison to the observations and 4) the similar performance compared to other developed GlobalSoilMap products. Nevertheless, the confidence intervals (CIs) were rather wide for all soil properties. The median predictions became less reliable with increasing depth, as indicated by the increase of CIs with depth. In addition, model accuracy and the corresponding CIs varied depending on the soil variable of interest, soil depth and geographic location. These findings indicated that the CIs are as informative as the model diagnostics. In conclusion, the presented method resulted in reasonably accurate predictions for the majority of the soil properties. End users can employ the products for different purposes, as was demonstrated with some practical examples. The mapping routine is flexible for cloud-computing and provides ample opportunity to be further developed when desired by its users. This allows regional and international GSM partners with fewer resources to develop their own products or, otherwise, to improve the current routine and work together towards a robust high-resolution digital soil map of the world.

Topography of the human corpus callosum.

This study was undertaken to determine the topographical organization of fibers coursing through the human corpus callosum. We correlated the distribution of Wallerian degeneration in the corpus callosum with the anatomical sites of focal cortical lesions due to ischemic infarctions or circumscribed contusions. Fibers from the inferior frontal and anterior inferior parietal regions course through the rostrum and genu of the corpus callosum. Callosal connections from the temporo-parieto-occipital junctional region course through the splenium and caudal portion of the body of the corpus callosum. Both the superior parietal lobule and the occipital cortex give rise to interhemispheric fibers that course exclusively through the splenium of the corpus callosum. No callosal degeneration was associated with a cortical lesion in the anterior superior frontal region. The topographical organization of fibers in the human corpus callosum appears to be fairly similar to that found in the rhesus monkey (Macaca mulatta).

Measures of gender differences in the human brain and their relationship to brain weight.

A series of gross brain linear measurements and cross-sectional surface areas were obtained in a sample of 69 postmortem adult human brains. Data indicate that a subset of these measurements are sexually dimorphic and can be used to discriminate between male and female brains. Results further suggest that studies on gender differences in neuromorphometry can be greatly enhanced if they account for sample variance in brain weight. Using 19 of the gross brain measures delineated in this study, it is possible to accurately predict brain weight. It is believed that the measures obtained in this study will facilitate expanded correlative studies of brain morphology and neuropsychological profiles using either postmortem material or in vivo magnetic resonance imaging scans.

The role of cortical connectivity in Alzheimer's disease pathogenesis: a review and model system.

Here we review current evidence in support of the cortical disconnection/cortical connectivity model of Alzheimer disease (AD) pathogenesis, a model which predicts that one of the first events in AD is damage to the entorhinal cortex and/or subiculum resulting in the disconnection of the hippocampal formation and neocortex, and the subsequent progression of the disease in a stepwise fashion along cortico-cortical connections. Much of the evidence for this model has been obtained from studies involving the limbic system where investigators have demonstrated a precise correspondence between established patterns of connectivity and the degenerative changes associated with AD. In addition, some studies of the distribution of neuritic plaques (NP) and neuro-fibrillary tangles (NFT) in the neocortex and subcortical structures have yielded corroborative data. The validity of the cortical disconnection/connectivity model in the neocortex remains to be established or refuted. We propose that testing of this model can be accomplished with systematic studies of the laminar and regional distribution of NP and NFT in a series of sequentially interconnected cytoarchitectural regions that also form part of two functional hierarchies--the paralimbic and occipitotemporal visual systems. To adequately control for variation between brains affected by AD, it is imperative that such studies be conducted in a large but varied population of AD cases exhibiting differences in several variables, including clinical and/or neuropathological severity of the disease, temporal duration of the disease, and clinical/neuropsychological profile. We believe that further understanding of the relationship between characteristic AD pathology and intrinsic anatomico-functional circuits will contribute not only to our comprehension of AD pathogenesis but also to our general knowledge of the human brain.

Analysis of sliding and pressure distribution during a repositioning of persons in a simulator chair.

This study was undertaken to investigate the effect of system tilt and back recline angles on sliding and pressure distribution of seated subjects. Ten able-bodied subjects adopted successively 12 postures on a multiadjustable simulator chair. The system tilt angle was varied from 0 degrees to 45 degrees posterior tilt, while the seat to back angle varied from 90 degrees to 120 degrees. A maximum of 40.2% of weight shift was found when combining a system tilt angle of 45 degrees to a seat to back angle of 120 degrees. Maximum value of 74 mm of sliding was observed for the acromion marker during repositioning. Significant weight shift at the level of the seat is obtained only when the system tilt angle exceeds 15 degrees in a posterior direction. We can put forward here that a small tilt < or =15 degrees can be used to adjust back pressure distribution, whereas large posterior tilts are used for an effective weight shift at the seat level. The peak pressure gradient remains in general in the interval of +/-30% from the neutral posture for the able-bodied subjects and is fairly constant at 15 degrees of tilt. A significant amount of displacement along the back and seat reference plane were found for the shoulder and hip markers, but this displacement does not necessarily correspond to a pure translation motion of the pelvic segment.

Clusters of travel associated legionnaires' disease in France, September 2001- August 2003.

Clusters of travel associated legionnaires' disease warrant urgent attention, and are detected by the French national surveillance system and the European network EWGLINET. Between September 2001 and August 2003, 37 clusters were identified in French tourist accommodation: 27 hotels and 10 campsites. The number of clinical cases per cluster was as follows: 30 clusters of 2 cases (81%), 6 clusters of 3 cases (16%) and one cluster of 4 cases (3%), a total of 82 cases. The local health authorities performed environmental investigations for 36 of the 37 clusters. Among the 36 clusters investigated, water samples were collected for 35. At 16 (46%) sites, Legionella pneumophila was found at a level of more than 103 cfu/litre. In all of the accommodation where risk assessment was found to be inadequate- control measures were implemented immediately. Six hotels were closed immediately following cluster alerts. Comparison of clinical and environmental isolates by pulsed field gel electrophoresis (PFGE) was possible in 3 clusters and identical genomic profiles of the isolates were found in all. During this two year period of surveillance, we found that on many sites there has been a risk of exposure to Legionella. This reinforces the importance of the European surveillance network and the timely notifications of all the cases to EWGLINET.

Evaluation of the new flexible contour backrest for wheelchairs.

A new flexible contour backrest for wheelchairs was designed with the objectives of offering adequate posture, uniform pressure distribution, and comfort to the users while keeping the advantages of conventional sling backrests, such as easy to fold, light weight, unobtrusive, and airy. The purpose of this study is to compare the new backrest with two commercially available wheelchair backrests, an adjustable-tension (AT) backrest and a back cushion on a rigid support (RS), in terms of pressure distribution, back profile accommodation, and short-term comfort. Evaluations were done with 15 nonimpaired subjects in a static position. It was shown that the new backrest distributes pressure in a more uniform way than the AT and in a way similar to the RS, while giving a better fit to subjects' trunks than other backrests because of its multiple adjustments. Finally, subjects felt that the new backrest is as comfortable as the RS and more comfortable than the AT.

[Contribution of corticosteroid to the treatment of pain in the acute phase of Guillain-Barré syndrome]. / Interêt de la corticothérapie dans le traitement de la douleur à la phase aiguë du syndrome de Guillain-Barré.

INTRODUCTION: Pain is a common problem in both adults and children with Guillain-Barré Syndrome (GBS). Corticosteroids are rarely used in the treatment of pain in the course of GBS, although some authors have pointed out their value for the treatment of neuropathic pain. We report four patients with GBS whose pain was rapidly relieved by administration of corticosteroids. METHODS: We reviewed retrospectively a series of four patients with GBS seen from September 2001 to February 2003. All patients had plexual (Case 3), trunkular (case 1), radicular (case 2) or focal (case 4) pain. Pain was treated with corticosteroids via oral (cases 1 and 2) or intravenous routes (cases 3 and 4). Corticoids where used after failure of other analgesic agents. RESULTS: Pain relief was obtained after the first administration and persisted even after tapering off steroid treatment. No particular complication was observed during treatment course. CONCLUSION: Our experience suggests that controlled studies should be set up to evaluate the place of corticosteroid treatment for the management of pain in patients with GBS.

The flexible contour backrest: a new design concept for wheelchairs.

Studies have shown that the use of a conventional sling backrest in a wheelchair may have a negative impact on the posture and health of users. To avoid such problems, this backrest is often replaced by a back cushion on a rigid surface. However, the use of the latter deprives many wheelchair users of the advantages provided by the sling backrest (easy folding, lightweight, low cost, unobtrusive, simplicity of design). In an effort to maintain these features while providing adequate posture, a new backrest was designed according to specific criteria. The "flexible contour backrest" has been developed so that it can be adapted to a person's back contour with stays, adjustable straps, and curved back posts. Preliminary comparisons done by some experts with commercially available backrests showed that design criteria were reached at 62.9% by the back cushion on a rigid surface, at 64% by the sling backrest, and at 67.7% by the adjustable-tension backrest. On the other hand, design criteria were reached at 80% by the new flexible contour backrest because its design brings together most of the positive features provided by these other backrests (easy to fold, light weight, unobtrusive, airy) as well as providing adequate posture and better fit to the user's morphology.

[Assisted circulation to the right ventricle through pulmonary counterpulsation using a biological method]. / Assistência circulatória ao coração direito através da contrapulsação pulmonar usando-se um método biológico.

PURPOSE: To study the hemodynamic effects of latissimus dorsi dynamic pulmonaroplasty in open chest animals. METHODS: Six anesthetized mongrel dogs were subjected to diastolic counterpulsation using electrically stimulated latissimus dorsi muscle flap wrapped around the aortic and pulmonary arteries roots and gated to the surface electrocardiogram. Aortic and Pulmonanary pressures as well as cardiac output and cardiac index were measured. RESULTS: Diastolic counterpulsation resulted in a significant increase in cardiac output (from 2.35 +/- 0.26 to 2.45 +/- 0.28 l/min) (p < 0.005) and cardiac index (from 0.108 +/- 0.020 to 0.113 +/- 0.020 l/min/kg) (p < 0.05). The diastolic pulmonary arterial efficiency index showed a significant increase when latissimus dorsi stimulation was on (from 8.37 +/- 0.60 to 11.65 +/- 0.83 mmHg); (p < 0.005). CONCLUSION: Latissimus dorsi dynamic pulmonaroplasty provides an effective means of arterial counter pulsation in open chest dogs.