Guillain-Barré syndrome during childhood: particular clinical and electrophysiological features

Introduction Guillain–Barré syndrome (GBS) has some specific characteristics in children. Methods In this study we reviewed the clinical, laboratory, electrophysiological, and prognosis features of the 19 children diagnosed with GBS at Nantes University Hospital from 2000 to 2011. Results Gait disturbance and leg pain were the most frequent presenting symptoms. Electrophysiological examinations revealed significant abnormalities even when performed within the first week after onset. Decreased distal CMAP amplitude was noted in 89% of cases. The pattern indicated an acute inflammatory demyelinating polyneuropathy in 95% of cases and acute motor axonal neuropathy in the remaining 5%. About two-thirds of the children were treated with intravenous immunoglobulin. After >1 year of follow-up, 17 patients had complete recovery. Conclusion Gait disorder, leg pain, a high rate of distal conduction block, and a good prognosis are among the main specific features of GBS in childhood. Muscle Nerve, 48: 247–251, 201

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Design of a dual-expander aerospike nozzle rocket engine

The University of Alabama’s Aerospace Engineering and Mechanics Department is developing a computational dual-expander aerospike nozzle (DEAN) upper stage rocket engine to demonstrate the engine’s performance capabilities and to establish a model by which the DEAN can be built. This research expands the base model developed by the Air Force Institute of Technology to more accurately represent the physics involved in both the fluid flow and geometrical properties of the engine. The DEAN engine was modeled using NASA’s Numerical Propulsion System Simulation (NPSS) and Chemical Equilibrium with Applications (CEA) software. The methodology implemented in this research was validated by modeling the RL-10A-3-3A upper stage engine in NPSS and comparing resulting outputs with NASA’s ROCket Engine Transient Simulator (ROCETS) analysis. The DEAN uses liquid oxygen and liquid hydrogen as its propellant and is being designed to produce a thrust of 30,000 [lbf] and a specific impulse of at least 465.5 [s], at an oxidizer-to-fuel ratio of 5.88, while also remaining within the size envelope of the RL-10B-2 upper stage engine. The performance and size objectives were established to meet the National Aeronautics and Space Administration’s (NASA) Advanced Upper Stage Engine Program (AUSEP) need for an upper stage rocket engine to replace the aging RL-10 series engines that have been in production since the 1960s. Results indicate that optimal performance for the feasible solution space examined in this research occurs at an expansion ratio of 30, a throat area of 23 [in2], and a characteristic length, L*, of 90 [in]. The optimal DEAN design point was shown to achieve a thrust of more than 5,000 [lbf] greater than the RL-10B-2, a Isp of 1.8 [s] greater, and a significantly reduced size envelope. (Published By University of Alabama Libraries

The effect of an orthopedic trauma room on after-hours surgery at a level one trauma center

PURPOSE: The purpose of this study is to examine the effect of establishing a dedicated operating room for unscheduled orthopedic cases and to evaluate a group of patients with isolated femur fractures. The frequency of after-hours surgery and the impact of patients who present with acute orthopedic injuries are reviewed. METHODS: A retrospective review of all orthopedic cases from the operating room scheduling system at a level-one trauma center was undertaken from October 2003 to September 2005. Before October 2004, unscheduled cases were placed on a shared add-on list, and no special priority was given to orthopedic cases. Additionally, a subset of adult patients with isolated femoral shaft fractures was identified to evaluate time from admission to surgery, operative time, frequency of transfer of care between surgeons, and total length of hospital stay. RESULTS: The number of orthopedic cases was 1799 in fiscal year 2004 (FY04) and 2046 in FY05, an increase of 14%. Overall, the hospital experienced an increase in level-one trauma activations from 1450 in FY04 to 1580 in FY05 (8.2%), and an increase in the number operative trauma cases from 447 to 494 (9.5%). Cases after 7:00 pm declined from 197 in FY04 to 165 in FY05, a decrease of 16%. Cases between midnight and 7:00 am declined from 63 in FY04 to 35 in FY05, a decrease of 44%. For the subset of femur fracture patients, transfer of care to another operating surgeon occurred 4.5 times more frequently. The median delay between admission and surgery increased from 5.7 hours to 10.9 hours. Median case duration increased from 106 to 127 minutes. CONCLUSIONS: It is possible to dramatically decrease the occurrence of after-hours orthopedic surgery in a level-one trauma center through the use of a dedicated room for unscheduled orthopedic trauma cases. Benefits include less frequent activation of after-hours operating room resources, fewer disruptions to the OR schedule and office hours, and more frequent fracture care by orthopedic traumatologists. The impact of a longer delay between admission and surgical treatment and more frequent transfer of care between surgeons deserves further evaluation

A gene for an autosomal recessive lower motor neuron disease with childhood onset maps to 1p36.

International audienceOBJECTIVE: To describe the clinical features of a novel variant of autosomal recessive lower motor neuron disease (LMND) with childhood onset and to map the disease-causing gene. METHODS: The authors performed a clinical study in a large consanguineous African family. After linkage exclusion to SMN1 and SOD1 loci, they performed a genome-wide linkage analysis to map the underlying genetic defect. RESULTS: This novel variant of LMND with childhood onset and autosomal recessive mode of inheritance is characterized by a progressive symmetric and generalized involvement of the musculature. Four of the five affected patients had muscle weakness since age 3, strongly worsening during childhood and leading to generalized tetraplegia in adulthood. Genetic analyses using homozygosity mapping strategy assigned this progressive generalized LMND locus to an interval of 3.9 cM (or 1.5 megabases) on chromosome 1p36, between loci D1S508 and D1S2633 (Z(max) = 3.79 at theta = 0.00 at locus D1S253). This region encloses 27 candidate genes. CONCLUSION: Genetic mapping of a novel rare phenotype of lower motor neuron disease opens the way toward the identification of a new gene involved in motor neuron degeneration, located in the 1p36 chromosomal region

Augmented Central Pain Processing in Vulvodynia

Vulvodynia (VVD) is a chronic pain disorder, wherein women display sensitivity to evoked stimuli at the vulva and/or spontaneous vulvar pain. Our previous work suggests generalized hyperalgesia in this population, however little is known about central neurobiological factors that may influence pain in VVD. Here we investigated local (vulvar) and remote (thumb) pressure evoked pain processing in 24 VVD patients compared to 13 age-matched, pain-free healthy controls (HC). As a positive control we also examined thumb pressure pain in 24 fibromyalgia (FM) patients. The VVD and FM patients displayed overlapping insular brain activations that were greater than HC, in response to thumb stimulation (P<0.005 corrected). Compared to HC, VVD participants displayed greater levels of activation during thumb stimulation within the insula, dorsal mid-cingulate, posterior cingulate and thalamus (P<0.005 corrected). Significant differences between VVD subgroups (primary versus secondary and provoked versus unprovoked) were seen within the posterior cingulate with thumb stimulation, and within the precuneus region with vulvar stimulation (provoked versus unprovoked only). The augmented brain activation in VVD patients in response to a stimulus remote from the vulva suggests central neural pathology in this disorder. Moreover, differing central activity between VVD subgroups suggests heterogeneous pathologies within this diagnosis