Peripheral nerve growth within a hydrogel microchannel scaffold supported by a kink‐resistant conduit

Nerve repair in several mm‐long nerve gaps often requires an interventional technology. Microchannel scaffolds have proven effective for bridging nerve gaps and guiding axons in the peripheral nervous system (PNS). Nonetheless, fabricating microchannel scaffolds at this length scale remains a challenge and/or is time consuming and cumbersome. In this work, a simple computer‐aided microdrilling technique was used to fabricate 10 mm‐long agarose scaffolds consisting of 300 µm‐microchannels and 85 µm‐thick walls in less than an hour. The agarose scaffolds alone, however, did not exhibit adequate stiffness and integrity to withstand the mechanical stresses during implantation and suturing. To provide mechanical support and enable suturing, poly caprolactone (PCL) conduits were fabricated and agarose scaffolds were placed inside. A modified salt‐leaching technique was developed to introduce interconnected porosity in PCL conduits to allow for tuning of the mechanical properties such as elastic modulus and strain to failure. It was shown that the PCL conduits were effective in stabilizing the agarose scaffolds in 10 mm‐long sciatic nerve gaps of rats for at least 8 weeks. Robust axon ingress and Schwann cell penetration were observed within the microchannel scaffolds without using growth factors. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 3392–3399, 2017.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139110/1/jbma36186_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139110/2/jbma36186.pd

Efficacy of Platelet-Rich Plasma for Bone Fusion in Transforaminal Lumbar Interbody Fusion

Study DesignRetrospective case series.PurposeTo examine the efficacy of platelet-rich plasma (PRP) for bone fusion in transforaminal lumbar interbody fusion (TLIF) using local bone grafting.Overview of LiteratureSeveral authors have reported the efficacy of PRP for bone union in animal models. However, the use of PRP for bone fusion in TLIF surgery has not been fully explored.MethodsTwenty patients underwent single-level TLIF surgery because of L4 spondylolisthesis. An interbody fusion cage and local bone were used in nine patients (control group) and an interbody fusion cage, local bone, and PRP were used in 11 patients (PRP group). PRP was prepared from the patients' blood samples (400 mL) immediately before surgery. The duration of bone union and postoperative bone fusion rate were assessed using plain radiography at every 3 months postoperatively and computed tomography at 12 or 24 months postoperatively, respectively. Lower back pain, leg pain, and leg numbness were evaluated using the visual analog scale preoperatively and at 3, 6, 12, and 24 months postoperatively.ResultsThe platelet count was 8.7 times higher in PRP than in blood. The bone union rate was significantly superior in the PRP group than in the control group (91% and 77%, respectively; p=0.035), whereas the average duration of bone union was not significantly different between the groups (7.7±0.74 and 10.0±2.00 months, respectively; p=0.131). There was no significant difference in lower back pain, leg pain, and leg numbness in both groups during follow-up (p>0.05).ConclusionsOur study suggests that the use of PRP in TLIF surgery increases bone fusion rate

Pregabalin for Refractory Radicular Leg Pain due to Lumbar Spinal Stenosis: A Preliminary Prospective Study

We investigated the efficacy of pregabalin (PGB) for neuropathic leg pain in lumbar spinal stenosis (LSS) patients with disturbed activities of daily living (ADL)/quality of life (QOL) in a prospective observational study. Subjects were a total of 104 LSS patients with neuropathic pain (NeP) in leg and neurological intermittent claudication (IMC) refractory to nonsteroidal anti-inflammatory drugs (NSAIDs) for at least a month. NeP was identified using screening tool, Pain DETECT questionnaire. Visual analog scale (VAS) scores and responses to the Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) were assessed before and 6 weeks after PGB treatment initiation. Changes in IMC distance and adverse events were also recorded. PGB significantly improved their VAS scores for pain and sleep quality (P<0.001). With respect to JOABPEQ, significant improvements were observed with regard to the following dimensions: pain-related disorders (P<0.01), lumbar spine dysfunction (P=0.031), gait disturbance (P=0.028), and psychological disorders (P=0.014). The IMC distance showed an improvement tendency after PGB treatment, albeit with no significance (P=0.063). Minor adverse events such as dizziness were observed. PGB can be effective for neuropathic leg pain refractory to NSAIDs in LSS patients, resulting in not only pain control but also improving lower back pain-related ADL/QOL scores

A Clinical Prospective Observational Cohort Study on the Prevalence and Primary Diagnostic Accuracy of Occult Vertebral Fractures in Aged Women with Acute Lower Back Pain Using Magnetic Resonance Imaging

Background. Elderly female patients complaints of acute low back pain (LBP) may involve vertebral fracture (VF), among which occult VF (OVF: early-stage VF without any morphological change) is often missed to be detected by primary X-ray examination. The current study aimed to investigate the prevalence of VF and OVF and the diagnostic accuracy of the initial X-ray in detecting OVF. Method. Subjects were elderly women (>70 years old) complaining of acute LBP with an accurate onset date. Subjects underwent lumbar X-ray, magnetic resonance imaging (MRI), and bone mineral density (BMD) measurement at their first visit. The distribution of radiological findings from X-ray and magnetic resonance imaging (MRI) as well as the calculation of the prevalence of VF and OVF are investigated. Results. The prevalence of VF among elderly women with LBP was 76.5% and L1 was the most commonly injured level. Among VF cases, the prevalence of OVF was 33.3%. Furthermore, osteoporotic patients tend to show increased prevalence of VF (87.5%). The predictive values in detecting VF on the initial plain X-ray were as follows: sensitivity, 51.3%; specificity, 75.0%; and accuracy rate, 56.7%. Conclusions. Acute LBP patients may suffer vertebral injury with almost no morphologic change in X-ray, which can be detected using MRI

Radiation hardness qualification of PbWO4 scintillation crystals for the CMS Electromagnetic Calorimeter

This is the Pre-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2010 IOPEnsuring the radiation hardness of PbWO4 crystals was one of the main priorities during the construction of the electromagnetic calorimeter of the CMS experiment at CERN. The production on an industrial scale of radiation hard crystals and their certification over a period of several years represented a difficult challenge both for CMS and for the crystal suppliers. The present article reviews the related scientific and technological problems encountered

Intercalibration of the barrel electromagnetic calorimeter of the CMS experiment at start-up

Calibration of the relative response of the individual channels of the barrel electromagnetic calorimeter of the CMS detector was accomplished, before installation, with cosmic ray muons and test beams. One fourth of the calorimeter was exposed to a beam of high energy electrons and the relative calibration of the channels, the intercalibration, was found to be reproducible to a precision of about 0.3%. Additionally, data were collected with cosmic rays for the entire ECAL barrel during the commissioning phase. By comparing the intercalibration constants obtained with the electron beam data with those from the cosmic ray data, it is demonstrated that the latter provide an intercalibration precision of 1.5% over most of the barrel ECAL. The best intercalibration precision is expected to come from the analysis of events collected in situ during the LHC operation. Using data collected with both electrons and pion beams, several aspects of the intercalibration procedures based on electrons or neutral pions were investigated

Low-Dose Tramadol and Non-Steroidal Anti-Inflammatory Drug Combination Therapy Prevents the Transition to Chronic Low Back Pain

Study DesignRetrospective study.PurposeTo determine whether low-dose tramadol plus non-steroidal anti-inflammatory drug combination therapy could prevent the transition of acute low back pain to chronic low back pain.Overview of LiteratureInadequately treated early low back pain transitions to chronic low back pain occur in approximately 30% of affected individuals. The administration of non-steroidal anti-inflammatory drugs is effective for treatment of low back pain in the early stages. However, the treatment of low back pain that is resistant to non-steroidal anti-inflammatory drugs is challenging.MethodsPatients who presented with acute low back pain at our hospital were considered for inclusion in this study. After the diagnosis of acute low back pain, non-steroidal anti-inflammatory drug administration was started. Forty patients with a visual analog scale score of >5 for low back pain 1 month after treatment were finally enrolled. The first 20 patients were included in a non-steroidal anti-inflammatory drug group, and they continued non-steroidal anti-inflammatory drug therapy for 1 month. The next 20 patients were included in a combination group, and they received low-dose tramadol plus non-steroidal anti-inflammatory drug combination therapy for 1 month. The incidence of adverse events and the improvement in the visual analog scale score at 2 months after the start of treatment were analyzed.ResultsNo adverse events were observed in the non-steroidal anti-inflammatory drug group. In the combination group, administration was discontinued in 2 patients (10%) due to adverse events immediately following the start of tramadol administration. At 2 months, the improvement in the visual analog scale score was greater in the combination group than in the non-steroidal anti-inflammatory drug group (p<0.001).ConclusionsLow-dose tramadol plus non-steroidal anti-inflammatory drug combination therapy might decrease the incidence of adverse events and prevent the transition of acute low back pain to chronic low back pain

Dose Optimization for Single Intradiscal Administration of the Tumor Necrosis Factor-α Inhibitor, Etanercept, in Rat Disc Injury Models

Study DesignExperimental animal study.PurposeWe aimed to determine the optimal dose of a single direct injection of the tumor necrosis factor (TNF)-α inhibitor, etanercept, by using the rat model of degenerative intervertebral disc from injury.Overview of LiteratureThe pain-related peptide expression was suppressed in the etanercept (100 µg and 1,000 µg)-administered groups in a dose-dependent manner.MethodsThe neurotracer FluoroGold (FG) was applied to the surfaces of L4/5 discs to label their innervating dorsal root ganglion (DRG) neurons (n=50). Ten rats were included in the nonpunctured disc sham surgery control group, whereas the other 40 were included in the experimental group in which intervertebral discs were punctured with a 23-gauge needle. Saline or etanercept (10 µg, 100 µg, or 1,000 µg) was injected into the punctured discs (n=10 for each treatment). After 14 days of surgery, DRGs from L1 to L6 were harvested, sectioned, and immunostained for calcitonin gene-related peptide (CGRP). The proportion of FG-labeled CGRP-immunoreactive DRG neurons was evaluated in all the groups.ResultsThere were no significant differences between the puncture+saline group and the puncture+10-µg etanercept group (p >0.05). However, a significant decrease in the percentage of FG and CGRP double-positive cells in FG-positive cells was observed in the etanercept (100 µg and 1,000 µg)-administered groups in a dose-dependent manner (p <0.05).ConclusionsWhen a low dose of the TNF-α inhibitor (10 µg of etanercept) was directly administered to the rat intervertebral disc in the rat model of degenerative intervertebral disc from injury, no suppressive effect on the pain-related peptide expression was observed. However, when a higher dose of etanercept (100 µg and 1,000 µg) was administered, the pain-related peptide expression was suppressed in a dose-dependent manner

X-ray emission from the Sombrero galaxy: discrete sources

We present a study of discrete X-ray sources in and around the bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival Chandra observations with a total exposure of ~200 ks. With a detection limit of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30 kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray binaries (LMXBs). We quantify the differential luminosity functions (LFs) for both the detected GC and field LMXBs, whose power-low indices (~1.1 for the GC-LF and ~1.6 for field-LF) are consistent with previous studies for elliptical galaxies. With precise sky positions of the GCs without a detected X-ray source, we further quantify, through a fluctuation analysis, the GC LF at fainter luminosities down to 1E35 erg/s. The derived index rules out a faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent findings in several elliptical galaxies and the bulge of M31. On the other hand, the 2-6 keV unresolved emission places a tight constraint on the field LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101 sources in the halo of Sombrero. The presence of these sources cannot be interpreted as galactic LMXBs whose spatial distribution empirically follows the starlight. Their number is also higher than the expected number of cosmic AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray surveys. We suggest that either the cosmic X-ray background is unusually high in the direction of Sombrero, or a distinct population of X-ray sources is present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres