bluuebunny/crossref_metadata_2025 huggingface dataset:
Liquid crystal functionalization of graphene nanoplatelets for improved thermal and mechanical properties of silicone resin composites
Authors: Gui Dayong , Yu Si , Xiong Weijian , Cai Xueqing , Liu Canqun , Liu Jianhong
Published: April 2016

A liquid crystalline molecule, polyurethane-imide (PUI), was used to functionalize graphene nanoplatelets (GNS) via covalent bond and π–π interactions.
Preparation and properties of a novel polymerizable amphiphilic anthraquinone derivative and its cationic colored copolymer latexes
Authors: Hu Yang , Shen Boyuan , Li Botian , Xu Min , Jiang Guoqiang , Kan Chengyou
Published: April 2016

Polymerizable amphiphilic dye was synthesized and used to prepare colored copolymer latexes. The amphiphilic structure overcomes the solubility limitation, dye conversion and color depth. The covalently colored film has enhanced light fastness.
A highly stable and biocompatible optical bioimaging nanoprobe based on carbon nanospheres
Authors: Liu Xiaolong , Wei Zuwu , Wu Ming , Zhang Xiaolong , Zhang Da , Li Buhong , Liu Jingfeng
Published: April 2016

In this report, a facile one-step synthesis strategy has been developed for producing fluorescent carbon nanospheres (CNs) using lactobionic acid (LBA) as a precursor.
Mono- and di-nuclear nickel(ii) complexes derived from NNO donor ligands: syntheses, crystal structures and magnetic studies of dinuclear analogues
Authors: Ghorai Pravat , Chakraborty Anindita , Panja Anangamohan , Mondal Tapan Kumar , Saha Amrita
Published: April 2016

Ferromagnetic interaction in dinickel(ii) complexes, supported by DFT calculations, is reported. Bis(phenoxo)-bridged compound is only the second example of ferromagnetically coupled system.
Ultrasonic-assisted synthesis of sodium lignosulfonate-grafted poly(acrylic acid-co-poly(vinyl pyrrolidone)) hydrogel for drug delivery
Authors: Wang Xiaohong , Zhou Zilong , Guo Xiaowei , He Qiang , Hao Chen , Ge Cunwang
Published: April 2016

Ultrasonic-assisted synthesis of sodium lignosulfonate-grafted hydrogel and the sustained release performance of the drug.
Platinum nanoparticles with superacid-doped polyvinylpyrrolidone coated carbon nanotubes: electrocatalyst for oxygen reduction reaction in high-temperature proton exchange membrane fuel cell
Authors: Pourjafari Amyab S. , Saievar-Iranizad E. , Bayat A.
Published: April 2016

In order to improve the catalytic activity and durability of proton-exchange-membrane-fuel-cells (PEMFCs), Nafion-free Pt-based catalyst using the superacid-doped polymer coated multiwall carbon nanotubes (MWCNTs) was investigated.
Progression from nano to macro science in soft matter systems: dimers to trimers and oligomers in twist-bend liquid crystals
Authors: Mandle Richard J. , Goodby John W.
Published: April 2016

In this article we report several unsymmetrical phenyl-benzoate bimesogens that exhibit the twist-bend nematic phase and present further examples of oligomeric systems that display this unusual state of matter.
All polymer solar cells with diketopyrrolopyrrole-polymers as electron donor and a naphthalenediimide-polymer as electron acceptor
Authors: Li Cheng , Zhang Andong , Wang Zhaowei , Liu Feng , Zhou Yi , Russell Thomas P. , Li Yongfang , Li Weiwei
Published: April 2016

Diketopyrrolopyrrole-polymers and N2200 were found to be highly miscible, which induced low efficiencies in all-polymer solar cells.
Fabrication and characterization of ferritin–chitosan–lutein shell–core nanocomposites and lutein stability and release evaluation in vitro
Authors: Yang Rui , Gao Yunjing , Zhou Zhongkai , Strappe Padraig , Blanchard Chris
Published: April 2016

The nano-sized ferritin and chitosan provide a platform for fabricating shell–core system to encapsulate lutein, exhibiting improved stability and prolonged release of lutein in simulated gastrointestinal tract digestion.
KMnO4/AcOH-mediated C3-selective direct arylation of coumarins with arylboronic acids
Authors: Yuan Jin-Wei , Yang Liang-Ru , Yin Qiu-Yue , Mao Pu , Qu Ling-Bo
Published: April 2016

An efficient protocol for KMnO4/AcOH-mediated C3-direct radical arylation of coumarins with arylboronic acids to afford 3-arylcoumarin derivatives is described.
Improved activity and stability of dealloyed bimodal nanoporous PtCo catalysts for CO oxidation
Authors: Li Dongwei , Wang Hui , Shi Chunying , Xu Xiaohong
Published: April 2016

An unsupported dealloyed bimodal nanoporous PtCo alloy exhibited significantly improved catalytic activity and stability for CO oxidation.
Sensitive colorimetric detection of glucose and cholesterol by using Au@Ag core–shell nanoparticles
Authors: Zhang Xuehong , Wei Min , Lv Bingjing , Liu Yuanjian , Liu Xu , Wei Wei
Published: April 2016

Sensitive colorimetric detection of glucose and cholesterol by using Au@Ag core–shell nanoparticles.
Hydrogen production from buffer-free anaerobic fermentation liquid of waste activated sludge using microbial electrolysis system
Authors: Cai Weiwei , Liu Wenzong , Cui Dan , Wang Aijie
Published: April 2016

Anaerobic fermentation liquid from waste activated sludge with a rich content of organics and phosphate ions is a promising source of carbon and electrolytes for MECs.
Application of spent mushroom (Lentinula edodes) substrate and acclimated sewage sludge on the bioremediation of polycyclic aromatic hydrocarbon polluted soil
Authors: Wang Can , Yu Dong , Shi Wenjin , Jiao Kai , Wu Bin , Xu Heng
Published: April 2016

A novel technology for remediation and improvement of soil was provided along with a new approach for waste recycling.
Facile preparation of hyaluronic acid-modified Fe3O4@Mn3O4 nanocomposites for targeted T1/T2 dual-mode MR imaging of cancer cells
Authors: Li Jingchao , Hu Yong , Sun Wenjie , Luo Yu , Shi Xiangyang , Shen Mingwu
Published: April 2016

HA-Modified Fe3O4@Mn3O4 nanocomposites with both r2 and r1 relaxivities can be prepared for T1/T2 dual-mode MR imaging of cancer cells.
Internal dynamics and guest binding of a sterically overcrowded host
Authors: Löffler Susanne , Lübben Jens , Wuttke Axel , Mata Ricardo A. , John Michael , Dittrich Birger , Clever Guido H.
Published: April 2016

Despite its cramped interior, a [Pd2L4] coordination cage consisting of bulky adamantyl ligands shows impressive motility and a rich encapsulation chemistry.
Crystal structures, intermolecular interactions and fluorescence properties of a series of symmetrical bi-1,3,4-oxadiazole derivatives
Authors: Chen Fangyi , Tian Taiji , Bai Binglian , Wang Jian , Wang Haitao , Li Min
Published: April 2016

This study discusses the substituent effect on molecular conformation and packing, exploring the driving force for different molecular aggregations.
Joint constellation size, energy allocation and relay location optimisation for energy‐efficient DF relaying
Authors: Mehrotra Rashi , Kundu Chinmoy , Bose Ranjan
Published: April 2016

Energy efficiency is a major issue in the energy‐constrained wireless sensor network to ensure longer battery life. In this study, minimisation of total energy per bit for multi‐hop decode‐and‐forward network employing M‐ary quadrature amplitude modulation is considered. An average bit error rate (ABER) requirement at the destination over an independent Rayleigh fading channel is assumed. A realistic energy model is considered. The authors have proposed joint optimisation of constellation size, energy allocation per bit and relay location assuming fixed end‐to‐end distance. The authors have considered two scenarios: one, that each hop employs the same constellation size per hop and two, it adapts independently to take different constellation size. A novel solution is implemented following least square method to find the approximate closed‐form solution of the optimal constellation size, which otherwise would not have been possible. It is observed that joint optimisation technique where the constellation size adapts independently per hop outperforms the one where the constellation size is same. Least amount of total energy is consumed per bit for balanced link. Finally, the analysis shows that for a realistic energy model, the dual hop network provides significant energy saving of 58% at 10 − 4 ABER over multi‐hop network with four hops.
Robust beamforming based on transmit power analysis for multiuser multiple‐input–single‐output interference channels with energy harvesting
Authors: Zhu Zhengyu , Wang Zhongyong , Chu Zheng , Gao Xiangchuan , Zhang Yanbin , Cui Jianhua
Published: April 2016

In this study, the authors study the robust transmit beamforming and receive power splitting design for simultaneous wireless information and power transfer in multiuser multiple‐input–single‐output interference channel with imperfect channel‐state information at the transmitter. Following the worst‐case model, they minimise the average total transmit power subject to a set of energy harvesting constraints and signal‐to‐interference‐and‐noise ratio constraints. On the basis of the Lagrangian multiplier method, they propose a robust design method based on tight bounds that is able to achieve an approximate optimum. To reduce the complexity, they transform this original problem into a relaxed semi‐definite programming problem based on loose bounds, which can be solved efficiently. It is shown from simulation results that their proposed methods outperform the non‐robust scheme.
Closed‐form two‐step weighted‐least‐squares‐based time‐of‐arrival source localisation using invariance property of maximum likelihood estimator in multiple‐sample environment
Authors: Park Chee‐Hyun , Chang Joon‐Hyuk
Published: April 2016

In this study, the authors propose a closed‐form time‐of‐arrival source localisation method and justify the employment of the invariance property of the maximum likelihood (ML) estimator in the source localisation context with multiple samples. The magnitude of the bias of the proposed sample vector function (the statistic that consists of the multiple observations set) using the invariance property of the ML estimator is smaller than that based on the sample mean. Therefore, the mean squared error (MSE) of the weighted least squares estimate using the proposed sample vector function is smaller than that based on the sample mean when the variances of both sample vector functions are the same. Furthermore, the authors investigate a situation in which sensors have erroneous position information. The simulation results show that the averaged MSE performance of the proposed method is superior to that of the existing methods irrespective of the number of samples.
Pyramid coding based rate control for variable bit rate video streaming
Authors: Venkata Phani Kumar Malladi , Ravi Chandra Varma Kalahasthi Chenchu , Mahapatra Sudipta
Published: April 2016

Multi‐pass encoding is preferred over single‐pass encoding for applications such as television broadcasting and video on demand to obtain a consistent visual quality media. This study presents a novel pyramid coding based two‐pass rate control scheme for variable bit rate video streaming. The proposed algorithm uses the statistics collected in the first pass to derive an optimal quantisation parameter for encoding the frames in the second pass. Simple linear estimation models are employed along with Gaussian filtering to update the frame quantisation parameter values in an adaptive manner, resulting in a smoother variation among these values and a better visual quality. The experimental results demonstrate that the proposed rate control scheme exhibits a better performance in terms of the peak signal‐to‐noise ratio and consistent perceptual visual quality in comparison with the existing rate control scheme in the joint model reference software while achieving the target bit rate.
Durer‐pentagon‐based complex network
Authors: Hou Rui , Chang Yuejiana , Chang Yuzhou
Published: April 2016

A novel Durer‐pentagon‐based complex network was constructed by adding a centre node. The properties of the complex network including the average degree, clustering coefficient, average path length, and fractal dimension were determined. The proposed complex network is small‐world and fractal.
Plantar Sweating as an Indicator of Lower Risk of Compensatory Sweating after Thoracic Sympathectomy
Authors: Kargi Ahmet
Published: April 2016

Background Hyperhidrosis is a dysfunction of the autonomic nervous system that results in regional excessive sweating, mostly in the hands, armpits, and feet. A permanent and effective treatment of hyperhidrosis can be achieved by interruption of the thoracic sympathetic chain with endoscopic thoracic sympathectomy (ETS). However, some side effects, particularly compensatory sweating (CS), are the limitations of this procedure. The mechanism of CS and the associated risk factors are still controversial. The aim of this retrospective study was to determine the relationship with various parameters associated with CS in patients undergoing ETS.

Materials and Methods ETS was performed on a total of 95 patients for palmar hyperhidrosis, axillary hyperhidrosis and facial blushing by the same surgeon. The mean age of the patients was 26.41 (± 7) years, and 54 (56.8%) were males. Palmar hyperhidrosis was present in 54 (56.8%) patients, axillary hyperhidrosis in 33 (34.7%) patients, and facial blushing in 8 (8.5%) patients. Moreover, 38 (40%) patients also had plantar sweating. The severity of CS was rated into three scales as less, moderate, and severe.

Results Regarding the severity of CS, 55 (57.9%) patients had no or less CS, 28 (29.5%) had moderate CS, and 12 (12.6%) patients had severe CS. Higher age group had a significant increased risk of severe CS (p = 0.03) (r = 0.262). Patients with body mass index (BMI) > 25 kg/m2 had a statistically significantly increased risk of severe CS (p = 0.016). Facial blushing resulted in severe CS in a significantly higher proportion of patients than by palmar and axillary hyperhidrosis (p = 0.001). The level of surgery was another important risk factor for CS, with the T2 level showing an increased risk of severe CS compared with T3 level (p < 0.001). Furthermore, plantar sweating was inversely and significantly related to the development of CS. Patients with plantar sweating had a significantly decreased incidence of developing CS (p = 0.015).

Conclusion CS after thoracic sympathectomy for primary hyperhidrosis is the most displeasing and restrictive side effect. This study demonstrates that older age, operation level, facial blushing, and high BMI are risk factors for CS, as have been shown in several similar studies. An interesting finding of the present study is that there was a decreased incidence of CS among patients with plantar sweating. This situation may help us to distinguish high risk for CS before ETS operation.
Thoracoscopic Approach for Congenital Diaphragmatic Hernia: A Useful Tool in Diagnosis and Treatment of Unexpected Associated Lung Lesion
Authors: Lima Mario , Maffi Michela , Gargano Tommaso , Ruggeri Giovanni , Libri Michele , Destro Francesca
Published: April 2016

We report the case of a neonate affected by prenatally diagnosed congenital diaphragmatic hernia (CDH), treated by thoracoscopy. During the procedure, we detected an associated extralobar pulmonary sequestration (EPS), which was preoperatively undiagnosed, and we removed it. EPS has been shown to be associated with CDH in up to 15 to 40% of cases. A possible explanation hypothesized is that pulmonary sequestration, which develops at 4 to 5 weeks of gestation, can disturb the fusion of the diaphragm and closure of the pleuroperitoneal canal. The thoracoscopic approach permitted us to identify the thoracic EPS that probably would have been otherwise missed.
Anterior Sagittal Approach and Total Urogenital Mobilization for the Treatment of Persistent Urogenital Sinus in a 2-Year-Old Girl
Authors: Lima Mario , Destro Francesca , Cantone Noemi , Shalaby Mohamed , Ruggeri Giovanni
Published: April 2016

Persistent urogenital sinus (UGS) is a developmental anomaly. It represents one of the most complex problems that a pediatric surgeon may deal with. We report the case of a patient with UGS treated at 3 years of age by anterior sagittal transrectal approach and en bloc sinus mobilization. The procedure was performed with the patient prone with the initial idea of performing an anterior sagittal transrectal approach. The described approach allows an excellent anatomical view with a midline muscle sparing incision, along with an easy identification of the vaginal confluence with the benefit of avoiding dissection between the urethra and vagina.
Future of Biologics for Spinal Fusion
Authors: Wang Jeffrey C.
Published: April 2016

The use of biologics will grow in the future in terms of bone healing, spine fusion, and disc regeneration. In addition, osteogenic material will always be needed for spinal fusion. The future will be a combination of improvements in bone graft materials that are safe, have no donor morbidity, and have an unlimited supply. This talk will discuss current and future options for bone healing. Bone grafts and bone graft substitutes are generally classified into one or more of the following groups: osteogenic, osteoinductive, osteoconductive, and structural. Structural grafts, such as a tricortical iliac crest graft or femoral ring allograft, provide mechanical support to the construct. Osteoconductive grafts provide a scaffold for bone formation. Osteoinductive grafts are able to induce osteoblastic differentiation of the progenitor cells. Osteogenic grafts are able to directly contribute cells for bone formation. Autograft has long been considered the gold standard as it has all of the above properties. However, limited supply of autograft, as well as the morbidity associated with its harvest, has led to the development of a plethora of bone graft substitutes and extenders which may contain one or more of the above properties. Allografts obtained from cadavers provide an osteoconductive scaffold, and are weakly osteoinductive. These grafts do not have any osteogenic potential, as all the cells are killed during the processing aimed to decrease the risk of infection transmission and antigenicity. Still, a minute risk of viral transmission, such as hepatitis, cytomegalovirus, and human immunodeficiency virus, still exists. Allografts may also undergo further processing such a demineralization, leading to demineralized bone matrix (DBM). DBM lacks the structural support of strut allografts, but still has osteoconductive and osteoinductive properties. Demineralized bone matrix (DBM) is a bone graft substitute with primarily osteoconductive and some osteoinductive properties. It is formed by acid extraction of allograft bone, resulting in the loss of mineralized component of bone while retaining the type 1 collagen framework and many growth factors. The osteoinductive quality of DBM varies among different products due to the variability in their content of the bone morphogenic proteins (BMPs). It is currently available in multiple forms, including putty, injectable gel, and flex strips. Ceramics are an attractive type of bone graft extenders and substitutes for several reasons. They can be manufactured in large quantities and a variety of shapes and sizes, do not carry a risk of disease transmission, are biodegradable, and are easy to sterilize. On the other hand, they only provide an osteoconductive scaffold, have little shear strength, and are brittle. As such, they cannot be used as structural grafts without the protection of rigid instrumentation. Commercially available forms of ceramics include calcium carbonate and β-tricalcium phosphate.
Synergistic Effect of Nerve Growth Factor and Insulin-Like Growth Factor-1 on Anti-Apoptosis and Extracellular Matrix Synthesis of Rat Intervertebral Disc Cells
Authors: Park Jong-Beom , Park Eun-Young
Published: April 2016

Introduction

Decreased cellularity due to excessive apoptosis of disc cells is a major predisposing factor for disc degeneration. Therefore, the inhibition of apoptosis of disc cells might be a possible therapeutic approach for modulating the process of disc degeneration. The purpose of the current study was to investigate the effect of nerve growth factor (NGF) and insulin-like growth factor-1 (IGF-1) in preventing apoptosis and increasing extracellular matrix synthesis in rat intervertebral disc cells.

Material and Methods

Expression of tropomyosin-related kinase A (TrkA) receptor for NGF and IGF-1 receptor (IGF-1R) for IGF-1 was examined in rat annulus fibrosus cells. In addition, rat annulus fibrosus cells were isolated, cultured, and placed in either 10% (normal control) or 0% (apoptosis-promoting condition) fetal bovine serum (FBS). We identified and quantified the degree of expression of TrkA and IGF-1R and apoptosis of the cells. Finally, we analyzed the effect of NGF (100 ng/ml) and IGF-1 (500 ng/ml) in preventing apoptosis and increasing synthesis of extracellular matrix proteins, such as aggrecan, collagen-1 and -2, in the cells, in 0% FBS.

Results

In situ expression of TrkA and IGF-1R was identified in rat annulus fibrosus cells. In addition, the degree of expression of TrkA and IGF-1R was decreased in the cells treated with 0% FBS but some degree of expression was still maintained. Apoptosis of the cells was increased in 0% FBS compared with 10% FBS ( p < 0.001). Despite extreme survival condition (0% FBS), each application of NGF (100 ng/ml) and IGF-1 (500 ng/ml) reduced apoptosis of the cells by 2% and 5%, respectively, which led to subsequently increased synthesis of aggrecan, collagen-1 and -2 (all, p < 0.05). The combined application of NGF (100 ng/ml) and IGF-1 (500 ng/ml) more significantly decreased apoptosis of the cells by 9% and increased synthesis of aggrecan, collagen-1 and -2 in the cells (all, p < 0.01).

Conclusion

The current findings demonstrate that apoptosis of intervertebral disc cells can be attenuated by NGF and IGF-1, which lead to increased extracellular matrix synthesis. Combined application of NGF and IGF-1 has a synergistic effect than single use of NGF and IGF-1. Our result suggests that NGF and IGF-1 may play a therapeutic role in slowing disc degeneration, which is due to inappropriate or excessive apoptosis of intervertebral disc cells.
The Role of Diabetes Type I in Intervertebral Disc Degeneration
Authors: Russo Fabrizio , Vadalà Gianluca , Ngo Kevin , Fan Yong , Trucco Massimo , Sowa Gwendolyn A. , Kang James D. , Vo Nam , Denaro Vincenzo
Published: April 2016

Introduction

Diabetes Mellitus (DM) affects 25.8 million people of all ages. Previous studies suggest a link between DM and several connective tissue pathologies including those of cartilage and bone, however the role of DM in intervertebral disc degeneration (IDD) is unclear. The goal of this study was to measure disc degenerative changes in a murine model of human type I diabetes to establish the contributive role of DM in IDD.

Material and Methods

Intervertebral discs (IVDs) were obtained from spines of Wt (C57Bl/6) mice and B6 Akita mouse model of type I DM. B6 Akita mice are hyperglycemic due to the Ins2Akita insulin mutation, which causes the insulin producing β cells to undergo apoptosis. Total disc proteoglycan (PG) content was measured by DMMB assay and safranin O/fast green histology. Glut1, a major glucose transporter in discs, was measured by quantitative RT-PCR, and cell death was assessed by TUNEL assay.

Results

DMMB assay and Safranin-O staining both showed decreased disc GAG content in diabetic B6 Akita mice compared with that in age-matched nondiabetic Wt controls. Discs of B6 Akita mice also exhibited decreased level (~5 fold) of Glut1 mRNA and increased level of TUNEL-positive cells.

Conclusion

IVDs of diabetic B6 Akita mice exhibit an overall decrease in PG content and increased cell death. These changes correlate with a decrease in Glut1 gene expression. Experiments are being done to evaluate that increased cell death in the IVDs of B6 Akita mice is a result of diminished glucose uptake (decreased Glut1) in disc tissue. These diabetic mice may represent a useful model to explore the mechanism of how diabetes affects IDD through its impacts on glucose metabolism in disc tissue.
Serum Levels of the Pro-Inflammatory cytokines IL-6 and TNF-alpha Vary Based on Diagnoses in Individuals with Low Back Pain
Authors: Weber Kathryn , Bloom Ona , Quraishi Shaheda , Overby M. Chris , Levine Mitchell , Chahine Nadeen
Published: April 2016

Introduction

Many intervertebral disc diseases cause low back pain (LBP). Pro-inflammatory cytokines and matrix metalloproteinases (MMPs) participate in disc pathology. This study examines levels of serum cytokines and MMPs in human subjects with diagnosis of disc herniation (DH), spinal stenosis (SS) or degenerative disc disease (DDD) relative to levels in control subjects. Comparison between subjects with DH versus other diagnoses (Other Dx, grouped from SS and DDD) was performed to elaborate a pathological mechanism based on systemic cytokine levels.

Material and Methods

Study participants were recruited from a spine neurosurgery practice ( n = 80), back pain management practice ( n = 27), or a control cohort ( n = 26). Serum samples were collected prior to treatment and were assayed by multiplex assays for levels of IL-1β, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12p70, IL-13, IFN-γ, TNF-α, MMP-1, MMP-3 and MMP-9. Inflammatory and degradative mediator levels were compared between diagnosis and treatment groups. Multivariate regression for relationships with age, BMI, pain duration and smoking history were also performed.

Results

Serum levels of IL-6 were significantly higher in LBP participants compared with controls. Participants with LBP due to Other Dx had significantly higher levels of IL-6 and TNF-α compared with DH and controls. Positive correlations were found between BMI and IL-6 levels, and TNF-α levels were positively correlated with age and BMI.

Conclusion

The findings of the current clinical study are the first to examine systemic cytokine levels in DDD and SS and provide evidence for a more extensive role of IL-6 and TNF-α in disc diseases and LBP, where patients with DDD or SS have even higher serum cytokine levels compared with those with DH or control subjects. These findings may assist in refining personalized diagnosis using systemic biochemical profiling of disc diseases.
Generation of a Vascularized, Scaffold Free Bone Graft by Direct Transdifferentiation of Fat Tissue
Authors: Eder Claudia , Schildboeck Sabrina , Klughofer Julia , Ogon Michael
Published: April 2016

Introduction

Bone grafts play an important role in spinal fusion surgery. Despite tremendous research efforts, synthetic or biological grafting materials equaling autologous bone habe not been developed so far. One of the major reasons is the achievement of sufficient graft vascularization. Aim of the presented study ist to test the concept of an autologous, scaffold-free, vascularized bone graft by converting the patient's fat tissue into bone. Methods and Materials: 10 fat tissue biopsies deriving from surgical waste material were used for the experiments. Samples were washed in sterile saline solution and divided into two parts. Part A served as control group and was cultivated in DMEM-F12 medium supplemented with 10% fetal calf serum and 2 mM L-Glutamine. Part B was transdifferentiated in toto using osteogenic differentiation medium and cultivated at 37°C, 95% humidity and 5% CO2 for 3 weeks. Histological evaluation of tissue mineralization was performed using H/E, van Kossa and Alizarin Red staining. Mineralization was quantified and angiogenesis and tissue integration were evaluated using the chick chorionallantoic membrane assay. Quantitative analysis were performed in triplicates. Statistical evaluation was performed using the Student's T-Test at a 0,05 level of significany.

Results

The osteogenic transdifferentiated fat graft showed an increase in collagen content and signs of mineralization as indicated by positive van Kossa and Alizarin Red staining. Average Calcium OD/mm sample was 50 for the transdifferentiated grafts after 3 weeks vs 24 for the corresponding control tissue ( p < 0,005). Transplantation onto the chick chorionallantoic membrane demonstrated excellent tissue integration and connection to the recipients vascular system after 5 days in vivo. Numerous small blood vessels were visible within the graft. Despite the deprivation of osteogenic differentiation factors, the osteogenic phenotype was maintained after heterotopic implantation.

Conclusion

The patient's own fat tissue can be transdifferented toward an osteogenic phenotype i n vitro and demonstrates excellent angiogenetic properties after in vivo implantation without losing the osteogenic phenotype. A transdifferentiated fat pat might therefore have the potential to serve as a fully autologous, vascularized graft to enhance osteogenesis in spinal fusion surgery.
Role of Bone Marrow Mesenchymal Stem Cells Concentrate Using Selective Retention Cell Technology in Posterolateral Spinal Fusion
Authors: Yousef Mohamed Abdelhamid Ali , La Maida Giovanni Andrea , Dionigi Paolo , Misaggi Bernardo , Re Valentina Vanessa , Frau Silvia
Published: April 2016

Introduction

With increasing rate of spinal fusion, the problem of pseudarthrosis which contributes to recurrent pain with patient disability is considered to be the most common cause of revision lumbar spine surgery. Intensive research is being performed to develop an alternative source of bone grafting and improve the spinal fusion rate.

Purpose

Was to evaluate the long-term clinical and radiological outcome of the use bone marrow mesenchymal stem cell concentrate obtained with selective cell retention technology using Cellect (Depuy Spine, USA) with a particular collagen scaffold, Healos (Depuy Spine, USA) for posterolateral spinal fusion.

Patient and Methods

Retrospective review of the hospital records was performed. Then, the identified patients were contacted to have a clinical and radiological evaluation follow-up visit. Demographic data were reported. Preoperative diagnosis, surgical procedure report, previous spine surgery, postoperative complications and any re-operations were registered. Clinical outcome was evaluated using visual analog scales for the back pain (VAS), Oswestry Disability Index (ODI) scores, and quality of life (EQ-5D) questionnaire. Radiological outcome was evaluated by performing plain radiographs including anterior-posterior and dynamic flexion/extension lateral views. Segmental Cobb angle of the fused segment was calculated in the flexion/extension lateral views. Any implant associated complication, development of adjacent segment degeneration and any alteration of normal spinal curvature were reported. Computed tomography (CT) scans were also performed.

Results

All patients (100%) achieved successful fusion. The mean difference of the segmental Cobb angle was 0.5°, ranging from 0.3°-0.7°. CT scans showed solid bilateral fusion with bridging bone (Grade I) in all patients but solid unilateral fusion with bridging bone (Grade II) was detected at 1 patient at one level. Patients started to resume working activities within a mean period of 3.5 months. The VAS score for the residual back pain was 4.2 ±2 while the ODI was 10.7± 5.6 points with the mean disability index was 21.4%.

Conclusion

The use of bone marrow mesenchymal stem cells concentrate obtained with selective cell retention technology is shown be an effective mean for augmentation of spinal fusion.
Postoperative Complications Associated with rhBMP2 use in Posterior Lumbar Fusion
Authors: Buser Zorica , Brodke Darrel , Esmail Nabil , Meisel Hans-Joerg , Park Jong-Beom , Myhre Sue Lynn , Youssef Jim , Wang Jeffrey C. , Yoon S. Tim
Published: April 2016

Introduction

The growing number of degenerative conditions in aging population has contributed to the increased rates of lumbar posterior spinal fusion (PLF). While PLF has been shown to be effective for the treatment of various different spinal disorders, variations in surgical technique (such as bone graft used) for PLF have potential for different complication profiles. Human recombinant bone morphogenetic protein 2 (rhBMP2) is a bone graft material commonly used in the US to enhance spinal fusion rates after PLF. There are some reports of complications related to the use of rhBMP-2 in PLF arising from relatively small case series. Aim of our study was to quantify the frequency of various complications in elderly patients undergoing PLF with and without rhBMP2.

Material and Methods

We queried the orthopaedic subset of the Medicare database (PearlDiver) between 2005 and 2011. Current Procedure Terminology (CPT) codes were used to identify patients undergoing PLF procedures with and without rhBMP2, and International Statistical Classifcation of Diseases 9 (ICD-9) codes were used for complications. Complication and re-operation rates were analyzed within 1 year after the index procedure. Complications included: Acute Renal Failure, Deep Vein Thrombosis, Dural Tear, Hematoma, Heterotopic Ossification, Incision and Drainage, Myocardial Infarction or other cardiac complication, Nerve, Osteolysis, PLF Reoperation, Pneumonia, Pseudoarthrosis, Pulmonary Embolism, Radiculopathy, Respiratory Complications, Sepsis, Urinary Retention, Urinary Tract Infection, Mechanical (failure of other internal orthopedic device, implant, and graft) and Wound Complications. Chi-square analysis was used to calculate the complication differences between the groups.

Results

There were 20,143 patients who underwent a PLF from 2005–2011, and 27% (5421) of those cases received rhBMP2, while 73% (14722) had the PLF procedure without it. The majority of PLF cases were female (62%) and 65–69 years of age (27%) patients. The overall complication rate was similar between the rhBMP2 and no-rhBMP2 groups, 78.8% and 76.4%, respectively. However, most of the complications had a significantly lower rate in the rhBMP2 group compared with the no-rhBMP2 group (Dural tear 2.2% versus 3%; Incision and Drainage 6.9% vs 7.8%; Myocardial Infraction 3.8% vs 4.4%; Nerve 1.1% vs 2%; Pulmonary Embolism 2.2% vs 2.8%; Radiculopathy 9.4% vs 11.1%; Sepsis 3% vs 3.9%; Wound 8.2% vs 9.6%, respectively). Complications that were in the rhBMP2 group were Mechanical 8% vs 6.2%; Pseudoarthrosis 3% vs 1.8%; Urinary retention 9.9% vs 8.7% ( p < 0.05) and Urinary Tract Infection 30.30% vs 29.60%. Interestingly, heterotopic ossification, demonstrated less than 11 patients in both groups.
The Relationship between HELQ Expression and Intervertebral Disc Degeneration
Authors: Huang Shanhu , Zhang Yu , Liu Zhili , Liu Jiaming
Published: April 2016

Introduction

Degeneration of the intervertebral disc, mainly of nucleus pulposus, is strongly implicated as a cause of low back pain. However, the mechanism of disc degeneration is not clear. This study is to investigate the expression level of HELQ protein in nucleus pulposus tissues and the relationship between HELQ expression and intervertebral disc degeneration.

Materials and Methods

A total of 84 samples of lumbar intervertebral disc degenerated of different degree were obtained from patients undergoing lumbar spinal surgery for low back pain. Degeneration degrees of all samples were classified by radiological and histopathologic methods. Immunohistochemistry (IHC) staining was performed to evaluate the expression level of HELQ protein in nucleus pulposus tissues. And the relationship between HELQ expression and radiological degeneration grades, histopathological degeneration grades of nucleus pulposus were analyzed.

Results

HELQ was expressed in human nucleus pulposus. The expression level of HELQ protein was significantly lower in nucleus pulposus with higher degeneration degree than those with lower degeneration degree. And HELQ expression level had significantly negative correlation with radiological degeneration grades(r = 0.333, p = yyyy0.002) and histopathological degeneration grade (r = −0.519, p = 0.000). However, no correlation were detected between HELQ expression and age ( p = 0.374), gender ( p = 0.063) or segments ( p = 0.676).

Conclusion

The results indicated that down-regulated expression of HELQ is a possible reason of intervertebral disc degeneration. Thus, targeting HELQ gene will be a new therapeutic strategy for patients with intervertebral discs degeneration.
The Intervertebral Disc Functional Cell Models: a New Revolution for in vitro Toxicology Testing
Authors: Velnar Tomaz , Bunc Gorazd , Maver Uros , Gradisnik Lidija
Published: April 2016

Introduction

For diagnostics of discogenic low back pain, local anaesthetics are often used, which may be cytotoxic to intervertebral disc cells. Studies so far have been mainly performed on animal cells. The study aim was to evaluate the effect of local anaesthetics on human intervertebral disc cells in vitro.

Material and Methods

Annulus fibrosus and nucleus pulposus cells were isolated from human lumbar intervertebral disc fragments and exposed to various concentrations of lidocaine, bupivacaine and their mixture. Saline solution was used as a control. Three different dilutions (undiluted, 1:2 and 1:4) of anaesthetics were tested. The cells were treated for 6, 24 and 48 hours and examined with for viability.

Results

Nulceus pulposus cells were more susceptible than annulus fibrosus cells to the toxic effects of both anaesthetics. Lidocaine was more toxic with the final cell survival fraction of 0%, 10% and 20%. Bupivacaine presented less cytotoxicity with the final survival of 10%, 60% and 80%. Lidocaine-bupivacaine mixture showed an intermediate toxicological effect.

Conclusion

Human intervertebral disc cells in vitro are useful for various toxicology tests. They are a valuable model for testing of anesthetic agents. According to the analysis, lidocaine and its mixtures should be avoided due to its high toxicity to the intervertebral disc cells. Bupivacaine was less toxic, especially in 1:4 dilutions and may be recommended for the intradiscal diagnostics.
Static Test of Flexo Compression in Posterior Thoracolumbar Spinal Fixation with Conical Cylindrical Screws
Authors: Nirino Carlos Mariano , Nemirovsky Carlos Eduardo
Published: April 2016

Introduction

The aim of this paper is to describe the results obtained of a static test of flexo compression in polyaxial transpedicular conical cylindrical screws; which we have used for more than 20 years; in posteriors thoracolumbar spine fixings based on the ASTM F 1717–04 standard. This trial was made at the National Institute of Industrial Technology at its Center for Research and Development in Mechanical in Buenos Aires, Argentina.

Material and Methods

Two spinal fixation systems were evaluated, both composed by transpedicular conical soul and cylindrical thread screws, bars and tulips. In Table 1 the information provided by the manufacturer of the screws and identification adopted in the test for each sample is presented. [Table: see text] A universal testing machine Tinius Olsen H50-KT was used for the study. The proposed paragraph 8.1.1 of ASTM F1717–04 procedure was followed. The assembly of the samples was performed using the steps proposed by us, the tulips were set at the distance established by the Standard and the terminal screw of them was set by applying a torque of 10 Nm. The assays were performed at a speed of 10 mm / min and were interrupted when the load drop was observed in the instant graphic verifying in this way the loss of poliaxiality. The test setup used and the location of the devices during the test are shown in Fig. 1 . [Figure: see text] The active length of longitudinal component (L) was revealed (see Fig. 1 ). From this value the corresponding displacement of 2% of the permanent deformation was calculated, Point B =Lx 0, 02 (see Fig. 2 ). From the assay were obtained (see Fig. 2 ): The Load-displacement curve; The fluence load flexo-compression (N) (point D); The fluence displacement 2% (mm) (point A) # the elastic displacement (mm): difference between the value of point A and point B. Elastic displacement = Point A-Point B # the flexo-compression rigidity (N / mm): ratio between the loading of flexo-compression fluence and the elastic displacement. Rigidity = Point D Point A – Point B # the final displacement (mm), and # the final load (N) [Figure: see text]

Results

Fig. 3 shows the curve Load versus Displacement obtained for samples 018565- (1–2) [Figure: see text] In Table 2 the results are described. [Table: see text]

Conclusion

Screws and prisoners remained adjusted and there were not apparent permanent deformation in any of the system components. Its cylindrical thread and conical soul provides a high strength profile improving primary fixation and the resistance to the pull out. The major diameter of the soul in the pedicle region increases the bending and the resistance in fixations without arthrodesis preventing the breaking of the screw. All tests were performed within the framework of Management System for Quality Assurance of INTI-Mechanics.
Spontaneous Resolution of Sequestrated Lumbar Disc Herniation: A Prospective Cohort Study
Authors: Rahimizadeh Abolfazl , Saghri Mohammad
Published: April 2016

Objective

Spontaneous regression of sequestrated lumbar disc well known entity. But, the current reports about this scenario are confined to case reports or small case series. To assess the chance of complete spontaneous resolution of sequestrated lumbar disc herniation and to report the outcome of regressed cases in a prospective study.

Method

From January 2010 to July 2015, 103 patients with acute lower limb mono-radiculopathy, but without neurological motor deficit secondary to a migrated lumbar disc herniation thought to be a sequestrated free disc fragment were prospectively studied for the possibility of their spontaneous regression with time. All the qualified patients initially fulfilled the study criteria. But seven patients were lost to follow up and 9 more cases preferred to do surgery within a few days to three weeks after clinical trial. Eighty seven patients remained for clinical evaluation and periodic magnetic resonance imaging for the possibility of spontaneous regression. These patients include 39 males and 48 females. The age of the patients ranged from 22 to67 years with the mean of 42.96, SD= 10.65.

Results

In 75 of these cases complete resolution of the offending disc occurred. This was associated with marked improvement or even disappearance of pain intensity in short and mid-term follow-up. Furthermore, where a case of same level contralateral disc herniation was seen, not a single case of same level same side recurrence could be encountered. The cost of treatment and work status of the patients were significantly better than surgically treated patients according to previously published reports. In mid-term follow, recovery rate (McNab Criteria %) of these 75 patients was either good or excellent. All these were satisfied and recommend this type of treatment for similar patients. The remaining 12 patients, ultimately underwent surgery. Surprisingly, all had subligamentous location

Conclusion

This study clarifies that conservative management might be considered as an appropriated cost-effective option in treatment of sequestrated lumbar disc herniation in the patients with minimal neurological impairment, with probably high chance of spontaneous regression of the offending disc. However, to compare conservative versus surgery, in this sub-type of disc herniation, further clinical trials are recommended.
Long-Term Follow-up of Disc Degeneration after Discography: Minimum 5-Year Follow-Up at a Single Center Experience
Authors: Hur Jung-Woo , Ryu Kyeong-Sik , Kim Jin-Sung , Seong Ji-Hoon
Published: April 2016

Introduction

Experimental studies have demonstrated accelerated disc degeneration after various intradiscal procedures. However, there are only a few long-term follow-up studies using MRI images to confirm the progressive disc degeneration after discography. The aim of this study is to evaluate disc degeneration after discography over 5-year follow-up and to determine possible risk factors for enhancing disc degenerations after discography

Material and Methods

239 subjects with chronic low back pain underwent multi-level discography to confirm discogenic pain in our institute from January 2006 to June 2009. Thirty-eight subjects who did not operate due to negative study with normal (Grade 1 and 2) to moderate (Grade 3) disc degeneration prior to discography and followed for more than 5 years were enrolled in our study. The routine multi-level discography technique and determination of positive study using original work by Walsh et al was performed in all study subjects. Pre- and post-discography MRI and CT scan were analyzed by two blind independent observers to evaluate degree of disc and endplate degenerations. The progression of disc degeneration was analyzed for correlation with 1) subjects demographic data, 2) pre-discography disc degeneration, 3) levels of discography and 4) discography findings.

Results

Mean age of the subjects at time of discography was 38.1 ± 6.4 years and mean time to final MRI follow-up was 68.0 ± 3.1 months. 2-level discography was done in 19 subjects and 3-level in 18; total 92 disc (L2/3: 5, L3/4: 30, L4/5: 36, L5/S1: 21) There was progression of disc degeneration in 23 disc (23.9%); 5 (6.4%) from normal and 18 (19.5%) from moderate disc degeneration group. There were 16 (17.3%) new disc herniation and 9 (9.7%) new HIZ, however, there was no significant difference between the locations of herniation. Moreover, the differences of mean disc height and endplate degeneration were not statistically significant. The progression of disc degeneration was significantly higher in young age group (<35 years), lower level disc group (L4/5 and L5/S1) and moderate (Grade 3 to 4) disc degeneration group. Multi-level injection, failed discography (annulography) and higher grade of discography findings revealed no positive correlation with progression of disc degeneration.

Conclusion

Diagnostic discography resulted in accelerated disc degeneration in 5-year follow-up study. However, MR findings suggested that annulus puncture with small gauze needle may not be the cause of new disc herniation. Younger age, lower level disc and advanced degeneration prior to discography were the risk factors for progression of disc degeneration. Careful consideration of risk and benefit should be used in recommending procedures involving disc injection.