bluuebunny/crossref_metadata_2025 huggingface dataset:
Spectral-Spatial Clustering with a Local Weight Parameter Determination Method for Remote Sensing Imagery
Authors: Ma Ailong , Zhong Yanfei , Zhang Liangpei
Published: February 2016

Remote sensing image clustering is a challenging task considering its intrinsic complexity. Recently, by combining the spectral and spatial information of the remote sensing data, the clustering performance can be dramatically enhanced, termed as Spectral-Spatial Clustering (SSC). However, it has always been difficult to determine the weight parameter for balancing the spectral term and spatial term of the clustering objective function. In this paper, spectral-spatial clustering with a local weight parameter determination method for remote sensing image was proposed, i.e., L-SSC. In L-SSC, considering the large scale of remote sensing images, the weight parameter can be determined locally in a patch image instead of the whole image. Afterwards, the local weight parameter was used in constructing the objective function of L-SSC. Thus, the remote sensing image clustering problem was transformed into an optimization problem. Finally, in order to achieve a better optimization performance, a variant of differential evolution (i.e., jDE) was used as the optimizer due to its powerful optimization capability. Experimental results on three remote sensing images, including a Wuhan TM image, a Fancun Quickbird image, and an Indian Pine AVIRIS image, demonstrated that the proposed L-SSC can acquire higher clustering accuracy in comparison to other spectral-spatial clustering methods.
Estimation of Forest Structural Diversity Using the Spectral and Textural Information Derived from SPOT-5 Satellite Images
Authors: Meng Jinghui , Li Shiming , Wang Wei , Liu Qingwang , Xie Shiqin , Ma Wu
Published: February 2016

Uneven-aged forest management has received increasing attention in the past few years. Compared with even-aged plantations, the complex structure of uneven-aged forests complicates the formulation of management strategies. Forest structural diversity is expected to provide considerable significant information for uneven-aged forest management planning. In the present study, we investigated the potential of using SPOT-5 satellite images for extracting forest structural diversity. Forest stand variables were calculated from the field plots, whereas spectral and textural measures were derived from the corresponding satellite images. We firstly employed Pearson’s correlation analysis to examine the relationship between the forest stand variables and the image-derived measures. Secondly, we performed all possible subsets multiple linear regression to produce models by including the image-derived measures, which showed significant correlations with the forest stand variables, used as independent variables. The produced models were evaluated with the adjusted coefficient of determination ( R a d j 2 ) and the root mean square error (RMSE). Furthermore, a ten-fold cross-validation approach was used to validate the best-fitting models ( R a d j 2 > 0.5). The results indicated that basal area, stand volume, the Shannon index, Simpson index, Pielou index, standard deviation of DBHs, diameter differentiation index and species intermingling index could be reliably predicted using the spectral or textural measures extracted from SPOT-5 satellite images.
Seasonal Variation in the NDVI–Species Richness Relationship in a Prairie Grassland Experiment (Cedar Creek)
Authors: Wang Ran , Gamon John , Montgomery Rebecca , Townsend Philip , Zygielbaum Arthur , Bitan Keren , Tilman David , Cavender-Bares Jeannine
Published: February 2016

Species richness generally promotes ecosystem productivity, although the shape of the relationship varies and remains the subject of debate. One reason for this uncertainty lies in the multitude of methodological approaches to sampling biodiversity and productivity, some of which can be subjective. Remote sensing offers new, objective ways of assessing productivity and biodiversity. In this study, we tested the species richness–productivity relationship using a common remote sensing index, the Normalized Difference Vegetation Index (NDVI), as a measure of productivity in experimental prairie grassland plots (Cedar Creek). Our study spanned a growing season (May to October, 2014) to evaluate dynamic changes in the NDVI–species richness relationship through time and in relation to environmental variables and phenology. We show that NDVI, which is strongly associated with vegetation percent cover and biomass, is related to biodiversity for this prairie site, but it is also strongly influenced by other factors, including canopy growth stage, short-term water stress and shifting flowering patterns. Remarkably, the NDVI-biodiversity correlation peaked at mid-season, a period of warm, dry conditions and anthesis, when NDVI reached a local minimum. These findings confirm a positive, but dynamic, productivity–diversity relationship and highlight the benefit of optical remote sensing as an objective and non-invasive tool for assessing diversity–productivity relationships.
A Compressed Sensing-Based Wearable Sensor Network for Quantitative Assessment of Stroke Patients
Authors: Yu Lei , Xiong Daxi , Guo Liquan , Wang Jiping
Published: February 2016

Clinical rehabilitation assessment is an important part of the therapy process because it is the premise for prescribing suitable rehabilitation interventions. However, the commonly used assessment scales have the following two drawbacks: (1) they are susceptible to subjective factors; (2) they only have several rating levels and are influenced by a ceiling effect, making it impossible to exactly detect any further improvement in the movement. Meanwhile, energy constraints are a primary design consideration in wearable sensor network systems since they are often battery-operated. Traditionally, for wearable sensor network systems that follow the Shannon/Nyquist sampling theorem, there are many data that need to be sampled and transmitted. This paper proposes a novel wearable sensor network system to monitor and quantitatively assess the upper limb motion function, based on compressed sensing technology. With the sparse representation model, less data is transmitted to the computer than with traditional systems. The experimental results show that the accelerometer signals of Bobath handshake and shoulder touch exercises can be compressed, and the length of the compressed signal is less than 1/3 of the raw signal length. More importantly, the reconstruction errors have no influence on the predictive accuracy of the Brunnstrom stage classification model. It also indicated that the proposed system can not only reduce the amount of data during the sampling and transmission processes, but also, the reconstructed accelerometer signals can be used for quantitative assessment without any loss of useful information.
Plastic Deformation of Micromachined Silicon Diaphragms with a Sealed Cavity at High Temperatures
Authors: Ren Juan , Ward Michael , Kinnell Peter , Craddock Russell , Wei Xueyong
Published: February 2016

Single crystal silicon (SCS) diaphragms are widely used as pressure sensitive elements in micromachined pressure sensors. However, for harsh environments applications, pure silicon diaphragms are hardly used because of the deterioration of SCS in both electrical and mechanical properties. To survive at the elevated temperature, the silicon structures must work in combination with other advanced materials, such as silicon carbide (SiC) or silicon on insulator (SOI), for improved performance and reduced cost. Hence, in order to extend the operating temperatures of existing SCS microstructures, this work investigates the mechanical behavior of pressurized SCS diaphragms at high temperatures. A model was developed to predict the plastic deformation of SCS diaphragms and was verified by the experiments. The evolution of the deformation was obtained by studying the surface profiles at different anneal stages. The slow continuous deformation was considered as creep for the diaphragms with a radius of 2.5 mm at 600 °C. The occurrence of plastic deformation was successfully predicted by the model and was observed at the operating temperature of 800 °C and 900 °C, respectively.
Development and Application of a Next Generation Air Sensor Network for the Hong Kong Marathon 2015 Air Quality Monitoring
Authors: Sun Li , Wong Ka , Wei Peng , Ye Sheng , Huang Hao , Yang Fenhuan , Westerdahl Dane , Louie Peter , Luk Connie , Ning Zhi
Published: February 2016

This study presents the development and evaluation of a next generation air monitoring system with both laboratory and field tests. A multi-parameter algorithm was used to correct for the impact of environmental conditions on the electrochemical sensors for carbon monoxide (CO) and nitrogen dioxide (NO2) pollutants. The field evaluation in an urban roadside environment in comparison to designated monitors showed good agreement with measurement error within 5% of the pollutant concentrations. Multiple sets of the developed system were then deployed in the Hong Kong Marathon 2015 forming a sensor-based network along the marathon route. Real-time air pollution concentration data were wirelessly transmitted and the Air Quality Health Index (AQHI) for the Green Marathon was calculated, which were broadcast to the public on an hourly basis. The route-specific sensor network showed somewhat different pollutant patterns than routine air monitoring, indicating the immediate impact of traffic control during the marathon on the roadside air quality. The study is one of the first applications of a next generation sensor network in international sport events, and it demonstrated the usefulness of the emerging sensor-based air monitoring technology in rapid network deployment to supplement existing air monitoring.
The Contribution of Energy-Optimized Urban Planning to Efficient Resource Use–A Case Study on Residential Settlement Development in Dhaka City, Bangladesh
Authors: Sikder Sujit , Eanes Francis , Asmelash Henok , Kar Shiba , Koetter Theo
Published: February 2016

This study examines and explores the contribution of an energy-optimized urban planning approach to efficient resource use in the context of Dhaka city, Bangladesh. A conceptual energy optimization model called the “EnUp” model has been developed and tested for feasibility and adaptation strategies to improve urban energy use in residential settlements. This study is based on a system analysis and grounded theory approach that involved field methods including key informant (KI) interviews and collection of data and information from local urban planning offices and other secondary sources. Results show that the adoption of an energy-optimized planning approach is possible and necessary in Dhaka city. The “EnUp“ model can be applied in new urban settlement planning and retrofitting existing urban settlements. Ensuring various stakeholders' participation, technical inputs, and adaptability could make this innovative model and approach replicable in many other cities in the world. The study facilitates a better documentation and visualization for comprehensive urban planning and energy planning process in developing countries, while providing useful insights to policy makers, planners, developers, and interested urban stakeholders in the transition to urban sustainability.
Research on Factors Influencing Municipal Household Solid Waste Separate Collection: Bayesian Belief Networks
Authors: Chu Zhujie , Wang Wenna , Wang Bairong , Zhuang Jun
Published: February 2016

Municipal household solid waste (MHSW) has become a serious problem in China over the course of the last two decades, resulting in significant side effects to the environment. Therefore, effective management of MHSW has attracted wide attention from both researchers and practitioners. Separate collection, the first and crucial step to solve the MHSW problem, however, has not been thoroughly studied to date. An empirical survey has been conducted among 387 households in Harbin, China in this study. We use Bayesian Belief Networks model to determine the influencing factors on separate collection. Four types of factors are identified, including political, economic, social cultural and technological based on the PEST (political, economic, social and technological) analytical method. In addition, we further analyze the influential power of different factors, based on the network structure and probability changes obtained by Netica software. Results indicate that technological dimension has the greatest impact on MHSW separate collection, followed by the political dimension and economic dimension; social cultural dimension impacts MHSW the least.
A review of the cellular and molecular effects of extracorporeal shockwave therapy
Authors: Chamberlain Georgina , Colborne Robert
Published: February 2016

Extracorporeal shockwave therapy (ESWT) is a novel therapeutic modality and its use in promoting connective tissue repair and analgesic effect has been advocated in the literature. It is convenient, cost-effective, and has negligible complications; it therefore bypasses many of the problems associated with surgical interventions. This paper reviews the proposed mechanisms of action in promoting tissue repair and regeneration as well as analysing its efficacy providing an analgesic effect in clinical applications. Further research will be required to not only identify the underlying mechanisms more precisely, but will also be critical for ensuring consistency across the literature so that the most beneficial treatment protocol can be developed. Extracorporeal shockwave therapy stands as a promising alternative modality in promoting tissue repair.
Short and long-term outcome following surgical stabilization of tarsocrural instability in dogs
Authors: Beever Lee , Kulendra Elvin , Meeson Richard
Published: February 2016

Objectives: To evaluate the outcome and complications following surgical stabilization of canine tarsocrural luxations.

Methods: Medical records of dogs which were surgically treated for tarsocrural joint instability between February 2007 and June 2014 were reviewed. Surgical technique, complications and long-term outcome (via questionnaire and Canine Brief Pain Inventory) were assessed.

Results: Twenty-four dogs (26 joints) were included. All injuries were traumatic. All joints had associated fractures; malleolar in 21/26 limbs (13/26 medial). Eight joints had internal fracture fixation and transarticular external skeletal fixator, six had external fixator alone, four had prosthetic ligaments with external fixator, and four had prosthetic ligaments with external coaptation. Two joints had pantarsal arthrodesis and two primary ligament repair. Complications occurred in 24/26 limbs giving 45 distinct complications; 16 were minor, 29 major, and 31 complications were external fixator associated. Prosthetic ligaments were significantly associated with major complications (p = 0.017); five out of eight required subsequent removal between 105–1006 days. Cost was significantly associated with major complications (p = 0.017) and soft tissue wounds (p = 0.03). Long-term lameness was seen in nine of 14 dogs. There was no association between pain severity (p = 0.3) and pain interference scores (p = 0.198) when comparing stabilization methods.

Clinical significance: Complications are common; however many are external fixator related. Prosthetic ligaments are significantly associated with major complications. Regardless of technique, a degree of ongoing lameness is likely.
Assessment of a computed tomography guided injection technique of the lumbo-sacral disc in sheep
Authors: Neveu Fabienne , Vandeweerd Jean-Michel , Kirschvink Nathalie , Nozry Kadhija , Gustin Pascal , Dugdale Alex , Bihin Benoît , Nisolle Jean-François
Published: February 2016

Objectives: Recent data indicate that degeneration of intervertebral discs occurs naturally in sheep, with a higher prevalence at the level of the lumbo-sacral disc. The objective of this ex vivo study was to evaluate a computed tomography (CT) guided method of injection into the ovine lumbo-sacral disc.

Methods: Six euthanatized sheep were used for identification of the approach plane, the optimal direction of the needle and the mean distance from skin to disc. Dissection after injection of coloured ink was used to determine the anatomical structures that were penetrated. In seven other animals, all spines were assessed beforehand by CT and magnetic resonance imaging to determine whether disc pathology was present. The final position of the needle was assessed by CT to determine the accuracy of the technique. Contrast agent was injected to identify any problems associated with administration of liquid into the disc.

Results: The CT guided injection technique was easy to perform and enabled adequate positioning of the needle into all (n = 7) lumbo-sacral discs. Distance between the skin and the disc ranged between 12 and 17 cm. No organ, vascular or nervous structure was penetrated and the needle path remained intramuscular without penetration of the peritoneal cavity. Contrast medium leaked out through three degenerate discs.

Clinical significance: The current study described a consistently safe and accurate CT guided injection technique to the lumbo sacral disc for future in vivo experimental studies that will use sheep as animal model for human intervertebral disc disease disease.
The Beneficial Effects of Electro-acupuncture at PC6 (Neiguan-point) of Gene and Protein Expressions of Classical Inward-rectifier Potassium Channels in Myocardial Ischemic Rats
Authors: Wang Ying , Zhang Xiao-lu , Wang Wei , Li Di , Dai Jian-yu , Li Ji-quan , Li Ji-quan , Chen Yi-guo , Rong Pei-jing
Published: February 2016

This study is aim to investigate the effect of electro-acupuncture at PC6 (Neiguan-point) on the gene and protein expressions of classical inward-rectifier potassium channels (Kir) in myocardial ischemia (MI) rats induced by isoproterenol (ISO). With ten for each one, 50 rats were divided
into 5 groups which were control group, MI group, PC6 group, LU7 (Lieque-point) group and non-acupoint group. The control group was injected normal saline solution (85mg/kg), the other groups were injected ISO (85mg/kg). All the rats were injected once daily for two days and recorded electrocardiograms
(ECGs) after every injection. Electro-acupuncture (EA) was operated at PC6, LU7 and non-acupoint respectively in the rats of PC6 group, LU7 group and non-acupoint group after twice injections. EA was performed to these three groups with disperse-dense wave (4-20Hz), pulse amplitude of 14V,
20mins a day remaining 7 days. The gene and protein expressions of Kir2.1, Kir2.2 and Kir2.3 were analyzed by Western Immunoblotting Technology (Western Blot) and Real-time Fluorescence Quantitative Polymerase Chain Reaction (RT-PCR). But it is regrettable that we did not detect meaningful
gene and protein expressions Kir2.3, and the expressions of Kir2.1 and Kir2.2 in MI induced groups were lower [The gene and protein decreased 39.4 ± 27.3% and 38.7 ± 17.1% respectively.] than control group (P<0.05). Compared with MI group, the results of PC6 group and
LU7 group increased [PC6 group: the gene and protein increased 42.9 ± 25.0% and 42.2 ± 10.0% respectively. LU7 group: the gene and protein increased 23.8 ± 50.1% and 21.1 ± 32.5% respectively.] obviously (P<0.05) after EA, furthermore the expressions of
PC6 group were higher [The gene and protein increased 15.4 ± 16.7% and 17.3 ± 60% respectively.] than LU7 group (P < 0.05). The results show that PC6 has a better positive effect than LU7 on MI rats, and the mechanism is probably that EA at PC6 can significantly increase
the gene and protein expressions of Kir2.1 and Kir2.2.
Coencapsulation of Target Effector Cells with Mesenchymal Stem Cells Reduces Pericapsular Fibrosis and Improves Graft Survival in a Xenotransplanted Animal Model
Authors: Vaithilingam Vijayaganapathy , Evans Margaret D. M. , Rowe Anthony , Bean Penelope A. , Tuch Bernard E.
Published: February 2016

Pericapsular fibrotic overgrowth (PFO) is a problem that thwarts full implementation of cellular replacement therapies involving encapsulation in an immunoprotective material, such as for the treatment of diabetes. Mesenchymal stem cells (MSCs) have inherent anti-inflammatory properties. We postulated that coencapsulation of MSCs with the target cells would reduce PFO. A hepatoinsulinoma cell line (HUH7) was used to model human target cells and was coencapsulated with either human or mouse MSCs at different ratios in alginate microcapsules. Viability of encapsulated cells was assessed in vitro and xenografted either intraperitoneally or subcutaneously into C57BL/6 mice. Graft retrieval was performed at 3 weeks posttransplantation and assessed for PFO. Coencapsulation of human MSCs (hMSCs) or mouse MSCs (mMSCs) with HUH7 at different ratios did not alter cell viability in vitro. In vivo data from intraperitoneal infusions showed that PFO for HUH7 cells coencapsulated with hMSCs and mMSCs in a ratio of 1:1 was significantly reduced by ~30% and ~35%, respectively, compared to HUH7 encapsulated alone. PFO for HUH7 cells was reduced by ~51% when the ratio of mMSC/HUH7 was increased to 2:1. Implanting the microcapsules subcutaneously rather than intraperitoneally substantially reduced PFO in all treatment groups, which was most significant in the mMSC/HUH7 2:1 group with a ~53% reduction in PFO compared with HUH7 alone. Despite the reduced PFO reaction to the individual microcapsules implanted subcutaneously, all microcapsule treatment groups were contained in a vascularized fibrotic pouch at 3 weeks. The presence of MSCs in microcapsules retrieved from these fibrotic pouches improved graft survival with significantly higher cell viabilities of 83.1 ± 0.6% and 79.1 ± 0.8% seen with microcapsules containing mMSC/HUH7 at 2:1 and 1:1 ratios, respectively, compared to HUH7 alone (51.5 ± 0.7%) transplanted subcutaneously. This study showed that coencapsulation of MSCs with target cells has a dose-dependent effect on reducing PFO and improving graft survival when implanted either intraperitoneally or subcutaneously in a stringent xenotransplantation setting.
Comparative Efficacies of Long-Term Serial Transplantation of Syngeneic, Allogeneic, Xenogeneic, or CTLA4Ig-Overproducing Xenogeneic Adipose Tissue-Derived Mesenchymal Stem Cells on Murine Systemic Lupus Erythematosus
Authors: Choi Eun Wha , Lee Hee Woo , Shin Il Seob , Park Ji Hyun , Yun Tae Won , Youn Hwa Young , Kim Sung-Joo
Published: February 2016

Allogeneic and xenogeneic transplantation are suitable alternatives for treating patients with stem cell defects and autoimmune diseases. The purpose of this study was to compare the effects of long-term serial transplantation of adipose tissue-derived mesenchymal stem cells (ASCs) from (NZB × NZW) F1 mice (syngeneic), BALB/c mice (allogeneic), or humans (xenogeneic) on systemic lupus erythematosus (SLE). The effects of transplanting human ASCs overproducing CTLA4Ig (CTLA4Ig-hASC) were also compared. Animals were divided into five experimental groups, according to the transplanted cell type. Approximately 500,000 ASCs were administered intravenously every 2 weeks from 6 to 60 weeks of age to all mice except for the control mice, which received saline. The human ASC groups (hASC and CTLA4Ig-hASC) showed a 13-week increase in average life spans and increased survival rates and decreased blood urea nitrogen, proteinuria, and glomerular IgG deposition. The allogeneic group also showed higher survival rates compared to those of the control, up to 40, 41, 42, 43, 44, 45, 52, and 53 weeks of age. Syngeneic ASC transplantation did not accelerate the mortality of the mice. The mean life span of both the syngeneic and allogeneic groups was prolonged for 6–7 weeks. Both human ASC groups displayed increased serum interleukin-10 and interleukin-4 levels, whereas both mouse ASC groups displayed significantly increased GM-CSF and interferon-γ levels in the serum. The strongest humoral immune response was induced by xenogeneic transplantation, followed by allogeneic, CTLA4Ig-xenogeneic, and syngeneic transplantations. Long-term serial transplantation of the ASCs from various sources displayed different patterns of cytokine expression and humoral responses, but all of them increased life spans in an SLE mouse model.
Human Lipoaspirate as Autologous Injectable Active Scaffold for One-Step Repair of Cartilage Defects
Authors: Bosetti Michela , Borrone Alessia , Follenzi Antonia , Messaggio Fanuel , Tremolada Carlo , Cannas Mario
Published: February 2016

Research on mesenchymal stem cells from adipose tissue shows promising results for cell-based therapy in cartilage lesions. In these studies, cells have been isolated, expanded, and differentiated in vitro before transplantation into the damaged cartilage or onto materials used as scaffolds to deliver cells to the impaired area. The present study employed in vitro assays to investigate the potential of intra-articular injection of microfragmented lipoaspirate as a one-step repair strategy; it aimed to determine whether adipose tissue can act as a scaffold for cells naturally present at their anatomical site. Cultured clusters of lipoaspirate showed a spontaneous outgrowth of cells with a mesenchymal phenotype and with multilineage differentiation potential. Transduction of lipoaspirate clusters by lentiviral vectors expressing GFP evidenced the propensity of the outgrown cells to repopulate fragments of damaged cartilage. On the basis of the results, which showed an induction of proliferation and ECM production of human primary chondrocytes, it was hypothesized that lipoaspirate may play a paracrine role. Moreover, the structure of a floating culture of lipoaspirate, treated for 3 weeks with chondrogenic growth factors, changed: tissue with a high fat component was replaced by a tissue with a lower fat component and connective tissue rich in GAG and in collagen type I, increasing the mechanical strength of the tissue. From these promising in vitro results, it may be speculated that an injectable autologous biologically active scaffold (lipoaspirate), employed intra-articularly, may 1) become a fibrous tissue that provides mechanical support for the load on the damaged cartilage; 2) induce host chondrocytes to proliferate and produce ECM; and 3) provide cells at the site of injury, which could regenerate or repair the damaged or missing cartilage.
Osteogenic Ability of Canine Adipose-Derived Mesenchymal Stromal Cell Sheets in Relation to Culture Time
Authors: Kuk Minyong , Kim Yongsun , Lee Seung Hoon , Kim Wan Hee , Kweon Oh-Kyeong
Published: February 2016

Cell sheets could be used for bone regeneration without requiring a scaffold and can be easily produced from autologous mesenchymal stromal cells (MSCs). We compared the osteogenic potential of MSC-derived cell sheets in relation to culture time. Undifferentiated cell sheets (U-CS) and osteogenic differentiated cell sheets (O-CS) were generated using canine adipose-derived MSCs. Undifferentiated cells (UCs) were used as the control. Osteogenic differentiation was assessed by assaying alkaline phosphatase (ALP) activity. Expression of osteogenesis-related genes was evaluated by reverse transcription-polymerase chain reaction at 4, 7, 14, and 21 days after initiation of culture. The calcium content in cells was measured, and the cells were stained with Alizarin red S (ARS). The mRNA expression of transforming growth factor-β in U-CS and O-CS at day 4 was higher than that in UCs ( p < 0.05). The level of bone morphogenetic protein 7 mRNA in O-CS increased significantly at day 4 and was significantly higher than that of U-CS at day 7. The mRNA level of runt-related transcription factor-2 in both sheet types increased significantly at 7 days of culture. The mRNA level of ALP in O-CS and U-CS increased significantly at day 7, and ALP activity was highest at days 7 and 14, respectively ( p < 0.05). The mRNA level of osteocalcin in U-CS and O-CS increased significantly at day 21. O-CS and U-CS showed negative ARS staining but their calcium contents increased marginally at day 21. The O-CS cells started to aggregate at days 10–12, and only a partial sheet remained at day 21. The upregulation of expression of genes related to osteogenic differentiation, peak in ALP activity, and morphological changes in cell sheets suggest that the optimal time for application of O-CS and U-CS is between 7 and 10 days and after 14 days of culture, respectively.
Cell Magnetic Targeting System for Repair of Severe Chronic Osteochondral Defect in a Rabbit Model
Authors: Mahmoud Elhussein Elbadry , Kamei Goki , Harada Yohei , Shimizu Ryo , Kamei Naosuke , Adachi Nobuo , Misk Nabil Ahmed , Ochi Mitsuo
Published: February 2016

The aim of this study was to investigate a cell delivery system for repair of severe chronic osteochondral defects using magnetically labeled mesenchymal stem cells (m-MSCs), with the aid of an external magnetic device, through the accumulation of a small number of m-MSCs into a desired area and to detect the suitable number of autologous m-MSCs needed for repair of the defect. Twenty-six male Japanese white rabbits aged 6 months were used. An osteochondral defect was created bilaterally at the weight-bearing surface of the medial femoral condyle of the rabbits' knees (3 mm diameter; 4 mm depth). At 4 weeks after creation of the defect, autogenic transplantation of the m-MSCs into the defect area was performed, followed by 10-min exposure to an external magnetic device, where animals were divided into four groups: high (1 × 106 m-MSCs), medium (2 × 105 m-MSCs), low (4 × 104 m-MSCs), and control (PBS injection). At 4 and 12 weeks posttransplantation of m-MSCs, repaired tissue was assessed histologically using the Fortier score with toluidine blue staining. Transplantation of a low number of m-MSCs was not enough to improve osteogenesis and chondrogenesis, but the medium and high groups improved repair of the chronic defect with chondrogenic tissues and showed histologically significantly better results than the control and low groups. The use of a magnetic targeting system for delivering m-MSCs has the potential to overcome the clinical hurdles for repair of the severe chronic osteochondral defect. Furthermore, this system is predicted to produce good clinical outcomes for humans, not only to repair osteochondral defects but also to repair a variety of damaged tissues.
Human Multipotent Mesenchymal Stromal Cells in the Treatment of Postoperative Temporal Bone Defect: An Animal Model
Authors: Skoloudik Lukas , Chrobok Viktor , Kalfert David , Koci Zuzana , Sykova Eva , Chumak Tetyana , Popelar Jiri , Syka Josef , Laco Jan , Dedková Jana , Dayanithi Govindan , Filip Stanislav
Published: February 2016

Canal wall down mastoidectomy is one of the most effective treatments for cholesteatoma. However, it results in anatomical changes in the external and middle ear with a negative impact on the patient's quality of life. To provide complete closure of the mastoid cavity and normalize the anatomy of the middle and external ear, we used human multipotent mesenchymal stromal cells (hMSCs), GMP grade, in a guinea pig model. A method for preparing a biomaterial composed of hMSCs, hydroxyapatite, and tissue glue was developed. Animals from the treated group were implanted with biomaterial composed of hydroxyapatite and hMSCs, while animals in the control group received hydroxyapatite alone. When compared to controls, the group implanted with hMSCs showed a significantly higher ratio of new bone formation ( p = 0.00174), as well as a significantly higher volume percentage of new immature bone ( p = 0.00166). Our results proved a beneficial effect of hMSCs on temporal bone formation and provided a promising tool to improve the quality of life of patients after canal wall down mastoidectomy by hMSC implantation.
Combined MSC-Secreted Factors and Neural Stem Cell Transplantation Promote Functional Recovery of PD Rats
Authors: Yao Yuan , Huang Chen , Gu Ping , Wen Tieqiao
Published: February 2016

Stem cell transplantation has enormous potential for the treatment of neurodegenerative disorders like Parkinson's disease (PD). Mesenchymal stem cells (MSCs) have attracted much attention because they can secrete a wide variety of cellular factors that promote cell growth. In this study, we prepared a conditioned medium (CM) using lyophilized MSC culture medium that contained the secretome of MSCs and applied this CM to the culture of neural stem cells (CM-NSCs) for the transplantation of PD model rats. Quantitative realtime PCR, Western blot, and immunocytochemistry were used to identify cell differentiation and expression of dopaminergic neuron-specific genes in vitro. Behavioral tests including rotational behavior and MWM training tests were also performed to assess the recovery. Our results indicated that combined treatment of CM and neural stem cell transplantation can significantly reduce apomorphine-induced rotational asymmetry and improve spatial learning ability. The CM-NSCs were able to differentiate into dopaminergic neurons in the ventral tegmental area (VTA) and medial forebrain bundle (MFB), and migrated around the lesion site. They showed a higher activity than untreated NSCs in cell survival, migration, and behavior improvement in the dopa-deficit rat model. These findings suggest that the neural stem cells treated with conditioned medium possess a great potential as a graft candidate for the treatment of Parkinson's disease.
Pulmonary Retention of Adipose Stromal Cells following Intravenous Delivery is Markedly Altered in the Presence of ARDS
Authors: Lu Hongyan , Cook Todd , Poirier Christophe , Merfeld-Clauss Stephanie , Petrache Irina , March Keith L. , Bogatcheva Natalia V.
Published: February 2016

Transplantation of mesenchymal stromal cells (MSCs) has been shown to effectively prevent lung injury in several preclinical models of acute respiratory distress syndrome (ARDS). Since MSC therapy is tested in clinical trials for ARDS, there is an increased need to define the dynamics of cell trafficking and organ-specific accumulation. We examined how the presence of ARDS changes retention and organ-specific distribution of intravenously delivered MSCs isolated from subcutaneous adipose tissue [adipose-derived stem cells (ADSCs)]. This type of cell therapy was previously shown to ameliorate ARDS pathology. ARDS was triggered by lipopolysaccharide (LPS) aspiration, 4 h after which 300,000 murine CRE+ ADSCs were delivered intravenously. The distribution of ADSCs in the lungs and other organs was assessed by real-time polymerase chain reaction (PCR) of genomic DNA. As anticipated, the majority of delivered ADSCs accumulated in the lungs of both control and LPS-challenged mice, with minor amounts distributed to the liver, kidney, spleen, heart, and brain. Interestingly, within 2 h following ADSC administration, LPS-challenged lungs retained significantly lower levels of ADSCs compared to control lungs (~7% vs. 15% of the original dose, respectively), whereas the liver, kidney, spleen, and brain of ARDS-affected animals retained significantly higher numbers of ADSCs compared to control animals. In contrast, 48 h later, only LPS-challenged lungs continued to retain ADSCs (~3% of the original dose), whereas the lungs of control animals and nonpulmonary organs in either control or ARDS mice had no detectable levels of ADSCs. Our data suggest that the pulmonary microenvironment during ARDS may lessen the pulmonary capillary occlusion by MSCs immediately following cell delivery while facilitating pulmonary retention of the cells.
Uterine-Derived CD11b Cells Significantly Increase Vasculogenesis and Promote Myocardial Healing in Ischemic Cardiomyopathy
Authors: Hatta Kota , Zhang Yuemei , Wu Jun , Sun Zhou , Weisel Richard D. , Li Ren-Ke
Published: February 2016

Ischemic heart disease is the leading cause of mortality in industrialized countries. Cell transplantation could restore function of the ischemic heart likely through the mechanism of cell-induced angiogenesis. We have previously shown that cells isolated from uteri increase angiogenesis and alleviate cardiac dysfunction when transplanted after MI. However, which uterine cell type contributes to angiogenesis is unknown. Here we report that uterine-derived CD11b cells significantly increase vasculogenesis and promote myocardial healing in ischemic cardiomyopathy. We have established a novel and simple methodology for uterine CD11b cell isolation and enrichment and demonstrate that this technique can be used for purifying and establishing viable CD11b cell cultures in rats. The isolated fresh CD11b cells were transplanted into ischemic rat hearts 5 days after injury. Following transplantation, vasculogenesis significantly increased in ischemic cardiac tissue, which reduced infarct size and restored myocardial function and perfusion compared with controls. Thus, uterine CD11b cells have the potential to promote functional healing when implanted after ischemic cardiomyopathy. Importantly, we have demonstrated a novel means by which CD11b cells can be easily purified and cultured for cell transplantation.
Safety and Therapeutic Potential of M2 Macrophages in Stroke Treatment
Authors: Chernykh Elena R. , Shevela Ekaterina Ya. , Starostina Nataliya M. , Morozov Sergey A. , Davydova Mariya N. , Menyaeva Elena V. , Ostanin Alexandr A.
Published: February 2016

Our objective was to evaluate the safety and clinical efficacy of autologous M2 macrophage transplantation in nonacute stroke patients. We also evaluated whether the intrathecal administration of macrophages influences the production of cytokines by peripheral blood cells and whether the levels of cytokines correlate with stroke severity and responsiveness to cell therapy. In this study, 13 patients (12 males and 1 female with a median age of 63 years) diagnosed with ischemic ( n = 10) or hemorrhagic ( n = 3) stroke were subjected to cell transplantation therapy (study group). On average, 21.9 × 106autologous M2 macrophages were injected intrathecally. Thirteen matched case-control stroke patients who did not receive cell therapy comprised the control group. We did not observe any serious adverse events (i.e., intrahospital mortality, neurological worsening, and seizures) related to the cell injection. One patient in the study group and two patients in the control group died during the 6-month follow-up period due to recurrent stroke. In the study group, the NIHSS score decreased from 11 to 6 ( p = 0.007) in 6 months after the therapy, whereas the patients in the control group showed a less pronounced neurological improvement (the NIHSS score decreased from 11 to 8, p = 0.07). The obvious positive response (the improvement of the NIHSS score ≥3) in the study group was observed in 75% versus 18% in the control group ( pFET= 0.03). M2 cell introduction did not significantly affect the production of various cytokines. Nevertheless, pretreated levels of IL-8, IL-10, and IL-4 correlated with stroke severity. Moreover, responder patients had lower spontaneous production of IL-10, FGF-β, PDGF, VEGF, and higher stimulation indexes of IL-1β, TNF-α, IFN-γ, and IL-6 than nonresponders. These findings suggest that the intrathecal administration of autologous M2 cells in stroke patients is safe and leads to a better neurological recovery, which could be mediated through the immunomodulatory activity of M2 macrophages.
Intracerebral Cell Implantation: Preparation and Characterization of Cell Suspensions
Authors: Rossetti Tiziana , Nicholls Francesca , Modo Michel
Published: February 2016

Intracerebral cell transplantation is increasingly finding a clinical translation. However, the number of cells surviving after implantation is low (5–10%) compared to the number of cells injected. Although significant efforts have been made with regard to the investigation of apoptosis of cells after implantation, very little optimization of cell preparation and administration has been undertaken. Moreover, there is a general neglect of the biophysical aspects of cell injection. Cell transplantation can only be an efficient therapeutic approach if an optimal transfer of cells from the dish to the brain can be ensured. We therefore focused on the in vitro aspects of cell preparation of a clinical-grade human neural stem cell (NSC) line for intracerebral cell implantation. NSCs were suspended in five different vehicles: phosphate-buffered saline (PBS), Dulbecco's modified Eagle medium (DMEM), artificial cerebral spinal fluid (aCSF), HypoThermosol, and Pluronic. Suspension accuracy, consistency, and cell settling were determined for different cell volume fractions in addition to cell viability, cell membrane damage, and clumping. Maintenance of cells in suspension was evaluated while being stored for 8 h on ice, at room temperature, or physiological normothermia. Significant differences between suspension vehicles and cellular volume fractions were evident. HypoThermosol and Pluronic performed best, with PBS, aCSF, and DMEM exhibiting less consistency, especially in maintaining a suspension and preserving viability under different storage conditions. These results provide the basis to further investigate these preparation parameters during the intracerebral delivery of NSCs to provide an optimized delivery process that can ensure an efficient clinical translation.
Microcarrier-Expanded Neural Progenitor Cells Can Survive, Differentiate, and Innervate Host Neurons Better When Transplanted as Aggregates
Authors: Qiu Lifeng , Lim Yu Ming , Chen Allen K. , Reuveny Shaul , Oh Steve K. W. , Tan Eng King , Zeng Li
Published: February 2016

Neuronal progenitor cells (NPCs) derived from human embryonic stem cells (hESCs) are an excellent cell source for transplantation therapy due to their availability and ethical acceptability. However, the traditional method of expansion and differentiation of hESCs into NPCs in monolayer cultures requires a long time, and the cell yield is low. A microcarrier (MC) platform can improve the expansion of hESCs and increase the yield of NPCs. In this study, for the first time, we transplanted microcarrier-expanded hESC-derived NPCs into the striatum of adult NOD-SCID IL2Rgc null mice, either as single cells or as cell aggregates. The recipient mice were perfused, and the in vivo survival, differentiation, and targeted innervation of the transplanted cells were assessed by immunostaining. We found that both the transplanted single NPCs and aggregate NPCs were able to survive 1 month posttransplantation, as revealed by human-specific neural cell adhesion molecule (NCAM) and human nuclear antigen staining. Compared to the single cells, the transplanted cell aggregates showed better survival over a 3-month period. In addition, both the transplanted single NPCs and the aggregate NPCs were able to differentiate into DCX-positive immature neurons and Tuj1-positive neurons in vivo by 1 month posttransplantation. However, only the transplantation of aggregate NPCs was shown to result in mature neurons at 3 months posttransplantation. Furthermore, we found that the cell aggregates were able to send long axons to innervate their targets. Our study provides preclinical evidence that the use of MCs to expand and differentiate hESC-derived NPCs and transplantation of these cells as aggregates produce longer survival in vivo.
Repair of Rat Sciatic Nerve Defects by Using Allogeneic Bone Marrow Mononuclear Cells Combined with Chitosan/Silk Fibroin Scaffold
Authors: Yao Min , Zhou Yi , Xue Chengbin , Ren Hechun , Wang Shengran , Zhu Hui , Gu Xingjian , Gu Xiaosong , Gu Jianhui
Published: February 2016

The therapeutic benefits of bone marrow mononuclear cells (BM-MNCs) in many diseases have been well established. To advance BM-MNC-based cell therapy into the clinic for peripheral nerve repair, in this study we developed a new design of tissue-engineered nerve grafts (TENGs), which consist of a chitosan/fibroin-based nerve scaffold and BM-MNCs serving as support cells. These TENGs were used for interpositional nerve grafting to bridge a 10-mm-long sciatic nerve defect in rats. Histological and functional assessments after nerve grafting showed that regenerative outcomes achieved by our developed TENGs were better than those achieved by chitosan/silk fibroin scaffolds and were close to those achieved by autologous nerve grafts. In addition, we used green fluorescent protein-labeled BM-MNCs to track the cell location within the chitosan/fibroin-based nerve scaffold and trace the cell fate at an early stage of sciatic nerve regeneration. The result suggested that BM-MNCs could survive at least 2 weeks after nerve grafting, thus helping to gain a preliminary mechanistic insight into the favorable effects of BM-MNCs on axonal regrowth.
Therapeutic Effect of Ligustilide-Stimulated Adipose-Derived Stem Cells in a Mouse Thromboembolic Stroke Model
Authors: Chi Kang , Fu Ru-Huei , Huang Yu-Chuen , Chen Shih-Yin , Lin Shinn-Zong , Huang Pi-Chun , Lin Po-Cheng , Chang Fu-Kuei , Liu Shih-Ping
Published: February 2016

Stroke is a result of cerebral ischemia that triggers a cascade of both physiological and biochemical events. No effective treatment is available for stroke; however, stem cells have the potential to rescue tissue from the effects of stroke. Adipose-derived stem cells (ADSCs) are an abundant source of adult stem cells; therefore, ADSC therapy can be considered as a future strategy for regenerative medicine. However, more research is required to improve the effectiveness of transplanted ADSCs as a treatment for stroke in the mouse stroke model. Ligustilide, isolated from the herb Angelica sinensis, exhibits a protective effect on neurons and inhibits inflammation. We also demonstrated that ligustilide treatment increases the expression levels of homing factors such as SDF-1 and CXCR4. In the present study, we evaluated the therapeutic effects of ADSC transplantation and ligustilide treatment in a mouse thromboembolic stroke model by behavioral tests, including beam walking, locomotor activity, and rotarod analysis. ADSCs pretreated with ligustilide were transplanted into the brains of stroke mice. The results showed that the therapeutic effect of ADSCs pretreated with ligustilide was better than that of ADSCs without ligustilide pretreatment. There was no difference between the recovery of mice treated by ADSC transplantation combined with subcutaneous ligustilide injection and that of mice treated only with ADSCs. The TUNEL assay showed fewer apoptotic cells in the brains of mice transplanted with ADSCs pretreated with ligustilide as well as in those without pretreatment. In summary, pretreatment of ADSCs with ligustilide improves the therapeutic efficacy of ADSC transplantation. The results of this study will help improve stem cell therapies being developed for future clinical applications.