A multiphysics-based artificial neural networks model for atherosclerosis

Atherosclerosis is a medical condition involving the hardening and/or thickening of arteries' walls. Mathematical multi-physics models have been developed to predict the development of atherosclerosis under different conditions. However, these models are typically computationally expensive. In this study, we used machine learning techniques, particularly artificial neural networks (ANN), to enhance the computational efficiency of these models. A database of multi-physics Finite Element Method (FEM) simulations was created and used for training and validating an ANN model. The model is capable of quick and accurate prediction of atherosclerosis development. A remarkable computational gain is obtained using the ANN model compared to the original FEM simulations.

Investigation of the Effect of PEG Detoxification on Diphtheria Vaccine

Immunization has been considered a successful global health program that saves many persons' lives each year. The vaccines reduce the risk of getting the disease by building immunity in the body. Therefore, the constant availability of essential vaccines is an important factor in community health. One of the most important vaccines is the diphtheria vaccine, which is usually used as Multivalent diphtheria-tetanus-pertussis (DTP) combination vaccines. The production of this vaccine takes about 45 days, from the initial bacterial culture to the end of toxin production. However, the production of this vaccine can be optimized in case the production stages are carried out under normal conditions. In this study, a significant amount of impurities was removed after washing with phosphate buffer saline, and the toxin was then purified by Sephadex G-50. In this method, the toxin was concentrated to be stored in a smaller space (this removes the concerns for the provision of a suitable space). Another problem with the diphtheria vaccine is that it is reversible after detoxification of the toxin using formaldehyde. For this reason, it is suggested to use MPEG for detoxification, which will produce more stable covalent bonds between PEG and the first type of amine groups in the toxin chain. Tests were performed to evaluate factors, such as in vivo cytotoxicity, lack of edemas formation, the neutralizing activity of serum from guinea pigs immunized with the diphtheria toxoid inactivated with MPEG, and the immunogenic activity of the purified and modified toxin. Comparison of this PEG detoxification toxoid with the standard toxoid produced in Razi Vaccine and Serum Institution, Karaj, Iran, showed that washing with PBS and purification with Sephadex G-50 was an efficient method. The stability and reversibility of the toxoid approved by MPEG were acceptable. Therefore, the results of animal tests showed that the obtained product was stable and caused no wound or necrosis in the tested animals.

Releasing and structural/mechanical properties of nano-particle/Punica granatum (Pomegranate) in poly(lactic-co-glycolic) acid/fibrin as nano-composite scaffold

The effect of poly(lactic‑co‑glycolic acid) (PLGA) on structure, degradation, drug release and mechanical properties of fibrin/pomegranate(F/POM)-based drug‑eluting scaffolds have been studied comprehensively.

METHODS AND MATERIAL

Nanoparticle-fibrin is prepared from thrombin and fibrinogen dissolved in NaOH and HCl. Then pomegranate powder is added to it. Nanoparticles/pom are provided by freeze drying and freeze milling. The 3-D scaffold of poly(lactide-co‑glycolic acid) (PLGA) was prepared via salt‑leaching solvent/casting leaching method and impregnated with nanofibrin-pom. Structural and chemical component of the scaffolds were evaluated by transmission and scanning electron microscopy and furrier transmission infrared spectroscopy, respectively. Moreover, the scaffolds were characterized from the degradation rate and drug releasing rate points of view of human Adipose Derive Stem Cells (hADSCs). Cytotoxicity effects of the scaffold were evaluated on hADSCs via MTT assay.

RESULTS

The results showed that the size of nanoparticles was about 100 nm. The scaffold had a slow degradation rate and it caused a sustained release pattern of pom. MTT assay indicated that nanoparticles had no cytotoxicity and fibrin-pom nanoparticles increased compressive strength of PLGA/scaffolds dramatically and also caused a proper compressive modulus.

CONCLUSIONS

By adding F/POM nanoparticle to PLGA and fabricating a three‑dimensional nanocomposite scaffold (PLGA/F/POM nanoparticle), special physical and mechanical properties also suitable for drug release and cell behavior were achieved, which makes it suitable for cartilage tissue engineering applications (Tab. 1, Fig. 7, Ref. 53) Keywords: hybrid composites, drug delivery, carrier, nanoparticles, scaffold.

Ionic liquid based distributed touch sensor using electrical impedance tomography

Inspired by the human skin sensory mechanism, there are growing interests in creating a sense of touch in robotics. This work describes a new impedance based design to create an artificial tactile sensing skin. It has demonstrated that the electrical impedance tomography imaging technique allows for detecting the pressure distribution in a large area by a distributed touch sensor. The sensor is fabricated by filling a circular shaped phantom with liquid conductor and covering with an elastic shell on the top. The proposed sensor can detect the pressure applied to the elastic top using electrical impedance tomography imaging method. The sensor can therefore operate as a touch sensor mimicking a piezo-impedance operation in a simple fashion. The new sensor can differentiate between various force levels and their locations and thus produces a distribution of pressure. Such a simple sensor can function as a large area skin, enabling smarter human-machine interactions in emerging augmented reality and robotic applications.

Patient-reported psychosocial distress in adolescents and young adults with germ cell tumours

PURPOSE

Germ cell tumours are the most common cancer of male adolescents and young adults (AYA, age 18-39). Men in this age group have been healthy much of their lives, and a diagnosis of cancer can cause significant psychosocial distress. We therefore sought to examine the psychosocial needs of patients with germ cell tumour and determine whether needs vary based on age (AYA vs non-AYA). We hypothesized that AYA experience more anxiety and distress in emotional, practical and physical domains.

METHODS

We evaluated the responses of all patients referred to British Columbia (BC) Cancer who completed a pre-consultation health assessment form. This is a validated screening questionnaire for distress, subclinical/clinical symptoms of depression and anxiety and includes the Canadian Problem Checklist domains of emotional, informational, practical, spiritual, social/family and physical concerns.

RESULTS

Data were collected for 349 patients (2011-2015). Patient population was predominantly AYA (n = 227) with median age 33 (range 18-83). The top 3 AYA concerns were financial, work/school, frustration and anger. AYA patients more commonly scored positive for symptoms of subclinical/clinical anxiety than non-AYA (39.4% vs. 27.9%, p = 0.028). Those AYA patients with subclinical/clinical anxiety symptoms experienced more fears and worries, concerns regarding work/school, lack of understanding of their disease, finances and frustration and anger.

CONCLUSIONS

The results of this study indicate that AYA with testicular cancer have unique needs and experience more self-reported anxiety symptoms with emotional, informational and practical concerns. This is valuable information to stakeholders for allocation of resources to address cancer survivorship amongst these patients.

Quantification of Melittin in Iranian Honey Bee (Apis mellifera meda) Venom by Liquid Chromatography-electrospray Ionization-ion Trap Tandem Mass Spectrometry (LC-ESI-IT-MS/MS)

The current research aimed to quantify melittin (MEL) in Iranian honey bee (Apis mellifera meda) venom. To this end, a liquid chromatography-electrospray ionization-ion trap tandem mass spectrometry (LC-ESI-IT-MS/MS) approach was employed. Melittin is the main toxic peptide of honey bee venom with various biological and pharmacological activities. It was extracted with pure water from the bee venom samples. The analyses were performed on XBridge BEH300 C4 column using a gradient method with the mobile phase consisting of ultrapure water and acetonitrile (containing 0.1% formic acid). Signals of the melittin were recorded with the selected reaction monitoring (SRM) mode, which is a quantitative approach capable of quantifying analyte peptides with high sensitivity and. The mass spectrum of MEL was obtained in the positive ion mode and the quantification analysis was performed using precursor to product ion transition of m/z 570.2/669.9. This method demonstrated good linearity (R2˃0.997) in the range of 1-100 µg mL-1, with a limit of quantification (LOQ) of 1.0 µg mL-1. The content of MEL in Iranian honey bee venom accounts for 43–55% of total dry weight. This method can be used to evaluate the quality and authenticity of bee venom samples for different therapeutic applications of MEL.

Phenol adsorption on high microporous activated carbons prepared from oily sludge: equilibrium, kinetic and thermodynamic studies

The purpose of this study was the preparation, characterization and application of high-performance activated carbons (ACs) derived from oily sludge through chemical activation by KOH. The produced ACs were characterized using iodine number, N₂ adsorption-desorption, Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The activated carbon prepared under optimum conditions showed a predominantly microporous structure with a BET surface area of 2263 m² g⁻¹, a total pore volume of 1.37 cm³ g⁻¹ and a micro pore volume of 1.004 cm³ g⁻¹. The kinetics and equilibrium adsorption data of phenol fitted well to the pseudo second order model (R² = 0.99) and Freundlich isotherm (R² = 0.99), respectively. The maximum adsorption capacity based on the Langmuir model (434 mg g⁻¹) with a relatively fast adsorption rate (equilibrium time of 30 min) was achieved under an optimum pH value of 6.0. Thermodynamic parameters were negative and showed that adsorption of phenol onto the activated carbon was feasible, spontaneous and exothermic. Desorption of phenol from the adsorbent using 0.1 M NaOH was about 87.8% in the first adsorption/desorption cycle and did not decrease significantly after three cycles. Overall, the synthesized activated carbon from oily sludge could be a promising adsorbent for the removal of phenol from polluted water.

Effect of crude oil-induced water repellency on transport of Escherichia coli and bromide through repacked and physically-weathered soil columns

Knowledge of the transport and fate of pathogenic Escherichia coli, especially in the areas contaminated with crude oil, is required to assess contamination of shallow groundwater resources. The present study aims to investigate the effect of crude oil-mediated water repellency on the movement of nalidixic acid-resistant Escherichia coli strain (E. coli NAR) and bromide (Br) as an inert tracer in two soil types. The soils were contaminated at three levels of 0, 0.5 and 1% w/w of total petroleum hydrocarbons (TPHs) using crude oil. Steady-state saturated flow in the soil columns was controlled using a tension infiltrometer. Leaching experiments were conducted through the columns of repacked (un-weathered) and physically-weathered clay loam (CL) and sandy loam (SL) soils. The columns leachate was sampled at specific times for 4 pore volumes. The shape of breakthrough curves for the E. coli NAR and Br depended on soil texture and structure and the TPHs level. Preferential flow in the crude oil-mediated water-repellent soils facilitated the transport of contaminants especially E. coli NAR. Filtration coefficient and relative adsorption index of bacteria were greatest in the repacked CL soils and were lowest in the weathered SL soils. Discontinuity of soil pores and lower flow velocity resulted in greater filtration of E. coli NAR in the repacked CL soil than other treatments. Physical weathering induced the formation of aggregates which reduced soil particle surfaces available for retention of water-repellent oil and contaminants. Movement of both bacteria and Br tracer in the weathered SL soil with 1% TPHs was higher than other treatments. This finding was attributed to low specific surface area, continuity of the pores and water repellency-mediated preferential pathways in the weathered SL soil columns. Our findings implied that shallow groundwater resources could be very sensitive to microbial contamination particularly in the oil-mediated water-repellent soils.

The impact of AlterG training on balance and structure of vestibulospinal tract in cerebral palsy children

We aimed to investigate the effects of an antigravity treadmill (AlterG) on the balance and structure of the vestibulospinal tract. The AlterG can reduce the weightbearing of patients and hence can facilitate their locomotion. Three children with cerebral palsy (CP) received AlterG training three days per week for eight weeks with each session lasting 45 minutes. The balance of children was evaluated using the Berg balance test and the Timed Up and Go (TUG) test. The diffusion tensor imaging (DTI) method was employed to quantify changes of the structure of the vestibulospinal tract. Evaluations were performed before and after the 8-week training. DTI metrics including fractional anisotropy (FA), mean diffusivity (MD), radial diffusivity (RD) and axial diffusivity (AD) were measured to evaluate the vestibulospinal tract structure. The results showed that the mean FA of the vestibulospinal tract increased and other metrics decreased for all subjects. Our findings indicated that the balance and structure of the vestibulospinal tract were improved up to 30% for all children following the 8-week AlterG training. This indicates that the balance improvement of the CP children following the AlterG training was accompanied with persistent neuroplasticity in their brain. The clinical implication is that the AlterG training has a potential to be used as an effective therapeutic tool for the treatment of balance impairment in CP children.

Capacitively Coupled Electrical Impedance Tomography for Brain Imaging

Electrical impedance tomography (EIT) is considered as a potential candidate for brain stroke imaging due to its compactness and potential use in bedside and emergency settings. The electrode-skin contact impedance and low conductivity of skull pose some practical challenges to the EIT head imaging. This paper studies the application of capacitively coupled electrical impedance tomography (CCEIT) in brain imaging for the first time. CCEIT is a new contactless EIT technique which uses voltage excitation without direct contact with the skin, as oppose to directly injecting the current to the skin in EIT. Because the safety issue of a new technique should be strictly treated, simulation work based on a simplified head model was carried out to investigate the safety aspects of CCEIT. By comparing with the standard EIT excited by a typical safe current level used in brain imaging, the safe excitation reference of CCEIT is obtained. This is done by comparing the maximum level of internal electrical field (internal current density) of EIT and that of CCEIT. Simulation results provide useful knowledge of excitation signal level of CCEIT and also show a critical comparison with traditional EIT. Practical experiments were carried out with a 12-electrode CCEIT phantom, saline, and carrot samples. Experimental results show the feasibility and potential of CCEIT for stroke imaging. In this paper, the anomaly diameter resolution is 10 mm (1/18 of the phantom diameter), which indicates that small-volume stroke could be detected. This is achieved by a low excitation voltage of 1 V, showing the possibility of even better performance when higher but yet safe level of excitation voltages is used.

Induction of miR-31 causes increased sensitivity to 5-FU and decreased migration and cell invasion in gastric adenocarcinoma

Drug resistance is the main obstacle in the treatment of gastric cancer, the third most common cause of cancer-related death in the world. Due to their small size, easy entrance to cells and multiple targets, microRNAs (miRs) are considered novel and attractive targets. In the current study, parental MKN-45, MKN-45-control vector, and MKN-45-miR-31 populations were compared in terms of cell cycle transitions, migration, cell invasion, and proliferation. In addition, downstream targets of miR-31, including E2F6, and SMUG1 were examined using Real-time RT-PCR and western blotting. MKN-45-miR-31 showed an increased sensitivity to 5-FU, decreased migration and cell invasion compared to the control groups (p = 0.0001, p = 0.01 and p = 0.01, respectively). There was a significant increase in the percentage of cells in G1/pre-G1 phase in MKN-45-miR-31 relative to the control groups (p = 0.001). Induction of miR-31 expression in MKN-45 caused a significant reduction of E2F6 and SMUG1 genes. Our findings indicated that induction of miR-31 expression could increase drug sensitivity, and diminish tumor cell migration and invasion of gastric cancer cells. Therefore, miR-31 can be considered as a potential target molecule in the targeted therapy of gastric cancer (Fig. 2, Ref. 43). Keywords: gastric cancer, miR-31, drug resistance, E2F6, SMUG1.

Inhibition of breast tumor growth and abnormal angiogenesis in mice treated with endothelial cells and their progenitor mesenchymal stem cells derived from bone marrow

Incorporation of endothelial cells or their progenitor cells into newly sprouting blood vessels can contribute to tissue vascularization after ischemic injury. However, the interaction of the stem cells-derived endothelial cells with angiogenesis within tumors is not well understood. The aim of this study was to examine the efficiency of endothelial-like cells derived from MSCs in controlling breast tumor growth associated with abnormal angiogenesis. For this purpose, Balb/c mouse model of breast carcinoma was developed and subjected to intra tumor (I.T)/intra venous (I.V) therapy with undifferentiated MSCs or endothelial cells derived from them. The homing of the stem cells was approved by measuring different markers as well as tracing green fluorescence protein (GFP)-labeled MSCs in the tumors. Tumor growth was measured following cell therapy using a digital caliper. At the end of treatment period (30 days) the angiogenesis markers; VEGFR2 expression as well as micro-vessel density (MVD) using CD31 were estimated in tumor tissues. Stem cell transplantation to mice bearing breast tumors resulted in tumor growth suppression in all experimental groups. The endothelial markers; CD31 and VEGFR2 were down regulated following I.T delivery of the endothelial cells. Accordingly, angiogenesis was suppressed following I.T administration of endothelial cells which was associated with increased focal necrosis in the tumors. In conclusion, data show that endothelial cells directly injected into tumors is more efficient compared to undifferentiated MSCs in controlling tumor-associated angiogenesis and tumor growth.

Nanofibrous Poly(ε-Caprolactone)/Poly(Vinyl Alcohol)/Chitosan Hybrid Scaffolds for Bone Tissue Engineering using Mesenchymal Stem Cells

In the present study, based on a biomimetic approach, novel 3D nanofibrous hybrid scaffolds consisting of poly(ε-caprolactone), polyvinyl alcohol), and chitosan were developed via a multi-jet electrospinning method. The influence of chemical, physical, and structural properties of the scaffolds on the differentiation of mesenchymal stem cells into osteoblasts, and the proliferation of the differentiated cells were investigated. Osteogenically induced cultures revealed that cells were well-attached, penetrated into the construct and were uniformly distributed. The expression of early and late phenotypic markers of osteoblastic differentiation was upregulated in the constructs cultured in osteogenic medium.

Functional Hepatocyte-Like Cells Derived from Human Bone Marrow Mesenchymal Stem Cells on a Novel 3-Dimensional Biocompatible Nanofibrous Scaffold

Aim

To supporting growth and functional differentiation of adult stem cells into hepatocytes in a well-controlled manner, we performed differentiation of human bone marrow mesenchymal stem cells (hBMSCs) to hepatocytes-like cells on a constructed 3-dimensional (3D) nanofibrous biocompatible scaffold.

Methods

After characterization of the hBMSCs isolated from human bone marrow, the performance of the cells seeded and their proliferation on the scaffold was evaluated by scanning electron microscopy (SEM) and 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Different approaches such as immunocytochemistry, reverse transcriptase polymerase chain reaction (RT-PCR), and biochemical assays were used to estimate the ability of hBMSC-derived cells to express hepatocyte-specific markers.

Results

Scanning electron micrographs and MTT analysis revealed the cells were able to expand and remained biologically and metabolically active for 21 days. Immunocytochemical analysis of albumin and α-fetoprotein showing the accumulation of these markers in differentiated cells was confirmed by RT-PCR. Additional markers such as cytochrome P450 3A4, cytokeratin-18, and cytokeratin-19 detected by RT-PCR showed progressive expression during 3 weeks of differentiation on 3D scaffold. The hepatocyte-like cells displayed several characteristics of metabolic functions as judged by production of albumin, urea, transferrin, serum glutamic pyruvic transaminase (SGPT), and serum oxaloacetate aminotransferase (SGOT). Levels of above-mentioned markers, except SGOT in differentiated cells on scaffold, were found to be significantly greater than in the 2D culture system (p<0.05).

Conclusion

Overall data suggest that the engineered nanofibrous scaffold is a conductive matrix for functional hBMSC-derived hepatocyte-like cells and is promising for maintenance of hepatocytes suitable for implantation.

Efficient Production of Hepatocyte-like Cells from Human-induced Pluripotent Stem Cells by Optimizing Growth Factors

BACKGROUND

Generating hepatocytes with complete liver functions is still a challenge and developing more functional hepatocytes is needed.

OBJECTIVE

To compare various differentiation factors and protocols and introducing a preferable protocol to differentiate human-induced pluripotent stem cells (hiPSCs) into hepatocyte-like cells (HLCs).

METHODS

After 3 days of the endoderm differentiation of hiPSCs, the cells were incubated with 5 hepatocyte differentiation culture media, protocols (P), for 14 days-P1: hepatocyte growth factor and fibroblast growth factor-4 (FGF-4) for the first week and oncostatin-M and dexamethasone for the second week; P2: similar to P1 but FGF4 was used in both the first and second weeks; P3: similar to P1 but FGF-4 was not used; P4: similar to P1 but FGF-4 and dexamethasone were not used; and P5: similar to P1 but FGF-4 and oncostatin-M were not used. After 17 days, characterization was done by qRT-PCR, immunofluorescence and ELISA.

RESULTS

The mRNA expression levels of hepatocyte markers (albumin, cytokeratin-18, tyrosine aminotransferase, hepatocyte nuclear factor-4α, cytochrome-P450 7A1) increased significantly (p<0.05) in the differentiated cells by 5 different protocols. Furthermore, significant protein expression and secretion of albumin were detected in the differentiated cells by 5 different protocols. In P3, the differentiated cells had the highest exhibit of hepatocyte characteristics and in P4 they had the lowest. Moreover, in P1 and P2 similar results were observed.

CONCLUSION

Since P3 gave us the best results among all protocols, we recommend it as an efficient protocol to differentiate the functional HLCs from hiPSCs, which can improve cell therapies.

The effect of fibrinogen concentrate on perioperative bleeding in transurethral resection of the prostate: a double-blind placebo-controlled and randomized study

Essentials Perioperative bleeding during prostate surgery is still a common morbidity. Anticoagulant and antiplatelet medications contribute to the risk of hemorrhage and prolonged hospital stay. Multiple pharmacological agents have been proposed, but none of them have been widely accepted. It is crucial to find a safe and effective modality to reduce hemorrhage.

SUMMARY

Background Hemorrhage during transurethral resection of the prostate (TUR-P) has always been a concern. Several studies have shown preoperative administration of fibrinogen concentrate to have promising results in reducing hemorrhage in cardiac surgery. Objectives To investigate the hemostatic effect of fibrinogen concentrate administration on reducing the amount of bleeding during TUR-P in patients with benign prostatic hyperplasia. Methods Sixty men with benign prostatic hyperplasia, who were chosen to undergo TUR-P, entered this prospective randomized double-blind placebo-controlled study. The participants were randomly assigned to two groups: treatment (n = 31) and placebo (n = 29). They received an infusion of 2 g of fibrinogen concentrate (treatment group) or normal saline (placebo group) before surgery. Data regarding the amount of bleeding, the operation and complications were recorded and analyzed. Results No difference was observed in bleeding between the fibrinogen and placebo groups during (521 mL versus 557 mL, respectively) and after (291 mL versus 341 mL, respectively) surgery. This lack of difference was also seen in operation time (43 min versus 42 min), irrigating fluid volume used during (17 L versus 19 L) and after (29 L versus 28 L) surgery, and resected adenoma volume (19 g versus 19 g). The mean blood pressure was also similar in both groups as a confounding factor for the amount of bleeding. Conclusion Preoperative administration of fibrinogen concentrate had no significant influence on intraoperative and postoperative bleeding in TUR-P surgery.

Modifying the mechanical properties of silk nanofiber scaffold by knitted orientation for regenerative medicine applications

Tissue reconstruction is among the increasing applications of polymer nanofibers. Fibrous scaffolds (mats) can be easily produced using the electrospinning method with structure and biomechanical properties similar to those of a cellular matrix. Electrospinning is widely used in the production of nanofibers and the GAP-method electrospinning is one of the means of producing fully aligned nanofibers. In this research, using the GAP-method, knitted fibrous scaffolds were made of silk fibroin, which is a biocompatible and biodegradable polymer. To extract fibroin from cocoons, the sodium chloride solution as well as dialysis and freeze-drying techniques were employed. The molecular weight of the extracted fibroin was measured with the SDS-Page electrophoresis technique. Moreover, the pure fibroin structure was examined using the ATR-FTIR method, and the viscosity of the solution used for electrospinning was measured with the Brookfield rotational viscometer. The scaffolds were prepared through electrospinning of the silk fibroin in pure formic acid solution. The following three structures were electrospun: 1) a random structure; 2) a knitted structure with an interstitial angle of 60 degrees; 3) a knitted structure with an interstitial angle of 90 degrees. Morphology of the resulting fibers was studied with a SEM (scanning electron microscope). Fibroin scaffolds are degradable in water. Therefore, they were fixated through immersion in methanol to be prepared for assays. The mechanical properties of the scaffolds were also studied using a tensile strength test device. The effect of methanol on the strength properties of the samples was also assessed. The hydrophilic potential of the samples was measured via a contact angle test. To increase the hydrophilicity of the scaffold surfaces, the cold oxygen plasma technique was employed. Finally, the biocompatibility and cell adhesion of the resulting scaffolds were examined through a HEK 293 cell culture, and the results were analyzed through the MTT, DAPI staining, and SEM imaging techniques. Results revealed that the oriented knitted structure contributed to the increase in Young&apos;s modulus and the maximum strength of scaffolds as compared to the random samples. Moreover, this structure can also be a suitable alternative to the typical chemical means of increasing strength.

Multiphase permittivity imaging using absolute value electrical capacitance tomography data and a level set algorithm

Multiphase flow imaging is a very challenging and critical topic in industrial process tomography. In this article, simulation and experimental results of reconstructing the permittivity profile of multiphase material from data collected in electrical capacitance tomography (ECT) are presented. A multiphase narrowband level set algorithm is developed to reconstruct the interfaces between three- or four-phase permittivity values. The level set algorithm is capable of imaging multiphase permittivity by using one set of ECT measurement data, so-called absolute value ECT reconstruction, and this is tested with high-contrast and low-contrast multiphase data. Simulation and experimental results showed the superiority of this algorithm over classical pixel-based image reconstruction methods. The multiphase level set algorithm and absolute ECT reconstruction are presented for the first time, to the best of our knowledge, in this paper and critically evaluated. This article is part of the themed issue 'Supersensing through industrial process tomography'.

EIT image reconstruction based on a hybrid FE-EFG forward method and the complete-electrode model

This paper presents the application of the hybrid finite element-element free Galerkin (FE-EFG) method for the forward and inverse problems of electrical impedance tomography (EIT). The proposed method is based on the complete electrode model. Finite element (FE) and element-free Galerkin (EFG) methods are accurate numerical techniques. However, the FE technique has meshing task problems and the EFG method is computationally expensive. In this paper, the hybrid FE-EFG method is applied to take both advantages of FE and EFG methods, the complete electrode model of the forward problem is solved, and an iterative regularized Gauss-Newton method is adopted to solve the inverse problem. The proposed method is applied to compute Jacobian in the inverse problem. Utilizing 2D circular homogenous models, the numerical results are validated with analytical and experimental results and the performance of the hybrid FE-EFG method compared with the FE method is illustrated. Results of image reconstruction are presented for a human chest experimental phantom.

A hybrid microfluidic system for regulation of neural differentiation in induced pluripotent stem cells

Controlling cellular orientation, proliferation, and differentiation is valuable in designing organ replacements and directing tissue regeneration. In the present study, we developed a hybrid microfluidic system to produce a dynamic microenvironment by placing aligned PDMS microgrooves on surface of biodegradable polymers as physical guidance cues for controlling the neural differentiation of human induced pluripotent stem cells (hiPSCs). The neuronal differentiation capacity of cultured hiPSCs in the microfluidic system and other control groups was investigated using quantitative real time PCR (qPCR) and immunocytochemistry. The functionally of differentiated hiPSCs inside hybrid system's scaffolds was also evaluated on the rat hemisected spinal cord in acute phase. Implanted cell's fate was examined using tissue freeze section and the functional recovery was evaluated according to the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale. Our results confirmed the differentiation of hiPSCs to neuronal cells on the microfluidic device where the expression of neuronal-specific genes was significantly higher compared to those cultured on the other systems such as plain tissue culture dishes and scaffolds without fluidic channels. Although survival and integration of implanted hiPSCs did not lead to a significant functional recovery, we believe that combination of fluidic channels with nanofiber scaffolds provides a great microenvironment for neural tissue engineering, and can be used as a powerful tool for in situ monitoring of differentiation potential of various kinds of stem cells. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1534-1543, 2016.

Oct4 transcription factor in conjunction with valproic acid accelerates myelin repair in demyelinated optic chiasm in mice

Multiple sclerosis is a demyelinating disease with severe neurological symptoms due to blockage of signal conduction in affected axons. Spontaneous remyelination via endogenous progenitors is limited and eventually fails. Recent reports showed that forced expression of some transcription factors within the brain converted somatic cells to neural progenitors and neuroblasts. Here, we report the effect of valproic acid (VPA) along with forced expression of Oct4 transcription factor on lysolecithin (LPC)-induced experimental demyelination. Mice were gavaged with VPA for one week, and then inducible Oct4 expressing lentiviral particles were injected into the lateral ventricle. After one-week induction of Oct4, LPC was injected into the optic chiasm. Functional remyelination was assessed by visual-evoked potential (VEP) recording. Myelination level was studied using FluoroMyelin staining and immunohistofluorescent (IHF) against proteolipid protein (PLP). IHF was also performed to detect Oct4 and SSEA1 as pluripotency markers and Olig2, Sox10, CNPase and PDGFRα as oligodendrocyte lineage markers. One week after injection of Oct4 expressing vector, pluripotency markers SSEA1 and Oct4 were detected in the rims of the 3rd ventricle. LPC injection caused extensive demyelination and significantly delayed the latency of VEP wave. Animals pre-treated with VPA+Oct4 expressing vector, showed faster recovery in the VEP latency and enhanced myelination. Immunostaining against oligodendrocyte lineage markers showed an increased number of Sox10+ and myelinating cells. Moreover, transdifferentiation of some Oct4-transfected cells (GFP+ cells) to Olig2+ and CNPase+ cells was confirmed by immunostaining. One-week administration of VPA followed by one-week forced expression of Oct4 enhanced myelination by converting transduced cells to myelinating oligodendrocytes. This finding seems promising for enhancing myelin repair within the adult brains.

Iron-activated carbon nanocomposite: synthesis, characterization and application for lead removal from aqueous solution

An iron-activated carbon nanocomposite synthesized by a facile, low temperature technique was successfully tested for Pb(ii) removal from aqueous solutions.

In Vitro and In Vivo investigations on fibronectin coated and hydroxyapatite incorporated scaffolds

Topological and biochemical aspects of the matrices are essential factors to be extensively studied for more successful tissue engineering. Other characteristics including biodegradability and biocompatibility should be also considered. Nanofibrous structure mimics topography of the natural matrix. Previous in vitro studies reported the favorable effects of nanohydroxyapatite (nHA) and fibronectin (Fn) on biodegradability and biocompatibility of scaffold. Herein, the synergistic outcome of co-application of Fn and nHA incorporation into aligned electrospun polycaprolactone (PCL) seeded by mouse mesenchymal stem cells (MSC) was investigated both in vitro and in vivo. Scanning Electron Microscopy (SEM), contact angle measurement and tensile test were applied for scaffold characterization. In vitro evaluation of the seeded cells was performed by MTT, SEM and cell-cycle analyses. In congruence with in vitro findings, in vivo assessment of four weeks fibronectin coated PCL/ nHA scaffold transplanted mice illustrated the suitable compact surrounding tissue with the most penetrated cells generation. Furthermore, Fn coating resulted in cell infiltration enhancement while nHA addition led to more scaffold biodegradation. In conclusion, fabrication of nanofiberous scaffold with this combination of biochemical composition and surface stimulation caused improved biodegradability and biocompatibility of the scaffold which are desirable in more effective tissue regeneration.

Enhanced osteoconductivity of polyethersulphone nanofibres loaded with bioactive glass nanoparticles in in vitro and in vivo models

OBJECTIVES

There is growing need for new scaffold constructions for synthetic bone graft substitutes to repair large bone lesions. A very promising and important class of new implants for tissue engineering is based on three-dimensional scaffolds and bioceramics.

MATERIALS AND METHODS

In this study, after investigation of mechanical properties of polyethersulphone (PES) nanofibres, fabricated by electrospinning methodology and coated with bioactive glass (BG), cells of the MG-63 line were cultured on surfaces of these scaffolds. Their capacity to support MG-63 proliferation was also investigated in vitro by MTT assay. Osteoconductivity on these scaffolds was investigated by the common osteogenic markers alkaline phosphatase (ALP) activity, calcium mineral deposition and bone-related gene activation. Next, a bone reconstruction of rat critical-size defects model was evaluated using radiographic imaging analysis (digital mammography), computed tomography and histological examination.

RESULTS

In vitro results indicated that biocompatibility and osteogenic markers of MG-63 cells were significantly enhanced after coating PES with BG. Based on in vivo results, new bone formation in the defect site was enhanced in implanted rats in comparison with a control group. The highest reconstruction was observed in animals implanted with BG-coated nanofibres.

CONCLUSIONS

Osteoconductivity of PES nanofibres was markedly enhanced after coating them with BG, and introduction of this construct as new bone-graft substitute for bone loss and defects is indicated.

Introduction: a brief overview of iterative algorithms in X-ray computed tomography

This paper presents a brief overview of some basic iterative algorithms, and more sophisticated methods are presented in the research papers in this issue. A range of algebraic iterative algorithms are covered here including ART, SART and OS-SART. A major limitation of the traditional iterative methods is their computational time. The Krylov subspace based methods such as the conjugate gradients (CG) algorithm and its variants can be used to solve linear systems of equations arising from large-scale CT with possible implementation using modern high-performance computing tools. The overall aim of this theme issue is to stimulate international efforts to develop the next generation of X-ray computed tomography (CT) image reconstruction software.

Motion-compensated cone beam computed tomography using a conjugate gradient least-squares algorithm and electrical impedance tomography imaging motion data

Cone beam computed tomography (CBCT) is an imaging modality that has been used in image-guided radiation therapy (IGRT). For applications such as lung radiation therapy, CBCT images are greatly affected by the motion artefacts. This is mainly due to low temporal resolution of CBCT. Recently, a dual modality of electrical impedance tomography (EIT) and CBCT has been proposed, in which the high temporal resolution EIT imaging system provides motion data to a motion-compensated algebraic reconstruction technique (ART)-based CBCT reconstruction software. High computational time associated with ART and indeed other variations of ART make it less practical for real applications. This paper develops a motion-compensated conjugate gradient least-squares (CGLS) algorithm for CBCT. A motion-compensated CGLS offers several advantages over ART-based methods, including possibilities for explicit regularization, rapid convergence and parallel computations. This paper for the first time demonstrates motion-compensated CBCT reconstruction using CGLS and reconstruction results are shown in limited data CBCT considering only a quarter of the full dataset. The proposed algorithm is tested using simulated motion data in generic motion-compensated CBCT as well as measured EIT data in dual EIT-CBCT imaging.

Oral delivery of nanoparticles containing anticancer SN38 and hSET1 antisense for dual therapy of colon cancer

An oral delivery system intended for treatment of colon cancer in HT29 cancerous cells was investigated by encapsulating hSET1 antisense and SN38 anticancer in nanoparticles based on cysteine trimethyl chitosan (cysTMC) and carboxymethyl dextran (CMD). Studies have shown hSET1 as the main type of histone methyltransferase (HMT) complex, is significantly overexpressed in malignant cells. In this study, hSET1 antisense was employed to inhibit gene expression. Additionally, SN38 was incorporated into nanoparticles to enhance the efficiency of the system by inhibition of topoisomerase 1. CysTMC was synthetized and characterized by (1)H NMR and FTIR. Nanoparticles were prepared through complexation of CMD and cysTMC. Particle size and surface charge was 100-150 nm and 17-21 mV respectively with drug content of around 2.6%. Gel electrophoresis assay proved the stability of antisense in simulated gastric and intestinal fluids. Nanoparticles showed high mucoadhesion and glutathione responsive release. Cellular uptake was observed by confocal microscopy and quantified by flow cytometry. Cytotoxicity of NPs was assessed using MTT assay. Results showed hSET1/SN38 nanoparticles had significantly higher cytotoxicity against HT29 cells compared with nanoparticles containing SN38, free SN38 or naked hSET1. Therefore, present system could be considered an effective combination therapy of highly hydrophobic SN38 and hSET1.

Expression pattern of key microRNAs in patients with newly diagnosed chronic myeloid leukemia in chronic phase

INTRODUCTION

Chronic myeloid leukemia (CML) is caused by reciprocal translocation in hematopoietic stem cells (HSCs). This translocation forms the BCR-ABL1 oncogene, which alters several signaling pathways that control malignancy. CML has three phases: chronic, accelerated, and blast crisis. The microRNAs (miRNAs or miRs) are noncoding RNAs that downregulate their target gene by targeting 3' UTR of mRNA or through translational inhibition. It has been shown that miRNAs regulate many biological processes, and dysregulation of these regulatory RNAs is involved in disease development, particularly in cancer. The important role of miRNAs as therapeutic agents and biomarkers has been demonstrated in CML patients at different phases of the disease.

METHODS

Stem-loop reverse transcription polymerase chain reaction was used to characterize differentially expressed miRNAs of leukocytes in the peripheral blood of 50 newly diagnosed CML patients in chronic phase.

RESULTS

Some onco-miRNAs were found to be downregulated (miR-155 and miR-106), and some tumor suppressor miRs (miR-16-1, miR-15a, miR-101, miR-568) were upregulated.

CONCLUSION

These results show that very few miRNAs alone would be good candidates for CML diagnosis independently of conflicting results, but together could be an additional tool for CML diagnosis. Moreover, miRNAs might be good candidates for prognosis prediction and CML therapy.

Tissue-specific somatic stem-cell isolation and characterization from human endometriosis. Key roles in the initiation of endometrial proliferative disorders

AIM

The endometrial-proliferation related diseases leads to endometrial hyperplasia, i.e., endometriosis. Endometrial progenitor and stem cells play key roles in the beginning of endometrial proliferative disorders. The purpose of this study was the isolation of stem cells in the endometriosis lesion as well as the evaluation and comparison of the stemness-related target genes in endometriosis endometrial stem cells (EESCs), normal endometrial stem cell (ESCs), endometrial lesions stem cell (ELSCs) and bone marrow mesenchymal stem cells (MSCs).

METHODS

EESCs, ESCs, ELSCs and MSCs were isolated. Flowcytometry and real-time PCR were utilized to detect the cell surface marker and expression pattern of 16 stemness genes. The proliferation of all stem cells was observed by MTT assay. The differentiation potential was evaluated by alizarin red, oil red O and RT-PCR method. The karyotyping was performed on EESCs and ELSCs at passage 20.

RESULTS

The unique patterns of gene expression were detected although EESCs, ESCs, ELSCs and MSCs have a background expression of stemness-related genes. Spindle-like morphology, normal karyotype, adipogenic and osteogenic potential, significantly expression of Oct4, SALL4, DPPA2, Sox2, Sox17 and also specific surface markers such as CD44, CD105, CD90, CD73 and CD146 in EESCs and ELSCs was observed.

CONCLUSION

According to our data, stem cells in endometriosis endometrial and endometriosis are such a informative tools to study of pathogenesis of gynecological diseases. Furthermore, endometrial stem/progenitor cells which easily obtain from tissue may be valuable targets for early diagnosis of endometrial disorders in the future.

Neuromuscular Responses to 14 Weeks of Traditional and Daily Undulating Resistance Training

This study compared traditional (TP) and daily undulating (DUP) periodization on muscle strength, EMG-estimated neural drive and muscle architecture of the quadriceps femoris (QF). 10 non-athletic females (24.4±3.2 years) performed 14 weeks of isometric training for the QF exercising 1 leg using TP and the contralateral leg using DUP. Intensities varied from 60% to 80% of MVC and the intensity zones and training volume were equated for each leg. Knee extension MVC, maximal voluntary QF-EMG activity and vastus lateralis (VL) muscle architecture were measured in both legs before, after 6 weeks and after 14 weeks of training using dynamometry, surface EMG and ultrasonography. Isometric MVC and maximal QF-EMG remained unaltered after 6 weeks of training, but were significantly (P<0.05) enhanced after 14 weeks in both legs (MVC: TP 24%, DUP 23%; QF-EMG: TP 45%, DUP 46%). VL-architecture remained unchanged following 6 weeks of training, but VL-muscle thickness (TP 17%, DUP 16%) and fascicle length (TP 16%, DUP 17%) displayed significant (P<0.05) enlargements after 14 weeks in both legs. Importantly, these temporal neuromuscular alterations displayed no significant differences between the training legs. Therefore, periodization may not act as a key trigger for neuromuscular adaptations.

Enhanced growth and osteogenic differentiation of Induced Pluripotent Stem cells by Extremely Low-Frequency Electromagnetic Field

It is accepted that induced pluripotent stem cells (iPSCs) have a great osteogenic potential differentiation, in the present study, we tried to improve this potentials using mechanical and biological stimulation. To achieve this goal, the influence of prolonged pulsed extremely low frequency electromagnetic field (ELF&mdash;EMF) (50 Hz and 1.5 mT) was investigated on cultured iPSCs. After evaluation of iPSCs biological behavior under radiation using MTT assay, osteogenic differentiation of stem cells was investigated via common important osteogenic markers such as alkaline phosphatase (ALP) activity, calcium mineral deposition and important bone&mdash;related genes. MTT result showed that proliferation rate of iPSCs significantly increased followed by stimulate with ELF&mdash;EMF. Osteogenic differentiation characterization demonstrated that potential of stem cells also was significantly increased while these cells cultured under both ELF&mdash;EMF and osteogenic medium (OM) in comparison to cultured under ELF&mdash;EMF or OM alone. According to the results, concluded that combination of OM and ELF&mdash;EMF can be a great supplement for bone differentiation of stem cells and appropriate candidate for use in the treatment of bone defects and osteoporosis patients by accelerating healing process.

Generation of Islet-like Cell Aggregates from Human Adipose Tissue-derived Stem Cells by Lentiviral Overexpression of PDX-1

BACKGROUND

Pancreatic duodenal homeobox1 (PDX-1) is a transcription factor that is important in regulating pancreas development and maintaining β-cell function. β-cell replacement is an effective approach for the treatment of type 1 diabetes. Human adipose-mesenchymal stem cells (hAMSCs) are the ideal population cells for differentiating into insulin-producing cells.

OBJECTIVE

To determine if islet-like cell aggregates production could be generated from hAMSCs by lentiviral overexpression of PDX-1.

METHODS

After isolation of hAMSCs, characteristics of these cells were identified by flow-cytometic analysis and multilineage differentiation studies. PDX-1 gene delivered into hAMSCs through lentiviral vector for differentiating hAMSCs into insulin-producing cells (IPCs) at the utilized protocol for 14 days. Characteristics of IPCs were evaluated by immunocytofluorescence, dithizone staining, and quantitative reverse transcription PCR. In response to high glucose medium, insulin release was detected by chemiluminescence enzyme immunoassay.

RESULTS

The islet-like cell aggregates appeared about 10 days after introduction of PDX-1 into hAMSCs. PDX-1 induced its own expression (auto-induction), a number of islet-related genes such as Ngn3, Nkx2-2, and insulin. The insulin-positive cells were detected in the PDX-1 transduced cells. In response to glucose challenge test, secretion of insulin hormone in the medium with high glucose concentration significantly increased in the PDX-1-transduced cells related to medium with low glucose concentration.

CONCLUSION

Introduction of lentiviral PDX-1 significantly induces hAMSCs to differentiate into islet-like cell aggregates, which may provide a source of adipose stem cells-derived insulin-producing cells for cell replacement therapy in type 1 diabetes.

Molecualr Cloning of the capsular antigen F1 of Yersinia pestis in pBAD/gIII plasmid

Yersinia pestis which is the causative agent of pneumonic plague and distributed in all continents has led to many deaths during the history. Because of its high mortality rate, it must be diagnosed and treated at the earliest time post infection and therefore, rapid diagnostic tests are required. In the present study, we cloned the coding sequence of F1 capsular antigen of the bacteria in the pBAD/gIII plasmid for later expression and purification of the protein to produce poly and monoclonal antibodies against this antigen, and subsequently to develop rapid and efficient diagnostics tools for Y. pestis infections.

Pluripotency properties of embryonic stem cells isolated from stage X blastoderm of Mazandaran native chicken

The aim of this study was to isolate Embryonic Stem Cells (ESCs) from native chicken and to characterize their pluripotency properties through the cellular and molecular markers. Samples obtained from fertilized eggs from Mazandaran native hens. Cells were isolated from area of pellucida from stage X native hens' blastoderm. Then the cells were cultured on inactivated mouse SNL feeder cells in the presence of LIF, IGF-1, bFGF, CNTF, OSM, SCF, Il-6, and Il-11 growth factors. The native chickens' ESCs colonies were picked up and subsequently passaged. To characterize the cells, they were analyzed for their alkaline phosphatase activity, and also for the expression of SSEA-4, and TRA-1-60 as embryonic-specific markers at the protein level. Furthermore, the expression of pluripotency (cPouV, Sox2, and Nanog) and cell lineage specific (Cvh, Brachyury, and Gata6) gene markers was evaluated at the level of mRNA using quantitative RT-PCR. Isolated cells were passaged repeatedly and successfully up to ten passages. The stemness of embryonic cells has been approved by the activity of the alkaline phosphatase, presence of the SSEA-4, and TRA-1-60 protein, and expression of the molecular marker (cPouV, Nanog, and Sox-2) genes. The spontaneous differentiation of chicken ESCs confirmed the pluripotecy of the cells in differentiation into specialized cell lineages. Our observation showed that ESCs can be isolated successfully from stage X blastoderm of Mazandaran native chickens and these cells maintain their stemness properties during multi-passages in vitro.

Comparison of osteogenic differentiation potential of human adult stem cells loaded on bioceramic-coated electrospun poly (L-lactide) nanofibres

OBJECTIVES

To compare potential of four types of stem cell in tissue engineering and regenerative medicine applications, osteogenic capacity of newly introduced mesenchymal stem cells (MSCs) derived from buccal fat pads (BFP) (an adipose-encapsulated mass of the oral cavity), was compared to those isolated from bone marrow (BM-MSCs), adipose tissue (AT-MSCs) and unrestricted somatic stem cells (USSCs). Cells were cultured on poly (L-lactide) (PLLA) nanofibres, Bio-Oss(®)-coated PLLA (PLLA-Bio), and culture plates (TCPS) as control.

MATERIALS AND METHODS

Capacity of proliferation and osteogenic differentiation of the stem cells was investigated by MTT assay and common osteogenic markers, alkaline phosphatase activity, calcium mineral deposition and bone-related genes.

RESULTS

Highest proliferation level was observed in cells cultured on PLLA-Bio, but with no significant difference between proliferation levels of the four types of stem cell. Over the period of study, BM-MSCs cultured on PLLA-Bio scaffolds exhibited greatest alkaline phosphatase (ALP) activity and mineralization with BFP-MSCs having the next closest results. However, AT-MSC had the lowest capacity for ALP activity and mineralization during osteogenic differentiation. Gene expression evaluation revealed that highest expression of three important bone-related genes was observed in stem cells cultured on bioceramic-coated nanofibrous scaffolds.

CONCLUSIONS

Results indicated Bio-Oss-coated PLLA to compose most appropriate substrates to support proliferation and osteogenic differentiation of stem cells in vitro. BFP-MSCs demonstrated the same osteogenic differentiation capacity as other stem cells tested and thus hold very promising potential for applications in bone tissue engineering and regenerative medicine.

Modified protocol for improvement of differentiation potential of menstrual blood-derived stem cells into adipogenic lineage

OBJECTIVES

To characterize potency of menstrual blood-derived stem cells (MenSCs) for future cell therapies, we examined differentiation potential of MenSCs into adipocytes.

MATERIALS AND METHODS

Differentiation potential of MenSCs in comparison to bone marrow stem cells (BMSCs) was assessed in conventional culture medium. Differentiation potential of MenSCs into adipocytes was improved using different combinations of growth factors and hormones.

RESULTS

First, we demonstrated that MenSCs preserve their appearance and karyotypic stability during passages. Although these cells express mesenchymal stem cells markers, they cannot simply be classified as mesenchymal stem cells due to expression of embryonic stem cells marker, OCT-4. Oil red O staining showed that differentiated MenSCs in conventional medium with/without retinoic acid (protocols 1 and 2) did not attain adipocyte characteristics, whereas differentiated BMSCs in conventional medium accumulated oil vacuoles typically. Nevertheless, real-time RT-PCR results showed that LPL gene expression was up-regulated in both protocols 1 and 2, whereas LEPR was up-regulated only in protocol 2 (fortified with retinoic acid). Surprisingly, protocol 3 (including rosiglitazone) had odd influence on mRNA expression of all genes (LEPR, LPL and PPAR-γ). Oil red O staining confirmed fat-producing ability of MenSCs under protocol 3.

CONCLUSIONS

Presented data suggest an efficient differentiation protocol for in vitro production of MenSC-derived adipocytes. These cells are suggested to be an apt alternative to BMSCs for future stem cell therapy of soft tissue injuries.