Polyvinyl Alcohol Sponge Research Articles

Production and Immobilization of Halophilic Invertase Produced from Honey Isolate Aspergillus niger EM77 (KF774181)

Honey isolate Aspergillus niger EM77 was a good halophilic invertase producer in the presence of wheat bran as a complete medium (114.55 U/g), using solid state fermentation technique. Different parameters influence the enzyme productivity such as different pH values, temperature, incubation period, nitrogen and carbon sources were investigated. The optimum pH, temperature and incubation period for enzyme production were 5.5, 30 o C and 72 hrs, respectively. Sucrose at 2 % was more suitable carbon source for invertase production (144.39 U/g) and (NH 4 ) 2 SO 4 at 0.15 % was the ideal nitrogen source. Among different metals ions MnSO 4 enhanced the enzyme productivity than other tested ions to 194.71 U/g. The partially purified enzyme was successfully entrapped in polyvinyl alcohol sponge shielded with agar starch layer (PVAsp Gs) and achieved 71% immobilization yield. The optimum conditions for immobilization were: pH 5.2, an incubation time of 15 min and a protein concentration of 250 mg/ml. Immobilized enzyme was reused 12 times with 29% activity loss. The free enzyme lost its activity completely at 70EsC after 45 minute and the immobilized form retained 80% of its activity at the same condition.The free and immobilized form reported extreme halophilic property since the highest enzyme activity was obtained between 3.5- 5 M.

Comparison study of the use of absorbable and nonabsorbable materials as internal splints after closed reduction for nasal bone fracture.

BackgroundThe authors sought to compare the use of the nonabsorbable polyvinyl alcohol sponge (PVA, Merocel) and absorbable synthetic polyurethane foam (SPF, Nasopore Forte plus) as intranasal splints after closed reduction of fractured nasal bones during the hospitalization period.MethodsThe medical records of 111 patients who underwent closed reduction for nasal bone fracture at Sanggye Paik Hospital, Inje University College of Medicine, from 2012 to 2013 were reviewed retrospectively. PVA (group A) or SPF (group B) was packed as an internal splint after closed reduction. The efficacy of the materials was compared and statistically analyzed.ResultsPVA was used in 82 patients, and SPF was used in 29 patients. The patients in group B complained significantly more of nasal pain on the first day after operation than the patients in group A. Headaches on the operation day were significantly more painful in group B than in group A. Bleeding on the fourth postoperative day was significantly reduced in group B as compared to group A. The patients in group B exhibited significantly more intensive nasal obstruction on the operation day and the following day than the patients in group A. However, on the third and fourth postoperative days, the nasal obstruction in group B was less than that in group A. The pain and bleeding related to the packing material was significantly reduced in group B as compared to group A.ConclusionsThe use of SPF as an absorbable packing material is a reasonable substitute for the traditional nonabsorbable material.

Dynamic simulation and finite element analysis of the human mandible injury protected by polyvinyl alcohol sponge

There have been intensive efforts to find a suitable kinetic energy absorbing material for helmet and bulletproof vest design. Polyvinyl alcohol (PVA) sponge is currently in extensive use as scaffolding material for tissue engineering applications. PVA can also be employed instead of commonly use kinetic energy absorbing materials to increase the kinetic energy absorption capacity of current helmet and bulletproof vest materials owing to its excellent mechanical properties. In this study, a combined hexahedral finite element (FE) model is established to determine the potential protection ability of PVA sponge in controlling the level of injury for gunshot wounds to the human mandible. Digital computed tomography data for the human mandible are used to establish a three-dimensional FE model of the human mandible. The mechanism by which a gunshot injures the protected mandible by PVA sponge is dynamically simulated using the LS-DYNA code under two different shot angles. The stress distributions in different parts of the mandible and sponge after injury are also simulated. The modeling results regardless of shot angle reveal that the substantial amount of kinetic energy of the steel ball (67%) is absorbed by the PVA sponge and, consequently, injury severity of the mandible is significantly decreased. The highest energy loss (170J) is observed for the impact at entry angle of 70°. The results suggest the application of the PVA sponge as an alternative reinforcement material in helmet and bulletproof vest design to absorb most of the impact energy and reduce the transmitted load.

Retraction notice

The following article has been included in a multiple retraction: Karimi A, Navidbakhsh M and Razaghi R. Dynamic finite element simulation of the human head damage mechanics protected by polyvinyl alcohol sponge. Int J Damage Mech, first published on 15 May 2014, DOI: 10.1177/1056789514535945. In 2015 SAGE became aware of author misconduct concerning the suspected fabrication of identities, as well as the impersonation of legitimate individuals, to manipulate the peer review process across three separate journal publications. SAGE and the journal Editors immediately launched an investigation and have decided to retract the following articles for reasons of author misconduct. Alireza Karimi was the submitting author on 12 of the articles. SAGE regrets the academic record was compromised by manipulation of the peer review process and apologises to readers.

Mechanical properties of polyvinyl alcohol sponge under different strain rates

Abstract Polyvinyl alcohol (PVA) is a suitable material for biomedical and pharmaceutical applications. This paper presents a scientific study on the stiffness, strength, and energy absorption characteristics of a fabricated PVA sponge under different strain rates with a view to using it as an alternative biodegradable and biocompatible material. A range of tensile tests, such as stress failure and cyclic, on PVA sponge have been carried out. The stress–strain curves in all strain rates (1, 20, 100 mm min−1) indicated a near constant plateau stress over a long strain range, which is ideal for energy absorption applications. It was found that the PVA sponge biomaterial exhibited remarkable stiffness, strength, and energy absorption capacities that are comparable to those of some biomaterials with the same density range. PVA sponge can also bear suitable stress both at low and high strain rates which enables it to be implemented in most tissue engineering scaffolds.

An experimental-finite element analysis on the kinetic energy absorption capacity of polyvinyl alcohol sponge

Polyvinyl alcohol (PVA) sponge is in widespread use for biomedical and tissue engineering applications owing to its biocompatibility, availability, relative cheapness, and excellent mechanical properties. This study reports a novel concept of design in energy absorbing materials which consist in the use of PVA sponge as an alternative reinforcement material to enhance the energy loss of impact loads. An experimental study is carried out to measure the mechanical properties of the PVA sponge under uniaxial loading. The kinetic energy absorption capacity of the PVA sponge is computed by a hexahedral finite element (FE) model of the steel ball and bullet through the LS-DYNA code under impact load at three different thicknesses (5, 10, 15mm). The results show that a higher sponge thickness invokes a higher energy loss of the steel ball and bullet. The highest energy loss of the steel ball and bullet is observed for the thickest sponge with 160 and 35J, respectively. The most common type of traumatic brain injury in which the head subject to impact load causes the brain to move within the skull and consequently brain hemorrhaging. These results suggest the application of the PVA sponge as a great kinetic energy absorber material compared to commonly used expanded polystyrene foams (EPS) to absorb most of the impact energy and reduces the transmitted load. The results might have implications not only for understanding of the mechanical properties of PVA sponge but also for use as an alternative reinforcement material in helmet and packaging material design.

RETRACTED: Experimental and numerical study on the mechanical behavior of rat brain tissue

Brain tissue is a very soft tissue in which the mechanical properties depend on the loading direction. While few studies have characterized these biomechanical properties, it is worth knowing that accurate characterization of the mechanical properties of brain tissue at different loading directions is a key asset for neuronavigation and surgery simulation through haptic devices. In this study, the hyperelastic mechanical properties of rat brain tissue were measured experimentally and computationally. Prepared cylindrical samples were excised from the parietal lobes of rats' brains and experimentally tested by a tensile testing machine. The effects of loading direction on the mechanical properties of brain tissue were measured by applying load on both longitudinal and circumferential directions. The general prediction ability of the proposed hyperelastic model was verified using finite element (FE) simulations of brain tissue tension experiments. The uniaxial experimental results compared well with those predicted by the FE models. The results revealed the influence of loading direction on the mechanical properties of brain tissue. The Ogden hyperelastic material model was suitably represented by the non-linear behavior of the brain tissue, which can be used in future biomechanical simulations. The hyperelastic properties of brain tissue provided here have interest to the medical research community as there are several applications where accurate characterization of these properties are crucial for an accurate outcome, such as neurosurgery, robotic surgery, haptic device design or car manufacturing to evaluate possible trauma due to an impact.

Morphine Inhibits Migration of Tumor-Infiltrating Leukocytes and Suppresses Angiogenesis Associated with Tumor Growth in Mice

Tumor cells secrete factors that stimulate the migration of peripheral blood leukocytes and enhance tumor progression by affecting angiogenesis. In these studies, we investigated the effect of morphine, a known immunosuppressant, on leukocyte migration and recruitment to conditioned media derived from long-term cultures of mouse Lewis lung carcinoma cells. Our results indicate that morphine treatment reduced the migration and recruitment of tumor-infiltrating leukocytes into Matrigel plugs and polyvinyl alcohol sponges containing conditioned media derived from long-term cultures of mouse Lewis lung carcinoma cells when compared with placebo. A reciprocal increase in peripheral blood leukocytes was observed at the time of plug or sponge removal in morphine-treated mice. Decreased angiogenesis was observed in conditioned media derived from long-term cultures of mouse Lewis lung carcinoma cells Matrigel plugs taken from morphine-treated wild-type mice when compared with placebo but was abolished in morphine-treated μ-opioid receptor knockout mice. In addition, in vitro studies using trans-well and electric cell substrate impedance sensing system studies reveal for the first time morphine's inhibitory effects on leukocyte migration and their ability to transmigrate across an activated endothelial monolayer. Taken together, these studies indicate that morphine treatment can potentially decrease leukocyte transendothelial migration and reduce angiogenesis associated with tumor growth. The use of morphine for cancer pain management may be beneficial through its effects on angiogenesis.

The Monocyte to Macrophage Transition in the Murine Sterile Wound

The origin of wound repair macrophages is incompletely defined and was examined here in sterile wounds using the subcutaneous polyvinyl alcohol sponge implantation model in mice. Phenotypic analysis identified F4/80+Ly6ChiCD64+MerTK– monocytes and F4/80+Ly6ClowCD64+MerTK+ macrophages in the wound. Circulating monocytes were the precursors of inflammatory Ly6Chi wound monocytes. Ly6ClowMerTK+ macrophages appeared later, expressed CD206, CD11c, and MHC class II, produced cytokines consistent with repair function, and lacked a gene expression profile compatible with mesenchymal transition or fibroblastic transdifferentiation. Data also demonstrated that Ly6Chi wound cells were precursors of Ly6Clow macrophages, although monocytes did not undergo rapid maturation but rather persisted in the wound as Ly6ChiMerTK– cells. MerTK-deficient mice were examined to determine whether MerTK-dependent signals from apoptotic cells regulated the maturation of wound macrophages. MerTK-deficient mice had day 14 cell compositions that resembled more immature wounds, with a smaller proportion of F4/80+ cells and higher frequencies of Ly6G+ neutrophils and Ly6Chi monocytes. The cytokine profile and number of apoptotic cells in day 14 wounds of MerTK-deficient mice was unaffected despite the alterations in cell composition. Overall, these studies identified a differentiation pathway in response to sterile inflammation in which monocytes recruited from the circulation acquire proinflammatory function, persist in the wound, and mature into repair macrophages.

Retraction notice

The following article has been included in a multiple retraction: Karimi A, Navidbakhsh M and Haghpanahi M. Constitutive model for numerical analysis of polyvinyl alcohol sponge under different strain rates . J Thermoplast Compos Mater, first published on 15 January 2014, DOI: 10.1177/0892705713520176. In 2015 SAGE became aware of author misconduct concerning the suspected fabrication of identities, as well as the impersonation of legitimate individuals, to manipulate the peer review process across three separate journal publications. SAGE and the journal Editors immediately launched an investigation and have decided to retract the following articles for reasons of author misconduct. Alireza Karimi was the submitting author on 12 of the articles. SAGE regrets the academic record was compromised by manipulation of the peer review process and apologises to readers.

A comparative study on the elastic modulus of polyvinyl alcohol sponge using different stress-strain definitions

There have been different stress-strain definitions to measure the elastic modulus of spongy materials, especially polyvinyl alcohol (PVA) sponge. However, there is no agreement as to which stress-strain definition should be implemented. This study was aimed to show how different results are given by the various definitions of stress-strain used, and to recommend a specific definition when testing spongy materials. A fabricated PVA sponge was subjected to a series of tensile tests in order to measure its mechanical properties. Three stress definitions (second Piola-Kichhoff stress, engineering stress, and true stress) and four strain definitions (Almansi-Hamel strain, Green-St. Venant strain, engineering strain, and true strain) were used to determine the elastic modulus. The results revealed that the Almansi-Hamel strain definition exhibited the highest non-linear stress-strain relation and, as a result, may overestimate the elastic modulus at different stress definitions (second Piola-Kichhoff stress, engineering stress, and true stress). The Green-St. Venant strain definition failed to address the non-linear stress-strain relation using different definitions of stress and invoked an underestimation of the elastic modulus values. Engineering stress and strain definitions were only valid for small strains and displacements, which make them impractical when analyzing spongy materials. The results showed that the effect of varying the stress definition on the maximum stress measurements was significant but not when calculating the elastic modulus. It is important to consider which stress-strain definition is employed when characterizing the mechanical properties of spongy materials. Although the true stress-true strain definition exhibits a non-linear relation, we favor it in spongy materials mechanics as it gives more accurate measurements of the material's response using the instantaneous values.

Hybrid Scaffolds Composed of Amino-Acid Coated Sponge and Hydroxyapatite for Hard Tissue Formation by Bone Marrow Cells

A formalin-treated polyvinyl-alcohol (PVF) sponge is convenient as a scaffold because its configuration is easily modified. However, coating the sponge with an adhesive chemical agent is necessary to attach bone marrow cells (BMCs) to the sponge structure. Moreover, it was considered that a hybrid scaffold composed of a sponge and enveloped cylindrical porous hydroxyapatite (HA) would be convenient. In this study, the effect of leucine (Leu) coating on a PVF sponge was examined for osteogenesis on an HA/PVF hybrid scaffold by rat BMCs (rBMCs). In an in vivo assessment, the sponge immersed in Leu solution (10 mg/ml) was inserted into the hollow center of cylindrical HA. The sponge received 1.5 × 106 rBMCs obtained from male Fischer 344 rats. The hybrid scaffolds were then implanted subcutaneously of syngeneic rats for 6 weeks. In vitro assessment of Leu to hard tissue formation with coating on the well or addition in rBMC culture medium was also performed in a 6-well plate for 2 weeks. In vivo examinations showed the excellent effect of Leu coating on PVF sponge. Leu-coated PVF sponge in the scaffolds showed marked new bone formation in the pores by histological examination. Leu-coated PVF sponge showed a high quantity of osteocalcine (OC). HA might prevent the release of rBMCs from PVF as a barrier. In in vitro examinations, the quantity of OC in rBMC culture with and without the addition of Leu in culture medium showed no significant difference. However, addition of Leu showed significant ALP activity level in culture medium. Leu coating in culture plate wells showed no influence on the quantity of OC. It was concluded from the results that Leu might prevent the emigration of rBMCs to the outside of the scaffold and promote the differentiation of cells to osteoblasts in the scaffold.

A visco-hyperelastic constitutive approach for modeling polyvinyl alcohol sponge

This study proposes the quasi-linear viscoelastic (QLV) model to characterize the time dependent mechanical behavior of poly(vinyl alcohol) (PVA) sponges. The PVA sponges have implications in many viscoelastic soft tissues, including cartilage, liver, and kidney as an implant. However, a critical barrier to the use of the PVA sponge as tissue replacement material is a lack of sufficient study on its viscoelastic mechanical properties. In this study, the nonlinear mechanical behavior of a fabricated PVA sponge is investigated experimentally and computationally using relaxation and stress failure tests as well as finite element (FE) modeling. Hyperelastic strain energy density functions, such as Yeoh and Neo-Hookean, are used to capture the mechanical behavior of PVA sponge at ramp part, and viscoelastic model is used to describe the viscose behavior at hold part. Hyperelastic material constants are obtained and their general prediction ability is verified using FE simulations of PVA tensile experiments. The results of relaxation and stress failure tests revealed that Yeoh material model can define the mechanical behavior of PVA sponge properly compared with Neo-Hookean one. FE modeling results are also affirmed the appropriateness of Yeoh model to characterize the mechanical behavior of PVA sponge. Thus, the Yeoh model can be used in future biomechanical simulations of the spongy biomaterials. These results can be utilized to understand the viscoelastic behavior of PVA sponges and has implications for tissue engineering as scaffold.

RETRACTED: Hyperelastic mechanical behavior of rat brain infected by Plasmodium berghei ANKA – Experimental testing and constitutive modeling

The following article has been included in a multiple retraction: Karimi A, Navidbakhsh M, Beigzadeh B, et al. Hyperelastic mechanical behavior of rat brain infected by Plasmodium berghei ANKA – experimental testing and constitutive modelling. Int J Damage Mech 2014;23:857–871, DOI: 10.1177/1056789513514072. In 2015 SAGE became aware of author misconduct concerning the suspected fabrication of identities, as well as the impersonation of legitimate individuals, to manipulate the peer review process across three separate journal publications. SAGE and the journal Editors immediately launched an investigation and have decided to retract the following articles for reasons of author misconduct. Alireza Karimi was the submitting author on 12 of the articles. SAGE regrets the academic record was compromised by manipulation of the peer review process and apologises to readers. OnlineFirst articles (these articles will not be published in an issue) International Journal of Damage Mechanics Karimi A, Navidbakhsh M and Razaghi R. Dynamic finite element simulation of the human head damage mechanics protected by polyvinyl alcohol sponge. Int J Damage Mech, first published on 15 May 2014, DOI: 10.1177/1056789514535945. Journal of Thermoplastic Composite Materials Karimi A, Navidbakhsh M and Haghpanahi M. Constitutive model for numerical analysis of polyvinyl alcohol sponge under different strain rates. J Thermoplast Compos Mater, first published on 15 January 2014, DOI: 10.1177/0892705713520176. Karimi A, Navidbakhsh M, Yousefi H et al. An experimental study on the elastic modulus of gelatin hydrogels using different stress–strain definitions. J Thermoplast Compos Mater, first published on 29 April 2014, DOI: 10.1177/0892705714533377. Elhamian MM, Alizadeh M, Shokrieh MM, et al. An innovative three-dimensional biphasic-laminated composite model for articular cartilage tissue. J Thermoplast Compos Mater, first published on 1 February 2015, DOI: 10.1177/0892705715569821. Perfusion Karimi A, Navidbakhsh M, Yamada H, et al. A comparative study on the quasilinear viscoelastic mechanical properties of the umbilical artery and the umbilical vein. Perfusion, first published on 22 May 2014, DOI: 10.1177/0267659114536761. Tehrani P, Rahmani S, Karimi A, et al. A novel cardiac assist device (AVICENA): a numerical study to compute the generated power. Perfusion, first published on 19 August 2014, DOI: 10.1177/ 0267659114547943. Elhamian SMM, Alizadeh M, Shokrieh MM, et al. The effect of collagen fiber volume fraction on the mechanical properties of articular cartilage by micromechanics models. Perfusion, first published on 20 August 2014, DOI: 10.1177/0267659114547942. Razaghi R, Karimi A, Navidbakhsh M, et al. Determination of the vulnerable plaque in a stenotic human coronary artery – finite element modelling. Perfusion, first published on 28 October 2014, DOI: 10.1177/0267659114557720. Articles published in an issue International Journal of Damage Mechanics Karimi A, Navidbakhsh M, Beigzadeh B, et al. Hyperelastic mechanical behavior of rat brain infected by Plasmodium berghei ANKA – experimental testing and constitutive modelling. Int J Damage Mech 2014;23:857–871, DOI: 10.1177/1056789513514072. Perfusion Karimi A, Navidbakhsh M and Faghihi S. A comparative study on plaque vulnerability using constitutive equations. Perfusion, 2014;29:178–183, DOI: 10.1177/0267659113502835. Abdi M, Karimi A, Navidbakhsh M, et al. Modeling of cerebral aneurysm using equivalent electrical circuit (Lumped Model). Perfusion 2014;29:142–152, DOI: 10.1177/0267659113498617. Karimi A, Navidbakhsh M and Faghihi S. Fabrication and mechanical characterization of a polyvinyl alcohol sponge for tissue engineering applications. Perfusion 2014;29:231–237, DOI: 10.1177/ 0267659113513823. Karimi A, Navidbakhsh M, Yousefi H, et al. Experimental and numerical study on the mechanical behavior of rat brain tissue. Perfusion 2014;29:307–314, DOI: 10.1177/0267659114522088.

Bone Marrow Cell Mobilization by the Systemic Use of Granulocyte Colony-Stimulating Factor (GCSF) Improves Wound Bed Preparation

Innovative approaches are needed to accelerate the healing of human chronic wounds not responding to conventional therapies. An evolving and promising treatment is the use of stem cells. Our group has previously described the use of expanded (in vitro) autologous stem cells aspirated from human bone marrow and applied topically in a fibrin spray to human acute and chronic wounds. More recently, we have sought ways to mobilize stem cells directly from the bone marrow, without in vitro expansion. In this report, we show that systemic injections of granulocyte colony-stimulating factor (GCSF) can mobilize stem cells from bone marrow into the peripheral blood and then to the wound site. Our objectives were to optimize parameters for this method by using mouse models and proof of principle in a human chronic wound situation. Mice were injected for 5 days with 2 different formulations of GCSF and compared to control saline. To monitor stem cell mobilization, flow cytometric measurements of Sca-1 and c-Kit and colony-forming cell assays were performed. Full-thickness tail wounds in mice were created and monitored for healing, and polyvinyl alcohol sponges were implanted dorsally to assess collagen accumulation. To determine bone marrow stem cell homing to the wound site, chimeric mice transplanted with Green Fluorescent Protein bone marrow cells were scanned by live imaging. Additionally, as proof of principle, we tested the systemic GCSF approach in a patient with a nonhealing venous ulcer. Our findings lay the ground work and indicate that the systemic administration of GCSF is effective in mobilizing bone marrow stem cells into the peripheral blood and to the wound site. These findings are associated with an increased accumulation of collagen and promising results in terms of wound bed preparation and healing.

RETRACTED: Fabrication and mechanical characterization of a polyvinyl alcohol sponge for tissue engineering applications

Polyvinyl alcohol (PVA) sponges are widely used for clinical applications, including ophthalmic surgical treatments, wound healing and tissue engineering. There is, however, a lack of sufficient data on the mechanical properties of PVA sponges. In this study, a biomechanical method is used to characterize the elastic modulus, maximum stress and strain as well as the swelling ratio of a fabricated PVA sponge (P-sponge) and it is compared with two commercially available PVA sponges (CENEFOM and EYETEC). The results indicate that the elastic modulus of the P-sponge is 5.32% and 13.45% lower than that of the CENEFOM and EYETEC sponges, while it bears 4.11% more and 10.37% less stress compared to the CENEFOM and EYETEC sponges, respectively. The P-sponge shows a maximum strain of 32% more than the EYETEC sponge as well as a 26.78% higher swelling ratio, which is a significantly higher absorbency compared to the CENEFOM. It is believed that the results of this study would help for a better understanding of the extension, rupture and swelling mechanism of PVA sponges, which could lead to crucial improvement in the design and application of PVA-based materials in ophthalmic and plastic surgeries as well as wound healing and tissue engineering.

Topical Levobupivacaine Efficacy in Pain Control after Functional Endoscopic Sinus Surgery

The aim of this study was to find out the efficacy of a polyvinyl alcohol (PVA) sponge (Merocel Kennedy; Medtronic Xomed, Jacksonville, Florida) sinus pack soaked with levobupivacaine hydrochloride to control postoperative pain and analgesic need following functional endoscopic sinus surgery (FESS). The study was designed as a prospective, double-blind, randomized, controlled study. Forty-one patients who underwent FESS were included in the analysis. Setting A tertiary referral hospital in Turkey. Patients who underwent FESS were divided into 2 groups. The PVA sponge sinus packs were soaked with 5 mL of levobupivacaine hydrochloride (chirocaine 25 mg/10 mL; Abbott, Nycomed Pharma AS, Elverum, Norway) in group I and with 5 mL of saline in group II. Postoperative pain levels were recorded using a visual analog scale (VAS score, 0-100) at 30 minutes and 1, 2, 8, 12, and 24 hours. There were no statistically significant differences between groups regarding age, sex, and American Society of Anesthesiologists status. Postoperative VAS values at 30 minutes and 1, 2, 8, 12, and 24 hours were significantly lower in group I than in group II (P < .05). Supplemental analgesia amount was significantly lower in group I than in group II (P = .003). Using levobupivacaine-soaked PVA sponge sinus packs after FESS is an effective, easy, and quick method to control postoperative pain, and it improves patient comfort and tolerability.

Non spherical polyvinyl alcohol versus gelatin sponge particles for uterine artery embolization for symptomatic fibroids

Purpose:To compare clinical and magnetic resonance imaging (MRI) outcomes after uterine artery embolization (UAE) with non spherical polyvinyl alcohol (nPVA) versus gelatin sponge particles. Material and methods: During ten months, from Jan 2011 to Oct 2011, 60 patients underwent UAE in a standardized manner. nPVA (n = 30) or gelatin sponge particles (n = 30) were used in all patients. Pelvic MRI and clinical symptoms were reviewed before and after the procedure. Changes in tumor, uterine volume and infarction rate of dominant tumor were assessed using MRI. Result:At three months after embolization, the outcome data were collected. The improvement of the mean bleeding score was more pronounced with gelatin sponge particles than with nPVA particles (p = 0.035). The mean volume reduction rate and infarction rate of dominant fibroid were 47.9 ± 20.8%, 97.7 ± 5.2% and 60.2 ± 18.1, 96 ± 7.0% after UAE with nPVA compared to gelatin sponge particles, respectively. Conclusion: This study showed the superiority of gelatin sponge particles over nPVA in terms of improvement of mean bleeding score and volume reduction rate of dominant fibroid at three months follow-up after UAE, although the infarction rate of dominant fibroid was similar across groups at three months.

RETRACTED: Modeling of cerebral aneurysm using equivalent electrical circuit (Lumped Model)

The circle of Willis (CoW) is a key asset in brain performance as it supports adequate blood supply to the brain. The lumped method (electrical equivalent circuits) is a useful model to simulate the process of the human cardiovascular system. In this study, the whole cardiovascular system is modeled, using an equivalent electrical circuit to investigate an aneurysm in an artery. The cerebrovascular system consists of 29 compartments, which includes the CoW. Each vessel is modeled by a resistor, a capacitor and an inductor. Using MATLAB Simulink, the left and right ventricles are modeled by controlled voltage sources and diodes. The effects of the left internal carotid artery aneurysm (Fusiform) on the pressure of the efferent arteries in the circle of Willis are studied. The modeling results are entirely in agreement with the available clinical observations. The results of the present study may have clinical implications for modeling different cardiovascular diseases, such as arterial stiffness and atherosclerosis.

Toll‐like receptor 4 signaling regulates the acute local inflammatory response to injury and the fibrosis/neovascularization of sterile wounds

The role of Toll-like receptor 4 (TLR4) in the regulation of inflammation and fibrosis in sterile wounds was investigated in TLR4 signal-deficient (C3H/HeJ or TLR4(-/-) ) and control mice using the subcutaneously implanted polyvinyl alcohol sponge wound model. Total and differential wound cell counts 1, 3, and 7 days after injury did not differ between C3H/HeJ and C3H/HeOuJ animals. Blood monocytes from both strains expressed CCR2 equally. Day one wounds in C3H/HeJ mice contained fewer Gr-1(high) wound macrophages, CCL3, and CCL5, and more CCL17 than those in controls. The accumulation of CCL2, CX3CL1, tumor necrosis factor-α, interleukin (IL)-6, IL-10, IL-12, and interferon-γ in wound fluids was not TLR4 dependent. Wound macrophages from C3H/HeJ and C3H/HeOuJ mice expressed CCR4 and CCR5, but not CCR1 or CCR3. Wound macrophage recruitment was not altered in CCR5(-/-) mice or in C3H/HeOuJ animals injected with neutralizing anti-CCL3 and anti-CCL5 antibodies. Neutralization of the CCR4 ligand CCL17 in C3H/HeJ mice did not alter wound macrophage populations. There was a twofold increase in collagen content and number of neovessels in 21-day-old wounds in C3H/HeJ vs. C3H/HeOuJ mice. There were no differences between strains in the number of myofibroblasts in the wounds 7 or 21 days postwounding. The increased fibrosis and angiogenesis in wounds from /HeJ mice correlated with higher concentrations of transforming growth factor-β and fibroblast growth factor 2 in wound fluids from these animals. Wound fluids did not contain detectable lipopolysaccharide and did not induce IκBα degradation in J774.A1 macrophages. Results support a role for endogenous ligands of TLR4 in the regulation of inflammation and repair in sterile wounds.