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Sample records for biomechanical in-vitro study

  1. A novel physiological testing device to study knee biomechanics in vitro

    NARCIS (Netherlands)

    van de Bunt, Fabian; Emanuel, Kaj S.; Wijffels, Thomas; Kooren, Peter N.; Kingma, Idsart; Smit, Theodoor H.

    2017-01-01

    Background To properly study knee kinetics, kinematics and the effects of injury and surgical treatment in vitro, the knee should be constrained as little as possible, while imposing physiological loads. A novel dynamic biomechanical knee system (BKS) is presented here. The aim of this study was to

  2. A novel physiological testing device to study knee biomechanics in vitro

    NARCIS (Netherlands)

    van de Bunt, Fabian; Emanuel, Kaj S.; Wijffels, Thomas; Kooren, Peter N.; Kingma, Idsart; Smit, Theodoor H.

    2017-01-01

    Background: To properly study knee kinetics, kinematics and the effects of injury and surgical treatment in vitro, the knee should be constrained as little as possible, while imposing physiological loads. A novel dynamic biomechanical knee system (BKS) is presented here. The aim of this study was to

  3. Stability of the elbow joint: relevant anatomy and clinical implications of in vitro biomechanical studies

    NARCIS (Netherlands)

    de Haan, J.; Schep, N. W. L.; Eygendaal, D.; Kleinrensink, G.-J.; Tuinebreijer, W. E.; den Hartog, D.

    2011-01-01

    The aim of this literature review is to describe the clinical anatomy of the elbow joint based on information from in vitro biomechanical studies. The clinical consequences of this literature review are described and recommendations are given for the treatment of elbow joint dislocation.The PubMed

  4. Stability of the Elbow Joint: Relevant Anatomy and Clinical Implications of In Vitro Biomechanical Studies

    NARCIS (Netherlands)

    J. de Haan (Jeroen); D. Eygendaal (Denise); N.W.L. Schep (Niels); G.J. Kleinrensink (Gert Jan); W.E. Tuinebreijer (Wim); D. den Hartog (Dennis)

    2011-01-01

    textabstractAbstract: The aim of this literature review is to describe the clinical anatomy of the elbow joint based on information from in vitro biomechanical studies. The clinical consequences of this literature review are described and recommendations are given for the treatment of elbow joint

  5. Low-cost microcontroller platform for studying lymphatic biomechanics in vitro.

    Science.gov (United States)

    Kornuta, Jeffrey A; Nipper, Matthew E; Dixon, J Brandon

    2013-01-04

    The pumping innate to collecting lymphatic vessels routinely exposes the endothelium to oscillatory wall shear stress and other dynamic forces. However, studying the mechanical sensitivity of the lymphatic endothelium remains a difficult task due to limitations of commercial or custom systems to apply a variety of time-varying stresses in vitro. Current biomechanical in vitro testing devices are very expensive, limited in capability, or highly complex; rendering them largely inaccessible to the endothelial cell biology community. To address these shortcomings, the authors propose a reliable, low-cost platform for augmenting the capabilities of commercially available pumps to produce a wide variety of flow rate waveforms. In particular, the Arduino Uno, a microcontroller development board, is used to provide open-loop control of a digital peristaltic pump using precisely timed serial commands. In addition, the flexibility of this platform is further demonstrated through its support of a custom-built cell-straining device capable of producing oscillatory strains with varying amplitudes and frequencies. Hence, this microcontroller development board is shown to be an inexpensive, precise, and easy-to-use tool for supplementing in vitro assays to quantify the effects of biomechanical forces on lymphatic endothelial cells. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Biomechanical characteristics of different regions of the human spine: an in vitro study on multilevel spinal segments

    NARCIS (Netherlands)

    Busscher, I.; van Dieen, J.H.; Kingma, I.; van der Veen, A.J.; Verkerke, G.J.; Veldhuizen, A.G.

    2009-01-01

    Study Design: An in vitro study on human multilevel spinal segments. Objective: To determine the differences in biomechanical characteristics between 4 separate regions of the human spine and to provide quantitative information is derived on the range of motion (ROM), neutral zone (NZ), neutral zone

  7. Biomechanical Characteristics of Different Regions of the Human Spine An In Vitro Study on Multilevel Spinal Segments

    NARCIS (Netherlands)

    Busscher, Iris; van Dieen, Jaap H.; Kingma, Idsart; van der Veen, Albert J.; Verkerke, Gijsbertus J.; Veldhuizen, Albert G.

    2009-01-01

    Study Design. An in vitro study on human multilevel spinal segments. Objective. To determine the differences in biomechanical characteristics between 4 separate regions of the human spine and to provide quantitative information is derived on the range of motion (ROM), neutral zone (NZ), neutral zone

  8. In vitro study on bone formation and surface topography from the standpoint of biomechanics.

    Science.gov (United States)

    Kawahara, H; Soeda, Y; Niwa, K; Takahashi, M; Kawahara, D; Araki, N

    2004-12-01

    Effect of surface topography upon cell-adhesion, -orientation and -differentiation was investigated by in vitro study on cellular responses to titanium substratum with different surface roughness. Cell-shape, -function and -differentiation depending upon the surface topography were clarified by use of bone formative group cells (BFGCs) derived from bone marrow of beagle's femur. BFGCs consisted of hematopoietic stem cells (HSC) and osteogenetic stem cells (OSC). Cell differentiation of BFGCs was expressed and promoted by structural changes of cytoskeleton, and cell-organella, which was caused by mechanical stress with cytoplasmic stretching of cell adhesions to the substratum. Phagocytic monocytes of HSC differentiated to osteomediator cells (OMC) by cytoplasmic stretching with cell adhesion to the substratum. The OMC mediated and promoted cell differentiation from OSC to osteoblast through osteoblastic phenotype cell (OBC) by cell-aggregation of nodules with "pile up" phenomenon of OBC onto OMC. The osteogenesis might be performed by coupling work of both cells, OMC originated from monocyte of HSC and OBC originated from OSC, which were explained by SEM, TEM and fluorescent probe investigation on BFGCs on the test plate of cp titanium plates with different topographies. This osteogenetic process was proved by investigating cell proliferation, DNA contents, cell-adhesion, alkaline phosphatase activity and osteocalcine productivity for cells on the titanium plates with different topographies. The study showed increased osteogenic effects for cells cultured on Ti with increased surface roughness. Possible mechanisms were discussed from a biomechanical perspective.

  9. [Foot stress simulator for biomechanical in vitro studies of lower leg segments].

    Science.gov (United States)

    Rosenbaum, D; Schmitt, H; Bertsch, C; Bauer, G; Claes, L

    1996-05-01

    In this paper we describe a foot-loading simulator that permits in vitro studies on human lower leg and foot specimens. The specimens are fixed in a jig and loaded axially with the aid of a pneumatic cylinder. The resulting transfer of forces through the ankle joint complex and Chopart's articulation (line) can be demonstrated on a pressure-sensitive film. Plantar pressure measurements obtained in patients or normal subjects can be used to ensure the comparability of in vivo and in vitro measurements. The supporting platform can be tilted in such a manner as to provide a range of foot positions up to 20 degrees in plantar- or dorsiflexion, eversion or inversion. The system is used for investigating the effects on the intra-articular pressures and plantar pressure patterns of physiological muscle activity and pathological conditions following fracture of the calcaneum or damage to the lateral ligament. By way of an example, the effects of muscle forces on plantar pressure distribution are presented.

  10. An in-vitro biomechanical study of different fixation techniques for the extended trochanteric osteotomy in revision THA.

    Science.gov (United States)

    Zhu, Zhonglin; Ding, Hui; Shao, Hongyi; Zhou, Yixin; Wang, Guangzhi

    2013-04-09

    The wire fixation and the cable grip fixation have been developed for the extended trochanteric osteotomy (ETO) in the revision of total hip arthroplasty (THA). Many studies reported the postoperative performance of the patients, but with little quantitative biomechanical comparison of the two fixation systems. An in-vitro testing approach was designed to record the loosening between the femoral bed and the greater trochanter after fixations. Ten cadaveric femurs were chosen in this study. Each femur underwent the THA, revision by ETO and fixations. The tension to the greater trochanter was from 0 to 500N in vertical and lateral direction, respectively. The translation and rotation of the greater trochanter with respect to the bony bed were captured by an optical tracking system. In the vertical tension tests, the overall translation of the greater trochanter was observed 0.4 mm in the cable fixations and 7.0 mm in the wire fixations. In the lateral tension tests, the overall motion of the greater trochanter was 2.0 mm and 1.2° in the cable fixations, while it was 6.2 mm and 5.3° in the wire fixations. The result was significantly different between the two fixation systems. The stability of the proximal femur after ETO using different fixations in the revision THA was investigated. The cable grip fixation was significantly more stable than the wire fixation.

  11. In-vivo corneal pulsation in relation to in-vivo intraocular pressure and corneal biomechanics assessed in-vitro. An animal pilot study.

    Science.gov (United States)

    Rogala, Maja M; Danielewska, Monika E; Antończyk, Agnieszka; Kiełbowicz, Zdzisław; Rogowska, Marta E; Kozuń, Marta; Detyna, Jerzy; Iskander, D Robert

    2017-09-01

    The aim was to ascertain whether the characteristics of the corneal pulse (CP) measured in-vivo in a rabbit eye change after short-term artificial increase of intraocular pressure (IOP) and whether they correlate with corneal biomechanics assessed in-vitro. Eight New Zealand white rabbits were included in this study and were anesthetized. In-vivo experiments included simultaneous measurements of the CP signal, registered with a non-contact method, IOP, intra-arterial blood pressure, and blood pulse (BPL), at the baseline and short-term elevated IOP. Afterwards, thickness of post-mortem corneas was determined and then uniaxial tensile tests were conducted leading to estimates of their Young's modulus (E). At the baseline IOP, backward stepwise regression analyses were performed in which successively the ocular biomechanical, biometric and cardiovascular predictors were separately taken into account. Results of the analysis revealed that the 3rd CP harmonic can be statistically significantly predicted by E and central corneal thickness (Models: R 2  = 0.662, p biomechanics in-vitro was confirmed. In particular, spectral analysis revealed that higher amplitude and power of the 3rd CP harmonic indicates higher corneal stiffness, while the 1st CP harmonic correlates positively with the corresponding harmonic of the BPL signal. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Direct lateral approach to lumbar fusion is a biomechanically equivalent alternative to the anterior approach: an in vitro study.

    Science.gov (United States)

    Laws, Cory J; Coughlin, Dezba G; Lotz, Jeffrey C; Serhan, Hassan A; Hu, Serena S

    2012-05-01

    A human cadaveric biomechanical study of lumbar mobility before and after fusion and with or without supplemental instrumentation for 5 instrumentation configurations. To determine the biomechanical differences between anterior lumbar interbody fusion (ALIF) and direct lateral interbody fusion (DLIF) with and without supplementary instrumentation. Some prior studies have compared various surgical approaches using the same interbody device whereas others have investigated the stabilizing effect of supplemental instrumentation. No published studies have performed a side-by-side comparison of standard and minimally invasive techniques with and without supplemental instrumentation. Eight human lumbosacral specimens (16 motion segments) were tested in each of the 5 following configurations: (1) intact, (2) with ALIF or DLIF cage, (3) with cage plus stabilizing plate, (4) with cage plus unilateral pedicle screw fixation (PSF), and (5) with cage plus bilateral PSF. Pure moments were applied to induce specimen flexion, extension, lateral bending, and axial rotation. Three-dimensional kinematic responses were measured and used to calculate range of motion, stiffness, and neutral zone. Compared to the intact state, DLIF significantly reduced range of motion in flexion, extension, and lateral bending (P = 0.0117, P = 0.0015, P = 0.0031). Supplemental instrumentation significantly increased fused-specimen stiffness for both DLIF and ALIF groups. For the ALIF group, bilateral PSF increased stiffness relative to stand-alone cage by 455% in flexion and 317% in lateral bending (P = 0.0009 and P < 0.0001). The plate increased ALIF group stiffness by 211% in extension and 256% in axial rotation (P = 0.0467 and P = 0.0303). For the DLIF group, bilateral PSF increased stiffness by 350% in flexion and 222% in extension (P < 0.0001 and P = 0.0008). No differences were observed between ALIF and DLIF groups supplemented with bilateral PSF. Our data support that the direct lateral approach

  13. Biomechanical study in vitro on the use of self-designed external fixator in diaphyseal III metacarpal fractures in horses.

    Science.gov (United States)

    Turek, B; Potyński, A; Wajler, C; Szara, T; Czopowicz, M; Drewnowska, O

    2015-01-01

    Diaphyseal fractures of the III metacarpal bone represent 22% of all fractures of the long bones in horses. Treatment of such cases is difficult. The most popular solution used in these types of fractures is two plates applied directly to the bone surface, but they are not applicable on contaminated and infected fractures. External fixators are quite commonly used in human medicine, although in veterinary practice there is no typical stabilizer designed for the treatment of diaphyseal fractures of the III metacarpal bone so far. In this study, an external semicircular fixator of our own design was used and in vitro strength tests were conducted to determine the maximum force which would lead to the destruction of non-fractured bone and fractured bone treated with the stabilizer. On the basis of the strength tests, we can conclude that the stabilizer can be strong enough to allow the horse to stand up after surgery. It also has many favorable features which make it easy to assemble and to take care of a wound, while being safe enough for the animal at the same time.

  14. Biopolymer augmentation of the lag screw in the treatment of femoral neck fractures - a biomechanical in-vitro study

    Directory of Open Access Journals (Sweden)

    Paech A

    2010-04-01

    Full Text Available Abstract The cut-out of the sliding screw is one of the most common complications in the treatment of intertrochanteric fractures. The reasons for the cut-out are: a suboptimal position of the hip-screw in the femoral head, the type of fracture and poor bone quality. The aim of this study was to reproduce the cut-out event biomechanically and to evaluate the possible prevention of this event by the use of a biopolymer augmentation of the hip screw. Concerning the density and compression force of osteoporotic femoral bone polyurethane foam according to the terms of the Association for Standard Testing Material (ASTMF 1839-97 was used as test material. The polyurethane foam Lumoltan 200 with a compression force of 3.3 Mpa and a density of 0.192 g/cm3 was used to reproduce the osteoporotic bone of the femoral fragment (density 12 lbm/ft3. A cylinder of 50 mm of length and 50 mm of width was produced by a rotary splint raising procedure with planar contact. The axial load of the system was performed by a hydraulic force cylinder of a universal test machine type Zwick 1455, Ulm, Germany. The CCD-angle of the used TGN-System was preset at 130 degrees. The migration pattern of the hip screw in the polyurethane foam was measured and expressed as a curve of the distance in millimeter [mm] against the applied load in Newton [N] up to the cut-out point. During the tests the implants reached a critical changing point from stable to unstable with an increased load progression of steps of 50 Newton. This unstable point was characterized by an increased migration speed in millimeters and higher descending gradient in the migration curve. This peak of the migration curve served as an indicator for the change of the hip screw position in the simulated bone material. The applied load in the non-augmented implant showed that in this group for a density degree of 12 (0,192 g/cm3 the mean force at the failure point was 1431 Newton (± 52 Newton. In the augmented

  15. Pullout characteristics of percutaneous pedicle screws with different cement augmentation methods in elderly spines: An in vitro biomechanical study.

    Science.gov (United States)

    Charles, Y P; Pelletier, H; Hydier, P; Schuller, S; Garnon, J; Sauleau, E A; Steib, J-P; Clavert, P

    2015-05-01

    Vertebroplasty prefilling or fenestrated pedicle screw augmentation can be used to enhance pullout resistance in elderly patients. It is not clear which method offers the most reliable fixation strength if axial pullout and a bending moment is applied. The purpose of this study is to validate a new in vitro model aimed to reproduce a cut out mechanism of lumbar pedicle screws, to compare fixation strength in elderly spines with different cement augmentation techniques and to analyze factors that might influence the failure pattern. Six human specimens (82-100 years) were instrumented percutaneously at L2, L3 and L4 by non-augmented screws, vertebroplasty augmentation and fenestrated screws. Cement distribution (2 ml PMMA) was analyzed on CT. Vertebral endplates and the rod were oriented at 45° to the horizontal plane. The vertebral body was held by resin in a cylinder, linked to an unconstrained pivot, on which traction (10 N/s) was applied until rupture. Load-displacement curves were compared to simultaneous video recordings. Median pullout forces were 488.5 N (195-500) for non-augmented screws, 643.5 N (270-1050) for vertebroplasty augmentation and 943.5 N (750-1084) for fenestrated screws. Cement augmentation through fenestrated screws led to significantly higher rupture forces compared to non-augmented screws (P=0.0039). The pullout force after vertebroplasty was variable and linked to cement distribution. A cement bolus around the distal screw tip led to pullout forces similar to non-augmented screws. A proximal cement bolus, as it was observed in fenestrated screws, led to higher pullout resistance. This cement distribution led to vertebral body fractures prior to screw pullout. The experimental setup tended to reproduce a pullout mechanism observed on radiographs, combining axial pullout and a bending moment. Cement augmentation with fenestrated screws increased pullout resistance significantly, whereas the fixation strength with the vertebroplasty

  16. The biomechanical effect of transverse connectors use in a pre- and postlaminectomy model of the posterior cervical spine: an in vitro cadaveric study.

    Science.gov (United States)

    Majid, Kamran; Gudipally, Manasa; Hussain, Mir; Moldavsky, Mark; Khalil, Saif

    2011-12-15

    An in vitro biomechanical study investigating the effect of transverse connectors on posterior cervical stabilization system in a laminectomy model. To evaluate the optimal design, number, and location of the transverse connectors in stabilizing long segment posterior instrumentation in the cervical spine. In the cervical spine, lateral mass screw (LMS) fixation is used for providing stability after decompression. Transverse connectors have been used to augment segmental posterior instrumentation. However, in the cervical region the optimal design, number, and the location of transverse connectors is not known. Seven fresh human cervicothoracic cadaveric spines (C2-T1) were tested by applying ±1.5 Nm moments in flexion (F), extension (E), lateral bending (LB), and axial rotation (AR). After testing the intact condition, LMS/rods were placed and then were tested with two different transverse connectors (top-loading connector [TL] and the head-to-head [HH] connector) in multiple levels, pre- and postlaminectomy (PL). LMS significantly reduced segmental motion by 77.2% in F, 75.6% in E, 86.6% in LB, and 86.1% in AR prelaminectomy and by 75.4% in F, 76% in E, 80.6% in LB, and 76.4% in AR postlaminectomy compared to intact (P transverse connectors is significant in AR, when using two connectors at the proximal and distal ends, compared to one connector. In a clinical setting, this data may guide surgeons on transverse connector configurations to consider during posterior cervical instrumentation.

  17. Kinematics and load-sharing of an anterior thoracolumbar spinal reconstruction construct with PEEK rods: An in vitro biomechanical study.

    Science.gov (United States)

    Zhou, Ruozhou; Huang, Zhiping; Liu, Xiang; Tong, Jie; Ji, Wei; Liu, Sheting; Zhu, Qingan

    2016-12-01

    Polyetheretherketone rod constructs provide adequate spinal stability. Kinematics and load sharing of anterior thoracolumbar reconstruction with polyetheretherketone rods under preload remains unknown. Eight human cadaveric specimens (T11-L3) were subjected to a pure moment of 5.0Nm in flexion-extension, lateral bending and axial rotation, and flexion-extension with a compressive preload of 300N. An anterior reconstruction of L1 corpectomy was conducted with a surrogate bone graft and anterior rod constructs (polyetheretherketone or titanium rods). An axial load-cell was built in the surrogate bone graft to measure the compressive force in the graft. Range of motion, neutral zone and compressive force in the graft were compared between constructs. The polyetheretherketone rod construct resulted in more motion than the titanium rod construct, particularly in extension (P=0.011) and axial rotation (P=0.001), but less motion than the intact in all directions except in axial rotation. There was no difference in range of motion or neutral zone between constructs in flexion-extension under preload. The polyetheretherketone rod construct kept the graft compressed 52N which was similar to the titanium rod construct (63N), but allowed the graft compressed more under the preload (203N vs. 123N, P=0.003). The compressive forces fluctuated in flexion-extension without preload, but increased in flexion and decreased in extension under preload. The polyetheretherketone rod construct allowed more motion compared to the titanium rod construct, but provided stability in flexion and lateral bending without preload, and flexion and extension under preload. The anterior graft shared higher load under preload, particularly for the polyetheretherketone rod construct. The results of this study suggest that rigidity of rods in the anterior reconstruction affects kinematic behavior and load sharing. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Evaluation of standardized porcine bone models to test primary stability of dental implants, using biomechanical tests and Micro-CT. An in vitro pilot study

    Directory of Open Access Journals (Sweden)

    C. Delmondes Freitas Dantas

    2015-06-01

    Full Text Available Aim This study evaluated a new porcine bone model to test the primary stability of different implants, analyzing Micro-CT, insertion torque, and pull-out strength. Materials and methods Bone cylinders were prepared from porcine bone and separated into 2 groups: 10 high density bone cylinders (HDB, and 10 low density bone cylinders (LDB. Then, 3D pre-implant analyses were performed, evaluating tridimensional bone density (ratio of trabecular bone volume and total tomographic volume, BV/TV, trabecular separation; percentage of closed pores; percentage of open pores; percentage of total porosity, in 3 bone levels (L1 bone volume corresponding to the internal part of the threads; L2 corresponding to the area between 0 to 0.5 mm from the end of threads; L3 corresponding to the area between 0.5 to 1.5 mm from the end of threads. Twenty implants of two different macrostructures were inserted in the bone cylinders, and divided into 4 groups (5 implants each: Group 1, e-Fix HE implant placed in HDB cylinder; Group 2, e-Fix HE implant in LDB cylinder; Group 3, e-Fix HE Silver implant placed in HDB cylinder; Group 4, e-Fix HE Silver implant in LDB cylinder. The insertion torque was recorded and bone cylinders were re-evaluated by Micro-CT (post-implant analysis. Then a pull-out strength test was performed. Results 3D analysis showed that pre- and post-implants intra-groups evaluation had statistically significant differences in Group 3 and 4, for all tomographic parameters assessed. Group 3 showed the best values for biomechanical tests (Friedman Test, p<0.05. Conclusion This methodology can produce standardized bone cylinders of high and low bone density, in which different implant designs are able to promote different effects, evidenced by biomechanical and image analysis.

  19. Creation of an in vitro biomechanical model of the trachea using rapid prototyping.

    Science.gov (United States)

    Walenga, Ross L; Longest, P Worth; Sundaresan, Gobalakrishnan

    2014-06-03

    Previous in vitro models of the airways are either rigid or, if flexible, have not matched in vivo compliance characteristics. Rapid prototyping provides a quickly evolving approach that can be used to directly produce in vitro airway models using either rigid or flexible polymers. The objective of this study was to use rapid prototyping to directly produce a flexible hollow model that matches the biomechanical compliance of the trachea. The airway model consisted of a previously developed characteristic mouth-throat region, the trachea, and a portion of the main bronchi. Compliance of the tracheal region was known from a previous in vivo imaging study that reported cross-sectional areas over a range of internal pressures. The compliance of the tracheal region was matched to the in vivo data for a specific flexible resin by iteratively selecting the thicknesses and other dimensions of tracheal wall components. Seven iterative models were produced and illustrated highly non-linear expansion consisting of initial rapid size increase, a transition region, and continued slower size increase as pressure was increased. Thickness of the esophageal interface membrane and initial trachea indention were identified as key parameters with the final model correctly predicting all phases of expansion within a value of 5% of the in vivo data. Applications of the current biomechanical model are related to endotracheal intubation and include determination of effective mucus suctioning and evaluation of cuff sealing with respect to gases and secretions. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Biomechanical in vitro evaluation of three stable internal fixation techniques used in sagittal osteotomy of the mandibular ramus: a study in sheep mandibles

    Directory of Open Access Journals (Sweden)

    Leandro Benetti de Olivera

    2012-08-01

    Full Text Available Among the osteotomies performed in orthognathic surgery, the sagittal osteotomy of the mandibular ramus (SOMR is the most common, allowing a great range of movements and stable internal fixation (SIF, therefore eliminating the need of maxillomandibular block in the postoperative period. OBJECTIVES: The purpose of this study was to evaluate the biomechanical resistance of three national systems used for SIF in SOMR in sheep mandibles. MATERIAL AND METHODS: The study was performed in 30 sheep hemi-mandibles randomly divided into 3 experimental groups, each containing 10 hemi-mandibles. The samples were measured to avoid discrepancies and then subjected to SOMR with 5-mm advancement. In group I, 2.0x12 mm screws were used for fixation, inserted in an inverted "L" pattern (inverted "L" group. In group II, fixation was performed with two 2.0x12 mm screws, positioned in a linear pattern and a 4-hole straight miniplate and four 2.0x6.0 mm monocortical screws (hybrid group. In group III, fixation was performed with two 4-hole straight miniplates and eight 2.0x6.0 mm monocortical screws (mini plate group. All materials used for SIF were supplied by Osteosin - SIN. The hemimandibles were subjected to vertical linear load test by Kratos K2000MP mechanical testing unit for loading registration and displacement. RESULTS: All groups showed similar resistance during mechanical test for loading and displacement, with no statistically significant differences between groups according to analysis of variance. CONCLUSION: These results indicate that the three techniques of fixation are equally effective for clinical fixation of SOMR.

  1. In vitro-analysis of kinematics and intradiscal pressures in cervical arthroplasty versus fusion--A biomechanical study in a sheep model with two semi-constrained prosthesis.

    Science.gov (United States)

    Daentzer, Dorothea; Welke, Bastian; Hurschler, Christof; Husmann, Nathalie; Jansen, Christina; Flamme, Christian Heinrich; Richter, Berna Ida

    2015-03-24

    investigated. The results of this biomechanical study indicate that single-level implantation of semi-constrained TDR lead to a certain hypermobility in the treated segments with lowering the ROM in the adjacent levels in almost all situations.

  2. Measurement system for an in-vitro characterization of the biomechanics and hemodynamics of arterial bifurcations

    International Nuclear Information System (INIS)

    Suárez-Bagnasco, D; Balay, G; Negreira, C A; Cymberknop, L; Armentano, R L

    2013-01-01

    Arterial behaviour in-vivo is influenced, amongst other factors, by the interaction between blood flow and the arterial wall endothelium, and the biomechanical properties of the arterial wall. This interaction plays an important role in pathogenic mechanisms of cardiovascular diseases such as atherosclerosis and arteriosclerosis. To quantify these interactions both from biomechanical and hemodynamical standpoints, a complete characterization and modelling of the arterial wall, blood flow, shear wall and circumferential wall stresses are needed. The development of a new multi-parameter measurement system (distances, pressures, flows, velocity profiles, temperature, viscosity) for an in-vitro characterization of the biomechanics and hemodynamics in arterial bifurcations (specially in carotid bifurcations) is described. This set-up represents an improvement relative to previous set-ups developed by the group FCIEN-FMED and is presently under development. Main subsystems interactions and environment-system interactions were identified and compensated to improve system's performance. Several interesting problems related with signal acquisition using a variety of sensors and some experimental results are shown and briefly discussed. Experimental data allow construction of meshes and parameter estimation of the biomechanical properties of the arterial wall, as well as boundary conditions, all suitable to be employed in CFD and FSI numerical simulation.

  3. Pull out Strength of Dual Outer Diameter Pedicle Screws Compared to Uncemented and Cemented Standard Pedicle Screws: A Biomechanical in vitro Study.

    Science.gov (United States)

    Lorenz, Andrea; Leichtle, Carmen I; Frantz, Sandra; Bumann, Marte; Tsiflikas, Ilias; Shiozawa, Thomas; Leichtle, Ulf G

    2017-05-01

    To analyze the potential of the dual outer diameter screw and systematically evaluate the pull-out force of the dual outer diameter screw compared to the uncemented and cemented standard pedicle screws with special regard to the pedicle diameter and the vertebra level. Sixty vertebrae of five human spines (T 6 -L 5 ) were sorted into three study groups for pairwise comparison of the uncemented dual outer diameter screw, the uncemented standard screw, and the cemented standard screw, and randomized with respect to bone mineral density (BMD) and vertebra level. The vertebrae were instrumented, insertion torque was determined, and pull-out testing was performed using a material testing machine. Failure load was evaluated in pairwise comparison within each study group. The screw-to-pedicle diameter ratio was determined and the uncemented dual outer diameter and standard screws were compared for different ratios as well as vertebra levels. Significantly increased pull-out forces were measured for the cemented standard screw compared to the uncemented standard screw (+689 N, P dual outer diameter screw (+403 N, P dual outer diameter screw to the uncemented standard screw in the total study group, a distinct but not significant increase was measured (+149 N, P = 0.114). Further analysis of these two screws, however, revealed a significant increase of pull-out force for the dual outer diameter screw in the lumbar region (+247 N, P = 0.040), as well as for a screw-to-pedicle diameter ratio between 0.6 and 1 (+ 488 N, P = 0.028). For clinical application, cement augmentation remains the gold standard for increasing screw stability. According to our results, the use of a dual outer diameter screw is an interesting option to increase screw stability in the lumbar region without cement augmentation. For the thoracic region, however, the screw-to-pedicle diameter should be checked and attention should be paid to screw cut out, if the dual outer diameter screw is considered.

  4. In vitro method for assessing the biomechanics of the patellofemoral joint following total knee arthroplasty.

    Science.gov (United States)

    Coles, L G; Gheduzzi, S; Miles, A W

    2014-12-01

    The patellofemoral joint is a common site of pain and failure following total knee arthroplasty. A contributory factor may be adverse patellofemoral biomechanics. Cadaveric investigations are commonly used to assess the biomechanics of the joint, but are associated with high inter-specimen variability and often cannot be carried out at physiological levels of loading. This study aimed to evaluate the suitability of a novel knee simulator for investigating patellofemoral joint biomechanics. This simulator specifically facilitated the extended assessment of patellofemoral joint biomechanics under physiological levels of loading. The simulator allowed the knee to move in 6 degrees of freedom under quadriceps actuation and included a simulation of the action of the hamstrings. Prostheses were implanted on synthetic bones and key soft tissues were modelled with a synthetic analogue. In order to evaluate the physiological relevance and repeatability of the simulator, measurements were made of the quadriceps force and the force, contact area and pressure within the patellofemoral joint using load cells, pressure-sensitive film, and a flexible pressure sensor. The results were in agreement with those previously reported in the literature, confirming that the simulator is able to provide a realistic physiological loading situation. Under physiological loading, average standard deviations of force and area measurements were substantially lower and comparable to those reported in previous cadaveric studies, respectively. The simulator replicates the physiological environment and has been demonstrated to allow the initial investigation of factors affecting patellofemoral biomechanics following total knee arthroplasty. © IMechE 2014.

  5. Three-dimensional biomechanical properties of human vocal folds: Parameter optimization of a numerical model to match in vitro dynamics

    Science.gov (United States)

    Yang, Anxiong; Berry, David A.; Kaltenbacher, Manfred; Döllinger, Michael

    2012-01-01

    The human voice signal originates from the vibrations of the two vocal folds within the larynx. The interactions of several intrinsic laryngeal muscles adduct and shape the vocal folds to facilitate vibration in response to airflow. Three-dimensional vocal fold dynamics are extracted from in vitro hemilarynx experiments and fitted by a numerical three-dimensional-multi-mass-model (3DM) using an optimization procedure. In this work, the 3DM dynamics are optimized over 24 experimental data sets to estimate biomechanical vocal fold properties during phonation. Accuracy of the optimization is verified by low normalized error (0.13 ± 0.02), high correlation (83% ± 2%), and reproducible subglottal pressure values. The optimized, 3DM parameters yielded biomechanical variations in tissue properties along the vocal fold surface, including variations in both the local mass and stiffness of vocal folds. That is, both mass and stiffness increased along the superior-to-inferior direction. These variations were statistically analyzed under different experimental conditions (e.g., an increase in tension as a function of vocal fold elongation and an increase in stiffness and a decrease in mass as a function of glottal airflow). The study showed that physiologically relevant vocal fold tissue properties, which cannot be directly measured during in vivo human phonation, can be captured using this 3D-modeling technique. PMID:22352511

  6. In vitro biomechanical and biocompatible evaluation of natural hydroxyapatite/chitosan composite for bone repair.

    Science.gov (United States)

    Lü, Xiaoying; Zheng, Buzhong; Tang, Xiaojun; Zhao, Lifeng; Lu, Jieyan; Zhang, Zhiwei; Zhang, Jizhong; Cui, Wei

    2011-01-01

    To evaluate the biomechanical properties and biocompatibility of natural hydroxyapatite/chitosan (HA/CS) composites. The natural HA/CS composites with a different proportion of HA and CS were prepared by the cross-linking method, and then the compressive strength, microstructure and pH values of extracts from these composites were measured by SEM and pH meter, respectively. Subsequently, the biocompatibility of the composites was evaluated by means of a series of biological tests, including MTT, acute systemic toxicity, heat source, and hemolysis tests in vitro. The chitosan content in the composites had significantly influenced the mechanical properties and microstructure of the composites. The pH value of the composite extract was approximately 7.0, which was very close to that of human plasma. Furthermore, the natural HA/CS composites showed no cytotoxicity, irritation, teratogenicity, carcinogenicity and special pyrogen. These results indicated that the natural HA/CS composite may be a potential bone repair material.

  7. Biomechanical study of percutaneous lumbar diskectomy

    International Nuclear Information System (INIS)

    Li Yuan; Huang Xianglong; Shen Tianzhen; Hu Zhou; Hong Shuizong; Mei Haiying

    2003-01-01

    Objective: To investigate the stiffness of lumbar spine after the injury caused by percutaneous diskectomy and evaluate the efficiency of percutaneous lumbar diskectomy by biomechanical study. Methods: Four fresh lumbar specimens were used to analyse load-displacement curves in the intact lumbar spine and vertical disc-injured lumbar spine. The concepts of average flexibility coefficient (f) and standardized average flexibility coefficient (fs) were also introduced. Results: The load-displacement curves showed a good stabilization effect of the intact lumbar spine and disc-injured lumbar spine in flexion, extension, right and left bending. The decrease of anti-rotation also can be detected (P<0.05). Conclusion: In biomechanical study, percutaneous lumbar diskectomy is one of the efficiency methods to treat lumbar diac hernia

  8. Evaluation of a minimally invasive procedure for sacroiliac joint fusion – an in vitro biomechanical analysis of initial and cycled properties

    Directory of Open Access Journals (Sweden)

    Lindsey DP

    2014-05-01

    Full Text Available Derek P Lindsey,1 Luis Perez-Orribo,2 Nestor Rodriguez-Martinez,2 Phillip M Reyes,2 Anna Newcomb,2 Alexandria Cable,2 Grace Hickam,2 Scott A Yerby,1 Neil R Crawford21SI-BONE, Inc., San Jose, CA, USA; 2Spinal Biomechanics Research Laboratory, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, AZ, USAIntroduction: Sacroiliac (SI joint pain has become a recognized factor in low back pain. The purpose of this study was to investigate the effect of a minimally invasive surgical SI joint fusion procedure on the in vitro biomechanics of the SI joint before and after cyclic loading.Methods: Seven cadaveric specimens were tested under the following conditions: intact, posterior ligaments (PL and pubic symphysis (PS cut, treated (three implants placed, and after 5,000 cycles of flexion–extension. The range of motion (ROM in flexion–extension, lateral bending, and axial rotation was determined with an applied 7.5 N • m moment using an optoelectronic system. Results for each ROM were compared using a repeated measures analysis of variance (ANOVA with a Holm–Šidák post-hoc test.Results: Placement of three fusion devices decreased the flexion–extension ROM. Lateral bending and axial rotation were not significantly altered. All PL/PS cut and post-cyclic ROMs were larger than in the intact condition. The 5,000 cycles of flexion–extension did not lead to a significant increase in any ROMs.Discussion: In the current model, placement of three 7.0 mm iFuse Implants significantly decreased the flexion–extension ROM. Joint ROM was not increased by 5,000 flexion–extension cycles.Keywords: biomechanics, iliosacral, arthrodesis, cadaver

  9. Biomechanical studies: science (f)or common sense?

    NARCIS (Netherlands)

    Mellema, Jos J.; Doornberg, Job N.; Guitton, Thierry G.; Ring, David; van der Zwan, A. L.; Spoor, A. B.; van Vugt, A. B.; Armstrong, A. D.; Shrivastava, A.; Wahegaonkar, A. L.; Shafritz, A. B.; Adams, J.; Ilyas, A.; Vochteloo, A. J. H.; Castillo, A. P.; Basak, A.; Andreas, P.; Barquet, A.; Kristan, A.; Berner, A.; Ranade, A. B.; Ashish, S.; Terrono, A. L.; Jubel, A.; Frieman, B.; Bamberger, H. B.; van den Bekerom, M. P. J.; Belangero, W. D.; Hearon, B. F.; Boler, J. M.; Walter, F. L.; Boyer, M.; Wills, B. P. D.; Broekhuyse, H.; Buckley, R.; Watkins, B.; Sears, B. W.; Calfee, R. P.; Ekholm, C.; Fernandes, C. H.; Swigart, C.; Cassidy, C.; Wilson, C. J.; Bainbridge, L. C.; Wilson, C.; Eygendaal, D.; Goslings, J. C.; Schep, N.; Kloen, P.; Haverlag, R.

    2014-01-01

    It is our impression that many biomechanical studies invest substantial resources studying the obvious: that more and larger metal is stronger. The purpose of this study is to evaluate if a subset of biomechanical studies comparing fixation constructs just document common sense. Using a web-based

  10. Biomechanical regulation of in vitro cardiogenesis for tissue-engineered heart repair.

    Science.gov (United States)

    Zimmermann, Wolfram-Hubertus

    2013-01-01

    The heart is a continuously pumping organ with an average lifespan of eight decades. It develops from the onset of embryonic cardiogenesis under biomechanical load, performs optimally within a defined range of hemodynamic load, and fails if acutely or chronically overloaded. Unloading of the heart leads to defective cardiogenesis in utero, but can also lead to a desired therapeutic outcome (for example, in patients with heart failure under left ventricular assist device therapy). In light of the well-documented relevance of mechanical loading for cardiac physiology and pathology, it is plausible that tissue engineers have integrated mechanical stimulation regimens into protocols for heart muscle construction. To achieve optimal results, physiological principles of beat-to-beat myocardial loading and unloading should be simulated. In addition, heart muscle engineering, in particular if based on pluripotent stem cell-derived cardiomyocytes, may benefit from staggered tonic loading protocols to simulate viscoelastic properties of the prenatal and postnatal myocardial stroma. This review will provide an overview of heart muscle mechanics, summarize observations on the role of mechanical loading for heart development and postnatal performance, and discuss how physiological loading regimens can be exploited to advance myocardial tissue engineering towards a therapeutic application.

  11. In vitro toxicological nanoparticle studies under flow exposure

    Energy Technology Data Exchange (ETDEWEB)

    Sambale, Franziska, E-mail: sambale@iftc.uni-hannover.de; Stahl, Frank; Bahnemann, Detlef; Scheper, Thomas [Gottfried Wilhelm Leibniz University Hanover, Institute for Technical Chemistry (Germany)

    2015-07-15

    The use of nanoparticles is becoming increasingly common in industry and everyday objects. Thus, extensive risk management concerning the potential health risk of nanoparticles is important. Currently, in vitro nanoparticle testing is mainly performed under static culture conditions without any shear stress. However, shear stress is an important biomechanical parameter. Therefore, in this study, a defined physiological flow to different mammalian cell lines such as A549 cells and NIH-3T3 cells has been applied. The effects of zinc oxide and titanium dioxide nanoparticles (TiO{sub 2}-NP), respectively, were investigated under both static and dynamic conditions. Cell viability, cell morphology, and adhesion were proven and compared to the static cell culture. Flow exposure had an impact on the cellular morphology of the cells. NIH-3T3 cells were elongated in the direction of flow and A549 cells exhibited vesicles inside the cells. Zinc oxide nanoparticles reduced the cell viability in the static and in the dynamic culture; however, the dynamic cultures were more sensitive. In the static culture and in the dynamic culture, TiO{sub 2}-NP did not affect cell viability. In conclusion, dynamic culture conditions are important for further in vitro investigations and provide more relevant results than static culture conditions.

  12. In vitro toxicological nanoparticle studies under flow exposure

    International Nuclear Information System (INIS)

    Sambale, Franziska; Stahl, Frank; Bahnemann, Detlef; Scheper, Thomas

    2015-01-01

    The use of nanoparticles is becoming increasingly common in industry and everyday objects. Thus, extensive risk management concerning the potential health risk of nanoparticles is important. Currently, in vitro nanoparticle testing is mainly performed under static culture conditions without any shear stress. However, shear stress is an important biomechanical parameter. Therefore, in this study, a defined physiological flow to different mammalian cell lines such as A549 cells and NIH-3T3 cells has been applied. The effects of zinc oxide and titanium dioxide nanoparticles (TiO 2 -NP), respectively, were investigated under both static and dynamic conditions. Cell viability, cell morphology, and adhesion were proven and compared to the static cell culture. Flow exposure had an impact on the cellular morphology of the cells. NIH-3T3 cells were elongated in the direction of flow and A549 cells exhibited vesicles inside the cells. Zinc oxide nanoparticles reduced the cell viability in the static and in the dynamic culture; however, the dynamic cultures were more sensitive. In the static culture and in the dynamic culture, TiO 2 -NP did not affect cell viability. In conclusion, dynamic culture conditions are important for further in vitro investigations and provide more relevant results than static culture conditions

  13. In vitro and biomechanical screening of polyethylene glycol and poly(trimethylene carbonate) block copolymers for annulus fibrosus repair.

    Science.gov (United States)

    Long, Rose G; Rotman, Stijn G; Hom, Warren W; Assael, Dylan J; Illien-Jünger, Svenja; Grijpma, Dirk W; Iatridis, James C

    2018-02-01

    Herniated intervertebral discs (IVDs) are a common cause of back and neck pain. There is an unmet clinical need to seal annulus fibrosus (AF) defects, as discectomy surgeries address acute pain but are complicated by reherniation and recurrent pain. Copolymers of polyethylene glycol with trimethylene carbonate (TMC) and hexamethylene diisocyanate (HDI) end-groups were formulated as AF sealants as the HDI form covalent bonds with native AF tissue. TMC adhesives were evaluated and optimized using the design criteria: stable size, strong adherence to AF tissue, high cytocompatibility, restoration of IVD biomechanics to intact levels following in situ repair, and low extrusion risk. TMC adhesives had high adhesion strength as assessed with a pushout test (150 kPa), and low degradation rates over 3 weeks in vitro. Both TMC adhesives had shear moduli (220 and 490 kPa) similar to, but somewhat higher than, AF tissue. The adhesive with three TMC moieties per branch (TMC3) was selected for additional in situ testing because it best matched AF shear properties. TMC3 restored torsional stiffness, torsional hysteresis area and axial range of motion to intact states. However, in a failure test of compressive deformation under fixed 5 ° flexion, some herniation risk was observed with failure strength of 5.9 MPa compared with 13.5 MPa for intact samples; TMC3 herniated under cyclic organ culture testing. These TMC adhesives performed well during in vitro and in situ testing, but additional optimization to enhance failure strength is required to further this material to advanced screening tests, such as long-term degradation. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  14. Developments in dynamic MR elastography for in vitro biomechanical assessment of hyaline cartilage under high-frequency cyclical shear.

    Science.gov (United States)

    Lopez, Orlando; Amrami, Kimberly K; Manduca, Armando; Rossman, Phillip J; Ehman, Richard L

    2007-02-01

    The design, construction, and evaluation of a customized dynamic magnetic resonance elastography (MRE) technique for biomechanical assessment of hyaline cartilage in vitro are described. For quantification of the dynamic shear properties of hyaline cartilage by dynamic MRE, mechanical excitation and motion sensitization were performed at frequencies in the kilohertz range. A custom electromechanical actuator and a z-axis gradient coil were used to generate and image shear waves throughout cartilage at 1000-10,000 Hz. A radiofrequency (RF) coil was also constructed for high-resolution imaging. The technique was validated at 4000 and 6000 Hz by quantifying differences in shear stiffness between soft ( approximately 200 kPa) and stiff ( approximately 300 kPa) layers of 5-mm-thick bilayered phantoms. The technique was then used to quantify the dynamic shear properties of bovine and shark hyaline cartilage samples at frequencies up to 9000 Hz. The results demonstrate that one can obtain high-resolution shear stiffness measurements of hyaline cartilage and small, stiff, multilayered phantoms at high frequencies by generating robust mechanical excitations and using large magnetic field gradients. Dynamic MRE can potentially be used to directly quantify the dynamic shear properties of hyaline and articular cartilage, as well as other cartilaginous materials and engineered constructs. (c) 2007 Wiley-Liss, Inc.

  15. Biomechanical evaluation of one-piece and two-piece small-diameter dental implants: In-vitro experimental and three-dimensional finite element analyses.

    Science.gov (United States)

    Wu, Aaron Yu-Jen; Hsu, Jui-Ting; Chee, Winston; Lin, Yun-Te; Fuh, Lih-Jyh; Huang, Heng-Li

    2016-09-01

    Small-diameter dental implants are associated with a higher risk of implant failure. This study used both three-dimensional finite-element (FE) simulations and in-vitro experimental tests to analyze the stresses and strains in both the implant and the surrounding bone when using one-piece (NobelDirect) and two-piece (NobelReplace) small-diameter implants, with the aim of understanding the underlying biomechanical mechanisms. Six experimental artificial jawbone models and two FE models were prepared for one-piece and two-piece 3.5-mm diameter implants. Rosette strain gauges were used for in-vitro tests, with peak values of the principal bone strain recorded with a data acquisition system. Implant stability as quantified by Periotest values (PTV) were also recorded for both types of implants. Experimental data were analyzed statistically using Wilcoxon's rank-sum test. In FE simulations, the peak value and distribution of von-Mises stresses in the implant and bone were selected for evaluation. In in-vitro tests, the peak bone strain was 42% lower for two-piece implants than for one-piece implants. The PTV was slightly lower for one-piece implants (PTV = -6) than for two-piece implants (PTV = -5). In FE simulations, the stresses in the bone and implant were about 23% higher and 12% lower, respectively, for one-piece implants than those for two-piece implants. Due to the higher peri-implant bone stresses and strains, one-piece implants (NobelDirect) might be not suitable for use as small-diameter implants. Copyright © 2016. Published by Elsevier B.V.

  16. An in vitro biomechanical comparison of anterior cruciate ligament reconstruction: single bundle versus anatomical double bundle techniques

    Directory of Open Access Journals (Sweden)

    Sandra Umeda Sasaki

    2008-01-01

    Full Text Available INTRODUCTION: Anterior cruciate ligament ruptures are frequent, especially in sports. Surgical reconstruction with autologous grafts is widely employed in the international literature. Controversies remain with respect to technique variations as continuous research for improvement takes place. One of these variations is the anatomical double bundle technique, which is performed instead of the conventional single bundle technique. More recently, there has been a tendency towards positioning the two bundles through double bone tunnels in the femur and tibia (anatomical reconstruction. OBJECTIVES: To compare, through biomechanical tests, the practice of anatomical double bundle anterior cruciate ligament reconstruction with a patellar graft to conventional single bundle reconstruction with the same amount of patellar graft in a paired experimental cadaver study. METHODS: Nine pairs of male cadaver knees ranging in age from 44 to 63 years were randomized into two groups: group A (single bundle and group B (anatomical reconstruction. Each knee was biomechanically tested under three conditions: intact anterior cruciate ligament, reconstructed anterior cruciate ligament, and injured anterior cruciate ligament. Maximum anterior dislocation, rigidity, and passive internal tibia rotation were recorded with knees submitted to a 100 N horizontal anterior dislocation force applied to the tibia with the knees at 30, 60 and 90 degrees of flexion. RESULTS: There were no differences between the two techniques for any of the measurements by ANOVA tests. CONCLUSION: The technique of anatomical double bundle reconstruction of the anterior cruciate ligament with bone-patellar tendon-bone graft has a similar biomechanical behavior with regard to anterior tibial dislocation, rigidity, and passive internal tibial rotation.

  17. Biomechanics of Hybrid Anterior Cervical Fusion and Artificial Disc Replacement in 3-Level Constructs: An In Vitro Investigation

    Science.gov (United States)

    Liao, Zhenhua; Fogel, Guy R.; Pu, Ting; Gu, Hongsheng; Liu, Weiqiang

    2015-01-01

    Background The ideal surgical approach for cervical disk disease remains controversial, especially for multilevel cervical disease. The purpose of this study was to investigate the biomechanics of the cervical spine after 3-level hybrid surgery compared with 3-level anterior cervical discectomy and fusion (ACDF). Material/Methods Eighteen human cadaveric spines (C2-T1) were evaluated under displacement-input protocol. After intact testing, a simulated hybrid construct or fusion construct was created between C3 to C6 and tested in the following 3 conditions: 3-level disc plate disc (3DPD), 3-level plate disc plate (3PDP), and 3-level plate (3P). Results Compared to intact, almost 65~80% of motion was successfully restricted at C3-C6 fusion levels (p0.05). 3PDP construct resulted in significant decrease of ROM at C3-C6 levels less than 3P (pbiomechanical advantages compared to fusion in normalizing motion. PMID:26529430

  18. Biomechanical effect of interspinous process distraction height after lumbar fixation surgery: An in vitro model.

    Science.gov (United States)

    Fu, Lin; Ma, Jianxiong; Lu, Bin; Jia, Haobo; Zhao, Jie; Kuang, Mingjie; Feng, Rui; Xu, Liyan; Bai, Haohao; Sun, Lei; Wang, Ying; Ma, Xinlong

    2017-07-01

    Pedicle screw fixation may induce abnormal activity at adjacent segment and accelerate the degeneration of lumbar vertebrae. Dynamic stabilizers could provide an intermediate solution between conservative treatment and fusion surgery. Lumbar vertebral segment cephalad to instrumented fixation was the most common localization of adjacent segment degeneration. The aim of this study is to explore the use of interspinous process devices in the lumbar vertebral segment cephalad to fixation segment in changing the mechanical distribution and limiting abnormal activity of the spine. Eight specimens were tested in the following groups: intact group, instability group (bilateral facetectomy at L3-L4), fixation group (bilateral facetectomy and pedicle screw fixation at L3-L4), and hybrid fixation group (fixation at L3-L4 and simulating interspinous device implantation of 6, 8, 10, 12, 14, 16, and 18 mm at L2-L3). Range of motion, motion of vertebral body, and strain distribution change were recorded. The range of motion in extension with 16- and 18-mm hybrid constructs was significantly lower than intact, instability, and fixation groups. In flexion and lateral bending, the strain values of L4 inferior articular process with 18-mm hybrid construct have a significant difference compared with other groups. In axial rotation, under the condition of a contralateral state, the strain values of L2 superior articular process with 18-mm hybrid construct have a significant difference compared with intact and fixation groups. The strain value of the L4 inferior articular process had negative correlation with height distraction in three dimensions, except extension. A negative correlation between the strain value of the L2 superior articular process and distraction height was found in contralateral bending and contralateral axial rotation. Interspinous process devices above the fixation segment can change the mechanical distribution of the spine and limit activity in some of the

  19. Biomechanical in vitro assessment of screw augmentation in locked plating of proximal humerus fractures.

    Science.gov (United States)

    Röderer, Götz; Scola, Alexander; Schmölz, Werner; Gebhard, Florian; Windolf, Markus; Hofmann-Fliri, Ladina

    2013-10-01

    Proximal humerus fracture fixation can be difficult because of osteoporosis making it difficult to achieve stable implant anchorage in the weak bone stock even when using locking plates. This may cause implant failure requiring revision surgery. Cement augmentation has, in principle, been shown to improve stability. The aim of this study was to investigate whether augmentation of particular screws of a locking plate aimed at a region of low bone quality is effective in improving stability in a proximal humerus fracture model. Twelve paired human humerus specimens were included. Quantitative computed tomography was performed to determine bone mineral density (BMD). Local bone quality in the direction of the six proximal screws of a standard locking plate (PHILOS, Synthes) was assessed using mechanical means (DensiProbe™). A three-part fracture model with a metaphyseal defect was simulated and fixed with the plate. Within each pair of humeri the two screws aimed at the region of the lowest bone quality according to the DensiProbe™ were augmented in a randomised manner. For augmentation, 0.5 ml of bone cement was injected in a screw with multiple outlets at its tip under fluoroscopic control. A cyclic varus-bending test with increasing upper load magnitude was performed until failure of the screw-bone fixation. The augmented group withstood significantly more load cycles. The correlation of BMD with load cycles until failure and BMD with paired difference in load cycles to failure showed that augmentation could compensate for a low BMD. The results demonstrate that augmentation of screws in locked plating in a proximal humerus fracture model is effective in improving primary stability in a cyclic varus-bending test. The augmentation of two particular screws aimed at a region of low bone quality within the humeral head was almost as effective as four screws with twice the amount of bone cement. Screw augmentation combined with a knowledge of the local bone quality

  20. Biomechanics of Artificial Disc Replacements Adjacent to a 2-Level Fusion in 4-Level Hybrid Constructs: An In Vitro Investigation

    Science.gov (United States)

    Liao, Zhenhua; Fogel, Guy R.; Wei, Na; Gu, Hongsheng; Liu, Weiqiang

    2015-01-01

    Background The ideal procedure for multilevel cervical degenerative disc diseases remains controversial. Recent studies on hybrid surgery combining anterior cervical discectomy and fusion (ACDF) and artificial cervical disc replacement (ACDR) for 2-level and 3-level constructs have been reported in the literature. The purpose of this study was to estimate the biomechanics of 3 kinds of 4-level hybrid constructs, which are more likely to be used clinically compared to 4-level arthrodesis. Material/Methods Eighteen human cadaveric spines (C2–T1) were evaluated in different testing conditions: intact, with 3 kinds of 4-level hybrid constructs (hybrid C3–4 ACDR+C4–6 ACDF+C6–7ACDR; hybrid C3–5ACDF+C5–6ACDR+C6–7ACDR; hybrid C3–4ACDR+C4–5ACDR+C5–7ACDF); and 4-level fusion. Results Four-level fusion resulted in significant decrease in the C3–C7 ROM compared with the intact spine. The 3 different 4-level hybrid treatment groups caused only slight change at the instrumented levels compared to intact except for flexion. At the adjacent levels, 4-level fusion resulted in significant increase of contribution of both upper and lower adjacent levels. However, for the 3 hybrid constructs, significant changes of motion increase far lower than 4P at adjacent levels were only noted in partial loading conditions. No destabilizing effect or hypermobility were observed in any 4-level hybrid construct. Conclusions Four-level fusion significantly eliminated motion within the construct and increased motion at the adjacent segments. For all 3 different 4-level hybrid constructs, ACDR normalized motion of the index segment and adjacent segments with no significant hypermobility. Compared with the 4-level ACDF condition, the artificial discs in 4-level hybrid constructs had biomechanical advantages compared to fusion in normalizing adjacent level motion. PMID:26694835

  1. In vitro metabolism and permeation studies in rat jejunum

    DEFF Research Database (Denmark)

    Gammelgaard, Bente; Jensen, K; Steffansen, B

    1999-01-01

    The purpose of these studies was to compare the in vitro absorption of two inorganic chromium(III) compounds: chromium chloride and chromium nitrate, with organic chromium(III)-picolinate; and to investigate if any in vitro metabolism of chromium(VI) takes place. The in vitro metabolism studies...

  2. Study in vitro of origin radioprotective food the radioprotective effect in vitro of food borne; Estudio in vitro de radioprotectores de origen alimentario

    Energy Technology Data Exchange (ETDEWEB)

    Soraino, J. M.; Sebastia, N.; Almonacid, M.; Alonso, O.; Cervera, J.; Such, E.; Silla, M. A.; Villaescusa, J. I.; Montoro, A.

    2012-07-01

    Study in vitro of origin radioprotective food the radioprotective effect in vitro of food borne substances studied is a first step in developing effective radioprotectors that can prevent radiation damage to healthy tissue., cannot forget that these studies must be accompanied by in vitro studies of toxicity and bioavailability to profile designing radioprotective substance.

  3. Effects of dorsal versus ventral shear loads on the rotational stability of the thoracic spine: a biomechanical porcine and human cadaveric study

    NARCIS (Netherlands)

    Kouwenhoven, J.W.M.; Smit, T.H.; van der Veen, A.J.; Kingma, I.; van Dieen, J.H.; Castelein, R.M.

    2007-01-01

    STUDY DESIGN. A biomechanical in vitro study on porcine and human spinal segments. OBJECTIVE. To investigate axial rotational stability of the thoracic spine under dorsal and ventral shear loads. SUMMARY OF BACKGROUND DATA. Idiopathic scoliosis is a condition restricted exclusively to humans. An

  4. Using Clinical Gait Case Studies to Enhance Learning in Biomechanics

    Science.gov (United States)

    Chester, Victoria

    2011-01-01

    Clinical case studies facilitate the development of clinical reasoning strategies through knowledge and integration of the basic sciences. Case studies have been shown to be more effective in developing problem-solving abilities than the traditional lecture format. To enhance the learning experiences of students in biomechanics, clinical case…

  5. Bonding brackets to porcelain: in vitro study

    Directory of Open Access Journals (Sweden)

    Sant'Anna Eduardo Franzotti

    2002-01-01

    Full Text Available The aim of this research was to verify, in vitro, the effect of various porcelain surface treatments on the shear strength of orthodontic brackets bonded to porcelain and the mode of fracture after debonding. Eighty-eight samples of metallic supported feldspathic porcelain were randomly divided into four groups according to their surface preparation as follows: the porcelain was maintained intact (GI, roughened with a diamond bur (GII, etched with 10% hydrofluoric acid (GIII, or sandblasted with aluminum oxide (GIV. The specimens were treated with silane (Scothprime and brackets were bonded with Concise. Each sample was subjected to a shear load at a crosshead speed of 1 mm/min and a recording was made at the point of failure. Bond strengths, adequate to withstand the application of orthodontic forces, were achieved in all groups. The Kruskal-Wallis statistical test showed no significant differences in bond strength between the groups (p>0.05. However, many more porcelain fractures occurred on deglazed porcelain. This study indicates that with the appropriate material selection, the silane/composite procedure alone may be adequate for bonding.

  6. An in vitro biomechanical comparison of equine proximal interphalangeal joint arthrodesis techniques: an axial positioned dynamic compression plate and two abaxial transarticular cortical screws inserted in lag fashion versus three parallel transarticular cortical screws inserted in lag fashion.

    Science.gov (United States)

    Sod, Gary A; Riggs, Laura M; Mitchell, Colin F; Hubert, Jeremy D; Martin, George S

    2010-01-01

    To compare in vitro monotonic biomechanical properties of an axial 3-hole, 4.5 mm narrow dynamic compression plate (DCP) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion (DCP-TLS) with 3 parallel transarticular 5.5 mm cortical screws inserted in lag fashion (3-TLS) for the equine proximal interphalangeal (PIP) joint arthrodesis. Paired in vitro biomechanical testing of 2 methods of stabilizing cadaveric adult equine forelimb PIP joints. Cadaveric adult equine forelimbs (n=15 pairs). For each forelimb pair, 1 PIP joint was stabilized with an axial 3-hole narrow DCP (4.5 mm) using 5.5 mm cortical screws in conjunction with 2 abaxial transarticular 5.5 mm cortical screws inserted in lag fashion and 1 with 3 parallel transarticular 5.5 mm cortical screws inserted in lag fashion. Five matching pairs of constructs were tested in single cycle to failure under axial compression, 5 construct pairs were tested for cyclic fatigue under axial compression, and 5 construct pairs were tested in single cycle to failure under torsional loading. Mean values for each fixation method were compared using a paired t-test within each group with statistical significance set at Pcycle to failure, of the DCP-TLS fixation were significantly greater than those of the 3-TLS fixation. Mean cycles to failure in axial compression of the DCP-TLS fixation was significantly greater than that of the 3-TLS fixation. The DCP-TLS was superior to the 3-TLS in resisting the static overload forces and in resisting cyclic fatigue. The results of this in vitro study may provide information to aid in the selection of a treatment modality for arthrodesis of the equine PIP joint.

  7. A Simplified Method of Opacifying and Mixing Acrylic Cement for Percutaneous Vertebroplasty: A Clinical and In Vitro Study

    International Nuclear Information System (INIS)

    Teng Gaojun; He Shicheng; Deng Gang; Guo Jinhe; Fang Wen; Zhu Guangyu

    2005-01-01

    The objective of this study was to simplify the opacifying mixing process of the bone cement and contrast used for percutaneous vertebroplasty (PVP). We performed a biomechanical study of polymethyl methacrylate (PMMA) (Corinplast TM 3) using three different mixtures of PMMA, monomer, and contrast: group I, 2:1; group II, 3:2; group III, 3:2:1 ratio of powder/monomer/iodinated contrast (Omnipaque). In vitro biomechanical testing of ultimate compressive strength was carried out in all samples. Following the conclusion of a proper bone cement mixture regimen drawn from the in vitro study, PVP was performed in 125 patients: 58 with cancer, 12 with hemangioma, and 54 with osteoporotic fracture. The ultimate compressive strength in group III was decreased by 38% compared to groups II and I. Proper fluoroscopic visualization was achieved in all PVP procedures using this mixture. There were no major complications associated with injection of the cement mixture. Complete (CR) and partial response (PR) was obtained in 64% and 32.8%, respectively. No further vertebral collapse occurred during follow-up. The regimen using iodinated contrast for cement visualization during PVP provides a simple and convenient new method for mixing. Although the biomechanical strength is altered by the contrast medium added, it seems insignificant in clinical practice based on the authors' limited experience

  8. In vitro study of interaction between quinine and Garcinia kola ...

    African Journals Online (AJOL)

    Purpose: To investigate the interaction between quinine and Garcinia kola using an in vitro adsorption study. Methods: In vitro interaction between quinine and G. kola was conducted at 37 ± 0.1 °C. Adsorption of quinine (2.5 - 40 μg/ml) to 2.5 % w/v G. kola suspension was studied. Thereafter, quinine desorption process ...

  9. Biomechanical Study about Lateral Ankle Laxity

    Directory of Open Access Journals (Sweden)

    Bogdan Voicu

    2009-12-01

    Full Text Available The objective of this paper is to study the contribution of the anterior talofibular ligament to ankle laxity at 18 cadaver ankles. For this, there was made an original, bipolar transoseus system, in a monitorized test stand Mx-500N Schmidt with a digital force gauge Imada. It was measured the motion response for applied antero-posterior force, inversion-eversion moment and internal-external rotary torque, in three positions of flexion of the ankle, with an intact anterior talofibular ligament and after it’s sectioning. The results showed a significant increases in laxity in plantar flexion for the inversion and internal rotary torque, this mechanism coresponding with common modes of injury.

  10. Biomechanical testing of isolated bones: holographic study

    Science.gov (United States)

    Silvennoinen, Raimo; Nygren, Kaarlo; Karna, Markku

    1992-08-01

    Holographic nondestructive testing (HNDT) is used to investigate the complex structures of bones of various shapes and sizes subjected to forces. Three antlered deer skulls of different species were investigated and significant species-specific differences were observed. The HNDT method was also used to verify the advanced healing of an osteosynthetized sheep jawbone. Radioulnar bones of a normal and an orphaned moose calf were subjected to a bending test. The undernourished calf showed torsio displacement combined with the bending of the bone, which was not seen in the normal calf. The effects of the masticatory forces on the moose skull surface were studied by simulating masseter muscle contractions with jawbones in occlusion. The fringe patterns showed fast-moving bone surfaces on the naso- maxillo-lacrimal region.

  11. An aetiological study on spondylolysis from a biomechanical aspect.

    Science.gov (United States)

    Ichikawa, N.; Ohara, Y.; Morishita, T.; Taniguichi, Y.; Koshikawa, A.; Matsukura, N.

    1982-01-01

    The authors report clinical studies on lumbar disorders (clinical symptoms, X-ray findings) in athletes in various sports. The sport items were divided into three groups according to the main dynamic load applied to the lumbar region. As a result, over 60% of the athletes suffered from "lumbago", and among them spondylolysis reached the high rate of 27%. Arising from these clinical observations, we performed biomechanical laboratory analyses on human cadaver material, axial compression and rotational bending. Our results suggest that the incidence of spondylolysis depends upon the extent and direction of the loads. Images Fig. 4 Fig. 5 Fig. 8 Fig. 9 Fig. 10 PMID:7139222

  12. Button fixation technique for Achilles tendon reinsertion: a biomechanical study.

    Science.gov (United States)

    Awogni, David; Chauvette, Guillaume; Lemieux, Marie-Line; Balg, Frédéric; Langelier, Ève; Allard, Jean-Pascal

    2014-01-01

    Chronic insertional tendinopathy of the Achilles tendon is a frequent and disabling pathologic entity. Operative treatment is indicated for patients for whom nonoperative management has failed. The treatment can consist of the complete detachment of the tendon insertion and extensive debridement. We biomechanically tested a new operative technique that uses buttons for fixation of the Achilles tendon insertion on the posterior calcaneal tuberosity and compared it with 2 standard bone anchor techniques. A total of 40 fresh-frozen cadaver specimens were used to compare 3 fixation techniques for reinserting the Achilles tendon: single row anchors, double row anchors, and buttons. The ultimate loads and failure mechanisms were recorded. The button assembly (median load 764 N, range 713 to 888) yielded a median fixation strength equal to 202% (range 137% to 251%) of that obtained with the double row anchors (median load 412 N, range 301 to 571) and 255% (range 213% to 317%) of that obtained with the single row anchors (median load 338 N, range 241 to 433N). The most common failure mechanisms were suture breakage with the buttons (55%) and pull out of the implant with the double row (70%) and single row (85%) anchors. The results of the present biomechanical cadaver study have shown that Achilles tendon reinsertion fixation using the button technique provides superior pull out strength than the bone anchors tested. Copyright © 2014 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  13. In vitro studies of human lung carcinogenesis.

    Science.gov (United States)

    Harris, C C; Lechner, J F; Yoakum, G H; Amstad, P; Korba, B E; Gabrielson, E; Grafstrom, R; Shamsuddin, A; Trump, B F

    1985-01-01

    Advances in the methodology to culture normal human lung cells have provided opportunities to investigate fundamental problems in biomedical research, including the mechanism(s) of carcinogenesis. Using the strategy schematically shown in Figure 1, we have initiated studies of the effects of carcinogens on the normal progenitor cells of the human cancers caused by these carcinogens. Extended lifespans and aneuploidy were found after exposure of mesothelial cells to asbestos and bronchial epithelial cells to nickel sulfate. These abnormal cells may be considered to be preneoplastic and at an intermediate position in the multistage process of carcinogenesis. Human bronchial epithelial cells can also be employed to investigate the role of specific oncogenes in carcinogenesis and tumor progression. Using the protoplast fusion method for high frequency gene transfection, vHa-ras oncogene initiates a cascade of events in the normal human bronchial cells leading to their apparent immortality, aneuploidy, and tumorigenicity in athymic nude mice. These results suggest that oncogenes may play an important role in human carcinogenesis.

  14. Relapse and stability of surgically assisted rapid maxillary expansion, an anatomical biomechanical study

    NARCIS (Netherlands)

    Koudstaal, M.J.; Smeets, J.B.J.; Kleinrensink, G.J.; Schulten, A.J.M.; van der Wal, K.G.H.

    2009-01-01

    Purpose: This anatomic biomechanical study was undertaken to gain insight into the underlining mechanism of tipping of the maxillary segments during transverse expansion using tooth-borne and bone-borne distraction devices. Materials and Methods: An anatomic biomechanical study was performed on 10

  15. The Role of Minimally Invasive Vertebral Body Stent on Reduction of the Deflation Effect After Kyphoplasty: A Biomechanical Study.

    Science.gov (United States)

    Wang, Dalin; Zheng, Shengnai; Liu, An; Xu, Jie; Du, Xiaotao; Wang, Yijin; Wang, Liming

    2018-03-15

    Biomechanical investigation using cadaver spines. The aim of the present study was to assess the magnitude of the deflation effect after balloon kyphoplasty (BKP) or use of minimally invasive vertebral body stent (MIVBS) in in vitro biomechanical condition. BKP is a well-established minimally invasive treatment option for osteoporotic vertebral compression fractures. However, this technique can lead to a secondary height loss-known as the "deflation effect"-causing intrasegmental kyphosis and an overall alignment failure. The study was conducted on 24 human cadaveric vertebral bodies (T12-L5). After creating a compression fracture model, the fractured vertebral bodies were reduced by BKP (n = 12) or by MIVBS (n = 12) and then augmented with polymethyl methacrylate bone cement. Each step of the procedure was performed under fluoroscopic guidance and the results were analyzed quantitatively. Finally, the strength and stiffness of augmented vertebral bodies were measured by biomechanical tests. Complete initial reduction of the fractured vertebral body height was achieved by both systems. Secondary loss of reduction after balloon deflation was significantly greater in the BKP group (2.36 ± 0.63 mm vs. 0.34 ± 0.43 mm in the MIVBS group; P deflation effect after BKP can be significantly decreased with the use of the MIVBS technique. N/A.

  16. Culture & differentiation of mesenchymal stem cell into osteoblast on degradable biomedical composite scaffold: In vitro study

    Directory of Open Access Journals (Sweden)

    Krishan G Jain

    2015-01-01

    Full Text Available Background & objectives: There is a significant bone tissue loss in patients from diseases and traumatic injury. The current autograft transplantation gold standard treatment has drawbacks, namely donor site morbidity and limited supply. The field of tissue engineering has emerged with a goal to provide alternative sources for transplantations to bridge this gap between the need and lack of bone graft. The aim of this study was to prepare biocomposite scaffolds based on chitosan (CHT, polycaprolactone (PCL and hydroxyapatite (HAP by freeze drying method and to assess the role of scaffolds in spatial organization, proliferation, and osteogenic differentiation of human mesenchymal stem cells (hMSCs in vitro, in order to achieve bone graft substitutes with improved physical-chemical and biological properties. Methods: Pure chitosan (100CHT and composites (40CHT/HAP, 30CHT/HAP/PCL and 25CHT/HAP/PCL scaffolds containing 40, 30, 25 parts per hundred resin (phr filler, respectively in acetic acid were freeze dried and the porous foams were studied for physicochemical and in vitro biological properties. Results: Scanning electron microscope (SEM images of the scaffolds showed porous microstructure (20-300 μm with uniform pore distribution in all compositions. Materials were tested under compressive load in wet condition (using phosphate buffered saline at pH 7.4. The in vitro studies showed that all the scaffold compositions supported mesenchymal stem cell attachment, proliferation and differentiation as visible from SEM images, [3-(4,5-dimethylthiazole-2-yl-2,5-diphenyltetrazolium bromide] (MTT assay, alkaline phosphatase (ALP assay and quantitative reverse transcription (qRT-PCR. Interpretation & conclusions: Scaffold composition 25CHT/HAP/PCL showed better biomechanical and osteoinductive properties as evident by mechanical test and alkaline phosphatase activity and osteoblast specific gene expression studies. This study suggests that this novel

  17. Determining the direction of tooth grinding: an in vitro study

    NARCIS (Netherlands)

    ten Berge, F.; te Poel, J.; Ranjitkar, S.; Kaidonis, J.A.; Lobbezoo, F.; Hughes, T.E.; Townsend, G.C.

    2012-01-01

    The analysis of microwear patterns, including scratch types and widths, has enabled reconstruction of the dietary habits and lifestyles of prehistoric and modern humans. The aim of this in vitro study was to determine whether an assessment of microwear features of experimental scratches placed on

  18. In vitro metabolism and pharmacokinetic studies on methylone

    DEFF Research Database (Denmark)

    Pedersen, Anders Just; Petersen, Trine Hedebrink; Linnet, Kristian

    2013-01-01

    Abuse of the stimulant designer drug methylone (methylenedioxymethcathinone) has been documented in most parts of the world. As with many of the new designer drugs that continuously appear in the illicit drug market, little is known about the pharmacokinetics of methylone. Using in vitro studies...

  19. In Vitro Antibiotic Susceptibility Studies Of Bacteria Associated With ...

    African Journals Online (AJOL)

    In vitro tests of the susceptibility of isolates of bacterial keratitis pathogens to antibiotics were carried out in this study. Staphylococcus aureus was the most frequently isolated organisms followed by Pseudomonas aeruginosa and Streptococcus pneumoniae. Antibiotic sensitivity testing showed a high susceptibility to ...

  20. A study on in vitro propagation of Castanopsis argentea

    Directory of Open Access Journals (Sweden)

    MUHAMMAD IMAM SURYA

    2017-03-01

    Full Text Available Abstract. Surya MI, Kurnita NI, Setyaningsih L, Ismaini L, Muttaqin Z. 2016. A study on in vitro propagation of Castanopsis argentea. Pros Sem Nas Masy Biodiv Indon 2: 10-15. Saninten (Castanopsis argentea is a keystone species that has highly potential as a food material. Mostly, the fruits of C. argentea are eaten by animals. It made us difficults to get the natural regeneration. In vitro propagation is an effort to produce considerable amounts of C. argentea. However, the information about in vitro propagation of C. argentea is still very limited. This study was aimed to determine the initiation methods to propagate C. argentea by in vitro propagation. Two methods of sterilization were used to sterilize the explant of seed and buds. Moreover, the explant was planted on modified MS and WPM. The results show that percentage of survival, number of buds and time of germination were found on seed explants sterilized by first method. The number of callus were found on bud explants sterilized by second method. Furthermore, planting media were not affected to the germination of seed explants, but affected to growth of bud explants.

  1. Comparison of revision strategies for failed C2-posterior cervical pedicle screws: a biomechanical study.

    Science.gov (United States)

    Mayer, Michael; Zenner, Juliane; Bogner, Robert; Hitzl, Wolfgang; Figl, Markus; von Keudell, Arvind; Stephan, Daniel; Penzkofer, Rainer; Augat, Peter; Korn, Gundobert; Resch, Herbert; Koller, Heiko

    2013-01-01

    With increasing usage within challenging biomechanical constructs, failures of C2 posterior cervical pedicle screws (C2-pCPSs) will occur. The purpose of the study was therefore to investigate the biomechanical characteristics of two revision techniques after the failure of C2-pCPSs. Twelve human C2 vertebrae were tested in vitro in a biomechanical study to compare two strategies for revision screws after failure of C2-pCPSs. C2 pedicles were instrumented using unicortical 3.5-mm CPS bilaterally (Synapse/Synthes, Switzerland). Insertion accuracy was verified by fluoroscopy. C2 vertebrae were potted and fixed in an electromechanical testing machine with the screw axis coaxial to the pullout direction. Pullout testing was conducted with load and displacement data taken continuously. The peak load to failure was measured in newtons (N) and is reported as the pullout resistance (POR). After pullout, two revision strategies were tested in each vertebra. In Group-1, revision was performed with 4.0-mm C2-pCPSs. In Group-2, revision was performed with C2-pedicle bone-plastic combined with the use of a 4-mm C2-pCPSs. For the statistical analysis, the POR between screws was compared using absolute values (N) and the POR of the revision techniques normalized to that of the primary procedures (%). The POR of primary 3.5-mm CPSs was 1,140.5 ± 539.6 N for Group-1 and 1,007.7 ± 362.5 N for Group-2; the difference was not significant. In the revision setting, the POR in Group-1 was 705.8 ± 449.1 N, representing a reduction of 38.1 ± 32.9 % compared with that of primary screw fixation. For Group-2, the POR was 875.3 ± 367.9 N, representing a reduction of 13.1 ± 23.4 %. A statistical analysis showed a significantly higher POR for Group-2 compared with Group-1 (p = 0.02). Although the statistics showed a significantly reduced POR for both revision strategies compared with primary fixation (p plastic, the POR can be significantly increased compared with the use of only an

  2. In vitro and in vivo studies of pulmonary artery flow

    International Nuclear Information System (INIS)

    Sahn, D.J.; Yoganathan, A.P.

    1986-01-01

    A variety of interesting intracardiac flow patterns have been recorded by pulsed and continuous wave Doppler technologies in humans with heart disease. Some of these patterns have, in fact, been difficult to explain and are now more easily understood using color Doppler flow mapping systems which show the spatial location of flow. The authors performed a number of studies in patients, as well as studies in in vitro systems to model some of the phenomenon that the authors observed in the pulmonary artery. Their studies with Doppler flow mapping in the clinical situation, in the in vitro model, and in the animal models of congenital heart disorders lend insights into the complex hydrodynamics present in the pulmonary artery

  3. Recent microfluidic devices for studying gamete and embryo biomechanics.

    Science.gov (United States)

    Lai, David; Takayama, Shuichi; Smith, Gary D

    2015-06-25

    The technical challenges of biomechanic research such as single cell analysis at a high monetary cost, labor, and time for just a small number of measurements is a good match to the strengths of microfluidic devices. New scientific discoveries in the fertilization and embryo development process, of which biomechanics is a major subset of interest, is crucial to fuel the continual improvement of clinical practice in assisted reproduction. The following review will highlight some recent microfluidic devices tailored for gamete and embryo biomechanics where biomimicry arises as a major theme of microfluidic device design and function, and the application of fundamental biomechanic principles are used to improve outcomes of cryopreservation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. In vitro biomechanical properties of 2 compression fixation methods for midbody proximal sesamoid bone fractures in horses.

    Science.gov (United States)

    Woodie, J B; Ruggles, A J; Litsky, A S

    2000-01-01

    To evaluate 2 methods of midbody proximal sesamoid bone repair--fixation by a screw placed in lag fashion and circumferential wire fixation--by comparing yield load and the adjacent soft-tissue strain during monotonic loading. Experimental study. 10 paired equine cadaver forelimbs from race-trained horses. A transverse midbody osteotomy of the medial proximal sesamoid bone (PSB) was created. The osteotomy was repaired with a 4.5-mm cortex bone screw placed in lag fashion or a 1.25-mm circumferential wire. The limbs were instrumented with differential variable reluctance transducers placed in the suspensory apparatus and distal sesamoidean ligaments. The limbs were tested in axial compression in a single cycle until failure. The cortex bone screw repairs had a mean yield load of 2,908.2 N; 1 limb did not fail when tested to 5,000 N. All circumferential wire repairs failed with a mean yield load of 3,406.3 N. There was no statistical difference in mean yield load between the 2 repair methods. The maximum strain generated in the soft tissues attached to the proximal sesamoid bones was not significantly different between repair groups. All repaired limbs were able to withstand loads equal to those reportedly applied to the suspensory apparatus in vivo during walking. Each repair technique should have adequate yield strength for repair of midbody fractures of the PSB immediately after surgery.

  5. The effects of creep and recovery on the in vitro biomechanical characteristics of human multi-level thoracolumbar spinal segments.

    Science.gov (United States)

    Busscher, Iris; van Dieën, Jaap H; van der Veen, Albert J; Kingma, Idsart; Meijer, Gerdine J M; Verkerke, Gijsbertus J; Veldhuizen, Albert G

    2011-06-01

    Several physiological and pathological conditions in daily life cause sustained static bending or torsion loads on the spine resulting in creep of spinal segments. The objective of this study was to determine the effects of creep and recovery on the range of motion, neutral zone, and neutral zone stiffness of thoracolumbar multi-level spinal segments in flexion, extension, lateral bending and axial rotation. Six human cadaveric spines (age at time of death 55-84 years) were sectioned in T1-T4, T5-T8, T9-T12, and L1-L4 segments and prepared for testing. Moments were applied of +4 to -4 N m in flexion-extension, lateral bending, and axial rotation. This was repeated after 30 min of creep loading at 2 N m in the tested direction and after 30 min of recovery. Displacement of individual motion segments was measured using a 3D optical movement registration system. The range of motion, neutral zone, and neutral zone stiffness of the middle motion segments were calculated from the moment-angular displacement data. The range of motion increased significantly after creep in extension, lateral bending and axial rotation (Pcreep showed an increasing trend as well, and the neutral zone after flexion creep increased by on average 36% (Pcreep in axial rotation (Pcreep loading. This higher flexibility of the spinal segments may be a risk factor for potential spinal instability or injury. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. IN VITRO ANTIBACTERIAL ACTIVITIES STUDY OF POLYMERIC CIPROFLOXACIN SUSPENSIONS

    OpenAIRE

    Sahoo Subhashree; Chakraborti Chandra Kanti; Behera Pradipta Kumar

    2012-01-01

    To study the in vitro antibacterial activities of mucoadhesive suspensions containing Ciprofloxacin, three different formulations were prepared by using three polymers, such as Hydroxypropyl methylcellulose (HPMC) (S1), Carbapol934 (S2) and Carbapol940 (S3), along with some common ingredients (bases). For the investigation, agar well diffusion method was performed taking Staphylococcus aureus (ATCC 25923), Bacillus subtilis and Escherichia coli (ATCC 25922). Apart from S. aureus, S1 and Cipro...

  7. In Vitro Bioavailability Study of an Antiviral Compound Enisamium Iodide

    OpenAIRE

    Eleonore Haltner-Ukomadu; Svitlana Gureyeva; Oleksii Burmaka; Andriy Goy; Lutz Mueller; Grygorii Kostyuk; Victor Margitich

    2018-01-01

    An investigation into the biopharmaceutics classification and a study of the in vitro bioavailability (permeability and solubility) of the antiviral compound enisamium iodide (4-(benzylcarbamoyl)-1-methylpyridinium iodide) were carried out. The solubility of enisamium iodide was determined in four different buffers. Apparent intestinal permeability (Papp) of enisamium iodide was assessed using human colon carcinoma (Caco-2) cells at three concentrations. The solubility of enisamium iodide in ...

  8. Studies on the in vitro cultivation of coccidia

    International Nuclear Information System (INIS)

    Schmatz, D.M.

    1985-01-01

    New approaches to the in vitro cultivation of coccidian parasites are described here, specifically for avian coccidia of the genus Eimeria. Firstly, an improved method of purifying the infectious stage of these parasites, known as sporozoites, over a DEAE-52 cellulose anion exchange column to eliminate toxic debris generated during excystation is described. The cultured cells used to support the intracellular development of these parasites, Madin-Darby Bovine Kidney Cells (MDBK), were cloned and it was demonstrated that some clones were more susceptible than others to infection with sporozoites. The use of sub-lethal doses of gamma radiation to pre-treat host cell monolayers prior to infecting has been found to prevent host cell overgrowth and subsequent peeling of the monolayers while not interfering with parasite development. Utilizing in vitro culture techniques developed here in conjunction with radiolabeling studies, an assay has been development using the parasite-specific incorporation of 3 H-uracil to assess the intracellular development of E. tenella and E. acervulina in vitro. As shown by both scintillation counts and autoradiography, 3 H-uracil was incorporated specifically into the intracellular parasites from the onset of infection and continued throughout the development of the first generation schizonts. Based on these findings, a semi-automated microscale incorporation assay was developed to determine parasite viability. The assay system is used in this study to investigate the effects of known anticoccidials, sporozoite antiserum, and varying the composition of the cell culture medium on parasite development

  9. Study of some factors affecting potato microtuber production in vitro

    International Nuclear Information System (INIS)

    Al-Safadi, B.; Ayyoubi, Z.; Jawdat, D.

    2000-01-01

    The effects of variety, growth regulators, sucrose, and low doses of gamma irradiation on the production of potato (Solanum tuberosum L.) microtubers in vitro were investigated. Nodal segments from virus free explants of 3 potato varieties were placed on six different media and irradiated with 4 doses of gamma radiation (2.5, 5, 10, 15 Gy).Potato varieties used in the study differed in their ability to produce microtubers. Variety Diamant was the best in microtuber production followed by Draga and Spunta. Kinetin played a significant role in inducing tuberization in vitro especially at a concentration of 4 mg -1 . Tuberization was also enhanced by sucrose especially when its level was increased from 3% to 6%. Irradiating the explants with 2.5 Gy of gamma radiation leads to a significant increase in number of microtubers (34% increase over the control). Weight of microtubers was not significantly influenced by low doses of gamma irradiation or media components. Draga microtubers were the largest followed by Diamant and Spunta. Microtubers resembled mature tubers in shape (Spunta was elongated and Draga and Diamant were round). Size of microtubers was crucial for sprouting in vivo. It is suggested that only microtubers larger than 250 mg (5 mm in diameter) can be used to produce minitubers in vivo. Since 2.5 Gy is a low dose, it can be used to enhance tuberization in vitro without fear of genetic changes in the used varieties. (author)

  10. Validation of an experimental polyurethane model for biomechanical studies on implant supported prosthesis - tension tests

    Directory of Open Access Journals (Sweden)

    Mariane Miyashiro

    2011-06-01

    Full Text Available OBJECTIVES: The complexity and heterogeneity of human bone, as well as ethical issues, frequently hinder the development of clinical trials. The purpose of this in vitro study was to determine the modulus of elasticity of a polyurethane isotropic experimental model via tension tests, comparing the results to those reported in the literature for mandibular bone, in order to validate the use of such a model in lieu of mandibular bone in biomechanical studies. MATERIAL AND METHODS: Forty-five polyurethane test specimens were divided into 3 groups of 15 specimens each, according to the ratio (A/B of polyurethane reagents (PU-1: 1/0.5, PU-2: 1/1, PU-3: 1/1.5. RESULTS: Tension tests were performed in each experimental group and the modulus of elasticity values found were 192.98 MPa (SD=57.20 for PU-1, 347.90 MPa (SD=109.54 for PU-2 and 304.64 MPa (SD=25.48 for PU-3. CONCLUSION: The concentration of choice for building the experimental model was 1/1.

  11. Influence of endodontic instrument-holder on sterilization efficacy. A pilot in-vitro study.

    Directory of Open Access Journals (Sweden)

    Angelo Carrizo

    2013-08-01

    Full Text Available Infection control is crucial in dentistry and various methods have been designed to assure its efficacy. However, little information exists regarding the influence it could have the instrument-holder of endodontic files. The aim of this research was to determine the influence of three instruments-holders on sterilization efficacy of endodontic files. Methods: A pilot in-vitro study. 60 endodontic files were contaminated by biomechanical preparation of extracted molars with periapical abscess, then processed according to the standard washing method. The endodontic files were divided into 3 groups (n=20 and assigned to 3 instrument-holders: Metallic box (MB, surgical gauze (SG and synthetic sponge (SS. Then, the files were packaged and sterilized by autoclaving (134°C/45min. Microbiological culture was performed in thioglycolate solution for each endodontic file (37ºC/5days. Results: The overall sterilization efficacy was 91.7%, 80% for MB, 100% for SS, and 95% for SG, with no statistically significant differences (p=0.06 between the groups. Conclusions: The lack of differences in the efficacy of sterilization may be due to the reduced sample; therefore, a full-size study is necessary to confirm this outcomes. The results of this study discourage the use of the MB as instrument-holder until a full-size study can confirm this data.

  12. Oncogenes and radiosensitivity: in vitro studies. Potential impact in radiotherapy

    International Nuclear Information System (INIS)

    Alapetite, C.; Moustacchi, E.; Cosset, J.M.

    1992-01-01

    It is of interest to address the question of whether or not activated oncogenes can influence tumorigenic cell response to radiations. Malignant transformation through transfection of oncogenes offers a possibility for in vitro comparison of transformed cells and parental cells. Murin cellular system analysis suggests an acquisition of radioresistance through some oncogenes transfection. In human cells, only a limited number of oncogenes (ras and myc) has been studied so far. To date, no crucial influence could be demonstrated. The extension of the analysis to other oncogenes and suppressor genes could potentially be helpful for the choice and the modalities of cancer treatment

  13. Mystery of alar ligament rupture: Value of MRI in whiplash injuries - biomechanical, anatomical and clinical studies

    International Nuclear Information System (INIS)

    Bitterling, H.; Brueckmann, H.; Staebler, A.

    2007-01-01

    Purpose: Whiplash injury of the cervical spine is a frequent issue in medical expertise and causes enormous consequential costs for motor insurance companies. Some authors accuse posttraumatic changes of alar ligaments to be causative for consequential disturbances. Materials and methods: Review of recent studies on biomechanics, anatomical and clinical MR imaging. Results: Biomechanical experiments can not induce according injuries of alar ligaments. Although MRI provides excellent visualization of alar ligaments, the range of normal variants is high. (orig.)

  14. In Vitro Study of Taenia solium Postoncospheral Form.

    Directory of Open Access Journals (Sweden)

    Nancy Chile

    2016-02-01

    Full Text Available The transitional period between the oncosphere and the cysticercus of Taenia solium is the postoncospheral (PO form, which has not yet been completely characterized. The aim of this work was to standardize a method to obtain T. solium PO forms by in vitro cultivation. We studied the morphology of the PO form and compared the expression of antigenic proteins among the PO form, oncosphere, and cysticerci stages.T. solium activated oncospheres were co-cultured with ten cell lines to obtain PO forms, which we studied at three stages of development--days 15, 30, and 60. A high percentage (32% of PO forms was obtained using HCT-8 cells in comparison to the other cell lines. The morphology was observed by bright field, scanning, and transmission electron microscopy. Morphology of the PO form changed over time, with the six hooks commonly seen in the oncosphere stage disappearing in the PO forms, and vesicles and microtriches observed in the tegument. The PO forms grew as they aged, reaching a diameter of 2.5 mm at 60 days of culture. 15-30 day PO forms developed into mature cysticerci when inoculated into rats. Antigenic proteins expressed in the PO forms are also expressed by the oncosphere and cysticerci stages, with more cysticerci antigenic proteins expressed as the PO forms ages.This is the first report of an in vitro production method of T. solium PO forms. The changes observed in protein expression may be useful in identifying new targets for vaccine development. In vitro culture of PO form will aid in understanding the host-parasite relationship, since the structural changes of the developing PO forms may reflect the parasite's immunoprotective mechanisms. A wider application of this method could significantly reduce the use of animals, and thus the costs and time required for further experimental investigations.

  15. In Vitro Study of Taenia solium Postoncospheral Form.

    Science.gov (United States)

    Chile, Nancy; Clark, Taryn; Arana, Yanina; Ortega, Ynes R; Palma, Sandra; Mejia, Alan; Angulo, Noelia; Kosek, Jon C; Kosek, Margaret; Gomez-Puerta, Luis A; Garcia, Hector H; Gavidia, Cesar M; Gilman, Robert H; Verastegui, Manuela

    2016-02-01

    The transitional period between the oncosphere and the cysticercus of Taenia solium is the postoncospheral (PO) form, which has not yet been completely characterized. The aim of this work was to standardize a method to obtain T. solium PO forms by in vitro cultivation. We studied the morphology of the PO form and compared the expression of antigenic proteins among the PO form, oncosphere, and cysticerci stages. T. solium activated oncospheres were co-cultured with ten cell lines to obtain PO forms, which we studied at three stages of development--days 15, 30, and 60. A high percentage (32%) of PO forms was obtained using HCT-8 cells in comparison to the other cell lines. The morphology was observed by bright field, scanning, and transmission electron microscopy. Morphology of the PO form changed over time, with the six hooks commonly seen in the oncosphere stage disappearing in the PO forms, and vesicles and microtriches observed in the tegument. The PO forms grew as they aged, reaching a diameter of 2.5 mm at 60 days of culture. 15-30 day PO forms developed into mature cysticerci when inoculated into rats. Antigenic proteins expressed in the PO forms are also expressed by the oncosphere and cysticerci stages, with more cysticerci antigenic proteins expressed as the PO forms ages. This is the first report of an in vitro production method of T. solium PO forms. The changes observed in protein expression may be useful in identifying new targets for vaccine development. In vitro culture of PO form will aid in understanding the host-parasite relationship, since the structural changes of the developing PO forms may reflect the parasite's immunoprotective mechanisms. A wider application of this method could significantly reduce the use of animals, and thus the costs and time required for further experimental investigations.

  16. The effect of tibial plateau leveling osteotomy position on cranial tibial subluxation: an in vitro study.

    Science.gov (United States)

    Kowaleski, Michael P; Apelt, Detlef; Mattoon, John S; Litsky, Alan S

    2005-01-01

    To compare centered versus distal tibial plateau leveling osteotomy (TPLO) position on cranial tibial subluxation, postoperative tibial plateau angle (TPA), and tibial long axis shift (TLAS). In vitro biomechanical evaluation. Six pairs of canine cadaveric hind limbs. One limb of each pair was randomly assigned to the distal (TPLO-D) or centered (TPLO-C) osteotomy group. Cranial tibial subluxation (CTS) under load was quantified sequentially under 3 conditions: intact, after cranial cruciate ligament transection, and after TPLO; a corrected CTS value was also calculated. Postoperative TPA and TLAS were measured. Comparisons were made using 1-way repeated measures ANOVA with a Tukey's multiple comparison post hoc test for CTS, and a Wilcoxon's sign rank test for TPA and TLAS. Significance was set at Pcranial tibial thrust. The centered osteotomy position is geometrically more precise, and biomechanically more effective than the distal position.

  17. LED photochemotherapy against Staphylococcus aureus: an in vitro study

    Science.gov (United States)

    de Oliveira, Susana C. P. S.; Monteiro, Juliana S. C.; Pires-Santos, Gustavo M.; Sampaio, Fernando José Pires; Soares, Luiz Guilherme P.; Soares, Amanda P.; Pinheiro, Antônio L. B.

    2018-02-01

    Bacterial resistance to antibiotics is reality and need for alternative treatments is urgent. The aim of this work was to evaluate, in vitro, the effect of LED photochemotherapy on Staphylococcus aureus (ATCC 23529) using 25 μg / mL of phenothiazine compound combined with LED light (λ632 +/- 2ηm) using 12 J/cm2 energy density. The experiments were carried out in triplicate and the samples were divided into groups: Control, Irradiated (treated only with light), Photosensitizer (treated only in the presence of the dye), LED-Photochemotherapy (treatment with light associated with dye). Counts of the colony forming units and the data obtained were statistically analyzed (ANOVA, Tukey's test, p<0.05). The present study demonstrated that the efficacy of LED-Photochemotherapy as the use of 25 μg/mL x 12 J/cm2 caused 91.57 % of inhibition of bacterial growth. It is concluded that using energy density of 12 J/cm2 associated to 25 μg/mL caused high in vitro inhibition of S. aureus.

  18. Studies on the human choroid plexus in vitro

    Directory of Open Access Journals (Sweden)

    Redzic Zoran B

    2013-02-01

    Full Text Available Abstract The role of human choroid plexus (CP epithelium in the transport of solutes between the blood and the cerebrospinal fluid and/or in secretion processes may be studied by employing several experimental approaches. There are a number of in vitro techniques for human CP epithelium (CPE and all have limitations that do not exclude them a priori, but that should be carefully taken into consideration. Developmental and morphological studies have been largely performed on human choroid plexus samples of either embryonic or post-mortem origin. Functional uptake studies may be performed on pathologically unaltered CP samples obtained during surgical removal of choroid plexus tumors. This approach can be used to explore transport processes mainly across the apical side of the CPE, but cannot be used to study vectorial transport across the CPE. Also, these samples have limited viability. A monolayer of CPE in culture, grown on permeable supports, provides the best available tool to study transport processes or polarized secretion by the CP, but thus far only limited attempts to culture these cells have been published and they mainly include data from neoplastic CPE. A study that used a human papilloma-derived cell line in culture showed that it forms a monolayer with barrier properties, although the cells express pleomorphic and neoplastic features and lack contact inhibition. Other cell cultures express some CPE markers but do not develop tight junctions/barrier properties. This article reviews the main characteristics and limitations of available in vitro methods to study human CPE, which could help researchers choose an appropriate experimental approach for a particular study.

  19. A scalable platform for biomechanical studies of tissue cutting forces

    International Nuclear Information System (INIS)

    Valdastri, P; Tognarelli, S; Menciassi, A; Dario, P

    2009-01-01

    This paper presents a novel and scalable experimental platform for biomechanical analysis of tissue cutting that exploits a triaxial force-sensitive scalpel and a high resolution vision system. Real-time measurements of cutting forces can be used simultaneously with accurate visual information in order to extract important biomechanical clues in real time that would aid the surgeon during minimally invasive intervention in preserving healthy tissues. Furthermore, the in vivo data gathered can be used for modeling the viscoelastic behavior of soft tissues, which is an important issue in surgical simulator development. Thanks to a modular approach, this platform can be scaled down, thus enabling in vivo real-time robotic applications. Several cutting experiments were conducted with soft porcine tissues (lung, liver and kidney) chosen as ideal candidates for biopsy procedures. The cutting force curves show repeated self-similar units of localized loading followed by unloading. With regards to tissue properties, the depth of cut plays a significant role in the magnitude of the cutting force acting on the blade. Image processing techniques and dedicated algorithms were used to outline the surface of the tissues and estimate the time variation of the depth of cut. The depth of cut was finally used to obtain the normalized cutting force, thus allowing comparative biomechanical analysis

  20. Fluconazole and testosterone: in vivo and in vitro studies.

    Science.gov (United States)

    Hanger, D P; Jevons, S; Shaw, J T

    1988-05-01

    Fluconazole (UK-49,858), a novel bis-triazole antifungal agent, was given orally to groups of 10 male volunteers at doses of 25 and 50 mg/day for 28 days. Blood samples for testosterone estimation were taken from these and from a placebo group at several time points on days 1, 14, and 28 of the study, and the assay results demonstrated that the compound had no significant effect on circulating testosterone levels. Similarly, in studies with rat Leydig cells in vitro, fluconazole at concentrations up to 10 micrograms/ml was found to be only a weak inhibitor of testosterone production, whereas ketoconazole caused more than 50% inhibition at 0.1 microgram/ml. It is concluded that fluconazole, in contrast to ketoconazole, has little effect on the biosynthesis of testosterone by mammalian cells.

  1. In vitro placental model optimization for nanoparticle transport studies

    Directory of Open Access Journals (Sweden)

    Cartwright L

    2012-01-01

    Full Text Available Laura Cartwright1, Marie Sønnegaard Poulsen2, Hanne Mørck Nielsen3, Giulio Pojana4, Lisbeth E Knudsen2, Margaret Saunders1, Erik Rytting2,51Bristol Initiative for Research of Child Health (BIRCH, Biophysics Research Unit, St Michael's Hospital, UH Bristol NHS Foundation Trust, Bristol, UK; 2University of Copenhagen, Faculty of Health Sciences, Department of Public Health, 3University of Copenhagen, Faculty of Pharmaceutical Sciences, Department of Pharmaceutics and Analytical Chemistry, Copenhagen, Denmark; 4Department of Environmental Sciences, Informatics and Statistics, University Ca' Foscari Venice, Venice, Italy; 5Department of Obstetrics and Gynecology, University of Texas Medical Branch, Galveston, Texas, USABackground: Advances in biomedical nanotechnology raise hopes in patient populations but may also raise questions regarding biodistribution and biocompatibility, especially during pregnancy. Special consideration must be given to the placenta as a biological barrier because a pregnant woman's exposure to nanoparticles could have significant effects on the fetus developing in the womb. Therefore, the purpose of this study is to optimize an in vitro model for characterizing the transport of nanoparticles across human placental trophoblast cells.Methods: The growth of BeWo (clone b30 human placental choriocarcinoma cells for nanoparticle transport studies was characterized in terms of optimized Transwell® insert type and pore size, the investigation of barrier properties by transmission electron microscopy, tight junction staining, transepithelial electrical resistance, and fluorescein sodium transport. Following the determination of nontoxic concentrations of fluorescent polystyrene nanoparticles, the cellular uptake and transport of 50 nm and 100 nm diameter particles was measured using the in vitro BeWo cell model.Results: Particle size measurements, fluorescence readings, and confocal microscopy indicated both cellular uptake of

  2. In vitro and in vivo approaches to study osteocyte biology.

    Science.gov (United States)

    Kalajzic, Ivo; Matthews, Brya G; Torreggiani, Elena; Harris, Marie A; Divieti Pajevic, Paola; Harris, Stephen E

    2013-06-01

    Osteocytes, the most abundant cell population of the bone lineage, have been a major focus in the bone research field in recent years. This population of cells that resides within mineralized matrix is now thought to be the mechanosensory cell in bone and plays major roles in the regulation of bone formation and resorption. Studies of osteocytes had been impaired by their location, resulting in numerous attempts to isolate primary osteocytes and to generate cell lines representative of the osteocytic phenotype. Progress has been achieved in recent years by utilizing in vivo genetic technology and generation of osteocyte directed transgenic and gene deficiency mouse models. We will provide an overview of the current in vitro and in vivo models utilized to study osteocyte biology. We discuss generation of osteocyte-like cell lines and isolation of primary osteocytes and summarize studies that have utilized these cellular models to understand the functional role of osteocytes. Approaches that attempt to selectively identify and isolate osteocytes using fluorescent protein reporters driven by regulatory elements of genes that are highly expressed in osteocytes will be discussed. In addition, recent in vivo studies utilizing overexpression or conditional deletion of various genes using dentin matrix protein (Dmp1) directed Cre recombinase are outlined. In conclusion, evaluation of the benefits and deficiencies of currently used cell lines/genetic models in understanding osteocyte biology underlines the current progress in this field. The future efforts will be directed towards developing novel in vitro and in vivo models that would additionally facilitate in understanding the multiple roles of osteocytes. Copyright © 2012 Elsevier Inc. All rights reserved.

  3. In vitro study of proteins surface activity by tritium probe

    International Nuclear Information System (INIS)

    Chernysheva, M.G.; Badun, G.A.

    2010-01-01

    A new technique for in vitro studies of biomacromolecules interactions, their adsorption at aqueous/organic liquid interfaces and distribution in the bulk of liquid/liquid systems was developed. The method includes (1) tritium labeling of biomolecules by tritium thermal activation method and (2) scintillation phase step with organic phase, which can be concerned as a model of cellular membrane. Two globular proteins lysozyme and human serum albumin tested. We have determined the conditions of tritium labeling when labeled by-products can be easy separated by means of dialysis and size-exclusion chromatography. Scintillation phase experiments were conducted for three types of organic liquids. Thus, the influences of the nature of organic phase on proteins adsorption and its distribution in the bulk of aqueous/organic liquid system were determined. It was found that proteins possess high surface activity at aqueous/organic liquid interface. Furthermore, values of hydrophobicity of globular proteins were found by the experiment. (author)

  4. Immunosuppressive effects of factor IX products: an in vitro study.

    Science.gov (United States)

    Grosset, A B; McGregor, J R; Samlowski, W E; Rodgers, G M

    1999-11-01

    The effects of a recombinant factor IX product (BeneFix), and of five plasma-derived factor IX products, AlphaNine, Immunine, Konyne, Mononine and Replinine on in vitro peripheral blood mononuclear cell (PBMC) immune function were compared in a blinded study. We assessed the effects of these products on Con-A-induced lymphocyte proliferation and interleukin-2 and interleukin-10 secretion, expression of lymphocyte activation markers, and nitric oxide secretion by stimulated mouse peritoneal macrophages. At 1 mL-1 for 48 h, Konyne reduced Con-A-induced mitogenesis by 50% (P < 0.05); AlphaNine, Mononine and BeneFix had no effect. At 10 IU mL-1, Con-A-induced mi- togenesis was at control levels with Mononine and BeneFix, but was reduced to <15% (P < 0.05) with each of the other products. IL-2 and IL-10 secretion by Con-A-stimulated lymphocytes was also markedly depressed by all the products tested except Mononine and BeneFix. Dialysis of these products did not substantially affect these results. Flow cytometric analysis of lymphocyte activation markers following Con-A stimulation showed that Konyne also decreased IL-2 receptor alpha and beta chain (CD25 and CD122) induction on PBMC. Konyne also inhibited nitric oxide secretion to levels <18% of controls. These results indicate that certain factor IX products, including some of purported higher purity, substantially depress in vitro immune function. The importance of these findings to in vivo immune function in haemophilia B patients remains to be established.

  5. Corrosion of orthodontic brackets in different spices: in vitro study.

    Science.gov (United States)

    Chaturvedi, T P

    2014-01-01

    Moist environment in the mouth varies and causes variable amounts of corrosion of dental materials. This is of concern particularly when metallic implants, metallic fillings, orthodontic appliances are placed in the hostile electrolytic environment in the human mouth. Components of diet rich in salt and spices are important factors influencing the corrosion of metallic appliances placed in the oral cavity. To study in vitro corrosion of orthodontic metallic brackets immersed in solutions of salt and spices in artificial saliva. Orthodontic brackets were used for corrosion studies in artificial saliva, salt, and spices using electrochemical technique and surface analysis. Electrochemical studies using different parameters were done in solutions of artificial saliva containing salt and spices. Photomicrographs from the optical microscope were also obtained. RESULTS of corrosion studies have clearly demonstrated that certain spices such as turmeric and coriander are effective in reducing corrosion, whereas salt and red chili have been found to enhance it. Surface analysis of small pits present on the surface of the as-received bracket will initiate corrosion which leads to more pitting.

  6. Mechanical Failure of Endocrowns Manufactured with Different Ceramic Materials: An In Vitro Biomechanical Study.

    Science.gov (United States)

    Aktas, Guliz; Yerlikaya, Hatice; Akca, Kivanc

    2018-04-01

    To evaluate the effect of different silica-based ceramic materials on the mechanical failure behavior of endocrowns used in the restoration of endodontically treated mandibular molar teeth. Thirty-six intact mandibular molar teeth extracted because of a loss of periodontal support received root canal treatment. The teeth were prepared with a central cavity to support the endocrowns, replacing the occlusal surface with mesial-lingual-distal walls. Data acquisition of the prepared tooth surfaces was carried out digitally with a powder-free intraoral scanner. Restoration designs were completed on manufactured restorations from three silicate ceramics: alumina-silicate (control), zirconia-reinforced (Zr-R), and polymer-infiltrated (P-I). Following adhesive cementation, endocrowns were subjected to thermal aging, and then, each specimen was obliquely loaded to record the fracture strength and define the mechanical failure. For the failure definition, the fracture type characteristics were identified, and further analytic measurements were made on the fractured tooth and ceramic structure. Load-to-fracture failure did not differ significantly, and the calculated mean values were 1035.08 N, 1058.33 N, and 1025.00 N for control, Zr-R, and P-I groups, respectively; however, the stiffness of the restoration-tooth complex was significantly higher than that in both test groups. No statistically significant correlation was established in paired comparisons of the failure strength, restorative stiffness, and fractured tooth distance parameters. The failure mode for teeth restored with zirconia-reinforced glass ceramics was identified as non-restorable. The resin interface in the control and P-I groups presented similar adhesive failure behavior. Mechanical failure of endocrown restorations does not significantly differ for silica-based ceramics modified either with zirconia or polymer. © 2016 by the American College of Prosthodontists.

  7. Poor relation between biomechanical and clinical studies for the proximal femoral locking compression plate

    DEFF Research Database (Denmark)

    Viberg, Bjarke; Voergård Rasmussen, Katrine Marie; Overgaard, Søren

    2017-01-01

    Background and purpose — The proximal femur locking compression plate (PF-LCP) is a new concept in the treatment of hip fractures. When releasing new implants onto the market, biomechanical studies are conducted to evaluate performance of the implant. We investigated the relation between biomecha......Background and purpose — The proximal femur locking compression plate (PF-LCP) is a new concept in the treatment of hip fractures. When releasing new implants onto the market, biomechanical studies are conducted to evaluate performance of the implant. We investigated the relation between...

  8. In vitro biological models in order to study BNCT

    International Nuclear Information System (INIS)

    Dagrosa, Maria A.; Kreimann, Erica L.; Schwint, Amanda E.; Juvenal, Guillermo J.; Pisarev, Mario A.; Farias, Silvia S.; Garavaglia, Ricardo N.; Batistoni, Daniel A.

    1999-01-01

    Undifferentiated thyroid carcinoma (UTC) lacks an effective treatment. Boron neutron capture therapy (BNCT) is based on the selective uptake of 10 B-boronated compounds by some tumours, followed by irradiation with an appropriate neutron beam. The radioactive boron originated ( 11 B) decays releasing 7 Li, gamma rays and alpha particles, and these latter will destroy the tumour. In order to explore the possibility of applying BNCT to UTC we have studied the biodistribution of BPA. In vitro studies: the uptake of p- 10 borophenylalanine (BPA) by the UTC cell line ARO, primary cultures of normal bovine thyroid cells (BT) and human follicular adenoma (FA) thyroid was studied. No difference in BPA uptake was observed between proliferating and quiescent ARO cells. The uptake by quiescent ARO, BT and FA showed that the ARO/BT and ARO/FA ratios were 4 and 5, respectively (p< 0.001). The present experimental results open the possibility of applying BNCT for the treatment of UTC. (author)

  9. The biomechanical assessment of the cervical inter-vertebral kinematics, between DDD patients ICR based study

    Science.gov (United States)

    Saveh, Amir Hossein; Zali, Ali Reza; Seddighi, Amir Saeed; Zarghi, Afsaneh; Chizari, Mahmoud; Hanafiah, Yussof

    2012-01-01

    Abstract: It is very important to pay more attention to spine from the biomechanical perspective. It would allow the analysis of initial conditions of the vertebral disc degeneration syndrome and adopting of normal spine kinematics to compare and match it with a degenerated disc and providing a biomechanical index as an indicator for the conduct of any surgical intervention including arthroplasty to maximize restoring spinal biomechanical motion. It is clear that the head movement is possible with the help of muscles. However, the shape and type of motion depends on the structure and shape of the cervical spine and the interaction between them. Cervical spine kinematics depends on the anatomy of the bones and joints. Bazhdok et al (2000) investigated the cervical kinematics and mechanical behavior of the spine and its anatomical connections. They have examined the atlanto- occipital joint motion during flexion-extension and rotation as well as the mechanism of paradoxical motion of atlanto- axial joint by radiography. Bifalkou et al (2011) studied the inter-vertebral motion based on arc kinematic commentary of video fluoroscopy. They showed that the diagnosis of biomechanical instability can be done based on the kinematic examination of the spine obtained in sagittal images. They also declared that the fluoroscopy can be used as a tool for study. Using an automated algorithm, image adaption was carried out and the motion direction of vertebrae was tracked. In the present study, some patients were selected among patients with cervical disc degeneration. Following imaging by fluoroscopy, the instantaneous center of the spinal action was calculated. It was used as a biomechanical criterion and the treatment group was compared with the healthy group. The loci of the instantaneous centers of the two groups were compared and its difference with the value of healthy group was calculated. A biomechanical criterion was introduced as a basis for comparison of normal and

  10. In Vitro Bioavailability Study of an Antiviral Compound Enisamium Iodide

    Directory of Open Access Journals (Sweden)

    Eleonore Haltner-Ukomadu

    2018-01-01

    Full Text Available An investigation into the biopharmaceutics classification and a study of the in vitro bioavailability (permeability and solubility of the antiviral compound enisamium iodide (4-(benzylcarbamoyl-1-methylpyridinium iodide were carried out. The solubility of enisamium iodide was determined in four different buffers. Apparent intestinal permeability (Papp of enisamium iodide was assessed using human colon carcinoma (Caco-2 cells at three concentrations. The solubility of enisamium iodide in four buffer solutions from pH 1.2 to 7.5 is about 60 mg/mL at 25 °C, and ranges from 130 to 150 mg/mL at 37 °C, depending on the pH. Based on these results, enisamium iodide can be classified as highly soluble. Enisamium iodide demonstrated low permeability in Caco-2 experiments in all tested concentrations of 10–100 μM with permeability coefficients between 0.2 × 10−6 cm s−1 and 0.3 × 10−6 cm s−1. These results indicate that enisamium iodide belongs to class III of the Biopharmaceutics Classification System (BCS due to its high solubility and low permeability. The bioavailability of enisamium iodide needs to be confirmed in animal and human studies.

  11. In vitro model to study cocaine and its contaminants.

    Science.gov (United States)

    Steinmetz, Aline; Steffens, Luiza; Morás, Ana Moira; Prezzi, Flávia; Braganhol, Elizandra; Saffi, Jenifer; Ortiz, Rafael Scorsatto; Barros, Helena M T; Moura, Dinara Jaqueline

    2018-04-01

    Cocaine is one of the most popular illicit drug worldwide. Due its great addictive potential, which leads to euphoria and hyperactivity, it is considered a public health concern. At the central nervous system, the drug acts inhibiting catecholamine re-uptake. It is now known that in addition to the toxicity of the drug itself, the contaminants present in the street drug have raised concern about the harmful effects on health. Toxicological in vivo and in vitro studies have demonstrated the toxic effects of cocaine correlated with the generation of reactive oxygen species (ROS), which in turn lead to oxidative damage to the cells. Therefore the aim of this work was to propose an in vitro model that reunites the main parameters of toxicity of the cocaine already observed in the literature so far, and we tested this model using cocaine and seizure cocaine sample (SCS), kindly provided by Federal Police of Brazil. For that, we used a C6 glioblastoma cells and evaluated cell death, oxygen reactive species induction, oxidation of macromolecules as membrane lipids and DNA and loss of mitochondrial membrane potential after cocaine exposure. The results showed that cocaine can decrease cellular viability in a dose-dependent way in the C6 cell immortalized and astrocytes primary culture. Cocaine also induced cellular death by apoptosis. However, in the seizure cocaine sample (SCS), the predominant cell death was due to necrosis. Using dichlorofluorescein (DCF) assay, we confirmed ROS production after cocaine exposition. In agreement with these findings, occurred an increasing in MDA production, as well as increased superoxide dismutase (SOD) and catalase (CAT) activity. The induction of DNA damage was observed after cocaine. Our results demonstrate the occurrence of mitochondrial dysfunction by depolarization of mitochondrial membrane as a consequence of cocaine treatment. In summary, these results demonstrated that cocaine can induce reactive oxygen species formation

  12. In Vitro Study of Directly Bioprinted Perfusable Vasculature Conduits.

    Science.gov (United States)

    Zhang, Yahui; Yu, Yin; Akkouch, Adil; Dababneh, Amer; Dolati, Farzaneh; Ozbolat, Ibrahim T

    2015-01-01

    The ability to create three dimensional (3D) thick tissues is still a major tissue engineering challenge. It requires the development of a suitable vascular supply for an efficient media exchange. An integrated vasculature network is particularly needed when building thick functional tissues and/or organs with high metabolic activities, such as the heart, liver and pancreas. In this work, human umbilical vein smooth muscle cells (HUVSMCs) were encapsulated in sodium alginate and printed in the form of vasculature conduits using a coaxial deposition system. Detailed investigations were performed to understand the dehydration, swelling and degradation characteristics of printed conduits. In addition, because perfusional, permeable and mechanical properties are unique characteristics of natural blood vessels, for printed conduits these properties were also explored in this work. The results show that cells encapsulated in conduits had good proliferation activities and that their viability increased during prolonged in vitro culture. Deposition of smooth muscle matrix and collagen was observed around the peripheral and luminal surface in long-term cultured cellular vascular conduit through histology studies.

  13. In vitro acellular dissolution of mineral fibres: A comparative study.

    Science.gov (United States)

    Gualtieri, Alessandro F; Pollastri, Simone; Bursi Gandolfi, Nicola; Gualtieri, Magdalena Lassinantti

    2018-05-04

    The study of the mechanisms by which mineral fibres promote adverse effects in both animals and humans is a hot topic of multidisciplinary research with many aspects that still need to be elucidated. Besides length and diameter, a key parameter that determines the toxicity/pathogenicity of a fibre is biopersistence, one component of which is biodurability. In this paper, biodurability of mineral fibres of social and economic importance (chrysotile, amphibole asbestos and fibrous erionite) has been determined for the first time in a systematic comparative way from in vitro acellular dissolution experiments. Dissolution was possible using the Gamble solution as simulated lung fluid (pH = 4 and at body temperature) so to reproduce the macrophage phagolysosome environment. The investigated mineral fibres display very different dissolution rates. For a 0.25 μm thick fibre, the calculated dissolution time of chrysotile is in the range 94-177 days, very short if compared to that of amphibole fibres (49-245 years), and fibrous erionite (181 years). Diffraction and SEM data on the dissolution products evidence that chrysotile rapidly undergoes amorphization with the formation of a nanophasic silica-rich fibrous metastable pseudomorph as first dissolution step whereas amphibole asbestos and fibrous erionite show minor signs of dissolution even after 9-12 months.

  14. In vitro study of transverse strength of fiber reinforced composites.

    Science.gov (United States)

    Mosharraf, R; Hashemi, Z; Torkan, S

    2011-01-01

    Reinforcement with fiber is an effective method for considerable improvement in flexural properties of indirect composite resin restorations. The aim of this in-vitro study was to compare the transverse strength of composite resin bars reinforced with pre-impregnated and non-impregnated fibers. Thirty six bar type composite resin specimens (3×2×25 mm) were constructed in three groups. The first group was the control group (C) without any fiber reinforcement. The specimens in the second group (P) were reinforced with pre-impregnated fibers and the third group (N) with non-impregnated fibers. These specimens were tested by the three-point bending method to measure primary transverse strength. Data were statistically analyzed with one way ANOVA and Tukey's tests. There was a significant difference among the mean primary transverse strength in the three groups (Ptransverse strength (Pstudy, it was concluded that reinforcement with fiber considerably increased the transverse strength of composite resin specimens, but impregnation of the fiber used implemented no significant difference in the transverse strength of composite resin samples.

  15. Biotelemetric Wireless Intracranial Pressure Monitoring: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Mohammad H. Behfar

    2015-01-01

    Full Text Available Assessment of intracranial pressure (ICP is of great importance in management of traumatic brain injuries (TBIs. The existing clinically established ICP measurement methods require catheter insertion in the cranial cavity. This increases the risk of infection and hemorrhage. Thus, noninvasive but accurate techniques are attractive. In this paper, we present two wireless, batteryless, and minimally invasive implantable sensors for continuous ICP monitoring. The implants comprise ultrathin (50 μm flexible spiral coils connected in parallel to a capacitive microelectromechanical systems (MEMS pressure sensor. The implantable sensors are inductively coupled to an external on-body reader antenna. The ICP variation can be detected wirelessly through measuring the reader antenna’s input impedance. This paper also proposes novel implant placement to improve the efficiency of the inductive link. In this study, the performance of the proposed telemetry system was evaluated in a hydrostatic pressure measurement setup. The impact of the human tissues on the inductive link was simulated using a 5 mm layer of pig skin. The results from the in vitro measurement proved the capability of our developed sensors to detect ICP variations ranging from 0 to 70 mmHg at 2.5 mmHg intervals.

  16. In vitro and biotransformational studies of aloe barbadensis mill

    International Nuclear Information System (INIS)

    Badar, Z.; Khan, S.; Ali, S.K.; Choudhary, M.I.

    2014-01-01

    Tissue culture technology can play an important role in the yield improvement of active ingredients of medicinal plants. In the present study, the potential of regeneration system of Aloe barbadensis along with biotransformational ability was explored. The maximum calli (5.65+-1.90; fresh weight) were induced under the dark condition on MS (Murashige and Skoog) medium supplemented with 2.0 mg/L of NAA (alpha-naphthaleneacetic acid), as compared to light. The highest number of shoots (12.725) were proliferated on MS regeneration medium, containing 1.0 mg/L of BAP (6-Benzyl Aminopurine) and 0.1 mg/L of IBA (Indole-3-Butyric Acid) incubated at 22 +- 2 degree C and 16/8 hr photoperiod provided by white fluorescent tube lights. These plantlets were then transferred onto root inducing medium and maximum number of roots (8.0 +- 0.70) with longer length (6.38 +- 0.34 cm) acquired at 1.0 mg/L of IBA within 14-20 days. The regenerated plants were shifted to green house for acclimatization. Effect of plant growth regulators and light was also assessed on callus cultures produced from conventionally propagated and in-vitro regenerated A. barbadensis plants. Biotransformation ability of Aloe barbadensis cell suspension culture was studied by incubation with (+)-adrenosterone (1), which afforded three products; D1-2-dehydroadrenosterone (2), 5a-androst-1-ene-3, 11, 17-trione (3) and 17b-hydroxyandrost-4-ene-3, 11-dione (4). These metabolites were structurally characterized on the basis of spectroscopic techniques. (author)

  17. Improving the fit of implant prosthetics: an in vitro study.

    Science.gov (United States)

    Yannikakis, Stavros; Prombonas, Anthony

    2013-01-01

    Accurate and passive fit between a prosthesis and its supporting implants has been considered a prerequisite for successful long-term osseointegration. The objective of this in vitro study was to evaluate the strain development during tightening of a five-unit screw-retained superstructure constructed using five different methods. Five-unit screw-retained fixed partial prostheses (n = 25) were fabricated on three implants embedded in an epoxy resin block using five different methods: (1) cobalt-chromium (Co-Cr), plastic cylinders, one-piece cast; (2) Co-Cr, plastic cylinders, framework sectioned, preceramic laser-welding soldering; (3) gold-platinum (Au-Pt), gold cylinders, one-piece cast; (4) Au-Pt, gold cylinders, framework sectioned, preceramic laser-welding soldering; (5) Co-Cr, one-piece cast, and cementation to "passive abutments" (Southern Implants) after final finishing and polishing. Strain gauges (SG) were attached to the fixed partial prosthesis (FPP) and to the resin block to measure the stress created during screw tightening. The combination of Co-Cr alloy and plastic cylinders in a one-piece cast showed such an inadequate fit among the fabricated methods that this group was excluded from the remainder of the experiment. Specimens of Au-Pt cast on gold cylinders in one piece showed higher strain development than the other groups used in this study, with strains ranging from 223.1 to 2,198.1 Μm/m. Sectioning and soldering significantly improved the overall fit. FPPs of Co-Cr in a one-piece cast cemented to "passive abutments" produced the best level of fit, with the least strain development in the prosthesis and the resin block (59 to 204.6 Μm/m). Absolute fit of superstructures on implants is not possible using conventional laboratory procedures. Cementing FPPs onto prefabricated cylinders directly onto the implants significantly reduces strain development compared to the other fabrication methods.

  18. Mechanism of oil-pulling therapy - in vitro study.

    Science.gov (United States)

    Asokan, Sharath; Rathinasamy, T K; Inbamani, N; Menon, Thangam; Kumar, S Senthil; Emmadi, Pamela; Raghuraman, R

    2011-01-01

    Oil pulling has been used extensively as a traditional Indian folk remedy without scientific proof for many years for strengthening teeth, gums and jaws and to prevent decay, oral malodor, bleeding gums and dryness of throat and cracked lips. The aim of this study was to evaluate the antibacterial activity of sesame oil and lignans isolated from sesame oil on oral microorganisms and to check whether saponification or emulsification occurs during oil-pulling therapy. The in vitro study was carried out in three different phases: (1) Antibacterial activity of the lignans and sesame oil were tested by minimum inhibitory concentration assay by agar dilution method and agar well diffusion method, respectively. (2) Increase in free fatty acid level of oil and the quantity of sodium hydroxide (NaOH) used up in the titration are good indicators of saponification process. This was assessed using analytical tests for vegetable oils. (3) Swished oil was observed under light microscope to assess the status of the oil, presence of microorganisms, oral debris and foreign bodies. Sesamin and sesamolin isolated from sesame oil did not have any antibacterial effect against oral microorganisms like Streptococcus mutans, Streptococcus mitis and Streptococcus viridans. Emulsification of sesame oil occurs during oil-pulling therapy. Increased consumption of NaOH in titration is a definite indication of a possible saponification process. The myth that the effect of oil-pulling therapy on oral health was just a placebo effect has been broken and there are clear indications of possible saponification and emulsification process, which enhances its mechanical cleaning action.

  19. In vitro study of the interaction between some fluoroquinolones and ...

    African Journals Online (AJOL)

    The cup diffusion method (CD) was used to evaluate the in vitro interaction of some fluoroquinolones (ciprofloxacin, pefloxacin and levofloxacin) with extracts of Kola nitida seed (KNS) against a clinical isolate of Escherichia coli. Minimum inhibitory concentration (MIC) of the drugs was determined separately and in ...

  20. In vitro study of interaction between quinine and Garcinia kola

    African Journals Online (AJOL)

    Methods: In vitro interaction between quinine and G. kola was conducted at 37 ± 0.1 °C. Adsorption of ... The amount of quinine adsorbed and desorbed was quantified using HPLC. A ..... first place, G. kola is known to contain flavonoids.

  1. Interaction between Protein, Phytate, and Microbial Phytase. In Vitro Studies

    NARCIS (Netherlands)

    Kies, A.K.; Jonge, de L.H.; Kemme, P.A.; Jongbloed, A.W.

    2006-01-01

    The interaction between protein and phytate was investigated in vitro using proteins extracted from five common feedstuffs and from casein. The appearance of naturally present soluble protein-phytate complexes in the feedstuffs, the formation of complexes at different pHs, and the degradation of

  2. Elasticity in Elastics-An in-vitro study.

    Science.gov (United States)

    Kamisetty, Supradeep Kumar; Nimagadda, Chakrapani; Begam, Madhoom Ponnachi; Nalamotu, Raghuveer; Srivastav, Trilok; Gs, Shwetha

    2014-04-01

    analyzed with student independent - t test, analysis of variance and the Tukey - HSD test at p elastics had greater cross sectional area than latex elastics in all types of elastics. Forestadent heavy elastics had grater cross sectional area than GAC and Glenroe. There was no statistically significant difference in the internal diameter in between all type of elastics. Forestadent non latex elastics had greater breaking force compared to GAC and Glenroe elastics. Forces generated by the elastics decreased over 48 hours to an average load approximating 65-75% of the manufacturer's values. Force degradation was greater in non latex elastics compared to latex elastics. The results of the study demonstrated that the clinical choice of elastics should be based on the patient's medical history and the specific mechanical properties of the type of elastic. How to cite the article: Kamisetty SK, Nimagadda C, Begam MP, Nalamotu R, Srivastav T, Shwetha GS. Elasticity in Elastics-An in-vitro study. J Int Oral Health 2014;6(2):96-105.

  3. Xyloside effects on in vitro hematopoiesis: Functional and biochemical studies

    International Nuclear Information System (INIS)

    Kirby, S.L.; Bentley, S.A.

    1991-01-01

    Xyloside supplementation of long-term bone marrow cultures (LTBMCs) has been reported to result in greatly enhanced proliferation of hematopoietic stem cells. This was presumed to be the result of xyloside-mediated perturbation of proteoglycan synthesis by marrow-derived stromal cells. To investigate this phenomenon, we first studied the effects of xyloside supplementation on proteoglycan synthesis by D2XRadII bone marrow stromal cells, which support hematopoietic stem cell proliferation in vitro. D2XRadII cells were precursor labelled with 35S-sulfate, and proteoglycans separated by ion exchange chromatography, isopyknic CsCl gradient centrifugation, and gel filtration HPLC. Xyloside-supplemented cultures showed an approximately fourfold increase in total 35S incorporation, mainly as free chondroitin-dermatan sulfate (CS/DS) glycosaminoglycan chains in the culture media. Both xyloside supplemented and nonsupplemented cultures synthesized DS1, DS2, and DS3 CS/DS proteoglycans as previously described. In contrast to previous reports, xyloside was found to inhibit hematopoietic cell growth in LTBMC. Inhibitory effects were observed both in cocultures of IL-3-dependent hematopoietic cell lines with supportive stromal cell lines and in primary murine LTBMCs. Xyloside was found to have a marked inhibitory effect on the growth of murine hematopoietic stem cells and IL-3-dependent hematopoietic cell lines in clonal assay systems and in suspension cultures. In contrast, dialyzed concentrated conditioned media from LTBMCs had no such inhibitory effects. These findings suggest that xyloside-mediated inhibition of hematopoietic cell growth in LTBMC resulted from a direct effect of xyloside on proteoglycan synthesis by hematopoietic cells

  4. Determining the direction of tooth grinding: an in vitro study.

    Science.gov (United States)

    ten Berge, F; te Poel, J; Ranjitkar, S; Kaidonis, J A; Lobbezoo, F; Hughes, T E; Townsend, G C

    2012-08-01

    The analysis of microwear patterns, including scratch types and widths, has enabled reconstruction of the dietary habits and lifestyles of prehistoric and modern humans. The aim of this in vitro study was to determine whether an assessment of microwear features of experimental scratches placed on enamel, perpendicularly to the direction of grinding, could predict the grinding direction. Experimental scratches were placed using a scalpel blade on standardised wear facets that had been prepared by wearing opposing enamel surfaces in an electromechanical tooth wear machine. These control 'baseline' facets (with unworn experimental scratches) were subjected to 50 wear cycles, so that differential microwear could be observed on the leading and trailing edges of the 'final' facets. In Group 1 (n=28), the 'footprint' microwear patterns corresponding to the known grinding direction of specimens in the tooth wear machine were identified. Then, they were used to predict the direction of tooth grinding blindly in the same sample after a 2-week intermission period. To avoid overfitting the predictive model, its sensitivity was also cross-validated in a new sample (Group 2, n=14). A crescent-shaped characteristic observed in most experimental scratches matched the grinding direction on all occasions. The best predictor of the direction of grinding was a combined assessment of the leading edge microwear pattern and the crescent characteristic (82.1% in Group 1 and 92.9% in Group 2). In conclusion, a simple scratch test can determine the direction of tooth grinding with high reliability, although further improvement in sensitivity is desirable. © 2012 Blackwell Publishing Ltd.

  5. Biomechanics and mechanobiology in functional tissue engineering

    Science.gov (United States)

    Guilak, Farshid; Butler, David L.; Goldstein, Steven A.; Baaijens, Frank P.T.

    2014-01-01

    The field of tissue engineering continues to expand and mature, and several products are now in clinical use, with numerous other preclinical and clinical studies underway. However, specific challenges still remain in the repair or regeneration of tissues that serve a predominantly biomechanical function. Furthermore, it is now clear that mechanobiological interactions between cells and scaffolds can critically influence cell behavior, even in tissues and organs that do not serve an overt biomechanical role. Over the past decade, the field of “functional tissue engineering” has grown as a subfield of tissue engineering to address the challenges and questions on the role of biomechanics and mechanobiology in tissue engineering. Originally posed as a set of principles and guidelines for engineering of load-bearing tissues, functional tissue engineering has grown to encompass several related areas that have proven to have important implications for tissue repair and regeneration. These topics include measurement and modeling of the in vivo biomechanical environment; quantitative analysis of the mechanical properties of native tissues, scaffolds, and repair tissues; development of rationale criteria for the design and assessment of engineered tissues; investigation of the effects biomechanical factors on native and repair tissues, in vivo and in vitro; and development and application of computational models of tissue growth and remodeling. Here we further expand this paradigm and provide examples of the numerous advances in the field over the past decade. Consideration of these principles in the design process will hopefully improve the safety, efficacy, and overall success of engineered tissue replacements. PMID:24818797

  6. Quantitative methods for reconstructing tissue biomechanical properties in optical coherence elastography: a comparison study

    International Nuclear Information System (INIS)

    Han, Zhaolong; Li, Jiasong; Singh, Manmohan; Wu, Chen; Liu, Chih-hao; Wang, Shang; Idugboe, Rita; Raghunathan, Raksha; Sudheendran, Narendran; Larin, Kirill V; Aglyamov, Salavat R; Twa, Michael D

    2015-01-01

    We present a systematic analysis of the accuracy of five different methods for extracting the biomechanical properties of soft samples using optical coherence elastography (OCE). OCE is an emerging noninvasive technique, which allows assessment of biomechanical properties of tissues with micrometer spatial resolution. However, in order to accurately extract biomechanical properties from OCE measurements, application of a proper mechanical model is required. In this study, we utilize tissue-mimicking phantoms with controlled elastic properties and investigate the feasibilities of four available methods for reconstructing elasticity (Young’s modulus) based on OCE measurements of an air-pulse induced elastic wave. The approaches are based on the shear wave equation (SWE), the surface wave equation (SuWE), Rayleigh-Lamb frequency equation (RLFE), and finite element method (FEM), Elasticity values were compared with uniaxial mechanical testing. The results show that the RLFE and the FEM are more robust in quantitatively assessing elasticity than the other simplified models. This study provides a foundation and reference for reconstructing the biomechanical properties of tissues from OCE data, which is important for the further development of noninvasive elastography methods. (paper)

  7. A simple and efficient in vitro method for metabolism studies of radiotracers

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang-Yoon; Choe, Yearn Seong E-mail: yschoe@samsung.co.krjeewoo@snu.ac.kr; Kim, Dong Hyun; Park, Bok-Nam; Kim, Sang Eun; Choi, Yong; Lee, Kyung-Han; Lee, Jeewoo E-mail: yschoe@samsung.co.krjeewoo@snu.ac.kr; Kim, Byung-Tae

    2001-05-01

    In vitro metabolism of acetylcholinesterase inhibitors containing 3-[{sup 18}F]fluoromethylbenzyl- ([{sup 18}F]1) and 4-[{sup 18}F]fluorobenzyl-piperidine moieties ([{sup 18}F]2) was studied and compared with the in vivo metabolism. Defluorination of the [{sup 18}F]1 mainly occurred to generate [{sup 18}F]fluoride ion both in vitro and in vivo. In contrast, the [{sup 18}F]2 was converted into an unknown polar metabolite in both metabolism methods and another metabolite, 4-[{sup 18}F]fluorobenzoic acid in vitro. These results demonstrated that the in vitro method can be used to predict the in vivo metabolism of both radiotracers.

  8. A simple and efficient in vitro method for metabolism studies of radiotracers

    International Nuclear Information System (INIS)

    Lee, Sang-Yoon; Choe, Yearn Seong; Kim, Dong Hyun; Park, Bok-Nam; Kim, Sang Eun; Choi, Yong; Lee, Kyung-Han; Lee, Jeewoo; Kim, Byung-Tae

    2001-01-01

    In vitro metabolism of acetylcholinesterase inhibitors containing 3-[ 18 F]fluoromethylbenzyl- ([ 18 F]1) and 4-[ 18 F]fluorobenzyl-piperidine moieties ([ 18 F]2) was studied and compared with the in vivo metabolism. Defluorination of the [ 18 F]1 mainly occurred to generate [ 18 F]fluoride ion both in vitro and in vivo. In contrast, the [ 18 F]2 was converted into an unknown polar metabolite in both metabolism methods and another metabolite, 4-[ 18 F]fluorobenzoic acid in vitro. These results demonstrated that the in vitro method can be used to predict the in vivo metabolism of both radiotracers

  9. Cytogenetic studies of three triazine herbicides. I. In vitro studies

    Science.gov (United States)

    Atrazine, simazine, and cyanazine are widely used pre-emergence and post-emergence triazine herbicides that have made their way into the potable water supply of many agricultural communities. Because of this and the prevalence of contradictory cytogenetic studies in the literatur...

  10. In vitro study of the photodynamic antimicrobial therapy (PACT) against promastigotes form of the leishmania (viannia) braziliensis: in vitro study

    Science.gov (United States)

    Barbosa, Artur F. S.; Sangiorgi, Bruno B.; Galdino, Suely L.; Pitta, Ivan R.; Barral-Netto, Manoel; Pinheiro, Antônio L. B.

    2013-03-01

    Leishmaniasis, a protozoan parasitic disease that remains a major worldwide health problem with high endemicity in developing countries. Treatment of cutaneous Leishmaniasis (CL) should be decided by the clinical lesions, etiological species and its potential to develop into mucosal Leishmaniasis. High cost, systemic toxicity, and diminished efficacy due to development of parasite resistance are the serious drawbacks of current treatment options. Thus, identifying new, effective, and safer anti-leishmanial drug(s) is of paramount importance. The aim of this study was to verify the effectiveness of PACT in vitro, as a new technique for the treatment of Leishmaniasis. For this, semiconductor laser (λ = 660nm, 40mW, 8.4J/cm2, CW) associated to phenothiazine's derivatives (5 and 10 μg/ml, TBO, Methylene Blue or Phenothiazine) on the promastigotes form of Leishmania braziliensis in a single session was used. Viability of the parasites was assessed in quadruplicates of each group. The samples were removed and analyzed in a hemocytometer 72h after PACT. We found an important decrease in the number of viable parasites on all treated groups in comparison to their controls. The results of present study showed significant percentage of lethality (above 92%) of the protocol. The 98.33% of lethality was achieved with 10 μg/ml of FTZ. No lethality was seen on groups treated neither with laser nor with each compounds separately. The results are promising and indicative that the use of PACT may be a powerful treatment of Leishmaniasis when compared to already available ones.

  11. The Influence of Artificial Cervical Disc Prosthesis Height on the Cervical Biomechanics: A Finite Element Study.

    Science.gov (United States)

    Yuan, Wei; Zhang, Haiping; Zhou, Xiaoshu; Wu, Weidong; Zhu, Yue

    2018-05-01

    Artificial cervical disc replacement is expected to maintain normal cervical biomechanics. At present, the effect of the Prestige LP prosthesis height on cervical biomechanics has not been thoroughly studied. This finite element study of the cervical biomechanics aims to predict how the parameters, like range of motion (ROM), adjacent intradiscal pressure, facet joint force, and bone-implant interface stress, are affected by different heights of Prestige LP prostheses. The finite element model of intact cervical spine (C3-C7) was obtained from our previous study, and the model was altered to implant Prestige LP prostheses at the C5-C6 level. The effects of the height of 5, 6, and 7 mm prosthesis replacement on ROM, adjacent intradiscal pressure, facet joint force, as well as the distribution of bone-implant interface stress were examined. ROM, adjacent intradiscal pressure, and facet joint force increased with the prosthesis height, whereas ROM and facet joint force decreased at C5-C6. The maximal stress on the inferior surface of the prostheses was greater than that on the superior surface, and the stresses increased with the prosthesis height. The biomechanical changes were slightly affected by the height of 5 and 6 mm prostheses, but were strongly affected by the 7-mm prosthesis. An appropriate height of the Prestige LP prosthesis can preserve normal ROM, adjacent intradiscal pressure, and facet joint force. Prostheses with a height of ≥2 mm than normal can lead to marked changes in the cervical biomechanics and bone-implant interface stress. Copyright © 2018 Elsevier Inc. All rights reserved.

  12. Human schistosomiasis mansoni: studies on in vitro granuloma modulation

    Directory of Open Access Journals (Sweden)

    Juçara C. Parra

    1992-01-01

    Full Text Available Infection with Schistosoma mansoni induces humoral and T cell mediated responses and leads to delayed hipersensitivity that results in granulomatous inflamatory disease around the parasite eggs. Regulation of these responses resulting in a reduction in this anti-egg inflamatory disease is appsrently determined by idiotypic repertoires of the patient, associated with genetic background and multiple external factors. We have previously reported on idiotype/anti-idiotype-receptor transactions in clinical human schistosomiasis. These findings support a hypothesis that anti-SEA cross-reactive idiotypes develop in some patients during the course of a chronic infection and participate in regulation of anti-SEA cellular immune responses. We repport here on experiments wich extend those observations to the regulation of granulomatous hypersensitivity measured by an in vitro granuloma model. T cells from chronic intestinal schistosomiasis patients were stimulated in vitro with anti-SEA idiotypes and assayed in an autologous in vitro granuloma assay for modulation of granuloma formation. These anti-SEA idiotype reactive T cells were capable of regulating autologous in vitro granuloma formation. This regulatory activity, initiated with stimulatory anti-SEA idiotypic antibodies, was antigenically specific and was dependent on the present of intact (F(ab'2 immunoglobulin molecules. The ability to elicit this regulatory activity appears to be dose dependent and is more easily demonstrated in chronically infected intestinal patients or SEA sensitized individuals. These data support the hypothesis that anti-SEA cross reactive idiotypes are important in regulating granulomatous hypersensitivy in chronic intestinal schistosomiasis patients and these cross-reactive idiotypes appear to play a major role in cell-cell interactions which result in the regulation of anti-SEA cellular immune responses.

  13. Toward characterization of craniofacial biomechanics.

    Science.gov (United States)

    Szwedowski, Tomasz D; Whyne, Cari M; Fialkov, Jeffrey A

    2010-01-01

    Surgical reconstruction of craniofacial deformities has advanced significantly in recent years. However, unlike orthopedic surgery of the appendicular skeleton, the biomechanical characterization of the human craniofacial skeleton (CFS) has yet to be elucidated. Attempts to simplify facial skeletal structure into straightforward mechanical device analogies have been insufficient in delineating craniofacial biomechanics. Advanced computational engineering analysis methods offer the potential to accurately and completely define the internal mechanical environment of the CFS. This study developed a finite element (FE) model in the I-deas 10 FEM software package of a preserved cadaveric human CFS and compared the predictions of this model against in vitro strain measurement of simulated occlusal loading forces from a single masseter muscle. The FE model applied shell element modeling to capture the behavior of the thin cortical bone that may play an important role in stabilizing the facial structures against functional loads. In vitro testing included strain measurements at 12 locations for a total of 16 independent channels with less than 150 N of tensile force applied through the masseter muscle into the zygomatic arch origin at 4 different orientations, with 3 trials of 500 recorded data points for each loading orientation. Linear regression analysis yielded a moderate prediction (r = 0.57) between the model and experimentally measured strains. Exclusion of strain comparisons in regions that required greater modeling assumptions greatly improved the correlation (r = 0.70). Future validation studies will benefit from improved placement of strain gauges as guided by FE model predicted strain patterns.

  14. Mechanism of H. pylori intracellular entry: an in vitro study

    Directory of Open Access Journals (Sweden)

    Hui eLiu

    2012-03-01

    Full Text Available The majority of H. pylori reside on gastric epithelial cell surfaces and in the overlying mucus, but a small fraction of H. pylori enter host epithelial and immune cells. To explore the role of the nudA invasin in host cell entry, a ΔnudA deletion derivative of strain J99 was constructed and transformants were verified by PCR and by fluorescence in situ hybridization. AGS cells were inoculated with either wild type (WT strain J99 or its ΔnudA mutant to determine the fraction of bacteria that were bound to the cells and inside these cells using the gentamicin protection assay. We observed no significant difference between either the density of H. pylori bound to AGS cell membranes or the density of intracellular H. pylori. To further explore this finding, separate chambers of each culture were fixed in glutaraldehyde for transmission electron microscopy (TEM and immunogold TEM. This addition to the classical gentamicin assay demonstrated that there were significantly more intracellular, and fewer membrane-bound, H. pylori in WT-infected AGS cells than in ΔnudA allele infected cells. Thus, the sum of intracellular and membrane-bound H. pylori was similar in the two groups. Since no other similar TEM study has been performed, it is at present unknown whether our observations can be reproduced by others Taken together however, our observations suggest that the classical gentamicin protection assay is not sufficiently sensitive to analyze H. pylori cell entry and that the addition of TEM to the test demonstrate that nudA plays a role in H. pylori entry into AGS cells in vitro. In addition, deletion of the invasin gene appears to limit H. pylori to the AGS cell surface, where it may be partly protected against gentamicin. In contrast, this specific environment may render H. pylori more vulnerable to host defense and therapeutic intervention, and less prone to trigger normal immune, carcinogenic, and other developmental response pathways.

  15. Radiosensitivity and in vitro studies of Citrus suhuiensis

    Energy Technology Data Exchange (ETDEWEB)

    Noor, N. M.; Jeevamoney, J. [School of Biosciences and Biotechnology, University Kebangsaan (Malaysia); Clyde, M. M. [School of Environmental and Natural Resource Sciences, University Kebangsaan (Malaysia); Rao, V. R. [3APO Office, Bioversity International, Serdang, Selangor (Malaysia)

    2009-05-15

    Radiosensitivity tests and in vitro studies were carried out on two varieties of Citrus suhuiensis, ‘limau madu’ and ‘limau langkat’. Fresh seeds were desiccated for periods of 1, 2, 3 and 4 days and irradiated with gamma ray doses of 50, 100, 150, 200 and 250Gy. Shoot tips were also irradiated with gamma ray doses of 5, 10, 15, 20 and 25Gy. Results showed that lower moisture content seeds were more resistant to irradiation dose. It was determined that the LD50 of the ‘limau madu’ seeds was 200Gy at 25.48% moisture content, while the LD50 for ‘limau langkat’ seeds was 50Gy at 44.97% moisture content. A test on the DNA content of irradiated and non-irradiated samples using flow cytometry methods proved that irradiation had affected the DNA content (C-value) of the plant cells. Generally the 2C DNA content (pg) increases with increasing dose of radiation. Though low doses of radiation (50-100 Gy) resulted in a prominent effect on 2C DNA content, a few plants showed another 4C DNA peak with various seed desiccation levels. In inducing multiple shoots from apical shoot tips, it was found that MS medium with the addition of 2.5mgL{sup -1} BAP was the optimal medium, where one explant was able to produce a mean of 13.5 adventitious shoots. Further results showed that MS medium with the addition of 0.6mgL{sup -1} GA3 was the best medium for shoot elongation. In inducing root formation, 0.2mgL{sup -1} NAA in MS medium proved to be the best medium. MT medium with the addition of growth regulators at different concentrations were tested on mature and immature embryos for the production of somatic embryos. It was found that immature embryos cultured on MT medium with 500mgL{sup -1} malt extract, 0.5-1.0mgL{sup -1} 2, 4-D and 0.5 1.0mgL{sup -1} BAP could produce proembryonic callus, which progressed to develop viable somatic embryos. (author)

  16. The effect of trochlear dysplasia on patellofemoral biomechanics: a cadaveric study with simulated trochlear deformities.

    Science.gov (United States)

    Van Haver, Annemieke; De Roo, Karel; De Beule, Matthieu; Labey, Luc; De Baets, Patrick; Dejour, David; Claessens, Tom; Verdonk, Peter

    2015-06-01

    Trochlear dysplasia appears in different geometrical variations. The Dejour classification is widely used to grade the severity of trochlear dysplasia and to decide on treatment. To investigate the effect of trochlear dysplasia on patellofemoral biomechanics and to determine if different types of trochlear dysplasia have different effects on patellofemoral biomechanics. Controlled laboratory study. Trochlear dysplasia was simulated in 4 cadaveric knees by replacing the native cadaveric trochlea with different types of custom-made trochlear implants, manufactured with 3-dimensional printing. For each knee, 5 trochlear implants were designed: 1 implant simulated the native trochlea (control condition), and 4 implants simulated 4 types of trochlear dysplasia. The knees were subjected to 3 biomechanical tests: a squat simulation, an open chain extension simulation, and a patellar stability test. The patellofemoral kinematics, contact area, contact pressure, and stability were compared between the control condition (replica implants) and the trochlear dysplastic condition and among the subgroups of trochlear dysplasia. The patellofemoral joint in the trochlear dysplastic group showed increased internal rotation, lateral tilt, and lateral translation; increased contact pressures; decreased contact areas; and decreased stability when compared with the control group. Within the trochlear dysplastic group, the implants graded as Dejour type D showed the largest deviations for the kinematical parameters, and the implants graded as Dejour types B and D showed the largest deviations for the patellofemoral contact areas and pressures. Patellofemoral kinematics, contact area, contact pressure, and stability are significantly affected by trochlear dysplasia. Of all types of trochlear dysplasia, the models characterized with a pronounced trochlear bump showed the largest deviations in patellofemoral biomechanics. Investigating the relationship between the shape of the trochlea and

  17. Cardiac spheroids as promising in vitro models to study the human heart microenvironment

    DEFF Research Database (Denmark)

    Polonchuk, Liudmila; Chabria, Mamta; Badi, Laura

    2017-01-01

    Three-dimensional in vitro cell systems are a promising alternative to animals to study cardiac biology and disease. We have generated three-dimensional in vitro models of the human heart ("cardiac spheroids", CSs) by co-culturing human primary or iPSC-derived cardiomyocytes, endothelial cells an...

  18. Study of the system of tuberous root induction in vitro from ...

    African Journals Online (AJOL)

    Abstract. This study investigated the induction system of tuberous root in vitro from Rehmannia glutinosa. The roles of plant growth substance, carbohydrates, and minerals were evaluated for induction and development of tuberous root in vitro. The results show that Murashige and Skoog (MS) contributed greatly to induction ...

  19. Candida albicans biofilm development in vitro for photodynamic therapy study

    International Nuclear Information System (INIS)

    Suzuki, Luis Claudio

    2009-01-01

    Photodynamic therapy (PDT) is a phototherapy based on the use of a photo sensitizer (PS) in the presence of low intensity light with resonant wavelength of absorption of the PS and biological systems that can raise awareness, generating reactive oxygen species. Studies show that PDT has a lethal effect on Candida albicans. The biofilm formed by C. albicans is the cause of infections associated with medical devices such as catheters, with a proven resistance to antifungal agents, and the removal of the catheter colonized almost always is necessary. However, few studies in literature report the behavior and response of biofilm organized by C. albicans against PDT. The aims of this study were to develop a methodology for in vitro biofilm formation of C. albicans, evaluate the sensitivity of the biofilm of C. albicans to antimicrobial photodynamic therapy using PS as the methylene blue (MB) and hypocrellin B: La +3 (HBL a+3 ) and analyze the biofilm by Optical Coherence Tomography (OCT). For biofilm formation, discs were made from elastomeric silicone catheters. The PS were dissolved in solution of PBS, and the MB had two different concentrations tested in the biofilm: 100μM and 1mM; HBLa +3 only one of 10μM. The irradiation of both dyes with the microorganism was done by two different LEDs, one with red emission at λ = 630nm ± 20nm and the other one blue emission at λ = 460nm ± 30nm. We performed a curve of survival fraction versus time of irradiation of each sample with biofilm and suspension of the microorganism in the yeast form to verify the susceptibility of the front PDT. The yeast showed 100% reduction using both PS, but at different times of irradiation (30s to HBLa +3 and 6 min for the MB at 100μM). When the therapy was applied in biofilm, the MB 100μM did not show any significant reduction, while at concentration of 1mM was reduced by 100% after 6 min of irradiation. The HBLa +3 biofilm group showed a lower reduction in the concentration of 10μM in

  20. Nano-TiO2/PEEK bioactive composite as a bone substitute material: in vitro and in vivo studies

    Science.gov (United States)

    Wu, Xiaomian; Liu, Xiaochen; Wei, Jie; Ma, Jian; Deng, Feng; Wei, Shicheng

    2012-01-01

    Background Compared with titanium (Ti) and other metal implant materials, poly(ether-ether ketone) (PEEK) shows outstanding biomechanical properties. A number of studies have also reported attractive bioactivity for nano-TiO2 (n-TiO2). Methods In this study, n-TiO2/PEEK nanocomposites were prepared, taking advantage of the unique properties of both PEEK polymer and n-TiO2. The in vitro and in vivo bioactivity of these nanocomposites was assessed against a PEEK polymer control. The effect of surface morphology or roughness on the bioactivity of the n-TiO2/PEEK nanocomposites was also studied. n-TiO2/PEEK was successfully fabricated and cut into disks for physical and chemical characterization and in vitro studies, and prepared as cylindrical implants for in vivo studies. Their presence on the surface and dispersion in the composites was observed and analyzed by scanning and transmission electron microscopy and X-ray photoelectron spectroscopy. Results Bioactivity evaluation of the nanocomposites revealed that pseudopods of osteoblasts preferred to anchor at areas where n-TiO2 was present on the surface. In a cell attachment test, smooth PEEK showed the lowest optical density value (0.56 ± 0.07) while rough n-TiO2/PEEK exhibited the highest optical density value (1.21 ± 0.34, P PEEK was approximately twice as large as that of PEEK (P PEEK, especially if it has a rough composite surface. A n-TiO2/PEEK composite with a rough surface could be a novel alternative implant material for orthopedic and dental applications. PMID:22419869

  1. Studies of the erythroid inductive microenvironment in vitro

    International Nuclear Information System (INIS)

    van Zant, G.; Goldwasser, E.; Pech, N.

    1977-01-01

    Spleen cells from radiated mice (XS), but not from normal mice (NS), when combined with mouse marrow cells in vitro, had two effects on hemoglobin synthesis: (1) increased baseline, and (2) augmented erythropoietin-induced, hemoglobin formation. Spleen cells from normal and radiated rats caused increased hemoglobin synthesis by rat marrow cells in a dose-dependent manner. In addition, lung and thymus cells from radiated rats, but not from normal rats, caused increased hemoglobin synthesis by rat marrow cells. Rat NS augmented hemoglobin formation by mouse marrow, but neither mouse NS nor mouse XS had an effect on rat marrow. Medium from rat NS cultures stimulated hemoglobin synthesis when added to rat marrow cells. The increases in baseline, and in the response to erythropoietin, were dependent on the amount of ''conditioned medium.'' The substance in the medium responsible for these effects was not erythropoietin

  2. Shoe heel abrasion and its possible biomechanical cause: a transversal study with infantry recruits.

    Science.gov (United States)

    Baumfeld, Daniel; Raduan, Fernando C; Macedo, Benjamim; Silva, Thiago Alexandre Alves; Baumfeld, Tiago; Favato, Danilo Fabrino; de Andrade, Marco Antonio Percope; Nery, Caio

    2015-11-19

    Excessive shoe heel abrasion is of concern to patients and shoe manufacturers, but little scientific information is available about this feature and its possible causes. The purpose of this study was to relate this phenomenon with biomechanical factors that could predispose to shoe heel abrasion. Ninety-seven recruits (median age 25) were enrolled in this study. Shoe abrasion was assessed manually with a metric plastic tape on the posterior part of the heel that comes in contact with the ground. The number of sprains, foot alignment, and calf muscle shortening (Silfverskiold test) was also assessed in order to relate it with shoe heel abrasion. After using our exclusion criteria, 86 recruits and 172 were considered for this study. The most common abrasion site was the lateral portion of the heel surface (50 %). Forty-four percent of the participants had neutral hind-foot alignment and 39 % had valgus alignment. Twenty-six (30 %) patients have had previous ankle or foot sprains. Neutral foot was related with less calf muscle shortening. On the other hand, valgus hind-foot alignment was more associated with Achilles shortening (p study was able to correlate shoe heel abrasion with biomechanical causes (neutral alignment-uniform abrasion/varus alignment-central and lateral abrasion). More effort has to be done to continue evaluating outsole abrasion with its possible biomechanical cause in order to predict and treat possible associated injuries.

  3. Comparison of transverse wires and half pins in Taylor Spatial Frame: A biomechanical study

    OpenAIRE

    Khurana, Ashish; Byrne, Carlton; Evans, Sam; Tanaka, Hiro; Haraharan, Kartik

    2010-01-01

    Abstract Background The aim of this study was to compare the stiffness characteristics of Taylor Spatial Frame (TSF) fixed with transverse wires and half pins. Design & Methods Experiments were carried out at the biomechanics laboratory at Cardiff University. All mechanical testing was performed with a servo hydraulic test frame (MTS 858 Mini Bionix II(R), MTS Corp., Mineapolis, USA). Custom built mounts were used to attach the bone rigidly to the one end of machine and the TSF ring to the ot...

  4. Comparative biomechanical study between fresh frozen bone and fresh frozen pasteurized bone process

    International Nuclear Information System (INIS)

    Ferdiansyah Abdurrahman

    1999-01-01

    To observe the biomechanical properties difference between fresh frozen bone and fresh frozen pasteurized bone process Thirty eight femurs bones taken from 6 years old primate.(macaca fascicularis) from Primate Nursery Center LIPI Bogor, 20 bones were 6 cm cut for bending test and 18 remains were 3 cm cut for compression test. All bones were frozen and then divided into two groups for each biomechanical study. First group (I 0 bones for bending test and 9 bones for compression test) were undergone fresh frozen procession only. The second group with the same amount was undergone fresh frozen and pasteurized on 60 degree C for three hours. Bending test was done until the bones were broken on control group and pasteurized group and the result was compared, the same procedure was done for compression test. The study was done in room temperature. The biomechanical test result was analyzed by two independent T tests. The bending test control group has ( mean 0.097 N / mm sup 2 (SD = 0.007) and the pasteurized group ( mean 0. I 0 1 N / mm sup 2 (SD = 0.0 1 3), there was no significant difference (p 0.399). The compression test control group has ( = mean 0.71 N / mm sup 2 (SD=0.128)where as the pasteurized group has(mean 0.50N/mm sup 2 (SD=0.111),there was significant difference (p =0.004) From the result biomechanical study on bending test, there was no significant difference of bone strength, whereas on compression test the fresh frozen with pasteurized bone group is 125% stronger than control group. The result of this study will be very useful for reconstruction bone allograft

  5. Cytokines in mycobacterial infections: `in vitro` and `ex vivo` studies

    Energy Technology Data Exchange (ETDEWEB)

    Flad, H.D.; Gercken, J.; Huebner, L.; Schlueter, C.; Ernst, M. [Forschungsinstitut Borstel (Germany). Inst. fuer Experimentelle Biologie und Medizin; Pryjma, J. [Uniwersytet Jagiellonski, Cracow (Poland)

    1995-12-31

    Different species of mycobacteria differ in their capacity to induce the production of tumor necrosis factor-{alpha} (TNF-{alpha}) by human monocytes `in vitro`. Whereas `M. tuberculosis` is a potent inducer of TNF-{alpha}, `M. leprae` is much less potent. TNF-{alpha} production is found to be associated with the availability of H{sub 2}O{sub 2} generated by activated monocytes, as superoxide enhancing H{sub 2}O{sub 2} concentration increases and catalase degrading H{sub 2}O{sub 2} decreases TNF-{alpha} production. Furthermore, `M. kansasii` with high intrinsic catalase induce less TNF-{alpha} than mycobacteria with low intrinsic catalase. `In vitro` infection of monocytes with `M. tuberculosis` leads to an impairment of the antigen-presenting capacity, as determined by a reduction of antigen-induced T cell proliferation and interferon {gamma} (IFN-{gamma}) production. Of crucial importance in this impairment is the `M. tuberculosis`-induced down-modulation of MHC class II antigens. The role of TNF-{alpha} `in vivo` is reflected in patients with various forms of leprosy. In skin lesions of lepromatous leprosy patients TNF-{alpha}, interleukin 1{beta} (IL-1{beta}), and IFN-{gamma} production are found to be rare, whereas these cytokines are well expressed in skin lesions of patients with tuberculoid leprosy. After multidrug chemotherapy an increase of local cytokine production is found. Taken together, these findings suggest that components of mycobacteria may interfere with local cell-mediated immune reactions `in vivo`. The molecular mechanisms involved in these local responses need to be defined. (author). 10 refs, 3 figs, 5 tabs.

  6. Cytokines in mycobacterial infections: 'in vitro' and 'ex vivo' studies

    International Nuclear Information System (INIS)

    Flad, H.D.; Gercken, J.; Huebner, L.; Schlueter, C.; Ernst, M.

    1995-01-01

    Different species of mycobacteria differ in their capacity to induce the production of tumor necrosis factor-α (TNF-α) by human monocytes 'in vitro'. Whereas 'M. tuberculosis' is a potent inducer of TNF-α, 'M. leprae' is much less potent. TNF-α production is found to be associated with the availability of H 2 O 2 generated by activated monocytes, as superoxide enhancing H 2 O 2 concentration increases and catalase degrading H 2 O 2 decreases TNF-α production. Furthermore, 'M. kansasii' with high intrinsic catalase induce less TNF-α than mycobacteria with low intrinsic catalase. 'In vitro' infection of monocytes with 'M. tuberculosis' leads to an impairment of the antigen-presenting capacity, as determined by a reduction of antigen-induced T cell proliferation and interferon γ (IFN-γ) production. Of crucial importance in this impairment is the 'M. tuberculosis'-induced down-modulation of MHC class II antigens. The role of TNF-α 'in vivo' is reflected in patients with various forms of leprosy. In skin lesions of lepromatous leprosy patients TNF-α, interleukin 1β (IL-1β), and IFN-γ production are found to be rare, whereas these cytokines are well expressed in skin lesions of patients with tuberculoid leprosy. After multidrug chemotherapy an increase of local cytokine production is found. Taken together, these findings suggest that components of mycobacteria may interfere with local cell-mediated immune reactions 'in vivo'. The molecular mechanisms involved in these local responses need to be defined. (author). 10 refs, 3 figs, 5 tabs

  7. Water-soluble non-aggregating zinc phthalocyanine and in vitro studies for photodynamic therapy

    Czech Academy of Sciences Publication Activity Database

    Makhseed, S.; Macháček, M.; Alfadly, W.; Tuhl, A.; Vinodh, M.; Šimůnek, T.; Nováková, V.; Kubát, Pavel; Rudolf, E.; Zimčík, P.

    2013-01-01

    Roč. 49, č. 95 (2013), s. 11149-11151 ISSN 1359-7345 Institutional support: RVO:61388955 Keywords : photosensitizers * in vitro studies * substituents Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 6.718, year: 2013

  8. Comparative analysis of perturbed molecular pathways identified in in vitro and in vivo toxicology studies

    NARCIS (Netherlands)

    Wiesinger, Martin; Mayer, Bernd; Jennings, Paul; Lukas, Arno

    The development of in vitro toxicological testing strategies are hampered by the difficulty in extrapolation to the intact organism. Academic toxicological literature contains a wealth of mechanistically rich information, especially arising from omic studies, which could potentially be utilized to

  9. Patellar Tendon Repair Augmentation With a Knotless Suture Anchor Internal Brace: A Biomechanical Cadaveric Study.

    Science.gov (United States)

    Rothfeld, Alex; Pawlak, Amanda; Liebler, Stephenie A H; Morris, Michael; Paci, James M

    2018-04-01

    Patellar tendon repair with braided polyethylene suture alone is subject to knot slippage and failure. Several techniques to augment the primary repair have been described. Purpose/Hypothesis: The purpose was to evaluate a novel patellar tendon repair technique augmented with a knotless suture anchor internal brace with suture tape (SAIB). The hypothesis was that this technique would be biomechanically superior to a nonaugmented repair and equivalent to a standard augmentation with an 18-gauge steel wire. Controlled laboratory study. Midsubstance patellar tendon tears were created in 32 human cadaveric knees. Two comparison groups were created. Group 1 compared #2 supersuture repair without augmentation to #2 supersuture repair with SAIB augmentation. Group 2 compared #2 supersuture repair with an 18-gauge stainless steel cerclage wire augmentation to #2 supersuture repair with SAIB augmentation. The specimens were potted and biomechanically loaded on a materials testing machine. Yield load, maximum load, mode of failure, plastic displacement, elastic displacement, and total displacement were calculated for each sample. Standard statistical analysis was performed. There was a statistically significant increase in the mean ± SD yield load and maximum load in the SAIB augmentation group compared with supersuture alone (mean yield load: 646 ± 202 N vs 229 ± 60 N; mean maximum load: 868 ± 162 N vs 365 ± 54 N; P augmented repairs (mean yield load: 495 ± 213 N vs 566 ± 172 N; P = .476; mean maximum load: 737 ± 210 N vs 697 ± 130 N; P = .721). Patellar tendon repair augmented with SAIB is biomechanically superior to repair without augmentation and is equivalent to repair with augmentation with an 18-gauge stainless steel cerclage wire. This novel patellar tendon repair augmentation is equivalent to standard 18-gauge wire augmentation at time zero. It does not require a second surgery for removal, and it is biomechanically superior to primary repair alone.

  10. Adhesive strength of hydroxyl apatite(HA) coating and biomechanics behavior of HA-coated prosthesis:an experimental study

    OpenAIRE

    Tian-yang ZHANG; Yong-hong DUAN; Shu ZHU; Jin-yu ZHU; Qing-sheng ZHU

    2011-01-01

    Objective To explore the influence of adhesive strength of hydroxyapatite(HA) coating on the post-implantation stability of HA-coated prosthesis.Methods The adhesive strength and biomechanics behavior of HA coating were studied by histopathological observation,material parameters and biomechanical testing,the titanium(Ti)-coated prosthesis was employed as control.Results Scratch test showed that the adhesive strength of HA coating was significantly lower than that of Ti coating(P < 0.01).Hist...

  11. In Vitro Studies and Preliminary Mathematical Model for Jet Fuel and Noise Induced Auditory Impairment

    Science.gov (United States)

    2015-06-01

    of JP-8 and a Fischer- Tropsch synthetic jet fuel following subacute inhalation exposure in rats. Toxicol Sci 116(1): 239-248. Gallinat, J...AFRL-RH-WP-TR-2015-0084 IN VITRO STUDIES AND PRELIMINARY MATHEMATICAL MODEL FOR JET FUEL AND NOISE INDUCED AUDITORY IMPAIRMENT...April 2014 – September 2014 4. TITLE AND SUBTITLE In Vitro Studies and Preliminary Mathematical Model for Jet Fuel and Noise Induced Auditory

  12. Case Study: Organotypic human in vitro models of embryonic ...

    Science.gov (United States)

    Morphogenetic fusion of tissues is a common event in embryonic development and disruption of fusion is associated with birth defects of the eye, heart, neural tube, phallus, palate, and other organ systems. Embryonic tissue fusion requires precise regulation of cell-cell and cell-matrix interactions that drive proliferation, differentiation, and morphogenesis. Chemical low-dose exposures can disrupt morphogenesis across space and time by interfering with key embryonic fusion events. The Morphogenetic Fusion Task uses computer and in vitro models to elucidate consequences of developmental exposures. The Morphogenetic Fusion Task integrates multiple approaches to model responses to chemicals that leaad to birth defects, including integrative mining on ToxCast DB, ToxRefDB, and chemical structures, advanced computer agent-based models, and human cell-based cultures that model disruption of cellular and molecular behaviors including mechanisms predicted from integrative data mining and agent-based models. The purpose of the poster is to indicate progress on the CSS 17.02 Virtual Tissue Models Morphogenesis Task 1 products for the Board of Scientific Counselors meeting on Nov 16-17.

  13. Study of the cetuximab-ionizing radiation association on a model of in vitro endothelial cells

    International Nuclear Information System (INIS)

    Vautravers-Dewas, C.; Rebucci, M.; Lansiaux, A.; Peixoto, P.; Lartigau, E.

    2009-01-01

    These data support the existence of functional signalling tracks downstream epidermal growth factor receptor (E.G.F.R.) in endothelial cells. But our in vitro model, in two dimensional calculations, did not allow to show a radiosensitivity by cetuximab. The study of functional consequences of the association cetuximab-irradiation treatment will be relevant in an in vitro three dimensional model and on xenografts. (N.C.)

  14. The in vitro isolated whole guinea pig brain as a model to study epileptiform activity patterns.

    Science.gov (United States)

    de Curtis, Marco; Librizzi, Laura; Uva, Laura

    2016-02-15

    Research on ictogenesis is based on the study of activity between seizures and during seizures in animal models of epilepsy (chronic condition) or in in vitro slices obtained from naïve non-epileptic brains after treatment with pro-convulsive drugs, manipulations of the extracellular medium and specific stimulation protocols. The in vitro isolated guinea pig brain retains the functional connectivity between brain structures and maintains interactions between neuronal, glial and vascular compartments. It is a close-to-in vivo preparation that offers experimental advantages not achieved with the use of other experimental models. Neurophysiological and imaging techniques can be utilized in this preparation to study brain activity during and between seizures induced by pharmacological or functional manipulations. Cellular and network determinants of interictal and ictal discharges that reproduce abnormal patterns observed in human focal epilepsies and the associated changes in extracellular ion and blood-brain permeability can be identified and analyzed in the isolated guinea pig brain. Ictal and interictal patterns recorded in in vitro slices may show substantial differences from seizure activity recorded in vivo due to slicing procedure itself. The isolated guinea pig brain maintained in vitro by arterial perfusion combines the typical facilitated access of in vitro preparations, that are difficult to approach during in vivo experiments, with the preservation of larger neuronal networks. The in vitro whole isolated guinea pig brain preparation offers an unique experimental model to study systemic and neurovascular changes during ictogenesis. Published by Elsevier B.V.

  15. Carboxylated nanodiamonds can be used as negative reference in in vitro nanogenotoxicity studies.

    Science.gov (United States)

    Moche, H; Paget, V; Chevalier, D; Lorge, E; Claude, N; Girard, H A; Arnault, J C; Chevillard, S; Nesslany, F

    2017-08-01

    Nanodiamonds (NDs) are promising nanomaterials for biomedical applications. However, a few studies highlighted an in vitro genotoxic activity for detonation NDs, which was not evidenced in one of our previous work quantifying γ-H2Ax after 20 and 100 nm high-pressure high-temperature ND exposures of several cell lines. To confirm these results, in the present work, we investigated the genotoxicity of the same 20 and 100 nm NDs and added intermediate-sized NDs of 50 nm. Conventional in vitro genotoxicity tests were used, i.e., the in vitro micronucleus and comet assays that are recommended by the French National Agency for Medicines and Health Products Safety for the toxicological evaluation of nanomedicines. In vitro micronucleus and in vitro comet assays (standard and hOGG1-modified) were therefore performed in two human cell lines, the bronchial epithelial 16HBE14o- cells and the colon carcinoma T84 cells. Our results did not show any genotoxic activity, whatever the test, the cell line or the size of carboxylated NDs. Even though these in vitro results should be confirmed in vivo, they reinforce the potential interest of carboxylated NDs for biomedical applications or even as a negative reference nanoparticle in nanotoxicology. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  16. Validation of an in vitro digestive system for studying macronutrient decomposition in humans.

    Science.gov (United States)

    Kopf-Bolanz, Katrin A; Schwander, Flurina; Gijs, Martin; Vergères, Guy; Portmann, Reto; Egger, Lotti

    2012-02-01

    The digestive process transforms nutrients and bioactive compounds contained in food to physiologically active compounds. In vitro digestion systems have proven to be powerful tools for understanding and monitoring the complex transformation processes that take place during digestion. Moreover, the investigation of the physiological effects of certain nutrients demands an in vitro digestive process that is close to human physiology. In this study, human digestion was simulated with a 3-step in vitro process that was validated in depth by choosing pasteurized milk as an example of a complex food matrix. The evolution and decomposition of the macronutrients was followed over the entire digestive process to the level of intestinal enterocyte action, using protein and peptide analysis by SDS-PAGE, reversed-phase HPLC, size exclusion HPLC, and liquid chromatography-MS. The mean peptide size after in vitro digestion of pasteurized milk was 5-6 amino acids (AA). Interestingly, mostly essential AA (93.6%) were released during in vitro milk digestion, a significantly different relative distribution compared to the total essential AA concentration of bovine milk (44.5%). All TG were degraded to FFA and monoacylglycerols. Herein, we present a human in vitro digestion model validated for its ability to degrade the macronutrients of dairy products comparable to physiological ranges. It is suited to be used in combination with a human intestinal cell culture system, allowing ex vivo bioavailability measurements and assessment of the bioactive properties of food components.

  17. Bio-mechanical Analysis of Human Joints and Extension of the Study to Robot

    OpenAIRE

    S. Parasuraman; Ler Shiaw Pei

    2008-01-01

    In this paper, the bio-mechanical analysis of human joints is carried out and the study is extended to the robot manipulator. This study will first focus on the kinematics of human arm which include the movement of each joint in shoulder, wrist, elbow and finger complexes. Those analyses are then extended to the design of a human robot manipulator. A simulator is built for Direct Kinematics and Inverse Kinematics of human arm. In the simulation of Direct Kinematics, the human joint angles can...

  18. Studies of cell biomechanics with surface micro-/nano-technology

    International Nuclear Information System (INIS)

    Wang Dong; Zhang Wei; Jiang Xingyu

    2011-01-01

    We report the recent progress in our studies of cell biology using micro-/nano-technology. Cells have a size of several to tens of microns, which makes them easily manipulated by micro-/nano-technology. The shape of the cell influences the alignment of the actin cytoskeleton, which bears the main forces of the cell, maintains the shape,and mediates a series of biochemical reactions. We invented a stretching device and studied the real-time actin filament dynamics under stretch. We found that one stretch cycle shortened the actin filaments and promoted their reassemble process. Cell migration is a complex mechanical process. We found that cell geometry determines the cell polarity and migration direction. We fabricated three-dimensional surfaces to mimic the topography in vivo, and further built a cell culture model by integrating the three-dimensional surface, microfluidics, cell patterning,and coculturing of multiple cell types. We also investigated the neuronal guidance by surface patterning. (authors)

  19. Biomechanical study of the final push-pull in archery.

    Science.gov (United States)

    Leroyer, P; Van Hoecke, J; Helal, J N

    1993-02-01

    The purpose of this study was to analyse archery performance among eight archers of different abilities by means of displacement pull-hand measurements during the final push-pull phase of the shoot. The archers showed an irregular displacement negatively related to their technical level. Displacement signal analysis showed high power levels in both the 0-5 Hz and 8-12 Hz ranges. The latter peak corresponds to electromyographic tremor observed during a prolonged push-pull effort. The results are discussed in relation to some potentially helpful training procedures such as biofeedback and strength conditioning.

  20. Study of osteoporosis through the measurement of bone density, trace elements, biomechanical properties and immunocytochemicals

    International Nuclear Information System (INIS)

    Aras, N.K.; Korkusuz, F.; Akkas, N.; Laleli, Y.; Kuscu, L.; Gunel, U.

    1996-01-01

    Osteoporosis is defined as an absolute decrease in the amount of bone to a level below required for mechanical support. It is an important bone disease in elderly people in many countries. Unfortunately, there is no reliable statistical data in Turkey for the incidence of osteoporosis. A decrease in bone mass is the important cause in fractures in osteoporosis. Therefore, we intend to study both bone density and other variables such as trace elements, biomechanical properties and other immunocytochemicals in bone, all combined might give an information about the cause and prevention of osteoporosis. (author)

  1. Knee Biomechanics During Jogging After Arthroscopic Partial Meniscectomy: A Longitudinal Study.

    Science.gov (United States)

    Hall, Michelle; Wrigley, Tim V; Metcalf, Ben R; Hinman, Rana S; Cicuttini, Flavia M; Dempsey, Alasdair R; Lloyd, David G; Bennell, Kim L

    2017-07-01

    Altered knee joint biomechanics is thought to play a role in the pathogenesis of knee osteoarthritis and has been reported in patients after arthroscopic partial meniscectomy (APM) while performing various activities. Longitudinally, understanding knee joint biomechanics during jogging may assist future studies to assess the implications of jogging on knee joint health in this population. To investigate knee joint biomechanics during jogging in patients 3 months after APM and a healthy control group at baseline and 2 years later at follow-up. Controlled laboratory study. Seventy-eight patients who underwent medial APM and 38 healthy controls underwent a 3-dimensional motion analysis during barefoot overground jogging at baseline. Sixty-four patients who underwent APM and 23 controls returned at follow-up. External peak moments (flexion and adduction) and the peak knee flexion angle during stance were evaluated for the APM leg, non-APM leg (nonoperated leg), and control leg. At baseline, the peak knee flexion angle was 1.4° lower in the APM leg compared with the non-APM leg ( P = .03). No differences were found between the moments in the APM leg compared with the control leg (all P > .05). However, the normalized peak knee adduction moment was 35% higher in the non-APM leg compared with the control leg ( P = .008). In the non-APM leg, the normalized peak knee adduction and flexion moments were higher compared with the APM leg by 16% and 10%, respectively, at baseline ( P ≤ .004). Despite the increase in the peak knee flexion moment in the APM leg compared with the non-APM leg ( P .05). Comparing the APM leg and control leg, no differences in knee joint biomechanics during jogging for the variables assessed were observed. Higher knee moments in the non-APM leg may have clinical implications for the noninvolved leg. Kinematic differences were small (~1.4°) and therefore of questionable clinical relevance. These results may facilitate future clinical research

  2. Plant Regeneration and Cellular Behaviour Studies in Celosia cristata Grown In Vivo and In Vitro

    Science.gov (United States)

    Taha, Rosna Mat; Wafa, Sharifah Nurashikin

    2012-01-01

    Tissue culture studies of Celosia cristata were established from various explants and the effects of various hormones on morphogenesis of this species were examined. It was found that complete plant regeneration occurred at highest percentage on MS medium supplemented with 2.0 mg/L NAA and 1.5 mg/L BAP, with the best response showed by shoot explants. In vitro flowering was observed on MS basal medium after six weeks. The occurrence of somaclonal variation and changes in cellular behavior from in vivo and in vitro grown plants were investigated through cytological studies and image analysis. It was observed that Mitotic Index (MI), mean chromosome numbers, and mean nuclear to cell area ratio of in vitro root meristem cells were slightly higher compared to in vivo values. However, in vitro plants produced lower mean cell areas but higher nuclear areas when compared to in vivo plants. Thus, no occurrence of somaclonal variation was detected, and this was supported by morphological features of the in vitro plants. PMID:22593677

  3. The effect of tendon loading on in-vitro carpal kinematics of the wrist joint

    NARCIS (Netherlands)

    Foumani, M.; Blankevoort, L.; Stekelenburg, C.; Strackee, S. D.; Carelsen, B.; Jonges, R.; Streekstra, G. J.

    2010-01-01

    Measurements of in-vitro carpal kinematics of the wrist provide valuable biomechanical data. Tendon loading is often applied during cadaver experiments to simulate natural stabilizing joint compression in the wrist joint. The purpose of this study was to investigate the effect of tendon loading on

  4. Study Of Phytohormone Autonomy In In Vitro In Petunia Hybrida

    OpenAIRE

    S. Sharmila Begum; A. Arundhati

    2016-01-01

    Petunia x hybrida is used as noble genetic material for somatic hybridization, molecular studies and hence is of concern in phylogenetic significance to serve as a useful models of physiology and host - parasite interaction. In the present study using two variants of Petunia hybrida, the phytohormone autonomy on different formulation of MS medium was carried out. The type of response on hormone free MS medium was rhizogenesis in both the variants. When hormones IAA was substituted...

  5. Study on bioactive compounds of in vitro cultured Calculus Suis and natural Calculus Bovis.

    Science.gov (United States)

    Wan, Tien-Chun; Cheng, Fu-Yuan; Liu, Yu-Tse; Lin, Liang-Chuan; Sakata, Ryoichi

    2009-12-01

    The purpose of the study was to investigate bioactive compounds of in vitro cultured Calculus Suis and natural Calculus Bovis obtained as valuable by-products from animals used for meat production. The results showed that the components of natural Calculus Bovis were rich in bilirubin and biliverdin and had higher content of essential amino acids. The major amino acids of in vitro cultured Calculus Suis were identified as glycine, alanine, glutamic acid and aspartic acid, and those for natural Calculus Bovis were found to be glutamic acid, aspartic acid, proline, and arginine. The methionine and cysteine contents of precursors for glutathione in natural Calculus Bovis were significantly higher than those of in vitro cultured Calculus Suis. The mineral contents of zinc, iron and manganese of natural Calculus Bovis were significantly higher than those of in vitro cultured Calculus Suis. The major bile acids in both products were cholic acid and dehydrocholic acid, respectively. The chenodeoxycholic and ursodeoxycholic acid content of in vitro cultured Calculus Suis was significantly higher than that of natural Calculus Bovis.

  6. In vitro study on biomineralization of biphasic calcium phosphate ...

    Indian Academy of Sciences (India)

    In this study, we report the preparation of a bone graft material, having cylindrical shape, containing biphasic calcium phosphate (BCP), gelatin (G), chitosan (C) and Terminalia chebula (TC) extract. TC extract was used as a crosslinker that gives stability to bone graft when it is placed in SBF. The graft was stable in the SBF ...

  7. Preparation, characterization and in vitro study of biocompatible ...

    African Journals Online (AJOL)

    The morphology and crystalline structure of lyophilized hydrogels were investigated by scanning electron microscopy (SEM) and wide-angle diffractometry, respectively while the surface functional groups were analyzed by FT-IR. The thermal behavior was also studied by means of differential scanning calorimetry and ...

  8. In-vitro Release Study of Carvedilol Phosphate Matrix Tablets ...

    African Journals Online (AJOL)

    Microcrystalline cellulose (Avicel PH 101), starch (Sta-Rx 1500) and lactose monohydrate were used as diluents in the formulations while the effect of sodium lauryl sulphate (wetting agent) was studied for some of the formulations. The tablets were characterized for carvedilol phosphate release in both simulated gastric and ...

  9. Monitoring dental erosion by colour measurement : An in vitro study

    NARCIS (Netherlands)

    Krikken, J. B.; Zijp, J. R.; Huysmans, M. C. D. N. J. M.

    Objectives: The aim of this study was to develop a method to monitor dental erosion by evaluation of the colour change of teeth as a function of enamel loss, and to evaluate the reproducibility of the method used. Methods: Light reflectance spectra of 12 extracted human incisors were measured using

  10. Effects of sex and obesity on gait biomechanics before and six months after total knee arthroplasty: A longitudinal cohort study.

    Science.gov (United States)

    Paterson, K L; Sosdian, L; Hinman, R S; Wrigley, T V; Kasza, J; Dowsey, M; Choong, P; Bennell, K L

    2018-03-01

    Gait biomechanics, sex, and obesity can contribute to suboptimal outcomes from primary total knee arthroplasty. The aims of this study were to i) determine if sex and/or obesity influence the amount of change in gait biomechanics from pre-surgery to six months post-surgery and; ii) assess if gait returns to normal in men and women. Three-dimensional gait analysis was performed on 43 patients undergoing primary total knee arthroplasty for knee osteoarthritis (pre- and six months post-operative) and 40 asymptomatic controls. Mixed linear regression models were fit to assess which factors influenced change in gait biomechanics within the arthroplasty cohort, and interaction terms were included to assess if biomechanics returned to normal following surgery. Male peak knee adduction moment (p biomechanics after arthroplasty. Men retained abnormal gait patterns after surgery, whilst women did not. Further research should determine the long-term implications of gait abnormalities seen in men after arthroplasty. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. Assessment of the suitability of biodegradable rods for use in posterior lumbar fusion: An in-vitro biomechanical evaluation and finite element analysis.

    Directory of Open Access Journals (Sweden)

    Fon-Yih Tsuang

    Full Text Available Interbody fusion with posterior instrumentation is a common method for treating lumbar degenerative disc diseases. However, the high rigidity of the fusion construct may produce abnormal stresses at the adjacent segment and lead to adjacent segment degeneration (ASD. As such, biodegradable implants are becoming more popular for use in orthopaedic surgery. These implants offer sufficient stability for fusion but at a reduced stiffness. Tailored to degrade over a specific timeframe, biodegradable implants could potentially mitigate the drawbacks of conventional stiff constructs and reduce the loading on adjacent segments. Six finite element models were developed in this study to simulate a spine with and without fixators. The spinal fixators used both titanium rods and biodegradable rods. The models were subjected to axial loading and pure moments. The range of motion (ROM, disc stresses, and contact forces of facet joints at adjacent segments were recorded. A 3-point bending test was performed on the biodegradable rods and a dynamic bending test was performed on the spinal fixators according to ASTM F1717-11a. The finite element simulation showed that lumbar spinal fusion using biodegradable implants had a similar ROM at the fusion level as at adjacent levels. As the rods degraded over time, this produced a decrease in the contact force at adjacent facet joints, less stress in the adjacent disc and greater loading on the anterior bone graft region. The mechanical tests showed the initial average fatigue strength of the biodegradable rods was 145 N, but this decreased to 115N and 55N after 6 months and 12 months of soaking in solution. Also, both the spinal fixator with biodegradable rods and with titanium rods was strong enough to withstand 5,000,000 dynamic compression cycles under a 145 N axial load. The results of this study demonstrated that biodegradable rods may present more favourable clinical outcomes for lumbar fusion. These polymer rods

  12. In vitro study revealed different size behavior of different nanoparticles

    International Nuclear Information System (INIS)

    Schaudien, Dirk; Knebel, Jan; Creutzenberg, Otto

    2012-01-01

    Toxicity of nanoparticles is depending not only on the size of the primary particles but on the size of their agglomerates. Therefore, further studies are needed to examine the behavior of nanoparticles after they have gotten in contact with cells. The presented study investigated the change of size of different commercially available nanoparticles after applying them to different cell lines such as A549, Calu-3, 16HBE14o and LK004 representative for the different parts of the human lung. The different nanoparticles exhibited differences in behavior of size. TiO 2 P25 showed a tendency to increase, whereas TiO 2 T805 and Printex ® 90 remained more or less at the same size. In contrast, ZnO < 50 nm particles showed a significant decrease of size.

  13. In vitro placental model optimization for nanoparticle transport studies

    DEFF Research Database (Denmark)

    Cartwright, Laura; Poulsen, Marie Sønnegaard; Nielsen, Hanne Mørck

    2012-01-01

    Background: Advances in biomedical nanotechnology raise hopes in patient populations but may also raise questions regarding biodistribution and biocompatibility, especially during pregnancy. Special consideration must be given to the placenta as a biological barrier because a pregnant woman...... placental choriocarcinoma cells for nanoparticle transport studies was characterized in terms of optimized Transwell® insert type and pore size, the investigation of barrier properties by transmission electron microscopy, tight junction staining, transepithelial electrical resistance, and fluorescein sodium...

  14. In vitro DNA binding studies of Aspartame, an artificial sweetener.

    Science.gov (United States)

    Kashanian, Soheila; Khodaei, Mohammad Mehdi; Kheirdoosh, Fahimeh

    2013-03-05

    A number of small molecules bind directly and selectively to DNA, by inhibiting replication, transcription or topoisomerase activity. In this work the interaction of native calf thymus DNA (CT-DNA) with Aspartame (APM), an artificial sweeteners was studied at physiological pH. DNA binding study of APM is useful to understand APM-DNA interaction mechanism and to provide guidance for the application and design of new and safer artificial sweeteners. The interaction was investigated using spectrophotometric, spectrofluorometric competition experiment and circular dichroism (CD). Hypochromism and red shift are shown in UV absorption band of APM. A strong fluorescence quenching reaction of DNA to APM was observed and the binding constants (Kf) of DNA with APM and corresponding number of binding sites (n) were calculated at different temperatures. Thermodynamic parameters, enthalpy changes (ΔH) and entropy changes (ΔS) were calculated to be +181kJmol(-1) and +681Jmol(-1)K(-1) according to Van't Hoff equation, which indicated that reaction is predominantly entropically driven. Moreover, spectrofluorometric competition experiment and circular dichroism (CD) results are indicative of non-intercalative DNA binding nature of APM. We suggest that APM interacts with calf thymus DNA via groove binding mode with an intrinsic binding constant of 5×10(+4)M(-1). Copyright © 2013 Elsevier B.V. All rights reserved.

  15. Studies of DNA supercoiling in vivo and in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Cook, D.N.

    1990-10-01

    This thesis describes a number of diverse experiments whose common theme is to elaborate some aspect of DNA supercoiling. The torsion elastic constant of DNA is measure as a function of superhelix density using the technique of picosecond Time Resolved Fluorescence Polarization Anisotropy (FPA) of intercalated ethidium bromide. The results agree with theories which predict that the anisotropy decay should vary with the square root of the relative viscosity. This experiment furthermore demonstrates a sensitivity of FPA to a change in torsion elastic constant of less than 10%. A number of covalently closed DNA samples, ranging in superhelix density from = [minus]0.123 to [plus]0.042, are then examined. A novel method for measuring changes in local supercoiling on a large PNA molecule which is sensitive to changes in supercoiling of regions of chromosomal DNA as short as 1 kilobase in length is presented. Study of chromosomal supercoiling regulating anaerobic gene expression in the facultative photosynthetic bacterium, Rhodobacter capsulatus showed that no stable change in chromosomal supercoiling upon a shift from aerobic respiratory growth to anaerobic photosynthetic conditions. Studies to detect transient changes in DNA supercoiling indicate that DNA downstream from heavily transcribed genes for the photosynthetic reaction center are relaxed or perhaps overwound upon the induction of photosynthetic metabolism. These results are interpreted in terms of the twin domain model of transcriptional supercoiling.

  16. Studies of DNA supercoiling in vivo and in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Cook, David Nelson [Univ. of California, Berkeley, CA (United States)

    1990-10-01

    This thesis describes a number of diverse experiments whose common theme is to elaborate some aspect of DNA supercoiling. The torsion elastic constant of DNA is measure as a function of superhelix density using the technique of picosecond Time Resolved Fluorescence Polarization Anisotropy (FPA) of intercalated ethidium bromide. The results agree with theories which predict that the anisotropy decay should vary with the square root of the relative viscosity. This experiment furthermore demonstrates a sensitivity of FPA to a change in torsion elastic constant of less than 10%. A number of covalently closed DNA samples, ranging in superhelix density from = -0.123 to +0.042, are then examined. A novel method for measuring changes in local supercoiling on a large PNA molecule which is sensitive to changes in supercoiling of regions of chromosomal DNA as short as 1 kilobase in length is presented. Study of chromosomal supercoiling regulating anaerobic gene expression in the facultative photosynthetic bacterium, Rhodobacter capsulatus showed that no stable change in chromosomal supercoiling upon a shift from aerobic respiratory growth to anaerobic photosynthetic conditions. Studies to detect transient changes in DNA supercoiling indicate that DNA downstream from heavily transcribed genes for the photosynthetic reaction center are relaxed or perhaps overwound upon the induction of photosynthetic metabolism. These results are interpreted in terms of the twin domain model of transcriptional supercoiling.

  17. Toxicity of formaldehyde and acrolein mixtures : in vitro studies using nasal epithelial cells

    NARCIS (Netherlands)

    Cassee, F.R.; Stenhuis, W.S.; Groten, J.P.; Feron, V.J.

    1996-01-01

    In vitro studies with human and rat nasal epithelial cells were carried out to investigate the combined toxicity of formaldehyde and acrolein and the role of aldehyde dehydrogenases in this process. These studies showed that the toxic effect of mixtures of aldehydes was additive. In addition,

  18. Bromelain enzyme from pineapple: in vitro activity study under different micropropagation conditions.

    Science.gov (United States)

    Vilanova Neta, Jaci Lima; da Silva Lédo, Ana; Lima, Aloisio André Bonfim; Santana, José Carlos Curvelo; Leite, Nadjma Souza; Ruzene, Denise Santos; Silva, Daniel Pereira; de Souza, Roberto Rodrigues

    2012-09-01

    The aim of this work was to evaluate the activity of bromelain in pineapple plants (Ananas comosus var. Comosus), Pérola cultivar, produced in vitro in different culture conditions. This enzyme, besides its pharmacological effects, is also employed in food industries, such as breweries and meat processing. In this work, the enzymatic activity was evaluated in the tissues of leaves and stems of plants grown in culture medium without plant growth regulator. The most significant levels of bromelain were observed in leaf tissue after 4 months of culture in vitro in medium with a filter paper bridge, followed by medium gelled by the agar. The results of this study, regarding the different structures of the pineapple (leaves and stems) in vitro showed that the activity of bromelain varied depending on the culture conditions, the time and structure of which was quantified, ensuring a viable strategy in the production of seedlings with high levels of bromelain in subsequent phases of micropropagation.

  19. In vitro and in vivo suppository studies with perturbed angular correlation and external scintigraphy

    International Nuclear Information System (INIS)

    Jay, M.; Beihn, R.M.; Snyder, G.A.; McClanahan, J.S.; Digenis, G.A.; Caldwell, L.; Mlodozeniec, A.

    1983-01-01

    Recently, there has been an increased interest in the rectal delivery of drugs as an alternative to parenteral administration. Because of their complexity, little is known about the release behavior of drugs from suppositories in vivo, and the universal applicability of most in vitro tests developed to date awaits broad acceptance. A novel technique has recently been utilized for the measurement of both in vitro and in vivo dissolution profiles of solid oral dosage forms. This technique, known as perturbed angular correlation (PAC), utilizes the property of cascading decay exhibited by indium-111. The authors now wish to report on the application of this technique for in vitro studies measuring the dissolution of an [ 111 In]salicylate coprecipitate incorporated in a suppository base. The PAC technique was also used in combination with external scintigraphic techniques for the in vivo measurement of the deformation and liquefaction of a suppository containing 111 In in humans in a totally non-invasive manner. (Auth.)

  20. In vitro and in vivo suppository studies with perturbed angular correlation and external scintigraphy

    Energy Technology Data Exchange (ETDEWEB)

    Jay, M.; Beihn, R.M.; Snyder, G.A.; McClanahan, J.S.; Digenis, G.A. (Kentucky Univ., Lexington (USA). College of Pharmacy and Medicine); Caldwell, L.; Mlodozeniec, A. (INTER Research Corporation, Lawrence, KS (USA). Merck, Sharp and Dohme Research Laboratories)

    1983-04-01

    Recently, there has been an increased interest in the rectal delivery of drugs as an alternative to parenteral administration. Because of their complexity, little is known about the release behavior of drugs from suppositories in vivo, and the universal applicability of most in vitro tests developed to date awaits broad acceptance. A novel technique has recently been utilized for the measurement of both in vitro and in vivo dissolution profiles of solid oral dosage forms. This technique, known as perturbed angular correlation (PAC), utilizes the property of cascading decay exhibited by indium-111. The authors now wish to report on the application of this technique for in vitro studies measuring the dissolution of an (/sup 111/In)salicylate coprecipitate incorporated in a suppository base. The PAC technique was also used in combination with external scintigraphic techniques for the in vivo measurement of the deformation and liquefaction of a suppository containing /sup 111/In in humans in a totally non-invasive manner.

  1. Invertebrate biomechanics.

    Science.gov (United States)

    Patek, S N; Summers, A P

    2017-05-22

    Invertebrate biomechanics focuses on mechanical analyses of non-vertebrate animals, which at root is no different in aim and technique from vertebrate biomechanics, or for that matter the biomechanics of plants and fungi. But invertebrates are special - they are fabulously diverse in form, habitat, and ecology and manage this without the use of hard, internal skeletons. They are also numerous and, in many cases, tractable in an experimental and field setting. In this Primer, we will probe three axes of invertebrate diversity: worms (Phylum Annelida), spiders (Class Arachnida) and insects (Class Insecta); three habitats: subterranean, terrestrial and airborne; and three integrations with other fields: ecology, engineering and evolution. Our goal is to capture the field of invertebrate biomechanics, which has blossomed from having a primary focus on discoveries at the interface of physics and biology to being inextricably linked with integrative challenges that span biology, physics, mathematics and engineering. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. In vitro studies with a pulsed neodymium/YAG laser.

    Science.gov (United States)

    Venkatesh, S; Guthrie, S; Foulds, W S; Lee, W R; Cruickshank, F R; Bailey, R T

    1985-02-01

    The relationships between the destructive effects of Q-switched Nd/YAG laser pulses and a number of experimental parameters were studied for various target materials including in particular excised, fixed samples of human trabecular meshwork. The laser parameters altered were the pulse energy, the convergence angle of the focused beam, and the position of the focus of the beam relative to the target's axial position. The main finding was that it was possible to make deep holes, of a diameter less than 100 micron, in virtually transparent samples of trabecular meshwork with a laser delivery system of 6 degrees convergence and pulse energies of 14 mJ or more. The relevance of this and the other experimental results to the development of a reliable system for performing internal trabeculotomies for the treatment of open-angle glaucoma is presented.

  3. Study of the radiosensitivity of three melanomas grown in vitro

    International Nuclear Information System (INIS)

    Weininger, J.

    1978-05-01

    This work studies the response to gamma irradiation of three human melanoma stems. Two cellular lines come from two ganglion metastases, the third from a primitive tumor. The influence of ''out-of-cycle''(quiescent cells on the radiosenitivity of a tumoral population was investigated in parallel with ''in cycle'' cells. The materials and methods used are described, and a number of cynetic parameters of the populations are given. The results of a series of experiments carried out on the IGR 11 stem are presented; this enables the evaluation of the repair capability of potentially lethal lesions of cells remaining in the plateau phase, after irradiation, without removal of the nutritional medium. The survival curves of the 3 stems, in both the exponential growth and the ''plateau phase'', are presented. A heterotransplant model of a human melanoma to ''nude'' mice is considered. (B.G.)

  4. In-Vitro Corrosion Studies of Bioabsorbable Alloys

    Science.gov (United States)

    Gill, P.; Munroe, N.

    Magnesium alloys have inspired a significant amount of attention from researchers all over the world for cardiovascular and orthopedic applications due to their light weight, mechanical integrity and degradation behavior. In this investigation, cast manufactured binary, ternary and quaternary magnesium alloys were studied for their degradation behavior by potentiodynamic polarization tests in phosphate buffer saline solution (PBS) and PBS containing amino acids (cysteine, C and tryptophan, W) at 37 °C. Electrochemical impedance spectroscopy (EIS) tests were performed to determine the charge transfer resistance and immersion tests were performed to assess corrosion rate and hydrogen evolution from the alloys. Furthermore, the surface morphology and surface chemistry of the alloys were observed by scanning electron microscopy (SEM) and X-ray diffraction (XRD).

  5. In vitro and in vivo studies on biodegradable magnesium alloy

    Directory of Open Access Journals (Sweden)

    Lida Hou

    2014-10-01

    Full Text Available The microstructure, mechanical property, electrochemical behavior and biocompatibility of magnesium alloy (BioDe MSM™ were studied in the present work. The experimental results demonstrated that grain refining induced by extrusion improves the alloy strength significantly from 162 MPa for the as-cast alloy to 241 MPa for the as-extruded one. The anticorrosion properties of the as-extruded alloy also increased. Furthermore, the hemolysis ratio was decreased from 4.7% for the as-cast alloy to 2.9% for the as-extruded one, both below 5%. BioDe MSM™ alloy shows good biocompatibility after being implanted into the dorsal muscle and the femoral shaft of the New Zealand rabbit, respectively, and there are no abnormalities after short-term implantation. In vivo observation indicated that the corrosion rate of this alloy varies with different implantation positions, with higher degradation rate in the femur than in the muscle.

  6. New generation of color bonding: A comparative in vitro study

    Directory of Open Access Journals (Sweden)

    Rajkumar Maurya

    2011-01-01

    Statistical Analysis: Comparison of the mean rank among the groups was done by Kruskal-Wallis one-way analysis of variance (ANOVA. To determine the mean difference among groups, the Mann-Whitney test with Bon Ferroni adjustment was applied. Observations: It was observed that light-cure conventional composite resin with the conventional etchant group had the highest and glass ionomer resin adhesive had the lowest shear bond strength. There was no statistically significant difference between conventional composite used with conventional etchant and color-changing composite resin used with conventional etchant or with self-etch primer. Conclusion: Considering the advantages of a color-changing composite and self-etch primer especially in patients having high DMFT scores or physically and mentally compromised patients unable to maintain their hygiene properly, it was concluded in the present study that it would be the most suitable material for direct bonding.

  7. Anabolic androgenic steroids reverse the beneficial effect of exercise on tendon biomechanics: an experimental study.

    Science.gov (United States)

    Tsitsilonis, Serafim; Chatzistergos, Panayiotis E; Panayiotis, Chatzistergos E; Mitousoudis, Athanasios S; Athanasios, Mitousoudis S; Kourkoulis, Stavros K; Stavros, Kourkoulis K; Vlachos, Ioannis S; Ioannis, Vlachos S; Agrogiannis, George; George, Agrogiannis; Fasseas, Konstantinos; Konstantinos, Fasseas; Perrea, Despina N; Despina, Perrea N; Zoubos, Aristides B; Aristides, Zoubos B

    2014-06-01

    The effect of anabolic androgenic steroids on tendons has not yet been fully elucidated. Aim of the present study was the evaluation of the impact of anabolic androgenic steroids on the biomechanical and histological characteristics of Achilles tendons. Twenty-four male Wistar rats were randomized into four groups with exercise and anabolic steroids (nandrolone decanoate) serving as variables. Protocol duration was 12 weeks. Following euthanasia, tendons' biomechanical properties were tested with the use of a modified clamping configuration. Histological examination with light and electron microscopy were also performed. In the group of anabolic steroids and exercise the lowest fracture stress values were observed, while in the exercise group the highest ones. Histological examination by light and electron microscopy revealed areas of collagen dysplasia and an increased epitendon in the groups receiving anabolic steroids and exercise. These findings suggest that anabolic androgenic steroids reverse the beneficial effect of exercise, thus resulting in inferior maximal stress values. Copyright © 2013 European Foot and Ankle Society. Published by Elsevier Ltd. All rights reserved.

  8. The use of the co-ordinate measuring machine for the study of three-dimensional biomechanics of the knee.

    Science.gov (United States)

    Veselko, M; Jenko, M; Lipuscek, I

    1998-07-01

    Original methodology for the study of three-dimensional biomechanics of the knee is presented in the paper. Defining the geometry of the rigid body in the body-fixed reference frame and the orientation of the body-fixed reference frame in the global co-ordinate system are the theoretic basis. The data in the form of co-ordinates of the Cartesian frame are gathered by the co-ordinate measuring machine and analysed by specially computer program. The theory and a practical example of the study of the three-dimensional biomechanics of the knee are presented. Various possibilities of the use of the methodology are discussed.

  9. Telmisartan Modulates Glial Activation: In Vitro and In Vivo Studies.

    Directory of Open Access Journals (Sweden)

    Nofar Torika

    Full Text Available The circulating renin-angiotensin system (RAS, including the biologically active angiotensin II, is a fundamental regulatory mechanism of blood pressure conserved through evolution. Angiotensin II components of the RAS have also been identified in the brain. In addition to pro-inflammatory cytokines, neuromodulators, such as angiotensin II can induce (through angiotensin type 1 receptor (AT1R some of the inflammatory actions of brain glial cells and influence brain inflammation. Moreover, in Alzheimer's disease (AD models, where neuroinflammation occurs, increased levels of cortical AT1Rs have been shown. Still, the precise role of RAS in neuroinflammation is not completely clear. The overall aim of the present study was to elucidate the role of RAS in the modulation of glial functions and AD pathology. To reach this goal, the specific aims of the present study were a. to investigate the long term effect of telmisartan (AT1R blocker on tumor necrosis factor-α (TNF-α, interleukin 1-β (IL1-β and nitric oxide (NO release from glial cells. b. to examine the effect of intranasally administered telmisartan on amyloid burden and microglial activation in 5X familial AD (5XFAD mice. Telmisartan effects in vivo were compared to those of perindopril (angiotensin converting enzyme inhibitor. Long-term-exposure of BV2 microglia to telmisartan significantly decreased lipopolysaccharide (LPS -induced NO, inducible NO synthase, TNF-α and IL1-β synthesis. The effect of Telmisartan on NO production in BV2 cells was confirmed also in primary neonatal rat glial cells. Intranasal administration of telmisartan (1 mg/kg/day for up to two months significantly reduced amyloid burden and CD11b expression (a marker for microglia both in the cortex and hipoccampus of 5XFAD. Based on the current view of RAS and our data, showing reduced amyloid burden and glial activation in the brains of 5XFAD transgenic mice, one may envision potential intervention with the

  10. Study of the in vitro antiplasmodial, antileishmanial and antitrypanosomal activities of medicinal plants from Saudi Arabia.

    Science.gov (United States)

    Al-Musayeib, Nawal M; Mothana, Ramzi A; Al-Massarani, Shaza; Matheeussen, An; Cos, Paul; Maes, Louis

    2012-09-25

    The present study investigated the in vitro antiprotozoal activity of sixteen selected medicinal plants. Plant materials were extracted with methanol and screened in vitro against erythrocytic schizonts of Plasmodium falciparum, intracellular amastigotes of Leishmania infantum and Trypanosoma cruzi and free trypomastigotes of T. brucei. Cytotoxic activity was determined against MRC-5 cells to assess selectivity. The criterion for activity was an IC₅₀ Albizia lebbeck pericarp, Caralluma sinaica, Periploca aphylla and Prosopius juliflora. Activity against T. brucei was obtained in Prosopis juliflora. Cytotoxicity (MRC-5 IC₅₀ < 10 μg/mL) and hence non-specific activities were observed for Conocarpus lancifolius.

  11. In vitro radioassay techniques in the study of reproductive hormones

    International Nuclear Information System (INIS)

    Rivarola, M.

    1980-01-01

    Testosterone (T) levels in the testicular tissue in varicocele were studied in relation to alterations of testicular function. Testicular T levels were measured by a modified radioimmunoassay procedure in which 3 H-testosterone was used as a tracer to monitor losses during extraction of the hormone. Serum follicle stimulating hormone (FSH), luteinizing hormone (LH) and T levels were measured by conventional radioimmunoassay. Testicular function was evaluated from patient histories and physical examinations, and from the results of sperm counts and histological examinations of biopsy specimens. In 4 control patients mean testicular T was 520 +- 127 ng/g tissue and the mean ratio testicular T/serum T 104 +- 47. In the majority of 17 patients with unilateral varicocele, testicular T was within normal limits, but in 3 patients with severe testicular damage values of 2700, 2373 and 1437 ng/g were recorded. Serum T levels were normal in the majority of patients and decreased in 2. Serum FSH levels were normal in the majority of patients and increased in 3. Serum LH levels were increased in approximately one half of patients. The results are considered indicative of impaired Leydig cell function in varicocele. It appears, however, that decreased T production is compensated by increased LH production and that the germinal cells are not deprived of T

  12. Diethyl Phthalate Causes Oxidative Stress: An in Vitro Study

    Directory of Open Access Journals (Sweden)

    Heena Prajapati

    2014-03-01

    Full Text Available Background: Phthalates are a group of multifunctional chemicals. Diethyl phthalate (DEP is one of the most frequently used phthalates in solvents and fixatives for numerous industrial products. Method: The present experiment was designed to assess oxidative stress, if any, caused by diethyl phthalate. For this the homogenates of liver and kidney were treated with different concentrations ( 10-40 µg/mL of DEP. 10% liver and kidney homogenates were prepared in phosphate buffered saline and used for estimation of lipid peroxidation.In final step lipid peroxidation and total protein content were analyzed. Results: The result revealed significant and dose - dependent increase in lipid peroxidation, whereas protein content reduced significantly. Maximum increase in LPO and decrease in protein content was observed at 40 µg/mL of DEP concentration. Conclusion: From this study, it can be concluded that different concentrations of DEP leads to dose- dependent significant increase in lipid peroxidation and decrease protein content.So at the different concentration of DEP cause oxidative stress.

  13. Development of midazolam sublingual tablets: in vitro study.

    Science.gov (United States)

    Odou, P; Barthelemy, C; Robert, H

    1998-01-01

    Midazolam is a benzodiazepine with short elimination half-life, used as induction or continuous agent for general anesthesia. At present, only injectable solution is available from French hospital pharmacies. The aim of the study is the development of 5 mg midazolam sublingual tablets to realize a short general anesthesia without intravenous or intramuscular injection. Incorporation of citric acid in the tablet formulation leads to an increase of dissolution rates of active drug, but a decrease of diffusion through lipid membranes is observed with 10 mg of citric acid when using the Dibbern's Resomat three phases apparatus. One explanation of this result is that midazolam (pKa = 6.1) in presence of 10 mg of citric acid is ionised. The ionised form, more hydrophilic, cannot cross the artificial lipid membrane and therefore the diffusion decreases. On the other hand, the decrease of diffusion's rate, when pH increases, is explained by the precipitation of midazolam at pH higher than 6. A compromise between dissolution and diffusion results leads us to choose the sublingual formulation containing 5 mg of citric acid per tablet.

  14. The study of teratogenic effect of Cyclosporine in vitro

    Directory of Open Access Journals (Sweden)

    Ostad SN

    2001-07-01

    Full Text Available The use of immunosuppressive medication such as Azathioprine, methoterxate and mercaptopurine in treatment of rheumatic disease in women at childbearing age has some risks of teratogeniesis. Cyclosporine is one of the newer medicines, which has been introduced for this disease but little is known about its teratogenicity. This study was designed to investigate the possible teratogenicity of this drug by using cultured rat limb bud cells, which were obtained from rat embryos 13 days after conception. Cells were incubated in trypsin-EDTA solution for 30 min at 37°C and then filtered through 50 µm nylon filters. The resultant cell suspension was cultivated in 1 ml Dulbecco modified Eagle medium (DMEM containing 10% fetal bovine serum and 445 µg/L L-glutamine at 37°C with 5% CO2. After 8 days of culture the differentiated foci extract were measured by staining with 1% alcian blue. To assess the teratogenic effects of cyclosporine, it was placed in the culture well together with the cells. Results showed that the decrease in the expression of the extracellular matrix at dose of 0.01 molar of cyclosporine is due to limb bud cell toxicity rather than inhibition of cell differentiation.

  15. In vitro toxicity studies of polymer-coated gold nanorods

    Energy Technology Data Exchange (ETDEWEB)

    Rayavarapu, Raja G; Petersen, Wilma; Manohar, Srirang; Van Leeuwen, Ton G [Biomedical Photonic Imaging Group, MIRA Institute for Biomedical Technology and Technical Medicine, Faculty of Science and Technology, University of Twente, PO Box 217, 7500AE Enschede (Netherlands); Hartsuiker, Liesbeth; Otto, Cees [Medical Cell Biophysics, MIRA Institute for Biomedical Technology and Technical Medicine, Faculty of Science and Technology, University of Twente, PO Box 217, 7500AE Enschede (Netherlands); Chin, Patrick; Van Leeuwen, Fijs W B [Division of Diagnostic Oncology, Netherlands Cancer Institute, 1066 CX Amsterdam (Netherlands); Janssen, Hans, E-mail: S.Manohar@utwente.nl [Division of Cell Biology, The Netherlands Cancer Institute, 1066 CX Amsterdam (Netherlands)

    2010-04-09

    We evaluated cellular responses to polymer-treated gold nanorods, which were synthesized using the standard wet-chemistry method that utilizes hexadecyltrimethylammonium bromide (CTAB). The nanorod dispersions were coated with either polystyrene sulfonate (PSS) or polyethylene glycol (PEG). Two sizes of nanorods were tested, with optical responses peaking at 628 and 773 nm. The cells were from mammary adenocarcinoma (SKBR3), Chinese Hamster Ovary (CHO), mouse myoblast (C2C12) and Human Leukemia (HL60) cell lines. Their mitochondrial function following exposure to the nanorods were assessed using the MTS assay. We found PEGylated particles to have superior biocompatibility compared with PSS-coated nanorods, which showed substantial cytotoxicity. Electron microscopy showed no cellular uptake of PEGylated particles compared with their PSS counterparts. PEGylated gold nanorods also exhibited better dispersion stability in the presence of cell growth medium; PSS-coated rods tended to flocculate or cluster. In the case of the PSS particles, toxicity correlated with surface area across the two sizes of nanorods studied.

  16. Effect of nephrotoxicants on renal membrane transport: In vitro studies

    International Nuclear Information System (INIS)

    Ansari, R.A.; Berndt, W.O.

    1990-01-01

    It is possible to study the effects of nephrotoxicants on membrane function free of other cellular influences. By the use of Percoll gradient centrifugation, highly purified preparations of right-side-out basolateral (BL) and brush border (BB) membrane vesicles can be obtained from rat (male, Sprague-Dawley) renal cortex. Membrane function can be monitored by evaluation of sodium driven transport: 14 C-p-aminohippurate (PAH) for BL and 14 C-glucose for BB. Transport was measured by the rapid filtration technique. Each vesicle preparation was preincubated with the nephrotoxicant for five minutes before initiation of transport. Control vesicles showed a prominant overshoot 1 to 2 minutes after start of transport. Mercuric ion (Hg) had no effect on transport by BB at concentrations as high as 10μM. Transport by BL was reduced significantly at Hg concentrations as low as 100 nM. Chromate (Cr) also reduced BL transport at 100 nM and had no effect on BB transport. Citrinin significantly reduced both BB and BL transport, but the sensitivity of the membrane preparations differed. These data are consistent with the hypothesis that some nephrotoxicants may act on either side of the renal tubular cell membrane

  17. Computational biomechanics

    International Nuclear Information System (INIS)

    Ethier, C.R.

    2004-01-01

    Computational biomechanics is a fast-growing field that integrates modern biological techniques and computer modelling to solve problems of medical and biological interest. Modelling of blood flow in the large arteries is the best-known application of computational biomechanics, but there are many others. Described here is work being carried out in the laboratory on the modelling of blood flow in the coronary arteries and on the transport of viral particles in the eye. (author)

  18. A pilot study of biomechanical assessment before and after an integrative training program for adolescents with juvenile fibromyalgia.

    Science.gov (United States)

    Tran, Susan T; Thomas, Staci; DiCesare, Christopher; Pfeiffer, Megan; Sil, Soumitri; Ting, Tracy V; Williams, Sara E; Myer, Gregory D; Kashikar-Zuck, Susmita

    2016-07-22

    Adolescents with juvenile fibromyalgia (JFM) tend to be very sedentary and avoid participation in physical activity. A prior study suggested that JFM patients show altered biomechanics compared to healthy adolescents which may make them more prone to pain/injury during exercise. A new intervention combining well established cognitive behavioral therapy (CBT) techniques with specialized neuromuscular exercise -Fibromyalgia Integrative Training for Teens (FIT Teens) was developed and shown to be promising in improving functioning in adolescents with JFM. In contrast to traditional exercise programs such as aerobic or resistance training, neuromuscular training is a tailored approach which targets gait, posture, balance and movement mechanics which form the foundation for safe exercise participation with reduced risk for injury or pain (and hence more tolerable by JFM patients). The aim of this pilot feasibility study was to establish whether objective biomechanical assessment including sophisticated 3-D motion analysis would be useful in measuring improvements in strength, balance, gait, and functional performance after participation in the 8-week FIT Teens program. Eleven female participants with JFM (ages 12-18 years) completed pre- and post-treatment assessments of biomechanics, including walking gait analysis, lower extremity strength assessment, functional performance, and dynamic postural stability. Descriptive data indicated that mechanics of walking gait and functional performance appeared to improve after treatment. Hip abduction strength and dynamic postural control also demonstrated improvements bilaterally. Overall, the results of this pilot study offer initial evidence for the utility of biomechanical assessment to objectively demonstrate observable changes in biomechanical performance after an integrated training intervention for youth with JFM. If replicated in larger controlled studies, findings would suggest that through the FIT Teens intervention

  19. Extended latanoprost release from commercial contact lenses: in vitro studies using corneal models.

    Directory of Open Access Journals (Sweden)

    Saman Mohammadi

    Full Text Available In this study, we compared, for the first time, the release of a 432 kDa prostaglandin F2a analogue drug, Latanoprost, from commercially available contact lenses using in vitro models with corneal epithelial cells. Conventional polyHEMA-based and silicone hydrogel soft contact lenses were soaked in drug solution (131 μg = ml solution in phosphate buffered saline. The drug release from the contact lens material and its diffusion through three in vitro models was studied. The three in vitro models consisted of a polyethylene terephthalate (PET membrane without corneal epithelial cells, a PET membrane with a monolayer of human corneal epithelial cells (HCEC, and a PET membrane with stratified HCEC. In the cell-based in vitro corneal epithelium models, a zero order release was obtained with the silicone hydrogel materials (linear for the duration of the experiment whereby, after 48 hours, between 4 to 6 μg of latanoprost (an amount well within the range of the prescribed daily dose for glaucoma patients was released. In the absence of cells, a significantly lower amount of drug, between 0.3 to 0.5 μg, was released, (p <0:001. The difference observed in release from the hydrogel lens materials in the presence and absence of cells emphasizes the importance of using an in vitro corneal model that is more representative of the physiological conditions in the eye to more adequately characterize ophthalmic drug delivery materials. Our results demonstrate how in vitro models with corneal epithelial cells may allow better prediction of in vivo release. It also highlights the potential of drug-soaked silicone hydrogel contact lens materials for drug delivery purposes.

  20. A Novel Biodegradable Polycaprolactone Fixator for Osteosynthesis Surgery of Rib Fracture: In Vitro and in Vivo Study

    Directory of Open Access Journals (Sweden)

    Yi-Hsun Yu

    2015-11-01

    Full Text Available Osteosynthesis surgery for rib fractures is controversial and challenging. This study developed a noval poly(ε-caprolactone (PCL-based biodegradable “cable-tie” fixator for osteosynthesis surgery for rib fractures. A biodegradable fixator specifically for fractured ribs was designed and fabricated by a micro-injection molding machine in our laboratory. The fixator has three belts that could be passed through matching holes individually. The locking mechanism allows the belt movement to move in only one direction. To examine the in vitro biomechanical performance, ribs 3–7 from four fresh New Zealand rabbits were employed. The load to failure and stress-strain curve was compared in the three-point bending test among native ribs, titanium plate-fixed ribs, and PCL fixator-fixed ribs. In the in vivo animal study, the sixth ribs of New Zealand rabbits were osteotomized and osteosynthesis surgery was performed using the PCL fixator. Outcomes were assessed by monthly X-ray examinations, a final micro-computed tomography (CT scan, and histological analysis. The experimental results suggested that the ribs fixed with the PCL fixator were significantly less stiff than those fixed with titanium plates (p < 0.05. All ribs fixed with the PCL fixators exhibited union. The bridging callus was confirmed by gross, radiographic micro-three-dimensional (3D CT, and histological examinations. In addition, there was no significant inflammatory response of the osteotomized ribs or the PCL-rib interface during application. The novel PCL fixator developed in this work achieves satisfactory results in osteosynthesis surgery for rib fractures, and may provide potential applications in other orthopedic surgeries.

  1. 75 FR 36425 - Guidance for Industry and Food and Drug Administration Staff; In Vitro Diagnostic Studies...

    Science.gov (United States)

    2010-06-25

    ... DEPARTMENT OF HEALTH AND HUMAN SERVICES Food and Drug Administration [Docket No. FDA-2007-D-0076] (formerly Docket No. 2007D-0387) Guidance for Industry and Food and Drug Administration Staff; In Vitro Diagnostic Studies--Frequently Asked Questions; Availability AGENCY: Food and Drug Administration, HHS...

  2. In Vitro Membrane Permeation Studies and in Vivo Antinociception of Glycosylated Dmt(1)-DALDA Analogues

    DEFF Research Database (Denmark)

    Ballet, Steven; Betti, Cecilia; Novoa, Alexandre

    2014-01-01

    In this study the μ opioid receptor (MOR) ligands DALDA (Tyr-d-Arg-Phe-Lys-NH2) and Dmt(1)-DALDA (Dmt-d-Arg-Phe-Lys-NH2, Dmt = 2',6'-dimethyltyrosine) were glycosylated at the N- or C-terminus. Subsequently, the modified peptides were subjected to in vitro and in vivo evaluation. In contrast to t...

  3. Minimally Invasive Cochlear Implantation Assisted by Bi-planar Device: An Exploratory Feasibility Study in vitro

    Directory of Open Access Journals (Sweden)

    Jia Ke

    2016-01-01

    Conclusions: This exploratory study demonstrated the safety of the newly developed image-guided minimally invasive cochlear implantation assisted by the bi-planar device and established the operational procedures. Further, more in vitro experiments are needed to improve the system operation and its safety.

  4. In vitro Studies of the Effectiveness of Five Plants Extracts Compared ...

    African Journals Online (AJOL)

    The crude aqueous extracts of five plants, Cleome viscosa L. Hyptis suaveolens Poit, Crotalaria retusa L., Jatropha curcas L., and Jatropha gossypifolia l., and a synthetic nematicide Carbofuran were studied in-vitro for their efficacy in controlling the rootknot nematode, Meloidogyne incognita (Kofoid and White) Chitwood.

  5. Leukocyte removal efficiency of cell-washed and unwashed whole blood: an in vitro study.

    NARCIS (Netherlands)

    Brinke, M. ten; Weerwind, P.W.; Teerenstra, S.; Feron, JC; Meer, W. van der; Brouwer, René

    2005-01-01

    Leukocyte filtration of the cardiopulmonary bypass (CPB) perfusate after cardiac surgery has evolved as an important technique to prevent effector functions mediated by activated leukocytes. However, little is known about the filtration efficiency. Therefore, an in vitro study was conducted to

  6. Study on in vitro anti-tumor activity of Bidens bipinnata L. extract ...

    African Journals Online (AJOL)

    We studied the in vitro anti-tumor activity of Bidens Bipinnata L. extract. MTT assay was used to investigate the inhibitory effect of different concentrations of the extracts on human hepatocellular carcinoma (HepG2) cell lines and human cervical carcinoma (Hela) cell lines, and the IC50 values were calculated. The Bidens ...

  7. Chromosomes and irradiation: in vitro study of the action of X-rays on human lymphocytes

    International Nuclear Information System (INIS)

    Mouriquand, C.; Patet, J.; Gilly, C.; Wolff, C.

    1966-01-01

    Radioinduced chromosomal aberrations were studied in vitro on leukocytes of human peripheral blood after x irradiation at 25, 50, 100, 200, and 300 R. The numeric and structural anomalies were examined on 600 karyotypes. The relationship between these disorders and the dose delivered to the blood are discussed. An explanation on their mechanism of formation is tentatively given. (authors) [fr

  8. 21 CFR 864.5425 - Multipurpose system for in vitro coagulation studies.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Multipurpose system for in vitro coagulation studies. 864.5425 Section 864.5425 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES HEMATOLOGY AND PATHOLOGY DEVICES Automated and Semi-Automated...

  9. [An in vitro method for studying the metabolism of young bone matrix].

    Science.gov (United States)

    Bonneton, C; Guest, M; Delbarre, F

    1977-07-04

    A method for studying in vitro bone resorption by the use of 35S labeled injection was investigated. Various substances (papaine) and hormones (calcitonin, vitamin D analogues) were tested and their effects on 35S and 45Ca metabolism were compared.

  10. The effects of simulated bone loss on the implant-abutment assembly and likelihood of fracture: an in vitro study.

    Science.gov (United States)

    Manzoor, Behzad; Suleiman, Mahmood; Palmer, Richard M

    2013-01-01

    The crestal bone level around a dental implant may influence its strength characteristics by offering protection against mechanical failures. Therefore, the present study investigated the effect of simulated bone loss on modes, loads, and cycles to failure in an in vitro model. Different amounts of bone loss were simulated: 0, 1.5, 3.0, and 4.5 mm from the implant head. Forty narrow-diameter (3.0-mm) implant-abutment assemblies were tested using compressive bending and cyclic fatigue testing. Weibull and accelerated life testing analysis were used to assess reliability and functional life. Statistical analyses were performed using the Fisher-Exact test and the Spearman ranked correlation. Compressive bending tests showed that the level of bone loss influenced the load-bearing capacity of implant-abutment assemblies. Fatigue testing showed that the modes, loads, and cycles to failure had a statistically significant relationship with the level of bone loss. All 16 samples with bone loss of 3.0 mm or more experienced horizontal implant body fractures. In contrast, 14 of 16 samples with 0 and 1.5 mm of bone loss showed abutment and screw fractures. Weibull and accelerated life testing analysis indicated a two-group distribution: the 0- and 1.5-mm bone loss samples had better functional life and reliability than the 3.0- and 4.5-mm samples. Progressive bone loss had a significant effect on modes, loads, and cycles to failure. In addition, bone loss influenced the functional life and reliability of the implant-abutment assemblies. Maintaining crestal bone levels is important in ensuring biomechanical sustainability and predictable long-term function of dental implant assemblies.

  11. Hydrophilic and lipophilic radiopharmaceuticals as tracers in pharmaceutical development: In vitro – In vivo studies

    International Nuclear Information System (INIS)

    Terán, Mariella; Savio, Eduardo; Paolino, Andrea; Frier, Malcolm

    2005-01-01

    Scintigraphic studies have been performed to assess the release, both in vitro and in vivo, of radiotracers from tablet formulations. Four different tracers with differing physicochemical characteristics have been evaluated to assess their suitability as models for drug delivery. In-vitro disintegration and dissolution studies have been performed at pH 1, 4 and 7. In-vivo studies have been performed by scintigraphic imaging in healthy volunteers. Two hydrophilic tracers, ( 99m Tc-DTPA) and ( 99m Tc-MDP), and two lipophilic tracers, ( 99m Tc-ECD) and ( 99m Tc-MIBI), were used as drug models. Dissolution and disintegration profiles, differed depending on the drug model chosen. In vitro dissolution velocity constants indicated a probable retention of the radiotracer in the formulation. In vivo disintegration velocity constants showed important variability for each radiopharmaceutical. Pearson statistical test showed no correlation between in vitro drug release, and in vivo behaviour, for 99m Tc-DTPA, 99m Tc-ECD and 99m Tc-MIBI. High correlation coefficients were found for 99m Tc-MDP not only for in vitro dissolution and disintegration studies but also for in vivo scintigraphic studies. Scintigraphic studies have made a significant contribution to the development of drug delivery systems. It is essential, however, to choose the appropriate radiotracers as models of drug behaviour. This study has demonstrated significant differences in release patterns, depending on the model chosen. It is likely that each formulation would require the development of a specific model, rather than being able to use a generic drug model on the basis of its physicochemical characteristics

  12. In vitro and in vivo study of commercial calcium phosphate cement HydroSet™.

    Science.gov (United States)

    Kent, Niall W; Blunn, Gordon; Karpukhina, Natalia; Davis, Graham; de Godoy, Roberta Ferro; Wilson, Rory M; Coathup, Melanie; Onwordi, Lyris; Quak, Wen Yu; Hill, Robert

    2018-01-01

    The commercial calcium phosphate cement, HydroSet™, was investigated in vitro, studying phase formation, compressive strength and setting time, followed by an ovine in vivo study to measure osseointegration, bone apposition and bone-to-graft contact. The X-ray diffraction and 31 P Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR) results showed the initial formation of octacalcium phosphate and hydroxyapatite at one hour. Over 7 days the octacalcium phosphate transformed to apatite, which was the only crystalline phase of the cement at 28 days. This apatite phase is thought to be a calcium deficient apatite. In the scanning electron microscopy, histological images of 12-week ovine in vivo results showed a high degree of osseointegration, 92.5%. Compressive strength comparisons between in vitro and in vivo measurements showed a dramatic difference between the in vitro measurements (highest 25.4 MPa) and in vivo (95 MPa), attributed to bone ingrowth into the cement in vivo. To the best of our knowledge this is the first time phase evolution of HydroSet™ and the properties studied in vitro complement the in vivo evaluation of the cement in a publication. The significance of the new finding of initial formation of octacalcium phosphate in this cement is discussed. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 21-30, 2018. © 2016 Wiley Periodicals, Inc.

  13. Development of pH-Dependent Nanospheres for Nebulisation- In vitro Diffusion, Aerodynamic and Cytotoxicity Studies.

    Science.gov (United States)

    Ige, Pradum P; Pardeshi, Sagar R; Sonawane, Raju O

    2018-04-17

    The aim of this work was to evaluate the in vitro performance of nebulized nanosuspension formulation when nebulized using ultrasonic nebulizer. The present investigation deals with successful formulation of Beclomethasone dipropionate loaded HPMCP nanospheres prepared by solvent evaporation technique using PEG 400 as a stabilizer. Beclomethasone dipropionate is a water insoluble drug molecule was encapsulated in HPMCP nanospheres to have pH dependent solubility at basic pH for targeted drug delivery in lung and studied for in vitro cytotoxicity and immediate release capability. The synthesized nanospheres were characterized through drug excipient compatibility, surface topography; mean particle size , zeta potential, PDI, entrapment efficiency and drug loading, in vitro diffusion, aerodynamic, in vitro cytotoxicity and stability studies. The mean particle size and PDI of the optimized batch (F1) had 197.6±0.40 nm and 0.324 ±0.35, respectively. The % entrapment efficiency and % drug loading was found to be 86.56±1.32 and 8.30±0.27, respectively. The optimized batch F1 showed % cumulative drug release 94.77±0.24 at 1 h. The formulation showed cell viability up to 91.28%. It can be concluded that, Beclomethasone dipropionate loaded HPMCP nanospheres was found to be safe, stable with significant increase in solubility and bypass the liver. © Georg Thieme Verlag KG Stuttgart · New York.

  14. In vivo and in vitro studies of cartilage differentiation in altered gravities

    Science.gov (United States)

    Montufar-Solis, D.; Duke, P. J.; D'Aunno, D.

    The in vivo model our laboratory uses for studies of cartilage differentiation in space is the rat growth plate. Differences between missions, and in rat age and recovery times, provided differing results from each mission. However, in all missions, proliferation and differentiation of chondrocytes in the epiphyseal plate of spaceflown rats was altered as was matrix organization. In vitro systems, necessary complements to in vivo work, provide some advantages over the in vivo situation. In vitro, centrifugation of embryonic limb buds suppressed morphogenesis due to precocious differentiation, and changes in the developmental pattern suggest the involvement of Hox genes. In space, embryonic mouse limb mesenchyme cells differentiating in vitro on IML-1 had smoother membranes and lacked matrix seen in controls. Unusual formations, possibly highly ruffled membranes, were found in flight cultures. These results, coupled with in vivo centrifugation studies, show that in vivo or in vitro, the response of chondrocytes to gravitational changes follows Hert's curve as modified by Simon, i.e. decreased loading decreases differentiation, and increased loading speeds it up, but only to a point. After that, additional increases again slow down chondrogenesis.

  15. The Use of Wearable Inertial Motion Sensors in Human Lower Limb Biomechanics Studies: A Systematic Review

    Directory of Open Access Journals (Sweden)

    Yue-Yan Chan

    2010-12-01

    Full Text Available Wearable motion sensors consisting of accelerometers, gyroscopes and magnetic sensors are readily available nowadays. The small size and low production costs of motion sensors make them a very good tool for human motions analysis. However, data processing and accuracy of the collected data are important issues for research purposes. In this paper, we aim to review the literature related to usage of inertial sensors in human lower limb biomechanics studies. A systematic search was done in the following search engines: ISI Web of Knowledge, Medline, SportDiscus and IEEE Xplore. Thirty nine full papers and conference abstracts with related topics were included in this review. The type of sensor involved, data collection methods, study design, validation methods and its applications were reviewed.

  16. The use of wearable inertial motion sensors in human lower limb biomechanics studies: a systematic review.

    Science.gov (United States)

    Fong, Daniel Tik-Pui; Chan, Yue-Yan

    2010-01-01

    Wearable motion sensors consisting of accelerometers, gyroscopes and magnetic sensors are readily available nowadays. The small size and low production costs of motion sensors make them a very good tool for human motions analysis. However, data processing and accuracy of the collected data are important issues for research purposes. In this paper, we aim to review the literature related to usage of inertial sensors in human lower limb biomechanics studies. A systematic search was done in the following search engines: ISI Web of Knowledge, Medline, SportDiscus and IEEE Xplore. Thirty nine full papers and conference abstracts with related topics were included in this review. The type of sensor involved, data collection methods, study design, validation methods and its applications were reviewed.

  17. Comparison of completely knotless and hybrid double-row fixation systems: a biomechanical study.

    Science.gov (United States)

    Chu, Thomas; McDonald, Erik; Tufaga, Michael; Kandemir, Utku; Buckley, Jenni; Ma, C Benjamin

    2011-04-01

    The purpose of this study was to compare the biomechanical performance of a completely knotless double-row repair system (SutureCross Knotless Anatomic Fixation System; KFx Medical, Carlsbad, CA) with 2 commonly used hybrid double-row repair (medial knot-tying, lateral knotless) systems (Bio-Corkscrew/PushLock [Arthrex, Naples, FL] and Spiralok/Versalok [DePuy Mitek, Raynham, MA]). Fourteen pairs of fresh-frozen cadaveric shoulders were harvested, the supraspinatus tendons were isolated, and full-thickness supraspinatus tears were created. One of each pair was repaired with the completely knotless system, and the contralateral side was repaired with either of the hybrid systems. The repairs were then subjected to cyclic loading followed by load to failure. Conditioning elongation, peak-to-peak elongation, ultimate load, and mechanism of failure were recorded and compared by use of paired t tests. Seven additional shoulders were tested to determine the effect of refrigeration storage on the completely knotless system by use of the same mechanical testing protocol. For the completely knotless repair group, 11 of 14 paired specimens failed during the cyclic loading period. Only 1 of 14 hybrid repair systems had failures during cyclic loading, and both hybrid repair systems had statistically lower conditioning elongation than the completely knotless repair group. The mean ultimate load of the SutureCross group was 166 ± 87 N, which was significantly lower than that in the Corkscrew/PushLock (310 ± 82 N) and Spiralok/Versalok (337 ± 44 N) groups. There was an effect of refrigeration storage on the peak-to-peak elongation and stiffness of the SutureCross group; however, there was no difference in ultimate tensile load or conditioning elongation. The completely knotless repair system has lower time-zero biomechanical properties than the other 2 hybrid systems. The SutureCross system has lower time-zero biomechanical properties when compared with other hybrid repair

  18. A Novel Biodegradable Polyurethane Matrix for Auricular Cartilage Repair: An In Vitro and In Vivo Study.

    Science.gov (United States)

    Iyer, Kartik; Dearman, Bronwyn L; Wagstaff, Marcus J D; Greenwood, John E

    2016-01-01

    Auricular reconstruction poses a challenge for reconstructive and burns surgeons. Techniques involving cartilage tissue engineering have shown potential in recent years. A biodegradable polyurethane matrix developed for dermal reconstruction offers an alternative to autologous, allogeneic, or xenogeneic biologicals for cartilage reconstruction. This study assesses such a polyurethane matrix for this indication in vivo and in vitro. To evaluate intrinsic cartilage repair, three pigs underwent auricular surgery to create excisional cartilage ± perichondrial defects, measuring 2 × 3 cm in each ear, into which acellular polyurethane matrices were implanted. Biopsies were taken at day 28 for histological assessment. Porcine chondrocytes ± perichondrocytes were cultured and seeded in vitro onto 1 × 1 cm polyurethane scaffolds. The total culture period was 42 days; confocal, histological, and immunohistochemical analyses of scaffold cultures were performed on days 14, 28, and 42. In vivo, the polyurethane matrices integrated with granulation tissue filling all biopsy samples. Minimal neocartilage invasion was observed marginally on some samples. Tissue composition was identical between ears whether perichondrium was left intact, or not. In vitro, the polyurethane matrix was biocompatible with chondrocytes ± perichondrocytes and supported production of extracellular matrix and Type II collagen. No difference was observed between chondrocyte culture alone and chondrocyte/perichondrocyte scaffold coculture. The polyurethane matrix successfully integrated into the auricular defect and was a suitable scaffold in vitro for cartilage tissue engineering, demonstrating its potential application in auricular reconstruction.

  19. High-Tensile Strength Tape Versus High-Tensile Strength Suture: A Biomechanical Study.

    Science.gov (United States)

    Gnandt, Ryan J; Smith, Jennifer L; Nguyen-Ta, Kim; McDonald, Lucas; LeClere, Lance E

    2016-02-01

    To determine which suture design, high-tensile strength tape or high-tensile strength suture, performed better at securing human tissue across 4 selected suture techniques commonly used in tendinous repair, by comparing the total load at failure measured during a fixed-rate longitudinal single load to failure using a biomechanical testing machine. Matched sets of tendon specimens with bony attachments were dissected from 15 human cadaveric lower extremities in a manner allowing for direct comparison testing. With the use of selected techniques (simple Mason-Allen in the patellar tendon specimens, whip stitch in the quadriceps tendon specimens, and Krackow stitch in the Achilles tendon specimens), 1 sample of each set was sutured with a 2-mm braided, nonabsorbable, high-tensile strength tape and the other with a No. 2 braided, nonabsorbable, high-tensile strength suture. A total of 120 specimens were tested. Each model was loaded to failure at a fixed longitudinal traction rate of 100 mm/min. The maximum load and failure method were recorded. In the whip stitch and the Krackow-stitch models, the high-tensile strength tape had a significantly greater mean load at failure with a difference of 181 N (P = .001) and 94 N (P = .015) respectively. No significant difference was found in the Mason-Allen and simple stitch models. Pull-through remained the most common method of failure at an overall rate of 56.7% (suture = 55%; tape = 58.3%). In biomechanical testing during a single load to failure, high-tensile strength tape performs more favorably than high-tensile strength suture, with a greater mean load to failure, in both the whip- and Krackow-stitch models. Although suture pull-through remains the most common method of failure, high-tensile strength tape requires a significantly greater load to pull-through in a whip-stitch and Krakow-stitch model. The biomechanical data obtained in the current study indicates that high-tensile strength tape may provide better repair

  20. Lutein bioavailability from lutein ester-fortified fermented milk: in vivo and in vitro study.

    Science.gov (United States)

    Granado-Lorencio, Fernando; Herrero-Barbudo, Carmer; Olmedilla-Alonso, Begoña; Blanco-Navarro, Inmaculada; Pérez-Sacristán, Belén

    2010-02-01

    We assessed the bioavailability of lutein from lutein-fortified fermented milk using in vivo and in vitro approaches. Twenty-four volunteers were randomized to take lutein-fortified fermented milk at two levels of fortification. Single-dose bioavailability study (2x100 ml, ca. 8 or 16 mg of lutein) was performed using a three-point approach (baseline, 3.5 and 6.5 h). Multiple-dose study consisted of consuming one serving/day (ca. 4 or 8 mg/100 ml) for 14 days. Blood samples for biochemical, hematological and lutein analysis were drawn at baseline, Day 7 and Day 14. In vitro bioaccessibility was assessed by a static gastrointestinal digestion model. Lutein content, in vitro ester hydrolysis and micellarization, and lutein concentrations achieved in serum were analyzed by HPLC. In vivo, post-prandial response was higher using the high content fermented milk, but the percentage of absorption was not different according to the dose consumed. Net increments at Day 7 and Day 14 were significantly higher on consuming the high-dose milk as well. In vitro, lutein ester hydrolysis was incomplete regardless of the amount initially present. Free lutein released was higher using the high-dose fermented milk, but the percentage of hydrolysis was similar at both levels of fortification. In the micellar phase, the percentage of free and total lutein was not different according to the dose. Our results support the suitability of the fermented milk as a carrier of lutein esters and an in vivo dose-dependent effect upon regular consumption and suggest the usefulness of in vitro models to provide relevant information to predict in vivo responses. Copyright 2010 Elsevier Inc. All rights reserved.

  1. Robots in human biomechanics--a study on ankle push-off in walking.

    Science.gov (United States)

    Renjewski, Daniel; Seyfarth, André

    2012-09-01

    In biomechanics, explanatory template models are used to identify the basic mechanisms of human locomotion. However, model predictions often lack verification in a realistic environment. We present a method that uses template model mechanics as a blueprint for a bipedal robot and a corresponding computer simulation. The hypotheses derived from template model studies concerning the function of heel-off in walking are analysed and discrepancies between the template model and its real-world anchor are pointed out. Neither extending the ground clearance of the swinging leg nor an impact reduction at touch-down as an effect of heel lifting was supported by the experiments. To confirm the relevance of the experimental findings, a comparison of robot data to human walking data is discussed and we speculate on an alternative explanation of heel-off in human walking, i.e. that the push-off powers the following leg swing.

  2. Quantum dots as mineral- and matrix-specific strain gages for bone biomechanical studies

    Science.gov (United States)

    Zhu, Peizhi; Xu, Jiadi; Morris, Michael; Ramamoorthy, Ayyalusamy; Sahar, Nadder; Kohn, David

    2009-02-01

    We report the use of quantum dots (Qdots) as strain gages in the study of bone biomechanics using solid state nuclear magnetic resonance (NMR) spectroscopy. We have developed solid state NMR sample cells for investigation of deformations of bone tissue components at loads up to several Mega Pascal. The size constraints of the NMR instrumentation limit the bone specimen diameter and length to be no greater than 2-3 mm and 30 mm respectively. Further, magic angle spinning (MAS) solid state NMR experiments require the use of non-metallic apparatus that can be rotated at kilohertz rates. These experimental constraints preclude the use of standard biomechanical measurement systems. In this paper we explore the use of quantum dot center of gravity measurement as a strain gage technology consistent with the constraints of solid state NMR. We use Qdots that bind calcium (625 nm emission) and collagen (705 nm emission) for measurement of strain in these components. Compressive loads are applied to a specimen in a cell through a fine pitch screw turned with a mini-torque wrench. Displacement is measured as changes in the positions of arrays of quantum dots on the surface of a specimen. Arrays are created by spotting the specimen with dilute suspensions of Qdots. Mineral labeling is achieved with 705 nm carboxylated dots and matrix labeling with 565 nm quantum dots conjugated to collagen I antibodies. After each load increment the new positions of the quantum dots are measured by fluorescence microscopy. Changes in Qdot center of gravity as a function of applied load can be measured with submicron accuracy.

  3. Biomechanical study on the bladder neck and urethral positions: simulation of impairment of the pelvic ligaments.

    Science.gov (United States)

    Brandão, Sofia; Parente, Marco; Mascarenhas, Teresa; da Silva, Ana Rita Gomes; Ramos, Isabel; Jorge, Renato Natal

    2015-01-21

    Excessive mobility of the bladder neck and urethra are common features in stress urinary incontinence. We aimed at assessing, through computational modelling, the bladder neck position taking into account progressive impairment of the pelvic ligaments. Magnetic resonance images of a young healthy female were used to build a computational model of the pelvic cavity. Appropriate material properties and constitutive models were defined. The impairment of the ligaments was simulated by mimicking a reduction in their stiffness. For healthy ligaments, valsalva maneuver led to an increase in the α angle (between the bladder neck-symphysis pubis and the main of the symphysis) from 91.8° (at rest) to 105.7°, and 5.7 mm of bladder neck dislocation, which was similar to dynamic imaging of the same woman (α angle from 80° to 103.3°, and 5mm of bladder neck movement). For 95% impairment, they enlarged to 124.28° and 12 mm. Impairment to the pubourethral ligaments had higher effect than that of vaginal support (115° vs. 108°, and 9.1 vs. 7.3mm). Numerical simulation could predict urethral motion during valsalva maneuver, for both healthy and impaired ligaments. Results were similar to those of continent women and women with stress urinary incontinence published in the literature. Biomechanical analysis of the pubourethral ligaments complements the biomechanical study of the pelvic cavity in urinary incontinence. It may be useful in young women presenting stress urinary incontinence without imaging evidence of urethral and muscle lesions or organ descend during valsalva, and for whom fascial damage are not expected. Copyright © 2014 Elsevier Ltd. All rights reserved.

  4. HISTORY OF in vitro CULTURE STUDIES ON Helianthus annuus L. IN TURKEY

    Directory of Open Access Journals (Sweden)

    Sergun DAYAN

    2016-12-01

    Full Text Available Tissue culture techniques offer important approaches about sunflower breeding and germplasm conservation. The available data on the subject in Turkey was reviewed in order to encourage the researchers to study on tissue culture of sunflower. In vitro studies on sunflower in Turkey started in the first half of the 90s. A large number of in vitro culture studies on sunflower using anthers, hypocotyls, cotyledons, petioles of cotyledon, shoot-tips, mature embryos, immature embryos, leaves, petioles, immature cotyledons and microspores as different explants have been published. Microspore culture, anther culture, embryo culture, slow growth storage, micropropagation and gene transfer with Agrobacterium were also used in these culture studies. Although these studies formed an important scientific knowledge about sunflower tissue culture in the country, it is still not sufficient. Therefore, there is an urgent need to make more in vitro studies on sunflower which is an important agricultural plant for Turkey. The transfer of the results of these studies to agricultural applications is also essential from a sectoral standpoint.

  5. Comparison of Antibacterial Effect of Fluoride and Chlorhexidine on Two Cariogenic Bacteria: An in Vitro Study

    OpenAIRE

    Poureslami HR; Barkam F; Poureslami P; Salari Z; Salari S

    2014-01-01

    Statement of problem: Dental plaque is the main source for dental caries and there is no proper vaccine that can affect dental plaques. Objectives: Daily use of an efficient anti-plaque product can be very beneficial in plaque control and, thus, prevention of caries. This study aims to evaluate the antibacterial effects of four products of Chlorhexidine and Fluoride on two types of cariogenic bacteria. Materials and Methods: In this in vitro study, the antibacterial effect of Chlorhe...

  6. Comparative assessment of antimicrobial efficacy of different hand sanitizers: An in vitro study

    OpenAIRE

    Jain, Vardhaman Mulchand; Karibasappa, Gundabaktha Nagappa; Dodamani, Arun Suresh; Prashanth, Vishwakarma K.; Mali, Gaurao Vasant

    2016-01-01

    Background: To evaluate the antimicrobial efficacy of four different hand sanitizers against Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Escherichia coli, and Enterococcus faecalis as well as to assess and compare the antimicrobial effectiveness among four different hand sanitizers. Materials and Methods: The present study is an in vitro study to evaluate antimicrobial efficacy of Dettol, Lifebuoy, PureHands, and Sterillium hand sanitizers against clinical i...

  7. Nano- and microstructured materials for in vitro studies of the physiology of vascular cells

    OpenAIRE

    Alexandra M. Greiner; Adria Sales; Hao Chen; Sarah A. Biela; Dieter Kaufmann; Ralf Kemkemer

    2016-01-01

    The extracellular environment of vascular cells in vivo is complex in its chemical composition, physical properties, and architecture. Consequently, it has been a great challenge to study vascular cell responses in vitro, either to understand their interaction with their native environment or to investigate their interaction with artificial structures such as implant surfaces. New procedures and techniques from materials science to fabricate bio-scaffolds and surfaces have enabled novel studi...

  8. Investigation of the influence of design details on short implant biomechanics using colorimetric photoelastic analysis: a pilot study

    Directory of Open Access Journals (Sweden)

    João César Zielak

    Full Text Available Introduction : The clinical survival of a dental implant is directly related to its biomechanical behavior. Since short implants present lower bone/implant contact area, their design may be more critical to stress distribution to surrounding tissues. Photoelastic analysis is a biomechanical method that uses either simple qualitative results or complex calculations for the acquisition of quantitative data. In order to simplify data acquisition, we performed a pilot study to demonstrate the investigation of biomechanics via correlation of the findings of colorimetric photoelastic analysis (stress transition areas; STAs of design details between two types of short dental implants under axial loads. Methods Implants were embedded in a soft photoelastic resin and axially loaded with 10 and 20 N of force. Implant design features were correlated with the STAs (mm2 of the colored fringes of colorimetric photoelastic analysis. Results Under a 10 N load, the surface area of the implants was directly related to STA, whereas under a 20 N load, the surface area and thread height were inversely related to STA. Conclusion A smaller external thread height seemed to improve the biomechanical performance of the short implants investigated.

  9. Biomechanical implant treatment complications: a systematic review of clinical studies of implants with at least 1 year of functional loading.

    Science.gov (United States)

    Hsu, Yung-Ting; Fu, Jia-Hui; Al-Hezaimi, Khalid; Wang, Hom-Lay

    2012-01-01

    The aim of this article is to discuss the current literature available on the etiology and management of biomechanical complications of dental implant treatment. An electronic search of the PubMed database for English-language articles published before May 31, 2011, was performed based on a focus question: "How can biomechanical implant treatment complications be managed and identified?" The key words used were "dental implant," "etiology," "management," "excessive occlusal forces," "occlusal forces," "occlusion," "parafunctional habits," "biomechanical failure," "biomechanical complications," and "occlusal overloading." Clinical trials with a minimum of 10 implants followed for at least 1 year after functional loading were included. The initial electronic search identified 2,087 publications, most of which were eliminated, as they were animal studies, finite element analyses, bench-top studies, case reports, and literature reviews. After the titles, abstracts, and full text of 39 potentially eligible publications were reviewed, 15 studies were found to fulfill the inclusion criteria. Occlusal overloading was thought to be the primary etiologic factor in biomechanical implant treatment complications, which commonly included marginal bone loss, fracture of resin/ceramic veneers and porcelain, retention device or denture base fracture of implant-supported overdentures, loosening or fracture of abutment screws, and even implant failure. Occlusal overloading was positively associated with parafunctional habits such as bruxism. An appreciation of the intricacy of implant occlusion would allow clinicians to take a more preventive approach when performing implant treatment planning, as avoidance of implant overloading helps to ensure the long-term stability of implant-supported prostheses.

  10. Serum amyloid P component inhibits influenza A virus infections: in vitro and in vivo studies

    DEFF Research Database (Denmark)

    Horvath, A; Andersen, I; Junker, K

    2001-01-01

    . These studies were extended to comprise five mouse-adapted influenza A strains, two swine influenza A strains, a mink influenza A virus, a ferret influenza A reassortant virus, a influenza B virus and a parainfluenza 3 virus. The HA activity of all these viruses was inhibited by SAP. Western blotting showed......Serum amyloid P component (SAP) binds in vitro Ca(2+)-dependently to several ligands including oligosaccharides with terminal mannose and galactose. We have earlier reported that SAP binds to human influenza A virus strains, inhibiting hemagglutinin (HA) activity and virus infectivity in vitro...... that SAP bound to HA trimers, monomers and HA1 and HA2 subunits of influenza A virus. Binding studies indicated that galactose, mannose and fucose moieties contributed to the SAP reacting site(s). Intranasal administration of human SAP to mice induced no demonstrable toxic reactions, and circulating...

  11. Human fetal antehypophysis in vitro. Immunocytological study and radioimmunoassay of LH and FSH

    International Nuclear Information System (INIS)

    Li, J.Y.; Begeot, M.; Dubois, P.M.; Claustrat, B.

    1977-01-01

    Human fetal antehypophysis (16 males, 16 females and 4 unknown sex) were cultivated during several weeks. By immunocytochemistry LH gonadotroph cells were determined with anti-hTSH and anti-pLH serum. The release in vitro of LH and FSH was studied by radioimmunoassay. At the first medium change, the quantity of LH and FSH release was related to the gestational age and sex. A rapid decline of both LH and FSH occured over the 10 first days. There after, a basal release of LH was maintained during several months; the release of FSH was generally maintained at the lower limit of the assay. After 1 month in vitro, the level of LH could not be related to the sex. Release of LH was stimulated by synthetic LRF. A significant increase was observed independently of the sex and age of the fetuses studied [fr

  12. Inflammation-Related Effects of Diesel Engine Exhaust Particles: Studies on Lung Cells In Vitro

    Science.gov (United States)

    Schwarze, P. E.; Totlandsdal, A. I.; Låg, M.; Refsnes, M.; Holme, J. A.; Øvrevik, J.

    2013-01-01

    Diesel exhaust and its particles (DEP) have been under scrutiny for health effects in humans. In the development of these effects inflammation is regarded as a key process. Overall, in vitro studies report similar DEP-induced changes in markers of inflammation, including cytokines and chemokines, as studies in vivo. In vitro studies suggest that soluble extracts of DEP have the greatest impact on the expression and release of proinflammatory markers. Main DEP mediators of effects have still not been identified and are difficult to find, as fuel and engine technology developments lead to continuously altered characteristics of emissions. Involved mechanisms remain somewhat unclear. DEP extracts appear to comprise components that are able to activate various membrane and cytosolic receptors. Through interactions with receptors, ion channels, and phosphorylation enzymes, molecules in the particle extract will trigger various cell signaling pathways that may lead to the release of inflammatory markers directly or indirectly by causing cell death. In vitro studies represent a fast and convenient system which may have implications for technology development. Furthermore, knowledge regarding how particles elicit their effects may contribute to understanding of DEP-induced health effects in vivo, with possible implications for identifying susceptible groups of people and effect biomarkers. PMID:23509760

  13. In vitro study of color stability of polycrystalline and monocrystalline ceramic brackets

    OpenAIRE

    de Oliveira, Cibele Braga; Maia, Luiz Guilherme Martins; Santos-Pinto, Ary; Gandini J?nior, Luiz Gonzaga

    2014-01-01

    OBJECTIVE: The aim of this in vitro study was to analyze color stability of monocrystalline and polycrystalline ceramic brackets after immersion in dye solutions. METHODS: Seven ceramic brackets of four commercial brands were tested: Two monocrystalline and two polycrystalline. The brackets were immersed in four dye solutions (coffee, red wine, Coke and black tea) and in artificial saliva for the following times: 24 hours, 7, 14 and 21 days, respectively. Color changes were measured by a...

  14. PRK by Er:YAG laser: in-vitro studies and first in-vivo experiences

    Science.gov (United States)

    Steiner, Rudolf W.; Leiacker, Richard; Russ, Detlef; Seiler, Theo

    1996-01-01

    Photorefractive keratectomy (PRK) is usually performed by an excimer laser at 193 nm wavelength. Ablatio of corneal tissue is, however, not only possible in the UV region of the optical spectrum but also in the IR where water is an excellent absorber. Therefore, an Er:YAG laser was used at 2.94 micrometer wavelength as an alternative laser light source to perform in vitro studies of corneal ablation and also first clinical experiments to correct myopia of patients with blind eyes.

  15. In vitro glucose uptake by isolated rat hemi-diaphragm study of Aegle marmelos Correa root

    Directory of Open Access Journals (Sweden)

    Subban Ravi

    2009-03-01

    Full Text Available The methanol extract of the root of Aegle marmelos, a medicinal plant, was fractionated into eight fractions using column chromatography. The anti-diabetic activity of all the fractions was studied using the glucose uptake by isolated rat hemi-diaphragm in vitro model. Using the bioassay-guided fractionation, two compounds 1 and 2 were isolated by column chromatography and identified as 6-methyl-4-chromanone and skimmianine respectively by NMR and mass spectral methods.

  16. In Vitro Studies Evaluating Leaching of Mercury from Mine Waste Calcine Using Simulated Human Body Fluids

    OpenAIRE

    Gray, John E.; Plumlee, Geoffrey S.; Morman, Suzette A.; Higueras, Pablo L.; Crock, James G.; Lowers, Heather A.; Witten, Mark L.

    2010-01-01

    In vitro bioaccessibility (IVBA) studies were carried out on samples of mercury (Hg) mine-waste calcine (roasted Hg ore) by leaching with simulated human body fluids. The objective was to estimate potential human exposure to Hg due to inhalation of airborne calcine particulates and hand-to-mouth ingestion of Hg-bearing calcines. Mine waste calcines collected from Hg mines at Almad?n, Spain, and Terlingua, Texas, contain Hg sulfide, elemental Hg, and soluble Hg compounds, which constitute prim...

  17. In vitro predictions of skin absorption of caffeine, testosterone, and benzoic acid: A multi-centre comparison study

    NARCIS (Netherlands)

    Sandt, J.J.M. van de; Burgsteden, J.A. van; Cage, S.; Carmichael, P.L.; Dick, I.; Kenyon, S.; Korinth, G.; Larese, F.; Limasset, J.C.; Maas, W.J.M.; Montomoli, L.; Nielsen, J.B.; Payan, J.-P.; Robinson, E.; Sartorelli, P.; Schaller, K.H.; Wilkinson, S.C.; Williams, F.M.

    2004-01-01

    To obtain better insight into the robustness of in vitro percutaneous absorption methodology, the intra- and inter-laboratory variation in this type of study was investigated in 10 European laboratories. To this purpose, the in vitro absorption of three compounds through human skin (9 laboratories)

  18. Functional modeling of the craniospinal system for in-vitro parameter studies on the pathogenesis of NPH

    Directory of Open Access Journals (Sweden)

    Benninghaus Anne

    2017-09-01

    Full Text Available Normal Pressure Hydrocephalus (NPH has become a common disease in the elderly coming along with typical symptoms of dementia, gait ataxia and urinary incontinence, which make the differential diagnosis with other forms of dementia difficult. Furthermore the pathogenesis of NPH is still not understood. About 10% of all demented patients might be suffering from NPH [1]. Many hypotheses suggest that modified biomechanical boundary conditions affect the craniospinal dynamics inducing the pathogenesis of NPH. We present a novel approach for an in-vitro model of the craniospinal system to investigate important hydrodynamic influences on the system such as (dynamic compliance of the vascular system and especially the spinal subarachnoid space (SAS as well as reabsorption and hydrostatics. The experimental set-up enables the individual adjustment of relevant parameters for sensitivity analyses regarding the impact of resulting CSF dynamics on the pathogenesis of NPH.

  19. Alginate hydrogel as a promising scaffold for dental-derived stem cells: an in vitro study.

    Science.gov (United States)

    Moshaverinia, Alireza; Chen, Chider; Akiyama, Kentaro; Ansari, Sahar; Xu, Xingtian; Chee, Winston W; Schricker, Scott R; Shi, Songtao

    2012-12-01

    The objectives of this study were to: (1) develop an injectable and biodegradable scaffold based on oxidized alginate microbeads encapsulating periodontal ligament (PDLSCs) and gingival mesenchymal stem cells (GMSCs); and (2) investigate the stem cell viability, and osteogenic differentiation of the stem cells in vitro. Stem cells were encapsulated using alginate hydrogel. The stem cell viability, proliferation and differentiation to adipogenic and osteogenic tissues were studied. To investigate the expression of both adipogenesis and ontogenesis related genes, the RNA was extracted and RT-PCR was performed. The degradation behavior of hydrogel based on oxidized sodium alginate with different degrees of oxidation was studied in PBS at 37 °C as a function of time by monitoring the changes in weight loss. The swelling kinetics of alginate hydrogel was also investigated. The results showed that alginate is a promising candidate as a non-toxic scaffold for PDLSCs and GMSCs. It also has the ability to direct the differentiation of these stem cells to osteogenic and adipogenic tissues as compared to the control group in vitro. The encapsulated stem cells remained viable in vitro and both osteo-differentiated and adipo-differentiated after 4 weeks of culturing in the induction media. It was found that the degradation profile and swelling kinetics of alginate hydrogel strongly depends on the degree of oxidation showing its tunable chemistry and degradation rate. These findings demonstrate for the first time that immobilization of PDLSCs and GMSCs in the alginate microspheres provides a promising strategy for bone tissue engineering.

  20. Preparation, characterization, and in vitro release study of albendazole-encapsulated nanosize liposomes

    Science.gov (United States)

    Panwar, Preety; Pandey, Bhumika; Lakhera, P C; Singh, K P

    2010-01-01

    The purpose of the present study was to formulate effective and controlled release albendazole liposomal formulations. Albendazole, a hydrophobic drug used for the treatment of hydatid cysts, was encapsulated in nanosize liposomes. Rapid evaporation method was used for the preparation of albendazole-encapsulated conventional and PEGylated liposomes consisting of egg phosphatidylcholine (PC) and cholesterol (CH) in the molar ratios of (6:4) and PC:CH: polyethylene glycol (PEG) (5:4:1), respectively. In this study, PEGylated and conventional liposomes containing albendazole were prepared and their characteristics, such as particle size, encapsulation efficiency, and in vitro drug release were investigated. The drug encapsulation efficiency of PEGylated and conventional liposomes was 81% and 72%, respectively. The biophysical characterization of both conventional and PEG-coated liposomes were done by transmission electron microscopy and UV-vis spectrophotometry. Efforts were made to study in vitro release of albendazole. The drug release rate showed decrease in albendazole release in descending order: free albendazole, albendazole-loaded conventional liposomes, and least with albendazole-loaded PEG-liposomes. Biologically relevant vesicles were prepared and in vitro release of liposome-entrapped albendazole was determined. PMID:20309396

  1. Bacterial resistance to antibiotics in acne vulgaris: An in vitro study

    Directory of Open Access Journals (Sweden)

    Hassanzadeh Parvin

    2008-01-01

    Full Text Available Background: Acne vulgaris is one of the most common skin disorders in youth especially during the puberty. Objective: This in vitro study was performed to determine the antibiotic resistance and sensitivity in acne vulgaris. Materials and Methods: Samples were collected from normal skin and nodulocystic and pustular skin lesions of one hundred youngsters (64 girls, 36 boys among college students in the age range of 18-24 years old. The specimens were cultured individually on blood agar and Muller-Hinton media. The cultures were then incubated under both aerobic and anaerobic conditions for 2 to 7 days. Bacteria were identified and their resistance to common antibiotics was evaluated according to the standard procedures. Results: In aerobic culture of pustular and nodulocystic skin lesions, Staphylococcus aureus was present in 41% of subjects, Staphylococcus epidermidis in 53% and Micrococcus spp in 45% of subjucts. In anaerobic bacterial culture of pustular and nodulocystic skin lesions, Staphylococcus aureus was present in 39%, Propionibacterium acne in 33% and Staphylococcus epidermidis in 21% of subjects. The results of present study revealed that clindamycin and erythromycin were the least effective antibiotics for Propionibacterium acne while tetracycline was the least effective for Staphylococcus aureus in vitro . A synergic effect of benzoyl peroxide, erythromycin or clindamycin was noticed. Rifampin was the most effective antibiotic in vitro . Conclusion: Our results showed that rifampin was the most sensitive antibiotic in vitro for acne vulgaris. To achieve a better treatment, a combination of rifampin with other antibiotics may be more efficient. We suggest in vivo studies for better evaluation and treatment of acne patients with rifampin.

  2. Andrographolide Enhances Proliferation and Prevents Dedifferentiation of Rabbit Articular Chondrocytes: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Li-ke Luo

    2015-01-01

    Full Text Available As the main active constituent of Andrographis paniculata that was applied in treatment of many diseases including inflammation in ancient China, andrographolide (ANDRO was found to facilitate reduction of edema and analgesia in arthritis. This suggested that ANDRO may be promising anti-inflammatory agent to relieve destruction and degeneration of cartilage after inflammation. In this study, the effect of ANDRO on rabbit articular chondrocytes in vitro was investigated. Results showed that not more than 8 μM ANDRO did no harm to chondrocytes (P0.05. The viability assay, hematoxylin-eosin, safranin O, and immunohistochemical staining also showed better performances in ANDRO groups. As to the doses, 3 μM ANDRO showed the best performance. The results indicate that ANDRO can accelerate proliferation of rabbit articular chondrocytes in vitro and meanwhile maintain the phenotype, which may provide valuable references for further exploration on arthritis.

  3. [Studies on preparation and dissolution test in vitro of sustained-release dropping pills of curcumin].

    Science.gov (United States)

    Fang, Yu; Xiang, Bai; Pan, Zhen-Hua; Cao, De-Ying

    2010-01-01

    To study the prescription and technique of sustained-release dropping pills of curcumin and inspect their release property in vitro. The orthogonal test was used to screen the prescription and technique which were definited with the colligation evaluation of release and formation of dropping pills. The optimization of prescription and technique were as follows: stearic acid 70 mg, glycery monostearate 25 mg, solutol 6 mg, viscosity of cooling liquid was 100 mm2/s; the temperature of material liquid was 80 degrees C; the cooling temperature was 30 - 0 degrees C; the dropping speed was (21 +/- 2) dripping/min. The release behavior of sustained-release dropping pills of curcumin coincidented with Higuchi equation well and the character of sustained-release was transparent. The sustained-release dropping pills of curcumin have good property of sustained-release in vitro and their release behavior in vivo need to be inspected.

  4. Combining microfluidics, optogenetics and calcium imaging to study neuronal communication in vitro.

    Science.gov (United States)

    Renault, Renaud; Sukenik, Nirit; Descroix, Stéphanie; Malaquin, Laurent; Viovy, Jean-Louis; Peyrin, Jean-Michel; Bottani, Samuel; Monceau, Pascal; Moses, Elisha; Vignes, Maéva

    2015-01-01

    In this paper we report the combination of microfluidics, optogenetics and calcium imaging as a cheap and convenient platform to study synaptic communication between neuronal populations in vitro. We first show that Calcium Orange indicator is compatible in vitro with a commonly used Channelrhodopsine-2 (ChR2) variant, as standard calcium imaging conditions did not alter significantly the activity of transduced cultures of rodent primary neurons. A fast, robust and scalable process for micro-chip fabrication was developed in parallel to build micro-compartmented cultures. Coupling optical fibers to each micro-compartment allowed for the independent control of ChR2 activation in the different populations without crosstalk. By analyzing the post-stimuli activity across the different populations, we finally show how this platform can be used to evaluate quantitatively the effective connectivity between connected neuronal populations.

  5. In vitro terahertz spectroscopy of gelatin-embedded human brain tumors: a pilot study

    Science.gov (United States)

    Chernomyrdin, N. V.; Gavdush, A. A.; Beshplav, S.-I. T.; Malakhov, K. M.; Kucheryavenko, A. S.; Katyba, G. M.; Dolganova, I. N.; Goryaynov, S. A.; Karasik, V. E.; Spektor, I. E.; Kurlov, V. N.; Yurchenko, S. O.; Komandin, G. A.; Potapov, A. A.; Tuchin, V. V.; Zaytsev, K. I.

    2018-04-01

    We have performed the in vitro terahertz (THz) spectroscopy of human brain tumors. In order to fix tissues for the THz measurements, we have applied the gelatin embedding. It allows for preserving tissues from hydration/dehydration and sustaining their THz response similar to that of the freshly-excised tissues for a long time after resection. We have assembled an experimental setup for the reflection-mode measurements of human brain tissues based on the THz pulsed spectrometer. We have used this setup to study in vitro the refractive index and the amplitude absorption coefficient of 2 samples of malignant glioma (grade IV), 1 sample of meningioma (grade I), and samples of intact tissues. We have observed significant differences between the THz responses of normal and pathological tissues of the brain. The results of this paper highlight the potential of the THz technology in the intraoperative neurodiagnosis of tumors relying on the endogenous labels of tumorous tissues.

  6. In vivo and in vitro study of /sub 90/Sr in developing rat molar enamel

    International Nuclear Information System (INIS)

    White, B.A.; Deaton, T.G.; Bawden, J.W.

    1980-01-01

    The uptake patterns of /sub 90/Sr in developing rat molar enamel were studied in vivo and in vitro. Autoradiographic methods were used that preclude loss or translocation of tracers associated with water-soluble compounds in the sections. In eight-day-old rats injected with the tracer, /sub 90/Sr uptake in the enamel was significantly less than for dentin and bone, particularly at early sacrifice times. The uptake pattern of 90Sr was somewhat different from that previously observed for /sub 45/Ca. The in vitro experiments indicated that the viable intact enamel organ limits uptake of /sub 90/Sr by enamel in both the secretory and maturation phases of enamel formation

  7. Antileishmanial Activity of Myrtle Methanolic Extract against Leishmaniamajor: an In Vitro Study

    Directory of Open Access Journals (Sweden)

    Hossein Mahmoudvand

    2017-12-01

    Full Text Available Background and Aim: In this study we assessed the in vitro antileishmanial activity of myrtle (Myrtus communis L. methanolic extract against Leishmania major. Materials and Methods: The in vitro antileishmanial effects of myrtle methanolic extract against L. major promastigote and amastigotes were determined by colorimetric cell viability (MTT assay and macrophage model, respectively. The IC50 values were also calculated by probit test in SPSS software. Results:The obtained results showed that myrtle extract was significantly inhibited promastigote growth of L. major based on a dose and time dependent manner. The measured IC50 values for myrtle methanolic extract and MA as control drug against promastigote forms of L. major were 23.6 µg/mL and 88.3 µg/mL, respectively. The obtained IC50 values were 13.8

  8. Serum amyloid P component inhibits influenza A virus infections: in vitro and in vivo studies

    DEFF Research Database (Denmark)

    Horvath, A; Andersen, I; Junker, K

    2001-01-01

    Serum amyloid P component (SAP) binds in vitro Ca(2+)-dependently to several ligands including oligosaccharides with terminal mannose and galactose. We have earlier reported that SAP binds to human influenza A virus strains, inhibiting hemagglutinin (HA) activity and virus infectivity in vitro...... that SAP bound to HA trimers, monomers and HA1 and HA2 subunits of influenza A virus. Binding studies indicated that galactose, mannose and fucose moieties contributed to the SAP reacting site(s). Intranasal administration of human SAP to mice induced no demonstrable toxic reactions, and circulating...... on day 10 and these mice approached normal body weight, whereas control mice (one out of five surviving on day 10) died. The data provide evidence of the potential of intranasally administered SAP for prophylactic treatment of influenza A virus infections in humans....

  9. In vitro antioxidant, antiinflammatory and in silico molecular docking studies of thiosemicarbazones

    Science.gov (United States)

    Subhashree, G. R.; Haribabu, J.; Saranya, S.; Yuvaraj, P.; Anantha Krishnan, D.; Karvembu, R.; Gayathri, D.

    2017-10-01

    A series of 5-methoxysalicylaldehyde appended thiosemicarbazones (1-4) and 2-hydroxy-1-naphthaldehyde appended thiosemicarbazones (5-8) was obtained from the reactions between 5-methoxysalicylaldehyde/2-hydroxy-1-naphthaldehyde and (un)substituted thiosemicarbazides with the view to ascertain their biological properties brought about by the change in substitution at N-terminal position of the thiosemicarbazide derivatives. The compounds were fully characterized by elemental analyses, and various spectroscopic techniques (UV-Visible, FT-IR, NMR and mass). The solid-state structure of three compounds (1, 2 and 7) was determined by single crystal X-ray diffraction method. The compounds (1, 2 and 7) have adopted a monoclinic crystal system with P21/c (1 and 2) or C2/c (7) space group. Antioxidant and non-haemolysis activities of the compounds (1-8) were analyzed by in vitro DPPH and haemolysis assays, respectively. Antiinflammatory potential was verified by in vitro PLA2 inhibition assay and in silico molecular docking study. In vitro and in silico studies revealed promising antiinflammatory potential of the thiosemicarbazone derivatives. Compounds 2, 4, 6, 7 and 8 showed significant antiinflammatory activity.

  10. Buccal delivery of thiocolchicoside: in vitro and in vivo permeation studies.

    Science.gov (United States)

    Artusi, M; Santi, P; Colombo, P; Junginger, H E

    2003-01-02

    Thiocolchicoside, a muscle-relaxant agent, is administered by the oral, intra-muscular and topical route. After oral administration the extent of bioavailability compared with intra-muscular administration is low, due to a first pass effect. In this paper, the delivery of thiocolchicoside through oral mucosa is studied to improve the bioavailability. Thiocolchicoside in vitro permeation through porcine oral mucosa and in vivo buccal transport in humans were investigated. Two dosage forms, a bioadhesive disc and a fast dissolving disc for buccal and sublingual administration of thiocolchicoside, respectively, were designed. The in vitro permeation of thiocolchicoside through porcine buccal mucosa from these dosage forms was evaluated and compared with in vivo absorption. Results from in vitro studies demonstrated that thiocolchicoside is quite permeable across porcine buccal mucosa and that permeation enhancers, such as sodium taurocholate and sodium taurodeoxycholate, were not able to increase its flux. The in vivo thiocolchicoside absorption experiments, in which the drug loss from oral cavity was measured, indicated that both formulations could be useful for therapeutic application. The fast dissolving (sublingual) form resulted in a quick uptake of 0.5 mg of thiocolchicoside within 15 min whereas with the adhesive buccal form the same dose can be absorbed over an extended period of time.

  11. A novel orbital tissue expander (OTE): design, in vitro, and in vivo studies

    Science.gov (United States)

    Lee, Elizabete; Tse, David; Pinchuk, Leonard; Acosta, Ana C.; Martin, John B.; Davis, Stewart B.; Hernandez, Eleut; Yamamoto, Hideo; Denham, David B.; Dubovy, Sander; Parel, Jean-Marie

    2006-02-01

    Purpose: To assess the efficacy of a novel orbital tissue expander (OTE) in treating congenital anophthalmic and microphthalmic infants. Methods: The OTE implant is an inflatable (0.5 to >6cc) silicone rubber globe sliding on a titanium T-shaped bone plate secured to the temporal bone with 1mm titanium screws. In vitro testing was performed to assess injection volume versus diameter measurements to determine consistency between devices, flex fatigue for durability of the implants when compressed, weight change in isotonic saline at 37°C to mimic human body temperature, seal durability by puncturing the globe numerous times while inflating, capacity before rupture to determine the maximum amount of saline it is able to contain, and effective sterilization. Ex-vivo testing was performed for adjustments prior to in vivo study. An OTE was then implanted in five 2-week old kittens (OS only) and inflated in 0.5cc increments. Three control animals received enucleation alone. All 8 animals were followed for 18 weeks and underwent euthanasia for morphological and histopathological analysis. Results: In vitro testing confirmed a effects in the normal maturation, weight gain, and food intake of the cats. Light microscopy showed no signs of foreign body reaction. Pictures of the implants were obtained by using a shadow-photogrammetry system to compare the explanted OTE with the OD control eye. Conclusion: In vitro and in vivo studies show the implant's potential to safely treat anophthalmic and microphthalmic infants.

  12. In vitro disintegration studies of weekly generic and branded risedronate sodium formulations available in Canada.

    Science.gov (United States)

    Walker, A D; Adachi, J D

    2011-09-01

    The aim of this study was to evaluate the in vitro disintegration of the five newly available Canadian generic risedronate 35 mg tablets compared to the innovator (branded) product, ACTONEL * *ACTONEL is a registered trade name of Warner Chilcott Company, LLC. (risedronate sodium) 35 mg. Tablets were inspected for colour and appearance. Disintegration times were determined using United States Pharmacopeia 33 (USP33-NF 28) methods. Disintegration onset time was also evaluated. The mean disintegration onset time values for the generic risedronate 35 mg tablets ranged from 2 to 29 seconds, and the mean disintegration completion times ranged from 81 to 260 seconds. The mean disintegration onset and completion time values for the ACTONEL 35 mg tablets were 23 and 43 seconds respectively. Four out of the five generic tablets tested had shorter disintegration onset times than the branded product; two of the generic tablet products had very fast disintegration onset times i.e. 2-3 seconds. Disintegration completion time for all five generic products tested was longer than that observed for the branded product; two generic products had disintegration completion time values five to six times longer than the branded product. Differences in the in vitro disintegration times were observed between the generic risedronate 35 mg tablets commercially available in Canada and the branded product, ACTONEL. The rapid disintegration onset times of two generic products may be important as this could increase the possibility of drug exposure in both the mouth and the esophagus during swallowing, resulting in unwanted localized irritation. However, it should be noted that an in vitro/in vivo correlation has not been established. Until such studies are completed it may be important to be aware of such in vitro disintegration differences when evaluating patients with newly presenting upper gastrointestinal complaints upon being switched from the branded product to generic formulations.

  13. In vitro-in vivo correlation study for the dermatopharmacokinetics of terbinafine hydrochloride topical cream.

    Science.gov (United States)

    Saeheng, Suwadee; Nosoongnoen, Wichit; Varothai, Supenya; Sathirakul, Korbtham

    2013-09-01

    To investigate the relationship between dermatopharmacokinetic (DPK) tape stripping from in vitro and in vivo using 1% terbinafine hydrochloride topical cream as the model formulation. In vitro and in vivo tape strippings were conducted on separated pig ear skin used as a biological membrane for franz diffusion cell testing and the non-hairy skin area at the ventral forearms of healthy volunteers, respectively. Terbinafine (1%) topical cream was applied to the skin for 0.5, 2, and 4 h. The drug profiles of terbinafine across the stratum corneum were determined immediately (time 0 h), and at 0.5, 1, 2, and 4 h after removing the formulation. The amounts of terbinafine were analyzed by a validated high-performance liquid chromatography-ultraviolet method. The area under the curve (AUC) and the maximum amounts of terbinafine absorption (Q(max)) were obtained from pharmacokinetic software. Partition coefficient (K(SC/veh)) and diffusion parameter (D/L²) were derived from the Fick's second law equation. During the schedule time of 8 h, the deviations of in vitro and in vivo data were 6.61 and 30.46% for AUC and Q(max), respectively. There was insignificant difference of the K(SC/veh) and the D/L² between excised pig ear and human skin. In addition, K(SC/veh) and D/L² at T(max) of 2 h were used to predict the AUC presented the value of 4.7481 %h whereas the true value calculated from pharmacokinetic software provided the value of 5.9311 %h differing from each other in approximate of 20%. In vitro tape stripping using the separated pig ear skin as a viable membrane of the franz diffusion cell testing demonstrates the potential to represent in vivo tape stripping in human for topical bioavailability/bioequivalence study of terbinafine hydrochloride 1% topical cream.

  14. Comparative study on major bioactive components in natural, artificial and in-vitro cultured Calculus Bovis.

    Science.gov (United States)

    Yan, Shi-Kai; Wu, Yan-Wen; Liu, Run-Hui; Zhang, Wei-Dong

    2007-01-01

    Major bioactive components in various Calculus Bovis, including natural, artificial and in-vitro cultured Calculus Bovis, were comparatively studied. An approach of high-performance liquid chromatography coupled with ultraviolet and evaporative light scattering detections (HPLC/UV/ELSD) was established to simultaneously determinate six bioactive components thereof, including five bile acids (cholic acid, deoxycholic acid, ursodeoxycholic, chenodeoxycholic acid, hyodeoxycholic acid) and bilirubin. ELSD and UV detector were applied to detect bile acids and bilirubin respectively. The assay was performed on a C(18) column with water-acetonitrile gradient elution and the investigated constituents were authenticated by comparing retention times and mass spectra with those of reference compounds. The proposed method was applied to analyze twenty-one Calculus Bovis extraction samples, and produced data with acceptable linearity, precision, repeatability and accuracy. The result indicated the variations among Calculus Bovis samples under different developmental conditions. Artificial and in-vitro cultured Calculus Bovis, especially in-vitro cultured ones, which contain total bioactive constituents no less than natural products and have the best batch-to-batch uniformity, suffice to be used as substitutes of natural Calculus Bovis.

  15. In-vitro studies of change in edge detection with changes in bone density

    International Nuclear Information System (INIS)

    Pocock, N.; Noakes, K.; Griffiths, M.

    1999-01-01

    Full text: Dual energy X-ray absorptiometry (DXA) requires edge detection software to identify the skeletal regions for quantitation of bone mineral density (BMD) and bone mineral content (BMC). As bone mass decreases, the detection of bone edges becomes more difficult and this potentially could cause errors in DXA estimations of areal BMD or BMC. To address this issue, we have used an in-vitro model to study the effects of 'bone loss' on calculated bone area, BMD and BMC. Multiple vertebral phantoms, of equal cross-sectional area but incrementally decreased areal BMD, were constructed using calcium sulphate hemihydrate. The weight of each phantom vertebra, measured accurately using an electronic balance, was used as an index of its true 'bone mass equivalent' (BME). The phantoms were scanned and analysed in the lumbar spine mode using a Lunar DPX-L (L) and Hologic QDR-1000 (H). The changes in BME were compared to changes in measured area, BMC and areal BMD. The results demonstrate that, in an in-vitro model, as bone mass decreases, measured bone area and consequently BMC will decrease as the edge detection algorithms have greater difficulty in detecting the true edges. In conclusion, in an in-vitro model, the DXA edge detection algorithms will underestimate bone area as bone mass decreases. This has potential implications for monitoring changes in bone mass in vivo

  16. In vitro study of nano-hydroxyapatite/chitosan–gelatin composites for bio-applications

    Directory of Open Access Journals (Sweden)

    Khaled R. Mohamed

    2014-03-01

    Full Text Available The present work aims to study the in vitro properties of nano-hydroxyapatite/chitosan–gelatin composite materials. In vitro behavior was performed in simulated body fluid (SBF to verify the formation of apatite layer onto the composite surfaces. The in vitro data proved the deposition of calcium and phosphorus ions onto hydroxyapatite /polymeric composite surfaces especially those containing high concentrations of polymer content. The degradation of the composites decreased with increase in the polymeric matrix content and highly decreased in the presence of citric acid (CA, especially these composites which contain 30% polymeric content. The water absorption of the composites increased with increase in the polymeric content and highly increased with CA addition. The Fourier transformed infrared reflectance (FT-IR and scanning electron microscope (SEM for the composites confirmed the formation of bone-like apatite layer on the composite surfaces, especially those containing high content of polymers (30% with 0.2 M of CA. These promising composites have suitable properties for bio-applications such as bone grafting and bone tissue engineering applications in the future.

  17. Titanium Dioxide Nanoparticles as Radiosensitisers: An In vitro and Phantom-Based Study.

    Science.gov (United States)

    Youkhana, Esho Qasho; Feltis, Bryce; Blencowe, Anton; Geso, Moshi

    2017-01-01

    Objective: Radiosensitisation caused by titanium dioxide nanoparticles (TiO 2 -NPs) is investigated using phantoms (PRESAGE ® dosimeters) and in vitro using two types of cell lines, cultured human keratinocyte (HaCaT) and prostate cancer (DU145) cells. Methods: Anatase TiO 2 -NPs were synthesised, characterised and functionalised to allow dispersion in culture-medium for in vitro studies and halocarbons (PRESAGE ® chemical compositions). PRESAGE ® dosimeters were scanned with spectrophotometer to determine the radiation dose enhancement. Clonogenic and cell viability assays were employed to determine cells survival curves from which the dose enhancement levels "radiosensitisation" are deduced. Results: Comparable levels of radiosensitisation were observed in both phantoms and cells at kilovoltage ranges of x-ray energies (slightly higher in vitro) . Significant radiosensitisation (~67 %) of control was also noted in cells at megavoltage energies (commonly used in radiotherapy), compared to negligible levels detected by phantoms. This difference is attributed to biochemical effects, specifically the generation of reactive oxygen species (ROS) such as hydroxyl radicals ( • OH), which are only manifested in aqueous environments of cells and are non-existent in case of phantoms. Conclusions: This research shows that TiO 2 -NPs improve the efficiency of dose delivery, which has implications for future radiotherapy treatments. Literature shows that Ti 2 O 3 -NPs can be used as imaging agents hence with these findings renders these NPs as theranostic agents.

  18. Advantages and disadvantages of the animal models v. in vitro studies in iron metabolism: a review.

    Science.gov (United States)

    García, Y; Díaz-Castro, J

    2013-10-01

    Iron deficiency is the most common nutritional deficiency in the world. Special molecules have evolved for iron acquisition, transport and storage in soluble, nontoxic forms. Studies about the effects of iron on health are focused on iron metabolism or nutrition to prevent or treat iron deficiency and anemia. These studies are focused in two main aspects: (1) basic studies to elucidate iron metabolism and (2) nutritional studies to evaluate the efficacy of iron supplementation to prevent or treat iron deficiency and anemia. This paper reviews the advantages and disadvantages of the experimental models commonly used as well as the methods that are more used in studies related to iron. In vitro studies have used different parts of the gut. In vivo studies are done in humans and animals such as mice, rats, pigs and monkeys. Iron metabolism is a complex process that includes interactions at the systemic level. In vitro studies, despite physiological differences to humans, are useful to increase knowledge related to this essential micronutrient. Isotopic techniques are the most recommended in studies related to iron, but their high cost and required logistic, making them difficult to use. The depletion-repletion of hemoglobin is a method commonly used in animal studies. Three depletion-repletion techniques are mostly used: hemoglobin regeneration efficiency, relative biological values (RBV) and metabolic balance, which are official methods of the association of official analytical chemists. These techniques are well-validated to be used as studies related to iron and their results can be extrapolated to humans. Knowledge about the main advantages and disadvantages of the in vitro and animal models, and methods used in these studies, could increase confidence of researchers in the experimental results with less costs.

  19. Radiation combined injury models to study the effects of interventions and wound biomechanics.

    Science.gov (United States)

    Zawaski, Janice A; Yates, Charles R; Miller, Duane D; Kaffes, Caterina C; Sabek, Omaima M; Afshar, Solmaz F; Young, Daniel A; Yang, Yunzhi; Gaber, M Waleed

    2014-12-01

    In the event of a nuclear detonation, a considerable number of projected casualties will suffer from combined radiation exposure and burn and/or wound injury. Countermeasure assessment in the setting of radiation exposure combined with dermal injury is hampered by a lack of animal models in which the effects of interventions have been characterized. To address this need, we used two separate models to characterize wound closure. The first was an open wound model in mice to study the effect of wound size in combination with whole-body 6 Gy irradiation on the rate of wound closure, animal weight and survival (morbidity). In this model the addition of interventions, wound closure, subcutaneous vehicle injection, topical antiseptic and topical antibiotics were studied to measure their effect on healing and survival. The second was a rat closed wound model to study the biomechanical properties of a healed wound at 10 days postirradiation (irradiated with 6 or 7.5 Gy). In addition, complete blood counts were performed and wound pathology by staining with hematoxylin and eosin, trichrome, CD68 and Ki67. In the mouse open wound model, we found that wound size and morbidity were positively correlated, while wound size and survival were negatively correlated. Regardless of the wound size, the addition of radiation exposure delayed the healing of the wound by approximately 5-6 days. The addition of interventions caused, at a minimum, a 30% increase in survival and improved mean survival by ∼9 days. In the rat closed wound model we found that radiation exposure significantly decreased all wound biomechanical measurements as well as white blood cell, platelet and red blood cell counts at 10 days post wounding. Also, pathological changes showed a loss of dermal structure, thickening of dermis, loss of collagen/epithelial hyperplasia and an increased density of macrophages. In conclusion, we have characterized the effect of a changing wound size in combination with radiation

  20. Single versus double row suture anchor fixation for greater tuberosity fractures - a biomechanical study.

    Science.gov (United States)

    Seppel, Gernot; Saier, Tim; Martetschläger, Frank; Plath, Johannes E; Guevara-Alvarez, Alberto; Henschel, Julia; Winkler, Martin; Augat, Peter; Imhoff, Andreas B; Buchmann, Stefan

    2017-12-01

    Fractures of the humeral greater tuberosity (GT) are a frequent injury progressively treated with arthroscopic suture anchor repair. Yet, no biomechanical study has been performed comparing fixation strength of arthroscopic single- (SR) vs. double row (DR) fixation. Standardized fractures of the greater tuberosity were created in 12 fresh frozen proximal humeri. After random assignation to the SR or DR group the fixed humeri were tested applying cyclic loading to the supraspinatus and infraspinatus tendon. Load to failure and fragment displacement were assessed by means of an electrodynamic material testing machine using an optical tracking system. Load to failure values were higher in the DR group (649 N; ±176) than in the SR group (490 N; ±145) however without statistical significance (p = .12). In greater tuberosity displacement of 3-5 mm surgical treatment is recommended. The fixing constructs in this study did not reach displacement landmarks of 3 or 5 mm before construct failure as shown in previous studies. Thus the applied traction force (N) at 1 mm displacement was analyzed. In the SR group the load at 1 mm displacement was 277 N; ±46 compared to 260 N; ±62 in the DR group (p = .65). The results suggest that both techniques are viable options for refixation of greater tuberosity fractures. Laboratory study.

  1. The history of biomechanics in total hip arthroplasty

    Directory of Open Access Journals (Sweden)

    Jan Van Houcke

    2017-01-01

    Full Text Available Biomechanics of the hip joint describes how the complex combination of osseous, ligamentous, and muscular structures transfers the weight of the body from the axial skeleton into the appendicular skeleton of the lower limbs. Throughout history, several biomechanical studies based on theoretical mathematics, in vitro, in vivo as well as in silico models have been successfully performed. The insights gained from these studies have improved our understanding of the development of mechanical hip pathologies such as osteoarthritis, hip fractures, and developmental dysplasia of the hip. The main treatment of end-stage degeneration of the hip is total hip arthroplasty (THA. The increasing number of patients undergoing this surgical procedure, as well as their demand for more than just pain relief and leading an active lifestyle, has challenged surgeons and implant manufacturers to deliver higher function as well as longevity with the prosthesis. The science of biomechanics has played and will continue to play a crucial and integral role in achieving these goals. The aim of this article, therefore, is to present to the readers the key concepts in biomechanics of the hip and their application to THA.

  2. Potent human uric acid transporter 1 inhibitors: in vitro and in vivo metabolism and pharmacokinetic studies

    Directory of Open Access Journals (Sweden)

    Wempe MF

    2012-11-01

    Full Text Available Michael F Wempe,1 Janet W Lightner,2 Bettina Miller,1 Timothy J Iwen,1 Peter J Rice,1 Shin Wakui,3 Naohiko Anzai,4 Promsuk Jutabha,4 Hitoshi Endou51Department of Pharmaceutical Sciences, School of Pharmacy, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO, USA; 2Department of Pharmacology, East Tennessee State University, Johnson City, TN, USA; 3Department of Toxicology, Azabu University School of Veterinary Medicine, Chuo Sagamihara, Kanagawa, Japan; 4Department of Pharmacology and Toxicology, Dokkyo Medical University School of Medicine, Mibu, Shimotsuga, Tochigi, Japan; 5Department of Pharmacology and Toxicology, Kyorin University School of Medicine, Mitaka, Tokyo, JapanAbstract: Human uric acid transporter 1 (hURAT1; SLC22A12 is a very important urate anion exchanger. Elevated urate levels are known to play a pivotal role in cardiovascular diseases, chronic renal disease, diabetes, and hypertension. Therefore, the development of potent uric acid transport inhibitors may lead to novel therapeutic agents to combat these human diseases. The current study investigates small molecular weight compounds and their ability to inhibit 14C-urate uptake in oocytes expressing hURAT1. Using the most promising drug candidates generated from our structure–activity relationship findings, we subsequently conducted in vitro hepatic metabolism and pharmacokinetic (PK studies in male Sprague-Dawley rats. Compounds were incubated with rat liver microsomes containing cofactors nicotinamide adenine dinucleotide phosphate and uridine 5'-diphosphoglucuronic acid. In vitro metabolism and PK samples were analyzed using liquid chromatography/mass spectrometry-mass spectrometry methods. Independently, six different inhibitors were orally (capsule dosing or intravenously (orbital sinus administered to fasting male Sprague-Dawley rats. Blood samples were collected and analyzed; these data were used to compare in vitro and in vivo metabolism and to

  3. Anatomical and biomechanical study on the interosseous membrane of the cadaveric forearm

    Directory of Open Access Journals (Sweden)

    YI Xian-hong

    2011-06-01

    Full Text Available 【Abstract】 Objective: To study the anatomical and biomechanical features of the interosseous membrane (IOM of the cadaveric forearm. Methods: Ten radius-IOM-ulna structures were har- vested from fresh-frozen cadavers to measure the length, width and thickness of the tendinous portion of IOM. Then, the tendinous portion was isolated along with the ulnar and radial ends to which the tendon attached after measurement. The proximal portion of the radius and the distal portion of the ulna were embedded and fixed in the dental base acrylic resin powder. The embedded specimen was clamped and fixed by the MTS 858 test machine using a 10 000 N load cell for the entire tensile test. IOM was stretched at a speed of 50 mm/min until it was ruptured. The load-displacement curve was depicted with a computer and the maximum load and stiffness were recorded at the same time. Results: The IOM of the forearm was composed of three portions: central tendinous tissue, membranous tis- sue and dorsal affiliated oblique cord. IOM was stretched at a neutral position, and flexed at pronation and supination positions. The tendinous portion of IOM was lacerated in 6 specimens when the point of the maximum load reached to 1 021.50 N± 250.13 N, the stiffness to 138.24 N/m±24.29 N/m, and the length of stretch to 9.77 mm±1.77 mm. Fracture occurred at the fixed end of the ulna before laceration of the tendinous portion in 4 specimens when the maximum load was 744.40 N±109.85 N, the stiffness was 151.17 N/m±30.68 N/m, and the length of the stretch was 6.51 mm±0.51 mm. Conclusions: The IOM of the forearm is a structure having ligamentous characteristics between the radius and the ulna. It is very important for maintenance of the longitu- dinal stability of the forearm. The anatomical and biome- chanical data can be used as an objective criterion for evalu- ating the reconstructive method of IOM of the forearm. Key words: Forearm; Anatomy; Biomechanics

  4. Improving gastric cancer preclinical studies using diverse in vitro and in vivo model systems

    International Nuclear Information System (INIS)

    Chang, Hae Ryung; Park, Hee Seo; Ahn, Young Zoo; Nam, Seungyoon; Jung, Hae Rim; Park, Sungjin; Lee, Sang Jin; Balch, Curt; Powis, Garth; Ku, Ja-Lok; Kim, Yon Hui

    2016-01-01

    “Biomarker-driven targeted therapy,” the practice of tailoring patients’ treatment to the expression/activity levels of disease-specific genes/proteins, remains challenging. For example, while the anti-ERBB2 monoclonal antibody, trastuzumab, was first developed using well-characterized, diverse in vitro breast cancer models (and is now a standard adjuvant therapy for ERBB2-positive breast cancer patients), trastuzumab approval for ERBB2-positive gastric cancer was largely based on preclinical studies of a single cell line, NCI-N87. Ensuing clinical trials revealed only modest patient efficacy, and many ERBB2-positive gastric cancer (GC) patients failed to respond at all (i.e., were inherently recalcitrant), or succumbed to acquired resistance. To assess mechanisms underlying GC insensitivity to ERBB2 therapies, we established a diverse panel of GC cells, differing in ERBB2 expression levels, for comprehensive in vitro and in vivo characterization. For higher throughput assays of ERBB2 DNA and protein levels, we compared the concordance of various laboratory quantification methods, including those of in vitro and in vivo genetic anomalies (FISH and SISH) and xenograft protein expression (Western blot vs. IHC), of both cell and xenograft (tissue-sectioned) microarrays. The biomarker assessment methods strongly agreed, as did correlation between RNA and protein expression. However, although ERBB2 genomic anomalies showed good in vitro vs. in vivo correlation, we observed striking differences in protein expression between cultured cells and mouse xenografts (even within the same GC cell type). Via our unique pathway analysis, we delineated a signaling network, in addition to specific pathways/biological processes, emanating from the ERBB2 signaling cascade, as a potential useful target of clinical treatment. Integrated analysis of public data from gastric tumors revealed frequent (10 – 20 %) amplification of the genes NFKBIE, PTK2, and PIK3CA, each of which

  5. In vitro study of dose rate effect on Leksell Gamma Knife Perfexion

    International Nuclear Information System (INIS)

    Pastykova, V.; Novotny, J. jr.; Vachelova, J.; Davidkova, M.; Liscak, R.

    2018-01-01

    The main purpose of the study is to evaluate the radiobiological effect of the dose rate changes in Leksell Gamma Knife (LGK) clinical conditions. In principle there are two reasons why dose rate on LGK is reduced during patient irradiation: 1) Co-60 sources decay with a half-life of 5.26 years and 2) using multiple iso-centers and conformal treatment plans (e.g. with blocked beams). This pilot study is an experimental work performed in vitro with medulloblastoma DAOY cells. Are there effects caused by low dose rate which could negatively influence the clinical outcome of the radiosurgery? (authors)

  6. In vitro culture of pre-implanted mouse embryos. A model system for studying combined effects

    International Nuclear Information System (INIS)

    Streffer, C.; Beuningen, D. van; Molls, M.; Pon, A.; Schulz, S.; Zamboglou, N.

    1978-01-01

    Studies on combined effects, e.g. interaction between chemical toxicants and ionizing radiation, are difficult to perform, as they are dependent on many factors (substance concentration, radiation dose, sequence of treatments, etc.). In order to obtain data from such studies it is necessary to establish a comparatively simple experimental model system. We have established such a model system by studying combined effects on pre-implanted mouse embryos cultured in vitro. This system has the following advantages: (1) The embryos can be cultivated for several days in vitro; (2) Their physiological intactness can be tested; and (3) Cell proliferation, cell killing and chromosomal damage can be investigated comparatively easily. The embryos are isolated at the 2-cell stage and incubated in a culture medium in vitro. The development of the embryos is followed under the microscope until the development of blastocysts or the hatching of blastocysts is observed. These blastocysts can be transplanted to fostered mice and the development of normal animals determined. The proliferation kinetics can be studied easily, and the methods are described. A method has also been developed to measure the DNA content of individual cells by microscope fluorometry. After treatment of the embryos with ionizing radiation or drugs the release of micronuclei has been observed from the cell nuclei, which is an expression for chromosomal damage. Substances or radionuclides can be added to the culture medium or external irradiation can be performed during the culture period. Also the combined effects of radiation and heating can be studied. The effects of X-rays and tritiated compounds have also been investigated. The combined effects of radiation with antibiotics such as actinomycin D, and environmental toxicants such as lead, have been determined. The system described has been useful to evaluate cytological, teratogenic and cytogenetic effects

  7. A pilot study of biomechanical assessment before and after an integrative training program for adolescents with juvenile fibromyalgia

    OpenAIRE

    Tran, Susan T.; Thomas, Staci; DiCesare, Christopher; Pfeiffer, Megan; Sil, Soumitri; Ting, Tracy V.; Williams, Sara E.; Myer, Gregory D.; Kashikar-Zuck, Susmita

    2016-01-01

    Background Adolescents with juvenile fibromyalgia (JFM) tend to be very sedentary and avoid participation in physical activity. A prior study suggested that JFM patients show altered biomechanics compared to healthy adolescents which may make them more prone to pain/injury during exercise. A new intervention combining well established cognitive behavioral therapy (CBT) techniques with specialized neuromuscular exercise ?Fibromyalgia Integrative Training for Teens (FIT Teens) was developed and...

  8. Comparison of temperature rise in the pulp chamber with different light curing units: An in-vitro study

    OpenAIRE

    Rajesh Ebenezar A; Anilkumar R; Indira R; Ramachandran S; Srinivasan M

    2010-01-01

    Aims/Objectives : This in vitro study was designed to measure and compare the temperature rise in the pulp chamber with different light curing units. Materials and Methods : The study was done in two settings-in-vitro and in-vivo simulation. In in-vitro setting, 3mm and 6mm acrylic spacers with 4mm tip diameter thermocouple was used and six groups were formed according to the light curing source- 3 Quartz-Tungsten-Halogen (QTH) units and 3 Light-Emitting-Diode (LED) units. For the LED units...

  9. Comparison of temperature rise in the pulp chamber with different light curing units: An in-vitro study

    OpenAIRE

    Rajesh Ebenezar, A V; Anilkumar, R; Indira, R; Ramachandran, S; Srinivasan, M R

    2010-01-01

    Aims/Objectives: This in vitro study was designed to measure and compare the temperature rise in the pulp chamber with different light curing units. Materials and Methods: The study was done in two settings-in-vitro and in-vivo simulation. In in-vitro setting, 3mm and 6mm acrylic spacers with 4mm tip diameter thermocouple was used and six groups were formed according to the light curing source- 3 Quartz-Tungsten-Halogen (QTH) units and 3 Light-Emitting-Diode (LED) units. For the LED units, th...

  10. Pig and guinea pig skin as surrogates for human in vitro penetration studies: a quantitative review.

    Science.gov (United States)

    Barbero, Ana M; Frasch, H Frederick

    2009-02-01

    Both human and animal skin in vitro models are used to predict percutaneous penetration in humans. The objective of this review is a quantitative comparison of permeability and lag time measurements between human and animal skin, including an evaluation of the intra and inter species variability. We limit our focus to domestic pig and rodent guinea pig skin as surrogates for human skin, and consider only studies in which both animal and human penetration of a given chemical were measured jointly in the same lab. When the in vitro permeability of pig and human skin were compared, the Pearson product moment correlation coefficient (r) was 0.88 (Ppig and 35% for human, and an inter species average coefficient of variation of 37% for the set of studied compounds (n=41). The lag times of pig skin and human skin did not correlate (r=0.35, P=0.26). When the in vitro permeability of guinea pig and human skin were compared, r=0.96 (Pguinea pig and 24% for human, and an inter species coefficient of variation of permeability of 41% for the set of studied compounds (n=15). Lag times of guinea pig and human skin correlated (r=0.90, Ppig skin (n=50) and guinea pig skin (n=25). For pig skin, 80% of measurements fell within the range 0.3guinea pig skin, 65% fell within that range. Both pig and guinea pig are good models for human skin permeability and have less variability than the human skin model. The skin model of choice will depend on the final purpose of the study and the compound under investigation.

  11. Bladder wall biomechanics: A comprehensive study on fresh porcine urinary bladder

    DEFF Research Database (Denmark)

    Sami Jokandan, Maryam; Ajalloueian, Fatemeh; Edinger, Magnus

    2018-01-01

    Regenerative medicine for reconstructive urogenital surgery has been widely studied during the last two decades. One of the key factors affecting the quality of bladder regeneration is the mechanical properties of the bladder scaffold. Insight into the biomechanics of this organ is expected to as...... applied here reveals distinct information, outcomes from the combination of the three can be considered as a helpful data-base to refer to for researchers aiming to regenerate the bladder......., the anisotropic behavior of bladder was evident at strain loads higher than 200%. According to DMA, storage modulus was found to be consistently higher than loss modulus in both directions, revealing the elasticity of the BW. The stress-strain curves of both uniaxial and BB tests showed similar trends. However......, the ultimate stress measured from BB was found to be around 5 times of the relevant stress from uniaxial loading. The ultimate strain in BB (389.9 ± 59.8) was interestingly an approximate average of longitudinal (358 ± 21) and circumferential (435 ± 69) rupture strains. Considering that each testing mode...

  12. Novel technique for repairing posterior medial meniscus root tears using porcine knees and biomechanical study.

    Directory of Open Access Journals (Sweden)

    Jia-Lin Wu

    Full Text Available Transtibial pullout suture (TPS repair of posterior medial meniscus root (PMMR tears was shown to achieve good clinical outcomes. The purpose of this study was to compare biomechanically, a novel technique designed to repair PMMR tears using tendon graft (TG and conventional TPS repair. Twelve porcine tibiae (n = 6 each TG group: flexor digitorum profundus tendon was passed through an incision in the root area, created 5 mm postero-medially along the edge of the attachment area. TPS group: a modified Mason-Allen suture was created using no. 2 FiberWire. The tendon grafts and sutures were threaded through the bone tunnel and then fixed to the anterolateral cortex of the tibia. The two groups underwent cyclic loading followed by a load-to-failure test. Displacements of the constructs after 100, 500, and 1000 loading cycles, and the maximum load, stiffness, and elongation at failure were recorded. The TG technique had significantly lower elongation and higher stiffness compared with the TPS. The maximum load of the TG group was significantly lower than that of the TPS group. Failure modes for all specimens were caused by the suture or graft cutting through the meniscus. Lesser elongation and higher stiffness of the constructs in TG technique over those in the standard TPS technique might be beneficial for postoperative biological healing between the meniscus and tibial plateau. However, a slower rehabilitation program might be necessary due to its relatively lower maximum failure load.

  13. Biomechanical pulping of kenaf

    Science.gov (United States)

    Aziz Ahmed; Masood Akhtar; Gary C. Myers; Gary M. Scott

    1999-01-01

    The objective of this study was to investigate the effect of fungal pretreatment of whole kenaf prior to refining on refiner electrical energy consumption, paper strength, and optical properties. We also explored the suitability of whole kenaf biomechanical pulp for making newsprint in terms of ISO brightness and strength properties. Kenaf was sterilized by autoclaving...

  14. In vitro and in vivo study of a nanoliposomal cisplatin as a radiosensitizer

    Directory of Open Access Journals (Sweden)

    Xiaomeng Zhang

    2011-02-01

    Full Text Available Xiaomeng Zhang1*, Huanjun Yang1*, Ke Gu1, Jian Chen2, Mengjie Rui2, Guo-Liang Jiang11Departments of Radiation Oncology, Fudan University Shanghai Cancer Center; Department of Oncology, Shanghai Medical College,Fudan University,Shanghai, People’s Republic of China; 2School of Pharmacy, Shanghai Jiao Tong University, Shanghai, People’s Republic of China; *Xiaomeng Zhang and Huanjun Yang share the first authorshipObjective: To investigate the in vitro and in vivo radiosensitization effect of an institutionally designed nanoliposome encapsulated cisplatin (NLE-CDDP.Materials and methods: NLE-CDDP was developed by our institute. In vitro radiosensitization of NLE-CDDP was evaluated by colony forming assay in A549 cells. In vivo radiosensitization was studied with tumor growth delay (TGD in Lewis lung carcinoma. The radiosensitization for normal tissue was investigated by jejunal crypt survival. The radiosensitization studies were carried out with a 72 h interval between drug administration and irradiation. The mice were treated with 6 mg/kg of NLE-CDDP or CDDP followed by single doses of 2 Gy, 6 Gy, 16 Gy, and 28 Gy. Sensitization enhancement ratio (SER was calculated by D0s of cell survival curves for A549 cells, doses needed to yield TGD of 20 days in Lewis lung carcinoma, or D0s of survival curves in crypt cells in radiation alone and radiation plus drug groups.Results: Our NLE-CDDP could inhibit A549 cells in vitro with half maximal inhibitory concentration of 1.12 µg/mL, and its toxicity was 2.35 times that observed in CDDP. For in vitro studies of A549 cells, SERs of NLE-CDDP and CDDP were 1.40 and 1.14, respectively, when combined with irradiation. For in vivo studies of Lewis lung carcinoma, the strongest radiosensitization was found in the 72 h interval between NLE-CDDP and irradiation. When given 72 h prior to irradiation, NLE-CDDP yielded higher radiosensitization than CDDP (SER of 4.92 vs 3.21 and slightly increased injury in jejunal

  15. Polyelectrolyte complex of vancomycin as a nanoantibiotic: Preparation, in vitro and in silico studies

    Energy Technology Data Exchange (ETDEWEB)

    Sikwal, Dhiraj R.; Kalhapure, Rahul S.; Rambharose, Sanjeev; Vepuri, Suresh; Soliman, Mahmoud; Mocktar, Chunderika; Govender, Thirumala, E-mail: govenderth@ukzn.ac.za

    2016-06-01

    Delivery of antibiotics by various nanosized carriers is proving to be a promising strategy to combat limitations associated with conventional dosage forms and the ever-increasing drug resistance problem. This method entails improving the pharmacokinetic parameters for accumulation at the target infection site and reducing their adverse effects. It has been proposed that antibiotic nanoparticles themselves are more effective delivery system than encapsulating the antibiotic in a nanosystem. In this study, we report on nanoparticles of vancomycin (VCM) by self-assembled amphiphilic–polyelectrolyte complexation between VCM hydrochloride and polyacrylic acid sodium (PAA). The size, polydispersity index and zeta potential of the developed nanoplexes were 229.7 ± 47.76 nm, 0.442 ± 0.075, − 30.4 ± 5.3 mV respectively, whereas complexation efficiency, drug loading and percentage yield were 75.22 ± 1.02%, 58.40 ± 1.03% and 60.60 ± 2.62% respectively. An in vitro cytotoxicity study on three mammalian cell lines using MTT assays confirmed the biosafety of the newly formulated nanoplexes. Morphological investigations using scanning electron microscope showed cube shaped hexagonal-like particles. In vitro drug release studies revealed that the drug was completely released from the nanoplexes within 12 h. In silico studies revealed that the nano-aggregation was facilitated by means of self-association of VCM in the presence of the polymer. The supramolecular pattern of the drug self-association was found to be similar to that of the VCM dimer observed in the crystal structure of the VCM available in Protein Data Bank. In vitro antibacterial activity against susceptible and resistant Staphylococcus aureus proved that the potency of VCM was retained after being formulated as the nanoplex. In conclusion, VCM nanoplexes could be a promising nanodrug delivery system to treat infections of S. aureus origin. - Highlights: • Self-assembly of vancomycin to form cube

  16. Polyelectrolyte complex of vancomycin as a nanoantibiotic: Preparation, in vitro and in silico studies

    International Nuclear Information System (INIS)

    Sikwal, Dhiraj R.; Kalhapure, Rahul S.; Rambharose, Sanjeev; Vepuri, Suresh; Soliman, Mahmoud; Mocktar, Chunderika; Govender, Thirumala

    2016-01-01

    Delivery of antibiotics by various nanosized carriers is proving to be a promising strategy to combat limitations associated with conventional dosage forms and the ever-increasing drug resistance problem. This method entails improving the pharmacokinetic parameters for accumulation at the target infection site and reducing their adverse effects. It has been proposed that antibiotic nanoparticles themselves are more effective delivery system than encapsulating the antibiotic in a nanosystem. In this study, we report on nanoparticles of vancomycin (VCM) by self-assembled amphiphilic–polyelectrolyte complexation between VCM hydrochloride and polyacrylic acid sodium (PAA). The size, polydispersity index and zeta potential of the developed nanoplexes were 229.7 ± 47.76 nm, 0.442 ± 0.075, − 30.4 ± 5.3 mV respectively, whereas complexation efficiency, drug loading and percentage yield were 75.22 ± 1.02%, 58.40 ± 1.03% and 60.60 ± 2.62% respectively. An in vitro cytotoxicity study on three mammalian cell lines using MTT assays confirmed the biosafety of the newly formulated nanoplexes. Morphological investigations using scanning electron microscope showed cube shaped hexagonal-like particles. In vitro drug release studies revealed that the drug was completely released from the nanoplexes within 12 h. In silico studies revealed that the nano-aggregation was facilitated by means of self-association of VCM in the presence of the polymer. The supramolecular pattern of the drug self-association was found to be similar to that of the VCM dimer observed in the crystal structure of the VCM available in Protein Data Bank. In vitro antibacterial activity against susceptible and resistant Staphylococcus aureus proved that the potency of VCM was retained after being formulated as the nanoplex. In conclusion, VCM nanoplexes could be a promising nanodrug delivery system to treat infections of S. aureus origin. - Highlights: • Self-assembly of vancomycin to form cube

  17. Characterisation, in vitro release study, and antibacterial activity of montmorillonite-gentamicin complex material

    International Nuclear Information System (INIS)

    Rapacz-Kmita, A.; Bućko, M.M.; Stodolak-Zych, E.; Mikołajczyk, M.; Dudek, P.; nd Department of Surgery, Kopernika 21, 31-501 Krakow (Poland))" data-affiliation=" (Jagiellonian University, Medical College, 2nd Department of Surgery, Kopernika 21, 31-501 Krakow (Poland))" >Trybus, M.

    2017-01-01

    The present paper concerns the potential use of montmorillonite as a drug carrier and focusses on the intercalation of the studied clay with gentamicin (an aminoglycoside antibiotic) at various temperatures (20, 50 and 80 °C). The experiments were performed to identify the temperature required for the optimum intercalation of gentamicin into the interlayer of montmorillonite. The structural and microstructural properties of gentamicin and the potential for introducing it between smectite clay layers were investigated by means of X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopic techniques, and SEM with EDS analysis. Additionally, the in vitro drug release behaviour of the montmorillonite-gentamicin complex and its antibacterial activity against Escherichia coli (E. coli) bacteria was investigated. Based on these studies, the impact of temperature on the intercalation of the drug between layers of smectite was evaluated. It was found that an intercalation temperature of 50 °C resulted in the highest shift in the position of principle peak d (001) as measured by XRD, suggesting, that the greatest amount of gentamicin had been introduced into the interlayer space of montmorillonite at this temperature. Subsequently, the montmorillonite-gentamicin complex material obtained at 50 °C revealed the greatest capacity for killing E. coli bacteria during an in vitro test. - Highlights: • A novel montmorillonite-gentamicin hybrid materials was prepared as potential drug carrier. • Optimal conditions for the intercalation of gentamicin into the interlayer space of montmorillonite were tested. • The MMT-G complex material obtained at 50 °C revealed the greatest capacity for killing E. coli during the inhibitory zone test. • Modulating drug delivery was monitored and confirmed in in vitro drug release study.

  18. Characterisation, in vitro release study, and antibacterial activity of montmorillonite-gentamicin complex material

    Energy Technology Data Exchange (ETDEWEB)

    Rapacz-Kmita, A., E-mail: kmita@agh.edu.pl [AGH University of Science and Technology, Faculty of Materials Science and Ceramics, Mickiewicza 30, 30-059 Krakow (Poland); Bućko, M.M.; Stodolak-Zych, E. [AGH University of Science and Technology, Faculty of Materials Science and Ceramics, Mickiewicza 30, 30-059 Krakow (Poland); Mikołajczyk, M. [The University Hospital in Krakow, Division of Microbiology, Kopernika 19, 31-501 Krakow (Poland); Dudek, P. [AGH University of Science and Technology, Faculty of Mechanical Engineering and Robotics, Mickiewicza 30, 30-059 Krakow (Poland); Trybus, M. [Jagiellonian University, Medical College, 2" n" d Department of Surgery, Kopernika 21, 31-501 Krakow (Poland)

    2017-01-01

    The present paper concerns the potential use of montmorillonite as a drug carrier and focusses on the intercalation of the studied clay with gentamicin (an aminoglycoside antibiotic) at various temperatures (20, 50 and 80 °C). The experiments were performed to identify the temperature required for the optimum intercalation of gentamicin into the interlayer of montmorillonite. The structural and microstructural properties of gentamicin and the potential for introducing it between smectite clay layers were investigated by means of X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopic techniques, and SEM with EDS analysis. Additionally, the in vitro drug release behaviour of the montmorillonite-gentamicin complex and its antibacterial activity against Escherichia coli (E. coli) bacteria was investigated. Based on these studies, the impact of temperature on the intercalation of the drug between layers of smectite was evaluated. It was found that an intercalation temperature of 50 °C resulted in the highest shift in the position of principle peak d{sub (001)} as measured by XRD, suggesting, that the greatest amount of gentamicin had been introduced into the interlayer space of montmorillonite at this temperature. Subsequently, the montmorillonite-gentamicin complex material obtained at 50 °C revealed the greatest capacity for killing E. coli bacteria during an in vitro test. - Highlights: • A novel montmorillonite-gentamicin hybrid materials was prepared as potential drug carrier. • Optimal conditions for the intercalation of gentamicin into the interlayer space of montmorillonite were tested. • The MMT-G complex material obtained at 50 °C revealed the greatest capacity for killing E. coli during the inhibitory zone test. • Modulating drug delivery was monitored and confirmed in in vitro drug release study.

  19. In vitro and in vivo motility studies of radiolabelled sperm cells

    International Nuclear Information System (INIS)

    Balogh, L.; Szasz, F.; Janoki, Gy.A.; Toth, L.; Zoldag, L.; Huszenicza, Gy.

    1994-01-01

    A new method for radiolabelling of sperm cells with 99m Tc HM-PAO (hexamethyl-propylene-amine-oxide) - LEUCO-SCINT kit, is investigated. The labelling technique for fresh rabbit, bull, sheep and horse as well as frozen-thawed bull sperm was optimized. The optimum conditions for sperm cell labelling (incubation volume, incubation time, initial activity of 99m Tc HM-PAO, cell number) yielded a high labelling efficiency (70-80%) and survival rate (50-60%). The labelled sperm cells were used to study their motility in vitro. The migrating at 37 o C cells incubated capillary tubes containing bovine cervical mucus. The tubes were cut and the activity of the parts measured and valued. We compared the results of living and killed sperm cells and the label alone by the change of species and running time. Ten minutes after the labelling procedures the total activity of microtubes was 2-3 times higher and the activity distribution was different from the results obtained 3 hours after the labelling. The sperm migration in vivo in the living female animals using a non invasive technique was also visualized. The sperm flow was clearly demonstrated in 3 different animal model (rabbit, ewe, hen) under gamma camera. The comparison of the in vivo migration of rabbit and bull sperm cells showed that the homologous sperm migrated faster and farther. On study of bull sperm migration in the ewe genital tract the cornu uteri was clearly visualized. In the hen model the whole genital tract was demonstrated with considerable free activity in the cavum abdominal 24 hours after the artificial insemination. The new method is developed and manufactured by NRIRR, Budapest, originally designed for radiolabelling leucocytes. The 99m Tc HM-PAO Labelled sperm cells with their retained migration properties are suitable for in vitro motility assays and in vitro migration studies in both human and veterinary medicine. (author)

  20. In vitro studies reveal antiurolithic effect of Terminalia arjuna using quantitative morphological information from computerized microscopy

    Directory of Open Access Journals (Sweden)

    A. Mittal

    2015-10-01

    Full Text Available ABSTRACT Purpose: For most cases, urolithiasis is a condition where excessive oxalate is present in the urine. Many reports have documented free radical generation followed by hyperoxaluria as a consequence of which calcium oxalate (CaOx deposition occurs in the kidney tissue. The present study is aimed to exam the antilithiatic potency of the aqueous extract (AE of Terminalia arjuna (T. arjuna. Materials and Methods: The antilithiatic activity of Terminalia arjuna was investigated in vitro nucleation, aggregation and growth of the CaOx crystals as well as the morphology of CaOx crystals using the inbuilt software ‘Image-Pro Plus 7.0’ of Olympus upright microscope (BX53. Antioxidant activity of AE of Terminalia arjuna bark was also determined in vitro. Results: Terminalia arjuna extract exhibited a concentration dependent inhibition of nucleation and aggregation of CaOx crystals. The AE of Terminalia arjuna bark also inhibited the growth of CaOx crystals. At the same time, the AE also modified the morphology of CaOx crystals from hexagonal to spherical shape with increasing concentrations of AE and reduced the dimensions such as area, perimeter, length and width of CaOx crystals in a dose dependent manner. Also, the Terminalia arjuna AE scavenged the DPPH (2, 2-diphenyl-1-picrylhydrazyl radicals with an IC50 at 13.1µg/mL. Conclusions: The study suggests that Terminalia arjuna bark has the potential to scavenge DPPH radicals and inhibit CaOx crystallization in vitro. In the light of these studies, Terminalia arjuna can be regarded as a promising candidate from natural plant sources of antilithiatic and antioxidant activity with high value.

  1. Generalized evaluation of the endocrine system using the results of radiodiagnostic studies in vitro

    International Nuclear Information System (INIS)

    Zaprudnova, S.N.; Tkacheva, G.A.; Narkevich, B.Ya.

    1984-01-01

    The paper is concerned with a comparative analysis of 3 different decision rules to give a summary evaluation of endocrine system function. The application of the rules to the evaluation of the hormonal status of patients with gastric cancer has shown that the index of the state of the endocrine system gets deteriorated compared to the normal one, however it greatly improves in clinically effective treatment. From the view-point of the quality of classifiers for an in vitro study of the endocrine status the best of the proposed classifiers is the determination of Euclidean distance from normal in the multidimensional space of the diagnostic signs

  2. A novel in vitro model for studying quiescence and activation of primary isolated human myoblasts

    DEFF Research Database (Denmark)

    Sellathurai, Jeeva; Cheedipudi, Sirisha; Dhawan, Jyotsna

    2013-01-01

    term exponentially proliferating cultures normally used for in vitro studies. Human myoblasts cultured through many passages inevitably consist of a mixture of proliferating and non-proliferating cells, while cells activated from G0 are in a synchronously proliferating phase, and therefore may...... be a better model for in vivo proliferating satellite cells. Furthermore, the temporal propagation of proliferation in these synchronized cultures resembles the pattern seen in vivo during regeneration. We therefore present this culture model as a useful and novel condition for molecular analysis...

  3. The SGBS cell strain as a model for the in vitro study of obesity and cancer.

    LENUS (Irish Health Repository)

    Allott, Emma H

    2012-10-01

    The murine adipocyte cell line 3T3-L1 is well characterised and used widely, while the human pre-adipocyte cell strain, Simpson-Golabi-Behmel Syndrome (SGBS), requires validation for use in human studies. Obesity is currently estimated to account for up to 41 % of the worldwide cancer burden. A human in vitro model system is required to elucidate the molecular mechanisms for this poorly understood association. This work investigates the relevance of the SGBS cell strain for obesity and cancer research in humans.

  4. Chlorophyll bleaching by UV-irradiation in vitro and in situ: Absorption and fluorescence studies

    International Nuclear Information System (INIS)

    Zvezdanovic, Jelena; Cvetic, Tijana; Veljovic-Jovanovic, Sonja; Markovic, Dejan

    2009-01-01

    Chlorophyll bleaching by UV-irradiation has been studied by absorbance and fluorescence spectroscopy in extracts containing mixtures of photosynthetic pigments, in acetone and n-hexane solutions, and in aqueous thylakoid suspensions. Chlorophyll undergoes destruction (bleaching) accompanied by fluorescent transient formation obeying first-order kinetics. The bleaching is governed by UV-photon energy input, as well as by different chlorophyll molecular organizations in solvents of different polarities (in vitro), and in thylakoids (in situ). UV-C-induced bleaching of chlorophylls in thylakoids is probably caused by different mechanisms compared to UV-A- and UV-B-induced bleaching

  5. Ultrasound Mediated Microbubbles Destruction Augmented Sonolysis: An In Vitro and In Vivo Study.

    Science.gov (United States)

    Cui, Hai; Zhu, Qiong; Gao, Yunhua; Xia, Hongmei; Tan, Kaibin; He, Ying; Liu, Zheng; Xu, Yali

    2017-01-01

    This study was aimed at exploring ultrasound mediated microbubbles destruction (UMMD) assisted sonolysis in both the in vitro and in vivo clots. Therapeutic ultrasound (TUS) and lipid microbubbles (MBs) were used in whole blood clots and divided into the control, TUS group, and TUS + MB group. Thrombolytic rates and microscopy were performed. Color Doppler flow imaging (CDFI) and angiography were performed to evaluate the recanalization rates and flow scores in femoral arterial thrombus (FAT) in rabbits. FAT were dyed with H&E. The average thrombolytic ratios of TUS + MB group were significantly higher than those of TUS group and the control group (both P cavitation via UMMD.

  6. Targeted femtosecond laser driven drug delivery within HIV-1 infected cells: In-vitro studies [conference paper

    CSIR Research Space (South Africa)

    Maphanga, Charles

    2017-01-01

    Full Text Available of SPIE 10062, Optical Interactions with Tissue and Cells XXVIIISan Francisco, California, USA, 26 January - 03 February 2017 Targeted femtosecond laser driven drug delivery within HIV-1 infected cells: In-vitro studies Charles Maphanga 1, 2...

  7. Anionic hexadeca-carboxylate tetrapyrazinoporphyrazine: synthesis and in vitro photodynamic studies of a water-soluble, non-aggregating photosensitizer

    Czech Academy of Sciences Publication Activity Database

    Macháček, M.; Kollár, J.; Miletin, M.; Kučera, R.; Kubát, Pavel; Šimůnek, T.; Nováková, V.; Zimčík, P.

    2016-01-01

    Roč. 6, JAN 2016 (2016), s. 10064-10077 ISSN 2046-2069 Institutional support: RVO:61388955 Keywords : synthesis * in vitro photodynamic studies * phthalocyanines Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.108, year: 2016

  8. Atorvastatin calcium loaded chitosan nanoparticles: in vitro evaluation and in vivo pharmacokinetic studies in rabbits

    Directory of Open Access Journals (Sweden)

    Abdul Baquee Ahmed

    2015-06-01

    Full Text Available In this study, we prepared atorvastatin calcium (AVST loaded chitosan nanoparticles to improve the oral bioavailability of the drug. Nanoparticles were prepared by solvent evaporation technique and evaluated for its particle size, entrapment efficiency, zeta potential, in vitro release and surface morphology by scanning electron microscopy (SEM. In addition, the pharmacokinetics of AVST from the optimized formulation (FT5 was compared with marketed immediate release formulation (Atorva(r in rabbits. Particle size of prepared nanoparticles was ranged between 179.3 ± 7.12 to 256.8 ± 8.24 nm with a low polydispersity index (PI value. Zeta potential study showed that the particles are stable with positive values between 13.03 ± 0.32 to 46.90 ± 0.49 mV. FT-IR studies confirmed the absence of incompatibility of AVST with excipient used in the formulations. In vitro release study showed that the drug release was sustained for 48 h. Results of pharmacokinetics study showed significant changes in the pharmacokinetic parameter (2.2 fold increase in AUC of the optimized formulation as compared to marketed formulation (Atorva(r. Thus, the developed nanoparticles evidenced the improvement of oral bioavailability of AVST in rabbit model.

  9. In vitro study of stem cell communication via gap junctions for fibrocartilage regeneration at entheses.

    Science.gov (United States)

    Nayak, Bibhukalyan Prasad; Goh, James Cho Hong; Toh, Siew Lok; Satpathy, Gyan Ranjan

    2010-03-01

    Entheses are fibrocartilaginous organs that bridge ligament with bone at their interface and add significant insertional strength. To replace a severely damaged ligament, a tissue-engineered graft preinstalled with interfacial fibrocartilage, which is being regenerated from stem cells, appears to be more promising than ligament-alone graft. Such a concept can be realized by a biomimetic approach of establishing a dynamic communication of stem cells with bone cells and/or ligament fibroblasts in vitro. The current study has two objectives. The first objective is to demonstrate functional coculture of bone marrow-derived stem cells (BMSCs) with mature bone cells/ligament fibroblasts as evidenced by gap-junctional communication in vitro. The second objective is to investigate the role of BMSCs in the regeneration of fibrocartilage within the coculture. Rabbit bone/ligament fibroblasts were dual-stained with DiI-Red and calcein (gap-junction permeable dye), and cocultured with unlabeled BMSCs at fixed ratio (1:10). The functional gap junction was demonstrated by the transfer of calcein from donor to recipient cells that was confirmed and quantified by flow cytometry. Type 2 collagen (cartilage extracellular matrix-specific protein) expressed by the mixed cell lines in the cocultures were estimated by real-time reverse transcription PCR and compared with that of the ligament-bone coculture (control). Significant transfer of calcein into BMSCs was observed and flow cytometry analyses showed a gradual increase in the percentage of BMSCs acquiring calcein with time. Cocultures that included BMSCs expressed significantly more type 2 collagen compared with the control. The current study, for the first time, reported the expression of gap-junctional communication of BMSCs with two adherent cell lines of musculoskeletal system in vitro and also confirmed that incorporation of stem cells augments fibrocartilage regeneration. The results open up a path to envisage a composite

  10. Comparative study for antibacterial potential of in vitro and in vivo grown Ocimum basilicum L. plant extracts

    Energy Technology Data Exchange (ETDEWEB)

    Shafique, M; Khan, S J [Pakistan Councile of Scientific and Industrial Research, Lahore (Pakistan). Dept. of Food and Biotechnology

    2011-09-15

    The antimicrobial activities of in vitro grown callus extract and in vivo grown Ocimum basilicum L. plant leaves extracts were studied and compared. Effect of extraction solvent was also assessed. These extracts were tested in vitro against eight bacterial strains following disc diffusion method. The results indicated that in vitro grown callus extracts of O. basilicum exhibited higher antimicrobial activity against tested Gram positive microorganisms as compared to in vivo grown plant material extract. These findings indicate towards potential use of biotechnology for natural therapeutic agent production. (author)

  11. Comparative study for antibacterial potential of in vitro and in vivo grown Ocimum basilicum L. plant extracts

    International Nuclear Information System (INIS)

    Shafique, M.; Khan, S.J.

    2011-01-01

    The antimicrobial activities of in vitro grown callus extract and in vivo grown Ocimum basilicum L. plant leaves extracts were studied and compared. Effect of extraction solvent was also assessed. These extracts were tested in vitro against eight bacterial strains following disc diffusion method. The results indicated that in vitro grown callus extracts of O. basilicum exhibited higher antimicrobial activity against tested Gram positive microorganisms as compared to in vivo grown plant material extract. These findings indicate towards potential use of biotechnology for natural therapeutic agent production. (author)

  12. Forty-five-degree or higher insertion angles are required to penetrate the opposite cortex in bicortical applications of Kirschner wires: an in vitro study on sheep bones.

    Science.gov (United States)

    Colak, Mehmet; Gurer, Burak; Sungur, Mehmet Ali; Eskandari, Metin Manouchehr

    2012-04-01

    Slippage of the wires over the opposite cortex from the endosteal side is frequent and can lead to insufficient stability. This in vitro biomechanical study was planned to investigate the angle of wire insertion that leads to trans cortex perforation. Long bones of sheep were cut longitudinally into two pieces and half bones were stabilised on a frame. Three orthopaedic surgeons performed the experiment using ten wires of four different diameters at two different drilling speeds. Each wire was introduced from the endosteal side at angles starting at 30° in 5° increments until perforation. When perforation was achieved, the angle was recorded. To determinate the critical angle of perforation, receiver operating characteristic (ROC) curve analyses was performed. Two-way factorial analysis of variance (ANOVA) and Kruskal-Wallis tests were used for statistical comparisons. Kirschner-wire insertion angles of ≥ 45° provided perforation with a percentage of 83.9 %. Wire diameter, drilling speed and surgeon variables had no effect on perforation angles (p > 0.05). If preoperative evaluation of fractures to be fixed by K wires reveals the need for oblique wire insertion angle < 45°, a standard trocar-tip K wire application would lead to slippage of the wire tip on the endosteal surface of the opposite cortex. According to this study, the operative plan should be changed if such obliquity of the K wire is mandatory during bicortical applications.

  13. Liquid crystalline systems for transdermal delivery of celecoxib: in vitro drug release and skin permeation studies.

    Science.gov (United States)

    Estracanholli, Eder André; Praça, Fabíola Silva Garcia; Cintra, Ana Beatriz; Pierre, Maria Bernadete Riemma; Lara, Marilisa Guimarães

    2014-12-01

    Liquid crystalline systems of monoolein/water could be a promising approach for the delivery of celecoxib (CXB) to the skin because these systems can sustain drug release, improve drug penetration into the skin layers and minimize side effects. This study evaluated the potential of these systems for the delivery of CXB into the skin based on in vitro drug release and skin permeation studies. The amount of CXB that permeated into and/or was retained in the skin was assayed using an HPLC method. Polarizing light microscopy studies showed that liquid crystalline systems of monoolein/water were formed in the presence of CXB, without any changes in the mesophases. The liquid crystalline systems decreased drug release when compared to control solution. Drug release was independent of the initial water content of the systems and CXB was released from cubic phase systems, irrespective of the initial water content. The systems released the CXB following zero-order release kinetics. In vitro drug permeation studies showed that cubic phase systems allowed drug permeation and retention in the skin layers. Cubic phase systems of monoolein/water may be promising vehicles for the delivery of CXB in/through the skin because it improved CXB skin permeation compared with the control solution.

  14. Controlled release effervescent buccal discs of buspirone hydrochloride: in vitro and in vivo evaluation studies.

    Science.gov (United States)

    Jaipal, A; Pandey, M M; Charde, S Y; Sadhu, N; Srinivas, A; Prasad, R G

    2016-01-01

    In the present study controlled release effervescent buccal discs of buspirone hydrochloride (BS) were designed using HPMC as rate controlling and bioadhesive polymer by direct compression method. Sodium bicarbonate and citric acid were used in varying amounts as effervescence forming agents. Carbon dioxide evolved due to reaction of sodium bicarbonate and citric acid was explored for its potential as buccal permeation enhancer. The designed buccal discs were evaluated for physical characteristics and in vitro drug release studies. Bioadhesive behavior of designed buccal discs was assessed using texture analyzer. In vivo animal studies were performed in rabbits to study bioavailability of BS in the designed buccal discs and to establish permeation enhancement ability of carbon dioxide. It was observed that effervescent buccal discs have faster drug release compared to non-effervescent buccal discs in vitro and effervescent buccal discs demonstrated significant increase in bioavailability of drug when compared to non-effervescent formulation. Hence, effervescent buccal discs can be used as an alternative to improve the drug permeation resulting in better bioavailability. However, the amount of acid and base used for generation of carbon dioxide should be selected with care as this may damage the integrity of bioadhesive dosage form.

  15. Factors Affecting the Shear Bond Strength of Orthodontic Brackets - a Review of In Vitro Studies.

    Science.gov (United States)

    Bakhadher, Waleed; Halawany, Hassan; Talic, Nabeel; Abraham, Nimmi; Jacob, Vimal

    2015-01-01

    The adhesive material used to bond orthodontic brackets to teeth should neither fail during the treatment period, resulting in treatment delays, untoward expenses or patient inconvenience nor should it damage the enamel on debonding at the end of the treatment. Although the effectiveness of a bonding system and any unfavorable effects on the enamel may be studied by conducting in-vivo studies, it is nearly impossible to independently analyze different variables that influence a specific bonding system in the oral environment. In-vitro studies, on the other hand, may utilize more standardized protocols for testing different bonding systems and materials available. Thus, the present review focused attention on in-vitro studies and made an attempt to discuss material-related, teeth-related (fluorotic vs non-fluorotic teeth) and other miscellaneous factors that influences the shear bond strength of orthodontic brackets. Within the limitations of this review, using conventional acid-etch technique, ceramic brackets and bonding to non-fluorotic teeth was reported to have a positive influence on the shear bond strength of orthodontic brackets, but higher shear bond strength found on using ceramic brackets can be dangerous for the enamel.

  16. Anatomical, germination and in vitro studies on shea tree (Vitellaria paradoxa.) seed

    International Nuclear Information System (INIS)

    Iddrisu, A.

    2013-07-01

    In vitro and in vivo germination and regeneration studies were conducted on the development of vitellaria paradoxa seedlings as an initial effort towards its domestication. However, to achieve this objective, the morphology and anatomy of the seeds were first studied because they influence germination. Although a smooth, brown coast enclosed a V. paradoxa seed, it did not impose dormancy on the embroyo. Transverse and longitudinal sections through the seed showed that the embrayo is surrounded by latex and fat-containing tissues which made its identification difficult. Thus, the embrayo was identified by immersing transversely cut seeds in 1.0 % tetrazolium chloride (TTC) solution for 24 hours which stained it red. When V. paradoxa seeds of similar size were sown on nursery beds, the resulting seedlings developed through seven stages namely sprouting, pseudoradicle elongation, bulging, appearance of the shoot on the pseudoradicle, shoot elongation, emergence and seedling establishment. The pseudoradicle is the fused petioles of the two cotyledons and a transverse section through it revealed an outer sheath and lactiferous vessels surrounding a central hollow tube. Longitudinal section also show the lactiferous vessels surrounding the central hallow tube in which the plumule moves through until it reaches the bulge of the pseudoradicle where it develops into a rudimentary shoot. The rudimentary shoot then pseudoradicle and grows upwards. Classifying seeds into three groups based on size significantly affected days to germination and the morphology of the resulting seedlings. Large seeds germinated within one week after sowing with vigorous growth compared to small and medium seeds. Although the seedcoat of V. paradoxa never imposed dormancy, deshelling (removal of the seedcoat) significantly led to early germination and synchronous seedling emergence compared to those for intact seeds (control). In vitro culture of intact and deshelled seeds on Muarashige and Skoog

  17. Shoe drop reduction influences the lower limb biomechanics of children tennis players during an open stance forehand: A longitudinal study.

    Science.gov (United States)

    Herbaut, Alexis; Simoneau-Buessinger, Emilie; Barbier, Franck; Gillet, Christophe; Roux, Maxime; Guéguen, Nils; Chavet, Pascale

    2017-11-01

    Compared to traditional tennis shoes, using 0-drop shoes was shown to induce an immediate switch from rear- to forefoot strike pattern to perform an open stance tennis forehand for 30% of children tennis players. The purpose of the study was to examine the long-term effects of a gradual reduction in the shoe drop on the biomechanics of children tennis players performing open stance forehands. Thirty children tennis players participated in 2 laboratory biomechanical test sessions (intermediate: +4 months and final: +8 months) after an inclusion visit where they were randomly assigned to control (CON) or experimental (EXP) group. CON received 12-mm-drop shoes twice, whereas EXP received 8 mm then 4-mm-drop shoes. Strike index indicated that all CON were rearfoot strikers in intermediate and final test sessions. All EXP were rearfoot strikers in intermediate test session, but half the group switched towards a forefoot strike pattern in final test session. This switch resulted in a decreased loading rate of the ground reaction force (-73%, p = .005) but increased peak ankle plantarflexors moment (+47%, p = .050) and peak ankle power absorption (+107%, p = .005) for these participants compared with CON. Biomechanical changes associated with the long-term use of partial minimalist shoes suggest a reduction in heel compressive forces but an increase in Achilles tendon tensile forces.

  18. Understanding how axial loads on the spine influence segmental biomechanics for idiopathic scoliosis patients: A magnetic resonance imaging study.

    Science.gov (United States)

    Little, J P; Pearcy, M J; Izatt, M T; Boom, K; Labrom, R D; Askin, G N; Adam, C J

    2016-02-01

    Segmental biomechanics of the scoliotic spine are important since the overall spinal deformity is comprised of the cumulative coronal and axial rotations of individual joints. This study investigates the coronal plane segmental biomechanics for adolescent idiopathic scoliosis patients in response to physiologically relevant axial compression. Individual spinal joint compliance in the coronal plane was measured for a series of 15 idiopathic scoliosis patients using axially loaded magnetic resonance imaging. Each patient was first imaged in the supine position with no axial load, and then again following application of an axial compressive load. Coronal plane disc wedge angles in the unloaded and loaded configurations were measured. Joint moments exerted by the axial compressive load were used to derive estimates of individual joint compliance. The mean standing major Cobb angle for this patient series was 46°. Mean intra-observer measurement error for endplate inclination was 1.6°. Following loading, initially highly wedged discs demonstrated a smaller change in wedge angle, than less wedged discs for certain spinal levels (+2,+1,-2 relative to the apex, (pbiomechanical data on in vivo spinal biomechanics of the scoliotic spine, for analysis of deformity progression and surgical planning. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Comparative evaluation of microleakage of various retrograde filling materials: An in vitro study.

    Science.gov (United States)

    Galhotra, Virat; Sofat, Anjali; Pandit, Inder K; Gambhir, Ramandeep Singh; Srivastava, Nikhil; Gugnani, Neeraj

    2013-07-01

    The present study is envisaged to evaluate and compare the microleakage of mineral trioxide aggregate (MTA) with commonly used retrograde filling materials, like light-cured composite with dentin-bonding agents, light-cured glass ionomer cement (LC GIC) and resin-modified zinc oxide eugenol. Ninety freshly extracted non-carious single-rooted human anterior teeth were used in the study. They were randomly divided into four experimental groups and two control groups of 15 each. Following the biomechanical preparation, all teeth were obturated and then the apices of the obturated teeth were resected by removing 3 mm of each apex at 90° to the long axis of the tooth with a straight fissure bur in a high-speed air-rotor handpiece with water coolant. A 3-mm-deep root end cavity was prepared and the root end fillings were placed as per the manufacturer's instructions and according to the groups divided. The samples were then immersed in 1% methylene blue at room temperature for 72 h, 96 h and 1 week and the dye penetration was measured. All the four materials used in the study showed some microleakage throughout the experimental period. The sealing ability in terms of microleakage can be summarized as: MTA > Composite resin with dentin bonding agent > LC GIC > Resin modified zinc oxide eugenol.

  20. Genotoxicity of antiobesity drug orlistat and effect of caffeine intervention: an in vitro study.

    Science.gov (United States)

    Chakrabarti, Manoswini; Ghosh, Ilika; Jana, Aditi; Ghosh, Manosij; Mukherjee, Anita

    2017-07-01

    Obesity is a major global health problem associated with various adverse effects. Pharmacological interventions are often necessary for the management of obesity. Orlistat is an FDA-approved antiobesity drug which is a potent inhibitor of intestinal lipases. In the current study, orlistat was evaluated for its genotoxic potential in human lymphocyte cells in vitro and was compared with that of another antiobesity drug sibutramine, presently withdrawn from market due its undesirable health effects. Caffeine intake may be an additional burden in people using anorectic drugs, therefore, further work is needed to be carried out to evaluate the possible effects of caffeine on orlistat-induced DNA damage. Human lymphocytes were exposed to orlistat (250, 500 and 1000 μg/ml), sibutramine (250, 500 and 1000 μg/ml) and caffeine (25, 50, 75, 100, 125 and 150 μg/ml) to assess their genotoxicity by comet assay in vitro. In addition, lymphocytes were co-incubated with caffeine (50, 75 and 100 μg/ml) and a single concentration of orlistat (250 μg/ml). Orlistat and sibutramine were genotoxic at all concentrations tested, sibutramine being more genotoxic. Caffeine was found to be genotoxic at concentrations 125 μg/ml and above. Co-treatment of orlistat with non-genotoxic concentrations (50, 75 and 100 μg/ml) of caffeine lead to a decrease in DNA damage. Orlistat can induce DNA damage in human lymphocytes in vitro and caffeine was found to reduce orlistat-induced genotoxicity.

  1. Anterior cruciate ligament regeneration using braided biodegradable scaffolds: in vitro optimization studies.

    Science.gov (United States)

    Lu, Helen H; Cooper, James A; Manuel, Sharron; Freeman, Joseph W; Attawia, Mohammed A; Ko, Frank K; Laurencin, Cato T

    2005-08-01

    The anterior cruciate ligament (ACL) is the most commonly injured intra-articular ligament of the knee, and limitations in existing reconstruction grafts have prompted an interest in tissue engineered solutions. Previously, we reported on a tissue-engineered ACL scaffold fabricated using a novel, three-dimensional braiding technology. A critical factor in determining cellular response to such a graft is material selection. The objective of this in vitro study was to optimize the braided scaffold, focusing on material composition and the identification of an appropriate polymer. The selection criteria are based on cellular response, construct degradation, and the associated mechanical properties. Three compositions of poly-alpha-hydroxyester fibers, namely polyglycolic acid (PGA), poly-L-lactic acid (PLLA), and polylactic-co-glycolic acid 82:18 (PLAGA) were examined. The effects of polymer composition on scaffold mechanical properties and degradation were evaluated in physiologically relevant solutions. Prior to culturing with primary rabbit ACL cells, scaffolds were pre-coated with fibronectin (Fn, PGA-Fn, PLAGA-Fn, PLLA-Fn), an important protein which is upregulated during ligament healing. Cell attachment and growth were examined as a function of time and polymer composition. While PGA scaffolds measured the highest tensile strength followed by PLLA and PLAGA, its rapid degradation in vitro resulted in matrix disruption and cell death over time. PLLA-based scaffolds maintained their structural integrity and exhibited superior mechanical properties over time. The response of ACL cells was found to be dependent on polymer composition, with the highest cell number measured on PLLA-Fn scaffolds. Surface modification of polymer scaffolds with Fn improved cell attachment efficiency and effected the long-term matrix production by ACL cells on PLLA and PLAGA scaffolds. Therefore based on the overall cellular response and its temporal mechanical and degradation properties

  2. Sustained release donepezil loaded PLGA microspheres for injection: Preparation, in vitro and in vivo study

    Directory of Open Access Journals (Sweden)

    Wenjia Guo

    2015-10-01

    Full Text Available The purpose of this study was to develop a PLGA microspheres-based donepezil (DP formulation which was expected to sustain release of DP for one week with high encapsulation efficiency (EE. DP derived from donepezil hydrochloride was encapsulated in PLGA microspheres by the O/W emulsion-solvent evaporation method. The optimized formulation which avoided the crushing of microspheres during the preparation process was characterized in terms of particle size, morphology, drug loading and EE, physical state of DP in the matrix and in vitro and in vivo release behavior. DP microspheres were prepared successfully with average diameter of 30 µm, drug loading of 15.92 ± 0.31% and EE up to 78.79 ± 2.56%. Scanning electron microscope image showed it has integrated spherical shape with no drug crystal and porous on its surface. Differential scanning calorimetry and X-ray diffraction results suggested DP was in amorphous state or molecularly dispersed in microspheres. The Tg of PLGA was increased with the addition of DP. The release profile in vitro was characterized with slow but continuous release that lasted for about one week and fitted well with first-order model, which suggested the diffusion governing release mechanism. After single-dose administration of DP microspheres via subcutaneous injection in rats, the plasma concentration of DP reached peak concentration at 0.50 d, and then declined gradually, but was still detectable at 15 d. A good correlation between in vitro and in vivo data was obtained. The results suggest the potential use of DP microspheres for treatment of Alzheimer's disease over long periods.

  3. Evaluation of a menstrual cup to collect shed endometrium for in vitro studies.

    Science.gov (United States)

    Koks, C A; Dunselman, G A; de Goeij, A F; Arends, J W; Evers, J L

    1997-09-01

    To evaluate whether a menstrual cup is a suitable instrument to collect antegradely shed endometrium for in vitro studies. A prospective, descriptive, cell biological and immunohistochemical study. Tertiary care university medical center. Nine female volunteers with regular cycles. Menstrual effluent was collected with a menstrual cup. Experience with the menstrual cup was described. Cytospin specimens, frozen sections, and cultures were prepared from the obtained menstrual tissue. The acceptability of the menstrual cup. The presence and viability of endometrial tissue was evaluated using immunohistochemical staining and culture outcome. All women except one described the menstrual cup as acceptable. Menstrual effluent contained single cells, clumps of cells, and glandlike structures. After 5 days of culture, the endometrial tissue appeared to be viable. Immunohistochemistry showed positive staining for vimentin in most cytospin specimens, in all cryostat specimens, and in 10 of 17 cultures. Cytokeratin 18 stained most cytospin specimens, all cryostat specimens, and 10 of 17 cultures. Positive staining for BW495/36 was observed in most cytospin specimens, all cryostat specimens, and 11 of 17 cultures. A menstrual cup in an acceptable instrument to collect antegradely shed menstrual tissue. Menstruum contains viable endometrial tissue that can be used for in vitro studies of endometrium and endometriosis.

  4. Resveratrol and endometriosis: In vitro and animal studies and underlying mechanisms (Review).

    Science.gov (United States)

    Kolahdouz Mohammadi, Roya; Arablou, Tahereh

    2017-07-01

    Endometriosis is characterized by the existence of endometrial tissue and stroma exterior to the uterus. Despite the high prevalence, the etiology of endometriosis remains elusive. The search for the most promising compounds for treatment of endometriosis has led to the identification of resveratrol. Resveratrol, a plant-derived polyphenolic phytoalexin, demonstrates broad-spectrum health beneficial effects, including anti-proliferative, anti-inflammatory, antineoplastic and antioxidant. Because of these properties and its wide distribution in plants, resveratrol is proposed as a great potential to treat endometriosis. In animal models of endometriosis, resveratrol supplementation has displayed beneficial results as it decreased the number and volume of endometrial implants, suppressed proliferation, vascularization, inflammation, cell survival and increased apoptosis. On the other hand, resveratrol treatment in-vitro studies, reduced invasiveness of endometriotic stromal cells (ESCs) and suppressed their inflammatory responses. In this review, we will summarize the recent studies in in-vitro and animal studies on resveratrol and endometriosis. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  5. 11C-harmine as a potential PET tracer for ductal pancreas cancer: in vitro studies

    International Nuclear Information System (INIS)

    Herlin, G.; Persson, B.; Laangstroem, B.; Aspelin, P.; Bergstroem, M.

    2003-01-01

    Our objective was to find a tracer in diagnosing human pancreatic cancer using positron emission tomography (PET). For this purpose in vitro test of pancreatic tissues with autoradiography was used. Autoradiography was performed with 11 C-harmine (a MAO-A-inhibitor) with and without competitive inhibition. Tissue preparations were obtained from normal human pancreas and pancreatic cancer. The uptake was compared with rat brain or pig brain, tissues with high expression of MAO-A. Nine autoradiography studies on 16 samples from five different human pancreatic cancers gave a significant level of specific binding of 11 C-harmine in 13, and 3 samples did not give a significant level of specific binding of 11 C-harmine. All 16 samples were analysed with autoradiography. Compared with rat brain, the uptake in the human cancers varied between 9 and 43% except for one tissue preparation which had a too low value for measurement. This study shows expression of MAO-A in human pancreatic cancer. This is readily characterised in vitro. The potential use of 11 C-harmine in the diagnosis of pancreatic cancer using PET might be limited, but further PET studies are necessary. (orig.)

  6. Polymeric nanoparticles containing diazepam: preparation, optimization, characterization, in-vitro drug release and release kinetic study

    Science.gov (United States)

    Bohrey, Sarvesh; Chourasiya, Vibha; Pandey, Archna

    2016-03-01

    Nanoparticles formulated from biodegradable polymers like poly(lactic-co-glycolic acid) (PLGA) are being extensively investigated as drug delivery systems due to their two important properties such as biocompatibility and controlled drug release characteristics. The aim of this work to formulated diazepam loaded PLGA nanoparticles by using emulsion solvent evaporation technique. Polyvinyl alcohol (PVA) is used as stabilizing agent. Diazepam is a benzodiazepine derivative drug, and widely used as an anticonvulsant in the treatment of various types of epilepsy, insomnia and anxiety. This work investigates the effects of some preparation variables on the size and shape of nanoparticles prepared by emulsion solvent evaporation method. These nanoparticles were characterized by photon correlation spectroscopy (PCS), transmission electron microscopy (TEM). Zeta potential study was also performed to understand the surface charge of nanoparticles. The drug release from drug loaded nanoparticles was studied by dialysis bag method and the in vitro drug release data was also studied by various kinetic models. The results show that sonication time, polymer content, surfactant concentration, ratio of organic to aqueous phase volume, and the amount of drug have an important effect on the size of nanoparticles. Hopefully we produced spherical shape Diazepam loaded PLGA nanoparticles with a size range under 250 nm with zeta potential -23.3 mV. The in vitro drug release analysis shows sustained release of drug from nanoparticles and follow Korsmeyer-Peppas model.

  7. Fucoxanthin bioavailability from fucoxanthin-fortified milk: In vivo and in vitro study.

    Science.gov (United States)

    Mok, Il-Kyoon; Lee, Jae Kwon; Kim, Jeong Hwa; Pan, Cheol-Ho; Kim, Sang Min

    2018-08-30

    Our previous study reported the improved stability of fucoxanthin (FX) fortified in whole milk (WM) and skimmed milk (SM). In this study, in vivo and in vitro FX bioavailability were investigated using FX-fortified milk (FX-SM and FX-WM) and microalga Phaeodactylum tricornutum biomass (Pt-powder). Organ tissue accumulation of FX and its metabolites (FXOH: fucoxanthinol, AXA: amarouciaxanthin A) after repeated oral administration was in the following order: FX-SM > FX-WM > Pt-powder. In vivo pharmacokinetic study with a single oral administration also demonstrated that the absorption of FXOH and AXA was the highest for FX-SM. To reinforce the in vivo results, in vitro-simulated digestion and Caco-2 cell uptake assays were performed, which revealed that FX-SM showed the highest FX bioaccessibility (release from food matrices) and cellular uptake efficiency of FX and FXOH. In conclusion, skimmed milk was validated as an excellent food matrix for FX application in terms of stability and bioavailability. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. Prospective Study of the Relation between Landing Biomechanics and Jumper's Knee

    NARCIS (Netherlands)

    der Worp, H van; van der Does, H T D; Brink, M.S.; Zwerver, J.; Hijmans, J.M.

    The literature on the relation between jump biomechanics and jumper's knee indicates that a jump with horizontal displacement poses a threat for developing jumper's knee. Subjects with jumper's knee have been shown to display a stiff landing pattern characterized by a small range of motion. However,

  9. Tensile strength comparison between peroneus longus and hamstring tendons: A biomechanical study

    Directory of Open Access Journals (Sweden)

    Rudy

    2017-01-01

    Conclusion: The tensile strength of the peroneus longus tendon, which is similar to that of hamstring, gives information that both have the same biomechanic properties. Peroneus longus should not be used as a first option in ACL reconstruction, but may be used as an alternative donor in cases involving multiple instability that require more tendon donors in the reconstruction.

  10. Shoulder biomechanics

    Energy Technology Data Exchange (ETDEWEB)

    Lugo, Roberto; Kung, Peter; Ma, C. Benjamin [Sports Medicine and Shoulder Service, University of California, San Francisco, 500 Parnassus Avenue, MU 320W-0728 San Francisco, CA 914143 (United States)], E-mail: maben@orthosurg.ucsf.edu

    2008-10-15

    The biomechanics of the glenohumeral joint depend on the interaction of both static and dynamic-stabilizing structures. Static stabilizers include the bony anatomy, negative intra-articular pressure, the glenoid labrum, and the glenohumeral ligaments along with the joint capsule. The dynamic-stabilizing structures include the rotator cuff muscles and the other muscular structures surrounding the shoulder joint. The combined effect of these stabilizers is to support the multiple degrees of motion within the glenohumeral joint. The goal of this article is to review how these structures interact to provide optimal stability and how failure of some of these mechanisms can lead to shoulder joint pathology.

  11. Precision cut lung slices as an efficient tool for in vitro lung physio-pharmacotoxicology studies.

    Science.gov (United States)

    Morin, Jean-Paul; Baste, Jean-Marc; Gay, Arnaud; Crochemore, Clément; Corbière, Cécile; Monteil, Christelle

    2013-01-01

    1.We review the specific approaches for lung tissue slices preparation and incubation systems and the research application fields in which lung slices proved to be a very efficient alternative to animal experimentation for biomechanical, physiological, pharmacological and toxicological approaches. 2.Focus is made on air-liquid interface dynamic organ culture systems that allow direct tissue exposure to complex aerosol and that best mimic in vivo lung tissue physiology. 3.A compilation of research applications in the fields of vascular and airway reactivity, mucociliary transport, polyamine transport, xenobiotic biotransformation, chemicals toxicology and complex aerosols supports the concept that precision cut lung slices are a very efficient tool maintaining highly differentiated functions similar to in vivo lung organ when kept under dynamic organ culture. They also have been successfully used for lung gene transfer efficiency assessment, for lung viral infection efficiency assessment, for studies of tissue preservation media and tissue post-conditioning to optimize lung tissue viability before grafting. 4.Taken all together, the reviewed studies point to a great interest for precision cut lung slices as an efficient and valuable alternative to in vivo lung organ experimentation.

  12. Biomechanical forces promote embryonic haematopoiesis

    Science.gov (United States)

    Adamo, Luigi; Naveiras, Olaia; Wenzel, Pamela L.; McKinney-Freeman, Shannon; Mack, Peter J.; Gracia-Sancho, Jorge; Suchy-Dicey, Astrid; Yoshimoto, Momoko; Lensch, M. William; Yoder, Mervin C.; García-Cardeña, Guillermo; Daley, George Q.

    2009-01-01

    Biomechanical forces are emerging as critical regulators of embryogenesis, particularly in the developing cardiovascular system1,2. After initiation of the heartbeat in vertebrates, cells lining the ventral aspect of the dorsal aorta, the placental vessels, and the umbilical and vitelline arteries initiate expression of the transcription factor Runx1 (refs 3–5), a master regulator of haematopoiesis, and give rise to haematopoietic cells4. It remains unknown whether the biomechanical forces imposed on the vascular wall at this developmental stage act as a determinant of haematopoietic potential6. Here, using mouse embryonic stem cells differentiated in vitro, we show that fluid shear stress increases the expression of Runx1 in CD41+c-Kit+ haematopoietic progenitor cells7,concomitantly augmenting their haematopoietic colony-forming potential. Moreover, we find that shear stress increases haematopoietic colony-forming potential and expression of haematopoietic markers in the paraaortic splanchnopleura/aorta–gonads–mesonephros of mouse embryos and that abrogation of nitric oxide, a mediator of shear-stress-induced signalling8, compromises haematopoietic potential in vitro and in vivo. Collectively, these data reveal a critical role for biomechanical forces in haematopoietic development. PMID:19440194

  13. Laser-assisted cartilage reshaping: in vitro and in vivo animal studies

    Science.gov (United States)

    Wang, Zhi; Pankratov, Michail M.; Perrault, Donald F., Jr.; Shapshay, Stanley M.

    1995-05-01

    Correction of cartilaginous defects in the head and neck area remains a challenge for the surgeon. This study investigated a new technique for laser-assisted cartilage reshaping. The pulsed 1.44 micrometers Nd:YAG laser was used in vitro and in vivo experiments to irradiate cartilage to change it's shape without carbonization or vaporization of tissue. Two watts of average power in non contact manner was used to irradiate and reshape the cartilage. The extracted reshaped cartilage specimens underwent testing of elastic force with a computer assisted measurement system that recorded the changes in elastic force in the specimens from 1 hr to 11 days post-irradiation. An animal model of defective tracheal cartilage (collapsed tracheal wall) was created, allowed to heal for 6 weeks and then corrected endoscopically with the laser-assisted technique. The results of the in vitro and in vivo investigations demonstrated that it was possible to alter the cartilage and that cartilage would retain its new shape. The clinical significance of the technique is evident and warrants further animal studies and clinical trials.

  14. Limited Interactions between Streptococcus Suis and Haemophilus Parasuis in In Vitro Co-Infection Studies

    Directory of Open Access Journals (Sweden)

    Annabelle Mathieu-Denoncourt

    2018-01-01

    Full Text Available Streptococcus suis and Haemophilus parasuis are normal inhabitants of the porcine upper respiratory tract but are also among the most frequent causes of disease in weaned piglets worldwide, causing inflammatory diseases such as septicemia, meningitis and pneumonia. Using an in vitro model of infection with tracheal epithelial cells or primary alveolar macrophages (PAMs, it was possible to determine the interaction between S. suis serotype 2 and H. parasuis strains with different level of virulence. Within H. parasuis strains, the low-virulence F9 strain showed higher adhesion levels to respiratory epithelial cells and greater association levels to PAMs than the high-virulence Nagasaki strain. Accordingly, the low-virulence F9 strain induced, in general, higher levels of pro-inflammatory cytokines than the virulent Nagasaki strain from both cell types. In general, S. suis adhesion levels to respiratory epithelial cells were similar to H. parasuis Nagasaki strain. Yet, S. suis strains induced a significantly lower level of pro-inflammatory cytokine expression from epithelial cells and PAMs than those observed with both H. parasuis strains. Finally, this study has shown that, overall and under the conditions used in the present study, S. suis and H. parasuis have limited in vitro interactions between them and use probably different host receptors, regardless to their level of virulence.

  15. More Realistic Face Model Surface Improves Relevance of Pediatric In-Vitro Aerosol Studies.

    Science.gov (United States)

    Amirav, Israel; Halamish, Asaf; Gorenberg, Miguel; Omar, Hamza; Newhouse, Michael T

    2015-01-01

    Various hard face models are commonly used to evaluate the efficiency of aerosol face masks. Softer more realistic "face" surface materials, like skin, deform upon mask application and should provide more relevant in-vitro tests. Studies that simultaneously take into consideration many of the factors characteristic of the in vivo face are lacking. These include airways, various application forces, comparison of various devices, comparison with a hard-surface model and use of a more representative model face based on large numbers of actual faces. To compare mask to "face" seal and aerosol delivery of two pediatric masks using a soft vs. a hard, appropriately representative, pediatric face model under various applied forces. Two identical face models and upper airways replicas were constructed, the only difference being the suppleness and compressibility of the surface layer of the "face." Integrity of the seal and aerosol delivery of two different masks [AeroChamber (AC) and SootherMask (SM)] were compared using a breath simulator, filter collection and realistic applied forces. The soft "face" significantly increased the delivery efficiency and the sealing characteristics of both masks. Aerosol delivery with the soft "face" was significantly greater for the SM compared to the AC (pmasks was observed with the hard "face." The material and pliability of the model "face" surface has a significant influence on both the seal and delivery efficiency of face masks. This finding should be taken into account during in-vitro aerosol studies.

  16. Limited Interactions between Streptococcus Suis and Haemophilus Parasuis in In Vitro Co-Infection Studies

    Science.gov (United States)

    Mathieu-Denoncourt, Annabelle; Letendre, Corinne; Auger, Jean-Philippe; Segura, Mariela; Aragon, Virginia; Lacouture, Sonia; Gottschalk, Marcelo

    2018-01-01

    Streptococcus suis and Haemophilus parasuis are normal inhabitants of the porcine upper respiratory tract but are also among the most frequent causes of disease in weaned piglets worldwide, causing inflammatory diseases such as septicemia, meningitis and pneumonia. Using an in vitro model of infection with tracheal epithelial cells or primary alveolar macrophages (PAMs), it was possible to determine the interaction between S. suis serotype 2 and H. parasuis strains with different level of virulence. Within H. parasuis strains, the low-virulence F9 strain showed higher adhesion levels to respiratory epithelial cells and greater association levels to PAMs than the high-virulence Nagasaki strain. Accordingly, the low-virulence F9 strain induced, in general, higher levels of pro-inflammatory cytokines than the virulent Nagasaki strain from both cell types. In general, S. suis adhesion levels to respiratory epithelial cells were similar to H. parasuis Nagasaki strain. Yet, S. suis strains induced a significantly lower level of pro-inflammatory cytokine expression from epithelial cells and PAMs than those observed with both H. parasuis strains. Finally, this study has shown that, overall and under the conditions used in the present study, S. suis and H. parasuis have limited in vitro interactions between them and use probably different host receptors, regardless to their level of virulence. PMID:29316613

  17. Corneal wound healing promoted by 3 blood derivatives: an in vitro and in vivo comparative study.

    Science.gov (United States)

    Freire, Vanesa; Andollo, Noelia; Etxebarria, Jaime; Hernáez-Moya, Raquel; Durán, Juan A; Morales, María-Celia

    2014-06-01

    The aim of this study was to compare the effect on corneal wound healing of 3 differently manufactured blood derivatives [autologous serum (AS), platelet-rich plasma, and serum derived from plasma rich in growth factors (s-PRGF)]. Scratch wound-healing assays were performed on rabbit primary corneal epithelial cultures and human corneal epithelial cells. Additionally, mechanical debridement of rabbit corneal epithelium was performed. Wound-healing progression was assessed by measuring the denuded areas remaining over time after treatment with each of the 3 blood derivatives or a control treatment. In vitro data show statistically significant differences in the healing process with all the derivatives compared with the control, but 2 of them (AS and s-PRGF) induced markedly faster wound healing. In contrast, although the mean time required to complete in vivo reepithelization was similar to that of AS and s-PRGF treatment, only wounds treated with s-PRGF were significantly smaller in size from 2.5 days onward with respect to the control treatment. All 3 blood derivatives studied are promoters of corneal reepithelization. However, the corneal wound-healing progresses differently with each derivative, being faster in vitro under AS and s-PRGF treatment and producing in vivo the greatest decrease in wound size under s-PRGF treatment. These findings highlight that the manufacturing process of the blood derivatives may modulate the efficacy of the final product.

  18. Antimicrobial activity Study of triclosan-loaded WBPU on Proteus mirabilis in vitro.

    Science.gov (United States)

    Tian, Ye; Jian, Zhongyu; Wang, Jianzhong; He, Wei; Liu, Qinyu; Wang, Kunjie; Li, Hong; Tan, Hong

    2017-04-01

    To evaluate the antimicrobial activity study of triclosan-loaded waterborne polyurethanes (WBPU) on Proteus mirabilis in vitro. Inhibition zone assays on petri plates with triclosan-loaded WBPU samples were used to test its antimicrobial activity on Proteus mirabilis. Models of the catheterized bladder supplied with artificial urine infected with Proteus mirabilis were employed to confirm the antimicrobial activity of triclosan-loaded WBPU. Bacteria colony counting, pH of the residual urine at each time point and catheter blockage time were recorded. Confocal laser scanning microscopy, scanning electron microscopy and encrustation deposits dry weighing were used for evaluating the biofilm formation. Inhibition zones formed in the triclosan-loaded WBPU groups in a dose-response manner (the radius for samples with 1, 0.1 and 0.01 mg triclosan were 9.93 ± 1.08, 6.07 ± 0.54 and 2.47 ± 0.25 mm, P Proteus mirabilis biofilm formation (33.9 ± 13.9 mg vs. 1.4 ± 1.5 mg, P = 0.016). Triclosan-loaded WBPU significantly inhibited Proteus mirabilis' growth and biofilm formation, indicating the promising antibacterial effects on Proteus mirabilis in vitro. Further efforts are under way that involves coating the material onto the urinary catheters and in vivo studies.

  19. Visualisation to enhance biomechanical tuning of ankle-foot orthoses (AFOs in stroke: study protocol for a randomised controlled trial

    Directory of Open Access Journals (Sweden)

    Carse Bruce

    2011-12-01

    Full Text Available Abstract Background There are a number of gaps in the evidence base for the use of ankle-foot orthoses for stroke patients. Three dimensional motion analysis offers an ideal method for objectively obtaining biomechanical gait data from stroke patients, however there are a number of major barriers to its use in routine clinical practice. One significant problem is the way in which the biomechanical data generated by these systems is presented. Through the careful design of bespoke biomechanical visualisation software it may be possible to present such data in novel ways to improve clinical decision making, track progress and increase patient understanding in the context of ankle-foot orthosis tuning. Methods A single-blind randomised controlled trial will be used to compare the use of biomechanical visualisation software in ankle-foot orthosis tuning against standard care (tuning using observation alone. Participants (n = 70 will have experienced a recent hemiplegia (1-12 months and will be identified by their care team as being suitable candidates for a rigid ankle-foot orthosis. The primary outcome measure will be walking velocity. Secondary outcome measures include; lower limb joint kinematics (thigh and shank global orientations & kinetics (knee and hip flexion/extension moments, ground reaction force FZ2 peak magnitude, step length, symmetry ratio based on step length, Modified Ashworth Scale, Modified Rivermead Mobility Index and EuroQol (EQ-5D. Additional qualitative measures will also be taken from participants (patients and clinicians at the beginning and end of their participation in the study. The main aim of the study is to determine whether or not the visualisation of biomechanical data can be used to improve the outcomes of tuning ankle-foot orthoses for stroke patients. Discussion In addition to answering the primary research question the broad range of measures that will be taken during this study are likely to contribute to a

  20. A BIOMECHANICAL STUDY OF LATERAL RELEASE AND ELMSLIE-TRILLAT PROCEDURES TO RESTABILISETHE MALTRACKTNG PATELLA

    Directory of Open Access Journals (Sweden)

    MM. Tahmasbi

    1999-09-01

    Full Text Available  The resistant* of pateSa against lateral displacement (Le. the stability, was studied tinder a range of conditions in vitro, at a range of knee flexion angles. Muscle forces were applied in physiological directions along the separate quadriceps muscles. Normal muscle actions with constant tension showed constant patellar stability up to sixty degrees knee flexion, and then a significant increase at ninety degrees. A pathological knee was simulated by relaxing vastus medians, and ■ lateral stability then dropped by 47%. Isolated rttlnaeular release in the pathological knee did not improve stability significantly towards normal, while 6mm tibial tubercle medlaEsatum restored stabtBty by 52% towards normal, except neat JuM extension. Combined release phis tubercle medtafisathm. restored stability 59% towards normal In knee flexion, and 23% up to ten degrees flexion.

  1. [A complex study of the movement biomechanics in patients with post-stroke hemiparesis].

    Science.gov (United States)

    Skvortsov, D V; Bulatova, M A; Kovrazhkina, E A; Suvorov, A Iu; Ivanova, G E; Skvortsova, V I

    2012-01-01

    The authors present results of a pilot study on biomechanics of non-cyclic movements of the human consequent verticalization in the ontogenesis of patients with post-stroke hemiparesis (10 patients in the acute stage of cerebral stroke) and 10 healthy volunteers without neurologic and orthopedic pathology. Some movements of therapeutic exercises Balance (a model of ontogenetic kinesitherapy) have been selected for the study. Cinematic parameters have been recorded using a system of motion 3D video analysis, a kinematic model was build in accordance to standard protocols. The skin (native and straightened) electromyogram (EMG) was recorded synchronously with kinematic data using 16-channel electromyography from the following pairs of muscles: mm. sternocleido-mastoideus, trapezius (горизонтальная порция), biceps brachii, triceps brachii, rectus femoris, adductor magnus. Major differences in the EMG picture between patients and controls were: 1) the EMG "monotony" with the involvement of multiple additional muscles in locomotions with the prevalence of the peculiar "tonic" muscle activity (low amplitudes without distinct peaks), stretching along the whole cycle of movement. In controls, EMG demonstrated variability and had mostly "phasic" character with distinct 1 or 2 peaks; 2) the asymmetry of EMG profile in symmetric movements. i.e. when performed simultaneously from the right and from the left sides. The latter feature may be considered as predictive because it was never found in healthy people. It allows to identify objectively weak muscles even in the absence of visible parethis during the routine neurological examination.

  2. The Posterior Bundle's Effect on Posteromedial Elbow Instability After a Transverse Coronoid Fracture: A Biomechanical Study.

    Science.gov (United States)

    Shukla, Dave R; Golan, Elan; Weiser, Mitch C; Nasser, Philip; Choueka, Jack; Hausman, Michael

    2018-04-01

    There has been increased interest in the role of the posterior bundle of the medial collateral ligament (pMUCL) in the elbow, particularly its effects on posteromedial rotatory stability. The ligament's effect in the context of an unfixable coronoid fracture has not been the focus of any study. The purposes of this biomechanical study were to evaluate the stabilizing effect of the pMUCL with a transverse coronoid fracture and to assess the effect of graft reconstruction of the ligament. We simulated a varus and internal rotatory subluxation in 7 cadaveric elbows at 30°, 60°, and 90° elbow flexion. The amount of ulnar rotation and medial ulnohumeral joint gapping were assessed in the intact elbow after we created a transverse coronoid injury, after we divided the pMUCL, and finally, after we performed a graft reconstruction of the pMUCL. At all angles tested, some stability was lost after cutting the pMUCL once the coronoid had been injured, because mean proximal ulnohumeral joint gapping increased afterward by 2.1, 2.2, and 1.3 mm at 90°, 60°, and 30°, respectively. Ulnar internal rotation significantly increased after pMUCL transection at 90°. At 60° and 30° elbow flexion, ulnar rotation increased after resection of the coronoid but not after pMUCL resection. An uninjured pMUCL stabilizes against varus internal rotatory instability in the setting of a transverse coronoid fracture at higher flexion angles. Further research is needed to optimize graft reconstruction of the pMUCL. The pMUCL is an important secondary stabilizer against posteromedial instability in the coronoid-deficient elbow. In the setting of an unfixable coronoid fracture, the surgeon should examine for posteromedial instability and consider addressing the pMUCL surgically. Copyright © 2018 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  3. Correlation of In Vivo Versus In Vitro Benchmark Doses (BMDs) Derived From Micronucleus Test Data: A Proof of Concept Study.

    Science.gov (United States)

    Soeteman-Hernández, Lya G; Fellows, Mick D; Johnson, George E; Slob, Wout

    2015-12-01

    In this study, we explored the applicability of using in vitro micronucleus (MN) data from human lymphoblastoid TK6 cells to derive in vivo genotoxicity potency information. Nineteen chemicals covering a broad spectrum of genotoxic modes of action were tested in an in vitro MN test using TK6 cells using the same study protocol. Several of these chemicals were considered to need metabolic activation, and these were administered in the presence of S9. The Benchmark dose (BMD) approach was applied using the dose-response modeling program PROAST to estimate the genotoxic potency from the in vitro data. The resulting in vitro BMDs were compared with previously derived BMDs from in vivo MN and carcinogenicity studies. A proportional correlation was observed between the BMDs from the in vitro MN and the BMDs from the in vivo MN assays. Further, a clear correlation was found between the BMDs from in vitro MN and the associated BMDs for malignant tumors. Although these results are based on only 19 compounds, they show that genotoxicity potencies estimated from in vitro tests may result in useful information regarding in vivo genotoxic potency, as well as expected cancer potency. Extension of the number of compounds and further investigation of metabolic activation (S9) and of other toxicokinetic factors would be needed to validate our initial conclusions. However, this initial work suggests that this approach could be used for in vitro to in vivo extrapolations which would support the reduction of animals used in research (3Rs: replacement, reduction, and refinement). © The Author 2015. Published by Oxford University Press on behalf of the Society of Toxicology.

  4. Properties of an interspinous fixation device (ISD) in lumbar fusion constructs: a biomechanical study.

    Science.gov (United States)

    Techy, Fernando; Mageswaran, Prasath; Colbrunn, Robb W; Bonner, Tara F; McLain, Robert F

    2013-05-01

    Segmental fixation improves fusion rates and promotes patient mobility by controlling instability after lumbar surgery. Efforts to obtain stability using less invasive techniques have lead to the advent of new implants and constructs. A new interspinous fixation device (ISD) has been introduced as a minimally invasive method of stabilizing two adjacent interspinous processes by augmenting an interbody cage in transforaminal interbody fusion. The ISD is intended to replace the standard pedicle screw instrumentation used for posterior fixation. The purpose of this study is to compare the rigidity of these implant systems when supplementing an interbody cage as used in transforaminal lumbar interbody fusion. An in vitro human cadaveric biomechanical study. Seven human cadaver spines (T12 to the sacrum) were mounted in a custom-designed testing apparatus, for biomechanical testing using a multiaxial robotic system. A comparison of segmental stiffness was carried out among five conditions: intact spine control; interbody spacer (IBS), alone; interbody cage with ISD; IBS, ISD, and unilateral pedicle screws (unilat); and IBS, with bilateral pedicle screws (bilat). An industrial robot (KUKA, GmbH, Augsburg, Germany) applied a pure moment (±5 Nm) in flexion-extension (FE), lateral bending (LB), and axial rotation (AR) through an anchor to the T12 vertebral body. The relative vertebral motion was captured using an optoelectronic camera system (Optotrak; Northern Digital, Inc., Waterloo, Ontario, Canada). The load sensor and the camera were synchronized. Maximum rotation was measured at each level and compared with the intact control. Implant constructs were compared with the control and with each other. A statistical analysis was performed using analysis of variance. A comparison between the intact spine and the IBS group showed no significant difference in the range of motion (ROM) in FE, LB, or AR for the operated level, L3-L4. After implantation of the ISD to augment

  5. Engineering Tocopherol Selectivity in α-TTP: A Combined In Vitro/In Silico Study

    Science.gov (United States)

    Helbling, Rachel E.; Aeschimann, Walter; Simona, Fabio; Stocker, Achim; Cascella, Michele

    2012-01-01

    We present a combined in vitro/in silico study to determine the molecular origin of the selectivity of -tocopherol transfer protein (-TTP) towards -tocopherol. Molecular dynamics simulations combined to free energy perturbation calculations predict a binding free energy for -tocopherol to -TTP 8.262.13 kcal mol lower than that of -tocopherol. Our calculations show that -tocopherol binds to -TTP in a significantly distorted geometry as compared to that of the natural ligand. Variations in the hydration of the binding pocket and in the protein structure are found as well. We propose a mutation, A156L, which significantly modifies the selectivity properties of -TTP towards the two tocopherols. In particular, our simulations predict that A156L binds preferentially to -tocopherol, with striking structural similarities to the wild-type--tocopherol complex. The affinity properties are confirmed by differential scanning fluorimetry as well as in vitro competitive binding assays. Our data indicate that residue A156 is at a critical position for determination of the selectivity of -TTP. The engineering of TTP mutants with modulating binding properties can have potential impact at industrial level for easier purification of single tocopherols from vitamin E mixtures coming from natural oils or synthetic processes. Moreover, the identification of a -tocopherol selective TTP offers the possibility to challenge the hypotheses for the evolutionary development of a mechanism for -tocopherol selection in omnivorous animals. PMID:23152872

  6. Nickel levels in convenience and fast foods: In vitro study of the dialyzable fraction

    International Nuclear Information System (INIS)

    Cabrera-Vique, Carmen; Mesias, Marta; Bouzas, Paula R.

    2011-01-01

    Nickel presence was determined in 170 samples of 43 different convenience and fast foods widely consumed in Spain. Electrothermal atomic absorption spectrometry was used as analytical technique. Reliability of the procedure was checked. Ni levels ranged from 18.50 to 95.00 ng g -1 (fresh weight of edible portion). The most elevated Ni concentrations were found in egg- and pork-based foods and in sauces but there is a high variability inside of each one of these foods. Ni content increases in products that contain spices and aromatic herbs, whole cereals, dry fruits, cheese and mushrooms. Mean Ni dialyzable fraction estimated by in vitro assays ranged from 4.50 to 7.75%. This study shows that the probability of exposure to health risks from these foods is overall small. However, the present findings are of potential use in food composition tables and to estimate the Ni dietary intake and tolerable intake levels in accordance with the current dietary habits. - Research highlights: →Ni levels in convenience and fast food range from 18.50 to 95.00 ng/g. →Ni content increases in products that contain spices and aromatic herbs, whole cereals, dry fruits, cheese and mushrooms. →Mean Ni dialyzable fraction estimated by in vitro assays ranges from 4.50 to 7.75%. →The probability of exposure to health risks from convenience and fast food is overall small.

  7. Proposal of a high dose rate brachytherapy model for in vitro radiobiology studies

    International Nuclear Information System (INIS)

    Geraldo, Jony M.; Nogueira, Luciana B.; Andrade, Lidia M.; Trindade, Cassia; Furtado, Clascidia A.; Ladeira, Luiz Orlando

    2016-01-01

    The aim of this research was to develop an easy and reproducible approach for experimental HDR brachytherapy allowing in vitro irradiation studies based on clinical parameters. An acrylic platform was designed to attach T25 tissue culture flasks and multi-well tissue culture plates as well as kept the catheters in a fixed position during irradiation. CT images were taken and the irradiation was planned for 550cGy dose applied on adherent tumor cells. Dosimetric measurements were done and all relevant uncertainties were taken into account in order to figure out the correct dose range received by the cells. Tumor cells were irradiated two times over an interval of 24h between irradiations. Proof of concepts of this approach was carried out by biological effects analysis using a radioresistant human epidermoid carcinoma A431 cell line. Cellular proliferation and cell cycle phase were assessed by Trypan blue exclusion assay and DNA content analysis by flow cytometry, respectively. This approach allowed uniform dose distribution around the arrangement in all types of tissue culture plastics evaluated. Corrections due to uncertainties were managed. Regarding in vitro assays there was a significant (p<0.05) decreasing of cellular proliferation rate in irradiated cells. Moreover, increased percentage of cells arrested in G2/M phase (32.3 ± 1.5%) were observed for treated group compared with untreated cells. (author)

  8. Preliminary results on in vitro mutagenesis studies on Lansium domesticum Corr

    International Nuclear Information System (INIS)

    Mohd Nazir Basiran; Shuhaimi Shamsuddin; Sakinah Ariffin

    2000-01-01

    Dokong (Lansium domesticum Corr.) which belongs to the family Meliaceae is an important fruit trees for the Malaysian fruit industry. Despite the various types that have been identified, the genetic variability is still too narrow for meaningful breeding efforts. Dokong also has long juvenility period and the fruits are pathenocarpically developed. The fruits are often not uniform in size, the tree is prone to bark borers, and the tree architecture needs a lot of pruning for better fruit formation and facilitate easier harvesting. A lot of breeding efforts is needed to improve the genetic characteristics of this species before it can really have an industrial impact. Induced mutation and in vitro culture are two approaches which may be more efficient for genetic improvement. Results of radiosensitivity studies showed that irradiation doses between 50 and 70 Gy is effective enough to induced mutations in seeds. Initial attempts to develop in vitro cultures of Lansium showed that shoot-tips and axillary buds can be cultured to produce plantlets in a medium containing 3 mg/L kinetin and 4 mg/L indoleacetic acid. The procedures can be optimised to develop an efficient micropropagation system. However, attempts to initiate callus cultures have not been successful

  9. Transcription factor Runx2 knockdown regulates colon cancer transplantation tumor growth in vitro: an experimental study

    Directory of Open Access Journals (Sweden)

    Bin Xu1

    2017-05-01

    Full Text Available Objective: To study the effect of transcription factor Runx2 knockdown on colon cancer transplantation tumor growth in vitro. Methods: Colon cancer cell lines HT29 were cultured and transfected with negative control (NC - shRNA plasmids and Runx2-shRNA plasmids respectively, the colon cancer cells transfected with shRNA were subcutaneously injected into C57 nude mice, and they were included in NC group and Runx2 knockdown group respectively. 1 week, 2 weeks and 3 weeks after model establishment, serum was collected to determine the contents of tumor markers, and tumor lesions were collected to determine proliferation and apoptosis gene expression. Results: CCSA-2, CEA and CA19-9 levels in serum as well as Rac1, Wnt3a, PLD2 and FAM96B protein expression in transplantation tumor lesions of Runx2 knockdown group were significantly lower than those of NC group while MS4A12, ASPP2 and Fas protein expression in transplantation tumor lesions of Runx2 knockdown group were significantly higher than those of NC group. Conclusion: Transcription factor Runx2 knockdown could inhibit the colon cancer transplantation tumor growth in vitro.

  10. In vitro disintegration studies of weekly generic alendronate sodium tablets (70 mg) available in the US.

    Science.gov (United States)

    Dansereau, Richard J; Crail, Debbie J; Perkins, Alan C

    2009-02-01

    Bisphosphonates as a class have the potential to cause upper gastrointestinal irritation. Although the generic alendronate sodium tablets are bioequivalent to the branded product, a potential concern is that the pharmaceutical attributes of the various generic formulations my affect the potential for local irritation and tolerability. The in vitro disintegration times were determined using the method described in the US Pharmacopeia 30 (USP 30). The disintegration of three generic alendronate sodium tablets 70 mg available in the United States was compared to that of the branded product. The mean disintegration times of the generic alendronate sodium tablets ranged from 9 to 10 s for the Barr lots to 108 s for the Watson lot. The disintegration time of the branded product (Fosamax) was 53 s. The three Barr lots and one Teva lot had rapid disintegration times which were similar to the disintegration standards (disintegrating tablets. Since there is no established disintegration time for alendronate sodium tablets there can be no assurance that the generic tablets are equivalent to the branded product in terms of esophageal exposure. However, the in vitro disintegration times have not been correlated with in vivo disintegration performance. Copies of generic alendronate sodium tablets are approved based on the results of single-dose bioavailability studies in healthy subjects and this is not considered adequate to establish similar disintegration characteristics.

  11. Antimicrobial photodynamic therapy with two photosensitizers on two oral streptococci: an in vitro study

    Science.gov (United States)

    Vahabi, S.; Fekrazad, R.; Ayremlou, S.; Taheri, S.; Lizarelli, R. F. Z.; Kalhori, K. A. M.

    2011-12-01

    Periodontal diseases are caused by infection of tissues supporting the teeth due to complex aggregate of bacteria known as biofilm and firstly colonized by streptococci. The aim of this in vitro study was to evaluate the effect of Radachlorin® and Toluidine Blue O (TBO)-mediated photodynamic therapy (PDT) on the viability of two oral streptococci. Bacterial suspensions of Streptococcus mutans and Streptococcus sanguis were subjected to either TBO or Radachlorin®, Then exposed to two different diode laser light at energy densities of 3, 6 J/cm2 at 633 nm and 6, 12 J/cm2 at 662 nm, respectively. The control groups were subjected to laser light alone, photosensitizer alone or received neither photosensitizer nor light exposure. The suspensions were then spread over specific agar mediums and viable microorganisms were counted after overnight incubation aerobically at 37°C, 5% CO2 and then reported as colony forming unit. The results indicated that photosensitization by the energy density of 6 J/cm2 with Radachlorin® and both 3 and 6 J/cm2 with TBO caused significant reduction in bacterial colony formation ( p < 0.05). Radachlorin® and TBO-mediated photodynamic therapy seem to show excellent potential in significantly killing of two oral streptococci in vitro.

  12. 20(S-Protopanaxadiol Phospholipid Complex: Process Optimization, Characterization, In Vitro Dissolution and Molecular Docking Studies

    Directory of Open Access Journals (Sweden)

    Yiqiong Pu

    2016-10-01

    Full Text Available 20(S-Protopanaxadiol (PPD, a bioactive compound extracted from ginseng, possesses cardioprotective, neuroprotective, anti-inflammatory, antiestrogenic, anticancer and anxiolytic effects. However, the clinical application of PPD is limited by its weak aqueous solubility. In this study, we optimized an efficient method of preparing its phospholipid complex (PPD-PLC using a central composite design and response surface analysis. The prepared PPD-PLC was characterized by differential scanning calorimetric, powder X-ray diffraction, Fourier-transformed infrared spectroscopy and nuclear magnetic resonance analyses associated with molecular docking calculation. The equilibrium solubility of PPD-PLC in water and n-octanol increased 6.53- and 1.53-times, respectively. Afterwards, using PPD-PLC as the intermediate, the PPD-PLC-loaded dry suspension (PPD-PLC-SU was prepared with our previous method. In vitro evaluations were conducted on PPD-PLC and PPD-PLC-SU, including dissolution behaviors and stability properties under different conditions. Results of in vitro dissolution behavior revealed the improved dissolution extents and rates of PPD-PLC and PPD-PLC-SU (p < 0.05. Results of the formulation stability investigation also exposed the better stability of PPD-PLC-SU compared with free PPD. Therefore, phospholipid complex technology is a useful formulation strategy for BCS II drugs, as it could effectively improve their hydrophilicity and lipophilicity.

  13. Studies of leukemogenesis by means of in vitro CA membrane method

    International Nuclear Information System (INIS)

    Seki, Masatoshi; Yoshida, Kazuko; Shimizu, Shizuko; Nishimura, Mayumi

    1978-01-01

    A new method of hematopoietic colony formation in vitro with macrophage-fibroblast (M-F) layer, which forms on cellulose acetate membrane in the peritoneal cavity of mouse, has been developed in this laboratory. Granuloid colonies develop in M-F layer without any external colony stimulating factors. Clear dose-response relationship between the number of seeded bone marrow cells and the colony counts has been obtained. Erythroid colonies can develop too, only when Erythropoietin is added in culture medium. With this method, the kinetics of granulopoiesis was studied. Granuloid cell line is consisted from two compartments, i.e. proliferative and maturative compartment. The presence of some unknown regulatory mechanism between those compartments has been suggested. In leukemia, the influx of promyclocyte, an element of proliferative compartment, into maturative compartment is inhibited to various extent, so that tremendous enlargement of the former takes place. M-F layer is proved to play an active role on the production and transfer of leukemic virus. Leukemic stem cells capable of forming clusters in conventional semisolid cultures make the well-developed colonies in M-F layer in vitro. (author)

  14. Nickel levels in convenience and fast foods: In vitro study of the dialyzable fraction

    Energy Technology Data Exchange (ETDEWEB)

    Cabrera-Vique, Carmen, E-mail: carmenc@ugr.es [Department of Nutrition and Bromatology, University of Granada, Granada (Spain); Mesias, Marta [Department of Nutrition and Bromatology, University of Granada, Granada (Spain); Bouzas, Paula R. [Department of Statistic, University of Granada, Granada (Spain)

    2011-03-15

    Nickel presence was determined in 170 samples of 43 different convenience and fast foods widely consumed in Spain. Electrothermal atomic absorption spectrometry was used as analytical technique. Reliability of the procedure was checked. Ni levels ranged from 18.50 to 95.00 ng g{sup -1} (fresh weight of edible portion). The most elevated Ni concentrations were found in egg- and pork-based foods and in sauces but there is a high variability inside of each one of these foods. Ni content increases in products that contain spices and aromatic herbs, whole cereals, dry fruits, cheese and mushrooms. Mean Ni dialyzable fraction estimated by in vitro assays ranged from 4.50 to 7.75%. This study shows that the probability of exposure to health risks from these foods is overall small. However, the present findings are of potential use in food composition tables and to estimate the Ni dietary intake and tolerable intake levels in accordance with the current dietary habits. - Research highlights: {yields}Ni levels in convenience and fast food range from 18.50 to 95.00 ng/g. {yields}Ni content increases in products that contain spices and aromatic herbs, whole cereals, dry fruits, cheese and mushrooms. {yields}Mean Ni dialyzable fraction estimated by in vitro assays ranges from 4.50 to 7.75%. {yields}The probability of exposure to health risks from convenience and fast food is overall small.

  15. Analytical study of avian reticuloendotheliosis virus dimeric RNA generated in vivo and in vitro.

    Science.gov (United States)

    Darlix, J L; Gabus, C; Allain, B

    1992-12-01

    The retroviral genome consists of two identical RNA molecules associated at their 5' ends by a stable structure called the dimer linkage structure. The dimer linkage structure, while maintaining the dimer state of the retroviral genome, might also be involved in packaging and reverse transcription, as well as recombination during proviral DNA synthesis. To study the dimer structure of the retroviral genome and the mechanism of dimerization, we analyzed features of the dimeric genome of reticuloendotheliosis virus (REV) type A and identified elements required for its dimerization. Here we report that the REV dimeric genome extracted from virions and infected cells, as well as that synthesized in vitro, is more resistant to heat denaturation than avian sarcoma and leukemia virus, murine leukemia virus, or human immunodeficiency virus type 1 dimeric RNA. The minimal domain required to form a stable REV RNA dimer in vitro was found to map between positions 268 and 452 (KpnI and SalI sites), thus corresponding to the E encapsidation sequence (J. E. Embretson and H. M. Temin, J. Virol. 61:2675-2683, 1987). In addition, both the 5' and 3' halves of E are necessary in cis for RNA dimerization and the extent of RNA dimerization is influenced by viral sequences flanking E. Rapid and efficient dimerization of REV RNA containing gag sequences in addition to the E sequences and annealing of replication primer tRNA(Pro) to the primer-binding site necessitate the nucleocapsid protein.

  16. Bevacizumab loaded solid lipid nanoparticles prepared by the coacervation technique: preliminary in vitro studies

    Science.gov (United States)

    Battaglia, Luigi; Gallarate, Marina; Peira, Elena; Chirio, Daniela; Solazzi, Ilaria; Giordano, Susanna Marzia Adele; Gigliotti, Casimiro Luca; Riganti, Chiara; Dianzani, Chiara

    2015-06-01

    Glioblastoma, the most common primary brain tumor in adults, has an inauspicious prognosis, given that overcoming the blood-brain barrier is the major obstacle to the pharmacological treatment of brain tumors. As neoangiogenesis plays a key role in glioblastoma growth, the US Food and Drug Administration approved bevacizumab (BVZ), an antivascular endothelial growth factor antibody for the treatment of recurrent glioblastoma in patients whose the initial therapy has failed. In this experimental work, BVZ was entrapped in solid lipid nanoparticles (SLNs) prepared by the fatty-acid coacervation technique, thanks to the formation of a hydrophobic ion pair. BVZ activity, which was evaluated by means of four different in vitro tests on HUVEC cells, increased by 100- to 200-fold when delivered in SLNs. Moreover, SLNs can enhance the permeation of fluorescently labelled BVZ through an hCMEC/D3 cell monolayer—an in vitro model of the blood brain barrier. These results are promising, even if further in vivo studies are required to evaluate the effective potential of BVZ-loaded SLNs in glioblastoma treatment.

  17. Mechanisms Underlying Cytotoxicity Induced by Engineered Nanomaterials: A Review of In Vitro Studies

    Science.gov (United States)

    Nogueira, Daniele R.; Mitjans, Montserrat; Rolim, Clarice M. B.; Vinardell, M. Pilar

    2014-01-01

    Engineered nanomaterials are emerging functional materials with technologically interesting properties and a wide range of promising applications, such as drug delivery devices, medical imaging and diagnostics, and various other industrial products. However, concerns have been expressed about the risks of such materials and whether they can cause adverse effects. Studies of the potential hazards of nanomaterials have been widely performed using cell models and a range of in vitro approaches. In the present review, we provide a comprehensive and critical literature overview on current in vitro toxicity test methods that have been applied to determine the mechanisms underlying the cytotoxic effects induced by the nanostructures. The small size, surface charge, hydrophobicity and high adsorption capacity of nanomaterial allow for specific interactions within cell membrane and subcellular organelles, which in turn could lead to cytotoxicity through a range of different mechanisms. Finally, aggregating the given information on the relationships of nanomaterial cytotoxic responses with an understanding of its structure and physicochemical properties may promote the design of biologically safe nanostructures. PMID:28344232

  18. Study On In Vitro Variation Generation Of Cymbidium Labell Anna Belle By Gamma Co-60 Irradiation

    International Nuclear Information System (INIS)

    Nguyen Huynh Phuong Uyen; Vo Thi Thu Ha; Le Quang Luan

    2011-01-01

    Radiation ionization is one of useful methods for mutation breeding of plants. In this study, γ-ray (Co-60) was used for generating morphological variations of Cymbidium Labell Anna Belle. The lethal doses of 50% samples (LD 50 ) after 4 months cultivation were determined at 35.0 Gy for protocorm like bodies (PLBs), 37.4 Gy for in vitro shoot bubs and 70.1 Gy for plantlets. PLBs were found as suitable samples for generation of variation of mentioned Cymbidium. The dose range from 20 to 50 Gy was determined with a high ability of variation on C. Labell Anna Belle. The highest frequency of variation was obtained ca. 3.82 x 10 -3 at the dose of 30 Gy. 157 in vitro variant plantlets were selected in M 1 V 1 generation, among variations, the variations were mainly found with 5 following types: removal of chlorophyll (8 plantlets), the leaves become shorter (64 plantlets), the leaves become longer (64 plantlets), increase of leaf number (11 plantlets) and the colour of pericardium was changed from green into violet (10 plantlets). Twenty one variant lines were selected in M 1 V 2 generation. (author)

  19. Ultrasound Mediated Microbubbles Destruction Augmented Sonolysis: An In Vitro and In Vivo Study

    Directory of Open Access Journals (Sweden)

    Hai Cui

    2017-01-01

    Full Text Available Objective. This study was aimed at exploring ultrasound mediated microbubbles destruction (UMMD assisted sonolysis in both the in vitro and in vivo clots. Methods. Therapeutic ultrasound (TUS and lipid microbubbles (MBs were used in whole blood clots and divided into the control, TUS group, and TUS + MB group. Thrombolytic rates and microscopy were performed. Color Doppler flow imaging (CDFI and angiography were performed to evaluate the recanalization rates and flow scores in femoral arterial thrombus (FAT in rabbits. FAT were dyed with H&E. Results. The average thrombolytic ratios of TUS + MB group were significantly higher than those of TUS group and the control group (both P<0.05. Clots had different pathological changes. Recanalization rates and flow scores in TUS + MB group were significantly higher than the control and TUS group. Flow scores and recanalization ratios were grade 0 in 0% of the control group, grade I in 25% of TUS group, and grade II or higher in 87.5% of TUS + MB group after 30 min sonolysis. Conclusions. Both the in vitro and in vivo sonolysis can be significantly augmented by the introduction of MBs without thrombolytic agents, which might be induced by the enhanced cavitation via UMMD.

  20. Factors influencing the tensile strength of repaired Achilles tendon: a biomechanical experiment study.

    Science.gov (United States)

    Jielile, Jiasharete; Bai, Jing Ping; Sabirhazi, Gulnur; Redat, Darebai; Yilihamu, Tuoheti; Xinlin, Baoltri; Hu, Geyang; Tang, Bin; Liang, Bing; Sun, Qi

    2010-10-01

    Operative treatment has been advocated as the method of choice to repair Achilles tendon rupture as surgery results in reduced re-rupture rate and faster rehabilitation. Many surgical techniques have been introduced allowing for postoperative early motion of the ankle joint. However, it is currently very difficult for surgeons to determine the optimal treatment conditions for ruptured Achilles tendon with an increasing number of end-to-end suture methods, suture materials, and epitenon suture techniques. In the present biomechanical experiment study based on an orthogonal design, thirty-two New Zealand white rabbits received Achilles tendon tenotomy and subsequent operative treatment to repair the tendon employing four end-to-end suture methods, four suture materials, and four epitenon suture techniques. The tensile strength of the repaired Achilles tendon was investigated at four rehabilitation periods, and in comparison with the results of another sixteen rabbits with normal Achilles tendons. The end-to-end suture method contributed most to the final Achilles tendon tensile strength in addition to rehabilitation period, with the highest values occurring with the use of the parachute-like ("Pa" bone) suture method. The other two factors, namely, suture material and epitenon suture technique, had relatively little influence on the results. The parachute-like ("Pa" bone) surgical technique is superior to the other three end-to-end suture methods, with enhanced tensile strength of the repaired tendon. This method allows for postoperative early kinesitherapy of the ankle and knee joints. Therefore, this technique is highly recommended in clinical situations for treatment of ruptured Achilles tendon. 2010 Elsevier Ltd. All rights reserved.

  1. The Protective Effect of Kevlar ® Socks Against Hockey Skate Blade Injuries: A Biomechanical Study

    Science.gov (United States)

    Nauth, Aaron; Aziz, Mina; Tsuji, Matthew; Whelan, Daniel B.; Theodoropoulos, John S.; Zdero, Rad

    2014-01-01

    Objectives: Several recent high profile injuries to elite players in the National Hockey League (NHL) secondary to skate blade lacerations have generated significant interest in these injuries and possible methods to protect against them. These injuries are typically due to direct contact of the skate blade of another player with posterior aspect of the calf resulting in a range of potential injuries to tendons or neurovascular structures. The Achilles tendon is most commonly involved. Kevlar® reinforced socks have recently become available for hockey players to wear and are cited as providing possible protection against such injuries. However, there has been no investigation of the possible protective effects of Kevlar® reinforced socks against skate blade injuries, and it is currently unknown what protective effects, if any, that these socks provide against these injuries. The proposed study sought to address this by conducting a biomechanical investigation of the protective effects of Kevlar® reinforced socks against Achilles tendon injuries in a simulated model of skate blade injury using human cadaver limbs. This novel investigation is the first to address the possible benefits to hockey players of wearing Kevlar® reinforced socks. Methods: Seven matched pairs of human cadaver lower limbs were fitted with a Kevlar ® reinforced sock comprised of 60% Kevlar®/20% Coolmax® polyester/18 % Nylon/12% Spandex (Bauer Elite Performance Skate Sock) on one limb and a standard synthetic sock comprised of 51% polyester/47% nylon/2% spandex (Bauer Premium Performance Skate Sock) on the contralateral limb as a control. Each limb was then mounted on a Materials Testing System (MTS) with the ankle dorsiflexed to 90° and the knee held in full extension using a custom designed jig. Specimens were then impacted with a hockey skate blade directed at the posterior calf, 12 cm above the heel, at an angle of 45° and a speed of 31m/s, to a penetration depth of 4.3 cm, to

  2. The biomechanics study of rabbit osteoporosis models treated by 99Tcm-MDP combined with GuKangLing

    International Nuclear Information System (INIS)

    Gao Kejia; Zhao Guoding; Ye Zhiwei; Mei Xiaogang; Tian Yingmin; Yan Chushun; Wang Wei; Li Wei; Cai Zhengyu; Song Haiping

    2011-01-01

    Objective: To study the bone biomechanics of the rabbit osteoporosis models induced by dexamethasone sodium phosphate injection (DX) using a combined treatment modality of 99 Tc-MDP and GuKangLing. Methods: Rabbits were intramuscularly injected with DX (2 mg/kg) twice a week for 6 weeks. The animal osteoporosis model group (Group C) and normal group (Group A) were compared to confirm the model was available. Another control group (Group B), the osteoporosis control group (Group D) were set for the comparison at the end of the experiment. The 99 Tc-MDP therapy group (Group E), GuKangLing therapy group (Group F) and 99 Tc-MDP plus GuKangLing therapy group (Group G) were included in the study. The treatment lasted for 16 weeks. The bone biomechanics, cytopathology bone histomorphology, bone mineral density (BMD), X-ray, CT, bone scintigraphy and serum bone alkaline phosphatase (BALP) and P (bone gla protein) were chosen as the markers or methods to evaluate the treatment results (excellent, effective and invalid). The analysis of variance (ANOVA) and t-test were used for group comparison analysis. Results: Cytopathology result indicated that there was no bone trabecular destruction in Group A. However, there was distinct bone destruction in Group C. The bone biomechanics (left femur head (265.914 ±52.773) N, L 4 (369.671 ±94.919) N), BMD (left femur (0.238 ±0.016) g/cm 2 , L 4 (0.236 ±0.016) g/cm 2 ) and bone histomorphology ((66.230 ± 10.848)%) in Group C reduced clearly as compared with Group A ((405.343±55.410) N, (750.870±53.718) N, (0.294±0.017) g/cm 2 , (0.302±0.023) g/cm 2 , (131.500 ± 21.846)%) (t ≥4.550, all P<0.01). Radionuclide bone scan also showed that the uptake of tracers was higher by the main arthrosis in Group C than that in Group A. Vertebra was not clearly visualized on bone scan image. There were significant differences between Group A and Group C in serum BALP and P ((45.000±7.303) vs (12.485 ±1.512) U/L, (0.168±0.018) vs (0.115

  3. In vitro drug interaction of levocetirizine and diclofenac: Theoretical and spectroscopic studies

    Science.gov (United States)

    Abo Dena, Ahmed S.; Abdel Gaber, Sara A.

    2017-06-01

    Levocetirizine dihydrochloride is known to interact with some anti-inflammatory drugs. We report here a comprehensive integrated theoretical and experimental study for the in vitro drug interaction between levocetirizine dihydrochloride (LEV) and diclofenac sodium (DIC). The interaction of the two drugs was confirmed by the molecular ion peak obtained from the mass spectrum of the product. Moreover, FTIR and 1HNMR spectra of the individual drugs and their interaction product were inspected to allocate the possible sites of interaction. In addition, quantum mechanical DFT calculations were performed to search for the interaction sites and to verify the types of interactions deduced from the spectroscopic studies such as charge-transfer and non-bonding π-π interactions. It was found that the studied drugs interact with each other in aqueous solution via four types of interactions, namely, ion-pair formation, three weak hydrogen bonds, non-bonding π-π interactions and charge-transfer from DIC to LEV.

  4. Spermicidal activity of the hexane extract of Piper longum: an in vitro study.

    Science.gov (United States)

    Sarwar, Abu Hasnath Md Golam; Nirala, Ranjeet Kumar; Arif, Mohammed; Khillare, Beena; Thakur, Sonu Chand

    2015-01-01

    This study was carried out to assess the spermicidal action of hexane extract from the fruits of Piper longum Linn. The sperm immobilisation studies showed that 20 mg/mL of hexane extract was able to immobilise sperms completely within 20 s. The sperm revival test revealed that the effects were spermicidal as sperm immobilisation effect was irreversible. There was also a significant reduction in sperm viability in the treated group in comparison to the control. The hypo-osmotic swelling of these sperms was significantly reduced, indicating that the hexane extract may probably cause injury to the sperm plasma membrane. Hence, this study showed that the hexane extract of P. longum possesses potential contraceptive spermicidal activity in vitro.

  5. In Vitro Study of Eight Indonesian Natural Extracts as Antiviral Against Dengue Virus

    Directory of Open Access Journals (Sweden)

    Leli Saptawati

    2017-07-01

    Full Text Available 800x600 Background: Dengue hemorrhagic fever (DHF caused by a dengue viruses is still a major problem in tropical countries, including Indonesia. World Health Organization data showed that over 40% of world population are at risk of DHF.1In 2014 there were 71.668 of DHF cases in 34 provinces with 641 death.2 In Central Java in 2013, the incidence rate and fatality rate of DHF was 45.52 in 100.000 populations and 1.21% respectively.3 Until nowadays, there is no vaccine or effective therapy is available as yet.4 Thus research on discovering specific antiviral against dengue is needed. Indonesia is rich in indigenous herbal plants, which may has potential antiviral activity, such as Psidium guajava (Jambu biji, Euphorbia hirta (Patikn kerbau, Piper bettle L (Sirih, Carica papaya (Pepaya, Curcuma longa L(Kunyit/turmeric, Phyllanthus niruri L (meniran, Andrographis paniculata (Sambiloto, Cymbopogon citrates (Serai. Previous studies show that these plants have antiviral and antibacterial properties.5However, there is only limited study of these plants against dengue virus . Objective: This study aimed to know whether these plants have potential activity against dengue virus in vitro. Method: Leave extracts of eight indigenous herbal plants as mention before were originated from Solo, Central Java, the crude extracts were tested in vitro against dengue virus serotype 2 (DENV-2 strain NGC using Huh7it-1 cell line. Those crude extracts were screened for antiviral activity using doses of 20mg/ml. Candidates that showed inhibition activity were further tested in various doses to determine IC50 and CC50. Result: From eight leave extracts tested, one of them i.e Carica papaya (pepaya inhibited virus replication up to 89,5%. Dose dependent assay with C.papaya resulted in IC50, CC50 and selectivity index 6,57 μg/mL, 244,76 μg/mL and 37, 25 μg/mL respectively. Conclusion: C.papaya has potential antiviral activity against dengue virus in vitro. Further study

  6. In vitro and in vivo studies in boron neutron capture therapy of malignant melanoma

    International Nuclear Information System (INIS)

    Allen, B.J.

    1982-01-01

    A multidisciplinary research project in boron neutron capture therapy of malignant melanoma is under consideration by the Australian Atomic Energy Commission. This paper reviews the biochemistry of melanoma and the properties of some melanoma-affined radiopharmaceuticals and their boron analogues. Human cell lines are being used for in vitro tests of uptake and incorporation of some of these compounds, and selected lines will then be implanted in nude mice for in vivo distribution studies. The fidelity of human melanoma xenografts in nude mice has been well studied, and results are reviewed in this paper. Boron concentration will be measured directly by plasma arc emission spectroscopy or liquid scintillation counting with 14 C-labelled boron analogues. Track-etch techniques will be used for the microscopic determination of boron in tumor sections. Neutron irradiation and radiobiology experiments are outlined

  7. [Comparative study on transdermal osmosis in vitro of Aconitum brachypodium liniment, gel and patcher].

    Science.gov (United States)

    Lin, Ya-ping; Zhao, Ying; Zhang, Yong-ping; Liang, Guang-yi

    2007-02-01

    To study the transdermal osmosis process of Aconitum brachypodum's liniment, gel and patcher to provide basis for selecting dosage form and controlling the quality. Taking the cumulate rate of transdermal as index, a imitated Fick's diffusion device was used for the investigating the transdermal osmosis course of the three preparations. The best transdermal mathematics models are obtained and the relations between the transdermal course and the release course are analysed. The three preparations have different characteristics of transdermal osmosis course. The liniment meets dynamics 0 order process, the gel and the patcher meet dynamic 0 order process of non-corroded drug system. And the relation is good cubic equation between their transdermal course and release course. The transdermal osmosis experiment in vitro for three preparations can provide basis for selecting dosage form and the quality control in future studies.

  8. Survival of enteric pathogens in common beverages: an in vitro study.

    Science.gov (United States)

    Sheth, N K; Wisniewski, T R; Franson, T R

    1988-06-01

    This in vitro study was undertaken to determine the potential for survival of enteric pathogens in common drinking beverages. Three carbonated soft drinks, two alcoholic beverages, skim milk, and water were inoculated with Salmonella, Shigella, and enterotoxigenic Escherichia coli, and quantitative counts were performed over 2 days. Our studies showed poorest survival of all three organisms in wine, and greatest growth in milk and water. Beer and cola allowed survival of small numbers of Salmonella and E. coli at 48 h, whereas sour mix and diet cola were sterile by 48 h. Survival features may correlate with pH of the beverages. These observations may be useful in guiding travellers for appropriate beverage consumption while visiting areas endemic for "traveller's diarrhea."

  9. Rapidly dissociated autologous meniscus tissue enhances meniscus healing: An in vitro study.

    Science.gov (United States)

    Numpaisal, Piya-On; Rothrauff, Benjamin B; Gottardi, Riccardo; Chien, Chung-Liang; Tuan, Rocky S

    Treatment of meniscus tears is a persistent challenge in orthopedics. Although cell therapies have shown promise in promoting fibrocartilage formation in in vitro and preclinical studies, clinical application has been limited by the paucity of autologous tissue and the need for ex vivo cell expansion. Rapid dissociation of the free edges of the anterior and posterior meniscus with subsequent implantation in a meniscus lesion may overcome these limitations. The purpose of this study was to explore the effect of rapidly dissociated meniscus tissue in enhancing neotissue formation in a radial meniscus tear, as simulated in an in vitro explant model. All experiments in this study, performed at minimum with biological triplicates, utilized meniscal tissues from hind limbs of young cows. The effect of varying collagenase concentration (0.1%, 0.2% and 0.5% w/v) and treatment duration (overnight and 30 minutes) on meniscus cell viability, organization of the extracellular matrix (ECM), and gene expression was assessed through a cell metabolism assay, microscopic examination, and quantitative real-time reverse transcription polymerase chain reaction analysis, respectively. Thereafter, an explant model of a radial meniscus tear was used to evaluate the effect of a fibrin gel seeded with one of the following: (1) fibrin alone, (2) isolated and passaged (P2) meniscus cells, (3) overnight digested tissue, and (4) rapidly dissociated tissue. The quality of in vitro healing was determined through histological analysis and derivation of an adhesion index. Rapid dissociation in 0.2% collagenase yielded cells with higher levels of metabolism than either 0.1% or 0.5% collagenase. When seeded in a three-dimensional fibrin hydrogel, both overnight digested and rapidly dissociated cells expressed greater levels of collagens type I and II than P2 meniscal cells at 1 week. At 4 and 8 weeks, collagen type II expression remained elevated only in the rapid dissociation group. Histological

  10. In vitro study of cerebrospinal fluid dynamics in a shaken basal cistern after experimental subarachnoid hemorrhage.

    Directory of Open Access Journals (Sweden)

    Ulrich Kertzscher

    Full Text Available Cerebral arterial vasospasm leads to delayed cerebral ischemia and constitutes the major delayed complication following aneurysmal subarachnoid hemorrhage. Cerebral vasospasm can be reduced by increased blood clearance from the subarachnoid space. Clinical pilot studies allow the hypothesis that the clearance of subarachnoid blood is facilitated by means of head shaking. A major obstacle for meaningful clinical studies is the lack of data on appropriate parameters of head shaking. Our in vitro study aims to provide these essential parameters.A model of the basal cerebral cistern was derived from human magnetic resonance imaging data. Subarachnoid hemorrhage was simulated by addition of dyed experimental blood to transparent experimental cerebrospinal fluid (CSF filling the model of the basal cerebral cistern. Effects of various head positions and head motion settings (shaking angle amplitudes and shaking frequencies on blood clearance were investigated using the quantitative dye washout method. Blood washout can be divided into two phases: Blood/CSF mixing and clearance. The major effect of shaking consists in better mixing of blood and CSF thereby increasing clearance rate. Without shaking, blood/CSF mixing and blood clearance in the basal cerebral cistern are hampered by differences in density and viscosity of blood and CSF. Blood clearance increases with decreased shaking frequency and with increased shaking angle amplitude. Head shaking facilitates clearance by varying the direction of gravitational force.From this in vitro study can be inferred that patient or head shaking with large shaking angles at low frequency is a promising therapeutic strategy to increase blood clearance from the subarachnoid space.

  11. The Biomechanics of Cycling with a Transtibial Prosthesis: A Case Study of a Professional Cyclist

    OpenAIRE

    D. Koutny; D. Palousek; P. Stoklasek; J. Rosicky; L. Tepla; M. Prochazkova; Z. Svoboda; P. Krejci

    2013-01-01

    The article deals with biomechanics of cyclist with unilateral transtibial amputation. Transtibial amputation completely removes ankle and part of muscles of a lower leg which are responsible for production of force during pedaling and causes significant geometric and power asymmetry between the limbs during cycling movement. The primary goal of this work is to assess the effects of length adjustment of the crank on the kinematics and muscle activity of cyclist. The paper presents experimenta...

  12. Design considerations for studies of the biomechanical environment of the femoropopliteal arteries.

    Science.gov (United States)

    Ansari, Farzana; Pack, Lindsay K; Brooks, Steven S; Morrison, Tina M

    2013-09-01

    The purpose of this study was to review the available literature regarding the biomechanics of the superficial femoral artery (SFA) and popliteal artery (PA) in patients with peripheral arterial disease (PAD). Stents are one of many available therapies used to treat patients with PAD. Because stents are permanent implants, they undergo a variety of deformations as patients go about their daily activities such as walking, sitting in a chair, or climbing stairs. As a part of the marketing application for United States Food and Drug Administration approval, stents need to be evaluated for long-term durability under a variety of loading modes. The information available in the literature provides direction for such evaluation. We performed a literature search of the PubMed database looking for "key vessel" and "mechanics" (all fields) or "deformation" (all fields) or "flexion" (all fields) or "mechanical environment" (all fields) or "tortuosity" (all fields) or "dynamics" (all fields) or "forces" (all fields), where the "key vessel" was "Femoral Artery," "Superficial Femoral Artery," "Popliteal Artery," and "Femoropopliteal." Using a decision tree, we found 12 relevant articles that focused solely on the nonradial cyclic deformations associated with musculoskeletal motion. Despite the many limitations associated with combining these studies, we learned that under walking conditions, the proximal and mid-SFA deforms, on average, by shortening in the axial direction 4.0%, by twisting 2.1°/cm, and by bending 72.1 mm; the distal SFA and proximal PA deform by shortening in the axial direction 13.9%, by twisting 3.5°/cm, and by being pinched such that the aspect ratio of the lumen changes 4.6%. The distal PA deforms by shortening in the axial direction 12.3%, by twisting 3.5°/cm, by bending 22.1 mm, and by being pinched such that the aspect ratio of the lumen changes 12.5%. A review of the current literature reveals heterogeneous study designs that confound interpretation

  13. In vitro study on dental erosion provoked by various beverages using electron probe microanalysis.

    Science.gov (United States)

    Willershausen, B; Schulz-Dobrick, B

    2004-09-29

    Tooth erosion is often based on chemical processes, among others the use of soft drinks or diverse beverages. The aim of this in vitro study was to analyse the erosive potential of different acidic beverages. Over a time span of 6 hours, dental slices (n=6 slices per tooth) from fully retained wisdom teeth were incubated with different beverages (coca cola, ice tea with lemon, apple juice and white wine). The controls were incubated with a 0.9% sodium chloride solution under the same conditions (37 degrees C, humidified atmosphere of 5% CO2 and 95% air). The quantitative elementary analysis for calcium, phosphorus, oxygen and other trace elements in the dental slices in various depths ranging from 5 to 50 microm was carried out using an electron probe micro-analyser (Jeol JXA 8900RL). A beverage-induced loss of minerals, particularly of the 2 main components calcium and phosphorus, especially in the uppermost layers of the enamel down to a depth of 30 microm could be observed. In the depth of 10 microm, the following total mineral loss could be determined: white wine (16%), coca cola (14.5%), apple juice (6.5%) and ice tea with lemon (6.5%). A direct correlation between the loss of minerals and the pH value of the beverages was not observed, because of the buffering effect of the drinks. The conversion of the weight percentages from the chemical analysis of Ca and P to their atomic percentages showed that during erosion the 2 main components were not dissolved in significantly different percentages. In this study the erosive potential of the tested soft drinks and other beverages could be demonstrated. However, it must be considered that numerous modifying factors influence the enamel surface, so an extrapolation from the in vitro study to an in vivo situation can only be applied with caution.

  14. [Primary study on fluro [ 19F] berberine derivative for human hepatocellular carcinoma targetting in vitro].

    Science.gov (United States)

    Zhang, Tong; Wu, Xiaoai; Cai, Huawei; Liang, Meng; Fan, Chengzhong

    2017-04-01

    [ 18 F]HX-01, a Fluorine-18 labeled berberine derivative, is a potential positron emission tomography (PET) tumor imaging agent, while [ 19 F]HX-01 is a nonradioactive reference substance with different energy state and has the same physical and chemical properties. In order to collect data for further study of [ 18 F]HX-01 PET imaging of hepatocellular carcinoma in vivo , this study compared the uptake of [ 19 F]HX-01 by human hepatocellular carcinoma and normal hepatocytes in vitro . The target compound, [ 19 F]HX-01, was synthesized in one step using berberrubine and 3-fluoropropyl 4-methylbenzenesulfonate. Cellular uptake and localization of [ 19 F]HX-01 were performed by a fluorescence microscope in human hepatocellular carcinoma HepG2, SMMC-7721 and human normal hepatocyte HL-7702. Cellular proliferation inhibition and cell cytotoxicity assay of the [ 19 F]HX-01 were conducted using cell counting kit-8 (CCK-8) on HepG2, SMMC-7721 and HL-7702 cells. Fluorescent microscopy showed that the combining ability of [ 19 F]HX-01 to the carcinoma SMMC-7721 and HepG2 was higher than that to the normal HL-7702. Cellular proliferation inhibition assay demonstrated that [ 19 F]HX-01 leaded to a dose-dependent inhibition on SMMC-7721, HepG2, and HL-7702 proliferation. Cell cytotoxicity assay presented that the cytotoxicity of [ 19 F]HX-01 to SMMC-7721 and HepG2 was obviously higher than that to HL-7702. This in vitro study showed that [ 19 F]HX-01 had a higher selectivity on human hepatocellular carcinoma cells (SMMC-7721, HepG2) but has less toxicity to normal hepatocytes (HL-7702). This could set up the idea that the radioactive reference substance [ 18 F]HX-01 may be worthy of further development as a potential molecular probe targeting human hepatocellular carcinoma using PET.

  15. Cyclosporine A Loaded PLGA Nanoparticles for Dry Eye Disease: In Vitro Characterization Studies

    International Nuclear Information System (INIS)

    Wagh, V.D.; Apar, D.U.

    2014-01-01

    Dry eye disease is a common disease of the tear film caused by decreased tear production or increased evaporation. The objective of this study was to develop and evaluate poly (dl-lactide-co-glycolide) (PLGA) nanoparticles for CsA (CsA) ophthalmic delivery, for the treatment of dry eye disease. Topical CsA is currently the only and safe pharmacologic treatment of severe dry eye symptoms. Nanoparticles (NPs) were prepared by W/O solvent evaporation technique followed by probe sonicator and characterized for various properties such as particle size, entrapment efficiency, zeta potential, in vitro drug release, in vitro permeation studies by Franz diffusion cells, XRD, DSC, SEM, and stability studies. The developed nano suspension showed a mean particle size in the range from 128 to 253.50 nm before freeze drying and after freeze drying 145.60 to 260.0 nm. The drug entrapment efficiency was from 58.35 to 95.69% and production yield was found between 52.29±2.4 and 85.30±2.1 % in all preparations. The zeta potential of the Eudragit RL containing nanoparticles was positive, that is, 20.3 mV to 34.5 mV. The NPs formulations exhibited a biphasic drug release with initial burst followed by a very slow drug release and total cumulative release up to 24 h ranged from 69.83 to 91.92%. Kinetically, the release profiles of CsA from NPs appeared to fit best with the Higuchi model. The change of surface characteristics of NPs represents a useful approach for improvement of ocular retention and drug availability.

  16. Controlled release hydrophilic matrix tablet formulations of isoniazid: design and in vitro studies.

    Science.gov (United States)

    Hiremath, Praveen S; Saha, Ranendra N

    2008-01-01

    The aim of the present investigation was to develop oral controlled release matrix tablet formulations of isoniazid using hydroxypropyl methylcellulose (HPMC) as a hydrophilic release retardant polymer and to study the influence of various formulation factors like proportion of the polymer, polymer viscosity grade, compression force, and release media on the in vitro release characteristics of the drug. The formulations were developed using wet granulation technology. The in vitro release studies were performed using US Pharmacopoeia type 1 apparatus (basket method) in 900 ml of pH 7.4 phosphate buffer at 100 rpm. The release kinetics was analyzed using Korsmeyer-Peppas model. The release profiles were also analyzed using statistical method (one-way analysis of variance) and f (2) metric values. The release profiles found to follow Higuchi's square root kinetics model irrespective of the polymer ratio and the viscosity grade used. The results in the present investigation confirm that the release rate of the drug from the HPMC matrices is highly influenced by the drug/HPMC ratio and viscosity grade of the HPMC. Also, the effect of compression force and release media was found to be significant on the release profiles of isoniazid from HPMC matrix tablets. The release mechanism was found to be anomalous non-Fickian diffusion in all the cases. In the present investigation, a series of controlled release formulations of isoniazid were developed with different release rates and duration so that these formulations could further be assessed from the in vivo bioavailability studies. The formulations were found to be stable and reproducible.

  17. In vitro eye corrosion study of agrochemicals on isolated chicken eye.

    Science.gov (United States)

    Buda, I; Budai, P; Szabó, R; Lehel, J

    2013-01-01

    Agrochemicals must undergo numberless toxicological tests before marketing. The eye irritation test is part of this test packet. Nowadays, OECD 405 can be used to classify the irritation potential of substances, the base of the OECD 405 guideline is the Draize test, which is one of the most criticized in vivo methods because of the injuries of the test animals and subjective nature of the test in recording the results. Therefore, several in vitro tests have been developed to replace totally or partly the in vivo eye irritation testing. The isolated chicken eye test method (OECD 438), which was used, is one of these alternative methods. Five different agrochemicals were examined in the following way: All test compounds were applied in a single dose onto the cornea of isolated chicken eyes in order to potentially classify the test compounds as ocular corrosive and/or severe irritant. The damages caused by the test substances were assessed by the determination of corneal swelling, opacity, fluorescein retention and morphological effects. These parameters were evaluated pre-treatment and starting at approximately 30, 75, 120, 180, and 240 minutes after the post-treatment rinse. The endpoints evaluated were corneal opacity, swelling, fluorescein retention and morphological effects. All of the endpoints, with the exception of fluorescein retention (which was determined only at pre-treatment and 30 minutes after test substance exposure) were determined at each of the above time points. Positive and negative controls were used and they showed the expected results in each study. In these in vitro eye corrosives and severe irritants studies, using the Isolated Chicken Eye model with five different products, no ocular corrosion or severe irritation potential were observed. These results correspond to the available information about the tested agrochemicals, so these studies with isolated chicken eye are considered to be successful.

  18. "STUDY ON THE EFFECT OF GARLIC ON THE IN VITRO ALBUMIN GLYCATION REACTION"

    Directory of Open Access Journals (Sweden)

    N. Sheikh

    2004-05-01

    Full Text Available Garlic, an antioxidant plant, can react with amino groups of proteins to form Schiff bases. As diabetes leads to glycation of various proteins and this in turn has some effects on the structure of proteins and biochemical activity of them, the inhibition of this process seems very vital. For several years researchers in this field have done their best to recognize the antidiabetic compounds. The aim of this study is to determine the effects of garlic on albumin glycation in vitro.In the presence of various concentrations of garlic, albumin was glycated and evaluated using TBA (thio-barbituric acid method. The results showed that garlic has a statistically significant (P<0.05 effect in inhibiting or decreasing the reaction of albumin glycation. The findings of this research shows that garlic probably inhibits the reaction of glycation and decreases complications occurring in diabetes.

  19. Biomimetic synthesis of modified calcium phosphate fine powders and their in vitro studies

    Energy Technology Data Exchange (ETDEWEB)

    Gergulova, R., E-mail: rumigg@yahoo.com; Tepavitcharova, S., E-mail: rumigg@yahoo.com; Rabadjieva, D., E-mail: rumigg@yahoo.com; Sezanova, K., E-mail: rumigg@yahoo.com; Ilieva, R., E-mail: rumigg@yahoo.com [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, Acad. G. Bonchev Str., Bl. 11, 1113 Sofia (Bulgaria); Alexandrova, R.; Andonova-Lilova, B. [Institute of Experimental Morphology, Pathology and Anthropology with Museum, BAS, Acad. G. Bonchev Str., Bl. 25, Sofia (Bulgaria)

    2013-12-16

    Biomimetic approach and subsequent high-temperature treatment were used to synthesize ion modified calcium phosphate fine powders. Thus, using Simulated Body Fluid (SBF) as an ion modifier, a bi-phase mixture of ion modified β-tricalcium phosphate and hydroxyapatite (β-TCP + HA) was prepared. The use of SBF electrolyte solution enriched with Mg{sup 2+} or Zn{sup 2+} yielded monophase β-tricalcium phosphate additionally modified with Mg{sup 2+} or Zn{sup 2+} (Mg-β-TCP or Zn-β-TCP). The in vitro behavior of the prepared powders on cell viability and proliferation of murine BALB/c 3T3 fibroblasts and of human Lep 3 cells was studied by MTT test assays and Mosmann method after 72 h incubation. The relative cell viability was calculated.

  20. A study of some problems in chromosome cultivation after ionization radiation of human blood in vitro

    International Nuclear Information System (INIS)

    Jiang Benrong; Yao Bo; Chen Zhijian

    1992-01-01

    The effects of Cytochalasin B (Cyt-B) and cultural time on mitotic index (MI) during chromosome culture of human peripheral blood irradiated by 6 MV X-ray in vitro were studied. The results showed: (1) a successful cultivation with enough mitotic figures could be carried out in order to estimate the irradiation dose with chromosome aberrations and when the predicted dose was above 6 Gy in a radiation accident, when the predicted dose was up to 15 Gy the cultural time should be prolonged and Cyt-B should be added to the cultural medium; (2) it was possible to establish a dose effect calibration curve for doses above 5 Gy by adding Cyt-B and prolonging the cultural time; so that its value as a biological dosimeter for clinical application might be increased than before

  1. In vitro studies on magnesium uptake by rumen epithelium using magnesium-28

    International Nuclear Information System (INIS)

    Martens, H.; Harmeyer, J.; Breves, G.

    1976-01-01

    Magnesium-28 transfer across the rumen epithelium has been studied using surviving epithelia in an in vitro system. Net absorption of magnesium in the direction from lumen to blood could be observed as the result of two opposite unidirectional fluxes of different magnitude. Net uptake of magnesium occurred against an electrical potential difference, and was associated with the presence of an unaltered transmural potential difference in the mucosal tissue. Both the net transfer of magnesium and the transmural potential difference decreased during two hours of incubation. Unidirectional fluxes of magnesium and net efflux from the lumen were markedly reduced although not completely inhibited by the addition of ouabain (10 -4 mol/l). The findings suggest that the mechanism of magnesium absorption by the rumen epithelium can be considered as an active transport process, and that the rumen is the main area of magnesium absorption in the living animal. (author)

  2. Study on constructing retroviral vector carrying HSV-tk gene and its antitumor effect in vitro

    International Nuclear Information System (INIS)

    Pan Yujun; Hui Guozhen; Hu Jin

    1997-01-01

    The author reports the construction of retroviral vector PLNTK carrying HsV-tk gene driven by pgk promoter and the successful transferring into cells NBA 2 and SHG 44 respectively as shown by PCR. In vitro study, HSV-tk-expressed-cells prove to be more sensitive to ACV than parent cells. The sensitivity of SHGLNTK and NBALNTK to ACV is 1000 and 500 times that of their parent cells respectively. 3 H-TdR test demonstrated that the DNA replication in gene modified cells is more suppressed than that of parent cells when treated with ACV. Moreover, the ACV sensitivity level of parent cells is enhanced when co-cultured with gene modified cells, which suggests the existence of the bystander effect

  3. Effects of ozone nano-bubble water on periodontopathic bacteria and oral cells - in vitro studies

    Science.gov (United States)

    Hayakumo, Sae; Arakawa, Shinichi; Takahashi, Masayoshi; Kondo, Keiko; Mano, Yoshihiro; Izumi, Yuichi

    2014-10-01

    The aims of the present study were to evaluate the bactericidal activity of a new antiseptic agent, ozone nano-bubble water (NBW3), against periodontopathogenic bacteria and to assess the cytotoxicity of NBW3 against human oral cells. The bactericidal activities of NBW3 against representative periodontopathogenic bacteria, Porphyromonas gingivalis (P. gingivalis) and Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) were evaluated using in vitro time-kill assays. The cytotoxicity of NBW3 was evaluated using three-dimensional human buccal and gingival tissue models. The numbers of colony forming units (CFUs)/mL of P. gingivalis and A. actinomycetemcomitans exposed to NBW3 dropped to below the lower limit of detection (bacteria and is not cytotoxic to cells of human oral tissues. The use of NBW3 as an adjunct to periodontal therapy would be promising.

  4. Preparation of berbamine loaded chitosan-agarose microspheres and in vitro release study

    Directory of Open Access Journals (Sweden)

    Zhang Hu

    2012-01-01

    Full Text Available Berbamine loaded chitosan-agarose microspheres were prepared using a water-in-oil emulsion technique. Optimum preparing parameters were determined by orthogonal experiments as follows: ratio of berbamine to chitosan (w/w is 1:10; percentage of emulsifier (span 80, v/v is 6%; volume of glutaraldehyde is 2 mL; and reaction temperature is 70 ºC. Under these optimal conditions, the encapsulation efficiency and loading capacity of microspheres are 84.57% and 8.44%, respectively. The swelling tests showed that the microspheres possessed higher swelling ratio at pH 7.4 than at pH 1.2. FTIR indicated that berbamine had been successfully loaded in the chitosan-agarose microspheres by physical entrapment. In vitro release studies showed that berbamine was released from microspheres in a significantly sustained fashion.

  5. Preliminary assessment of hydroxyapatite and tricalcium phosphate: in-vitro and in-vivo studies

    International Nuclear Information System (INIS)

    Annuar, B.O.; Muhammad Hasib, A.; Noor Rabihah, A.; Sharifah Anum, Z.; Yaakob, T.A.; Inayat Hussain, S.H.; Rajab, N.F.; Saadiah, S.; Hing, H.L.; Sahidan, S.

    2004-01-01

    Full text: Eight extracts of hydroxyapatite (HA) and tricalcium phosphate (TCP) were evaluated for potential in vitro cytotoxicity, and for dermal irritation and sensitization in vivo. The samples were assessed to determine their viability in L929 murine fibroblast cultures by neutral red (NR) assay, and were evaluated for skin irritation and sensitization in rabbits and guinea pigs, respectively. Results of the NR assay indicate that a majority of extract produced no adverse reaction m L929 cells with cell viability levels exceeding 800/6. However, there was a slight decrease in viability with two HA samples producing a cytotoxicity score of 1. In the animal study, all eight extracts did not promote any dermal irritation and sensitization reactions both in the rabbits and guinea pigs. These results establish that the synthesized HA and TCP am promising biocompatible materials for orthopaedic implants. (Author)

  6. Comparative drug susceptibility study of five clonal strains of Trichomonas vaginalis in vitro

    Institute of Scientific and Technical Information of China (English)

    Hemantkumar Somabhai Chaudhari; Prati Pal Singh

    2011-01-01

    Objective: To produce comparative data on a group of Trichomonas vaginalis clonal strains with varied drug responses using identical methods and materials. Methods: Five clonal strains of Trichomonas vaginalis were isolated from reference strain using agar plate technique. The variability of growth kinetic and susceptibility of clonal strain to metronidazole, tinidazole, satranidazole and nitazoxanide were observed in 96 well microtitre plate. Results: Among these clonal strains there was a good correlation between rates of growth with the relative susceptibility of the strains to drugs in vitro. Regarding metronidazole, tinidazole and satranidazole susceptibility, different degrees of susceptibility were determined. However, no difference in nitazoxanide susceptibility was found between the clonal strain tested and a reference strain.Conclusions: This is the first description of biological variability in clonal stock of Trichomonas vaginalis. Different degrees of drug susceptibility were determined among clonal strains tested. Further studies will be necessary to ascertain the importance of this variability in clinical infection.

  7. In vitro permeation studies of nanoemulsions containing ketoprofen as a model drug.

    Science.gov (United States)

    Kim, Beom Su; Won, Myoung; Lee, Kang Min; Kim, Cheo Sang

    2008-09-01

    We prepared a nanoemulsion system with benzyl alcohol/ ethanol/Solutol/smash(R) HS 15 /water. Ketoprofen was used as a model drug in this study. The nanoemulsions of this system evidenced a high degree of stability. The droplet diameter did not change over a period of at least 3 months. The nanoemulsion containing 4% benzyl alcohol evidenced a permeation rate higher than was observed with the 1% and 2% nanoemulsions. Also the nanoemulsion containing 1% Solutol(R) HS 15 provided a permeation rate higher than was seen with the 2% and 4% nanoemulsions. All ketoprofen-loaded nanoemulsions enhanced the in vitro permeation rate through mouse skins as compared to the control.

  8. Toxicity of Transition Metal Oxide Nanoparticles: Recent Insights from in vitro Studies

    Directory of Open Access Journals (Sweden)

    Robert S. Aronstam

    2010-10-01

    Full Text Available Nanotechnology has evolved to play a prominent role in our economy. Increased use of nanomaterials poses potential human health risk. It is therefore critical to understand the nature and origin of the toxicity imposed by nanomaterials (nanotoxicity. In this article we review the toxicity of the transition metal oxides in the 4th period that are widely used in industry and biotechnology. Nanoparticle toxicity is compellingly related to oxidative stress and alteration of calcium homeostasis, gene expression, pro-inflammatory responses, and cellular signaling events. The precise physicochemical properties that dictate the toxicity of nanoparticles have yet to be defined, but may include element-specific surface catalytic activity (e.g., metallic, semiconducting properties, nanoparticle uptake, or nanoparticle dissolution. These in vitro studies substantially advance our understanding in mechanisms of toxicity, which may lead to safer design of nanomaterials.

  9. In Vitro Study on the Adhesion and Colonization of Candida Albicans on Metal and Acrylic Piercings

    Directory of Open Access Journals (Sweden)

    Stamenov N.

    2016-03-01

    Full Text Available Oral/perioral piercing may provide an ideal environment for adhesion and colonization of microorganisms. The aim of this study is to perform an “in vitro” research on the capabilities of adhesion of Candida albicans on oral piercings made of plastic and metal. Acrylic and metal piercings were incubated with Candida albicans and then were observed using scanning electron microscopy under different magnifications. A lot of irregularities and roughness were observed on the surface of the plastic piercing unlike the surface of the metal one, which is not so rough. Nevertheless, the number of Candida albicans colonies was considerably larger on the scanned metal surface in comparison to the plastic surface. In vitro the metal surface of the piercing creates better environment for the adhesion and colonization of microorganisms than the acrylic. This could be attributed to the electrostatic forces that most likely attract Candida albicans to the metal piercing in the early stages of biofilm formation.

  10. Synthesis of 99mTc-nimotuzumab with tricarbonyl ion: in vitro and in vivo studies.

    Science.gov (United States)

    Garcia, Maria Fernanda; Camacho, Ximena; Calzada, Victoria; Fernandez, Marcelo; Porcal, Williams; Alonso, Omar; Gambini, Juan Pablo; Cabral, Pablo

    2012-01-01

    The Epidermal growth factor receptor (EGFR) family plays an important role in carcinogenesis. CIMAher® (Nimotuzumab), is a humanized monoclonal antibody, which recognizes EGFR with high affinity. The aim of this work was to perform the direct labeling of Nimotuzumab with [99mTc(CO)3(H2O)3]+ as precursor and to evaluate its labeling conditions, in vitro and in vivo stability and biodistrution in normal C57 BL/6J mice. 99mTc(CO3)-Nimotuzumab labeling yields were up to 90%. More than 90% of the complex remained intact after 24 h of incubation with L-Histidine (1/300 molar ratio). Biodistribution studies in normal mice were also performed. Inmunoreactivity was confirmed by cell binding assays with A431cells. These results encourage the evaluation of the potential role of 99mTc(CO)3-Nimotuzumab as a novel tumor-avid radiotracer for targeting in vivo EGFR expression.

  11. Curcumin for neuropsychiatric disorders: a review of in vitro, animal and human studies.

    Science.gov (United States)

    Lopresti, Adrian L

    2017-03-01

    Turmeric has been used in traditional medicine for centuries to treat a range of ailments. Its primary active constituent curcumin, can influence an array of biological activities. Many of these, such as its anti-inflammatory, antioxidant, neuroprotective, and monoaminergic effects are dysregulated in several neuropsychiatric disorders. In this systematic review, in vitro, animal, and human studies investigating the potential of curcumin as a treatment for neuropsychiatric disorders such as major depressive disorder, post-traumatic stress disorder (PTSD), obsessive-compulsive disorder (OCD), bipolar disorder, psychotic disorders, and autism are reviewed, and directions for future research are proposed. It is concluded that curcumin is a promising, natural agent for many of these conditions, however, further research utilising robust, clinical designs are essential. The problem associated with the poor oral bioavailability of standard curcumin also requires consideration. Currently the greatest support for the efficacy of curcumin is for the treatment of major depressive disorder.

  12. In vitro study of antioxidant activity and phenolic content of Chrysanthemum balsamita varieties.

    Science.gov (United States)

    Benedec, Daniela; Filip, Lorena; Vlase, Laurian; Bele, Constantin; Sevastre, Bogdan; Raita, Oana; Olah, Neli-Kinga; Hanganu, Daniela

    2016-07-01

    The purpose of our study was to identify the phenolic substances of two varieties of Chrysanthemum balsamita (balsamita and tanacetoides) and to measure the overall antioxidant activity. The phenolic compounds were determined by HPLC. The evaluation of the polyphenolic content was performed by colorimetric analysis. The antioxidant activity was measured by three in vitro assay models: the DPPH, the silver nanoparticles antioxidant capacity (SNPAC) and EPR radical detection. Using HPLC-MS analysis, phenolic acids, flavonoids and flavonoid aglycone were detected. The highest antioxidant activity was showed by Chrysanthemum balsamita var. balsamita, while the lowest for the Chrysanthemum balsamita var. tanacetoides extract, in accord with the polyphenolic content. The results show that Chrysanthemum balsamita var. balsamita might be a source of antioxidant flavonoids, especially rutin and isoquercitrin.

  13. Optimal protocol for teleconsultation with a cellular phone for dentoalveolar trauma: an in-vitro study

    International Nuclear Information System (INIS)

    Park, Won Se; Lee, Hae Na; Jeong, Jin Sun; Kwon, Jung Hoon; Lee, Grace H; Kim, Kee Dong

    2012-01-01

    Dental trauma is frequently unpredictable. The initial assessment and urgent treatment are essential for dentists to save the patient's teeth. Mobile-phone-assisted teleconsultation and telediagnosis for dental trauma could be an aid when a dentist is not available. In the present in-vitro study, we evaluated the success rate and time to transfer images under various conditions. We analyzed the image quality of cameras built into mobile phones based on their resolution, autofocus, white-balance, and anti-movement functions. The image quality of most built-in cameras was acceptable to perform the initial assessment, with the autofocus function being essential to obtain high-quality images. The transmission failure rate increased markedly when the image size exceeded 500 kB and the additional text messaging did not improve the success rate or the transmission time. Our optimal protocol could be useful for emergency programs running on the mobile phones.

  14. Optimal protocol for teleconsultation with a cellular phone for dentoalveolar trauma: an in-vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Park, Won Se; Lee, Hae Na; Jeong, Jin Sun; Kwon, Jung Hoon; Lee, Grace H; Kim, Kee Dong [College of Dentistry, Yonsei University, Seoul (Korea, Republic of)

    2012-06-15

    Dental trauma is frequently unpredictable. The initial assessment and urgent treatment are essential for dentists to save the patient's teeth. Mobile-phone-assisted teleconsultation and telediagnosis for dental trauma could be an aid when a dentist is not available. In the present in-vitro study, we evaluated the success rate and time to transfer images under various conditions. We analyzed the image quality of cameras built into mobile phones based on their resolution, autofocus, white-balance, and anti-movement functions. The image quality of most built-in cameras was acceptable to perform the initial assessment, with the autofocus function being essential to obtain high-quality images. The transmission failure rate increased markedly when the image size exceeded 500 kB and the additional text messaging did not improve the success rate or the transmission time. Our optimal protocol could be useful for emergency programs running on the mobile phones.

  15. In Vitro and In Vivo Models for the Study of Human Polyomavirus Infection

    Directory of Open Access Journals (Sweden)

    Heidi Barth

    2016-10-01

    Full Text Available Developments of genome amplification techniques have rapidly expanded the family of human polyomaviruses (PyV. Following infection early in life, PyV persist in their hosts and are generally of no clinical consequence. High-level replication of PyV can occur in patients under immunosuppressive or immunomodulatory therapy and causes severe clinical entities, such as progressive multifocal leukoencephalopathy, polyomavirus-associated nephropathy or Merkel cell carcinoma. The characterization of known and newly-discovered human PyV, their relationship to human health, and the mechanisms underlying pathogenesis remain to be elucidated. Here, we summarize the most widely-used in vitro and in vivo models to study the PyV-host interaction, pathogenesis and anti-viral drug screening. We discuss the strengths and limitations of the different models and the lessons learned.

  16. Comparative in vitro study for orthodontic adhesives relatively to sorption and solubility

    Science.gov (United States)

    Muntean, A.; Mesaros, A.; Festila, D.; Moldovan, M.; Boboia, S.; Mesaros, M.

    2015-12-01

    Water sorption and solubility correspond to undesirable physical characteristics because it may cause micro leakage and dissolution for composite materials used for orthodontic attachment bonding. The aim of this study was to evaluate the performance of four composite materials employed in orthodontic as adhesives, relatively to water and 50% alcoholic solution, by means of in vitro tests of sorption and solubility. We used an experimental composite sealer SO® (ICCRR Cluj Napoca) and 3 commercial products already on the market: Blugloo® (Ormco), Opal Bond MV® (Ultradent) and Bond It® (DB orthodontics). Data were recorded and specific statistic tests were performed, revealing significant differences for all materials relatively to tested solutions. The materials expressed an adequate performance in terms of sorption and solubility, offering various alternatives for orthodontists.

  17. Antiseptic mouthwash against pharyngeal Neisseria gonorrhoeae: a randomised controlled trial and an in vitro study.

    Science.gov (United States)

    Chow, Eric Pf; Howden, Benjamin P; Walker, Sandra; Lee, David; Bradshaw, Catriona S; Chen, Marcus Y; Snow, Anthony; Cook, Stuart; Fehler, Glenda; Fairley, Christopher K

    2017-03-01

    Gonorrhoea is increasing among men who have sex with men (MSM). We aimed to determine whether Listerine, a commercial mouthwash product, has an inhibitory effect against Neisseria gonorrhoeae in a randomised controlled trial (RCT) and an in vitro study, and therefore may be a potentially useful agent for gonorrhoea control. In vitro: a suspension of ∼10 8 colony forming units per mL (CFU/mL) of N. gonorrhoeae was added to a serial of dilutions (up to 1:32) of alcohol-containing Listerine mouthwashes (Cool Mint and Total Care) for 1 min. A 10 µL aliquot was spread over the surface of a gonococcal agar plate and the number of N. gonorrhoeae colonies present at each dilution was calculated. The phosphate buffered saline (PBS) was used as a control. RCT: we recruited MSM with pharyngeal gonorrhoea who returned for treatment at the Melbourne Sexual Health Centre between May 2015 and February 2016. Untreated men were randomised to rinse and gargle either Listerine Cool Mint or saline for 1 min. Pharyngeal swabs were taken before and after rinsing and gargling for culture of N. gonorrhoeae . The analysis included only men who were culture positive for N. gonorrhoeae before using the allocated solution on the day of recruitment. In vitro: Listerine mouthwashes at dilutions of up to 1:4 for 1 min resulted in significant reduction of total N. gonorrhoeae counts but PBS has no inhibitory effect against N. gonorrhoeae . RCT: a total of 196 MSM were recruited, 58 (30%) were culture positive before using the solution. After gargling the allocated solution, men in the Listerine group were significantly less likely to be culture positive on the pharyngeal surface (52%) compared with men in the saline group (84%) (p=0.013). This data suggest Listerine, significantly reduces the amount of N. gonorrhoeae on the pharyngeal surface. With daily use it may increase gonococcal clearance and have important implications for prevention strategies. ACTRN12615000716561. Published by

  18. Bioactivity of sol-gel-derived TiO2 coating on polyetheretherketone: In vitro and in vivo studies.

    Science.gov (United States)

    Shimizu, Takayoshi; Fujibayashi, Shunsuke; Yamaguchi, Seiji; Yamamoto, Koji; Otsuki, Bungo; Takemoto, Mitsuru; Tsukanaka, Masako; Kizuki, Takashi; Matsushita, Tomiharu; Kokubo, Tadashi; Matsuda, Shuichi

    2016-04-15

    A polyetheretherketone (PEEK) surface was modified using a sol-gel-derived TiO2 coating in order to confer bone-bonding ability. To enhance the bonding strength of the coating layer, pretreatment with either O2 plasma or sandblasting was performed prior to sol-gel coating. Additionally, post-treatment with acid was carried out to confer apatite (calcium phosphate)-forming ability to the surface. Biomechanical and histological analyses performed using an in vivo rabbit tibia model showed that PEEK surfaces modified with sol-gel-derived TiO2 and acid post-treatment had better bone-bonding properties than uncoated PEEK surfaces. These modified surfaces also performed well in terms of their in vitro cell responses due to their modified surface chemistries and topographies. Although O2 plasma or sandblasting treatment were, for the most part, equivocal in terms of performance, we conclude that sol-gel-derived TiO2 coating followed by acid post-treatment significantly improves the bone bonding ability of PEEK surfaces, thus rendering them optimal for their use in surgical implants. The role of polyetheretherketone (PEEK) as an alternative biomaterial to conventional metallic implant materials has become increasingly important. However, its low bone bonding ability is yet to be resolved. This in vivo and in vitro investigation on the functionalization of PEEK surfaces highlights the utility of this material in clinical interventions that require implants, and may extend range of applications of PEEK. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  19. Micropropagation, Micromorphological Studies, and In Vitro Flowering in Rungia pectinata L.

    Science.gov (United States)

    Shekhawat, Mahipal S; Manokari, M; Ravindran, C P

    2016-01-01

    A tissue culture protocol was developed for an important medicinal plant Rungia pectinata L. in the present study. Nodal shoots were used as explants and surface-sterilized with 0.1% HgCl2 solution. Murashige and Skoog (MS) medium was used to establish the cultures of R. pectinata. The bud break was reported on MS medium supplemented with 1.0 mg L(-1) 6-benzylaminopurine (BAP). About 98% response was observed with this media combination and maximum 3.2 shoots per explant with 4.3 cm length were recorded. The shoots were further multiplied using MS medium augmented with 0.5 mg L(-1) each of BAP and kinetin (Kin) + 0.1 mg L(-1) indole-3 acetic acid (IAA). Maximum 13.2 shoots per explant with 5.2 cm length were observed. All the shoots were rooted (4.9 roots per shoot with 3.5 cm length) on half strength MS medium fortified with 2.0 mg L(-1) indole-3 butyric acid (IBA). In vitro flowering was induced from the shoots on half strength MS medium supplemented with same concentrations and combinations of growth regulators used for shoot multiplication under 12/12 hr light/dark photoperiod. The plantlets were hardened in the greenhouse for two months and finally transferred to the field. The foliar micromorphological studies revealed the developmental changes in stomata, vein density, and trichomes during the culture of shoots under in vitro conditions.

  20. Micropropagation, Micromorphological Studies, and In Vitro Flowering in Rungia pectinata L.

    Directory of Open Access Journals (Sweden)

    Mahipal S. Shekhawat

    2016-01-01

    Full Text Available A tissue culture protocol was developed for an important medicinal plant Rungia pectinata L. in the present study. Nodal shoots were used as explants and surface-sterilized with 0.1% HgCl2 solution. Murashige and Skoog (MS medium was used to establish the cultures of R. pectinata. The bud break was reported on MS medium supplemented with 1.0 mg L−1 6-benzylaminopurine (BAP. About 98% response was observed with this media combination and maximum 3.2 shoots per explant with 4.3 cm length were recorded. The shoots were further multiplied using MS medium augmented with 0.5 mg L−1 each of BAP and kinetin (Kin + 0.1 mg L−1 indole-3 acetic acid (IAA. Maximum 13.2 shoots per explant with 5.2 cm length were observed. All the shoots were rooted (4.9 roots per shoot with 3.5 cm length on half strength MS medium fortified with 2.0 mg L−1 indole-3 butyric acid (IBA. In vitro flowering was induced from the shoots on half strength MS medium supplemented with same concentrations and combinations of growth regulators used for shoot multiplication under 12/12 hr light/dark photoperiod. The plantlets were hardened in the greenhouse for two months and finally transferred to the field. The foliar micromorphological studies revealed the developmental changes in stomata, vein density, and trichomes during the culture of shoots under in vitro conditions.

  1. Reduced injection pressures using a compressed air injection technique (CAIT): an in vitro study.

    Science.gov (United States)

    Tsui, Ban C H; Knezevich, Mark P; Pillay, Jennifer J

    2008-01-01

    High injection pressures have been associated with intraneural injection and persistent neurological injury in animals. Our objective was to test whether a reported simple compressed air injection technique (CAIT) would limit the generation of injection pressures to below a suggested 1,034 mm Hg limit in an in vitro model. After ethics board approval, 30 consenting anesthesiologists injected saline into a semiclosed system. Injection pressures using 30 mL syringes connected to a 22 gauge needle and containing 20 mL of saline were measured for 60 seconds using: (1) a typical "syringe feel" method, and (2) CAIT, thereby drawing 10 mL of air above the saline and compressing this to 5 mL prior to and during injections. All anesthesiologists performed the syringe feel method before introduction and demonstration of CAIT. Using CAIT, no anesthesiologist generated pressures above 1,034 mm Hg, while 29 of 30 produced pressures above this limit at some time using the syringe feel method. The mean pressure using CAIT was lower (636 +/- 71 vs. 1378 +/- 194 mm Hg, P = .025), and the syringe feel method resulted in higher peak pressures (1,875 +/- 206 vs. 715 +/- 104 mm Hg, P = .000). This study demonstrated that CAIT can effectively keep injection pressures under 1,034 mm Hg in this in vitro model. Animal and clinical studies will be needed to determine whether CAIT will allow objective, real-time pressure monitoring. If high pressure injections are proven to contribute to nerve injury in humans, this technique may have the potential to improve the safety of peripheral nerve blocks.

  2. Cariostatic Effect of Green Tea in Comparison with Common Anticariogenic Agents: An in Vitro Study

    Directory of Open Access Journals (Sweden)

    Mina Jazaeri

    2015-03-01

    Full Text Available Background and aims. Anticariogenic effects of different mouthrinses have been shown previously. In this in vitro study the anticariogenic effects of polyphenol extract of green tea with 0.05% fluoride, 0.2% chlorhexidine and fluoride-chlorhexidine were compared. Materials and methods. This in vitro study was performed on 50 maxillary premolars in 5 groups: 1 normal saline; 2 a 10% solution of green tea polyphenol extract; 3 0.05% fluoride; 4 0.2% chlorhexidine; and 5 fluoride-chlorhexidine. Each tooth was placed in a tube which contained a cariogenic solution. Every day the teeth were washed (depending on the ex-perimental groups with 5 mL of mouthrinse solution. The depth of the caries was measured under a polarized light micro-scope. Data were analyzed using SPSS 13.0 with Kolmogorov–Smirnov, one-way ANOVA and Tukey tests. Results. The mean and standard deviation (in m of caries depth were 194±16.43, 175±17.94, 142±9.34, 155±13.27, and 144±8.57 in groups 1 to 5, respectively, with significant differences between the groups (P0.001, they were significantly less than those in groups 3 to 5 (P0.001. Conclusion. The anticariogenic effect of fluoride-chlorhexidine was the highest among the groups. Although green tea showed higher cariostatic effects than normal saline, in comparison with other mouthrinses, it is less effective. More re-search is strongly recommended for clinical use of green tea as an anticariogenic agent.

  3. Formulation Study of Topically Applied Lotion: In Vitro and In Vivo Evaluation

    Directory of Open Access Journals (Sweden)

    Syed Nisar Hussain Shah

    2013-01-01

    Full Text Available ntroduction: This article presents the development and evaluation of a new topical formulation of diclofenac diethylamine (DDA as a locally applied analgesic lotion. Methods: To this end, the lotion formulations were formulated with equal volume of varying concentrations (1%, 2%, 3%, 4%; v/v of permeation enhancers, namely propylene glycol (PG and turpentine oil (TO. These lotions were subjected to physical studies (pH, viscosity, spreadability, homogeneity, and accelerated stability, in vitro permeation, in vivo animal studies and sensatory perception testing. In vitro permeation of DDA from lotion formulations was evaluated across polydimethylsiloxane membrane and rabbit skin using Franz cells. Results: It was found that PG and TO content influenced the permeation of DDA across model membranes with the lotion containing 4% v/v PG and TO content showed maximum permeation enhancement of DDA. The flux values for L4 were 1.20±0.02 μg.cm-2.min-1 and 0.67 ± 0.02 μg.cm-2.min-1 for polydimethylsiloxane and rabbit skin, respectively. Flux values were significantly different (p < 0.05 from that of the control. The flux enhancement ratio of DDA from L4 was 31.6-fold and 4.8-fold for polydimethylsiloxane and rabbit skin, respectively. In the in vivo animal testing, lotion with 4% v/v enhancer content showed maximum anti-inflammatory and analgesic effect without inducing any irritation. Sensatory perception tests involving healthy volunteers rated the formulations between 3 and 4 (values ranging between -4 to +4, indicating a range of very bad to excellent, respectively. Conclusion: It was concluded that the DDA lotion containing 4% v/v PG and TO exhibit the best performance overall and that this specific formulation should be the basis for further clinical investigations.

  4. Effects of Nebulizer Position, Gas Flow, and CPAP on Aerosol Bronchodilator Delivery: An In Vitro Study.

    Science.gov (United States)

    Ball, Lorenzo; Sutherasan, Yuda; Caratto, Valentina; Sanguineti, Elisa; Marsili, Maria; Raimondo, Pasquale; Ferretti, Maurizio; Kacmarek, Robert M; Pelosi, Paolo

    2016-03-01

    The aim of this study was to investigate the effects of different delivery circuit configurations, nebulizer positions, CPAP levels, and gas flow on the amount of aerosol bronchodilator delivered during simulated spontaneous breathing in an in vitro model. A pneumatic lung simulator was connected to 5 different circuits for aerosol delivery, 2 delivering CPAP through a high-flow generator tested at 30, 60, and 90 L/min supplementary flow and 5, 10, and 15 cm H2O CPAP and 3 with no CPAP: a T-piece configuration with one extremity closed with a cap, a T-piece configuration without cap and nebulizer positioned proximally, and a T-piece configuration without cap and nebulizer positioned distally. Albuterol was collected with a filter, and the percentage amount delivered was measured by infrared spectrophotometry. Configurations with continuous high-flow CPAP delivered higher percentage amounts of albuterol compared with the configurations without CPAP (9.1 ± 6.0% vs 6.2 ± 2.8%, P = .03). Among configurations without CPAP, the best performance was obtained with a T-piece with one extremity closed with a cap. In CPAP configurations, the highest delivery (13.8 ± 4.4%) was obtained with the nebulizer placed proximal to the lung simulator, independent of flow. CPAP at 15 cm H2O resulted in the highest albuterol delivery (P = .02). Based on our in vitro study, without CPAP, a T-piece with a cap at one extremity maximizes albuterol delivery. During high-flow CPAP, the nebulizer should always be placed proximal to the patient, after the T-piece, using the highest CPAP clinically indicated. Copyright © 2016 by Daedalus Enterprises.

  5. Antibacterial Inhibitory Effects of Punica Granatum Gel on Cariogenic Bacteria: An in vitro Study.

    Science.gov (United States)

    Millo, Grazielle; Juntavee, Apa; Ratanathongkam, Ariya; Nualkaew, Natsajee; Peerapattana, Jomjai; Chatchiwiwattana, Supaporn

    2017-01-01

    This study evaluated the in vitro antibacterial effects of the formulated Punica granatum (PG) gel against Streptococcus mutans, Streptococcus sanguinis, and Lactobacillus casei. The PG extract was dissolved in water at 500 mg/mL. High performance liquid chromatography (HPLC) was used for identification and quantification of chemical marker punicalagin. Minimum bactericidal concentration (MBC) and time-kill assay (TKA) were investigated. Antibacterial activities of the formulated PG gel, 2% chlorhexidine (CHX) gel and blank gel were tested by measuring the zones of inhibition through agar well diffusion method. The HPLC results showed presence of punicalagin at 2023.58 ± 25.29 pg/mL in the aqueous PG extract and at 0.234% (w/w) in the formulated PG gel. The MBC for S. mutans, S. Sanguinis, and L. casei were 250, 125, and 500 mg/mL respectively. The TKA of 500 mg/mL aqueous PG extract showed total inhibition of S. mutans, S. Sanguinis, and L. casei at 6, 1, and 24 hours contact time respectively. Agar well diffusion revealed that for S. mutans, CHX gel > PG gel > blank gel; for S. sanguinis, CHX gel = PG gel > blank gel; for L. casei, CHX gel > PG gel = blank gel. Comparison of the PG gel potency showed that S. sanguinis = S. mutans > L. casei. The PG gel equivalent to 0.234% punicalagin (w/w) inhibited S. mutans and S. sanguinis but not L. casei within 24 hours incubation period and has the potential to be used for caries prevention. Millo G, Juntavee A, Ratanathongkam A, Nualkaew N, Peerapattana J, Chatchiwiwattana S. Antibacterial Inhibitory Effects of Punica Granatum Gel on Cariogenic Bacteria: An in vitro Study. Int J Clin Pediatr Dent 2017;10(2):152-157.

  6. Full arch scans: conventional versus digital impressions--an in-vitro study.

    Science.gov (United States)

    Ender, A; Mehl, A

    2011-01-01

    The digital intraoral impression has become a central part of the CAD/CAM technique. The objective of the present study was to compare the accuracy (trueness and precision) of digital impressions of the full arch with that of conventional impressions on the in-vitro model. For this purpose, a master model was acquired with a new reference scanning process, the measuring trueness of which was +/- 4.1 microm and the precision +/- 2.5 microm. On the one hand, conventional impressions and then plaster models (n = 5) were produced from this master model, and on the other hand, digital impressions were made with the Cerec AC Bluecam and the Lava COS system (each n = 5). The plaster models were also scanned with the reference scanner. The available data records were superimposed and the differences determined. The deviation from the master model defines the trueness of the impression method. The deviations of the models among one another demonstrate the precision of the method. The trueness of the impressions was 55 +/- 21.8 microm in the conventional impression group, for digital impressions with Cerec Bluecam it was 49 +/- 14.2 microm and for digital impressions with Lava COS 40.3 +/- 14.1 microm. The precision was 61.3 +/- 17.9 microm for conventional impression with Impregum, 30.9 +/- 7.1 microm for digital impression with the Cerec Bluecam and 60.1 +/- 31.3 microm for digital impression with Lava COS. These in-vitro results show that accuracy of the digital impression is similar to that of the conventional impression. These results will have to be confirmed in further clinical studies.

  7. In vivo biological performance of a novel highly bioactive glass-ceramic (Biosilicate®): A biomechanical and histomorphometric study in rat tibial defects.

    Science.gov (United States)

    Granito, Renata N; Rennó, Ana Claudia; Ravagnani, Christian; Bossini, Paulo S; Mochiuti, Daniel; Jorgetti, Vanda; Driusso, Patricia; Peitl, Oscar; Zanotto, Edgar D; Parizotto, Nivaldo A; Oishi, Jorge

    2011-04-01

    This study aimed to investigate bone responses to a novel bioactive fully crystallized glass-ceramic of the quaternary system P(2)O(5)-Na(2)O-CaO-SiO(2) (Biosilicate®). Although a previous study demonstrated positive effects of Biosilicate® on in vitro bone-like matrix formation, its in vivo effect was not studied yet. Male Wistar rats (n = 40) with tibial defects were used. Four experimental groups were designed to compare this novel biomaterial with a gold standard bioactive material (Bioglass® 45S5), unfilled defects and intact controls. A three-point bending test was performed 20 days after the surgical procedure, as well as the histomorphometric analysis in two regions of interest: cortical bone and medullary canal where the particulate biomaterial was implanted. The biomechanical test revealed a significant increase in the maximum load at failure and stiffness in the Biosilicate® group (vs. control defects), whose values were similar to uninjured bones. There were no differences in the cortical bone parameters in groups with bone defects, but a great deal of woven bone was present surrounding Biosilicate® and Bioglass® 45S5 particulate. Although both bioactive materials supported significant higher bone formation; Biosilicate® was superior to Bioglass® 45S5 in some histomorphometric parameters (bone volume and number of osteoblasts). Regarding bone resorption, Biosilicate® group showed significant higher number of osteoclasts per unit of tissue area than defect and intact controls, despite of the non-significant difference in the osteoclastic surface as percentage of bone surface. This study reveals that the fully crystallized Biosilicate® has good bone-forming and bone-bonding properties. Copyright © 2011 Wiley Periodicals, Inc.

  8. A review of biomechanics of the shoulder and biomechanical concepts of rotator cuff repair

    Directory of Open Access Journals (Sweden)

    Nobuyuki Yamamoto

    2015-01-01

    Full Text Available In this article, we describe the basic knowledge about shoulder biomechanics, which is thought to be useful for surgeons. Some clinical reports have described that the excellent outcome after cuff repair without acromioplasty and a limited acromioplasty might be enough for subacromial decompression. It was biomechanically demonstrated that a 10-mm medial shift of the tendon repair site has a minimum effect on biomechanics. Many biomechanical studies reported that the transosseous equivalent repair was superior to other techniques, although the tendon may lose its inherent elasticity. We herein introduce our recent experiment data and latest information on biomechanics.

  9. A biomechanical evaluation of proximal femoral nail antirotation with respect to helical blade position in femoral head: A cadaveric study

    Directory of Open Access Journals (Sweden)

    Jin-Ho Hwang

    2012-01-01

    Full Text Available Objective: Despite new developments in the management of osteoporotic fractures, complications like screw cutout are still found in the fixation of proximal femur fractures even with biomechanically proven better implants like proximal femoral nail antirotation (PFNA. The purpose of this cadaveric study was to investigate the biomechanical stability of this device in relation to two common positions (center-center and inferior-center of the helical blade in the femoral head in unstable trochanteric fractures. Materials and Methods: Eight pairs of human cadaveric femurs were used; in one group [center-center (C-C group], the helical blade of PFNA was fixed randomly in central position both in anteroposterior and lateral view, whereas in the other group it was fixed in inferior one-third position in anteroposterior and in central position in lateral view [inferior-center (I-C group]. Unstable intertrochanteric fracture was created and each specimen was loaded cyclically till load to failure Results: Angular and rotational displacements were significantly higher within the C-C group compared to the I-C group in both unloaded and loaded condition. Loading to failure was higher in the I-C group compared to the C-C group. No statistical significance was found for this parameter. Correlations between tip apex distance, cyclic loading which lead to femoral head displacement, and ultimate load to failure showed a significant positive relationship. Conclusion: The I-C group was superior to the C-C group and provided better biomechanical stability for angular and rotational displacement. This study would be a stimulus for further experimental studies with larger number specimens and complex loading protocols at multicentres.

  10. An in vitro study: Evaluation of intracanal calcium hydroxide removal with different file systems

    Directory of Open Access Journals (Sweden)

    Atul Jain

    2017-01-01

    Full Text Available Background: Calcium hydroxide (Ca(OH2 is the most commonly used intracanal material; it needs to be removed in entirety before obturation. Several techniques have been used for the same including use of various hand and rotary files. Aim: This study was carried out to compare the efficacy of Hand K files and single and multiple rotary file system in removal of Ca(OH2. Methodology: Distobuccal root of 45 maxillary molars were selected on the basis of specified inclusion and exclusion criteria. They were divided into three groups - Group 1 (H and K file, Group 2 (HERO Shaper, and Group 3 (One Shape. Biomechanical preparation (BMP was carried out as per the manufacturer's instructions; 2.5% sodium hypochlorite was used as the irrigant and 17% ethylenediaminetetraacetic acid as the penultimate irrigant. Ca(OH2powder was mixed with normal saline to obtain a paste; canals were filled with this paste using a Lentulo spiral and were sealed. After 7 days, Ca(OH2was removed, using the same file system as that used for BMP. Samples were sectioned longitudinally and evaluated under a stereomicroscope. Statistical Analysis: Statistical analysis of the obtained data was carried out using one-way analysis of variance test. Results: HERO Shaper displayed better removal of Ca(OH2than One Shape and Hand K file. Moreover, removal was better in the middle third of canal than apical third. Conclusion: Multiple rotary file system (HERO Shaper is more effective in removal of Ca(OH2than the single file system (One Shape

  11. Improving in vitro to in vivo extrapolation by incorporating toxicokinetic measurements: A case study of lindane-induced neurotoxicity

    Energy Technology Data Exchange (ETDEWEB)

    Croom, Edward L.; Shafer, Timothy J.; Evans, Marina V.; Mundy, William R.; Eklund, Chris R.; Johnstone, Andrew F.M.; Mack, Cina M.; Pegram, Rex A., E-mail: pegram.rex@epa.gov

    2015-02-15

    Approaches for extrapolating in vitro toxicity testing results for prediction of human in vivo outcomes are needed. The purpose of this case study was to employ in vitro toxicokinetics and PBPK modeling to perform in vitro to in vivo extrapolation (IVIVE) of lindane neurotoxicity. Lindane cell and media concentrations in vitro, together with in vitro concentration-response data for lindane effects on neuronal network firing rates, were compared to in vivo data and model simulations as an exercise in extrapolation for chemical-induced neurotoxicity in rodents and humans. Time- and concentration-dependent lindane dosimetry was determined in primary cultures of rat cortical neurons in vitro using “faux” (without electrodes) microelectrode arrays (MEAs). In vivo data were derived from literature values, and physiologically based pharmacokinetic (PBPK) modeling was used to extrapolate from rat to human. The previously determined EC{sub 50} for increased firing rates in primary cultures of cortical neurons was 0.6 μg/ml. Media and cell lindane concentrations at the EC{sub 50} were 0.4 μg/ml and 7.1 μg/ml, respectively, and cellular lindane accumulation was time- and concentration-dependent. Rat blood and brain lindane levels during seizures were 1.7–1.9 μg/ml and 5–11 μg/ml, respectively. Brain lindane levels associated with seizures in rats and those predicted for humans (average = 7 μg/ml) by PBPK modeling were very similar to in vitro concentrations detected in cortical cells at the EC{sub 50} dose. PBPK model predictions matched literature data and timing. These findings indicate that in vitro MEA results are predictive of in vivo responses to lindane and demonstrate a successful modeling approach for IVIVE of rat and human neurotoxicity. - Highlights: • In vitro to in vivo extrapolation for lindane neurotoxicity was performed. • Dosimetry of lindane in a micro-electrode array (MEA) test system was assessed. • Cell concentrations at the MEA EC

  12. Development of molecular markers for zebrafish (Danio rerio) ovarian follicle growth assessment following in-vitro culture in cryopreservation studies.

    Science.gov (United States)

    Anil, Siji; Rawson, David; Zhang, Tiantian

    2018-05-29

    Development of in vitro culture protocol for early stage ovarian follicles of zebrafish is important since cryopreserved early stage ovarian follicles would need to be matured in vitro following cryopreservation before they can be fertilised. Development of molecular markers for zebrafish (Danio rerio) ovarian follicle growth assessment following in vitro culture of early stage zebrafish ovarian follicles in ovarian tissue fragments is reported here for the first time although some work has been reported for in vitro culture of isolated early stage zebrafish ovarian follicles. The main aim of the present study was to develop molecular markers in an optimised in vitro culture protocol for stage I and stage II zebrafish ovarian follicles in ovarian tissue fragments. The effect of concentration of the hormones human chorionic gonadotropin and follicle stimulating hormones, and additives such as Foetal Bovine Serum and Bovine Serum Albumin were studied. The results showed that early stage zebrafish ovarian fragments containing stage I and stage II follicles which are cultured in vitro for 24 h in 20% FBS and 100mIU/ml FSH in 90% L-15 medium at 28 °C can grow to the size of stage II and stage III ovarian follicles respectively. More importantly the follicle growth from stage I to stage II and from stage II to stage III were confirmed using molecular markers such as cyp19a1a (also known as P450aromA) and vtg1 genes respectively. However, no follicle growth was observed following cryopreservation and in vitro culture. Copyright © 2018 Elsevier Inc. All rights reserved.

  13. [Study on Rapid Micropropagation in Vitro Technique of Guangfeng Medicinal Yam (Dioscorea opposita) Plantlets].

    Science.gov (United States)

    Yin, Ming-Hua; Xu, Zhi-Jian; Zhang, Sheng-qin; Lv, Si-Jie; Zeng, Yan-hong; Fu, You-zhang; Hong, Sen-rong

    2015-11-01

    In order to provide methodology reference for virus-free and germplasm conservation of Guangfeng medicinal yam (Dioscorea opposita) plantlets, rapid micropropagation in vitro technique of Guangfeng medicinal yam plantlets was studied. Using the method of plant tissue culture, single factor test and flow-cytometry, the basic procedure of Guangfeng medicinal yam tissue culture was established and the DNA content of Guangfeng medicinal yam plantlets and its potted seedlings was detected. The best disinfection procedure of stems with a bud of Guangfeng medicinal yam was washed with sterile water for three times after sterilized with 70% alcohol for 20 - 30 s and then washed with sterile water for three times again after sterilized with 0.1% mercuric chloride for 10 - 12 min; The best explants of stems with a bud of Guangfeng medicinal yam was slightly woody and more mature stems witha bud; The best proliferation culture medium of stems with a bud of Guangfeng medicinal yam was MS + 6-BA 2.0 mg/L + NAA 0.1 mg/L; The best rooting culture medium of stems with a bud of Guangfeng medicinal yam was MS + NAA 0.5 mg/L; The best culture method of Guangfeng medicinal yam plantlets was liquid culture; The best transplanting matrix of Guangfeng medicinal yam plantlets was the mixture of paddy clay and fine sand (1: 2) or the mixture of perlite and vermiculite (1: 2); The DNA content between Guangfeng medicinal yam plantlets and its potted seedlings had no significant difference. A fast and efficient micropropagation in vitro technological system of stems with a bud of Guangfeng medicinal yam is established, and the flow cytometry detect results also show the genetic stability of Guangfeng medicinal yam plantlets, whose results provide the technical and theoretical basis for the large-scale production of Guangfeng medicinal yam plantlets.

  14. Dual effect of insulin resistance and cadmium on human granulosa cells - In vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Belani, Muskaan, E-mail: muskaanbelani@gmail.com [Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara 390 002, Gujarat, India. (India); Shah, Preeti, E-mail: preeti.shah@novaivifertility.com [Nova IVI Fertility, Behind Xavier' s Ladies Hostel, 108, Swastik Society Rd., Navrangpura, Ahmedabad 390009, Gujarat, India. (India); Banker, Manish, E-mail: manish.banker@novaivifertility.com [Nova IVI Fertility, Behind Xavier' s Ladies Hostel, 108, Swastik Society Rd., Navrangpura, Ahmedabad 390009, Gujarat, India. (India); Gupta, Sarita, E-mail: saritagupta9@gmail.com [Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara 390 002, Gujarat, India. (India)

    2016-12-15

    Combined exposure of cadmium (Cd) and insulin resistance (IR) might be responsible for subfertility. In the present study, we investigated the effects of Cd in vitro in IR human granulosa cells. Isolated human granulosa cells from control and polycystic ovary syndrome (PCOS) follicular fluid samples were confirmed for IR by decrease in protein expression of insulin receptor-β. Control and IR human granulosa cells were then incubated with or without 32 μM Cd. The combined effect of IR with 32 μM Cd in granulosa cells demonstrated significant decrease in expression of StAR, CYP11A1, CYP19A1, 17β-HSD, 3β-HSD, FSH-R and LH-R. Decrease was also observed in progesterone and estradiol concentrations as compared to control. Additionally, increase in protein expression of cleaved PARP-F2, active caspase-3 and a positive staining for Annexin V and PI indicated apoptosis as the mode of increased cell death ultimately leading to decreased steroidogenesis, as observed through the combined exposure. Taken together the results suggest decrease in steroidogenesis ultimately leading to abnormal development of the follicle thus compromising fertility at the level of preconception. - Highlights: • Protein expression of INSR-β in granulosa cells to differentiate PCOS-IR and NIR • Cd and IR together decrease steroidogenesis in human granulosa cells in vitro. • Cd and IR increase human granulosa cell death by increase in apoptosis. • Environment and life style are set to hamper pregnancies at preconception level.

  15. Dual effect of insulin resistance and cadmium on human granulosa cells - In vitro study

    International Nuclear Information System (INIS)

    Belani, Muskaan; Shah, Preeti; Banker, Manish; Gupta, Sarita

    2016-01-01

    Combined exposure of cadmium (Cd) and insulin resistance (IR) might be responsible for subfertility. In the present study, we investigated the effects of Cd in vitro in IR human granulosa cells. Isolated human granulosa cells from control and polycystic ovary syndrome (PCOS) follicular fluid samples were confirmed for IR by decrease in protein expression of insulin receptor-β. Control and IR human granulosa cells were then incubated with or without 32 μM Cd. The combined effect of IR with 32 μM Cd in granulosa cells demonstrated significant decrease in expression of StAR, CYP11A1, CYP19A1, 17β-HSD, 3β-HSD, FSH-R and LH-R. Decrease was also observed in progesterone and estradiol concentrations as compared to control. Additionally, increase in protein expression of cleaved PARP-F2, active caspase-3 and a positive staining for Annexin V and PI indicated apoptosis as the mode of increased cell death ultimately leading to decreased steroidogenesis, as observed through the combined exposure. Taken together the results suggest decrease in steroidogenesis ultimately leading to abnormal development of the follicle thus compromising fertility at the level of preconception. - Highlights: • Protein expression of INSR-β in granulosa cells to differentiate PCOS-IR and NIR • Cd and IR together decrease steroidogenesis in human granulosa cells in vitro. • Cd and IR increase human granulosa cell death by increase in apoptosis. • Environment and life style are set to hamper pregnancies at preconception level.

  16. The study of ascorbate peroxidase, catalase and peroxidase during in vitro regeneration of Argyrolobium roseum.

    Science.gov (United States)

    Habib, Darima; Chaudhary, Muhammad Fayyaz; Zia, Muhammad

    2014-01-01

    Here, we demonstrate the micropropagation protocol of Argyrolobium roseum (Camb.), an endangered herb exhibiting anti-diabetic and immune-suppressant properties, and antioxidant enzymes pattern is evaluated. Maximum callogenic response (60 %) was observed from leaf explant at 1.0 mg L(-1) 1-nephthalene acetic acid (NAA) and 0.5 mg L(-1) 6-benzyl aminopurine (BA) in Murashige and Skoog (MS) medium using hypocotyl and root explants (48 % each). Addition of AgNO3 and PVP in the culture medium led to an increase in callogenic response up to 86 % from leaf explant and 72 % from hypocotyl and root explants. The best shooting response was observed in the presence of NAA, while maximum shoot length and number of shoots were achieved based on BA-supplemented MS medium. The regenerated shoots were rooted and successfully acclimatized under greenhouse conditions. Catalase and peroxidase enzymes showed ascending pattern during in vitro plant development from seed while ascorbate peroxidase showed descending pattern. Totally reverse response of these enzymes was observed during callus induction from three different explants. During shoot induction, catalase and peroxidase increased at high rate while there was a mild reduction in ascorbate peroxidase activity. Catalase and peroxidase continuously increased; on the other hand, ascorbate peroxidase activity decreased during root development and acclimatization states. The protocol described here can be employed for the mass propagation and genetic transformation of this rare herb. This study also highlights the importance and role of ascorbate peroxidase, catalase, and peroxidase in the establishment of A. roseum in vitro culture through callogenesis and organogenesis.

  17. In vitro and in vivo genetic toxicology studies with diethylene glycol monohexyl ether.

    Science.gov (United States)

    Ballantyne, B; Vergnes, J S

    2001-01-01

    Diethylene glycol monohexyl ether (DEGHE; CAS no. 112-59-4), an industrial chemical, was investigated for the potential to produce genotoxic effects using three in vitro and two in vivo tests. No mutagenic activity occurred in either the absence or presence of metabolic activation with a Salmonella typhimurium reverse assay using strains TA98, TA100, TA1535, TA1537 and TA1538. In a Chinese hamster ovary (CHO) forward gene mutation test (HGPRT locus) there was an increase in the mutation frequencies, which were relatively small compared with the solvent control values, somewhat inconsistent between duplicate cultures and occurred particularly in the presence of metabolic activation. Linear regression analysis indicated a marginally significant trend for dosage versus mutation frequency, suggesting that DEGHE was weakly positive in this test. A sister chromatid exchange test in CHO cells showed no significant dosage-related effects in the presence or absence of metabolic activation. A peripheral blood micronucleus test in mice by dosing with an intraperitoneal injection of DEGHE did not show any potential for DEGHE to increase the incidence of micronucleated polychromatophilic erythrocytes. In a first femoral bone marrow chromosome aberration test in the rat by peroral dosing, DEGHE did not cause any increase in aberrations for 12-h and 24-h samples with males and females or with females at 48-h sampling. However, with males at 48 h the two lowest doses showed an increased number of aberrations, but not at the high doses. A repeat study in males with a larger number of doses and 24-h and 48-h samples did not replicate this finding. It is concluded that DEGHE may have limited weak mutagenic activity in vitro but is devoid of clastogenic potential. Copyright 2001 John Wiley & Sons, Ltd.

  18. Biomechanical evaluation of an integrated fixation cage during fatigue loading: a human cadaver study.

    Science.gov (United States)

    Palepu, Vivek; Peck, Jonathan H; Simon, David D; Helgeson, Melvin D; Nagaraja, Srinidhi

    2017-04-01

    OBJECTIVE Lumbar cages with integrated fixation screws offer a low-profile alternative to a standard cage with anterior supplemental fixation. However, the mechanical stability of integrated fixation cages (IFCs) compared with a cage with anterior plate fixation under fatigue loading has not been investigated. The purpose of this study was to compare the biomechanical stability of a screw-based IFC with a standard cage coupled with that of an anterior plate under fatigue loading. METHODS Eighteen functional spinal units were implanted with either a 4-screw IFC or an anterior plate and cage (AP+C) without integrated fixation. Flexibility testing was conducted in flexion-extension (FE), lateral bending (LB), and axial rotation (AR) on intact spines, immediately after device implantation, and post-fatigue up to 20,000 cycles of FE loading. Stability parameters such as range of motion (ROM) and lax zone (LZ) for each loading mode were compared between the 2 constructs at multiple stages of testing. In addition, construct loosening was quantified by subtracting post-instrumentation ROM from post-fatigue ROM. RESULTS IFC and AP+C configurations exhibited similar stability (ROM and LZ) at every stage of testing in FE (p ≥ 0.33) and LB (p ≥ 0.23) motions. In AR, however, IFCs had decreased ROM compared with AP+C constructs at pre-fatigue (p = 0.07) and at all post-fatigue time points (p ≤ 0.05). LZ followed a trend similar to that of ROM in AR. ROM increased toward intact motion during fatigue cycling for AP+C and IFC implants. IFC specimens remained significantly (p < 0.01) more rigid than specimens in the intact condition during fatigue for each loading mode, whereas AP+C construct motion did not differ significantly (p ≥ 0.37) in FE and LB and was significantly greater (p < 0.01) in AR motion compared with intact specimens after fatigue. Weak to moderate correlations (R 2 ≤ 56%) were observed between T-scores and construct loosening, with lower T

  19. In vitro and in vivo studies of gadolinium-159 liposomes in cancer treatment

    International Nuclear Information System (INIS)

    Soares, Daniel Cristian Ferreira

    2011-01-01

    In Brazil, estimates of new cancer cases, valid for the years 2010 and 2011 show that the disease will be responsible for the deaths of about 500,000 people. As an alternative therapy the radiotherapy technique, widely used in treating various types of tumors, act indiscriminate tumoral and healthy cells. Seeking to minimize these effects, nano structured carriers containing radioisotopes, such as liposomes, have been studied with the aim of improving the specificity of action of ionizing radiation, delivering and retaining adequate amounts of radioactive material in tumor cells, leading them to death. In this context, the present study, we prepared liposomes stealth pH-sensitive metal complex containing the radioactive 159 Gd-DTPA-BMA ( 159 Gd-SpHL) aiming to study in vitro and in vivo its effects in cancer treatment. The vesicles showed encapsulation rate of about 20%, average diameter of 100 nm and low release kinetics of radioactivity in biological media. The formulation was characterized through physic-chemical and morphological studies and the results revealed a low polydispersity index and negative Zeta potential. We studied in vitro and in vivo its action against the cells of Ehrlich tumor models and RT2 (rat glioma). The results of in vitro studies showed that the complex has significant radioactive cytotoxicity against the cells of two of the three models studied and that, being encapsulated in liposomes, the cytotoxicity was greatly enhanced. Additionally, we investigated the involvement of caspase-3 protein in Ehrlich and RT2 cell death. The results suggest that the main mechanism involved in the cytotoxic action of radioactive complex is related to apoptosis. The results of in vivo studies showed that liposomes containing 159 Gd-DTPA-BMA accumulated significantly in Ehrlich solid tumor in mice. Aiming to improve this uptake, we prepared pH-sensitive liposomes coated with folate containing the same radioactive complex ( 159 Gd-FTSpHL). The results

  20. Confidence crisis of results in biomechanics research.

    Science.gov (United States)

    Knudson, Duane

    2017-11-01

    Many biomechanics studies have small sample sizes and incorrect statistical analyses, so reporting of inaccurate inferences and inflated magnitude of effects are common in the field. This review examines these issues in biomechanics research and summarises potential solutions from research in other fields to increase the confidence in the experimental effects reported in biomechanics. Authors, reviewers and editors of biomechanics research reports are encouraged to improve sample sizes and the resulting statistical power, improve reporting transparency, improve the rigour of statistical analyses used, and increase the acceptance of replication studies to improve the validity of inferences from data in biomechanics research. The application of sports biomechanics research results would also improve if a larger percentage of unbiased effects and their uncertainty were reported in the literature.

  1. A motor learning approach to training wheelchair propulsion biomechanics for new manual wheelchair users: A pilot study.

    Science.gov (United States)

    Morgan, Kerri A; Tucker, Susan M; Klaesner, Joseph W; Engsberg, Jack R

    2017-05-01

    Developing an evidence-based approach to teaching wheelchair skills and proper propulsion for everyday wheelchair users with a spinal cord injury (SCI) is important to their rehabilitation. The purpose of this project was to pilot test manual wheelchair training based on motor learning and repetition-based approaches for new manual wheelchair users with an SCI. A repeated measures within-subject design was used with participants acting as their own controls. Six persons with an SCI requiring the use of a manual wheelchair participated in wheelchair training. The training included nine 90-minute sessions. The primary focus was on wheelchair propulsion biomechanics with a secondary focus on wheelchair skills. During Pretest 1, Pretest 2, and Posttest, wheelchair propulsion biomechanics were measured using the Wheelchair Propulsion Test and a Video Motion Capture system. During Pretest 2 and Posttest, propulsion forces using the WheelMill System and wheelchair skills using the Wheelchair Skills Test were measured. Significant changes in area of the push loop, hand-to-axle relationship, and slope of push forces were found. Changes in propulsion patterns were identified post-training. No significant differences were found in peak and average push forces and wheelchair skills pre- and post-training. This project identified trends in change related to a repetition-based motor learning approach for propelling a manual wheelchair. The changes found were related to the propulsion patterns used by participants. Despite some challenges associated with implementing interventions for new manual wheelchair users, such as recruitment, the results of this study show that repetition-based training can improve biomechanics and propulsion patterns for new manual wheelchair users.

  2. Strength of suture anchor versus transosseous tunnel in anatomic reconstruction of the ankle lateral ligaments: a biomechanical study.

    Science.gov (United States)

    Li, Hong-Yun; Hua, Ying-Hui; Wu, Zi-Ying; Chen, Bo; Chen, Shi-Yi

    2013-11-01

    The purpose of this study was to compare the biomechanical characteristics of fixation with 2-suture anchors versus transosseous tunnel fixation in anatomic reconstruction of the ankle lateral ligaments. Six matched pairs of human cadaveric ankles underwent anatomic lateral ankle reconstruction, and fixation of the graft on the talus was achieved with 2 suture anchors or a transosseous tunnel. Ankles for the transosseous tunnel group were chosen at random, with the paired contralateral ankles used for the 2-suture anchor group. Half of the peroneus brevis tendon was harvested as a graft. For each technique, one end of the tendon was secured to the original insertion point of the anterior talofibular ligament (ATFL) at the talus, whereas the other end was armed with 2 No. 5 nonabsorbable sutures (Ethicon, Somerville, NJ) and passed through the bone tunnel in the fibula. Biomechanical testing was performed by applying the force in line with the graft. Load to failure was determined at a displacement rate of 50 mm/min. The load-displacement curve, maximum load at failure (N), and stiffness (N/mm) were recorded and compared between the 2 techniques. There was no difference between constructs in the 2-suture anchor group and the transosseous tunnel group in terms of the ultimate load and stiffness (161.8 ± 47.6 N v 171.9 ± 76.0 N; P = .92; 4.59 ± 1.85 N/mm v 5.77 ± 1.98 N/mm; P = .35). Most constructs failed because of anchor pullout in the 2-suture anchor group (5 of 6) and fracture of the bony bridge in the transosseous tunnel group (6 of 6). The strength of fixation with suture anchors in anatomic reconstruction of the ankle lateral ligaments was equivalent to transosseous tunnel fixation as determined with biomechanical testing. However, this study did not prove that one is advantageous over the other. Both techniques showed excellent biomechanical results. Therefore, the 2-suture anchor fixation approach can be safely used in anatomic reconstruction of the

  3. Bioaccessibility and bioavailability of methylmercury from seafood commonly consumed in North America: In vitro and epidemiological studies.

    Science.gov (United States)

    Siedlikowski, Maia; Bradley, Mark; Kubow, Stan; Goodrich, Jaclyn M; Franzblau, Alfred; Basu, Niladri

    2016-08-01

    Methylmercury (MeHg) is a global contaminant of concern and human exposures are largely realized via seafood consumption. While it is assumed that 95-100% of the ingested MeHg from seafood reaches systemic circulation, recent in vitro studies have yielded results to suggest otherwise. Of the published studies to have characterized the bioaccessibility or bioavailability of MeHg from seafood, only a handful of seafood species have been characterized, there exists tremendous variability in data within and across species, few species of relevance to North America have been studied, and none of the in vitro studies have adapted results to an epidemiology study. The objective of the current study was two-fold: (a) to characterize in vitro MeHg bioaccessibility and bioavailability from ten commonly consumed types of seafood in North America; and (b) to apply the bioaccessibility and bioavailability data from the in vitro study to an existing human MeHg exposure assessment study. Raw seafood samples (cod, crab, halibut, salmon, scallop, shrimp, tilapia, and three tuna types: canned light, canned white, fresh) were purchased in Montreal and their MeHg concentrations generally overlapped with values reported elsewhere. The bioaccessibility of MeHg from these samples ranged from 50.1±19.2 (canned white tuna) to 100% (shrimp and scallop) of the amount measured in the raw undigested sample. The bioavailability of MeHg from these samples ranged from 29.3±10.4 (crab) to 67.4±9.7% (salmon) of the value measured in the raw undigested sample. There were significant correlations between the initial MeHg concentration in seafood with the percent of that Hg that was bioaccessible (r=-0.476) and bioavailable (r=-0.294). When the in vitro data were applied to an existing MeHg exposure assessment study, the estimated amount of MeHg absorbed into systemic circulation decreased by 25% and 42% when considering bioaccessibility and bioavailability, respectively. When the in vitro data

  4. STUDIES ON TUBERCULIN FEVER. 3. MECHANISMS INVOLVED IN THE RELEASE OF ENDOGENOUS PYROGEN IN VITRO.

    Science.gov (United States)

    ATKINS, E; HEIJN, C

    1965-08-01

    In a search for the source of the circulating endogenous pyrogen (EP) that mediates tuberculin-induced fever, tuberculin was incubated in vitro with various tissues of rabbits sensitized by intravenous infection with BCG. Evidence was obtained that tuberculin specifically stimulates cells in the blood of sensitized rabbits to generate pyrogen in vitro, whereas both lymph node and spleen cells from the same donors were inactive. Since normal blood cells, incubated in plasma of sensitized donors, were similarly activated, it is postulated that circulating antibodies play a role in sensitizing cells (presumably granulocytes) to release pyrogen on contact with tuberculin) both in vitro and in vivo. Release of endogenous pyrogen in vitro may be a sensitive means of detecting immunologic reactions between antigen and specifically sensitized blood cells-in other allergic states accompanied by fever.

  5. Pulmonary toxicity of nanomaterials: a critical comparison of published in vitro assays and in vivo inhalation or instillation studies.

    Science.gov (United States)

    Landsiedel, Robert; Sauer, Ursula G; Ma-Hock, Lan; Schnekenburger, Jürgen; Wiemann, Martin

    2014-11-01

    To date, guidance on how to incorporate in vitro assays into integrated approaches for testing and assessment of nanomaterials is unavailable. In addressing this shortage, this review compares data from in vitro studies to results from in vivo inhalation or intratracheal instillation studies. Globular nanomaterials (ion-shedding silver and zinc oxide, poorly soluble titanium dioxide and cerium dioxide, and partly soluble amorphous silicon dioxide) and nanomaterials with higher aspect ratios (multiwalled carbon nanotubes) were assessed focusing on the Organisation for Economic Co-Operation and Development (OECD) reference nanomaterials for these substances. If in vitro assays are performed with dosages that reflect effective in vivo dosages, the mechanisms of nanomaterial toxicity can be assessed. In early tiers of integrated approaches for testing and assessment, knowledge on mechanisms of toxicity serves to group nanomaterials thereby reducing the need for animal testing.

  6. Physico-chemical and biological study of excision-repair of UV-irradiated PHIX 174 RF DNA in vitro

    International Nuclear Information System (INIS)

    Heijneker, H.L.

    1975-01-01

    A study is presented on the excision repair of ultraviolet-irradiated PHIX 174 RFI DNA in vitro with UV-specific endonuclease from micrococcus luteus, DNA polymerase I from E. coli and DNA ligase from phage T 4 infected E. coli. Excision repair was measured by physico-chemical and by biological methods. It is shown that more than 90% of the pyrimidine dimers can be repaired in vitro and that the repaired molecules have regained full biological activity. Endonuclease III was not essential for excision repair in vitro and did not stimulate repair; from this it was concluded that UV-endo generates 3' OH endgroups. The usefulness of the methods with regard to the study of excision repair is discussed

  7. Development of highly potent melanogenesis inhibitor by in vitro, in vivo and computational studies

    Directory of Open Access Journals (Sweden)

    Abbas Q

    2017-07-01

    Full Text Available Qamar Abbas,1 Zaman Ashraf,2 Mubashir Hassan,1 Humaira Nadeem,3 Muhammad Latif,4 Samina Afzal,5 Sung-Yum Seo1 1Department of Biology, College of Natural Sciences, Kongju National University, Gongju, Republic of Korea; 2Department of Chemistry, Allama Iqbal Open University, Islamabad, 3Riphah Institute of Pharmaceutical Sciences, Riphah International University, Islamabad, Pakistan; 4Center for Genetics and Inherited Diseases, Taibah University, Almadinah Almunawwarah, Kingdom of Saudi Arabia; 5Faculty of Pharmacy, Bahauddin Zakria University, Multan, Pakistan Abstract: The present work describes the synthesis of few hydroxylated amide derivatives as melanogenesis inhibitors. In vitro, in vivo and computational studies proved that compound 6d is a highly potent melanogenesis inhibitor compared to standard kojic acid. The title amides 4a–e and 6a–e were synthesized following simple reaction routes with excellent yields. Most of the synthesized compounds exhibited good mushroom tyrosinase inhibitory activity, but compound 6d showed excellent activity (IC50 0.15 µM compared to standard kojic acid (IC50 16.69 µM. Lineweaver–Burk plots were used for the determination of kinetic mechanism, and it was found that compounds 4c and 6d showed non-competitive inhibition while 6a and 6b showed mixed-type inhibition. The kinetic mechanism further revealed that compound 6d formed irreversible complex with the target enzyme tyrosinase. The Ki values determined for compounds 4c, 6a, 6b and 6d are 0.188, 0.84, 2.20 and 0.217 µM respectively. Results of human tyrosinase inhibitory activity in A375 human melanoma cells showed that compound 6d exhibited 91.9% inhibitory activity at a concentration of 50 µg/mL. In vivo cytotoxicity evaluation of compound 6d in zebrafish embryos showed that it is non-toxic to zebrafish. Melanin depigmentation assay performed in zebrafish indicated that compound 6d possessed greater potential in decreasing melanin contents

  8. Efeito da nicotina na viabilidade e morfologia de fibroblastos: estudo in vitro Effect of nicotine on the viability and morphology of fibroblasts: in vitro study

    Directory of Open Access Journals (Sweden)

    Aurora Esmeralda Traverso Martinez

    2002-09-01

    Full Text Available O objetivo do estudo foi avaliar in vitro o efeito da nicotina sobre a viabilidade e a morfologia celular utilizando-se uma linhagem contínua de fibroblastos. Para tal, foram formados dois grupos experimentais segundo a dose (0 - controle, 10 mig, 100 mig, 0,5 mg, 1 mg e o tempo de condicionamento (1 e 24 horas. Cada um dos 12 orifícios de uma placa para cultura celular recebeu 2 ml de meio de Eagle, e 1 ml de suspensão de meio de cultura contendo aproximadamente 1 × 10(5 células/ml. Foi, então, acrescentada a solução de nicotina nas diferentes concentrações. Após o condicionamento com a droga, nos dois períodos testados, as células foram coradas com azul de trypan 0,4%, e observadas em microscópio invertido por um examinador cego para os grupos experimentais, que avaliou a viabilidade e a morfologia segundo o índice de Gamal. Os experimentos foram repetidos 5 vezes. Quanto à morfologia, os resultados obtidos demonstraram, no grupo condicionado por 1 h, que os controles apresentaram diferenças estatisticamente significantes em relação apenas à maior dose de nicotina; no entanto, foram encontradas diferenças estatisticamente significantes entre o controle e todas as concentrações após 24 horas de condicionamento. Na viabilidade celular, um maior número de células não viáveis foi observado nas diferentes concentrações de nicotina em comparação aos controles tanto após 1 quanto 24 horas de condicionamento (p The aim of this study was to evaluate, in vitro, the effect of nicotine on the viability and morphology of fibroblasts from a continuous lineage. Two experimental groups were prepared, with different drug dosages (0 - control, 10 mug, 100 mug, 0.5 mg, 1 mg and conditioning time (1 and 24 hours. Twelve-well microplates were utilized. Each well received 2 ml of fresh culture medium and 1 ml of a solution containing 1 × 10(5 cells/ml. Nicotine was then added to the wells, at the tested concentrations. After the

  9. Migration of phthalates on culture plates - an important challenge to consider for in vitro studies.

    Science.gov (United States)

    Frohnert Hansen, Juliana; Boas, Malene; Møller Brorson, Marianne; Frederiksen, Hanne; Hartoft-Nielsen, Marie-Louise; Krogh Rasmussen, Åse; Main, Katharina M; Feldt-Rasmussen, Ulla

    2016-01-01

    Phthalates are endocrine disruptors of the reproductive system and suspected to influence many other organ and hormone systems. They are also semi-volatile organic compounds present in the gas phase in the environment. Their mode of action has been investigated in numerous in vitro studies. Multi-well culture plates are typically used to study phthalates in cell cultures. In a pilot study, we observed evidence of phthalate migration in 24-well culture plates. As this has not previously been described, we investigated the phenomenon in more detail. Primary human thyroid epithelial cell cultures (n = 8 cultures) were exposed to either di-ethyl phthalate (DEP), di-n-butyl phthalate (DnBP), mono-n-butyl phthalate (MnBP) or di-(2-ethylhexyl) phthalate (DEHP). Measurement of phthalate metabolites by mass spectrometry demonstrated that the short-branched DEP was able to migrate to adjacent wells when added to cell culture plates. DnBP also seemed to be able to migrate, unlike the long-branched DEHP or the monoester MnBP which did not seem to have this ability. High background levels of phthalate metabolites were also observed, which might compromise results from low dose phthalate studies. In conclusion, the migration of phthalates which is probably caused by their volatile properties might lead to false interpretation of study results.

  10. Nano- and microstructured materials for in vitro studies of the physiology of vascular cells

    Directory of Open Access Journals (Sweden)

    Alexandra M. Greiner

    2016-11-01

    Full Text Available The extracellular environment of vascular cells in vivo is complex in its chemical composition, physical properties, and architecture. Consequently, it has been a great challenge to study vascular cell responses in vitro, either to understand their interaction with their native environment or to investigate their interaction with artificial structures such as implant surfaces. New procedures and techniques from materials science to fabricate bio-scaffolds and surfaces have enabled novel studies of vascular cell responses under well-defined, controllable culture conditions. These advancements are paving the way for a deeper understanding of vascular cell biology and materials–cell interaction. Here, we review previous work focusing on the interaction of vascular smooth muscle cells (SMCs and endothelial cells (ECs with materials having micro- and nanostructured surfaces. We summarize fabrication techniques for surface topographies, materials, geometries, biochemical functionalization, and mechanical properties of such materials. Furthermore, various studies on vascular cell behavior and their biological responses to micro- and nanostructured surfaces are reviewed. Emphasis is given to studies of cell morphology and motility, cell proliferation, the cytoskeleton and cell-matrix adhesions, and signal transduction pathways of vascular cells. We finalize with a short outlook on potential interesting future studies.

  11. In vitro study of RRS HA injectable mesotherapy/biorevitalization product on human skin fibroblasts and its clinical utilization.

    Science.gov (United States)

    Deglesne, Pierre-Antoine; Arroyo, Rodrigo; Ranneva, Evgeniya; Deprez, Philippe

    2016-01-01

    Mesotherapy/biorevitalization with hyaluronic acid (HA) is a treatment approach currently used for skin rejuvenation. Various products with a wide range of polycomponent formulations are available on the market. Most of these formulations contain noncross-linked HA in combination with a biorevitalization cocktail, formed by various amounts of vitamins, minerals, amino acids, nucleotides, coenzymes, and antioxidants. Although ingredients are very similar among the different products, in vitro and clinical effects may vary substantially. There is a real need for better characterization of these products in terms of their action on human skin or in vitro skin models. In this study, we analyzed the effect of the RRS(®) (Repairs, Refills, Stimulates) HA injectable medical device on human skin fibroblasts in vitro. Skin fibroblast viability and its capacity to induce the production of key extracellular matrix were evaluated in the presence of different concentrations of RRS HA injectable. Viability was evaluated through colorimetric MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay, and key extracellular matrix genes, type I collagen and elastin, were quantified by quantitative polymerase chain reaction. Results demonstrated that RRS HA injectable could promote human skin fibroblast viability (+15%) and increase fibroblast gene expression of type I collagen and elastin by 9.7-fold and 14-fold in vitro, respectively. These results demonstrate that mesotherapy/biorevitalization products can, at least in vitro, effectively modulate human skin fibroblasts.

  12. Study of the cetuximab-ionizing radiation association on a model of in vitro endothelial cells; Etude de l'association cetuximab-radiations ionisantes sur un modele de cellules endotheliales in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Vautravers-Dewas, C.; Rebucci, M.; Lansiaux, A. [Centre Oscar-Lambret, Inserm U837, Lab. de Pharmacologie Antitumorale, 59 - Lille (France); Peixoto, P. [Inserm U837, 59 - Lille (France); Lartigau, E. [Centre Oscar-Lambret, Dept. Universitaire de Radiotherapie, 59 - Lille (France)

    2009-10-15

    These data support the existence of functional signalling tracks downstream epidermal growth factor receptor (E.G.F.R.) in endothelial cells. But our in vitro model, in two dimensional calculations, did not allow to show a radiosensitivity by cetuximab. The study of functional consequences of the association cetuximab-irradiation treatment will be relevant in an in vitro three dimensional model and on xenografts. (N.C.)

  13. Dinosaur biomechanics

    Science.gov (United States)

    Alexander, R. McNeill

    2006-01-01

    Biomechanics has made large contributions to dinosaur biology. It has enabled us to estimate both the speeds at which dinosaurs generally moved and the maximum speeds of which they may have been capable. It has told us about the range of postures they could have adopted, for locomotion and for feeding, and about the problems of blood circulation in sauropods with very long necks. It has made it possible to calculate the bite forces of predators such as Tyrannosaurus, and the stresses they imposed on its skull; and to work out the remarkable chewing mechanism of hadrosaurs. It has shown us how some dinosaurs may have produced sounds. It has enabled us to estimate the effectiveness of weapons such as the tail spines of Stegosaurus. In recent years, techniques such as computational tomography and finite element analysis, and advances in computer modelling, have brought new opportunities. Biomechanists should, however, be especially cautious in their work on animals known only as fossils. The lack of living specimens and even soft tissues oblige us to make many assumptions. It is important to be aware of the often wide ranges of uncertainty that result. PMID:16822743

  14. Combined effects of scaffold stiffening and mechanical preconditioning cycles on construct biomechanics, gene expression, and tendon repair biomechanics.

    Science.gov (United States)

    Nirmalanandhan, Victor Sanjit; Juncosa-Melvin, Natalia; Shearn, Jason T; Boivin, Gregory P; Galloway, Marc T; Gooch, Cynthia; Bradica, Gino; Butler, David L

    2009-08-01

    Our group has previously reported that in vitro mechanical stimulation of tissue-engineered tendon constructs significantly increases both construct stiffness and the biomechanical properties of the repair tissue after surgery. When optimized using response surface methodology, our results indicate that a mechanical stimulus with three components (2.4% strain, 3000 cycles/day, and one cycle repetition) produced the highest in vitro linear stiffness. Such positive correlations between construct and repair stiffness after surgery suggest that enhancing structural stiffness before surgery could not only accelerate repair stiffness but also prevent premature failures in culture due to poor mechanical integrity. In this study, we examined the combined effects of scaffold crosslinking and subsequent mechanical stimulation on construct mechanics and biology. Autologous tissue-engineered constructs were created by seeding mesenchymal stem cells (MSCs) from 15 New Zealand white rabbits on type I collagen sponges that had undergone additional dehydrothermal crosslinking (termed ADHT in this manuscript). Both constructs from each rabbit were mechanically stimulated for 8h/day for 12 consecutive days with half receiving 100 cycles/day and the other half receiving 3000 cycles/day. These paired MSC-collagen autologous constructs were then implanted in bilateral full-thickness, full-length defects in the central third of rabbit patellar tendons. Increasing the number of in vitro cycles/day delivered to the ADHT constructs in culture produced no differences in stiffness or gene expression and no changes in biomechanical properties or histology 12 weeks after surgery. Compared to MSC-based repairs from a previous study that received no additional treatment in culture, ADHT crosslinking of the scaffolds actually lowered the 12-week repair stiffness. Thus, while ADHT crosslinking may initially stiffen a construct in culture, this specific treatment also appears to mask any benefits

  15. Acromioclavicular joint reconstruction using a tendon graft: a biomechanical study comparing a novel “sutured throughout” tendon graft to a standard tendon graft

    Directory of Open Access Journals (Sweden)

    Naziri Qais

    2016-01-01

    Full Text Available Background: With a recurrence rate of over 30%, techniques that offer stronger acromioclavicular (AC joint reconstruction through increased graft strength may provide longevity. The purpose of our study was to determine the biomechanical strength of a novel tendon graft sutured throughout compared to a native tendon graft in Grade 3 anatomical AC joint reconstruction. Methods: For this in vitro experiment, nine paired (n = 18 embalmed cadaveric AC joints of three males and six females (age 86 years, range 51–94 years were harvested. Anatomic repair with fresh bovine Achilles tendon grafts without bone block was simulated. Specimens were divided into two groups; with group 1 using grafts with ultra-high molecular-weight polyethylene (UHMWPE suture ran throughout the entire length. In group 2, reconstruction with only native allografts was performed. The distal scapula and humerus were casted in epoxy compound and mounted on the mechanical testing machine. Tensile tests were performed using a mechanical testing machine at the rate of 50 mm/min. Maximum load and displacement to failure were collected. Results: The average load to failure was significantly higher for group 1 compared to group 2, with mean values of 437.5 N ± 160.7 N and 94.4 N ± 43.6 N, (p = 0.001. The average displacement to failure was not significantly different, with 29.7 mm ± 10.6 mm in group 1 and 25 mm ± 9.1 mm in group 2 (p = 0.25. Conclusion: We conclude that a UHMWPE suture reinforced graft can provide a 3.6 times stronger AC joint reconstruction compared to a native graft.

  16. Cholic acid-modified polyethylenimine: in vitro and in vivo studies

    Directory of Open Access Journals (Sweden)

    Dube B

    2018-03-01

    Full Text Available Brahmanand Dube,1,2 Abhijeet Pandey,1 Ganesh Joshi,3 Rita Mulherkar,3 Krutika Sawant1 1Pharmacy Department, Faculty of Pharmacy, The Maharaja Sayajirao University of Baroda, Vadodara, 2Wockhardt Research Centre, Wockhardt Ltd, Aurangabad, India; 3Genetic Engineering Laboratory, ACTREC Tata Memorial Centre, Kharghar, Navi Mumbai Abstract: Low-molecular-weight polyethylenimine has lower cytotoxicity than high molecular weight polyethylenimine, but it is not an efficient transfection agent because of limitations of DNA delivery into the cytoplasm. Therefore, in the present study, the hydrophobic modification of low-molecular-weight polyethylenimine (PEI 2 kDa [PEI2] by cholic acid (ChA was performed to form PEI2-ChA, and in vitro and in vivo studies were performed. Results indicate that the nanoplexes of PEI2-ChA with gWIZ-GFP have greater transfection efficiency (27% in NT8e cell lines as evaluated by flow cytometry and also observed by fluorescence imaging. The present study concluded that the transferrin-containing nanoplexes of PEI2-ChA conjugates with plasmid p53 warrant clinical trials in humans after exhaustive animal studies for use as a novel gene delivery system. Keywords: polyethylenimine, biodistribution, tumor regression

  17. Chemical toxicity and radioactivity of depleted uranium: The evidence from in vivo and in vitro studies.

    Science.gov (United States)

    Asic, Adna; Kurtovic-Kozaric, Amina; Besic, Larisa; Mehinovic, Lejla; Hasic, Azra; Kozaric, Mirza; Hukic, Mirsada; Marjanovic, Damir

    2017-07-01

    The main aim of this review is to summarize and discuss the current state of knowledge on chemical toxicity and radioactivity of depleted uranium (DU) and their effect on living systems and cell lines. This was done by presenting a summary of previous investigations conducted on different mammalian body systems and cell cultures in terms of potential changes caused by either chemical toxicity or radioactivity of DU. In addition, the authors aimed to point out the limitations of those studies and possible future directions. The majority of both in vitro and in vivo studies performed using animal models regarding possible effects caused by acute or chronic DU exposure has been reviewed. Furthermore, exposure time and dose, DU particle solubility, and uranium isotopes as factors affecting the extent of DU effects have been discussed. Special attention has been dedicated to chromosomal aberrations, DNA damage and DNA breaks, as well as micronuclei formation and epigenetic changes, as DU has recently been considered a possible causative factor of all these processes. Therefore, this approach might represent a novel area of study of DU-related irradiation effects on health. Since different studies offer contradictory results, the main aim of this review is to summarize and briefly discuss previously obtained results in order to identify the current opinion on DU toxicity and radioactivity effects in relation to exposure type and duration, as well as DU properties. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. Human in vivo and in vitro studies on gastrointestinal absorption of titanium dioxide nanoparticles.

    Science.gov (United States)

    Jones, Kate; Morton, Jackie; Smith, Ian; Jurkschat, Kerstin; Harding, Anne-Helen; Evans, Gareth

    2015-03-04

    The study was designed to conduct human in vivo and in vitro studies on the gastrointestinal absorption of nanoparticles, using titanium dioxide as a model compound, and to compare nanoparticle behaviour with that of larger particles. A supplier's characterisation data may not fully describe a particle formulation. Most particles tested agreed with their supplied characterisation when assessed by particle number but significant proportions of 'nanoparticle formulations' were particles >100nm when assessed by particle weight. Oral doses are measured by weight and it is therefore important that the weight characterisation is taken into consideration. The human volunteer studies demonstrated that very little titanium dioxide is absorbed gastrointestinally after an oral challenge. There was no demonstrable difference in absorption for any of the three particle sizes tested. All tested formulations were shown to agglomerate in simulated gastric fluid, particularly in the smaller particle formulations. Further agglomeration was observed when dispersing formulations in polymeric or elemental foods. Virtually no translocation of titanium dioxide particles across the cell layer was demonstrated. This study found no evidence that nanoparticulate titanium dioxide is more likely to be absorbed in the gut than micron-sized particles. Crown Copyright © 2015. Published by Elsevier Ireland Ltd. All rights reserved.

  19. The effects of mechanical loading on tendons--an in vivo and in vitro model study.

    Directory of Open Access Journals (Sweden)

    Jianying Zhang

    Full Text Available Mechanical loading constantly acts on tendons, and a better understanding of its effects on the tendons is essential to gain more insights into tendon patho-physiology. This study aims to investigate tendon mechanobiological responses through the use of mouse treadmill running as an in vivo model and mechanical stretching of tendon cells as an in vitro model. In the in vivo study, mice underwent moderate treadmill running (MTR and intensive treadmill running (ITR regimens. Treadmill running elevated the expression of mechanical growth factors (MGF and enhanced the proliferative potential of tendon stem cells (TSCs in both patellar and Achilles tendons. In both tendons, MTR upregulated tenocyte-related genes: collagen type I (Coll. I ∼10 fold and tenomodulin (∼3-4 fold, but did not affect non-tenocyte-related genes: LPL (adipocyte, Sox9 (chondrocyte, Runx2 and Osterix (both osteocyte. However, ITR upregulated both tenocyte (Coll. I ∼7-11 fold; tenomodulin ∼4-5 fold and non-tenocyte-related genes (∼3-8 fold. In the in vitro study, TSCs and tenocytes were stretched to 4% and 8% using a custom made mechanical loading system. Low mechanical stretching (4% of TSCs from both patellar and Achilles tendons increased the expression of only the tenocyte-related genes (Coll. I ∼5-6 fold; tenomodulin ∼6-13 fold, but high mechanical stretching (8% increased the expression of both tenocyte (Coll. I ∼28-50 fold; tenomodulin ∼14-48 fold and non-tenocyte-related genes (2-5-fold. However, in tenocytes, non-tenocyte related gene expression was not altered by the application of either low or high mechanical stretching. These findings indicate that appropriate mechanical loading could be beneficial to tendons because of their potential to induce anabolic changes in tendon cells. However, while excessive mechanical loading caused anabolic changes in tendons, it also induced differentiation of TSCs into non-tenocytes, which may lead to the development

  20. Resveratrol and Clinical Trials: The Crossroad from In Vitro Studies to Human Evidence

    Science.gov (United States)

    Tomé-Carneiro, Joao; Larrosa, Mar; González-Sarrías, Antonio; Tomás-Barberán, Francisco A.; García-Conesa, María Teresa; Espín, Juan Carlos

    2013-01-01

    Resveratrol (3,5,4’-trihydroxy-trans-stilbene) is a non-flavonoid polyphenol that may be present in a limited number of food-stuffs such as grapes and red wine. Resveratrol has been reported to exert a plethora of health benefits through many different mechanisms of action. This versatility and presence in the human diet have drawn the worldwide attention of many research groups over the past twenty years, which has resulted in a huge output of in vitro and animal (preclinical) studies. In line with this expectation, many resveratrol-based nutraceuticals are consumed all over the world with questionable clinical/scientific support. In fact, the confirmation of these benefits in humans through randomized clinical trials is still very limited. The vast majority of preclinical studies have been performed using assay conditions with a questionable extrapolation to humans, i.e. too high concentrations with potential safety concerns (adverse effects and drug interactions), short-term exposures, in vitro tests carried out with non-physiological metabolites and/or concentrations, etc. Unfortunately, all these hypothesis-generating studies have contributed to increased the number of ‘potential’ benefits and mechanisms of resveratrol but confirmation in humans is very limited. Therefore, there are many issues that should be addressed to avoid an apparent endless loop in resveratrol research. The so-called ‘Resveratrol Paradox’, i.e., low bioavailability but high bioactivity, is a conundrum not yet solved in which the final responsible actor (if any) for the exerted effects has not yet been unequivocally identified. It is becoming evident that resveratrol exerts cardioprotective benefits through the improvement of inflammatory markers, atherogenic profile, glucose metabolism and endothelial function. However, safety concerns remain unsolved regarding chronic consumption of high RES doses, specially in medicated people. This review will focus on the currently

  1. Effect of different dental ceramic systems on the wear of human enamel: An in vitro study.

    Science.gov (United States)

    Zandparsa, Roya; El Huni, Rabie M; Hirayama, Hiroshi; Johnson, Marc I

    2016-02-01

    The wear of tooth structure opposing different advanced dental ceramic systems requires investigation. The purpose of this in vitro study was to compare the wear of advanced ceramic systems against human enamel antagonists. Four ceramic systems (IPS e.max Press, IPS e.max CAD, Noritake Super Porcelain EX-3, and LAVA Plus Zirconia) and 1 control group containing human enamel specimens were used in this study (n = 12). All specimens were fabricated as disks 11 mm in diameter and 3 mm thick. The mesiopalatal cusps of the maxillary third molars were prepared to serve as the enamel styluses. All specimens were embedded individually in 25 mm(3) autopolymerizing acrylic resin blocks. Wear was measured with a cyclic loading machine and a newly designed wear simulator. All enamel styluses (cusps) were scanned using the Activity 880 digital scanner (SmartOptics). Data from the base line and follow-up scans were collected and compared with Qualify 2012 3-dimensional (3D) and 2D digital inspection software (Geomagic), which aligned the models and detected the geometric changes and the wear caused by the antagonist specimen. One-way ANOVA was used to analyze the collected data. After 125,000 bidirectional loading cycles, the mean loss of opposing enamel volume for the enamel disks in the control group was 37.08 μm(3), the lowest mean value for IPS e.max Press system was 39.75 μm(3); 40.58 μm(3) for IPS e.max CAD; 45.08 μm(3) for Noritake Super Porcelain EX-3 system; and 48.66 μm(3) for the Lava Plus Zirconia system. No statically significant differences were found among the groups in opposing enamel volume loss (P=.225) or opposing enamel height loss (P=.149). In terms of opposing enamel height loss, Lava Plus Zirconia system showed the lowest mean value of 27.5 μm. The mean value for the IPS e.max CAD system was 27.91 μm; 29.08 μm for the control enamel; 33.25 μm for the IPS e.max Press system; and 34.75 μm for the Noritake Super Porcelain EX-3 system. Within the

  2. A facile in vitro model to study rapid mineralization in bone tissues.

    Science.gov (United States)

    Deegan, Anthony J; Aydin, Halil M; Hu, Bin; Konduru, Sandeep; Kuiper, Jan Herman; Yang, Ying

    2014-09-16

    Mineralization in bone tissue involves stepwise cell-cell and cell-ECM interaction. Regulation of osteoblast culture microenvironments can tailor osteoblast proliferation and mineralization rate, and the quality and/or quantity of the final calcified tissue. An in vitro model to investigate the influencing factors is highly required. We developed a facile in vitro model in which an osteoblast cell line and aggregate culture (through the modification of culture well surfaces) were used to mimic intramembranous bone mineralization. The effect of culture environments including culture duration (up to 72 hours for rapid mineralization study) and aggregates size (monolayer culture as control) on mineralization rate and mineral quantity/quality were examined by osteogenic gene expression (PCR) and mineral markers (histological staining, SEM-EDX and micro-CT). Two size aggregates (on average, large aggregates were 745 μm and small 79 μm) were obtained by the facile technique with high yield. Cells in aggregate culture generated visible and quantifiable mineralized matrix within 24 hours, whereas cells in monolayer failed to do so by 72 hours. The gene expression of important ECM molecules for bone formation including collagen type I, alkaline phosphatase, osteopontin and osteocalcin, varied temporally, differed between monolayer and aggregate cultures, and depended on aggregate size. Monolayer specimens stayed in a proliferation phase for the first 24 hours, and remained in matrix synthesis up to 72 hours; whereas the small aggregates were in the maturation phase for the first 24 and 48 hour cultures and then jumped to a mineralization phase at 72 hours. Large aggregates were in a mineralization phase at all these three time points and produced 36% larger bone nodules with a higher calcium content than those in the small aggregates after just 72 hours in culture. This study confirms that aggregate culture is sufficient to induce rapid mineralization and that aggregate

  3. Minibeam radiotherapy with small animal irradiators; in vitro and in vivo feasibility studies

    Science.gov (United States)

    Bazyar, Soha; Inscoe, Christina R.; O'Brian, E. Timothy; Zhou, Otto; Lee, Yueh Z.

    2017-12-01

    Minibeam radiation therapy (MBRT) delivers an ultrahigh dose of x-ray (⩾100 Gy) in 200-1000 µm beams (peaks), separated by wider non-irradiated regions (valleys) usually as a single temporal fraction. Preclinical studies performed at synchrotron facilities revealed that MBRT is able to ablate tumors while maintaining normal tissue integrity. The main purpose of the present study was to develop an efficient and accessible method to perform MBRT using a conventional x-ray irradiator. We then tested this new method both in vitro and in vivo. Using commercially available lead ribbon and polyethylene sheets, we constructed a collimator that converted the cone beam of an industrial irradiator to 44 identical beams (collimator size  ≈  4  ×  10 cm). The dosimetry characteristics of the generated beams were evaluated using two different radiochromic films (beam FWHM  =  246  ±  32 µm center-to-center  =  926  ±  23 µm peak-to-valley dose ratio  =  24.35  ±  2.10 collimator relative output factor  =  0.84  ±  0.04). Clonogenic assays demonstrated the ability of our method to induce radiobiological cell death in two radioresistant murine tumor cell lines (TRP  =  glioblastoma B16-F10  =  melanoma). A radiobiological equivalent dose (RBE) was calculated by evaluating the acute skin response to graded doses of MBRT and conventional radiotherapy (CRT). Normal mouse skin demonstrated resistance to doses up to 150 Gy on peak. MBRT significantly extended the survival of mice with flank melanoma tumors compared to CRT when RBE were applied (overall p  film. In conclusion, the initial dosimetric, in vitro and in vivo evaluations confirmed the utility of this affordable and easy-to-replicate minibeam collimator for future preclinical studies.

  4. Three-dimensional visualization and characterization of bone structure using reconstructed in-vitro μCT images: A pilot study for bone microarchitecture analysis

    Energy Technology Data Exchange (ETDEWEB)

    Latief, Fourier Dzar Eljabbar, E-mail: fourier@fi.itb.ac.id [Physics of Earth and Complex Systems, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia); Dewi, Dyah Ekashanti Octorina [2Biomedical Engineering Research Division, School of Electrical Engineering and Informatics, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia); Shari, Mohd Aliff Bin Mohd [Faculty of Electrical Engineering, Universiti Teknologi MARA Malaysia, 40000 Shah Alam, Selangor (Malaysia)

    2014-03-24

    Micro Computed Tomography (μCT) has been largely used to perform micrometer scale imaging of specimens, bone biopsies and small animals for the study of porous or cavity-containing objects. One of its favored applications is for assessing structural properties of bone. In this research, we perform a pilot study to visualize and characterize bone structure of a chicken bone thigh, as well as to delineate its cortical and trabecular bone regions. We utilize an In-Vitro μCT scanner Skyscan 1173 to acquire a three dimensional image data of a chicken bone thigh. The thigh was scanned using X-ray voltage of 45 kV and current of 150 μA. The reconstructed images have spatial resolution of 142.50 μm/pixel. Using image processing and analysis e.i segmentation by thresholding the gray values (which represent the pseudo density) and binarizing the images, we were able to visualize each part of the bone, i.e., the cortical and trabecular regions. Total volume of the bone is 4663.63 mm{sup 3}, and the surface area of the bone is 7913.42 mm{sup 2}. The volume of the cortical is approximately 1988.62 mm{sup 3} which is nearly 42.64% of the total bone volume. This pilot study has confirmed that the μCT is capable of quantifying 3D bone structural properties and defining its regions separately. For further development, these results can be improved for understanding the pathophysiology of bone abnormality, testing the efficacy of pharmaceutical intervention, or estimating bone biomechanical properties.

  5. Effects of in vitro fertilization and maternal characteristics on perinatal outcomes : a population-based study using siblings

    NARCIS (Netherlands)

    Seggers, Jorien; Pontesilli, Martina; Ravelli, Anita C. J.; Painter, Rebecca C.; Hadders-Algra, Mijna; Heineman, Maas Jan; Repping, Sjoerd; Mol, Ben Willem J.; Roseboom, Tessa J.; Ensing, Sabine

    Objective: To study birthweight in consecutively born sibling singletons conceived with and without in vitro fertilization (IVF) to disentangle the effects of maternal characteristics from those of the IVF treatment itself. Design: Population-based study. Setting: Not applicable. Patient(s):

  6. Cytogenetic effects study of in vitro irradiation in peripheral blood lymphocytes of persons working with ionizing radiation

    International Nuclear Information System (INIS)

    Hadzhidekova, V.; Benova, D.; Bulanova, M.

    1998-01-01

    The genome radiosensitivity of persons working in the NPP 'Kozloduy', as well as controls are studied. An indicator of genome radiosensitivity is the chromosomal damage induced by in vitro irradiation. A cytogenetic analysis of peripheral blood lymphocytes before and after in vitro irradiation with a dose of 1.5 Gy gamma rays is carried out. The frequency of chromosomal aberrations and micronuclei before and after the irradiation is scored. In certain cases the technique of fluorescent in situ hybridization for recording stable chromosome rearrangements is applied. The data obtained show a decreased chromosome radiosensitivity in occupationally engaged persons as compared to low doses, over a long period of time, may induce the so called 'adaptive response' which makes cells more resistant of subsequent in vitro irradiation with a high dose (author)

  7. Sustained-release of caffeine from a polymeric tablet matrix: An in vitro and pharmacokinetic study

    International Nuclear Information System (INIS)

    Tan, Donna; Zhao Bin; Moochhala, Shabbir; Yang Yiyan

    2006-01-01

    Caffeine is utilized as a stimulant to impart a desired level of alertness during certain working hours. Usually, a single dose of caffeine induces 2-3 h of alertness coupled with side effects whereas a longer effect of 8-12 h is very useful for both daily life and military action. Thus, there is a need to deliver the stimulant continuously to an individual at one time to impart an increased level of alertness for the period stated after administration. This study aimed to design a polymeric microparticle system for sustained delivery of caffeine using a polymeric matrix. Poly(ethylene oxide) (PEO) was used as the erodible matrix material and the caffeine polymeric tablets were fabricated by compression using a Graseby Specac hydraulic press. In vitro release profiles as well as the pharmacokinetics studies data were obtained. Caffeine tablets fabricated using various polymers showed a high initial burst release type profile as compared to the caffeine-PEO-tablet. The PK studies showed sustained delivery of caffeine resulted in two expected phenomena: a reduction in the initial high rate of caffeine release (burst release) as well as a reduction in the change in caffeine concentration in the systemic circulation. A simple two-component system for sustained-release caffeine formulation therefore has been achieved

  8. Collaborative study for the validation of alternative in vitro potency assays for human tetanus immunoglobulins.

    Science.gov (United States)

    Gross, S; Janssen, S W J; de Vries, B; Terao, E; Daas, A; Buchheit, K-H

    2010-07-01

    An international collaborative study to validate 2 alternative in vitro methods for the potency testing of human tetanus immunoglobulin products was organised by the European Directorate for the Quality of Medicines & HealthCare (EDQM). The study, run in the framework of the Biological Standardisation Programme (BSP) under the aegis of the European Commission and the Council of Europe, involved 21 official medicines control and industry laboratories from 15 countries. Both methods, an enzyme-linked immunoassay (EIA) and a toxoid inhibition assay (TIA), showed good reproducibility, repeatability and precision. EIA and TIA discriminated between low, medium and high potency samples. Potency estimates correlated well and both values were in close agreement with those obtained by in vivo methods. Moreover, these alternative methods allowed to resolve discrepant results between laboratories that were due to product potency loss and reporting errors. The study demonstrated that EIA and TIA are suitable quality control methods for tetanus immunoglobulin, which can be standardised in a control laboratory using a quality assurance system. Consequently, the Group of Experts on Human Blood and Blood Products of the European Pharmacopoeia revised the monograph on human tetanus immunoglobulins to include both the methods as compendial alternatives to the in vivo mouse challenge assay. 2010 The International Association for Biologicals. Published by Elsevier Ltd. All rights reserved.

  9. In-vitro tensile testing machine for vibration study of fresh rabbit Achilles tendon

    Science.gov (United States)

    Revel, Gian M.; Scalise, Alessandro; Scalise, Lorenzo; Pianosi, Antonella

    2001-10-01

    A lot of people, overall athletic one suffer from tendinitis or complete rupture of the Achilles tendon. This structure becomes inflamed and damaged mainly from a variety of mechanical forces and sometimes due to metabolic problems, such as diabetes or arthritis. Over the past three decades extensive studies have been performed on the structural and mechanical properties of Achilles tendon trying to explain the constitutive equations to describe and foresee tendon behavior. Among the various mechanical parameters, the vibrational behavior is also of interest. Several investigations are performed in order to study how the Achilles tendon vibrations influence the response of the muscle proprioception and human posture. The present article describes how in vitro tensile experiments can be performed, taking into account the need to simulate physiological condition of Achilles tendon and thus approaching some opened problems in the design of the experimental set-up. A new system for evaluating tendon vibrations by non contact techniques is proposed. Preliminary simple elongation tests are made extracting the main mechanical parameters: stress and strain at different fixed stretches, in order to characterize the tissue. Finally, a vibration study is made at each pretensioned tendon level evaluating the oscillating curves caused by a small hammer.

  10. In vitro drug interaction of levocetirizine and diclofenac: Theoretical and spectroscopic studies.

    Science.gov (United States)

    Abo Dena, Ahmed S; Abdel Gaber, Sara A

    2017-06-15

    Levocetirizine dihydrochloride is known to interact with some anti-inflammatory drugs. We report here a comprehensive integrated theoretical and experimental study for the in vitro drug interaction between levocetirizine dihydrochloride (LEV) and diclofenac sodium (DIC). The interaction of the two drugs was confirmed by the molecular ion peak obtained from the mass spectrum of the product. Moreover, FTIR and 1 HNMR spectra of the individual drugs and their interaction product were inspected to allocate the possible sites of interaction. In addition, quantum mechanical DFT calculations were performed to search for the interaction sites and to verify the types of interactions deduced from the spectroscopic studies such as charge-transfer and non-bonding π-π interactions. It was found that the studied drugs interact with each other in aqueous solution via four types of interactions, namely, ion-pair formation, three weak hydrogen bonds, non-bonding π-π interactions and charge-transfer from DIC to LEV. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Sustained-release of caffeine from a polymeric tablet matrix: An in vitro and pharmacokinetic study

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Donna [Defence Medical and Environmental Research Institute, DSO National Laboratories (Kent Ridge), 27 Medical Drive, 12-00, Singapore 117597 (Singapore); Zhao Bin [Defence Medical and Environmental Research Institute, DSO National Laboratories (Kent Ridge), 27 Medical Drive, 12-00, Singapore 117597 (Singapore); Moochhala, Shabbir [Defence Medical and Environmental Research Institute, DSO National Laboratories (Kent Ridge), 27 Medical Drive, 12-00, Singapore 117597 (Singapore)]. E-mail: mshabbir@dso.org.sg; Yang Yiyan [Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, 04-01, The Nanos, Singapore 138669 (Singapore)

    2006-07-25

    Caffeine is utilized as a stimulant to impart a desired level of alertness during certain working hours. Usually, a single dose of caffeine induces 2-3 h of alertness coupled with side effects whereas a longer effect of 8-12 h is very useful for both daily life and military action. Thus, there is a need to deliver the stimulant continuously to an individual at one time to impart an increased level of alertness for the period stated after administration. This study aimed to design a polymeric microparticle system for sustained delivery of caffeine using a polymeric matrix. Poly(ethylene oxide) (PEO) was used as the erodible matrix material and the caffeine polymeric tablets were fabricated by compression using a Graseby Specac hydraulic press. In vitro release profiles as well as the pharmacokinetics studies data were obtained. Caffeine tablets fabricated using various polymers showed a high initial burst release type profile as compared to the caffeine-PEO-tablet. The PK studies showed sustained delivery of caffeine resulted in two expected phenomena: a reduction in the initial high rate of caffeine release (burst release) as well as a reduction in the change in caffeine concentration in the systemic circulation. A simple two-component system for sustained-release caffeine formulation therefore has been achieved.

  12. Antioxidant, Anti-Nephrolithe Activities and in Vitro Digestibility Studies of Three Different Cyanobacterial Pigment Extracts

    Directory of Open Access Journals (Sweden)

    Chetan Paliwal

    2015-08-01

    Full Text Available Phycobiliprotein-containing water and carotenoid-containing methanolic extracts of three different cyanobacteria, Pseudanabaena sp., Spirulina sp. and Lyngbya sp., were studied for their DPPH scavenging, iso-bolographic studies, and anti-nephrolithe activities. The best EC50 values for DPPH scavenging were in Lyngbya water (LW, 18.78 ± 1.57 mg·mg−1 DPPH and Lyngbya methanol (LM, 59.56 ± 37.38 mg·mg−1 DPPH extracts. Iso-bolographic analysis revealed most of the combinations of extracts were antagonistic to each other, although LM—Spirulina methanol (SM 1:1 had the highest synergistic rate of 86.65%. In vitro digestion studies showed that DPPH scavenging activity was considerably decreased in all extracts except for Pseudanabaena methanol (PM and LM after the simulated digestion. All of the extracts were effective in reducing the calcium oxalate crystal size by nearly 60%–65% compared to negative control, while PM and Spirulina water (SW extracts could inhibit both nucleation and aggregation of calcium oxalate by nearly 60%–80%.

  13. In vitro study on the degradation of lithium-doped hydroxyapatite for bone tissue engineering scaffold

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yaping; Yang, Xu; Gu, Zhipeng; Qin, Huanhuan [College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 (China); Li, Li [Department of Oncology, The 452 Hospital of Chinese PLA, Chengdu, Sichuan Province 610021 (China); Liu, Jingwang [College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 (China); Yu, Xixun, E-mail: yuxixun@163.com [College of Polymer Science and Engineering, Sichuan University, Chengdu 610065 (China)

    2016-09-01

    Li-doped hydroxyapatite (LiHA) which is prepared through introducing low dose of Li into hydroxyapatite (HA) has been increasingly studied as a bone tissue-engineered scaffold. The degradation properties play a crucial role in the success of long-term implantation of a bone tissue-engineered construct. Herein, the in vitro degradation behaviors of LiHA scaffolds via two approaches were investigated in this study: solution-mediated degradation and osteoblast-mediated degradation. In solution-mediated degradation, after being immersed in simulated body fluid (SBF) for some time, some characteristics of these scaffolds (such as release of ionized lithium and phosphate, pH change, mechanical properties, cytocompatibility and SEM surface characterization) were systematically tested. A similar procedure was also employed to research the degradation behaviors of LiHA scaffolds in osteoblast-mediated degradation. The results suggested that the degradation in SBF and degradation in culture medium with cell existed distinguishing mechanisms. LiHA scaffolds were degraded via a hydrolytic mechanism when they were soaked in SBF. Upon degradation, an apatite precipitation (layer) was formed on the surfaces of scaffolds. While a biological mechanism was presented for the degradation of scaffolds in cell-mediated degradation. Compared with pure HA, LiHA scaffolds had a better effect on the growth of osteoblast cells, meanwhile, the release amount of PO{sub 4}{sup 3−} in a degradation medium indicated that osteoblasts could accelerate the degradation of LiHA due to the more physiological activities of osteoblast. According to the results from compressive strength test, doping Li into HA could enhance the strength of HA. Moreover, the results from MTT assay and SEM observation showed that the degradation products of LiHA scaffolds were beneficial to the proliferation of osteoblasts. The results of this research can provide the theoretical basis for the clinical application of Li

  14. Biomimetic Implant Surface Functionalization with Liquid L-PRF Products: In Vitro Study

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    Marco Lollobrigida

    2018-01-01

    Full Text Available Objective. Platelet-rich fibrin (PRF clots and membranes are autologous blood concentrates widely used in oral surgical procedures; less is known, however, about the liquid formulations of such products. The aim of this in vitro study is to assess the behavior of different implant surfaces when in contact with two liquid leucocyte- and platelet-rich fibrin (L-PRF products. Methods. Six commercial pure titanium discs, of 9.5 mm diameter and 1.5 mm thickness, were used. Three of these samples had a micro/nano-rough surface; three were machined. Three different protocols were tested. Protocols involved the immersion of the samples in (1 a platelets, lymphocytes, and fibrinogen liquid concentrate (PLyF for 10 minutes, (2 an exudate obtained from L-PRF clots rich in fibronectin and vitronectin for 5 minutes, and (3 the fibronectin/vitronectin exudate for 2 minutes followed by immersion in the PLyF concentrate for further 8 minutes. After these treatments, the samples were fixed and observed using a scanning electron microscope (SEM. Results. Under microscopic observation, (1 the samples treated with the PLyF concentrate revealed a dense fibrin network in direct contact with the implant surface and a significant number of formed elements of blood; (2 in the samples treated with the fibronectin/vitronectin exudates, only a small number of white and red blood cells were detectable; and (3 in samples exposed to the combined treatment, there was an apparent increase in the thickness of the fibrin layer. When compared to the machined surface, the micro/nano-rough samples showed an overall increased retention of fibrin, leading to a thicker coating. Conclusions. Liquid L-PRF products promote the formation of a dense fibrin clot on micro/nano-rough implant surfaces in vitro. The adjunctive treatment of surfaces with the fibronectin/vitronectin exudate could provide support to contact of the fibrin with the surface, though it is not essential for the clot

  15. Studies on in vitro biostability and blood compatibility of polyurethane potting compound based on aromatic polymeric MDI for extracorporeal devices.

    Science.gov (United States)

    Hridya, V K; Jayabalan, M

    2009-12-01

    Polyurethane potting compound based on aromatic isocyanurate of polymeric MDI, poly propylene glycol (PPG400) and trimethylol propane (TMP) has significant favourable properties, good pot life and setting characteristics. The cured potting compound of this formulation has appreciable thermal stability and mechanical properties. In vitro biostability of cured potting compound has been found to be excellent without any significant degradation in simulated physiological media and chemical environment. Studies on blood-material interaction and cytotoxicity reveal in vitro blood compatibility and compatibility with cells of this potting compound.

  16. In vitro co-cultures of Pinus pinaster with Bursaphelenchus xylophilus: a biotechnological approach to study pine wilt disease.

    Science.gov (United States)

    Faria, Jorge M S; Sena, Inês; Vieira da Silva, Inês; Ribeiro, Bruno; Barbosa, Pedro; Ascensão, Lia; Bennett, Richard N; Mota, Manuel; Figueiredo, A Cristina

    2015-06-01

    Co-cultures of Pinus pinaster with Bursaphelenchus xylophilus were established as a biotechnological tool to evaluate the effect of nematotoxics addition in a host/parasite culture system. The pinewood nematode (PWN), Bursaphelenchus xylophilus, the causal agent of pine wilt disease (PWD), was detected for the first time in Europe in 1999 spreading throughout the pine forests in Portugal and recently in Spain. Plant in vitro cultures may be a useful experimental system to investigate the plant/nematode relationships in loco, thus avoiding the difficulties of field assays. In this study, Pinus pinaster in vitro cultures were established and compared to in vivo 1 year-old plantlets by analyzing shoot structure and volatiles production. In vitro co-cultures were established with the PWN and the effect of the phytoparasite on in vitro shoot structure, water content and volatiles production was evaluated. In vitro shoots showed similar structure and volatiles production to in vivo maritime pine plantlets. The first macroscopic symptoms of PWD were observed about 4 weeks after in vitro co-culture establishment. Nematode population in the culture medium increased and PWNs were detected in gaps of the callus tissue and in cavities developed from the degradation of cambial cells. In terms of volatiles main components, plantlets, P. pinaster cultures, and P. pinaster with B. xylophilus co-cultures were all β- and α-pinene rich. Co-cultures may be an easy-to-handle biotechnological approach to study this pathology, envisioning the understanding of and finding ways to restrain this highly devastating nematode.

  17. The influence of storage and heat treatment on a magnesium-based implant material: an in vitro and in vivo study.

    Science.gov (United States)

    Bracht, Katja; Angrisani, Nina; Seitz, Jan-Marten; Eifler, Rainer; Weizbauer, Andreas; Reifenrath, Janin

    2015-10-19

    Magnesium alloys are recommended as a potential material for osteosynthesis. It is known that storage-induced property modifications can occur in materials like aluminum. Thus the aim of this study was to analyze the influence of storage durations of up to 48 weeks on the biomechanical, structural, and degradation properties of the degradable magnesium alloy LAE442. Extruded implants (n = 104; Ø 2.5 mm × 25 mm) were investigated after storage periods of 0, 12, 24, and 48 weeks in three different sub-studies: (I) immediately after the respective storage duration and after an additional (II) 56 days of in vitro corrosion in simulated body fluid (SFB), and (III) 48 weeks in vivo corrosion in a rabbit model, respectively. In addition, the influence of a T5-heat treatment (206 °C for 15 h in an argon atmosphere) was tested (n = 26; 0 week of storage). Evaluation was performed by three-point bending, scanning electron microscopy, radiography, µ-computed tomography, evaluation of the mean grain size, and contrast analysis of precipitations (such as aluminum or lithium). The heat treatment induced a significant reduction in initial stability, and enhanced the corrosion resistance. In vivo experiments showed a good biocompatibility for all implants. During the storage of up to 48 weeks, no significant changes occurred in the implant properties. LAE442 implants can be safely used after up to 48 weeks of storage.

  18. Comparative evaluation of debris removal from root canal wall by using EndoVac and conventional needle irrigation: An in vitro study

    Directory of Open Access Journals (Sweden)

    Vandana J Gade

    2013-01-01

    Full Text Available Context: Microbial control is of paramount importance in Clinical Endodontics. Therefore, cleaning and disinfection of root canals are essential to achieve endodontic success. Aims: The purpose of this study is to compare the efficacy of EndoVac irrigation system and conventional needle (30 gauges side venting needle irrigation for removal of debris from the root canal walls at coronal, middle and apical third by using the scanning electron microscopy (SEM. Settings and Design: An in vitro randomized control trial study. Materials and Methods: A total of 20 mandibular premolars with completely formed roots were selected and randomly divided into two groups - Group 1: Irrigation with the Conventional system and Group 2: EndoVac irrigation. After access opening and working length determination biomechanical preparation completed up to a rotary protaper F4 file. Groupwise irrigation with sodium hypochlorite and ethylenediaminetetraacetic acid was done with each canal in between instrumentation. Then, the teeth were sectioned in buccolingual direction and the halves were sputter-coated with gold palladium and coronal, middle and apical third were examined by SEM at x2000 magnification. Statistical Analysis: Mann-Whitney test for comparison between methods, Kruskal-Wallis test for comparison among thirds and Miller test for individual comparisons. Results: The apical, middle and cervical root canal thirds were evaluated and the results were analyzed statistically by the Mann-Whitney test for comparison between methods, Kruskal-Wallis test for comparison among thirds and Miller test for individual comparisons. Conclusions: EndoVac group resulted in significantly less debris at apical third compared with the conventional needle irrigation group. There was no statistical significant difference found in debris removal at coronal and middle third of root canal wall between the EndoVac group and conventional needle irrigation group.

  19. An in vitro study of the effects of low-level laser radiation on human blood

    Science.gov (United States)

    Siposan, Dan G.; Lukacs, Adalbert

    2003-12-01

    In the last time the study of the effects of LLLR on the blood is considered to be a subject of great importance in elucidating the mechanisms of action between LLLR and biologic tissues. Different methods of therapy by blood irradiation have been developed and used in clinical purposes with benefic effects. This study investigates some in vitro effects of LLLR on some selected rheologic indices of human blood. After establishing whether or not damaging effects could appear due to laser irradiation of the blood, we tried to find a new method for rejuvenating the blood preserved in MacoPharma-type bags. Blood samples were obtained from adult regular donors (volunteers). HeNe laser and laser diodes were used as radiation source, in a wide range of wavelengths, power densities, doses and other parameters of irradiation protocol. In the first series of experiments we established that LLLR does not alter the fresh blood from healthy donors, for doses between 0 and 10 J/cm3 and power densities between 30 and 180 mW/cm3. In the second series of experiments we established that LLLR does have, in some specific conditions, a revitalizing effect on the erythrocytes in preserved blood. We concluded that laser irradiation of the preserved blood, following a selected protocol of irradiation, could be used as a new method to improve the performances of preservation: prolonging the period of storage and blood rejuvenation before transfusion.

  20. Loxosceles gaucho venom-induced acute kidney injury--in vivo and in vitro studies.

    Directory of Open Access Journals (Sweden)

    Rui V Lucato

    Full Text Available BACKGROUND: Accidents caused by Loxosceles spider may cause severe systemic reactions, including acute kidney injury (AKI. There are few experimental studies assessing Loxosceles venom effects on kidney function in vivo. METHODOLOGY/PRINCIPAL FINDINGS: In order to test Loxosceles gaucho venom (LV nephrotoxicity and to assess some of the possible mechanisms of renal injury, rats were studied up to 60 minutes after LV 0.24 mg/kg or saline IV injection (control. LV caused a sharp and significant drop in glomerular filtration rate, renal blood flow and urinary output and increased renal vascular resistance, without changing blood pressure. Venom infusion increased significantly serum creatine kinase and aspartate aminotransferase. In the LV group renal histology analysis found acute epithelial tubular cells degenerative changes, presence of cell debris and detached epithelial cells in tubular lumen without glomerular or vascular changes. Immunohistochemistry disclosed renal deposition of myoglobin and hemoglobin. LV did not cause injury to a suspension of fresh proximal tubules isolated from rats. CONCLUSIONS/SIGNIFICANCE: Loxosceles gaucho venom injection caused early AKI, which occurred without blood pressure variation. Changes in glomerular function occurred likely due to renal vasoconstriction and rhabdomyolysis. Direct nephrotoxicity could not be demonstrated in vitro. The development of a consistent model of Loxosceles venom-induced AKI and a better understanding of the mechanisms involved in the renal injury may allow more efficient ways to prevent or attenuate the systemic injury after Loxosceles bite.

  1. Toxicity of nanoparticles embedded in paints compared to pristine nanoparticles, in vitro study.

    Science.gov (United States)

    Smulders, Stijn; Luyts, Katrien; Brabants, Gert; Golanski, Luana; Martens, Johan; Vanoirbeek, Jeroen; Hoet, Peter H M

    2015-01-22

    The unique physicochemical properties of nanomaterials has led to an increased use in the paint and coating industry. In this study, the in vitro toxicity of three pristine ENPs (TiO2, Ag and SiO₂), three aged paints containing ENPs (TiO₂, Ag and SiO₂) and control paints without ENPs were compared. In a first experiment, cytotoxicity was assessed using a biculture consisting of human bronchial epithelial (16HBE14o-) cells and human monocytic cells (THP-1) to determine subtoxic concentrations. In a second experiment, a new coculture model of the lung-blood barrier consisting of 16HBE14o- cells, THP-1 and human lung microvascular endothelial cells (HLMVEC) was used to study pulmonary and extrapulmonary toxicity. The results show that the pristine TiO₂ and Ag ENPs have some cytotoxic effects at relative high dose, while pristine SiO₂ ENPs and all aged paints with ENPs and control paints do not. In the complex triculture model of the lung-blood barrier, no considerable changes were observed after exposure to subtoxic concentration of the different pristine ENPs and paint particles. In conclusion, we demonstrated that although pristine ENPs show some toxic effects, no significant toxicological effects were observed when they were embedded in a complex paint matrix. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  2. Temporary Vascular Occlusion by Rapid Reverse Phase Polymer: A Preliminary In Vitro Study of Retrograde Injection

    Directory of Open Access Journals (Sweden)

    Einar Dregelid

    2012-01-01

    Full Text Available During vascular surgical operations, there is a need for a simpler and more reliable method of temporary arterial occlusion than those currently employed, especially of heavily calcified arteries. A thermosensitive polymer, LeGoo (LG (Pluromed, Woburn, MA, has been used successfully for temporary vascular occlusion. It has hitherto been injected by a cannula that has been introduced into the artery to be occluded, here henceforth called the “cannulation method.” Injection into arterial ostia without cannulation, using an injection device that arrests blood flow during the injection, here henceforth called “a retrograde method” may enable temporary hemostasis when ostial stenoses render it impossible to inject LG using the cannulation method. The objective of the present study was to study the feasibility of a retrograde method and to compare it with the cannulation method in an in vitro model, incorporating a narrow orifice to simulate ostial stenosis, using tap water at 37°C instead of blood. The retrograde method of LG injection, using a modified paediatric Foley catheter, turned out to be feasible to produce a durable LG plug more reliably, at higher water pressure and with less deep LG injection than with the cannulation method.

  3. The sintered microsphere matrix for bone tissue engineering: in vitro osteoconductivity studies.

    Science.gov (United States)

    Borden, Mark; Attawia, Mohamed; Laurencin, Cato T

    2002-09-05

    A tissue engineering approach has been used to design three-dimensional synthetic matrices for bone repair. The osteoconductivity and degradation profile of a novel polymeric bone-graft substitute was evaluated in an in vitro setting. Using the copolymer poly(lactide-co-glycolide) [PLAGA], a sintering technique based on microsphere technology was used to fabricate three-dimensional porous scaffolds for bone regeneration. Osteoblasts and fibroblasts were seeded onto a 50:50 PLAGA scaffold. Morphologic evaluation through scanning electron microscopy demonstrated that both cell types attached and spread over the scaffold. Cells migrated through the matrix using cytoplasmic extensions to bridge the structure. Cross-sectional images indicated that cellular proliferation had penetrated into the matrix approximately 700 microm from the surface. Examination of the surfaces of cell/matrix constructs demonstrated that cellular proliferation had encompassed the pores of the matrix by 14 days of cell culture. With the aim of optimizing polymer composition and polymer molecular weight, a degradation study was conducted utilizing the matrix. The results demonstrate that degradation of the sintered matrix is dependent on molecular weight, copolymer ratio, and pore volume. From this data, it was determined that 75:25 PLAGA with an initial molecular weight of 100,000 has an optimal degradation profile. These studies show that the sintered microsphere matrix has an osteoconductive structure capable of functioning as a cellular scaffold with a degradation profile suitable for bone regeneration. Copyright 2002 Wiley Periodicals, Inc.

  4. Release of metal ions from fixed orthodontic appliance: an in vitro study in continuous flow system.

    Science.gov (United States)

    Mikulewicz, Marcin; Chojnacka, Katarzyna; Wołowiec, Paulina

    2014-01-01

    To evaluate the release of metal ions from fixed orthodontic appliances. A new system for in vitro testing of dental materials was constructed and consisted of a thermostatic glass reactor that enabled immersion of the studied material. Experimental conditions reflected the human oral cavity, with a temperature of 37°C and a saliva flow rate of 0.5mL/min. The simulated fixed orthodontic appliance made of stainless steel was evaluated. Sampling was performed at several time points during the 28-day study, and the metal ion concentration was determined by inductively coupled plasma optical emission spectrometry. The total mass of released metal ions from the appliance during 4 weeks of the experiment was as follows nickel 18.7 μg, chromium 5.47 μg, copper 31.3 μg. The estimated doses of nickel, chromium, and copper determined by extrapolation of experimental data released during the treatment period were far below the toxic dose to humans. This shows that orthodontic treatment might not be a significant source of exposure to these metal ions.

  5. An in vitro study of mesiobuccal root thickness of maxillary first molars.

    Science.gov (United States)

    Mohammadzadeh Akhlaghi, Nahid; Ravandoust, Yasaman; Najafi, Mohammad; Dadresanfar, Bahareh

    2012-01-01

    Understanding the internal anatomy of root canal system can significantly influence outcomes of root canal treatment. The aim of this in vitro study was to measure the thickness of mesiobuccal root at different levels in maxillary first molars. In this cross-sectional study, forty extracted human maxillary first molars were radiographed; accordingly, the mesial and distal root thicknesses of mesiobuccal (MB) roots were measured at four parallel horizontal levels. The samples were sectioned at the measured levels and then sections were scanned and saved in the computer. Buccal (B), Palatal (P), Mesial (M) and Distal (D) aspects of root thicknesses in single-canalled roots were measured. In two-canalled mesiobuccal roots, Distobuccal (DB) and Distopalatal (DP) aspects were evaluated alongside other measurements. Average radicular thickness in each aspect and each level was compared using ANOVA and t-test. A total of 25 had two canals and 15 had one canal in MB root. In single-canalled roots M and D aspects were the thinnest whereas in two-canalled samples, the thicknesses of DP and DB aspects were significantly less than others (Pmolar roots in order to avoid technical mishaps.

  6. Geometrical accuracy of metallic objects produced with additive or subtractive manufacturing: A comparative in vitro study.

    Science.gov (United States)

    Braian, Michael; Jönsson, David; Kevci, Mir; Wennerberg, Ann

    2018-04-06

    To evaluate the accuracy and precision of objects produced by additive manufacturing systems (AM) for use in dentistry and to compare with subtractive manufacturing systems (SM). Ten specimens of two geometrical objects were produced by five different AM machines and one SM machine. Object A mimics an inlay-shaped object, while object B imitates a four-unit bridge model. All the objects were sorted into different measurement dimensions (x, y, z), linear distances, angles and corner radius. None of the additive manufacturing or subtractive manufacturing groups presented a perfect match to the CAD file with regard to all parameters included in the present study. Considering linear measurements, the precision for subtractive manufacturing group was consistent in all axes for object A, presenting results of additive manufacturing groups had consistent precision in the x-axis and y-axis but not in the z-axis. With regard to corner radius measurements, the SM group had the best overall accuracy and precision for both objects A and B when compared to the AM groups. Within the limitations of this in vitro study, the conclusion can be made that subtractive manufacturing presented overall precision on all measurements below 0.050mm. The AM machines also presented fairly good precision, additive techniques are now being implemented. Thus all these production techniques need to be tested, compared and validated. Copyright © 2018 The Academy of Dental Materials. Published by Elsevier Inc. All rights reserved.

  7. Axial flow velocity patterns in a normal human pulmonary artery model: pulsatile in vitro studies.

    Science.gov (United States)

    Sung, H W; Yoganathan, A P

    1990-01-01

    It has been clinically observed that the flow velocity patterns in the pulmonary artery are directly modified by disease. The present study addresses the hypothesis that altered velocity patterns relate to the severity of various diseases in the pulmonary artery. This paper lays a foundation for that analysis by providing a detailed description of flow velocity patterns in the normal pulmonary artery, using flow visualization and laser Doppler anemometry techniques. The studies were conducted in an in vitro rigid model in a right heart pulse duplicator system. In the main pulmonary artery, a broad central flow field was observed throughout systole. The maximum axial velocity (150 cm s-1) was measured at peak systole. In the left pulmonary artery, the axial velocities were approximately evenly distributed in the perpendicular plane. However, in the bifurcation plane, they were slightly skewed toward the inner wall at peak systole and during the deceleration phase. In the right pulmonary artery, the axial velocity in the perpendicular plane had a very marked M-shaped profile at peak systole and during the deceleration phase, due to a pair of strong secondary flows. In the bifurcation plane, higher axial velocities were observed along the inner wall, while lower axial velocities were observed along the outer wall and in the center. Overall, relatively low levels of turbulence were observed in all the branches during systole. The maximum turbulence intensity measured was at the boundary of the broad central flow field in the main pulmonary artery at peak systole.

  8. Fracture Resistance of Implant Abutments Following Abutment Alterations by Milling the Margins: An In Vitro Study.

    Science.gov (United States)

    Patankar, Anuya; Kheur, Mohit; Kheur, Supriya; Lakha, Tabrez; Burhanpurwala, Murtuza

    2016-12-01

    This in vitro study evaluated the effect of different levels of preparation of an implant abutment on its fracture resistance. The study evaluated abutments that incorporated a platform switch (Myriad Plus Abutments, Morse Taper Connection) and Standard abutments (BioHorizons Standard Abutment, BioHorizons Inc). Each abutment was connected to an appropriate implant and mounted in a self-cured resin base. Based on the abutment preparation depths, 3 groups were created for each abutment type: as manufactured, abutment prepared 1 mm apical to the original margin, and abutment prepared 1.5 mm to the original margin. All the abutments were prepared in a standardized manner to incorporate a 0.5 mm chamfer margin uniformly. All the abutments were torqued to 30 Ncm on their respective implants. They were then subjected to loading until failure in a universal testing machine. Abutments with no preparation showed the maximum resistance to fracture for both groups. As the preparation depth increased, the fracture resistance decreased. The fracture resistance of implant abutment junction decreases as the preparation depth increases.

  9. Three-Dimensional Blood-Brain Barrier Model for in vitro Studies of Neurovascular Pathology

    Science.gov (United States)

    Cho, Hansang; Seo, Ji Hae; Wong, Keith H. K.; Terasaki, Yasukazu; Park, Joseph; Bong, Kiwan; Arai, Ken; Lo, Eng H.; Irimia, Daniel

    2015-10-01

    Blood-brain barrier (BBB) pathology leads to neurovascular disorders and is an important target for therapies. However, the study of BBB pathology is difficult in the absence of models that are simple and relevant. In vivo animal models are highly relevant, however they are hampered by complex, multi-cellular interactions that are difficult to decouple. In vitro models of BBB are simpler, however they have limited functionality and relevance to disease processes. To address these limitations, we developed a 3-dimensional (3D) model of BBB on a microfluidic platform. We verified the tightness of the BBB by showing its ability to reduce the leakage of dyes and to block the transmigration of immune cells towards chemoattractants. Moreover, we verified the localization at endothelial cell boundaries of ZO-1 and VE-Cadherin, two components of tight and adherens junctions. To validate the functionality of the BBB model, we probed its disruption by neuro-inflammation mediators and ischemic conditions and measured the protective function of antioxidant and ROCK-inhibitor treatments. Overall, our 3D BBB model provides a robust platform, adequate for detailed functional studies of BBB and for the screening of BBB-targeting drugs in neurological diseases.

  10. In vitro study on tooth enamel lesions related to whitening dentifrice.

    Science.gov (United States)

    de Araújo, Danilo Barral; Silva, Luciana Rodrigues; Campos, Elisângela de Jesus; Correia de Araújo, Roberto Paulo

    2011-01-01

    The tooth whitening substances for extrinsic use that are available in Brazil contain hydrogen peroxide or carbamide peroxide. Several studies have attributed the appearance of lesions in the enamel morphology, including hypersensitivity, to these substances. Such lesions justify fluoride therapy and application of infrared lasers, among other procedures. However, there is no consensus among researchers regarding the relevance of the severity of lesions detected on the tooth surface. The present study was carried out with an aim of evaluating in vitro the effects of the hydrogen peroxide, carbamide peroxide and sodium bicarbonate contained in dentifrice formulations, on human tooth enamel. After darkening process in laboratory, human premolars were brushed using dentifrice containing the two whitening substances (Rembrandt - carbamide peroxide and Mentadent - hydrogen peroxide) and the abrasive product (Colgate - sodium bicarbonate). The degree of specimen staining before and after this procedure was determined using spectrophotometry. Scanning electron microscopy (SEM) was used to obtain images, which were analyzed to show the nature of the lesions that appeared on the enamel surface. The effectiveness of the whitening caused by hydrogen peroxide and carbamide peroxide and the abrasion caused by bicarbonate were confirmed, given that the treated test pieces returned to their original coloration. Based on SEM, evaluation of the enamel surfaces subjected to the test products showed that different types of morphologic lesions of varying severity appeared. Whitening dentifrice containing hydrogen peroxide and carbamide peroxide produced lesions on the enamel surface such that the greatest sequelae were associated with exposure to hydrogen peroxide.

  11. Inhibitory Effect of Curcumin on Candida-albicans compared with Nystatin: an in-vitro Study

    Directory of Open Access Journals (Sweden)

    Neda Babaii

    2016-10-01

    Full Text Available Introduction: Curcumin is the active ingredient in the traditional herbal remedy and dietary spice turmeric (Curcuma longa. Curcumin has a surprisingly wide range of beneficial properties, including anti-inflammatory, antioxidant, chemopreventive and chemotherapeutic activity. on basis of recent studies; it has antifungal and antibacterial effects. The aim of this study was in-vitro evaluation of antifungal effect of curcumin on candida albicans and comparing it with nystatin. Methods: after preparing curcumin powder, 3 laboratory methods were used to evaluate antifungal effect. The first method was cell count technique, used to evaluate the amount of candida albicans after time, in different concentrations of curcumin in Dimethyl sulfoxide (DMSO. The second was cup bioassay, in which inhibitory a zone of curcumin in DMSO was evaluated in sabouraud culture plates; and in third method, inhibitory zones of dried disks; which contained curcumin in DMSO were evaluated. Results: the result of all three methods showed that curcumin has antifungal effect and this effect increases in more concentrations. Conclusion: curcumin has apparent and dose dependent antifungal effect on candida albicans.

  12. Active humidification with Boussignac CPAP: in vitro study of a new method.

    Science.gov (United States)

    Alonso-Iñigo, José M; Almela, Amadeo; Albert, Alejandro; Carratalá, José M; Fas, María J

    2013-04-01

    To carry out an in vitro study of Boussignac CPAP valve performance with a new humidification method, using a heated humidifier. Two heated humidifiers were evaluated: Fisher & Paykel MR850, and Covidien Kendall Aerodyne 2000. Baseline measurements were taken in all experimental conditions without humidification. The Boussignac valve was adapted to the input of the humidification chamber. The system was connected to a test lung to assess the degree of pressurization. Hygrometric and pressure measurements were performed with the following gas flows: 10, 20, 30 and 40 L/min. The mean values of pressure generated by the Boussignac valve were 1.99 ± 0.02, 6.97 ± 0.05, 16.61 ± 0.08 and 21.24 ± 0.08 cm H2O, 10, 20, 30 and 40 L/min, respectively, no differences being detected between study groups. Overall absolute humidity was significantly greater with a heated humidifier than without humidification (range 40.01 ± 0.57-25.46 ± 0.49 compared to 0.16 ± 0.13 mgH2O/L, P humidification yielded humidity values above 25 mg H2O/L regardless of the heated humidifier and flow used. Pressurization values remained constant in each experimental situation and were not influenced by adding humidification. These data open up the possibility of using Boussignac CPAP on different types of patients, with different interfaces and for long periods of time.

  13. Biodegradation of nickel and chromium from space maintainers: An in vitro study

    Directory of Open Access Journals (Sweden)

    Bhaskar V

    2010-03-01

    Full Text Available Band materials are often used in the practice of pediatric dentistry. Nickel and Chromium are the main ingredients of these materials. The potential health hazards of nickel and chromium and their compounds have been the focus of attention for more than 100 years. It has established that these metals could cause hypersensitivity. The study was undertaken to analyze in vitro biodegradation of space maintainers made out of stainless steel band materials from manufacturers Dentaurum and Unitek. The leaching effect simulating the use of one, two, three, and four space maintainers in clinical practice was studied by keeping the respective number of space maintainers in the artificial saliva incubating at 37°C and analyzing for nickel and chromium release after 1,7,14,21 and 28 days using atomic absorption spectrophotometer. Results showed that there was measurable release of both nickel and chromium which reached maximum level at the end of 7 days which was statistically significant (P < 0.05 and was very much below the dietary average intake even for four bands used and was not capable of causing any toxicity.

  14. Low molecular weight chitosan conjugated with folate for siRNA delivery in vitro: optimization studies

    Science.gov (United States)

    Fernandes, Julio C; Qiu, Xingping; Winnik, Francoise M; Benderdour, Mohamed; Zhang, Xiaoling; Dai, Kerong; Shi, Qin

    2012-01-01

    The low transfection efficiency of chitosan is one of its drawbacks as a gene delivery carrier. Low molecular weight chitosan may help to form small-sized polymer-DNA or small interfering RNA (siRNA) complexes. Folate conjugation may improve gene transfection efficiency because of the promoted uptake of folate receptor-bearing cells. In the present study, chitosan was conjugated with folate and investigated for its efficacy as a delivery vector for siRNA in vitro. We demonstrate that the molecular weight of chitosan has a major influence on its biological and physicochemical properties, and very low molecular weight chitosan (below 10 kDa) has difficulty in forming stable complexes with siRNA. In this study, chitosan 25 kDa and 50 kDa completely absorbed siRNA and formed nanoparticles (≤220 nm) at a chitosan to siRNA weight ratio of 50:1. The introduction of a folate ligand onto chitosan decreased nanoparticle toxicity. Compared with chitosan-siRNA, folate-chitosan-siRNA nanoparticles improved gene silencing transfection efficiency. Therefore, folate-chitosan shows potential as a viable candidate vector for safe and efficient siRNA delivery. PMID:23209368

  15. Developing high-frequency ultrasound tomography for testicular tumor imaging in rats: An in vitro study

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chih-Chung, E-mail: cchuang@mail.ncku.edu.tw [Department of Biomedical Engineering, National Cheng Kung University, Tainan 701, Taiwan (China); Chen, Wei-Tsen [Department of Electrical Engineering, Fu Jen Catholic University, New Taipei City 24205, Taiwan (China)

    2014-01-15

    Purpose: This paper describes a feasibility study for developing a 35-MHz high-frequency ultrasound computed-tomography (HFUCT) system for imaging rat testicles. Methods: The performances of two kinds of HFUCT-attenuation and sound-speed UCT-based on transmission and pulse-echo modes were investigated in this study. Experiments were carried out using phantoms and actual rat testiclesin vitro. HFUCT images were reconstructed using a filtered backprojection algorithm. Results: The phantom experimental results indicated that all types of HFUCT can determine the dimensions of a plastic cylinder with a diameter of 500μm. Compared to sound-speed HFUCT, attenuation HFUCT exhibited a better performance in recognizing a tiny sclerosed region in a gelatin phantom. Therefore, the in vitro testicular experiments were performed using attenuation HFUCT based on transmission and pulse-echo modes. The experimentally measured attenuation coefficient and sound speed for healthy rat testicles were 2.92 ± 0.25 dB/mm and 1537 ± 25 m/s, respectively. Conclusions: A homogeneous texture was evident for healthy testicles using both modes. An artificial sclerosed tumor could also be clearly observed using two- and three-dimensional attenuation HFUCT in both modes. However, an object artifact was apparent in pulse-echo mode because of ultrasound beam refraction. All of the obtained experimental results indicate the potential of using HFUCT as a novel tool for monitoring the preclinical responses of testicular tumors in small animals.

  16. Developing high-frequency ultrasound tomography for testicular tumor imaging in rats: An in vitro study

    International Nuclear Information System (INIS)

    Huang, Chih-Chung; Chen, Wei-Tsen

    2014-01-01

    Purpose: This paper describes a feasibility study for developing a 35-MHz high-frequency ultrasound computed-tomography (HFUCT) system for imaging rat testicles. Methods: The performances of two kinds of HFUCT-attenuation and sound-speed UCT-based on transmission and pulse-echo modes were investigated in this study. Experiments were carried out using phantoms and actual rat testiclesin vitro. HFUCT images were reconstructed using a filtered backprojection algorithm. Results: The phantom experimental results indicated that all types of HFUCT can determine the dimensions of a plastic cylinder with a diameter of 500μm. Compared to sound-speed HFUCT, attenuation HFUCT exhibited a better performance in recognizing a tiny sclerosed region in a gelatin phantom. Therefore, the in vitro testicular experiments were performed using attenuation HFUCT based on transmission and pulse-echo modes. The experimentally measured attenuation coefficient and sound speed for healthy rat testicles were 2.92 ± 0.25 dB/mm and 1537 ± 25 m/s, respectively. Conclusions: A homogeneous texture was evident for healthy testicles using both modes. An artificial sclerosed tumor could also be clearly observed using two- and three-dimensional attenuation HFUCT in both modes. However, an object artifact was apparent in pulse-echo mode because of ultrasound beam refraction. All of the obtained experimental results indicate the potential of using HFUCT as a novel tool for monitoring the preclinical responses of testicular tumors in small animals

  17. PCL-coated hydroxyapatite scaffold derived from cuttlefish bone: In vitro cell culture studies

    International Nuclear Information System (INIS)

    Milovac, Dajana; Gamboa-Martínez, Tatiana C.; Ivankovic, Marica; Gallego Ferrer, Gloria; Ivankovic, Hrvoje

    2014-01-01

    In the present study, we examined the potential of using highly porous poly(ε-caprolactone) (PCL)-coated hydroxyapatite (HAp) scaffold derived from cuttlefish bone for bone tissue engineering applications. The cell culture studies were performed in vitro with preosteoblastic MC3T3-E1 cells in static culture conditions. Comparisons were made with uncoated HAp scaffold. The attachment and spreading of preosteoblasts on scaffolds were observed by Live/Dead staining Kit. The cells grown on the HAp/PCL composite scaffold exhibited greater spreading than cells grown on the HAp scaffold. DNA quantification and scanning electron microscopy (SEM) confirmed a good proliferation of cells on the scaffolds. DNA content on the HAp/PCL scaffold was significantly higher compared to porous HAp scaffolds. The amount of collagen synthesis was determined using a hydroxyproline assay. The osteoblastic differentiation of the cells was evaluated by determining alkaline phosphatase (ALP) activity and collagen type I secretion. Furthermore, cell spreading and cell proliferation within scaffolds were observed using a fluorescence microscope. - Highlights: • Hydroxyapatite/poly(ε-caprolactone) scaffold with interconnected pores was prepared • Cytotoxicity test showed that the scaffold was not cytotoxic towards MC3T3-E1 cells • The scaffold supported the attachment, proliferation and differentiation of cells • A 3D cell colonization was confirmed using the fluorescence microscopy • The scaffold might be a promising candidate for bone tissue engineering

  18. In vitro studies of osteoblasts response onto zinc aluminate ceramic films

    Directory of Open Access Journals (Sweden)

    Marco Antonio Alvarez-Pérez

    2009-01-01

    Full Text Available Zinc based or doped ceramics have shown to be capable of increasing osteoblasts proliferation, biomineralization and bone formation. However, studies regarding the biological applications processes in ZnAl2O4 ceramic films are very scarce. For this reason, the objective of this in vitro study was to investigate the response of osteoblasts cells cultured onto ZnAl2O4 films. Our results showed a good biological response related to attachment and viability, with good cell morphology attached to the semi-spherical grains of the ceramic and the analysis of mineral-like tissue showed a high quantity of mineral deposited and organized as tiny spherical-like nodules attached to nanostructure surface of ZnAl2O4 material films. Based in our results, ZnAl2O4 films stimulated the bioactivity of osteoblasts cells and provide a microenvironment that favors cell differentiation and mineralization processes, suggesting their potential use as osteoconductive coating onto currently orthopedic and dental implants.

  19. In vivo and in vitro studies on a muscarinic presynaptic antagonist and postsynaptic agonist: BM-5

    International Nuclear Information System (INIS)

    Nordstrom, O.; Bartafi, T.; Frieder, B.; Grimm, V.; Ladinsky, H.; Unden, A.

    1986-01-01

    This paper reports on in vitro and in vivo studies with compound BM-5 which, at proper dosage, could have great potential since it could enhance cholinergic transmission by being a presynaptic antagonist and postsynaptic agonist. Binding studies are described in which tritium-4-NMPB, a muscarinic antagonist, was displaced by compound BM-5 in membranes from striatum, cerebral cortex, cerebellum and hippocampus. The binding data are summarized, which for each brain area involved 86-92 data points evaluated by means of nonlinear regression methods. Compound BM-5 recognized in each brain region a population of high and a population of low affinity binding sites; both of which were labelled with tritium-4-NMPB. It is shown that compound BM-5 causes muscarinic cholinergic agonist-like effects such as redness of the eye, increased motility in the gut, and impairment of locomotor behavior. It also produces muscarinic super-sensitivity upon chronic treatment, and decreases rat striatial ACh content by acute treatment

  20. In-vitro study on haemodiluted blood flow in a sinusoidal microstenosis.

    Science.gov (United States)

    Kang, M J; Ji, H-S; Lee, S J

    2010-01-01

    In-vitro experiments were carried out to investigate the haemodynamic and haemorheological behaviours of haemodiluted blood flow through a microstenosis using a micro-particle image velocimetry (PIV) technique. The micro-PIV system employed in this study consisted of a two-head neodymium:yttrium-aluminium-garnet (Nd:YAG) laser, a cooled charge-coupled device camera, and a delay generator. To simulate blood flow in a stenosed vascular vessel, a polydimethylsiloxane (PDMS) microchannel with a sinusoidal throat of 80 per cent severity was employed. The width and depth of the microchannel were 100 microm and 50 microm, respectively. To compare the flow characteristics in the microstenosis, the same experiments were repeated in a straight microchannel under the same flow conditions. Using a syringe pump, human blood with 5 per cent haematocrit was supplied into the microstenosis channel. The flow characteristics and transport of blood cells through the microstenosis were investigated with various flowrates. The mean velocity fields were nearly symmetric with respect to the channel centreline. In the contraction section, the oncoming blood flow was accelerated rapidly, and the maximum velocity at the throat was almost 4.99 times faster than that of the straight microchannel without stenosis. In the diffusion section, the blood cells show rolling, deformation, twisting, and tumbling motion due to the flow-choking characteristics at the stenotic region. The results from this study will provide useful basic data for comparison with those obtained by clinical researchers.

  1. 3D polylactide-based scaffolds for studying human hepatocarcinoma processes in vitro

    International Nuclear Information System (INIS)

    Scaffaro, Roberto; Lo Re, Giada; Rigogliuso, Salvatrice; Ghersi, Giulio

    2012-01-01

    We evaluated the combination of leaching techniques and melt blending of polymers and particles for the preparation of highly interconnected three-dimensional polymeric porous scaffolds for in vitro studies of human hepatocarcinoma processes. More specifically, sodium chloride and poly(ethylene glycol) (PEG) were used as water-soluble porogens to form porous and solvent-free poly(L,D-lactide) (PLA)-based scaffolds. Several characterization techniques, including porosimetry, image analysis and thermogravimetry, were combined to improve the reliability of measurements and mapping of the size, distribution and microarchitecture of pores. We also investigated the effect of processing, in PLA-based blends, on the simultaneous bulk/surface modifications and pore architectures in the scaffolds, and assessed the effects on human hepatocarcinoma viability and cell adhesion. The influence of PEG molecular weight on the scaffold morphology and cell viability and adhesion were also investigated. Morphological studies indicated that it was possible to obtain scaffolds with well-interconnected pores of assorted sizes. The analysis confirmed that SK-Hep1 cells adhered well to the polymeric support and emitted surface protrusions necessary to grow and differentiate three-dimensional systems. PEGs with higher molecular weight showed the best results in terms of cell adhesion and viability. (paper)

  2. 3D polylactide-based scaffolds for studying human hepatocarcinoma processes in vitro

    Science.gov (United States)

    Scaffaro, Roberto; Lo Re, Giada; Rigogliuso, Salvatrice; Ghersi, Giulio

    2012-08-01

    We evaluated the combination of leaching techniques and melt blending of polymers and particles for the preparation of highly interconnected three-dimensional polymeric porous scaffolds for in vitro studies of human hepatocarcinoma processes. More specifically, sodium chloride and poly(ethylene glycol) (PEG) were used as water-soluble porogens to form porous and solvent-free poly(L,D-lactide) (PLA)-based scaffolds. Several characterization techniques, including porosimetry, image analysis and thermogravimetry, were combined to improve the reliability of measurements and mapping of the size, distribution and microarchitecture of pores. We also investigated the effect of processing, in PLA-based blends, on the simultaneous bulk/surface modifications and pore architectures in the scaffolds, and assessed the effects on human hepatocarcinoma viability and cell adhesion. The influence of PEG molecular weight on the scaffold morphology and cell viability and adhesion were also investigated. Morphological studies indicated that it was possible to obtain scaffolds with well-interconnected pores of assorted sizes. The analysis confirmed that SK-Hep1 cells adhered well to the polymeric support and emitted surface protrusions necessary to grow and differentiate three-dimensional systems. PEGs with higher molecular weight showed the best results in terms of cell adhesion and viability.

  3. In vitro comparative study of manual and mechanical rotary instrumentation of root canals using computed tomography.

    Science.gov (United States)

    Limongi, Orlando; de Albuquerque, Diana Santana; Baratto Filho, Flares; Vanni, José Roberto; de Oliveira, Elias P Motcy; Barletta, Fernando Branco

    2007-01-01

    This in vitro study compared, using computed tomography (CT), the amount of dentin removed from root canal walls by manual and mechanical rotary instrumentation techniques. Forty mandibular incisors with dental crown and a single canal were selected. The teeth were randomly assigned to two groups, according to the technique used for root canal preparation: Group I - manual instrumentation with stainless steel files; Group II - mechanical instrumentation with RaCe rotary nickel-titanium instruments. In each tooth, root dentin thickness of the buccal, lingual, mesial and distal surfaces in the apical, middle and cervical thirds of the canal was measured (in mm) using a multislice CT scanner (Siemens Emotion, Duo). Data were stored in the SPSS v. 11.5 and SigmaPlot 2001 v. 7.101 softwares. After crown opening, working length was determined, root canals were instrumented and new CT scans were taken for assessment of root dentin thickness. Pre- and post-instrumentation data were compared and analyzed statistically by ANOVA and Tukey's post-hoc test for significant differences (p=0.05). Based on the findings of this study, it may be concluded that regarding dentin removal from root canal walls during instrumentation, neither of the techniques can be considered more effective than the other.

  4. Biomechanics in Schools.

    Science.gov (United States)

    Vincent, J. F. V.

    1980-01-01

    Examines current usage of the term "biomechanics" and emphasizes the importance of differentiating between structure and material. Describes current prolects in biomechanics and lists four points about the educational significance of the field. (GS)

  5. Primary Spinal OPC Culture System from Adult Zebrafish to Study Oligodendrocyte Differentiation In Vitro

    Directory of Open Access Journals (Sweden)

    Volker Kroehne

    2017-09-01

    Full Text Available Endogenous oligodendrocyte progenitor cells (OPCs are a promising target to improve functional recovery after spinal cord injury (SCI by remyelinating denuded, and therefore vulnerable, axons. Demyelination is the result of a primary insult and secondary injury, leading to conduction blocks and long-term degeneration of the axons, which subsequently can lead to the loss of their neurons. In response to SCI, dormant OPCs can be activated and subsequently start to proliferate and differentiate into mature myelinating oligodendrocytes (OLs. Therefore, researchers strive to control OPC responses, and utilize small molecule screening approaches in order to identify mechanisms of OPC activation, proliferation, migration and differentiation. In zebrafish, OPCs remyelinate axons of the optic tract after lysophosphatidylcholine (LPC-induced demyelination back to full thickness myelin sheaths. In contrast to zebrafish, mammalian OPCs are highly vulnerable to excitotoxic stress, a cause of secondary injury, and remyelination remains insufficient. Generally, injury induced remyelination leads to shorter internodes and thinner myelin sheaths in mammals. In this study, we show that myelin sheaths are lost early after a complete spinal transection injury, but are re-established within 14 days after lesion. We introduce a novel, easy-to-use, inexpensive and highly reproducible OPC culture system based on dormant spinal OPCs from adult zebrafish that enables in vitro analysis. Zebrafish OPCs are robust, can easily be purified with high viability and taken into cell culture. This method enables to examine why zebrafish OPCs remyelinate better than their mammalian counterparts, identify cell intrinsic responses, which could lead to pro-proliferating or pro-differentiating strategies, and to test small molecule approaches. In this methodology paper, we show efficient isolation of OPCs from adult zebrafish spinal cord and describe culture conditions that enable

  6. In vitro kinetic studies on the mechanism of oxygen-dependent cellular uptake of copper radiopharmaceuticals

    Energy Technology Data Exchange (ETDEWEB)

    Holland, Jason P; Bell, Stephen G; Wong, Luet-Lok; Dilworth, Jonathan R [Department of Chemistry, University of Oxford, Chemistry Research Laboratory, 12 Mansfield Road, Oxford, OX1 3TA (United Kingdom); Giansiracusa, Jeffrey H [Department of Mathematics, Mathematical Institute, University of Oxford, 24-29 St Giles' , Oxford, OX1 3LB (United Kingdom)], E-mail: hollanj3@mskcc.org, E-mail: jasonpholland@gmail.com

    2009-04-07

    The development of hypoxia-selective radiopharmaceuticals for use as therapeutic and/or imaging agents is of vital importance for both early identification and treatment of cancer and in the design of new drugs. Radiotracers based on copper for use in positron emission tomography have received great attention due to the successful application of copper(II) bis(thiosemicarbazonato) complexes, such as [{sup 60/62/64}Cu(II)ATSM] and [{sup 60/62/64}Cu(II)PTSM], as markers for tumour hypoxia and blood perfusion, respectively. Recent work has led to the proposal of a revised mechanism of hypoxia-selective cellular uptake and retention of [Cu(II)ATSM]. The work presented here describes non-steady-state kinetic simulations in which the reported pO{sub 2}-dependent in vitro cellular uptake and retention of [{sup 64}Cu(II)ATSM] in EMT6 murine carcinoma cells has been modelled by using the revised mechanistic scheme. Non-steady-state (NSS) kinetic analysis reveals that the model is in very good agreement with the reported experimental data with a root-mean-squared error of less than 6% between the simulated and experimental cellular uptake profiles. Estimated rate constants are derived for the cellular uptake and washout (k{sub 1} = 9.8 {+-} 0.59 x 10{sup -4} s{sup -1} and k{sub 2} = 2.9 {+-} 0.17 x 10{sup -3} s{sup -1}), intracellular reduction (k{sub 3} = 5.2 {+-} 0.31 x 10{sup -2} s{sup -1}), reoxidation (k{sub 4} = 2.2 {+-} 0.13 mol{sup -1} dm{sup 3} s{sup -1}) and proton-mediated ligand dissociation (k{sub 5} = 9.0 {+-} 0.54 x 10{sup -5} s{sup -1}). Previous mechanisms focused on the reduction and reoxidation steps. However, the data suggest that the origins of hypoxia-selective retention may reside with the stability of the copper(I) anion with respect to protonation and ligand dissociation. In vitro kinetic studies using the nicotimamide adenine dinucleotide (NADH)-dependent ferredoxin reductase enzyme PuR isolated from the bacterium Rhodopseudomonas palustris have

  7. Cerclage handling for improved fracture treatment. A biomechanical study on the twisting procedure.

    Science.gov (United States)

    Wähnert, D; Lenz, M; Schlegel, U; Perren, S; Windolf, M

    2011-01-01

    Twisting is clinically the most frequently applied method for tightening and maintaining cerclage fixation. The twisting procedure is controversially discussed. Several factors during twisting affect the mechanical behaviour of the cerclage. This in vitro study investigated the influence of different parameters of the twisting procedure on the fixation strength of the cerclage in an experimental setup with centripetal force application. Cortical half shells of the femoral shaft were mounted on a testing fixture. 1.0 mm, 1.25 mm and 1.5 mm stainless ste- el wire cerclages as well as a 1.0mm cable cerclage were applied to the bone. Pretension of the cerclage during the installation was measured during the locking procedure. Subsequently, cyclic testing was performed up to failure. Higher pretension could be achieved with increasing wire diameter. However, with larger wire diameter the drop of pre- tension due to the bending and cutting the twist also increased. The cable cerclage showed the highest pretension after locking. Cerclages twisted under traction revealed significantly higher initial cerclage tension. Plastically deformed twists offered higher cerclage pretension compared to twists which were deformed in the elastic region of the material. Cutting the wire within the twist caused the highest loss of cerclage tension (44% initial tension) whereas only 11 % was lost when cutting the wire ends separately. The bending direction of the twist significantly influenced the cerclage pretension. 45% pretension was lost in forward bending of the twist, 53% in perpendicular bending and 90% in backward bending. Several parameters affect the quality of a cerclage fixation. Adequate installation of cerclage wires could markedly improve the clinical outcome of cerclage.

  8. Why National Biomechanics Day?

    Science.gov (United States)

    DeVita, Paul

    2018-04-11

    National Biomechanics Day (NBD) seeks to expand the influence and impact of Biomechanics on our society by expanding the awareness of Biomechanics among young people. NBD will manifest this goal through worldwide, synchronized and coordinated celebrations and demonstrations of all things Biomechanics with high school students. NBD invites all Biomechanists to participate in NBD 2018, http://nationalbiomechanicsday.asbweb.org/. Copyright © 2018 Elsevier Ltd. All rights reserved.

  9. Hydrogel based tissue mimicking phantom for in-vitro ultrasound contrast agents studies.

    Science.gov (United States)

    Demitri, Christian; Sannino, Alessandro; Conversano, Francesco; Casciaro, Sergio; Distante, Alessandro; Maffezzoli, Alfonso

    2008-11-01

    Ultrasound medical imaging (UMI) is the most widely used image analysis technique, and often requires advanced in-vitro set up to perform morphological and functional investigations. These studies are based on contrast properties both related to tissue structure and injectable contrast agents (CA). In this work, we present a three-dimensional structure composed of two different hydrogels reassembly the microvascular network of a human tissue. This phantom was particularly suitable for the echocontrastographic measurements in human microvascular system. This phantom has been characterized to present the acoustic properties of an animal liver, that is, acoustic impedance (Z) and attenuation coefficient (AC), in UMI signal analysis in particular; the two different hydrogels have been selected to simulate the target organ and the acoustic properties of the vascular system. The two hydrogels were prepared starting from cellulose derivatives to simulating the target organ parenchyma and using a PEG-diacrylate to reproduce the vascular system. Moreover, harmonic analysis was performed on the hydrogel mimicking the liver parenchyma hydrogel to evaluate the ultrasound (US) distortion during echographic measurement. The phantom was employed in the characterization of an experimental US CA. Perfect agreement was found when comparing the hydrogel acoustical properties materials with the corresponding living reference tissues (i.e., vascular and parenchimal tissue).

  10. In vitro adsorption study of fluoxetine in activated carbons and activated carbon fibres

    Energy Technology Data Exchange (ETDEWEB)

    Nabais, J.M. Valente; Mouquinho, A.; Galacho, C.; Carrott, P.J.M.; Ribeiro Carrott, M.M.L. [Centro de Quimica de Evora e Departamento de Quimica da Universidade de Evora, Rua Romao Ramalho no. 59, 7000-671 Evora (Portugal)

    2008-05-15

    We study the in vitro adsorption of fluoxetine hydrochloride by different adsorbents in simulated gastric and intestinal fluid, pH 1.2 and 7.5, respectively. The tested materials were two commercial activated carbons, carbomix and maxsorb MSC30, one activated carbon fibre produced in our laboratory and also three MCM-41 samples, also produced by us. Selected samples were modified by liquid phase oxidation and thermal treatment in order to change the surface chemistry without significant modifications to the porous characteristics. The fluoxetine adsorption follows the Langmuir model. The calculated Q{sub 0} values range from 54 to 1112 mg/g. A different adsorption mechanism was found for the adsorption of fluoxetine in activated carbon fibres and activated carbons. In the first case the most relevant factors are the molecular sieving effect and the dispersive interactions whereas in the activated carbons the mechanism seams to be based on the electrostatic interactions between the fluoxetine molecules and the charged carbon surface. Despite the different behaviours most of the materials tested have potential for treating potential fluoxetine intoxications. (author)

  11. In vitro study of stimulation effect on endothelialization by a copper bearing cobalt alloy.

    Science.gov (United States)

    Jin, Shujing; Qi, Xun; Wang, Tongmin; Ren, Ling; Yang, Ke; Zhong, Hongshan

    2018-02-01

    Endothelialization is an important process after stenting in coronary artery. Recovery of the injured site timely can reduce the neointima formation and platelet absorbance, leading to a lower risk of in-stent restenosis. Copper is known to be critical in vascular construction. Thus a combination of copper with stent materials is a meaningful attempt. A copper bearing L605-Cu cobalt alloy was prepared and its effect on human umbilical vein endothelial cells (HUVECs) was evaluated in vitro in this study. It was found that HUVECs attached and stretched better on the surface of L605-Cu compared with L605, and the apoptosis of cells was decreased simultaneously. The migration and tube formation of HUVECs were also enhanced by the extract of L605-Cu. Furthermore, L605-Cu increased the mRNA expression of VEGF in HUVECs significantly. However it had no effect on the secretion of NO or mRNA expression of eNOS. The result of blood clotting test indicated that L605-Cu had better blood compatibility. These results above have demonstrated that the L605-Cu alloy is promising to be a new stent material with function of accelerating endothelialization. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 561-569, 2018. © 2017 Wiley Periodicals, Inc.

  12. Ontogeny of phorbol ester receptors in rat brain studied by in vitro autoradiography

    International Nuclear Information System (INIS)

    Miyoshi, R.; Kito, S.

    1990-01-01

    The ontogeny of phorbol ester receptors, which have been considered to correspond to protein kinase C, in the rat brain was studied through in vitro autoradiography with 3 H-phorbol 12,13-dibutyrate ( 3 H-PDBu). The distribution of 3 H-PDBu binding sites in the adult rat brain was similar to the previous reports by other researchers. The developmental pattern of 3 H-PDBu binding sites varried with brain region. 3 H-PDBu binding sites in the amygdala, thalamus, stratum pyramidale of CA 1 of the hippocampus, dentate gyrus, superior colliculus, substantia nigra, interpeduncular nucleus and cerebellar molecular layer were postnatally increased to adult levels and after that they remained constant. On the other hand, in the stratum oriens and stratum radiatum of CA 1 of the hippocampus, and in the lateral and medial geniculate bodies, 3 H-PDBu binding sites reached peaks at 21 or 28 days of postnatal age and after that they declined to adult levels. The cerebellar granular layer showed a low level of 3 H-PDBu binding sites throughout all the ontogenetic stages. A distinct ontogenetic pattern of phorbol ester receptors in various regions of the brain may reflect a role of protein kinase C in the neural development of each discrete area. (Authors)

  13. Influence of different beverages on the force degradation of intermaxillary elastics: an in vitro study

    Directory of Open Access Journals (Sweden)

    Jorge César Borges Leão Filho

    2013-04-01

    Full Text Available Objective: The aim of this study was to evaluate in vitro the effects of frequently ingested beverages on force degradation of intermaxillary elastics. Material and Methods: One hundred and eighty 1/4-inch intermaxillary elastics (TP Orthodontics were immersed into six different beverages: (1 Coca-Cola®; (2 Beer; (3 Orange juice; (4 Red wine; (5 Coffee and (6 artificial saliva (control. The period of immersion was 15 min for the first and second cycles and 30 min for the third to fifth cycles. Tensile forces were read in a tensile testing machine before and after the five immersion cycles. One-way repeated measures ANOVA was used to identify significant differences. Results: Force degradation was seen in all evaluated groups and at all observation periods (p<0.05. A greater degree of degradation was present at the initial periods, decreasing gradually over time. However, no statistically significant differences were seen among groups at the same periods, showing that different groups behaved similarly. Conclusions: The chemical nature of the evaluated beverages was not able to influence the degree of force degradation at all observation periods.

  14. An In Vitro Study of the Antimicrobial Effects of Indigo Naturalis Prepared from Strobilanthes formosanus Moore

    Directory of Open Access Journals (Sweden)

    Yin-Ru Chiang

    2013-11-01

    Full Text Available Indigo naturalis is effective in treating nail psoriasis coexisting with microorganism infections. This study examines the antimicrobial effects of indigo naturalis prepared from Strobilanthes formosanus Moore. Eight bacterial and seven fungal strains were assayed using the agar diffusion method to examine the effects of indigo naturalis and its bioactive compounds. The bioactive compounds of indigo naturalis were purified sequentially using GFC, TLC, and HPLC. Their structures were identified using mass spectrometry and NMR spectroscopy. UPLC-MS/MS was applied to compare the metabolome profiles of indigo naturalis ethyl-acetate (EA extract and its source plant, Strobilanthes formosanus Moore. The results of in vitro antimicrobial assays showed that indigo naturalis EA-extract significantly (≥1 mg/disc inhibits Gram-positive bacteria (Staphylococcus aureus, S. epidermis and methicillin-resistant S. aureus (MRSA and mildly inhibits non-dermatophytic onychomycosis pathogens (Aspergillus fumigates and Candida albicans, but has little effect on dermatophyes. Isatin and tryptanthrin were identified as the bioactive compounds of indigo naturalis using S. aureus and S. epidermis as the bioassay model. Both bioactive ingredients had no effect on all tested fungi. In summary, indigo naturalis prepared from Strobilanthes formosanus Moore exhibits antimicrobial effects on Staphylococcus and non-dermatophytic onychomycosis pathogens. Tryptanthrin and isatin may be its major bioactive ingredients against Staphylococcus and the inhibitory effect on MRSA may be due to other unidentified ingredients.

  15. Experimental results using 3-bromopyruvate in mesothelioma: in vitro and in vivo studies.

    Science.gov (United States)

    Icard, Philippe; Philippe, Icard; Zhang, Xiao-Dong; Xiao-Dong, Zhang; Lemoisson, Edwige; Edwige, Lemoisson; Louis, Marie-Hélène; Marie-Hélène, Louis; Allouche, Stéphane; Stéphane, Allouche; Lincet, Hubert; Hubert, Lincet; Poulain, Laurent; Laurent, Poulain

    2012-02-01

    Over many years we have taken advantage of the special metabolism of cancer cells involving an increased consumption of glucose associated with lactic acid production even in the presence of oxygen, a phenomenon referred to as the "Warburg effect", to counteract cancer cell growth. We have tested 3-bromopyruvate (3-BrPA), an inhibitor of pyruvate-associated reactions. Firstly, we tested this agent, in vitro, in two mesothelioma cell lines. Cellular response would appear to depend on the mode of administration (immediately or 24 h after seeding). Depending on the line, 3-BrPA induced a cytostatic or cytotoxic effect. This effect was accompanied by cell death induction even in cells highly refractory to cisplatin. Mitochondrial apoptotic death appeared to involve both lines; however, a different death pathway such as necrosis cannot be excluded. Interestingly, 3-BrPA leads to a diminution of the expression of the anti-apotptoic protein Mcl-1. We then tested 3-BrPA in vivo. Survival of nude mice bearing human mesothelioma was significantly prolonged (p < 0.0001). Toxicity and clinical studies should be performed to test 3- BrPA as local therapy for patients suffering from pleural or peritoneal mesothelioma. Association with cisplatin should be particularly considered.

  16. [In vitro study with techniques of imaging of the composition of urinary calculi].

    Science.gov (United States)

    Tellez Martínez-Fornés, M; Burgos Revilla, F J; Sáez Garrido, J C; Soria Descalzo, J; Barbero González, J; Sánchez Corral, J; Minaya Minaya, A; Vallejo Herrador, J

    1997-02-01

    Pre-treatment knowledge of the lithiasic composition can be useful to design the most appropriate therapeutic scheme for each kind of stone. The relationship between the stone's densitometry information provided by the different imaging techniques, conventional radiology (RX), computerized axial tomography (CAT) and dual energy radiographic densitometry (DO) is analyzed, as well as the elemental composition determined by the microanalysis of fragments obtained post-lithotrity using a scanning electronic microscope (SEM) associated to X-ray dispersion energy (XDE). 60 stones, 12 for each pure composition selected (calcium oxalate mono and dihydro, phosphocarbonate, magnesium ammonium phosphate and uric acid), were studied with XR, CAT and DO and were later subjected to lithofragmentation in vitro. Fragments analysis was carried out post-lithotrity with SEM associated to XDE. The X-ray does not allow to establish the composition of some calculi. CAT quantifies the mineral contents of the oxalocalcic and infective calculi and differentiates the uric acid from the other compositions because the mean density values are under 500 Hounsfield Units. DO evaluates the lithiasic content in phosphocarbonate salts which are structurally similar to bone hydroxyapatite.

  17. Prevention of enamel demineralization during orthodontic treatment: an in vitro comparative study.

    Science.gov (United States)

    Bichu, Yashodhan M; Kamat, Nandini; Chandra, Pavan Kumar; Kapoor, Aditi; Razmus, Thomas; Aravind, N K S

    2013-01-01

    Enamel demineralization is considered to be the most prevalent and significant iatrogenic effect associated with fixed orthodontic treatment and can seriously jeopardize both tooth longevity and dental esthetics. This in vitro study was undertaken to compare the effectiveness of four different commercially available surface treatment medicaments for the inhibition of enamel demineralization. Seventy-five intact maxillary premolars extracted from patients undergoing orthodontic treatment were divided into five equal groups and were subjected to one of the following protocols: no treatment (control group) or treatment with one of the following four medicaments: fluoride varnish (Fluor Protector [FP]), casein phosphopeptide-amorphous calcium phosphate (GC Tooth Mousse [TM]), calcium sodium phosphosilicate (SHY-NM), and casein phosphopeptide-amorphous calcium phosphate with fluoride (GC Tooth Mousse Plus [TMP]). All the teeth were subjected to ten Cate demineralization solution?for 96 hours and subsequently evaluated under polarized light microscopy to obtain the mean depths of enamel demineralization. One-way analysis of variance and Bonferroni comparison tests were used to obtain statistically significant differences between the five different groups at P < .05. All four surface treatment medicaments provided statistically significant reduction in the depths of enamel demineralization as compared with the control group. FP provided the greatest protection of enamel surface in terms of reduction of lesion depth, followed by TMP, SHY-NM, and TM. The use of these commercially available medicaments could prove to be beneficial for patients undergoing orthodontic treatment and who are at a risk for developing enamel decalcification.

  18. High-Performance Liquid Chromatographic Ultraviolet Determination of Memantine Hydrochloride after In Vitro Transdermal Diffusion Studies

    Directory of Open Access Journals (Sweden)

    Sergio del Rio-Sancho

    2013-01-01

    Full Text Available The purpose of the present work was to validate an accurate and precise high-performance liquid chromatography (HPLC method involving ultraviolet detection for the quantitative analysis of memantine hydrochloride. In order to analyze a molecule with no chromophoric groups that could be detected by a UV/visible detector, it was necessary to extract the drug and to perform a dansylation reaction that enabled the UV/visible detection of the derivatized molecule. Separation was carried out with a 150 mm Kromasil C18 column at room temperature. The detection response, at 218 nm, was found to be linear in the concentration range from 0.5 to 50 μg/mL. The method was validated for specificity, linearity, precision, accuracy, limit of detection, limit of quantification, and robustness. The limit of detection (LOD was 0.144 μg/mL, and the limit of quantification (LOQ was 0.437 μg/mL. The dansylated memantine complex was stable for at least five days in all the conditions evaluated. The potential use of this method has been demonstrated by the quantification of memantine hydrochloride contained in samples from the study of its in vitro transdermal permeation.

  19. In Vitro Antioxidant Activities of Three Red Wine Polyphenols and Their Mixtures: An Interaction Study

    Directory of Open Access Journals (Sweden)

    Elena Kurin

    2012-12-01

    Full Text Available The well-known antioxidant activity of red wine is explained mostly by its polyphenols content, where the final effect is based on the wine components’ interaction. The aim of our work was the study of the interaction of three red wine polyphenols—quercetin, resveratrol and caffeic acid—alone and in their equimolar binary and ternary mixtures in different antioxidant/scavenging assays (inhibition of 2-deoxy-D-ribose degradation by hydroxyl radical, FRAP, Fe(III reducing power, DPPH, ABTS and NO scavenging, respectively. Interaction analysis, based on median effect equation, was performed for the determination of synergy and/or antagonism. The obtained results indicate that the mutual interactions of tested polyphenols in their mixtures are markedly different from each other, depending on the reaction mechanism of the assay used. The measured antioxidant activity of individual polyphenols is not a constant value when other substances are present in the mixture with this polyphenol. Interactions can cause the finally observed synergy/antagonism/additive effects without any possibility of predicting them from the known activities of single compounds. This “unpredictability” claim based on in vitro assay results should be very important in multiple systems and processes in Nature, where the interactions among compounds in mixtures need to be take into account.

  20. Design, synthesis, in vitro Evaluation and docking studies on dihydropyrimidine-based urease inhibitors.

    Science.gov (United States)

    Iftikhar, Fatima; Ali, Yousaf; Ahmad Kiani, Farooq; Fahad Hassan, Syed; Fatima, Tabeer; Khan, Ajmal; Niaz, Basit; Hassan, Abbas; Latif Ansari, Farzana; Rashid, Umer

    2017-10-01

    In our previous report, we have identified 3,4-dihydropyrimidine scaffold as promising class of urease inhibitor in a structure based virtual screen (SBVS) experiment. In present study, we attempted to optimize the scaffold by varying C-5 substituent. The elongation of the C-5 chain was achieved by the reaction of C-5 ester with hydrazine leading to C-5 carbohydrazides which were further used as building blocks for the synthesis of fifteen new compounds having diverse moieties. A significantly higher in vitro urease inhibitory activity with IC 50 values in submicromolar range was observed for semithiocarbazide derivatives (4a-c, 0.58-0.79µM) and isatin Schiff base derivative 5a (0.23µM). Docking analysis suggests that the synthesized compounds were anchored well in the catalytic site and extending to the entrance of binding pocket and thus restrict the mobility of the flap by interacting with its key amino acid residues. The overall results of urease inhibition have shown that these compounds can be further optimized and developed as lead urease inhibitors. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Development of in vitro models for cellular and molecular studies in toxicology and chemoprevention

    Energy Technology Data Exchange (ETDEWEB)

    Mace, K.; Offord, E.A.; Harris, C.C.; Pfeifer, A.M.A. [Nestle Research Center, Lausanne (Switzerland)

    1998-12-31

    Many natural dietary phytochemicals found compounds found in fruits, vegetables, spices and tea have been shown in recent years to be protective against cancer in various animal models. In the light of the potential impact of these compounds on human health it is important to elucidate the mechanisms involved. We therefore developed and characterized relevant in vitro models using immortalized human epithelial cell lines derived from target tissues in carcinogenesis, such as lung, liver and colon. Assays were established, allowing the evaluation of the cytotoxic and genotoxic effects of various procarcinogens, including nitrosamines, mycotoxins and heterocyclic amines on these metabolically-competent human epithelial cell lines. These cellular models appeared to be a useful tool to study the capacity of certain food components to block the initiation stage of carcinogenesis. The ability of carnosol and carnosic acid from rosemary as well as the synthetic dithiolethione, oltipraz, to block the formation of DNA adducts, and their effects on the expression of phase I and phase II enzymes was investigated. We have observed that both rosemary extracts and oltiprax inhibited benzo(a)pyrene- or aflatoxin B{sub 1}-induced DNA adduct formation by strongly inhibiting CYP{sub 450} activities and inducing the expression of glutathione S-transferase. These results in human cell models give some insight into the different mechanisms involved in the chemopreventive action of both natural and synthetic compounds in relation to phase I and phase II enzymes. (orig.)

  2. Replica of human dentin treated with different desensitizing agents: a methodological SEM study in vitro

    Directory of Open Access Journals (Sweden)

    Pereira Jose Carlos

    2002-01-01

    Full Text Available This is a preliminary study to determine a methodological sequence in vitro which may allow the reproduction of dentin for SEM analysis, after the use of different desensitizing agents. Dentin discs obtained from extracted human third molars were etched with 6% citric acid, an artificial smear layer was created and the surface dentin discs were divided into four quadrants. Quadrants 2, 3 and 4 of each disc were conditioned with 6% citric acid. The desensitizing agents (Oxa-Gel®, Gluma Desensitizer and an experimental agent were applied to quadrants 3 and 4. To evaluate the acid resistance of the treatment, quadrant 4 was etched again with 6% citric acid. An impression was then taken with Aquasil ULV. After a setting period of 6 min, each disc was removed from the impression and stored in a moist-free environment for 24 h at 37ºC. After that time, a low-viscosity epoxy resin (Araltec GY 1109 BR was poured into the impression and cured for 24 h. All specimens were metal-coated for SEM analysis. Comparison of the photomicrographs of dentin discs with their respective impressions and resin replicas showed that this technique can reproduce the characteristics of the dentin surface treated with desensitizing agents.

  3. Effects of ozone nano-bubble water on periodontopathic bacteria and oral cells - in vitro studies

    International Nuclear Information System (INIS)

    Hayakumo, Sae; Izumi, Yuichi; Arakawa, Shinichi; Kondo, Keiko; Takahashi, Masayoshi; Mano, Yoshihiro

    2014-01-01

    The aims of the present study were to evaluate the bactericidal activity of a new antiseptic agent, ozone nano-bubble water (NBW3), against periodontopathogenic bacteria and to assess the cytotoxicity of NBW3 against human oral cells. The bactericidal activities of NBW3 against representative periodontopathogenic bacteria, Porphyromonas gingivalis (P. gingivalis) and Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) were evaluated using in vitro time-kill assays. The cytotoxicity of NBW3 was evaluated using three-dimensional human buccal and gingival tissue models. The numbers of colony forming units (CFUs)/mL of P. gingivalis and A. actinomycetemcomitans exposed to NBW3 dropped to below the lower limit of detection (<10 CFUs mL −1 ) after only 0.5 min of exposure. There were only minor decreases in the viability of oral tissue cells after 24 h of exposure to NBW3. These results suggest that NBW3 possesses potent bactericidal activity against representative periodontopathogenic bacteria and is not cytotoxic to cells of human oral tissues. The use of NBW3 as an adjunct to periodontal therapy would be promising. (paper)

  4. A Partnership and Coping Enhancement Program for Couples Undergoing In Vitro Fertilization Treatment: An Intervention Study.

    Science.gov (United States)

    Ying, Liying; Wu, Xiangli; Wu, Lai Har; Shu, Jing; Loke, Alice Yuen

    2018-02-15

    This is a feasibility study to examine the effects of a partnership and coping enhancement program (PCEP) on improving the psychological well-being and marital functions of couples undergoing in vitro fertilization treatment. A total of 100 couples were recruited consecutively and assigned to a PCEP intervention group or a routine care control group. The couples in the PCEP group received an additional face-to-face, couple-based, 90-minute session on enhancing partnership and coping on the day of the embryo transfer (ET). The outcome measures were assessed at baseline (T0), 10 days after the ET (T1), and one month after the ET (T2). The level of anxiety of the women was lower in the intervention than in the control group at T1. Significant improvements in partnership and dyadic coping were seen in women at T2. The men of infertile couples reported a significant improvement in the scores for partnership at T2. The PCEP had no significant effects on marital satisfaction and marital adjustment for both the females and males of the infertile couples. The findings indicated that the PCEP is feasible and acceptable. Before a larger simple-size randomized controlled trial with participants drawn from multiple reproductive medical centers is conducted to further confirm its effectiveness.

  5. Antifungal Activity of Oleuropein against Candida albicans—The In Vitro Study

    Directory of Open Access Journals (Sweden)

    Nataša Zorić

    2016-11-01

    Full Text Available In the present study we investigated activity of oleuropein, a complex phenol present in large quantities in olive tree products, against opportunistic fungal pathogen Candida albicans. Oleuropein was found to have in vitro antifungal activity with a minimal inhibitory concentration (MIC value of 12.5 mg·mL−1. Morphological changes in the nuclei after staining with fluorescent DNA-binding dyes revealed that apoptosis was a primary mode of cell death in the analyzed samples treated with subinhibitory concentrations of oleuropein. Our results suggest that this antifungal agent targets virulence factors essential for establishment of the fungal infection. We noticed that oleuropein modulates morphogenetic conversion and inhibits filamentation of C. albicans. The hydrophobicity assay showed that oleuropein in sub-MIC values has significantly decreased, in both aerobic and anaerobic conditions, the cellular surface hydrophobicity (CSH of C. albicans, a factor associated with adhesion to epithelial cells. It was also demonstrated that the tested compound inhibits the activity of SAPs, cellular enzymes secreted by C. albicans, which are reported to be related to the pathogenicity of the fungi. Additionally, we detected that oleuropein causes a reduction in total sterol content in the membrane of C. albicans cells, which might be involved in the mechanism of its antifungal activity.

  6. Effects of ozone nano-bubble water on periodontopathic bacteria and oral cells - in vitro studies

    Energy Technology Data Exchange (ETDEWEB)

    Hayakumo, Sae; Izumi, Yuichi [Department of Periodontology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510 (Japan); Arakawa, Shinichi; Kondo, Keiko [Department of Lifetime Oral Health Care Science, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510 (Japan); Takahashi, Masayoshi [National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki, 305-8569 (Japan); Mano, Yoshihiro [Hyperbaric Medical Center, Hospital of Medicine, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo, 113-8510 (Japan)

    2014-10-15

    The aims of the present study were to evaluate the bactericidal activity of a new antiseptic agent, ozone nano-bubble water (NBW3), against periodontopathogenic bacteria and to assess the cytotoxicity of NBW3 against human oral cells. The bactericidal activities of NBW3 against representative periodontopathogenic bacteria, Porphyromonas gingivalis (P. gingivalis) and Aggregatibacter actinomycetemcomitans (A. actinomycetemcomitans) were evaluated using in vitro time-kill assays. The cytotoxicity of NBW3 was evaluated using three-dimensional human buccal and gingival tissue models. The numbers of colony forming units (CFUs)/mL of P. gingivalis and A. actinomycetemcomitans exposed to NBW3 dropped to below the lower limit of detection (<10 CFUs mL{sup −1}) after only 0.5 min of exposure. There were only minor decreases in the viability of oral tissue cells after 24 h of exposure to NBW3. These results suggest that NBW3 possesses potent bactericidal activity against representative periodontopathogenic bacteria and is not cytotoxic to cells of human oral tissues. The use of NBW3 as an adjunct to periodontal therapy would be promising. (paper)

  7. Effect of a novel bioactive glass-ceramic on dentinal tubule occlusion: an in vitro study.

    Science.gov (United States)

    Zhong, Y; Liu, J; Li, X; Yin, W; He, T; Hu, D; Liao, Y; Yao, X; Wang, Y

    2015-03-01

    This in vitro study aimed to assess the ability and efficacy of HX-BGC, a novel bioactive glass-ceramic (SiO2-P2 O5-CaO-Na2 O-SrO), to reduce dentine tubule permeability. Dentine discs from human third molars were etched and randomly allocated into five groups: Group 1--distilled water; Group 2--Sensodyne Repair toothpaste (containing NovaMin®); Group 3--HX-BGC toothpaste (containing 7.5% HX-BGC); Group 4--control toothpaste (without HX-BGC); and Group 5--HX-BGC powder. Specimens were treated daily by brushing with an electric toothbrush for 20 seconds. Between daily treatments (7 days total), specimens were immersed in artificial saliva for 24 hours. Dentine permeability was measured at baseline, after the first treatment, after the first 24-hour immersion in artificial saliva and at the end of day 7. Dentine morphology and surface deposits were observed by scanning electron microscopy after one day and 7 days of treatment, respectively. Sensodyne Repair and bioactive glass-ceramic toothpaste significantly and immediately lowered dentine permeability. The HX-BGC powder group showed the highest reduction in dentine permeability after 7 days of treatment. The novel bioactive glass-ceramic material HX-BGC is effective in reducing dentine permeability by occluding open dentine tubules, indicating that HX-BGC may be a potential treatment for dentine hypersensitivity. © 2015 Australian Dental Association.

  8. Radiation cytogenetic in vitro studies on human donors in the development of a suitable biological dosimeter

    International Nuclear Information System (INIS)

    Barjaktarovic, N.

    1988-02-01

    The final report is on the work carried out under the Agency research contract 3173/RB entitled ''Radiation cytogenetic in vitro studies on human donors in the development of a suitable biological dosimeter'', at the Clinical Hospital Centre ''Zvezdara'' in Belgrade, Yugoslavia. In co-operation and co-ordination dissemination with an international team of cytogeneticists under the IAEA CRP, the development of a suitable biological dosimetry system has been accomplished at the national institute to assist reliably in the absorbed radiation-dose assessment of accidentally-over-exposed personnel. The quantitative yield of asymmetrical chromosomal aberrations, such as dicentrics, rings and fragments consequent to exposure(s) to radiation overdose, help in such estimation of vital prognostic and radiation protection significance. This biological dosimeter system is particularly essential where the exposed person was not wearing any physical dosemeter during the accident. Prerequisite for implementation of an effective biological dosimetry is the availability of a reliable standard dose-response curve and an adherence to a protocol for lymphocytic chromosome analysis in first division phase of lymphocytes. The validation of the reported biological dosimeter is established through its successful analysis of a simulated over-exposure incident, with the associated error of less than 10%. Analytical cytogenetic methods for whole- and part-body acute exposures have been discussed. Part of the results have been reported in the publications under the CRP concerned

  9. In vitro studies evaluating leaching of mercury from mine waste calcine using simulated human body fluids

    Science.gov (United States)

    Gray, John E.; Plumlee, Geoffrey S.; Morman, Suzette A.; Higueras, Pablo L.; Crock, James G.; Lowers, Heather A.; Witten, Mark L.

    2010-01-01

    In vitro bioaccessibility (IVBA) studies were carried out on samples of mercury (Hg) mine-waste calcine (roasted Hg ore) by leaching with simulated human body fluids. The objective was to estimate potential human exposure to Hg due to inhalation of airborne calcine particulates and hand-to-mouth ingestion of Hg-bearing calcines. Mine waste calcines collected from Hg mines at Almadén, Spain, and Terlingua, Texas, contain Hg sulfide, elemental Hg, and soluble Hg compounds, which constitute primary ore or compounds formed during Hg retorting. Elevated leachate Hg concentrations were found during calcine leaching using a simulated gastric fluid (as much as 6200 μg of Hg leached/g sample). Elevated Hg concentrations were also found in calcine leachates using a simulated lung fluid (as much as 9200 μg of Hg leached/g), serum-based fluid (as much as 1600 μg of Hg leached/g), and water of pH 5 (as much as 880 μg of