Transfer Method (transfer + method)

Distribution by Scientific Domains

Kinds of Transfer Method

  • gene transfer method

  • Selected Abstracts

    Influence of Ovulation Status, Seasonality and Embryo Transfer Method on Development of Cloned Porcine Embryos

    OJ Koo
    Contents To improve pig cloning efficiency, the present study evaluated the effect of ovulation status, seasonality and embryo transfer (ET) method on in vivo development of cloned porcine embryos. Cloned embryos were transferred to surrogate mothers on the same day of somatic cell nuclear transfer. In pre-ovulation stage (PO), pregnancy rate (PR) and delivery rate (DR) were 36.3% and 9.4%, respectively. In post-ovulation stage, 22.7% PR and 2.1% DR were recorded (both PR and DR are significantly higher in PO). When ET was performed during winter (December,February), spring (March,May), summer (June,August) and autumn (September,November), the PRs were 13.4%, 37.3%, 24.6% and 51.0%, while DRs were 0%, 12.7%, 4.3% and 7.8%, respectively. The highest PRs were recorded in autumn groups. However, DRs were significantly lower in autumn (7.8%) group compared with spring (12.7%) group. The PR was the lowest and no piglets were born in winter group, which might be because of the effect of low temperature during ET. To overcome the low PR in winter group, 0.25 ml straws were used for ET to minimize exposure time of embryos to ambient temperature. The straw ET group showed significantly higher PR in the winter group (23. 9%) compared with the conventional catheter-loading group (7.7%). We suggest that using PO recipient and ET in spring is the best condition for pig cloning. In addition, alternative method to reduce cold shock during ET in winter is necessary. [source]

    Practical causal hysteretic damping

    Naohiro Nakamura
    Abstract A number of experiments indicate that the internal damping corresponding to the energy dissipation of many materials is essentially frequency independent. Accordingly, an analysis model that can express such characteristics (called a hysteretic damping model) in the time domain is needed. Although a great number of investigations into this subject have been carried out, there are a few practical methods. In this paper, a simple hysteretic damping model which satisfies the causality condition is presented using an extension of the complex stiffness transfer method that the author has proposed. Compared with the energy proportional damping model and the Biot model, the applicability and the efficiency of this model to time history response analyses were confirmed well by example problems. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    Effect of neurotrophin-3 on reinnervation of the larynx using the phrenic nerve transfer technique

    Paul J. Kingham
    Abstract Current techniques for reinnervation of the larynx following recurrent laryngeal nerve (RLN) injury are limited by synkinesis, which prevents functional recovery. Treatment with neurotrophins (NT) may enhance nerve regeneration and encourage more accurate reinnervation. This study presents the results of using the phrenic nerve transfer method, combined with NT-3 treatment, to selectively reinnervate the posterior cricoarytenoid (PCA) abductor muscle in a pig nerve injury model. RLN transection altered the phenotype and morphology of laryngeal muscles. In both the PCA and thyroarytenoid (TA) adductor muscle, fast type myosin heavy chain (MyHC) protein was decreased while slow type MyHC was increased. These changes were accompanied with a significant reduction in muscle fibre diameter. Following nerve repair there was a progressive normalization of MyHC phenotype and increased muscle fibre diameter in the PCA but not the TA muscle. This correlated with enhanced abductor function indicating the phrenic nerve accurately reinnervated the PCA muscle. Treatment with NT-3 significantly enhanced phrenic nerve regeneration but led to only a small increase in the number of reinnervated PCA muscle fibres and minimal effect on abductor muscle phenotype and morphology. Therefore, work exploring other growth factors, either alone or in combination with NT-3, is required. [source]

    Antitumor effect of simultaneous transfer of interleukin-12 and interleukin-18 genes and its mechanism in a mouse bladder cancer model

    Abstract Background:, The objectives of this study were to evaluate the antitumor effects of the simultaneous introduction of interleukin 12 (IL-12) and IL-18 genes into a mouse bladder cancer cell line (MBT2). We intended to compare these with those of either gene alone and to investigate the mechanism of the effects induced by the transfer of IL-12 and/or IL-18 genes in this model system. Methods:, We transfected the IL-12 and/or IL-18 genes into MBT2 cells by the liposome-mediated gene transfer method. We confirmed the secretion of IL-12 and/or IL-18 by enzyme-linked immunosorbent assay. Parental (MBT2/P), IL-12-transfected (MBT2/IL-12), IL-18-transfected (MBT2/IL-18) or both IL-12- and IL-18-transfected (MBT2/Both) cells were subcutaneously or intravenously injected into syngeneic C3H mice. To analyze the mechanism of tumor rejection, these clones were subcutaneously injected into naive nude mice and those depleted with natural killer (NK) cells by antibody. Results:, MBT2/IL-12, MBT2/IL-18 and MBT2/Both were completely rejected when they were injected subcutaneously or intravenously into syngeneic mice. However, MBT2/IL-12, but not MBT2/IL-18, could grow in nude mice. Moreover, the antitumor effect of MBT2/IL-18 was partially abrogated when injected into nude mice of which NK cells were depleted by antibody treatment. MBT2/Both was completely rejected in both nude mice with and without NK cells. Conclusion:, The results of the present study indicate that T cells and NK cells seem to play important roles in the antitumor effects by the secretion of IL-12 and IL-18, respectively, and MBT2/Both possesses both mechanisms. [source]

    Kinematic modeling of mobile robots by transfer method of augmented generalized coordinates

    Wheekuk Kim
    A kinematic modeling method, which is directly applicable to any type of planar mobile robots, is proposed in this work. Since holonomic constraints have the same differential form as nonholonomic constraints, the instantaneous motion of the mobile robot at current configuration can be modeled as that of a parallel manipulator. A pseudo joint model denoting the interface between the wheel and the ground (i.e., the position of base of the mobile robot) enables the derivation of this equivalent kinematic model. The instantaneous kinematic structures of four different wheels are modeled as multiple pseudo joints. Then, the transfer method of augmented generalized coordinates, which has been popularly employed in modeling of parallel manipulators, is applied to obtain the instantaneous kinematic models of mobile robots. The kinematic models of six different types of planar mobile robots are derived to show the effectiveness of the proposed modeling method. Lastly, for the mobile robot equipped with four conventional wheels, an algorithm estimating a sensed forward solution for the given information of the rotational velocities of the four wheels is discussed. © 2004 Wiley Periodicals, Inc. [source]

    Irsogladine maleate counters the interleukin-1,-induced suppression in gap-junctional intercellular communication but does not affect the interleukin-1,-induced zonula occludens protein-1 levels in human gingival epithelial cells

    T. Fujita
    Background and Objective:, Irsogladine maleate counters gap junctional intercellular communication reduction induced by interleukin-8 or Actinobacillus actinomycetemcomitans in cultured human gingival epithelial cells. Interleukin-1, is involved in periodontal disease. Little is known, however, about the effect of interleukin-1, on intercellular junctional complexes in human gingival epithelial cells. Furthermore, irsogladine maleate may affect the actions of interleukin-1,. In this study, we examined how interleukin-1, affected gap junctional intercellular communication, connexin 43 and zonula occludens protein-1, and how irsogladine maleate modulated the interleukin-1,-induced changes in the intercellular junctional complexes in human gingival epithelial cells. Material and Methods:, Human gingival epithelial cells were exposed to interleukin-1,, with or without irsogladine maleate. Connexin 43 and zonula occludens protein-1 were examined at mRNA and protein levels by real-time polymerase chain reaction and western blotting, respectively. Gap junctional intercellular communication was determined using the dye transfer method. The expression of zonula occludens protein-1 was also confirmed by immunofluorescence. Results:, Interleukin-1, decreased connexin 43 mRNA levels, but increased zonula occludens protein-1 mRNA levels. Irsogladine maleate countered the interleukin-1,-induced reduction in gap junctional intercellular communication and connexin 43 levels. However, irsogladine maleate did not influence the increased zonula occludens protein-1 levels. Conclusion:, The effect of interleukin-1, on gap junctional intercellular communication and tight junctions of human gingival epithelial cells is different. The recovery of gap junctional intercellular communication by irsogladine maleate in the gingival epithelium may be a normal process in gingival epithelial homeostasis. [source]

    Preparation of nitrocellulose (NC) immuno-affinity membrane for purification of rAPC antibody

    Haixiang Sun
    Abstract In this study, recombinant allophycocyanin (rAPC) with a purity of 98% was transferred from a gel to a nitrocellulose (NC) membrane to develop a simple and efficient immuno-affinity membrane. Atomic force microscopy (AFM) was used to investigate the surface topography of the affinity membrane and its characterization indicated that rAPC easily forms trimers or hexamers on the membrane surface on use of the given transfer method. The hydrodynamic radius (Rh) of the rAPC aggregation was equal to 103 nm or 365 nm according to dynamic light scattering (DLS), which was in agreement with the result obtained by AFM. Based on the specific immunological reaction of antigen and antibody, anti-APC antibodies were purified from rabbit polyclonal serum in a single step. The amount of absorbed antibody was 5.79 mg/g membrane according to analysis by ELISA methods. The purity of antibodies was up to 98% according to SDS-PAGE. The adsorption-desorption cycle of rAPC was repeated six times using the same immuno-affinity membrane, and there was no significant loss in adsorption capacity. The method provides a novel and efficient immunological affinity membrane for the purification of antibodies. [source]

    Measuring the acute effect of insulin infusion on ATP turnover rate in human skeletal muscle using phosphorus-31 magnetic resonance saturation transfer spectroscopy

    NMR IN BIOMEDICINE, Issue 8 2010
    Ee Lin Lim
    Abstract Mitochondrial dysfunction has been proposed to underlie the insulin resistance of type 2 diabetes. However, the relative time course of insulin action in stimulating ATP turnover rate and glucose uptake in skeletal muscle has not been examined. These two parameters were measured in young healthy subjects using the 31P MRS saturation transfer method in conjunction with the euglycaemic hyperinsulinaemic clamp technique respectively. Glucose infusion rate rose rapidly from 0 to 2.90,±,0.11,mg/kgffm/min during the first 10,min of insulin infusion and further to 6.17,±,0.57,mg/kgffm/min between 15 and 45,min. In contrast, baseline ATP turnover rate was 9.0,±,0.4,µmol/g/min of muscle and did not change during the first 45,min of insulin infusion. Between 50 and 80,minutes ATP turnover rate increased by 8% and remained steady to 150,minutes (9.7,±,0.5 µmol/g/min of muscle, p,=,0.03 vs baseline). The in vivo time course of insulin stimulation of skeletal muscle ATP turnover rate is not consistent with a rate limiting effect upon the initiation of insulin-stimulated glycogen synthesis. Copyright © 2010 John Wiley & Sons, Ltd. [source]

    InGaAs/GaAs quantum wells and quantum dots on GaAs(11n) substrates studied by photoreflectance spectroscopy

    J. S. Rojas-Ramirez
    Abstract Pseudomorphic InGaAs/GaAs quantum wells (QWs) and self-assembled InAs quantum dots (QDs) were grown by molecular beam epitaxy (MBE) on GaAs(11n)A substrates. Photoreflectance spectroscopy was employed to investigate the transitions in the heterostructures. The transitions in QWs have two contributions, a blue shift due to the compressive strain, and a red shift due to the quantum confined Stark effect produced by the piezoelectric field. A traditional theoretical interpretation of the QWs transitions employing a simple well model with sharp interfaces shows discrepancies with the experimental results. In order to satisfactorily explain the transitions we proposed to include segregation effects of Indium at the wells interfaces. The matrix transfer method was implemented to numerically solve the Schrödinger equation taking into account In segregation effects by including an asymmetric potential well with a profile depending on the details of the In incorporation. With segregation effects included, the calculated transitions fit very well the PR spectra. On the other hand, the transitions in self-assembled QDs were obtained by fitting the PR spectra employing a first derivative line-shape function. For n = 2, 4, 5, two functions were required to fit the spectra. For n = 3 only one function was required, in agreement with the more uniform QDs size distribution observed by atomic force microscopy on GaAs(113)A. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

    Ex vivo hypothermic recirculatory adenoviral gene transfer to the transplanted pig heart

    Keiji Oi
    Abstract Background To facilitate the application of adenoviral gene therapy in clinical heart transplantation, we developed an ex vivo hypothermic recirculatory adenoviral gene transfer method to the transplanted pig heart. Methods Experimental animals were assigned into three groups; controls, 1 × 108 plaque-forming units (pfu)/ml group and 1 × 109 pfu/ml group. During the 30 min gene transfer perfusion, 200 ml of University of Wisconsin solution containing the adenoviral vector was recirculated through the coronary vessels. The myocardial temperature was maintained below 4 °C and the perfusion pressure was adjusted at 50 mmHg. Results Cardiac myocyte transduction efficiencies in the 1 × 108 pfu/ml group were 0.04% and 0.07%, whereas transduction efficiencies in the 1 × 109 pfu/ml group were widely distributed from 0.45% to 22.62%. The gene transduction efficiency increased with the virus titer. Additionally, no difference in the transduction efficiency was observed between different segments of the left ventricle. The current gene transfer method at 1 × 109 pfu/ml of adenovirus titer enabled homogeneous gene transduction into the transplanted pig heart up to a maximum of 22.62%. Conclusions This model can be applied to a large isolated heart and will greatly facilitate the investigation of gene therapy in large animal models of heart transplantation. Copyright © 2006 John Wiley & Sons, Ltd. [source]

    An efficient gene transfer method mediated by ultrasound and microbubbles into the kidney

    Hiromi Koike
    Abstract Background Safety issues are of paramount importance in clinical human gene therapy. From this point of view, it would be better to develop a novel non-viral efficient gene transfer method. Recently, it was reported that ultrasound exposure could induce cell membrane permeabilization and enhance gene expression. Methods In this study, we examined the potential of ultrasound for gene transfer into the kidney. First, we transfected rat left kidney with luciferase plasmid mixed with microbubbles, Optison, to optimize the conditions (duration of ultrasound and concentration of Optison). Then, 4, 7, 14 and 21 days after gene transfer, luciferase activity was measured. Next, localization of gene expression was assessed by measuring luciferase activity and green fluorescent protein (GFP) expression. Expression of GFP plasmid was examined under a fluorescence microscope at 4 and 14 days after gene transfer. Finally, to examine the side effects of this gene transfer method, biochemical assays for aspartate aminotransferase (AST), alanine aminotransferase (ALT), blood urea nitrogen (BUN) and creatinine (Cre) were performed. Results Optison and/or ultrasound significantly enhanced the efficiency of gene transfer and expression in the kidney. Especially, 70,80% of total glomeruli could be transfected. Also, a significant dose-dependent effect of Optison was observed as assessed by luciferase assay (Optison 25%: 12.5 × 105 relative light units (RLU)/g tissue; 50%: 31.3 × 105 RLU/g tissue; 100%: 57.9 × 105 RLU/g tissue). GFP expression could be observed in glomeruli, tubules and interstitial area. Results of blood tests did not change significantly after gene transfer. Conclusions Overall, an ultrasound-mediated gene transfer method with Optison enhanced the efficiency of gene transfer and expression in the rat kidney. This novel non-viral method may be useful for gene therapy for renal disease. Copyright © 2004 John Wiley & Sons, Ltd. [source]

    Suppressive role of leukocyte cell,derived chemotaxin 2 in mouse anti,type II collagen antibody,induced arthritis

    ARTHRITIS & RHEUMATISM, Issue 2 2008
    Akinori Okumura
    Objective We previously reported that the Val58Ile polymorphism of the leukocyte cell,derived chemotaxin 2 gene (LECT2) is associated with the severity of rheumatoid arthritis (RA). To define the role of LECT2 in inflammatory arthritides, we investigated the development of collagen antibody,induced arthritis (CAIA) in LECT2-deficient (LECT2,/,) mice. Methods CAIA was induced in mice by administering anti,type II collagen antibodies followed by lipopolysaccharide. Daily assessment of hind paw swelling was used to monitor the development of arthritis. The histopathologic features and expression of inflammatory cytokines were also analyzed. We confirmed the role of LECT2 by introducing a LECT2 expression vector into LECT2,/, mice, using a hydrodynamic gene transfer method. Results Arthritis in LECT2,/, mice was significantly exacerbated compared with that in wild-type (WT) controls. Histopathologic assessment of the tarsal joints showed that inflammation and erosion of cartilage and bone in LECT2,/, mice were more severe than that in controls. Interleukin-1, (IL-1,), IL-6, and certain chemokines were present at significantly higher levels in the arthritic hind paws of LECT2,/, mice. In contrast, the amount of LECT2 in the serum and locally in the hind paws was higher in arthritic WT mice. Finally, hydrodynamic gene transfer experiments revealed that the severity of arthritis was reduced by the systemic expression of exogenous mouse LECT2 protein in LECT2,/, mice. Conclusion These results strongly suggest that LECT2 directly suppresses the development of CAIA. Manipulation of LECT2 might provide a rationale for novel therapeutic approaches to the treatment of inflammatory arthritides such as RA. [source]

    Non-viral strategies of intra-ocular gene delivery

    Purpose Systemic anti TNF strategies are efficient to treat intraocular inflammation but require repeated injections and are associated to severe systemic side effects. Our aim was to develop a non viral gene transfer method to produce locally anti-inflammatory proteins in a sustained and minimally invasive manner in the ocular media. For this purpose, we have transformed the ciliary muscle into a bioreactor, using an electrically assisted gene transfer technique. Methods Electrotransfer (ET) of plasmids, encoding for different variants of TNF alpha soluble receptors, was performed in the ciliary muscle cells. Using toptimized conditions, soluble receptors were dosed in the ocular media up to 8 months after a single treatment. The technique has been applied in two models of intraocular inflammation: Endotoxin-Induced Uveitis (EIU) and auto immune experimental uveitis (EAU) in rats. Results When performed 8 days or 3 months before the LPS challenge, ET significantly reduced both clinical and histological signs of EIU. Particularly, iNOS, IL6 and TNF were down regulated while IL10 was upregulated. Importantly, systemic TNF alpha was not decreased demonstrating a local effect of the treatment. In EAU, ET significantly delayed the onset of EAU and deceased its severity. Similarly, a switch towards a Th2 cytokines profile was observed in the ocular media without any effect on systemic TNF alpha. Conclusion - ET is a safe and efficient non viral method to produce locally TNF alpha soluble receptors. - Local anti TNF allows for a local intraocular immunomodulation, without affecting systemic TNF. ET could therefore be used to reduce systemic side effects of anti TNF and prevent repeated injections. [source]