Activation of a chondrocyte volume-sensitive Cl(-) conductance prior to macroscopic cartilage lesion formation in the rabbit knee anterior cruciate ligament transection osteoarthritis model.

OBJECTIVE: The anterior cruciate ligament transection (ACLT) rabbit osteoarthritis (OA) model confers permanent knee instability and induces joint degeneration. The degeneration process is complex, but includes chondrocyte apoptosis and OA-like loss of cartilage integrity. Previously, we reported that activation of a volume-sensitive Cl(-) current (ICl,vol) can mediate cell shrinkage and apoptosis in rabbit articular chondrocytes. Our objective was therefore to investigate whether ICl,vol was activated in the early stages of the rabbit ACLT OA model. DESIGN: Adult Rabbits underwent unilateral ACLT and contralateral arthrotomy (sham) surgery. Rabbits were euthanized at 2 or 4 weeks. Samples were analyzed histologically and with assays of cell volume, apoptosis and electrophysiological characterization of ICl,vol. RESULTS: At 2 and 4 weeks post ACLT cartilage appeared histologically normal, nevertheless cell swelling and caspase 3/7 activity were both significantly increased compared to sham controls. In cell-volume experiments, exposure of chondrocytes to hypotonic solution led to a greater increase in cell size in ACLT compared to controls. Caspase-3/7 activity, an indicator of apoptosis, was elevated in both ACLT 2wk and 4wk. Whole-cell currents were recorded with patch clamp of chondrocytes in iso-osmotic and hypo-osmotic external solutions under conditions where Na(+), K(+) and Ca(2+) currents were minimized. ACLT treatment resulted in a large increase in hypotonic-activated chloride conductance. CONCLUSION: Changes in chondrocyte ion channels take place prior to the onset of apparent cartilage loss in the ACLT rabbit model of OA. Further studies are needed to investigate if pharmacological inhibition of ICl,vol decreases progression of OA in animal models.

Evaluation of the potassium adsorption capacity of a potassium adsorption filter during rapid blood transfusion.

The concentration of extracellular potassium in red blood cell concentrates (RCCs) increases during storage, leading to risk of hyperkalemia. A potassium adsorption filter (PAF) can eliminate the potassium at normal blood transfusion. This study aimed to investigate the potassium adsorption capacity of a PAF during rapid blood transfusion. We tested several different potassium concentrations under a rapid transfusion condition using a pressure bag. The adsorption rates of the 70-mEq/l model were 76·8%. The PAF showed good potassium adsorption capacity, suggesting that this filter may provide a convenient method to prevent hyperkalemia during rapid blood transfusion.

Application of two-dimensional temperature response functions for reconstruction of divertor heat flux profile in commercial fusion reactors.

To keep the tritium breeding rate TBR > 1 and to meet the high heat load and neutron shielding requirements for the first wall and divertor in fusion demonstration (DEMO) reactors, the number of port plugs and other openings must be limited. To accomplish this, it is necessary to develop alternatives to the use of infrared (IR) thermography to determine the peak heat flux and the heat flux profile onto divertor targets. A divertor tile equipped with multiple temperature monitoring channels can be used to reproduce the temperature profile. To avoid the high temperatures and high neutron flux environment in a DEMO, the monitoring positions can be set well away from the irradiated surface. However, the spatial resolution of this method is lower than that provided by IR thermography. In the present work, we apply two-dimensional temperature response functions and the corresponding heat conduction model to temperature data obtained from a divertor tile surface in the large helical device to study the effects of the spatial resolution of the monitored temperature profile on the reconstructed heat flux profile. The findings provide information that will be useful in defining a method for embedding thermocouples into the divertor tiles of future DEMO reactors.

Optimization of a fast deuterium diagnostic method based on visible energetic 3He spectroscopy for high electron density plasmas.

Fast ions play a crucial role in plasma heating, and their behavior in the plasma must be accurately understood. A diagnostics method based on charge exchange emission from the n = 4 - 3 transition (λ0 = 468.6 nm) of energetic 3He produced by the deuteron-deuteron reaction has been proposed as a for fast deuterons with energies in the order of MeV. The proposed method has the following advantages: No beam emission interferes with the spectra, the direction of the measuring line of sight, and the injection angle of the diagnostic beam can be freely determined. In previous studies, due to competing bremsstrahlung, it was expected that the proposed method will not be practical in the case of high electron density operation. This paper makes the proposed method available for measurement even at high electron densities by optimizing the measurement line of sight direction and the diagnostic beam incidence angle. This allows an electron density five times larger than the range of applications shown in previous studies. This result will contribute to measure of DT alpha in ITER.

Presence of store-operated Ca2+ entry in C57BL/6J mouse ventricular myocytes and its suppression by sevoflurane.

BACKGROUND: Store-operated Ca(2+) entry (SOCE) has been implicated in various pathological conditions of the heart including ischaemia/reperfusion and ventricular hypertrophy. This study investigated the effects of sevoflurane on SOCE. METHODS: Fluorescence imaging was performed on fluo-3- and mag-fluo-4-loaded mouse ventricular myocytes to measure the cytosolic and intraluminal sarcoplasmic reticulum (SR) Ca(2+) levels, respectively, using a confocal laser scanning microscope. Whole-cell membrane currents were recorded using the patch-clamp technique. Ventricular myocytes were exposed to thapsigargin and angiotensin II to deplete SR Ca(2+) stores and thereby activate SOCE. RESULTS: The combined application of thapsigargin and angiotensin II to the Ca(2+)-free medium evoked a significant decrease in the SR Ca(2+) levels, which was followed by the elevation of cytosolic Ca(2+) and the development of cellular hypercontracture upon subsequent addition of extracellular Ca(2+). This cytosolic Ca(2+) elevation was inhibited by 2-aminoethoxydiphenyl borate but not by verapamil and KB-R7943, which indicates that SOCE was present in mouse ventricular myocytes. Sevoflurane concentration-dependently inhibited the SOCE-mediated Ca(2+) overload (IC(50) of 137 µM, which corresponds to 0.96%) with a significant reduction occurring at concentrations of ≥2%. Patch-clamp experiments revealed that the SOCE current was also concentration-dependently blocked by sevoflurane (IC(50) of 144 µM, which corresponds to 1.0%). CONCLUSIONS: Sevoflurane at concentrations of ≥2% significantly inhibits the SOCE activity and prevents the resultant cellular Ca(2+) overload that leads to hypercontracture in ventricular myocytes. This inhibitory action may be involved in the cardioprotective effect of sevoflurane against Ca(2+) overload-mediated injury.

Drug delivery observation of hydrophobe ferrofluid and magnetite nanoparticals by SPring-8 synchrotron radiation.

In this study, the composite magnetic nanoparticles of coated SiO nano film with about 8 nm size and high saturation magnetization value, were synthesized by liquid phase precipitation method. The magnetic nanoparticles can be dispersed in various liquid media, widely known as magnetic fluids or ferrofluids with both magnetic and liquid properties. The materials been collected great interests and more and more attentions to focus into Drug Delivery System (DDS) as a new technology in this paper. We use the composite nanoparticles to disperse H2O and inject the solutions into rat's in-vivo organs. And, in the experiments by using a strong photon beam of SPring-8 Synchrotron Radiation facility, the distribution stat and the effects of magnetic field as well as drug delivery behaviour of nanoparticles in the rat' kidney are verified by the in-vivo observations.

Fast deuteron diagnostics using visible light spectra of 3He produced by deuteron-deuteron reaction in deuterium plasmas.

The fast deuteron (non-Maxwellian component) diagnostic method, which is based on the higher resolution optical spectroscopic measurement, has been developed as a powerful tool. Owing to a decrease in the D-H charge-exchange cross section, the diagnostic ability of conventional optical diagnostic methods should be improved for ∼MeV energy deuterons. Because the 3He-H charge-exchange cross section is much larger than that of D-H in the ∼MeV energy range, the visible light (VIS) spectrum of 3He produced by the dueteron-dueteron (DD) reaction may be a useful tool. Although the density of 3He is small because it is produced via the DD reaction, improvement of the emissivity of the VIS spectrum of 3He can be expected by using a high-energy beam. We evaluate the VIS spectrum of 3He for the cases when a fast deuteron tail is formed and not formed in the ITER-like beam injected deuterium plasma. Even when the beam energy is in the MeV energy range, a large change appears in the half width at half maximum of the VIS spectrum. The emissivity of the VIS spectrum of 3He and the emissivity of bremsstrahlung are compared, and the measurable VIS spectrum is obtained. It is shown that the VIS spectrum of 3He is a useful tool for the MeV beam deuteron tail diagnostics.

Vestigial and scalloped in the ladybird beetle: a conserved function in wing development and a novel function in pupal ecdysis.

In Drosophila melanogaster, Vestigial (Vg) and Scalloped (Sd) form a transcription factor complex and play a crucial role in wing development. To extend our knowledge of insect wing formation, we isolated vg and sd homologues from two ladybird beetle species, Henosepilachna vigintioctopunctata and Harmonia axyridis. Although the ladybird beetle vg homologues had only low homology with D. melanogaster vg, ectopic expression of H. vigintioctopunctata vg induced wing-like tissues in antennae and legs of D. melanogaster. Subsequent larval RNA interference (RNAi) analysis in H. vigintioctopunctata demonstrated conserved functions of vg and sd in wing development, and an unexpected novel function of sd in pupal ecdysis. Furthermore, our results can be applied to the production of a flightless ladybird beetle for biological control purposes using larval RNAi.

Electron optical injection with head-on and countercrossing colliding laser pulses.

A high stability electron bunch is generated by laser wakefield acceleration with the help of a colliding laser pulse. The wakefield is generated by a laser pulse; the second laser pulse collides with the first pulse at 180 degrees and at 135 degrees realizing optical injection of an electron bunch. The electron bunch has high stability and high reproducibility compared with single pulse electron generation. In the case of 180 degrees collision, special measures have been taken to prevent damage. In the case of 135 degrees collision, since the second pulse is countercrossing, it cannot damage the laser system.

Pathological fracture of the mandible resulting from osteomyelitis successfully treated with only intermaxillary elastic guiding.

Treatment of mandibular pathological fractures differs according to etiology. Closed reduction with intermaxillary fixation is usually performed when fractures occur as a result of osteomyelitis. Here is reported a case of pathological fracture of the mandible resulting from osteomyelitis that was successfully treated with intermaxillary elastics only.

Soret forced Rayleigh scattering instrument for simultaneous detection of two-wavelength signals to measure Soret coefficient and thermodiffusion coefficient in ternary mixtures.

We describe an instrument for the measurement of the Soret and thermodiffusion coefficients in ternary systems based on the transient holographic grating technique, which is called Soret forced Rayleigh scattering (SFRS) or thermal diffusion forced Rayleigh scattering (TDFRS). We integrated the SFRS technique and the two-wavelength detection technique, which enabled us to obtain two different signals to determine the two independent Soret coefficients and thermodiffusion coefficients in ternary systems. The instrument has been designed to read the mass transport simultaneously by two-wavelength lasers with wavelengths of λ = 403 nm and λ = 639 nm. The irradiation time of the probing lasers is controlled to reduce the effect of laser absorption to the sample with dye (quinizarin), which is added to convert the interference pattern of the heating laser of λ = 532 nm to the temperature grating. The result of the measurement of binary benchmark mixtures composed of 1,2,3,4-tetrahydronaphthalene (THN), isobutylbenzene (IBB), and n-dodecane (nC12) shows that the simultaneous two-wavelength observation of the Soret effect and the mass diffusion are adequately performed. To evaluate performance in the measurement of ternary systems, we carried out experiments on the ternary benchmark mixtures of THN/IBB/nC12 with the mass fractions of 0.800/0.100/0.100 at a temperature of 298.2 K. The Soret coefficient and thermodiffusion coefficient agreed with the ternary benchmark values within the range of the standard uncertainties (23% for the Soret coefficient of THN and 30% for the thermodiffusion coefficient of THN).

Stimulatory action of protein kinase C(epsilon) isoform on the slow component of delayed rectifier K+ current in guinea-pig atrial myocytes.

BACKGROUND AND PURPOSE: Protein kinase C (PKC) comprises at least twelve isoforms and has an isoform-specific action on cardiac electrical activity. The slow component of delayed rectifier K(+) current (I (Ks)) is one of the major repolarizing currents in the hearts of many species and is also potentiated by PKC activation. Little is known, however, about PKC isoform(s) functionally involved in the potentiation of I (Ks) in native cardiac myocytes. EXPERIMENTAL APPROACH: I (Ks) was recorded from guinea-pig atrial myocytes, using the whole-cell configuration of patch-clamp method. KEY RESULTS: Bath application of phenylephrine enhanced I (Ks) concentration-dependently with EC(50) of 5.4 microM and the maximal response (97.1+/-11.9% increase, n=16) was obtained at 30 microM. Prazosin (1 microM) almost totally abolished the potentiation of I (Ks) by phenylephrine, supporting the involvement of alpha(1)-adrenoceptors. The stimulatory action of phenylephrine was significantly, if not entirely, inhibited by the general PKC inhibitor bisindolylmaleimide I but was little affected by Gö-6976, Gö-6983 and rottlerin. Furthermore, this stimulatory effect was significantly reduced by dialyzing atrial myocytes with PKCepsilon-selective inhibitory peptide epsilonV1-2 but was not significantly affected by conventional PKC isoform-selective inhibitory peptide betaC2-4. Phorbol 12-myristate 13-acetate (PMA) at 100 nM substantially increased I (Ks) by 64.2+/-1.3% (n=6), which was also significantly attenuated by an internal dialysis with epsilonV1-2 but not with betaC2-4. CONCLUSIONS AND IMPLICATIONS: The present study provides experimental evidence to suggest that, in native guinea-pig cardiac myocytes, activation of PKC contributes to alpha(1)-adrenoceptor-mediated potentiation of I (Ks) and that epsilon is the isoform predominantly involved in this PKC action.

The role of muscle grafts in temporomandibular joint ankylosis: short-term experimental study in sheep.

The temporalis muscle flap can be used as an inter-positional graft placed into a gap arthroplasty site in temporomandibular joint (TMJ) ankylosis. The purpose of this study was to investigate the role of the muscle graft in sheep. Five pure-bred adult Merino sheep were used and ankylosis was induced in all right TMJs. At 3 months, the ankylosis was released by gap arthroplasty and reconstructed with a masseter muscle graft, because the temporalis muscle is short and poorly vasculized in sheep. The sheep were killed at 3 months after muscle grafting. The maximal mouth opening was recorded before and after operation and at death. The joints were examined radiologically and histologically. In 4 sheep mouth opening remained at the pre-operative level. A clear radiolucent space remained between the smooth temporal and ramus stumps. Histologically, the muscle graft remained vital but with some fibrous tissue formation between the bone ends. One sheep developed an infection at the operative site following the muscle graft; this partly resolved with antibiotics, but the TMJ developed a fibrous reankylosis that was demonstrated clinically, radiologically and histologically. These results indicate that an uncomplicated temporalis muscle graft reconstruction with gap arthroplasty is a successful and stable procedure in human TMJ ankylosis.

Inhibition of tumor cell growth by aggregation of a tumor-associated glycolipid antigen: a close functional association between gangliotriaosylceramide and transferrin receptor in mouse lymphoma L-5178Y.

The growth of mouse lymphoma L-5178Y cells with a high degree of gangliotriaosylceramide expression (high-expressor clone AA12) was inhibited by the addition of a biotinylated mouse immunoglobulin M monoclonal antibody (2D4) directed to gangliotriaosylceramide followed by cross-linking with avidin or a second antibody (anti-mouse immunoglobulin M). This growth inhibition was observed in both serum-containing medium and a chemically defined medium containing transferrin as the only growth factor. Cell growth was not inhibited by the addition of biotinylated antibody 2D4 alone, avidin alone, or the biotinylated derivative of an immunoglobulin M monoclonal anti-N-acetyllactosamine antibody (1B2) cross-linked with avidin. The growth of lymphoma L-5178Y 27AV cells, which do not express gangliotriaosylceramide (non-expressor clone), was not inhibited by either of these monoclonal antibodies or their biotinylated derivatives plus avidin. In the presence of biotinylated antibody 2D4 and avidin, cells of the high-expressor clone (L-5178Y AA12) displayed a capping of gangliotriaosyl antigen. In contrast, the transferrin receptor and the major glycoproteins (concanavalin A receptors) were not capped in the presence of biotinylated antibody 2D4 and avidin but were homogeneously distributed on the cell surface. Cells whose growth was inhibited by the addition of biotinylated antibody 2D4 and avidin showed an inhibition of 125I-transferrin internalization, although binding of 125I-transferrin to the cell surface was similar to that of control cells. These results indicate that the tumor antigen gangliotriaosylceramide is functionally associated with the transferrin receptor and may regulate the process of internalization of transferrin.

Distribution of oncofetal fibronectin in human mammary tumors: immunofluorescence study on histological sections.

Two types of human fibronectin have been detected by the reactivity of specific monoclonal antibody FDC-6: (a) those present in normal plasma and adult tissues, which do not react with FDC-6 (normal fibronectin or norFN); and (b) those present in fetal tissues and in tumoral cell lines, which do react with FDC-6 (oncofetal fibronectin or onfFN) (H. Matsuura and S. I. Hakomori, Proc. Natl. Acad. Sci. USA, 82: 6517-6521, 1985). We compared the distribution of norFN and onfFN in normal breast tissue (15 samples), breast fibroadenoma (ten samples), and breast adenocarcinoma (80 samples), using an immunofluorescence technique with monoclonal antibody FDC-6. A polyclonal antiserum against human normal fibronectin was used as a control. While norFN was diffusely present in normal gland and in benign and malignant tumors, onfFN was absent in normal gland and in benign tumors. In carcinomas, however, its presence was frequent, as we found it in 60% of cases. Among classical prognosis factors in breast carcinomas, onfFN distribution was significantly correlated with histological grade. Indeed, the presence of FDC-6 labeling was significantly linked with intermediary and high malignancy grades, while its absence was significantly linked with low malignancy grade. onfFN could be considered a marker of the neoplastic state; its immunohistological detection may represent a new prognosis factor in breast carcinomas.