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BACKGROUND: 'In body tissue architecture' technology is a practical concept of regenerative medicine that uses the living recipient body's reaction to a foreign object as a reactor for autologous tissue organization. A novel autologous valved conduit was produced by creating a specially designed conduit-mold composite and elastomeric scaffold for this unique in vivo tissue engineering. METHODS: Convex and concave plastic molds assembled with a small aperture of 500-800 microm were inserted into a microporous elastomeric conduit scaffold. The assembly was placed in a subcutaneous pocket of Japanese white rabbits for 1 month. The molds were pulled out from the edge of the harvested implant to obtain the valved conduit. RESULTS: Homogenous and well-balanced trileaflet of membranous tissue was developed in the optimized aperture of molds. The valve leaflet closed and opened rapidly in synchronization with the backward and forward flow of the pulsatile flow circuit in vitro. CONCLUSIONS: A tissue-engineered conduit incorporated with a functional autologous trileaflet valve was developed in an in vivo reactor by optimizing the microstructures of conduit scaffolds and newly designing the composite molds. The method holds promise for a safe, biocompatible, and economical heart valve prosthesis. [ABSTRACT FROM AUTHOR]

Ce 4f electronic states in an antiferromagnetic Kondo compound CePd[sub 2]Si[sub 2] and a strong intermediatevalence compound CeNi[sub 2]Si[sub 2] have been investigated by means of high-resolution Ce 4d-4f resonant photoemission spectroscopy at 12 K. The relative intensity of the f[sub 5/2]¹ to f[sub 7/2]¹ final state in the Ce 4f spectrum for CeNi[sub 2]Si[sub 2] is stronger than the relative intensity for CePd[sub 2]Si[sub 2], indicating that the intensity of Kondo resonance scales the Kondo temperature since the Ce 4f spectrum near the Fermi level dominantly reflects the bulk component. Both Ce 4f spectra have been well fitted by the spectral calculations based on a single impurity Anderson model with consideration of the bulk and surface components. Our present calculation indicates that the model is applicable to the analyses of the Ce 4f spectra of the weakly and strongly hybridized systems. [ABSTRACT FROM AUTHOR]

Although prostaglandins have been shown to inhibit the evolution of the nephritis in NZB/W mice, the mechanisms of this effect are unknown. To characterize such inhibition, we injected the prostacyclin (PGI2) analogue. beraprost, into NZB/W mice, using 0.5 mg, 1.0 mg or 5.0 mg beraprost/kg body weight of test animals three times in 1 week when the mice were 2 months old. Evaluation included measurement of urine albumin excretion, serological parameters and splenic T cell subset, as well as examination of renal histology by light and fluorescence microscopy. Mice given beraprost showed a marked decrease in urine albumin excretion and in glomerular hypercellularity compared with untreated controls. Maximal beneficial effects occurred when the dose was 5.0 mg/kg of beraprost. These effects correlated with a reduction of immune complex deposition in glomeruli. In addition, beraprost reduced serum levels of immunoglobulins and anti-double-stranded DNA antibodies, and decreased the number of helper (L3T4+) T cells in splenocytes. These results indicate that beraprost attenuates the nephritis of NZB/W mice, and that the source of this effect is the reduced production of autoantibodies and deposition of immune complexes in glomeruli. [ABSTRACT FROM AUTHOR]

A variety of mechanisms have been proposed for the regulation of ion channel molecules. As integral membrane proteins, ion channels may interact with the cytoskeleton. Regulation of channels by the actin network may therefore be important. In the present study we used cytochalasin D and exogenous actin to test this possibility. The Cl- channel of the apical membrane of renal proximal epithelium was detected in its active state after prolonged depolarization. Within 6 sec after its addition, cytochalasin D (0.05 microgram/ml) significantly decreased the number of open channels and mean open probability (NPo) of the Cl- channel. Colchicine (1 mM), which affects microtubules, did not influence channel activation. Cytochalasin D is known to not only disrupt the F-actin network but to inhibit polymerization of F-actin as well. The latter effect is also produced by DNaseI. Cytochalasin D, but not DNaseI, inactivated Cl- channels in cell-free membrane patches, suggesting that cytochalasin D inactivated the channel by disrupting the actin network. Cytochalasin D appeared to specifically affect the channel, as opposed to membrane permeability, since only the activated whole-cell Cl- currents were altered by cytochalasin D. Addition of actin polymer, but not actin monomer, reactivated the cytochalasin-D-depressed channel. Thus, repair of the disrupted F-actin network with actin polymer apparently restored the activity and number of open Cl- channels. We therefore conclude that the F-actin network interacts with and possibly regulates the Cl- channel of renal proximal tubule epithelia. [ABSTRACT FROM AUTHOR]

We report here results of DC and AC magnetization, and magnetic specific heat measurements of a geometrically frustrated pyrochlore Tb2Nb2O7. The DC susceptibility χ is consistent with collective paramagnetism down to a temperature scale set by effective nearest-neighbor interactions, Jeff≈–1.5 K. However, AC susceptibility χac peak exhibits a frequency-dependence at Tf∼0.8 K, signaling a spin-glass-like freezing of Tb3+ spins in Tb2Nb2O7. [Copyright &y& Elsevier]

We investigated the frequency of air bubbles in the subclavian (SCV) or internal jugular (IJV) vein in 200 patients who underwent contrast-enhanced CT of the head and neck. Half the patients were reviewed retrospectively (group 1), while the other half were investigated prospectively after the radiologists who administered the contrast medium were instructed to be careful not to inject even a single air bubble during the procedure (group 2). Air bubbles were observed in the SCV or IJV in 15 of the 100 patients in group 1, while in group 2, there were 4 such patients. Air injection, a common “complication”, can be reduced by care during the procedure. [ABSTRACT FROM AUTHOR]

The effect of Sairei-to, an oriental traditional medicine, against gentamicin nephrotoxicity was examined in gentamicin nephrotoxicity rat models. Gentamicin nephrotoxicity was induced by s. c. injection of gentamicin (100 mg/kg/day, for 3 days) in male Sprague-Dawley rats. Renal functions of two rat groups were compared, one eating rat chow containing 2.5% Sairei-to, the other eating normal rat chow. Sairei-to administration reduced the increase of urinary N-acetyl-β-D-glucosaminidase (NAG) and protein excretion, and decreased creatinine clearance induced by gentamicin. Gentamicin increased renal cortical malondialdehyde (MDA) concentration in normal diet group but not in the Sairei-to diet group. The renal cortical gentamicin concentration was not different between the two groups. In conclusion, Sairei-to shows reno-protective action against gentamicin nephrotoxicity, possibly through its anti-oxidant action. [ABSTRACT FROM AUTHOR]