Taste-modifying protein from miracle fruit.

The active principle of miracle fruit (Synsepalum dulcificum) is a basic glycoprotein with a probable molecular weight of 44,000. Application of the protein to the tongue modifies the taste so that one tastes sour substances as sweet.

Plasmonic devices with controllable resonances--an avenue towards high-speed and mass fabrication of optical meta-materials.

We report on the fabrication of plasmonic devices with adjustable resonances in the visible portion employing a thermal lithography method. The genuine approach enables the fabrication of nanostructured pattern at a spatial resolution comparable to other nanofabrication techniques, but at significantly larger speeds and over extended spatial domains. The fabricated structures consisted in periodically arranged nanoholes in a silver thin film and supported localized plasmon resonance (LPR) in the vicinity of 370 nm. Results from measured spectral properties were in good agreement with simulations based on rigorous diffraction theory. The method was evaluated towards a potential application to realize large-scale meta-materials with effective negative refractive index in the visible.

Fabrication and optical properties of Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3) thin films on Si substrates using the PLD method.

Epitaxial 0.67Pb(Mg(1/3)Nb(2/3))O(3)-PbTiO(3)-0.33PbTiO(3) (PMN-PT) thin films with electro-optic effects were fabricated on (PMN-PT) thin films with electro-optic effects were fabricated on (La0(0.5)Sr0(0.5))CoO(3) (LSCO)/CeO(2)/YSZ-buffered Si(001) substrates using double-pulse excitation pulsed laser deposition (PLD) method with a mask placed between the target and the substrate. Epitaxial growth of PMN-PT thin films was undertaken using the two-step growth method of PMN-PT film. The PMN-PT seed layer was deposited at 500 degrees C on the LSCO/CeO(2)/YSZ/Si, which temperature was the same as that used for LSCO deposition. The PMN-PT thin films were deposited on the PMN-PT seed layer at 600 degrees C, which enables growth of high-crystallinity PMN-PT films with smooth surfaces. We obtained optimum fabrication conditions of PMNPT film with micrometer-order thickness. Resultant films showed high crystallinity with full width at half maximum (FWHM) = 0.73 deg and 1.6 mum thickness. Electro-optic properties and the refractive index value were measured at 633 nm wavelength using the prism coupling method. The obtained refractive index was 2.59. The electro-optic coefficients r(13) and r(33) were determined by applying the electrical field between a semitransparent, thin top electrode of Pt and a bottom LSCO electrode. The electro-optic coefficient was r(13) = 17 pm/V at transverse electric field (TE) mode and r(33) = 55 pm/V at transverse magnetic field (TM) mode.

Effectiveness of Preceding Solo Kidney Transplantation for Type 1 Diabetes With End-Stage Renal Failure.

Preceding solo kidney transplantation for type 1 diabetes with end-stage renal failure is controversial because of less pancreatic graft survival in pancreas transplantation after kidney transplantation (PAK) than in simultaneous pancreas and kidney transplantation (SPK). METHODS: To study the effectiveness of preceding solo kidney transplantation for type 1 diabetes with end-stage renal failure, comparative retrospective analysis was performed between SPK (n = 232) and PAK (n = 39) that were performed until December 2016. RESULTS: At 1, 3, and 5 years, pancreatic graft survival in SPK was 87.5%, 86.4%, and 82.8%, respectively, and 87.1%, 65.0%, and 49.1%, respectively, in PAK, which showed lesser long-term graft survival than SPK. Because 10 cases out of 16 (62.5%) failed into pancreatic graft loss with rejection in PAK, which was about 3 times more than in SPK, control of rejection is very important; rejection episodes were decreased by rabbit antithymocyte globulin induction resulting in improved graft survival. Five-year patient survival was 88.0% in SPK and 96.6% in PAK. CONCLUSION: Considering patient survival, preceding solo kidney transplantation for type 1 diabetes with end-stage renal failure should be performed if a donor is available.

Preoperative Muscle Volume Predicts Graft Survival After Pancreas Transplantation: A Retrospective Observational Cohort Study.

BACKGROUND: Several studies have suggested that decreased muscle volume is associated with attenuation of immune function. The recipient's immune system is responsible for rejection of transplanted organs, which is a major cause of graft loss after transplantation. We aimed to determine whether muscle volume is correlated with graft survival after pancreas transplantation (PT). METHODS: Forty-three patients underwent PT for type 1 diabetes mellitus at our institution from August 2001 to May 2016. The quantity of skeletal muscle was evaluated using the psoas muscle mass index (PMI). The correlation between PMI and outcome after PT was assessed. RESULTS: A total of 32 and 11 recipients underwent simultaneous pancreas-kidney transplantation (SPK) and PT alone/pancreas after kidney transplantation, respectively. Patients with a surviving graft showed a significantly lower PMI than those with graft loss (P = .0451). We divided the recipients into two groups according to the PMI cutoff values, which were established using receiver operating characteristic curves. The cumulative graft survival rate was significantly higher in patients with a low PMI (P = .0206). A multivariate Cox regression analysis revealed that a low PMI (P = .0075) is an independent predictive factor for better graft survival. A low PMI was not a significant predictive factor for acute rejection, but was an independent predictive factor for graft survival after the first acute rejection (P = .0025). CONCLUSIONS: Our data suggest that muscle volume could be a predictor of graft survival after PT.

Laparoscopy-Assisted Spleen-Preserving Distal Pancreatectomy for Living-Donor Pancreas Transplantation.

BACKGROUND: Living pancreas transplantation plays an important role in the treatment of patients with severe type 1 diabetes. However, pancreatectomy is very invasive for the donor, and less-invasive surgical procedures are needed. Although some reports have described hand-assisted laparoscopic surgery for distal pancreatectomy in living-donor operations, less-invasive laparoscopy-assisted (LA) procedures are expected to increase the donor pool. We herein report the outcomes of four cases of LA spleen-preserving distal pancreatectomy (Warshaw technique [WT]) in living pancreas donors. PATIENTS AND METHODS: Four living pancreas donors underwent LA-WT at our institution from September 2010 to January 2013. All donors fulfilled the donor criteria established by the Japan Society for Pancreas and Islet Transplantation. RESULTS: The median donor age was 54 years. Two donors underwent left nephrectomy in addition to LA-WT for simultaneous pancreas-kidney transplantation. The median donor operation time for pancreatectomy was 340.5 minutes. The median pancreas warm ischemic time was 3 minutes. The median donor blood loss was 246 g. All recipients immediately achieved insulin independence. One donor required reoperation because of obstructive ileus resulting from a port-site hernia. Another donor developed a pancreatic fistula (International Study Group of Pancreatic Fistula grade B), which was controlled with conservative management. After a maximum follow-up of 73 months, no clinically relevant adverse events had occurred. These results were comparable with those of previous studies concerning living-donor pancreas transplantation. CONCLUSION: The LA-WT is a safe and acceptable operation for living-donor pancreas transplantation.

Retroperitoneal hand-assisted laparoscopic surgery for endoscopic adrenalectomy.

Although hand-assisted laparoscopic surgery (HALS) is very common in various laparoscopic procedures, it is rarely used for retroperitoneal endoscopic adrenalectomy because of the small working area. The authors evaluate HALS in endoscopic adrenalectomy with respect to its use as a rescue procedure in complicated cases. In their department, 47 patients underwent endoscopic adrenalectomies between 1998 and 2004. Mainly because of complicated anatomy, three primary aldosteronism cases were converted to retroperitoneal HALS. This involved making an additional 6 cm skin incision, into which the surgeon's left hand was inserted, with the palm used to create a sufficient visual field and working area. The fingers were used for tactile sensation and blunt resection. For these three cases, successful retroperitoneal HALS in endoscopic adrenalectomy resulted in no mortality or morbidity. These findings indicate that this procedure is a feasible technique for complicated benign adrenal tumor cases.

Similarity of ion dependence of odorant responses between lipid bilayer and olfactory system.

In a previous paper (Nomura and Kurihara (1987) Biochemistry 26, 6135-6140), we demonstrated that the lipid bilayer membranes exhibit membrane potential changes in response to various odorants similarly to olfactory cells. The present study demonstrated that ion dependence of the responses of the lipid membranes to odorants is related to that in the carp olfactory system in the following point. (1) The responses to odorants diminished at low concentrations of salts and recovered upon addition of salts to stimulating solutions. (2) Divalent cations were effective in supporting the responses to odorants at much lower concentrations that monovalent cations. (3) Impermeable organic cations were effective in supporting the responses. The present results suggest that the initial process of generation of the receptor potential in olfactory cells resembles that in the lipid membranes.

Liposomes having high sensitivity to odorants.

The conditions to increase the sensitivities of liposomes to odorants were examined. The results obtained are as follows. (1) The minimum concentration of amyl acetate to induce the membrane potential changes (threshold) in phosphatidylcholine (PC) liposomes was about 10(-4) M and addition of 10 or 20% phosphatidylserine (PS) lowered the threshold to about 10(-9) M, which was lower than the thresholds for amyl acetate in the turtle and frog olfactory systems. (2) Similar to amyl acetate, addition of PS to PC greatly lowered the threshold for beta-ionone. On the other hand, addition of PS to PC in certain ratio increased the threshold for citral, suggesting that addition of PS to PC does not always increase the responses to all odorants. (3) The membrane fluidity change of the liposomes in response to odorants occurred at similar concentration region where the membrane potential changes occurred. The presence of CaCl2 in external solution much greatly increased both the magnitude of the membrane potential changes and the membrane fluidity changes of the PC-PS liposomes in response to amyl acetate than the presence of NaCl and MgCl2. These results suggest that the membrane fluidity change is related to generation of the membrane potential change. (4) It was estimated that adsorption of less than a few molecules of amyl acetate on single liposome elicits detectable changes in the membrane potential and the membrane fluidity.

Contribution of electrostatic and hydrophobic interactions of bitter substances with taste receptor membranes to generation of receptor potentials.

The effects of changed ionic environments on the frog taste nerve responses to the bitter substances were examined. The responses to quinine and strychnine carrying a positive charge were suppressed by an increase in ionic strength of stimulating solutions. It was concluded that electrostatic interaction of these positive bitter substances with the receptor membranes greatly contributes to the adsorption of the substances on the membranes and that this interaction was suppressed by an increase in ionic strength. The responses to neutral bitter substances (caffeine and theophylline) were unchanged by an increase in salt concentration. The zeta potential of the mouse neuroblastoma (N-18 clone), which was depolarized by various bitter substances similarly to a taste cell, was measured in the presence of the bitter substances. The zeta potential was a little changed by quinine and practically unchanged by strychnine, caffeine and theophylline. The membrane fluidity of the N-18 cell monitored with 2-(9-anthroyloxy)stearic acid was changed in response to the bitter substances, while the fluidity monitored with 12-(9-anthroyloxy)stearic acid or 1,6-diphenyl-1,3,5-hexatriene was unchanged. This suggested that the bitter substances are adsorbed on the hydrophobic region near the surface and induce a conformational change at the region. The depolarization by the bitter substances seems to stem from changes in the "boundary potential" at the region near the surface within the membrane interior.

Photoinduced charge separation in liposomes containing chlorophyll a. I. Photoreduction of copper(II) by potassium ascorbate through liposome bilayer containing purified chlorophyll a.

Photosensitivity of dispersion of phosphatidylcholine bilayer liposomes containing purified chlorophyll alpha was examined. The reduction of Cu(II) in the solution outside liposomes was observed upon illumination with visible light under anaerobic condition by means of ESR. The rate of photoreduction was significantly increased by a reductant, potassium ascorbate, localized in the solution of the opposite side of the membrane. The aciton spectrum of the reduction agreed with the absorption spectrum of chlorphyll a in the dispersion. The amount of bleach chlorophyll a was negligible compared with that of reduced (Cu(II). These facts lead to the conclusion that the potoinduced redox reactions at both the membrane-solution interfaces are coupled with each other through the bilayer of each liposome. Kinetic analysis of the reactions based on a possible reaction scheme was carried out and some of the kinetic parameters were determined.

Selective modification of positive chemotaxis in the true slime mold Physarum polycephalum by ethylenediaminetetraacetic acid treatment.

The plasmodium of the true slime mold Physarum polycephalum was treated with EDTA or EGTA and the effect of the treatment on the chemotactic response was examined by measuring the chemotactic motive force with the double-chamber method. The results obtained were as follows: (1) The treatment of the plasmodium with 5 mM EDTA (pH 7.0, 20 min) did not give any significant effect on the protoplasmic streaming or motility. (2) The plasmodium treated with EDTA exhibited no chemotactic response to non-electrolyte attractants (D-glucose, D-galactose, D-mannose, and maltose) and negative chemotaxis to electrolyte attractants (cyclic AMP and NaH2PO4). (3) The EDTA treatment gave no effect on the chemotactic response to repellents (D-fructose, NaCl, CaCl2, MgCl2). (4) The EDTA-treated plasmodium exhibited changes in the membrane potential in response to both attractants and repellents as similar to the untreated plasmodium. (5) The treatment of the plasmodium with 5 mM EGTA (pH 7.0, 20 min) gave results similar to those obtained with the EDTA treatment. The results obtained suggested that EDTA (or EGTA) treatment did not affect the receptor sites but modified the transduction mechanism from reception into tactic movement.

Purification and characterization of membrane-bound prostaglandin E synthase from bovine heart.

Prostaglandin (PG) E synthase was solubilized with 6 mM sodium deoxycholate from the microsomal fraction of bovine hearts. The enzyme was purified by about 800-fold to apparent homogeneity. The specific activity of the purified enzyme was about 830 mU/mg of protein, and the K(m) value for PGH(2) was 24 microM. The molecular weight of the enzyme was about 31000 on SDS-polyacrylamide gel electrophoresis and was about 60000 by gel filtration. The enzyme was separated from glutathione (GSH) S-transferase by DEAE-Toyopearl column chromatography, and did not exhibit any GSH S-transferase activity towards four different substrates. The purified enzyme was active in the absence of GSH, but it was activated by various SH-reducing reagents including dithiothreitol, GSH, or beta-mercaptoethanol. This is the first reported purification of membrane-bound PGE synthase to apparent homogeneity.

Characteristics of phosphatidic acid-containing lipoproteins which selectively inhibit bitter taste: high affinity to frog tongue surface and hydrophobic model membranes.

In previous studies (Katsuragi and Kurihara (1993) Nature 365,213--214; Katsuragi et al. (1995) Pharm. Res. 12,658--662) we showed that a lipoprotein composed of phosphatidic acid (PA) and beta-lactoglobulin (LG) selectively suppressed the taste responses to bitter substances without affecting those to other taste stimuli in the frog and man, while complexes composed of other lipids except for phosphatidylserine and LG had little inhibitory activity. In the present study, we found that the lipoproteins having inhibitory activity are adsorbed on the frog tongue surface, while those having no inhibitory activity are not adsorbed. We also examined adsorption of the lipoproteins on model lipid membranes coated on a quartz-crystal microbalance by measuring changes in its frequency. The lipoproteins having inhibitory activity were well adsorbed on the hydrophobic lipid membranes, while the lipoproteins having no inhibitory activity were little adsorbed on the membranes. It seems that receptor sites for bitter substances on the taste cell membranes are hydrophobic and those for other taste stimuli such as salts, acids and sugars are hydrophilic. Hence, the binding of PA-LG to hydrophobic sites of the receptor membranes will lead to selective inhibition of bitterness.

Relative degradation of different arachidonoyl molecular species of choline glycerophospholipids in opsonized zymosan-stimulated rabbit alveolar macrophages.

The relative degradation of arachidonoyl molecular species of glycerophospholipids prelabeled with [3H]20:4 caused by opsonized zymosan was studied in rabbit alveolar macrophages using a recently developed high-performance liquid chromatographic method. The opsonized zymosan caused the release of [3H]20:4 only from choline glycerophospholipids, no significant changes being observed in the radioactivities of other glycerophospholipids and triacylglycerol. Choline glycerophospholipids were resolved into seven arachidonoyl molecular species, which differed as to the alkyl ether or acyl residue bound at the 1-position, by high-performance liquid chromatography. Arachidonate was predominantly located in the alkyl type having 16:0 at the 1-position which comprised more than half of the total arachidonoyl molecular species of choline glycerophospholipids. The radioactivities of all arachidonoyl molecular species of choline glycerophospholipids, except for the 18:2-20:4 and 18:1-20:4 species of diacylglycerophosphocholine, decreased to 80-85% of the control values as a result of the challenge with opsonized zymosan for 1 h. However, 50% of the released 20:4 came from the 16:0-20:4 species of alkylacylglycerophospholipids, which were the most predominant species of choline glycerophospholipids. The present results indicate that the 16:0-20:4 species of alkylacylglycerophosphocholine is a significant source of arachidonate and 1-O-alkyl-2-lysoglycerophosphocholine, the precursor of the platelet-activating factor, relative to other arachidonoyl species in activated alveolar macrophages.

Identification of c-fos related genes and their induction by neural activation in rainbow trout brain.

A number of studies have shown that the induction of c-fos gene is an indicator of the responses of cells and tissues to the environmental stimuli. In the present study, using RT-PCR-based strategy, we isolated, from the brain of the rainbow trout, two partial cDNA clones (RT-fos1 and RT-fos2) that code proteins homologous to c-Fos proteins of higher vertebrates. Sequence analysis of the two clones indicated that the two rainbow trout clones are very similar to each other over the entire cloned region (88% amino acid identity) and showed moderate similarity to c-Fos proteins of higher vertebrates (40% amino acid identity with human c-Fos). Two functionally important domains (i.e. the leucine zipper and zinc finger) are highly conserved among all the vertebrate species analyzed, although the region between the two domains was highly variable between different species. Intraperitoneal administration of kainic acid, a stable agonist of glutamate receptors, transiently induced the mRNAs for both RT-fos1 and RT-fos2 in the rainbow trout brain. These results indicate that the expression pattern of the two clones can be utilized as a suitable anatomical marker for the increased neural activities in salmonid fish brain to investigate the higher order behavior such as the learning and imprinting of odors of the home river.

Pysicochemical studies of taste reception. V. Suppressive effect of salts on sugar response of the frog.

The tast responses of frog to various kinds of sugars were measured quantitatively by use of the glossopharyngeal nerve activity under an appropriate condition where the water response was completely suppressed. The concentration dependences of response of frog tongue to D-fructose, D-glucose, and sucrose were almost the same, D-galactose, however, elicited a much larger response in comparison with the other sugars in the whole range of concentrations examined. The sugar response was suppressed extensively by the presence of small amount of salts in the stimulating sugar solution. The suppressive effects of NaCl, KCl, MgCl2, MgSO4, and K4Fe(CN)6 were examined with a fixed concentration of sugar. The results obtained with these salts, added in various concentrations, fell on a single curve when the data were plotted against the ionic strength in the stimulating solution. The present results were consistent with the notion that the taste receptor potential for salts or acids is attributable to a change in the phase boundary potential at the membrane-solution interface as proposed in the previous papers of this series.

Selective electrode for dibenzyl dimethyl ammonium cation as indicator of the membrane potential in biological systems.

The electrode sensitive to dibenzyl dimethyl ammonium (DDA+), which is considered to be an indicator of the membrane potential, was constructed by using tetraphenyl borone (TPB-) embedded in dichloroethane. Rapid and Nernstian responses were exhibited against DDA+ solutions ranging between 10(-2) and 3 - 10(-6) M in concentration. High selectivity for DDA+ was observed in the presence of various inorganis salts, ADP, ATP, oxidizable substrates and sugars. The electrode developed here was used to measure the DDA+ uptake in Streptococcus faecalis and the results agreed with those reported by Harold, F.M. and Papineau, D. ((1972) J. Membrane Biol. 8, 27-44 and 45-62). While they determined the DDA+ concentration in the medium by measuring the absorbance of the filtrate treated with the ion-exchangers, the electrode can measure directly the DDA+ concentration in the bacterial suspension without any any pretreatment. It was also shown that the electrode can measure the DDA+ uptake in mitochondria during energization.

Change in zeta potential and membrane potential of slime mold Physarum polycephalum in response to chemical stimuli.

Electrophoretic study of microplasmodia of the true slime mold Physarum polycephalum was carried out in the presence of various concentrations of inorganic salts, nucleotides and sugars, and the zeta potential at the surface of the plasmodia was determined from the electrophoretic mobilities. The membrane potential of the plasmodia was also measured under the same external conditions. It was shown that changes in the membrane potential induced by the chemical stimuli agreed approximately with those induced in the zeta potential in all cases examined. These results suggested that the phase boundary potential at the membrane-solution interface is mainly responsible for the membrane potential in the chemoreception of the slime mold.