Search

Chemical identification of individual surface atoms has been achieved by measuring the chemical bonds between tip and surface atoms using atomic force microscopy. On the other hand, the discrimination of chemical species at the tip apex is still a challenging task, even though the differences of the species have significant effects on atomic-scale contrast and atom manipulation. Here, we perform the chemical identification of a foremost tip atom using bond energies measured on precharacterized atomic species on a Si surface. We find that chemically different tips show different trends in the chemical bond energy on the sites and that Pauling's equation for polar covalent bonds well describes those trends. On the basis of this knowledge, in situ chemical identification becomes possible. Using the chemically identified (here, Si and Al) tips, we determine the electronegativity of locally formed silicon oxide solely by experiments. Previously such determination was difficult without the help of theoretical calculations. These successful results confirm the validity and versatility of Pauling's equation for application to atomic-scale objects.

Study of the crystal structures of the title compounds reveals that the solid-state photochemical nitro–nitrito linkage isomerization is restricted by inter­molecular C—H⋯O,O contacts in the 3-hy­droxy­pyridine phase., The reaction cavities of the nitro groups in the title compounds, trans-bis­(acetyl­acetonato-κ2 O,O′)(nitro)(pyridine-κN)cobalt(III), [Co(C5H7O2)2(NO2)(C5H5N)], (I), trans-bis­(acetyl­acetonato-κ2 O,O′)(4-methyl­pyridine-κN)(nitro)cobalt(III), [Co(C5H7O2)2(NO2)(C6H7N)], (II), and trans-bis­(acetyl­acetonato-κ2 O,O′)(3-hy­droxy­pyridine-κN)(nitro)cobalt(III) monohydrate, [Co(C5H7O2)2(NO2)(C5H5NO)]·H2O, (III), have been investigated to reveal that bifurcated inter­molecular C(py)—H⋯O,O contacts in (III) are unfeasible for the nitro–nitrito photochemical linkage isomerization process. In each structure, the pyridine ring and the Co atom lie on a crystallographic mirror plane; in (I) and (II) the nitro group lies in the same plane, whereas in (III), which crystallizes as a monohydrate, the nitro group is disordered over three orientations in a 0.672 (16):0.164 (8):0.164 (8) ratio; the water mol­ecule of crystallization is statistically disordered over two sites adjacent to the mirror plane. In the crystals of (I) and (II), the mol­ecules are linked into [100] chains by C—H⋯O hydrogen bonds, whereas the extended structure of (III) features (010) layers linked by O—H⋯O and C—H⋯O hydrogen bonds. Compounds (I) and (II) were refined as inversion twins.

Various Grubbs–Hoveyda second-generation catalysts activated by intramolecular steric strain were prepared. The variant bearing a 9-anthracenyl group in the ligand moiety exhibited the highest catalytic activity. The new anthracenyl-type-activated catalyst was used in a ring-closing metathesis reaction to effectively provide a 4-substituted product effectively.

We presented allele frequencies of 27 X-chromosomal short tandem repeats (DXS6807, DXS9902, DXS6795, DXS6810, DXS10076, DXS10077, DXS10078, DXS10162, DXS10163, DXS10164, DXS7132, DXS981, DXS6800, DXS6803, DXS6809, DXS6789, DXS6799, DXS7424, DXS101, DXS7133, GATA172D05, DXS10103, HPRTB, GATA31E08, DXS8377, DXS10147, and DXS7423) obtained from 352 unrelated individuals in Egypt. No deviation from Hardy-Weinberg equilibrium was detected. Two pairs of adjacent loci showed significant linkage disequilibrium. In the principal component analysis plot, the Egyptian data were located between Europe and sub-Saharan Africa, away from Asia.

Silicene, a two-dimensional (2D) honeycomb arrangement of Si atoms, is expected to have better electronic properties than graphene and has been mostly synthesized on Ag surfaces. Although scanning tunneling microscopy (STM) has been used for visualizing its atomic structure in real space, the interpretation of STM contrast is not straightforward and only the topmost Si atoms were observed on the $(4\ifmmode\times\else\texttimes\fi{}4)$ silicene/Ag(111) surface. Here, we demonstrate that high-resolution atomic force microscopy (AFM) can resolve all constituent Si atoms in the buckled honeycomb arrangement of the $(4\ifmmode\times\else\texttimes\fi{}4)$ silicene. Site-specific force spectroscopy attributes the origin of the high-resolution AFM images to chemical bonds between the AFM probe apex and the individual Si atoms on the $(4\ifmmode\times\else\texttimes\fi{}4)$ silicene. A detailed analysis of the geometric parameters suggests that the pulling up of lower-buckled Si atoms by the AFM tip could be a key for high-resolution AFM, implying a weakening of the Si-Ag interactions at the interface. We expect that high-resolution AFM will also unveil atomic structures of edges and defects of silicene, or other emerging 2D materials.

Introduction: The aim of this study was to quantify the effects of diabetes with pharmacotherapy-treated breast cancer on care resource use. Materials and Methods: The study was designed as a single institutional retrospective cohort study using hospital administrative data. The subjects were 152 patients admitted to a hospital from 2008 to 2012 diagnosed with breast cancer, and who underwent pharmacotherapy. We identified diabetes group and nondiabetes group in addition to other variables and quantified the effects of diabetes with breast cancer patients undergoing pharmacotherapy on care resource use, using a multilevel linear regression model. Results: Diabetes was significantly correlated to both longer length of stay (coefficient standard error: 0.75 [0.19], P < 0.001) and higher total hospital charge (0.72 [0.18], P < 0.001), controlled for age, pharmacotherapeutic agent, steroid use, admission route, procedures, and postpharmacotherapy events. Conclusion: This study showed that diabetes itself is a risk factor for greater care resource use after controlling for confounding factors. Pharmacotherapy for breast cancer may influence poor glycemic control, thus leading to greater care resource use. Early detection and careful monitoring of diabetes are essential in malignancy to eliminate this burden on the health care system.

Antithrombin (AT) inhibits several blood coagulation proteases, including activated factor X (FXa), by forming stable complexes with these proteases. Herein, we demonstrate that AT forms a stable complex with zymogen factor X (FX). Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and size-exclusion chromatography analyses showed that AT and FX formed an SDS-stable complex, which is distinct in apparent molecular mass from an FXa-AT complex, in the presence of heparin. Amino-terminal sequence analysis of the complex following SDS-PAGE under reducing conditions provided clear evidence that AT forms this complex with the heavy chain of FX, because two sequences, HGSPVDI (residues 1-7 of AT) and SVAQATS (residues 1-7 of the heavy chain of FX), were identified. Furthermore, sequence SLNPNRV, which corresponds to residues 394-400 of AT, was identified in the non-reduced FX-AT complex, indicating that FX cleaved the Arg393-Ser394 bond in a reactive centre loop of AT. Unfractionated heparin induced FX-AT complex formation more effectively than low-molecular weight heparin or AT-binding pentasaccharide, and appeared to promote complex formation mainly via a template effect. These data suggest that AT is capable of forming a stable complex with zymogen FX by acting as an inhibitor in the presence of heparin.

The processes for polishing a ZnO surface were investigated with the aim of establishing a process for obtaining an atomically flat surface with high crystalline quality. The defects in a layer undergoing mechanical polishing were monitored through photoluminescence measurements, and the purity of the polished surface was characterized by SIMS. An atomicallyfishing process.

Aim: Hyperuricaemia is a significant factor in a variety of diseases, including gout and cardiovascular diseases. The kidney plays a dominant role in maintaining plasma urate levels through the excretion process. Human renal urate transporter URAT1 is thought to be an essential molecule that mediates the reabsorption of urate on the apical side of the proximal tubule. In this study the pharmacological characteristics and clinical implications of URAT1 were elucidated. Methods: Madin–Darby canine kidney (MDCK) cells stably expressing URAT1 (MDCK-URAT1) were established and examined the interactions of URAT1 with various drugs such as benzbromarone and its metabolites including 6-hydroxybenzbromarone, angiotensin-converting enzyme inhibitors, non-steroidal anti-inflammatory drugs and urate transport inhibitors including E3040 and probenecid. Results: MDCK-URAT1 cells exhibited a time- and dose-dependent increase in urate uptake, with a Km value of 570.7 µmol/L. When an URAT1-green fluorescent protein fusion protein construct was expressed in MDCK cells, the protein was sorted mainly to the apical side of the membrane. The drugs except for captoril dose-dependently inhibited urate uptake mediated by URAT1, with half maximal inhibitory concentration (IC50) values ranging 0.05–716 µmol/L. Conclusion: Comparing these IC50 values with intratubular concentrations of unbound drugs in humans, it is thought that URAT1 is a target molecule of uricosuric drugs, including 6-hydroxybenzbromarone, probenecid, indomethacin and salicylate, to inhibit urate reabsorption in vivo. In addition, a cell line that stably expressing URAT1 could be a useful tool for the development of uricosuric drugs.

Introduction We previously reported that a combination of factors VIIa (FVIIa) and X (FX) might represent an effective and attractive alternative to recombinant factor VIIa (rFVIIa) and plasma-derived activated prothrombin complex concentrate (APCC) for controlling bleeding in hemophiliacs with inhibitors. The present study describes the standardization and preparation of a virus-inactivated and nano-filtrated plasma-derived FVIIa/FX concentrate. We hypothesized that the hemostatic capacity was equivalent to or better than current bypassing agents as evaluated by measurements of waveform APTT clotting and thrombin generation. Results Kinetic analyses showed that a "normal" FX concentration of approximately 140 nM in plasma did not induce maximum catalytic efficacy of FVIIa and that an increase in the concentration of FX in hemophilic plasma enhanced the thrombin generation potential of FVIIa. Thus, the FVIIa/FX mixture was prepared by assembling plasma-derived FVIIa and FX at a weight ratio of 1:10. The FVIIa/FX mixture proved superior to rFVIIa with regards to shortening the APTT and accelerating the thrombin generation in hemophilic plasma. The FVIIa/FX mixture promoted the generation of thrombin more than did rFVIIa. Conclusions Increasing the FX concentration in hemophilic plasma gives a higher clotting potential of FVIIa. A FVIIa/FX concentrate may serve as a new alternative bypassing agent.

Renal aquaporin-2 (AQP2) expression plays a key role in urine concentration. However, it is not known whether metabolic acidosis affects urine-concentrating ability through AQP2 expression in the kidney and urine. We examined urinary excretion and renal expression of AQP2 in control and acidosis rats, using RT-competitive PCR, immunoblot and immunocytochemistry. Urinary excretion of AQP2 is decreased by 92% even with the increase in AQP2 mRNA and protein expressions in the collecting ducts by metabolic acidosis in rats. Urine osmolality in control rats was 1670+/-198 mOsm per kg H(2)O, and immunocytochemistry revealed the presence of AQP2 in the apical plasma membrane of the principal cells in the collecting ducts. Urine osmolality in acidosis rats was lower than that in control (1397+/-243 mOsm per kg H(2)O), and immunocytochemistry showed the diffuse presence of AQP2 in the cytoplasm of the principal cells. Differential centrifugation-coupled immunoblot showed a significant decrease in the ratio of AQP2 in plasma membrane-enriched fraction to that in intracellular vesicle-enriched fraction by metabolic acidosis. In summary, AQP2 translocation is largely decreased by metabolic acidosis even with increased expression in the collecting ducts. A disorder of AQP2 translocation in the collecting ducts with acidosis may be responsible for the diuresis in patients with chronic renal failure.

We obtained blue photoluminescence from tantalum oxide films deposited by radio-frequency magnetron sputtering after annealing. The maximum peak intensity of the photoluminescence was observed from a sample annealed at 600°C for 20min, and the peak wavelength was approximately 430nm. Tantalum oxide films that emit blue light may be useful materials for novel active optical devices utilizing Ta2O5/SiO2 multilayered photonic crystals.

The proton-coupled peptide transporter PEPT2 ( SLC15A2 ) mediates the high-affinity low-capacity transport of small peptides as well as various oral peptide-like drugs in the kidney. In contrast to its well-characterized transport properties, there is less information available on its regulatory mechanism, although the interaction of PEPT2 to the PDZ (PSD-95, DglA, and ZO-1)-domain protein PDZK1 has been preliminarily reported. To examine whether PDZK1 is a physiological partner of PEPT2 in kidneys, we started from a yeast two-hybrid screen of a human kidney cDNA library with the C-terminus of PEPT2 (PEPT2 C-terminus (PEPT2-CT)) as bait. We could identify PDZK1 as one of the positive clones. This interaction requires the PDZ motif of PEPT2-CT detected by a yeast two-hybrid assay, in vitro binding assay and co-immunoprecipitation. The binding affinities of second and third PDZ domains of PDZK1 to PEPT2-CT were measured by surface plasmon resonance. Co-immunoprecipitation using human kidney membrane fraction and localization of PEPT2 in renal apical proximal tubules revealed the physiological meaning of this interaction in kidneys. Furthermore, we clarified the mechanism of enhanced glycylsarcosine (Gly-Sar) transport activity in PEPT2-expressing HEK293 cells after the PDZK1 coexpression. This augmentation was accompanied by a significant increase in the V max of Gly-Sar transport via PEPT2 and it was also associated with the increased surface expression level of PEPT2. These results indicate that the PEPT2–PDZK1 interaction thus plays a physiologically important role in both oligopeptide handling as well as peptide-like drug transport in the human kidney.

Recent advances in molecular biology have identified three organic anion transporter families: the organic anion transporter (OAT) family encoded by SLC22A, the organic anion transporting peptide (OATP) family encoded by SLC21A ( SLCO), and the multidrug resistance-associated protein (MRP) family encoded by ABCC. These families play critical roles in the transepithelial transport of organic anions in the kidneys as well as in other tissues such as the liver and brain. Among these families, the OAT family plays the central role in renal organic anion transport. Knowledge of these three families at the molecular level, such as substrate selectivity, tissue distribution, and gene localization, is rapidly increasing. In this review, we will give an overview of molecular information on renal organic anion transporters and describe recent topics such as the regulatory mechanisms and molecular physiology of urate transport. We will also discuss the physiological roles of each organic anion transporter in the light of the transepithelial transport of organic anions in the kidneys.

Physiological and pharmacological studies indicate that the renal and hepatic organic anion transport systems are responsible for the elimination of numerous compounds, such as drugs, environmental substances and metabolites of both endogenous and exogenous origins. Recently, the molecular identity of the organic anion transport system, the OAT family, was revealed. To date, six OAT members have been identified and shown to have important roles not only in detoxification in the kidneys, liver and brain, but also in the reabsorption of essential compounds such as urate. The OAT family members are closely associated with the pharmacokinetics, drug–drug interactions and toxicity of anionic substances such as nephrotoxic drugs and uremic toxins. The molecular characterization of the OAT family encoded by SLC22A will be discussed.

The urate-anion exchanger URAT1 is a member of the organic anion transporter (OAT) family that regulates blood urate level in humans and is targeted by uricosuric and antiuricosuric agents. URAT1 is expressed only in the kidney, where it is thought to participate in tubular urate reabsorption. We found that the multivalent PDZ (PSD-95, Drosophila discs-large protein, Zonula occludens protein 1) domain-containing protein, PDZK1 interacts with URAT1 in a yeast two-hybrid screen. Such an interaction requires the PDZ motif of URAT1 in its extreme intracellular C-terminal region and the first, second, and fourth PDZ domains of PDZK1 as identified by yeast two-hybrid assay, in vitro binding assay and surface plasmon resonance analysis (K(D) = 1.97-514 nM). Coimmunoprecipitation studies revealed that the wild-type URAT1, but not its mutant lacking the PDZ-motif, directly interacts with PDZK1. Colocalization of URAT1 and PDZK1 was observed at the apical membrane of renal proximal tubular cells. The association of URAT1 with PDZK1 enhanced urate transport activities in HEK293 cells (1.4-fold), and the deletion of the URAT1 C-terminal PDZ motif abolished this effect. The augmentation of the transport activity was accompanied by a significant increase in the V(max) of urate transport via URAT1 and was associated with the increased surface expression level of URAT1 protein from HEK293 cells stably expressing URAT1 transfected with PDZK1. Taken together, the present study indicates the novel role of PDZK1 in regulating the functional activity of URAT1-mediated urate transport in the apical membrane of renal proximal tubules.

Human organic anion transporter OAT4 is expressed in the kidney and placenta and mediates high-affinity transport of estrone-3-sulfate (E1S). Because a previous study demonstrated no trans-stimulatory effects by E1S, the mode of organic anion transport via OAT4 remains still unclear. In the present study, we examined the driving force of OAT4 using mouse proximal tubular cells stably expressing OAT4 (S2 OAT4). OAT4-mediated E1S uptake was inhibited by glutarate (GA) (IC50: 1.25 mM) and [14C]GA uptake via S2 OAT4 was significantly trans-stimulated by unlabeled GA (5 mM) (P

A 32-year-old man was admitted to our hospital complaining of abdominal pain in the left upper quadrant. A mass was palpable on the left side of the umbilicus. Laboratory data revealed anemia, elevated erythrocyte sedimentation rate, hypergammaglobulinemia, and prolonged prothrombin time. Computed tomography demonstrated a soft tissue mass in the mesentery of the jejunum, portal venous thrombosis, and cavernomatous transformation in the porta hepatis. The patient was eventually diagnosed by laparoscopic partial resection as having inflammatory pseudotumor of the mesentery. Four months later, all of his symptoms and abnormal laboratory findings completely disappeared without any therapy. Inflammatory pseudotumor should be kept in mind as a cause of portal venous thrombosis, and/or cavernomatous transformation although it is rare.

The separation of a factor, which inhibits the degradation of myosin heavy chain in washed meat paste around 40°C, from the sarcoplasmic protein of fish meats was examined. The factor was extracted easily with water from meat. After the extract was mixed with DEAE-ion exchange resin, the factor was eluted with 0.1 M NaCl solution. On the other hand, when the extract was fractionated by ammonium sulfate, the factor was contained in a 50-70% saturated fraction. Then ammonium sulfate fractionation, after ion exchange treatment, gave an almost single peak chromatogram in gel filtration. The peak was 80, 000-90, 000 in molecular weight and showed no transglutaminase activity. Furthermore, this factor was separated from various kinds of fish meats, that is even from fish meat of which modori at 40°C is not induced by meat washing, which varies in modori behavior.

Transporters for vitamin C and its oxidized form dehydroascorbic acid (DHA) are crucial to maintain physiological concentrations of this important vitamin that is used in a variety of biochemical processes. The human SLC23 family consists of the Na(+)-dependent vitamin C transporters SVCT1 (encoded by the SLC23A1 gene) and SVCT2 (SLC23A2) as well as an orphan transporter SVCT3 (SLC23A3). Phylogenetically, the SLC23 family belongs to the nucleobase-ascorbate transporter (NAT) family, although no nucleobase transport has yet been demonstrated for the human members of this family. The SVCT1 and SVCT2 transporters are rather specific for ascorbic acid, which is an important antioxidant and plays a crucial role in a many metal-containing enzymes. SVCT1 is expressed predominantly in epithelial tissues such as intestine where it contributes to the supply and maintenance of whole-body ascorbic acid levels. In contrast to various other mammals, humans are not capable of synthesizing ascorbic acid from glucose and therefore the uptake of ascorbic acid from the diet via SVCT1 is essential for maintaining appropriate concentrations of vitamin C in the human body. The expression of SVCT2 is relatively widespread, where it serves to either deliver ascorbic acid to tissues with high demand of the vitamin for enzymatic reactions or to protect metabolically highly active cells or specialized tissues from oxidative stress. The murine Slc23a3 gene encoding the orphan transporter SVCT3 was originally cloned from mouse yolk sac, and subsequent studies showed that it is expressed in the kidney. However, the function of SVCT3 has not been reported and it remains speculative as to whether SVCT3 is a nucleobase transporter.

Low-vacuum scanning electron microscopy (LV-SEM) has been developed which enables the observation of soft, moist, and electrically insulating materials without any pretreatment unlike conventional scanning electron microscopy, in which samples must be solid, dry and usually electrically conductive. The purpose of this study was to assess the usefulness of LV-SEM for renal biopsy specimens. We analyzed 20 renal biopsy samples obtained for diagnostic purposes. The sections were stained with periodic acid methenamine silver to enhance the contrast, and subsequently examined by LV-SEM. LV-SEM showed a precise and fine structure of the glomerulus in both formalin fixed paraffin and glutaraldehyde-osmium tetroxide-fixed epoxy resin sections up to 10,000-fold magnification. The spike formation on the basement membrane was clearly observed in the membranous nephropathy samples. Similarly to transmission electron microscopy, electron dense deposits were observed in the epoxy resin sections of the IgA nephropathy and membranous nephropathy samples. LV-SEM could accurately show various glomerular lesions at high magnification after a simple and rapid processing of the samples. We consider that this is a novel and useful diagnostic tool for renal pathologies.

Hyperuricaemia is a significant factor in a variety of diseases, including gout and cardiovascular diseases. The kidney plays a dominant role in maintaining plasma urate levels through the excretion process. Human renal urate transporter URAT1 is thought to be an essential molecule that mediates the reabsorption of urate on the apical side of the proximal tubule. In this study the pharmacological characteristics and clinical implications of URAT1 were elucidated.Madin-Darby canine kidney (MDCK) cells stably expressing URAT1 (MDCK-URAT1) were established and examined the interactions of URAT1 with various drugs such as benzbromarone and its metabolites including 6-hydroxybenzbromarone, angiotensin-converting enzyme inhibitors, non-steroidal anti-inflammatory drugs and urate transport inhibitors including E3040 and probenecid.MDCK-URAT1 cells exhibited a time- and dose-dependent increase in urate uptake, with a Km value of 570.7 µmol/L. When an URAT1-green fluorescent protein fusion protein construct was expressed in MDCK cells, the protein was sorted mainly to the apical side of the membrane. The drugs except for captoril dose-dependently inhibited urate uptake mediated by URAT1, with half maximal inhibitory concentration (IC(50) ) values ranging 0.05-716 µmol/L.Comparing these IC(50) values with intratubular concentrations of unbound drugs in humans, it is thought that URAT1 is a target molecule of uricosuric drugs, including 6-hydroxybenzbromarone, probenecid, indomethacin and salicylate, to inhibit urate reabsorption in vivo. In addition, a cell line that stably expressing URAT1 could be a useful tool for the development of uricosuric drugs.

804 GASTROINTESTINAL ENDOSCOPY VOLUME 53, NO. 7, 2001 From the First Department of Medicine, Second Department of Surgery, and Department of Surgical Pathology, School of Medicine, Hokkaido University, Japan. Reprint requests: Toshiyuki Harada, MD, First Department of Medicine, School of Medicine, Hokkaido University, North 15, West 7, Kita-ku, Sapporo, 060-8638, Japan. Copyright © 2001 by the American Society for Gastrointestinal Endoscopy 0016-5107/2001/$35.00 + 0 37/4/114960 doi:10.1067/mge.2001.114960 Carcinoid tumor detected in gastric adenoma during long-term follow-up

Introduction MC710 is a mixture agent consisting of plasma-derived activated factor VII (FVIIa) and factor X (FX) at a weight ratio of 1:10 developed as a novel bypassing agent for the management of the bleeding of hemophilia patients with inhibitors. The pharmacokinetics, distribution, and excretion of 125I-labeled-FVIIa (125I-FVIIa) and -FX (125I-FX) were studied in male rats after a single intravenous administration of 125I-FVIIa or 125I-FX combined with MC710. Methods 125I-FVIIa or 125I-FX was administered intravenously with MC710 to male rats in a single dosage (FVIIa 0.4 mg and FX 4 mg/kg body weight) and radioactivity and antigen levels in plasma were quantified for 24 h. Urine and feces were sampled to study the excretion of radioactivity during 168 h after dosing. Whole-body autoradiography was performed to evaluate the qualitative distribution of radioactivity 168 h after dosing. Results and conclusions The half-life (t1/2α and t1/2β) of radioactivity and FVIIa antigen were 0.704 and 6.27 h, and 0.496 and 1.66 h, respectively and the area under the plasma concentration–time curve (AUC0–∞) of radioactivity and FVIIa antigen were 17,932 and 8671 ng·h/mL, respectively. The t1/2 of radioactivity and FX antigen were 4.06 and 3.05 h, respectively, and the AUC0–∞ of radioactivity and FX antigen were 320,143 and 395,794 ng·h/mL, respectively. About 80% of the administered dose of radioactivity was excreted in urine and feces by 168 h after administration. Tissue distribution experiments showed that FVIIa- and FX-related 125I accumulated in bone and bone marrow, and disappeared slowly.

Objective We compared the effect of treatments in the long-term renal survival of IgA nephropathy. Methods One hundred and fourteen patients with biopsy-proven IgA nephropathy were retrospectively divided into 4 groups, reflecting shifts in treatment trends from 1985 to 2005: patients without treatment (no treatment group; n=36), patients treated only with anti-platelet drugs (anti-platelet group; n=12), those treated mainly with angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) (ACEI/ARB group; n =29), and prednisolone-treated patients (PSL group; n =37). Results Baseline blood pressure, serum creatinine and renal histological findings were similar among the 4 groups; however, the urinary protein level was significantly severer in the PSL group. After a mean follow-up of 7.0±0.5 years, end-stage renal disease occurred in 11 patients (31%) in the no treatment group, 5 patients (42%) in the anti-platelet group and 3 patients (8%) in the PSL group, but in only 1 patient (3%) in the ACEI/ARB group. Kaplan-Meier renal survival after 20 years was significantly better in the ACEI/ARB group than in the anti-platelet group or in the no treatment group (p

The neuropeptide hormone arginine-vasopressin (AVP) is well known to exert its antidiuretic effect via the vasopressin V2 receptor (V2R), whereas the role of the vasopressin V1a receptor (V1aR) in the kidney remains to be clarified. Previously, we reported decreased plasma volume and blood pressure in V1a receptor-deficient (V1aR−/−) mice (Koshimizu T, Nasa Y, Tanoue A, Oikawa R, Kawahara Y, Kiyono Y, Adachi T, Tanaka T, Kuwaki T, Mori T. Proc Natl Acad Sci USA 103: 7807–7812, 2006). In this study, we investigated the role of V1aR in urine concentration, renal function, and the renin-angiotensin system (RAS) using V1aR−/−mice. Urine volume of V1aR−/−mice was greater than that of wild-type mice, particularly when water was loaded, while the glomerular filtration rate (GFR), urinary NaCl excretion, AVP-dependent cAMP generation, V2R, and aquaporin 2 (AQP2) expression in the kidney were lower, indicating that the diminished GFR and V2R-AQP2 system led to impaired urinary concentration in V1aR−/−mice. Since the GFR and V2R-AQP2 system are regulated by RAS, we analyzed renin and angiotensin II in V1aR−/−mice and found that the plasma renin and angiotensin II were decreased. The expression of renin in granule cells was decreased in V1aR−/−mice, which led to a decreased level of plasma renin. In addition, the expression of renin stimulators such as neuronal nitric oxide synthase and cyclooxygenase-2 in macula densa (MD) cells, where V1aR was specifically expressed, was decreased in V1aR−/−mice. These data indicate that AVP regulates body fluid homeostasis and GFR via the V1aR in MD cells by activating RAS and subsequently the V2R-AQP2 system.

In this study, we demonstrate that a putative membrane unknown solute transporter 1 of the rat kidney (UST1r; Slc22a9) is a multispecific transporter of organic anions (OAs). When expressed in Xenopus oocytes, UST1r mediated uptake of ochratoxin A (OTA; K(m) = 1.0 microM) and sulfate conjugates of steroids, such as estrone-3-sulfate (ES; K(m) = 3.1 microM) and dehydroepiandrosterone sulfate (DHEAS; K(m) = 2.1 microM) in a sodium-independent manner. We herein propose that UST1r be renamed OA transporter 8 (rOat8). rOat8 interacted with chemically heterogenous anionic compounds, such as nonsteroidal anti-inflammatory drugs, diuretics, probenecid, taurocholate, and methotrexate, but not with the organic cation tetraethylammonium. The rOat8-mediated ES transport was: a) cis-inhibited by 4-methylumbelliferyl sulfate and beta-estradiol sulfate, but not by glucuronide conjugates of these compounds, b) cis-inhibited by four- and five- carbon (C4/C5) dicarboxylates (succinate and glutarate (GA)), and c) trans-stimulated by GA, whereas the efflux of GA was significantly trans-stimulated by ES. By RT-PCR, rOat8 mRNA was expressed in proximal convoluted tubules and cortical and outer medullary collecting ducts, whereas in immunochemical studies, Oat8 was identified as the ñ58 kDa protein that in the collecting duct colocalized with the V-ATPase in plasma membranes and intracellular vesicles in various subtypes of intercalated cells. Molecular identification of Oat8 in these cells indicates a possible novel role of OAT family in the renal secretion/reabsorption of OA and acids and bases via affecting the V-ATPase-dependent functions.

Vasopressin V1aand V2receptors (V1aR and V2R, respectively) distribute in the collecting duct of the kidney. Although the function of V2R mediating the antidiuretic effect of AVP has been investigated in detail, the role of V1aR in the collecting ducts has not been elucidated. In the present study, we have investigated the role of the V1aR pathway in V2R promoter activity. We cloned the 5′-flanking region of rat V2R (rV2R) and investigated rV2R promoter activity in the LLC-PK1cell line transfected to express rat V1aR (rV1aR) dominantly (LLC-PK1/rV1aR). AVP induced a transient increase, followed by a sustained decrease, of rV2R promoter activity in these cells. This AVP-induced decrease of rV2R promoter activity was inhibited by V1aR, but not V2R, antagonist. PMA mimicked this decrease of rV2R promoter activity. On the contrary, 8-(4-chlorophenylthio)-cAMP increased rV2R promoter activity. These PMA- and 8-(4-chlorophenylthio)-cAMP-induced effects were not observed on the deletion segment of the 5′-flanking region lacking CAAT and SP1 sites. In conclusion, 1) expression of the V2R is downregulated via the V1aR pathway in LLC-PK1/rV1aR cells, and 2) expression of the V2R is downregulated by the PMA-induced PKC pathway and upregulated by the cAMP-PKA pathway. These opposite effects of PKC and PKA appear to be regulated by the same promoter region of CAAT and SP1.

Humans excrete uric acid as the final breakdown product of unwanted purine nucleotides. Urate scavenges potential harmful radicals in our body. However, in conjunction with genetic or environmental (especially dietary) factors, urate may cause gout, nephrolitiasis, hypertension, and vascular disease. Blood levels of urate are maintained by the balance between generation and excretion. Excretion requires specialized transporters located in renal proximal tubule cells, intestinal epithelial cells, and vascular smooth muscle cells. The recently identified human urate transporters URAT1, MRP4, OAT1, and OAT3 are thought to play central roles in homeostasis and may prove interesting targets for future drug development.

Objective: N-Acetylglucosaminyltransferase V (GnT-V) is a key enzyme in the formation of branching asparagine-linked oligosaccharides and is linked to tumor invasion and metastasis in colon and breast cancers. In normal esophageal epithelium, β1,6-branched asparagine-linked oligosaccharides synthesized by GnT-V are seen in the basal cell layers but not in the superficial cell layers, and its presence has been shown in invasive esophageal cancers. However, neither GnT-V expression nor its clinical significance has been previously examined in human normal, premalignant and malignant esophageal tissues. Methods: GnT-V expression was studied by immunohistochemistry using a specific monoclonal antibody in 121 surgically resected specimens of esophageal squamous cell carcinomas (SCCs) and adjacent tissues, and was analyzed statistically in relation to various characteristics. Results: GnT-V expression was observed in none (0%) of the 19 normal epithelial tissues, 1 (2%) of the 43 hyperplastic tissues, 30 (54%) of the 56 mildly dysplastic tissues, 27 (63%) of the 43 moderately dysplastic tissues, 21 (44%) of the 48 in situ SCCs and 29 (26%) of the 110 invasive SCCs (p < 0.005). GnT-V expression was observed significantly more frequently in mildly and moderately dysplastic tissues when compared with normal epithelial and hyperplastic tissues (p < 0.005), and its frequency was decreased in in situ and invasive SCCs (p < 0.005). GnT-V expression was frequently observed in SCCs of small size and without distant metastasis or lymph node metastasis. Conclusions: Increased expression of GnT-V is associated with the early event of esophageal tumorigenesis.

Lactoferrin (LF), an iron-binding glycoprotein, exhibits several biological activities, including anti-viral activity and immunomodulatory functions. LF has been reported to inhibit hepatitis C virus (HCV) infection in cultured human hepatocytes and HCV viremia in low pretreatment HCV RNA titers of patients with chronic hepatitis C (CHC). However, the combination of interferon (IFN) alpha-2b plus ribavirin with LF for CHC has not been previously investigated. Thirty-six CHC patients, who were positive for HCV RNA with high serum levels of HCV RNA or who did not respond to or relapsed after interferon monotherapy, were randomly assigned to two groups: IFN alpha-2b and ribavirin plus LF for 24 weeks (18 patients), and IFN alpha-2b and ribavirin plus placebo (18 patients). Treatment was discontinued in three patients (17%) in the LF group and eight patients (44%) in the placebo group. For the 25 patients who finished the 24 weeks of treatment, virological sustained response was seen in 6 (40%) patients in the LF group and in 5 (50%) patients in the placebo group and there was no statistically significant difference between the two groups (p=0.7). Serum alanine aminotransferase concentrations remained normal throughout the follow-up period in nine patients (60%) in the LF group as compared with five patients (50%) in the placebo group (p=0.7). The proportion of patients with a virological or biochemical response at the end of the treatment period did not differ between the two groups. Furthermore, there were no statistically significant differences between the two groups in hemoglobin concentration, serum iron, ferritin, Th1/Th2 ratio or ribavirin concentration throughout the treatment and follow-up periods. In conclusion, we could not demonstrate that LF in combination with IFN alpha-2b and ribavirin increases the virological and biochemical response rate for CHC patients with high serum levels of HCV RNA or for CHC patients who do not response to or relapse after IFN monotherapy.

Many proteins including ion channels mediate a variety of biological activities of cells through forming large molecular assemblies via protein-protein interactions. Hence, to understand the function of a particular protein, it is often useful to identify other proteins with which it associates. The two-hybrid system is a widely used yeast-based genetic approach for detecting protein-protein interactions and provides a powerful way of isolating ion channel-associated proteins in an in vivo setting without purifying both proteins. This system is thought to be one of the important techniques for "Proteome" analysis in the post-genomic era. In this article, we describe the yeast two-hybrid assay we have used to identify proteins binding to asic-sensing ion channel ASIC3 and urate transporter 1 (URAT1) and discuss some general and specific considerations about using ion channel proteins in the two-hybrid system.

We describe a case of diabetes mellitus complicated by neurosensory hearing loss, cardiomyopathy, and sleep apnea syndrome. A 48-year-old man who was admitted for treatment of a lacerated tendon of the right shoulder was also found to require preoperative control of diabetes, a condition that had been diagnosed 4 years earlier. The family pedigree suggested maternal inheritance of diabetes. The patient also had neurosensory hearing loss and the central type of sleep apnea syndrome. His myocardium was hypertrophic and the ultrastructural analysis showed morphologically abnormal mitochondria. On the basis of the apparent characteristic manifestations, we speculated that he had a mitochondrial disease. To elucidate the responsible mutation of mitochondrial DNA, we sequenced the patient's entire mitochondrial DNA derived from blood leukocytes and found 40 sequence variants. Three of those, 5466 A/G, 7912 G/A, and 10601 T/C, have not yet been reported. Nine of the 40 variants were accompanied by an amino acid replacement, including 5466 A/G. Although we could not determine the most significant mutation, the variants of mitochondrial DNA may have been associated with this patient's unusually variable clinical manifestations.