Altered gap junctional communication and renal haemodynamics in Zucker fatty rat model of type 2 diabetes

AIMS/HYPOTHESIS

We examined the link between altered gap junctional communication and renal haemodynamic abnormalities in diabetes in studies performed on Zucker lean (ZL) and the Zucker diabetic fatty (ZDF) rat model of type 2 diabetes.

METHODS

The abundance of connexin (Cx) 37, 40 and 43 was assessed by western blot and immunohistochemistry. Renal haemodynamics was characterised with GAP peptides, which are Cx mimetics, to inhibit gap junctions as a probe in both strains.

RESULTS

ZDF rats exhibited higher plasma glucose, 8-epi-prostaglandin F2α excretion, renal plasma flow and GFR than ZL rats. In ZDF rat kidney phosphorylation of Cx43 was enhanced compared with that in ZL rats. Immunohistochemical study revealed that the density of abundance of Cx37 in renin-secreting cells was significantly reduced in ZDF rats. Although renal autoregulation was markedly impaired in ZDF rats, it was preserved in ZL rats. GAP27 for Cx37,43 and for Cx40 impaired renal autoregulation in ZL rats, but failed to induce further alterations in renal autoregulation in ZDF rats.

CONCLUSIONS/INTERPRETATION

Our findings indicate that ZDF rats have glomerular hyperfiltration with impaired autoregulation. They also demonstrate enhanced phosphorylation of Cxs and reduced production of Cxs in ZDF rat kidney, especially of Cx37 in renin-secreting cells. Finally, our data suggest that an impairment of gap junctional communication in juxtaglomerular apparatus plays a role in altered renal autoregulation in diabetes.

Four-color laser white illuminant demonstrating high color-rendering quality

Solid-state lighting is currently based on light-emitting diodes (LEDs) and phosphors. Solid-state lighting based on lasers would offer significant advantages including high potential efficiencies at high current densities. Light emitted from lasers, however, has a much narrower spectral linewidth than light emitted from LEDs or phosphors. Therefore it is a common belief that white light produced by a set of lasers of different colors would not be of high enough quality for general illumination. We tested this belief experimentally, and found the opposite to be true. This result paves the way for the use of lasers in solid-state lighting.

Optical properties of Si nanowires on a Si {111} surface

We have investigated optical properties of straight silicon nanowires by means of in-situ cathodoluminescence spectroscopy in a transmission electron microscope. The nanowires, grown on a Si{111} surface via vapor-liquid-solid growth mechanism, have no structural defects such as kink, and the diameter and growth direction are controlled by varying the growth conditions. We have found that the nanowires emit intense light. These lines have not been observed in other kinds of Si nanostructures such as porous Si.

Observation of the fractional quantum Hall effect in an oxide

The quantum Hall effect arises from the cyclotron motion of charge carriers in two-dimensional systems. However, the ground states related to the integer and fractional quantum Hall effect, respectively, are of entirely different origin. The former can be explained within a single-particle picture; the latter arises from electron correlation effects governed by Coulomb interaction. The prerequisite for the observation of these effects is extremely smooth interfaces of the thin film layers to which the charge carriers are confined. So far, experimental observations of such quantum transport phenomena have been limited to a few material systems based on silicon, III-V compounds and graphene. In ionic materials, the correlation between electrons is expected to be more pronounced than in the conventional heterostructures, owing to a large effective mass of charge carriers. Here we report the observation of the fractional quantum Hall effect in MgZnO/ZnO heterostructures grown by molecular-beam epitaxy, in which the electron mobility exceeds 180,000 cm(2) V(-1) s(-1). Fractional states such as ν = 4/3, 5/3 and 8/3 clearly emerge, and the appearance of the ν = 2/5 state is indicated. The present study represents a technological advance in oxide electronics that provides opportunities to explore strongly correlated phenomena in quantum transport of dilute carriers.

Change in carrier type in high-k gate carbon nanotube field-effect transistors by interface fixed charges

We study the phenomenon of change in carrier type in carbon nanotube field-effect transistors (CNFETs) caused by the atomic layer deposition (ALD) of a HfO(2) gate insulator. When a HfO(2) layer is deposited on a CNFET, the type of carrier changes from p-type to n-type. The so-obtained n-type device has good performance and stability in air. The conductivity of such a device with a channel length of 0.7 microm is 11% of the quantum conductance 4e(2)/h. The contact resistance for electron current is estimated to be 14 kOmega. The n-type conduction of this CNFET is maintained for more than 100 days. The change in carrier type is attributed to positive fixed charges introduced at the interface between the HfO(2) and SiO(2) layers. We also propose a novel technique to control the type of conduction by utilizing interface fixed charges; this technique is compatible with Si CMOS process technology.

Administration of dalteparin based on the activated clotting time for prophylaxis of hepatic vessel thrombosis in living donor liver transplantation

Beginning in 2004, dalteparin doses based on activated clotting time (ACT) were administered for hepatic vessel thrombosis prophylaxis in living donor liver transplantation (LDLT). We verified the feasibility of this new therapy by comparing it with the previous one. From 1993 through 2008, 42 metabolic liver patients who underwent LDLT were divided into two groups. Group A (1993-2003, n = 32) was administered a fixed dalteparin dose and a large amount of fresh frozen plasma (FFP); Group B (2004-2008, n = 10) was administered an appropriate dosage of dalteparin to maintain the ACT levels from 140 to 150 seconds and a small amount of FFP. Group B was administered a lesser amount of FFP and more dalteparin. This resulted in longer activated partial thromboplastin time, lower fibrinogen degradation products D-dimer, and lower aspartate aminotransferase levels compared to group A; all differences were significant. Group B showed neither thrombotic nor hemorrhagic complications. Anticoagulation therapy comprising adjustment of the dalteparin dose based on ACT reduces thrombotic complications without increasing hemorrhagic complications. ACT measurement is a simple, reliable method for bedside monitoring of dalteparin anticoagulant effects for LDLT.

Time process study with UML

OBJECTIVES

We propose a new business-process analysis approach, Time Process Study (TPS), which comprises process analysis and time and motion studies (TMS). TPS offsets weaknesses of TMS; the cost of field studies and the difficulties in applying them to tasks whose time span differs from those of usual tasks.

METHODS

In TPS, the job procedures are first displayed using a unified modeling language (UML). Next, time and manpower for each procedure are studied through interviews and TMS, and the information is appended to the UML diagram. We applied TPS in the case of a hospital-based cancer registry (HCR) of a university hospital to clarify the work procedure and the time required, and investigated TPS's availability.

RESULTS

Meetings for the study were held once a month from July to September in 2008, and one inquirer committed a total of eight hours to the hospital survey. TPS revealed that HCR consisted of three tasks and 14 functions. The registration required 123 hours/month/person, the quality control required 6.5 hours/ 6 months/person and filing data into the population-based cancer registry required 0.5 hours/6 months/person. Of the total tasks involved in registration, 116.5 hours/month/person were undertaken by a registration worker, which shows the necessity of employing one full-time staff.

CONCLUSION

With TPS, it is straightforward to share the concept among the study-team because the job procedure is first displayed using UML. Therefore, it requires a few workload to conduct TMS and interview. The obtained results were adopted for the review of staff assignment of HCR by Japanese government.

Gene expression profiling in rat liver treated with compounds inducing elevation of bilirubin

We have constructed a large-scale transcriptome database of rat liver treated with various drugs. In an effort to identify a biomarker for the diagnosis of elevated total bilirubin (TBIL) and direct bilirubin (DBIL), we extracted 59 probe sets of rat hepatic genes from the data for seven typical drugs, gemfibrozil, phalloidin, colchicine, bendazac, rifampicin, cyclosporine A, and chlorpromazine, which induced this phenotype from 3 to 28 days of repeated administration in the present study. Principal component analysis (PCA) using these probes clearly separated dose- and time-dependent clusters in the treated groups from their controls. Eighteen more drugs in the database, reported to elevate TBIL and DBIL, were estimated by PCA using these probe sets. Of these, 12 drugs, that is methapyrilene, thioacetamide, ticlopidine, ethinyl estradiol, alpha-naphthylisothiocyanate, indomethacin, methyltestosterone, penicillamine, allyl alcohol, aspirin, iproniazid, and isoniazid were also separated from the control clusters, as were the seven typical drugs causing elevation of TBIL and DBIL. The principal component 1 (PC1) value showed high correlation with TBIL and DBIL. In the cases of colchicine, bendazac, chlorpromazine, gemfibrozil, and phalloidin, the possible elevation of TBIL and DBIL could be predicted by expression of these genes 24 h after single administration. We conclude that these identified 59 probe sets could be useful to diagnose the cause of elevation of TBIL and DBIL, and that toxicogenomics would be a promising approach for prediction of this type of toxicity.

Converting an insulating silicon nanochain to a conducting carbon nanotube by electrical breakdown

Electrical breakdowns of individual silicon nanochains, in which silicon nanoparticles are covered with and connected by oxide alternatively forming nanowires, are studied by in situ transmission electron microscopy using a microprobe system. Individual silicon nanochains can endure a current typically as large as 10(0) nA, and we found that a silicon nanochain can be converted to a nanotube by applying a current as large as 10(1) nA. In the nanotubes, some silicon particles are left. Experimental results suggest that nanotubes are heavily distorted carbon nanotubes, which are formed through the aggregation of contaminating carbon on the nanochain surface and the evaporation of the oxide core due to Joule heating.

New indicators for the evaluation of community policies based on period and cohort effects in cerebrovascular disease mortality rates

INTRODUCTION

Countermeasures against cerebrovascular diseases (CVD) are one of the important health policies in Japan. This study proposes new indicators that are based on period and cohort effects in CVD mortality rates. The main aim of the study is to contribute to community diagnosis with the existing policies.

METHODS

CVD mortality rates for all prefectures in Japan were analyzed according to age, time period, and cohort effects, using the Bayesian Poisson age-period-cohort model. Several indicators were extracted based on the principal component analysis of the estimates of the effects.

RESULTS

Two indicators named the change-in-magnitude and the time-of-decrease were extracted from estimates of the period effects, and three indicators named the change-cohort-of-improvement were extracted from estimates of the cohort effects. These were considered to be related to the countermeasures against CVD.

CONCLUSION

Under the assumption that the new indicators reflect the result of past policies, the new indicators allow us to evaluate the validity of past policies, and to suggest the necessity for improvement in the conventional policies.

Reconstruction of the Achilles tendon and overlying soft tissue using an anteromedial thigh flap for a post-burn pes equinus deformity: a case report

We present a 36-year-old man with a severe pes equinus deformity of the ankle and an intractable ulcer over the Achilles tendon after a 4th-degree burn. He underwent a one-stage reconstructive surgical procedure using an anteromedial thigh flap with its vascularised fascia. After lengthening of the Achilles tendon and posterior release of the ankle, the anteromedial thigh fasciocutaneous flap was transferred. The ischaemic Achilles tendon was wrapped with the vascularised femoral fascia for vascularisation and reinforcement. The skin defect was covered with the skin paddle of the combined flap. There were no postoperative complications. At the 3-year follow up, the range of movement of the ankle was almost normal. The patient was able to walk and climb stairs without support, and the ulcer was cured.

Multipulse operation and optical detection of nuclear spin coherence in a GaAs/AlGaAs quantum well

We demonstrate manipulation of nuclear spin coherence in a GaAs/AlGaAs quantum well by optically detected nuclear magnetic resonance (NMR). A phase shift of the Larmor precession of photoexcited electron spins is detected to read out the hyperfine-coupled nuclear spin polarization. Multipulse NMR sequences are generated to control the population and examine the phase coherence in quadrupolar-split spin-3/2 75As nuclei. The phase coherence among the multilevel nuclear spin states is addressed by application of pulse sequences that are used in quantum gate operations.

Stereoselective glucuronidation and hydroxylation of etodolac by UGT1A9 and CYP2C9 in man

1. In vitro metabolic studies with etodolac were performed. S- and R-etodolac were converted to the acylglucuronide and hydroxylated metabolites by UDP-glucuronosyltransferase (UGT) and cytochrome P450 in microsomes. However, the stereoselectivities of UGT and P450 for the isomers were opposite. S-etodolac was glucuronidated preferentially than R-etodolac by UGT. In contrast, R-etodolac was hydroxylated preferentially than S-etodolac by P450. 2. Of several human P450 enzymes, CYP2C9 had the greatest activity for hydroxylation of R-etodolac. Sulfaphenazole, an inhibitor of CYP2C9, and anti-CYP2C9 antibody inhibited the hydroxylation of R-etodolac in human liver microsomes. CYP2C9 therefore contributes to the stereoselective hydroxylation of R-etodolac. 3. Of several human UGT enzymes, UGT1A9 had the greatest activity for glucuronidation of S-etodolac. Propofol and thyroxine, inhibitors of UGT1A9, inhibited the glucuronidation of S-etodolac in human liver microsomes. Therefore, UGT1A9 is mainly responsible for the stereoselective glucuronidation of S-etodolac. 4. Because S-etodolac was metabolized more rapidly than R-etodolac in human cryopreserved hepatocytes, the stereoselectivities of UGT1A9 for etodolac substantially influenced the overall metabolism of S- and R-etodolac in man.