Weak signal extraction enabled by deep neural network denoising of diffraction data.

The removal or cancellation of noise has wide-spread applications in imaging and acoustics. In applications in everyday life, such as image restoration, denoising may even include generative aspects, which are unfaithful to the ground truth. For scientific use, however, denoising must reproduce the ground truth accurately. Denoising scientific data is further challenged by unknown noise profiles. In fact, such data will often include noise from multiple distinct sources, which substantially reduces the applicability of simulation-based approaches. Here we show how scientific data can be denoised by using a deep convolutional neural network such that weak signals appear with quantitative accuracy. In particular, we study X-ray diffraction and resonant X-ray scattering data recorded on crystalline materials. We demonstrate that weak signals stemming from charge ordering, insignificant in the noisy data, become visible and accurate in the denoised data. This success is enabled by supervised training of a deep neural network with pairs of measured low- and high-noise data. We additionally show that using artificial noise does not yield such quantitatively accurate results. Our approach thus illustrates a practical strategy for noise filtering that can be applied to challenging acquisition problems.

Vacuum cleaving of superconducting niobium tips to optimize noise filtering and with adjustable gap size for scanning tunneling microscopy.

Superconducting (SC) tips for scanning tunneling microscopy (STM) can enhance a wide range of surface science studies because they offer exquisite energy resolution, allow the study of Josephson tunneling, or provide spatial contrast based on the local interaction of the SC tip with the sample. The appeal of a SC tip is also practical. An SC gap can be used to characterize and optimize the noise of a low-temperature apparatus. Unlike typical samples, SC tips can be made with less ordered materials, such as from SC polycrystalline wires or by coating a normal metal tip with a superconductor. Those recipes either require additional laboratory infrastructure or are carried out in ambient conditions, leaving an oxidized tip behind. Here, we revisit the vacuum cleaving of an Nb wire to prepare fully gapped tips in an accessible one-step procedure. To show their utility, we measure the SC gap of Nb on Au(111) to determine the base temperature of our microscope and to optimize its RF filtering. The deliberate coating of the Nb tip with Au fully suppresses the SC gap and we show how sputtering with Ar+ ions can be used to gradually recover the gap, promising tunability for tailored SC gaps sizes. • Oxide free superconducting STM tips • RF filter optimization.

Optical vortex induced spatio-temporally modulated superconductivity in a high-Tc cuprate.

We report an experimental approach to produce spatially localized photoinduced superconducting state in a cuprate superconductor using optical vortices with ultrafast pulses. The measurements were carried out using coaxially aligned three-pulse time-resolved spectroscopy, in which an intense vortex pulse was used for coherent quenching of superconductivity and the resulting spatially modulated metastable states were analyzed by the pump-probe spectroscopy. The transient response after quenching shows a spatially localized superconducting state that remains unquenched at the dark core of the vortex beam for a few picoseconds. Because the quenching is instantaneously driven by photoexcited quasiparticles, the vortex beam profile can be transferred directly to the electron system. By using the optical vortex-induced superconductor, we demonstrate spatially resolved imaging of the superconducting response and show that the spatial resolution can be improved using the same principle as that of super-resolution microscopy for fluorescent molecules. The demonstration of spatially controlled photoinduced superconductivity is significant for establishing a new method for exploring novel photoinduced phenomena and applications in ultrafast optical devices.

Neuronal expression, cytosolic localization, and developmental regulation of the organic solute carrier partner 1 in the mouse brain.

Organic solute carrier partner 1 (OSCP1) is a mammalian, transporter-related protein that is able to facilitate the uptake of structurally diverse organic compounds into the cell when expressed in Xenopus laevis oocytes. This protein has been implicated in testicular handling of organic solutes because its mRNA expression is almost exclusive in the testis. However, in this study, we demonstrated significant expression of OSCP1 protein in mouse brain, the level of which was rather higher than that in the testis, although the corresponding mRNA expression was one-tenth of the testicular level. Immunohistochemistry revealed that OSCP1 was broadly distributed throughout the brain, and various neuronal cells were immunostained, including pyramidal cells in the cerebral cortex and hippocampus. However, there was no evidence of OSCP1 expression in glia. In primary cultures of cerebral cortical neurons, double-labeling immunofluorescence localized OSCP1 to the cytosol throughout the cell body and neurites including peri-synaptic regions. This was consistent with the subcellular fractionation of brain homogenates, in which OSCP1 was mainly recovered after centrifugation both in the cytosolic fraction and the particulate fraction containing synaptosomes. Immunoelectron microscopy of brain sections also demonstrated OSCP1 in the cytosol near synapses. In addition, it was revealed that changes in the expression level of OSCP1 correlated with neuronal maturation during postnatal development of mouse brain. These results indicate that OSCP1 may have a role in the brain indirectly mediating substrate uptake into the neurons in adult animals.

Intestinal absorption mechanism of tebipenem pivoxil, a novel oral carbapenem: involvement of human OATP family in apical membrane transport.

Tebipenem pivoxil (TBPM-PI) is an oral carbapenem antibiotic for treating otolaryngologic and respiratory infections in pediatric patients. This agent is a prodrug to improve intestinal absorption of TBPM, an active form, and an absorption rate of TBPM-PI is higher than those of other prodrug-type ß-lactam antibiotics. In the present study, we hypothesized that a certain mechanism other than simple diffusion is involved in the process of improved intestinal absorption of TBPM-PI and examined the mechanism. TBPM-PI uptake by Caco-2 cells was decreased by ATP-depletion and lowering the temperature to 4 °C, suggesting the contribution of carrier-mediated transport mechanisms. This uptake was partially decreased by ACE inhibitors, and the reduction of the absorption by captopril was observed by in vivo study and in situ single-pass intestinal perfusion study in rat, supporting the contribution of influx transporters. Since some ACE inhibitors and ß-lactam antibiotics are reported to be substrates of PEPT and OATP families, we measured transporting activity of TBPM-PI by intestinally expressed transporters, PEPT1, OATP1A2, and OATP2B1. As a result, significant transport activities were observed by both OATP1A2 and OATP2B1 but not by PEPT1. Interestingly, pH dependence of TBPM-PI transports was different between OATP1A2 and OATP2B1, showing highest activity by OATP1A2 at pH 6.5, while OATP2B1-mediated uptake was higher at neutral and weak alkaline pH. OATP1A2 exhibited higher affinity for TBPM-PI (K(m) = 41.1 µM) than OATP2B1 (K(m) > 1 mM) for this agent. These results suggested that TBPM-PI has high intestinal apical membrane permeability due to plural intestinal transport routes, including the uptake transporters such as OATP1A2 and OATP2B1 as well as simple diffusion.

[Pharmacokinetics of tebipenem pivoxil, a novel oral carbapenem antibiotic, in experimental animals].

Pharmacokinetics of tebipenem pivoxil (TBPM-PI), a novel oral carbapenem antibiotic, were known in various laboratory animal. (1) In mouse, rat, dog and monkey, TBPM-PI were absorbed quickly, and the bioavailability was (71.4, 59.1, 34.8 and 44.9%, respectively. (2) TBPM-PI was quickly converted to tebipenem (TBPM), an active form of TBPM-PI. Through blood circulation, TBPM was distributed into the kidney at a high concentration and eliminated quickly. There was no other tissue than the kidney, in which TBPM was highly distributed and remained for a long time. In addition, low penetration to the central nervous system was confirmed. The penetration ratio of TBPM to ELF, that is the ratio of ELF concentration to plasma concentration of TBPM, was 21.8 +/- 14.7%. (3) Serum protein bindings of TBPM in the range of 0.1-100 microg/ml were 90.4-98.3% for mouse, 78.5-90.0% for rat, 15.7-18.7% for dog, 35.3-39.3% for monkey and 59.7-73.9% for human. (4) In vitro metabolism was investigated in plasma, liver S9 fractions and small intestinal S9 fractions derived from infant and adult animals. TBPM-PI was transformed into TBPM quickly in any matrices. It was confirmed that absorbed TBPM-PI was quickly transformed into TBPM or LJC 11,562 (opened ring TBPM) in the plasma after oral administration of 14C-TBPM-PI to infant or adult rat and monkey. TBPM-PI and opened ring TBPM-PI was not detected in plasma and urine samples. In rat and monkey, the oral absorption, distribution, metabolite and excretion of TBPM-PI were not so much different between infant and adult animals. (5) Liver metabolic enzyme system was little affected by 7-days repeated administration of 1-100 mg/kg TBPM-PI. IC50 values of TBPM-PI and TBPM for human CYP isoforms were estimated to be 100 microg/ml or higher. (6) After single oral administration of 10 mg/kg 14C-TBPM-PI to rat, 36.9-42.7% and 58.3-62.2% of radioactivity was excreted to urine and feces, respectively, by 120 hours after administration. The majority of dosage was excreted out of body by 48 hours after administration. After single intravenous administration of 10 mg/kg 14C-TBPM, 87.4% and 11.4% of radioactivity was excreted in urine and bile, respectively, by 24 hours after administration. The majority of dosage was excreted out of body by 4 hours after administration.

[Convulsive liability of an oral carbapenem antibiotic, tebipenem pivoxil].

Tebipenem pivoxil (TBPM-PI), the first oral carbapenem antibiotic both in Japan and abroad, was examined on its convulsive liability. We used ICR male mice and Sprague-Dawley male rats to examine the pro-convulsive effect and anticonvulsive effect of TBPM-PI and its active metabolite, TBPM. (1) When mice were treated with TBPM-PI (30-1000 mg/kg, p.o.) or TBPM (10-300 mg/kg, i.v.), no convulsion was noted at any dose level. When rats were treated with TBPM (300 mg/kg, i.v.), no convulsant effects were noted in electroencephalography or behavioral observation. In intraventricular injection of TBPM in mice, clonic convulsion was observed in 7/10 animals at 100 microg but no effect at 30 microg. On the other hand, the administration of 10/10 microg imipenem/cilastatin (IPM/CS) resulted in clonic convulsion in all animals and tonic convulsion in 3/10 animals, and 4/10 animals died. The administration of 100 microg meropenem did not cause any effects. (2) When mice were co-administered with pentylenetetrazole (45 mg/kg: maximum dose level at which no convulsion is induced) and TBPM-PI (30-300 mg/kg, p.o.) or TBPM (300 mg/kg, i.v.), convulsion enhancing effect was not noted. On the other hand, the co-administration of pentylenetetrazole with IPM/CS (300/300 mg/kg, i.v.) enhanced a convulsive effect of pentylenetetrazole. (3) When mice were treated with TBPM-PI (30-300 mg/kg, p.o.) or TBPM (100 mg/kg, i.v.), inhibitory effect was not noted on convulsions induced by electrostimulation, pentylenetetrazole or strychinine. In conclusion, there were no pro-convulsive effects or anticonvulsive effect in the oral administration of TBPM-PI or intravenous administration of TBPM. Pro-convulsive effect was observed in the intraventricular injection of TBPM as in the case of other carbapenem antibiotics, but such action was weaker than that in IPM/CS administration. Accordingly, the risk of occurrence of convulsion related to TBPM-PI administration was low compared to IPM/CS administration, and TBPM-PI was considered to be less potential to induce convulsions in clinical use.

[Pharmacokinetics analysis of tebipenem pivoxil in a phase II clinical trial in otolaryngological infections].

In a phase IIb clinical study (dose-finding test, 450 mg dosing group: 150 mg t.i.d., 500 mg dosing group: 250 mg b.i.d., 900 mg dosing group: 300 mg t.i.d.) of tebipenem pivoxil (TBPM-PI) for treatment of otolaryngological infections in adults, TBPM concentrations in the patient plasma were quantified. The primary pharmacokinetic parameters such as ka, kel, Vd/F and Tlag were estimated by the Bayesian method and then the secondary pharmacokinetic parameters such as tmax, Cmax, t1/2 and AUC were calculated. As for the patients whose primary parameters were not properly estimated by the Bayesian method, the secondary parameters were calculated by the trapezoidal method. The primary pharmacokinetic parameters obtained by the Bayesian method in 450 mg dosing group (150 mg t.i.d.), 500 mg dosing group (250 mg b.i.d.), and 900 mg dosing group (300 mg t.i.d.) were 5.64 +/- 2.76, 5.11 +/- 3.06 and 2.51 +/- 1.13 hr(-1) for ka, 1.75 +/- 0.25, 2.03 +/- 0.10 and 1.34 +/- 0.27 hr(-1) for kel, 17.62 +/- 5.09, 15.83 +/- 6.14 and 19.34 +/- 8.80 L for Vd/F, and 0.48 +/- 0.11, 0.38 +/- 0.03 and 0.39 +/- 0.26 hr for Tlag, respectively. The secondary parameters obtained by the Bayesian method and the trapezoidal method were 0.85 +/- 0.29, 0.81 +/- 0.33 and 1.18 +/- 1.53 hr for tmax, 5.08 +/- 2.05, 7.92 +/- 4.02 and 8.69 +/- 4.01 microg/ml for Cmax, 0.40 +/- 0.06, 0.34 +/- 0.01 and 0.54 +/- 0.10 hr for t1/2, 5.22 +/- 1.90, 7.93 +/- 4.04 and 13.62 +/- 6.29 microg x hr/ml for AUC after each dosing (AUC(0-8h) or AUC(0-12h)) and 15.65 +/- 5.70, 15.85 +/- 8.08 and 40.87+/- 18.87 microg x hr/ml for AUC(0-24h), respectively. As shown in the above, Cmax and AUC after each dosing were increased with a rise in the dose level, and AUC(0-24h) was increased with a rise in the total dose level per day. Regardless of the dosage, tmax was about 0.8-1.2 hr and t1/2 was about 0.3-0.5 hr, showing almost constant values. Changes in the regimen and dosage did not influence the pharmacokinetic properties of TBPM-PI. Pharmacokinetics of TBPM-PI in adult patients with otolaryngological infection were similar to those in healthy subjects.

Active uptake of ulifloxacin from plasma to lung that controls its concentration in epithelial lining fluid.

Ulifloxacin is a new quinolone antibiotic and it is effective against pneumonia. We previously showed that it is highly distributed into the epithelial lining fluid (ELF) in rats, which might be resulting from certain active transport. The transport system has not been, however, clarified yet. In this study, we attempted to characterize the distribution mechanism of ulifloxacin into the rat ELF. We also aimed to elucidate the feature of ulifloxacin uptake in rat lung and human lung adenocarcinoma cells (Calu-3). In infusion studies, ulifloxacin concentrations in the ELF and lung were higher than that in the plasma, and decreased by co-administration of sparfloxacin or azithromycin to the level of plasma concentration. Integration plot analysis showed that active uptake of ulifloxacin from the plasma to lung was also inhibited by sparfloxacin and azithromycin. In in vitro studies, time and temperature-dependent uptake into Calu-3 was observed, and this uptake was inhibited by sparfloxacin and azithromycin as observed in the rat lung. Additionally sparfloxacin inhibited the active uptake of ulifloxacin into Calu-3 more strongly than levofloxacin as observed in the rat lung. These results suggest that active uptake of ulifloxacin from the plasma to lung controls the distribution of ulifloxacin from the plasma to ELF, and that the uptake of ulifloxacin into Calu-3 has partly similar characteristics to its uptake into the rat lung. We believe our study will contribute to much better understanding of antibiotic efficacy against pathogens which cause pneumonia.

Bile acid-induced elevated oxidative stress in the absence of farnesoid X receptor.

The major function of farnesoid X receptor (FXR) is to maintain bile acid and lipid homeostasis. Fxr-null mice, in which the levels of hepatic bile acid and lipid have been elevated, develop spontaneous liver tumors. We evaluated differences in hepatic bile acid and triglyceride concentrations, and in generation of oxidative stress between wild-type mice and Fxr-null mice. The hepatic levels of 8-hydroxy-2'-deoxyguanosine (8OHdG), thiobarbituric acid-reactive substance (TBARS) and hydroperoxides, oxidative stress-related genes, and nuclear factor (erythroid-2 like) factor 2 (Nrf2) protein in Fxr-null mice were significantly higher than those in wild-type mice. An increase in the hepatic bile acid concentration in Fxr-null mice fed a cholic acid (CA) diet resulted in an increase in the hepatic levels of hydroperoxides, TBARS and 8OHdG, whereas a decrease in the hepatic concentration in mice fed a diet containing ME3738 (22beta-methoxyolean-12-ene-3beta,24(4beta)-diol) resulted in a decrease in these oxidative stress marker levels. A good correlation was observed between the hepatic bile acid concentrations and the hepatic oxidative stress marker levels, although there was no significant correlation between the hepatic triglyceride concentrations and oxidative stress. The results show that oxidative stress is spontaneously enhanced in Fxr-null mice, which may be attributable to a continuously high level of hepatic bile acids.

Physiological models are good tools to predict rat bioavailability of EF5154 prodrugs from in vitro intestinal parameters.

There are only a few reports on the methods that predict in vivo bioavailability from in vitro intestinal parameters. In the present study, we constructed physiological models where we examined if in vivo rat bioavailability was predictable from in vitro intestinal parameters using prodrugs of EF5154, a potent glycoprotein IIb/IIIa receptor antagonist, and other prodrugs. Apparent fraction absorbed (F(a),pred) was calculated using the physiological models that consist of absorption number calculated from Caco-2 cell membrane permeability (P(app)), and Damkohler number calculated from apparent degradation rate constant (K(dapp)) in rat small intestinal fluid. The predicted rat bioavailability that was calculated from F(a),pred corresponded to the observed rat bioavailability, and root mean square error (RMSE) and squared correlation coefficient (r(2)) were 4.58 and 0.904, respectively, suggesting that the physiological models consisting of the membrane permeability and degradation rate constant are good tools for predicting rat bioavailability of EF5154 prodrugs. As for other prodrugs where the chemical structure of their active forms differs from EF5154, the predicted rat bioavailability was not different from fraction absorbed (or rat bioavailability), suggesting the physiological models are generalized to various prodrugs that are not the substrates for active transporters.

Effects of cacao liquor polyphenols on cardiovascular and autonomic nervous functions in hypercholesterolaemic rabbits.

Many epidemiological studies have shown that polyphenols can reduce the risk of mortality from cardiovascular diseases. This study tested the hypothesis that cacao liquor polyphenols have the properties to restore the cardiovascular and autonomic nervous function in an animal model of familial hypercholesterolaemia. Male Kurosawa and Kusanagi-hypercholesterolaemic rabbits were housed in individual cages in a room where a 12-hr light:dark cycle (lights-on at 8:00 and lights-off at 20:00) was maintained. At 3 months of age, they were divided into two groups (standard diet and cacao liquor polyphenol) and the animals received 100 g of the respective diets per day and were provided with tap water ad libitum. Heart rate and blood pressure were measured by a telemetry system. To clarify the autonomic nervous function, power spectral analysis of heart rate variability, baroreflex sensitivity and autonomic nervous tone were measured. After 6 months of dietary administration of cacao liquor polyphenols, heart rate and blood pressure were lowered but plasma lipid concentrations were unchanged. The area of atherosclerotic lesions in the aorta in the cacao liquor polyphenol group was significantly smaller than that in the standard diet group. The high-frequency power of heart rate variability in the rabbits in the standard diet group was significantly decreased with ageing, but that in the cacao liquor polyphenol group was not different between short-term and long-term treatment. Moreover, cacao liquor polyphenols preserved parasympathetic nervous tone, although that in the standard diet group was significantly decreased with ageing. We conclude that cacao liquor polyphenols may play an important role to protect cardiovascular and autonomic nervous functions.

Proposal of membrane transport mechanism of protein-unbound ulifloxacin into epithelial lining fluid determined by improved microdialysis.

Microdialysis method (MD) is useful for sampling protein-unbound substances in vivo. Generally in the MD, a reference compound is used to correct differences in drug permeation clearance through a dialysis membrane in vivo and in vitro. No reference compound was, however, used for determination of a protein-unbound drug concentration in the epithelial lining fluid (ELF). In this study, we firstly examined the propriety of endogenous urea as a reference compound to determine the protein-unbound ulifloxacin concentrations in rat ELF by MD. Endogenous urea was used to correct differences in the permeation clearance in vivo and in vitro which reflect the differences in the extent of contact between a tip probe and ELF in vivo and in vitro. The results showed that our MD is applicable to determine the various concentrations of ulifloxacin and urea, and that we can use endogenous urea as a reference compound even if the extent of the contact between a tip of the probe and the ELF is small. In addition, use of urea concentrations does not affect drug distribution from plasma to ELF because we used endogenous urea. These results support usefulness of endogenous urea as a reference compound to determine protein-unbound drug concentration in ELF by MD. In addition, our results also suggest the existence of certain distribution mechanisms which cause the high penetration ulifloxacin into ELF. Our MD can help progress in pharmacokinetic-pharmacodynamic analysis of various antibiotics in the case where the concentrations in ELF are not equal to that in plasma.

Intratesticular localization of the organic solute carrier protein, OSCP1, in spermatogenic cells in mice.

Organic solute carrier protein 1 (OSCP1) is a recently described human gene that facilitates the transport of various organic solutes into the cell, when expressed in frog eggs. In this study, we cloned a mouse ortholog of OSCP1 encoding 379 amino acid protein, with 94% homology to the human counterpart. The mouse OSCP1 mRNA was predominantly expressed in the testis, in which it was attributed to the spermatogenic cells, except the spermatogonia. Immunohistochemistry confirmed that OSCP1 protein is continuously expressed during spermatogenesis in a stage- and cell type-specific manner, in the leptotene spermatocytes at stage IX through step 15 spermatids. Subcellular fractionation of mouse testis homogenates indicated that OSCP1 is a 45-kDa cytosolic protein. Moreover, when green fluorescent protein-OSCP1 fusion constructs were transfected into cultured cells, the fluorescence localized evenly in the cytoplasm. These results suggest that mouse testis OSCP1 may indirectly mediate substrate uptake into meiotic and spermiogenic germ cells, within the cytosol.

New concept and a theoretical consideration of the mechanism-based pharmacokinetics/ pharmacodynamics (PK/PD) modeling for antimicrobial agents.

Pharmacodynamic (PD) characterization (concentration-dependent, time-dependent, etc.) of antibiotics is determined by aspects of the pharmacodynamic interaction between antibiotics and microorganisms. There are three major aspects of the pharmacodynamic interaction between antibiotics and microorganisms; 1) the minimum drug concentration required for the exhibition of antibacterial activity (MIC: minimum inhibitory concentration, MBC: minimum bactericidal concentration, etc.), 2) the relationship between drug concentration and bactericidal activity and 3) the magnitude of any persistent antibiotic activity (sub-MIC effect, post antibiotic effect, etc.). In the PK/PD approach based on the MIC (static MIC approach), information concerning aspect 1) alone is treated as the quantitative PD parameter (MIC), while information concerning aspects 2) and 3) are not represented as quantified PD parameters in spite of their importance in in vivo pharmacodynamic situation. On the other hand, in the PK/PD approach based on the time-kill profile (dynamic PK/PD approach), information concerning aspects 1) - 3) can all be represented as quantitative dynamic PD parameters (epsilon; the maximum kill rate constant, gamma; the Hill coefficient and EC50; the antibiotic concentration at which 50% of the maximum effect is obtained) together with the growth rates of the organisms (lambda). We thought that the PD characterization of antibiotics should be determined by integrating the dynamic PD parameters and the growth rates, so we developed a new concept integrating these parameters so that a good approximation of the time course of in vivo antibacterial activity exhibited by a antibiotic might be predicted from these parameters and the pharmacokinetics of the drug. To achieve this, we analyzed the time-kill profiles of a wide range of antibiotics against various microorganisms and obtained the dynamic PD parameters and the growth rates for the various combinations of antibiotics and microorganisms. Then we analyzed the causal relationship between the PD characteristics of the antibiotics and the dynamic PD parameters and the growth rates. As a result, we derived the following criteria for predicting the PD characteristics of antibiotics. (i) if the epsilon/lambda is greater than about 10 and gamma is less than one, the pharmacodynamics should be concentration-dependent (ii) if the epsilon/lambda is within the range 1-2 and gamma is about 5 or more, the pharmacodynamics should be time-dependent (iii) if the epsilon/lambda is within the range 1-4 and gamma is in the range 1-12, the pharmacodynamics should be time-dependent or both time- and concentration-dependent. The PD characterization of antibiotics against various strains of different microorganisms can be predicted relatively easily and quickly by utilizing these criteria. These findings make it possible to determine the kinds of causative pathogens to which the antibiotics should be applicable in the clinical sites. Furthermore, it is expected that effective strategies for development and establishing the optimum dosage regimen of novel antibiotics could be worked out more scientifically and efficiently than ever on the basis of the PK/PD parameters corresponding to the predicted PD characters.

Population pharmacokinetics of tebipenem pivoxil (ME1211), a novel oral carbapenem antibiotic, in pediatric patients with otolaryngological infection or pneumonia.

Tebipenem pivoxil (TBPM-PI, ME1211) has been under development as the world's first oral carbapenem for treatment of otolaryngological/respiratory infections caused by drug-resistant S. pneumoniae in pediatric patients. In order to treat these infections effectively, it is important to design optimal dosing regimens based on the pharmacokinetics/pharmacodynamics (PK/PD) relationships, which can be characterized by clarifying the pharmacokinetics of tebipenem (TBPM) in the pediatric population. We therefore performed an population pharmacokinetic analysis using plasma TBPM concentrations obtained from pediatric patients with otolaryngological infection or bacterial pneumonia (0.5-16 years old; n=217, 395 points), after repeated oral administration of TBPM-PI at a dose of 4 or 6 mg/kg b.i.d. A one-compartment model with first-order absorption was adopted. In analysis, weight-normalized creatinine clearance (Ccr) and age were the most significant covariates that respectively explained inter-subject variability in weight-normalized apparent clearance (CL/F) and volume of distribution (Vd/F) of TBPM. The CL/F of TBPM increased with Ccr, and the Vd/F decreased with age. Based on the results of the present analysis, validity of the presently recommended dosage regimen of TBPM-PI in pediatric patients is discussed.

Transporter-mediated hepatic uptake of ulifloxacin, an active metabolite of a prodrug-type new quinolone antibiotic prulifloxacin, in rats.

Prulifloxacin (PUFX) is a prodrug-type new quinolone antibiotic and immediately converted to an active metabolite, ulifloxacin (UFX). It has been previously reported that UFX is highly excreted into the bile, although the hepatic uptake process of UFX has not been investigated yet. In this study, we attempted to characterize the mechanism of hepatic uptake of UFX in rats. The hepatic uptake in vivo was evaluated by integration plot analysis. Furthermore, the uptake of [(14)C]-UFX by isolated rat hepatocytes was measured, and the effects of several transporter inhibitors and other quinolone antibiotics on the uptake were examined. The hepatic uptake clearance of UFX (1 mg/kg) was calculated to be 37.7 mL/min/kg, which was larger than those at doses of 5 and 25 mg/kg and was decreased by co-administration of cyclosporine A (CysA; 30 mg/kg). The uptake of [(14)C]-UFX by isolated rat hepatocytes linearly increased up to 1 min and also inhibited by CysA. Other quinolone antibiotics inhibited the [(14)C]-UFX uptake in a concentration-dependent manner, whereas taurocholate and estrone-3-sulfate partially inhibited the [(14)C]-UFX uptake. These results demonstrate that a carrier-mediated transport system which is common to the quinolone antibiotics is involved in the uptake of UFX in the rat liver.

ME3738 protects against lithocholic acid-induced hepatotoxicity, which is associated with enhancement of biliary bile acid and cholesterol output.

ME3738 (22beta-methoxyolean-12-ene-3beta, 24(4beta)-diol), a derivative of soyasapogenol, attenuates liver disease in several models of chronic liver inflammation. In the present study, we have investigated a protective effect of ME3738 in a typical bile acid-induced cholestatic liver model, lithocholate (LCA) feeding mouse. Co-administration of ME3738 resulted in decreases in plasma alanine aminotransferase (ALT) and alkaline phosphatase (ALP) activities and hepatic bile acid level, and increases in biliary outputs of bile acid and cholesterol, as compared with the results in mice treated with LCA alone. LCA sulfation by hydroxysteroid sulfotransferase 2a and hydroxylation have been reported to be involved in protection against LCA-induced hepatotoxicity. ME3738-treatment, however, had no clear influence on the hydroxysteroid sulfotransferase 2a protein level and LCA 6alpha-, 6beta- and 7alpha-hydroxylase activities, but increased biliary cholesterol output. Cholate (CA)-treatment has been shown to induce hepatotoxicity in farnesoid X receptor-null mice, which is scarcely dependent on bile acid sulfation and hydroxylation but associated with decreased biliary bile acid output. Co-administration of ME3738 decreased the ALT and ALP activities and hepatic bile acid level, and increased biliary outputs of bile acid and cholesterol in farnesoid X receptor-null mice, as compared with the results in the mice treated with CA. Moreover, a clear correlation between biliary outputs of cholesterol and bile acid was observed in these two bile acid-induced hepatotoxicity mouse models. These results suggest that ME3738 protects against bile acid-induced hepatotoxicity through increased biliary bile acid output that is not related to bile acid metabolism but associated with cholesterol output.

Protective effects of alpha1-acid glycoprotein and serum amyloid A on concanavalin A-induced liver failure via interleukin-6 induction by ME3738.

We examined whether the 22beta-methoxyolean-12-ene-3beta,24(4beta)-diol (ME3738)-mediated selective induction of interleukin-6 increased alpha1-acid glycoprotein and serum amyloid A expression, and whether these proteins protected against liver injury in vitro and in vivo. ME3738 treatment in male mice increased gene expression of alpha1-acid glycoprotein subtypes and serum amyloid A 2 genes, and plasma concentration of serum amyloid A. Treatment with alpha1-acid glycoprotein at 5 mg/animal or serum amyloid A at 0.03 and 0.1 mg/animal prior to concanavalin A administration reduced multifocal necrosis in the liver. Treatment with alpha1-acid glycoprotein and serum amyloid A, but not alpha1-antitrypsin, protected Hep G2 cells against cell injury. These results suggest that alpha1-acid glycoprotein and serum amyloid A, increased by ME3738-induced interleukin-6, might protect against concanavalin A-induced liver injury.

Suppressive effects of cacao liquor polyphenols (CLP) on LDL oxidation and the development of atherosclerosis in Kurosawa and Kusanagi-hypercholesterolemic rabbits.

We investigated the properties of cacao liquor polyphenols (CLP), which have an antioxidative effect on low-density lipoprotein (LDL) and an anti-atherosclerotic effect in the spontaneous familial hypercholesterolemic model, the Kurosawa and Kusanagi-hypercholesterolemic (KHC) rabbit. After 6 months of dietary administration of CLP at 1% (w/w) to the KHC rabbits, a higher total cholesterol concentration was observed in the treatment group compared to the control group. However, no other effects were noted in lipid profiles in plasma or lipoproteins. The plasma concentration of thiobarbituric acid reactive substances (TBARS), which is a lipid-peroxidation index, was significantly decreased 1 month after the start of CLP administration compared to that of the control group. The antioxidative effect of CLP on LDL was observed from 2 to 4 months of administration. The area of atherosclerotic lesions in the aorta in the CLP group (32.01+/-1.58%) was significantly smaller than that in the control group (47.05+/-3.29%), and the tissue cholesterol and TBARS concentrations were lower in the CLP group than in the control group. The anti-atherosclerotic effect of CLP was confirmed both rheologically and histopathologically. An in vitro study using KHC rabbit-derived LDL revealed that CLP significantly prolonged the lag time of LDL oxidation that was induced by a lipophilic azo-radical initiator, 2,2'-azobis(4-methoxy)-2,4-dimethylvaleronitrile (V-70), or Cu(2+) from a low concentration of 0.1 microg/mL. The antioxidative effect of CLP was superior to those of the well-known antioxidative substances, vitamin C, vitamin E and probucol. Therefore, CLP suppressed the generation of atherosclerosis, and its antioxidative effect appeared to have an important role in its anti-atherosclerotic activity.