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Organ culture systems are useful for elucidating the process of testicular differentiation from mammalian undifferentiated genetically male gonads, as they permit various experiments, including experiments involving the control of gene expression. However, without addition of testicular differentiation-related factors, it is difficult to induce the formation of testis cord from immature gonads by a time point earlier 12 tail somites (ts) that corresponding to 11.0 days post coitum (dpc). In this study, we attempted to establish an organ culture system that induces testis formation from immature gonads (around 8 ts: 10.5 dpc) just before Sry (sex-determining region of the Y chromosome) expression. A paired gonad-mesonephros complex of around 8 ts was placed in the groove of an agarose gel block and put the semi-cylindrical piece of agarose gel to maintain the gonad morphology. The gonads were cultured in the gas phase for 96 hr. As a result, testis cord-like structures appeared in many genetically male gonads. Cells expressing the Sertoli cell markers Sox9 (SRY-box 9) and Amh (anti-Mullerian hormone) were observed, while granulosa cell marker Foxl2 (forkhead box L2) was not detected. In addition, Sox9- and Amh-expressing cells were observed throughout the entire gonad in many individuals. Amh mRNA expression was also upregulated. Surprisingly, formation of a partial testicular structure was observed from more immature gonads (6 ts). These results show that our gonadal organ culture system is useful for elucidating the regulation mechanism of Sry expression in undifferentiated bipotential gonads.

Neonicotinoid pesticides (NNs) act as agonists on nicotinic acetylcholine receptors (nAChRs) of insects, and there have been concerns about the effects of NNs on the health of mammals. Since nAChRs are expressed in immune cells, it is possible that NNs disturb the immune system. However, few reports have examined the immunotoxicity of clothianidin (CLO), a widely-used NN. Here, we report the effects of CLO on immune organs and type IV allergic reactions in ear auricles. We orally administered CLO at 0, 30 and 300 mg/kg/day (CLO-0, 30 and 300) to Sprague-Dawley rats for 28 days. The effects were evaluated by organ and body weights, histopathology, and immunohistochemistry (TCRαβ, CD4, CD8, CD11b, CD68, CD103). In addition, some cecal contents were subjected to preliminary gut microbiota analysis, because microbiota contribute to host homeostasis, including the immunity. Our results showed loose stool, suppression of body weight gain, significant changes in organ weights (thymus: decreased; liver: increased) and changes of the gut microbiota in the CLO-300 group. There were no obvious histopathological changes in immune organs. Granulomas of the ear auricles were found in one rat of each of the CLO-30 and 300 groups, but CLO had no apparent effect on the thickness or immunohistochemistry in the ear auricles. We present new evidence that CLO affects the thymus and intestine, and might enhance the local inflammatory response. These findings should contribute to the appropriate evaluation of the safety of NNs in the future.

The poultice formulation is a patch containing a large amount of water. It is known that the water contained in the adhesive polymer layer (ADPL) of poultice affects the cooling sensation and skin permeability of the active pharmaceutical ingredient (API). In this study, we evaluated the relationship between the water content in a ketoprofen poultice formulation and the amount of time the poultice was left out at room temperature after removal from the airtight container, as well as the influence of the decreasing water content on the skin permeability of the API. After removing the poultice from the container for 1 h, the mass of the ADPL decreased by approximately 40%. When the near-infrared (NIR) spectrum of the ADPL of poultice was measured, the peaks reflecting the hydroxyl group were attenuated depending on the time left out at room temperature. It is suggested that the changes in the mass and NIR spectrum of the ADPL are caused by the change in the water content. Moreover, when the permeability of API was evaluated on hairless mouse skin, the cumulative skin permeation amount and flux decreased, while the lag time was prolonged as the time left out increased. These results suggest that the skin permeability of the API is impaired by water evaporation and that maintaining the water in the ADPL in poultice is very important from not only the viewpoint of cooling sensation, tackiness and moisturizing but also the skin permeability of the API.

Although neonicotinoids are among the major classes of pesticides that affect mammalian nervous systems, little is known about sex differences in their effects. This study aimed to examine whether the neurobehavioral effects of a neonicotinoid, clothianidin (CLO), differed between sexes. Male and female C57BL/6N mice were orally administered CLO (5 or 50 mg/kg) at or below the chronic no-observed-adverse-effect-level (NOAEL) and sub- jected to behavioral tests of emotional and learning functions. Changes in neuroactivity in several brain regions and the concentrations of CLO and its metabolites in blood and urine were measured. Acute CLO exposure caused sex-related behavioral effects; decreases in locomotor activities and elevation of anxiety-like behaviors were more apparent in males than in females. In addition, male-specific impairment of short- and long-term learning memory by CLO exposure was observed in both the novel recognition test and the Barnes maze test. Male- dominant increases in the number of c-fos positive cells were observed in the paraventricular thalamic nu- cleus in the thalamus and in the dentate gyrus in the hippocampus, which are related to the stress response and learning function, respectively. The concentrations of CLO and most metabolites in blood and urine were higher in males. These results support the notion that male mice are more vulnerable than females to the neuro- behavioral effects of CLO and provide novel insights into the risk assessment of neonicotinoids in mammalian neuronal function.

Neonicotinoids, which act as agonists of the nicotinic acetylcholine receptors of insects, are widely used pesticides worldwide. Although epidemiological studies revealed that the detection amounts of neonicotinoids in urine are higher in the elderly population than other age-groups, there is no available information regarding the risks of neonicotinoids to older mammals. This study was aimed to investigate aging-related differences in the behavioral effects of the neonicotinoid pesticide clothianidin (CLO). We acutely administered a sub-NOAEL level (5 mg/kg) of CLO to adult (12-week-old) and aging (90-week-old) mice and conducted four behavioral tests focusing on the emotional behavior. In addition, we measured the concentrations of CLO and its metabolites in blood, brain and urine. There were age-related changes in most parameters in all behavioral tests, and CLO significantly decreased the locomotor activity in the open field test and elevated plus-maze test in the aging group, but not in the adult group. The concentrations of most CLO and its metabolites were significantly higher in the blood and brain and were slightly lower in the urine in the aging group compared to the adult group. These findings should contribute to our understanding of age-related differences in the adverse effects of neonicotinoids in mammals.

Neonicotinoids (NNs), a widely used class of systemic pesticides, are regarded as exhibiting selective toxicity in insects. However, NNs are suspected of exerting adverse effects on mammals as well, including humans. To date, only adult male animal models have been subjected to general toxicity studies of NNs; fetuses have yet to be considered in this context. Here, we focused on the NN clothianidin (CLO) for the first quantitative LC–MS/MS analysis of maternal-to-fetal transfer and residual property of once-daily (single or multiple days), orally administered CLO and its metabolites in mice. The results revealed the presence of CLO and its five metabolites at approximately the same respective blood levels in both dams and fetuses. In the dams, CLO showed a peak value 1 h after administration, after which levels rapidly decreased at 3 and 6 h. In the fetuses of each group, levels of CLO were almost the same as those observed in the corresponding dams. The present results clearly demonstrated rapid passage of CLO through the placental barrier. However, metabolite-dependent differences observed in blood pharmacokinetics and residual levels. This is the first quantitative demonstration of the presence of CLO and its metabolites in fetal mouse blood.

Evaluation of accidental sodium leak, combustion, and its thermal consequence is one of the important issues to be assessed in the field of sodium-cooled fast reactor (SFR) since the liquid sodium is chemically active and might give thermal load to plant building structure due to its exothermic reaction with oxygen in air atmosphere. Therefore, many experimental investigations and numerical simulation tools development have been and still now are being carried out to understand the details of sodium fire behaviors and to contribute to the investigation and preparation of appropriate mitigation measures in the plant design. From various kinds of sodium fire situations, the present paper treats the sodium pool fire and subsequent heat transfer behavior in air atmosphere two-cell geometry both experimentally and analytically because such two-cell configuration is considered as the typical one to possess important characteristic of multi-compartment system seen in an actual plant. Main description of this paper consists of a sodium pool fire experiment that was performed in a rectangular-shaped two-cell system with an opening between the cells, and the discussion of the experimental results. Inner volume of the experimental cells is about 70 m3. The amount of used sodium and the prepared pool surface area in the experiment are about 55 kg and 2.25 m2, respectively. The experiment has provided the temperature data measured in more than 100 positions for atmospheric gas and structures other than the data of oxygen concentration and suspended sodium aerosols concentration in the cells. The analyses of the measured data clarify the basic characteristics of sodium pool combustion and consequential heat and mass transfer in the cells, for instance, suggesting several features of multidimensional thermal-hydraulic behaviors such as thermal stratification near the opening between the two cells. In the discussion, numerical analysis using a lumped-parameter based zonal model safety analysis code ‘SPHINCS’ and the comparison of its results with the experimental data are also carried out to investigate the validity and applicability of the code to this type of sodium fire situation.

The Japan Sodium-cooled Fast Reactor (JSFR) adopts a double boundary for all sodium components. In this paper, design measures are investigated against a secondary sodium fire inside the reactor building, which might be assumed as design extension conditions. Candidate sodium fire measures for the secondary sodium systems compared in terms of safety are the sodium drain, nitrogen injection, pressure release valve, catch pan, and drain system for leaked sodium. Various sodium fires in the steam generator room have been analyzed by the SPHINCS code to evaluate the performance of the candidate sodium fire measures.

High cycle thermal fatigue on a structure caused by thermal striping phenomena is one of the most important issues in the design of fast breeder reactors (FBRs). In development of numerical simulation codes and in plant design and estimation by using the numerical estimation code, implementation of verification and validation (V&V) is indispensable process and also scaling issue from the subscale experiments to the full scale reactor should be considered. Therefore, a procedure called as V2UP (verification and validation plus uncertainty quantification and prediction) was made by referring to the existing guidelines on V&V (ASME V&V-10 and 20) and the methodologies of the safety assessment (CSAU, ISTIR, EMDAP). The V2UP consisted of five components as follows: (1) phenomena analysis with the Phenomena Identification and Ranking Table (PIRT) method, (2) implementation of the V&V, (3) design and rearrangement of experiments for the V&V, (4) uncertainty quantification in each problem and integration of uncertainties and (5) numerical prediction (estimation) for the target issue. Although the complete application of the procedure has not been performed at this moment, a flow chart of the V2UP procedure was described in this paper with recent results of the examinations.

In a sodium-cooled fast reactor (SFR), if considering hypothetical severe accidental condition such as the steel liner failure of structural concrete caused by intensive leakage of liquid sodium (N...

In this study, the kinetic behavior of the sodium (Na)–silica (SiO2) reaction was investigated for an assessment method of reactivity/stability of siliceous concrete against the sodium–concrete reaction (SCR) by postulating a severe accidental condition in the sodium-cooled fast reactor (SFR). The reaction behavior was tracked using a differential scanning calorimetry (DSC) equipped with a videoscope for viewing the changes in the sample during the reaction. The reaction was characterized as a partially overlapping multistep process controlled by physico-geometrical reaction scheme. The kinetic behavior in view of the change in the temperature at the maximum reaction rate with heating rate was analyzed using the simplified Kissinger method and the approximated Ozawa method. Further by separating the kinetic data for the overall reaction into five component reaction stages, the kinetic information for the second and third reaction stages was extracted. By comparing the kinetic results, it was revealed that the kinetic results determined from the kinetic data at the maximum reaction rate can be interpreted as is for the major reaction stage (the third reaction stage) controlled by an autocatalytic reaction. In addition, the second reaction stage was characterized as a possible premonitory process for the major reaction stage. Through the comprehensive interpretation of the kinetic results, significance of the kinetic analysis for the Na–SiO2 reaction using DSC for the reactivity/stability evaluation against SCR and for the safety assessment of SFR is discussed.

In the numerical analysis of sodium fire event following coolant leakage in a sodium-cooled fast reactor, sufficient understanding is needed for the liquid jet atomization to estimate the combustion rate accurately. In the present work, a liquid jet was emanated vertically downward from a circular nozzle onto a liquid film formed on a horizontal plate. The droplets produced at the impact point were investigated. The splash ratio (the ratio of the mass of the splashed droplets to the jet flow rate) was measured under varied experimental conditions of nozzle diameter, fall height and flow rate of liquid jet. The experimental result depended significantly on the morphology of liquid jet upon impact. The splashing rate was negligibly small when the liquid jet impinged as the continuous jet but a significant amount of liquid was splashed when the liquid jet impinged as the broken jet. Thus, we developed a method to estimate the impact frequency. It was shown that the splash ratio can be correlated well if the impact frequency is included in the correlation.

In the volume-of-fluid algorithm, the calculations of the interface normal and curvature are crucially important for accurately simulating interfacial flows. However, few methods have been proposed for the high-precision interface calculation on an unstructured grid. In this paper, the authors develop a height function method that works appropriately on an unstructured grid. In the process, the definition of the height function is discussed, and the high-precision calculation method of the interface normal is developed to meet the necessary condition for a second-order method. This new method has highly reduced computational cost compared with a conventional high-precision method because the interface normal calculation is completed by solving relatively simple algebraic equations. The curvature calculation method is also discussed and the approximated quadric curve of an interface is employed to calculate the curvature. Following a basic verification, the developed height function method is shown to successfully provide superior calculation accuracy and highly reduced computational cost compared with conventional calculation methods in terms of the interface normal and curvature. In addition, the height function method succeeds in calculating accurately the slotted-disk revolution problem and the oscillating drop on unstructured grids. Therefore, the developed height function method is confirmed to be an efficient technique for the high-precision numerical simulation of interfacial flows on an unstructured grid.

JAEA has developed sodium fire analysis codes, SPHINCS and AQUA-SF, to evaluate the consequences of sodium fire events, which are a key issue in sodium-cooled fast reactor (SFR) plants. This paper describes a PIRT (Phenomena Identification and Ranking Table) process for such events. The present PIRT can be utilized to validate the sodium fire analysis codes. Because a sodium fire event in an SFR plant involves complex phenomena, various figures of merit (FOMs) for importance ranking could exist in the PIRT process. Therefore, the FOMs are specified through a factor analysis. Associated phenomena in a sodium fire event are identified through both element- and sequence-based phenomena analyses. The importance of each associated phenomenon is evaluated by considering the sequence-based analysis of associated phenomena related to the FOMs. Then, a ranking table for the event is established. An assessment matrix of important phenomena and experiments is completed. Sufficiency of experimental data is confirmed for the validation of models corresponding to the identified important phenomena in the sodium fire analysis codes. Additional assessments are discussed specifically for the aerosol module and the CFD module in three-dimensional codes from a perspective of careful validation.

11β-hydroxysteroid dehydrogenase (HSD11B) catalyzes the interconversion between active and inactive glucocorticoid, and is known to exist as two distinct isozymes: HSD11B1 and HSD11B2. A third HSD11B isozyme, HSD11B1L (SCDR10b), has recently been identified. Human HSD11B1L, which was characterized as a unidirectional NADP(+)-dependent cortisol dehydrogenase, appears to be specifically expressed in the brain. We previously reported that HSD11B1 and abundant HSD11B2 isozymes are expressed in neonatal pig testis and the Km for cortisol of NADP(+)-dependent dehydrogenase activity of testicular microsomes obviously differs from the same activity catalyzed by HSD11B1 from pig liver microsomes. Therefore, we hypothesized that the neonatal pig testis also expresses the third type of HSD11B isozyme, and we herein examined further evidence regarding the expression of HSD11B1L. (1) The inhibitory effects of gossypol and glycyrrhetinic acid on pig testicular microsomal NADP(+)-dependent cortisol dehydrogenase activity was clearly different from that of pig liver microsomes. (2) A highly conserved human HSD11B1L sequence was observed by RT-PCR in a pig testicular cDNA library. (3) mRNA, which contains the amplified sequence, was evaluated by real-time PCR and was most strongly expressed in pig brain, and at almost the same levels in the kidney as in the testis, but at lower levels in the liver. Based on these results, neonatal pig testis appears to express glycyrrhetinic acid-resistant HSD11B1L as a third HSD11B isozyme, and it may play a physiologically important role in cooperation with the abundantly expressed HSD11B2 isozyme in order to prevent Leydig cell apoptosis or GC-mediated suppression of testosterone production induced by high concentrations of activated GC in neonatal pig testis.

A liquid jet is of considerable importance in many industrial fields including jet cleaning, jet engine and combustion. As an important example, the Monju nuclear power plant in Japan experienced a sodium leak in 1995. This led to a fire accident because the sodium reacted with oxygen in the air. To predict the significance of the fire accident, accurate evaluation of the amount of splashed droplets caused by the sodium jet impingement is of great importance. In this work, the relationship between the condition of a liquid jet and the amount of splashed droplets is explored experimentally. In the experiments, a liquid jet was emanated vertically downward from a circular nozzle onto a liquid film formed on a horizontal plate. Visualization using a high speed camera was performed to observe the condition of the liquid jet. From the nozzle, the mode of the liquid jet changed jet, lump and drop. Here, the jet mode means the continuous jet with smooth surface, the lump mode the continuous jet with disturbed surface and the drop mode the broken jet. Dependences of the transition length to each mode on the important parameters such as the jet velocity and the nozzle diameter were investigated. Measurement was also conducted for the splash ratio that is defined as the ratio of the amount of splashed droplets to the jet flow rate. It was found that the splash ratio is high when the liquid jet is in the drop mode at the impact point. It was shown that the splash ratio can be correlated well as a function of the impact Weber number and the Strouhal number of the droplets impinging the liquid film.Copyright © 2016 by ASME

The effects of bisphenol A (BPA), an endocrine disruptor, on aromatase (CYP19) expression in human osteoblastic (SV-HFO) and ovarian granulosa-like (KGN) cell lines were examined. CYP19 enzyme activity was suppressed in the presence of BPA in a dose-dependent fashion in both cell lines. CYP19 gene transcript expression, as well as activities of promoter I.4 in SV-HFO and promoter II in KGN, was down-regulated by BPA, suggesting that BPA affects CYP19 at the gene-expression level. These data and the previous finding that BPA induced the down-regulation of promoter I.1 activity within the human placental cell line suggest that there may be a conserved signaling pathway that down-regulates CYP19 expression in response to BPA in both cell lines. Additionally, differences between promoter I.4 and II suggest that there may be cell- and promoter-specific down-regulating mechanisms downstream from the actions of BPA.

We recently established a method for quantitative determination of human catalytically active UDP-glucuronosyltransferases (UGTs) other than UGT2A1 and UGT2B28 by real-time reverse transcription-polymerase chain reaction (RT-PCR), and applied the method to an exhaustive analysis of localization in various human tissues. We report here an additional quantitative determination method targeting UGT2B28. To date, there have been no reports on the distribution of UGT2B28 mRNA expression in human tissues based on quantitative determination. Human UGT2B28 was clearly detected in the breast and adipose tissue. UGT2B28 expression in the breast was comparatively low, about 1.6% of GAPDH mRNA levels, and was less than 5% of normalized (against GAPDH) UGT2B7 and 2B10 mRNA expression levels in the liver. Although the UGT2B28 has 97% identity with UGT2B11 at the cDNA sequence level, the primers constructed for UGT2B28 did not detect UGT2B11. In addition, significant expression of UGT2B11 was detected in the liver, breast and kidney, and was clearly different from the distribution of UGT2B28. Therefore, we conclude that the real-time RT-PCR method established here is very specific for human UGT2B28 isozyme.

Validation of a numerical simulation method is carried out for thermal stratification phenomena in the reactor vessel upper plenum of advanced sodium-cooled fast reactors. The study mainly focuses on the fundamental applicability of commercial computational fluid dynamics (CFD) codes as well as an inhouse code to the evaluation of thermal stratification behavior including the simulation methods such as spatial mesh distribution and RANS-type turbulence models in the analyses. Two kinds of thermal stratification tests are used in the validation, which is done for relatively simple- and conventional-type upper plenum geometries with water and sodium as working fluids. Quantitative comparison between the simulation and test results clarifies that when used with a high-order discretization scheme of the convection term, the investigated CFD codes are applicable to evaluations of the basic behaviors of thermal stratification and especially the vertical temperature gradient of the stratification interface, whic...

Pig 11beta-hydroxysteroid dehydrogenase (11beta-HSD) type 1 cDNA was cloned from neonatal pig testis, and 15 nucleotides were found to differ from the sequence in GenBank (Accession No. NM_214248). It was an exclusive clone obtained as pig 11beta-HSD type 1, and the sequence of 11beta-HSD type 1 cDNA cloned from pig liver was identical to that from testis. Amino acid sequence, deduced from cloned cDNA, also had a conserved triad of catalytically important Ser, Tyr and Lys residues for the short-chain dehydrogenase/reductase family, a membrane-spanning domain consisting of hydrophobic amino acid and a glycine motif in the cofactor binding region. The protein translated from this clone on expression in mammalian HEK293 cells exhibited oxo-reduction activity of cortisone and oxidation activity of cortisol. Furthermore, this oxo-reduction activity of cortisone was stimulated by co-expression of human H6PDH, while oxidation activity of cortisol was suppressed by H6PDH co-expression in HEK293 cells. Based on these results, the sequence of newly cloned cDNA is considered to correspond to an active enzyme form of pig 11beta-HSD type 1.

The mechanism for transcriptional suppression of CYP19 by mono-ethylhexyl phthalate (MEHP) in a human ovarian granulosa cell line (KGN) was investigated. It is known that the CYP19 gene transcript in KGN cells predominantly includes exon PII among the 11 alternate exon I sequences. MEHP was found to significantly suppress Forskolin (FSK)-induced CYP19 gene transcription, CYP19 promoter II activity and CYP19 enzyme activity in a dose-dependent manner. Promoter assays using 5'-deleted promoter II reporter constructs suggested that the region important for responsiveness to MEHP exposure includes a putative CRE-like sequence and an SF-1 (NR5A1)/LRH-1 (NR5A2) binding sequence. Meanwhile, MEHP exposure rapidly and transiently induced nuclear receptor 4A (NR4A) mRNA, and gradually and continuously induced gonadotropin-inducible ovarian transcription factor-1 (GIOT-1; ZNF461) mRNA in KGN cells. The ectopic expression of NR4As and GIOT-1 suppressed promoter II activity, while among the NR4As expressed, only Nur77 (NR4A1) secondarily induced GIOT-1 mRNA expression. Based on these results, we believe that induction of the Nur77-GIOT-1 system by MEHP is involved in the transcriptional suppression of the CYP19 gene, and GIOT-1 may attenuate the promoter II activity due to suppression of SF-1 and/or LRH-1 transactivation in KGN cells.

11beta-Hydroxysteroid dehydrogenase (11beta-HSD) isozymes, designated types 1 and 2, catalyze the interconversion of physiologically active glucocorticoids and inactive 11-keto forms. The presence of types 1 and 2 was determined in neonatal pig testis and Leydig cells purified from testes by reverse transcription polymerase chain reaction, Western blotting, and immunohistochemical staining. Type 2 mRNA was expressed at a high level in neonatal pig testis. In particular, in the entire testis, a higher level of type 2 was expressed compared to type 1. Furthermore, these expression levels in the testis were compared with the expression levels of the respective isozymes in pig liver and kidney, which are known to have high levels. Next, the direction of glucocorticoid metabolism in intact Leydig cells was examined, and only oxidation from cortisol to cortisone was detected. Virtually no reduction of cortisone to cortisol was detected. Using a microsomal enzyme preparation from Leydig cells, type 2 exhibited potent oxidation activity, and the activity was higher than the oxidation activity catalyzed by the type 1 isozyme. In kinetic analysis, the K(m) and V(max) for type 1 were 1.36 microM and 0.91 nmol/(h mg), respectively, and 0.38 microM and 1.25 nmol/(h mg), respectively, for type 2. The results of the present study using neonatal pig testis suggest that not only 11beta-HSD type 1 but also type 2, which is abundantly expressed, plays important roles in cortisol inactivation in pig Leydig cells, and furthermore, that excess cortisol will cause glucocorticoid-mediated suppression of testosterone production in even neonatal pig Leydig cells.

Sodium combustion tests were performed to investigate both the pool burning behavior and the maximum temperature of a steel-made floor liner in the case of small-scale sodium leakage from a secondary loop of a fast breeder reactor. Sodium leakage heights, humidity in an atmosphere and sodium leakage rate were changed as parameters in the tests. This paper mainly described thermal influence to the steel liner. Main conclusions are as follows. The maximum liner temperature becomes higher with the increase in the leakage height and humidity. When the leakage rate decreases, the maximum temperature tends to become lower, and this behavior has the relation with final pool size that affects to heat release toward radial direction. Sodium leakage rate has no dependency on the sodium burning rate and pool expanding speed while it affects to the final pool size. The surface shape of sodium combustion pool has influence on both the pool expanding speed and the final pool size.

Experimental study using the transpiration method investigates equilibrium evaporation behavior of radionuclide polonium (210Po) generated and accumulated in liquid lead-bismuth eutectic (LBE) cool...

A highly collision-resistive RFID system multiplexes communications between thousands of tags and a single reader in combination with time-domain multiplexing code division multiple access (TD-CDMA), CRC error detection, and re-transmission for error recovery. The collision probability due to a random selection of CDMA codes and TDMA channels bounds the number of IDs successfully transmitted to a reader during a limited time frame. However, theoretical analysis showed that the re-transmission greatly reduced the collision probability and that an ID error rate of 2.5 × 10-9 could be achieved when 1,000 ID tags responded within a time frame of 400 msec in ideal communication channels. The proposed collision-resistive communication scheme for a thousand multiplexed channels was modeled on a discrete-time digital expression and an FPGA-based emulator was built to evaluate a practical ID error rate under the presence of background noise in communication channels. To achieve simple anti-noise communication in a multiple-response RFID system, as well as unurged re-transmission of ID data, adjusting of correlator thresholds provides a significant improvement to the error rate. Thus, the proposed scheme does not require a reader to request ID transmission to erroneously responding tags. A reader also can lower noise influence by using correlator thresholds, since the scheme multiplexes IDs by CDMA-based communication. The effectiveness of the re-transmission was confirmed experimentally even in noisy channels, and the ID error rate derived from the emulation was 1.9 × 10-5. The emulation was useful for deriving an optimum set of RFID system parameters to be used in the design of mixed analog and digital integrated circuits for RFID communication.

Epidemiological evidence implicates dietary isoflavone intake as protective against prostate disease. A putative mechanism is attenuated circulating androgen levels in male populations consuming an isoflavone rich diet. We investigated this hypothesis by collecting plasma from 60 Japanese and 60 New Zealand males aged between 21 and 31 years each consuming their traditional diets. We measured plasma testosterone, dihydrotestosterone (DHT), androstenedione, dehydroepiandrosterone sulfate (DHEAS), the combined levels of androsterone sulfate and epiandrosterone sulfate (AoS/epiAoS), sex hormone-binding globulin, and cortisol and corticosteroid-binding globulin as well as the isoflavones genistein and equol. Plasma genistein and equol levels were several times higher in Japanese males as would be expected from an isoflavone rich diet. However, androstenedione, DHEAS, calculated free testosterone and paradoxically markers of 5alpha-reductase, DHT and AoS/epiAoS were all also significantly higher in Japanese rather than the New Zealand male counterparts. All other comparisons were not significant. Plasma DHT and DHEAS correlated positively with plasma equol and plasma AoS/epiAoS correlated positively with genistein levels. Taken together the results suggest that, rather than reduced levels of steroidogenesis, Japanese males may have increased 5alpha-reductase activity and possibly altered 17beta OH steroid dehydrogenase activity. Significantly the positive association between isoflavones levels and 5alpha-steroids is counter-intuitive to isoflavone intake offering prostate protection, unless this is postulated to occur through other mechanisms.

We previously reported that tributyltin chloride (TBT) and triphenyltin chloride (TPT) powerfully suppressed human chorionic gonadotropin- and 8-bromo-cAMP-stimulated testosterone production in pig Leydig cells at concentrations that were not cytotoxic [Nakajima Y, Sato Q, Ohno S, Nakajin S. Organotin compounds suppress testosterone production in Leydig cells from neonatal pig testes. J Health Sci 2003;49:514-9]. This study investigated the effects of these organotin compounds on the activity of enzymes involved in testosterone biosynthesis in pig testis. At relatively low concentrations of TPT, 17beta-hydroxysteroid dehydrogenase (17beta-HSD; IC(50)=2.6microM) and cytochrome P450 17alpha-hydroxylase/C(17-20) lyase (IC(50)=117microM) activities were inhibited, whereas cholesterol side-chain cleavage cytochrome P450 and 3beta-HSD/Delta(4)-Delta(5) isomerase activities were less sensitive. Overall, TPT was more effective than TBT. TPT also inhibited both ferredoxin reductase and P450 reductase activities at concentrations over 30microM; however, TBT had no effect, even at 100microM. The IC(50) values of TPT were estimated to be 25.7 and 22.8microM for ferredoxin reductase and P450 reductase, respectively. The inhibitory effect of TPT (30microM) on microsomal 17beta-HSD activity from pig testis was eliminated by pretreatment with the reducing agents dithiothreitol (1mM) and dithioerythritol (1mM). On the other hand, TPT (0.03microM) or TBT (0.1microM) exposure suppressed the testosterone production from androstenedione in pig Leydig cells indicating that these organotins inhibit 17beta-HSD activity in vivo as well as in vitro, and the IC(50) values of TPT and TBT for 17beta-HSD activity were estimated to be 48 and 114nM, respectively. Based on these results, it appears possible that the effects of TBT and TPT are largely due to direct inhibition of 17beta-HSD activity in vivo.

An experimental study on the equilibrium evaporation of lead-bismuth eutectic (LBE) was conducted to acquire essential and fundamental knowledge about the vaporization of LBE. The experiments were conducted using the transpiration method in which saturated vapor in an isothermal evaporation pot was transported by inert carrier gas and collected outside of the pot. The weight of the LBE pool in the pot was about 500 g. The investigated temperature range was from 450 to 750° C. We obtained data on the saturated vapor pressure of LBE, the vapor concentration of Pb, Bi and Bi2 in the LBE saturated gas phase, the activity coefficient of Pb in the LBE, and the LBE evaporation rate. The LBE vapor pressure equation is represented by logP LBE(Pa)=10.2–10, 100/T(K) in the temperature range from 550 to 750°C.

Objective: Recent progress supports the importance of local estrogen secretion in human bone tissues to increase and maintain bone mineral density. In a previous study, we reported that the expression of aromatase (CYP19) is dexamethasone (Dex)-dependent and oncostatin M (OSM) increases the expression synergistically with Dex. In the present study, we examined the effects of forskolin (FSK) as another potential synergistic factor. Results: Co-administration of 100 nM Dex and 10 μM FSK increased aromatase activity 4-fold compared with Dex alone. The results of reverse transcriptase (RT)-PCR suggest that the amount of CYP19 gene transcript was also up-regulated by FSK synergistically with Dex, and that promoter I.4, which is not activated by FSK alone, is activated by FSK synergistically with Dex. The results of RT-PCR also suggest that promoter II, which responds to FSK, was not activated even in the presence of FSK in SV-HFO. The promoter I.4 sequence that was transfected into SV-HFO was activated by FSK synergistically with Dex. Conclusions: Synergistic up-regulation of aromatase activity, CYP19 gene transcript, and promoter I.4 activity were Dex-dependent and not up-regulated by FSK alone. The results of this work may form the basis of bone-specific estrogen-replacement therapy that increases the estrogen concentration in bone tissue only.

Besides residue of the catalytic triad that is conserved in the short-chain dehydrogenase/reductase (SDR) superfamily, a Cys side chain reportedly plays functional roles in NADP-dependent 15-hydroxyprostaglandin dehydrogenase and human carbonyl reductase (CR). The three-dimensional structure of porcine 3alpha/beta,20beta-hydroxysteroid dehydrogenase, also known as porcine testicular carbonyl reductase, demonstrates the proximity of the Cys 226 side chain to the bound NADP. However, no clear explanation with respect to the basis of the catalytic function of the Cys residue is yet available. By chemical modification, point mutation, and kinetic analysis, we determine that two Cys residues, Cys 149 and Cys 226, are involved in the enzyme activity. Furthermore, we found that pretreatment with NADP markedly protects the enzyme from inactivation by 4-(hydroxyl mercury) benzoic acid (4-HMB), thereby confirming that Cys 226 is involved in binding of the cofactor. On the basis of the tertiary structure of 3alpha/beta,20beta-HSD, the possible roles of Cys residues, especially that of Cys 226, in enzyme action and in the binding of cofactor NADPH are discussed.

The inhibitory effects of various flavonoids on human 3beta-hydroxysteroid dehydrogenase/Delta(5)-Delta(4)-isomerase type II (3beta-HSD type II), overexpressed in baculovirus, were investigated, and the structure-inhibition relationship was examined. The isoflavone derivatives daidzein, genistein, formononetin and biochanin A inhibited 3beta-HSD type II activity at a concentration of 10 microM and of these, genistein was the most potent inhibitor. 6-Hydroxyflavone (6-HF), a synthetic flavone, also strongly inhibited 3beta-HSD activity but 5-HF, 7-HF and other natural flavones were less potent. Energy minimization structures of the flavonoids, as produced using MOE software, showed that isoflavones and flavones have an almost flat A-C ring structure, and that flavonoids that acted as inhibitors had similar steric structures to DHEA. Genistein, 6-HF and cyanoketone, which is known as a typical 3beta-HSD inhibitor, were found to act as competitive inhibitors with K(i) values of 0.12 microM, 0.19 microM and 0.67 nM, respectively. Furthermore, the LUMO (lowest unoccupied molecular orbital (LUMO)) values, as calculated using WinMOPAC (Fujitsu, Japan), of the inhibitors were correlated with the IC(50) values (r2 = 0.84). From these results, it appears that inhibitory effects of flavonoids are due to the combination of steric structure and electron affinity between the active center of 3beta-HSD type II and the flavonoid molecule.