Electrically induced ambipolar spin vanishments in carbon nanotubes.

Carbon nanotubes (CNTs) exhibit various excellent properties, such as ballistic transport. However, their electrically induced charge carriers and the relation between their spin states and the ballistic transport have not yet been microscopically investigated because of experimental difficulties. Here we show an electron spin resonance (ESR) study of semiconducting single-walled CNT thin films to investigate their spin states and electrically induced charge carriers using transistor structures under device operation. The field-induced ESR technique is suitable for microscopic investigation because it can directly observe spins in the CNTs. We observed a clear correlation between the ESR decrease and the current increase under high charge density conditions, which directly demonstrated electrically induced ambipolar spin vanishments in the CNTs. The result provides a first clear evidence of antimagnetic interactions between spins of electrically induced charge carriers and vacancies in the CNTs. The ambipolar spin vanishments would contribute the improvement of transport properties of CNTs because of greatly reduced carrier scatterings.

Natural contamination of dietary rice straw with zearalenone and urinary zearalenone concentrations in a cattle herd.

The present study was conducted to 1) identify the natural source of feed contamination by zearalenone (ZEN), which was suspected to have caused persistently increased urinary ZEN concentrations in one of our experimental cattle herds, and 2) evaluate the effects of intervention against this source of contamination. As an experimental model, a fattening Japanese Black cattle herd showing persistently increased urinary ZEN concentrations was identified. Urinary ZEN concentrations of cows fed with new rice straw (experimental group, n = 6) vs. cows that continued to feed on the old rice straw (control group, n = 4) were measured at the start (d 1) and at 2 wk (d 14) after the onset of feeding with straw. In addition, the ZEN concentration in feed and water samples was measured by using both the ELISA and HPLC methods. Furthermore, isolation and identification of fungi from rice straw and concentrate feed samples were performed. The urinary ZEN concentration [ZEN (pg/mL)/creatinine (mg/mL) = pg/mg of creatinine] of cows fed with new rice straw was significantly (P < 0.05) less (843 pg/mg of creatinine) than that of cows fed with old rice straw (15,951 pg/mg of creatinine). On both d 1 and 14, the ZEN concentrations of old rice straw were greater than those of new rice straw. In addition, fungal colonies were observed in the culture media that was obtained from the old rice straw suspected of ZEN contamination, but not in the culture media from new rice straw or other feed samples. In conclusion, our field trials clearly indicate that the rice straw fed to the cows was naturally contaminated with ZEN, and that the monitoring of urinary ZEN concentrations could prove to be a useful tool for detecting the exposure of cattle to ZEN contamination at the farm level.

Measurement of urinary zearalenone concentrations for monitoring natural feed contamination in cattle herds: On-farm trials.

The aims of the present study were to investigate the efficacy of measuring bovine urinary zearalenone (ZEN) concentrations by using a commercially available ELISA method in cattle kept under different feeding conditions to monitor the natural contamination of feeds at the farm level, and to investigate the effects of supplementation of a mycotoxin adsorbent (MA) product in the feed based on urinary ZEN concentration. First, Japanese Black cattle herds kept for breeding (4 herds) and fattening (4 herds) purposes were provided with similar feeding conditions. Then, urinary samples from 5 cows in each herd were collected and analyzed. Second, dairy cows from 1 herd fed with total mixed rations (TMR) were selected. After thorough mixing of the MA (40 g/d) with TMR, the supplemented TMR was fed according to the following schedule: with MA for 2 wk, without MA for 3 wk; then with MA for 2 wk and without MA for 6 wk. Urine samples were collected from cows (n = 6 to 7) and examined before and after each interval. Zearalenone concentrations were measured by the ELISA and liquid chromatography-tandem mass spectrometry methods. The concentration of ZEN and its metabolites was expressed after creatinine (Crea) correction [ZEN or metabolites (pg/mL)/Crea (mg/dL); pg/mg of Crea]. In the first experiment, the urinary concentrations of ZEN and its metabolites were variable in all herds, and significant differences were observed between herds. In 1 fattening herd, in particular, urinary ZEN concentrations were greater (P < 0.001) than in the other 3 herds. This might reflect significant natural ZEN contamination of the feed at the farm level. In Exp. 2, urinary ZEN concentrations displayed peculiar trends after supplementation with MA. After 2 wk of supplementation, a significant decrease of ZEN (P < 0.05) was observed. Zearalenone concentrations remained at a reduced amount during 3 wk without MA supplementation and 2 wk with MA supplementation. When MA was not added to the feed for the next 6 wk, the concentrations increased to the original quantity. These findings indicate the usefulness of measuring concentrations of urinary ZEN and its metabolites not only for monitoring the natural ZEN contamination of cattle feed at the farm level but also for in vivo evaluation of MA function after supplementing feeds with MA.

Evaluation of the safety and pharmacokinetics of the multi-targeted receptor tyrosine kinase inhibitor sunitinib during embryo-fetal development in rats and rabbits.

BACKGROUND: Angiogenesis plays a key role in embryo-fetal development and, based on nonclinical safety data, the majority of vascular endothelial growth factor (VEGF)-targeted antiangiogenic agents used in cancer therapy are not recommended during pregnancy. We investigated the effects of sunitinib (an oral inhibitor of multiple receptor tyrosine kinases [RTKs] including VEGF-receptors) on embryo-fetal development. METHODS: Presumed-pregnant Sprague-Dawley rats and New Zealand White rabbits received repeated daily oral doses of sunitinib (0-30 mg/kg/day), during the major period of organogenesis. Clinical/physical examinations were performed throughout the gestation phase, and blood samples were collected to determine systemic exposure. Necropsy (including uterine examination) was performed on all animals and fetal morphology was examined. RESULTS: The no-observed-adverse-effect level was 1-5 mg/kg/day for maternal toxicity and 3 mg/kg/day for developmental toxicity in rats; 1 and 0.5 mg/kg/day, respectively, in rabbits. Embryo-fetal toxicity included decreases in the number of live fetuses and increases in the numbers of resorptions and post-implantation/complete litter losses; these were observed at doses of > or =5 mg/kg/day in rats and 5 mg/kg/day in rabbits. Malformations included fetal skeletal malformations (generally thoracic/lumbar vertebral alterations) in rats and cleft lip/palate in rabbits. These developmental effects were observed at approximately 5.5- (rats) and approximately 0.3-times (rabbits) the human systemic exposure at the approved sunitinib dose (50 mg/day). CONCLUSIONS: Similar effects have been reported with the prototype monoclonal antibody bevacizumab. As is typically observed for potent inhibitors of RTKs involved in angiogenesis, sunitinib was associated with embryo-fetal developmental toxicity in rats and rabbits at clinically relevant dose levels.

Rapid expansion of human adipose-derived stromal cells preserving multipotency.

BACKGROUND: Adipose-derived stromal (stem) cells (ASC) have been shown to be of great therapeutic use in pre-clinical studies in diverse fields, but a standard expansion method has not been established. We investigated the effects of an endothelial growth medium (EGM-2) on ASC, focusing on proliferation and differentiation potentials. METHODS: ASC were cultured in EGM-2 and DMEM. Doubling time and total cell number were compared between the two media. The proliferative effect of each growth factor supplemented in EGM-2 was also examined. Cultured cells in each medium were examined for surface marker expression using flow cytometry. Differentiation into the adipogenic, chondrogenic and osteogenic lineages was analyzed after culture in each medium. RESULTS: ASC cultured with EGM-2 proliferated much more rapidly (10(5) times in 2 weeks) and reached the stationary phase earlier than those cultured with DMEM. Among the supplements contained in EGM-2, only fibroblast growth factor-2 (FGF-2) significantly promoted proliferation of ASC, although the proliferative effect of FGF-2 was much less than that of EGM-2, suggesting a synergism among other supplement factors. Flow cytometry and differentiation assays suggested that ASC cultured in EGM-2 preserved immunophenotype and differentiation capacity for at least three mesenchymal lineages (adipogenic, chondrogenic and osteogenic), similar to those cultured with DMEM. DISCUSSION: The present expansion method markedly accelerates proliferation of ASC, preserving their multipotent differentiation capacities, and lays the groundwork for establishing a practical route to mega-expansion of ASC for clinical applications.

National character does not reflect mean personality trait levels in 49 cultures.

Most people hold beliefs about personality characteristics typical of members of their own and others' cultures. These perceptions of national character may be generalizations from personal experience, stereotypes with a "kernel of truth," or inaccurate stereotypes. We obtained national character ratings of 3989 people from 49 cultures and compared them with the average personality scores of culture members assessed by observer ratings and self-reports. National character ratings were reliable but did not converge with assessed traits. Perceptions of national character thus appear to be unfounded stereotypes that may serve the function of maintaining a national identity.

Purification of follicular regulatory protein: possible plasminogen identity.

A partially purified protein (the SR fraction) of porcine and human origin has been extensively characterized as Follicular Regulatory Protein (FRP). In the current study, 1A8D5, one of several monoclonal antibodies raised against FRP, was used to further purify the protein. The monoclonal antibody cross-reacted only with porcine plasminogen, a key fibrinolytic proenzyme. A commercial polyclonal antibody for human plasminogen confirmed the relationship between plasminogen and bands of the SR fraction of the porcine follicular fluid. Sequencing of the N-terminal amino acids (54 kd) of the SR fraction indicated that it shared 100% identity with the short form of porcine plasminogen chain A and 93% identity to human plasminogen. Moreover, we demonstrated that this purified protein from human follicular fluid inhibited aromatase activity of granulosa cells, a key biological property of FRP. Given that plasminogen possesses most of the proposed properties of the protein termed FRP, we conclude that FRP is likely plasminogen itself or a plasminogen-related protein and not a novel protein.

Congenital leiomyomatous epulis: a case report with immunohistochemical study.

The histologic and immunohistochemical findings of an extremely rare case of congenital soft tissue mass on the alveolar ridge in an infant are reported. The lesion clinically mimicked an ordinary congenital epulis (congenital granular cell epulis, granular cell tumor of the newborn); however, histologically it consisted of a conglomerate of spindle-shaped cells, akin to smooth muscle cells, which formed interlacing and whorled fasciculi. Nerve fibers with myxoid degeneration, capillaries and muscle walled small vessels intermingled with fasciculi of spindle-shaped cells. The border between the conglomerate of spindle-shaped cells and the surrounding connective tissue was not evident. Immunohistochemically, most of the spindle-shaped cells were intensely positive for antibodies to alpha-smooth muscle actin, HHF-35 and desmin. These findings suggest that the lesion was composed of mature smooth muscle cells that were of hamartomatous or choristomatous nature. The term 'congenital leiomyomatous epulis' is proposed.

Evaluations of Outcome Sequences.

We extend the literature on intertemporal choice by investigating how possession of knowledge related to the present value of future outcomes (PV knowledge) affects the extent to which individuals weight certain attributes when evaluating outcome sequences. While PV-knowledgeable individuals can ascribe value to attributes according to their PV relevance (or irrelevance), unknowledgeable individuals cannot do so. Such knowledge, therefore, likely interacts with outcome-sequence attributes to affect the extent to which individuals exhibit impatience when evaluating outcome sequences. The main experimental findings indicate that higher PV knowledge increases the extent to which individuals value impatience (as opposed to improvement). However, these findings also reinforce a need to distinguish among impatience, improvement, and PV because some higher PV knowledge participants willingly sacrifice PV while exhibiting impatience (while others do so in order to gain improvement). Overall, PV considerations appear central, but not determinative, in higher PV-knowledgeable individuals' evaluations of outcome sequences. Copyright 2000 Academic Press.

Mutagenic activity and DNA adduct formation by 1, 2-epoxy-3-(p-nitrophenoxy)propane, an HIV-1 protease inhibitor and GST substrate.

Acid protease inhibitor 1,2-epoxy-3-(p-nitrophenoxy)propane (ENPP) is commonly used in research as a substrate for glutathione-S-transferase activity (GST) and recently was found to inhibit human immunodeficiency virus 1 (HIV-1) protease. The question of DNA-adduct formation and mutagenicity was investigated and found that ENPP causes DNA damage and acts directly to induce mutagenicity in Salmonella. Using HPLC analysis, ENPP was shown to bind covalently to guanine residues. The Salmonella mutagenicity assay indicated that ENPP enhanced the mutation frequencies in the base-substitution strain TA00 by more than 20 times above the background. Its mutagenic potency was comparable to that of well-known carcinogens, N-methyl-N-nitrosourea (MNU) and aflatoxin B(1)-8,9-epoxide (AFB(1)-8,9-epoxide). The results suggest that ENPP should be classified as a mutagenic compound and a potential carcinogen.

DNA-damaging effects of genotoxins in mixture: nonadditive effects of aflatoxin B1 and N-acetylaminofluorene on their mutagenicity in Salmonella typhimurium.

Most animal genotoxicity studies have used exposures to single chemicals; humans, however, are potentially exposed to mixtures of genotoxins. Cancer and developmental toxicity risks associated with genotoxins in mixture are generally estimated by assuming additivity of the components. Two or more genotoxins acting sequentially or simultaneously may present a greater or lesser hazard than that predicted by simple addition of their potencies. Previously, we studied the effect of one genotoxin on the binding of a second genotoxin to DNA in an in vitro system and demonstrated that consecutive binding of the two toxins was not additive. In the present study, the effect of one genotoxin on the mutagenicity of another was evaluated for two well-known genotoxins using the Salmonella assay. Pretreatment of frameshift strains TA98 and TA1538 with AFB1-8,9-epoxide (17.3 ng/plate) enhanced the mutagenicity induced by subsequent exposure to N-acetoxy-acetylaminofluorene (N-AcO-AAF) approximately 2-3 times above theoretical values for additivity. Pretreatment of base-substitution strain TA100 with N-AcO-AAF (0.1 microg/plate) inhibited the mutagenicity following subsequent exposure to AFB1-8,9-epoxide by 3 times below the theoretical additive value. Concentration-response relationships for these enhancing or inhibitory effects were demonstrated using increasing concentrations of the first genotoxin during pretreatment. These results demonstrate effects, other than additive, of sequential exposures to two genotoxins on the induction of mutations in a bacterial system.

Re-evaluation of anti-HTLV-I Western blot assay using HTLV-I and HTLV-II serum panels.

BACKGROUND: Western blot assay is accepted to be a confirmatory test of anti-HTLV-I antibodies, and several WB criteria have been proposed for confirming HTLV-I seropositivity. There is a necessity for comprehensive study on the criteria. OBJECTIVES: This study was performed to evaluate anti-HTLV-I WB kits and feasibility of the WB criteria. STUDY DESIGN: We tested 3 commercially available WB kits: PROBLOT HTLV-I, Eitest ATL-WB and HTLV BLOT 2.2, by a standard HTLV-I serum panel which had been established in our previous study. Sensitivity and specificity to detect each component of HTLV-I antigens were evaluated by the correlation coefficient, R-value. Specificity of the anti-HTLV-I WB kits and HTLV BLOT 2.3 was further evaluated by a standard HTLV-II serum panel established from the HTLV-I/II epidemiological surveillance of Colombian natives. RESULTS: PROBLOT HTLV-I showed high R-values (>/=0.980) for p28, p53 and gp46, but low R-values (<0.900) for p19 and p24. Eitest ATL-WB showed a high R-value for p19, but low R-values for p53, gp46 and rgp21. HTLV BLOT 2.2 showed high R-values for p28 and recombinant gp46-I, but low R-values for p53 and gp46. The HTLV-II serum panel showed positive reactions with p24 and p19 of HTLV-I but a little if any reactions with p28 and gp46 of HTLV-I. Although these reactions could not define HTLV-II-specific WB patterns in anti-HTLV-I WB, HTLV-I- and HTLV-II-specific recombinant gp46 in HTLV BLOT 2.3 were useful to distinguish anti-HTLV-II antibodies. CONCLUSIONS: The currently available anti-HTLV-I WB kits are sufficient for confirmatory testing of anti-HTLV-I antibodies with WHO criteria using one gag and one env positivity, but they are inadequate for anti-HTLV-II confirmatory testing.

Cultural differences in attitudes, values, and beliefs about osteoporosis in first and second generation Japanese-American women.

This study examines attitudinal differences related to osteoporosis between first and second generation Japanese-American women. In an interview, the women completed a battery of tests assessing their attitudes, values, and beliefs about the diagnosis, treatment, and follow-up care of osteoporosis. The groups differed in their general knowledge of osteoporosis, perceptions of the disease, attributions of its causes, anticipated and preferred support mechanisms for care, and anticipated areas of concern for self-or other-care. There were also considerable differences in treatment compliance and feelings toward physicians. The findings were discussed in relation to the effects of culture on health-care attitudes and behaviors.

Evaluation of commercial HTLV-1 test kits by a standard HTLV-1 serum panel.

To evaluate the performance of currently available test kits for human T-cell lymphotropic virus type 1 (HTLV-1), we examined two particle agglutination (PA) tests and nine enzyme immunoassays (EIA) using a standard serum panel consisting of HTLV-1-positive and HTLV-1-negative sera that had been characterized by immunofluorescence and the polymerase chain reaction (PCR). The PA kits exhibited 94.0-100.0% sensitivity and 99.5-100.0% specificity; the sensitivity range was ascribed to the quality of the HTLV-1 antigens coated on the particles. The EIA kits had 99.5-100% sensitivity and 98.5-100% specificity; the 98.5%-99.5% specificity exhibited by five of the EIA kits could have been due to nonspecific reactions that were detected through use of an inadequate cut-off value and the use of recombinant proteins. It can be concluded that the sensitivity of the currently available PA and EIA kits is sufficient to permit their use for screening purposes; however, the specificity of some EIA kits should be optimized.

Geographic independence of HTLV-I and HTLV-II foci in the Andes highland, the Atlantic coast, and the Orinoco of Colombia.

To clarify the ethnic specificity of human T cell leukemia virus type I (HTLV-I) and type II (HTLV-II) carriers among Colombian native Indians, we investigated the geographic distribution of HTLV-I and HTLV-II seroprevalence among the isolated ethnic groups of Mongoloid origin in the Andes highlands and the Atlantic coast of Colombia. HTLV-I carriers were found in 1.6% (1/62 samples) of Inga, 8.5% (5/59) of Kamsa, and 0% (0/55) of Cumbal Indians who live in the Andes highlands at 3000 m above sea level. On the other hand, HTLV-II carriers were found in 4.1% (5/123) of Wayuu Indians, who live in the Guajira region of the Atlantic coast of Colombia at a distance of 1000 km from the Andes highlands. This ethnic specificity of HTLV-II was similarly observed among Guahibo Indians in the Orinoco. The seroprevalence of HTLV-I and HTLV-II was mutually exclusive among Inga, Kamsa, and Wayuu Indians. These results suggest that HTLV-I and HTLV-II may have evolved among Mongoloid populations and been independently transmitted among two different lineages of Colombian native Indians, Andes highlanders and Atlantic coast lowlanders.