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  1. 2,3,7,8-Tetrachlorodibenzo-p-dioxin

    Integrated Risk Information System (IRIS)

    2,3,7,8 - Tetrachlorodibenzo - p - dioxin ( TCDD ) ; CASRN 1746 - 01 - 6 This document has been provided for review to EPA scientists , interagency reviewers from other federal agencies and White House offices , and the public , and peer reviewed by independent scientists external to EPA . Sections

  2. Health Risk Assessment Approach for 2,3,7,8 ...

    EPA Pesticide Factsheets

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is one of the most toxic and environmentally stable pollutants. In addition to various toxic effects, TCDD has been found to cause teratogenic, fetocidal, reproductive and carcinogenic effects in animals. In humans it adversely affects various organ systems and is probably carcinogenic as well. The report documents the methodologies utilized by the United States Environmental Protection Agency in its development of health risk assessment from exposure to TCDD. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is one of the most toxic and environmentally stable pollutants. In addition to various toxic effects, TCDD has been found to cause teratogenic, fetocidal, reproductive and carcinogenic effects in animals. In humans it adversely affects various organ systems and is probably carcinogenic as well.

  3. Synthesis of 3-aryl-8-oxo-5,6,7,8-tetrahydroindolizines via a palladium-catalyzed arylation and heteroarylation.

    PubMed

    Gracia, Stéphanie; Cazorla, Clément; Métay, Estelle; Pellet-Rostaing, Stéphane; Lemaire, Marc

    2009-04-17

    A selective palladium-catalyzed arylation and heteroarylation of 8-oxo-5,6,7,8-tetrahydroindolizines has been developed. Mechanistic studies assume an electrophilic substitution pathway for this transformation. This method provides an efficient one-step synthesis of 3-aryl-8-oxo-5,6,7,8-tetrahydroindolizines.

  4. Bioavailability of 2,3,7,8-TCDD, 2,3,7,8-TCDF and PCBs to marine benthos from passaic river sediments

    SciTech Connect

    Rubinstein, N.I.; Pruell, R.J.; Taplin, B.K.; LiVolsi, J.A.; Norwood, C.B.

    1990-01-01

    The bioaccumulation and depuration of 2,3,7,8-tetrachlorodibenzo-p-dioxin, 2,3,7,8-tetrachlorodibenzofuran and polychlorinated biphenyls by marine benthos exposed to environmentally contaminated sediment were measured in a laboratory study. Sandworms (Nereis virens), clams (Macoma nasuta) and shrimp (Palaemonetes pugio) were exposed to sediment from the Passaic River, New Jersey for up to 180 days. Worms accumulated the highest concentrations of these compounds. Uptake and depuration rates were slowest in the worms and most rapid in the clams.

  5. Energy levels of Th+ between 7.3 and 8.3 eV

    NASA Astrophysics Data System (ADS)

    Herrera-Sancho, O. A.; Nemitz, N.; Okhapkin, M. V.; Peik, E.

    2013-07-01

    Using resonant two-step laser excitation of trapped 232Th+ ions, we observe 43 previously unknown energy levels within the energy range from 7.3 to 8.3 eV. The high density of states promises a strongly enhanced electronic bridge excitation of the 229mTh nuclear state that is expected in this energy range. From the observation of resonantly enhanced three-photon ionization of Th+, the second ionization potential of thorium can be inferred to lie within the range between 11.9 and 12.3 eV. Pulsed laser radiation in a wide wavelength range from 237 to 289 nm is found to provide efficient photodissociation of molecular ions that are formed in reactions of Th+ with impurities in the buffer gas, leading to a significantly increased storage time for Th+ in the ion trap.

  6. Ternary borides Nb7Fe3B8 and Ta7Fe3B8 with Kagome-type iron framework.

    PubMed

    Zheng, Qiang; Gumeniuk, Roman; Borrmann, Horst; Schnelle, Walter; Tsirlin, Alexander A; Rosner, Helge; Burkhardt, Ulrich; Reissner, Michael; Grin, Yuri; Leithe-Jasper, Andreas

    2016-06-21

    Two new ternary borides TM7Fe3B8 (TM = Nb, Ta) were synthesized by high-temperature thermal treatment of samples obtained by arc-melting. This new type of structure with space group P6/mmm, comprises TM slabs containing isolated planar hexagonal [B6] rings and iron centered TM columns in a Kagome type of arrangement. Chemical bonding analysis in Nb7Fe3B8 by means of the electron localizability approach reveals two-center interactions forming the Kagome net of Fe and embedded B, while weaker multicenter bonding present between this net and Nb atoms. Magnetic susceptibility measurements reveal antiferromagnetic order below TN = 240 K for Nb7Fe3B8 and TN = 265 K for Ta7Fe3B8. Small remnant magnetization below 0.01μB per f.u. is observed in the antiferromagnetic state. The bulk nature of the magnetic transistions was confirmed by the hyperfine splitting of the Mössbauer spectra, the sizable anomalies in the specific heat capacity, and the kinks in the resistivity curves. The high-field paramagnetic susceptibilities fitted by the Curie-Weiss law show effective paramagnetic moments μeff≈ 3.1μB/Fe in both compounds. The temperature dependence of the electrical resistivity also reveals metallic character of both compounds. Density functional calculations corroborate the metallic behaviour of both compounds and demonstrate the formation of a sizable local magnetic moment on the Fe-sites. They indicate the presence of both antiferro- and ferrromagnetic interactions.

  7. Calculation of 2,3,7,8-TCDD equivalent concentrations of complex environmental contaminant mixtures

    PubMed Central

    Eadon, George; Kaminsky, Laurence; Silkworth, Jay; Aldous, Kenneth; Hilker, David; O'Keefe, Patrick; Smith, Robert; Gierthy, John; Hawley, John; Kim, Nancy; DeCaprio, Anthony

    1986-01-01

    Sufficient toxicological data are now available to permit use of conventional risk assessment techniques to estimate the hazards associated with human exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD). However, many real-world exposures involve complex mixtures of dibenzodioxins, dibenzofurans, and related compounds. Historical approaches to risk assessment on such mixtures have ranged from ignoring all compounds except 2,3,7,8-TCDD itself to assuming that all compounds have potencies equal to 2,3,7,8-TCDD. An alternative approach which uses existing literature data and analytical results to calculate the “2,3,7,8-TCDD equivalent” concentration of a mixture in order to “predict” its biological potency relative to 2,3,7,8-TCDD itself is advanced here. Previously reported in vivo acute and subchronic studies and some recently obtained analytical chemistry data are integrated here to clarify the utility of this important approach and to assess the uncertainties associated with its use. This predictive approach, and various conceptually similar ones, have now found wide applicability to the risk assessment process associated with exposure to complex mixtures of dioxins, dibenzofurans, and related compounds. PMID:3830107

  8. Anti-platelet activity of erythro-(7S,8R)-7-acetoxy-3,4,3',5'-tetramethoxy-8-O-4'-neolignan from Myristica fragrans.

    PubMed

    Kang, Jung Won; Min, Byung-Sun; Lee, Jeong-Hyung

    2013-11-01

    Platelets play a critical role in pathogenesis of cardiovascular disorders and strokes. The inhibition of platelet function is beneficial for the treatment and prevention of these diseases. In this study, we investigated the anti-platelet activity of erythro-(7S,8R)-7-acetoxy-3,4,3',5'-tetramethoxy-8-O-4'-neolignan (EATN), a neolignan isolated from Myristica fragrans, using human platelets. EATN preferentially inhibited thrombin- and platelet-activating factor (PAF)-induced platelet aggregation without affecting platelet damage in a concentration-dependent manner with IC50 values of 3.2 ± 0.4 and 3.4 ± 0.3 μM, respectively. However, much higher concentrations of EATN were required to inhibit platelet aggregation induced by arachidonic acid. EATN also inhibited thrombin-induced serotonin and ATP release, and thromboxane B2 formation in human platelets. Moreover, EATN caused an increase in cyclic AMP (cAMP) levels and attenuated intracellular Ca(2+) mobilization in thrombin-activated human platelets. Therefore, we conclude that the inhibitory mechanism of EATN on platelet aggregation may increase cAMP levels and subsequently inhibit intracellular Ca(2+) mobilization by interfering with a common signaling pathway rather than by directly inhibiting the binding of thrombin or PAF to their receptors. This is the first report of the anti-platelet activity of EATN isolated from M. fragrans.

  9. Fingerprinting 2,3,7,8-tetrachlorodibenzodioxin contamination within the lower Passaic River.

    PubMed

    Quadrini, James D; Ku, Wen; Connolly, John P; Chiavelli, Deborah A; Israelsson, Peter H

    2015-07-01

    The lower Passaic River is an operable unit of the Diamond Alkali Superfund site at 80 and 120 Lister Avenue in Newark, New Jersey, USA. Between 1948 and 1969, the Diamond Shamrock Chemicals Company and its predecessors manufactured chemicals such as pesticides and phenoxy herbicides, including 2,4,5-trichlorophenol, which is a precursor to 2,4,5-trichlorophenoxyacetic acid, one of the primary components used to make the military defoliant Agent Orange. A by-product of this manufacturing process was 2,3,7,8-tetrachlorodibenzodioxin (2,3,7,8-TCDD), and the site is considered the dominant source of 2,3,7,8-TCDD to the lower Passaic River and its environs. Several investigators have identified the ratio of 2,3,7,8-TCDD to total TCDD as a fingerprint for the site source. The present study presents data that establish polychlorinated dibenzodioxin/polychlorinated dibenzofuran (collectively, PCDD/F) congener and homolog fingerprints of soil and sump samples from the site. It then compares those fingerprints to the PCDD/F congener and homolog patterns in lower Passaic River sediments. The similarity of the patterns in lower Passaic River sediments to the site fingerprint indicates the site is the dominant source of the 2,3,7,8-TCDD in sediments within approximately the lower 14 miles of the lower Passaic River, excluding, for the purposes of the present discussion, Newark Bay. In addition, PCDD/F congener data indicate that the ratio of 1,3,7,8-TCDD to 2,3,7,8-TCDD is another marker of the site and corroborates the findings from the other fingerprints.

  10. Fingerprinting 2,3,7,8-tetrachlorodibenzodioxin contamination within the lower Passaic River

    PubMed Central

    Quadrini, James D; Ku, Wen; Connolly, John P; Chiavelli, Deborah A; Israelsson, Peter H

    2015-01-01

    The lower Passaic River is an operable unit of the Diamond Alkali Superfund site at 80 and 120 Lister Avenue in Newark, New Jersey, USA. Between 1948 and 1969, the Diamond Shamrock Chemicals Company and its predecessors manufactured chemicals such as pesticides and phenoxy herbicides, including 2,4,5-trichlorophenol, which is a precursor to 2,4,5-trichlorophenoxyacetic acid, one of the primary components used to make the military defoliant Agent Orange. A by-product of this manufacturing process was 2,3,7,8-tetrachlorodibenzodioxin (2,3,7,8-TCDD), and the site is considered the dominant source of 2,3,7,8-TCDD to the lower Passaic River and its environs. Several investigators have identified the ratio of 2,3,7,8-TCDD to total TCDD as a fingerprint for the site source. The present study presents data that establish polychlorinated dibenzodioxin/polychlorinated dibenzofuran (collectively, PCDD/F) congener and homolog fingerprints of soil and sump samples from the site. It then compares those fingerprints to the PCDD/F congener and homolog patterns in lower Passaic River sediments. The similarity of the patterns in lower Passaic River sediments to the site fingerprint indicates the site is the dominant source of the 2,3,7,8-TCDD in sediments within approximately the lower 14 miles of the lower Passaic River, excluding, for the purposes of the present discussion, Newark Bay. In addition, PCDD/F congener data indicate that the ratio of 1,3,7,8-TCDD to 2,3,7,8-TCDD is another marker of the site and corroborates the findings from the other fingerprints. Environ Toxicol Chem 2015;34:1485–1498. © 2015 The Authors. Published by SETAC. PMID:25726763

  11. Gridded atmospheric emission inventory of 2,3,7,8-TCDD in China

    NASA Astrophysics Data System (ADS)

    Huang, Tao; Tian, Chongguo; Zhang, Kai; Gao, Hong; Li, Yi-Fan; Ma, Jianmin

    2015-05-01

    Establishment of the dioxins emission inventory has been considered as a crucial step toward risk assessment and elimination of dioxins contaminations. Based on a total dioxin emission inventory in China from different emission categories in 2004, this study created a gridded emission inventory of 2,3,7,8-TCDD, the most toxic congener in dioxins, in China in 2009 with a 1/4° longitude by 1/4° latitude resolution. It was estimated that annually total 371 ± 53 g (average ± standard deviation) of 2,3,7,8-TCDD was released into the atmosphere in 2009 over China, increasing approximately by 37% compared with its emission in 2004. Differing from most developed countries where municipal waste incinerations were regarded as a major atmospheric emission source, in China ferrous and non-ferrous metal production made the largest contribution to 2,3,7,8-TCDD air emission (138 ± 16 g), followed by waste incineration (109 ± 12 g), power and heating generation (62 ± 9 g), and production of mineral products (47 ± 8 g). The rest of sources contributed approximately 3% to the total 2,3,7,8-TCDD emission in 2009. Iron and steel industries are mainly located in Beijing-Tianjin-Hebei (BTH) and Yangtze River Delta (YRD) regions, whereas waste incinerators are mainly located in Pearl River Delta (PRD) region. Higher 2,3,7,8-TCDD emissions were found in these three regions. While the BTH, YRD, and PRD accounted for only about 4% of total land area of China, they contributed approximately 14%, 15%, and 5% to the total 2,3,7,8-TCDD emission in 2009 in China, respectively.

  12. The interactions of 2,3,7,8-tetrachlorodibenzo-p-dioxin(TCDD) and 6-methyl-1,3,8-trichlorodibenzofuran (MCDF) in TCDD-induced porphyria

    SciTech Connect

    Yao, Cheng Catsby.

    1989-01-01

    Halogenated aryl hydrocarbon(HAH)-induced porphyria is caused by alteration of porphyrin metabolism and results in the accumulation of hepatic and urinary porphyrins. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (75 {mu}/kg) caused significant increases of hepatic porphyrin levels in C57BL/6 male, female and ovariectomized female, and C57BL/10 male mice 3 weeks after treatment. In contrast, 6-methyl-1,3,8-trichlorodibenzofuran (MCDF) was inactive at a dose of 750 {mu}mol/kg. Cotreatment with MCDF (750 {mu}mol/kg) and 2,3,7,8-TCDD (75 {mu}g/kg) resulted in partial antagonism of 2,3,7,8-TCDD-induced porphyrin accumulation in female but not in male mice. In female C57BL/6 mice, 2,3,7,8-TCDD-induced porphyria was accompanied by the induction of hepatic microsomal aryl hydrocarbon hydroxylase (AHH) and ethoxyresorufin O-deethylase (EROD) activities and the inhibition of uroporphyrinogen decarboxylase (UROD) activity. MCDF (750 {mu}mol/kg) did not significantly affect these enzyme activities. In coadministration studies, MCDF partially antagonized 2,3,7,8-TCDD-induced hepatic porphyrin accumulation but did not affect the activities of hepatic AHH, EROD or UROD. These results demonstrate that the induction of the monooxygenase enzyme activities and the inhibition of UROD activity by 2,3,7,8-TCDD and the development of porphyria are not coordinately regulated in C57BL/6 female mice. In cultured chick embryo hepatocytes, 2,3,7,8-TCDD caused a significant increase in porphyrin levels and induced AHH and EROD activities. MCDF and Aroclor 1254 partially antagonized the 2,3,7,8-TCDD induced AHH and EROD activities but not the porphyrin accumulation.

  13. Engine component improvement: Performance improvement, JT9D-7 3.8 AR fan

    NASA Technical Reports Server (NTRS)

    Gaffin, W. O.

    1980-01-01

    A redesigned, fuel efficient fan for the JT9D-7 engine was tested. Tests were conducted to determine the effect of the 3.8 AR fan on performance, stability, operational characteristics, and noise of the JT9D-7 engine relative to the current 4.6 AR Bill-of-Material fan. The 3.8 AR fan provides increased fan efficiency due to a more advanced blade airfoil with increased chord, eliminating one part span shroud and reducing the number of fan blades and fan exit guide vanes. Engine testing at simulated cruise conditions demonstrated the predicted 1.3 percent improvement in specific fuel consumption with the redesigned 3.8 AR fan. Flight testing and sea level stand engine testing demonstrated exhaust gas temperature margins, fan and low pressure compressor stability, operational suitability, and noise levels comparable to the Bill-of-Material fan.

  14. SORPTION OF 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN FROM WATER BY SURFACE SOILS

    EPA Science Inventory

    The sorption of l4C-labeled 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD) from water by two uncontaminated surface soils from the Times Beach, MO, area was evalu- ated by using batch shake testing. Sorption isotherm plots for the soil with the lower fraction organic carbon (f,) wer...

  15. ANALYSIS OF 2,3,7,8-TCDD TUMOR PROMOTION ACTIVITY AND ITS RELATIONSHIP TO CANCER

    EPA Science Inventory

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has a high estimated cancer potency in animals which has been reasoned to imply that TCDD might be carcinogenic to man. The animal cancer data show that TCDD can act in a solitary manner causing tumors without the participation of other ...

  16. Health Risk Assessment Approach for 2,3,7,8-Tetrachlorodibenzo-P-Dioxin (Draft)

    EPA Science Inventory

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is one of the most toxic and environmentally stable pollutants. In addition to various toxic effects, TCDD has been found to cause teratogenic, fetocidal, reproductive and carcinogenic effects in animals. In humans it adversely affects v...

  17. Higher Expression of Toll-like Receptors 3, 7, 8, and 9 in Pityriasis Rosea

    PubMed Central

    El-Ela, Mostafa Abou; El-Komy, Mohamed; Hay, Rania Abdel; Hegazy, Rehab; Sharobim, Amin; Rashed, Laila; Amr, Khalda

    2017-01-01

    Background Pityriasis rosea (PR) is a common papulosquamous skin disease in which an infective agent may be implicated. Toll-like receptors (TLRs) play an important role in immune responses and in the pathophysiology of inflammatory skin diseases. Our aim was to determine the possible roles of TLRs 3, 7, 8, and 9 in the pathogenesis of PR. Methods Twenty-four PR patients and 24 healthy individuals (as controls) were included in this case control study. All recruits were subjected to routine laboratory investigations. Biopsies were obtained from one active PR lesion and from healthy skin of controls for the detection of TLR 3, 7, 8, and 9 gene expression using real-time polymerase chain reaction. Results This study included 24 patients (8 females and 16 males) with active PR lesions, with a mean age of 28.62 years. Twenty four healthy age- and sex-matched individuals were included as controls (8 females and 16 males, with a mean age of 30.83 years). The results of the routine laboratory tests revealed no significant differences between both groups. Significantly elevated expression of all studied TLRs were detected in PR patients relative to healthy controls (p < .001). Conclusions TLRs 3, 7, 8, and 9 might be involved in the pathogenesis of PR. PMID:28192646

  18. Organic light-emitting diodes using 3,6-difluoro-2,5,7,7,8,8-hexacyanoquinodimethane as p-type dopant

    NASA Astrophysics Data System (ADS)

    Mi, Bao Xiu; Gao, Zhi Qiang; Cheah, Kok Wai; Chen, Chin H.

    2009-02-01

    We demonstrate that 3,6-difluoro-2,5,7,7,8,8-hexacyanoquinodimethane (F2-HCNQ) can serve as an excellent electrical doping material for hole transport materials with the highest occupied molecular orbital level as high as 5.4 eV, such as N ,N'-di(naphthalene-1-yl)-N ,N'-diphenyl-benzidine (NPB). With its relatively strong electron-accepting ability and high thermal stability, F2-HCNQ doped NPB organic light-emitting diode (OLED) showed improved power efficiency with low driving voltage. The tris(8-hydroxyquinoline)aluminum based OLED with F2-HCNQ doped NPB layer and Cs2O doped bathophenanthroline electron transport layer exhibits power efficiency of 3.6 lm/W with driving voltage of 3.2 V at 100 cd/m2.

  19. Tris(dibenzoyl-methanido-κO,O')[(6R,8R)-(-)-7,7-dimethyl-3-(2-pyrid-yl)-5,6,7,8-tetra-hydro-6,8-methano-isoquinoline-κN,N']terbium(III).

    PubMed

    Chen, Lei-Qi; Guo, Jian-Nan; Xuan, Wei-Min; Lin, Yi-Ji; Zhang, Hui

    2009-06-06

    In the title compound, [Tb(C(15)H(11)O(2))(3)(C(17)H(18)N(2))], the 7,7-dimethyl-3-(2-pyrid-yl)-5,6,7,8-tetra-hydro-6,8-methano-iso-quin-oline (L(RR)) ligand coordinates to Tb(III) through the two N atoms of the heterocycle. The metal centre is also chelated by three deprotonated 1,3-diphenyl-propane-1,3-dione (dbm) ligands, forming enanti-omerically pure [Tb(dbm)(3)L(RR)]. The Tb(III) atom is located in a distorted square anti-prism of eight coordinating atoms (six O and two N atoms).

  20. Hexachlorodibenzo-p-dioxin (HxCDD), mixture of 1,2,3,6,7,8-HxCDD and 1,2,3,7,8,9-HxCDD

    Integrated Risk Information System (IRIS)

    Hexachlorodibenzo - p - dioxin ( HxCDD ) , mixture of 1,2,3,6,7,8 - HxCDD and 1,2,3,7,8,9 - HxCDD ; CASRN 57653 - 85 - 7 and 19408 - 74 - 3 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in

  1. Summary of External Peer Review and Public Comments and Disposition for 1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8,-hexamethylcyclopenta[γ]-2-benzopyran (HHCB)

    EPA Pesticide Factsheets

    This document summarizes the public and external peer review comments that the EPA’s Office of Pollution Prevention and Toxics (OPPT) received for the draft work plan risk assessment for 1,3,4,6,7,8-Hexahydro-4,6,6,7,8,8-hexamethylcyclopenta--2-benzopyran

  2. Dynamical D4-D8 and D3-D7 branes in supergravity

    SciTech Connect

    Binetruy, Pierre; Sasaki, Misao; Uzawa, Kunihito

    2009-07-15

    We present a class of dynamical solutions for intersecting D4-D8 and D3-D7 brane systems in ten-dimensional type IIA and IIB supergravity. We discuss if these solutions can be recovered in lower-dimensional effective theories for the warped compactification of a general p-brane system. It is found that an effective p+1-dimensional description is not possible in general due to the entanglement of the transverse coordinates and the p+1-dimensional coordinates in the metric components. For the D4-D8 brane system, the dynamical solutions reduces to a static warped AdS{sub 6}xS{sup 4} geometry in a certain spacetime region. For the D3-D7 brane system, we find a dynamical solution whose metric form is similar to that of a D3-brane solution. The main difference is the existence of a nontrivial dilaton configuration in the D3-D7 solution. Then we discuss cosmology of these solutions. We find that they behave like a Kasner-type cosmological solution at {tau}{yields}{infinity}, while it reduces to a warped static solution at {tau}{yields}0, where {tau} is the cosmic time.

  3. Radiolytic degradation of 2,3,7,8-TCDD in artificially contaminated soils

    SciTech Connect

    Hillarides, R.J.; Gray, K.A. ); Guzzetta, J.; Cortellucci, N.; Sommer, C. )

    1994-12-01

    This paper reports results of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) destruction on artificially contaminated soil using cobalt-60 ([sup 60]Co) [gamma] radiation. Important parameters (soil moisture content, surfactant type/concentration, equilibration, and radiation dose) and their optimum ranges are identified. Scavenger (N[sub 2]O, O[sub 2], 2-propanol) studies were conducted to explore the consequences of controlling oxidative and reductive conditions in the soil, and reaction byproducts have been analyzed under selected reaction conditions. A standard soil (EPA SSM-91) was artificially contaminated with 2,3,7,8-TCDD to 100 ppb, and in the presence of 25% water and 2% surfactant (RA-40) and at a high irradiation dose (800 kGy), greater than 92% TCDD destruction was achieved, resulting in a final TCDD concentration of less than 7 ppb. Results of scavenger and byproduct studies and theoretical target theory calculations indicate that TCDD destruction is caused primarily by direct radiation effects and proceeds through reductive dechlorination. 53 refs., 6 figs., 3 tabs.

  4. Elimination of 2,3,7,8-tetrachlorodibenzo-p-dioxine in goat milk.

    PubMed

    Arstila, A U; Reggiani, G; Sorvari, T E; Räisänen, S; Wipf, H K

    1981-11-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxine (TCDD) 200 ng/day, was given orally to 7 goats for 2 months, followed by an elimination period of 1 month. Then a daily dose of 400 ng TCDD was given for 1 month to the same animals. Two animals were killed and the rest of the animals were observed for several months. The excretion of TCDD in milk was studied by glass capillary gas fragmentography, where the minimal detectable concentration was below 5 ppt. After the first feeding the concentration of TCDD in milk achieved a maximum of 20.8 +/- 6.6 ppt while a similar value of 19.3 +/- 6.6 ppt was observed after the second feeding. After this period, the concentration of TCDD decreased slowly with values, after 18 weeks, of 4, 2 +/-, 3 and 6 ppt. The concentration of TCDD in the liver in the two animals killed was 1039.0 and 898.0 ppt. There were no differences in clinical observations or blood and urine analyses when experimental animals were compared with controls.

  5. 2,3,7,8-DIBENZO-P-DIOXINS IN MINED CLAY PRODUCTS ...

    EPA Pesticide Factsheets

    Ball clay was the source of dioxin contamination discovered in selected chickens analyzed as part of a joint U.S. Department of Agriculture/U.S. Environmental Protection Agency national survey of the U.S. poultry supply conducted in 1997. The affected animals, which had been raised in the southern United States, represented approximately 5% of the national poultry production . All of these chickens and other animal food sources (i.e., farm-raised catfish), similarly contaminated, were fed a diet of animal feed containing ball clay as an anti-caking additive. The clay was mined in northwestern Mississippi within a geological formation referred to as the Mississippi Embayment. Individual raw and processed ball clay samples were analyzed for the presence of the 2,3,7,8-PCDDs/PCDFs. The average toxic equivalents (TEQs) for the raw and processed samples were 1513 and 996 ppt dry weight, respectively. Other mined clay-based products used in animal feeds revealed lower TEQs. All of the products exhibited either an absence of detectable concentrations of 2,3,7,8-PCDFs or concentrations 2-3 orders of magnitude lower than the PCDDs. The isomer distribution, specific isomer identification, and congener profile of the PCDDs in the clay were established and compared to known sources of dioxin contamination. Several unique features of this isomer distribution are characteristic of the clays and are distinguishable from those other known sources. These characteristic

  6. Gas-phase tropospheric chemistry of 2,3,7,8-tetrafuorinated dibenzo-p-dioxin.

    PubMed

    Zhang, Chenxi; Sun, Xiaomin

    2014-01-15

    Growing attention has been devoted to understanding the formation and destruction of polyfluorinated dibenzo-p-dioxins (PFDDs). High-accuracy molecular orbital calculations have been performed to investigate the tropospheric oxidation reaction of 2,3,7,8-tetrafuorinated dibenzo-p-dioxin (TFDD) initiated by OH radical, NO3 radical and O3. The rate constant of TFDD reaction triggered by the OH radical, NO3 radical and O3 is about 2.30 × 10(-11)cm(3) molecule(-l) s(-l), 3.18 × 10(-13)cm(3) molecule(-l) s(-l), and 3.30 × 10(-19)cm(3) molecule(-l) s(-l), respectively. OH radical is the major gas phase tropospheric sink for TFDD. Once TFDD-OH intermediates are produced in the initial reactions, they can react with tropospheric O2 subsequently to generate peroxy radical isomers. The TFDD-OH-O2 can further react with tropospheric NO via isomerization or combination, resulting that the dioxin ring will be ruptured completely. This study can serve as a template for tropospheric degradation of the gaseous PFDDs, which is beneficial for assessing their tropospheric behaviors.

  7. Crystal structure of 2-amino-7,7-dimethyl-5-oxo-4-(pyridin-4-yl)-5,6,7,8-tetrahydro-4 H-chromene-3-carbonitrile hemihydrate

    NASA Astrophysics Data System (ADS)

    Sharma, N.; Banerjee, B.; Brahmachari, G.; Kant, R.; Gupta, V. K.

    2015-12-01

    The title compound, 2-amino-7,7-dimethyl-5-oxo-4-(pyridin-4-yl)-5,6,7,8-tetrahydro-4 Hchromene-3-carbonitrile was synthesized by multicomponent reaction at room temperature using commercially available urea as inexpensive and environmentally benign organo-catalyst. Its structure was determined by X-ray structure analysis. The crystals are monoclinic, sp. gr. C2/ c, a = 22.010(6), b = 11.0364(10), c = 17.147(4) Å, β = 130.37(4)°, Z = 8, R = 0.0433 for 2377 observed reflections.

  8. Phosphine-boranes as bidentate ligands: formation of [8,8-eta(2)-(eta(2)-(BH(3)).dppm)-nido-8,7-RhSB(9)H(10)] and [9,9-eta(2)-(eta(2)-(BH(3)).dppm)-nido-9,7,8-RhC(2)B(8)H(11)] from [8,8-(eta(2)-dppm)-8-(eta(1)-dppm)-nido-8,7-RhSB(9)H(10)] and [9,9-(eta(2)-dppm)-9-(eta(1)-dppm)-nido-9,7,8-RhC(2)B(8)H(11)], respectively.

    PubMed

    Volkov, Oleg; Macías, Ramón; Rath, Nigam P; Barton, Lawrence

    2002-11-04

    The two clusters [8,8-(eta(2)-dppm)-8-(eta(1)-dppm)-nido-8,7-RhSB(9)H(10)] (1) and [9,9-(eta(2)-dppm)-9-(eta(1)-dppm)-nido-9,7,8-RhC(2)B(8)H(11)] (2) (dppm = PPh(2)CH(2)PPh(2)), both of which contain pendant PPh(2) groups, react with BH(3).thf to afford the species [8,8-eta(2)-(eta(2)-(BH(3)).dppm)-nido-8,7-RhSB(9)H(10)] (3) and [9,9-eta(2)-(eta(2)-(BH(3)).dppm))-nido-9,7,8-RhC(2)B(8)H(11)] (4), respectively. These two species are very similar in that they both contain the bidentate ligand [(BH(3)).dppm], which coordinates to the Rh center via a PPh(2) group and also via a eta(2)-BH(3) group. Thus, the B atom in the BH(3) group is four-coordinate, bonded to Rh by two bridging hydrogen atoms, to a terminal H atom, and to a PPh(2) group. At room temperature, the BH(3) group is fluxional; the two bridging H atoms and the terminal H atom are equivalent on the NMR time scale. The motion is arrested at low temperature with DeltaG++ = ca. 37 and 42 kJ mol(-1), respectively, for 3 and 4. Both species are characterized completely by NMR and mass spectral measurements as well as by elemental analysis and single-crystal structure determinations.

  9. Effects of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane doping on diketopyrrolopyrrole-based, low crystalline, high mobility polymeric semiconductor

    SciTech Connect

    Yoon, Seongwon; Cho, Jangwhan; Chung, Dae Sung; Lee, Han-Koo; Park, Sungmin; Son, Hae Jung

    2015-09-28

    The effects of 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) doping on diketopyrrolo-pyrrole-based polymeric semiconductors in terms of charge transport behavior and structural ordering are systematically investigated. Although the energy level offset between the polymeric semiconductor and the F4TCNQ acceptor was not particularly large, ultraviolet photoelectron spectroscopy analyses revealed that a low doping ratio of 1 wt. % is sufficient to tune the energy distance between the Fermi level and the HOMO level, reaching saturation at roughly 5 wt. %, which is further confirmed by the depletion mode measurements of field effect transistors (FETs). Structural analyses using grazing-incidence X-ray diffraction (GIXD) show that the overall degree of edge-on orientation is disturbed by the addition of dopants, with significant influence appearing at high doping ratios (>3 wt. %). The calculated charge carrier mobility from accumulation mode measurements of FETs showed a maximum value of 2 cm{sup 2}/V·s at the optimized doping ratio of 1%, enabled by additional holes in the channel region, which results in a roughly 40% increase relative to the undoped device. Further increases in the doping ratio, however, resulted in worse FET performance, which can be attributed to structural deformation. This result suggests that the electrochemical doping method can be also applied to donor-acceptor copolymers to further enhance their charge transport characteristics, once the optimized doping condition has been established.

  10. Potential mosquito repellent compounds of Ocimum species against 3N7H and 3Q8I of Anopheles gambiae.

    PubMed

    Gaddaguti, Venugopal; Venkateswara Rao, Talluri; Prasada Rao, Allu

    2016-06-01

    Mosquitoes are exceptionally efficient in detecting their hosts for blood meal using odorant binding proteins, viz. 3N7H and 3Q8I and spread several dreadful diseases. DEET is a synthetic mosquito repellent widely used all over world for protection against mosquito bite. Reports reveal that, synthetic mosquito repellents may pose health problems in considerably large population. In view of the above fact, we made an attempt to discover efficient and novel natural mosquito repellent compounds with least impact on human health. Methanolic leaf extracts of Ocimum basilicum Linn. var. pilosum (willd.)-Benth and Ocimum tenuiflorum var. CIM-AYU were subjected to GC-MS analysis and obtained 35 phytochemical constituents. Repellent potentiality of the Ocimum compounds was assessed against 3Q8I and 3N7H of Anopheles gambiae. PDB structures of mosquito odorant binding proteins were downloaded, processed and docking studies were performed along with reference ligand DEET using Schrodinger MAESTRO 9.2 software. Molecular docking results reveal that phenol, 2-methoxy-3-(2-propenyl)-, licopersin, gamma sitosterol and benzene, 1,2-dimethoxy-4-(2-propenyl)- from O. tenuiflorum var. CIM-AYU are strongly bound with 3N7H. Whereas, 4h-1-benzopyran-4-one, 5-hydroxy-6,7-dimethoxy-2-(4-methoxyphenyl)-, catechol and monoacetin from O. basilicum Linn. var. pilosum (willd.)-Benth. show high binding affinity with odorant binding protein 3Q8I. All natural compounds tested in the present study display better docking scores than DEET. The results further substantiate that the 12 out of 35 compounds of the two Ocimum species found to be ideal candidates for design and development of potential mosquito repellents. ADME properties of the tested compounds further confirm that bioactive compounds of Ocimum species were found to be in acceptable range. Synchronized application of at least two different natural compounds (with best docking scores) which target 3N7H and 3Q8I (Odorant Binding Proteins

  11. Biomagnification of bioassay derived 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents

    USGS Publications Warehouse

    Jones, P.D.; Ankley, G.T.; Best, D. A.; Crawford, R.; DeGalan, N.; Giesy, J.P.; Kubiak, T.J.; Ludwig, J. P.; Newsted, J.L.; Tillitt, D. E.; Verbrugge, D.A.

    1993-01-01

    In recent years contamination of the Great Lakes ecosystem with planar chlorinated hydrocarbons (PCHs) has attracted considerable concern due to their known reproductive and teratogenic effects. The H4IIE bioassay has been standardized as a means of measuring the biological potency of a PCH mixture as 2,3,7,8-tetrachloro-p-dibenzodioxin equivalents (TCDD-EQ). Using this bioassay we have investigated the biomagnification of TCDD-EQ in a semi-closed ecosystem. The biomagnification of TCDD-EQ is demonstrated and results indicate that the food chain is the major pathway for TCDD-EQ through this ecosystem. The H4IIE assay system is demonstrated to be a viable integrative measure of the total concentration of TCDD-EQ in different trophic levels.

  12. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and long term immunologic memory.

    PubMed

    Sherr, David H

    2004-06-01

    The highlighted article by B. Paige Lawrence and Beth Vorderstrasse addresses an oft forgotten aspect of immunotoxicity, the effects of environmental toxins on immunologic memory. Here, the authors take a step towards filling that information gap by evaluating the effects of a prototypic environmental toxin, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), on memory responses to a real-world pathogen, influenza A virus, presented to an animal model in a physiologically relevant manner. Multiple outcomes are evaluated, the vast majority of which suggest important and long-term TCDD-induced changes in the immune system after both primary and secondary exposure to this pathogen. The implications of these studies with regard to the immuno-competence of TCDD-exposed individuals are far reaching.

  13. 2,3,7,8-Tetrachlorodibenzo-p-dioxin alters sebaceous gland cell differentiation in vitro.

    PubMed

    Ju, Qiang; Fimmel, Sabine; Hinz, Norbert; Stahlmann, Ralf; Xia, Longqing; Zouboulis, Christos C

    2011-04-01

    Chloracne is a characteristic marker of intoxication by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or related compounds. Decreased lipogenesis is a prominent clinical sign in this disease. However, the activity of dioxins on human sebaceous glands is still unclear. In this study, the effects of TCDD on sebaceous gland differentiation were studied both in human skin samples maintained ex vivo and in cultured SZ95 sebocytes. Aryl hydrocarbon receptor (AhR) protein expression, the receptor for dioxin, was detected in SZ95 sebocytes. Its expression was markedly inhibited by TCDD. Furthermore, we detected a reduced release of neutral lipids (10(-10) -10(-8) M; P<0.001) and decreased expression of epithelial membrane antigen and keratin 7, all of which are specific markers of sebaceous differentiation. Markedly, increased expression of the keratinocyte differentiation marker keratin 10 and of peroxisome proliferators-activated receptor-δ was assessed in SZ95 sebocytes treated with TCDD. To corroborate these in vitro data, an ex vivo sebaceous gland-rich skin culture model was investigated. Obvious shrinkage of sebaceous glands with sebaceous duct hyperplasia and increased expression of keratin 10 in the atrophic sebaceous glands were observed on the 5th day of TCDD treatment. In conclusion, TCDD affects the differentiation of sebaceous gland cells probably by switching human sebaceous into keratinocyte-like differentiation. In addition and together with the results of a parallel study (J Dermatol Sci 58, 2010, 211), we provide evidence that TCDD effects on human sebocytes are mediated through the AhR signalling pathway.

  14. EFFECTS OF 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN ...

    EPA Pesticide Factsheets

    While the effect that TCDD has on humoral immunity in the mouse has been well documented, it has not been for the rat. n this study, the effect that TCDD has on the antibody plaque-forming cell (PFC) response to sheep red blood cells (SRBC) in adult female B6C3F1 mice and F344 rats was compared. ice or rats were given a single intraperitoneal injection of TCDD at doses ranging from 0.1 to 30 ug/kg, 7 days prior to intravenous immunization with SRBC. our days later the PFC response to SRBC was determined. ice showed a dose related suppression of the PFC response, with an ED50 of 0.71 ug/kg TCDD. n contrast, TCDD failed to suppress and in fact enhanced the PFC response to SRBC in rats at doses as high as 30 ug/kg. he inability of TCDD to suppress the PFC response in rats was unrelated to hepatic CYP1A1 and CYP1A2 induction which was detectable at doses of 1 and 0.3 ug/kg TCDD, respectively. here was no shift in the time to peak PFC response in rats dosed with TCDD, nor was the failure of TCDD to suppress the PFC response in rats related to gender or strain. henotypic analysis of thymocytes and splenic lymphocytes from TCDD-dosed (i.e., 3, 10 or 30 ug/kg) and SREC-immunized mice and rats revealed that CD4-CD8+ splenocytes were reduced in a dose related manner in rats only and that this reduction in CD4-CD8+ was accompanied by a dose related increase in IgM+ splenocytes. hese results demonstrate species differences in the effect of TCDD on the PFC response to SRBC w

  15. Soybean plastidal omega-3 fatty acid desaturase genes GmFAD7 and GmFAD8: structure and expression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The genomic structure and deduced protein sequence of soybean FAD7 and FAD8 have features similar to higher plant plastidal '-3 desaturases: 8 exons and 7 introns, predicted proteins of 453 amino acid residues containing three conserved histidine motifs, amino terminal chloroplast transit peptides, ...

  16. Partial antagonism of 2,3,7,8-tetrachlorodibenzo-p-dioxin-mediated induction of aryl hydrocarbon hydroxylase by 6-methyl-1,3,8-trichlorodibenzofuran: mechanistic studies.

    PubMed

    Harris, M; Zacharewski, T; Astroff, B; Safe, S

    1989-05-01

    6-Methyl-1,3,8-trichlorodibenzofuran (MCDF) binds with moderate affinity to the aryl hydrocarbon (Ah) receptor protein (4.9 x 10(-8) M) but is a weak Ah receptor agonist. Cotreatment of male Long Evans rats with MCDF (50 mumol/kg) and a dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) that causes a near-maximal induction of hepatic microsomal aryl hydrocarbon hydroxylase and ethoxyresorufin O-deethylase activities resulted in a significant inhibition of these activities for up to 96 hr. Comparable results were obtained with MCDF (10(-7) M) and TCDD (10(-8) M) in rat hepatoma H-4-II E cells in culture over 36 hr. TCDD treatment of rats resulted in an initial decrease of hepatic cytosolic Ah receptor within 6 hr and this was followed by a subsequent 138% increase in cytosolic receptor levels 72 hr after treatment. Although MCDF (50 mumol/kg) did not significantly alter rat hepatic cytosolic Ah receptor levels in animals cotreated with TCDD plus MCDF, the latter compound significantly inhibited TCDD-mediated replenishment of the cytosolic Ah receptor. In contrast, treatment of rat hepatoma H-4-II E cells with TCDD (10(-8) M) resulted in the rapid (within 1 hr) depletion of cytosolic Ah receptor, which remained undetectable for up to 36 hr; cotreatment of the cells with MCDF (10(-7) M) and TCDD (10(-8) M) resulted in cytosolic Ah receptor levels that were similar to those observed after treatment with TCDD alone. The effects of MCDF on the uptake and persistence of nuclear [3H]TCDD-Ah receptor complex levels were also determined in rat liver and rat hepatoma H-4-II E cells in culture. MCDF did not significantly decrease levels of occupied nuclear Ah receptor complexes in the rat or rat hepatoma cells. Moreover, using the sucrose density gradient assay procedure, the sedimentation coefficients of the cytosolic and nuclear TCDD-Ah receptor complexes in the presence or absence of MCDF were comparable. The results of these and other related studies with 6-substituted-1,3,8

  17. Performance characteristics of a 1.8 by 3.7 meter Fresnel lens solar concentrator

    NASA Technical Reports Server (NTRS)

    Hastings, L. J.; Allums, S. L.

    1979-01-01

    Line-focusing acrylic Fresnel lenses with application potential in the 200 to 370 C range were analytically and experimentally investigated. The measured solar concentration characteristics of a 1.8 by 3.7 m lens and its utilization in a solar collection mode are presented. A measured peak concentration ratio of 62 with 90 percent of the transmitted energy focused into a 5.0cm width was achieved. A peak concentration of 59 and a 90 percent target width of 4.3 cm were analytically computed. The experimental and analytical lens transmittance was 78 percent and 86 percent, respectively. The lens was also interfaced with a nonevacuated receiver assembly and operated in the collection mode. With a natural oxide absorber tube coating (alpha/epsilon = 0.79/0.10), the measured collection efficiency ranged from 43 percent to 200 C to 34 percent at 260 C. Efficiency improvements to the 40 to 50 percent range can be achieved with second generation lenses and higher performance absorptive coatings.

  18. Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure on bone material properties.

    PubMed

    Finnilä, Mikko A J; Zioupos, Peter; Herlin, Maria; Miettinen, Hanna M; Simanainen, Ulla; Håkansson, Helen; Tuukkanen, Juha; Viluksela, Matti; Jämsä, Timo

    2010-04-19

    Dioxins are known to decrease bone strength, architecture and density. However, their detailed effects on bone material properties are unknown. Here we used nanoindentation methods to characterize the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on nanomechanical behaviour of bone matrix. Pregnant rats were treated with a single intragastric dose of TCDD (1 microg/kg) or vehicle on gestational day 11. Tibias of female offspring were sampled on postnatal day (PND) 35 or 70, scanned at mid-diaphysis with pQCT, and evaluated by three-point bending and nanoindentation. TCDD treatment decreased bone mineralization (p<0.05), tibial length (p<0.01), cross-sectional geometry (p<0.05) and bending strength (p<0.05). Controls showed normal maturation pattern between PND 35 and 70 with decreased plasticity by 5.3% and increased dynamic hardness, storage and complex moduli by 26%, 13% and 12% respectively (p<0.05), while similar maturation was not observed in TCDD-exposed pups. In conclusion, for the first time, we demonstrate retardation of bone matrix maturation process in TCDD-exposed animals. In addition, the study confirms that developmental TCDD exposure has adverse effects on bone size, strength and mineralization. The current results in conjunction with macromechanical behaviour suggest that reduced bone strength caused by TCDD is more associated with the mineralization and altered geometry of bones than with changes at the bone matrix level.

  19. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) inhibits human ovarian cancer cell proliferation

    PubMed Central

    Li, Yan; Wang, Kai; Jiang, Yi-Zhou; Chang, Xin-Wen; Dai, Cai-Feng

    2017-01-01

    Purpose The aryl hydrocarbon receptor (AhR), a ligand-activated transcription factor, mediates a broad spectrum of biological processes, including ovarian growth and ovulation. Recently, we found that an endogenous AhR ligand (ITE) can inhibit ovarian cancer proliferation and migration via the AhR. Here, we tested whether 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, an exogenous AhR ligand) may exert similar anti-ovarian cancer activities using human ovarian cancer and non-cancerous human ovarian surface epithelial cells. Methods Two human ovarian cancer cell lines (SKOV-3 and OVCAR-3) and one human ovarian surface epithelial cell line (IOSE-385) were used. Cell proliferation and migration activities were determined using crystal violet and FluoroBlok insert system assays, respectively. AhR protein expression was assessed by Western blotting. Expression of cytochrome P450, family 1, member A1 (CYP1A1) and member B1 (CYP1B1) mRNA was assessed by qPCR. Small interfering RNAs (siRNAs) were used to knock down AhR expression. Results We found that TCDD dose-dependently suppressed OVCAR-3 cell proliferation, with a maximum effect (~70 % reduction) at 100 nM. However, TCDD did not affect SKOV-3 and IOSE-385 cell proliferation and migration. The estimated IC50 of TCDD for inhibiting OVCAR-3 cell proliferation was 4.6 nM. At 10 nM, TCDD time-dependently decreased AhR protein levels, while it significantly increased CYP1A1 and CYP1B1 mRNA levels in SKOV-3, OVCAR-3 and IOSE-385 cells, indicating activation of AhR signaling. siRNA-mediated AhR knockdown readily blocked TCDD-mediated suppression of OVCAR-3 cell proliferation. Conclusion Our data indicate that TCDD can suppress human ovarian cancer cell proliferation via the AhR signaling pathway and that TCDD exhibits an anti-proliferative activity in at least a subset of human ovarian cancer cells. PMID:25404385

  20. In Ovo 2,3,7,8-Tetrachlorodibenzo-p-dioxin Exposure in Three Avian Species

    PubMed

    Janz; Bellward

    1996-08-01

    As opposed to mammals, the heterogametic sex in birds is female, and sexual differentiation of the central nervous system away from the intrinsic male pattern is dependent on ovarian estrogen secretions during the perinatal period. The contamination of aquatic systems with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds has been suggested to be responsible for decreased reproductive success in certain wild fish-eating bird populations. Since TCDD has been shown to alter estrogenic status in laboratory animals, we determined the effects of in ovo TCDD exposure on hepatic estrogen receptor (ER) concentrations and affinities, and plasma estradiol concentrations during the perinatal period in the domestic chicken (Gallus gallus), domestic pigeon (Columba livia), and great blue heron (Ardea herodias). Plasma testosterone levels were also determined in herons as an indication of androgenic status. [3H]TCDD was injected into the air cell of chicken eggs on Embryonic Day 4.5 (0.1 μg/kg egg), pigeon eggs on Embryonic Day 3.5 (1 μg/kg egg) and Embryonic Day 14 (3 μg/kg egg), and heron eggs at approximately Embryonic Day 13 (2 μg/kg egg). Chickens were euthanized on Embryonic Days 17 and 19, hatch, and Days 2 and 4 after hatch. Pigeons and herons were either euthanized at hatch or fed an uncontaminated diet for 7 days prior to termination. Between 5 and 10% of the injected [3H]TCDD dose was measured in the liver of hatchlings. There was no effect of in ovo TCDD exposure on hepatic ER levels or plasma estradiol concentrations in female chickens and pigeons exposed early in incubation. In female pigeons exposed during the latter third part of incubation to a TCDD dose that would cause high embryo lethality if injected early in incubation, hepatic ER concentrations were elevated (p < 0.001) and plasma estradiol concentrations were decreased (p < 0.01) at hatch. There was no effect of TCDD exposure on plasma estradiol levels in male pigeons. In herons, TCDD

  1. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) enhances placental inflammation.

    PubMed

    Peltier, Morgan R; Arita, Yuko; Klimova, Natalia G; Gurzenda, Ellen M; Koo, Hchi-Chi; Murthy, Amitasrigowri; Lerner, Veronica; Hanna, Nazeeh

    2013-06-01

    Preterm birth is a leading cause of perinatal morbidity and mortality that is often associated with ascending infections from the lower genital tract. Recent studies with animal models have suggested that developmental exposure to the environmental toxin 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) can increase the risk of preterm birth in the offspring. How TCDD may modify placental immunity to ascending infections is unclear. Therefore, we studied the effects of TCDD treatment on basal and Escherichia coli-stimulated cytokine production by placental explants. Cultures of second-trimester placentas were treated with up to 40 nM TCDD for 72 h and then stimulated with 10(7)CFU/ml E. coli for an additional 24h. Concentrations of cytokines and PGE2 were measured in conditioned medium by immunoassay. TCDD exposure increased mRNA levels of IL-1β by unstimulated cultures, but no effects on protein levels of this cytokine were detected. TNF-α production was unaffected by TCDD for unstimulated cultures, but pre-treatment with 40 nM TCDD significantly increased E. coli-stimulated TNF-α production. Both basal and bacteria-stimulated PGE2 and COX-2 gene expression were enhanced by TCDD pretreatment. In contrast, production of the anti-inflammatory cytokine, IL-10, was reduced by TCDD pretreatment for both unstimulated and E. coli-stimulated cultures. No effect of TCDD on the viability of the cultures was detected. These results suggest that TCDD exposure may shift immunity to enhance a proinflammatory phenotype at the maternal-fetal interface that could increase the risk of infection-mediated preterm birth.

  2. IR, FT-ICR-MS studies on (1'S, 6'S)-1-cyclopropyl-7-(2,8-diazabicyclo[4.3.0] non-8-yl)-6-fluoro-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid hydrochloride salt.

    PubMed

    Lin, Zhiwei

    2014-01-01

    The infrared spectra of (1'S, 6'S)-1-cyclopropyl-7-(2,8-diazabicyclo[4.3.0] non-8-yl)-6-fluoro-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylic acid hydrochloride salt (CLF-HCl) were studied and compared with free base. Their fragmentation pathways were investigated using tandem mass spectrometric (MS/MS) techniques on Fourier-transform ion cyclotron resonance spectrum, and many characteristic fragment ions were found.

  3. 2,3,7,8-TCDD exposure, endothelial dysfunction and impaired microvascular reactivity.

    PubMed

    Pelclová, Daniela; Prázny, Martin; Skrha, Jan; Fenclová, Zdenka; Kalousová, Marta; Urban, Pavel; Navrátil, Tomás; Senholdová, Zdenka; Smerhovsky, Zdenek

    2007-09-01

    Vascular function was examined in subjects with long-term high level of serum 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD) during their follow-up visits. Their earlier mean peak TCDD level at the time of exposure in 1965-1968 was estimated in the range of 3300-74 000 pg/g lipids. Ten former pesticide production workers heavily exposed to TCDD (age 57 +/- 2 years, TCDD about 170 pg/g lipids) were examined in 2001. Extended group of 15 TCDD-exposed men (age 59 +/- 3 years, TCDD about 130 pg/g lipids) underwent the same examination in 2004. Findings were compared with a control group of 14 healthy men (age 54 +/- 2 years). Skin microvascular reactivity (MVR) was measured by laser Doppler perfusion monitoring in the forearm during post-occlusive reactive hyperemia (PORH) and thermal hyperemia (TH). Several parameters of MVR in men exposed to TCDD were significantly impaired, compared with the control group and further progression of the impairment of MVR has been observed between years 2001 and 2004. Serum concentration of E-selectin and inhibitor of tissue plasminogen activator 1 (PAI-1) was significantly higher in exposed subjects (56.0 +/- 18.4 ng/mL versus 40.0 +/- 12.0 ng/mL, P = 0.022 and 90.9 +/- 33.3 ng/mL versus 45.0 +/- 18.0, P = 0.002, respectively). In addition, PORH in the forearm was significantly negatively associated with SOD activity (r = -0.77, P = 0.009) as well as the velocity of perfusion increase during TH (r = -0.68, P = 0.03) and TH% (r = -0.78, P = 0.008). Our data document the presence of endothelial dysfunction in TCDD-exposed men.

  4. 8 CFR 287.7 - Detainer provisions under section 287(d)(3) of the Act.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... REGULATIONS FIELD OFFICERS; POWERS AND DUTIES § 287.7 Detainer provisions under section 287(d)(3) of the Act... designated individually or as a class, by the Commissioner of CBP, the Assistant Secretary for ICE, or...

  5. Oxidative stress in lake sturgeon orally exposed to 2,3,7,8-tetrachlorodibenzofuran

    SciTech Connect

    Palace, V.P.; Dick, T.A.; Brown, S.B.; Baron, C.L.; Klaverkamp, J.F. |

    1994-12-31

    Juvenile lake sturgeon were orally dosed with gelatin containing nominal concentrations of 0, 0.16 or 1.6 ng 2,3,7,8-tetrachlorodibenzofuran (TCDF)/Kg fish weight. Liver, kidney and blood were collected 10 and 27 days after exposure. Phase 1 (mixed function oxidase MFO) and Phase 2 (glucuronyltransferase) enzyme activities were determined in liver. In addition, concentrations of nonenzymatic (ascorbic acid, tocopherol, retinoids) and enzymatic (superoxide dismutase, catalase, glutathione peroxidase) antioxidant parameters were quantified in liver and kidney. TCDF concentrations were elevated in liver and kidney of both dose groups at 10 and 27 days. However, lower tissue concentrations of TCDF at 27 days compared with 10 day exposures, as well as the presence of polar metabolites in bile, suggest rapid metabolism and clearance of the contaminant. Phase 1 and Phase 2 enzyme activities were induced in a dose dependent manner with activities at the two sample periods reflecting the different TCDF concentrations. Indicators of oxidative stress responded similarly.

  6. Severe 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) intoxication: clinical and laboratory effects.

    PubMed Central

    Geusau, A; Abraham, K; Geissler, K; Sator, M O; Stingl, G; Tschachler, E

    2001-01-01

    A variety of health effects have been attributed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), but little information is available on the course of a verified high-level TCDD intoxication. In this paper we describe two cases of heavy intoxication with TCDD and present a 2-year follow-up including clinical, biochemical, hematologic, endocrine, and immunologic parameters monitored in two women, 30 and 27 years of age, who suffered from chloracne due to TCDD intoxication of unknown origin. Patient 1, who had the highest TCDD level ever recorded in an individual (144,000 pg/g blood fat), developed severe generalized chloracne, whereas in the second patient, despite heavy intoxication (26,000 pg/g blood fat), only mild facial acne lesions occurred. Both patients initially experienced nonspecific gastrointestinal symptoms. In Patient 1 we observed a moderate elevation of blood lipids, leukocytosis, anemia, and secondary amenorrhoea. The laboratory parameters in Patient 2 were all normal. Despite the high TCDD levels, apart from chloracne, only few clinical and biochemical health effects were observed within the first 2 years after TCDD intoxication. PMID:11564625

  7. ANALYSIS OF 2,3,7,8-TCDD TUMOR PROMOTION ACTIVITY ...

    EPA Pesticide Factsheets

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has a high estimated cancer potency in animals which has been reasoned to imply that TCDD might be carcinogenic to man. The animal cancer data show that TCDD can act in a solitary manner causing tumors without the participation of other known factors. owever, there exist animal cancer data indicating that TCDD can act as a tumor-promoting compound. This analysis examines which type of carcinogen and which mechanism best characterize TCDD cancer activity. It is suggested that TCDD acts by a hormonal mechanism to cause cancer in solitary manner, at low doses, in two species, and in a number of different organs, including rare sites. These observations in toto characterize TCDD as a complete carcinogen, which by definition encompasses both initiation and promotion carcinogenic activities. This analysis examines which type of carcinogen and which mechanism best characterize TCDD cancer activity. It is suggested that TCDD acts by a hormonal mechanism to cause cancer in solitary manner, at low doses, in two species, and in a number of different organs, including rare sites

  8. Application of pharmacokinetic modelling for 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure assessment.

    PubMed

    Ruiz, P; Aylward, L L; Mumtaz, M

    2014-01-01

    Polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and mono- and non-ortho polychlorinated biphenyls (dioxin-like PCBs) are identified as a family or group of organic compounds known as 'dioxins' or dioxin-like chemicals (DLCs). The most toxic member of this group is 2,3,7,8-tetrachlorodibenzo-(p)-dioxin (TCDD). Historically, DLCs have caused a variety of negative human health effects, but a disfiguring skin condition known as chloracne is the only health effect reported consistently. As part of translational research to make computerized models accessible to health risk assessors, the Concentration- and Age-Dependent Model (CADM) for TCDD was recoded in the Berkeley Madonna simulation language. The US Agency for Toxic Substances and Disease Registry's computational toxicology laboratory used the recoded model to predict TCDD tissue concentrations at different exposure levels. The model simulations successfully reproduced the National Health and Nutrition Examination Survey (NHANES) 2001-2002 TCDD data in age groups from 6 to 60 years and older, as well as in other human datasets. The model also enabled the estimation of lipid-normalized serum TCDD concentrations in breastfed infants. The model performed best for low background exposures over time compared with a high acute poisoning case that could due to the large dose and associated liver toxicity. Hence, this model may be useful for interpreting human biomonitoring data as a part of an overall DLC risk assessment.

  9. Cancer mortality in workers exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin

    SciTech Connect

    Fingerhut, M.A.; Halperin, W.E.; Marlow, D.A.; Piacitelli, L.A.; Honchar, P.A.; Sweeney, M.H.; Greife, A.L.; Dill, P.A.; Steenland, K.; Suruda, A.J. )

    1991-01-24

    In both animal and epidemiologic studies, exposure to dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin, or TCDD) has been associated with an increased risk of cancer. We conducted a retrospective cohort study of mortality among the 5172 workers at 12 plants in the United States that produced chemicals contaminated with TCDD. Occupational exposure was documented by reviewing job descriptions and by measuring TCDD in serum from a sample of 253 workers. Causes of death were taken from death certificates. Mortality from several cancers previously associated with TCDD (stomach, liver, and nasal cancers, Hodgkin's disease, and non-Hodgkin's lymphoma) was not significantly elevated in this cohort. Mortality from soft-tissue sarcoma was increased, but not significantly (4 deaths; standardized mortality ratio (SMR), 338; 95 percent confidence interval, 92 to 865). In the subcohort of 1520 workers with greater than or equal to 1 year of exposure and greater than or equal to 20 years of latency, however, mortality was significantly increased for soft-tissue sarcoma (3 deaths; SMR, 922; 95 percent confidence interval, 190 to 2695) and for cancers of the respiratory system (SMR, 142; 95 percent confidence interval, 103 to 192). Mortality from all cancers combined was slightly but significantly elevated in the overall cohort (SMR, 115; 95 percent confidence interval, 102 to 130) and was higher in the subcohort with greater than or equal to 1 year of exposure and greater than or equal to 20 years of latency (SMR, 146; 95 percent confidence interval, 121 to 176). This study of mortality among workers with occupational exposure to TCDD does not confirm the high relative risks reported for many cancers in previous studies. Conclusions about an increase in the risk of soft-tissue sarcoma are limited by small numbers and misclassification on death certificates.

  10. Gestational 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure effects on sensory cortex function.

    PubMed

    Hood, Darryl B; Woods, Letha; Brown, La'nissa; Johnson, Salynn; Ebner, Ford F

    2006-12-01

    Gestational exposure to environmental contaminants such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) poses a significant threat to normal growth and differentiation of the developing brain. To characterize the impact of gestational TCDD exposure on subsequent cortical function, pregnant Long Evans rats were exposed to a single acute dose (100 or 700ng/kg b.w. via gavage) on gestational day 15. This dosing regimen had no significant effect on birth index. After the TCDD-exposed animals were born and reached maturity, neural activity was recorded under urethane anesthesia from neurons in primary somatic sensory cortex. Spontaneous activity was reduced by approximately 50% in barrel cortex compared to corn oil vehicle controls. The magnitude of neuronal response to sensory (whisker) stimuli also was significantly reduced, and responses did not achieve control levels at any stimulus intensity. The greatest deficit was in the short latency component of the cortical responses. These decrements in cortical responsiveness were present in young F1 generation TCDD-exposed animals and persisted for up to 180 days. Because glutamate receptors are crucial to the evoked responses and show developmental regulation, selected iontotropic glutamate receptor subunits (NMDA NR2A+NR2B and GluR1) were profiled for RNA levels in the cortex of F1 generation rats. The expression of NR2B (NMDA receptor) and GluR1 (AMPA receptor) subunits was significantly reduced in the TCDD-exposed F1 generation animals compared to vehicle controls. The results indicate that gestational TCDD exposure results in cortical deficits that are paralled by diminished expression of certain NMDA and AMPA receptor subunits at a time when synapses are being formed for the first time in cortex.

  11. Nevada Test Site Radionuclide Inventory and Distribution Program: Report No. 3, Areas 3, 7, 8, 9, and 10

    SciTech Connect

    McArthur, R D; Mead, S W

    1987-02-01

    As part of the Nevada Test Site Radionuclide Inventory and Distribution Program, 115 soil samples were collected and more than 1200 in situ measurements of gamma-emitting radionuclides were made in the northern and eastern parts of Yucca Flat. Analysis of the data led to estimated inventories of 215 Ci of /sup 239,240/Pu, 128 Ci of /sup 137/Cs, 92 Ci of /sup 90/Sr, 36 Ci each of /sup 241/Am and /sup 60/Co, 31 Ci of /sup 102m/Rh, 27 Ci of /sup 238/Pu, 25 Ci of /sup 174/Lu, 10 Ci of /sup 152/Eu, 8 Ci of /sup 155/Eu, 7 Ci of /sup 154/Eu, 5 Ci of /sup 125/Sb, 4 Ci of /sup 101/Rh, and 2 Ci of /sup 134/Cs in the surface soil of the accessible portion of Areas 8 and 10. Similar calculations with the data from Areas 3, 7, and 9 gave estimates of 145 Ci of /sup 239,240/Pu, 89 Ci of /sup 152/Eu, 62 Ci of /sup 90/Sr, 25 Ci of /sup 137/Cs, 14 Ci of /sup 154/Eu, 11 Ci of /sup 241/Am, 6 Ci each of /sup 60/Co and /sup 238/Pu, and 4 Ci of /sup 155/Eu. Additional in situ measurements at 30 locations in the southern part of Yucca Flat confirmed the low levels of radioactivity found there by an aerial survey. 1 ref., 57 figs., 10 tabs.

  12. Fate of 3-tert-Butyl-4-hydroxyanisole, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8- hexamethylcyclopenta(g)-2-benzopyrane and chlorpyrifos in a Conventional Wastewater Treatement Plant

    NASA Astrophysics Data System (ADS)

    Thomas, S. M.; Bodour, A.; Inniss, E. C.; Murray, K. E.

    2007-12-01

    Emerging contaminants (ECs) are a major concern in the environment, particularly those found in waters. Wastewater treatment plants (WWTPs) play a key role in reducing the concentrations in the environment because compounds may be transformed under either aerobic or anaerobic conditions or may sorb to wastewater sludges and therefore be removed from waters. If these ECs are not contained or treated then effluent discharged from the WWTP and to a receiving stream may contain hazardous levels of these contaminants. Reported here is a study of the fate of three emerging contaminants (ECs): 3-tert-Butyl-4-hydroxyanisole (BHA), 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta(g)-2-benzopyrane (HHCB) and chlorpyrifos. Experiments were conducted on a laboratory scale by emulating conditions of a conventional WWTP in San Antonio, TX. The goal of the research was to determine general characteristics for both sorption (to wastewater sludges) and degradation. The sorption experiments were performed by exposing the sludge to a variety of initial concentration of ECs for 24 hours. After exposure these three ECs were extracted and analyzed using gas chromatography followed by flame ionization detector (GC/FID). Sorption experiments indicated that HHCB and chlorpyrifos are more hydrophobic than BHA and, therefore, would be mostly contained in the sludges. The degradation rates for these ECs were also considered for both aerobic and anaerobic conditions using different bench-scale reactor setups for 21 days. The differences between the reactor setups included volume of reactor, amount of sludge, mode of supply of nutrients and acclimatization of sludge to the ECs. One sludge was first acclimated to EC concentrations and then used in the experiment. The acclimated reactor had reaction rate constants approximately double that of the non-acclimated sludge reactor setups and followed first order reaction kinetics. Aerobic degradation occurred more readily for all three compounds

  13. 7 CFR 8.7 - Continued use.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Agriculture, United States Department of Agriculture, for approval. (b) ... 7 Agriculture 1 2014-01-01 2014-01-01 false Continued use. 8.7 Section 8.7 Agriculture Office of the Secretary of Agriculture 4-H CLUB NAME AND EMBLEM § 8.7 Continued use. (a) The...

  14. 7 CFR 8.7 - Continued use.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Agriculture, United States Department of Agriculture, for approval. (b) ... 7 Agriculture 1 2013-01-01 2013-01-01 false Continued use. 8.7 Section 8.7 Agriculture Office of the Secretary of Agriculture 4-H CLUB NAME AND EMBLEM § 8.7 Continued use. (a) The...

  15. 7 CFR 8.7 - Continued use.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Agriculture, United States Department of Agriculture, for approval. (b) ... 7 Agriculture 1 2012-01-01 2012-01-01 false Continued use. 8.7 Section 8.7 Agriculture Office of the Secretary of Agriculture 4-H CLUB NAME AND EMBLEM § 8.7 Continued use. (a) The...

  16. 7 CFR 8.7 - Continued use.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Continued use. 8.7 Section 8.7 Agriculture Office of the Secretary of Agriculture 4-H CLUB NAME AND EMBLEM § 8.7 Continued use. (a) The Cooperative Extension Services, land-grant institutions, local 4-H Clubs and groups and other officially affiliated...

  17. Process for manufacturing bis(2-methoxyethyl)-2,3,6,7-tetracyano-1,4,5,8,9,10-hexazaanthracene

    DOEpatents

    Rasmussen, Paul George; Lawton, Richard Graham

    2014-06-03

    A process to manufacture substituted tetracyano-hexaazatricyclics with the substitutions occurring at the 9 and 10 hydrogens. The process begins with 2,3-dichloro-5,6-dicyanopyrazine, which is reacted to form the desired tetracyano-hexaazatricyclic. Different process embodiments enable different reaction paths to the desired tetracyano-hexaazatricyclic. Different tetracyano-hexaazatricyclic embodiments include bis(2-methoxyethyl)-2,3,6,7-tetracyano-1,4,5,8,9,10-hexazaanthracene and bis(2-methoxyethoxyethyl)-2,3,6,7-tetracyano-1,4,5,8,9,10-hexazaanthracen- e.

  18. Synthesis, characterization, stereochemistry and antibacterial activity of N-acyl-2,4,6,8-tetraphenyl-3,7-diazabicyclo[3.3.1]nonanes

    NASA Astrophysics Data System (ADS)

    Ponnuswamy, S.; Pushpalatha, S.; Akila, A.; Raghuvarman, B.; Aravindhan, S.

    2016-12-01

    Three new N-acyl-2,4,6,8-tetraphenyl-3,7-diazabicyclo[3.3.1]nonanes 3-5 have been synthesized. The structural characterization and the conformational preferences of the compounds 3-5 have been carried out using IR, 1D and 2D NMR spectral data. The NMR spectral data indicate that the N-acyl-2,4,6,8-tetraphenyl-3,7-diazabicyclo[3.3.1]nonanes 3-5 prefer to exist in twin-chair conformation with partial flattening at amide nitrogen end. In order to avoid A1,3-strain with coplanar acyl groups, the phenyl groups at the amide nitrogen end are forced to occupy axial orientation. X-ray crystal structure of the N-dichloroacetyl-2,4,6,8-tetraphenyl-3,7-diazabicyclo[3.3.1]nonane 4 also supports the twin-chair conformation in the solid state. Furthermore, the antibacterial activity for the compounds 2-5 has been carried out.

  19. The concentration and distribution of 2,3,7,8-dibenzo-p-dioxins/-furans in chickens

    NASA Technical Reports Server (NTRS)

    Ferrario, J.; Byrne, C.

    2000-01-01

    The concentrations of the 2,3,7,8-Cl substituted dibenzo-p-dioxins/-furans (PCDDs/PCDFs) were determined in the edible tissues of whole chicken fryers and compared with the values found in their abdominal fat. The values are presented both on a whole weight basis and on a lipid adjusted basis for each tissue. While there is a marked difference in the concentration of the 2,3,7,8-dibenzo-p-dioxins in the edible tissues expressed on a whole weight basis, the lipid-adjusted concentrations of the individual dioxins were not statistically different in the various tissues. This validates the use of lipid adjusted concentrations of 2,3,7,8-PCDDs/PCDFs in abdominal fat for the determination of the presence of these compounds in different tissues.

  20. Development, characterization, and biological properties of meningococcal immunotype L3,7,(8),9-specific monoclonal antibodies.

    PubMed Central

    Verheul, A F; Kuipers, A J; Braat, A K; Dekker, H A; Peeters, C C; Snippe, H; Poolman, J T

    1994-01-01

    In this study, we characterize the properties of nine monoclonal antibodies (MAbs) that recognize meningococcal lipopolysaccharides (LPS). The following three specific MAbs that had not been described previously were elicited in BALB/c mice by using an immunotype L3,7,9 oligosaccharide-tetanus toxoid conjugate in combination with Quil A: 4D1-B3, 3A12-E1, and 4A8-B2. These MAbs reacted with L3,7,9 LPS on immunoblots and in the LPS enzyme-linked immunosorbent assay (ELISA) and recognised strains containing L3, L3,7, L8 (except 3A12-E1), or L9 LPS in the whole-cell ELISA. The six other MAbs have been described in previous studies (K. Saukkonen, M. Leinonen, H. Abdillahi, and J.T. Poolman, Vaccine 7:325-328, 1989; R.J.P.M. Scholten, B. Kuipers, H.A. Valkenburg, J. Danjert, W.D. Zollinger, and J.T. Poolman, J. Med. Microbiol., in press) and were obtained after immunization with outer membrane protein complexes containing LPS: MN15A11, MN15A8-1, MN15A17-1, MN11A11G, MN14F20-11, and MN14F21-11. MN15A11 was specific for L3,7,9 LPS and displayed properties similar to those of 3A12-E1. MN15A17-1, MN14F20-1, and MN11A11G were cross-reactive, and MN14F21-11 was specific for the L1,8 immunotype. Epitope specificities of MAbs reacting with L3,7,(8),9 strains were analyzed. MAbs 4D1-B3, 3A12-E1, and 4A8-B2 recognized phosphoethanolamine group-containing oligosaccharide-specific epitopes. MN15A11 and MN15A17-1 were probably directed against a conformational epitope, although for MN5A11 recognition of an unknown L3,7,9-specific epitope in the 2-keto-3-deoxyoctulosonic acid (KDO)-lipid A region cannot be excluded. MN15A8-1, a strongly cross-reactive MAb, recognized a determinant which included the KDO-lipid A region and the more terminal saccharides.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8556528

  1. Shigella IpaH7.8 E3 ubiquitin ligase targets glomulin and activates inflammasomes to demolish macrophages

    PubMed Central

    Suzuki, Shiho; Mimuro, Hitomi; Kim, Minsoo; Ogawa, Michinaga; Ashida, Hiroshi; Toyotome, Takahito; Franchi, Luigi; Suzuki, Masato; Sanada, Takahito; Suzuki, Toshihiko; Tsutsui, Hiroko; Núñez, Gabriel; Sasakawa, Chihiro

    2014-01-01

    When nucleotide-binding oligomerization domain–like receptors (NLRs) sense cytosolic-invading bacteria, they induce the formation of inflammasomes and initiate an innate immune response. In quiescent cells, inflammasome activity is tightly regulated to prevent excess inflammation and cell death. Many bacterial pathogens provoke inflammasome activity and induce inflammatory responses, including cell death, by delivering type III secreted effectors, the rod component flagellin, and toxins. Recent studies indicated that Shigella deploy multiple mechanisms to stimulate NLR inflammasomes through type III secretion during infection. Here, we show that Shigella induces rapid macrophage cell death by delivering the invasion plasmid antigen H7.8 (IpaH7.8) enzyme 3 (E3) ubiquitin ligase effector via the type III secretion system, thereby activating the NLR family pyrin domain-containing 3 (NLRP3) and NLR family CARD domain-containing 4 (NLRC4) inflammasomes and caspase-1 and leading to macrophage cell death in an IpaH7.8 E3 ligase-dependent manner. Mice infected with Shigella possessing IpaH7.8, but not with Shigella possessing an IpaH7.8 E3 ligase-null mutant, exhibited enhanced bacterial multiplication. We defined glomulin/flagellar-associated protein 68 (GLMN) as an IpaH7.8 target involved in IpaH7.8 E3 ligase-dependent inflammasome activation. This protein originally was identified through its association with glomuvenous malformations and more recently was described as a member of a Cullin ring ligase inhibitor. Modifying GLMN levels through overexpression or knockdown led to reduced or augmented inflammasome activation, respectively. Macrophages stimulated with lipopolysaccharide/ATP induced GLMN puncta that localized with the active form of caspase-1. Macrophages from GLMN+/− mice were more responsive to inflammasome activation than those from GLMN+/+ mice. Together, these results highlight a unique bacterial adaptation that hijacks inflammasome activation via

  2. SORPTION OF 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN TO SOILS FROM WATER/METHANOL MIXTURES

    EPA Science Inventory

    Sorption of 14C-labeled 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to soils from water/methanol mixtures has been evaluated by batch shake testing. Uncontaminated soils from Times Beach, MO, were used in these experiments and ranged in fraction organic carbon (U...

  3. TERATOGENIC RESPONSES OF TGFALPHA KNOCKOUT FETUSES TO 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD)

    EPA Science Inventory

    ABBOTT1, B.D., A.R. BUCKALEW1, and P.L. BRYANT2. 1Reproductive Toxicology Division, EPA, RAP, NC; 2Dept. Environ. Sciences & Engineering, UNC, Chapel Hill, NC. Teratogenic responses of TGF knockout fetuses to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD).

    TCDD induces cl...

  4. CYP1A2 IS NOT REQUIRED FOR 2, 3, 7, 8-TETRACHLORODIBENZO-P-DIOXIN-INDUCED IMMUNOSUPPRESSION

    EPA Science Inventory

    ABSTRACT
    One of the most sensitive and reproducible immunotoxic endpoints of 2,3,7,8-tetrachloro-dibenzo-p-dioxin (TCDD) exposure is suppression of the antibody response to sheep red blood cells (SRBCs) in mice. Immunosuppression occurs in concert with hepatomegaly and associ...

  5. Fine Mutational Analysis of 2B8 and 3H7 Tag Epitopes with Corresponding Specific Monoclonal Antibodies.

    PubMed

    Kim, Tae-Lim; Cho, Man-Ho; Sangsawang, Kanidta; Bhoo, Seong Hee

    2016-06-30

    Bacteriophytochromes are phytochrome-like light-sensing photoreceptors that use biliverdin as a chromophore. To study the biochemical properties of the Deinococcus radiodurans bacteriophytochrome (DrBphP) protein, two anti-DrBphP mouse monoclonal antibodies (2B8 and 3H7) were generated. Their specific epitopes were identified in our previous report. We present here fine epitope mapping of these two antibodies by using truncation and substitution of original epitope sequences in order to identify minimized epitope peptides. The previously reported original epitope sequences for 2B8 and 3H7 were truncated from both sides. Our analysis showed that the minimal peptide sequence lengths for 2B8 and 3H7 antibodies were nine amino acids (RDPLPFFPP) and six amino acids (PGEIEE), respectively. We further characterized these peptides in order to investigate their reactivity after single deletion and single substitution of the original peptides. We found that single-substituted 2B8 epitope (RDPLPAFPP) and dual-substituted 3H7 epitope (PGEIAD) showed significantly increased reactivity. These two antibodies with high reactivity for the short modified peptide sequences are valueble for developing new peptide tags for protein research.

  6. Fine Mutational Analysis of 2B8 and 3H7 Tag Epitopes with Corresponding Specific Monoclonal Antibodies

    PubMed Central

    Kim, Tae-Lim; Cho, Man-Ho; Sangsawang, Kanidta; Bhoo, Seong Hee

    2016-01-01

    Bacteriophytochromes are phytochrome-like light-sensing photoreceptors that use biliverdin as a chromophore. To study the biochemical properties of the Deinococcus radiodurans bacteriophytochrome (DrBphP) protein, two anti-DrBphP mouse monoclonal antibodies (2B8 and 3H7) were generated. Their specific epitopes were identified in our previous report. We present here fine epitope mapping of these two antibodies by using truncation and substitution of original epitope sequences in order to identify minimized epitope peptides. The previously reported original epitope sequences for 2B8 and 3H7 were truncated from both sides. Our analysis showed that the minimal peptide sequence lengths for 2B8 and 3H7 antibodies were nine amino acids (RDPLPFFPP) and six amino acids (PGEIEE), respectively. We further characterized these peptides in order to investigate their reactivity after single deletion and single substitution of the original peptides. We found that single-substituted 2B8 epitope (RDPLPAFPP) and dual-substituted 3H7 epitope (PGEIAD) showed significantly increased reactivity. These two antibodies with high reactivity for the short modified peptide sequences are valueble for developing new peptide tags for protein research. PMID:27137090

  7. THE CONCENTRATION AND DISTRIBUTION OF 2,3,7,8-DIBENZO-P-DIOXINS / - FURANS IN CHICKENS

    EPA Science Inventory

    The concentrations of 2,3,7,8-Cl substituted dibenzo-p-dioxins/-furans (PCDDs/PCDFs) were determined in the edible tissues of whole chicken fryers and compared with the values found in their abdominal fat. The values are presented both on a whole weight basis and on a lipid-adju...

  8. Percutaneous Absorption of 2,3,7,8-Tetrachlorodibenzo-P-Dioxin (TCDD) From Soil (Journal Article)

    EPA Science Inventory

    Eight dermal absorption (two in vivo; six in vitro) and one intravenous experiment were conducted using 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) either neat (high dose at ~250 µg/cm2 and low dose at 10 ng/cm2) or sorbed on a low organic (LOS) or high organic (HOS) soil at 1 ppm...

  9. Li-Ion Conduction and Stability of Perovskite Li3/8Sr7/16Hf1/4Ta3/4O3.

    PubMed

    Huang, Bing; Xu, Biyi; Li, Yutao; Zhou, Weidong; You, Ya; Zhong, Shengwen; Wang, Chang-An; Goodenough, John B

    2016-06-15

    A solid Li-ion conductor with a high room temperature Li-ion conductivity and small interfacial resistance is required for its application in next-generation Li-ion batteries. Here, we prepared a cubic perovskite-related oxide with the general formula Li3/8Sr7/16Hf1/4Ta3/4O3 (LSHT) by a conventional solid-state reaction method, which was studied by X-ray diffraction, electrochemical impedance spectroscopy, and (7)Li MAS NMR. Li3/8Sr7/16Hf1/4Ta3/4O3 has a high Li-ion conductivity of 3.8 × 10(-4) S cm(-1) at 25 °C and a low activation energy of 0.36 eV in the temperature range 298-430 K. It exhibits both high stability and small interfacial resistance with commercial organic liquid electrolytes, which makes it promising as a separator in Li-ion batteries.

  10. Plate Tectonics at 3.8-3.7 Ga: Field Evidence from the Isua Accretionary Complex, Southern West Greenland.

    PubMed

    Komiya; Maruyama; Masuda; Nohda; Hayashi; Okamoto

    1999-09-01

    A 1&rcolon;5000 scale mapping was performed in the Isukasia area of the ca. 3.8-Ga Isua supracrustal belt, southern West Greenland. The mapped area is divided into three units bounded by low-angle thrusts: the Northern, Middle, and Southern Units. The Southern Unit, the best exposed, is composed of 14 subunits (horses) with similar lithostratigraphy, bound by layer-parallel thrusts. Duplex structures are widespread in the Isua belt and vary in scale from a few meters to kilometers. Duplexing proceeded from south to north and is well documented in the relationship between link- and roof-thrusts. The reconstructed lithostratigraphy of each horse reveals a simple pattern, in ascending order, of greenstone with low-K tholeiitic composition with or without pillow lava structures, chert/banded iron-formation, and turbidites. The cherts and underlying low-K tholeiites do not contain continent- or arc-derived material. The lithostratigraphy is quite similar to Phanerozoic "oceanic plate stratigraphy," except for the abundance of mafic material in the turbidites. The evidence of duplex structures and oceanic plate stratigraphy indicates that the Isua supracrustal belt is the oldest accretionary complex in the world. The dominantly mafic turbidite composition suggests that the accretionary complex was formed in an intraoceanic environment comparable to the present-day western Pacific Ocean. The duplex polarity suggests that an older accretionary complex should occur to the south of the Isua complex. Moreover, the presence of seawater (documented by a thick, pillow, lava unit at the bottom of oceanic plate stratigraphy) indicates that the surface temperature was less than ca. 100 degrees C in the Early Archean. The oceanic geotherm for the Early Archean lithosphere as a function of age was calculated based on a model of transient half-space cooling at given parameters of surface and mantle temperatures of 100 degrees and 1450 degrees C, respectively, suggesting that the

  11. 8 CFR 287.7 - Detainer provisions under section 287(d)(3) of the Act.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...) of the Act. 287.7 Section 287.7 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION... chapter 1. Any authorized immigration officer may at any time issue a Form I-247, Immigration Detainer...; (4) Immigration inspectors; (5) Adjudications officers; (6) Immigration enforcement agents;...

  12. 8 CFR 287.7 - Detainer provisions under section 287(d)(3) of the Act.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...) of the Act. 287.7 Section 287.7 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION... chapter 1. Any authorized immigration officer may at any time issue a Form I-247, Immigration Detainer...; (4) Immigration inspectors; (5) Adjudications officers; (6) Immigration enforcement agents;...

  13. 8 CFR 287.7 - Detainer provisions under section 287(d)(3) of the Act.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...) of the Act. 287.7 Section 287.7 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION... chapter 1. Any authorized immigration officer may at any time issue a Form I-247, Immigration Detainer...; (4) Immigration inspectors; (5) Adjudications officers; (6) Immigration enforcement agents;...

  14. 8 CFR 287.7 - Detainer provisions under section 287(d)(3) of the Act.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...) of the Act. 287.7 Section 287.7 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION... chapter 1. Any authorized immigration officer may at any time issue a Form I-247, Immigration Detainer...; (4) Immigration inspectors; (5) Adjudications officers; (6) Immigration enforcement agents;...

  15. Molecular modelling, synthesis and acetylcholinesterase inhibition of ethyl 5-amino-2-methyl-6,7,8,9-tetrahydrobenzo[b][1,8]naphthyridine-3-carboxylate.

    PubMed

    Soriano, Elena; Samadi, Abdelouahid; Chioua, Mourad; de los Ríos, Cristóbal; Marco-Contelles, José

    2010-05-01

    In silico analysis of ethyl 5-amino-2-methyl-6,7,8,9-tetrahydrobenzo[b][1,8]naphthyridine-3-carboxylate (2) predicts that this molecule should be successfully docked in the PAS, and easily accommodated in the CAS of AChE. The synthesis and the AChE/BuChE inhibition studies are reported, confirming that compound 2 is a potent and selective AChE inhibitor, and consequently, a new lead compound for further development into new dual CAS/PAS cholinergic agents for the treatment of Alzheimer's disease.

  16. 28 CFR 8.7 - Judicial forfeiture.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Judicial forfeiture. 8.7 Section 8.7 Judicial Administration DEPARTMENT OF JUSTICE FBI FORFEITURE AUTHORITY FOR CERTAIN STATUTES § 8.7 Judicial... 5312(a)(3) of title 31 of the United States Code, the Special Agent in Charge of the FBI field...

  17. 28 CFR 8.7 - Judicial forfeiture.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 1 2012-07-01 2012-07-01 false Judicial forfeiture. 8.7 Section 8.7 Judicial Administration DEPARTMENT OF JUSTICE FBI FORFEITURE AUTHORITY FOR CERTAIN STATUTES § 8.7 Judicial... 5312(a)(3) of title 31 of the United States Code, the Special Agent in Charge of the FBI field...

  18. 28 CFR 8.7 - Judicial forfeiture.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 1 2011-07-01 2011-07-01 false Judicial forfeiture. 8.7 Section 8.7 Judicial Administration DEPARTMENT OF JUSTICE FBI FORFEITURE AUTHORITY FOR CERTAIN STATUTES § 8.7 Judicial... 5312(a)(3) of title 31 of the United States Code, the Special Agent in Charge of the FBI field...

  19. (9S,13R,14R)-7,8-Didehydro-3,4,7-trimeth-oxy-17-methyl-morphinan-6-one.

    PubMed

    Li, Yu-Feng; Qian, Yi; Yin, Li-He; Lv, Ran; Zhu, Hong-Jun

    2009-03-06

    The title compound, C(20)H(25)NO(4), was synthesized by a Mitsunobu reaction of sinomenine [(9S,13R,14R)-7,8-didehydro-4-hydroxy-3,7-dimethoxy-17-methylmorphinan-6-one] with methanol. The chiral centers were unchanged during the reaction. Intra-molecular C-H⋯O hydrogen bonds result in the formation of six-membered rings.

  20. Crystal structure of 7,8-di-chloro-4-oxo-4H-chromene-3-carbaldehyde.

    PubMed

    Ishikawa, Yoshinobu

    2015-08-01

    In the title compound, C10H4Cl2O3, a dichlorinated 3-formyl-chromone derivative, the fused-ring system is slightly puckered [dihedral angle between the benzene and pyran rings = 3.66 (10)°]. The dihedral angle between the pyran ring and the formyl plane is 8.64 (7)°. In the crystal, mol-ecules are linked through π-π stacking inter-actions [centroid-centroid distance between the benzene and pyran rings = 3.727 (2) Å], C-H⋯O hydrogen bonds and short C⋯O contacts [2.838 (4) Å]. Halogen bonds between the formyl O atoms and the Cl atoms at the 7-position [Cl⋯O = 2.984 (3) Å, C-Cl⋯O = 170.83 (12)° and Cl⋯O-C = 116.05 (19)°] are also formed along the a axis, resulting in helical structures constructed by C-H⋯O hydrogen bonds and Cl⋯O halogen bonds along the b axis. In addition, type II halogen-halogen contacts between the chlorine atoms at the 7- and 8-positions [Cl⋯Cl = 3.519 (2) Å, C-Cl⋯Cl = 171.24 (10)° and 88.74 (11)°] are observed.

  1. The synthesis and formation process of a new cubic conductive Cu7O(8-y)(NO3) compound

    NASA Astrophysics Data System (ADS)

    Yazawa, Ichiro; Sugise, Ryoji; Terada, Norio; Jo, Masatoshi; Oka, Kunihiko

    1990-08-01

    The synthesis and formation process of a new cubic conductive Cu7O(8-y)(NO3) compound was studied. This material was formed as an intermediate compound in the decomposition process of copper nitrate by a firing process in oxygen flowing gas. It has a CuO2 plane in its lattice structure and is a parent material of the new metallic copper oxide compounds.

  2. An analytical and experimental investigation of a 1.8 by 3.7 meter Fresnel lens solar concentrator

    NASA Technical Reports Server (NTRS)

    Hastings, L. J.; Allums, S. L.; Jensen, W. S.

    1977-01-01

    Line-focusing acrylic Fresnel lenses with application potential in the 200-370 C range are being analytically and experimentally investigated. The measured solar concentration characteristics of a 1.8 by 3.7 m lens and its utilization in a solar collection mode are summarized in this paper. A peak concentration ratio of 64 with 90% of the transmitted energy focused into a 5 cm width was achieved and demonstrated the feasibility of the Fresnel lens solar concentrator concept.

  3. DIVWAG Model Documentation. Volume II. Programmer/Analyst Manual. Part 3. Chapter 7 Through 8.

    DTIC Science & Technology

    1976-07-01

    weapon types q carried by the same trans- port as weapon type i. The model utilizes Gauss -Legendre integration, the 10-point formula, to evaluate... Gauss -Legendre 10-point fohmula. he values of these parameters are specified in Equation IV-7-142e: w 1 0.295524225 ri = 0.148874339 w 2 - 0.269266719...firing of all transports within each unit. The true kill fractions are obtained by Gauss -Legendre inte- gration with the results given in Equation IV

  4. Investigation of ionospheric TEC precursors related to the M7.8 Nepal and M8.3 Chile earthquakes in 2015 based on spectral and statistical analysis

    NASA Astrophysics Data System (ADS)

    ikonomouE, Christina; Haralambous, Haris; Muslim, Buldan

    2016-10-01

    Ionospheric total electron content (TEC) variations prior to 2 large earthquakes in Nepal (M = 7.8) and Chile (M = 8.3) in 2015 were analyzed using measurements from global navigation satellite system network with the aim to detect possible ionospheric anomalies associated to these seismic events and describe their main features, by applying statistical and spectral analysis. It was shown that abnormal TEC variations appeared few days up to few hours before the events lasting up to 8 h, whereas intensified TEC wave-like oscillations with periods 20 and 2-5 min were also identified that could be linked to the impending earthquakes. An unusual modification of the equatorial ionospheric anomaly 5 days before the main shock was also detected. Spectral analysis on TEC satellite measurements proved an effective method for the discrimination between seismically induced ionospheric waves and those of different origin such as the solar terminator transition and geomagnetic storms

  5. 2,3,4,7,8-Pentachlorodibenzofuran is far less potent than 2,3,7,8-tetrachlorodibenzo-p-dioxin in disrupting the pituitary–gonad axis of the rat fetus

    SciTech Connect

    Taura, Junki; Takeda, Tomoki; Fujii, Misaki; Hattori, Yukiko; Ishii, Yuji; Kuroki, Hiroaki; Tsukimori, Kiyomi; Uchi, Hiroshi; Furue, Masutaka; Yamada, Hideyuki

    2014-11-15

    The effect of 2,3,4,7,8-pentachlorodibenzofuran (PnCDF) on the fetal pituitary–gonad axis was compared with that produced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in Wistar rats. Maternal treatment at gestational day (GD) 15 with PnCDF and TCDD reduced the fetal expression at GD20 of pituitary luteinizing hormone (LH) and the testicular proteins necessary for steroidogenesis. The relative potencies of PnCDF ranged from 1/42nd to 1/63rd of the TCDD effect. While PnCDF, at a dose sufficient to cause a reduction in fetal LH, provoked defects in sexual behavior at adulthood, a dose less than the ED{sub 50} failed to produce any abnormality. There was a loss of fetal body weight following in utero exposure to PnCDF, and the effect of PnCDF was also much less than that of TCDD. The disturbance in fetal growth was suggested to be due to a reduction in the level of fetal growth hormone (GH) by dioxins. The disorder caused by PnCDF/TCDD in the fetal pituitary–gonad axis occurred at doses less than those needed to cause wasting syndrome in pubertal rats. The harmful effect of PnCDF relative to TCDD was more pronounced in fetal rats than in pubertal rats. These lines of evidence suggest that: 1) PnCDF as well as TCDD imprints defects in sexual behavior by disrupting the fetal pituitary–gonad axis; 2) these dioxins hinder fetal growth by reducing the expression of fetal GH; and 3) the fetal effects of PnCDF/TCDD are more sensitive than sub-acute toxicity during puberty, and the relative effect of PnCDF varies markedly depending on the indices used. - Highlights: • 2,3,4,7,8-Pentachlorodibenzofuran (PnCDF) lowers gonadal steroidogenesis in fetuses. • PnCDF exerts the above effect through an initial attenuation in gonadotropin level. • PnCDF imprints sexual immaturity by transiently disrupting the pituitary–gonad axis. • PnCDF also disturbs pup growth probably due to a reduction in growth hormone level. • The above effects are far lesser in PnCDF than 2,3,7,8

  6. Iterative Approach to the Discovery of Novel Degarelix Analogues: Substitutions at Positions 3, 7 and 8. Part II

    PubMed Central

    Samant, Manoj P.; Gulyas, Jozsef; Hong, Doley J.; Croston, Glenn; Rivier, Catherine; Rivier, Jean

    2008-01-01

    Degarelix, (FE200486, Ac-d-2Nal1-d-4Cpa2-d-3Pal3-Ser4-4Aph(l-Hor)5-d-4Aph(Cbm)6-Leu7-Ilys8-Pro9-d-Ala10-NH2) is a potent and very long acting antagonist of gonadotropin-releasing hormone (GnRH) after subcutaneous administration in mammals including humans. Analogues of degarelix were synthesized, characterized and screened for the antagonism of GnRH-induced response in a reporter gene assay in HEK-293 cells expressing the human GnRH receptor. The duration of action was also determined in the castrated male rat assay in order to measure the extent (efficacy and duration of action) of inhibition of luteinizing hormone (LH) release. Structurally, this series of analogues has novel substitutions at positions 3, 7, 8 and Nα-methylation at positions 6, 7 and 8 in the structure of degarelix. These substitutions were designed to probe the spatial limitations of the receptors cavity and to map the steric and ionic boundaries. Some functional groups were introduced that were hypothesized to influence the phamacokinetic properties of the analogues like bioavailability, solubility, intra- or inter-molecular hydrogen bond forming capacity and ability to bind carrier proteins. Substitutions at positions 3 ([Nβ-(2-pyridyl-methyl)d-Dap3]degarelix, IC50 = 2.71 nM) (5), 7 ([Pra7]degarelix, IC50 = 2.11 nM) (16), 8 ([Nδ-(IGly)Orn8]degarelix, IC50 = 1.38 nM) (20), and N-methylation ([Nα-methyl-Leu7]degarelix, IC50 = 1.47 nM) (32) yielded analogues that were equipotent to degarelix (2) in vitro (IC50 = 1.64 nM) but shorter acting in vivo. Out of the 33 novel analogues tested for the duration of action in this series, two analogues ([Nε-cyclohexyl-Lys8]degarelix, IC50 = 1.50 nM) (23) and ([Nβ-(IβAla)Dap8]degarelix, IC50 = 1.98 nM) (26) had antagonist potencies and duration of action similar to that of azaline B {inhibited LH (>80%) release for >72 h after sc injection to castrated male rats at a standard dose of 50 µg/rat in 5% mannitol}. Under similar conditions analogues ([N

  7. Theoretical vibrations of carbon chains C3, C4, C5, C6, C7, C8, and C9

    NASA Technical Reports Server (NTRS)

    Kurtz, Joe; Adamowicz, Ludwik

    1991-01-01

    The MBPT (2) procedure with the 6-31g (asterisk) basis set was used to study nearly linear carbon chains. The theoretical vibrational frequencies of the molecules C3 through C9 are presented and, for C3 through C6, compared to experimental stretching frequencies and their (C-13)/(C-12) isotopomers. Predictions for C7, C8, and C9 stretching frequencies are calculated by directly scaling the theoretical frequencies with factors derived from experimental-to-theoretical ratios known for the smaller molecules.

  8. Effect of thyroidectomy and thyroxine on 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced immunotoxicity

    SciTech Connect

    Pazdernik, T.L.; Rozman, K.K.

    1985-02-18

    Radiothyroidectomy protected against 2,3,7,8-tetrachloro dibenzo-p-dioxin (TCDD)-induced immunotoxicity in rats as assessed by the spleen anti-SRBC plaque-forming cell assay. Thyroxin (T/sub 4/) replacement therapy partially reversed the effects of thyroidectomy on T/sub 4/ and triiodothyronine (T/sub 3/) serum levels, body weight and immune function as well as restored TCDD-induced immunotoxicity. Thus, hypothyroidism induced by TCDD exposure can be viewed as a protective response of the organism to reduce the insult caused by TCDD.

  9. Developmental and posthatch effects of in ovo exposure to 2,3,7,8-TCDD, 2,3,4,7,8-PECDF, and 2,3,7,8-TCDF in Japanese quail (Coturnix japonica), common pheasant (Phasianus colchicus), and white leghorn chicken (Gallus gallus domesticus) embryos.

    PubMed

    Cohen-Barnhouse, Andrew M; Zwiernik, Matthew J; Link, Jane E; Fitzgerald, Scott D; Kennedy, Sean W; Giesy, John P; Wiseman, Steve; Jones, Paul D; Newsted, John L; Kay, Denise; Bursian, Steven J

    2011-07-01

    An egg injection study was conducted to confirm a proposed model of relative sensitivity of three avian species to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-like chemicals. It was previously reported that the order of species sensitivity to in ovo exposure to TCDD, 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), or 2,3,7,8-tetrachlorodibenzofuran (TCDF) at doses ranging from 0.044 to 37 picomoles (pmol)/g egg was the chicken (Gallus gallus domesticus), common pheasant (Phasianus colchicus), and Japanese quail (Coturnix japonica) based on embryo mortality and hepatic enzyme induction. In the present study, the incidence of developmental deformities, changes in body and relative organ masses, and organ pathology of hatchlings as additional indicators of species sensitivity were assessed; in addition, embryo mortality in the three species was categorized by stage of development. Embryo mortality varied temporally with significant increases generally occurring after organogenesis and just prior to hatching. A significant increase in the percentage of developmental deformities was observed only in Japanese quail exposed to TCDF. Body and relative organ masses of quail, pheasants, and chickens dosed in ovo with TCDD, PeCDF, or TCDF were not consistently affected. Chemical-related pathology occurred only in livers of quail at the greatest doses of each compound. These results indicated that the incidence of developmental deformities, changes in body and relative organ masses and organ pathology could not be used as indicators of species sensitivity or chemical potency.

  10. Diatom-derived oxylipins induce cell death in sea urchin embryos activating caspase-8 and caspase 3/7.

    PubMed

    Ruocco, Nadia; Varrella, Stefano; Romano, Giovanna; Ianora, Adrianna; Bentley, Matt G; Somma, Domenico; Leonardi, Antonio; Mellone, Stefano; Zuppa, Antonio; Costantini, Maria

    2016-07-01

    Diatoms are an important class of unicellular algae that produce bioactive secondary metabolites with cytotoxic activity collectively termed oxylipins, including polyunsaturated aldehydes (PUAs), hydroxyacids (HEPEs), oxo-acids and epoxyalcohols. Previous results showed that at higher concentrations, the PUA decadienal induced apoptosis on copepods and sea urchin embryos via caspase-3 activation; at lower concentrations decadienal affected the expression levels of the caspase-8 gene in embryos of the sea urchin Paracentrotus lividus. In the present work, we studied the effects of other common oxylipins produced by diatoms: two PUAs (heptadienal and octadienal) and four hydroxyacids (5-, 9- 11- and 15-HEPE) on P. lividus cell death and caspase activities. Our results showed that (i) at higher concentrations PUAs and HEPEs induced apoptosis in sea urchin embryos, detected by microscopic observation and through the activation of caspase-3/7 and caspase-8 measured by luminescent assays; (ii) at low concentrations, PUAs and HEPEs affected the expression levels of caspase-8 and caspase-3/7 (isolated for the first time here in P. lividus) genes, detected by Real Time qPCR. These findings have interesting implications from the ecological point of view, given the importance of diatom blooms in nutrient-rich aquatic environments.

  11. Dystonia and tremor following exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin

    SciTech Connect

    Klawans, H.L.

    1987-01-01

    Forty-seven railroad workers who were exposed to polychlorinated phenols, including dioxin (TCDD), during 1979 while cleaning up the chemical spillage following damage to a tank car filled with these chemicals were followed medically for the subsequent 6 years. Two committed suicide. The initial neurological complaints included a sense of fatigue and muscle aching, both of which have been reported in other individuals following dioxin exposure. On detailed neurological examination in December, 1985, 24 of 45 had dystonic writer's cramp and/or other action dystonias of the hands. None of the involved individuals had a family history of dystonia, and all 24 dated the onset of the dystonia to the first 2 to 3 years subsequent to their toxic exposure. The dystonias varied in severity but were usually mild. No other types of dystonic involvement were recognized. Thirty-five of the 45 individuals also manifested postural and terminal intention tremor which resembled benign essential tremor. None of the involved individuals had a family history of tremor, and all 35 of those affected dated the onset of the tremor to some time subsequent to their toxic exposure. Forty-three of 45 patients had histories and findings suggestive of peripheral neuropathy. This is the first report relating any type of dystonia to prior dioxin exposure and the first report relating action dystonia, such as dystonic writer's cramp, and postural/terminal intention tremor, to toxic exposure of any type.

  12. The tissue distribution of 2,3,7,8-chlorine substituted dibenzo-p-dioxins in humans who died of cancer

    SciTech Connect

    Muto, Hajime; Shinada, Masayuki; Abe, Touru; Takizawa, Yukio )

    1991-01-01

    The tissue distribution of 2,3,7,8-chlorine substituted dibenzo-p-dioxins was conducted in 11 patients who died of cancer. The concentration of octachlorodibenzo-p-dioxin(octa-CDD) was the highest in each organ and tissue and hepta-CDD was also found at relatively high levels, second only to OCDD. The levels of 1,2,3,7,8-penta-CDD and 1,2,3,6,7,8-hexa-CDD in the spleen were the highest, respectively. 2,3,7,8-Tetra-CDD was also detected and its concentration was the highest in the gonad. From the 2,3,7,8-TCDD toxic equivalent calculations, the highest equivalent value was obtained from a 54-year-old female who died of cancerous goiter. This individual had the highest concentrations of 2,3,7,8-substituted penta- and hexa-CDDs among the 11 patients.

  13. 8 CFR 246.7 - Appeals.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Appeals. 246.7 Section 246.7 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS RESCISSION OF ADJUSTMENT OF STATUS § 246.7 Appeals. Pursuant to 8 CFR part 3, an appeal shall lie from a decision of an immigration judge under...

  14. 8 CFR 246.7 - Appeals.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Appeals. 246.7 Section 246.7 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS RESCISSION OF ADJUSTMENT OF STATUS § 246.7 Appeals. Pursuant to 8 CFR part 3, an appeal shall lie from a decision of an immigration judge under...

  15. Effects and mechanisms of 8-prenylnaringenin on osteoblast MC3T3-E1 and osteoclast-like cells RAW264.7

    PubMed Central

    Luo, Dan; Kang, Lumei; Ma, Yuhui; Chen, Hongping; Kuang, Haibin; Huang, Qiren; He, Ming; Peng, Weijie

    2014-01-01

    8-Prenylnaringenin (8-PN) is a phytoestrogen with the highest estrogenic activity. The objective of the present study was to confirm the superiority of 8-PN on bone metabolisms and the estrogen receptor (ER) subtype mediating effects of 8-PN. The osteoblast MC3T3-E1 and osteoclast-like cell line RAW264.7 were treated with 17β-estradiol (10−8 mol/L), genistein (10−5 mol/L), daidzein (10−5 mol/L), 8-PN (10−5 mol/L) alone or in the presence of ERα antagonist MPP (10−7 mol/L) and ERβ antagonist PTHPP (1.5 × 10−7 mol/L). It has been found that 8-PN did not affect osteoblast proliferation, and that 8-PN increased alkaline phosphatase (ALP) activity, osteocalcin (OCN) concentrations, and the mineralized nodules. 8-PN inhibited RAW264.7 differentiating into osteoclasts and reduced the pit area of bone resorption. 8-PN could also inhibit the protein and mRNA expression of receptor activator of nuclear factor-κB ligand (RANKL) in osteoblasts, and conversely promote the expression of osteoprotegerin (OPG). These effects of 8-PN were mainly inhibited not by PTHPP but by MPP and they were weaker than estrogen's effects but stronger than those of genistein and daidzein. In conclusion, the effects of 8-PN on promoting osteoblastic bone formation and inhibiting osteoclastic bone resorption were mediated by ERα instead of ERβ and the efficacy was more potent than that of the two classic phytoestrogens: genistein and daidzein. PMID:25473491

  16. 2,3,7,8-Tetrachlorodibenzo-p-dioxin induces premature activation of the KLF2 regulon during thymocyte development.

    PubMed

    McMillan, Brian J; McMillan, Susanne N; Glover, Ed; Bradfield, Christopher A

    2007-04-27

    The environmental pollutant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, dioxin) causes numerous and diverse toxic events via activation of the aryl hydrocarbon receptor, including atrophy of the thymus. Exposure to TCDD induces acute thymocyte cell loss, which occurs concomitantly with proliferation arrest and premature emigration of triple negative (TN; CD4(-), CD8(-), CD3(-)) T cell progenitors. In this report, we demonstrate that TCDD exposure results in dysregulation of KLF2 (Kruppel-like factor 2) expression in developing thymocytes. The Klf2 gene encodes an Sp1-like zinc finger transcription factor that functions as a central regulator of T lymphocyte proliferation and trafficking. During normal thymocyte development, KLF2 is expressed exclusively in CD4 and CD8 single positive T cells and promotes a nonproliferative, promigratory phenotype. In mice exposed to TCDD, however, the Klf2 gene is prematurely expressed in TN thymocytes. Administration of a 100 microg/kg dose of TCDD results in a approximately 15-fold induction of KLF2 as early as the TN2 (CD44(+), CD25(+)) stage of development and immediately precedes acute cell loss in the TN3, TN4, and double positive (CD4(+), CD8(+)) cell stages. Induction of KLF2 occurs within 12 h of TCDD exposure and is fully dependent on expression of the aryl hydrocarbon receptor. In addition, TCDD exposure alters the expression of several factors comprising the KLF2 regulon, including Edg1/S1P(1), beta(7) integrin, CD52, Cdkn2d (cyclin-dependent kinase inhibitor 2D), s100a4, and IL10R alpha. These findings indicate that the pollutant TCDD interferes with early thymopoeisis via ectopic expression of the KLF2 regulon.

  17. Helix 8 and the i3 loop of the muscarinic M3 receptor are crucial sites for its regulation by the Gβ5-RGS7 complex.

    PubMed

    Karpinsky-Semper, Darla; Tayou, Junior; Levay, Konstantin; Schuchardt, Brett J; Bhat, Vikas; Volmar, Claude-Henry; Farooq, Amjad; Slepak, Vladlen Z

    2015-02-03

    The muscarinic M3 receptor (M3R) is a Gq-coupled receptor and is known to interact with many intracellular regulatory proteins. One of these molecules is Gβ5-RGS7, the permanently associated heterodimer of G protein β-subunit Gβ5 and RGS7, a regulator of G protein signaling. Gβ5-RGS7 can attenuate M3R-stimulated release of Ca(2+) from intracellular stores or enhance the influx of Ca(2+) across the plasma membrane. Here we show that deletion of amino acids 304-345 from the central portion of the i3 loop renders M3R insensitive to regulation by Gβ5-RGS7. In addition to the i3 loop, interaction of M3R with Gβ5-RGS7 requires helix 8. According to circular dichroism spectroscopy, the peptide corresponding to amino acids 548-567 in the C-terminus of M3R assumes an α-helical conformation. Substitution of Thr553 and Leu558 with Pro residues disrupts this α-helix and abolished binding to Gβ5-RGS7. Introduction of the double Pro substitution into full-length M3R (M3R(TP/LP)) prevents trafficking of the receptor to the cell surface. Using atropine or other antagonists as pharmacologic chaperones, we were able to increase the level of surface expression of the TP/LP mutant to levels comparable to that of wild-type M3R. However, M3R-stimulated calcium signaling is still severely compromised. These results show that the interaction of M3R with Gβ5-RGS7 requires helix 8 and the central portion of the i3 loop.

  18. (8aS)-7,8,8a,9-Tetra­hydro­thieno[3,2-f]indolizin-6(4H)-one

    PubMed Central

    Švorc, Ľubomír; Vrábel, Viktor; Kožíšek, Jozef; Marchalín, Štefan; Šafář, Peter

    2009-01-01

    In the mol­ecular structure of the title compound, C10H11NOS, the central six-membered ring of the indolizine unit adopts an envelope conformation, the maximum deviations from the mean plane of the ring being 0.533 (2) Å. The fused thieno ring is nearly coplanar [mean deviation = 0.007 (2) Å]. The conformation of the fused oxopyrrolidine ring is close to that of a flat-envelope, with a maximum deviation of 0.339 (3) Å. The crystal structure is stabilized by C—H⋯O hydrogen bonds. PMID:21582436

  19. (8aRS)-8,8a-Dihydro­furo[3,2-f]indolizine-6,9(4H,7H)-dione

    PubMed Central

    Vrábel, Viktor; Sivý, Július; Švorc, Łubomír; Šafář, Peter; Marchalín, Štefan

    2011-01-01

    The title compound, C10H9NO3, is a chiral mol­ecule with one stereogenic carbon atom, but which crystallizes as a racemate in the centrosymmetric space group P21/n. The central six-membered ring of the indolizine moiety adopts a definite envelope conformation, while the conformation of the oxopyrrolidine ring is close to that of a flat-envelope with a maximum deviation of 0.352 (1) Å for the flap atom. PMID:22091063

  20. Immunological abnormalities 17 years after accidental exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

    PubMed Central

    Jennings, A M; Wild, G; Ward, J D; Ward, A M

    1988-01-01

    Eighteen workers were reviewed 17 years after accidental exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (dioxin). Clinical assessment showed that they were in good health. A study of several biochemical and immunological parameters in these subjects and in 15 carefully matched controls showed no difference in serum concentrations of hepatic enzymes between exposed workers and controls. Although mean serum concentrations of cholesterol and triglyceride were higher in exposed subjects than in controls, the results did not reach statistical significance. Antinuclear antibodies and immune complexes were detected significantly more frequently in the peripheral blood of workers exposed to dioxin. There was no significant difference between exposed workers and controls in the number of T lymphocytes, B lymphocytes, and helper and suppressor T cell counts in peripheral blood, but the number of natural killer cells identified by the monoclonal antibody Leu-7 was significantly higher in workers exposed to dioxin. PMID:3264183

  1. Study on the 8He ground state via 8He(p, d)7He and 8He(p, t)6He reaction at 82.3 MeV/nucleon

    NASA Astrophysics Data System (ADS)

    Lou, J. L.; Ye, Y. L.; Pang, D. Y.; Cao, Z. X.; Jiang, D. X.

    2013-03-01

    The differential cross sections for reactions 8He(p, d)7Heg.s and 8He(p, t)6He2+ were measured by the coincidence of d + 6 He and t + 4He in a wide angular range from 15 to 130 degree in the center-of-mass system. The cross sections of the 8He(p, t)6Heg.s reaction were extremely lower than that of 8He(p, t)6He2+ reaction, and was not obtained from the present data. The experimental results were compared to the preliminary theoretical calculations in the frame of adiabatic distorted-wave approximation with the code Fresco. The results show that the configuration of (1p3/2)2(1p1/2)2 may have some probability in the ground state wave function of 8He. The cluster structure of 8He = 5H + 3H could not be neglected.

  2. Synthesis and biological evaluation of 3,7-diazabicyclo[4.3.0]nonan-8-ones as potential nootropic and analgesic drugs.

    PubMed

    Martini, Elisabetta; Di Cesare Mannelli, Lorenzo; Bartolucci, Gianluca; Bertucci, Carlo; Dei, Silvia; Ghelardini, Carla; Guandalini, Luca; Manetti, Dina; Scapecchi, Serena; Teodori, Elisabetta; Romanelli, Maria Novella

    2011-04-14

    A series of cis and trans 3,7-diazabicyclo[4.3.0]nonan-8-ones has been synthesized and tested for their ability to revert scopolamine-induced amnesia in the mouse passive-avoidance test. The racemates of the most potent compounds 4 and 7 were separated and tested, but no enantioselectivity was found for the nootropic activity. Compounds 4 and 7 and their enantiomers displayed interesting antihyperalgesic activity in two models of neuropathic pain (streptozotocin-induced and oxalilplatin-induced neuropathy) in comparison with pregabalin.

  3. Validating Geant4 Versions 7.1 and 8.3 Against 6.1 for BaBar

    SciTech Connect

    Banerjee, Swagato; Brown, David N.; Chen, Chunhui; Cote, David; Dubois-Felsmann, Gregory P.; Gaponenko, Igor; Kim, Peter C.; Lockman, William S.; Neal, Homer A.; Simi, Gabriele; Telnov, Alexandre V.; Wright, Dennis H.; /SLAC

    2011-11-08

    Since 2005 and 2006, respectively, Geant4 versions 7.1 and 8.3 have been available, providing: improvements in modeling of multiple scattering; corrections to muon ionization and improved MIP signature; widening of the core of electromagnetic shower shape profiles; newer implementation of elastic scattering for hadronic processes; detailed implementation of Bertini cascade model for kaons and lambdas, and updated hadronic cross-sections from calorimeter beam tests. The effects of these changes in simulation are studied in terms of closer agreement of simulation using Geant4 versions 7.1 and 8.3 as compared to Geant4 version 6.1 with respect to data distributions of: the hit residuals of tracks in BABAR silicon vertex tracker; the photon and K{sub L}{sup 0} shower shapes in the electromagnetic calorimeter; the ratio of energy deposited in the electromagnetic calorimeter and the flux return of the magnet instrumented with a muon detection system composed of resistive plate chambers and limited-streamer tubes; and the muon identification efficiency in the muon detector system of the BABAR detector.

  4. Effects of quercetin and chrysin on 2,3,7,8-tetrachlorodibenzo-p-dioxin induced hepatotoxicity in rats.

    PubMed

    Ciftci, Osman; Vardi, Nigar; Ozdemir, Ilknur

    2013-03-01

    The objective of current study is to investigate the effects of the administration of chrysin (CH) and quercetin (Q) on rat liver in which oxidative and histological damage had been induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Rats were randomly divided into six equal groups. TCDD was orally administered at the dose of 2 μg/kg/week, and Q and CH were orally administered at the doses of 20 mg/kg day and 50 mg/kg/day, respectively, by gavages dissolved in corn oil. The liver samples to be analyzed for the determination of oxidative and histological alternations were taken from rats at 60 days. The results indicated that although 2,3,7,8-TCDD significantly induced (P ≤ 0.01) lipid peroxidation (increase of MDA levels), it positively affected oxidant/antioxidant system (a decline in the levels of GSH, CAT, GSH-Px, and CuZn-SOD) in rats significantly. The histological changes observed in the liver correlated with the biochemical findings. However, these effects of TCDD on oxidative and histological changes were eliminated by Q and CH treatment. In conclusion, TCDD caused an adverse effect on rat's liver. When Q and CH were given together with TCDD, they prevented hepatotoxicty induced by TCDD. Thus, it is thought that Q and CH may be useful as a new category of anti-TCDD toxicity agent.

  5. Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on development of anuran amphibians

    SciTech Connect

    Jung, R.E.; Walker, M.K.

    1997-02-01

    The authors exposed anuran eggs and tadpoles to vehicle control (0.7% acetone) or waterborne [{sup 3}H]2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) for 24 h and subsequently raised them in clean water. Neither American toads nor green frogs exhibited TCDD-related mortality, but leopard frogs showed significantly increased mortality over controls. Eggs and tadpoles eliminated TCDD relatively quickly compared with published data for other vertebrates, with t{sub {1/2}} of 1 to 5 d (American toad), 2 to 7 d (leopard frog), and 4 to 6 d (green frog). Elimination rates were slowest for tadpoles fed nothing, fastest for those fed a low-fat diet, and intermediate for those fed a high-fat diet. Although not significant, American toads exposed to {ge}0.03 {micro}g TCDD/L appeared to metamorphose earlier, and those exposed to higher TCDD treatments appeared to metamorphose at a larger body mass than controls. Comparisons of these results with studies of fish early life stages suggest that anuran eggs and tadpoles eliminate TCDD more rapidly and are 100- to 1,000-fold less sensitive to its deleterious effects during development. These differences may be related to differences in metabolic rate, patterns of lipid storage and utilization, and aryl hydrocarbon receptor binding and signal transduction.

  6. 2,3,7,8-Tetrachlorodibenzo-p-dioxin-mediated gene expression in the immature rat thymus.

    PubMed

    Olnes, M J; Verma, M; Kurl, R N

    1994-01-01

    To examine the effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on thymic gene expression in vitro, freshly isolated rat thymocytes were incubated with 10 nM TCDD, and reverse transcriptase polymerase chain reaction experiments were performed using primers specific for prostaglandin G/H synthase (PGHS) and glyceraldehyde 3-phosphate dehydrogenase. TCDD selectively repressed PGHS gene expression, with maximal inhibition occurring within 60 min. Gel retardation assays demonstrated that dioxin transiently induced binding of the ubiquitous transcription factor NF kappa B to its cognate response element at early time points. However, TCDD had little ability to induce transformation of the Ah receptor to the xenobiotic responsive element in thymic cytosol. These results indicate that TCDD exerts changes in thymocyte gene expression prior to inducing toxicity.

  7. Estimates of the half-life of 2,3,7,8-tetrachlorodibenzo-p-dioxin in Vietnam veterans of operation ranch hand

    SciTech Connect

    Pirkle, J.L.; Wolfe, W.H.; Patterson, D.G.; Needham, L.L.; Philips, D.L. ); Michalek, J.E.; Miner, J.C.; Peterson, M.R. )

    1989-01-01

    A half-life of 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD; commonly known as dioxin) in serum has been measured in 36 Air Force Vietnam Veterans of Operation Ranch Hand, which was the operation that aerially sprayed the herbicide Agent Orange in Vietnam. From serum specimens taken in 1982 and 1987, the median half-life of 2,3,7,8-TCDD in these Ranch Hand veterans was found to be 7.1 yr (95% confidence interval about the median of 5.8-9.6 yr). These veterans reported no civilian exposure to dioxin or herbicides. Concentrations of 2,3,7,8-TCDD in the 1982 serum specimens from these veterans ranged from 16.9 to 423 parts per trillion on a lipid weight basis. The half-life estimates were not associated with the concentration of 2,3,7,8-TCDD in the 1982 serum specimens. This half-life of 7.1 yr is much longer than the half-life of 2,3,7,8-TCDD reported in animals but is consistent with recent evidence from other human exposures to 2,3,7,8-TCDD.

  8. Dietary selenium, glutathione peroxidase activity, and toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin

    SciTech Connect

    Hassan, M.Q.; Stohs, S.J.; Murray, W.J.; Birt, D.F.

    1985-01-01

    TCDD has been shown to inhibit selenium-dependent glutathione peroxidase activity. The role of selenium in TCDD toxicity is not known. The authors have therefore examined the effect of TCDD administration on hepatic glutathione peroxidase, aryl hydrocarbon hydroxlase, glutathione reductase, and glutathione S-transferase activities, glutathione content, and lipid peroxidation in rats fed 0, 0.10, and 2.0 ppm dietary selenium. TCDD treatment significantly inhibited selenium-dependent glutathione peroxidase in animals on diets containing 0.10 and 2.0 ppm selenium. The selenium-dependent glutathione peroxidase activities in rats on 0.10 and 2.0 ppm dietary selenium were 8.3- and 4.7-fold greater than in animals fed a diet containing 0 ppm selenium. TCDD administration enhanced hepatic microsomal lipid peroxidation by factors of 4.0, 4.9, and 9.8 in animals fed diets containing 0, 0.10, and 2.0 ppm selenium, respectively. The administration of a lethal dose of TCDD to rats fed diets containing 0, 0.10, and 2.0 ppm selenium, respectively. The administration of a lethal dose of TCDD to rats fed diets containing 0, 0.10, and 2.0 ppm selenium resulted in 0, 46, and 7% survival, respectively, after 66 d. Aryl hydrocarbon hydroxylase, glutathione S-transferase, and glutathione reductase activities were induced by TCDD. The results indicate that optimum dietary selenium provides partial protection from the toxic effects of TCDD.

  9. 2,3,7,8-Tetrachlorodibenzo-p-dioxin equivalents in tissues of birds at Green Bay, Wisconsin, USA

    USGS Publications Warehouse

    Jones, Paul D.; Giesy, John P.; Newsted, John L.; Verbrugge, David A.; Beaver, Donald L.; Ankley, Gerald T.; Tillitt, Donald E.; Lodge, Keith B.; Niemi, Gerald J.

    1993-01-01

    The environment has become contaminated with complex mixtures of planar, chlorinated hydrocarbons (PCHs) such as polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and structurally similar compounds. Because the potencies of individual congeners to cause the same adverse effects vary greatly and the relative as well as absolute concentrations of individual PCH vary among samples from different locations, it is difficult to assess the toxic effects of these mixtures on wildlife. These compounds can cause a number of adverse effects, however, because the toxic effects which occur at ecologically-relevant concentrations such as embryo-lethality and birth defects appear to be mediated through the same mechanism, the potency of individual congeners can be reported relative to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) which is the most toxic congener in the PCH class. The concentations of 2,3,7,8-TCDD Equivalents (TCDD-EQ) were determined in the tissues of aquatic and terrestrial birds of Green Bay, Wisconsin by the H4IIE bioassay system and compared toxic equivalency factors (TEFs) with the concentration predicted by the use of toxic equivalency factors applied to concentrations of PCH, which were determined by instrumental analyses. Concentrations of TCDD-EQ ranged from 0.52 to 440 ng/kg, wet weight. The greatest concentrations occurred in the fish-eating birds. Concentrations of TCDD-EQ, which were determined by the two methods were significantly correlated, but the additive model which used the TEFs with concentrations of measured PCB, PCDD and PCDF congeners underestimated the concentrations of TCDD-EQ measured by the H4IIE bioassay by an average of 57%. This is thought to be due to contributions from un-quantified PCH, which are known to occur in the environment. Of the quantified PCH congeners, PCDD and PCDF contributed a small portion of the TCDD-EQ in the aquatic birds, while most of the

  10. Axially Chiral Bifunctional 8,8'-Biquinolyl: Synthesis of 7,7'-Dihydroxymethyl-8,8'-biquinolyl via Pd-Catalyzed Double C-H Oxidation of 7,7'-Dimethyl-8,8'-biquinolyl.

    PubMed

    Kitamura, Mitsuru; Fukuma, Hiroaki; Kobayashi, Mitsuaki; Okayama, Shinya; Okauchi, Tatsuo

    2016-05-06

    Bifunctional C2-symmetric 7,7'-dihydroxymethyl-8,8'-biquinolyl (2) was synthesized in short steps via (i) Cu/Pd-catalyzed homo coupling of 7-methyl-8-bromoquinoline and (ii) Pd(II)-catalyzed double C-H oxidation. Axial chirality of 2 and its synthetic precursor 7,7'-dimethyl-8,8'-biquinolyl (3) is stable. Optically active 2 was obtained through separation of racemic 2 by chiral column HPLC or Pd(II)-catalyzed double C-H oxidation of optically active 3. The absolute stereochemistry of enantiomers of 2 and 3 was determined using the exciton chirality method.

  11. Mechanism of inhibition of GluA2 AMPA receptor channel opening by 2,3-benzodiazepine derivatives: functional consequences of replacing a 7,8-methylenedioxy with a 7,8-ethylenedioxy moiety.

    PubMed

    Qneibi, Mohammad S; Micale, Nicola; Grasso, Silvana; Niu, Li

    2012-02-28

    2,3-Benzodiazepine (2,3-BDZ) compounds are a group of AMPA receptor inhibitors and are drug candidates for treating neurological diseases involving excessive AMPA receptor activity. We investigated the mechanism by which GluA2Q(flip) receptor channel opening is inhibited by two 2,3-BDZ derivatives, i.e., 1-(4-aminophenyl)-3,5-dihydro-7,8-ethylenedioxy-4H-2,3-benzodiazepin-4-one (2,3-BDZ-11-2) and its 1-(4-amino-3-chlorophenyl) analogue (2,3-BDZ-11-4). Both compounds have a 7,8-ethylenedioxy moiety instead of the 7,8-methylenedioxy feature present in the structure of GYKI 52466, the prototypic 2,3-BDZ compound. Using a laser-pulse photolysis approach with a time resolution of ~60 μs and a rapid solution flow technique, we characterized the effect of the two compounds on the channel opening process of the homomeric GluA2Q(flip) receptor. We found that both 2,3-BDZ-11-2 and 2,3-BDZ-11-4 are noncompetitive inhibitors with specificity for the closed-channel conformation of the GluA2Q(flip) receptor. However, 2,3-BDZ-11-4 is ~10-fold stronger, defined by its inhibition constant for the closed-channel conformation (i.e., K(I) = 2 μM), than 2,3-BDZ-11-2. From double-inhibitor experiments, we determined that both compounds bind to the same site, but this site is different from two other known, noncompetitive binding sites on the GluA2Q(flip) receptor previously reported. Our results provide both mechanistic clues to improve our understanding of AMPA receptor regulation and a structure-activity relationship for designing more potent 2,3-BDZ compounds with predictable properties for this new noncompetitive site.

  12. An analytical and experimental investigation of a 1.8 by 3.7 meter Fresnel lens solar concentrator

    NASA Technical Reports Server (NTRS)

    Hastings, L. J.; Allums, S. L.; Jensen, W. S.

    1977-01-01

    Line-focusing acrylic Fresnel lenses with application potential in the 200 to 370 C range are being analytically and experimentally evaluated. Investigations previously conducted with a 56 cm wide lens have been extended by the present study to experimentation/analyses with a 1.8 by 3.7 m lens. A measured peak concentration ratio of 64 with 90 percent of the transmitted energy focused into a 5.0 cm width was achieved. A peak concentration of 61 and a 90 percent target width of 4.5 cm were analytically computed. The experimental and analytical lens transmittance was 81 percent and 86 percent, respectively. The lens also was interfaced with a receiver assembly and operated in the collection mode. The collection efficiency ranged from 42 percent at 100 C to 26 percent at 300 C.

  13. Perinatal 2,3,7,8-Tetrachlorodibenzo-p-dioxin Exposure Sensitizes Offspring to Angiotensin II-induced Hypertension

    PubMed Central

    Aragon, Andrea C.; Goens, M. Beth; Carbett, Eleanor; Walker, Mary K.

    2013-01-01

    In utero and lactational exposure of mice to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) leads to cardiac hypertrophy and hydronephrosis in adulthood. We tested the hypothesis that perinatal TCDD exposure increases the susceptibility to cardiovascular disease when offspring are exposed to a common cardiovascular disease risk factor, angiotensin II (Ang II). Pregnant C57BL/6N mice were exposed to corn oil (control) or 6.0 µg/kg TCDD on gestation day 14.5. Male offspring were then exposed to a subpressor (0.1 mg/kg/d) or pressor (0.7 mg/kg/d) dose of Ang II at 3.5 mo and cardiac morphology and blood pressure analyzed, respectively. Perinatal TCDD exposure increased left ventricular cavity dilation during diastole, and wall thickness during diastole and systole. While Ang II stimulated an increase in wall thickness, the degree of increase was equivalent between control and TCDD offspring. In contrast, perinatal TCDD exposure did not alter basal blood pressure. However, Ang II increased systolic blood pressure more rapidly and to a greater degree in TCDD offspring. Further, Ang II stimulated renal myofibroblast differentiation and collagen deposition to a greater degree, and tended to increase procollagen I mRNA in TCDD offspring, compared to controls. These data suggest that perinatal TCDD exposure increases the susceptibility of offspring to renal fibrosis and hypertension in adulthood. PMID:18670907

  14. Perinatal 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure sensitizes offspring to angiotensin II-induced hypertension.

    PubMed

    Aragon, Andrea C; Goens, M Beth; Carbett, Eleanor; Walker, Mary K

    2008-01-01

    In utero and lactational exposure of mice to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) leads to cardiac hypertrophy and hydronephrosis in adulthood. We tested the hypothesis that perinatal TCDD exposure increases the susceptibility to cardiovascular disease when offspring are exposed to a common cardiovascular disease risk factor, angiotensin II (Ang II). Pregnant C57BL/6N mice were exposed to corn oil (control) or 6.0 microg/kg TCDD on gestation day 14.5. Male offspring were then exposed to a subpressor (0.1 mg/kg/day) or pressor (0.7 mg/kg/day) dose of Ang II at 3.5 months and cardiac morphology and blood pressure analyzed, respectively. Perinatal TCDD exposure increased left ventricular cavity dilation during diastole, and wall thickness during diastole and systole. While Ang II stimulated an increase in wall thickness, the degree of increase was equivalent between control and TCDD offspring. In contrast, perinatal TCDD exposure did not alter basal blood pressure. However, Ang II increased systolic blood pressure more rapidly and to a greater degree in TCDD offspring. Further, Ang II stimulated renal myofibroblast differentiation and collagen deposition to a greater degree, and tended to increase procollagen I mRNA in TCDD offspring, compared to controls. These data suggest that perinatal TCDD exposure increases the susceptibility of offspring to renal fibrosis and hypertension in adulthood.

  15. CeNi3-type rare earth compounds: crystal structure of R3Co7Al2 (R=Y, Gd-Tm) and magnetic properties of {Gd-Er}3Co7Al2, {Tb, Dy}3Ni8Si and Dy3Co7.68Si1.32

    NASA Astrophysics Data System (ADS)

    Morozkin, A. V.; Yapaskurt, V. O.; Nirmala, R.; Quezado, S.; Malik, S. K.

    2017-03-01

    The crystal structure of new CeNi3-type {Y, Gd-Tm}3Co7Al2 (P63/mmc. N 194, hP24) compounds has been established using powder X-ray diffraction studies. The magnetism of Tb3Ni8Si and Dy3Ni8Si is dominated by rare earth sublattice and the magnetic properties of R3Co7Al2 (R =Gd-Er) and Dy3Co7.68Si1.32 are determined by both rare earth and cobalt sublattices. Magnetization data indicate ferromagnetic ordering of {Tb, Dy}3Ni8Si at 32 K and 21 K, respectively. Gd3Co7Al2 and Tb3Co7Al2 exhibit ferromagnetic ordering at 309 K and 209 K, respectively, whereas Dy3Co7Al2, Ho3Co7Al2, Er3Co7Al2 and Dy3Co7.68Si1.32 show a field dependent ferromagnetic-like ordering at 166 K, 124 K, 84 K and 226 K, respectively followed by a low temperature transition at 34 K for Dy3Co7Al2, 18 K for Ho3Co7Al2, 56 K for Er3Co7Al2, 155 K and 42 K for Dy3Co7.68Si1.32. Among these compounds, Dy3Ni8Si shows largest magnetocaloric effect (isothermal magnetic entropy change) of -11.6 J/kg·K at 18 K in field change of 50 kOe, whereas Tb3Co7Al2, Dy3Co7Al2 and Dy3Co7.68Si1.32 exhibit best permanent magnet properties in the temperature range of 2-5 K with remanent magnetization of 11.95 μB/fu, 12.86 μB/fu and 14.4 μB/fu, respectively and coercive field of 3.0 kOe, 1.9 kOe and 4.4 kOe, respectively.

  16. Turtle sex determination assay: Mass balance and responses to 2,3,7,8-tetrachlorodibenzo-p-dioxin and 3,3',4,4',5-pentachlorobiphenyl

    USGS Publications Warehouse

    Gale, Robert W.; Bergeron, Judith M.; Willingham, Emily J.; Crews, David

    2002-01-01

    Polyhalogenated hydrocarbons have been implicated in the anomalous sexual differentiation of mammals and reptiles. Here, a temperature-sensitive turtle sex determination assay using the red-eared slider (Trachemys scripta elegans) was used to determine the estrogenic or antiestrogenic activity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and 3,3′,4,4′,5-pentachlorobiphenyl (PCB-126). Neither TCDD nor PCB-126 showed a statistically significant difference in the resulting sex ratios (Fisher's exact test, p < 0.45). As a consequence of the dosing technique (eggshell spotting), the shell retained 90 and 96% of the dose for PCB-126 and TCDD, respectively, similar to retention of estradiol-17β. However, the dosing allowed transfer of sufficient chemical to achieve tissue concentrations that were greater than most concentrations reported for environmentally incurred residues. Similar relative mass distributions of PCB-126 and TCDD were observed in albumin (14–20%), yolk (55–70%), and embryo (16–25%). Relative concentration distributions in the embryo approached those in the yolk, 37 to 40% and 40 to 52%, respectively, while relative concentrations in the albumin remained at 11 to 20%. Lipid-normalized TCDD and PCB-126 concentrations were 30- to 40-fold greater in the embryo than in the yolk. It is hypothesized that nonpassive partitioning processes may have occurred in the embryo.

  17. Toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin to embryos of the fathead minnow (Pimephales promelas, Rafinesque)

    SciTech Connect

    Olivieri, C.; Cooper, K.

    1995-12-31

    This study correlates the 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) residue and its toxicity to the fathead minnow embryo exposed to levels lower than the TCDD solubility range. The TCDD tissue doses in the embryo/larvae were related to gross lesions, delayed hatching, and death. A 7-day bioconcentration factor on a lipid basis (BCF{sub L}) was calculated. Embryos at the blatsula stage were exposed to [{sup 3}H] TCDD water concentrations (0.37, 0.59, 1.2, 2.83, and 10.1 6 ng/L), a nontreatment control and a solvent carrier control. Lesions were qualified as mild and severe based on their onset and their pathogenesis. Thus, mild lesions developed just prior to hatching or post-hatching at the fifth day of development. The severe lesions appeared at the third day of development. Embryos with tissue doses {le}2.46 {+-} 1.34 ng/g consistently developed mild lesions, while embryos with tissue doses {ge} 12.07 {+-} 4.91 ng/g developed severe lesions. The lowest observable adverse effect level was 0.04 {+-} 0.02 ng/g. The calculated 7-day ED{sub 50} was 0.14 ng/g. There was no delayed hatching at any of the concentrations tested. Embryo death occurred at a tissue concentration {ge}2.46 ng/g. The calculated 7-day LD{sub 50} was 25.71 ng/g. The relationship between the concentration of TCDD in the water (x = ng/L) and in the tissue dose (y = ng/g) fitted a linear curve y = {minus}1,143 + 3,792.5x, r{sup 2} = 0.98. The calculated BCF{sub L} (wet weight) was dose dependent. Embryos with tissue doses of 0.04 and 0.16 ng/g had BCF{sub L} of 2,700 and 3,325, respectively. Embryos with tissue doses of 2.46, 12.07, and 37.07 ng/g, had a BCF{sub L} of 104,225, 106,625 and 91,075, respectively.

  18. Immunotoxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin in a complex environmental mixture from the Love Canal.

    PubMed

    Silkworth, J B; Cutler, D S; Sack, G

    1989-02-01

    The organic phase of the leachate (OPL) from the Love Canal chemical dump site contains more than 100 organic compounds including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The immunotoxic potential of OPL was determined in two mouse strains which differ in their sensitivity to aromatic hydrocarbon (Ah) receptor-mediated toxicity. OPL was administered in corn oil in a single oral gavage to male BALB/cByJ (Ahb/Ahb) mice (0.5, 0.8, or 1.1 g/kg) and DBA/2J (Ahd/Ahd) mice (0.6, 0.9, or 1.3 g/kg). TCDD was similarly administered at 0.25, 1.0, 4.0, or 16.0 micrograms/kg. Two days later all mice were immunized with sheep erythrocytes (SRBC). The antibody response (PFC) and organ weights were evaluated 4 days later. OPL produced thymic atrophy and hepatomegaly in both strains at all dose levels. The PFC/spleen in BALB/cByJ mice was significantly reduced at the three doses to 34, 13, and 15%, respectively, of the control response. Serum anti-SRBC antibody levels and relative spleen weights were also reduced. The only immune effect in the DBA/2J mice was a decrease of the PFC/spleen to 58% of the control at the highest dose. TCDD decreased the relative thymus and spleen weights only in BALB/cByJ mice. However, TCDD produced hepatomegaly, a decrease in serum antibody, and a decrease in PFC/spleen in both BALB/cByJ and DBA/2J mice to 3 and 15%, respectively, at 16 micrograms/kg. Thus, the TCDD dose required to cause a 50% suppression (ED50) of PFC/spleen for the BALB/cByJ and DBA/2J strains was 1.84 and 3.89 micrograms/kg, respectively. The ED50 for OPL was 0.24 g/kg in BALB/cByJ mice. The TCDD concentration in the OPL was estimated to be 7.6 ppm, which agrees closely with the chemical analysis (3 ppm). The results suggest that the immunosuppression caused by OPL in BALB/cByJ mice was primarily due to TCDD, that the non-TCDD components of OPL diminished the TCDD immunotoxicity in the DBA/2J strain, and that the thymic atrophy and hepatomegaly were caused primarily by the non

  19. Immunotoxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin in a complex environmental mixture from the Love Canal

    SciTech Connect

    Silkworth, J.B.; Cutler, D.S.; Sack, G.

    1989-02-01

    The organic phase of the leachate (OPL) from the Love Canal chemical dump site contains more than 100 organic compounds including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). The immunotoxic potential of OPL was determined in two mouse strains which differ in their sensitivity to aromatic hydrocarbon (Ah) receptor-mediated toxicity. OPL was administered in corn oil in a single oral gavage to male BALB/cByJ (Ahb/Ahb) mice (0.5, 0.8, or 1.1 g/kg) and DBA/2J (Ahd/Ahd) mice (0.6, 0.9, or 1.3 g/kg). TCDD was similarly administered at 0.25, 1.0, 4.0, or 16.0 micrograms/kg. Two days later all mice were immunized with sheep erythrocytes (SRBC). The antibody response (PFC) and organ weights were evaluated 4 days later. OPL produced thymic atrophy and hepatomegaly in both strains at all dose levels. The PFC/spleen in BALB/cByJ mice was significantly reduced at the three doses to 34, 13, and 15%, respectively, of the control response. Serum anti-SRBC antibody levels and relative spleen weights were also reduced. The only immune effect in the DBA/2J mice was a decrease of the PFC/spleen to 58% of the control at the highest dose. TCDD decreased the relative thymus and spleen weights only in BALB/cByJ mice. However, TCDD produced hepatomegaly, a decrease in serum antibody, and a decrease in PFC/spleen in both BALB/cByJ and DBA/2J mice to 3 and 15%, respectively, at 16 micrograms/kg. Thus, the TCDD dose required to cause a 50% suppression (ED50) of PFC/spleen for the BALB/cByJ and DBA/2J strains was 1.84 and 3.89 micrograms/kg, respectively. The ED50 for OPL was 0.24 g/kg in BALB/cByJ mice. The TCDD concentration in the OPL was estimated to be 7.6 ppm, which agrees closely with the chemical analysis (3 ppm).

  20. Density functional theory calculations of UO2 oxidation: evolution of UO(2+x), U4O(9-y), U3O7, and U3O8.

    PubMed

    Andersson, D A; Baldinozzi, G; Desgranges, L; Conradson, D R; Conradson, S D

    2013-03-04

    Formation of hyperstoichiometric uranium dioxide, UO2+x, derived from the fluorite structure was investigated by means of density functional theory (DFT) calculations. Oxidation was modeled by adding oxygen atoms to UO2 fluorite supercells. For each compound ab initio molecular dynamics simulations were performed to allow the ions to optimize their local geometry. A similar approach was used for studying the reduction of U3O8. In agreement with the experimental phase diagram we identify stable line compounds at the U4O9-y and U3O7 stoichiometries. Although the transition from fluorite to the layered U3O8 structure occurs at U3O7 (UO2.333) or U3O7.333 (UO2.444), our calculated low temperature phase diagram indicates that the fluorite derived compounds are favored up to UO2.5, that is, as long as the charge-compensation for adding oxygen atoms occurs via formation of U(5+) ions, after which the U3O8-y phase becomes more stable. The most stable fluorite UO2+x phases at low temperature (0 K) are based on ordering of split quad-interstitial oxygen clusters. Most existing crystallographic models of U4O9 and U3O7, however, apply the cuboctahedral cluster. To better understand these discrepancies, the new structural models are analyzed in terms of existing neutron diffraction data. DFT calculations were also performed on the experimental cuboctahedral based U4O9-y structure, which enable comparisons between the properties of this phase with the quad-interstitial ones in detail.

  1. Teratology of 2,3,7,8-tetrachlorodibenzo-p-dioxin in a complex environmental mixture from the Love Canal

    SciTech Connect

    Silkworth, J.B.; Cutler, D.S.; Antrim, L.; Houston, D.; Tumasonis, C.; Kaminsky, L.S. )

    1989-07-01

    The organic phase of a leachate (OPL) from the Love Canal chemical dump site contains more than 100 organic compounds including 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD). The teratogenic potential of OPL was determined in two inbred and one hybrid mouse strain which differ in their sensitivity to aromatic hydrocarbon (Ah) receptor-mediated toxicity. OPL was orally administered in corn oil on Days 6-15 of gestation to C57BL/6J mice (Ahb/Ahb) at doses of 0, 0.1, 0.3, 0.5, and 0.7 g kg-1 day-1 and to DBA/2J (Ahd/Ahd) females, which were mated with either DBA/2J or C57BL/6J males, at 0, 0.5, 1, and 2.0 g kg-1 day-1. In C57BL/6J mice, which express a high-affinity Ah receptor that avidly binds TCDD, the ED50's of OPL for cleft palate and hydronephrosis were 0.44 and 0.11 g OPL kg-1 day-1, respectively. Maternal mortality was 5% at the highest dose. In DBA/2J fetuses, which express a low-affinity receptor, neither treatment-related cleft palate nor hydronephrosis was induced by dose levels that caused 36% maternal mortality. In hybrid D2B6F1 fetuses, the incidence of cleft palate reached only 8% at 2 g OPL kg-1 day-1 but the ED50 for hydronephrosis was 0.76 g OPL kg-1 day-1. TCDD was similarly administered to pregnant C57BL/6J mice at 0, 0.5, 1, 2, and 4 micrograms kg-1 day-1 and to DBA/2J mice at 0, 0.5, 2, 4, and 8 micrograms kg-1 day-1. In C57BL/6J fetuses, the ED50's for cleft palate and hydronephrosis were 4.6 and 0.73 microgram TCDD kg-1 day-1, respectively. In DBA/2J fetuses the ED50's for cleft palate and hydronephrosis were 15.0 and 6.4 micrograms TCDD kg-1 day-1, respectively. Both the OPL and TCDD caused maternal hepatomegaly and thymic atrophy in all strains, but increased only C57BL/6J fetal weights. OPL decreased the number of fetuses per C57BL/6J dam at the two highest doses but there were no other reproductive effects in any of the groups.

  2. 1,5-Dichloro-3(2,7),7(2,7)-dinaphthal-ena-2,4,6,8-tetra-oxa-1(2,6),5(2,6)-di(1,3,5-triazina)octa-phane.

    PubMed

    Sang, Qiu-Guang; Yang, Jing-Kui

    2011-09-01

    In the macrocyclic title compound, C(26)H(12)Cl(2)N(6)O(4), an O-atom-bridged calix[2]naphthalene-[2]triazine synthesized using a one-pot approach from naphthalene-2,7-diol and cyanuric chloride, the two isolated naphthalene planes and the two triazine-2,6-di-oxy planes adopt a 1,3-alternate configuration, with a dihedral angle of 84.10 (8)° between the naphthalene rings and a dihedral angle of 39.02 (14)° between the triazine rings. In the crystal, weak inter-molecular π-π stacking inter-actions are found between face-to-face naphthalene rings [centroid-centroid distance = 3.662 (7) Å].

  3. Synthesis, structures, electrochemical studies and antioxidant activity of 5-aryl-4-oxo-3,4,5,8-tetrahydropyrido[2,3-d]pyrimidine-7-carboxylic acids

    NASA Astrophysics Data System (ADS)

    Quiroga, Jairo; Romo, Pablo E.; Ortiz, Alejandro; Isaza, José Hipólito; Insuasty, Braulio; Abonia, Rodrigo; Nogueras, Manuel; Cobo, Justo

    2016-09-01

    The synthesis of 5-aryl-4-oxo-3,4,5,8-tetrahydropyrido[2,3-d]pyrimidine-7-carboxylic acids 3 from the reaction of 6-aminopyrimidines 1 with arylidene derivatives of pyruvic acid 2 under microwave and ultrasound irradiation is described. The orientation of cyclization process was determined by NMR measurements. The methodology provides advantages such as high yields and friendly to the environment without the use of solvents. The antioxidant properties, DPPH free radical scavenging, ORAC, and anodic potential oxidation of the new pyridopyrimidines were studied.

  4. Immunotoxic effects of prolonged dietary exposure of male rats to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

    PubMed

    Badesha, J S; Maliji, G; Flaks, B

    1995-12-07

    The effects of low level exposure of rats to 2,3,7,8-tetrachlorodibenzo-p- dioxin (TCDD) on their immune system was investigated Dietary administration to young adult male Leeds strain rats of a total dose of 3 micrograms/kg body weight of TCDD resulted in an exposure duration-dependent reduction of in vitro lipopolysaccharide-induced production of interleukin (IL)-1 in cultures of their splenic macrophages. A 30-day exposure produced approximately 30% suppression and 180-day exposure produced approximately 52% suppression. This reduction did not negatively influence lipopolysaccharide- induced proliferation of B cells, instead an enhancement of B cell proliferation was observed after 30 days exposure. A 180 day exposure significantly suppressed the generation of IL-2 by either concanavalin A or phorbol myristate acetate/calcium ionophore stimulation, and reduced the lectin-induced proliferation of splenic T cells. The 30-day TCDD exposure showed no such immunotoxicity. TCDD at both exposure durations suppressed the expression of the alpha chain of the IL-2 receptor in concanavalin A-activated T cells, without affecting the CD4+/CD8+ ratio. The results suggest that exposure to a low dietary dose of TCDD suppresses the functions of several T cell subsets, some of the immunotoxic effects being produced early, while others require a longer exposure also down-regulates the IL-1 production function of macrophages. A common mechanism of TCDD immunotoxicity may be on the multifunctional signal transduction pathways downstream to the activation of protein kinase C and Ca2+ flux.

  5. 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents in extracts of Baltic white-tailed sea eagles

    SciTech Connect

    Koistinen, J.; Giesy, J.P.; Koivusaari, J.; Nuuja, I.; Vuorinen, P.J.; Paasivirta, J.

    1997-07-01

    Concentrations of 2,3,7,8-tetrachlorodibenzo-p-dioxin-(TCDD) equivalents were measured in extracts of Baltic white-tailed sea eagle tissues. Extracts of salmon, ringed seal, and grey seal were analyzed as other predatory species of the same area. Concentrations in eagle and seal tissues were greater than those in salmon. Concentrations of TCDD equivalents (TCDD-EQs) determined by the H4IIE bioassay were compared with toxic equivalents (TEQs) derived from instrumental chemical analyses in fractions containing polychlorinated dibenzo-P-dioxins and polychlorinated dibenzofurans (PCDD/PCDF) or coplanar polychlorinated biphenyls (PCBs). Toxic equivalents were calculated by use of an additive model in which the product of the concentrations of instrumentally measured individual congeners were multiplied by their TCDD equivalency factors and were summed to give a total concentration of TEQs. The TCDD-EQs were compared with TEQs to develop a mass balance to determine whether all the TCDD-like activity was accounted for. The TEQs determined by chemical analyses for coplanar PCBs was 770 pg/g fw, and that of PCDD/PCDFs was 270 pg/g fw in this eagle. Thus, concentrations of TCDD-EQs were approx. 20% greater than those of TEQs. The true difference in activities is probably greater because of lower recoveries and infra-additivities among congeners in the bioassay. This indicates that there are compounds present in the extracts that can contribute to the total concentrations of TCDD-EQs in white-tailed sea eagle eggs to the no-observable-adverse-effect concentration, ranged from 7.3 to 141. This indicates that current concentrations of TCDD-EQs in these eggs are likely causing adverse effects in the Baltic populations of white-tailed sea eagles. This study indicated that the H4IIE bioassay is useful for monitoring the presence and biological activity of TCDD-like compounds in environmental samples like white-tailed sea eagles.

  6. Sensitivity of lake sturgeon (Acipenser fulvescens) early life stages to 2,3,7,8-tetrachlorodibenzo-P-dioxin and 3,3',4,4',5-pentachlorobiphenyl.

    PubMed

    Tillitt, Donald E; Buckler, Justin A; Nicks, Diane K; Candrl, James S; Claunch, Rachel A; Gale, Robert W; Puglis, Holly J; Little, Edward E; Linbo, Tiffany L; Baker, Mary

    2017-04-01

    The aquatic food web of the Great Lakes has been contaminated with polychlorinated biphenyls (PCBs) since the mid-20th century. Threats of PCB exposures to long-lived species of fish, such as lake sturgeon (Acipenser fulvescens), have been uncertain because of a lack of information on the relative sensitivity of the species. The objective of the present study was to evaluate the sensitivity of early-life stage lake sturgeon to 3,3',4,4',5-pentachlorobiphenyl (PCB-126) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure. Mortality, growth, morphological and tissue pathologies, swimming performance, and activity levels were used as assessment endpoints. Pericardial and yolk sac edema, tubular heart, yolk sac hemorrhaging, and small size were the most commonly observed pathologies in both TCDD and PCB-126 exposures, beginning as early as 4 d postfertilization, with many of these pathologies occurring in a dose-dependent manner. Median lethal doses for PCB-126 and TCDD in lake sturgeon were 5.4 ng/g egg (95% confidence interval, 3.9-7.4 ng/g egg) and 0.61 ng/g egg (0.47-0.82 ng/g egg), respectively. The resulting relative potency factor for PCB-126 (0.11) was greater than the World Health Organization estimate for fish (toxic equivalency factor = 0.005), suggesting that current risk assessments may underestimate PCB toxicity toward lake sturgeon. Swimming activity and endurance were reduced in lake sturgeon survivors from the median lethal doses at 60 d postfertilization. Threshold and median toxicity values indicate that lake sturgeon, like other Acipenser species, are more sensitive to PCB and TCDD than the other genus of sturgeon, Scaphirhynchus, found in North America. Indeed, lake sturgeon populations in the Great Lakes and elsewhere are susceptible to PCB/TCDD-induced developmental toxicity in embryos and reductions in swimming performance. Environ Toxicol Chem 2017;36:988-998. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This

  7. Inhibition of apoptosis during 2,3,7,8-tetrachlorodibenzo-p-dioxin-mediated tumour promotion in rat liver.

    PubMed

    Stinchcombe, S; Buchmann, A; Bock, K W; Schwarz, M

    1995-06-01

    The effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on cell division and cell death (apoptosis) in glutathione S-transferase (GST-P)-positive liver foci were analyzed in diethylnitrosamine-initiated female Wistar rats that were treated with TCDD, either acutely for 3 days or chronically for 115 days. Apoptotic bodies were quantitated in liver sections simultaneously stained for GST-P expression and H&E using a novel fluorescence microscopic detection method which greatly facilitates recognition of apoptotic bodies due to their high level of eosin fluorescence. While TCDD treatment only marginally affected cell division in GST-P-positive liver foci, as estimated by 5-bromo-2'-deoxyuridine-labelling, apoptotic indices were decreased to approximately 60% and approximately 10% of control values after acute and chronic TCDD treatment, respectively. In normal liver tissue, apoptotic indices were only slightly reduced by TCDD treatment, suggesting selective inhibition of apoptosis in the enzyme-altered cell population by the dioxin. Since inhibition of apoptosis in GST-P-positive liver foci was by far more pronounced than changes in cell division, our data suggest that the promoting activity of TCDD is preferentially mediated by a decrease of apoptosis in enzyme-altered liver foci.

  8. Low-Cycle Fatigue Behavior of 95.8Sn-3.5Ag-0.7Cu Solder Joints

    NASA Astrophysics Data System (ADS)

    Tang, Y.; Li, G. Y.; Shi, X. Q.

    2013-01-01

    Low-cycle fatigue (LCF) behavior of 95.8Sn-3.5Ag-0.7Cu solder joints was investigated over a range of test temperatures (25°C, 75°C, and 125°C), frequencies (0.001 Hz, 0.01 Hz, and 0.1 Hz), and strain ranges (0.78%, 1.6%, and 3.1%). Effects of temperature and frequency on the LCF life were studied. Results show that the LCF lifetime decreases with an increase in test temperature or a decrease of test frequency, which is attributed to the longer exposure time to creep and the stress relaxation mechanism during fatigue testing. A modified Coffin-Manson model considering effects of temperature and frequency on the LCF life is proposed. The fatigue exponent and ductility coefficient were found to be influenced by both the temperature and frequency. By fitting the experimental data, the mathematical relations between the fatigue exponent and temperature, and ductility coefficient and temperature, were analyzed. Scanning electron microscopy (SEM) of the cross-sections and fracture surfaces of failed specimens at different temperature and frequency was applied to verify the failure mechanisms.

  9. Atg8 Transfer from Atg7 to Atg3: A Distinctive E1-E2 Architecture and Mechanism in the Autophagy Pathway

    SciTech Connect

    Taherbhoy, Asad M.; Tait, Stephen W.; Kaiser, Stephen E.; Williams, Allison H.; Deng, Alan; Nourse, Amanda; Hammel, Michal; Kurinov, Igor; Rock, Charles O.; Green, Douglas R.; Schulman, Brenda A.

    2012-07-11

    Atg7 is a noncanonical, homodimeric E1 enzyme that interacts with the noncanonical E2 enzyme, Atg3, to mediate conjugation of the ubiquitin-like protein (UBL) Atg8 during autophagy. Here we report that the unique N-terminal domain of Atg7 (Atg7{sup NTD}) recruits a unique 'flexible region' from Atg3 (Atg3{sup FR}). The structure of an Atg7{sup NTD}-Atg3{sup FR} complex reveals hydrophobic residues from Atg3 engaging a conserved groove in Atg7, important for Atg8 conjugation. We also report the structure of the homodimeric Atg7 C-terminal domain, which is homologous to canonical E1s and bacterial antecedents. The structures, SAXS, and crosslinking data allow modeling of a full-length, dimeric (Atg7 {approx} Atg8-Atg3){sub 2} complex. The model and biochemical data provide a rationale for Atg7 dimerization: Atg8 is transferred in trans from the catalytic cysteine of one Atg7 protomer to Atg3 bound to the N-terminal domain of the opposite Atg7 protomer within the homodimer. The studies reveal a distinctive E1 {approx} UBL-E2 architecture for enzymes mediating autophagy.

  10. Atg8 transfer from Atg7 to Atg3: a distinctive E1-E2 architecture and mechanism in the autophagy pathway.

    PubMed

    Taherbhoy, Asad M; Tait, Stephen W; Kaiser, Stephen E; Williams, Allison H; Deng, Alan; Nourse, Amanda; Hammel, Michal; Kurinov, Igor; Rock, Charles O; Green, Douglas R; Schulman, Brenda A

    2011-11-04

    Atg7 is a noncanonical, homodimeric E1 enzyme that interacts with the noncanonical E2 enzyme, Atg3, to mediate conjugation of the ubiquitin-like protein (UBL) Atg8 during autophagy. Here we report that the unique N-terminal domain of Atg7 (Atg7(NTD)) recruits a unique "flexible region" from Atg3 (Atg3(FR)). The structure of an Atg7(NTD)-Atg3(FR) complex reveals hydrophobic residues from Atg3 engaging a conserved groove in Atg7, important for Atg8 conjugation. We also report the structure of the homodimeric Atg7 C-terminal domain, which is homologous to canonical E1s and bacterial antecedents. The structures, SAXS, and crosslinking data allow modeling of a full-length, dimeric (Atg7~Atg8-Atg3)(2) complex. The model and biochemical data provide a rationale for Atg7 dimerization: Atg8 is transferred in trans from the catalytic cysteine of one Atg7 protomer to Atg3 bound to the N-terminal domain of the opposite Atg7 protomer within the homodimer. The studies reveal a distinctive E1~UBL-E2 architecture for enzymes mediating autophagy.

  11. Synthesis and acetylcholinesterase/butyrylcholinesterase inhibition activity of 4-amino-2, 3-diaryl-5, 6, 7, 8-tetrahydrofuro(and thieno)[2, 3-b]-quinolines, and 4-amino-5, 6, 7, 8, 9-pentahydro-2, 3-diphenylcyclohepta[e]furo(and thieno)-[2, 3-b]pyridines.

    PubMed

    Marco, José L; De Los Ríos, Cristóbal; Carreiras, María C; Baños, Josep E; Badia, Albert; Vivas, Nuria M

    2002-07-01

    The acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibition activities of a series of 4-amino-2, 3-diaryl-5, 6, 7, 8-tetrahydrofuro[2, 3-b]quinolines (10-12)/4-amino-5, 6, 7, 8-tetrahydro-2, 3-diphenylthieno[2, 3-b]quinoline (14) and 4-amino-5, 6, 7, 8, 9-pentahydro-2, 3-diphenylcyclohepta[e]furo[2, 3-b]pyridine (13)/4-amino-5, 6, 7, 8, 9-pentahydro-2, 3-phenylcyclohepta[e]thieno[2, 3-b]pyridine (15) are described. These compounds are tacrine (THA) analogues which have been prepared either from readily available 2-amino-3-cyano-4, 5-diarylfurans (16-18) or from 2-amino-3-cyano-4, 5-diphenylthiophene (19), via Friedländer condensation with cyclohexanone or cycloheptanone. These compounds are competitive inhibitors for acetylcholinesterase, the more potent being compound (13) which is three-fold less active than tacrine. The butyrylcholinesterase inhibition activity is significant only in compounds 10 and133, which are ten-fold less active than tacrine. It is found that the products 11 and 12 strongly inhibit acetylcholinesterase, and show excellent selectivity regarding butyrylcholinesterase.

  12. 2.3.7.8-Tetrachlorodibenzo-p-Dioxin Induced Immunosuppression: Its Possible Alteration by In Vivo Administration of Specific Hepatic Enzyme Inducers.

    DTIC Science & Technology

    1987-06-27

    England .2 LIST OF ACOREVIAT:CNS AND SYMBOLS TCDD =2.3.7.8-tetrachlorodibenzo-p-dioxtn TCDF = 2.3.7 8-IOetrachlo’dibenzofuran 3MC =3-methyicholanthrene...this research program was to clarify whether drugs that in vitro inhibit TCDD binding to the hepatic cytosolic Ah "rec3ptor" such as 3MC , PNF and TCDF...these enzymes has also been performed. The study of this year has been concentrated on the effects of only two inducers, that is TCDF and 3MC , since

  13. Altered regulation of luteinizing hormone secretion in 2,3,7,8-tetrachlorodibenzo-p-dioxin-treated male rats

    SciTech Connect

    Bookstaff, R.C.

    1989-01-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) severely decreases plasma androgen concentrations, yet plasma luteinizing hormone (LH) concentrations remain unchanged. The mechanism by which TCDD prevents the expected compensatory increase in plasma LH was investigated. No effect on the plasma disappearance rate of LH or on pituitary capacity to synthesize or secrete LH was detected. Rather, TCDD altered the regulation of LH secretion by substantially increasing the potency of both androgens and estrogens as feedback inhibitors of LH secretion. The mechanism by which TCDD alters androgen-regulated LH secretion was further investigated. Seven days after dosing, TCDD decreased plasma testosterone concentrations but prevented the expected compensatory increases in pituitary gonadotropin-releasing hormone (GnRH) receptor number, pituitary responsiveness to GnRH, and plasma LH concentrations as seen in similarly hypoandrogenic vehicle dosed rats. Furthermore, the TCDD dose-response relationships for preventing the compensatory increases in pituitary GnRH receptor number and plasma LH concentration were similar. However, in the absence of gonadal steroids (7 days after castration) TCDD did not affect the compensatory increases in pituitary GnRH receptor number, pituitary responsiveness to GnRH, or plasma LH concentration. All of these parameters increased substantially relative to intact TCDD treated rats, and to levels virtually identical to those seen in castrated control rats. Treatment of castrated rats with testosterone restored the ability of TCDD to prevent these compensatory increases. Taken together, these results demonstrate that the presence of androgens is required for TCDD to alter the regulation of pituitary GnRH receptors.

  14. 2,3,7,8-Tetrachlorodibenzo-p-dioxin Upregulates FoxQ1b in Zebrafish Jaw Primordium

    PubMed Central

    Planchart, Antonio; Mattingly, Carolyn J.

    2010-01-01

    Vertebrate jaw development can be disrupted by exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)—a potent activator of the aryl hydrocarbon receptor (AHR) transcription factor required for transducing the toxic effects of TCDD. We used zebrafish (Danio rerio) embryos to investigate transcriptional responses to TCDD with the goal of discovering novel, jaw-specific genes affected by TCDD exposure. Our results uncovered a novel target of TCDD-activated Ahr belonging to the evolutionarily conserved family of forkhead box transcription factors. Quantitative real-time polymerase chain reaction analysis demonstrated that FoxQ1b was upregulated by TCDD 7- and 10-fold at 24 and 48 h postfertilization (hpf), respectively. The rate of TCDD-induced FoxQ1b expression was more rapid than that of Cyp1a, a known direct target of TCDD-activated Ahr. TCDD-mediated induction of FoxQ1b was suppressed in the presence of an Ahr antagonist, α-naphthoflavone, as well as following knockdown of Ahr2 expression using an Ahr2-specific morpholino antisense oligonucleotide. In situ hybridization analysis of FoxQ1b expression at 48 hpf demonstrated that FoxQ1b is specifically expressed in the jaw primordium where it discretely outlines a developing jaw structure known as Meckel’s cartilage—a conserved structure in all jawed vertebrates that develops abnormally in the presence of TCDD. These results identify a novel target of TCDD-activated Ahr and suggest that FoxQ1b may play a role in craniofacial abnormalities induced by developmental exposure to TCDD. PMID:20055451

  15. Internally quenched fluorescent peptide substrates disclose the subsite preferences of human caspases 1, 3, 6, 7 and 8.

    PubMed Central

    Stennicke, H R; Renatus, M; Meldal, M; Salvesen, G S

    2000-01-01

    Subsite interactions are considered to define the stringent specificity of proteases for their natural substrates. To probe this issue in the proteolytic pathways leading to apoptosis we have examined the P(4), P(1) and P(1)' subsite preferences of human caspases 1, 3, 6, 7 and 8, using internally quenched fluorescent peptide substrates containing o-aminobenzoyl (also known as anthranilic acid) and 3-nitro-tyrosine. Previous work has demonstrated the importance of the S(4) subsite in directing specificity within the caspase family. Here we demonstrate the influence of the S(1) and S(1)' subsites that flank the scissile peptide bond. The S(1) subsite, the major specificity-determining site of the caspases, demonstrates tremendous selectivity, with a 20000-fold preference for cleaving substrates containing aspartic acid over glutamic acid at this position. Thus caspases are among the most selective of known endopeptidases. We find that the caspases show an unexpected degree of discrimination in the P(1)' position, with a general preference for small amino acid residues such as alanine, glycine and serine, with glycine being the preferred substituent. Large aromatic residues are also surprisingly well-tolerated, but charged residues are prohibited. While this describes the general order of P(1)' subsite preferences within the caspase family, there are some differences in individual profiles, with caspase-3 being particularly promiscuous. Overall, the subsite preferences can be used to predict natural substrates, but in certain cases the cleavage site within a presumed natural substrate cannot be predicted by looking for the preferred peptide cleavage sites. In the latter case we conclude that second-site interactions may overcome otherwise sub-optimal cleavage sequences. PMID:10947972

  16. Induction of CYP1A and ABC transporters in European sea bass (Dicentrarchus labrax) upon 2,3,7,8-TCDD waterborne exposure.

    PubMed

    Della Torre, Camilla; Mariottini, Michela; Vannuccini, Maria Luisa; Trisciani, Anna; Marchi, Davide; Corsi, Ilaria

    2014-08-01

    The aim of this study was to characterize the responsiveness of CYP1A and ABC transport proteins in European Sea bass (Dicentrarchus labrax) waterborne exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) (46 pg/L) for 24 h and 7 days. Genes modulation (abcb1, abcc1-2, cyp1a), EROD activity were investigated in liver and 2,3,7,8-TCDD bioconcentration in liver and muscle. TCDD induced significantly cyp1a gene expression and EROD activity at 24 h and 7 d. A significant up-regulation of abcb1 was also observed but only after 7 days. No modulation of abcc1 and abcc2 genes was observed. Waterborne TCDD exposure was able to induce CYP1A and abcb1 encoding for P-glycoprotein in juvenile of European sea bass.

  17. Teratology of 2,3,7,8-tetrachlorodibenzo-p-dioxin in a complex environmental mixture from the love canal.

    PubMed

    Silkworth, J B; Cutler, D S; Antrim, L; Houston, D; Tumasonis, C; Kaminsky, L S

    1989-07-01

    The organic phase of a leachate (OPL) from the Love Canal chemical dump site contains more than 100 organic compounds including 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD). The teratogenic potential of OPL was determined in two inbred and one hybrid mouse strain which differ in their sensitivity to aromatic hydrocarbon (Ah) receptor-mediated toxicity. OPL was orally administered in corn oil on Days 6-15 of gestation to C57BL/6J mice (Ahb/Ahb) at doses of 0, 0.1, 0.3, 0.5, and 0.7 g kg-1 day-1 and to DBA/2J (Ahd/Ahd) females, which were mated with either DBA/2J or C57BL/6J males, at 0, 0.5, 1, and 2.0 g kg-1 day-1. In C57BL/6J mice, which express a high-affinity Ah receptor that avidly binds TCDD, the ED50's of OPL for cleft palate and hydronephrosis were 0.44 and 0.11 g OPL kg-1 day-1, respectively. Maternal mortality was 5% at the highest dose. In DBA/2J fetuses, which express a low-affinity receptor, neither treatment-related cleft palate nor hydronephrosis was induced by dose levels that caused 36% maternal mortality. In hybrid D2B6F1 fetuses, the incidence of cleft palate reached only 8% at 2 g OPL kg-1 day-1 but the ED50 for hydronephrosis was 0.76 g OPL kg-1 day-1. TCDD was similarly administered to pregnant C57BL/6J mice at 0, 0.5, 1, 2, and 4 micrograms kg-1 day-1 and to DBA/2J mice at 0, 0.5, 2, 4, and 8 micrograms kg-1 day-1. In C57BL/6J fetuses, the ED50's for cleft palate and hydronephrosis were 4.6 and 0.73 microgram TCDD kg-1 day-1, respectively. In DBA/2J fetuses the ED50's for cleft palate and hydronephrosis were 15.0 and 6.4 micrograms TCDD kg-1 day-1, respectively. Both the OPL and TCDD caused maternal hepatomegaly and thymic atrophy in all strains, but increased only C57BL/6J fetal weights. OPL decreased the number of fetuses per C57BL/6J dam at the two highest doses but there were no other reproductive effects in any of the groups. It was concluded that the OPL is teratogenic and that hydronephrosis is a sensitive measure of TCDD toxicity in a

  18. 2 μm fluorescence of Ho3+:5I7 → 5I8 transition sensitized by Er3+ in tellurite germanate glasses

    NASA Astrophysics Data System (ADS)

    Chen, Rong; Tian, Ying; Li, Bingpeng; Wang, Fengchao; Jing, Xufeng; Zhang, Junjie; Xu, Shiqing

    2015-11-01

    This paper investigated the mid-infrared luminescence properties of Er3+/Ho3+ co-doped tellurite germanate glass at 2 μm pumped by 980 nm. Thermal stability of the system, absorption spectra and fluorescence spectra of the Er3+/Ho3+ co-doped glass sample were measured. Besides, the absorption spectra of the Ho3+ singly doped sample was measured. According to the measured absorption spectra and the Judd-Ofelt theory, the Judd-Ofelt intensity parameters Ωt (t = 2, 4, 6), spontaneous radiative transition probability, branching ratio and lifetime of Ho3+ were calculated. And the upconversion emission in Er3+ doped and Er3+/Ho3+ co-doped tellurite germanate glasses pumped by 980 nm have been investigated. Then the spectroscopic properties and possible energy transfer mechanisms between Ho3+ and Er3+ ions were discussed in detail. Meanwhile, the FWHM (146 nm), σepeak × FWHM (659.92 cm3) and emission cross section (4.52 × 10-21 cm2) of 5I8 → 5I7 transition of Ho3+ were obtained, respectively. The results indicate that Er3+/Ho3+ co-doped tellurite germanate glass is a promising host material for 2 μm solid laser.

  19. Embryo toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin to the wood duck (Aix sponsa)

    USGS Publications Warehouse

    Augspurger, T.P.; Tillitt, D.E.; Bursian, S.J.; Fitzgerald, S.D.; Hinton, D.E.; Di Giulio, R.T.

    2008-01-01

    We examined the sensitivity of the wood duck (Aix sponsa) embryo to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) by injecting the toxicant into their eggs. Six groups of wood duck eggs (n = 35 to 211 per trial) were injected with 0 to 4600 pg TCDD/g egg between 2003 and 2005. Injections were made into yolk prior to incubation, and eggs were subsequently incubated and assessed weekly for mortality. Significant TCDD-induced mortality was not observed through day 25 (90% of incubation). Liver, heart, eye, and brain histology were generally unremarkable. Hepatic ethoxyresorufin-O-deethylase activity, a biomarker of dioxin-like compound exposure, was induced by 12-fold in the 4600 pg/g treatment relative to controls. The median lethal dose for chicken (Gallus domesticus) eggs we dosed identically to wood duck eggs was about 100 pg/g, similar to other assessments of chickens. Among dioxin-like compound embryo lethality data for 15 avian genera, the wood duck 4600 pg/g no-observed-effect level ranks near the middle. Because no higher doses were tested, wood ducks may be like other waterfowl (order Anseriformes), which are comparatively tolerant to embryo mortality from polychlorinated dibenzo-p-dioxins and dibenzofurans when exposed by egg injection. ?? 2008 US Government.

  20. 2,3,7,8-TCDD effects on visual structure and function in swim-up rainbow trout

    USGS Publications Warehouse

    Carvalho, Paulo S. M.

    2004-01-01

    An understanding of mechanisms of contaminant effects across levels of biological organization is essential in ecotoxicology if we are to generate predictive models for population-level effects. We applied a suite of biochemical, histological, and behavioral end points related to visual structure and function and foraging behavior to evaluate effects of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) on swim-up rainbow trout. We detected a dose-dependent decrease in densities of retinal ganglion cells (RGC), key retinal neurons that link the eye with the brain. These changes resulted in corresponding deficits in visual/motor function including reductions in visual acuity and in scotopic and photopic thresholds due to TCDD. The loss of RGCs suggests an increase in convergence of synapses from photoreceptors to RGCs as a cellular mechanism for the visual deficits. Dose-dependent increases in immunohistochemical detection of CYP1A protein in the vasculature of the brain and eye choroid was proportional with decreased ganglion cell densities in the retina. TCDD-induced AHR-regulated effects on these tissues might be involved in the detected decrease in ganglion cell densities. Prey capture rate decreased after TCDD exposure only at the highest treatment groups evaluated. Collectively, these results show that TCDD causes biochemical and structural changes in the eye and brain of rainbow trout that are associated with behavioral deficits leading to decreased individual fitness.

  1. 2,3,7,8-Tetrachlorodibenzo-p-dioxin Exposure Prevents Cardiac Valve Formation in Developing Zebrafish

    PubMed Central

    Mehta, Vatsal; Peterson, Richard E.; Heideman, Warren

    2008-01-01

    Cardiovascular malformations are one of the most common congenital birth defects observed in humans. Defects in cardiac valves disrupt normal blood flow. Zebrafish are an outstanding experimental model for studying the effects that environmental contaminants have on developmental processes. Previous research has shown that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) causes blood regurgitation in the heart and reduces peripheral blood flow in embryonic zebrafish, suggesting some form of valve failure. To test this we used video microscopy to examine valve function and structure in developing zebrafish exposed to TCDD. TCDD exposure produced blood regurgitation at both the atrioventricular (AV) and bulboventricular (BV) junctions. In marked contrast to control embryos exposed to the vehicle dimethyl sulfoxide, embryos exposed to TCDD failed to form valve leaflets as the heart matured. In addition, whereas TCDD did not block initial formation of the bulbus arteriosus, we found that TCDD exposure prevented the normal growth and development of this portion of the outflow tract. TCDD altered the localization of endothelial cells at the AV and BV junctions and altered the localized expression of mRNAs bmp4 and notch1b normally associated with the nascent valves. Taken together, our results demonstrate that although TCDD does not prevent the initial specification of the presumptive valve locations, TCDD exposure produces severe alterations in valve development, leading to blood regurgitation and failing circulation in the developing zebrafish. PMID:18477685

  2. Enhanced suppressor cell activity as a mechanism of immunosuppression by 2,3,7,8-tetrachlorodibenzo-p-dioxin

    SciTech Connect

    Clark, D.A.; Gauldie, J.; Szewczuk, M.R.; Sweeney, G.

    1981-11-01

    TCDD (2,3,7,8-tetrachlorodibenzo-p-dioxin), a toxic halogenated aromatic hydrocarbon, acts in the body as a cumulative poison. The chronic immunotoxic effects of TCDD were studied in C57B1/6 male mice. Total doses of 100 ..mu..g/kg or greater produced cellular depletion in thymus, spleen, and lymph nodes, and the animals appeared sick. No cellular depletion was seen following 0.4 ..mu..g/kg, and only thymus was affected by 4 and 40 ..mu..g/kg. The antibody response to SRBC and TNP-Brucella abortus was impaired following ..mu..g/kg and the generation of alloantigen-specific cytotoxic T cells (CTL) was sensitive to as little as 0.004 ..mu..g/kg TCDD. In vitro analysis of the mechanism of suppression using limiting dilution techniques showed that TCDD did not deplete the precursors of CTL but generated cells capable of suppressing CTL generation in vitro.

  3. Endocrine and metabolic aspects of the acute toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)

    SciTech Connect

    Gorski, J.R.

    1988-01-01

    Toxic responses to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were characterized in male Sprague-Dawley rats in order to elucidate the mechanism of acute toxicity of this potent halogenated hydrocarbon. Studies in TCDD-treated, pair-fed control and ad libitum-fed control rates, as well as in thyroidectomized, adrenalectomized and hypophysectomized, revealed differential hormonal, toxicologic and histophathologic responses suggesting that these manifestations of TCDD exposure are the results of an insult to intermediary metabolism. Tissue specific alterations in de novo fatty acid synthesis were directly related to differential changes observed in thyroid hormone homeostasis. The increased hepatic de novo fatty acid synthesis provided a likely mechanism for the documented fact that TCDD-treated rats lose more body weight than corresponding pair-fed controls because de novo fatty acid synthesis represents an energy inefficient metabolic process. Experiments in adrenalectomized and hypophysectomized rats led to the hypothesis that severe hypoglycemia due to inhibition of gluconeogenesis is the cause of TCDD-induced death. A subsequent characterization of gluconeogenesis in TCDD-treated rats confirmed this hypothesis.

  4. Trends in 2,3,7,8-TCDD concentrations in fish tissues downstream of pulp mills bleaching with chlorine

    SciTech Connect

    Abbott, J.D.; Hinton, S.W.

    1996-07-01

    Field measurements of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) concentrations in fish tissues from riverine environments impacted by treated pulp and paper industry effluent in the US were analyzed. Data from 39 sites in 14 states across the four major US paper-making regions were assembled and analyzed to determine the annual change in lipid-normalized concentrations of TCDD in fish tissue. The results provide strong evidence of a nationwide trend of decreasing lipid-normalized TCDD concentrations in fish tissue, with 84% of the examined sites showing a decrease. While the paucity of data currently limits any conclusions regarding the statistical significance at individual sites, the overall median rate calculated indicates a 0.36 annual fractional decrease in lipid-normalized concentrations of TCDD in fish tissue (0.18 to 0.51, 95% confidence interval); the average annual fractional decrease was 0.35 (0.23 to 0.47, 95% confidence interval). Subdividing fish into benthic and nonbenthic categories resulted in rates which were not significantly different from one another for both the median and mean statistics.

  5. Phytotoxicity effects and biological responses of Arabidopsis thaliana to 2,3,7,8-tetrachlorinated dibenzo-p-dioxin exposure.

    PubMed

    Hanano, Abdulsamie; Almousally, Ibrahem; Shaban, Mouhnad

    2014-06-01

    Dioxins are persistent organic pollutants. Their bioaccumulation in the food chain makes dioxins a considerable risk for human health. The use of plants for removing toxic organic compounds, including dioxins, is a safe and efficient strategy. Herein we studied the toxicity effects and the biological responses in Arabidopsis thaliana to 2',3',7',8'-tetrachlorinated dibenzo-p-dioxin (TCDD) exposure. First, TCDD-induced toxicity was demonstrated using several parameters including, a decrease in seed germination, a loss in fresh weight with a striking decrease in chlorophyll content, but not in carotenoids, and an augmentation in the biomass of the lateral roots system, but not in the elongation of the primary root. Uptake of TCDD by Arabidopsis was confirmed. Responses to TCDD-exposure were marked by an enhanced level of hydrogen peroxide H2O2 production and a massive stimulation of anti-oxidative enzyme activities. Moreover, a significant variation in the transcript level of transcription factor genes, bHLH, MYB and AP2-EREBP was detected in Arabidopsis shoot and an up-regulation of WRKY, MYB and IAA was observed in the root. Our results illustrate the TCDD-induced toxicity effects and the biological responses of Arabidopsis to TCDD. Better understanding of the plants ability to detoxifydioxins would help to improve their use as a safe bioremediators.

  6. 2,3,7,8-Tetrachlorodibenzo-p-dioxin exposure prevents cardiac valve formation in developing zebrafish.

    PubMed

    Mehta, Vatsal; Peterson, Richard E; Heideman, Warren

    2008-08-01

    Cardiovascular malformations are one of the most common congenital birth defects observed in humans. Defects in cardiac valves disrupt normal blood flow. Zebrafish are an outstanding experimental model for studying the effects that environmental contaminants have on developmental processes. Previous research has shown that 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) causes blood regurgitation in the heart and reduces peripheral blood flow in embryonic zebrafish, suggesting some form of valve failure. To test this we used video microscopy to examine valve function and structure in developing zebrafish exposed to TCDD. TCDD exposure produced blood regurgitation at both the atrioventricular (AV) and bulboventricular (BV) junctions. In marked contrast to control embryos exposed to the vehicle dimethyl sulfoxide, embryos exposed to TCDD failed to form valve leaflets as the heart matured. In addition, whereas TCDD did not block initial formation of the bulbus arteriosus, we found that TCDD exposure prevented the normal growth and development of this portion of the outflow tract. TCDD altered the localization of endothelial cells at the AV and BV junctions and altered the localized expression of mRNAs bmp4 and notch1b normally associated with the nascent valves. Taken together, our results demonstrate that although TCDD does not prevent the initial specification of the presumptive valve locations, TCDD exposure produces severe alterations in valve development, leading to blood regurgitation and failing circulation in the developing zebrafish.

  7. Toxicity and bioaccumulation of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) by Chironomus tentans and Lumbriculus variegatus

    SciTech Connect

    West, C.W.; Ankley, G.T.; Elonen, G.E.; Phipps, G.W.; Fernandez, J.D.; Libal, J.J.; Nessa, D.

    1994-12-31

    Invertebrate exposure to 2,3,7,8-TCDD is important, not necessarily because of their sensitivity (which appears to be less than that of fish) , but as a vector from chemical reservoirs in sediments, through the food chain, to sensitive species. Chironomus tentans and Lumbriculus variegatus are not only vectors for TCDD to fish species, but C. tentans may also be a direct vector to avian species which feed upon emergent insects. For this reason determination of the kinetics of TCDD uptake by invertebrates is important, especially for those with short life spans such as midges, or those that reproduce as rapidly as oligochaetes. In these experiments, these two species were fed contaminated food at three different TCDD levels spanning three orders of magnitude. Tissue residue levels were measured over a time period which included several different life stages and points in the reproductive cycle of the two species and uptake and deputation rates determined. As expected, no significant impacts of TCDD on growth, reproduction or biomass of the invertebrates were observed. From this information predictions can be made on bioaccumulation of TCDD from differing levels of contamination, and potential food chain transfer of the compound to more sensitive species.

  8. 7, 8, 3'-Trihydroxyflavone Promotes Neurite Outgrowth and Protects Against Bupivacaine-Induced Neurotoxicity in Mouse Dorsal Root Ganglion Neurons.

    PubMed

    Shi, Haohong; Luo, Xingjing

    2016-07-02

    BACKGROUND 7, 8, 3'-trihydroxyflavone (THF) is a novel pro-neuronal small molecule that acts as a TrkB agonist. In this study, we examined the effect of THF on promoting neuronal growth and protecting anesthetics-induced neurotoxicity in dorsal root ganglion (DRG) neurons in vitro. MATERIAL AND METHODS Neonatal mouse DRG neurons were cultured in vitro and treated with various concentrations of THF. The effect of THF on neuronal growth was investigated by neurite outgrowth assay and Western blot. In addition, the protective effects of THF on bupivacaine-induced neurotoxicity were investigated by apoptosis TUNEL assay, neurite outgrowth assay, and Western blot, respectively. RESULTS THF promoted neurite outgrowth of DRG neurons in dose-dependent manner, with an EC50 concentration of 67.4 nM. Western blot analysis showed THF activated TrkB signaling pathway by inducing TrkB phosphorylation. THF also rescued bupivacaine-induced neurotoxicity by reducing apoptosis and protecting neurite retraction in DRG neurons. Furthermore, the protection of THF in bupivacaine-injured neurotoxicity was directly associated with TrkB phosphorylation in a concentration-dependent manner in DRG neurons. CONCLUSIONS THF has pro-neuronal effect on DRG neurons by promoting neurite growth and protecting against bupivacaine-induced neurotoxicity, likely through TrkB activation.

  9. Serum 2,3,7,8-tetrachlorodibenzo-p-dioxin levels in US Army Vietnam-era veterans

    SciTech Connect

    Not Available

    1988-09-02

    This study investigates whether military records can be used to identify US Army Vietnam veterans who were likely to be exposed to the herbicide Agent Orange. Serum levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a toxic contaminant in Agent Orange, were obtained for 646 ground combat troops who served in heavily sprayed areas of Vietnam and for 97 veterans who did not serve in Vietnam. The distributions of current TCDD levels in Vietnam and non-Vietnam veterans were nearly identical (mean in each group, approx. = 4 parts per trillion (ppt)). Only two men (both Vietnam veterans) had clearly elevated levels (> 20 ppt). Levels of TCDD did not tend to increase with greater likelihood of exposure to Agent Orange, as estimated from either military records of self-reported exposure. This study is consistent with other studies and suggests that most US Army ground troops who served in Vietnam were not heavily exposed to TCDD, except perhaps men whose jobs involved handling herbicides.

  10. Crystal structure of (1S,3R,8R,9R)-2,2-di-chloro-3,7,7-tri-methyl-10-methylenetri-cyclo-[6.4.0.0(1,3)]dodecan-9-ol.

    PubMed

    Benzalim, Ahmed; Auhmani, Aziz; Bimoussa, Abdoullah; Ait Itto, My Youssef; Daran, Jean-Claude; Auhmani, Abdelwahed

    2016-08-01

    The title compound, C16H24Cl2O, was synthesized by treating (1S,3R,8S,9R,10S)-2,2-di-chloro-3,7,7,10-tetra-methyl-9,10-ep-oxy-tri-cyclo-[6.4.0.0(1,3)]dodecane with a concentrated solution of hydro-bromic acid. It is built up from three fused rings: a cyclo-heptane ring, a cyclo-hexyl ring bearing alkene and hy-droxy substituents, and a cyclo-propane ring bearing two chlorine atoms. The asymmetric unit contains two mol-ecules linked by an O-H⋯O hydrogen bond. In the crystal, further O-H⋯O hydrogen bonds build up an R 4 (4)(8) cyclic tetra-mer. One of the mol-ecules presents disorder that affects the seven-membered ring. In both mol-ecules, the six-membered rings display a chair conformation, whereas the seven-membered rings display conformations inter-mediate between boat and twist-boat for the non-disordered mol-ecule and either a chair or boat and twist-boat for the disordered mol-ecule owing to the disorder. The absolute configuration for both mol-ecules is 1S,3R,8R,9R and was deduced from the chemical pathway and further confirmed by the X-ray structural analysis.

  11. Tris(dibenzoyl­methanido-κ2 O,O′)[(6R,8R)-(−)-7,7-dimethyl-3-(2-pyrid­yl)-5,6,7,8-tetra­hydro-6,8-methano­isoquinoline-κ2 N,N′]terbium(III)

    PubMed Central

    Chen, Lei-Qi; Guo, Jian-Nan; Xuan, Wei-Min; Lin, Yi-Ji; Zhang, Hui

    2009-01-01

    In the title compound, [Tb(C15H11O2)3(C17H18N2)], the 7,7-dimethyl-3-(2-pyrid­yl)-5,6,7,8-tetra­hydro-6,8-methano­iso­quin­oline (LRR) ligand coordinates to TbIII through the two N atoms of the heterocycle. The metal centre is also chelated by three deprotonated 1,3-diphenyl­propane-1,3-dione (dbm) ligands, forming enanti­omerically pure [Tb(dbm)3 LRR]. The TbIII atom is located in a distorted square anti­prism of eight coordinating atoms (six O and two N atoms). PMID:21582651

  12. 7 CFR 97.8 - Specimen requirements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Specimen requirements. 97.8 Section 97.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE (CONTINUED) COMMODITY LABORATORY TESTING PROGRAMS PLANT VARIETY AND PROTECTION...

  13. 7 CFR 246.8 - Nondiscrimination.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 4 2010-01-01 2010-01-01 false Nondiscrimination. 246.8 Section 246.8 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE... nondiscrimination laws and regulations; (3) Collection and reporting of racial and ethnic participation data...

  14. Ocular Hypotensive Response in Nonhuman Primates of (8R)-1-[(2S)-2-Aminopropyl]-8,9-dihydro-7H-pyrano[2,3-g]indazol-8-ol a Selective 5-HT2 Receptor Agonist.

    PubMed

    May, Jesse A; Sharif, Najam A; McLaughlin, Marsha A; Chen, Hwang-Hsing; Severns, Bryon S; Kelly, Curtis R; Holt, William F; Young, Richard; Glennon, Richard A; Hellberg, Mark R; Dean, Thomas R

    2015-11-25

    Recently, it has been reported that 5-HT2 receptor agonists effectively reduce intraocular pressure (IOP) in a nonhuman primate model of glaucoma. Although 1-[(2S)-2-aminopropyl]indazol-6-ol (AL-34662) was shown to have good efficacy in this nonhuman primate model of ocular hypertension as well as a desirable physicochemical and permeability profile, subsequently identified cardiovascular side effects in multiple species precluded further clinical evaluation of this compound. Herein, we report selected structural modifications that resulted in the identification of (8R)-1-[(2S)-2-aminopropyl]-8,9-dihydro-7H-pyrano[2,3-g]indazol-8-ol (13), which displayed an acceptable profile to support advancement for further preclinical evaluation as a candidate for proof-of-concept studies in humans.

  15. Estimation of occupational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin using a minimal physiologic toxicokinetic model.

    PubMed Central

    Thomaseth, K; Salvan, A

    1998-01-01

    In this study we investigated estimation of occupational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) based on a minimal physiologic toxicokinetic model in humans. Our purpose was to obtain a mathematical tool for dose-response studies based on human data. We first simplified an existing model of TCDD kinetics in humans and estimated its parameters (i.e., liver elimination and background input of TCDD) using repeated measures of serum dioxin taken in Vietnam veterans (Ranch Hand data and data from an unexposed reference group). We carried out computer simulation and estimation of the model parameters both under a nonlinear weighted least-squares model (naive pooled data approach) and under a nonlinear mixed-effects model. The best parameter estimates were obtained with log-transformed data under a mixed-effects model: liver elimination parameter kf = 0.022 days-1 (95% confidence interval [CI] = 0.020, 0.024), and background input rate input = 0.1251 pg/kg/day (95% CI = 0.071, 0.179). The dioxin kinetic model and its estimated parameters were then used to provide dose estimates for a cohort of workers with exposure to TCDD at chemical plants in the United States. First, the model was used to estimate the rate of occupational intake of TCDD in a subset of the cohort consisting of 253 subjects for whom one measure of serum TCDD was available. A model of change in body-mass index over time was also identified for this subsample. The occupational exposure rate was estimated by linear regression using the above values of kinetic parameters and assuming an initial condition for serum TCDD of 7 ppt, i.e., the average level found in unexposed workers. The estimate of the occupational exposure parameter was 232.7 pg/kg/day (95% CI 192, 273). This value can be applied to the full cohort to obtain for each cohort member the time course of serum dioxin concentration from which exposure indices can be derived. Sensitivity coefficients to model parameters (background

  16. Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increases human hepatic stellate cell activation.

    PubMed

    Harvey, Wendy A; Jurgensen, Kimberly; Pu, Xinzhu; Lamb, Cheri L; Cornell, Kenneth A; Clark, Reilly J; Klocke, Carolyn; Mitchell, Kristen A

    2016-02-17

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a halogenated aromatic hydrocarbon that elicits toxicity through the aryl hydrocarbon receptor (AhR). In the liver, gross markers of TCDD toxicity are attributed to AhR activation in parenchymal hepatocytes. However, less is known regarding the consequences of TCDD treatment on non-parenchymal cells in the liver. Hepatic stellate cells (HSCs) are non-parenchymal cells that store vitamin A when quiescent. Upon liver injury, activated HSCs lose this storage ability and instead function in the development and maintenance of inflammation and fibrosis through the production of pro-inflammatory mediators and collagen type I. Reports that TCDD exposure disrupts hepatic retinoid homeostasis and dysregulates extracellular matrix remodeling in the liver led us to speculate that TCDD treatment may disrupt HSC activity. The human HSC line LX-2 was used to test the hypothesis that TCDD treatment directly activates HSCs. Results indicate that exposure to 10nM TCDD almost completely inhibited lipid droplet storage in LX-2 cells cultured with retinol and palmitic acid. TCDD treatment also increased LX-2 cell proliferation, expression of α-smooth muscle actin, and production of monocyte chemoattractant protein-1 (MCP-1), all of which are characteristics of activated HSCs. However, TCDD treatment had no effect on Col1a1 mRNA levels in LX-2 cells stimulated with the potent profibrogenic mediator, transforming growth factor-β. The TCDD-mediated increase in LX-2 cell proliferation, but not MCP-1 production, was abolished when phosphoinositide 3-kinase was inhibited. These results indicate that HSCs are susceptible to direct modulation by TCDD and that TCDD likely increases HSC activation through a multi-faceted mechanism.

  17. Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increases human hepatic stellate cell activation

    PubMed Central

    Harvey, Wendy A.; Jurgensen, Kimberly; Pu, Xinzhu; Lamb, Cheri L.; Cornell, Kenneth A.; Clark, Reilly J.; Klocke, Carolyn; Mitchell, Kristen A.

    2016-01-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a halogenated aromatic hydrocarbon that elicits toxicity through the aryl hydrocarbon receptor (AhR). In the liver, gross markers of TCDD toxicity are attributed to AhR activation in parenchymal hepatocytes. However, less is known regarding the consequences of TCDD treatment on non-parenchymal cells in the liver. Hepatic stellate cells (HSCs) are non-parenchymal cells that store vitamin A when quiescent. Upon liver injury, activated HSCs lose this storage ability and instead function in the development and maintenance of inflammation and fibrosis through the production of pro-inflammatory mediators and collagen type I. Reports that TCDD exposure disrupts hepatic retinoid homeostasis and dysregulates extracellular matrix remodeling in the liver led us to speculate that TCDD treatment may disrupt HSC activity. The human HSC line LX-2 was used to test the hypothesis that TCDD treatment directly activates HSCs. Results indicate that exposure to 10 nM TCDD almost completely inhibited lipid droplet storage in LX-2 cells cultured with retinol and palmitic acid. TCDD treatment also increased LX-2 cell proliferation, expression of α-smooth muscle actin, and production of monocyte chemoattractant protein-1 (MCP-1), all of which are characteristics of activated HSCs. However, TCDD treatment had no effect on Col1a1 mRNA levels in LX-2 cells stimulated with the potent profibrogenic mediator, transforming growth factor-β. The TCDD-mediated increase in LX-2 cell proliferation, but not MCP-1 production, was abolished when phosphoinositide 3-kinase was inhibited. These results indicate that HSCs are susceptible to direct modulation by TCDD and that TCDD likely increases HSC activation through a multifaceted mechanism. PMID:26860701

  18. Long-term fate and bioavailability of sediment associated 2,3,7,8-tetrachlorodibenzofuran in littoral enclosures

    SciTech Connect

    Currie, R.S.; Fairchild, W.L.; Holoka, M.H.; Muir, D.C.G.

    2000-06-01

    the fate and bioavailability of 2,3,7,8-tetrachlorodibenzofuran (TCDF; 4,6-tritium labeled) was examined over a 3-year period in littoral enclosures in a small oligotrophic lake in the Experimental Lakes Area. Tetrachlorodibenzofuran was added as a single dose or as five small multiple additions over a 5-d period in a sediment slurry. Tetrachlorodibenzofuran was rapidly redistributed, mainly to bottom sediments reflecting removal on settling particles. Between 0 and 120 d. 80 to 90% of TCDF in the water column was associated with particles (>1 {micro}m). The highest concentration of TCDF in suspended particles was consistently observed in the smallest size fraction (0.22--1 {micro}m) at 326 to 464 d post treatment. Mode of addition had no effect on TCDF concentrations in water or surficial sediments or pore waters throughout the experiment. Mean TCDF concentrations in surficial sediment were 1.830 {+-} 1.180 pg/g whereas they averaged 1.260 {+-} 596 pg/g OC from 318 to 851 d post treatment. Increasing concentrations of TCDE in lower sediment layers at 952 d suggests that TCDF was either diffusing into the sediment or undergoing burial. Fugacity (f) calculations indicated that the TCDF in enclosures shifted from disequilibrium favoring the water column to a disequilibrium with respect to bottom sediments from day 21 onward. Initially, TCDF was more bioavailable to filtering and deposit feeders (mussels, Chironomidae, Hexagenia sp., and zooplankton) in enclosures receiving multiple additions; however, differences were rarely statistically significant. Concentrations of TCDF in all organisms were initially high, and they decreased in later sampling periods. Biota--sediment-accumulation factors (BSAFs) in mussels and crayfish were >1 in the early sampling periods, which reflected greater bioavailability of the added particle-borne TCDF. By 851 d, BSAFs had declined to 0.02 to 0.04, reflecting removal of TCDF from the water column and from surficial sediments.

  19. Aromatic hydrocarbon responsiveness-receptor agonists generated from indole-3-carbinol in vitro and in vivo: Comparisons with 2,3,7,8-tetrachlorodibenzo-p-dioxin

    SciTech Connect

    Bjeldanes, L.F.; Jinyoung Kim; Grose, K.R.; Bartholomew, J.C. ); Bradfield, C.A. )

    1991-11-01

    Indole-3-carbinol (I3C) is a secondary plant metabolite produced in vegetables of the Brassica genus, including cabbage, cauliflower, and brussels sprouts. I3C is both an anti-initiator and a promoter of carcinogenesis. Consumption of I3C by humans and rodents can lead to marked increases in activities of cytochrome P-450-dependent monooxygenases and in a variety of phase II drug-metabolizing enzymes. The authors have reported previously that the enzyme-inducing activity of I3C is mediated through a mechanism requiring exposure of the compound to the low-pH environment of the stomach. They report here the aromatic hydrocarbon responsiveness-receptor K{sub d} values (22 nM-90 nM), determined with C57BL/6J mouse liver cytosol and the in vitro- and in vivo-molar yields of the major acid condensation products of I3C. They also show that indolo (3,2-b)carbazole (ICZ) is produced form I3C in yields on the order of 0.01% in vitro and, after oral intubation, in vivo. ICZ has a K{sub d} of 190 pM for aromatic hydrocarbon responsiveness-receptor binding and an EC{sub 50} of 269 nM for induction of cytochrome P4501A1, as measured by ethoxyresorufin O-deethylase activity in murine hepatoma Hepa 1c1c7 cells. The binding affinity of ICZ is only a factor of 3.7 {times} 10{sup {minus}2} lower than that of the highly toxic environmental contaminant and cancer promoter 2,3,7,8-tetrachlorodibenzo-p-dioxin. ICZ and related condensation products appear responsible for the enzyme-inducing effects of dietary I3C.

  20. Potentiation and antagonism of 2,3,7,8-tetrachlorodibenzo-p-dioxin effects in a complex environmental mixture.

    PubMed

    Silkworth, J B; Cutler, D S; O'Keefe, P W; Lipinskas, T

    1993-04-01

    There is increasing need to understand the toxicity of complex environmental mixtures. The organic phase of a leachate (OPL) from the Love Canal chemical dump site is a complex mixture that contains over 100 organic compounds, including 0.74 ppm 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Mice congenic at the Ah locus were used to evaluate several toxic effects of the OPL, including immune function and hepatic enzyme induction. OPL toxicity was compared with that of pure TCDD in both C57BL/6J Ahb/b and congenic C57BL/6 Ahd/d (B6.D2) mice. Mice were given single oral doses of up to 2 g OPL/kg or 100 micrograms TCDD/kg, immunized, and evaluated after 7 days. The TCDD equivalent of the OPL was determined to be 3.9 and 5.0 ppm in C57BL/6J and B6.D2 mice, respectively. This is six times the TCDD content. The Ah phenotype-dependent response ratio was calculated by dividing the dose required to cause an effect in the B6.D2 strain by the dose causing the same effect in the C57BL/6J strain. Ratios based on both ED50s and the lowest observed adverse effect levels were used to determine whether each adverse effect was Ah phenotype-dependent, the extent to which TCDD contributed to the effect, whether there were interactive effects between the AhR ligands and nonligands and if they were additive, antagonistic, or synergistic, and whether the response was predictable based on the known chemical composition of the mixture. It was concluded that the non-TCDD component potentiated TCDD immune suppression, and possibly thymic atrophy, through AhR mechanisms. In contrast, this analysis indicated that the non-TCDD component of the OPL antagonized the ability of the TCDD component to induce hepatic AHH activity whereas OPL hepatomegaly was caused primarily by the non-TCDD component of the OPL. This study demonstrates that the toxicity of mixtures containing TCDD may not be accurately predicted based on the TCDD content alone and that this approach could be useful in the toxicologic

  1. Insulin-like growth factor binding protein 7 modulates estrogen-induced trophoblast proliferation and invasion in HTR-8 and JEG-3 cells.

    PubMed

    Liu, Zhen-Kun; Liu, Hai-Yan; Fang, Wen-Ning; Yang, Ying; Wang, Hong-Mei; Peng, Jing-Pian

    2012-05-01

    Previous research has reported that IGFBP7 functions as a tumor suppressor gene in different tumors, but its role in the trophoblast has not been elucidated. In this research, we studied the regulation mechanism of IGFBP7 in trophoblast proliferation and invasion in HTR-8 and JEG-3 cell lines. We found that IGFBP7 was abundantly expressed in normal human syncytiotrophoblast tissue samples but that this was lacking in hydatidiform moles. The proliferation and invasion capacities of HTR-8 and JEG-3 cells were significantly inhibited by recombinant IGFBP7. Estrogen (E2) stimulated the expression of IGFBP7 at a concentration of 5-10 ng/mL. This stimulation was inhibited by the estrogen receptor antagonist Fulvestrant (ICI182.780) and a TGFβ-neutralizing antibody. In conclusion, our data reveals that estrogen stimulates the expression of IGFBP7 through estrogen receptors and TGFβ. The expression of IGFBP7 could be stimulated by TGFβ in a dose-dependent manner and inhibited by IFNγ in HTR-8 and JEG-3 cells. IGFBP7 could also inhibit the phosphorylation of ERK and the expression of PCNA, MMP2 and MMP9 in HTR-8 and JEG-3 cells. These findings suggest that IGFBP7 is a key regulator of E2-induced trophoblast proliferation and invasion.

  2. Inter-strain heterogeneity in rat hepatic transcriptomic responses to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)

    SciTech Connect

    Yao, Cindy Q.; Prokopec, Stephenie D.; Watson, John D.; Pang, Renee; P'ng, Christine; Chong, Lauren C.; Harding, Nicholas J.; Pohjanvirta, Raimo; Okey, Allan B.; Boutros, Paul C.

    2012-04-15

    The biochemical and toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) have been the subject of intense study for decades. It is now clear that essentially all TCDD-induced toxicities are mediated by DNA–protein interactions involving the Aryl Hydrocarbon Receptor (AHR). Nevertheless, it remains unknown which AHR target genes cause TCDD toxicities. Several groups, including our own, have developed rodent model systems to probe these questions. mRNA expression profiling of these model systems has revealed significant inter-species heterogeneity in rodent hepatic responses to TCDD. It has remained unclear if this variability also exists within a species, amongst rodent strains. To resolve this question, we profiled the hepatic transcriptomic response to TCDD of diverse rat strains (L-E, H/W, F344 and Wistar rats) and two lines derived from L-E × H/W crosses, at consistent age, sex, and dosing (100 μg/kg TCDD for 19 h). Using this uniquely consistent dataset, we show that the majority of TCDD-induced alterations in mRNA abundance are strain/line-specific: only 11 genes were affected by TCDD across all strains, including well-known dioxin-responsive genes such as Cyp1a1 and Nqo1. Our analysis identified two novel universally dioxin-responsive genes as well as 4 genes induced by TCDD in dioxin-sensitive rats only. These 6 genes are strong candidates to explain TCDD-related toxicities, so we validated them using 152 animals in time-course (0 to 384 h) and dose–response (0 to 3000 μg/kg) experiments. This study reveals that different rat strains exhibit dramatic transcriptional heterogeneity in their hepatic responses to TCDD and that inter-strain comparisons can help identify candidate toxicity-related genes.

  3. Embryotoxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin in the ring-necked pheasant

    SciTech Connect

    Nosek, J.A.; Craven, S.R. . Dept. of Wildlife Ecology); Sullivan, J.R. . Wisconsin Dept. of Natural Resources); Gendron-Fitzpatrick, A. . Research Animal Veterinarian and Research Animal Resource Committee); Peterson, R.E. . School of Pharmacy and Environmental Toxicology Center)

    1993-07-01

    Fertilized eggs of ring-necked pheasants (Phasianus colchicus) were injected into the albumin or yolk with vehicle or graded doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), on day 0 of embryonic development and toxicity was assessed in 1-d-old hatchlings and 28-d-old chicks. The most sensitive effect of in ovo TCDD exposure was induction of hepatic ethoxyresorufin-O-deethylase (EROD) activity in 1-d-old hatchlings. The ED50 for this response was 312 pg TCDD/g egg. Embryo mortality was the most sensitive sign of toxicity. The TCDD dose that caused 50% mortality above control (LD50) when injected into the egg albumin or yolk was 1,354 and 2,182 pg TCDD/g egg, respectively. At egg TCDD doses up to and including 1,000 pg TCDD/g egg, no effect was detected in 1-d-old hatchlings and 28-d-old chicks in body growth, organ weights, carcass morphometrices, incidence of edema, or incidence of histological alterations in the liver, spleen, heart, Bursa of Fabricius, or thymus. Egg TCDD doses as high as 1,000 pg TCDD/g egg also had no effect on cardiac morphometrices or incidence of cardiac malformations in 1-d-old hatchlings, or on antibody-mediated immunity in 28-d-old chicks. The authors conclude that embryo mortality is the most sensitive sign of TCDD toxicity in the ring-necked pheasant following in ovo exposure.

  4. 2,3,7,8-Tetracholorodibenzo-p-dioxin exposure disrupts granule neuron precursor maturation in the developing mouse cerebellum.

    PubMed

    Collins, Loretta L; Williamson, Mary A; Thompson, Bryan D; Dever, Daniel P; Gasiewicz, Thomas A; Opanashuk, Lisa A

    2008-05-01

    The widespread environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has been linked to developmental neurotoxicity associated with abnormal cerebellar maturation in both humans and rodents. TCDD mediates toxicity via binding to the aryl hydrocarbon receptor (AhR), a transcription factor that regulates the expression of xenobiotic metabolizing enzymes and growth regulatory molecules. Our previous studies demonstrated that cerebellar granule neuron precursor cells (GNPs) express transcriptionally active AhR during critical developmental periods. TCDD exposure also impaired GNP proliferation and survival in vitro. Therefore, this study tested the hypothesis that TCDD exposure disrupts cerebellar development by interfering with GNP differentiation. In vivo experiments indicated that TCDD exposure on postnatal day (PND) 6 resulted in increased expression of a mitotic marker and increased thickness of the external granule layer (EGL) on PND10. Expression of the early differentiation marker TAG-1 was also more pronounced in postmitotic, premigratory granule neurons of the EGL, and increased apoptosis of GNPs was observed. On PND21, expression of the late GNP differentiation marker GABA(A alpha 6) receptor (GABAR(A alpha 6)) and total estimated cell numbers were both reduced following exposure on PND6. Studies in unexposed adult AhR(-/-) mice revealed lower GABAR(A alpha 6) levels and DNA content. In vitro studies showed elevated expression of the early differentiation marker p27/Kip1 and the GABAR(A alpha 6) in GNPs following TCDD exposure, and the expression patterns of proteins related to granule cell neurite outgrowth, beta III-tubulin and polysialic acid neural cell adhesion molecule, were consistent with enhanced neuroblast differentiation. Together, our data suggest that TCDD disrupts a normal physiological role of AhR, resulting in compromised GNP maturation and neuroblast survival, which impacts final cell number in the cerebellum.

  5. Inhibition of apoptosis by 2,3,7,8-tetrachlorodibenzo-p-dioxin depends on protein biosynthesis.

    PubMed

    Chopra, Martin; Gährs, Maike; Haben, Melina; Michels, Christine; Schrenk, Dieter

    2010-08-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a highly toxic persistent organic pollutant. Most of the toxic effects of TCDD are believed to be mediated by high-affinity binding to the aryl hydrocarbon receptor (AhR) and subsequent effects on gene transcription and protein expression. TCDD causes cancer in multiple tissues in different animal species and is classified as a class 1 human carcinogen. In initiation-promotion studies, TCDD was shown to be a potent liver-tumor promotor. Among other theories it has been hypothesized that TCDD promotes tumor growth by preventing initiated cells from correctly executing apoptosis. In this study, we examined the effects of TCDD on apoptosis induced by UV-C light, ochratoxin A (OTA), and cycloheximide (CHX) in primary rat hepatocytes. Both UV-C light and OTA caused caspase activation and nuclear apoptotic effects. CHX did not activate caspases but nevertheless caused DNA fragmentation and chromatin condensation. TCDD inhibited UV-C light-induced apoptosis and this effect seemed to be dependent on AhR-activation as was shown by employing an AhR antagonist. In contrast to UV-C light-induced apoptosis, TCDD failed to protect primary rat hepatocytes from OTA- or CHX-induced apoptosis. Since both of these compounds inhibit protein biosynthesis as was demonstrated by measuring the incorporation of radiolabeled leucin and protein expression of cytochrome P450 1A1, we propose that the inhibition of apoptosis by TCDD depends on protein biosynthesis. Either TCDD induces some anti-apoptotic protein in an AhR-dependent manner or inhibits pro-apoptotic proteins induced by UV irradiation.

  6. Aryl hydrocarbon receptor activation by 2,3,7,8-tetrachlorodibenzo-p-dioxin impairs human B lymphopoiesis.

    PubMed

    Li, Jinpeng; Phadnis-Moghe, Ashwini S; Crawford, Robert B; Kaminski, Norbert E

    2017-03-01

    The homeostasis of peripheral B cell compartment requires lifelong B lymphopoiesis from hematopoietic stem cells (HSC). As a result, the B cell repertoire is susceptible to disruptions of hematopoiesis. Increasing evidence, primarily from rodent models, shows that the aryl hydrocarbon receptor (AHR) regulates hematopoiesis. To study the effects of persistent AHR activation on human B cell development, a potent AHR agonist and known environmental contaminant, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was utilized. An in vitro B cell development model system was established by co-culturing human cord blood-derived HSCs with irradiated human primary bone marrow stromal cells. Using this in vitro model, we found that TCDD significantly suppressed the total number of hematopoietic stem and progenitor cells (HSPC) in a concentration-dependent manner. Cell death analysis demonstrated that the decrease in cell number was not due to cytotoxicity by TCDD. In addition, TCDD markedly decreased CD34 expression on HSPCs. Structure-activity relationship studies using dioxin congeners demonstrated a correlation between the relative AHR binding affinity and the magnitude of decrease in the number of HSPCs and CD34 expression, suggesting that AHR mediates the observed TCDD-elicited changes in HSPCs. Moreover, a significant reduction in lineage committed B cell-derived from HSCs was observed in the presence of TCDD, indicating impairment of human B cell development. Similar effects of TCDD were observed regardless of the use of stromal cells in cultures indicating a direct effect of TCDD on HSCs. Collectively, we demonstrate that AHR activation by TCDD on human HSCs impairs early stages of human B lymphopoiesis.

  7. Synergistic effects of tributyltin and 2,3,7,8-tetrachlorodibenzo-p-dioxin on differentiating osteoblasts and osteoclasts

    SciTech Connect

    Koskela, Antti; Viluksela, Matti; Keinänen, Meeri; Tuukkanen, Juha; Korkalainen, Merja

    2012-09-01

    The purpose of this study was to examine the effects of the persistent and accumulative environmental pollutants tributyltin (TBT) and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) individually and in combination on differentiating bone cells. TBT and TCDD are chemically distinct compounds with different mechanisms of toxicity, but they typically have the same sources of exposure and both have been shown to affect bone development at low exposure levels. Bone marrow stem cells were isolated from femurs and tibias of C57BL/6 J mice, differentiated in culture into osteoblasts or osteoclasts and exposed to 0.1–10 nM TBT, 0.01–1 nM TCDD or 10 nM TBT + 1 nM TCDD. In osteoblasts, the combined exposure to TBT and TCDD significantly decreased the mRNA expression of alkaline phosphatase and osteocalcin more than TBT or TCDD alone. PCR array showed different gene expression profiles for TBT and TCDD individually, and the combination evoked several additional alterations in gene expression. Expression of aryl hydrocarbon receptor repressor (AHRR) was increased by TCDD as expected, but simultaneous exposure to TBT prevented the increase thus potentially strengthening AHR-mediated effects of TCDD. The number of osteoclasts was reduced by TCDD alone and in combination with TBT, but TBT alone had no effect. However, the total area of resorbed bone was remarkably lower after combined exposure than after TBT or TCDD alone. In conclusion, very low concentrations of TBT and TCDD have synergistic deleterious effects on bone formation and additive effects on bone resorption. -- Highlights: ► Combined exposure to TCDD and TBT evoked a unique gene expression profile. ► Osteoblast differentiation was synergistically disturbed after combined exposure. ► Bone resorbing activity was additively decreased after combined exposure.

  8. Determination of ( sup 3 H)-2,3,7,8-tetrachlorodibenzo-p-dioxin in human feces to ascertain its relative metabolism in man

    SciTech Connect

    Wendling, J.M.; Orth, R.G.; Poiger, H. )

    1990-04-15

    Human feces samples from a self-dosing experiment were analyzed by gas chromatography/mass spectrometry (GC/MS) for ({sup 3}H)-2,3,7,8-tetrachlorodibenzo-p-dioxin ({sup 3}H-2378-TCDD) to determine that 36-44% of the radioactivity was attributable to the parent compound. This method, using isotope dilution analysis, proved to be difficult due to the unexpectedly higher native 2378-TCDD background which created abnormally large precision ranges around the calculated feces concentrations of 0.1-0.2 pg/g. These results were supported by additional analyses involving the GC/MS chemical cleanup method combined with liquid scintillation counting which showed that at most, 50% of the radioactivity was due to 2378-TCDD metabolites resulting in a minimum metabolism of 50% for these samples.

  9. Optical Temperature Sensor Through Upconversion Emission from the Er3+ Doped SrBi8Ti7O27 Ferroelectrics

    NASA Astrophysics Data System (ADS)

    Zou, Hua; Wang, Xusheng; Hu, Yifeng; Zhu, Xiaoqing; Sui, Yongxing; Song, Zhitang

    2016-06-01

    Er doped SrBi8Ti7O27 (SBT) ferroelectric ceramics were prepared by a solid-state reaction technique. By Er doping, the intensive green upconversion emissions were recorded under 980 nm diode laser excitation with 20 mW. The fluorescence spectrum was investigated in the temperature range of 150-580 K. By the fluorescence intensity ratio technique, the green emission band was studied as a function of temperature with a maximum sensing sensitivity of 0.0028 at 510 K. These results indicate that the Er doped SBT ferroelectric ceramics are promising multifunctional sensing materials.

  10. Effects of Cooling Rates on Glass Formation and Magnetic Behavior for the Fe73.0C7.0Si3.3B5.0P8.7Mo3.0 Bulk Metallic Glass

    NASA Astrophysics Data System (ADS)

    Gao, J. E.; Li, H. X.; Jiang, F.; Winiarski, B.; Withers, P. J.; Liaw, P. K.; Lu, Z. P.

    2013-05-01

    In this paper, effects of cooling rates on glass formation and magnetic behavior of the Fe73.0C7.0Si3.3B5.0P8.7Mo3.0 (at. pct) alloy were investigated via different purging gases ( i.e., helium and argon) during suction casting. X-ray diffraction patterns and transmission electron microscopy characterization confirmed that the maximum attainable diameter for glass formation is increased from 5 to 7 mm with the helium as the purging gas, relative to the argon. Meanwhile, the coercivity value ( H c) of the sample cast in helium is almost 5 times larger than that fabricated in argon, although the magnetization saturation in these two alloys is similar. Our pair distribution function analysis, density, and positron annihilation lifetime spectroscopy measurements indicated that the sample cast in helium possesses more free volume; however, the difference between them is insubstantial. Further, experimental results revealed that the residual stress in the samples cast under helium is much larger than that in those prepared in Argon, which could be responsible for the abrupt change in the coercivity.

  11. Synthesis and luminescence of Eu(3+)-doped in triple phosphate Ca8MgBi(PO4)7 with whitlockite structure.

    PubMed

    Zhang, Zhi-Wei; Ren, Yan-Jun; Liu, Lu; Zhang, Jian-Ping; Peng, You-Shun

    2015-12-01

    Triple whitlockite-type structure-based red phosphors Ca8 MgBi1-x(PO4)7:xEu(3+) (x = 0.10, 0.20, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80 and 1.00) were synthesized by a conventional solid-state reaction route and characterized by their X-ray crystal structures. The X-ray diffraction (XRD) patterns, Fourier transform infrared spectra, morphologies, photoluminescence spectra, UV/Vis reflectance spectra, decay times and the International Commission on Illumination (CIE) chromaticity coordinates of Ca8MgBi1-x(PO4)7:xEu(3+) were analyzed. Eu-doped Ca8MgBi(PO4)7 phosphors exhibited strong red luminescence with peaks at 616 nm due to the (5)D0 → (7)F2 electric dipole transition of Eu(3+) ions after excitation at 396 nm. The UV/Vis spectra indicated that the band gap of Ca8MgBi0.30(PO4)7:0.70Eu(3+) is larger than that of Ca8MgBi(PO4)7. The phosphor developed in this study has great potential as a red-light-emitting phosphor for UV light-emitting diodes.

  12. Coulomb Stress Change and Seismic Hazard of Rift Zones in Southern Tibet after the 2015 Mw7.8 Nepal Earthquake and Its Mw7.3 Aftershock

    NASA Astrophysics Data System (ADS)

    Dai, Z.; Zha, X.; Lu, Z.

    2015-12-01

    In southern Tibet (30~34N, 80~95E), many north-trending rifts, such as Yadong-Gulu and Lunggar rifts, are characterized by internally drained graben or half-graben basins bounded by active normal faults. Some developed rifts have become a portion of important transportation lines in Tibet, China. Since 1976, eighty-seven >Mw5.0 earthquakes have happened in the rift regions, and fifty-five events have normal faulting focal mechanisms according to the GCMT catalog. These rifts and normal faults are associated with both the EW-trending extension of the southern Tibet and the convergence between Indian and Tibet. The 2015 Mw7.8 Nepal great earthquake and its Mw7.3 aftershock occurred at the main Himalayan Thrust zone and caused tremendous damages in Kathmandu region. Those earthquakes will lead to significant viscoelastic deformation and stress changes in the southern Tibet in the future. To evaluate the seismic hazard in the active rift regions in southern Tibet, we modeled the slip distribution of the 2015 Nepal great earthquakes using the InSAR displacement field from the ALOS-2 satellite SAR data, and calculated the Coulomb failure stress (CFS) on these active normal faults in the rift zones. Because the estimated CFS depends on the geometrical parameters of receiver faults, it is necessary to get the accurate fault parameters in the rift zones. Some historical earthquakes have been studied using the field data, teleseismic data and InSAR observations, but results are in not agreement with each other. In this study, we revaluated the geometrical parameters of seismogenic faults occurred in the rift zones using some high-quality coseismic InSAR observations and teleseismic body-wave data. Finally, we will evaluate the seismic hazard in the rift zones according to the value of the estimated CFS and aftershock distribution.

  13. 2,3,7,8-TCDD enhances the sensitivity of mice to concanavalin A immune-mediated liver injury

    SciTech Connect

    Fullerton, Aaron M.; Roth, Robert A.; Ganey, Patricia E.

    2013-01-15

    Inflammation plays a major role in immune-mediated liver injury, and exposure to environmental pollutants such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) has been reported to alter the inflammatory response as well as affect immune cell activity. In this study, we tested the hypothesis that TCDD pretreatment exacerbates hepatotoxicity in a murine model of immune-mediated liver injury induced by concanavalin A (Con A) administration. Mice were pretreated with 30 μg/kg TCDD or vehicle control on day zero and then given either Con A or saline intravenously on day four. Mice treated with TCDD did not develop liver injury; however, TCDD pretreatment increased liver injury resulting from moderate doses of Con A (4–10 mg/kg). TCDD-pretreated mice had altered plasma concentrations of inflammatory cytokines, including interferon gamma (IFNγ), and TCDD/Con A-induced hepatotoxicity was attenuated in IFNγ knockout mice. At various times after treatment, intrahepatic immune cells were isolated, and expression of cell activation markers as well as cytolytic proteins was determined. TCDD pretreatment increased the proportion of activated natural killer T (NKT) cells and the percent of cells expressing Fas ligand (FasL) after Con A administration. In addition FasL knockout mice and mice treated with CD18 antiserum were both protected from TCDD/Con A-induced hepatotoxicity, suggesting a requirement for direct cell–cell interaction between effector immune cells and parenchymal cell targets in the development of liver injury from TCDD/Con A treatment. In summary, exposure to TCDD increased NKT cell activation and exacerbated immune-mediated liver injury induced by Con A through a mechanism involving IFNγ and FasL expression. -- Highlights: ► TCDD pretreatment sensitizes mice to Con A-induced hepatotoxicity. ► TCDD pretreatment increased concentration of IFNγ in plasma after Con A. ► Con A-induced activation of NKT cells was increased by TCDD pretreatment. ► Fas

  14. 2,3,7,8-Tetrachlorodibenzo-p-dioxin stimulates proliferation of HAPI microglia by affecting the Akt/GSK-3β/cyclin D1 signaling pathway.

    PubMed

    Xu, Guangfei; Li, Yuanye; Yoshimoto, Katsuhiko; Wu, Qiyun; Chen, Gang; Iwata, Takeo; Mizusawa, Noriko; Wan, Chunhua; Nie, Xiaoke

    2014-01-30

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an environmental toxin that induces apoptosis of neurons and a pro-inflammatory response in microglial cells. First, we found that TCDD induced proliferation of HAPI microglial cells in a dose- and time-dependent manner. Flow cytometry analysis showed that this proliferation by TCDD was due to mainly enhancing the G1 to S phase transition. Next, it was found that TCDD treatment led to up-regulation of cyclin D1, which induces cell cycle progression from G1 to S phase, in a time-dependent manner. As for molecular mechanism, we revealed that TCDD was capable of inducing Akt phosphorylation and activation, resulting in phosphorylation and inactivation of glycogen synthase kinase-3β (GSK-3β). Inactivated GSK-3β attenuated proteasomal degradation of cyclin D1 by reducing Thr(286)-phosphorylated cyclin D1 levels. Moreover, inactivated GSK-3β increased cyclin D1 gene transcription by increasing its transcription factor β-catenin in the nucleus. Further, blockage of phosphoinositide 3-kinase/Akt kinase with their specific inhibitors, LY294002 and Akt 1/2 kinase inhibitor, significantly reduced TCDD-enhanced proliferation of HAPI microglial cells. In conclusion, TCDD stimulates proliferation of HAPI microglial cells by affecting the Akt/GSK-3β/cyclin D1 signaling pathway.

  15. Sintered powder cores of high Bs and low coreloss Fe84.3Si4B8P3Cu0.7 nano-crystalline alloy

    NASA Astrophysics Data System (ADS)

    Zhang, Yan; Sharma, Parmanand; Makino, Akihiro

    2013-06-01

    Nano-crystalline Fe-rich Fe84.3Si4B8P3Cu0.7 alloy ribbon with saturation magnetic flux density (Bs) close to Si-steel exhibits much lower core loss (Wt) than Si-Steels. Low glass forming ability of this alloy limits fabrication of magnetic cores only to stack/wound types. Here, we report on fabrication, structural, thermal and magnetic properties of bulk Fe84.3Si4B8P3Cu0.7 cores. Partially crystallized ribbons (obtained after salt-bath annealing treatment) were crushed into powdered form (by ball milling), and were compacted to high-density (˜88%) bulk cores by spark plasma sintering (SPS). Nano-crystalline structure (consisting of α-Fe grain in remaining amorphous matrix) similar to wound ribbon cores is preserved in the compacted cores. At 50 Hz, cores sintered at Ts = 680 K show Wt < 10 W/kg (f = 50 Hz, Bm ˜1 T). Coating/mixing of powders with an insulating agent like SiO2 is shown to be effective in further reduction of Wt at f > 1 kHz. A trade-off between porosity and electrical resistivity is necessary to get low Wt at higher f. In the f range of ˜1 to 100 kHz, we have shown that the cores mixed with SiO2 exhibit much lower Wt than Fe-powder cores, non-oriented Si-steel sheets and commercially available sintered cores. We believe our core material is very promising to make power electronics/electrical devices much more energy-efficient.

  16. Dietary Omega-3 Polyunsaturated Fatty Acids Prevent Vascular Dysfunction and Attenuate Cytochrome P4501A1 Expression by 2,3,7,8-Tetrachlorodibenzo-P-Dioxin.

    PubMed

    Wiest, Elani F; Walsh-Wilcox, Mary T; Rothe, Michael; Schunck, Wolf-Hagen; Walker, Mary K

    2016-11-01

    Omega-3 polyunsaturated fatty acids (n-3 PUFAs) found in fish protect against cardiovascular morbidity and mortality; however, many individuals avoid fish consumption due to concerns about pollutants. We tested the hypothesis that n-3 PUFAs would prevent vascular dysfunction induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). C57Bl/6 male mice were fed a chow or n-3 PUFA diet for 10 weeks and were exposed to vehicle or 300 ng/kg/d TCDD during the final 2 weeks on each diet. Aortic vasoconstriction mediated by arachidonic acid (AA) ± SKF525 (P450 inhibitor) or SQ29548 (thromboxane/prostanoid [TP] receptor antagonist) was assessed. RBC fatty acids and expression of n-3 and n-6 PUFA metabolites were analyzed. Cytochrome P4501A1 (CYP1A1), CYP1B1, and aryl hydrocarbon receptor (AHR) expression was measured. TCDD significantly increased AA-mediated vasoconstriction on a chow diet by increasing the contribution of P450s and TP receptor to the constriction response. In contrast, the n-3 PUFA diet prevented the TCDD-induced increase in AA vasoconstriction and normalized the contribution of P450s and TP receptor. Although TCDD increased the levels of AA vasoconstrictors on the chow diet, this increase was prevent by the n-3 PUFA diet. Additionally, the n-3 PUFA diet significantly increased the levels of n-3 PUFA-derived vasodilators and TCDD increased these levels further. Interestingly, the n-3 PUFA diet significantly attenuated CYP1A1 induction by TCDD without a significant effect on AHR expression. These data suggest that n-3 PUFAs can prevent TCDD-induced vascular dysfunction by decreasing vasoconstrictors, increasing vasodilators, and attenuating CYP1A1 induction, which has been shown previously to contribute to TCDD-induced vascular dysfunction.

  17. Synthesis and resolution of (+-)-7-chloro-8-hydroxy-1-(3'-iodophenyl)-3-methyl-2,3,4,5-tetrahydro- 1H-3- benzazepine (TISCH): A high affinity and selective iodinated ligand for CNS D1 dopamine receptor

    SciTech Connect

    Chumpradit, S.; Kung, M.P.; Billings, J.J.; Kung, H.F. )

    1991-03-01

    The synthesis and resolution of (+-)-7-chloro-8-hydroxy-1-(3'-iodophenyl)-3-methyl-2,3,4,5-tetrahydro-1 H-3- benzazepine, (+/-)-TISCH (8) has been achieved by resolution of intermediate 4, the O-methoxyl, 3'-bromo derivative, as the diastereomeric camphor sulfonate salt. The final products, R-(+)-8 and S-(-)-8, were prepared by treatment of R-(+)- or S-(-)-7, the 3'-tributyltin intermediates, with iodine in chloroform, followed by O-demethylation. By using HPLC with a chiral column, the optical purity (greater than 99%) of the intermediates and the final compounds was determined. Radioiodination was achieved by an iodo-destannylation reaction with sodium (125I)iodide and hydrogen peroxide. As expected, the R-(+)-(125I)-8 (the active isomer) displayed high affinity and selectivity to the CNS D-1 receptor in rat striatum tissue preparation (Kd = 0.205 nM). The rank order of potency was as follows: SCH-23390 (1a) greater than (+/-)-8 greater than (+)-butaclamol greater than spiperone, WB4101 greater than dopamine, 5-HT. After an iv injection, the R-(+)-(125I)-8 penetrated the blood-brain barrier with ease and displayed specific regional distribution corresponding to the D-1 receptor density, while the S-(-)-(125I)-8 showed no specific uptake. The data suggest that the ligand may be useful as a pharmacological tool for characterizing the D-1 dopamine receptor. When labeled with I-123, this ligand is a potential agent for in vivo imaging of CNS D-1 dopamine receptor.

  18. 2,3,7,8-Substituted PCDDs and PCDFs in sea lion (Otaria flavescens) skin biopsies from two South-western Atlantic populations.

    PubMed

    Jimènez, B; Gonzàlez, M J; Hernández, L M; Eljarrat, E; Rivera, J; Fossi, M C

    1999-02-01

    Congener specific 2,3,7,8-chlorinated PCDDs and PCDFs were determined in skin biopsies taken from sea lions (Otaria flavescens) living in two areas of the South-western Atlantic on the coast of Argentina (Mar del Plata and Punta Bermeja). This is the first report on PCDDs and PCDFs in sea lion skin biopsies from the southern hemisphere. Differences were found in the congener pattern according to the sampling area. Animals living in the polluted area (Mar del Plata harbour) had detectable levels of all seventeen 2,3,7,8-substituted congeners. Sea lions living in a control environment (Punta Bermeja, Patagonia) only exhibited 5 detectable congeners out of all seventeen 2,3,7,8-substituted congeners. However, total levels were low in both colonies studied. These data are consistent with previous work which has indicated that dioxins occur at relatively low levels in marine mammals, possibly due to rapid catabolism or elimination.

  19. Current skin symptoms of Yusho patients exposed to high levels of 2,3,4,7,8-pentachlorinated dibenzofuran and polychlorinated biphenyls in 1968.

    PubMed

    Mitoma, Chikage; Mine, Yoshiko; Utani, Atsushi; Imafuku, Shinichi; Muto, Masahiko; Akimoto, Takamichi; Kanekura, Takuro; Furue, Masutaka; Uchi, Hiroshi

    2015-10-01

    Yusho was a mass food poisoning event due to the ingestion of rice oil contaminated with polychlorinated biphenyls (PCBs) and various dioxins and dioxin-like compounds. At its outbreak in 1968, Yusho patients suffered severe skin symptoms. Although the blood concentrations of PCBs and dioxins, especially highly toxic 2,3,4,7,8-pentachlorinated dibenzofuran (2,3,4,7,8-PeCDF) remain high in these patients, extensive analysis has not been performed on their current skin symptoms. We categorized and evaluated the specific skin symptoms in Yusho in 2012 by grading their severity using an arbitrary scoring system, and analyzed their correlations with the blood concentrations of 2,3,4,7,8-PeCDF and PCBs. A total of 352 Yusho patients underwent annual dermatological check-ups, in which five skin symptoms: black comedones, acneiform eruptions, scar formation, pigmentation and nail deformity, were evaluated for their distribution and severity. Approximately one-third of Yusho patients still presented with black comedones, acneiform eruptions and scar formation; the distributions of these symptoms were similar to those at the time of the Yusho outbreak. The mean blood concentrations of 2,3,4,7,8-PeCDF and total PCBs in Yusho patients were still higher than those in controls. The prevalence and severity of black comedones were correlated with age. Severity scores of black comedones and scar formation were positively correlated with 2,3,4,7,8-PeCDF blood level, and those of black comedones, scar formation, and pigmentation were positively correlated with total PCBs blood level. This study suggests that 2,3,4,7,8-PeCDF and PCBs remaining in Yusho patients still play crucial roles in the development of skin symptoms in Yusho.

  20. Love Canal Emergency Declaration Area habitability study. Volume 4. Soil assessment: 2,3,7,8-TCDD (tetrachlorodibenzo-p-dioxin). Final report

    SciTech Connect

    Not Available

    1988-03-01

    Environmental studies were conducted to provide data that could be used by the Commissioner of Health for the State of New York in determining whether the Emergency Declaration Area (EDA) surrounding the Love Canal hazardous-waste site is habitable. A soil assessment for 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was conducted to determine whether the soil in the EDA contains 2,3,7,8-TCDD at levels above the level of concern set by the Centers for Disease Control: 1.0 ppb. Samples of surface soil were collected at 2,274 locations throughout the EDA.

  1. Nucleic acid-sensing toll-like receptors 3, 7 and 8 in esophageal epithelium, barrett’s esophagus, dysplasia and adenocarcinoma

    PubMed Central

    Helminen, Olli; Huhta, Heikki; Lehenkari, Petri P.; Saarnio, Juha; Karttunen, Tuomo J.; Kauppila, Joonas H.

    2016-01-01

    ABSTRACT Toll-like receptors (TLRs) are immunological receptors recognizing various microbial and endogenous ligands, such as DNA, RNA, and other microbial and host components thus activating immunological responses. The expression of TLRs in esophageal adenocarcinoma is not well known. The aim of this study was to evaluate expression patterns of those TLRs that sense nucleic acids in Barrett’s esophagus with and without dysplasia and in esophageal adenocarcinoma. TLRs 3, 7 and 8 were stained immunohistochemically and evaluated in a cohort of patients with esophageal adenocarcinoma or dysplasia. Specimens with normal esophagus (n = 88), gastric (n = 67) or intestinal metaplasia (n = 51) without dysplasia, and low-grade (n = 42) or high-grade dysplasia (n = 37) and esophageal adenocarcinoma (n = 99) were studied. We used immunofluorescence to confirm the subcellular localization of TLRs. We found abundant expression of TLR3, 7 and 8 in esophageal squamous epithelium, columnar metaplasia, dysplasia and adenocarcinoma. Cytoplasmic expression of TLR3, TLR7 or TLR8 did not associate to clinicopathological parameters or prognosis in esophageal cancer. High nuclear expression of TLR8, confirmed with immunofluorescence, in cancer cells was observed in tumors of high T-stage (p < 0.01) and in tumors with organ metastasis (p < 0.001). High nuclear TLR8 expression was associated with poor prognosis (p < 0.001). The expression of TLR3, TLR7 and TLR8 increased toward dysplasia and adenocarcinoma. We demonstrated nuclear localization of TLR8, which associates with metastasis and poor prognosis. TLR3 and TLR7 do not seem to have prognostic significance in esophageal adenocarcinoma. PMID:27467941

  2. Environmentally relevant concentrations of arsenite and monomethylarsonous acid inhibit IL-7/STAT5 cytokine signaling pathways in mouse CD3+CD4-CD8- double negative thymus cells.

    PubMed

    Xu, Huan; Lauer, Fredine T; Liu, Ke Jian; Hudson, Laurie G; Burchiel, Scott W

    2016-04-15

    Environmental arsenic exposure is a public health issue. Immunotoxicity induced by arsenic has been reported in humans and animal models. The purpose of this study was to evaluate mechanisms of As(+3) and MMA(+3) toxicity in mouse thymus cells. Because we know that MMA(+3) inhibits IL-7 signaling in mouse bone marrow pre-B cells, we studied the influence of As(+3) and MMA(+3) on T cell development in the thymus at the earliest stage of T cell development (CD4-CD8-, double negative, DN) which requires IL-7 dependent signaling. We found in a DN thymus cell line (D1) that a low concentration of MMA(+3) (50 nM) suppressed IL-7 dependent JAK1, 3 and STAT5 signaling. As(+3) suppressed STAT5 and JAK3 at higher concentrations (500 nM). Cell surface expression of the IL-7 receptor (CD127) was also suppressed by 50 nM MMA(+)3, but was increased by 500 NM As(+3), indicating possible differences in the mechanisms of action of these agents. A decrease in cyclin D1 protein expression was observed in D1 cells exposed to As(+3) at 500 nM and MMA(+3) starting at 50 nM, suggesting that arsenic at these environmentally-relevant doses suppresses early T cell development through the inhibition of IL-7 signaling pathway.

  3. Measurement of the water-octanol partition coefficient of 2,3,7,8-tetrachlorodibenzo-p-dioxin

    SciTech Connect

    Marple, L.; Berridge, B.; Throop, L.

    1986-04-01

    The problems inherent in the shake flask method for measurement of water-octanol partition coefficients were avoided by the use of a cell in which dioxin was allowed to diffuse from the octanol phase into the water phase. Starting from mutually presaturated water and octanol phases, dioxin equilibration appears to be complete within 1 week. Partition coefficients ranged from 3.48 x 10/sup 6/ to 8.87 x 10/sup 6/. Starting from unsaturated phases, we observed a rapid transport of dioxin from the octanol phase into the water phase, followed by a reversal that corresponds to the formation of hydrated dioxin. The average of all partition coefficient measurements for systems at equilibrium is (4.24 +/- 2.73) x 10/sup 6/, giving a log K/sub ow/ of 6.64. 12 references, 2 tables.

  4. Electrical transport properties of (110)-oriented PrBa2(Cu0.8Ga0.2)3O7 thin films

    NASA Astrophysics Data System (ADS)

    Kandel, Hom; Chen, Tar-Pin; Bourdo, Shawn; Iliev, Milko N.; Watanabe, Fumiya; Seo, Hye-Won; Viswanathan, Tito

    2012-06-01

    The electrical transport properties of (110)-oriented PrBa2(Cu0.8Ga0.2)3O7 (PBCGO) thin films have been investigated. The electrical resistivity, ρ(T), of (110)-oriented PBCGO thin films is 8.91 × 105 Ω-cm at 77 K, about five orders of magnitude higher than that of the (110)-oriented PrBa2Cu3O7 thin films and follows Mott's T-1/4 law up to room temperature. Our experimental results suggest filling and localization of holes in Cu-O chains of (110)-oriented PBCGO thin films. We observed very less proximity effect on YBa2Cu3O7 (YBCO)/PBCGO multilayers indicating that the (110)-oriented PBCGO thin films may serve as effective insulators in YBCO SIS tunneling Josephson junction.

  5. 7-Ketocholesterol induces ATM/ATR, Chk1/Chk2, PI3K/Akt signalings, cytotoxicity and IL-8 production in endothelial cells

    PubMed Central

    Chang, Mei-Chi; Chen, Yi-Jane; Liou, Eric Jein-Wein; Tseng, Wan-Yu; Chan, Chiu-Po; Lin, Hseuh-Jen; Liao, Wan-Chuen; Chang, Ya-Ching; Jeng, Po-Yuan; Jeng, Jiiang-Huei

    2016-01-01

    Cardiovascular diseases (atherosclerosis, stroke, myocardiac infarction etc.) are the major systemic diseases of elder peoples in the world. This is possibly due to increased levels of oxidized low-density lipoproteins (oxLDLs) such as 7-ketocholesterol (7-KC) and lysophosphatidylcholine (LPC) that damage vascular endothelial cells, induce inflammatory responses, to elevate the risk of cardiovascular diseases, Alzheimer's disease, and age-related macular degeneration. However the toxic effects of 7-KC on endothelial cells are not known. In this study, 7-KC showed cytotoxicity to endothelial cells at concentrations higher than 10 μg/ml. 7-KC stimulated ATM/Chk2, ATR-Chk1 and p53 signaling pathways in endothelial cells. 7-KC also induced G0/G1 cell cycle arrest and apoptosis with an inhibition of Cyclin dependent kinase 1 (Cdk1) and cyclin B1 expression. Secretion and expression of IL-8 in endothelial cells were stimulated by 7-KC. 7-KC further induced intracellular ROS production as shown by increase in DCF fluorescence and Akt phosphorylation. LY294002 attenuated the 7-KC-induced apoptosis and IL-8 mRNA expression of endothelial cells. These results indicate that oxLDLs such as 7-KC may contribute to the pathogenesis of atherosclerosis, thrombosis and cardiovascular diseases by induction of endothelial damage, apoptosis and inflammatory responses. These events are associated with ROS production, activation of ATM/Chk2, ATR/Chk1, p53 and PI3K/Akt signaling pathways. PMID:27740938

  6. 7-Ketocholesterol induces ATM/ATR, Chk1/Chk2, PI3K/Akt signalings, cytotoxicity and IL-8 production in endothelial cells.

    PubMed

    Chang, Mei-Chi; Chen, Yi-Jane; Liou, Eric Jein-Wein; Tseng, Wan-Yu; Chan, Chiu-Po; Lin, Hseuh-Jen; Liao, Wan-Chuen; Chang, Ya-Ching; Jeng, Po-Yuan; Jeng, Jiiang-Huei

    2016-11-15

    Cardiovascular diseases (atherosclerosis, stroke, myocardiac infarction etc.) are the major systemic diseases of elder peoples in the world. This is possibly due to increased levels of oxidized low-density lipoproteins (oxLDLs) such as 7-ketocholesterol (7-KC) and lysophosphatidylcholine (LPC) that damage vascular endothelial cells, induce inflammatory responses, to elevate the risk of cardiovascular diseases, Alzheimer's disease, and age-related macular degeneration. However the toxic effects of 7-KC on endothelial cells are not known. In this study, 7-KC showed cytotoxicity to endothelial cells at concentrations higher than 10 µg/ml. 7-KC stimulated ATM/Chk2, ATR-Chk1 and p53 signaling pathways in endothelial cells. 7-KC also induced G0/G1 cell cycle arrest and apoptosis with an inhibition of Cyclin dependent kinase 1 (Cdk1) and cyclin B1 expression. Secretion and expression of IL-8 in endothelial cells were stimulated by 7-KC. 7-KC further induced intracellular ROS production as shown by increase in DCF fluorescence and Akt phosphorylation. LY294002 attenuated the 7-KC-induced apoptosis and IL-8 mRNA expression of endothelial cells. These results indicate that oxLDLs such as 7-KC may contribute to the pathogenesis of atherosclerosis, thrombosis and cardiovascular diseases by induction of endothelial damage, apoptosis and inflammatory responses. These events are associated with ROS production, activation of ATM/Chk2, ATR/Chk1, p53 and PI3K/Akt signaling pathways.

  7. Defining the Borders of Dose Addition: Mixture Effects of 2,3,7,8-Tetrachlorodibenzo-p-dioxin and Dibutyl phthalate on Male Rat Reproductive Tract Development

    EPA Science Inventory

    In utero exposure to either dibutyl phthalate (DBP) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) disrupts male rat reproductive tract differentiation. However, they act via different modes of toxicity and induce distinct postnatal phenotypes. DBP exposure decreases anogenital di...

  8. CYP1A2 DOES NOT PLAY A CRITICAL ROLE IN 2, 3 7, 8-TETRACHLORODIBENZO-P-DIOXIN-INDUCED IMMUNOSUPRESSION

    EPA Science Inventory

    CYP1A2 IS NOT REQUIRED FOR 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN-INDUCED IMMUNOSUPPRESSION Smialowicz, Ralph J1; Burgin, Deborah E2; Williams, Wanda C1; Diliberto, Janet J1; Birnbaum, Linda S1
    1 Experimental Toxicology Division, US EPA, RTP, NC, USA; 2Curriculum in Toxicology, U...

  9. 2,3,7, 8-TETRACHLORODIBENZO-P-DIOXIN (TCDD)-MEDIATED OXIDATIVE STRESS IN FEMALE CYP1A-2 KNOCKOUT (CYP1A2-/-) MICE

    EPA Science Inventory

    2,3,7,8-Tetrachlordibenzo-p-dioxin (TCDD)-Mediated Oxidative Stress in Female CYP1A2 Knockout (CYP1A2-/-) Mice

    Deborah Burgin1, Janet Diliberto2, Linda Birnbaum2
    1UNC Toxicology; 2USEPA/ORD/NHEERL, RTP, NC

    Most of the effects due to TCDD exposure are mediated via...

  10. Exposure and Human Health Reassessment of 2,3,7,8-Tetrachlorodibenzo-P-Dioxin (Tcdd) and Related Compounds: Science Advisory Board (External Review Draft) (2000)

    EPA Science Inventory

    Dioxin Reassessment, SAB Review Draft

    The U.S. Environmental Protection Agency's (EPA) is progressing toward completion of its comprehensive reassessment of dioxin science entitled, "Exposure and Human Health Reassessment of 2,3,7,8-Tetrachlorodibe...

  11. PERSISTENT ABNORMALITIES IN THE RAT MAMMARY GLAND FOLLOWING GESTATIONAL AND LACTATIONAL EXPOSURE TO 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD)

    EPA Science Inventory

    SUMMARY

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) exposure during gestation has revealed reproductive anomalies in rat offspring, including inconclusive reports of stunted mammary development in females (Brown et al., 1998, Lewis et al., 2001). The current studies wer...

  12. COMPARATIVE SENSITIVITY OF DIFFERENT LIFE-STAGES OF MEDAKA (ORYZIAS LATIPES) AND BROOK TROUT (SALVELINUS FONTINALIS) TO 2,3,7,8-TCDD

    EPA Science Inventory

    The early life stages of fish are known to be more sensitive than the adults to the toxicological effects of 2,3,7,8-tetrachlorodibenzo(p)dioxide (TCDD). TCDD concentrations in surface waters are sufficiently low that direct exposure of the developing embryo is unlikely to be o...

  13. 2,3,7,8-Tetrachlorodibenzo-P-Dioxin (Tcdd) Dose-Response Studies: Preliminary Literature Search Results and Request for Additional Studies

    EPA Science Inventory

    EPA invited the public to comment on the preliminary list of in vivo mammalian dose-response citations for 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD). This list was compiled as a first step in the development of EPA’s response to the National Academy of Sciences comments (NAS, 2...

  14. In utero and lactational 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure: Effects on fetal and adult cardiac gene expression and adult cardiac and renal morphology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mouse heart is a target of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during fetal development, and microarray analysis demonstrates significant changes in expression of cardiac genes involved in extracellular matrix (ECM) remodeling. We tested the hypothesis that developmental TCDD exposure wo...

  15. UTILIZATION OF A PBPK MODEL TO PREDICT THE DISTRIBUTION OF 2, 3, 7-8 TETRACHLORODIBENZO-P-DIOXIN (TCDD) IN HUMANS DURING CRITICAL WINDOWS OF DEVELOPMENT

    EPA Science Inventory

    Utilization of A PBPK model to predict the distribution of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) in humans during critical windows of development.
    C Emond1, MJ DeVito2 and LS Birnbaum2
    1National Research Council, US EPA, ORD, NHEERL, (ETD, PK), RTP, NC, 27711, USA 2 US...

  16. TERATOGENICITY OF 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD) IN MICE LACKING THE EXPRESSION OF EGF AND/OR TGFALPHA

    EPA Science Inventory

    Abstract
    2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure produces hydronephrosis and cleft palate in mice. These responses are correlated with disruption of expression of epidermal growth factor (EGF) receptor ligands, primarily EGF and transforming growth factor-alpha ...

  17. Hypertension, Cardiac Hypertrophy, and Impaired Vascular Relaxation Induced by 2,3,7,8-Tetrachlorodibenzo-p-Dioxin are Associated with Increased Superoxide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The mechanisms by which 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) increases the incidence of human cardiovascular disease are not known. We investigated the degree to which cardiovascular disease develops in mice following subchronic TCDD exposure. Adult male C57BL/6 mice were dosed with vehicle o...

  18. TEMPORAL TRENDS IN ETHOXYRESORUFIN-O-DEETHYLASE ACITIVITY OF BROOK TROUT (SALVELINUS FONTINALIS) FED 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN

    EPA Science Inventory

    Changes in ethoxyresorufin-0-deethylase (EROD) activity were monitored through an extended 6-month dietary exposure to determine the relationship between EROD activity and uptake of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in brook trout, Salvelinus fontinalis. Brook trout wer...

  19. TEMPORAL TRENDS IN ETHOXYRESORUFIN-O-DEETHYLASE ACTIVITY OF BROOK TROUT (SALVELINUS FONTINALIS) FED 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN

    EPA Science Inventory

    Changes in ethoxyresorufin-O-deethylase (EROD) activity were monitored through an extended 6-month dietary exposure to determine the relationship between EROD activity and uptake of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in brook trout, Salvelinus fontinalis. Brook trout were...

  20. Cytochrome P4501A1 is Required for Vascular Dysfunction and Hypertension Induced by 2,3,7,8-Tetrachlorodibenzo-p-dioxin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    National Health and Nutrition Examination Survey data show an association between hypertension and exposure to dioxin-like halogenated aromatic hydrocarbons (HAH). Further, chronic exposure of mice to the prototypical HAH, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), induces reactive oxygen species (...

  1. TEMPORAL CHANGES IN PURITY AND SPECIFIC ACTIVITY OF TRITIUM-LABELED 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN: RADIOPURITY MODEL FOR TOXICOLOGY

    EPA Science Inventory

    Changes in the specific activity (S) and radiopurity (R) of tritiated 2,3,7,8-TCDD were measured by gas chromatography/mass spectrometry in order to accurately characterize TCDD doses received by invertebrates, fish, and fish embryos in several toxicology studies conducted over a...

  2. SEVESO WOMEN'S HEALTH STUDY: A STUDY OF THE EFFECTS OF 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN ON REPRODUCTIVE HEALTH. (R824761)

    EPA Science Inventory

    Abstract

    Although reproductive effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure have been reported in numerous investigations of animals, studies of this association in humans are limited. In 1976, an explosion in Seveso, Italy exposed the surround...

  3. 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN (TCDD) DISRUPTS EARLY MORPHOGENETIC EVENTS THAT FORM THE LOWER REPRODUCTIVE TRACT IN FEMALE RAT FETUSES

    EPA Science Inventory

    In female rats, in utero exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during critical periods of organogenesis causes a permanent thread of tissue across the vaginal opening, which consists of a core of mesenchyme surrounded by keratinized epithelia. The objective of t...

  4. TOXICITY OF 2,3,7,8-TETRACHLORODIBENZO-P-DIOXIN TO EARLY LIFE STAGE BROOK TROUT (SALVELINUS FONTINALIS) FOLLOWING PARTENTAL DIETARY EXPOSURE

    EPA Science Inventory

    The toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to the early life stages of F1 generation brook trout (Salvelinus fontinalis) was determined, when dosed by maternal transfer.Effects were compared across six treatments, including a control.The experimental groups, based...

  5. 7 CFR 319.8-8 - Lint, linters, and waste.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 5 2013-01-01 2013-01-01 false Lint, linters, and waste. 319.8-8 Section 319.8-8 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION... Britain and Northern Ireland (United Kingdom), Iceland, Liechtenstein, Luxembourg, Netherlands,...

  6. 7 CFR 319.8-8 - Lint, linters, and waste.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 5 2012-01-01 2012-01-01 false Lint, linters, and waste. 319.8-8 Section 319.8-8 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION... Britain and Northern Ireland (United Kingdom), Iceland, Liechtenstein, Luxembourg, Netherlands,...

  7. 7 CFR 319.8-8 - Lint, linters, and waste.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 5 2011-01-01 2011-01-01 false Lint, linters, and waste. 319.8-8 Section 319.8-8 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION... Britain and Northern Ireland (United Kingdom), Iceland, Liechtenstein, Luxembourg, Netherlands,...

  8. 7 CFR 319.8-8 - Lint, linters, and waste.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Lint, linters, and waste. 319.8-8 Section 319.8-8 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION... Britain and Northern Ireland (United Kingdom), Iceland, Liechtenstein, Luxembourg, Netherlands,...

  9. 7 CFR 319.8-8 - Lint, linters, and waste.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 5 2014-01-01 2014-01-01 false Lint, linters, and waste. 319.8-8 Section 319.8-8 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION... Kingdom), Iceland, Liechtenstein, Luxembourg, Netherlands, Norway, Portugal, Sweden, and Switzerland....

  10. Applications of the in vitro aryl hydrocarbon hydroxylase induction assay for determining "2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents": pyrolyzed brominated flame retardants.

    PubMed

    Zacharewski, T; Harris, M; Safe, S; Thoma, H; Hutzinger, O

    1988-10-01

    The pyrolysis of brominated flame retardants FR 300 BA (decabromobiphenyl) ether, FireMaster BP-6 (polybrominated biphenyls), Bromkal 70-5-DE (primarily pentabromodiphenylether), Bromkal 70-DE (primarily penta and tetrabromodiphenylether) and Bromkal G1 (pentabromodiphenylether) resulted in the formation of relatively high levels of polybrominated dibenzofurans (PBDFs) and dibenzo-p-dioxins (PBDDs as determined by gas chromatography-mass spectrometric analysis. The dose response EC50 values for the induction of aryl hydrocarbon hydroxylase (AHH) and ethoxyresorufin O-deethylase (EROD) by the flame retardant pyrolysates was determined in rat hepatoma H-4-II E cells and compared to the relative induction activities of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and the concentrations of "2,3,7,8-TCDD equivalents" were calculated. The range of "2,3,7,8-TCDD equivalents" levels (micrograms/g or ppm) derived from values obtained from the AHH and EROD bioassays for each of the pyrolyzed flame retardant samples was: 174-194, 480-1400, 2140-4680, 6740-8780 and 3920-5260 ppm for FR 300 BA, FireMaster BP-6, Bromkal 70 DE, Bromkal 70-5 DE and Bromkal G1, respectively. The in vivo dose-response effects of 2 pyrolyzed flame retardants were determined in immature male Wistar rats and compared to the dose-response activities of 2,3,7,8-TCDD. The in vivo responses which were measured included hepatic microsomal AHH and EROD induction, body weight loss and thymic atrophy. For the pyrolyzed FireMaster BP-6 and Bromkal 70-5 DE samples, the range of calculated in vivo "2,3,7,8-TCDD equivalents" (ppm in sample) for the 4 in vivo bioassays was 520-1780 ppm and 3860-8960 ppm, respectively. The excellent overlap between the in vivo and in vitro 2,3,7,8-TCDD equivalents for the 2 flame retardant pyrolysate extracts supports the utility of the in vitro induction bioassay for quantitatively determining "2,3,7,8-TCDD equivalents" for mixtures containing toxic halogenated aryl hydrocarbons.

  11. Identification of X-ray spectra in the Na-like to O-like rubidium ions in the range of 3.8-7.3 Å

    NASA Astrophysics Data System (ADS)

    Denis-Petit, D.; Comet, M.; Bonnet, T.; Hannachi, F.; Gobet, F.; Tarisien, M.; Versteegen, M.; Gosselin, G.; Méot, V.; Morel, P.; Pain, J.-Ch.; Gilleron, F.; Frank, A.; Bagnoud, V.; Blazevic, A.; Dorchies, F.; Peyrusse, O.; Cayzac, W.; Roth, M.

    2014-11-01

    The X-rays emitted by a rubidium plasma source created by the PHELIX laser at an intensity of about 6×1014 W/cm2 were studied. The lines have been measured using Bragg crystals in the wavelength range between 3.8 and 7.3 Å and identified by means of a numerical method developed to describe highly charged rubidium ions in LTE plasma. The experimental plasma temperature, density and charge state distributions have been estimated using non-LTE codes such as CHIVAS and AVERROES. The LTE plasma temperature and density used in the calculations are those allowing to reproduce the calculated NLTE charge state distribution. In order to optimize the use of computational resources, a criterion is established to select the configurations contributing most to the spectra among all those obtained in detailed level accounting based on the MCDF code. Seventy Rb X-rays have been identified among which forty-nine are reported for the first time. The capabilities of our method are demonstrated by the good agreement of our identifications with previously published data when available.

  12. 33 CFR 8.7 - Information.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Information. 8.7 Section 8.7... GUARD RESERVE § 8.7 Information. (a) Information concerning the Coast Guard Reserve may be obtained from Commandant (CG-13), 2100 2nd St. SW., Stop 7801, Washington, DC 20593-7801. (b) Information and...

  13. 33 CFR 8.7 - Information.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Information. 8.7 Section 8.7... GUARD RESERVE § 8.7 Information. (a) Information concerning the Coast Guard Reserve may be obtained from Commandant (CG-13), 2100 2nd St. SW., Stop 7801, Washington, DC 20593-7801. (b) Information and...

  14. 1 CFR 8.7 - Agency cooperation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 1 General Provisions 1 2011-01-01 2011-01-01 false Agency cooperation. 8.7 Section 8.7 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER SPECIAL EDITIONS OF THE FEDERAL REGISTER CODE OF FEDERAL REGULATIONS § 8.7 Agency cooperation. Each agency shall cooperate in keeping publication of...

  15. 22 CFR 8.7 - Security.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Security. 8.7 Section 8.7 Foreign Relations DEPARTMENT OF STATE GENERAL ADVISORY COMMITTEE MANAGEMENT § 8.7 Security. (a) All officers and members of a committee must have a security clearance for the subject matter level of security at which the...

  16. 22 CFR 8.7 - Security.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Security. 8.7 Section 8.7 Foreign Relations DEPARTMENT OF STATE GENERAL ADVISORY COMMITTEE MANAGEMENT § 8.7 Security. (a) All officers and members of a committee must have a security clearance for the subject matter level of security at which the...

  17. 1 CFR 8.7 - Agency cooperation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 1 General Provisions 1 2010-01-01 2010-01-01 false Agency cooperation. 8.7 Section 8.7 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER SPECIAL EDITIONS OF THE FEDERAL REGISTER CODE OF FEDERAL REGULATIONS § 8.7 Agency cooperation. Each agency shall cooperate in keeping publication of...

  18. 1 CFR 8.7 - Agency cooperation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 1 General Provisions 1 2012-01-01 2012-01-01 false Agency cooperation. 8.7 Section 8.7 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER SPECIAL EDITIONS OF THE FEDERAL REGISTER CODE OF FEDERAL REGULATIONS § 8.7 Agency cooperation. Each agency shall cooperate in keeping publication of...

  19. 1 CFR 8.7 - Agency cooperation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 1 General Provisions 1 2014-01-01 2012-01-01 true Agency cooperation. 8.7 Section 8.7 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER SPECIAL EDITIONS OF THE FEDERAL REGISTER CODE OF FEDERAL REGULATIONS § 8.7 Agency cooperation. Each agency shall cooperate in keeping publication of...

  20. 1 CFR 8.7 - Agency cooperation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 1 General Provisions 1 2013-01-01 2012-01-01 true Agency cooperation. 8.7 Section 8.7 General Provisions ADMINISTRATIVE COMMITTEE OF THE FEDERAL REGISTER SPECIAL EDITIONS OF THE FEDERAL REGISTER CODE OF FEDERAL REGULATIONS § 8.7 Agency cooperation. Each agency shall cooperate in keeping publication of...

  1. 7 CFR 7.8 - Conduct of community committee elections.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Conduct of community committee elections. 7.8 Section 7.8 Agriculture Office of the Secretary of Agriculture SELECTION AND FUNCTIONS OF AGRICULTURAL STABILIZATION AND CONSERVATION STATE, COUNTY AND COMMUNITY COMMITTEES § 7.8 Conduct of community...

  2. Matrix metalloproteinases -1, -2, -3, -7, -8, -12, and -13 in gingival crevicular fluid during orthodontic tooth movement: a longitudinal randomized split-mouth study.

    PubMed

    Canavarro, Cristiane; Teles, Ricardo Palmier; Capelli Júnior, Jonas

    2013-10-01

    This randomized split-mouth study aimed to examine the levels of matrix metalloproteinases (MMPs) -1, -2, -3, -7, -8, -12, and -13 in the gingival crevicular fluid (GCF) at different time points during orthodontic tooth movement. A total of 16 healthy orthodontic subjects (7 females, 9 males; mean age, 17.7 years) who needed their first upper premolars extracted were enrolled. One randomly chosen maxillary canine was subjected to a distalizing force and was considered to be the test side. The contralateral canine, which was not subjected to any force but was included in the orthodontic appliance, was used as a control side. GCF sampling was performed at both the mesial (tension) and distal (pressure) test and control sites at baseline, immediately before applying the orthodontic appliance, and after 1 and 24 hours and 7, 14, and 21 days. A multiplexed bead immunoassay was used to analyse the GCF samples. The mean levels of the MMP-1, -2, -3, -7, -8, -12, and -13 were not significantly different between the test and control groups in each time showed. The comparisons between the tension and pressure sites were also not significantly different at each individual time. A few variations focused on MMP-1 and -3, but the expression of MMP-8 was higher than that of the other MMPs. MMPs are released in sufficient quantities such that tooth movement occurs but with no significant increase in GCF levels.

  3. Transcriptome reveals the overexpression of a kallikrein gene cluster (KLK1/3/7/8/12) in the Tibetans with high altitude-associated polycythemia

    PubMed Central

    Li, Kang; Gesang, Luobu; Dan, Zeng; Gusang, Lamu

    2017-01-01

    High altitude-associated polycythemia (HAPC) is a very common disease. However, it the disease is still unmanageable and the related molecular mechanisms remain largely unclear. In the present study, we aimed to explore the molecular mechanisms responsible for the development of HAPC using transcriptome analysis. Transcriptome analysis was conducted in 3 pairs of gastric mucosa tissues from patients with HAPC and healthy residents at a similar altitude. Endoscopy and histopathological analyses were used to examine the injury to gastric tissues. Molecular remodeling was performed for the interaction between different KLK members and cholesterol. HAPC was found to lead to morphological changes and pathological damage to the gastric mucosa of patients. A total of 10,304 differentially expressed genes (DEGs) were identified. Among these genes, 4,941 DEGs were upregulated, while 5,363 DEGs were downregulated in the patients with HAPC (fold change ≥2, P<0.01 and FDR <0.01). In particular, the kallikrein gene cluster (KLK1/3/7/8/12) was upregulated >17-fold. All the members had high-score binding cholesterol, particularly for the polymers of KLK7. The kallikrein gene cluster (KLK1/3/7/8/12) is on chromosome 19q13.3–13.4. The elevated levels of KLK1, KLK3, KLK7, KLK8 and KLK12 may be closely associated with the hypertension, inflammation, obesity and other gastric injuries associated with polycythemia. The interaction of KLKs and cholesterol maybe play an important role in the development of hypertension. The findings of the present study revealed that HAPC induces gastric injury by upregulating the kallikrein gene cluster (KLK1/3/7/8/12), which can bind cholesterol and result in kallikrein hypertension. These findings provide some basic information for understanding the molecular mechanisms responsible for HAPC and HAPC-related diseases. PMID:28000848

  4. Synthesis, in vitro antimycobacterial evaluation and docking studies of some new 5,6,7,8-tetrahydropyrido[4',3':4,5]thieno[2,3-d]pyrimidin-4(3H)-one schiff bases.

    PubMed

    Malothu, Narender; Bhandaru, Jaswanth S; Kulandaivelu, Umasankar; Jojula, Malathi; Adidala, Raghuram Reddy; K R, Umadevi; A V N, Dusthackeer; Kaki, Venkat Rao; Akkinepally, Raghuram R

    2016-02-01

    Development of multidrug resistant (MDR) and extensively drug resistant (XDR) tuberculosis (TB) has been considered as major health burden, globally. In order to develop novel, potential molecules against drug resistant TB, twenty two (22) new 3-substituted-7-benzyl-5,6,7,8-tetrahydropyrido[4',3':4,5]thieno[2,3-d]pyrimidin-4(3H)-one (6a-k) and 3-substituted-7-benzyl-2-methyl-5,6,7,8-tetrahydropyrido[4',3':4,5]thieno[2,3-d]pyrimidin-4(3H)-one (7a-k) derivatives were designed and synthesized by using appropriate synthetic protocols. Pantothenate synthetase (PS) was considered as the target for the molecular docking studies and evaluated the binding pattern at active site, as PS plays a significant role in the biosynthesis of pantothenate in Mycobacterium tuberculosis (MTB). The preliminary in vitro antibacterial screening of test compounds was carried out against two strains of Gram-positive (Bacillus subtilis and Staphylococcus aureus) and Gram-negative (Escherichia coli and Klebsiella pneumoniae) bacteria. The antimycobacterial screening was performed against MTB H37Rv and an isoniazid-resistant clinical isolate of MTB. The compounds 6b, 6c, 6d, 6k, 7b, 7c, 7d and 7k exhibited promising antibacterial activity MIC in the range of 15-73 μM against all bacterial strains used and compounds 6d and 7b showed antimycobacterial activity (IC50 <340 μM in LRP assay) and (MIC <9 μM in broth microdilution method).

  5. Crystal structure of 4,4'-[(1,3,5,7-tetra-oxo-1,3,3a,4,4a,5,7,7a,8,8a-deca-hydro-4,8-etheno-pyrrolo-[3,4-f]iso-indole-2,6-di-yl)bis-(methyl-ene)]bis-(pyridin-1-ium) dinitrate.

    PubMed

    Liu, Zhimin

    2015-12-01

    In the title salt, C24H22N4O4 (2+)·2NO3 (-), the cation is U-shaped with the two iso-indole dione rings inclined to one another by 60.41 (13)°, while the two outer pyridine rings are inclined to one another by 2.77 (12)°. The dihedral angles between the pyridine ring and the adjacent iso-indole dione ring are 71.82 (12) and 86.44 (13)°. In the crystal, each nitrate anion is linked to a protonated pyridine ring by N-H⋯O hydrogen bonds. These units are linked by a series of C-H⋯O hydrogen bonds, forming a three-dimensional structure.

  6. Rapid cytochrome c release, activation of caspases 3, 6, 7 and 8 followed by Bap31 cleavage in HeLa cells treated with photodynamic therapy.

    PubMed

    Granville, D J; Carthy, C M; Jiang, H; Shore, G C; McManus, B M; Hunt, D W

    1998-10-16

    Photodynamic therapy (PDT) is a clinical approach that utilizes light-activated drugs for the treatment of a variety of pathologic conditions. The initiating events of PDT-induced apoptosis are poorly defined. It has been shown for other proapoptotic stimuli that the integral endoplasmic reticulum protein Bap31 is cleaved by caspases 1 and 8, but not by caspase-3. Further, a 20 kDa Bap31 cleavage fragment is generated which can induce apoptosis. In the current report, we sought to determine whether Bap31 cleavage and generation of p20 is an early event in PDT-induced apoptosis. The mitochondrial release of cytochrome c, involvement of caspases 1, 2, 3, 4, 6, 7, 8, and 10 and the status of several known caspase substrates, including Bap31, were evaluated in PDT-treated HeLa cells. Cytochrome c appeared in the cytosol immediately following light activation of the photosensitizer benzoporphyrin derivative monoacid ring A. Activation of caspases 3, 6, 7, and 8 was evident within 1-2 h post PDT. Processing of caspases 1, 2, 4, and 10 was not observed. Cleavage of Bap31 was observed at 2-3 h post PDT. The caspase-3 inhibitor DEVD-fmk blocked caspase-8 and Bap31 cleavage suggesting that caspase-8 and Bap31 processing occur downstream of caspase-3 activation in PDT-induced apoptosis. These results demonstrate that release of mitochondrial cytochrome c into the cytoplasm is a primary event following PDT, preceding caspase activation and cleavage of Bap31. To our knowledge, this is the first example of a chemotherapeutic agent inducing caspase-8 activation and demonstrates that caspase-8 activation can occur after cytochrome c release.

  7. Absorption and emission spectra of Ga1.7Ge25As8.3S65 glasses doped with rare-earth ions

    NASA Astrophysics Data System (ADS)

    Lupan, E. V.; Iaseniuc, O. V.; Ciornea, V. I.; Iovu, M. S.

    2016-12-01

    Excellent optical properties of chalcogenide glasses make them interesting for optoelectronic devices in the visible (VIS) and, especially, in the near- and mid-infrared (NIR and MIR) spectral regions. The rare-earth (RE3+) doped Ga17Ge25As8.3S65 glasses were prepared in evacuated ( 10-5 Pa) silica-glass ampoules which were heated up to 1000 °C at 2-4°C min-1, and then the melt was quenched. The absorption and photoluminescence spectra in the visible and near IR regions for GA1.7Ge25As8.3S65 doped with rare-earth RE+) ions (Sm3+, Nd3+, Pr3+, Dy3+ and co-doped with Ho3++Dy3+) are investigated. The energy transfer of the absorbed light in the broad band Urbach region of the host glass to the RE3+ ions is suggested for increasing the emission efficiency. The investigated Ga17Ge25As8.3S65 glasses doped with RE3+ ions are promising materials for optical amplifiers operating at 1300 and 1500 nm telecommunication windows.

  8. Hepatic estrogen receptor and plasma 17{beta}-estradiol concentrations as biomarkers of 2,3,7,8-TCDD exposure in avian hatchlings

    SciTech Connect

    Janz, D.M.; Bellward, G.D.

    1995-12-31

    The authors have been investigating the sensitivity of various toxicologically relevant endpoints as environmental biomarkers in avian hatchlings exposed in ovo to 2,3,7,8-TCDD. Potential biomarkers included various endocrine endpoints such as plasma 17{beta}-estradiol (E{sub 2}), hepatic estrogen receptor (ER) affinities and concentrations, and plasma thyroid hormones, which were compared to hepatic ethoxyresorufin O-deethylase (EROD) induction. The animal models used were domestic chickens and pigeons, and great blue herons. An experiment conducted in pigeon hatchlings compared ``early`` (embryonic day 4; E4) vs. ``late`` (E14) in ovo exposure to 1 {micro}g/kg and 3 {micro}g/kg of TCDD, respectively. Birds were sacrificed on day of hatch (H) and day 7 after hatch (D7). In the late exposure experiment, plasma E{sub 2} concentrations were reduced at H and elevated at D7 in the TCDD-exposed birds (p < 0.05). Hepatic ER concentrations were elevated at H (p < 0.01). Although EROD was half-maximally induced at H and D7 in the early exposure experiment in pigeons, there was no effect of TCDD treatment on E, or ER levels. The nominal TCDD concentration in these pigeons (1 {micro}g/kg egg) was within the range observed in wild piscivorous bird eggs collected from aquatic systems contaminated with TCDD and related chemicals (approx. 0.5--2 ng TEQ/g egg). In herons exposed to 2 {micro}g/kg of TCDD at the midpoint of incubation, hepatic ER affinities (Kd) and concentrations (Bmax) were elevated in treated birds at H (p < 0.05); however there was no effect on plasma E, levels. Liver [{sup 3}H]-TCDD concentrations were 11.3 {+-} 0.8 ng/g at H, and 0.8 {+-} 0.1 ng/g at D7, representing 9.9% and 4.9% of the nominal TCDD dose, respectively.

  9. 7 CFR 735.8 - Appeals.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Operations, Farm Service Agency, United States Department of Agriculture, STOP 0550, 1400 Independence Avenue... REGULATIONS FOR WAREHOUSES REGULATIONS FOR THE UNITED STATES WAREHOUSE ACT General Provisions § 735.8 Appeals... 7 Agriculture 7 2014-01-01 2014-01-01 false Appeals. 735.8 Section 735.8 Agriculture...

  10. 7 CFR 735.8 - Appeals.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Operations, Farm Service Agency, United States Department of Agriculture, STOP 0550, 1400 Independence Avenue... REGULATIONS FOR WAREHOUSES REGULATIONS FOR THE UNITED STATES WAREHOUSE ACT General Provisions § 735.8 Appeals... 7 Agriculture 7 2012-01-01 2012-01-01 false Appeals. 735.8 Section 735.8 Agriculture...

  11. 7 CFR 784.8 - Appeals.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Appeals. 784.8 Section 784.8 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE SPECIAL PROGRAMS 2004 EWE LAMB REPLACEMENT AND RETENTION PAYMENT PROGRAM § 784.8 Appeals. The appeal...

  12. 8 CFR 1246.7 - Appeals.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Appeals. 1246.7 Section 1246.7 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS RESCISSION OF ADJUSTMENT OF STATUS § 1246.7 Appeals. Pursuant to 8 CFR part 1003, an appeal shall lie from...

  13. 8 CFR 1246.7 - Appeals.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Appeals. 1246.7 Section 1246.7 Aliens and Nationality EXECUTIVE OFFICE FOR IMMIGRATION REVIEW, DEPARTMENT OF JUSTICE IMMIGRATION REGULATIONS RESCISSION OF ADJUSTMENT OF STATUS § 1246.7 Appeals. Pursuant to 8 CFR part 1003, an appeal shall lie from...

  14. Electrocaloric effect and freezing temperature in (Pb0.8Ba0.2)[(Zn1/3Nb2/3)0.7Ti0.3]O3 relaxor ferroelectric ceramic

    NASA Astrophysics Data System (ADS)

    Peláiz-Barranco, A.; Calderón-Piñar, F.; Mendez-González, Y.

    2016-08-01

    The electrocaloric effect (ECE) is studied in (Pb0.8Ba0.2)[(Zn1/3Nb2/3)0.7Ti0.3]O3 relaxor ferroelectric ceramic by using an “indirect method”. The electric dependence for the polarization (hysteresis loops) has been obtained for several temperatures showing typical relaxor characteristics. The temperature change ΔT, which is associated with the ECE, is calculated by using the temperature dependence for the polarization. A maximum value for ΔT is observed for temperatures close above the freezing temperature, showing an indirect evidence of that critical temperature. The results are discussed considering the contribution of the polar nanoregions to the polarization.

  15. HDAC8 Inhibition Blocks SMC3 Deacetylation and Delays Cell Cycle Progression without Affecting Cohesin-dependent Transcription in MCF7 Cancer Cells.

    PubMed

    Dasgupta, Tanushree; Antony, Jisha; Braithwaite, Antony W; Horsfield, Julia A

    2016-06-10

    Cohesin, a multi-subunit protein complex involved in chromosome organization, is frequently mutated or aberrantly expressed in cancer. Multiple functions of cohesin, including cell division and gene expression, highlight its potential as a novel therapeutic target. The SMC3 subunit of cohesin is acetylated (ac) during S phase to establish cohesion between replicated chromosomes. Following anaphase, ac-SMC3 is deacetylated by HDAC8. Reversal of SMC3 acetylation is imperative for recycling cohesin so that it can be reloaded in interphase for both non-mitotic and mitotic functions. We blocked deacetylation of ac-SMC3 using an HDAC8-specific inhibitor PCI-34051 in MCF7 breast cancer cells, and examined the effects on transcription of cohesin-dependent genes that respond to estrogen. HDAC8 inhibition led to accumulation of ac-SMC3 as expected, but surprisingly, had no influence on the transcription of estrogen-responsive genes that are altered by siRNA targeting of RAD21 or SMC3. Knockdown of RAD21 altered estrogen receptor α (ER) recruitment at SOX4 and IL20, and affected transcription of these genes, while HDAC8 inhibition did not. Rather, inhibition of HDAC8 delayed cell cycle progression, suppressed proliferation and induced apoptosis in a concentration-dependent manner. We conclude that HDAC8 inhibition does not change the estrogen-specific transcriptional role of cohesin in MCF7 cells, but instead, compromises cell cycle progression and cell survival. Our results argue that candidate inhibitors of cohesin function may differ in their effects depending on the cellular genotype and should be thoroughly tested for predicted effects on cohesin's mechanistic roles.

  16. Evidence in rat and mouse liver for temporal control of two forms of cytochrome P-450 inducible by 2,3,7,8-tetrachlorodibenzo-p-dioxin.

    PubMed

    Guenthner, T M; Nebert, D W

    1978-11-15

    In the liver of perinatal rats or mice, the ratio of 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced aryl hydrocarbon hydroxylase to total cytochrome P-450 content decreases, whereas the ratio of 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced acetanilide 4-hydroxylase to total cytochrome P-450 content increases, between 18 or 19 days and 22 days following conception. The ontogenesis of inducible aryl hydrocarbon hydroxylase corresponds well with increases in a 56000-Mr electrophoretic band; we suggest this band represents the cytochrome P1-450 subunit. The later temporal expression of inducible acetanilide 4-hydroxylase closely parallels 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced increases in size of a 54000-Mr electrophoretic band and a 2--3-nm hypsochromic shift in the Soret peak of the total microsomal reduced cytochrome P-450 . CO complex. We suggest this band represents the cytochrome P-448 subunit. Previous work from this laboratory has shown that this developmental difference is separated by several weeks in rabbit liver, as compared with several day's separation shown in this report with rat or mouse liver. The data here therefore provide evidence in the rodent for temporal control of the expression of different structural gene products regulated by the Ah locus.

  17. 2-Amino-7,7-dimethyl-5-oxo-4-[3-(trifluoro­meth­yl)phen­yl]-1,4,5,6,7,8-hexa­hydro­quinoline-3-carbonitrile

    PubMed Central

    Kant, Rajni; Gupta, Vivek K.; Kapoor, Kamini; Patil, D. R.; Mulik, A. G.; Deshmukh, Madhukar B.

    2013-01-01

    In the title mol­ecule, C19H18F3N3O, the dihydro­pyridine and cyclo­hexene rings both adopt sofa conformations. The five essentially planar atoms of the dihydro­pyridine ring [maximum deviation = 0.039 (2) Å] form a dihedral angle of 88.19 (8)° with the benzene ring. The F atoms of the trifluoro­methyl group were refined as disordered over two sets of sites in a 0.840 (3):0.160 (3) ratio. In the crystal, N—H⋯O and N—H⋯N hydrogen bonds link mol­ecules into a two-dimensional network parallel to (100). PMID:23476367

  18. Synthesis and unusual properties of the first 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetraalkylporphyrin

    SciTech Connect

    NELSON,NORA Y.; MEDFORTH,CRAIG J.; NURCO,DANIEL J.; JIA,SONG-LING; SHELNUTT,JOHN A.; SMITH,KEVIN M.

    2000-03-06

    The new perhalogenated porphyrin 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetrakis(trifluoromethyl)porphinato-nickel(II) exhibits several striking features, including an extremely ruffled macrocycle with a very short Ni-N distance, an unusually red-shifted optical spectrum, and, surprisingly, hindered rotation of the meso-trifluoromethyl substituents ({Delta}G{sub 278}{sup +} = 47 kJ/mol).

  19. 47 CFR 25.138 - Licensing requirements for GSO FSS Earth Stations in the 18.3-18.8 GHz (space-to-Earth), 19.7-20...

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false Licensing requirements for GSO FSS Earth Stations in the 18.3-18.8 GHz (space-to-Earth), 19.7-20.2 GHz (space-to-Earth), 28.35-28.6 GHz (Earth-to-space), and 29.25-30.0 GHz (Earth-to-space) bands. 25.138 Section 25.138 Telecommunication...

  20. 7 CFR 1001.8 - Nonpool plant.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 9 2011-01-01 2011-01-01 false Nonpool plant. 1001.8 Section 1001.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1001.8 Nonpool plant. See § 1000.8....

  1. 7 CFR 1030.8 - Nonpool plant.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Nonpool plant. 1030.8 Section 1030.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1030.8 Nonpool plant. See § 1000.8....

  2. 7 CFR 1001.8 - Nonpool plant.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Nonpool plant. 1001.8 Section 1001.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1001.8 Nonpool plant. See § 1000.8....

  3. 7 CFR 1006.8 - Nonpool plant.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 9 2011-01-01 2011-01-01 false Nonpool plant. 1006.8 Section 1006.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1006.8 Nonpool plant. See § 1000.8....

  4. 7 CFR 1007.8 - Nonpool plant.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 9 2011-01-01 2011-01-01 false Nonpool plant. 1007.8 Section 1007.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1007.8 Nonpool plant. See § 1000.8....

  5. 7 CFR 1126.8 - Nonpool plant.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 9 2011-01-01 2011-01-01 false Nonpool plant. 1126.8 Section 1126.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1126.8 Nonpool plant. See § 1000.8....

  6. 7 CFR 1124.8 - Nonpool plant.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 9 2011-01-01 2011-01-01 false Nonpool plant. 1124.8 Section 1124.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Definitions § 1124.8 Nonpool plant. See § 1000.8....

  7. 7 CFR 1124.8 - Nonpool plant.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Nonpool plant. 1124.8 Section 1124.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Definitions § 1124.8 Nonpool plant. See § 1000.8....

  8. 7 CFR 1005.8 - Nonpool plant.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 9 2011-01-01 2011-01-01 false Nonpool plant. 1005.8 Section 1005.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1005.8 Nonpool plant. See § 1000.8....

  9. 7 CFR 1030.8 - Nonpool plant.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 9 2011-01-01 2011-01-01 false Nonpool plant. 1030.8 Section 1030.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1030.8 Nonpool plant. See § 1000.8....

  10. 7 CFR 1032.8 - Nonpool plant.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Nonpool plant. 1032.8 Section 1032.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1032.8 Nonpool plant. See § 1000.8....

  11. 7 CFR 1131.8 - Nonpool plant.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Nonpool plant. 1131.8 Section 1131.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1131.8 Nonpool plant. See § 1000.8....

  12. 7 CFR 1131.8 - Nonpool plant.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 9 2011-01-01 2011-01-01 false Nonpool plant. 1131.8 Section 1131.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1131.8 Nonpool plant. See § 1000.8....

  13. 7 CFR 1126.8 - Nonpool plant.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Nonpool plant. 1126.8 Section 1126.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1126.8 Nonpool plant. See § 1000.8....

  14. 7 CFR 1007.8 - Nonpool plant.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Nonpool plant. 1007.8 Section 1007.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1007.8 Nonpool plant. See § 1000.8....

  15. 7 CFR 1005.8 - Nonpool plant.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Nonpool plant. 1005.8 Section 1005.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1005.8 Nonpool plant. See § 1000.8....

  16. 7 CFR 1006.8 - Nonpool plant.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Nonpool plant. 1006.8 Section 1006.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1006.8 Nonpool plant. See § 1000.8....

  17. 7 CFR 1032.8 - Nonpool plant.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 9 2011-01-01 2011-01-01 false Nonpool plant. 1032.8 Section 1032.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1032.8 Nonpool plant. See § 1000.8....

  18. 7 CFR 1033.8 - Nonpool plant.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 9 2011-01-01 2011-01-01 false Nonpool plant. 1033.8 Section 1033.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1033.8 Nonpool plant. See § 1000.8....

  19. 7 CFR 1033.8 - Nonpool plant.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Nonpool plant. 1033.8 Section 1033.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1033.8 Nonpool plant. See § 1000.8....

  20. 7 CFR 981.8 - Inedible kernel.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Inedible kernel. 981.8 Section 981.8 Agriculture... Regulating Handling Definitions § 981.8 Inedible kernel. Inedible kernel means a kernel, piece, or particle of almond kernel with any defect scored as serious damage, or damage due to mold, gum, shrivel,...

  1. 7 CFR 1131.8 - Nonpool plant.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 9 2013-01-01 2013-01-01 false Nonpool plant. 1131.8 Section 1131.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Handling Definitions § 1131.8 Nonpool plant. See § 1000.8....

  2. 7 CFR 1001.8 - Nonpool plant.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 9 2014-01-01 2013-01-01 true Nonpool plant. 1001.8 Section 1001.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Handling Definitions § 1001.8 Nonpool plant. See § 1000.8....

  3. 7 CFR 1033.8 - Nonpool plant.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 9 2014-01-01 2013-01-01 true Nonpool plant. 1033.8 Section 1033.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Handling Definitions § 1033.8 Nonpool plant. See § 1000.8....

  4. 7 CFR 1131.8 - Nonpool plant.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 9 2012-01-01 2012-01-01 false Nonpool plant. 1131.8 Section 1131.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1131.8 Nonpool plant. See § 1000.8....

  5. 7 CFR 1124.8 - Nonpool plant.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 9 2014-01-01 2013-01-01 true Nonpool plant. 1124.8 Section 1124.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Regulating Handling Definitions § 1124.8 Nonpool plant. See § 1000.8....

  6. 7 CFR 1033.8 - Nonpool plant.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 9 2012-01-01 2012-01-01 false Nonpool plant. 1033.8 Section 1033.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1033.8 Nonpool plant. See § 1000.8....

  7. 7 CFR 1007.8 - Nonpool plant.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 9 2014-01-01 2013-01-01 true Nonpool plant. 1007.8 Section 1007.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Handling Definitions § 1007.8 Nonpool plant. See § 1000.8....

  8. 7 CFR 1001.8 - Nonpool plant.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 9 2013-01-01 2013-01-01 false Nonpool plant. 1001.8 Section 1001.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Handling Definitions § 1001.8 Nonpool plant. See § 1000.8....

  9. 7 CFR 1126.8 - Nonpool plant.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 9 2013-01-01 2013-01-01 false Nonpool plant. 1126.8 Section 1126.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Handling Definitions § 1126.8 Nonpool plant. See § 1000.8....

  10. 7 CFR 1005.8 - Nonpool plant.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 9 2013-01-01 2013-01-01 false Nonpool plant. 1005.8 Section 1005.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Handling Definitions § 1005.8 Nonpool plant. See § 1000.8....

  11. 7 CFR 1007.8 - Nonpool plant.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 9 2013-01-01 2013-01-01 false Nonpool plant. 1007.8 Section 1007.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Handling Definitions § 1007.8 Nonpool plant. See § 1000.8....

  12. 7 CFR 1126.8 - Nonpool plant.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 9 2012-01-01 2012-01-01 false Nonpool plant. 1126.8 Section 1126.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1126.8 Nonpool plant. See § 1000.8....

  13. 7 CFR 1006.8 - Nonpool plant.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 9 2013-01-01 2013-01-01 false Nonpool plant. 1006.8 Section 1006.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Handling Definitions § 1006.8 Nonpool plant. See § 1000.8....

  14. 7 CFR 1032.8 - Nonpool plant.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 9 2012-01-01 2012-01-01 false Nonpool plant. 1032.8 Section 1032.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1032.8 Nonpool plant. See § 1000.8....

  15. 7 CFR 1005.8 - Nonpool plant.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 9 2014-01-01 2013-01-01 true Nonpool plant. 1005.8 Section 1005.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Handling Definitions § 1005.8 Nonpool plant. See § 1000.8....

  16. 7 CFR 1033.8 - Nonpool plant.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 9 2013-01-01 2013-01-01 false Nonpool plant. 1033.8 Section 1033.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Handling Definitions § 1033.8 Nonpool plant. See § 1000.8....

  17. 7 CFR 1005.8 - Nonpool plant.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 9 2012-01-01 2012-01-01 false Nonpool plant. 1005.8 Section 1005.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1005.8 Nonpool plant. See § 1000.8....

  18. 7 CFR 1126.8 - Nonpool plant.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 9 2014-01-01 2013-01-01 true Nonpool plant. 1126.8 Section 1126.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Handling Definitions § 1126.8 Nonpool plant. See § 1000.8....

  19. 7 CFR 1124.8 - Nonpool plant.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 9 2012-01-01 2012-01-01 false Nonpool plant. 1124.8 Section 1124.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Regulating Handling Definitions § 1124.8 Nonpool plant. See § 1000.8....

  20. 7 CFR 1124.8 - Nonpool plant.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 9 2013-01-01 2013-01-01 false Nonpool plant. 1124.8 Section 1124.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Regulating Handling Definitions § 1124.8 Nonpool plant. See § 1000.8....

  1. 7 CFR 1007.8 - Nonpool plant.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 9 2012-01-01 2012-01-01 false Nonpool plant. 1007.8 Section 1007.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1007.8 Nonpool plant. See § 1000.8....

  2. 7 CFR 1131.8 - Nonpool plant.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 9 2014-01-01 2013-01-01 true Nonpool plant. 1131.8 Section 1131.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Handling Definitions § 1131.8 Nonpool plant. See § 1000.8....

  3. 7 CFR 1030.8 - Nonpool plant.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 9 2012-01-01 2012-01-01 false Nonpool plant. 1030.8 Section 1030.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1030.8 Nonpool plant. See § 1000.8....

  4. 7 CFR 1032.8 - Nonpool plant.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 9 2014-01-01 2013-01-01 true Nonpool plant. 1032.8 Section 1032.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Handling Definitions § 1032.8 Nonpool plant. See § 1000.8....

  5. 7 CFR 1030.8 - Nonpool plant.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 9 2013-01-01 2013-01-01 false Nonpool plant. 1030.8 Section 1030.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Handling Definitions § 1030.8 Nonpool plant. See § 1000.8....

  6. 7 CFR 1030.8 - Nonpool plant.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 9 2014-01-01 2013-01-01 true Nonpool plant. 1030.8 Section 1030.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Handling Definitions § 1030.8 Nonpool plant. See § 1000.8....

  7. 7 CFR 1001.8 - Nonpool plant.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 9 2012-01-01 2012-01-01 false Nonpool plant. 1001.8 Section 1001.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1001.8 Nonpool plant. See § 1000.8....

  8. 7 CFR 1006.8 - Nonpool plant.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 9 2012-01-01 2012-01-01 false Nonpool plant. 1006.8 Section 1006.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Handling Definitions § 1006.8 Nonpool plant. See § 1000.8....

  9. 7 CFR 1006.8 - Nonpool plant.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 9 2014-01-01 2013-01-01 true Nonpool plant. 1006.8 Section 1006.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Handling Definitions § 1006.8 Nonpool plant. See § 1000.8....

  10. 7 CFR 1032.8 - Nonpool plant.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 9 2013-01-01 2013-01-01 false Nonpool plant. 1032.8 Section 1032.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Handling Definitions § 1032.8 Nonpool plant. See § 1000.8....

  11. 7 CFR 984.8 - Walnuts.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Walnuts. 984.8 Section 984.8 Agriculture Regulations... Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Order Regulating Handling Definitions § 984.8 Walnuts. Walnuts means only walnuts of the “English” (Juglans regia)...

  12. 7 CFR 984.8 - Walnuts.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Walnuts. 984.8 Section 984.8 Agriculture Regulations... ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Order Regulating Handling Definitions § 984.8 Walnuts. Walnuts means only walnuts of the “English” (Juglans regia)...

  13. 7 CFR 984.8 - Walnuts.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Walnuts. 984.8 Section 984.8 Agriculture Regulations... ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Order Regulating Handling Definitions § 984.8 Walnuts. Walnuts means only walnuts of the “English” (Juglans regia)...

  14. 7 CFR 984.8 - Walnuts.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Walnuts. 984.8 Section 984.8 Agriculture Regulations... Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Order Regulating Handling Definitions § 984.8 Walnuts. Walnuts means only walnuts of the “English” (Juglans regia)...

  15. 7 CFR 984.8 - Walnuts.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Walnuts. 984.8 Section 984.8 Agriculture Regulations... Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE WALNUTS GROWN IN CALIFORNIA Order Regulating Handling Definitions § 984.8 Walnuts. Walnuts means only walnuts of the “English” (Juglans regia)...

  16. Stability of molybdenum nanoparticles in Sn-3.8Ag-0.7Cu solder during multiple reflow and their influence on interfacial intermetallic compounds

    SciTech Connect

    Haseeb, A.S.M.A. Arafat, M.M. Johan, Mohd Rafie

    2012-02-15

    This work investigates the effects of molybdenum nanoparticles on the growth of interfacial intermetallic compound between Sn-3.8Ag-0.7Cu solder and copper substrate during multiple reflow. Molybdenum nanoparticles were mixed with Sn-3.8Ag-0.7Cu solder paste by manual mixing. Solder samples were reflowed on a copper substrate in a 250 Degree-Sign C reflow oven up to six times. The molybdenum content of the bulk solder was determined by inductive coupled plasma-optical emission spectrometry. It is found that upon the addition of molybdenum nanoparticles to Sn-3.8Ag-0.7Cu solder, the interfacial intermetallic compound thickness and scallop diameter decreases under all reflow conditions. Molybdenum nanoparticles do not appear to dissolve or react with the solder. They tend to adsorb preferentially at the interface between solder and the intermetallic compound scallops. It is suggested that molybdenum nanoparticles impart their influence on the interfacial intermetallic compound as discrete particles. The intact, discrete nanoparticles, by absorbing preferentially at the interface, hinder the diffusion flux of the substrate and thereby suppress the intermetallic compound growth. - Highlights: Black-Right-Pointing-Pointer Mo nanoparticles do not dissolve or react with the SAC solder during reflow. Black-Right-Pointing-Pointer Addition of Mo nanoparticles results smaller IMC thickness and scallop diameter. Black-Right-Pointing-Pointer Mo nanoparticles influence the interfacial IMC through discrete particle effect.

  17. Interfacial chemical and electronic structure of cobalt deposition on 2,7-dioctyl[1]benzothieno[3,2-b]benzothiophene (C8-BTBT)

    NASA Astrophysics Data System (ADS)

    Zhu, Menglong; Lyu, Lu; Niu, Dongmei; Zhang, Hong; Zhang, Yuhe; Liu, Peng; Gao, Yongli

    2017-04-01

    Interfacial chemical and electronic structure of Co deposition on 2,7-dioctyl[1]benzothieno[3,2-b]benzothiophene(C8-BTBT) was investigated by ultraviolet photoemission spectroscopy (UPS) and X-ray photoemission spectroscopy (XPS). Chemical reaction of cobalt with C8-BTBT at the interface is confirmed by a new component of S 2s peak which is electron-rich compared to the original one of C8-BTBT molecules. Intensity evolution of the core level in XPS indicates that the adsorption of Co atoms is mainly at the surface without deeper diffusion into C8-BTBT layer. Initial deposition of Co atoms downward shifts the core levels of C8-BTBT by electron transfer from isolated Co atoms or clusters to the C8-BTBT. Further deposition of Co upward shifts the core levels of C8-BTBT because of the neutralization of the thicker metal Co film. Our investigation suggests an inert buffer layer inserted to protect organic layer from reaction or decomposition and to lower the carrier barriers for both the electron and hole to improve the performance of Co/C8-BTBT-based OFETs.

  18. Signature of 3-4 day planetary waves in the equatorial ionospheric F layer height and medium frequency radar winds over Tirunelveli (8.7oN)

    NASA Astrophysics Data System (ADS)

    Sundararaman, Sathishkumar

    Signature of 3-4 day planetary waves in the equatorial ionospheric F layer height and medium frequency radar winds over Tirunelveli (8.7oN) S. Sathishkumar1, R. Dhanya1, K. Emperumal1, D. Tiwari2, S. Gurubaran1 and A. Bhattacharyya2 1. Equatorial Geophysical Research Laboratory, Indian Institute of Geomagnetism, Tirunelveli, India 2. Indian Institute of Geomagnetism, Navi Mumbai, India Email: sathishmaths@gmail.com Abstract The equatorial atmosphere-ionosphere system has been studied theoretically and observationally in the past. In the equatorial atmosphere, oscillations with periods of 3-4 days are often observed in the medium frequency (MF) radar over Tirunelveli (8.7oN, 77.8oE, 1.34oN geomag. lat.). Earlier observations show the clear evidence that these waves can propagate from the stratosphere to ionosphere. A digital ionosonde has been providing useful information on several ionospheric parameters from the same site. Simultaneous observations of mesospheric winds using medium frequency radar and F-layer height (h'F) from ionosonde reveal that the 3-4 day wave was evident in both the component during the 01 June 2007 and 31 July 2007. The 3-4 day wave could have an important role in the day to day variability of the equatorial ionosphere evening uplift. Results from an extensive analysis that is being carried out in the direction of 3-4 day wave present in the ionosphere will be presented.

  19. Suppression of allergic immune responses to house dust mite (HDM) in rats exposed to 2,3,7,8-TCDD.

    PubMed

    Luebke, R W; Copeland, C B; Daniels, M; Lambert, A L; Gilmour, M I

    2001-07-01

    Exposure to various xenobiotics, including oxidant gases, diesel exhaust, and certain pesticides, has been reported to exacerbate pulmonary allergic hypersensitivity responses. Increased lymphocyte proliferative responses to parasite antigens or increased antibody responses to sheep erythrocyte have also been reported in rats exposed to TCDD before infection or immunization. As a result, these studies were conducted to test the hypothesis that TCDD exposure exacerbates the allergic response to house dust mite antigen. Brown Norway rats were injected, ip, with 0, 1, 10, or 30 microg TCDD/kg 7 days before intratracheal (it) sensitization to semipurified house dust mite allergen (HDM). Fourteen days later, rats were challenged with HDM and immediate bronchospasm was measured. At this time point, plus 2 and 7 days later, inflammatory cells in bronchoalveolar lavage fluid (BALF), HDM-specific IgE levels in serum, and HDM-driven cell proliferation in bronchial lymph nodes and spleen were evaluated. TCDD exposure decreased both immediate bronchoconstriction and specific IgE synthesis after the HDM challenge; 7 days later, HDM-specific IgE responses remained suppressed. Total serum IgE levels were similar in all groups. HDM challenge alone significantly increased cellular and biochemical indicators of lung injury, both of which were suppressed by TCDD exposure. The proliferative response of lymph node cells, but not of spleen cells, to HDM was also suppressed at the highest TCDD dose, although the splenic response to Concanavalin A was elevated. It appears that early events in the response to HDM are affected by TCDD exposure, since message for IL5 was dramatically reduced 2 days after sensitization, but not after challenge. We therefore conclude that TCDD exposure suppressed, rather than enhanced the development of allergic immune responses and the expression of immune-mediated lung disease.

  20. Tourmaline in the 3.7-3.8 Ga Isua Supracrustal Belt, West Greenland - A window to Boron Concentrations in the Eoarchean Eon

    NASA Astrophysics Data System (ADS)

    Grew, E. S.; Dymek, R. F.; De Hoog, J. C.; Harley, S. L.; Hazen, R. M.; Yates, M. G.

    2013-12-01

    The distribution and mineralogical context of trace elements in Earth's oldest rocks provide insights on Earth's accretion, differentiation, and primordial evolution. One example is boron, which is highly concentrated in Earth's crust and oceans relative to primitive mantle, and, thus the amount of boron on Earth's surface should increase with increasing volume of crust. The earliest B mineral reported in the geological record is metamorphic tourmaline in the Isua Supracrustal Belt, where its abundance belies the notion of there being less boron in the Eoarchean than in more recent time. Chaussidon & Appel (1997, Chem. Geol., 136, 171-180) reported δ11B = --17.3 to --25.0‰ in tourmaline in Isua metachert ("conglomerate"), and δ11B = --12.6 to +5.8 ‰ on tourmaline in Isua metamorphosed mafic volcaniclastics. The large range in the latter rocks was attributed to fractionation during hydrothermal reworking, whereas the more negative values in the metacherts suggested metamorphic tourmaline formed from breakdown of clays with an average δ11B calculated to be about -8 × 7‰ deposited in an ocean having δ11B = +27×11‰, compared to +40 ‰ today, consistent with δ11B = +28‰ calculated from the Chaussidon & Albarède (1992, EPSL, 108, 229-241) model relating increase in sea-water δ11B to proportion of B extracted from Earth's mantle into the oceans and crust. This estimate of Eoarchean seawater δ11B is consistent with fractionation associated with illitization of smectite formed in a marine environment (estimated to be about --35‰) and with crystallization of metamorphic tourmaline from intergranular fluid having the same δ11B as the host metachert (another --2‰ at 500 °C based on tourmaline-water fractionation from Meyer et al. 2008, Contrib. Mineral. Petrol., 156, 259-267). However, this scenario does not adequately explain three rock types in the Isua supracrustals: (1) a tourmaline-quartz lens with ~50% modal tourmaline; (2) a dolomite

  1. Design, synthesis, and evaluation of aza-peptide Michael acceptors as selective and potent inhibitors of caspases-2, -3, -6, -7, -8, -9, and -10.

    PubMed

    Ekici, Ozlem Dogan; Li, Zhao Zhao; Campbell, Amy J; James, Karen Ellis; Asgian, Juliana L; Mikolajczyk, Jowita; Salvesen, Guy S; Ganesan, Rajkumar; Jelakovic, Stjepan; Grütter, Markus G; Powers, James C

    2006-09-21

    Aza-peptide Michael acceptors are a novel class of inhibitors that are potent and specific for caspases-2, -3, -6, -7, -8, -9, and -10. The second-order rate constants are in the order of 10(6) M(-1) s(-1). The aza-peptide Michael acceptor inhibitor 18t (Cbz-Asp-Glu-Val-AAsp-trans-CH=CH-CON(CH(2)-1-Naphth)(2) is the most potent compound and it inhibits caspase-3 with a k(2) value of 5620000 M(-1) s(-1). The inhibitor 18t is 13700, 190, 6.4, 594, 37500, and 173-fold more selective for caspase-3 over caspases-2, -6, -7, -8, -9, and -10, respectively. Aza-peptide Michael acceptors designed with caspase specific sequences are selective and do not show any cross reactivity with clan CA cysteine proteases such as papain, cathepsin B, and calpains. High-resolution crystal structures of caspase-3 and caspase-8 in complex with aza-peptide Michael acceptor inhibitors demonstrate the nucleophilic attack on C2 and provide insight into the selectivity and potency of the inhibitors with respect to the P1' moiety.

  2. Modeling, Synthesis and Biological Evaluation of Potential Retinoid-X-Receptor (RXR) Selective Agonists: Novel Analogs of 4-[1-(3,5,5,8,8-Pentamethyl-5,6,7,8-tetrahydro-2-naphthyl)ethynyl]benzoic Acid (Bexarotene) and (E)-3-(3-(1,2,3,4-tetrahydro-1,1,4,4,6-pentamethylnaphthalen-7-yl)-4-hydroxyphenyl)acrylic acid (CD3254)

    PubMed Central

    Jurutka, Peter W.; Kaneko, Ichiro; Yang, Joanna; Bhogal, Jaskaran S.; Swierski, Johnathon C.; Tabacaru, Christa R.; Montano, Luis A.; Huynh, Chanh C.; Jama, Rabia A.; Mahelona, Ryan D.; Sarnowski, Joseph T.; Marcus, Lisa M.; Quezada, Alexis; Lemming, Brittney; Tedesco, Maria A.; Fischer, Audra J.; Mohamed, Said A.; Ziller, Joseph W.; Ma, Ning; Gray, Geoffrey M.; van der Vaart, Arjan; Marshall, Pamela A.; Wagner, Carl E.

    2014-01-01

    Three unreported analogs of 4-[1-(3,5,5,8,8-pentamethyl-5-6-7-8-tetrahydro-2-naphthyl)ethynyl]benzoic acid (1), otherwise known as bexarotene, as well as four novel analogs of (E)-3-(3-(1,2,3,4-tetrahydro-1,1,4,4,6-pentamethylnaphthalen-7-yl)-4-hydroxyphenyl)acrylic acid (CD3254) are described, and evaluated for their retinoid-X-receptor (RXR)-selective agonism. Compound 1 has FDA approval as a treatment for cutaneous T-cell lymphoma (CTCL); though, treatment with 1 can elicit side-effects by disrupting other RXR-heterodimer receptor pathways. Of the 7 modeled novel compounds, all analogs stimulate RXR-regulated transcription in mammalian-2-hybrid and RXRE-mediated assays, possess comparable or elevated biological activity based on EC50 profiles, and retain similar or improved apoptotic activity in CTCL assays compared to 1. All novel compounds demonstrate selectivity for RXR and minimal crossover onto the retinoic-acid-receptor (RAR) compared to all-trans-retinoic acid, with select analogs also reducing inhibition of other RXR-dependent pathways (e.g., VDR-RXR). Our results demonstrate that further improvements in biological potency and selectivity of bexarotene can be achieved through rational drug design. PMID:24180745

  3. Theoretical study of stereoselectivity of the [1 + 2] cycloaddition reaction between (1S,3R,8S)-2,2-dichloro-3,7,7,10-tetramethyltricyclo[6,4,0,0(1.3)]dodec-9-ene and dibromocarbene using density functional theory (DFT) B3LYP/6-31G*(d).

    PubMed

    Zeroual, Abdellah; Benharref, Ahmed; El Hajbi, Abdeslam

    2015-03-01

    In this work we used density functional theory (DFT) B3LYP/6-31G*(d) to study the stoichiometric reaction between the product (1S,3R,8S)-2,2-dichloro-3,7,7,10-tetramethyltricyclo[6,4,0,0(1.3)]dodec-9-ene (referred to here as P1) and dibromocarbene. We have shown that P1 behaves as a nucleophile, while dibromocarbene behaves as an electrophile; that the chemical potential of dibromocarbene is superior to that of P1 in absolute terms; and that P1 reacts with an equivalent quantity of dibromocarbene to produce two products: (1S,3R,8R,9S,11R)-10,10-dibromo-2,2-dichloro-3,7,7,11-tetramethyltetracyclo[6,5,0,0(1.3),0(9.11)] tridecane (referred to here as P2) and (1S,3R,8R,9R,11S)-10,10-dibromo-2,2-dichloro-3,7,7,11-tetramethyltetracyclo[6,5,0,0(1.3),0(9.11)] tridecane (referred to here as P3). P2 and P3 are formed at the α and β sides, respectively, of the C2 = C3 double bond of P1. This reaction is exothermic, stereoselective and chemospecific, and is controlled by charge transfer. Regioselectivity of the reaction was interpreted using the Lee-Yang-Parr functional.

  4. A densitometric analysis of IIaO film flown aboard the space shuttle transportation system STS #3, 7, and 8

    NASA Technical Reports Server (NTRS)

    Hammond, Ernest C., Jr.

    1989-01-01

    Since the United States of America is moving into an age of reusable space vehicles, both electronic and photographic materials will continue to be an integral part of the recording techniques available. Film as a scientifically viable recording technique in astronomy is well documented. There is a real need to expose various types of films to the Shuttle environment. Thus, the main objective was to look at the subtle densitometric changes of canisters of IIaO film that was placed aboard the Space Shuttle 3 (STS-3).

  5. Transcriptome reveals the overexpression of a kallikrein gene cluster (KLK1/3/7/8/12) in the Tibetans with high altitude-associated polycythemia.

    PubMed

    Li, Kang; Gesang, Luobu; Dan, Zeng; Gusang, Lamu

    2017-02-01

    High altitude-associated polycythemia (HAPC) is a very common disease. However, it the disease is still unmanageable and the related molecular mechanisms remain largely unclear. In the present study, we aimed to explore the molecular mechanisms responsible for the development of HAPC using transcriptome analysis. Transcriptome analysis was conducted in 3 pairs of gastric mucosa tissues from patients with HAPC and healthy residents at a similar altitude. Endoscopy and histopathological analyses were used to examine the injury to gastric tissues. Molecular remodeling was performed for the interaction between different KLK members and cholesterol. HAPC was found to lead to morphological changes and pathological damage to the gastric mucosa of patients. A total of 10,304 differentially expressed genes (DEGs) were identified. Among these genes, 4,941 DEGs were upregulated, while 5,363 DEGs were downregulated in the patients with HAPC (fold change ≥2, P<0.01 and FDR <0.01). In particular, the kallikrein gene cluster (KLK1/3/7/8/12) was upregulated >17-fold. All the members had high-score binding cholesterol, particularly for the polymers of KLK7. The kallikrein gene cluster (KLK1/3/7/8/12) is on chromosome 19q13.3-13.4. The elevated levels of KLK1, KLK3, KLK7, KLK8 and KLK12 may be closely associated with the hypertension, inflammation, obesity and other gastric injuries associated with polycythemia. The interaction of KLKs and cholesterol maybe play an important role in the development of hypertension. The findings of the present study revealed that HAPC induces gastric injury by upregulating the kallikrein gene cluster (KLK1/3/7/8/12), which can bind cholesterol and result in kallikrein hypertension. These findings provide some basic information for understanding the molecular mechanisms responsible for HAPC and HAPC-related diseases.

  6. 7 CFR 774.8 - Limitations.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 7 2014-01-01 2014-01-01 false Limitations. 774.8 Section 774.8 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE... for any purpose which contributes to excessive erosion of highly erodible land or to the conversion...

  7. 7 CFR 774.8 - Limitations.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 7 2011-01-01 2011-01-01 false Limitations. 774.8 Section 774.8 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE... for any purpose which contributes to excessive erosion of highly erodible land or to the conversion...

  8. 7 CFR 774.8 - Limitations.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 7 2010-01-01 2010-01-01 false Limitations. 774.8 Section 774.8 Agriculture Regulations of the Department of Agriculture (Continued) FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE... for any purpose which contributes to excessive erosion of highly erodible land or to the conversion...

  9. Disorder of the dimeric TCNQ-TCNQ unit in the crystal structure of [Ni(bpy)3]2(TCNQ-TCNQ)(TCNQ)2·6H2O (TCNQ is 7,7,8,8-tetra-cyano-quinodi-methane).

    PubMed

    Černák, Juraj; Kuchár, Juraj; Hegedüs, Michal

    2017-01-01

    Crystallization from an aqueous methanol system composed of Ni(NO3)2, 2,2'-bipyridine (bpy) and LiTCNQ (TCNQ is 7,7,8,8-tetra-cyano-quinodi-methane) in a 1:3:2 molar ratio yielded single crystals of bis-[tris-(2,2'-bi-pyridine-κ(2)N,N')nickel(II)] bis-(7,7,8,8-tetra-cyano-quinodi-methane radical anion) bi[7,7,8,8-tetra-cyano-quino-dimethanide] hexa-hydrate, [Ni(C10H8N2)3]2(C24H8N8)(C12H4N4)2·6H2O or [Ni(bpy)3]2(TCNQ-TCNQ)(TCNQ)2·6H2O. The crystal structure comprises [Ni(bpy)3](2+) complex cations, two centrosymmetric crystallographically independent TCNQ (·-) anion radicals with π-stacked exo groups, and an additional dimeric TCNQ-TCNQ unit which comprises 75.3 (9)% of a σ-dimerized (TCNQ-TCNQ)(2-) dianion and 24.7 (9)% of two TCNQ(·-) anion radicals with tightly π-stacked exo groups. The title complex represents the first example of an Ni(II) complex containing a σ-dimerized (TCNQ-TCNQ)(2-) dianion. Disordered solvent water mol-ecules present in the crystal structure participate in hydrogen-bonding inter-actions.

  10. Mechanism of action of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on intermediary metabolism in the rat

    SciTech Connect

    Lakshman, M.R.; Ghosh, P.; Chirtel, S.J. )

    1991-03-11

    The effects of three days of exposure to a single 20 {mu}g/kg dosage of TCDD on fat mobilization and the fates of the mobilized fatty acids and glycerol were determined. It was found that TCDD caused a significant mobilization of depot fat into the plasma compartment resulting in 1.5-2.8 fold increase in plasma free-fatty acid concentrations. The same treatment of TCDD caused a 32% inhibition of the rate of hepatic oleate oxidation to CO{sub 2} without significantly affecting the rate of fatty acid esterification to triglycerides. In contrast, hepatic ketogenic rate from oleate and octanoate was markedly stimulated by 85% and 69% respectively. These results support the concept that although the translocation of long chain fatty acids from the outer mitochondrial membrane into the inner mitochondrial membrane via the carnitine pathway and their subsequent beta-oxidation of the fatty acids must be working normally, their complete oxidation to CO{sub 2}via the TCA cycle is impaired. At the same time, TCDD seems to preferentially divert the acetyl CoA generated from the beta-oxidation of fatty acids to the ketogenic pathway. Surprisingly, TCDD treatment inhibited the hepatic ketogenic rate from glycerol by 21% and its oxidation by 31% without affecting its esterification.

  11. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) toxicity at three stages of lake trout egg development

    SciTech Connect

    Zabel, E.W.; Peterson, R.E.

    1994-12-31

    Although injection of newly fertilized eggs has proven useful for exposure of rainbow trout early life stages to polyhalogenated aromatic hydrocarbons (PHAHs), it has been unsuccessful in lake trout due to injection-related egg mortality. Waterborne exposure of lake trout eggs to vehicle or graded doses of TCDD within 48 hours after fertilization and injection of vehicle or graded doses of TCDD 3 weeks and < 1 week pre-hatch were used to determine the success of egg injection after eye-up and characterize the toxicity of TCDD at later egg stages. A smaller percentage of mortality in later injection groups was associated with signs of TCDD toxicity that have been seen previously (yolk sac edema, hemorrhages, craniofacial malformations and hatching mortality) and the lethal potency of TCDD was reduced. LD50s calculated using probit analysis were 75 pg/g for exposure as newly fertilized eggs and 196 pg/g for injection 3 weeks pre-hatch. The highest dose of 269 pg/g resulted in 30% mortality when injected < 1 week pre-hatch. Because injection-related mortality was very low, with an average of 1% of eggs lost before hatch, injection of eggs after eye-up may be useful for determining the relative potencies of PHAH congeners in lake trout early life stages.

  12. Crystal structure of 1-butyl-2,3-di-methyl-imidazolium dicarba-7,8-nido-undeca-borate.

    PubMed

    Klemes, M J; Soderstrom, L; Hunting, J L; Larsen, A S

    2015-03-01

    In the title mol-ecular salt, C9H17N2 (+)·C2H12B9 (-), the carborane cage has a bridging B-H-B bond on the open B3C2 face. The butyl side chain of the cation adopts an extended conformation [C-C-C-C = 179.6 (1)°]. In the crystal, the imidazolium ring is almost coplanar with the open face of the carborane anion. The cations stack in the [010] direction and the dihedral angle between the imidazolium rings of adjacent cations is 68.45 (6)°. The butyl chains extend into the space between carborane anions.

  13. 7 CFR 1291.8 - Grant agreements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Grant agreements. 1291.8 Section 1291.8 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE SPECIALTY CROP BLOCK GRANT PROGRAM-FARM BILL § 1291.8 Grant agreements. (a) After approval of a grant application, AMS will enter into...

  14. 7 CFR 1290.8 - Grant agreements.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 10 2014-01-01 2014-01-01 false Grant agreements. 1290.8 Section 1290.8 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE SPECIALTY CROP BLOCK GRANT PROGRAM § 1290.8 Grant agreements. (a) After review and approval of a grant application, AMS will enter into...

  15. 7 CFR 47.8 - The answer.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false The answer. 47.8 Section 47.8 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... UNDER THE PERISHABLE AGRICULTURAL COMMODITIES ACT Rules Applicable to Reparation Proceedings § 47.8...

  16. 7 CFR 1000.8 - Nonpool plant.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 9 2011-01-01 2011-01-01 false Nonpool plant. 1000.8 Section 1000.8 Agriculture... Definitions § 1000.8 Nonpool plant. Nonpool plant means any milk receiving, manufacturing, or processing plant other than a pool plant. The following categories of nonpool plants are further defined as follows:...

  17. 7 CFR 1000.8 - Nonpool plant.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 9 2010-01-01 2009-01-01 true Nonpool plant. 1000.8 Section 1000.8 Agriculture... Definitions § 1000.8 Nonpool plant. Nonpool plant means any milk receiving, manufacturing, or processing plant other than a pool plant. The following categories of nonpool plants are further defined as follows:...

  18. 7 CFR 3200.8 - Costs.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 15 2011-01-01 2011-01-01 false Costs. 3200.8 Section 3200.8 Agriculture Regulations... PERSONAL PROPERTY § 3200.8 Costs. Excess personal property obtained under this part is provided free of charge. However, the institution must pay all costs associated with packaging and transportation....

  19. 7 CFR 3200.8 - Costs.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 15 2010-01-01 2010-01-01 false Costs. 3200.8 Section 3200.8 Agriculture Regulations... PERSONAL PROPERTY § 3200.8 Costs. Excess personal property obtained under this part is provided free of charge. However, the institution must pay all costs associated with packaging and transportation....

  20. 7 CFR 1.8 - Multitrack processing.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 1 2013-01-01 2013-01-01 false Multitrack processing. 1.8 Section 1.8 Agriculture Office of the Secretary of Agriculture ADMINISTRATIVE REGULATIONS Official Records § 1.8 Multitrack processing. (a) When an agency has a significant number of requests, the nature of which precludes...

  1. 7 CFR 1.8 - Multitrack processing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Multitrack processing. 1.8 Section 1.8 Agriculture Office of the Secretary of Agriculture ADMINISTRATIVE REGULATIONS Official Records § 1.8 Multitrack processing. (a) When an agency has a significant number of requests, the nature of which precludes...

  2. 7 CFR 356.8 - Return procedure.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 5 2012-01-01 2012-01-01 false Return procedure. 356.8 Section 356.8 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE FORFEITURE PROCEDURES § 356.8 Return procedure. If, at the conclusion...

  3. 7 CFR 17.8 - Ocean transportation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 1 2012-01-01 2012-01-01 false Ocean transportation. 17.8 Section 17.8 Agriculture... THE AGRICULTURAL TRADE DEVELOPMENT AND ASSISTANCE ACT OF 1954, AS AMENDED § 17.8 Ocean transportation. (a) General. (1) This section applies to the financing of ocean freight or ocean freight...

  4. 7 CFR 17.8 - Ocean transportation.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 1 2014-01-01 2014-01-01 false Ocean transportation. 17.8 Section 17.8 Agriculture... THE AGRICULTURAL TRADE DEVELOPMENT AND ASSISTANCE ACT OF 1954, AS AMENDED § 17.8 Ocean transportation. (a) General. (1) This section applies to the financing of ocean freight or ocean freight...

  5. 7 CFR 17.8 - Ocean transportation.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 1 2013-01-01 2013-01-01 false Ocean transportation. 17.8 Section 17.8 Agriculture... THE AGRICULTURAL TRADE DEVELOPMENT AND ASSISTANCE ACT OF 1954, AS AMENDED § 17.8 Ocean transportation. (a) General. (1) This section applies to the financing of ocean freight or ocean freight...

  6. 7 CFR 12.8 - Affiliated persons.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 1 2014-01-01 2014-01-01 false Affiliated persons. 12.8 Section 12.8 Agriculture Office of the Secretary of Agriculture HIGHLY ERODIBLE LAND AND WETLAND CONSERVATION General Provisions § 12.8 Affiliated persons. (a) Ineligibility of affiliated persons. Ineligibility of an individual...

  7. 7 CFR 12.8 - Affiliated persons.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Affiliated persons. 12.8 Section 12.8 Agriculture Office of the Secretary of Agriculture HIGHLY ERODIBLE LAND AND WETLAND CONSERVATION General Provisions § 12.8 Affiliated persons. (a) Ineligibility of affiliated persons. Ineligibility of an individual...

  8. 7 CFR 623.8 - Easement value.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 6 2013-01-01 2013-01-01 false Easement value. 623.8 Section 623.8 Agriculture Regulations of the Department of Agriculture (Continued) NATURAL RESOURCES CONSERVATION SERVICE, DEPARTMENT OF AGRICULTURE WATER RESOURCES EMERGENCY WETLANDS RESERVE PROGRAM § 623.8 Easement value. NRCS offers...

  9. 7 CFR 12.8 - Affiliated persons.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 1 2013-01-01 2013-01-01 false Affiliated persons. 12.8 Section 12.8 Agriculture Office of the Secretary of Agriculture HIGHLY ERODIBLE LAND AND WETLAND CONSERVATION General Provisions § 12.8 Affiliated persons. (a) Ineligibility of affiliated persons. Ineligibility of an individual...

  10. 7 CFR 12.8 - Affiliated persons.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 1 2011-01-01 2011-01-01 false Affiliated persons. 12.8 Section 12.8 Agriculture Office of the Secretary of Agriculture HIGHLY ERODIBLE LAND AND WETLAND CONSERVATION General Provisions § 12.8 Affiliated persons. (a) Ineligibility of affiliated persons. Ineligibility of an individual...

  11. 7 CFR 12.8 - Affiliated persons.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 1 2012-01-01 2012-01-01 false Affiliated persons. 12.8 Section 12.8 Agriculture Office of the Secretary of Agriculture HIGHLY ERODIBLE LAND AND WETLAND CONSERVATION General Provisions § 12.8 Affiliated persons. (a) Ineligibility of affiliated persons. Ineligibility of an individual...

  12. 7 CFR 983.8 - Committee.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Committee. 983.8 Section 983.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN CALIFORNIA, ARIZONA,...

  13. 7 CFR 983.8 - Committee.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Committee. 983.8 Section 983.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE PISTACHIOS GROWN IN CALIFORNIA, ARIZONA,...

  14. 7 CFR 923.8 - Committee.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 8 2012-01-01 2012-01-01 false Committee. 923.8 Section 923.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE SWEET CHERRIES GROWN IN DESIGNATED...

  15. 7 CFR 923.8 - Committee.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 8 2010-01-01 2010-01-01 false Committee. 923.8 Section 923.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE SWEET CHERRIES GROWN IN DESIGNATED...

  16. 7 CFR 923.8 - Committee.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 8 2011-01-01 2011-01-01 false Committee. 923.8 Section 923.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements and Orders; Fruits, Vegetables, Nuts), DEPARTMENT OF AGRICULTURE SWEET CHERRIES GROWN IN DESIGNATED...

  17. 7 CFR 923.8 - Committee.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 8 2014-01-01 2014-01-01 false Committee. 923.8 Section 923.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE SWEET CHERRIES GROWN IN DESIGNATED...

  18. 7 CFR 923.8 - Committee.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 8 2013-01-01 2013-01-01 false Committee. 923.8 Section 923.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; FRUITS, VEGETABLES, NUTS), DEPARTMENT OF AGRICULTURE SWEET CHERRIES GROWN IN DESIGNATED...

  19. 7 CFR 226.8 - Audits.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 4 2013-01-01 2013-01-01 false Audits. 226.8 Section 226.8 Agriculture Regulations of... NUTRITION PROGRAMS CHILD AND ADULT CARE FOOD PROGRAM State Agency Provisions § 226.8 Audits. (a) Unless otherwise exempt, audits at the State and institution levels must be conducted in accordance with Office...

  20. 7 CFR 226.8 - Audits.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 4 2014-01-01 2014-01-01 false Audits. 226.8 Section 226.8 Agriculture Regulations of... NUTRITION PROGRAMS CHILD AND ADULT CARE FOOD PROGRAM State Agency Provisions § 226.8 Audits. (a) Unless otherwise exempt, audits at the State and institution levels must be conducted in accordance with Office...

  1. 7 CFR 1773.8 - Audit date.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 12 2012-01-01 2012-01-01 false Audit date. 1773.8 Section 1773.8 Agriculture... (CONTINUED) POLICY ON AUDITS OF RUS BORROWERS RUS Audit Requirements § 1773.8 Audit date. (a) The annual audit must be performed as of the end of the same calendar month each year unless prior approval...

  2. 7 CFR 1773.8 - Audit date.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 12 2011-01-01 2011-01-01 false Audit date. 1773.8 Section 1773.8 Agriculture... (CONTINUED) POLICY ON AUDITS OF RUS BORROWERS RUS Audit Requirements § 1773.8 Audit date. (a) The annual audit must be performed as of the end of the same calendar month each year unless prior approval...

  3. 7 CFR 1773.8 - Audit date.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 12 2014-01-01 2013-01-01 true Audit date. 1773.8 Section 1773.8 Agriculture... (CONTINUED) POLICY ON AUDITS OF RUS BORROWERS RUS Audit Requirements § 1773.8 Audit date. (a) The annual audit must be performed as of the end of the same calendar month each year unless prior approval...

  4. 7 CFR 226.8 - Audits.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 4 2012-01-01 2012-01-01 false Audits. 226.8 Section 226.8 Agriculture Regulations of... NUTRITION PROGRAMS CHILD AND ADULT CARE FOOD PROGRAM State Agency Provisions § 226.8 Audits. (a) Unless otherwise exempt, audits at the State and institution levels must be conducted in accordance with Office...

  5. 7 CFR 226.8 - Audits.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 4 2011-01-01 2011-01-01 false Audits. 226.8 Section 226.8 Agriculture Regulations of... NUTRITION PROGRAMS CHILD AND ADULT CARE FOOD PROGRAM State Agency Provisions § 226.8 Audits. (a) Unless otherwise exempt, audits at the State and institution levels must be conducted in accordance with Office...

  6. 7 CFR 3402.8 - Fellowship activities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 15 2013-01-01 2013-01-01 false Fellowship activities. 3402.8 Section 3402.8... AGRICULTURE FOOD AND AGRICULTURAL SCIENCES NATIONAL NEEDS GRADUATE AND POSTGRADUATE FELLOWSHIP GRANTS PROGRAM Program Description § 3402.8 Fellowship activities. A USDA Graduate Fellow shall be enrolled as a...

  7. 7 CFR 3402.8 - Fellowship activities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 15 2011-01-01 2011-01-01 false Fellowship activities. 3402.8 Section 3402.8... AGRICULTURE FOOD AND AGRICULTURAL SCIENCES NATIONAL NEEDS GRADUATE AND POSTGRADUATE FELLOWSHIP GRANTS PROGRAM Program Description § 3402.8 Fellowship activities. A USDA Graduate Fellow shall be enrolled as a...

  8. 7 CFR 3402.8 - Fellowship activities.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false Fellowship activities. 3402.8 Section 3402.8... AGRICULTURE FOOD AND AGRICULTURAL SCIENCES NATIONAL NEEDS GRADUATE AND POSTGRADUATE FELLOWSHIP GRANTS PROGRAM Program Description § 3402.8 Fellowship activities. A USDA Graduate Fellow shall be enrolled as a...

  9. 7 CFR 3402.8 - Fellowship activities.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 15 2012-01-01 2012-01-01 false Fellowship activities. 3402.8 Section 3402.8... AGRICULTURE FOOD AND AGRICULTURAL SCIENCES NATIONAL NEEDS GRADUATE AND POSTGRADUATE FELLOWSHIP GRANTS PROGRAM Program Description § 3402.8 Fellowship activities. A USDA Graduate Fellow shall be enrolled as a...

  10. 7 CFR 1709.8 - Electronic submission.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 11 2010-01-01 2010-01-01 false Electronic submission. 1709.8 Section 1709.8... AGRICULTURE ASSISTANCE TO HIGH ENERGY COST COMMUNITIES General Requirements § 1709.8 Electronic submission... announcement and grant agreements or if other regulations provide for electronic submission. Any...

  11. 7 CFR 1291.8 - Grant agreements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Grant agreements. 1291.8 Section 1291.8 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE SPECIALTY CROP BLOCK GRANT PROGRAM-FARM BILL § 1291.8 Grant agreements. (a) After approval of a grant application, AMS will enter into...

  12. 7 CFR 1290.8 - Grant agreements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Grant agreements. 1290.8 Section 1290.8 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE SPECIALTY CROP BLOCK GRANT PROGRAM § 1290.8 Grant agreements. (a) After review and approval of a grant application, AMS will enter into...

  13. 7 CFR 1290.8 - Grant agreements.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 10 2012-01-01 2012-01-01 false Grant agreements. 1290.8 Section 1290.8 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE SPECIALTY CROP BLOCK GRANT PROGRAM § 1290.8 Grant agreements. (a) After review and approval of a grant application, AMS will enter into...

  14. 7 CFR 3401.8 - Grant awards.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 15 2014-01-01 2014-01-01 false Grant awards. 3401.8 Section 3401.8 Agriculture... RESEARCH GRANTS PROGRAM General § 3401.8 Grant awards. (a) General. Within the limit of funds available for such purpose, the awarding official shall make research project grants to those responsible,...

  15. 7 CFR 1291.8 - Grant agreements.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Grant agreements. 1291.8 Section 1291.8 Agriculture... AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE SPECIALTY CROP BLOCK GRANT PROGRAM-FARM BILL § 1291.8 Grant agreements. (a) After approval of a grant application, AMS will enter into...

  16. 7 CFR 226.8 - Audits.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 4 2010-01-01 2010-01-01 false Audits. 226.8 Section 226.8 Agriculture Regulations of... NUTRITION PROGRAMS CHILD AND ADULT CARE FOOD PROGRAM State Agency Provisions § 226.8 Audits. (a) Unless otherwise exempt, audits at the State and institution levels must be conducted in accordance with Office...

  17. 7 CFR 319.8-23 - Treatment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Treatment. 319.8-23 Section 319.8-23 Agriculture....8-23 Treatment. (a)(1) Vacuum fumigation as required in this subpart shall consist of fumigation, in... the substitution of processing, utilization, or other form of treatment for vacuum fumigation when...

  18. 7 CFR 1400.8 - Equitable treatment.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Equitable treatment. 1400.8 Section 1400.8... AND SUBSEQUENT CROP, PROGRAM, OR FISCAL YEARS General Provisions § 1400.8 Equitable treatment. (a... Administrator deems necessary to provide fair and equitable treatment to such person or legal entity....

  19. 7 CFR 1709.8 - Electronic submission.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 11 2011-01-01 2011-01-01 false Electronic submission. 1709.8 Section 1709.8... AGRICULTURE ASSISTANCE TO HIGH ENERGY COST COMMUNITIES General Requirements § 1709.8 Electronic submission... announcement and grant agreements or if other regulations provide for electronic submission. Any...

  20. 7 CFR 1000.8 - Nonpool plant.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 9 2012-01-01 2012-01-01 false Nonpool plant. 1000.8 Section 1000.8 Agriculture... Definitions § 1000.8 Nonpool plant. Nonpool plant means any milk receiving, manufacturing, or processing plant other than a pool plant. The following categories of nonpool plants are further defined as follows:...

  1. 7 CFR 1000.8 - Nonpool plant.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 9 2014-01-01 2013-01-01 true Nonpool plant. 1000.8 Section 1000.8 Agriculture... Definitions § 1000.8 Nonpool plant. Nonpool plant means any milk receiving, manufacturing, or processing plant other than a pool plant. The following categories of nonpool plants are further defined as follows:...

  2. 7 CFR 1000.8 - Nonpool plant.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 9 2013-01-01 2013-01-01 false Nonpool plant. 1000.8 Section 1000.8 Agriculture... Definitions § 1000.8 Nonpool plant. Nonpool plant means any milk receiving, manufacturing, or processing plant other than a pool plant. The following categories of nonpool plants are further defined as follows:...

  3. 7 CFR 17.8 - Ocean transportation.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Ocean transportation. 17.8 Section 17.8 Agriculture... THE AGRICULTURAL TRADE DEVELOPMENT AND ASSISTANCE ACT OF 1954, AS AMENDED § 17.8 Ocean transportation. (a) General. (1) This section applies to the financing of ocean freight or ocean freight...

  4. 7 CFR 17.8 - Ocean transportation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 1 2011-01-01 2011-01-01 false Ocean transportation. 17.8 Section 17.8 Agriculture... THE AGRICULTURAL TRADE DEVELOPMENT AND ASSISTANCE ACT OF 1954, AS AMENDED § 17.8 Ocean transportation. (a) General. (1) This section applies to the financing of ocean freight or ocean freight...

  5. 7 CFR 47.8 - The answer.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 2 2013-01-01 2013-01-01 false The answer. 47.8 Section 47.8 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... UNDER THE PERISHABLE AGRICULTURAL COMMODITIES ACT Rules Applicable to Reparation Proceedings § 47.8...

  6. 7 CFR 47.8 - The answer.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 2 2014-01-01 2014-01-01 false The answer. 47.8 Section 47.8 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... UNDER THE PERISHABLE AGRICULTURAL COMMODITIES ACT Rules Applicable to Reparation Proceedings § 47.8...

  7. 7 CFR 47.8 - The answer.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 2 2011-01-01 2011-01-01 false The answer. 47.8 Section 47.8 Agriculture Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing... UNDER THE PERISHABLE AGRICULTURAL COMMODITIES ACT Rules Applicable to Reparation Proceedings § 47.8...

  8. 7 CFR 924.8 - Committee.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... means the Washington-Oregon Fresh Prune Marketing Committee established pursuant to § 924.20. ... 7 Agriculture 8 2010-01-01 2010-01-01 false Committee. 924.8 Section 924.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements...

  9. 8-bromo-7-methoxychrysin induces apoptosis by regulating Akt/FOXO3a pathway in cisplatin-sensitive and resistant ovarian cancer cells

    PubMed Central

    DING, QING; CHEN, YI; ZHANG, QING; GUO, YANLING; HUANG, ZHI; DAI, LIQING; CAO, SUDAN

    2015-01-01

    8-bromo-7-methoxychrysin (BrMC), a novel chrysin analog, was reported to have anti-cancer activities. The aim of the present study was to investigate the molecular mechanism of 8-bromo-7-methoxychrysin (BrMC)-induced apoptosis via the Akt/forkhead box O3a (FOXO3a) pathway in cisplatin (DDP)-sensitive and -resistant ovarian cancer cells. The human ovarian cancer cell lines A2780 and A2780/DDP were cultured in vitro. Various molecular techniques were used to assess the expression of FOXO3a and B cell lymphoma 2 (Bcl-2)-interacting mediator of cell death (Bim) in cisplatin-sensitive and -resistant ovarian cancer cells. Different concentrations of BrMC induced apoptosis in cisplatin-sensitive and -resistant ovarian cancer cells. BrMC-induced apoptotic cell death occurred mainly by the activation of Akt, which was accompanied by the overexpression of transcription factor FOXO3a, with a concomitant increase in the expression levels of Bim. Silencing Bim expression by using small interfering RNA, attenuated the induction of apoptosis by BrMC treatment. The results indicated that BrMC-induced apoptosis in cisplatin-sensitive and -resistant ovarian cancer cells may occur via the regulation of Akt/FOXO3a, leading to Bim transcription. PMID:26151347

  10. 8 CFR 286.7 - Penalties.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 8 Aliens and Nationality 1 2012-01-01 2012-01-01 false Penalties. 286.7 Section 286.7 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS IMMIGRATION USER FEE § 286.7 Penalties. Failure of any air or sea carrier to comply with the provisions of section 286 of the Act and this...

  11. 8 CFR 286.7 - Penalties.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 8 Aliens and Nationality 1 2010-01-01 2010-01-01 false Penalties. 286.7 Section 286.7 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS IMMIGRATION USER FEE § 286.7 Penalties. Failure of any air or sea carrier to comply with the provisions of section 286 of the Act and this...

  12. 8 CFR 286.7 - Penalties.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 8 Aliens and Nationality 1 2014-01-01 2014-01-01 false Penalties. 286.7 Section 286.7 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS IMMIGRATION USER FEE § 286.7 Penalties. Failure of any air or sea carrier to comply with the provisions of section 286 of the Act and this...

  13. 8 CFR 286.7 - Penalties.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 8 Aliens and Nationality 1 2013-01-01 2013-01-01 false Penalties. 286.7 Section 286.7 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS IMMIGRATION USER FEE § 286.7 Penalties. Failure of any air or sea carrier to comply with the provisions of section 286 of the Act and this...

  14. 8 CFR 286.7 - Penalties.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 8 Aliens and Nationality 1 2011-01-01 2011-01-01 false Penalties. 286.7 Section 286.7 Aliens and Nationality DEPARTMENT OF HOMELAND SECURITY IMMIGRATION REGULATIONS IMMIGRATION USER FEE § 286.7 Penalties. Failure of any air or sea carrier to comply with the provisions of section 286 of the Act and this...

  15. Analysis of the ν 8+ ν 9Band of HNO 3, Line Positions and Intensities, and Resonances Involving the v6= v7= 1 Dark State

    NASA Astrophysics Data System (ADS)

    Perrin, A.; Flaud, J.-M.; Keller, F.; Goldman, A.; Blatherwick, R. D.; Murcray, F. J.; Rinsland, C. P.

    1999-03-01

    Using a high-resolution (R= 0.0025 cm-1) Fourier transform spectrum of nitric acid recorded at room temperature in the 1100-1240 cm-1region, it has been possible to perform a more extended analysis of the ν8+ ν9band of HNO3centered at 1205.7075 cm-1. As in a recent analysis of this band [W. F. Wang, P. P. Ong, T. L. Tan, E. C. Looi, and H. H. Teo,J. Mol. Spectrosc.183, 407-413 (1997)], the Hamiltonian used for the line positions calculation takes into account, for the upper state, the ΔK= ±2 anharmonic resonance linking the rotational levels of thev8=v9= 1 "bright" vibrational state and those of the "dark"v6=v7= 1 vibrational state. More than 4800 lines were assigned in the ν8+ ν9band, which involve significantly higher rotational quantum numbers than in previous works. On the other hand, and surprisingly as compared to previous studies, the ν8+ ν9band appears to be a hybrid band. In fact, nonnegligibleB-type transitions could be clearly identified among the much strongerA-type lines. Accordingly, a set of individual line intensities were measured for lines of both types and were introduced in a least-squares fit to get theA- andB-type components of the transition moment operator. Finally, a synthetic spectrum of the 8.3-μm region of HNO3has been generated, using for the line positions and line intensities the Hamiltonian constants and the expansion of the transition moment operator which were determined in this work. In this way, theB-type and theA-type components of the ν8+ ν9band appear to contribute for about {1}/{4} and {3}/{4}, respectively, to the total band intensity.

  16. Curcumin, myrecen and cineol modulate the percentage of lymphocyte subsets altered by 2,3,7, 8-tetracholorodibenzo-p-dioxins (TCDD) in rats.

    PubMed

    Ciftci, Osman; Tanyildizi, Sadettin; Godekmerdan, Ahmet

    2011-12-01

    The aim of this study was to investigate the toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a persistent environmental pollutant, on the percentage of T-cell subsets and B-lymphocyte and effectiveness of curcumin, β-myrcene (myrcene) and 1,8-cineole (cineol) on this toxicity in rats. Rats (n = 112) were divided randomly into 8 equal groups. One group was kept as control and given corn oil as carrier. TCDD was orally administered at the dose of 2 µg/kg/week. Curcumin, myrcene and cineol were orally administered by gavages at the doses of 100, 200 and 100 mg/kg/day, respectively, dissolved in corn oil with and without TCDD. The blood samples were taken from half of the rats on day 30 and from the rest on day 60 for the determination of lymphocyte subsets (CD3(+), CD4(+), CD8(+), CD161(+), CD45RA, CD4(+)CD25(+) and total lymphocyte). The results indicated that although TCDD significantly (p < 0.05) decreased the percentage of CD3(+), CD4(+), CD161(+), CD45RA, CD4(+)CD25(+) and total lymphocyte, it caused a significant increase in the percentage of CD8(+) cells. In contrast, curcumin, myrcene and cineol significantly decreased CD8(+) cells levels but increased CD3(+), CD4(+), CD161(+), CD45RA, CD4(+)CD25(+) and total lymphocyte cells populations. The beneficial effects of curcumin, myrcene and cineol and the toxic effects of TCDD were increased at day 60 compared to day 30. In conclusion, curcumin, myrcene and cineol showed immunomodulatory effects and eliminated TCDD-induced immune suppressive effects in rats.

  17. Early life stage toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in zebrafish (Danio rerio)

    SciTech Connect

    Henry, T.R.; Hornung, M.W.; Abnet, C.C.; Peterson, R.E.

    1995-12-31

    TCDD and related compounds cause toxicity in fish early life stages, characterized by edema, regional ischemia, craniofacial malformations, growth retardation and mortality. Determining the mechanism of these effects requires understanding normal early life stage development, which has been studied extensively in the zebrafish. Establishing zebrafish as a model for TCDD developmental toxicity requires demonstration that TCDD adversely affects zebrafish early life stages. Toxicity of TCDD to zebrafish early life stages was characterized by exposing newly fertilized eggs for 1 hr to water containing acetone or graded concentrations of [{sup 3}H]-TCDD and observed for signs of toxicity at 12 hr intervals for 240 hr post fertilization (hpf). TCDD did not increase embryo mortality during the egg stage (0--48 hpf) nor did it affect the time to hatching (48--96 hpf). At the highest TCDD egg doses (4.5--6.5 ng/g) the earliest sign of toxicity was pericardial edema (72 hpf) followed by the onset of yolk sac edema (96 hpf) onset of mortality (132 hpf). At lower egg doses the same effects were seen but after a longer delay period. Other signs of toxicity included craniofacial malformations, cranial edema and loss of swimming activity prior to death. To determine the dose-response relationship for pericardial and yolk sac edema and larval mortality the cumulative incidence of each effect was determined at 240 hpf. The ED{sub 50}s (95% fiducial limits) for pericardial edema and yolk sac edema were 2.1 6 (1.82--2.48) and 2.43 (2.12--2.72) ng TCDD/g egg, respectively. The LD{sub 50} was 2.45 (1.94--2.89) ng TCDD/g egg. In conclusion, the signs of TCDD early life stage toxicity in zebrafish are essentially identical to those in other fish species, however, larger egg doses of TCDD are required to elicit the effects.

  18. A honeycomb network based on hybrid lanthanum complexes encircling a [β-Mo8O26]4- isomer: Synthesis, characterization and crystal structure of [La (η2-NO3) (dmso)7]2 [β-Mo8O26

    NASA Astrophysics Data System (ADS)

    Khélifa, Arbia Ben; Ezzayani, Khaireddine; Belkhiria, Mouhamed Salah

    2016-10-01

    A novel isopolymolybdates functionalized by rare earth complexes namely, [La (η2-NO3) (dmso)7]2 [β-Mo8O26] (1) has been successfully synthesized and characterized by routine methods: IR, X-ray powder diffraction, UV-Visible absorption and single crystal X-ray diffraction. The title compound is crystallized in monoclinic space group P21/n with a = 11.566 (2) Å, b = 28.522 (6) Å, c = 12.644 (3) Å, β = 91.94 (3)°. The structural feature of 1 is that lanthanum complexes form a honeycomb network, in which resides the [β-Mo8O26]4- isomer. The cohesion structure is ensured by non typical hydrogen bonding interactions causes a 3D supramolecular network. Absorption spectrum, optical band gap energies have been investigated.

  19. Nrf2 protects against 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced oxidative injury and steatohepatitis

    SciTech Connect

    Lu Hong; Cui Wei; Klaassen, Curtis D.

    2011-10-15

    Previous studies demonstrate that Nrf2, a master regulator of antioxidative responses, is essential in mediating induction of many antioxidative enzymes by acute activation of the AhR. However, the role of Nrf2 in protecting against oxidative stress and DNA damage induced by sustained activation of the AhR remains unknown and was investigated herein. Tissue and blood samples were collected from wild-type (WT) and Nrf2-null mice 21 days after administration of a low-toxic dose (10 {mu}g/kg ip) of TCDD. Only Nrf2-null mice lost body weight after TCDD treatment; however, blood levels of ALT were not markedly changed in either genotype, indicating a lack of extensive necrosis. Compared to livers of TCDD-treated WT mice, livers of TCDD-treated Nrf2-null mice had: 1) degenerated hepatocytes, lobular inflammation, marked fat accumulation, and higher mRNA expression of inflammatory and fibrotic genes; 2) depletion of glutathione, elevation in lipid peroxidation and marker of DNA damage; 3) attenuated induction of phase-II enzymes Nqo1, Gsta1/2, and Ugt2b35 mRNAs, but higher induction of cytoprotective Ho-1, Prdx1, Trxr1, Gclc, and Epxh1 mRNAs; 4) higher mRNA expression of Fgf21 and triglyceride-synthesis genes, but down-regulation of bile-acid-synthesis genes and cholesterol-efflux transporters; and 5) trend of induction/activation of c-jun and NF-kB. Additionally, TCDD-treated Nrf2-null mice had impaired adipogenesis in white adipose tissue. In conclusion, Nrf2 protects livers of mice against oxidative stress, DNA damage, and steatohepatitis induced by TCDD-mediated sustained activation of the AhR. The aggravated hepatosteatosis in TCDD-treated Nrf2-null mice is due to increased lipogenesis in liver and impaired lipogenesis in white adipose tissue. - Highlights: > TCDD causes hepatosteatosis and induction of Nrf2-target genes in wild-type mice. > TCDD causes weight loss, oxidative injury, and steatohepatitis in Nrf2-null mice. > Livers of TCDD-treated Nrf2-null mice have

  20. Crystal structure of (1R,3S,8R,11R)-11-acetyl-3,7,7-trimethyl-10-oxatri­cyclo­[6.4.0.01,3]dodecan-9-one

    PubMed Central

    Bismoussa, Abdoullah; Ait Itto, My Youssef; Daran, Jean-Claude; Auhmani, Abdelwahed; Auhmani, Aziz

    2015-01-01

    The title compound, C16H24O3, is built up from three fused rings, a six-membered, a seven-membered and a three-membered ring. The absolute configuration of the title compound was determined as (1R,3S,8R,11R) based on the synthetic pathway. The six-membered ring has an half-chair conformation whereas the seven-membered ring displays a boat conformation. In the cyrstal, C—H⋯O hydrogen bonds build up a two-dimensional network parallel to (0 0 1). The crystal studied was an inversion twin with a minor twin component of 34%. PMID:26870471

  1. 41 CFR 105-8.170-7 - Investigation/conciliation.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 41 Public Contracts and Property Management 3 2011-01-01 2011-01-01 false Investigation/conciliation. 105-8.170-7 Section 105-8.170-7 Public Contracts and Property Management Federal Property Management Regulations System (Continued) GENERAL SERVICES ADMINISTRATION 8-ENFORCEMENT OF...

  2. Volumetric Properties of the Mixture Propan-2-ol C3H8O + C7H16O Heptan-1-ol (VMSD1511, LB3551_V)

    NASA Astrophysics Data System (ADS)

    Cibulka, I.; Fontaine, J.-C.; Sosnkowska-Kehiaian, K.; Kehiaian, H. V.

    This document is part of Subvolume C 'Binary Liquid Systems of Nonelectrolytes III' of Volume 26 'Heats of Mixing, Vapor-Liquid Equilibrium, and Volumetric Properties of Mixtures and Solutions' of Landolt-Börnstein Group IV 'Physical Chemistry'. It contains the Chapter 'Volumetric Properties of the Mixture Propan-2-ol C3H8O + C7H16O Heptan-1-ol (VMSD1511, LB3551_V)' providing data from direct measurement of low-pressure thermodynamic speed of sound at variable mole fraction and constant temperature, in the single-phase region(s).

  3. Oligodeoxynucleotide inhibition of Toll-like receptors 3, 7, 8, and 9 suppresses cytokine production in a human rheumatoid arthritis model.

    PubMed

    Sacre, Sandra; Lo, Alexandra; Gregory, Bernard; Stephens, Matthew; Chamberlain, Giselle; Stott, Philip; Brennan, Fionula

    2016-03-01

    Toll-like receptors (TLRs) are innate immune receptors that respond to both exogenous and endogenous stimuli and are suggested to contribute to the perpetuation of chronic inflammation associated with rheumatoid arthritis (RA). In particular, the endosomal TLRs 3, 7, 8, and 9 have more recently been postulated to be of importance in RA pathogenesis. In this study, pan inhibition of the endosomal TLRs by a phosphorothioate-modified inhibitory oligodeoxynucleotide (ODN) is demonstrated in primary human B cells, macrophages, and RA fibroblasts. Inhibition of TLR8 was of particular interest as TLR8 has been associated with RA pathogenesis in both human and murine arthritis models. ODN1411 competitively inhibited TLR8 signaling and was observed to directly bind to a purified TLR8 ectodomain, suggesting inhibition was through a direct interaction with the receptor. Addition of ODN1411 to human RA synovial membrane cultures significantly inhibited spontaneous cytokine production from these cultures, suggesting a potential role for one or more of the endosomal TLRs in inflammatory cytokine production in RA and the potential for inhibitory ODNs as novel therapies.

  4. The anti/syn conformation of 8-oxo-7,8-dihydro-2'-deoxyguanosine is modulated by Bacillus subtilis PolX active site residues His255 and Asn263. Efficient processing of damaged 3'-ends.

    PubMed

    Zafra, Olga; Pérez de Ayala, Lucía; de Vega, Miguel

    2017-04-01

    8-oxo-7,8-dihydro-2'-deoxyguanosine (8oxodG) is a major lesion resulting from oxidative stress and found in both DNA and dNTP pools. Such a lesion is usually removed from DNA by the Base Excision Repair (BER), a universally conserved DNA repair pathway. 8oxodG usually adopts the favored and promutagenic syn-conformation at the active site of DNA polymerases, allowing the base to hydrogen bonding with adenine during DNA synthesis. Here, we study the structural determinants that affect the glycosidic torsion-angle of 8oxodGTP at the catalytic active site of the family X DNA polymerase from Bacillus subtilis (PolXBs). We show that, unlike most DNA polymerases, PolXBs exhibits a similar efficiency to stabilize the anti and syn conformation of 8oxodGTP at the catalytic site. Kinetic analyses indicate that at least two conserved residues of the nucleotide binding pocket play opposite roles in the anti/syn conformation selectivity, Asn263 and His255 that favor incorporation of 8oxodGMP opposite dA and dC, respectively. In addition, the presence in PolXBs of Mn(2+)-dependent 3'-phosphatase and 3'-phosphodiesterase activities is also shown. Those activities rely on the catalytic center of the C-terminal Polymerase and Histidinol Phosphatase (PHP) domain of PolXBs and, together with its 3'-5' exonuclease activity allows the enzyme to resume gap-filling after processing of damaged 3' termini.

  5. LLNL Yucca Mountain project - near-field environment characterization technical area: Letter report: EQ3/6 version 8: differences from version 7

    SciTech Connect

    Wolery, T.J.

    1994-09-29

    EQ3/6 is a software package for geochemical modeling of aqueous systems, such as water/rock or waste/water rock. It is being developed for a variety of applications in geochemical studies for the Yucca Mountain Site Characterization Project. The software has been extensively rewritten for Version 8. The source code has been extensively modernized. The software is now written in Fortran 77 with the most common extensions that are part of the new Fortran 90 standard. The architecture of the software has been improved for better performance and to allow the incorporation of new functional capabilities in Version 8 and planned subsequent versions. In particular, the structure of the major data arrays has been significantly altered and extended. Three new major functional capabilities have been incorporated in Version 8. The first of these allows the treatment of redox disequilibrium in reaction-path modeling. This is a natural extension of the long-running capability of providing for such disequilibrium in static speciation-solubility calculations. Such a capability is important, for example, when dealing with systems containing organic species and certain dissolved gas species. The user defines (and sets the controls for) the components in disequilibrium. Such corrections can now be made if the requisite data are present on a supporting data file. At present, this capability is supported only by the SHV data file, which is based on SUPCRT92. Equilibrium constants and other thermodynamic quantities are correct1961ed for pressures which lie off a standard curve, which is defined on the supporting data file and ordinarily corresponds to 1.013 bar up to IOOC, and the steam/liquid water equilibrium pressure up to 300C. The third new major capability is generic ion exchange option previously developed in prototype in a branch Version 7 level version of EQ3/6 by Brian Viani, Bill Bourcier, and Carol Bruton. This option has been modified to fit into the Version 8 data

  6. Terminal Substituent Effects on the Reactivity, Thermodynamics, and Stereoselectivity of the 8π–6π Electrocyclization Cascades of 1,3,5,7-Tetraenes

    PubMed Central

    2015-01-01

    M06-2X/6-31+G(d,p) computations are reported for the 8π–6π electrocyclization cascades of 1,3,5,7-tetraenes. The rate-determining step for these cascades is typically the second (6π) ring closure. According to experiment and theory, un- and monosubstituted tetraenes readily undergo 8π electrocyclic ring closure to form 1,3,5-cyclooctatrienes; however, the 6π electrocyclizations of these cyclooctatriene intermediates are slow and reversible, and mixtures of monocyclic and bicyclic products are formed. Computations indicate that di- and trisubstituted tetraenes undergo facile but less exergonic 8π electrocyclization due to a steric clash that destabilizes the 1,3,5-cyclooctatriene intermediates. Relief of this steric clash ensures the subsequent 6π ring closures of these intermediates are both kinetically facile and thermodynamically favorable, and only the bicyclic products are observed for the cascade reactions of naturally occurring tri- and tetrasubstituted tetraenes (in agreement with computations). The 6π electrocyclization step of these cascade electrocyclizations is also potentially diastereoselective, and di- and trisubstituted tetraenes often undergo cascade reactions with high diastereoselectivities. The exo mode of ring closure is favored for these 6π electrocyclizations due to a steric interaction that destabilizes the endo transition state. Thus, theory explains both the recalcitrance of the unsubstituted 1,3,5,7-octatetraene and 1-substituted tetraenes toward formation of the bicyclo[4.2.0]octa-2,4-diene products, as well as the ease and the stereoselectivity with which terminal di- and trisubstituted tetraenes are known to react biosynthetically. PMID:25358094

  7. Toxicity and disposition of 2,3,4,7,8-pentachlorodibenzofuran (4PeCDF) in the rhesus monkey (Macaca mulatta)

    SciTech Connect

    Brewster, D.W.; Elwell, M.R.; Birnbaum, L.S.

    1988-04-01

    The toxicity and disposition of 2,3,4,7,8-pentachlorodibenzofuran (4PeCDF), a ubiquitous and acutely toxic environmental contaminant, was examined in three adult male Rhesus monkeys administered a single iv dose of 34 micrograms (0.1 mumol)/kg. Within 20 min, 4PeCDF was eliminated from the blood and was distributed to the liver, skin, adipose, and muscle tissues. Excretion occurred primarily via the feces with a minimum whole body half-life approximately 38 days. Within 7-14 days after administration, the packed cell volume and serum triglyceride and bile acid concentrations were significantly increased while serum cholesterol, protein, and albumin concentrations were decreased relative to pretreatment levels. Thyroid hormone levels were also altered with an increase in TSH and a decrease in T3 and T4 concentrations. After 28 days, two monkeys began exhibiting alopecia, hyperkeratinization of the toe and finger nails, facial chloracne-like lesions, and loss of body weight. They subsequently died 40 and 48 days after treatment. Similar symptoms of toxicity were observed in the third animal 58 days after 4PeCDF administration, but this animal appeared to fully recover and was administered 4PeCDF orally and (3H)1,2,3,7,8-pentachloro-dibenzofuran (1PeCDF) dermally 238 days after the initial iv dose. In this animal, approximately 2% of an oral dose of (14C)-4PeCDF was absorbed from the stomach and small intestine in 6 hr and was distributed mainly to the muscle and skin and less than 99% of a dermal dose of 1PeCDF remained at the site of application. Pathological findings in the monkeys that died indicated hyperplastic and metaplastic changes in the gastric mucosa, the Meibomian glands of the eyelid, and the ceruminous glands of the ear. Regression of these lesions was present in the surviving animal.

  8. Discovery of novel 5,6,7,8-tetrahydro[1,2,4]triazolo[4,3-a]pyridine derivatives as γ-secretase modulators (Part 2).

    PubMed

    Takai, Takafumi; Koike, Tatsuki; Nakamura, Minoru; Kajita, Yuichi; Yamashita, Toshiro; Taya, Naohiro; Tsukamoto, Tetsuya; Watanabe, Tomomichi; Murakami, Koji; Igari, Tomoko; Kamata, Makoto

    2016-07-15

    γ-Secretase modulators (GSMs), which lower pathogenic amyloid beta (Aβ) without affecting the production of total Aβ or Notch signal, have emerged as a potential therapeutic agent for Alzheimer's disease (AD). A novel series of 5,6,7,8-tetrahydro[1,2,4]triazolo[4,3-a]pyridine derivatives was discovered and characterized as GSMs. Optimization of substituents at the 8-position of the core scaffold using ligand-lipophilicity efficiency (LLE) as a drug-likeness guideline led to identification of various types of high-LLE GSMs. Phenoxy compound (R)-17 exhibited especially high LLE as well as potent in vivo Aβ42-lowering effect by single administration. Furthermore, multiple oral administration of (R)-17 significantly reduced soluble and insoluble brain Aβ42, and ameliorated cognitive deficit in novel object recognition test (NORT) using Tg2576 mice as an AD model.

  9. Orientation-dependent energy level alignment and film growth of 2,7-diocty[1]benzothieno[3,2-b]benzothiophene (C8-BTBT) on HOPG

    SciTech Connect

    Lyu, Lu; Niu, Dongmei Xie, Haipeng; Cao, Ningtong; Zhang, Hong; Zhang, Yuhe; Liu, Peng; Gao, Yongli

    2016-01-21

    Combining ultraviolet photoemission spectroscopy, X-ray photoemission spectroscopy, atomic force microscopy, and X-ray diffraction measurements, we performed a systematic investigation on the correlation of energy level alignment, film growth, and molecular orientation of 2,7-diocty[1]benzothieno[3,2-b]benzothiophene (C8-BTBT) on highly oriented pyrolytic graphite. The molecules lie down in the first layer and then stand up from the second layer. The ionization potential shows a sharp decrease from the lying down region to the standing up region. When C8-BTBT molecules start standing up, unconventional energy level band-bending-like shifts are observed as the film thickness increases. These shifts are ascribed to gradual decreasing of the molecular tilt angle about the substrate normal with the increasing film thickness.

  10. Microwave microstrip resonator measurements of Y1Ba2Cu3O(7-x) and Bi2Sr2Ca1Cu2O(8-y) thin films

    NASA Technical Reports Server (NTRS)

    Lichtenberg, Christopher L.; Wosik, Jaroslaw; Davis, Matthew; Wolfe, J. C.

    1989-01-01

    Radio frequency (RF) surface resistance measurement experiments on high T(sub c) thin films were performed. The method uses a microstrip resonator comprising a top gold conductor strip, an alumina dielectric layer, and a separate superconductivity ground plane. The surface resistance of the superconducting ground plane can be determined, with reference to a gold calibration standard, from the measured quality factor of the half-wave resonator. Initial results near 7 GHz over the temperature range from 25 to 300 K are presented for YBa2Cu3O(7-x) and Bi2Sr2CaCu2O(8-y) thin film samples deposited by an electron beam flash evaporation process. The RF surface resistance at 25 K for both materials in these samples was found to be near 25 milliohms.

  11. Carcinogenesis Bioassay of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (CAS No. 1746-01-6) in Swiss-Webster Mice (Dermal Study).

    PubMed

    1982-02-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin occurs as a highly toxic impurity found in herbicides containing 2,4,5-trichlorophenoxyacetic acid (2,4,5-T) and 2,4,5-T- derivatives, as well as in other chemicals synthesized using 2,4,5-trichlorophenol. The herbicide 2,4,5-T has been marketed in the United States since 1948. Production increased sharply between 1960 and 1970 when a 1:1 mixture of 2,4,5-T and 2,4-dichlorophenoxyacetic acid (2,4-D) was used as a defoliant in Vietnam under the names of "herbicide agent orange, herbicide orange, agent orange, and orange". During this 10-year period, about 106 million pounds of 2,4,5-T were sprayed. A carcinogenesis bioassay was conducted by applying an acetone suspension of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to the clipped backs of 30 male and female Swiss-Webster mice 3 days per week for 99 or 104 weeks. Similar groups were pretreated with 1 application of 50 &mgr;g dimethylbenzanthracene (DMBA) in 0.1 ml acetone 1 week before TCDD administration began. Female mice received 0.005 &mgr;g TCDD per application, and the male mice received 0.001 &mgr;g TCDD. As vehicle controls, 45 mice of each sex received 0.1 ml acetone three times per week. Thirty animals of each sex were used as untreated controls. Throughout the bioassay, mean body weights of the male and female mice administered TCDD, or TCDD following DMBA, were essentially the same as those of the corresponding vehicle control group. Mean body weights of dosed and vehicle control groups of males were less thanthose of the untreated control group throughout the study; for the females, mean body weights were less than the untreated controls during the first 80 weeks. In female mice, the incidences of fibrosarcoma in the integumentary system in dosed groups with TCDD were significantly (P=0.007) higher than that in the corresponding controls (2/41, 5%; 8/27, 30%). An increase in the same tumor type, although not statistically significant (P=0.084), was also observed in

  12. 7 CFR 246.8 - Nondiscrimination.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 4 2012-01-01 2012-01-01 false Nondiscrimination. 246.8 Section 246.8 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS SPECIAL SUPPLEMENTAL NUTRITION PROGRAM FOR WOMEN, INFANTS AND...

  13. 7 CFR 246.8 - Nondiscrimination.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 4 2011-01-01 2011-01-01 false Nondiscrimination. 246.8 Section 246.8 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS SPECIAL SUPPLEMENTAL NUTRITION PROGRAM FOR WOMEN, INFANTS AND...

  14. 7 CFR 246.8 - Nondiscrimination.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 4 2014-01-01 2014-01-01 false Nondiscrimination. 246.8 Section 246.8 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS SPECIAL SUPPLEMENTAL NUTRITION PROGRAM FOR WOMEN, INFANTS AND...

  15. 7 CFR 246.8 - Nondiscrimination.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 4 2013-01-01 2013-01-01 false Nondiscrimination. 246.8 Section 246.8 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS SPECIAL SUPPLEMENTAL NUTRITION PROGRAM FOR WOMEN, INFANTS AND...

  16. 7 CFR 278.8 - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 4 2010-01-01 2010-01-01 false 278.8 Section 278.8 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE FOOD STAMP AND FOOD DISTRIBUTION PROGRAM PARTICIPATION OF RETAIL FOOD STORES, WHOLESALE FOOD CONCERNS AND...

  17. 7 CFR 278.8 - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 4 2011-01-01 2011-01-01 false 278.8 Section 278.8 Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE FOOD STAMP AND FOOD DISTRIBUTION PROGRAM PARTICIPATION OF RETAIL FOOD STORES, WHOLESALE FOOD CONCERNS AND...

  18. 7 CFR 371.8 - International Services.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... their effect on the agriculture industry. (6) Developing and directing programs to enhance the trade in... 7 Agriculture 5 2011-01-01 2011-01-01 false International Services. 371.8 Section 371.8 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH...

  19. 7 CFR 371.8 - International Services.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... their effect on the agriculture industry. (6) Developing and directing programs to enhance the trade in... 7 Agriculture 5 2012-01-01 2012-01-01 false International Services. 371.8 Section 371.8 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH...

  20. 7 CFR 3401.8 - Grant awards.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 15 2011-01-01 2011-01-01 false Grant awards. 3401.8 Section 3401.8 Agriculture Regulations of the Department of Agriculture (Continued) NATIONAL INSTITUTE OF FOOD AND AGRICULTURE RANGELAND... rangelands, and it supports the efforts of experienced scientists with records of outstanding...

  1. 7 CFR 1291.8 - Grant agreements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Grant agreements. 1291.8 Section 1291.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE SPECIALTY CROP BLOCK GRANT...

  2. 7 CFR 1290.8 - Grant agreements.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 10 2011-01-01 2011-01-01 false Grant agreements. 1290.8 Section 1290.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE SPECIALTY CROP BLOCK GRANT...

  3. 7 CFR 1215.8 - Industry information.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... of new markets, new marketing strategies, or increased efficiency for the popcorn industry, or... 7 Agriculture 10 2010-01-01 2010-01-01 false Industry information. 1215.8 Section 1215.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE...

  4. 7 CFR 1215.8 - Industry information.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... of new markets, new marketing strategies, or increased efficiency for the popcorn industry, or... 7 Agriculture 10 2011-01-01 2011-01-01 false Industry information. 1215.8 Section 1215.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE...

  5. 7 CFR 1215.8 - Industry information.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... of new markets, new marketing strategies, or increased efficiency for the popcorn industry, or... 7 Agriculture 10 2013-01-01 2013-01-01 false Industry information. 1215.8 Section 1215.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE...

  6. 7 CFR 1215.8 - Industry information.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... of new markets, new marketing strategies, or increased efficiency for the popcorn industry, or... 7 Agriculture 10 2014-01-01 2014-01-01 false Industry information. 1215.8 Section 1215.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE...

  7. 7 CFR 1215.8 - Industry information.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... of new markets, new marketing strategies, or increased efficiency for the popcorn industry, or... 7 Agriculture 10 2012-01-01 2012-01-01 false Industry information. 1215.8 Section 1215.8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE...

  8. Cytoplasmic immunoreactivity of thyroid transcription factor-1 (clone 8G7G3/1) in hepatocytes: true positivity or cross-reaction?

    PubMed

    Gu, Keni; Shah, Veena; Ma, Chan; Zhang, Lixin; Yang, Maozhou

    2007-09-01

    The nuclear immunoreactivity for thyroid transcription factor-1 (TTF-1) is a useful marker for identification of carcinomas of thyroid and lung origin. Our aim was to determine whether cytoplasmic staining in the liver is a result of cross-reaction of anti-TTF-1 antibody (clone 8G7G3/1, DAKO, Carpinteria, CA) or true positivity resulting from aberrant expression of TTF-1 or products of the alternatively sliced TTF-1 gene. Fresh tissue samples from liver, thyroid, and lung were obtained for H&E-stained sections, TTF-1 immunostaining, and RNA and protein analyses. Western blot revealed an abundant band corresponding to an approximately 160-kd protein from liver but not either thyroid or lung tissue samples. By reverse transcriptase-polymerase chain reaction, messenger RNA of TTF-1 was not detectable in liver tissue. Our study demonstrates that TTF-1 immunoreactivity (clone 8G7G3/1) in the hepatocyte cytoplasm is due to an approximately 160-kd protein; this unique protein is not an alternative splicing product of TTF-1 and neither is it expressed in thyroid and lung tissues.

  9. Toll-like receptors 3, 7 and 8 are upregulated in the placental caruncle and fetal spleen of Neospora caninum experimentally infected cattle.

    PubMed

    Marin, M S; Hecker, Y P; Quintana, S; Pérez, S E; Leunda, M R; Cantón, G J; Cobo, E R; Moore, D P; Odeón, A C

    2017-03-15

    Innate immune responses at the maternal-fetal interface are key in the pathogenesis of Neospora caninum, an obligate parasite that causes abortion in cattle. Herein, we determined the gene expression of endosomal Toll-like receptors (TLRs) in the placenta and fetuses from both non-infected pregnant heifers and pregnant heifers intravenously challenged with live tachyzoites of N. caninum on day 70 of gestation. On day 104 of pregnancy, mRNA expression of TLRs 3 and 8, as well as that of TLRs 7 and 9, was high in the spleen of fetuses from N. caninum-infected heifers. Gene expression levels of endosomal TLRs were also detectable in the placenta and the maternal caruncle from infected heifers, being TLRs 3, 7 and 8 particularly upregulated, mostly in the caruncle. Basal TLR levels were higher in fetal spleen than in placental tissues. This study provides novel information on how innate TLR responses are induced at the maternal-fetal interface of cattle in response to intracellular N. caninum.

  10. Effects of 3,3',4,4',5-pentachlorobiphenyl and 2,3,7,8-tetrachlorodibenzo-p-dioxin injected into the yolks of double-crested cormorant (Phalacrocorax auritus) eggs prior to incubation

    USGS Publications Warehouse

    Powell, D.C.; Aulerich, R.J.; Meadows, J.C.; Tillitt, D.E.; Kelly, M.E.; Stromborg, K.L.; Melancon, M.J.; Fitzgerald, S.D.; Bursian, S.J.

    1998-01-01

    Double-crested cormorant (Phalacrocorax auritus) eggs were injected with either 3,3',4,4',5-pentachlorobiphenyl (polychlorinated biphenyl [PCB] 126; 70-698 ?g/kg egg) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; 1.3-11.7 ?g/kg egg) prior to incubation. These compounds were injected into the yolks of cormorant eggs collected from incomplete clutches at isolated colonies on Lake Winnipegosis, Manitoba, Canada. Eggs were incubated for approximately 26 to 28 d. After hatching the brain, bursa, heart, liver, and spleen were dissected and weighed. Torsos were preserved in formalin for examination of the gonads. Median lethal doses (LD50s) calculated from mortality data at hatching were 177 and 4.0 ?g/kg egg for PCB 126 and TCDD, respectively. No significant differences were found in the incidence of developmental abnormalities in any of the treatment groups. Bursa weights were significantly less in the greatest (11.7 ?g/kg egg) TCDD group compared to the vehicle control group. Spleen weights were significantly less in the 349 ?g PCB 126/kg egg and the 5.4 and 11.7 ?g TCDD/kg egg groups when compared to the vehicle control group. No histological alterations of the gonads were found. Hepatic ethoxyresorufin-O-deethylase activity in all PCB 126 and TCDD dose groups was significantly greater compared to the control activity. The toxic equivalency factor for PCB 126 was 0.02

  11. Molecular characterization of mutation and comparison of mutation profiles in the hprt gene of Chinese hamster ovary cells treated with benzo[a]pyrene trans-7,8-diol-anti-9,10-epoxide, 1-nitrobenzol[a]pyrene trans-7,8-diol-anti-9,10-epoxide, and 3-nitrobenzol[a]pyrene trans-7,8-diol-anti-9,10-epoxide

    SciTech Connect

    Zhan, D.J.; Heflich, R.H.; Fu, P.P.

    1996-12-31

    Both 1- and 3-nitrobenzol[a] pyrene (nitro-BaP) are environmental contaminants, potent mutagens in Salmonella, and moderate mutagens in Chinese hamster ovary (CHO) cells. The mutagenicity of their oxidized metabolites, trans-7,8-dihydroxy-anti-9, 10-epoxy-7,8,9,10-tetrahydro-1-nitrobenzol[a]pyrene (1-nitro-BaP-DE) and trans-7,8-dihydroxy-anti-9, 10-epoxy-7,8,9,10-tetrahydro-3-nitrobenzo[a]pyrene (3-nitro-BaP-DE), together with trans-7,8-dihydroxy-anti-9,10-epoxy-7,8,9,10-tetrahydrobenzol[a]pyren (BaP-DE), was determined in CHO-K1 cells, and the resulting mutations at the hprt locus were characterized by polymerase chain reaction (PCR) amplification of reverse-transcribed hprt mRNA, followed by DNA sequence analysis. The mutant frequencies, in mutants/10{sup 6} clonable cells, at 30 and 100 ng/ml, were BaP-DE, 248 and 456; 1-nitro-BaP-DE, 68 and 260; 3-nitro-BaP-DE, 81 and 232, respectively. In general, the three diolepoxides exhibited similar mutational spectra: (1) 64% (23/36 sequenced mutants) of BaP-DE, 53% (19/36) of 1-nitro-BaP-DE, and 64% (23/36) of 3-nitro-BaP-DE mutants resulted from simple base pair substitution, with the predominant mutation being G{r_arrow}T transversion: (2) 90%, 100%, and 100% of mutations at G:C had the mutated dG on the nontranscribed DNA strand; and (3) about one quarter of the mutants produced by each mutagen had one or more PCR products with partial or complete exon deletions. 61 refs., 1 fig., 7 tabs.

  12. Comparison of 2,3,7,8-tetrachlorodibenzo-p-dioxin-mediated hepatotoxicity in C57BL/6J and DBA/2J mice.

    PubMed

    Shen, E S; Gutman, S I; Olson, J R

    1991-04-01

    The toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was examined by clinical chemistry and liver histopathology in Ah-responsive C57BL/6J (C57) and Ah-nonresponsive DBA/2J (DBA) mice. Hepatotoxicity was assessed at 1, 3, and 7 d following a single ip injection of TCDD at doses that maximally induce hepatic aryl hydrocarbon hydroxylase (AHH) activity (3 micrograms/kg for C57 and 30 micrograms/kg for DBA mice) and at doses approaching the LD50 (150 micrograms/kg for C57 and 600 micrograms/kg for DBA mice). Histological examination of liver sections was found to be a more sensitive detection method for TCDD-induced hepatic changes than clinical chemistry analyses. Dramatic differences in the development and type of liver injury were observed between TCDD-treated C57 and DBA mice. C57 mice given 3 micrograms TCDD/kg developed mild to moderate hepatic lipid accumulation in the absence of both inflammation and necrosis. Severe fatty change and mild inflammation and necrosis occurred in C57 mice that received 150 micrograms TCDD/kg. In contrast, DBA mice exposed to 30 micrograms TCDD/kg developed hepatocellular necrosis and inflammation without any fatty change. Only slight hepatic lipid accumulation occurred with some necrosis and inflammation in DBA mice given 600 micrograms TCDD/kg. The Ah locus may play a role in determining the sensitivity of C57 mice to the steatotic effects of TCDD.

  13. Characterization of the Pathogenesis of H10N3, H10N7, and H10N8 Subtype Avian Influenza Viruses Circulating in Ducks

    PubMed Central

    Zhang, Miaomiao; Zhang, Xingxing; Xu, Kaidi; Teng, Qiaoyang; Liu, Qinfang; Li, Xuesong; Yang, Jianmei; Xu, Jianqing; Chen, Hongjun; Zhang, Xiaoyan; Li, Zejun

    2016-01-01

    Three H10 subtype avian influenza viruses were isolated from domestic ducks in China, designated as SH602/H10N8, FJ1761/H10N3 and SX3180/H10N7, with an intravenous pathogenicity index (IVPI) of 0.39, 1.60, and 1.27, respectively. These H10 viruses showed a complex pathology pattern in different species, although full genome characterizations of the viruses could not identify any molecular determinant underlying the observed phenotypes. Our findings describe the pathobiology of the three H10 subtype AIVs in chickens, ducks, and mice. FJ1761/H10N3 evolved E627K and Q591K substitutions in the gene encoding the PB2 protein in infected mice with severe lung damage, suggesting that H10 subtype avian influenza viruses are a potential threat to mammals. PMID:27678170

  14. A Raman spectroscopic study of a hydrated molybdate mineral ferrimolybdite, Fe2(MoO4)3·7-8H2O.

    PubMed

    Sejkora, Jiří; Cejka, Jiří; Malíková, Radana; López, Andrés; Xi, Yunfei; Frost, Ray L

    2014-09-15

    Raman spectra of two well-defined ferrimolybdite samples, Fe2(3+)(Mo6+O4)3·7-8H2O, from the Krupka deposit (northern Bohemia, Czech Republic) and Hůrky near Rakovník occurrence (central Bohemia, Czech Republic) were studied and tentatively interpreted. Observed bands were assigned to the stretching and bending vibrations of molybdate anions, Fe-O units and water molecules. Number of Raman and infrared bands assigned to (MoO4)(2-) units and water molecules proved that symmetrically (structurally) nonequivalent (MoO4)(2-) and H2O are present in the crystal structure of ferrimolybdite. Approximate O-H⋯O hydrogen bond lengths (2.80-2.73 Å) were inferred from the published infrared spectra.

  15. New lithium copper borates with BO3 triangles: Li6CuB4O10, Li3CuB3O7, Li8Cu7B14O32, and Li2Cu9B12O28.

    PubMed

    Kuratieva, N V; Bànki, M; Tsirlin, A A; Eckert, J; Ehrenberg, H; Mikhailova, D

    2013-12-16

    Crystal structures of three new lithium copper borates, Li3CuB3O7, Li8Cu7B14O32, and Li2Cu9B12O28, and a new Li6CuB4O10 polymorph were solved by single-crystal X-ray diffraction. In all of the structures, the boron cations form BO3 triangles, which are connected with each other and with copper polyhedra only via corners in Li6CuB4O10 and Li3CuB3O7 and via both corners and edges in Li8Cu7B14O32 and Li2Cu9B12O28. The Li3CuB3O7 and Li8Cu7B14O32 compounds were synthesized as pure samples with only trace amounts of impurities; hence, their magnetic properties could be investigated and analyzed in terms of underlying magnetic couplings. Other compositions always represented multiphase mixtures. Li3CuB3O7 features infinite Cu,O chains formed by Cu2O6 units consisting of edge-shared CuO4 squares. Together with two apical oxygen atoms with long interatomic Cu-O distances of 2.7-2.8 Å, the Cu2O6 units form chains extended along the a axis. These pseudochains are responsible for strong anisotropic thermal expansion behavior. The temperature dependence of the magnetization between 4 and 380 K for Li3CuB3O7 could be fit well by a spin-dimer model. The magnetic susceptibility of Li8Cu7B14O32 showed a more complex temperature dependence, with two different Curie-Weiss regimes in the temperature range of 2-380 K.

  16. Revised structural phase diagram of (Ba{sub 0.7}Ca{sub 0.3}TiO{sub 3})-(BaZr{sub 0.2}Ti{sub 0.8}O{sub 3})

    SciTech Connect

    Keeble, Dean S.; Thomas, Pam A.; Benabdallah, Feres; Maglione, Mario; Kreisel, Jens

    2013-03-04

    The temperature-composition phase diagram of barium calcium titanate zirconate (x(Ba{sub 0.7}Ca{sub 0.3}TiO{sub 3})-(1 - x)(BaZr{sub 0.2}Ti{sub 0.8}O{sub 3}); BCTZ) has been reinvestigated using high-resolution synchrotron x-ray powder diffraction. Contrary to previous reports of an unusual rhombohedral-tetragonal phase transition in this system, we have observed an intermediate orthorhombic phase, isostructural to that present in the parent phase, BaTiO{sub 3}, and we identify the previously assigned T-R transition as a T-O transition. We also observe the O-R transition coalescing with the previously observed triple point, forming a phase convergence region. The implication of the orthorhombic phase in reconciling the exceptional piezoelectric properties with the surrounding phase diagram is discussed.

  17. 7-Methyl-6,7,8,9,14,15-hexahydro-5H-benz[d]indolo[2,3-g]azecine: a new heterocyclic system and a new lead compound for dopamine receptor antagonists.

    PubMed

    Witt, T; Hock, F J; Lehmann, J

    2000-05-18

    Partially hydrogenated derivatives of the new heterocyclic ring systems benz[d]indolo[2,3-g]azecine and bisindolo[3,2-d][2, 3-g]azecine were synthesized starting from lactones and amines via the described synthetic methods. In binding assays with rat striatal receptors, 7-methyl-6,7,8,9,14,15-hexahydro-5H-benz[d]indolo[2, 3-g]azecine (LE 300) proved to be of high affinity for the D(1) binding site (K(i) = 0.08 nmol for displacement of [(3)H]SCH23390), being superior in this assay to standards such as butaclamol and SCH23390. This compound was characterized as a dopamine antagonist by conditioned avoidance response test with mice. Thus, LE 300 represents the lead of a new class of dopamine antagonists for future investigations.

  18. Regulation of the FOXO3a/Bim signaling pathway by 5,7-dihydroxy-8-nitrochrysin in MDA-MB-453 breast cancer cells

    PubMed Central

    ZHAO, XIAO-CHUN; CAO, XIAO-CHENG; LIU, FEI; QUAN, MEI-FANG; REN, KAI-QUN; CAO, JIAN-GUO

    2013-01-01

    We previously demonstrated that 5,7-dihydroxy-8-nitrochrysin (NOC), a novel synthetic chrysin analog, preferentially inhibits HER-2/neu-overexpressing MDA-MB-453 breast cancer cell growth by inducing apoptosis; however, the precise molecular mechanism was unclear. In this study, we demonstrated that NOC significantly induces apoptosis of MDA-MB-453 cells and that this is primarily mediated through a mitochondrial death cascade. This was presented as a loss of mitochondrial membrane potential, release of cytochrome c and activation of caspase-9. NOC induces a significant increase in levels of the BH3-only protein Bim. Small interfering RNA-mediated knockdown of Bim markedly attenuated NOC-induced apoptosis. An upstream transcriptional regulator of Bim, forkhead box O3a transcription factor (FOXO3a), experienced a decrease in phosphorylation and nuclear translocation. Silencing of FOXO3a resulted in a marked attenuation in the expression of Bim, as well as protection against NOC-mediated apoptosis. Furthermore, NOC-induced activation and nuclear localization of FOXO3a was associated with reduced levels of Akt phosphorylation. These results suggest that NOC induces apoptosis in MDA-MB-453 human breast cancer cells via caspase activation and modulation of the Akt/FOXO3a pathway. PMID:23425937

  19. Determination of 5-log reduction times for Escherichia coli O157:H7, Salmonella enterica, or Listeria monocytogenes in acidified foods with pH 3.5 or 3.8 3.

    PubMed

    Breidt, F; Kay, K; Cook, J; Osborne, J; Ingham, B; Arritt, F

    2013-07-01

    A critical factor in ensuring the safety of acidified foods is the establishment of a thermal process that assures the destruction of acid-resistant vegetative pathogenic and spoilage bacteria. For acidified foods such as dressings and mayonnaises with pH values of 3.5 or higher, the high water phase acidity (acetic acid of 1.5 to 2.5% or higher) can contribute to lethality, but there is a lack of data showing how the use of common ingredients such as acetic acid and preservatives, alone or in combination, can result in a 5-log reduction for strains of Escherichia coli O157:H7, Salmonella enterica, and Listeria monocytogenes in the absence of a postpackaging pasteurization step. In this study, we determined the times needed at 10° C to achieve a 5-log reduction of E. coli O157:H7, S. enterica, and L. monocytogenes in pickling brines with a variety of acetic and benzoic acid combinations at pH 3.5 and 3.8. Evaluation of 15 different acid-pH combinations confirmed that strains of E. coli O157:H7 were significantly more acid resistant than strains of S. enterica and L. monocytogenes. Among the acid conditions tested, holding times of 4 days or less could achieve a 5-log reduction for vegetative pathogens at pH 3.5 with 2.5% acetic acid or at pH 3.8 with 2.5% acetic acid containing 0.1% benzoic acid. These data indicate the efficacy of benzoic acid for reducing the time necessary to achieve a 5-log reduction in target pathogens and may be useful for supporting process filings and the determination of critical controls for the manufacture of acidified foods.

  20. Disorder of the dimeric TCNQ–TCNQ unit in the crystal structure of [Ni(bpy)3]2(TCNQ–TCNQ)(TCNQ)2·6H2O (TCNQ is 7,7,8,8-tetra­cyano­quinodi­methane)

    PubMed Central

    Černák, Juraj; Kuchár, Juraj; Hegedüs, Michal

    2017-01-01

    Crystallization from an aqueous methanol system composed of Ni(NO3)2, 2,2′-bipyridine (bpy) and LiTCNQ (TCNQ is 7,7,8,8-tetra­cyano­quinodi­methane) in a 1:3:2 molar ratio yielded single crystals of bis­[tris­(2,2′-bi­pyridine-κ2 N,N′)nickel(II)] bis­(7,7,8,8-tetra­cyano­quinodi­methane radical anion) bi[7,7,8,8-tetra­cyano­quino­dimethanide] hexa­hydrate, [Ni(C10H8N2)3]2(C24H8N8)(C12H4N4)2·6H2O or [Ni(bpy)3]2(TCNQ–TCNQ)(TCNQ)2·6H2O. The crystal structure comprises [Ni(bpy)3]2+ complex cations, two centrosymmetric crystallographically independent TCNQ·− anion radicals with π-stacked exo groups, and an additional dimeric TCNQ–TCNQ unit which comprises 75.3 (9)% of a σ-dimerized (TCNQ–TCNQ)2− dianion and 24.7 (9)% of two TCNQ·− anion radicals with tightly π-stacked exo groups. The title complex represents the first example of an NiII complex containing a σ-dimerized (TCNQ–TCNQ)2− dianion. Disordered solvent water mol­ecules present in the crystal structure participate in hydrogen-bonding inter­actions. PMID:28083123

  1. Health effects in family pets and 2,3,7,8-TCDD contamination in Missouri: a look at potential animal sentinels

    SciTech Connect

    Schilling, R.J.; Stehr-Green, P.A.

    1987-05-01

    In 1971, waste oils containing 2,3,7,8:tetrachlorodibenzodioxin (TCDD) were sprayed in Missouri for dust control. To determine if pets could serve as sentinels of human health risks associated with this contamination, we asked pet owners in a pilot study of exposed human populations about their pets' illnesses. Of 13 pets with owner-reported illnesses, 8 had potential TCDD exposures and 5 did not (p less than .05 by Mantel-Haenzel chi-square analysis stratified by age). Owner-reported illnesses in 2 of 8 illness categories were associated with TCDD contamination after adjusting for age. Although these findings suggest that pets in TCDD-contaminated areas may have greater health risks, the small sample size, unlikely pathologic groupings, and unconfirmed nature of the data fail to support a relationship between pet illnesses and possible TCDD exposure and thus make extrapolation to human populations inappropriate. The limited validity found for owner-reported pet illnesses should caution against using such data in future environmental health studies.

  2. 2,3,7,8-tetrachlorodibenzo-p-dioxin: examination of biochemical effects involved in the proliferation and differentiation of XB cells

    SciTech Connect

    Knutson, J.C.; Poland, A.

    1984-10-01

    XB, a cell line derived form a mouse teratoma, differentiates into stratified squamous epithelium when incubated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). To examine the mediators of this response the effects produced by TCDD and those elicited by other compounds which stimulated epidermal proliferation and/or differentiation in mice were compared, XB/3T3 cultures keratinize when incubated with cholera toxin, epidermal growth factor (EGF), or TCDD , but not 12-0-tetradecanoylphorbol-13-acetate (TPA). Incubation of XB cells with TCDD for 48 hours produces an increase in thymidine incorporation, a response which is neither as large nor as rapid as that produced by cholera toxin, TPA, or EGF. Although both cholera toxin and TCDD stimulate differentiation and thymidine incorporation in XB/3T3 cultures, cholera toxin increases cAMP 30-fold in these cells, while TCDD does not affect cAMP accumulation. Inhibitors of arachidonic acid metabolism, which block epidermal proliferative responses to TPA in vivo, do not prevent the differentiation of XB cells in response to TCDD. In XB/3T3 cultures, TPA stimulates arachidonic acid release at all times tested (1,6, and 24 hours) and increases the incorporation of /sup 32/P/sub i/ into total phospholipids and phosphatidyl-choline after 3 hours. In contrast, D affects neither arachidonic acid release nor the turnover of phosphatidylinositol, or phosphatidylcholine at any of the times tested. Although biochemical effects which have been suggested as part of the mechanism of TCDD and produced by other epidermal proliferative compounds in XB cells were examined, no mediator of the TCDD-produced differentiation of XB/3T3 cultures was observed.

  3. 2,3,7,8-Tetrachlorodibenzo-p-dioxin-mediated depression of rat testicular heme synthesis and microsomal cytochrome P-450.

    PubMed

    Tofilon, P J; Piper, W N

    1982-11-15

    Exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) produces hirsutism, alopecia, and chloracne, symptoms that suggest a possible alteration of endocrine function. Therefore, the effects of TCDD on rat testicular cytochrome P-450 content were investigated. Forty-eight hours after a single, oral dose of TCDD (25 microgram/kg) testicular microsomal cytochrome P-450 levels were depressed by approximately 24%. Microsomal cytochrome P-450 continued to decrease to 62% of control levels at 4 days and remained at approximately the same levels 7 days following treatment. Testicular microsomal heme content exhibited a similar pattern after administration of TCDD. No alterations in testicular delta-aminolevulinic acid (ALA) synthase were detected. The incorporation of [14C]ALA into microsomal heme was decreased to approximately 36% of control values at 24 hr after TCDD administration. Testicular weights were not altered during the 7-day experimental period. These data suggest that TCDD depresses cytochrome P-450 levels in the rat testis through an inhibition of the synthesis of testicular heme.

  4. A novel technique for measurement of thermal rate constants and temperature dependences of dissociative recombination: CO2+, CF3+, N2O+, C7H8+, C7H7+, C6H6+, C6H5+, C5H6+, C4H4+, and C3H3+

    NASA Astrophysics Data System (ADS)

    Fournier, Joseph A.; Shuman, Nicholas S.; Melko, Joshua J.; Ard, Shaun G.; Viggiano, Albert A.

    2013-04-01

    A novel technique using a flowing afterglow-Langmuir probe apparatus for measurement of temperature dependences of rate constants for dissociative recombination (DR) is presented. Low (˜1011 cm-3) concentrations of a neutral precursor are added to a noble gas/electron afterglow plasma thermalized at 300-500 K. Charge exchange yields one or many cation species, each of which may undergo DR. Relative ion concentrations are monitored at a fixed reaction time while the initial plasma density is varied between 109 and 1010 cm-3. Modeling of the decrease in concentration of each cation relative to the non-recombining noble gas cation yields the rate constant for DR. The technique is applied to several species (O2+, CO2+, CF3+, N2O+) with previously determined 300 K values, showing excellent agreement. The measurements of those species are extended to 500 K, with good agreement to literature values where they exist. Measurements are also made for a range of CnHm+ (C7H7+, C7H8+, C5H6+, C4H4+, C6H5+, C3H3+, and C6H6+) derived from benzene and toluene neutral precursors. CnHm+ DR rate constants vary from 8-12 × 10-7 cm3 s-1 at 300 K with temperature dependences of approximately T-0.7. Where prior measurements exist these results are in agreement, with the exception of C3H3+ where the present results disagree with a previously reported flat temperature dependence.

  5. A novel technique for measurement of thermal rate constants and temperature dependences of dissociative recombination: CO2(+), CF3(+), N2O(+), C7H8(+), C7H7(+), C6H6(+), C6H5(+), C5H6(+), C4H4(+), and C3H3(+).

    PubMed

    Fournier, Joseph A; Shuman, Nicholas S; Melko, Joshua J; Ard, Shaun G; Viggiano, Albert A

    2013-04-21

    A novel technique using a flowing afterglow-Langmuir probe apparatus for measurement of temperature dependences of rate constants for dissociative recombination (DR) is presented. Low (~10(11) cm(-3)) concentrations of a neutral precursor are added to a noble gas∕electron afterglow plasma thermalized at 300-500 K. Charge exchange yields one or many cation species, each of which may undergo DR. Relative ion concentrations are monitored at a fixed reaction time while the initial plasma density is varied between 10(9) and 10(10) cm(-3). Modeling of the decrease in concentration of each cation relative to the non-recombining noble gas cation yields the rate constant for DR. The technique is applied to several species (O2(+), CO2(+), CF3(+), N2O(+)) with previously determined 300 K values, showing excellent agreement. The measurements of those species are extended to 500 K, with good agreement to literature values where they exist. Measurements are also made for a range of CnHm(+) (C7H7(+), C7H8(+), C5H6(+), C4H4(+), C6H5(+), C3H3(+), and C6H6(+)) derived from benzene and toluene neutral precursors. CnHm(+) DR rate constants vary from 8-12 × 10(-7) cm(3) s(-1) at 300 K with temperature dependences of approximately T(-0.7). Where prior measurements exist these results are in agreement, with the exception of C3H3(+) where the present results disagree with a previously reported flat temperature dependence.

  6. Crystal structure of ethyl 2-[9-(5-bromo-2-hy-droxy-phen-yl)-1,8-dioxo-1,2,3,4,5,6,7,8,9,10-deca-hydro-acridin-10-yl]acetate.

    PubMed

    Mohamed, Shaaban K; Akkurt, Mehmet; Jasinski, Jerry P; Abdelhamid, Antar A; Tamam, Asmaa H; Albayati, Mustafa R

    2015-12-01

    In the title compound, C23H24BrNO5, the central 1,4-di-hydro-pyridine ring of the 1,2,3,4,5,6,7,8,9,10-deca-hydro-acridine ring system adopts a half-chair conformation. The two cyclo-hexene rings fused to the central ring both have a twisted-boat conformation. The mean planes of the bromo-hydroxy-phenyl ring and the major and minor components of the disordered ethyl amino-acetate moiety make dihedral angles of 78.99 (12), 85.9 (2) and 88.3 (9)°, respectively, with the 1,4-di-hydro-pyridine ring. The terminal ethyl group of the ethyl amino-acetate moiety is disordered over two sets of sites with refined occupancies of 0.768 (17) and 0.232 (17). The mol-ecular conformation is stabilized by an intra-molecular O-H⋯O hydrogen bond, forming an S(8) ring motif. In the crystal, C-H⋯O hydrogen bonds connect the mol-ecules into layers parallel to (001), enclosing R 1 (2)(7) ring motifs.

  7. Enthalpy Effect of Adding Cobalt to Liquid Sn-3.8Ag-0.7Cu Lead-Free Solder Alloy: Difference between Bulk and Nanosized Cobalt

    PubMed Central

    2016-01-01

    Heat effects for the addition of Co in bulk and nanosized forms into the liquid Sn-3.8Ag-0.7Cu alloy were studied using drop calorimetry at four temperatures between 673 and 1173 K. Significant differences in the heat effects between nano and bulk Co additions were observed. The considerably more exothermic values of the measured enthalpy for nano Co additions are connected with the loss of the surface enthalpy of the nanoparticles due to the elimination of the surface of the nanoparticles upon their dissolution in the liquid alloy. This effect is shown to be independent of the calorimeter temperature (it depends only on the dropping temperature through the temperature dependence of the surface energy of the nanoparticles). Integral and partial enthalpies of mixing for Co in the liquid SAC-alloy were evaluated from the experimental data. PMID:26877829

  8. Retinoids inhibit 2,3,7,8-tetrachlorodibenzo-p-dioxine-induced activity of benzo[a]pyrene metabolizing enzymes in human diploid fibroblasts.

    PubMed

    Kohl, F V; Rüdiger, H W

    1980-09-01

    Retinoids are known to inhibit the substrate mediated enzyme induction of benzo[a]pyrene metabolizing enzymes. Consequently, the effect of two retinoids on the induction of benzo[a]pyrene metabolizing enzymes by the more potent inductor 2,3,7,8-tetrachlorodibenzo-p-dioxine (TCDD) was investigated. The studies were performed with human diploid fibroblasts in culture. Vitamin A palmitate and all-trans-retinoic-acid were found to prevent the TCDD induced increase of benzo[a]pyrene metabolism in a dose-dependent manner. The fact that this effect was immediately reversible makes it unlikely that it was due to non-specific toxic effects. The data suggest that retinoids cause a preferential inhibition of the de novo synthesis of benzo[a]pyrene metabolizing enzymes.

  9. A novel class of apical sodium--dependent bile salt transporter inhibitors: 1-(2,4-bifluorophenyl)-7-dialkylamino-1,8-naphthyridine-3-carboxamides.

    PubMed

    Liu, Hongtao; Pang, Guoxun; Ren, Jinfeng; Zhao, Yue; Wang, Juxian

    2017-03-01

    The apical sodium--dependent bile acid transporter (ASBT) is the main transporter to promote re-absorption of bile acids from the intestinal tract into the enterohepatic circulation. Inhibition of ASBT could increase the excretion of bile acids, thus increasing bile acid synthesis and consequently cholesterol consumption. Therefore, ASBT is an attractive target for developing new cholesterol-lowering drugs. In this report, a series of 1-(2,4-bifluorophenyl)-7-dialkylamino-1,8-naphthyridine-3-carboxamides were designed as inhibitors of ASBT. Most of them demonstrated potency against ASBT transport of bile acids. In particular, compound 4a1 was found to have the best activity, resulting in 80.1% inhibition of ASBT at 10 μmol/L.

  10. Effects of selective lattice deformation on YbBa2Cu4O8 and YBa2Cu3O7 epitaxial films

    NASA Astrophysics Data System (ADS)

    Mito, M.; Matsui, H.; Imakyurei, T.; Deguchi, H.; Horide, T.; Matsumoto, K.; Ichinose, A.; Yoshida, Y.

    2014-03-01

    Alternating current magnetic measurements of YbBa2Cu4O8 (Yb-124) and YBa2Cu3O7 (Y-123) epitaxial films were performed under hydrostatic pressure (HP). Here, the strain under HP results in uniaxial strain along the c-axis, in addition to the biaxial strain due to mismatching with the substrate. This uniaxial effect on Yb-124 film brings about a prominent increase in the superconducting transition temperature (Tc) against the initial strain. However, a nearly optimal Y-123 film hardly exhibits an initial change in Tc, and even an underdoped one only exhibits an increase in Tc, that is, one-third as much as that in the Yb-124 film. Effective carrier doping by the use of effective out-of-plane contraction prominently appears in the 124-structure rather than in the 123-structure.

  11. Oxygen desorption from YBa2Cu3O(7-x) and Bi2CaSr2Cu2O(8 + delta) superconductors

    NASA Technical Reports Server (NTRS)

    Mesarwi, A.; Levenson, L. L.; Ignatiev, A.

    1991-01-01

    Oxygen desorption experiments from YBa2Cu3O(7-x) (YBCO) and Bi2CaSr2Cu2O(8 + delta) (BSCCO) superconductors were carried out using a quadrupole mass spectrometer for monitoring the desorbing species and X-ray photoemission spectroscopy for surface characterization. Molecular oxygen was found to desorb from both superconductors following photoirradiation with ultraviolet/optical radiation and subsequent heating at over 150 C. Both YBCO and BSCCO were found to have similar oxygen desorption rates and similar activation energies. The desorption data as well as the X-ray photoemission data indicate that the oxygen desorption is not intrinsic to the superconductors but rather due to molecular oxygen entrapped in the material.

  12. Enthalpy Effect of Adding Cobalt to Liquid Sn-3.8Ag-0.7Cu Lead-Free Solder Alloy: Difference between Bulk and Nanosized Cobalt.

    PubMed

    Yakymovych, Andriy; Kaptay, George; Roshanghias, Ali; Flandorfer, Hans; Ipser, Herbert

    2016-01-28

    Heat effects for the addition of Co in bulk and nanosized forms into the liquid Sn-3.8Ag-0.7Cu alloy were studied using drop calorimetry at four temperatures between 673 and 1173 K. Significant differences in the heat effects between nano and bulk Co additions were observed. The considerably more exothermic values of the measured enthalpy for nano Co additions are connected with the loss of the surface enthalpy of the nanoparticles due to the elimination of the surface of the nanoparticles upon their dissolution in the liquid alloy. This effect is shown to be independent of the calorimeter temperature (it depends only on the dropping temperature through the temperature dependence of the surface energy of the nanoparticles). Integral and partial enthalpies of mixing for Co in the liquid SAC-alloy were evaluated from the experimental data.

  13. Comparison of the inhibition of biliary excretion produced by certain inducing agents including 2,3,7,8-tetrachlorodibenzo-p-dioxin

    SciTech Connect

    Berman, E.F.; Schaus, P.; Fujimoto, J.M.

    1986-01-01

    Rats were treated with chlordecone, mirex, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and respective solvent vehicle. Under urethane or pentobarbital anesthesia, the bile duct was cannulated and radioactive morphine, imipramine, or ouabain was given by segmented retrograde intrabiliary injection. The spectrum of inhibition of biliary excretion by chlordecone and mirex were similar in that morphine glucuronide and in part polar imipramine metabolite recoveries in bile were decreased; ouabain recovery was unaffected. TCDD was different in that it markedly decreased the recovery of ouabain. Thus, it appears that chlordecone, mirex, and TCDD inhibit the canalicular transport of the glucuronide metabolites of morphine and imipramine into bile, and TCDD affects in addition the canalicular transport of ouabain into bile.

  14. We are Family: the Conformations of 1-FLUOROALKANES, C_nH2n+1F (n = 2,3,4,5,6,7,8)

    NASA Astrophysics Data System (ADS)

    Obenchain, Daniel A.; Orellana, W.; Cooke, S. A.

    2016-06-01

    he pure rotational spectra of the n = 5, 6, 7, and 8 members of the 1-fluoroalkane family have been recorded between 7 GHz and 14 GHz using chirped pulse Fourier transform microwave spectroscopy. The spectra have been analyzed and results will be presented and compared with previous work on the n= 2, 3, and 4 members. The lowest energy conformer for all family members has the common feature that the fluorine is in a gauche position relative to the alkyl tail for which all other heavy atom dihedral angles, where appropriate, are 180 degrees. For the n = 3 and higher family members the second lowest energy conformer has all heavy atom dihedral angles equal to 180 degrees. For each family member transitions carried by both low energy conformers were observed in the collected rotational spectra. Quantum chemical calculations were performed and trends in the energy separations between these two common conformers will be presented as a function of chain length. Furthermore, longer chain lengths have been examined using only quantum chemical calculations and results will be presented. M. Hayashi, M. Fujitake, T. Inagusa, S. Miyazaki, J.Mol.Struct., 216, 9-26, 1990 W. Caminati, A. C. Fantoni, F. Manescalchi, F. Scappini, Mol.Phys., 64, 1089 ,1988 L. B. Favero, A. Maris, A. Degli Esposti, P. G. Favero, W. Caminati, G. Pawelke, Chem.Eur.J., 6(16), 3018-3025, 2000

  15. 2,3,7,8-Tetrachlorodibenzo-p-dioxin specifically reduces mRNA for the mineralization-related dentin sialophosphoprotein in cultured mouse embryonic molar teeth

    SciTech Connect

    Kiukkonen, Anu . E-mail: Anu.Kiukkonen@helsinki.fi; Sahlberg, Carin; Lukinmaa, Pirjo-Liisa; Alaluusua, Satu; Peltonen, Eija; Partanen, Anna-Maija

    2006-11-01

    Previous studies show that the most toxic dioxin congener, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), interferes with mineralization of the dental matrices in developing mouse and rat teeth. Culture of mouse embryonic molar teeth with TCDD leads to the failure of enamel to be deposited and dentin to undergo mineralization. Lactationally exposed rats show defectively matured enamel and retardation of dentin mineralization. To see if the impaired mineralization is associated with changes in the expression of dentin sialophosphoprotein (Dspp), Bono1 and/or matrix metalloproteinase-20 (MMP-20), thought to be involved in mineralization of the dental hard tissues, we cultured mouse (NMRI) E18 mandibular molars for 3, 5 or 7 days and exposed them to 1 {mu}M TCDD after 2 days of culture. As detected by in situ hybridization of tissue sections, localization and intensity of Bono1 and MMP-20 expression showed no definite difference between the control and exposed tooth explants, suggesting that TCDD does not affect their expression. On the contrary, TCDD reduced or prevented the expression of Dspp in secretory odontoblasts and decreased it in presecretory ameloblasts. The results suggest that the retardation of dentin mineralization by TCDD in mouse molar teeth involves specific interference with Dspp expression.

  16. Synthesis and Characterization of Novel Cu(II), Pd(II) and Pt(II) Complexes with 8-Ethyl-2-hydroxytricyclo(7.3.1.0(2,7))tridecan-13-one-thiosemicarbazone: Antimicrobial and in Vitro Antiproliferative Activity.

    PubMed

    Pahonțu, Elena; Paraschivescu, Codruța; Ilieș, Diana-Carolina; Poirier, Donald; Oprean, Camelia; Păunescu, Virgil; Gulea, Aurelian; Roșu, Tudor; Bratu, Ovidiu

    2016-05-21

    New Cu(II), Pd(II) and Pt(II) complexes, (Cu(L)(H₂O)₂(OAc)) (1), (Cu(HL)(H₂O)₂(SO₄)) (2), (Cu(L)(H₂O)₂(NO₃)) (3), (Cu(L)(H₂O)₂(ClO₄)) (4), (Cu(L)₂(H₂O)₂) (5), (Pd(L)(OAc))H₂O (6), and (Pt(L)₂) (7) were synthesized from 8-ethyl-2-hydroxytricyclo(7.3.1.0(2,7))tridecan-13-one thiosemicarbazone (HL). The ligand and its metal complexes were characterized by IR, ¹H-NMR, (13)C-NMR, UV-Vis, FAB, EPR, mass spectroscopy, elemental and thermal analysis, magnetic susceptibility measurements and molar electric conductivity. The free ligand and the metal complexes have been tested for their antimicrobial activity against E. coli, S. enteritidis, S. aureus, E. faecalis, C. albicans and cytotoxicity against the NCI-H1573 lung adenocarcinoma, SKBR-3 human breast, MCF-7 human breast, A375 human melanoma and HL-60 human promyelocytic leukemia cell lines. Copper complex 2 exhibited the best antiproliferative activities against MCF-7 human breast cancer cells. A significant inhibition of malignant HL-60 cell growth was observed for copper complex 2, palladium complex 6 and platinum complex 7, with IC50 values of 1.6 µM, 6.5 µM and 6.4 µM, respectively.

  17. Synthesis and oxidation behavior of 2,4,5,7,8-pentamethyl-4H-1,3-benzodioxin-6-ol, a multifunctional oxatocopherol-type antioxidant.

    PubMed

    Rosenau, Thomas; Potthast, Antje; Elder, Thomas; Lange, Thomas; Sixta, Herbert; Kosma, Paul

    2002-05-31

    2,4,5,7,8-Pentamethyl-4H-1,3-benzodioxin-6-ol (PBD, 1) is a novel 3-oxa-tocopherol-type stabilizer, which is obtained as a mixture of two diastereomers by condensation of trimethylhydroquinone with acetaldehyde in an acid-catalyzed reaction. The oxidation behavior of 1 is governed by the amount of water available. In aqueous media, 1 is oxidized by one oxidation equivalent to 2,5-dihydroxy-3,4,6-trimethylacetophenone (3) via 2-(1-hydroxyethyl)-3,5,6-trimethylbenzo-1,4-quinone (2). The acid-catalyzed conversion of 2 into 3 proceeds in solution with first-order kinetics with regard to 2 but works also in solid phase. Oxidation in the presence of just 1 equiv of water produces acetophenone 3 as well, but according to a different mechanism involving o-quinone methide 5 and styrene derivative 6, from which finally acetaldehyde is released. A [1,5]-sigmatropic proton shift from the C-4a methyl group to the exocyclic methylene group in 5 causes formation of 6, as demonstrated by labeling experiments. In addition, the presence of both intermediates was proven by hetero-Diels-Alder trapping reactions. In the absence of water, oxidation of 1 produces chromenone 10 via the intermediates 5 and 6 and chromanone 9, and oxidation of 9 to 10 is preferred to oxidation of starting material 1. When the formation of an exocyclic methylene group at C-4 is impossible as a result of structural prerequisites, as in the diphenyl derivative 12, the initially generated o-quinone methide 5 cannot form 6 but undergoes dimerization to spiro-compounds. The transformation of p-quinone 2 into acetophenone 3 might contribute to the chemistry of tocopherols oxidized at C-4, i.e., 4-hydroxy-alpha-tocopherol and 4-oxo-alpha-tocopherol, which have been proposed as precursors of natural vitamin E metabolites.

  18. Coseismic deformation fields and a fault slip model for the Mw7.8 mainshock and Mw7.3 aftershock of the Gorkha-Nepal 2015 earthquake derived from Sentinel-1A SAR interferometry

    NASA Astrophysics Data System (ADS)

    Zuo, Ronghu; Qu, Chunyan; Shan, XinJian; Zhang, Guohong; Song, Xiaogang

    2016-08-01

    Coseismic deformation fields caused by the moment magnitude (Mw)7.8 mainshock and Mw7.3 aftershock of the 2015 Gorkha-Nepal earthquake are obtained by analyzing Sentinel-1A/IW ascending and descending interferometry data. Results show that the deformation field associated with the Mw7.8 mainshock roughly resembles a prolate ellipse, extending from the epicenter about 20° east by south. The main region of deformation is about 160 km by 110 km, comprising a large southern area of uplift, and a small northern area of subsidence. Assuming that rupture occurred in a homogeneous elastic half-space, the coseismic fault slip models of the mainshock and aftershock are inverted based on a shallow dip fault constrained by the three data sets, Sentinel-1A/IW descending data, ascending data, and ALOS-2 descending data, separately or in combination. Mainshock slip distributions generated from all three data sets are similar, and inversion constrained by all three in combination reveal a comprehensive fault slip model. Indeed, coseismic slip is mainly distributed within a narrow 40 km zone to the north of the Main Frontal Trust (MFT), and at 6-15 km subsurface depth. In addition, the maximum slip in this event was about 5.1 m, the Mw7.8 mainshock ruptured the deep part of the seismogenic zone, while the region between the southern boundary of the rupture area and the MFT remained locked. Therefore, a considerable earthquake risk remains to the south of Kathmandu. The inverted coseismic slip of the Mw7.3 aftershock was concentrated in a small area, close to, and southeast of the epicenter, with maximum displacement of about 3 m. Finally, because there is no overlap between the two slip areas of the mainshock and aftershock, the gap between them, about 15 km in length, has additional potential to generate future earthquakes.

  19. A single prenatal exposure to the endocrine disruptor 2,3,7,8-tetrachlorodibenzo-p-dioxin alters developmental myelination and remyelination potential in the rat brain.

    PubMed

    Fernández, M; Paradisi, M; D'Intino, G; Del Vecchio, G; Sivilia, S; Giardino, L; Calzà, L

    2010-11-01

    Polychlorinated dibenzo-dioxins, furans and dioxin-like polychlorinated biphenyls are ubiquitous in foodstuffs of animal origin and accumulate in the fatty tissues of animals and humans. The most toxic congener is 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a lipophilic endocrine-disrupting molecule that accumulates in adipose tissue, placenta and milk. polychlorinated biphenyls and TCDD are known to interfere with thyroid hormone metabolism and signaling in the developing brain. As thyroid hormone is critical in the myelination process during development, we investigated the effect of a single dose of TCDD prenatal exposure (gestational day 18) on the myelination process. A semi-quantitative analysis of oligodendrocyte markers at different stages of maturation was performed in the offspring's medulla oblongata, cerebellum, diencephalon and telenchephalon at different postnatal days (2/3, 14, 30 and 135). The most significant alterations observed were: (i) cerebellum and medulla oblongata: altered expression of oligodendroglial lineage and platelet-derived growth factor alpha receptor, myelin basic protein (MBP) mRNAs (P2/3, P135) and MBP protein (P135); (ii) diencephalon: increase in platelet- derived growth factor alpha receptor mRNA level (P2/3); (iii) telenchephalon: decrease in MBP mRNA expression. The oligodendroglial generation capability of adult neural stem/precursor cells obtained ex vivo from TCDD and vehicle-treated dams was then explored. TCDD impairs neurosphere proliferation and retards CNPase-positive cell generation from adult neurospheres.

  20. Effects of embryonic and adult exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin on hepatic microsomal testosterone hydroxylase activities in great blue herons (Ardea herodias)

    SciTech Connect

    Sanderson, J.T.; Giesy, J.P.; Janz, D.M.; Bellward, G.D.

    1997-06-01

    In a continuing effort to evaluate biomarkers of exposure of great blue herons (Ardea herodias) to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related halogenated aromatic hydrocarbons, the authors examined the effect of TCDD on hepatic microsomal testosterone hydroxylase activities. Heron embryos were exposed in ovo to 2 {micro}g TCDD/kg egg (or corn oil vehicle) and sacrificed at hatch or 7 d posthatch. Adult herons were exposed intraperitoneally to 20 {micro}g TCDD/kg and sacrificed 2 weeks later. The sex of the birds was known for the adults only. Hepatic microsomes of herons of each age group were able to hydroxylate testosterone at the 2{beta}, 6{beta}, 15{alpha}, 16{alpha}, or 16{beta} positions. In 7-d-old chicks, an additional unidentified compound was formed. The age of the untreated herons had a strong influence on the activities of the five hydroxylases, with changes of up to 17-fold. The TCDD significantly induced 2{beta}-, 6{beta}, and 15{alpha}-testosterone hydroxylase activities in the adult females, 15{alpha} in the adult males, and 6{beta}-testosterone hydroxylase activity in the hatchlings. In the 7-d-old chicks, induction was no longer apparent. A significant correlation existed between hepatic microsomal ethoxyresorufin O-deethylase (EROD) and 6{beta}-testosterone hydroxylase activity in hatchlings and adult female herons. The TCDD-induced changes in testosterone hydroxylase activities occurred at doses that resulted in tissue concentrations and levels of EROD induction that were environmentally relevant, but did not result in overt toxicities.

  1. 7 CFR 160.8 - Steam distilled wood turpentine.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 3 2011-01-01 2011-01-01 false Steam distilled wood turpentine. 160.8 Section 160.8... STANDARDS FOR NAVAL STORES General § 160.8 Steam distilled wood turpentine. The designation “steam distilled wood turpentine” shall refer to the kind of spirits of turpentine obtained by steam distillation...

  2. 7 CFR 160.8 - Steam distilled wood turpentine.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 3 2013-01-01 2013-01-01 false Steam distilled wood turpentine. 160.8 Section 160.8... STANDARDS FOR NAVAL STORES General § 160.8 Steam distilled wood turpentine. The designation “steam distilled wood turpentine” shall refer to the kind of spirits of turpentine obtained by steam distillation...

  3. 7 CFR 160.8 - Steam distilled wood turpentine.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 3 2014-01-01 2014-01-01 false Steam distilled wood turpentine. 160.8 Section 160.8... STANDARDS FOR NAVAL STORES General § 160.8 Steam distilled wood turpentine. The designation “steam distilled wood turpentine” shall refer to the kind of spirits of turpentine obtained by steam distillation...

  4. 7 CFR 160.8 - Steam distilled wood turpentine.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 3 2012-01-01 2012-01-01 false Steam distilled wood turpentine. 160.8 Section 160.8... STANDARDS FOR NAVAL STORES General § 160.8 Steam distilled wood turpentine. The designation “steam distilled wood turpentine” shall refer to the kind of spirits of turpentine obtained by steam distillation...

  5. 7 CFR 201.56-8 - Flax family, Linaceae.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Flax family, Linaceae. 201.56-8 Section 201.56-8 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... REGULATIONS Germination Tests in the Administration of the Act § 201.56-8 Flax family, Linaceae. Kind of...

  6. 7 CFR 160.8 - Steam distilled wood turpentine.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Steam distilled wood turpentine. 160.8 Section 160.8... STANDARDS FOR NAVAL STORES General § 160.8 Steam distilled wood turpentine. The designation “steam distilled wood turpentine” shall refer to the kind of spirits of turpentine obtained by steam distillation...

  7. 7 CFR 371.8 - International Services.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... maintaining systems for observing the effects of plant and animal diseases in foreign countries and evaluating their effect on the agriculture industry. (6) Developing and directing programs to enhance the trade in... 7 Agriculture 5 2010-01-01 2010-01-01 false International Services. 371.8 Section...

  8. 7 CFR 371.8 - International Services.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... maintaining systems for observing the effects of plant and animal diseases in foreign countries and evaluating their effect on the agriculture industry. (6) Developing and directing programs to enhance the trade in... 7 Agriculture 5 2013-01-01 2013-01-01 false International Services. 371.8 Section...

  9. 7 CFR 371.8 - International Services.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... maintaining systems for observing the effects of plant and animal diseases in foreign countries and evaluating their effect on the agriculture industry. (6) Developing and directing programs to enhance the trade in... 7 Agriculture 5 2014-01-01 2014-01-01 false International Services. 371.8 Section...

  10. Gestational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin alters retinoid homeostasis in maternal and perinatal tissues of the Holtzman rat

    SciTech Connect

    Kransler, Kevin M. Tonucci, David A. McGarrigle, Barbara P. Napoli, Joseph L. Olson, James R.

    2007-10-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), one of the most widely studied environmental contaminants, causes a variety of adverse health effects including teratogenesis and altered development which may be related to disruptions in retinoid homeostasis. The purpose of this study was to determine the effect that gestational administration of TCDD has on retinoid homeostasis in both pregnant Holtzman rats and developing fetuses and neonates. A single oral dose of TCDD (0, 1.5, 3, or 6 {mu}g/kg) was administered to pregnant rats on gestation day 10, with fetuses analyzed on gestation days 17 and 20, and neonates analyzed on post natal day 7. Exposure to TCDD generally produced decreases in the concentrations of retinyl esters, such as retinyl palmitate, and retinol in maternal and perinatal liver and lung, while increasing levels in the maternal kidney. Additionally, perinatal hepatic retinol binding protein 1-dependent retinyl ester hydrolysis was also decrease by TCDD. Sensitivity of the developing perinates to TCDD appeared to have an age-related component demonstrated by an increased rate of mortality and significant alterations to body weight and length on post natal day 7 relative to that observed at gestation day 20. A unique observation made in this study was a significant decrease in lung weight observed in the perinates exposed to TCDD. Taken together, these data demonstrate that TCDD significantly alters retinoid homeostasis in tissues of the developing fetus and neonate, suggesting that their unique sensitivity to TCDD may at least be in part the result of altered retinoid homeostasis.

  11. Efficient Catalyst One-Pot Synthesis of 7-(Aryl)-10,10-dimethyl-10,11-dihydrochromeno[4,3-b]chromene-6,8(7H,9H)-dione Derivatives Complemented by Antibacterial Activity

    PubMed Central

    Al-Majedy, Yasameen K.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar

    2016-01-01

    The problem of bacteria resistance to many known agents has inspired scientists and researchers to discover novel efficient antibacterial drugs. Three rapid, clean, and highly efficient methods were developed for one-pot synthesis of 7-(aryl)-10,10-dimethyl-10,11-dihydrochromeno[4,3-b]chromene-6,8(7H,9H)-dione derivatives. Three components are condensed in the synthesis, 4-hydroxycoumarin, 5,5-dimethyl-1,3-cyclohexanedione, and aromatic aldehydes, using tetrabutylammonium bromide (TBAB), diammonium hydrogen phosphate (DAHP), or ferric chloride (FeCl3), respectively. Each method has different reaction mechanisms according to the catalyst. The present methods have advantages, including one-pot synthesis, excellent yields, short reaction times, and easy isolation of product. All catalysts utilized in our study could be reused several times without losing their catalytic efficiency. All synthesized compounds were fully characterized and evaluated for their antibacterial activity. PMID:27563671

  12. Molecular metals based on 1,2,7,8-tetrahydrodicyclopenta[cd:lm]perylene and iodine, (CPP){sub 2}(I{sub 3}){sub 1-{delta}}

    SciTech Connect

    Morgado, J. |; Santos, I.C.; Henriques, R.T.; Almeida, M.; Fourmigue, M.; Matias, P.; Veiros, L.F.; Duarte, M.T.; Alcacer, L.; Calhorda, M.J. |

    1994-12-01

    The synthesis and characterization of molecular metals derived from 1,2,7,8-tetrahydrodicyclopenta[cd:lm]perylene (CPP) by partial oxidation with iodine and with general formula (CPP){sub 2}(I{sub 3}){sub 1-{delta}}, {delta} = 0-0.13, are reported. Single crystals, obtained either by electrocrystallization or by diffusion-controlled iodine oxidation of CPP, present two types of morphologies, elongated diamond or thinner needle-shaped crystals, both with a monoclinic cell, space group P2{sub 1}/a, a = 4.3757(9), b = 19.3681(11), c = 10.0860(11) {angstrom}, {beta} = 98.050(8){degrees}, V = 846.4(2) {angstrom}{sup 3}, Z = 2. The structure of the diamond-shaped crystal was solved by X-ray diffraction to a final R(F) = 0.096, R{sub w}(F) = 0.069. It consists of regular stacks of CPP molecules along a with a 3.41 {angstrom} spacing and uncorrected one-dimensional chains of I{sub 3}{sup {minus}} located in channels between four CPP stacks corresponding to (CPP){sub 2}(I{sub 3}){sub 0.892}. The thin needle crystals have the same unit cell but an unspecified and slightly different iodine content. Band structure calculations in this structure by the extended Hueckel method indicate a one-dimensional conduction band 0.55 eV wide. These thin needle crystals present, at room temperature, an electrical conductivity along the a axis {alpha}{sub a}(RT) = 200 S/cm and thermopower S{sub a}(RT) = 30 {mu}V/K, while for the diamond-shaped crystals {alpha}{sub a}(RT) = 2 S/cm and S{sub a}(RT) = -8 {mu}V/K. These transport coefficients for both types of crystals indicate a metallic behavior from room temperature down to {approx_equal}63 K, where a metal-to-insular (M-I) transition takes place. EPR studies in single crystals show an almost isotropic line at g = 2.0044 and with a width of {approx_equal}6 G in the range 80-300 K and without significant differences between the two types of crystals. 53 refs., 9 figs., 4 tabs.

  13. Developmental exposure to 2,3,7,8 tetrachlorodibenzo-p-dioxin attenuates later-life Notch1-mediated T cell development and leukemogenesis

    SciTech Connect

    Ahrenhoerster, Lori S.; Leuthner, Tess C.; Tate, Everett R.; Lakatos, Peter A.; Laiosa, Michael D.

    2015-03-01

    Over half of T cell acute lymphoblastic leukemia (T-ALL) patients have activating mutations in the Notch gene. Moreover, the contaminant 2,3,7,8 tetrachlorodibenzo-p-dioxin (TCDD) is a known carcinogen that mediates its toxicity through the aryl hydrocarbon receptor (AHR), and crosstalk between activated AHR and Notch signaling pathways has previously been observed. Given the importance of Notch signaling in thymocyte development and T-ALL disease progression, we hypothesized that the activated AHR potentiates disease initiation and progression in an in vivo model of Notch1-induced thymoma. This hypothesis was tested utilizing adult and developmental exposure paradigms to TCDD in mice expressing a constitutively active Notch1 transgene (Notch{sup ICN-TG}). Following exposure of adult Notch{sup ICN-TG} mice to a single high dose of TCDD, we observed a significant increase in the efficiency of CD8 thymocyte generation. We next exposed pregnant mice to 3 μg/kg of TCDD throughout gestation and lactation to elucidate effects of developmental AHR activation on later-life T cell development and T-ALL-like thymoma susceptibility induced by Notch1. We found that the vehicle-exposed Notch{sup ICN-TG} offspring have a peripheral T cell pool heavily biased toward the CD4 lineage, while TCDD-exposed Notch{sup ICN-TG} offspring were biased toward the CD8 lineage. Furthermore, while the vehicle-exposed NotchICN-TG mice showed increased splenomegaly and B to T cell ratios indicative of disease, mice developmentally exposed to TCDD were largely protected from disease. These studies support a model where developmental AHR activation attenuates later-life Notch1-dependent impacts on thymocyte development and disease progression. - Highlights: • Adult mice exposed to 30 μg/kg TCDD have higher efficiency of CD8 thymocyte generation. • Mice carrying a constitutively active Notch transgene were exposed to 3 μg/kg TCDD throughout development. • Progression of Notch

  14. Bioaccumulation of 2,3,7,8-tetrachlorodibenzo-p-dioxin in feral fish collected from a bleach-kraft paper mill receiving stream

    SciTech Connect

    Schell, J.D. ); Campbell, D.M.; Lowe, E. )

    1993-11-01

    Bleach-kraft mill (BKM) processes may result in the formation and release of a number of chlorinated organic compounds, including 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Contamination of aquatic ecosystems by TCDD is of concern due to the chemical's toxicity, bioaccumulation potential, and persistence in the environment. Sediment samples and tissues from three species of fish an done invertebrate were collected downstream from a BKM facility and were analyzed for TCDD. Concentrations of TCDD were greatest in the bowfin, particularly in the ovary of a gravid female. There appeared to be no correlation between either trophic position of habitat classification (i.e., epibenthic or pelagic) and TCDD tissue concentrations. Sediments collected near the mill outfall contained elevated levels of TCDD as great as 52.8 ppt. Sediment-based BAFs and lipid- and carbon-normalized bioavailability indexes (BI) were calculated for the fish livers and gonads, and blue crab hepatopancreas. BAF*s varied by a factor of 27, depending on species and organ, whereas BIs had an approximate seven-fold variation. It appears that organic carbon- and lipid-normalization factors may be more accurate predictors of the extent of bioaccumulation in resident biota from TCDD-contaminated sediments than either BAF*s or BCFs. As there is currently only a limited understanding of species variability in absorption and deposition of TCDD, a more accurate estimation of TCDD levels in feral fish tissues may not be possible.

  15. DFT study of the adsorption of 2,3,7,8-tetrachlorodibenzo-p-dioxin on pristine and Ni-doped boron nitride nanotubes.

    PubMed

    Wang, Ruoxi; Zhang, Dongju; Liu, Chengbu

    2017-02-01

    Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are highly toxic to humans and the environment. Developing efficient methods to detect or remove these pollutants is particularly important and urgent. Boron nitride nanotubes (BNNTs) with low dimension and high surface-to-volume ratio might be one of promising materials for the adsorption of PCDD/Fs. Here we present a density functional theory (DFT) study on the interaction of the pristine and Ni doped (8,0) single-walled BNNTs with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), the most toxic congener among PCDD/F family. The calculated results show that the pristine BNNT intrinsically interacts with TCDD via physisorption with π-π stacking interaction, in contrast, the Ni-doped BNNT presents much higher reactivities toward TCDD. The impurity Ni atom plays a crucial role for capturing TCDD molecule. We also find that the Ni doping introduces the local electronic states within the band gap of the BNNT and induces magnetism in the doped systems. The present results are expected to provide useful guidance for the potential application of BNNTs as adsorption materials for detecting or removing dioxin pollutants.

  16. RDamage 6, 7, 8 & 9 Cassettes

    SciTech Connect

    Griego, Jeffrey R; Kaul, Ann

    2012-06-08

    The RDamage series of ten experiments is part of a long-term collaboration with RFNC/VNIIEF in pulsed power technology. These experiments use a cylindrical configuration to study spallation damage, which allows for a natural recollection of the damaged material under proper driving conditions and post-shot collection of the damaged target material for subsequent metallographic analysis. Dynamic insitu experimental velocimetry diagnostics are also employed. LANL is responsible for the design of the experimental load and velocimetry system. VNIIEF is responsible for the design and construction of the driving explosive magnetic generator. In the RDamage-0, -1 and -2 experiments, data was collected about failure initiation of a well-characterized material (aluminum) in a cylindrical geometry. The RDamage-3, -4 and -5 experiments produced data on the behavior of material recollected after damage from pressures in the damage initiation regime. Data on the behavior of material recollected after complete failure was collected in the RDamage-6, -7, -8 and -9 experiments. This presentation shows the evolution of the load assembly through the experimental series.

  17. 2,3,7,8-Tetrachlorodibenzo-p-dioxin-mediated oxidative stress in CYP1A2 knockout (CYP1A2-/-) mice.

    PubMed

    Slezak, B P; Diliberto, J J; Birnbaum, L S

    1999-10-22

    The objective of the study was to compare alterations in indicators of oxidative stress following 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure in cytochrome P4501A2 (CYP1A2) knockout mice and their parental lineage strains (C57BL/6N and 129/Sv). This study will aid in determining the role, if any, of CYP1A2 in TCDD-mediated oxidative stress. Formation of thiobarbituric acid-reactive substances (TBARS) as a measurement of lipid peroxidation, production of reactive oxygen species (ROS) via the in vitro reduction of cytochrome c in tissue homogenate, and changes in the biochemical antioxidant glutathione were monitored to determine oxidative stress 7 days following a single oral dose of 25 microg TCDD/kg. TBARS, reduction of cytochrome c, and changes in glutathione demonstrated a similar response in CYP1A2 knockout and parental strains. These data suggest that CYP1A2 does not play a critical role in the acute oxidative stress response following TCDD exposure.

  18. Impact of 2,3,7,8-TCDD exposure on survival, growth, and behavior of osprey`s breeding in Wisconsin, USA

    SciTech Connect

    Woodford, J.E.; Karasov, W.H.; Meyer, M.W.; Chambers, L.

    1998-07-01

    Osprey (Pandion halieatus) eggs collected from areas 7 km downstream from two bleached-kraft mill facilities from 1992 to 1996 contained much higher levels of 2,3,7,8-tetrachlordibenzo-p-dioxin than eggs collected from two reference areas upstream. Levels in eggs of the remaining planar halogenated hydrocarbon congeners and other nonplanar organochlorines were not statistically different between the contaminated and upstream areas. The authors placed eggs from the contaminated area into nests at both reference areas (group A) and eggs from the reference areas into nests at the contaminated area (group B). No significant differences in egg hatching or chick fledging rates were observed between these groups and nests left unmanipulated at both reference areas (group C) and the contaminated area (group D). Mass increase rates of chicks differed significantly, with the highest rates from group C and the lowest rates from group B. This difference cannot be easily attributed to differences in parental test attentiveness or food provisioning, which were greater at the contaminated area. The authors conclude that although current planar halogenated hydrocarbon exposure levels were not affecting hatching and fledging rates, they may have affected chick growth.

  19. 2,3,7,8-Tetrachlorodibenzo-p-dioxin induces apoptotic cell death and cytochrome P4501A expression in developing Fundulus heteroclitus embryos

    USGS Publications Warehouse

    Toomey, B.H.; Bello, S.; Hahn, M.E.; Cantrell, S.; Wright, P.; Tillitt, D.E.; Di Giulio, R.T.

    2001-01-01

    Fundulus heteroclitus embryos were exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during early development using nanoinjection or water bath exposure. TCDD caused developmental abnormalities that included hemorrhaging, loss of vascular integrity, edema, stunted development and death. The LC50 and LD50 of TCDD for Fundulus embryos were ???19.7??9.5 pg TCDD/??l (water bath) and 0.25??0.09 ng TCDD/g embryo (nanoinjection). To identify a possible cause for these developmental abnormalities we analyzed the effects of TCDD on apoptotic cell death and cytochrome P4501A (CYP1A) expression in the embryos. TCDD exposure increased apoptotic cell death in several tissues including brain, eye, gill, kidney, tail, intestine, heart, and vascular tissue. CYP1A expression was also increased in the TCDD-exposed embryos predominantly in liver, kidney, gill, heart, intestine, and in vascular tissues throughout the embryo. There was co-occurrence of TCDD-induced apoptosis and CYP1A expression in some, but not all, cell types. In addition the dose response relationships for apoptosis and mortality were similar, while CYP1A expression appeared more sensitive to TCDD induction. Copyright ?? 2001 Elsevier Science B.V.

  20. Solvent effect on the absorption and fluorescence spectra of 7-acetoxy-6-(2,3-dibromopropyl)-4,8-dimethylcoumarin: determination of ground and excited state dipole moments.

    PubMed

    Gülseven Sıdır, Yadigar; Sıdır, Isa

    2013-02-01

    The ground state (μ(g)) and excited state (μ(e)) dipole moments of 7-acetoxy-6-(2,3-dibromopropyl)-4,8-dimethylcoumarin (abbreviated as 7ADDC) are estimated from solvatochromic shifts of absorption and fluorescence spectra as a function of the dielectric constant (ε) and refractive index (n). While the ground state dipole moment is determined by using Bilot-Kawski method, the excited state dipole moment is calculated by using Bilot-Kawski, Lippert-Mataga, Bakhshiev, Kawski-Chamma-Viallet and Reichardt correlation methods. Excited state dipole moment is observed as larger than the ground state dipole moment due to substantial π-electron density redistribution. The ground state and excited state dipole moments are observed as parallel to each other with angle of 0°. Solute-solvent interactions are analyzed by means of linear solvation free energy relationships (LSER) using dielectric constant function (f(ε)), refractive index function (f(n)) and Kamlet-Taft parameters (α and β). Atomic charges, electron densities and molecular orbitals are calculated in vacuum and with solvent effect by using both DFT and TDDFT methods. Solvent accessible surface, molecular electrostatic potential (MEP) and electrostatic potential (ESP) are visualized as a result of DFT calculations.

  1. Solvent effect on the absorption and fluorescence spectra of 7-acetoxy-6-(2,3-dibromopropyl)-4,8-dimethylcoumarin: Determination of ground and excited state dipole moments

    NASA Astrophysics Data System (ADS)

    Gülseven Sıdır, Yadigar; Sıdır, İsa

    2013-02-01

    The ground state (μg) and excited state (μe) dipole moments of 7-acetoxy-6-(2,3-dibromopropyl)-4,8-dimethylcoumarin (abbreviated as 7ADDC) are estimated from solvatochromic shifts of absorption and fluorescence spectra as a function of the dielectric constant (ɛ) and refractive index (n). While the ground state dipole moment is determined by using Bilot-Kawski method, the excited state dipole moment is calculated by using Bilot-Kawski, Lippert-Mataga, Bakhshiev, Kawski-Chamma-Viallet and Reichardt correlation methods. Excited state dipole moment is observed as larger than the ground state dipole moment due to substantial π-electron density redistribution. The ground state and excited state dipole moments are observed as parallel to each other with angle of 0°. Solute-solvent interactions are analyzed by means of linear solvation free energy relationships (LSER) using dielectric constant function (f(ɛ)), refractive index function (f(n)) and Kamlet-Taft parameters (α and β). Atomic charges, electron densities and molecular orbitals are calculated in vacuum and with solvent effect by using both DFT and TDDFT methods. Solvent accessible surface, molecular electrostatic potential (MEP) and electrostatic potential (ESP) are visualized as a result of DFT calculations.

  2. Anti-Inflammatory Effect of 1,3,5,7-Tetrahydroxy-8-isoprenylxanthone Isolated from Twigs of Garcinia esculenta on Stimulated Macrophage.

    PubMed

    Zhang, Dan-Dan; Zhang, Hong; Lao, Yuan-zhi; Wu, Rong; Xu, Jin-wen; Murad, Ferid; Bian, Ka; Xu, Hong-Xi

    2015-01-01

    Garcinia Linn. plants having rich natural xanthones and benzophenones with anti-inflammatory activity attracted a great deal of attention to discover and develop them as potential drug candidates. Through screening targeting nitric oxide accumulation in stimulated macrophage, we found that 1,3,5,7-tetrahydroxy-8-isoprenylxanthone (TIE) had potential anti-inflammatory effect. To understand how TIE elicits its anti-inflammatory activity, we uncovered that it significantly inhibits the production of nitric oxide (NO) and prostaglandin E2 (PGE2) in LPS/IFNγ-stimulated RAW264.7 cells. In further study, we showed that TIE reduced the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), two key molecules responsible for the production of NO and PGE2 during inflammation progress. Additionally, TIE also suppressed the expression of inflammatory cytokines IL-6, IL-12, and TNF-α. TIE-led suppression in iNOS, COX-2, and cytokines production were probably the consequence of TIE's capability to block ERK and p38MAPK signaling pathway. Moreover, TIE blocked activation of nuclear factor-kappa B (NF-κB) as well as NF-κB regulation of miR155 expression. Our study suggests that TIE may represent as a potential therapeutic agent for the treatment of inflammatory diseases.

  3. Evaluation of chronic bronchitis, chronic obstructive pulmonary disease, and ventilatory function among workers exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin

    SciTech Connect

    Calvert, G.M.; Sweeney, M.H.; Morris, J.A.; Fingerhut, M.A.; Hornung, R.W.; Halperin, W.E. )

    1991-12-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is produced as an undesirable contaminant in the manufacture of 2,4,5-trichlorophenol (TCP) and its derivatives. There is considerable concern about the health effects that may be associated with exposure to TCDD-contaminated substances. A cross-sectional medical study that included a comprehensive medical history, medical examination, and measurement of pulmonary function was conducted on workers employed more than 15 yr earlier in the manufacture of NaTCP and its derivatives at two chemical plants. The workers had substantial exposure to substances contaminated with TCDD, as evidenced by a mean serum TCDD level, lipid adjusted, of 200 ppt compared with a mean of 7 ppt in the unexposed reference group. The comparison group consisted of individuals with no occupational exposure to phenoxy herbicides who lived in the same communities as the workers. A total of 281 workers and 260 unexposed referents participated in the medical examination. Logistic and linear regression analyses, which contained categorical and continuous measures of TCDD exposure, were performed to control for important confounders, including cigarette and alcohol consumption. No difference was found between workers and referents in the risk for chronic bronchitis or COPD. Analysis of the ventilatory function data revealed no association between history of exposure to substances contaminated with TCDD and the forced expiratory volume at one second (FEV1), forced vital capacity (FVC), or the ratio of FEV1 to FVC (FEV1/FVC%).

  4. Anti-Inflammatory Effect of 1,3,5,7-Tetrahydroxy-8-isoprenylxanthone Isolated from Twigs of Garcinia esculenta on Stimulated Macrophage

    PubMed Central

    Zhang, Dan-Dan; Zhang, Hong; Lao, Yuan-zhi; Wu, Rong; Xu, Jin-wen; Murad, Ferid; Bian, Ka; Xu, Hong-Xi

    2015-01-01

    Garcinia Linn. plants having rich natural xanthones and benzophenones with anti-inflammatory activity attracted a great deal of attention to discover and develop them as potential drug candidates. Through screening targeting nitric oxide accumulation in stimulated macrophage, we found that 1,3,5,7-tetrahydroxy-8-isoprenylxanthone (TIE) had potential anti-inflammatory effect. To understand how TIE elicits its anti-inflammatory activity, we uncovered that it significantly inhibits the production of nitric oxide (NO) and prostaglandin E2 (PGE2) in LPS/IFNγ-stimulated RAW264.7 cells. In further study, we showed that TIE reduced the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), two key molecules responsible for the production of NO and PGE2 during inflammation progress. Additionally, TIE also suppressed the expression of inflammatory cytokines IL-6, IL-12, and TNF-α. TIE-led suppression in iNOS, COX-2, and cytokines production were probably the consequence of TIE's capability to block ERK and p38MAPK signaling pathway. Moreover, TIE blocked activation of nuclear factor-kappa B (NF-κB) as well as NF-κB regulation of miR155 expression. Our study suggests that TIE may represent as a potential therapeutic agent for the treatment of inflammatory diseases. PMID:26538826

  5. Effects of steroids and dioxin (2,3,7,8-TCDD) on the developing wolffian ducts of the tiger salamander (Ambystoma tigrinum).

    PubMed

    Vajda, Alan M; Norris, David O

    2005-03-01

    This study was undertaken to investigate effects of the prototypical dioxin, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on steroid-dependent development of the wolffian ducts of an amphibian, the tiger salamander (Ambystoma tigrinum). Larvae with immature gonads and undeveloped mullerian ducts were injected with the steroid hormones estradiol (E2), dihydrotestosterone (DHT), or vehicle alone. Additionally, steroid-treated and vehicle-control larvae were immersed in sub-lethal solutions of technical grade TCDD (0, 0.0003, 0.003, 0.03, 0.3, and 3.0 microg TCDD/L). Both steroid treatments stimulated hypertrophy of the wolffian duct epithelium and an increase in mean epithelial cell size. Only DHT treatment stimulated epithelial cell proliferation. TCDD stimulated wolffian duct hypertrophy through an increase in mean epithelial cell size. TCDD acted as an androgen agonist on wolffian duct epithelial area and epithelial cell size. TCDD had no effect on wolffian duct epithelium among E2-injected animals. Stimulatory effects on cell size were observed at 0.0003 microg/L TCDD in saline-injected animals and at 0.003 microg/L TCDD in DHT-injected animals. Both E2 and DHT stimulated growth of the wolffian ducts early in development. Technical grade TCDD alone mimics E2 and DHT action but exhibits an androgen-agonistic action in the presence of exogenously administered DHT. Implications of possible interactions between TCDD and xenosteroids are discussed.

  6. Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on the in vivo and in vitro dechlorination of pentachlorophenol.

    PubMed

    Ahlborg, U G; Thunberg, T

    1978-02-21

    The metabolism of pentachlorophenol has been studied in the rat after pretreatments with phenobarbital, 3-methyl cholanthrene or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In addition to the previously identified metabolite, tetrachloro-p-hydroquinone, trichloro-p-hydroquinone has been identified in urine as a metabolite. The formation of the latter represents a type dechlorination different from that of the formation of tetrachlorohydroquinone. The inducing agents, 3-methylcholanthrene and TCDD have similar effects on the dechlorination and increase the formation of tetrachloro-p-hydroquinone more pronounced than does phenobarbital. In contrast to phenobarbital they also increase the formation of trichloro-p-hydroquinone and the total elimination of pentachlorophenol and its metabolites. The in vivo findings are supported by in vitro studies with microsomes from rats pretreated with phenobarbital or TCDD. Use of the inhibitor beta-diethylaminoethyl-diphenyl propylacetate (SKF 525-A) in vitro showed a more pronounced inhibition on microsomes from phenobarbital-treated rats than on microsomes from untreated or TCDD-treated rats. Gas chromatography-mass spectrometry have been used for the identification and quantification of pentachlorophenol and its metabolites.

  7. Boron isotopes in tourmaline from the ca. 3.7-3.8 Ga Isua supracrustal belt, Greenland: Sources for boron in Eoarchean continental crust and seawater

    NASA Astrophysics Data System (ADS)

    Grew, Edward S.; Dymek, Robert F.; De Hoog, Jan C. M.; Harley, Simon L.; Boak, Jeremy; Hazen, Robert M.; Yates, Martin G.

    2015-08-01

    Boron is highly concentrated in Earth's crust relative to primitive mantle. However, when present-day crustal concentrations were achieved remains debatable. It has been proposed that seawater boron δ11B was lower than at present, consistent with a model relating increase in sea-water δ11B to the proportion of B extracted from Earth's mantle into the oceans and crust. Our in situ ion microprobe analyses of tourmaline in 17 samples from the Eoarchean Isua supracrustal belt, Southwest Greenland, gave the following average δ11B with uncertainties ranging from ±0.4 to ±1.9‰: δ11B = -7.1 to -11.5‰ in amphibolite; δ11B = -10.5 to -25.3‰ in mica schist; δ11B = -19.2‰ in metachert (one sample), and δ11B = -21.9‰ in metaconglomerate (one sample). Tourmaline is largely schorl-dravite, rarely uvite-feruvite, and shows color and compositional zoning. δ11B varies from grain to grain in most samples; grains in a kyanite-staurolite schist are isotopically zoned, possibly because the rims incorporated B released by muscovite breakdown. The patterns in color-zoned tourmaline grains in our samples are not consistent with detrital origin of the cores, which rules out the possibility of there being tourmaline detritus from pre-existing continental crust in the studied samples. The tourmaline-bearing rocks are found in both the ca. 3700 Ma northern and ca. 3800 Ma southern terranes in the Isua supracrustal belt. Following an approach suggested by Chaussidon and Appel, we estimated Eoarchean seawater δ11B by calculating back from δ11B of tourmaline in metasedimentary rocks using fractionation of boron isotopes between clays and muscovite, tourmaline and aqueous fluid. This calculation gave an estimated δ11B ≈ +14 ± 15‰ for Eoarchean seawater, 25‰ lower than present-day seawater (δ11B = +39.5‰). For comparison, an estimate obtained simply by direct comparison of δ11B for Eoarchean and Phanerozoic tourmaline presumed to have crystallized in similar

  8. Potencies of polychlorinated dibenzo-p-dioxin, dibenzofuran, and biphenyl congeners, relative to 2,3,7,8-tetrachlorodibenzo-p-dioxin, for producing early life stage mortality in rainbow trout (Oncorhynchus mykiss)

    USGS Publications Warehouse

    Walker, Mary K.; Peterson, Richard E.

    1991-01-01

    The presence of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and biphenyls (PCBs) in feral lake trout eggs (Salvelinus namaycush) may increase the risk of lake trout early life stage mortality in the Great Lakes. To assess the combined toxicity of PCDDs, PCDFs, and PCBs to lake trout early development, toxic potencies, relative to 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD), were determined for individual PCDD, PCDF, and PCB congeners, based on rainbow trout (Oncorhynchus mykiss) early life stage mortality. Newly fertilized rainbow trout eggs were injected with graded doses of 2,3,7,8-TCDD, or a PCDD, PCDF, or PCB congener. LD50 values were determined based on the egg dose that caused mortality from hatching onset to swim-up. Toxic equivalency factors (TEFs) were calculated as 2,3,7,8-TCDD LD50/congener LD50. TEFs were for PCDDs: 2,3,7,8-TCDD = 1.0; 1,2,3,7,8-PeCDD = 0.730;and 1,2,3,4,7,8-HxCDD = 0.319; for PCDFs: 2,3,4,7,8-PeCDF = 0.359; 1,2,3,4,7,8-HxCDF = 0.280; 1,2,3,7,8-PeCDF = 0.034; and 2,3,7,8-TCDF = 0.028; and for PCBs: 3,3',4,4',5-PeCB = 0.005; 3,3',4,4'-TCB = 0.00016; 2,3,3',4,4'-PeCB and 2,3',4,4',5-PeCB ortho-chlorinated analogues of the coplanar PCBs fish-specific TEFs were 1/14 to 1/80 less than both those determined in H4IIE cells and proposed for risk assessment. Using these fish-specific TEFs, the risk associated with exposure of early life stages of Sake trout to complex mixtures of PCDDs, PCDFs, and PCBs in the Great Lakes can be estimated.

  9. Involvement of SREBPs in 2,3,7,8-tetrachlorodibenzo-p-dioxin-induced disruption of lipid metabolism in male guinea pig

    SciTech Connect

    Nishiumi, Shin; Yabushita, Yoshiyuki; Furuyashiki, Takashi; Fukuda, Itsuko; Ashida, Hitoshi

    2008-06-15

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has multiple toxic effects causing a wasting syndrome characterized by a loss of body weight accompanied by a decrease in adipose tissue weight. To elucidate the mechanism behind this syndrome, we investigated the changes in lipid metabolism 7 and 21 days after a single intraperitoneal injection of TCDD at 1 {mu}g/kg body weight to male guinea pigs. TCDD caused the symptoms of the syndrome, body weight loss with a decrease in adipose tissue weight, while it increased the levels of triacylglycerols, total cholesterols, and free fatty acids in plasma. On day 7, TCDD decreased the levels of CCAAT/enhancer binding protein (C/EBP) {alpha}, peroxisome proliferator activated receptor {gamma}, and glucose transporter 4, adipogenesis-related factors, in adipose tissue, whereas the levels of retinoid X receptor {alpha}, C/EBP{beta}, C/EBP{delta}, and c-Myc remained unchanged. TCDD also reduced the levels of both p125 precursor and p68 active forms of sterol regulatory element binding protein (SREBP)-1 and -2, the lypogenesis-related factors, and downregulated their DNA binding activity in adipose tissue, while it raised the levels of their p68 active forms and increased their DNA binding activity in the liver. TCDD decreased mRNA and protein levels of acetyl-CoA carboxylase and HMG-CoA synthase in the liver and adipose tissue. Similar results were obtained on day 21. These results suggest that TCDD disrupts lipid metabolism through changes in the expression levels of the adipogenesis-related and lipogenesis-related proteins in the liver and adipose tissue, and SREBPs would be involved in the development of the wasting syndrome.

  10. Chromatographic determination of 7,8-methylenedioxy-4H-2,3-benzodiazepin-4-ones in rat plasma: relationship to their anticonvulsant activity.

    PubMed

    Rizzo, M; De Sarro, G; Zappalà, M; Grasso, S

    2002-07-25

    The present investigation was designed to develop an assay suitable for pharmacokinetic studies of new compounds, i.e. the novel 7,8-methylenedioxy-4H-2,3-benzodiazepin-4-one derivatives (2a and 2b), acting as non-competitive AMPA-receptor antagonists. A reversed-phase high-performance liquid chromatographic method has been developed to determine the time-course of plasma concentrations of derivatives 2a and 2b administered intraperitoneally to Sprague-Dawley rats. The separation of compounds studied and a N-methyl-2,3-benzodiazepin-4-one derivative as internal standard (I.S.) from plasma, were carried out by liquid-liquid extraction using diethyl ether. The samples were injected onto the analytical column (Partisil 10 ODS) eluted with acetonitrile/0.01 M acetate buffer (pH 5.3) at a flow-rate of 2 ml/min and detected at 240 nm. Compounds 2a, 2b and I.S. gave retention times of 8.5, 5.25 and 11.1 min, respectively. The selectivity of the method was satisfactory. The mean recovery from spiked rat plasma ranged from 86.7 to 91.6% for 2a, and from 85.1 to 87.0% for 2b. The procedures were validated with a good reproducibility and linear response from 0.0625 to 2 microg/ml, with a regression coefficient of 0.9932 for 2a and 0.9854 for 2b. The lower limit of quantification (LOQ) was taken as 15 ng/ml for the two compounds. 2a and 2b showed no signs of significant degradation in rat plasma during storage at -20 degrees C and following freeze/thaw cycles. Moreover, plasma levels of the tested compounds have been correlated with their anticonvulsant activity, determined in vivo in genetically epilepsy-prone rats. Due to its sensitivity, the method was suitable for application to pharmacokinetic study.

  11. Synergistic effect of 2,2',4,4',5,5'-hexachlorobiphenyl and 2,3,7,8-tetrachlorodibenzo-p-dioxin on hepatic porphyrin levels in the rat.

    PubMed Central

    van Birgelen, A P; Fase, K M; van der Kolk, J; Poiger, H; Brouwer, A; Seinen, W; van den Berg, M

    1996-01-01

    We studied the effect of polychlorinated biphenyls (PCBs) on hepatic porphyrin accumulation in female Sprague-Dawley rats by feeding them diets containing 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 2,2',4,4',5,5'-hexachlorobiphenyl (PCB 153), 2,3,3',4,4',5-hexachlorobiphenyl (PCB 156), 3,3',4,4',5-pentachlorobiphenyl (PCB 126), or combinations of the single PCB congeners with TCDD for 13 weeks. A dose-dependent increase in hepatic porphyrin accumulation occurred after TCDD, PCB 126, or PCB 156 administration, reaching maximal levels of about twice control values. The lowest dose levels for which a significant increase in hepatic porphyrin accumulation was found were 0.7 microgram TCDD/kg diet, 50 micrograms PCB 126/kg diet, or 6 mg PCB 156/kg diet. These doses are equivalent to 47 ng TCDD/kg/day, 3.2 micrograms PCB 126/kg/day, and 365 micrograms PCB 156/kg/day. Relative potencies for hepatic porphyrin accumulation, using TCDD as a reference, ranged from 0.015 to 0.06 for PCB 126 and from 0.0001 to 0.0003 for PCB 156. CYP1A2 activities significantly correlated with hepatic porphyrin levels, with coefficients of 0.629, 0.483, or 0.808 for TCDD, PCB 126, or PCB 156, respectively. Administration of PCB 153 alone did not result in hepatic porphyrin accumulation. Co-administration of PCB 153 and TCDD revealed a strong synergistic effect on porphyrin accumulation (about 800 times control levels). This synergistic effect was significant in rats fed diets containing any combination of PCB 153 with TCDD. Uroporphyrin III and heptacarboxylic porphyrin were accumulated in porphyrinogenic livers. These results suggest that TCDD induction of CYP1A2 may be involved, leading to oxidation of uroporphyrinogen III to uroporphyrin III, in combination with an increase in delta-aminolevulinic acid synthetase induced by PCB 153. Under porphyrinogenic conditions, an inhibitor of CYP1A2 activity may also be formed. The interactive effects on porphyrin accumulation after co

  12. Accumulation of 2,3,7,8-tetrachlorodibenzo-p-dioxin by rainbow trout (Onchorhynchus mykiss) at environmentally relevant dietary concentrations

    USGS Publications Warehouse

    Jones, Paul D.; Kannan, Kurunthachalam; Newsted, John L.; Tillitt, Donald E.; Williams, Lisa L.; Giesy, John P.

    2001-01-01

    Rainbow trout were fed a diet containing 1.8, 18, or 90 pg/g 3H-2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) for up to 320 d. Concentrations of TCDD were determined in muscle, liver, and ovaries at 100, 150, 200, and 250 d. Concentrations of TCDD reached an apparent steady-state concentration in liver after 100 d of exposure, whereas concentrations in other tissues continued to increase until 150 d of exposure. The greatest portion of the total mass of TCDD was present in the muscle tissue with lesser proportions in other organs. As the ovaries developed before spawning, an increase occurred in the total mass of TCDD present in this tissue. The assimilation rate of TCDD during the initial 100 d of the exposure was determined to be between 10 and 30%. This is somewhat less than estimates derived based on both uptake and elimination constants determined during shorter exposures. Biomagnification factors (BMFs) were estimated for all tissues and exposure concentrations, and at all exposure periods. Lipid-normalized BMFs for muscle ranged from 0.38 to 1.51, which is consistent with the value of 1.0 predicted from fugacity theory. Uptake and depuration rate constants were determined and used to predict individual organ TCDD concentrations. Comparison with observed values indicated that the model could be used to predict tissue concentrations from the known concentrations of TCDD in food. This model will allow more refined risk assessments by predicting TCDD concentrations in sensitive tissues such as developing eggs.

  13. Aryl hydrocarbon receptor knockout rats are insensitive to the pathological effects of repeated oral exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

    PubMed

    Harrill, Joshua A; Layko, Debra; Nyska, Abraham; Hukkanen, Renee R; Manno, Rosa Anna; Grassetti, Andrea; Lawson, Marie; Martin, Greg; Budinsky, Robert A; Rowlands, J Craig; Thomas, Russell S

    2016-06-01

    Sustained activation of the aryl hydrocarbon receptor (AHR) is believed to be the initial key event in AHR receptor-mediated tumorigenesis in the rat liver. The role of AHR in mediating pathological changes in the liver prior to tumor formation was investigated in a 4-week, repeated-dose study using adult female wild-type (WT) and AHR knockout (AHR-KO) rats treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Beginning at 8 weeks of age, AHR-KO and WT rats were dosed by oral gavage with varying concentrations of TCDD (0, 3, 22, 100, 300 and 1000 ng kg(-1)  day(-1) ). Lung, liver and thymus histopathology, hematology, serum chemistry and the distribution of TCDD in liver and adipose tissue were examined. Treatment-related increases in the severity of liver and thymus pathology were observed in WT, but not AHR-KO rats. In the liver, these included hepatocellular hypertrophy, bile duct hyperplasia, multinucleated hepatocytes and inflammatory cell foci. A loss of cellularity in the thymic cortex and thymic atrophy was observed. Treatment-related changes in serum chemistry parameters were also observed in WT, but not AHR-KO rats. Finally, dose-dependent accumulation of TCDD was observed primarily in the liver of WT rats and primarily in the adipose tissue of AHR-KO rats. The results suggest that AHR activation is the initial key event underlying the progression of histological effects leading to liver tumorigenesis following TCDD treatment. Copyright © 2015 John Wiley & Sons, Ltd.

  14. Developmental exposure to 2,3,7,8 tetrachlorodibenzo-p-dioxin attenuates capacity of hematopoietic stem cells to undergo lymphocyte differentiation

    SciTech Connect

    Ahrenhoerster, Lori S.; Tate, Everett R.; Lakatos, Peter A.; Wang, Xuexia; Laiosa, Michael D.

    2014-06-01

    The process of hematopoiesis, characterized by long-term self-renewal and multi-potent lineage differentiation, has been shown to be regulated in part by the ligand-activated transcription factor known as the aryl hydrocarbon receptor (AHR). 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD), a ubiquitous contaminant and the most potent AHR agonist, also modulates regulation of adult hematopoietic stem and progenitor cell (HSC/HPC) homeostasis. However, the effect of developmental TCDD exposure on early life hematopoiesis has not been fully explored. Given the inhibitory effects of TCDD on hematopoiesis and lymphocyte development, we hypothesized that in utero exposure to TCDD would alter the functional capacity of fetal HSC/HPCs to complete lymphocyte differentiation. To test this hypothesis, we employed a co-culture system designed to facilitate the maturation of progenitor cells to either B or T lymphocytes. Furthermore, we utilized an innovative limiting dilution assay to precisely quantify differences in lymphocyte differentiation between HSC/HPCs obtained from fetuses of dams exposed to 3 μg/kg TCDD or control. We found that the AHR is transcribed in yolk sac hematopoietic cells and is transcriptionally active as early as gestational day (GD) 7.5. Furthermore, the number of HSC/HPCs present in the fetal liver on GD 14.5 was significantly increased in fetuses whose mothers were exposed to TCDD throughout pregnancy. Despite this increase in HSC/HPC cell number, B and T lymphocyte differentiation is decreased by approximately 2.5 fold. These findings demonstrate that inappropriate developmental AHR activation in HSC/HPCs adversely impacts lymphocyte differentiation and may have consequences for lymphocyte development in the bone marrow and thymus later in life.

  15. Developmental Exposure to 2,3,7,8 Tetrachlorodibenzo-p-dioxin Attenuates Capacity of Hematopoietic Stem Cells to Undergo Lymphocyte Differentiation

    PubMed Central

    Ahrenhoerster, Lori S.; Tate, Everett R.; Lakatos, Peter A.; Wang, Xuexia; Laiosa, Michael D.

    2014-01-01

    The process of hematopoiesis, characterized by long-term self-renewal and multi-potent lineage differentiation, has been shown to be regulated in part by the ligand-activated transcription factor known as the aryl hydrocarbon receptor (AHR). 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a ubiquitous contaminant and the most potent AHR agonist, also modulates regulation of adult hematopoietic stem and progenitor cell (HSC/HPC) homeostasis. However, the effect of developmental TCDD exposure on early life hematopoiesis has not been fully explored. Given the inhibitory effects of TCDD on hematopoiesis and lymphocyte development, we hypothesized that in utero exposure to TCDD would alter the functional capacity of fetal HSC/HPCs to complete lymphocyte differentiation. To test this hypothesis, we employed a co-culture system designed to facilitate the maturation of progenitor cells to either B or T lymphocytes. Furthermore, we utilized an innovative limiting dilution assay to precisely quantify differences in lymphocyte differentiation between HSC/HPCs obtained from fetuses of dams exposed to 3μg/kg TCDD or control. We found that the AHR is transcribed in yolk sac hematopoietic cells and is transcriptionally active as early as gestational day (GD) 7.5. Furthermore, the number of HSC/HPCs present in the fetal liver on GD 14.5 was significantly increased in fetuses whose mothers were exposed to TCDD throughout pregnancy. Despite this increase in HSC/HPC cell number, B and T lymphocyte differentiation is decreased by approximately 2.5 fold. These findings demonstrate that inappropriate developmental AHR activation in HSC/HPCs adversely impacts lymphocyte differentiation and may have consequences for lymphocyte development in the bone marrow and thymus later in life. PMID:24709672

  16. B-9972 (D-Arg-[Hyp3,Igl5,Oic7,Igl8]-bradykinin) is an inactivation-resistant agonist of the bradykinin B2 receptor derived from the peptide antagonist B-9430 (D-Arg-[Hyp3,Igl5,D-Igl7,Oic8]-bradykinin): pharmacologic profile and effective induction of receptor degradation.

    PubMed

    Bawolak, Marie-Thérèse; Gera, Lajos; Morissette, Guillaume; Stewart, John M; Marceau, François

    2007-11-01

    The bradykinin B(2) receptor is a heptahelical receptor regulated by a cycle of phosphorylation, endocytosis, and extensive recycling at the cell surface following agonist stimulation. B-9430 (d-Arg-[Hyp(3),Igl(5),D-Igl(7),Oic(8)]-bradykinin) is a second generation peptide antagonist found to be competitive at the human B(2) receptor and insurmountable at the rabbit B(2) receptor (contractility assays, isolated human umbilical and rabbit jugular veins). Two isomers of this peptide were prepared: B-10344 (D-Arg-[Hyp(3),Igl(5),Oic(7),D-Igl(8)]-bradykinin; inverted sequence Oic(7), D-Igl(8)) and B-9972 (D-Arg-[Hyp(3),Igl(5),Oic(7),Igl(8)]-bradykinin); they are low- and high-potency agonists, respectively, in vascular preparations. The potency gap between bradykinin and B-9972 is narrow in contractility assays, despite the fact that B-9972 affinity is 7-fold inferior at the rabbit B(2) receptor (radioligand binding competition assay). The effects of agonists on receptors were compared using two chimerical constructions based on rabbit B(2) receptors: conjugate of the B(2) receptor with green fluorescent protein (B(2)R-GFP) and the N-terminally tagged conjugate of the myc epitope with the B(2) receptor. Imaging and immunoblotting showed that B-9972 induced a persistent endocytosis of cell surface B(2) receptors in human embryonic kidney 293 cells with slow receptor degradation (weak after 3 h of treatment, important at 12 h) and B(2)R-GFP desensitization ([(3)H]bradykinin endocytosis and extracellular signal-regulated kinase 1/2 phosphorylation assays). Bradykinin was not active in this respect but when combined with captopril, induced some degradation. B-9430 reduced the endocytosis and degradation of B(2) receptors by the agonists. The results illustrate the agonist-antagonist transition in B(2) receptor peptide ligands with a constrained C-terminal structure, the importance of species in their pharmacological profile, and the possibility of selectively degrading

  17. Effect of tocopherol on biochemical blood parameters in pleuritis-induced rats treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin.

    PubMed

    Całkosiński, Ireneusz; Rosińczuk-Tonderys, Joanna; Bronowicka-Szydełko, Agnieszka; Dzierzba, Katarzyna; Bazan, Justyna; Dobrzyński, Maciej; Majda, Jacek; Gamian, Andrzej

    2015-06-01

    The aim of this study was to evaluate the effect of tocopherol on pleuritis-induced rats exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Rats were treated with a single TCDD dose of 5 μg/kg body weight (b.w.) and then for 3 weeks they were daily supplemented with tocopherol at a dose of 30 mg/kg b.w. The inflammation was initiated by intrapleural injection of a single dose of 1% carrageenin solution in a volume of 0.15 ml. Changes in biochemical blood parameters were measured three times at the 24th, 72nd and 120th hour of pleuritis and the blood was collected from 20 animals of each group of rats (group with the control inflammation; group treated with TCDD and with control inflammation; group treated with TCDD, supplemented with tocopherol and with the inflammation). The following biochemical parameters were measured: tumor necrosis factor (TNF), interleukin-1 (IL-1), IL-2, IL-4, IL-6, procollagen, telopeptide, fibrinogen, cholesterol, urea, creatinine, aspartate aminotransferase (AspAT) and alanine aminotransferase (AlAT). Daily supplementation of tocopherol caused significant changes in the level of TNF, IL-1, IL-4, IL-6, urea, creatinine, AspAT and AlAT. According to the results of these studies, we suggest that tocopherol supplementation in high doses could act as a protective treatment to improve liver metabolism.

  18. Soils containing 2,3,7,8-tetrachlorodibenzo-p-dioxin: aspects of their microbial activity and the potential for their microbially-mediated decontamination

    SciTech Connect

    Arthur, M.F.

    1987-01-01

    Three soils from Missouri and a soil from New Jersey, containing between 0.008 and 26.3 ug/g of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), were examined for microbial activity; the Missouri soils were also monitored for TCDD biodegradation. The objective was to simulate TCDD biodegradation by the indigenous microflora in order to develop a cost-effective method to decontaminate soils in situ. Microbial activity in TCDD soils was examined by enumeration of aerobic eutrophic and oligotrophic bacteria, actinomycetes, and fungi; determination of soil enzyme activity, including dehydrogenase, acid and alkaline phosphatase, arylsulfatase, and rhodanese; and measurement of soil respiration. The Missouri soils were subsequently amended with fertilizer, /sup 14/C-TCDD and a TCDD-solubilizing nonionic surfactant in order to improve the availability of TCDD to the indigenous soil microflora. Biodegradation of TCDD was monitored by the evolution of /sup 14/CO/sub 2/ and by high resolution gas chromatography/mass spectrometry (CC/MS).

  19. Design, synthesis and biological evaluation of pyrido[2,3-d]pyrimidin-7-(8H)-ones as HCV inhibitors.

    PubMed

    Camarasa, Marta; Puig de la Bellacasa, Raimon; González, Àlex L; Ondoño, Raül; Estrada, Roger; Franco, Sandra; Badia, Roger; Esté, José; Martínez, Miguel Ángel; Teixidó, Jordi; Clotet, Bonaventura; Borrell, José I

    2016-06-10

    The design and selection of a combinatorial library of pyrido[2,3-d]pyrimidin-7(8H)-ones (4) has allowed the synthesis of 121 compounds, using known and new synthetic methodologies, and the evaluation of the inhibitory activity against hepatitis C virus (HCV) genotype 1b replicon. Among these compounds, 21{4,10} and 24{2,10} presented very high activities [EC50 = 0.027 μM (CC50 = 5.3 μM) and EC50 = 0.034 μM (CC50 = 13.5 μM), respectively] and high selectivity indexes, 196 and 397. These values are similar to the EC50 reported for sofosbuvir (2) (0.048 μM) using a similar methodological approach and the same virus subtype. 21{4,10} and 24{2,10} are obtained through shorter synthetic itineraries than sofosbuvir and 24{2,10} is achiral contrary to sofosbuvir which presents 4 stereogenic centers. In silico studies suggest that 21{4,10} and 24{2,10} inhibits NS5B polymerase through allosteric site binding.

  20. Suppressive effects of estradiol on 2,3,7,8-tetrachlorodibenzo-p-dioxin-mediated transcriptional activation of murine Cyp1a-1 in mouse hepatoma Hepa 1c1c7 cells.

    PubMed

    Jeong, H G; Lee, S S

    1998-11-27

    Cultured mouse hepatoma Hepa lclc7 cells were treated with either estradiol or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or in combination to assess the role of estradiol in the process of Cypla-1 induction. Estradiol at a concentration as high as 1 microM slightly increased the activity of Cypla-1-specific 7-ethoxyresorufin O-deethylase (EROD); in contrast, TCDD-induced EROD activity and Cypla-1 mRNA levels were markedly reduced in the concomitant treatment of TCDD and estradiol in a dose-dependent manner. Treatment with tamoxifen, an anti-estrogen which acts through the estrogen receptor, did not affect the suppressive effects of estradiol on TCDD-induced EROD activity. Electrophoretic mobility shift assay using nuclear extract of cells revealed that estradiol reduced transformation of the Ah receptor to the form capable of specifically binding to an oligonucleotide containing dioxin-response element (DRE) sequence. Consistent with this, estradiol decreased TCDD-induced increased chloramphenicol acetyltransferase (CAT) activity from a DRE-containing CAT reporter plasmid after transient transfection into the cells. The levels of the cytosolic [3H]TCDD-Ah receptor complex were reduced by estradiol in competitive Ah receptor binding assay using [3H]TCDD. This study demonstrated that estradiol acts as an antagonist to TCDD and can regulate Cyp1a-1 expression in an Ah receptor-dependent manner but not through estradiol receptor in Hepa 1c1c7 cells.

  1. Toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin on the peripheral nervous system of developing red seabream (Pagrus major).

    PubMed

    Iida, Midori; Kim, Eun-Young; Murakami, Yasunori; Shima, Yasuhiro; Iwata, Hisato

    2013-03-15

    We investigated 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-induced effects on the morphology of peripheral nervous system (PNS) in the developing red seabream (Pagrus major) embryos. The embryos at 10h post-fertilization (hpf) were treated with 0, 0.1, 0.4 or 1.7 μg/L of TCDD in seawater for 80 min. The morphology of PNS was microscopically observed with florescence staining using an anti-acetylated tubulin antibody at 48, 78, 120 and 136 hpf. Axon length of facial nerve (VII) was found to be shortened by TCDD exposure. Axon guidance in the glossopharyngeal nerve (IX) and vagus nerve (X) was altered at 120 and 136 hpf in a TCDD dose-dependent manner. Lowest observable effect level of TCDD (0.1 μg/L) that induced the morphological alteration of PNS was lower than those of other endpoints on morphological deformities so far reported. Given that the growth cone at the tip of growing nerve axons advances under the influence of its surrounding tissues, we hypothesized that TCDD exposure would affect (1) the nerve cell proliferation/differentiation, (2) the structure of muscle as an axon target and (3) the nerve guidance factor in the embryos. By the immunostaining of embryos with an antibody against the neuronal specific RNA-binding protein, HuD, and an antibody against the sarcomeric myosin, no morphological effects were observed on the neural proliferation/differentiation and the structure of facial muscles of TCDD-treated embryos. In contrast, whole mount in situ hybridization of semaphorin 3A (Sema3A), a secretory axon repulsion factor, revealed the altered expression pattern of its transcripts in TCDD-treated embryos. Our findings suggest that TCDD treatment affects the projection of PNS in the developing red seabream embryos through the effects on the axonal growth cone guidance molecule such as Sema3A, but not on the neuronal differentiation/proliferation and axon target. The PNS in developing embryos may be one of the most sensitive biomarkers to the exposure

  2. Overexpressed Proteins in Hypervirulent Clade 8 and Clade 6 Strains of Escherichia coli O157:H7 Compared to E. coli O157:H7 EDL933 Clade 3 Strain

    PubMed Central

    Amigo, Natalia; Zhang, Qi; Amadio, Ariel; Zhang, Qunjie; Silva, Wanderson M.; Cui, Baiyuan; Chen, Zhongjian; Larzabal, Mariano; Bei, Jinlong; Cataldi, Angel

    2016-01-01

    Escherichia coli O157:H7 is responsible for severe diarrhea and hemolytic uremic syndrome (HUS), and predominantly affects children under 5 years. The major virulence traits are Shiga toxins, necessary to develop HUS and the Type III Secretion System (T3SS) through which bacteria translocate effector proteins directly into the host cell. By SNPs typing, E. coli O157:H7 was separated into nine different clades. Clade 8 and clade 6 strains were more frequently associated with severe disease and HUS. In this study, we aimed to identify differentially expressed proteins in two strains of E. coli O157:H7 (clade 8 and clade 6), obtained from cattle and compared them with the well characterized reference EDL933 strain (clade 3). Clade 8 and clade 6 strains show enhanced pathogenicity in a mouse model and virulence-related properties. Proteins were extracted and analyzed using the TMT-6plex labeling strategy associated with two dimensional liquid chromatography and mass spectrometry in tandem. We detected 2241 proteins in the cell extract and 1787 proteins in the culture supernatants. Attention was focused on the proteins related to virulence, overexpressed in clade 6 and 8 strains compared to EDL933 strain. The proteins relevant overexpressed in clade 8 strain were the curli protein CsgC, a transcriptional activator (PchE), phage proteins, Stx2, FlgM and FlgD, a dienelactone hydrolase, CheW and CheY, and the SPATE protease EspP. For clade 6 strain, a high overexpression of phage proteins was detected, mostly from Stx2 encoding phage, including Stx2, flagellin and the protease TagA, EDL933_p0016, dienelactone hydrolase, and Haemolysin A, amongst others with unknown function. Some of these proteins were analyzed by RT-qPCR to corroborate the proteomic data. Clade 6 and clade 8 strains showed enhanced transcription of 10 out of 12 genes compared to EDL933. These results may provide new insights in E. coli O157:H7 mechanisms of pathogenesis. PMID:27880834

  3. A Study of 2,3,7,8-Tetrachlorodibenzo-p-dioxin Induced Liver Injury in Jian Carp (Cyprinus carpio var. Jian) Using Precision-Cut Liver Slices.

    PubMed

    Du, Jin-Liang; Cao, Li-Ping; Liu, Ying-Juan; Jia, Rui; Yin, Guo-Jun

    2016-01-01

    The aim of this study was to establish a model for the study of liver injury induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in Jian carp using precision-cut liver slices (PCLS). PCLS were treated with TCDD at concentrations of 0, 0.05, 0.1, 0.3, and 0.6 μg/L for 6 h, followed by collection of the culture supernatant and PCLS for analysis. Several biochemical indices were analyzed, including glutamic pyruvic transaminase (GPT), glutamic oxaloacetic transaminase (GOT), lactate dehydrogenase (LDH), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA). Expression of mRNA was also estimated for cytochrome P4501A (CYP1A), aryl hydrocarbon receptor2 (AhR2), and aryl hydrocarbon receptor nuclear translocator2 (ARNT2). Results showed that some significant effects (p < 0.05) in MDA, GSH-Px and PCLS viability were observed at a TCDD concentration as low as 0.05 µg/L, and the observed effects increased with exposure concentration. Following exposure to TCDD for 6 h at a concentration of 0.3 μg/L, significant increases (p < 0.01) in the content of GPT, GOT, MDA, and LDH were observed, while SOD activity, GSH-Px activity, and PCLS viability were decreased (p < 0.01 or p < 0.05). Exposure to 0.3 μg/L TCDD also resulted in increased expression of mRNA for CYP1A, AhR2, and ARNT2. Overall, these results provide evidence of TCDD-induced liver injury and oxidative stress in Jian carp. These results also support the use of PCLS as an in vitro model for the evaluation of hepatotoxicity in Jian carp.

  4. Phosphate Tether-Mediated Ring-Closing Metathesis for the Generation of P-Stereogenic, Z-Configured Bicyclo[7.3.1]- and Bicyclo[8.3.1]phosphates.

    PubMed

    Markley, Jana L; Maitra, Soma; Hanson, Paul R

    2016-02-05

    A phosphate tether-mediated ring-closing metathesis (RCM) study to the synthesis of Z-configured, P-stereogenic bicyclo[7.3.1]- and bicyclo[8.3.1]phosphates is reported. Investigations suggest that C3-substitution, olefin substitution, and proximity of the forming olefin to the bridgehead carbon of the bicyclic affect the efficiency and stereochemical outcome of the RCM event. This study demonstrates the utility of phosphate tether-mediated desymmetrization of C2-symmetric, 1,3-anti-diol-containing dienes in the generation of macrocyclic phosphates with potential synthetic and biological utility.

  5. A Single-Composition Trichromatic White-Light-Emitting Phosphor Based on Sr8ZnY(PO4)7 Coactivated with Ce3+, Tb3+, and Mn2+

    NASA Astrophysics Data System (ADS)

    Guan, Anxiang; Wang, Guofang; Xia, Siyu; Zhang, Xinguo; Hu, Xiaoxi; Zhou, Liya; Meng, Yingbin; Yao, Chunying; Pan, Haiman

    2016-12-01

    Ce3+/Tb3+/Mn2+-codoped Sr8ZnY(PO4)7 (SZYP) white-emitting phosphors have been synthesized via solid-state reaction technology. The overlapping spectra between the excitation bands of Mn2+ and Tb3+ ions and the emission band of Ce3+ suggest that Ce3+ → Mn2+ and Ce3+ → Tb3+ energy transfer occurs. The emission hues exhibited by Ce3+/Tb3+- and Ce3+/Mn2+-codoped phosphors could be modulated from bluish to greenish region and from bluish to reddish region by simply adjusting the relative content of Ce3+/Tb3+ and Ce3+/Mn2+, respectively. SZYP:Ce3+,Tb3+,Mn2+ samples exhibited three dominant bands at 410 nm, 545 nm, and 600 nm, attributable to electronic transitions of Ce3+, Tb3+, and Mn2+ ions, respectively. Thus, color-tunable emission was achieved by accurately modulating the concentrations of Ce3+, Tb3+, and Mn2+ ions. SZYP:0.05Ce3+,0.11Mn2+,0.11Tb3+ was found to be an ideal white-light-emitting phosphor with color coordinates of (0.34, 0.33) and correlated color temperature of about 5144.83 K. The results indicate that Ce3+/Tb3+/Mn2+ -tridoped SZYP phosphors are potential single-component white-emitting candidates for application in ultraviolet- and white-light-emitting diodes.

  6. A Single-Composition Trichromatic White-Light-Emitting Phosphor Based on Sr8ZnY(PO4)7 Coactivated with Ce3+, Tb3+, and Mn2+

    NASA Astrophysics Data System (ADS)

    Guan, Anxiang; Wang, Guofang; Xia, Siyu; Zhang, Xinguo; Hu, Xiaoxi; Zhou, Liya; Meng, Yingbin; Yao, Chunying; Pan, Haiman

    2017-03-01

    Ce3+/Tb3+/Mn2+-codoped Sr8ZnY(PO4)7 (SZYP) white-emitting phosphors have been synthesized via solid-state reaction technology. The overlapping spectra between the excitation bands of Mn2+ and Tb3+ ions and the emission band of Ce3+ suggest that Ce3+ → Mn2+ and Ce3+ → Tb3+ energy transfer occurs. The emission hues exhibited by Ce3+/Tb3+- and Ce3+/Mn2+-codoped phosphors could be modulated from bluish to greenish region and from bluish to reddish region by simply adjusting the relative content of Ce3+/Tb3+ and Ce3+/Mn2+, respectively. SZYP:Ce3+,Tb3+,Mn2+ samples exhibited three dominant bands at 410 nm, 545 nm, and 600 nm, attributable to electronic transitions of Ce3+, Tb3+, and Mn2+ ions, respectively. Thus, color-tunable emission was achieved by accurately modulating the concentrations of Ce3+, Tb3+, and Mn2+ ions. SZYP:0.05Ce3+,0.11Mn2+,0.11Tb3+ was found to be an ideal white-light-emitting phosphor with color coordinates of (0.34, 0.33) and correlated color temperature of about 5144.83 K. The results indicate that Ce3+/Tb3+/Mn2+ -tridoped SZYP phosphors are potential single-component white-emitting candidates for application in ultraviolet- and white-light-emitting diodes.

  7. Science Teaching in New Brunswick Grades 7, 8 and 9: Results of a Teacher Survey Conducted in May, 1990. Research Report Number 3.

    ERIC Educational Resources Information Center

    McFadden, Charles P.

    A survey of grade 7, 8 and 9 science teachers was conducted as part of a research program to determine the consequences for teaching and learning of the recent introduction of the SciencePlus Program developed by the Atlantic Science Curriculum Project and the need for further curriculum and professional development. The survey explored some of…

  8. Production of Biologically Active 7,10-dihydroxy-8(E)-octadecenoic Acid from Korean Pine Seed Oil by Pseudomonas aeruginosa PR3.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hydroxyl group of hydroxyl fatty acid (HFA) cause HFA to carry special properties such as higher viscosity and reactivity compared with other non-hydroxy fatty acids. Microbial conversion of oleic acid into 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) caused DOD to carry strong antibacterial activit...

  9. Evidence for the mechanism of action of the 2,3,7,8-tetrachlorodibenzo-p-dioxin-mediated decrease of nuclear estrogen receptor levels in wild-type and mutant mouse Hepa 1c1c7 cells.

    PubMed

    Zacharewski, T; Harris, M; Safe, S

    1991-06-15

    Treatment of wild-type Hepa 1c1c7 cells with 1 nM [3H]-17 beta-estradiol resulted in the rapid accumulation of the nuclear estrogen receptor complex whose levels were maximized within 1 hr. Cotreatment of the cells with 10 nM 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and [3H]-17 beta-estradiol did not affect the nuclear estrogen receptor levels 1 hr after addition of the radioligand; however, pretreatment of the cells for 1, 6, 24 or 42 hr with 10 nM TCDD prior to the addition of the radiolabeled hormone caused a greater than 50% decrease in nuclear estrogen receptor levels (determined by velocity sedimentation analysis) 1 hr after the addition of [3H]-17 beta-estradiol. In parallel experiments in which 10 nM TCDD was added 6 hr prior to the radiolabeled hormone, TCDD caused a 63 and 74% decrease in immunodetectable cytosolic and nuclear estrogen receptor protein levels, respectively, in the wild-type Hepa 1c1c7 cells. The nuclear estrogen receptor was also detected in two Hepa 1c1c7 mutant (class 1 and class 2) cell lines which have been characterized previously as TCDD non-responsive due to either decreased aryl hydrocarbon (Ah) receptor levels or a defect in the accumulation of transcriptionally active nuclear Ah receptor complexes, respectively. Treatment of these mutant cell lines with TCDD and [3H]-17 beta-estradiol (as described above) caused only a minimum (class 1) or non-detectable (class 2) decrease in nuclear estrogen receptor binding activity or immunodetectable protein levels. These results, coupled with the structure-dependent differences in the activities of TCDD (a strong Ah receptor agonist) and 2,8-dichlordibenzo-p-dioxin (a weak Ah receptor agonist) in this assay system, support a role for the Ah receptor in the TCDD-mediated decrease of the nuclear estrogen receptor in mouse Hepa 1c1c7 cells. In addition, actinomycin D and cycloheximide both inhibited the TCDD-mediated decrease of nuclear estrogen receptor levels in the Hepa 1c1c7 wild

  10. In utero and lactational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin alters postnatal development of seminal vesicle epithelium.

    PubMed

    Hamm, J T; Sparrow, B R; Wolf, D; Birnbaum, L S

    2000-04-01

    2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has been shown to alter male reproductive development of laboratory animals through in utero and lactational exposure. As a result of exposure, the accessory glands of the male reproductive tract, including the seminal vesicle, are decreased in size as determined by total weight of the tissue. Analysis of seminal vesicle weights over time suggests that the changes may be transient. Administration of 1.0 microg/kg TCDD during gestation caused a significant decrease in seminal vesicle weights of offspring 8-11 months of age. We examined the effects of TCDD on seminal vesicles from rats exposed in utero and lactationally. Pregnant Long Evans rats were gavaged on gestation day 15 with 1.0 microg/kg TCDD in corn oil. Male pups were euthanized and necropsied on postnatal days (PND) 15, 25, 32, 49, 63, and 120. Seminal vesicles were weighed and then fixed in 10% neutral buffered formalin and processed for microscopic examination. Seminal vesicle weights were not significantly decreased until PND 32. Androgen receptor mRNA expression in PND 25 seminal vesicles was not different from control. In the present study, TCDD exposure decreased seminal vesicle epithelial branching and differentiation. Control epithelial cells had tall columnar morphology with relatively abundant cytoplasm, whereas TCDD-treated cells had rounded nuclei and less cytoplasm. In addition, immunolocalization of proliferating nuclear antigen was confined to undifferentiated basal epithelial cells of controls but was found in both basal and luminal cells of the treated seminal vesicle. Results indicate that the TCDD-induced impaired growth of the rat seminal vesicles is associated with a dramatic decrease in the development of the epithelium.

  11. Comparative toxicity of 2,3,7,8-tetrachlorodibenzo-p-dioxin to seven freshwater fish species during early life-stage development

    SciTech Connect

    Elonen, G.E.; Spehar, R.L.; Holcombe, G.W.; Johnson, R.D.; Fernandez, J.D.; Erickson, R.J.; Tietge, J.E.; Cook, P.M.

    1998-03-01

    The toxic effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to fathead minnow (Pimephales promelas), channel catfish (Ictalurus punctatus), lake herring (Coregonus artedii), medaka (Oryzias latipes), white sucker (Catastomus commersoni), northern pike (Esox lucius), and zebrafish (Danio danio) were observed during early life-stage development after waterborne exposure of fertilized eggs. Species sensitivity based on TCDD-C{sub egg} (TCDD concentration in eggs) was determined by effects observed over a 32-d period for all species except lake herring in which a 100-d period was used. Signs of TCDD toxicity, including edema, hemorrhaging, and craniofacial malformations were essentially identical to those observed in salmonids following TCDD egg exposure and preceded or accompanied mortality most often during the period from hatch through swim-up. The no-observed-effect concentrations and lowest-observed-effect concentrations, based on significant decreases in survival and growth as compared to the controls, ranged from 175 and 270 pg/g for lake herring to 424 and 2,000 pg/g for zebrafish, respectively. Shapes of concentration-response curves, expressed as TCDD-C{sub egg} versus percent mortality, were similar for all species and were consistently steep suggesting that the mechanism of action of TCDD is the same among these species. The LC{sub egg}50s ranged from 539 pg/g for the fathead minnow to 2,610 pg/g for zebrafish. Comparisons of LC{sub egg}50s indicate that the tested species were approximately 8 to 38 times less sensitive to TCDD than lake trout, the most sensitive species evaluated to date. When LC{sub egg}50s are normalized to the fraction lipid in eggs (LC{sub egg,f}50s), the risk to early life stage survival for the species tested ranges from 16- to 180-fold less than for lake trout.

  12. Attenuation of 2,3,7,8-tetrachlorodibenzo-p-dioxin toxicity by resveratrol: a comparative study with different routes of administration.

    PubMed

    Ishida, Takumi; Takeda, Tomoki; Koga, Takayuki; Yahata, Masahiro; Ike, Ayako; Kuramoto, Chihiro; Taketoh, Junko; Hashiguchi, Isamu; Akamine, Akifumi; Ishii, Yuji; Yamada, Hideyuki

    2009-05-01

    The activation of aryl hydrocarbon receptor with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is known to be antagonized by co-treatment with resveratrol. However, such a protective effect has been suggested from studies using subcutaneous injection of this polyphenol. To evaluate the practical usefulness of resveratrol, this study examined the protective effect of oral resveratrol on the sub-acute toxic effects of TCDD in C57BL/6J mice. A TCDD-induced wasting syndrome was not alleviated by treating mice for 28 d with oral resveratrol. However, subcutaneous injection of resveratrol for 5 d significantly improved the symptoms. Neither oral nor subcutaneous administration of resveratrol alleviated TCDD-induced hepatomegaly and thymic atrophy. Steatosis produced by TCDD was markedly counteracted by co-treatment with oral resveratrol, whereas resveratrol injected subcutaneously had no effect. The reason for the lack of protective effect via the latter dosing route was assumed to be due to the minor accumulation of hepatic lipids 5 d after TCDD treatment. To clarify the mechanisms, the activity of ethoxyresorufin O-deethylase and the content of thiobarbituric acid-reactive substances in the liver were measured. Both indices increased by TCDD treatment were significantly suppressed by subcutaneous injection of resveratrol. In contrast, oral resveratrol failed to rescue them. In agreement with the greater protective effects of subcutaneously-injected resveratrol, pharmacokinetic studies indicated that the area under the curve extrapolated to infinity (AUC(infinity)) was 8.2-times greater following subcutaneous injection compared with oral administration. These data suggest that 1) oral resveratrol is attractive candidate as an agent capable of combating dioxin toxicity and 2) increasing the bioavailability of this polyphenol enhances its protective effect.

  13. Evaluation of essential trace and toxic elements in biological samples of normal and night blindness children of age groups 3-7 and 8-12 years.

    PubMed

    Afridi, Hassan Imran; Kazi, Tasneem Gul; Kazi, Naveed; Kandhro, Ghulam Abbas; Baig, Jameel Ahmed; Shah, Abdul Qadir; Wadhwa, Sham Kumar; Khan, Sumaira; Kolachi, Nida Fatima; Shah, Faheem; Jamali, Mohammad Khan; Arain, Mohammad Balal; Sirajuddin

    2011-10-01

    The most common cause of blindness in developing countries is vitamin A deficiency. The World Health Organization estimates 13.8 million children to have some degree of visual loss related to vitamin A deficiency. The causes of night blindness in children are multifactorial, and particular consideration has been given to childhood nutritional deficiency, which is the most common problem found in underdeveloped countries. Such deficiency can result in physiological and pathological processes that in turn influence biological samples composition. Vitamin and mineral deficiency prevents more than two billion people from achieving their full intellectual and physical potential. This study was designed to compare the levels of Zn, Mg, Ca, K, Na, As, Cd, and Pb in scalp hair, blood, and urine of night blindness children age ranged 3-7 and 8-12 years of both genders, comparing them to sex- and age-matched controls. A microwave-assisted wet acid digestion procedure was developed as a sample pretreatment, for the determination of As, Ca, Cd, K, Pb, Mg, Na, and Zn in biological samples of night blindness children. The proposed method was validated by using conventional wet digestion and certified reference samples of hair, blood, and urine. The concentrations of trace and toxic elements were measured by atomic absorption spectrophotometer prior to microwave-assisted acid digestion. The results of this study showed that the mean values of As, Cd, Na, and Pb were significantly higher in scalp hair, blood, and urine samples of male and female night blindness children than in referents (p < 0.001), whereas the concentrations of Zn, Ca, K, and Mg were lower in the scalp hair and blood but higher in the urine samples of night blindness children. These data present guidance to clinicians and other professional investigating deficiency of essential mineral elements in biological samples (scalp hair and blood) of night blindness children.

  14. Lead-free 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 nanowires for energy harvesting.

    PubMed

    Zhou, Zhi; Bowland, Christopher C; Malakooti, Mohammad H; Tang, Haixiong; Sodano, Henry A

    2016-03-07

    Lead-free piezoelectric nanowires (NWs) show strong potential in sensing and energy harvesting applications due to their flexibility and ability to convert mechanical energy to electric energy. Currently, most lead-free piezoelectric NWs are produced through low yield synthesis methods and result in low electromechanical coupling, which limit their efficiency as energy harvesters. In order to alleviate these issues, a scalable method is developed to synthesize perovskite type 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 (BZT-BCT) NWs with high piezoelectric coupling coefficient. The piezoelectric coupling coefficient of the BZT-BCT NWs is measured by a refined piezoresponse force microscopy (PFM) testing method and shows the highest reported coupling coefficient for lead-free piezoelectric nanowires of 90 ± 5 pm V(-1). Flexible nanocomposites utilizing dispersed BZT-BCT NWs are fabricated to demonstrate an energy harvesting application with an open circuit voltage of up to 6.25 V and a power density of up to 2.25 μW cm(-3). The high electromechanical coupling coefficient and high power density demonstrated with these lead-free NWs produced via a scalable synthesis method shows the potential for high performance NW-based devices.

  15. Lead-free 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 nanowires for energy harvesting

    NASA Astrophysics Data System (ADS)

    Zhou, Zhi; Bowland, Christopher C.; Malakooti, Mohammad H.; Tang, Haixiong; Sodano, Henry A.

    2016-02-01

    Lead-free piezoelectric nanowires (NWs) show strong potential in sensing and energy harvesting applications due to their flexibility and ability to convert mechanical energy to electric energy. Currently, most lead-free piezoelectric NWs are produced through low yield synthesis methods and result in low electromechanical coupling, which limit their efficiency as energy harvesters. In order to alleviate these issues, a scalable method is developed to synthesize perovskite type 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 (BZT-BCT) NWs with high piezoelectric coupling coefficient. The piezoelectric coupling coefficient of the BZT-BCT NWs is measured by a refined piezoresponse force microscopy (PFM) testing method and shows the highest reported coupling coefficient for lead-free piezoelectric nanowires of 90 +/- 5 pm V-1. Flexible nanocomposites utilizing dispersed BZT-BCT NWs are fabricated to demonstrate an energy harvesting application with an open circuit voltage of up to 6.25 V and a power density of up to 2.25 μW cm-3. The high electromechanical coupling coefficient and high power density demonstrated with these lead-free NWs produced via a scalable synthesis method shows the potential for high performance NW-based devices.

  16. DFT studies on a high-energy density cage compound 1, 3, 5, 7, 9, 11-hexo(N(CH3)NO2)-2, 4, 6, 8, 10, 12-hexaazatetracyclo[5, 5, 0, 0, 0] dodecane

    NASA Astrophysics Data System (ADS)

    Li, Xiao-Hong; Yong, Yong-Liang; Zhang, Xian-Zhou

    2014-04-01

    The infrared and Raman spectra, heat of formation (HOF) and thermodynamic properties were investigated by B3LYP/6-31G** method for a new designed polynitro cage compound 1,3,5,7,9,11-hexo(N(CH3)NO2)-2,4,6,8,10,12-hexaazatetracyclo[5,5,0,0,0]dodecane. The detonation velocity (D) and pressure (P) were predicted by the Kamlet-Jacobs equations based on the theoretical density and condensed HOF. The bond dissociation energies and bond orders for the weakest bonds were analysed to investigate the thermal stability of the title compound. The computational result shows that the detonation velocity and pressure of the title compound are superior to those of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), but inferior to those of 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX) and hexanitrohexaazaisowurtzitane (HNIW). And the analysis of thermal stability shows that the first step of pyrolysis is the rupture of the N7-NO2 bond. The crystal structure obtained by molecular mechanics belongs to the P21 space group, with the lattice parameters Z = 2, a = 11.8246 Å, b = 10.4632 Å, c = 15.9713 Å, ρ = 1.98 g cm-3.

  17. 2,3,7,8-tetrachlorodibenzo-p-dioxin decrease expression of aryl hydrocarbon receptor in peripheral lymphocyte of β-thalassemia major patients

    PubMed Central

    Ghatrehsamani, Mahdi; Soleimani, Masoud; Esfahani, Behjat Al-Sadat Moayedi; Hakemi, Mazdak Ganjalikhani; Shirzad, Hedayatollah; Eskandari, Nahid; Adib, Minoo

    2015-01-01

    Background: β-thalassemia major is a hereditary disease with inefficient erythropoiesis. Level of inflammatory cytokine is elevated in these patients. In this study, we investigate the effect of aryl hydrocarbon receptor (AhR) ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), on the expression of inflammatory mediators in β-thalassemia major patient's lymphocytes. Materials and Methods: Peripheral blood mononuclear cells of patients and healthy participants was isolated and cultured in favor of lymphocytes increment. Based on the treatment, we divided the cell into four groups. The orders of group's treatments were no treatment, tumor necrosis factor-α (TNF-α) treatment, TNF-α and TCDD treatment, TCDD treatment in Group 1–4, respectively. After cell culture, we extracted the cells RNA and converted them to cDNA. Real-time polymerase chain reaction was performed to assessment relative expression of caspase-1, NLRP3, and AhR. We compared all patient groups with equal healthy (control) groups. Results: Results showed that expression of caspase-1 in patients (Groups 1 and 2) was significantly lower than healthy individuals (P < 0.05). Although, no significant difference was found (Groups 1, 2, and control) in AhR gene expression (P > 0.05). Expression of AhR in other groups of patients (3 and 4) was significantly lower than control groups (P < 0.05). Expression of caspase-1 in Group 4 was significantly larger than the control group (P < 0.001). Conclusions: We show here that chronic inflammation decrease caspase-1 expression and exposure of human lymphocytes to TCDD promote caspase-1 expression. Furthermore, activation of AhR with TCDD decreases AhR expression in lymphocytes of β-thalassemia major disease. PMID:26605247

  18. In utero and lactational 2,3,7,8-tetrachlorodibenzo-p-dioxin exposure: effects on fetal and adult cardiac gene expression and adult cardiac and renal morphology.

    PubMed

    Aragon, Andrea C; Kopf, Phillip G; Campen, Matthew J; Huwe, Janice K; Walker, Mary K

    2008-02-01

    The mouse heart is a target of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) during fetal development, and microarray analysis demonstrates significant changes in expression of cardiac genes involved in extracellular matrix (ECM) remodeling. We tested the hypothesis that developmental TCDD exposure would disrupt cardiac ECM expression and be associated with changes in cardiac morphology in adulthood. In one study, time-pregnant C57BL/6 mice were dosed with corn oil or 1.5, 3.0, or 6.0 microg TCDD/kg on gestation day (GD) 14.5 and sacrificed on GD 17.5, when changes in fetal cardiac mRNA expression were analyzed using quantitative PCR. TCDD induced mRNA expression of genes associated with ECM remodeling (matrix metalloproteinase 9 and 13, preproendothelin-1 [preproET-1]), cardiac hypertrophy (atrial natriuretic peptide, beta-myosin heavy chain, osteopontin), and aryl hydrocarbon receptor (AHR) activation (cytochrome P4501A1, AHR repressor). Further, all TCDD-induced changes required the AHR since gene expression was not altered in AHR knockout fetuses. In a second study, time-pregnant mice were treated with corn oil or 6.0 microg TCDD/kg on GD 14.5, and male offspring were assessed for changes in cardiac gene expression and cardiac and renal morphology at 3 months. All TCDD-induced changes in cardiac gene expression observed fetally, except for preproET-1, remained induced in the hearts of adult male offspring. Adult male offspring of TCDD-exposed dams also displayed cardiac hypertrophy, decreased plasma volume, and mild hydronephrosis. These results demonstrate that in utero and lactational TCDD exposures alter cardiac gene expression and cardiac and renal morphology in adulthood, which may increase the susceptibility to cardiovascular dysfunction.

  19. Polychlorinated biphenyls and 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents in tree swallows from the upper Hudson River, New York State, USA

    USGS Publications Warehouse

    Secord, A.L.; McCarty, J.P.; Echols, K.R.; Meadows, J.C.; Gale, R.W.; Tillitt, D.E.

    1999-01-01

    The upper Hudson River of New York State, USA, is contaminated with polychlorinated biphenyls (PCBs) as a result of industrial discharges throughout the latter half of this century. In 1994 and 1995, we monitored the transfer of PCBs from aquatic sediments to a terrestrial wildlife community using the tree swallow (Tachycineta bicolor) as a model organism. Tree swallow eggs and nestlings were collected at four colonies established along a 40-km stretch of the upper Hudson River watershed. Samples were analyzed for total PCBs and PCB congeners, including non-ortho- and mono- ortho-substituted PCBs. Mean concentrations of PCBs in tree swallow eggs and nestlings ranged from 721 to 62,200 ng/g and were as much as 15 times greater than PCB concentrations in tree swallow eggs and nestlings collected from PCB-contaminated areas within the Great Lakes ecosystem. The corresponding 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQs) calculated using avian toxic equivalency factors ranged from 410 to 25,400 pg/g. Concentrations of PCB congener 77 (3,3',4,4'-tetrachlorobiphenyl) were extremely elevated and were major contributors to the calculated TEQs. Homologue pattern comparisons between Hudson River and Saginaw River (Michigan, USA) ecosystems supported the hypothesis that a consistent Hudson River PCB source was the major contributor to PCBs in Hudson River tree swallows. The high concentrations of PCBs in Hudson River sediments and resultant concentrations observed in tree swallows were indicative of a potential elevated risk to these and other wildlife linked to the aquatic food web of the Hudson River ecosystem.

  20. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) plasma concentrations in residents of Paritutu, New Zealand: evidence of historical exposure.

    PubMed

    Fowles, J; Noonan, M; Stevenson, C; Baker, V; Gallagher, L; Read, D; Phillips, D

    2009-05-01

    An assessment of community exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) was undertaken in Paritutu, New Zealand. The suburb lies adjacent to an agrichemical facility that produced 2,4,5-trichlorophenoxyacetic acid (2,4,5-T), between 1962 and 1987. Soil TCDD measurements from 73 nearby addresses demonstrated a pattern of TCDD deposition consistent with an aerial plume following the prevailing local wind patterns and the agrichemical plant as the point source. Blood samples were taken from 52 volunteers having lived for three or more years in Paritutu between 1962 and 1987. Candidate selection focused primarily on individuals who were most likely to show elevated TCDD blood lipid levels when compared to age and gender stratified national average blood concentrations, and secondarily on individuals that provided additional information about specific exposure periods, potential exposures of younger age groups, and specific dietary patterns. A multipathway exposure model was used to estimate serum TCDD levels in each participant. Age and gender-specific TCDD elimination kinetics were also considered. Historical TCDD environmental concentrations were back-calculated from soil concentrations at each residence assuming TCDD releases occurred pre-dominantly between 1962 and 1975. Serum was analysed for chlorinated dibenzodioxins and dibenzofurans, and a subset was analysed for dioxin-like polychlorinated biphenyls. TCDD in serum lipid exceeded two standard deviations above national background levels for 14 participants, and 3 standard deviations for 10 participants. The highest TCDD lipid concentration was 33.3 ng/kg-lipid, or 11 times higher than the comparative 1997 national average. Elevated TCDD concentrations were observed primarily, but not exclusively, in the older study participants who had been in residence in Paritutu before 1968. The study demonstrated TCDD exposure in this community, occurring most likely through the aerial route, and most probably