Science.gov

Sample records for 3-h laboratory period

  1. Cometary implications of recent laboratory experiments on the photochemistry of the C2H and C3H2 radicals

    NASA Technical Reports Server (NTRS)

    Jackson, William M.; Bao, Yihan; Urdahl, Randall S.; Song, Xueyu; Gosine, Jai; Lu, Chi

    1992-01-01

    Recent laboratory results on the photodissociation of the C2H and C3H2 radicals are described. These studies show that the C2 and C3 radicals are produced by the 193 nm photolysis of the C2H and C3H2 radicals, respectively. The quantum state distributions that were determined for the C2 radicals put certain constraints on the initial conditions for any models of the observed C2 cometary spectra. Experimental observations of C2 formed by the 212.8 nm photolysis of C2H are used to calculate a range of photochemical lifetimes for the C2H radical.

  2. LABORATORY GAS-PHASE DETECTION OF THE CYCLOPROPENYL CATION (c-C{sub 3}H{sub 3} {sup +})

    SciTech Connect

    Zhao, Dongfeng; Doney, Kirstin D.; Linnartz, Harold

    2014-08-20

    The cyclopropenyl cation (c-C{sub 3}H{sub 3} {sup +}) is the smallest aromatic hydrocarbon molecule and considered to be a pivotal intermediate in ion-molecule reactions in space. An astronomical identification has been prohibited so far, because of a lack of gas-phase data. Here we report the first high resolution infrared laboratory gas-phase spectrum of the ν {sub 4} (C-H asymmetric stretching) fundamental band of c-C{sub 3}H{sub 3} {sup +}. The c-C{sub 3}H{sub 3} {sup +} cations are generated in supersonically expanding planar plasma by discharging a propyne/helium gas pulse, yielding a rotational temperature of ∼35 K. The absorption spectrum is recorded in the 3.19 μm region using sensitive continuous-wave cavity ring-down spectroscopy. The analysis of about 130 ro-vibrational transitions results in precise spectroscopic parameters. These constants allow for an accurate comparison with high-level theoretical predictions, and provide the relevant information needed to search for this astrochemically relevant carbo-cation in space.

  3. 3H And 90Sr In Urine Radiobioassay Intercomparison Results From The Intercomparison Studies Program At Oak Ridge National Laboratory: Statistical Analysis Of Laboratory Performance

    SciTech Connect

    Bores, Norman; Schultz, Michael K

    2009-01-01

    The Intercomparison Studies Program (ISP) at the Oak Ridge National Laboratory (ORNL, Oak Ridge, TN USA) provides natural-matrix human urine quality-assurance/quality-control (QA/QC) samples to radiobioassay analysis laboratories. Samples are provided to these laboratories as 'single-blind' or 'double-blind' unknowns, spiked with radioactive-solution standards at 'low' levels (e.g., 0.7-7 Bq g{sup -1} for {sup 3}H and 0.7-7 Bq kg{sup -1} for {sup 90}Sr). Participants use the results as a tool for self-evaluation and a measure of performance. In this paper, sample preparation and the results of testing during the years 2001-2005 for {sup 3}H and {sup 90}Sr are presented and discussed.

  4. 2011 Mars Science Laboratory Launch Period Design

    NASA Technical Reports Server (NTRS)

    Abilleira, Fernando

    2011-01-01

    The Mars Science Laboratory mission, set to launch in the fall of 2011, has the primary objective of landing the most advanced rover to date to the surface of Mars to assess whether Mars ever was, or still is today, able to sustain carbon-based life. Arriving at Mars in August 2012, the Mars Science Laboratory will also demonstrate the ability to deliver large payloads to the surface of Mars, land more accurately (than previous missions) in a 20-km by 25-km ellipse, and traverse up to 20 km. Following guided entry and parachute deployment, the spacecraft will descend on a parachute and a Powered Descent Vehicle to safely land the rover on the surface of Mars. The launch/arrival strategy is driven by several key requirements, which include: launch vehicle capability, atmosphere-relative entry speed, communications coverage during Entry, Descent and Landing, latitude accessibility, and dust storm season avoidance. Notable among these requirements is maintaining a telecommunications link from atmospheric entry to landing plus one minute, via a Direct-To-Earth X-band link and via orbital assets using an UHF link, to ensure that any failure during Entry, Descent and Landing can be reconstructed in case of a mission anomaly. Due to concerns related to the lifetime of the relay orbiters, two additional launch/arrival strategies have been developed to improve Entry, Descent, and Landing communications. This paper discusses the final launch/arrival strategy selected prior to the launch period down-selection that is scheduled to occur in August 2011. It is also important to note that this paper is an update to Ref. 1 in that it includes two new Type 1 launch periods and drops the Type 2 launch period that is no longer considered.

  5. LABORATORY ROTATIONAL SPECTRUM OF l-C{sub 3}H{sup +} AND CONFIRMATION OF ITS ASTRONOMICAL DETECTION

    SciTech Connect

    Brünken, Sandra; Kluge, Lars; Stoffels, Alexander; Asvany, Oskar; Schlemmer, Stephan

    2014-03-01

    The rotational spectrum of l-C{sub 3}H{sup +} has been measured in the millimeter-wave band in a 4 K cryogenic ion trap apparatus employing a novel mass-selective action spectroscopy method based on light induced reactions (LIR). Line positions of four rotational transitions (J = 1-2 up to J = 4-5) were observed with a relative precision of 3 × 10{sup –7}. The experimental transition frequencies and derived spectroscopic constants agree with those from recent astronomical observations, and unambiguously confirm the detection of this astrochemically relevant carbocation in the Horsehead photodissociation region and toward Sgr B2(N)

  6. a Laboratory Search for the Carrier of U-Lines Attributed to l-C_3H^+ in the Horsehead Nebula PDR

    NASA Astrophysics Data System (ADS)

    McCarthy, Michael C.; Crabtree, Kyle N.; Martinez, Oscar, Jr.

    2013-06-01

    Recent radio observations of the Horsehead nebula PDR in the millimeter-wave band by Pety et al. detected a series of unidentified lines which have been attributed to l-C_3H^+, a molecular cation for which no high-resolution laboratory data presently exist. We have detected a pair of rotational lines in the centimeter-wave band at frequencies predicted from their derived spectroscopic constants using Fourier transform microwave and microwave-microwave double resonance spectroscopies. Experimental evidence strongly suggests that the laboratory and astronomical lines arise from a common carrier, and that the carrier is a closed-shell, reactive hydrocarbon containing a linear or nearly-linear three carbon atom backbone. Pety et al. Astron. & Astrophys. 548, A68 (2012).

  7. Effects of Withdrawal from Chronic Intermittent Ethanol Vapor on the Level and Circadian Periodicity of Running-Wheel Activity in C57BL/6J and C3H/HeJ Mice

    PubMed Central

    Logan, Ryan W.; McCulley, Walter D.; Seggio, Joseph A.; Rosenwasser, Alan M.

    2011-01-01

    Background Alcohol withdrawal is associated with behavioral and chronobiological disturbances that may persist during protracted abstinence. We previously reported that C57BL/6J (B6) mice show marked but temporary reductions in running-wheel activity, and normal free-running circadian rhythms, following a 4-day chronic intermittent ethanol vapor (CIE) exposure (16 hours of ethanol vapor exposure alternating with 8 hours of withdrawal). In the present experiments, we extend these observations in two ways: (1) by examining post-CIE locomotor activity in C3H/HeJ (C3H) mice, an inbred strain characterized by high sensitivity to ethanol withdrawal, and (2) by directly comparing the responses of B6 and C3H mice to a longer-duration CIE protocol. Methods In Experiment 1, C3H mice were exposed to the same 4-day CIE protocol used in our previous study with B6 mice (referred to here as the 1-cycle CIE protocol). In Experiment 2, C3H and B6 mice were exposed to three successive 4-day CIE cycles, each separated by 2 days of withdrawal (the 3-cycle CIE protocol). Running-wheel activity was monitored prior to and following CIE, and post-CIE activity was recorded in constant darkness to allow assessment of free-running circadian period and phase. Results C3H mice displayed pronounced reductions in running-wheel activity that persisted for the duration of the recording period (up to 30 days) following both 1-cycle (Experiment 1) and 3-cycle (Experiment 2) CIE protocols. In contrast, B6 mice showed reductions in locomotor activity that persisted for about one week following the 3-cycle CIE protocol, similar to the results of our previous study using a 1-cycle protocol in this strain. Additionally, C3H mice showed significant shortening of free-running period following the 3-cycle, but not the 1-cycle, CIE protocol, while B6 mice showed normal free-running rhythms. Conclusions These results reveal genetic differences in the persistence of ethanol withdrawal-induced hypo

  8. The thermal behaviour and structural stability of nesquehonite, MgCO3.3H2O, evaluated by in situ laboratory parallel-beam X-ray powder diffraction: New constraints on CO2 sequestration within minerals.

    PubMed

    Ballirano, Paolo; De Vito, Caterina; Ferrini, Vincenzo; Mignardi, Silvano

    2010-06-15

    In order to gauge the appropriateness of CO(2) reaction with Mg chloride solutions as a process for storing carbon dioxide, the thermal behaviour and structural stability of its solid product, nesquehonite (MgCO(3).3H(2)O), were investigated in situ using real-time laboratory parallel-beam X-ray powder diffraction. The results suggest that the nesquehonite structure remains substantially unaffected up to 373 K, with the exception of a markedly anisotropic thermal expansion acting mainly along the c axis. In the 371-390 K range, the loss of one water molecule results in the nucleation of a phase of probable composition MgCO(3).2H(2)O, which is characterized by significant structural disorder. At higher temperatures (423-483 K), both magnesite and MgO.2MgCO(3) coexist. Finally, at 603 K, periclase nucleation starts and the disappearance of carbonate phases is completed at 683 K. Consequently, the structural stability of nesquehonite at high temperatures suggests that it will remain stable under the temperature conditions that prevail at the Earth's surface. These results will help (a) to set constraints on the temperature conditions under which nesquehonite may be safely stored and (b) to develop CO(2) sequestration via the synthesis of nesquehonite for industrial application. PMID:20167421

  9. New Brunswick Laboratory progress report for the period October 1988--September 1989

    SciTech Connect

    Not Available

    1990-04-01

    The mission of the New Brunswick Laboratory (NBL) of the US Department of Energy (DOE) is to provide and maintain a nuclear material measurements and standards laboratory as a technical response to DOE's statutory responsibility to assure the safeguarding of nuclear materials. This report summarizes the mission-fulfilling activities of NBL for the period October 1988 through September 1989.

  10. 3H-Penciclovir (3H-PCV) Uptake Assay

    PubMed Central

    Sekar, Thillai V; Paulmurugan, Ramasamy

    2016-01-01

    Thymidine Kinase from human Herpes simplex virus type 1 (HSV1-TK) in combination with specific substrate prodrug nucleotide analogue ganciclovir (GCV) has been widely used as suicidal therapeutic gene for cancer gene therapy. HSV1, and its mutant (HSV1-sr39TK) with improved substrate specificity, were used as reporter genes for PET-imaging of various biological functions in small animals, by combining with radiolabeled substrates such as 18F-FHBG and 124I-FIAU. 3H-Penciclovir (PCV) uptake assay is a method of choice used to determine the expression level of HSV1-TK in mammalian cells and tissues. HSV1-TK phosphorylate PCV and result in the formation of penciclovir monophosphate, and its subsequent phopsphorylation by cellular TK lead to the formation of penciclovir triphosphate, which is trapped selectively in cells expressing HSV-TK. 3H-Penciclovir enables the detection of penciclovir uptake of mammalian cells and tissues by radioactive procedures such as scintillation counting. Here we describe the protocol to carry out 3H-Penciclovir uptakes in mammalian cells.

  11. Connecting Solubility, Equilibrium, and Periodicity in a Green, Inquiry Experiment for the General Chemistry Laboratory

    ERIC Educational Resources Information Center

    Cacciatore, Kristen L.; Amado, Jose; Evans, Jason J.; Sevian, Hannah

    2008-01-01

    We present a novel first-year chemistry laboratory experiment that connects solubility, equilibrium, and chemical periodicity concepts. It employs a unique format that asks students to replicate experiments described in different sample lab reports, each lacking some essential information, rather than follow a scripted procedure. This structure is…

  12. An Activation Energy Experiment for a Second-Order Reaction in a Single Laboratory Period.

    ERIC Educational Resources Information Center

    Barile, Raymond C.; Michiels, Leo P.

    1983-01-01

    Describes modification of a chemical reaction to a single 4 1/2-hour laboratory period. Reaction kinetics between 2, 4-initrochlorobenzene and piperidine to form 2, 4-dinitrophenyl-piperidine and piperidinium hydrochloride are followed conductometrically at three temperatures to obtain data to calculate activation parameters. (Author/JN)

  13. Laboratory Tests Ordered By a Chiropractic Sports Physician on Elite Athletes Over a 1-Year Period

    PubMed Central

    Nabhan, Dustin C.; Moreau, William J.; Barylski, Chad

    2015-01-01

    Objective The purpose of this study is to describe and discuss laboratory tests ordered on elite athletes in an interdisciplinary sports medicine clinic by a doctor of chiropractic over 1 calendar year. Methods A retrospective review of laboratory tests ordered during routine clinical practice as standard screening and diagnostic tests from November 1, 2009, to November 1, 2010 was performed. Data were collected during clinical encounters at one sports medicine clinic and entered into a database for analysis. Descriptive and frequency statistics were used to describe the tests ordered and the frequency of abnormal findings. Results Five hundred and thirty-nine studies were ordered for diagnostic and routine screenings on 137 athlete patients (86 males, 51 females), representing 49 types of tests. Sample sources included blood, urine, skin lesions, and fecal matter. The most commonly ordered tests were complete blood count, comprehensive metabolic panel, serum ferritin, creatine kinase, serum iron and total iron binding capacity, total cortisol, thyroid stimulating hormone, and lipid panels. There were 217 studies (40%) flagged as abnormal by the reporting laboratory. Conclusion This report provides greater insight into the diverse array of laboratory studies ordered over a 1-year period for diagnosis and screening of elite athletes. A high percentage of the results were flagged as abnormal by the laboratory. These findings show that the unique physiology of the elite athlete must be considered when interpreting laboratory findings in this population. PMID:26257590

  14. Results of Laboratory and Industrial Tests of Periodic-Type Gas Generators

    NASA Astrophysics Data System (ADS)

    Karp, I. N.; P‧yanykh, K. E.; Antoshchuk, T. A.; Lysenko, A. A.

    2015-05-01

    Results of laboratory and industrial tests of periodic-type gas generators burning various solid biofuels have been presented. The tests were carried out with the aim of obtaining producer gas which could totally or partly replace natural gas in power equipment burning gaseous fuel. The energy and environmental characteristics of a boiler unit burning a mixture of producer gas and natural gas have been assessed.

  15. [Periodicity of oviposition of females of Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae) in laboratory and field].

    PubMed

    Gomes, Adriana Dos Santos; de Sá Sciavico, Célia J; Eiras, Alvaro Eduardo

    2006-01-01

    The object of this work was to determine of gonotrophic diel pattern of female Aedes aegypti in laboratory and field conditions. Three day-old female mosquitoes were the fed on chicken blood and transferred to bioassay cages. Four oviposition substrates were offered: paper sulfite, filter, butter and towel. The results showed that filter paper received a significantly higher (40.4%) percentage of deposited eggs than the other oviposition substrates. After their first blood meal, females started to oviposit on the 3rd model day; 35.7% of the total number of eggs deposited. The oviposition diel patterns of females were observed every two hours during the photoperiod in the laboratory and in the field. In the laboratory, the periodicity of oviposition showed that the highest egg deposition occurred during the 9th- 12th h of photophase and 1st - 2nd h of scotophase. In the field, the highest egg deposition occurred during the 9th - 12th h of photophase and 1st - 4th h of scotophase. These results point out that Aedes aegypti showed an oviposition periodicity pattern that can subsidize monitoring and or control of vector insect. itis suggested that ovitraps should be placed in the field during the morning hours since the captures occur during afternoon. PMID:17119745

  16. Adapting non-library facilities for periodical collections at Brookhaven National Laboratory

    SciTech Connect

    Ryan, K.; Galli, M.

    1983-01-01

    In order to cope with space limitations and rapidly growing periodical collections, Brookhaven National Laboratory Research Library undertook to investigate the use of various recycled non-library facilities to be used as a library annex. Several interim solutions are discussed and details of a low-cost use of industrial shelving in a former chapel/theatre are given. Advisory support from plant engineers and architects, as well as from a library user advisory committee, was shown to be essential in arriving at a viable and cost-effective solution to a serious space problem.

  17. Imperfection works: Survival, transmission and persistence in the system of Heliothis virescens ascovirus 3h (HvAV-3h), Microplitis similis and Spodoptera exigua

    PubMed Central

    Li, Shun-Ji; Hopkins, Richard J.; Zhao, Yi-Pei; Zhang, Yun-Xuan; Hu, Jue; Chen, Xu-Yang; Xu, Zhi; Huang, Guo-Hua

    2016-01-01

    Ascoviruses are insect-specific large DNA viruses that mainly infect noctuid larvae, and are transmitted by parasitoids in the fields. Heliothis virescens ascovirus 3h (HvAV-3h) has been recently isolated from Spodoptera exigua, without parasitoid vector identified previously. Here we report that Microplitis similis, a solitary endoparasitoid wasp, could transmit HvAV-3h between S. exigua larvae in the laboratory. When the female parasitoid wasp acquired the virus and served as a vector, the period of virion viability on the ovipositor was 4.1 ± 1.4 days. Infected host larvae were still acceptable for egg laying by parasitoids, and the parasitoids thereafter transmitted virus to healthy hosts. Virus acquisition occurred only from donor hosts between 3 and 9 days post infection. The peak of virus acquisition (80.9 ± 6.3%) was found when M. similis wasps oviposited in larvae that had been inoculated with the virus 7 days previously. When virus infection of the host took place during the life cycle of the parasitoid wasp, it caused 1- to 4-day-old immature parasitoids death in the host, whilst a small proportion of 5- to 6-day-old and the majority of 7-day-old parasitoids larvae survived from the virus-infected hosts. Viral contamination did not reduce the life span or fecundity of female M. similis. PMID:26878829

  18. Imperfection works: Survival, transmission and persistence in the system of Heliothis virescens ascovirus 3h (HvAV-3h), Microplitis similis and Spodoptera exigua.

    PubMed

    Li, Shun-Ji; Hopkins, Richard J; Zhao, Yi-Pei; Zhang, Yun-Xuan; Hu, Jue; Chen, Xu-Yang; Xu, Zhi; Huang, Guo-Hua

    2016-01-01

    Ascoviruses are insect-specific large DNA viruses that mainly infect noctuid larvae, and are transmitted by parasitoids in the fields. Heliothis virescens ascovirus 3h (HvAV-3h) has been recently isolated from Spodoptera exigua, without parasitoid vector identified previously. Here we report that Microplitis similis, a solitary endoparasitoid wasp, could transmit HvAV-3h between S. exigua larvae in the laboratory. When the female parasitoid wasp acquired the virus and served as a vector, the period of virion viability on the ovipositor was 4.1 ± 1.4 days. Infected host larvae were still acceptable for egg laying by parasitoids, and the parasitoids thereafter transmitted virus to healthy hosts. Virus acquisition occurred only from donor hosts between 3 and 9 days post infection. The peak of virus acquisition (80.9 ± 6.3%) was found when M. similis wasps oviposited in larvae that had been inoculated with the virus 7 days previously. When virus infection of the host took place during the life cycle of the parasitoid wasp, it caused 1- to 4-day-old immature parasitoids death in the host, whilst a small proportion of 5- to 6-day-old and the majority of 7-day-old parasitoids larvae survived from the virus-infected hosts. Viral contamination did not reduce the life span or fecundity of female M. similis. PMID:26878829

  19. (New Brunswick Laboratory): Progress report for the period October 1985 through September 1986

    SciTech Connect

    Not Available

    1987-03-01

    This report summarizes the mission activities of the New Brunswick Laboratory (NBL) of the US Department of Energy (DOE). NBL's mission is to provide and maintain a nuclear material measurements and standards laboratory as a technical response to DOE's statutory responsibility to assure the safeguarding of nuclear materials.

  20. (New Brunswick Laboratory): Progress report for the period October 1986 through September 1987

    SciTech Connect

    Not Available

    1988-03-01

    This report summarizes the mission activities of the New Brunswick Laboratory (NBL) of the US Department of Energy (DOE). NBL's mission is to provide and maintain a nuclear material measurements and standards laboratory as a technical response to DOE's statutory responsibility to assure the safeguarding of nuclear materials.

  1. SPAWNING PERIODICITY OF THE INLAND SILVERSIDE MENIDIA BERYLLINA (PISCES: ATHERINIDAE) IN THE LABORATORY: RELATIONSHIP TO LUNAR CYCLES

    EPA Science Inventory

    The reproductive periodicity of the inland silverside, Menidia beryllina, was determined in laboratory experiments with two independent populations of fish. hese populations were maintained in a non-tidal environment for 85 days and the daily number of eggs produced was enumerate...

  2. Savannah River Ecology Laboratory. Annual technical progress report of ecological research, period ending July 31, 1994

    SciTech Connect

    Not Available

    1994-07-31

    The Savannah River Ecology Laboratory (SREL) is a research unit of the University of Georgia (UGA) that is managed in conjunction with the University`s Institute of Ecology. The laboratory`s overall mission is to acquire and communicate knowledge of ecological processes and principles. SREL conducts basic and applied ecological research, as well as education and outreach programs, under an M&O contract with the US Department of Energy at the Savannah River Site. Significant accomplishments were made during the year ending July 31, 1994 in the areas of research, education and service. Reviewed in this document are research projects in the following areas: Environmental Operations Support (impacted wetlands, streams, trace organics, radioecology, database synthesis, wild life studies, zooplankton, safety and quality assurance); wood stork foraging and breeding ecology; defence waste processing facility; environmental risk assessment (endangered species, fish, ash basin studies); ecosystem alteration by chemical pollutants; wetlands systems; biodiversity on the SRS; Environmental toxicology; environmental outreach and education; Par Pond drawdown studies in wildlife and fish and metals; theoretical ecology; DOE-SR National Environmental Research Park; wildlife studies. Summaries of educational programs and publications are also give.

  3. Survey of the nob5 mutation in C3H substrains

    PubMed Central

    2015-01-01

    Purpose A no b-wave (nob) electroretinography (ERG) phenotype arose spontaneously in a colony of C3H mice and was named nob5. A mutation was identified in the Gpr179 gene in homozygous nob5 mice. There is a concern that this mutation is also present in additional C3H sublines and may compromise retinal research performed using these lines. In this report, therefore, we provide a phenotype and genotype survey of nob5 in six C3H substrains present at the Jackson Laboratory. Methods Fundus changes were evaluated in the six C3H substrains with image-guided optical coherence tomography (OCT), and retinal function was assessed with ERG. The substrains were genotyped with PCR using appropriate primers for the nob5 mutation. Additionally, the genomic sequences of C3H/HeJ, available from the Jackson Laboratory, and C3H/HeH, available from the Wellcome Trust Sanger Institute, were examined for the Gpr179nob5 mutation. Results Two C3H congenic strains, C3Sn.BLiA-Pde6b+/DnJ and C3A.BLiA-Pde6b+/J, wild-type for Pde6b, used as the sighted control strains and had normal fundi, OCT, and ERG responses. Four C3H strains C3H/HeJ, C3HeB/FeJ, C3H/HeOuJ, and C3H/HeSnJ bearing the Pde6brd1 allele exhibited a grainy fundus appearance, retinal degeneration on OCT, and no rod and cone ERG responses. The nob5 mutation was not observed in the six C3H strains assessed with PCR genotyping. Further, the genomic sequences of C3H/HeJ and C3H/HeH did not contain the nob5 mutation. Conclusions The Gpr179nob5 allele is not present in C3H substrains at the Jackson Laboratory. Therefore, the usefulness of these C3H strains as commonly used models to study the effects of photoreceptor degeneration is not compromised. PMID:26396487

  4. Savannah River Ecology Laboratory: Annual report of ecological research for the period ending July 31, 1987

    SciTech Connect

    Wein, G.R.; West, P.J.

    1987-09-01

    The SREL research programs are especially important to DOE in providing the needed ecological information during a time of increased environmental awareness and constraints on industrial activities. The various activities that affect the environment and the land resources of the SRP point to the need for an overall land management plan that incorporates DOE goals of ecological research as well as industrial production and timber management. At a time of impending discontinuity in the operating contractor for the SRP, there is an even greater need for continuity in the ecological programs on the SRP site. The SRP encompasses a rare combination of thermally and chemically altered environments, as well as a wide variety of natural terrestrial and freshwater ecosystems. SREL has a strong tradition of field-oriented research that emphasizes maximum use of this unique environment. Research facilities include general propose and specialty laboratories, offices and support facilities, greenhouses, ponds for alligators and other reptiles, a rhizotron for studying soil and root relationships, and aviaries. Also available are field laboratories at lake, swamp, and old-field sites, and boats and docks on SRP reservoirs. Such extensive and varied facilities provide support for SREL personnel to pursue diverse research interests. Research highlights during FY 1987 are presented in this Annual Report. Within each research division at SREL, several major studies are summarized. In addition, a listing of all publications during FY 1987 is included.

  5. Savannah River Ecology Laboratory: Annual report of ecological research for the period ending July 31, 1988

    SciTech Connect

    Strojan, C.L.; West, P.J.

    1988-09-01

    This year the laboratory published 104 scientific papers in the peer-reviewed literature; an additional 82 are in press. SREL researchers also make numerous presentations at professional meetings and symposia, and at colleges and universities. SREL research concepts, techniques, and findings are presented to the general public through presentations at local civic and educational organizations and by publishing articles in popular magazines and newspapers. One of the highlights of this year is the construction of an addition to the SREL environmental chemistry laboratory. Located at the HWCTR facility, the 2400 square foot addition will allow SREL researchers to conduct research not easily done here now. Research at SREL is conducted by three primary research divisions: the Division of Biogeochemical Ecology, the Division of Stress and the Division of Wetlands Ecology. The biogeochemical Ecology Division researchers strive to understand the biogeochemical cycling of various contaminants in the environment. The Stress and Wildlife group focuses on the study of natural populations and communities of animals, with special emphasis on the influence of human-caused disturbances. The Wetlands Ecology group focuses on the study of biological community development and the factors that affect this development in natural and disturbed wetlands. Research is addressed by the research staff of each division in an interactive and collaborative manner.

  6. Further study on fallout sup 3 H ingestion in Akita, Japan

    SciTech Connect

    Hisamatsu, S.; Takizawa, Y.; Katsumata, T.; Itoh, M.; Ueno, K.; Sakanoue, M. )

    1989-10-01

    To study fallout {sup 3}H ingestion in Japan, 16 separate food-group samples were collected from Akita City in northern Japan during early summer and late autumn in 1986. Furthermore, total diet samples which are duplicate composite food samples consumed by five or six persons for a period of 1 d were also obtained in Akita City. The {sup 3}H concentration in free water and that in a tissue-bound form were determined separately. Seasonal changes of {sup 3}H concentration in the food samples and the total diet samples were not found clearly. The average {sup 3}H concentration in the free water including tap water was 1.6 Bq L-1. The mean ratio of specific activity of tissue-bound {sup 3}H to that of {sup 3}H in free water was found to be 1.2. The average total {sup 3}H ingestion was estimated to be 4.0 Bq d-1, while the proportion of tissue-bound form {sup 3}H ingestion to total {sup 3}H ingestion was 11%. Cereal was the greatest contributing food group to ingestion of tissue-bound {sup 3}H. These findings were consistent with our previous results for food samples collected in 1985.

  7. Understanding the C3H2 cyclic-to-linear ratio in L1544

    NASA Astrophysics Data System (ADS)

    Sipilä, O.; Spezzano, S.; Caselli, P.

    2016-06-01

    Aims: We aim to understand the high cyclic-to-linear C3H2 ratio (32 ± 4) that has been observed toward L1544. Methods: We combined a gas-grain chemical model with a physical model for L1544 to simulate the column densities of cyclic and linear C3H2 observed toward L1544. The most important reactions for the formation and destruction of both forms of C3H2 were identified, and their relative rate coefficients were varied to find the best match to the observations. Results: We find that the ratio of the rate coefficients of C3H3+ + e- ➝ C3H2 + H for cyclic and linear C3H2 must be ~ 20 to reproduce the observations, depending on the branching ratios assumed for the C3H3+ + e- ➝ C3H + H2 reaction. In current astrochemical networks it is assumed that cyclic and linear C3H2 are formed in a 1:1 ratio in the aforementioned reactions. Laboratory studies and/or theoretical calculations are needed to confirm the results of our chemical modeling, which is based on observational constraints.

  8. Synthesis of [1,2-3H2]cholecalciferol and metabolism of [4-14C,1,2-3H2]- and [4-14C,1-3H]-cholecalciferol in rachitic rats and chicks

    PubMed Central

    Lawson, D. E. M.; Pelc, B.; Bell, P. A.; Wilson, P. W.; Kodicek, E.

    1971-01-01

    [1,2-3H2]Cholecalciferol has been synthesized with a specific radioactivity of 508mCi/mmol by using tristriphenylphosphinerhodium chloride, the homogeneous hydrogen catalyst. With doses of 125ng (5i.u.) of [4-14C,1-3H2]cholecalciferol the tissue distribution in rachitic rats of cholecalciferol and its metabolites (25-hydroxycholecalciferol and peak P material) was similar to that found in chicken with 500ng doses of the double-labelled vitamin. The only exceptions were rat kidney, with a very high concentration of vitamin D, and rat blood, with a higher proportion of peak P material, containing a substance formed from vitamin D with the loss of hydrogen from C-1. Substance P formed from [4-14C,1,2-3H2]cholecalciferol retained 36% of 3H, the amount expected from its distribution between C-1 and C-2, the 3H at C-1 being lost. 25-Hydroxycholecalciferol does not seem to have any specific intracellular localization within the intestine of rachitic chicks. The 3H-deficient substance P was present in the intestine and bone 1h after a dose of vitamin D and 30min after 25-hydroxycholecalciferol. There was very little 25-hydroxycholecalciferol in intestine at any time-interval, but bone and blood continued to take it up over the 8h experimental period. It is suggested that the intestinal 3H-deficient substance P originates from outside this tissue. The polar metabolite found in blood and which has retained its 3H at C-1 is not a precursor of the intestinal 3H-deficient substance P. PMID:4329870

  9. Laboratory study of nitrification, denitrification and anammox processes in membrane bioreactors considering periodic aeration.

    PubMed

    Abbassi, Rouzbeh; Yadav, Asheesh Kumar; Huang, Shan; Jaffé, Peter R

    2014-09-01

    The possibility of using membrane bioreactors (MBRs) in simultaneous nitrification-anammox-denitrification (SNAD) by considering periodic aeration cycles was investigated. Two separate reactors were operated to investigate the effect of different anammox biomass in the presence of nitrifying and denitrifying biomass on the final nitrogen removal efficiency. The results illustrated that the reactor with higher anammox biomass was more robust to oxygen cycling. Around 98% Total Nitrogen (TN) and 83% Total Organic Carbon (TOC) removal efficiencies were observed by applying one hour aeration over a four-hour cycle. Decreasing the aeration time to 30, 15, and 2 min during a four-hour cycle affected the final TN removal efficiencies. However, the effect of decreasing aeration on the TN removal efficiencies in the reactor with higher anammox biomass was much lower compared to the regular reactor. The nitrous oxide (N2O) emission was a function of aeration as well, and was lower in the reactor with higher anammox biomass. The results of q-PCR analysis confirmed the simultaneous co-existence of nitrifiers, anammox, and denitrifiers in both of the reactors. To simulate the TN removal in these reactors as a function of the aeration time, a new model, based on first order reaction kinetics for both denitrification and anammox was developed and yielded a good agreement with the experimental observations. PMID:24814548

  10. Differential binding of /sup 3/H-imipramine and /sup 3/H-mianserin in rat cerebral cortex

    SciTech Connect

    Dumbrille-Ross, A.; Tang, S.W.; Coscina, D.V.

    1981-11-16

    Drug competition profiles, effect of raphe lesion, and sodium dependency of the binding of two antidepressant drugs /sup 3/H-imipramine and /sup 3/H-mianserin to rat cerebral cortex homogenate were compared to examine whether the drugs bound to a common ''antidepressant receptor.'' Of the neurotransmitters tested, only serotonin displaced binding of both /sup 3/H-imipramine and /sup 3/H-mianserin. /sup 3/H-Mianserin binding was potently displaced by serotonin S/sub 2/ antagonists and exhibited a profile similar to that of /sup 3/H-spiperone binding. In the presence of the serotonin S/sub 2/ antagonist spiperone, antihistamines (H/sub 1/) potently displaced /sup 3/H-mianserin binding. /sup 3/H-Imipramine binding was displaced potently by serotonin uptake inhibitors. The order of potency of serotonergic drugs in displacing /sup 3/H-imipramine binding was not similar to their order in displacing /sup 3/H-spiperone or -3H-serotonin binding. Prior midbrain raphe lesions greatly decreased the binding of /sup 3/H-imipramine but did not alter binding of /sup 3/H-mianserin. Binding of /sup 3/H-imipramine but not /sup 3/H-mianserin was sodium dependent. These results show that /sup 3/H-imipramine and /sup 3/H-mianserin bind to different receptors. /sup 3/H-Imipramine binds to a presynaptic serotonin receptor which is probably related to a serotonin uptake recognition site, the binding of which is sodium dependent. /sup 3/H-Mianserin binds to postsynaptic receptors, possibly both serotonin S/sub 2/ and histamine H/sub 1/ receptors, the binding of which is sodium independent.

  11. Methodological issues in the preparation and assay of platelet 3H-imipramine binding.

    PubMed

    Severson, J A; Schneider, L S; Fredrickson, E R

    1990-07-01

    preparation that is commonly used to prepare platelets for 3H-IMI binding resulted in similar binding values when compared to a method that prepares the entire platelet population. The results suggest that some, but not all, variations in laboratory methods used to prepare platelets and assay for platelet 3H-IMI binding may affect clinical studies examining this measure. PMID:1699244

  12. Mechanistic aspects of initiation and promotion in C3H/10T1/2 cells.

    PubMed

    Boreiko, C J

    1985-01-01

    The transformation of C3H/10T1/2 cells can be made to proceed through discrete stages of initiation and promotion. Studies of the effect of cell density upon focus formation in cultures treated with MNNG and TPA suggest that initiation by MNNG is due to a relatively infrequent, irreversible event induced by a single carcinogen treatment. In contrast, promotion appears to be a reversible process requiring multiple treatments with TPA over a protracted period of time. Some evidence suggests that promotion may entail the induction of phenotypic changes which impart a growth advantage to phenotypically unstable "initiated" cell populations. The actual cellular mechanism(s) for most of the phenomena observed in C3H/10T1/2 cultures have eluded precise definition and widely divergent hypotheses have been advanced to explain transformation, initiation, and promotion. Conceivably there are multiple mechanisms responsible for each of these phenomenon. Some agents may transform by a multistage mechanism whereas others may exert their effects in a more direct fashion. Some of the foci produced by promotion may be the result of simple selective processes, others the product of more complex inductive events. Variations would thus be expected between laboratories working with different protocols and agents. As demonstrated by the possible involvement of an MCA residue in transformation, it is also apparent that fundamental technical aspects of this conceptually simple cell transformation system are poorly understood. While it is natural to develop mechanistic models based on quantitative observations of transformation, a limited understanding of the basic cell culture variables which modulate both the induction and expression of transformation dictate that caution be exercised in extrapolating the significance of such models to in vivo carcinogenesis. PMID:4053071

  13. Comparison of (/sup 3/H)nicotine and (/sup 3/H)acetylcholine binding in mouse brain: regional distribution

    SciTech Connect

    Sershen, H.; Reith, M.E.; Hashim, A.; Lajtha, A.

    1985-06-01

    In a continuing study of nicotine binding sites, the authors determined the relative amount of nicotine binding and acetylcholine binding in various brain regions of C57/BL and of DBA mice. Although midbrain showed the highest and cerebellum the lowest binding for both (/sup 3/H)nicotine and (/sup 3/H)acetylcholine, the ratio of nicotine to acetylcholine binding showed a three-fold regional variation. Acetylcholine inhibition of (/sup 3/H)nicotine binding indicated that a portion of nicotine binding was not inhibited by acetylcholine. These results indicate important differences between the binding of (+/-)-(/sup 3/H)nicotine and that of (/sup 3/H)acetylcholine.

  14. Modeling 3H-3He Gas-Liquid Phase Transport for Interpretation of Groundwater Age

    NASA Astrophysics Data System (ADS)

    Carle, S. F.; Esser, B.; Moran, J. E.

    2009-12-01

    California’s Groundwater Ambient Monitoring and Assessment (GAMA) Program has measured many hundreds of tritium (3H) and helium-3 (3He) concentrations in well water samples to derive estimates of groundwater age at production and monitoring wells in California basins. However, a 3H-3He age differs from an ideal groundwater age tracer in several respects: (1) the radioactive decay of 3H results in the accumulation of 3He being first-order with respect to 3H activity (versus a zero-order age-mass accumulation process for an ideal tracer), (2) surface concentrations of 3H as measured in precipitation over the last several decades have not been uniform, and (3) the 3H-3He “clock” begins at the water table and not at the ground surface where 3H source measurements are made. To better understand how these non-idealities affect interpretation of 3H-3He apparent groundwater age, we are modeling coupled gas-liquid phase flow and 3H-3He transport including processes of radiogenic decay, phase equilibrium, and molecular diffusion for water, air, 3H, and 3He components continuously through the vadose zone and saturated zone. Assessment of coupled liquid-gas phase processes enables consideration of 3H-3He residence time and dispersion within the vadose zone, including partitioning of tritiogenic 3He to the gas phase and subsequent diffusion into the atmosphere. The coupled gas-liquid phase modeling framework provides direct means to compare apparent 3H-3He age to ideal mean or advective groundwater ages for the same groundwater flow conditions. Examples are given for common groundwater flow systems involving areal recharge, discharge to streams or long-screened wells, and aquifer system heterogeneity. The Groundwater Ambient Monitoring and Assessment program is sponsored by the California State Water Resources Control Board and carried out in cooperation with the U.S. Geological Survey. This work was performed under the auspices of the U.S. Department of Energy by

  15. Synthesis and characterization of 3H-labelled tetrahydrobiopterin.

    PubMed Central

    Werner, E R; Schmid, M; Werner-Felmayer, G; Mayer, B; Wachter, H

    1994-01-01

    We synthesized [3'-3H]-5,6,7,8-tetrahydrobiopterin from [8,5'-3H]guanosine 5'-triphosphate ([8,5'-3H]GTP) using GTP cyclohydrolase (EC 3.5.4.16), 6-pyruvoyltetrahydropterin synthase and sepiapterin reductase (EC 1.1.1.153). After purification by cation-exchange h.p.l.c. a solution of radiochemically pure (> 95%) [3'-3H]-5,6,7,8-tetrahydrobiopterin with a specific activity of 9.2 Ci/mmol was obtained. The product proved well suited for studying the binding of tetrahydrobiopterin to nitric-oxide synthase. PMID:7528005

  16. The 3 H(d , γ) Reaction at Ec . m . <= 300 keV

    NASA Astrophysics Data System (ADS)

    Parker, C. E.; Brune, C. R.; Massey, T. N.; O'Donnell, J. E.; Richard, A. L.; Sayre, D. B.

    2015-04-01

    The 3 H(d , γ) 5He reaction has been measured using a 500-keV pulsed deuteron beam incident on a stopping titanium tritide target at the Edwards Accelerator Laboratory. The time-of-flight technique has been used to distinguish the γ-rays from neutrons in the bismuth germinate (BGO) γ-ray detector. A stilbene scintillator and an NE-213 scintillator have been used to detect the neutrons from the 3 H(d , n) α reaction using both the pulse-shape discrimination and time-of-flight techniques. A newly designed target holder with a silicon surface barrier detector to simultaneously measure α-particles to normalize the number of neutrons, along with a new titanium tritide target, was incorporated for subsequent measurements. The γ-rays have been measured at laboratory angles of 0 °, 45 °, 90 °, and 135 °. Information about the γ-ray energy distribution for the unbound ground state and first excited state of 5He can be obtained experimentally by comparing the BGO data to Monte Carlo simulations. The 3 H(d , γ) /3 H(d , n) branching ratio has also been measured. Data analysis is currently underway for the subsequent measurements. This work is supported in part by Lawrence Livermore National Laboratory and the U.S. D.O.E. (NNSA) through Grant No. DE-NA0001837.

  17. Uptake, incorporation and metabolism of ( sup 3 H)triolein in the isolated perfused rabbit heart

    SciTech Connect

    Weis, M.T.; Palazzo, A.J.; Williams, J.L. Jr.; Malik, K.U. )

    1990-08-01

    The purpose of these experiments was to study the uptake and metabolism of exogenous triglyceride in the isolated perfused rabbit heart. When infused into the rabbit heart, (9,10-3H(N))triolein was retained and incorporated into a lipid fraction that had the chromatographic mobility of authentic triolein. Incorporation of labeled triolein was not likely to be the result of a lipoprotein lipase-mediated lipolysis/resynthesis cycle, since: (i) The distribution of radioactivity following administration of (3H)oleic acid was markedly different from the distribution of radioactivity following the administration of (3H)triolein; (ii) heparin was administered to the rabbits at the time of sacrifice; and (iii) the hearts were perfused with a protein-free buffer for 20 min prior to the labelling period. When isoproterenol was administered to hearts labelled with (3H)triolein, there was an increased output of total radioactivity, composed of labelled free fatty acids, diacylglycerol and monoacylglycerol. In these same hearts, there was an increased output of glycerol in response to isoproterenol. However, following the administration of bradykinin or angiotensin II, neither the radioactivity nor the glycerol content of the perfusate was changed. These data suggest that (3H)triolein is selectively incorporated into the triglyceride pool of the isolated perfused rabbit heart. Furthermore, this (3H)triolein is available to hormonally-activated lipolytic enzymes.

  18. Partial chemical characterization of cyclopyrrolones ((/sup 3/H) suriclone) and benzodiazepines ((/sup 3/H)flunitrazepam) binding site: Differences

    SciTech Connect

    Zundel, J.L.; Blanchard, J.C.; Julou, L.

    1985-06-10

    Rat hippocampus membranes were treated with several protein modifying reagents (iodoacetamide, N-ethylmaleimide, tetranitromethane and N-acetylimidazole). The effects of these treatments on the binding sites of cyclopyrrolones ((/sup 3/H) suriclone), a new chemical family of minor tranquilizers, and benzodiazepines ((/sup 3/H) flunitrazepam) were investigated. Here the authors show that both ligands are similarly sensitive to cysteine alkylation: (/sup 3/H) suriclone and (/sup 3/H) flunitrazepam binding are reduced by iodoacetamide and slightly increased by N-ethylmaleimide. On the contrary they are clearly differentiated by tyrosine modification: (/sup 3/H) suriclone binding is not changed whereas (/sup 3/H) flunitrazepam binding is increased by tetranitromethane and decreased by N-acetylimidazole. The present findings and published evidence suggest cyclopyrrolones and benzodiazepines bind to distinct sites or to different allosteric forms of the benzodiazepine receptor. 28 references, 6 figures.

  19. Screening Test. Battery for Dental Laboratory Specialist Course: Development and Validation. Final Report for Period July 1974-June 1977.

    ERIC Educational Resources Information Center

    Mathews, John J.; Jensen, Harald E.

    In order to develop a valid replacement for the difficult to administer and costly Chalk Carving Test presently used in screening Dental Laboratory Specialist (DLS) candidates, an experimental battery of perceptual tests was given to 172 prospective DLS students. Dexterity tests were also given to a subsample. Experimental laboratory ratings and…

  20. Parkinson's disease: decreased density of /sup 3/H-imipramine and /sup 3/H-paroxetine binding sites in putamen

    SciTech Connect

    Raisman, R.; Cash, R.; Agid, Y.

    1986-04-01

    The density of high-affinity /sup 3/H-imipramine and /sup 3/H-paroxetine binding sites (two serotonin-uptake blockers) was decreased in the putamen of parkinsonian patients. The correlation between serotonin levels and the number of /sup 3/H-imipramine and /sup 3/H-paroxetine binding sites suggests that they are located on serotoninergic nerve terminals and could be used to study serotoninergic innervation in the human brain. Since imipramine and paroxetine are powerful antidepressants, these results furthermore suggest that decreased serotoninergic transmission may be implicated in the pathophysiology of depression in Parkinson's disease.

  1. Comparison of ( sup 3 H)Phencyclidine (( sup 3 H)PCP) and ( sup 3 H) N-(1-(2-thienyl) cyclohexyl)piperidine (( sup 3 H)TCP) binding properties to rat and human brain membranes

    SciTech Connect

    Vignon, J.; Chaudieu, I.; Allaoua, H.; Journod, L.; Javoy-Agid, F.; Agid, Y.; Chicheportiche, R.

    1989-01-01

    The investigation of ({sup 3}H)PCP and ({sup 3}H)TCP binding properties to rat cerebrum and cerebellum resulted in the demonstration of multiple binding sites for the two drugs. In the two tissue preparations PCP had a lower affinity than TCP. In membranes from the cerebrum an equal number of high affinity binding sites were present for ({sup 3}H)PCP and ({sup 3}H)TCP. However, low affinity binding sites were two times more numerous for ({sup 3}H)PCP than for ({sup 3}H)TCP. In the cerebellum, the number of high and low affinity sites labeled by the two radioligands was identical, but the number of high affinity sites was about 7 fold lower than in cerebrum. In human cerebral cortex samples ({sup 3}H)TCP also bound to two different sites. The number of high and low affinity sites were 12 and 3 times, respectively, less abundant than in the rat cerebrum. Low affinity sites were of higher affinity than corresponding sites in the rat brain. In the human cerebellum ({sup 3}H)TCP binding parameters were identical to those measured in the same region in the rat.

  2. (3)H activity comparison between FTMC, VNIIM and LNE-LNHB.

    PubMed

    Cassette, Philippe; Butkus, Paulius; Gudelis, Arunas; Shilnikova, Tatiana

    2016-03-01

    An activity comparison of tritiated water was organized in 2013 between 3 laboratories: FTMC (Lithuania), LNE-LNHB (France) and VNIIM (Russia). The solution was prepared by LNHB and ampoules were sent to the others laboratories. This solution was standardized in terms of activity per unit mass by participant laboratories using the Triple to Double Coincidence Ratio (TDCR) method in liquid scintillation counting (LSC). The tritiated water solution is traceable to the solution prepared by LNHB for the CCRI(II)-K2.H-3 2009 (3)H international comparison. PMID:26651170

  3. Correlation between (/sup 3/H)dopamine specific uptake and (/sup 3/H)GBR 12783 specific binding during the maturation of rat striatum

    SciTech Connect

    Bonnet, J.J.; Costentin, J.

    1989-01-01

    The development of the specific uptake of dopamine in the rat striatum during the early postnatal period is compared with the ontogenetic changes of the specific binding of (/sup 3/H)GBR 12783 to the site of uptake inhibition. During maturation, the increase in the specific binding of (/sup 3/H)GBR 12783 parallels the increase in the specific uptake of dopamine. (/sup 3/H)GBR 12783 specific binding sites increase in number from day 1 postpartum until 40 days, when they reach the adult level. In 40 day-old rats, the weight of the striatum represents 80% of adult values. The affinity of (/sup 3/H)GBR 12783 for the inhibition site is similar in membrane preparations obtained from 6 day-old pups and adults; this results in a same ability of the inhibitor to block the specific uptake of dopamine into synaptosomes obtained from pups or adult rats. These data support the hypothesis of the existence of a single molecular entity including both the inhibition site and the carrier itself.

  4. Fallout /sup 3/H ingestion in Akita, Japan

    SciTech Connect

    Hisamatsu, S.; Takizawa, Y.; Abe, T.; Katsumata, T.

    1987-09-01

    To study fallout /sup 3/H ingestion in Japan, 16 separate food group samples were collected from Akita during 1985. The /sup 3/H concentration in free water and that in a tissue-bound form were determined separately. The average /sup 3/H concentration in the tissue-bound form was 2.2 Bq L-1, 1.7 times higher than in the free water of the food. The ingestions of /sup 3/H in the tissue-bound form and as free water in the diet were 0.60 Bq d-1 and 1.0 Bq d-1, respectively. Cereals represented the food group that contributed the most to the ingestion of tissue-bound /sup 3/H. Total /sup 3/H ingestion was estimated to be 4.1 Bq d-1. The contribution of the tissue-bound form to the total ingestion was 15%, considerably lower than reported for Italian diets. The ratio of /sup 3/H ingestion in the tissue-bound form to the free water form in the diet was similar to the ratio reported for New York City.

  5. Laboratory investigation of the distribution of travel distance and rest period of sediment particles from PTV data

    NASA Astrophysics Data System (ADS)

    Ferreira, Rui M. L.; Antico, Federica

    2016-04-01

    We analyze paths of sediment particles on cohesionless granular bet subjected to a turbulent open-channel flow. The key objective is to provide further insights on particle dispersion including resting times. Hence, we focus on the spatial and temporal scale identified by Nikora et al. (2002) as the global range, defined as the particle path composed of many intermediate range paths, i.e with several "starts" and "stops". This requires the calculation of the probability distribution functions of particle travel distances and of rest periods. The experimental work was performed at the Hydraulics Laboratory of IST-UL in a 12.5 m long, 0.405 m wide glass-walled flume recirculating water and sediment through independent circuits. The granular bed was a 4.0 m long and 2.5 cm deep reach filled with 5 mm diameter glass beads packed (with some vibration) to a void fraction of 0.356, typical of random packing. Upstream the mobile bed reach the bed was composed of glued particles to ensure the development of a boundary layer with the same roughness. Laboratory tests were run under conditions of weak beadload transport with Shields parameter (θ) in the range 0.007 to 0.030, Froude numbers (Fr) between 0.630 and 0.950 and boundary Reynolds number (Re_ast) in the range 130 to 300. White-coated particles with 5.0 mm diameter were introduced in the flow 3 m upstream the mobile bed reach. Particle motion was registered from above using a high-speed camera AVT Bonito CL-400 with resolution set to 2320 × 1000 px2 and frame rate of 170 fps. The field of view recorded was 77.0 cm long and 38.0 cm wide, covering almost all the width of the flume. The maximum duration of the runs was 20 min, during which more than 500 particle paths, including resting times, were registered. The video footage was subjected to a PTV (Particle Tracking Velocimetry) developed for the problem at hand. The algorithm includes the application of Gaussian filters and thresholding operations to identify the

  6. Laboratory investigation of the distribution of travel distance and rest period of sediment particles from PTV data

    NASA Astrophysics Data System (ADS)

    Ferreira, Rui M. L.; Antico, Federica

    2016-04-01

    We analyze paths of sediment particles on cohesionless granular bet subjected to a turbulent open-channel flow. The key objective is to provide further insights on particle dispersion including resting times. Hence, we focus on the spatial and temporal scale identified by Nikora et al. (2002) as the global range, defined as the particle path composed of many intermediate range paths, i.e with several "starts" and "stops". This requires the calculation of the probability distribution functions of particle travel distances and of rest periods. The experimental work was performed at the Hydraulics Laboratory of IST-UL in a 12.5 m long, 0.405 m wide glass-walled flume recirculating water and sediment through independent circuits. The granular bed was a 4.0 m long and 2.5 cm deep reach filled with 5 mm diameter glass beads packed (with some vibration) to a void fraction of 0.356, typical of random packing. Upstream the mobile bed reach the bed was composed of glued particles to ensure the development of a boundary layer with the same roughness. Laboratory tests were run under conditions of weak beadload transport with Shields parameter (θ) in the range 0.007 to 0.030, Froude numbers (Fr) between 0.630 and 0.950 and boundary Reynolds number (Re_ast) in the range 130 to 300. White-coated particles with 5.0 mm diameter were introduced in the flow 3 m upstream the mobile bed reach. Particle motion was registered from above using a high-speed camera AVT Bonito CL-400 with resolution set to 2320 × 1000 px2 and frame rate of 170 fps. The field of view recorded was 77.0 cm long and 38.0 cm wide, covering almost all the width of the flume. The maximum duration of the runs was 20 min, during which more than 500 particle paths, including resting times, were registered. The video footage was subjected to a PTV (Particle Tracking Velocimetry) developed for the problem at hand. The algorithm includes the application of Gaussian filters and thresholding operations to identify the

  7. Characterizing a sewage plume using the 3H-3He dating technique

    USGS Publications Warehouse

    Shapiro, Stephanie Dunkle; LeBlanc, Denis; Schlosser, Peter; Ludin, Andrea

    1999-01-01

    An extensive 3H-3He study was performed to determine detailed characteristics of a regional flow system and a sewage plume over a distance of 4 km in a sand and gravel aquifer at Otis Air Base in Falmouth, Massachusetts. 3H-3He ages increase with depth in individual piezometer clusters and with distance along flowpaths. However, the age gradient with depth (Δt/Δz) is smaller in the plume than that in the regional waters, due to the intense recharge in the infiltration beds. The 1960s bomb peak of tritium in precipitation is archived longitudinally along a flowline through the main axis of the plume and vertically in individual piezometer clusters. On the eastern side of the sampling area, where water from Ashumet Pond forces plume water deeper into the flow system, 3H-3He ages are young at depth because the 3H-3He "clock" is reset due to outgassing of helium in the pond. A reconstruction of the tritium input functions for the regional and plume samples shows that there is no offset in the peak [3H]+[3Hetrit] concentrations for the plume and regional water, indicating that the water from supply wells for use on the base is young. The 3H-3He ages and detergent concentrations in individual wells are consistent with the beginning of use of detergents and the time period when their concentrations in sewage would have been greatest. Ages and hydraulic properties calculated using the 3H-3He data compare well with those from previous investigations and from particle-tracking simulations.

  8. Platelet 3H-imipramine binding sites in obsessive-compulsive behavior.

    PubMed

    Kim, S W; Dysken, M W; Pandey, G N; Davis, J M

    1991-09-01

    Several studies indicate a serotonergic dysfunction in patients with obsessive-compulsive disorder (OCD). We examined serotonergic function in OCD by determining platelet 3H-impiramine binding sites in patients with OCD during a drug-free baseline period as well as normal control volunteers. The maximum number of binding sites (Bmax) and apparent dissociation constant (Kd) was determined using 3H-imipramine (IMI) as the binding ligand. We observed that the mean 3H-IMI binding Bmax (fmol/mg protein) determined in 24 patients with OCD was not significantly different from that in 23 normal control subjects. There were no significant differences in the Kd between patients with OCD and normal control subjects. Our results are thus similar to those reported by Insel et al (1985) and Black et al (1990), who observed no significant differences in platelet 3H-IMI binding between OCD patients and controls; but different from those reported by Weizmann et al (1986), who observed decreased 3H-IMI Bmax in OCD patients. The discrepancy in the results is not clear, but may be related to several factors. Our results thus indicate that any abnormality in serotonergic function present in patients with OCD is not related to imipramine binding sites in the platelets. However, the possibility that there may be an abnormal platelet serotonin uptake or other serotonergic function in OCD cannot be ruled out. PMID:1657222

  9. Fallout sup 3 H in human tissue at Akita, Japan

    SciTech Connect

    Hisamatsu, S.; Takizawa, Y.; Itoh, M.; Ueno, K.; Katsumata, T.; Sakanoue, M. )

    1989-10-01

    The {sup 3}H concentration in Japanese human tissue samples is reported in this paper. Four brain, 10 liver, and nine lung samples from 11 cases were collected from Akita Prefecture in northern Japan from January to July 1986. The median of free-water {sup 3}H concentration was similar in these tissues and agreed well with the concentrations in the diet, including tap water. The median specific activity ratio of tissue-bound {sup 3}H to free-water {sup 3}H was 1.1 and was slightly lower than that in the diet. The specific activity ratio was also lower than that reported in the United States and significantly lower than in Italy.

  10. Optimized Syntheses of Cyclopentadienyl Nickel Chloride Compounds Containing "N"-Heterocyclic Carbene Ligands for Short Laboratory Periods

    ERIC Educational Resources Information Center

    Cooke, Jason; Lightbody, Owen C.

    2011-01-01

    Experiments are described for the preparation of imidazolium chloride precursors to "N"-heterocyclic carbenes and their cyclopentadienyl nickel chloride derivatives. The syntheses have been optimized for second- and third-year undergraduate laboratories that have a maximum programmed length of three hours per week. The experiments are flexible and…

  11. Stereospecific binding of 3H-phencyclidine in brain membranes.

    PubMed

    Hampton, R Y; Medzihradsky, F; Woods, J H; Dahlstrom, P J

    1982-06-21

    Phencyclidine (PCP) displaceable binding of 3H-PCP to glass-fiber filters was eliminated and total binding markedly reduced by initial treatment of the discs with 0.05% polyethyleneimine. Assessed with treated filters, unlabeled PCP displaced 3H-PCP in both rat and pigeon brain membranes with an EC50 of 1 microM. Of similar high inhibitory potency were dextrorphan, levorphanol, SKF 10047 and ketamine, while morphine, naloxone and etorphine had EC50 values higher then 1 mM. Using the dissociative anesthetic dexoxadrol and its inactive isomer levoxadrol as displacing agents, stereospecific binding of 3H-PCP was obtained in rat and pigeon brain membranes. The markedly higher potency of dexoxadrol, relative to levoxadrol, in displacing bound 3H-PCP is compatible with behavioral data for these enantiomers. However, they were equipotent in displacing 3H-PCP bound to glass-fiber filters in the absence of tissue. Heat denaturation, but not freezing, abolished stereospecific binding of 3H-PCP, which was also absent in rat liver membranes. The stereospecific binding component in brain displayed biphasic saturability at 60-70 nM and 300-400 nM, respectively. PMID:7109842

  12. (/sup 3/H)-beta-endorphin binding in rat brain

    SciTech Connect

    Houghten, R.A.; Johnson, N.; Pasternak, G.W.

    1984-10-01

    The binding of (/sup 3/H)-beta-endorphin to rat brain homogenates is complex. Although Scatchard analysis of saturation studies yields a straight line, detailed competition studies are multiphasic, suggesting that even at low concentrations of the compound, the /sup 3/H-ligand is binding to more than one class of site. A portion of (/sup 3/H)-beta-endorphin binding is sensitive to low concentrations of morphine or D-Ala2-Leu5-enkephalin (less than 5 nM). The inhibition observed with each compound alone (5 nM) is the same as that seen with both together (each at 5 nM). Thus, the binding remaining in the presence of both morphine and the enkephalin does not correspond to either mu or delta sites. The portion of (/sup 3/H)-beta-endorphin binding that is inhibited under these conditions appears to be equally sensitive to both morphine and the enkephalin and may correspond to mu1 sites. Treating membrane homogenates with naloxonazine, a mu1 selective antagonist, lowers (/sup 3/H)-beta-endorphin binding to the same degree as morphine and D-Ala2-Leu5-enkephalin alone or together. This possible binding of (/sup 3/H)-beta-endorphin to mu1 sites is consistent with the role of mu1 sites in beta-endorphin analgesia and catalepsy in vivo.

  13. Uptake of /sup 3/H-choline and synthesis of /sup 3/H-acetylcholine by human penile corpus cavernosum

    SciTech Connect

    Blanco, R.; Saenz de Tejada, I.; Azadzoi, K.; Goldstein, I.; Krane, R.J.; Wotiz, H.H.; Cohen, R.A.

    1986-03-05

    The neuroeffectors which relax penile smooth muscle and lead to erection are unknown; physiological studies of human corpus cavernosum, in vitro, have suggested a significant role of cholinergic neurotransmission. To further characterize the importance of cholinergic nerves, biopsies of human corpus cavernosum were obtained at the time of penile prosthesis implantation. Tissues were incubated in /sup 3/H-choline (10/sup -5/M, 80 Ci/mmol) in oxygenated physiological salt solution at 37/sup 0/C, pH 7.4 for 1 hour. Radiolabelled compounds were extracted with perchloric acid (0.4 M) and acetylcholine and choline were separated by HPLC; /sup 14/C-acetylcholine was used as internal standard. /sup 3/H-choline was accumulated by the tissues (20 +/- 1.9 fmol/mg), and /sup 3/H-acetylcholine was synthesized (4.0 +/- 1.1 fmol/mg). In control experiments, heating of the tissue blocked synthesis of /sup 3/H-acetylcholine. Inhibition of high affinity choline transport by hemicholinium-3 (10/sup -5/M) diminished tissue accumulation of /sup 3/H-choline and significantly reduced the synthesis of /sup 3/H-acetylcholine (0.5 +/ 0.2 fmol/mg, p < 0.05). These results provide direct evidence of neuronal accumulation of choline and enzymatic conversion to acetylcholine in human corpus cavernosum. Taken together with the physiological studies, it can be concluded that cholinergic neurotransmission in human corpus cavernosum plays a role in penile erection.

  14. Quantifying 3H-thymidine incorporation rates by a phylogenetically defined group of marine planktonic bacteria (Bacteriodetes phylum).

    PubMed

    van Mooy, Benjamin A S; Devol, Allan H; Keil, Richard G

    2004-10-01

    The rate of [(3)H-methyl] thymidine ((3)H-TdR) incorporation into DNA has been applied extensively to measure cell production by bacterial communities in aquatic environments. Here we describe a method to quantify (3)H-TdR incorporation by specific, phylogenetically defined members of the bacterial community. The method involves selectively capturing DNA from targeted groups of bacteria and then quantifying its (3)H radioactivity. The method was applied to measure (3)H-TdR incorporation by the members of the phylum Bacteriodetes whose members, which include the Cytophaga-Flavobacter cluster, are ubiquitous in coastal waters. (3)H-labelled DNA from Bacteriodetes was selectively biotinylated in PCR-like reactions that contained a Bacteriodetes-specific 16S rRNA gene primer, thermostable DNA polymerase and biotinylated dUTP. The biotinylated DNA was then captured on streptavidin-coated beads and its (3)H radioactivity determined by scintillation counting. We have termed this method 'selective nucleic acid polymerase-biotinylation and capture' or 'SNAP-BAC'. Internal (33)P-labelled DNA standards were used to quantify the recovery of (3)H-labelled DNA from the SNAP-BAC reactions. The method was verified by successfully targeting Bacteriodetes in simple laboratory mixtures of (3)H-labelled DNA extracted from pure cultures of Bacteriodetes and gamma-proteobacteria. Field application of this method in Puget Sound and off the Washington coast determined that Bacteriodetes were responsible for 56 +/- 17% and 32 +/- 5% of community (3)H-TdR incorporation (1.3 +/- 0.3 and 9.9 +/- 1.7 pmol l(-1) h(-1)) at these two locations. PMID:15344931

  15. Pharmacological studies on quaternized 4(3H)-quinazolinones.

    PubMed

    Buyuktimkin, S; Ekinci, A C; Buyuktimkin, N; Otuk, G

    1992-11-01

    Locomotor activity-inhibiting, anticonvulsant, muscle relaxant, analgesic, and antimicrobial properties of 2-methyl-3-pyridinium-acetylamino-4(3H)-quinazolinone chloride (1), 2-methyl-3-(4-methylpyridinium)acetylamino-4(3H)-quinazolinone chloride (2), 2-methyl-3-(4-ethylpyridinium)acetylamino-4(3H)-quinazolinone chloride (3), 2-methyl-3-(3-carboxamidopyridinium)acetylamino-4(3H)-quinazolinon e chloride (4), and 2-methyl-3-(4-carboxamidopyridinium)-acetylamino-4(3H)- quinazolinone chloride (5) were investigated. The locomotor activity-inhibiting properties and anticonvulsant activity of 2 were almost equal to those of methaqualone. The analgesic activities of 2 and 3 in the hot-plate test were equal to that of aspirin, whereas in the Koster test, the analgesic activity of 2 was higher. The compounds did not exhibit antimicrobial or muscle relaxant properties. Most active compounds had higher lipophilicity values than those of inactive compounds. PMID:1447711

  16. Review of PV module performance at DOE/MIT Lincoln Laboratory test sites during the period 1977 to 1982

    SciTech Connect

    Forman, S E; Themelis, M P

    1982-01-01

    During the years 1977 to 1982, over 11,000 photovoltaic (PV) modules have been placed at experimental PV power generating systems in a number of field test sites in the United States. Prominent among these are a 100-kW system at Natural Bridges National Monument in Utah, a 25-kWp system at Mead, Nebraska, and a 15-kW system at Bryan, Ohio. Through a program of periodic surveillance, measurements, and inspections at the aforementioned sites, electrically failed modules were located, removed and analyzed during this six-year period. The principal causes of failure were: (1) cells cracked due to weathering or internal module stresses, (2) failed solder joints, (3) interconnects not soldered to rear sides of cells at assembly, (4) cells or interconnects electrically shorted to metallic substrates, and (5) broken or split interconnects. Details and photographs of many of the different types of failures are presented and some of the analysis techniques used to locate the failures are described.

  17. R-matrix description of particle energy spectra produced by low-energy 3H + 3H reactions

    DOE PAGESBeta

    Brune, C. R.; Caggiano, J. A.; Sayre, D. B.; Bacher, A. D.; Hale, G. M.; Paris, M. W.

    2015-07-20

    An R-matrix model for three-body final states is presented and applied to a recent measurement of the neutron energy spectrum from the 3H + 3H→ 2n + α reaction. The calculation includes the n alpha and n n interactions in the final state, angular momentum conservation, antisymmetrization, and the interference between different channels. A good fit to the measured spectrum is obtained, where clear evidence for the 5He ground state is observed. The model is also used to predict the alpha-particle spectrum from 3H + 3H as well as particle spectra from 3He + 3He. The R-matrix approach presented heremore » is very general, and can be adapted to a wide variety of problems with three-body final states.« less

  18. A study of the C3H2 isomers and isotopologues: first interstellar detection of HDCCC

    NASA Astrophysics Data System (ADS)

    Spezzano, S.; Gupta, H.; Brünken, S.; Gottlieb, C. A.; Caselli, P.; Menten, K. M.; Müller, H. S. P.; Bizzocchi, L.; Schilke, P.; McCarthy, M. C.; Schlemmer, S.

    2016-02-01

    The partially deuterated linear isomer HDCCC of the ubiquitous cyclic carbene (c-C3H2) was observed in the starless cores TMC-1C and L1544 at 96.9 GHz, and a confirming line was observed in TMC-1 at 19.38 GHz. To aid the identification in these narrow line sources, four centimetre-wave rotational transitions (two in the previously reported Ka = 0 ladder and two new ones in the Ka = 1 ladder) and 23 transitions in the millimetre band between 96 and 272 GHz were measured in high-resolution laboratory spectra. Ten spectroscopic constants in a standard asymmetric top Hamiltonian allow the main transitions of astronomical interest in the Ka ≤ 3 rotational ladders to be calculated to within 0.1 km s-1 in radial velocity up to 400 GHz. Conclusive identification of the two astronomical lines of HDCCC was provided by the VLSR, which is the same as for the normal isotopic species (H2CCC) in the three narrow line sources. In these sources, deuterium fractionation in singly substituted H2CCC (HDCCC/H2CCC ~4-19%) is comparable to that in c-C3H2 (c-C3H2/c-C3HD ~5-17%) and similarly in doubly deuterated c-C3H2 (c-C3D2/c-C3HD ~3-17%), implying that the efficiency of the deuteration processes in the H2CCC and c-C3H2 isomers are comparable in dark clouds. Based on observations carried out with the IRAM 30 m Telescope. IRAM is supported by INSU/CNRS (France), MPG (Germany) and IGN (Spain).

  19. Annual summary report of the decontamination and decommissioning surveillance and maintenance program at Oak Ridge National Laboratory for period ending September 30, 1991

    SciTech Connect

    Ford, M.K.; Holder, L. Jr.

    1991-09-01

    The Surplus Facilities Management Program and Defense Facilities Decommissioning Program were established at Oak Ridge National Laboratory (ORNL) in 1976 in order to provide collective management of all surplus sites under ORNL control on the Oak Ridge Reservation. Some 34 facilities, classified into 3 civilian-related and 8 defense-related projects, are currently managed by the recently integrated Decontamination and Decommissioning Program. Support includes (1) surveillance and maintenance (S M) planning, (2) routine S M, and (3) special maintenance projects. This report documents routine S M, special projects, and special maintenance performed on these facilities for the period of October 1990 through September 1991.

  20. Annual summary report of the Decontamination and Decommissioning Surveillance and Maintenance Program at Oak Ridge National Laboratory for period ending September 30, 1994

    SciTech Connect

    Anderson, L.A.; Burwinkle, T.W.; Ford, M.K.; Gaddis, H.R.; Holder, L. Jr.; Mandry, G.J.; Nelson, T.R.; Patton, B.D.

    1995-03-01

    The Surplus Facilities Management Program (SFMP) was established at Oak Ridge National Laboratory (ORNL) in 1976 to provide collective management of all surplus sites under ORNL`s control on the Oak Ridge Reservation. Presently, over 50 facilities, grouped into projects, are currently managed by the Decontamination and Decommissioning Program, the successor program to the SFMP. Support includes (1) surveillance and maintenance planning; (2) routine surveillance and maintenance; and (3) special maintenance projects. This report documents routine surveillance and maintenance, special projects, and special maintenance performed on these facilities for the period of October 1993 through September 1994.

  1. Quantitation of uveoscleral outflow in normotensive and glaucomatous Beagles by /sup 3/H-labeled dextran

    SciTech Connect

    Barrie, K.P.; Gum, G.G.; Samuelson, D.A.; Gelatt, K.N.

    1985-01-01

    In uveoscleral outflow, aqueous humor leaves the anterior chamber and passes caudally through the trabecular meshwork and the sclerociliary cleft to enter the supraciliary and suprachoroidal spaces. The fluid is then absorbed by choroidal and scleral circulations. Using /sup 3/H-labeled dextran, uveoscleral outflow was quantitated in normotensive and glaucomatous Beagles under general anesthesia. The intrascleral plexus was isolated and /sup 3/H-labeled dextran was injected into the anterior chamber. Intrascleral plexus contents were sampled every 5 minutes over a 30- to 60-minute period. The eyes were enucleated, sectioned, and prepared for scintillation counting. Uveoscleral outflow accounted for 15% and 3% of the total aqueous humor outflow in the normotensive dogs and in the advanced glaucomatous dogs, respectively. In the advanced glaucomatous Beagle, conventional and uveoscleral outflow pathways were reduced and contributed to the etiopathogenesis of glaucoma.

  2. Highly accurate quartic force fields, vibrational frequencies, and spectroscopic constants for cyclic and linear C3H3(+).

    PubMed

    Huang, Xinchuan; Taylor, Peter R; Lee, Timothy J

    2011-05-19

    High levels of theory have been used to compute quartic force fields (QFFs) for the cyclic and linear forms of the C(3)H(3)(+) molecular cation, referred to as c-C(3)H(3)(+) and l-C(3)H(3)(+). Specifically, the singles and doubles coupled-cluster method that includes a perturbational estimate of connected triple excitations, CCSD(T), has been used in conjunction with extrapolation to the one-particle basis set limit, and corrections for scalar relativity and core correlation have been included. The QFFs have been used to compute highly accurate fundamental vibrational frequencies and other spectroscopic constants by use of both vibrational second-order perturbation theory and variational methods to solve the nuclear Schrödinger equation. Agreement between our best computed fundamental vibrational frequencies and recent infrared photodissociation experiments is reasonable for most bands, but there are a few exceptions. Possible sources for the discrepancies are discussed. We determine the energy difference between the cyclic and linear forms of C(3)H(3)(+), obtaining 27.9 kcal/mol at 0 K, which should be the most reliable available. It is expected that the fundamental vibrational frequencies and spectroscopic constants presented here for c-C(3)H(3)(+) and l-C(3)H(3)(+) are the most reliable available for the free gas-phase species, and it is hoped that these will be useful in the assignment of future high-resolution laboratory experiments or astronomical observations. PMID:21510653

  3. Preformance Analysis of NH3-H2O Absorption Cycle

    NASA Astrophysics Data System (ADS)

    Tsujimori, Atsushi; Ozaki, Eiichi

    Different from H2O-LiBr absorption cycle, it is necessary to have rectifier between generator and condenser in NH3-H2O absorption cycle, because there mixes some steam in refrigerant vapor in the process of regenerating refrigerant from the ammonia strong aqueous solution. And in some case ex. partial load or heating, the efficiency of rectifier might decrease, if the flow rate of refrigerant vapor and ammonia aqueous solution decrease. As a result, steam flow into condenser with ammonia refrigerant vapor, which reduces cycle COPs of cooling and heating. Accordingly in order to evaluate the effect of ammonia concentration in refrigerant for the performance of NH3-H2O absorption heat pump, the simple design approach of modeling condenser and evaporator is introduced in this paper. In the model, the calculation of heat rate in condenser and evaporator was simplified considering the characteristic of NH3-H2O liquid-vapor equilibrium. Then the simulation for cycle perforance based on GAX absorption cycle was made using the efficiency of rectifier that established the ammonia concentration in refrigerant and it was derived that 3 [%] decrease of ammonia concentration in refrigerant induced 15 [%] decrcase of cooling COP and 7 [%] decrease of heating COP and that there existed the most suitable circulation ratio for each ammonia concentration in refrigerant.

  4. (/sup 3/H)nitrendipine binding to adrenal capsular membranes

    SciTech Connect

    Finkel, M.S.; Aguilera, G.; Catt, K.J.; Keiser, H.R.

    1984-08-20

    The physiologic regulation of aldosterone secretion is dependent on extracellular calcium and appears to be mediated by increases in cytosolic free calcium concentration in the zona glomerulosa cell. A specific role for voltage-dependent calcium channels was suggested by previous studies with the calcium channel antagonist verapamil. The authors therefore studied the (/sup 3/H)nitrendipine calcium channel binding site in adrenal capsules. These studies revealed a single class of saturable, high affinity sites with K/sub D/ = .26 +/- .04 nM and B/sub max/ = 105 +/- 5.7 fmol/mg protein. Specific binding of (/sup 3/H)nitrendipine was inhibited by calcium channel antagonists with potencies nitrendipine = nifedipine >> verapamil, while diltiazem had no inhibitory effect. In the rat, binding sites for (/sup 3/H)nitrendipine were located in the adrenal capsule and medulla and were undetectable in the zona fasciculata. Physiologic studies with collagenase-dispersed adrenal glomerulosa cells demonstrated that nifedipine selectively inhibited angiotensin-II and potassium-stimulated steroidogenesis. These observations suggest both a pharmacologic and physiologic role for the nitrendipine binding site in aldosterone production. 17 references, 2 figures, 1 table.

  5. Astronomical identification of the C3H radical

    NASA Astrophysics Data System (ADS)

    Thaddeus, P.; Gottlieb, C. A.; Hjalmarson, A.; Johansson, L. E. B.; Irvine, W. M.; Friberg, P.; Linke, R. A.

    1985-07-01

    The C3H radical has been identified in the millimeter-wave spectra of IRC +10216 and TMC-1. In IRC +10216, four rotational transitions have been observed, three in the lower fine-structure ladder (2Pi1/2) and one in the upper (2Pi3/2), each a resolved or partially resolved lambda-doublet. In TMC-1, both lambda components of the lowest lying 3/2-1/2 transition of the 2Pi1/2 ladder have been observed, each with well-resolved hfs. In IRC +10216, the excitation of C3H is similar to that of SiCC: the rotational temperature Trot within the 2Pi1/2 ladder is low (8.5 K), because of rapid radiative decay, while Trot across the ladders is high (about 52 K), because interconnecting far-IR radiative transitions are only weakly permitted. The column density of C3H in IRC +10216 averaged over the estimated source diameter of 84 arcsec is 2.8 x 10 to the 13th/sq cm, an order of magnitude less than that of C2H and C4H.

  6. Evaluation of Level of Agreement in Bordetella Species Identification in Three U.S. Laboratories during a Period of Increased Pertussis

    PubMed Central

    Lee, Adria D.; Bowden, Katherine E.; Faulkner, Amanda E.; Seaton, Brent L.; Lembke, Bryndon D.; Cartwright, Charles P.; Martin, Stacey W.; Tondella, M. Lucia

    2015-01-01

    While PCR is the most common method used for detecting Bordetella pertussis in the United States, most laboratories use insertion sequence 481 (IS481), which is not specific for B. pertussis; therefore, the relative contribution of other Bordetella species is not understood. The objectives of this study were to evaluate the proportion of other Bordetella species misidentified as B. pertussis during a period of increased pertussis incidence, determine the level of agreement in Bordetella species detection between U.S. commercial laboratories and the CDC, and assess the relative diagnostic sensitivity of CDC's PCR assay when using a different PCR master mix. Specimens collected between May 2012 and May 2013 were tested at two U.S. commercial laboratories for B. pertussis and B. parapertussis detection. Every fifth specimen positive for IS481 and/or IS1001 with cycle threshold (CT) values of ≤35 was sent to CDC for PCR testing that identifies Bordetella species. Specimens with indeterminate or negative results in the CDC PCR were tested using an alternate PCR master mix. Of 755 specimens, there was agreement in species identification for 83.4% (n = 630). Of the specimens with different identifications (n = 125), 79.2% (n = 99) were identified as indeterminate B. pertussis at CDC. Overall, 0.66% (n = 5) of the specimens were identified as B. holmesii or B. bronchiseptica at CDC. Of 115 specimens with indeterminate or negative results, 46.1% (n = 53) were B. pertussis positive when tested by an alternate master mix, suggesting a possible increase in assay sensitivity. This study demonstrates good agreement between the two U.S. commercial laboratories and CDC and little misidentification of Bordetella species during the 2012 U.S. epidemic. PMID:25809969

  7. Dehydrohalogenation and Dehydration Reactions of i-C3H7Br and i-C3H7OH by Sodium Ions Studied by Guided Ion Beam Techniques and Quantum Chemical Methods.

    PubMed

    López, E; Lucas, J M; de Andrés, J; Albertí, M; Bofill, J M; Aguilar, A

    2016-07-14

    Dehydrohalogenation and dehydration reactions of gas-phase i-C3H7Br and i-C3H7OH molecules induced by collision with Na(+), all participants being in their electronic ground state, were studied experimentally in our laboratory using a radiofrequency-guided ion beam apparatus and covering the 0.10-10.00 eV center of mass (CM) energy range. In Na(+) + i-C3H7Br collisions the formation of [C3H6-Na](+) and [HBr-Na](+) by dehydrohalogenation was observed and quantified, as well as that of the ion-molecule adduct [Na-i-C3H7Br](+) together with its decomposition products C3H7(+) and NaBr. In Na(+) + i-C3H7OH collisions the dehydration product [H2O-Na](+) was also found, while [C3H6-Na](+) was hardly detected. Moreover, the [Na-i-C3H7OH](+) adduct formation as well as its decomposition into C3H7(+) and NaOH were also quantified. For all these processes, absolute reaction cross sections were measured as a function of the CM collision energy. From measured excitation functions, rate constants for the formation of [C3H6-Na](+), [HBr-Na](+), and [H2O-Na](+) at 303 K were obtained. Complementing the experiments, exhaustive ab initio structure calculations at the MP2 level of theory were performed, giving information on the most relevant features of the potential energy surfaces (PESs) where the dehydrohalogenation, dehydration, and decomposition reactions take place adiabatically for both collision systems. On these PESs different stationary points associated with potential energy minima and transition state barriers were characterized, and their connectivity was ensured using the intrinsic-reaction-coordinate method. The main topology features of the ab initio calculated PESs allowed a qualitative interpretation of the experimental data also exposing the role of the sodium ion as a catalyst in elimination reactions. PMID:26811987

  8. Interaction of [3H] estradiol - and [3H] monohydroxytamoxifen-estrogen receptor complexes with a monoclonal antibody.

    PubMed

    Tate, A C; DeSombre, E R; Greene, G L; Jensen, E V; Jordan, V C

    1983-01-01

    The aim of this study was to compare and contrast the interaction of estrogen [( 3H]17 beta-estradiol)- or antiestrogen [( 3H]monohydroxytamoxifen)-receptor complexes from human breast tumor cytosols with monoclonal antibodies raised to the human breast tumor estrogen receptor. Breast tumor cytosols containing estrogen receptor which sedimented as radiolabeled peaks in either the 8S, 8S and 4S, or 4S regions of sucrose density gradients, interacted with the monoclonal antibody D547 to produce a broad 9-10S peak, a broad 8S-10S peak, or a more discrete 8S peak, respectively. On high salt (0.4M KC1) sucrose density gradients the 4S ligand-receptor complex plus antibody produced a binding peak at approximately the 8S region of the gradient. These sedimentation studies with the monoclonal antibody D547, and similar studies with the monoclonal antibody D58, could detect no differences in the cytosolic estrogen receptor whether complexed with [3H]estradiol or with [3H]monohydroxytamoxifen. These observations were confirmed by Scatchard equilibrium saturation analysis and sucrose density gradient analysis of cytosols from the MCF-7 human breast cancer cell line. The antibody D547 interacted with 8S ER from these cytosols to produce a broad 8S-10S peak, but the antibody produced no change in the affinity or number of binding sites present in these cytosols. It seems, therefore, that the antigenic determinants recognized by these particular antibodies on the breast tumor cytosolic receptor are not significantly altered by the binding of either an estrogen or an antiestrogen to the receptor. PMID:6671136

  9. Temporal pattern of incorporation of /sup 3/H precursors into pituitary glycoproteins and their subsequent release

    SciTech Connect

    Grotjan, H.E. Jr.

    1982-04-01

    The temporal pattern of incorporation of various /sup 3/H precursors into glycoproteins by rat anterior pituitaries incubated in vitro and the release of /sup 3/H-glycoproteins was examined. (/sup 3/H)Leucine incorporation was linear with respect to time and (/sup 3/H)leucine-containing macromolecules appeared in the media in about 1 hr. The temporal pattern of (/sup 3/H)mannose incorporation and release was similar. (/sup 3/H)Galactose and (/sup 3/H)fucose were incorporated after apparent time of delays of approximately 15 min and soon thereafter (20-25 min) appeared in the medium in /sup 3/H-glycoproteins. Thus, these precursors appear to be added as terminal residues. (/sup 3/H)Glucosamine exhibited a pattern intermediate between (/sup 3/H)leucine and (/sup 3/H)fucose whereas (/sup 3/H)GlcNAc appeared to be incorporated as a terminal residue.

  10. A single-vial biphasic liquid extraction assay for choline acetyltransferease using (/sup 3/H)choline

    SciTech Connect

    Rand, J.B.; Johnson, C.D.

    1981-09-15

    A single-vial liquid extraction assay for choline acetyltransferase that uses (/sup 3/H)choline as the labeled substrate has been devised. (/sup 3/H)Choline is incubated with an excess of acetyl-CoA in a small reaction vial which also serves as a scintillation vial. After a suitable reaction period, unreacted (/sup 3/H)choline is quickly and quantitatively converted to phosphoryl-(/sup 3/H)choline by the addition of an excess of choline kinase. This treatment is followed by the addition of scintillation fluid containing sodium tetraphenylboron after which the vial is capped, shaken, and counted. A two-phase system is produced in which product (/sup 3/H)choline is selectively extracted into the scintillation fluid, where is is counted. Phosphoryl-(/sup 3/H)choline remains in the aqueous phase and is not counted. This assay is rapid, simple, and quite sensitive. In comparison to assays using acetyl-CoA as the labeled substrate, it is less sensitive to interference by other enzymes and thus more suitable for measuring choline acetyltransferase in crude extracts and in the initial stages of purificaton. Similar single-vial radiometric assays are described for choline kinase and acetyl-CoA hydrolases.

  11. Proton transfer dynamics in the hydrogen bond. Inelastic neutron scattering, infrared and Raman spectra of Na 3H(SO 4) 2, K 3H(SO 4) 2 and Rb 3H(SO 4) 2

    NASA Astrophysics Data System (ADS)

    Fillaux, F.; Lautié, A.; Tomkinson, J.; Kearley, G. J.

    1991-06-01

    Na 3H(SO 4) 2, K 3H(SO 4) 2 and Rb 3H(SO 4) 2 crystals are composed of (SO 4HSO 4) -3 dimers linked by rather strong hydrogen bonds ( RO…O=2.43 Å for Na 3H(SO 4) 2, RO…O=2.48 Å for Rb 3H(SO 4) 2 and RO…O=2.49 Å for K 3H(SO 4) 2). Crystallographic data of the salts at room temperature indicate either asymmetric (Na 3H(SO 4) 2) or symmetric (K 3H(SO 4) 2 and Rb 3H(SO 4) 2) hydrogen bonds. Inelastic neutron scattering (INS), infrared and Raman spectra of crystal powders at 20 K are reported for these three compounds. The OH bending modes, which give large INS intensities, appear only weakly in the infrared. The two bending modes are degenerate in Na 3H(SO 4) 2 which has the shortest hydrogen bond but are well separated in K 3H(SO 4) 2 and Rb 3H(SO 4) 2. The OH stretching band profiles in INS are also quite different from those in the infrared. Strong INS bands at 57 and 44 cm -1 for K 3H(SO 4) 2 and Rb 3H(SO 4) 2, respectively, are assigned to 0→1 transitions in quasi-symmetric double-minimum potentials for the OH stretching coordinates. For K 3H(SO 4) 2 the frequency is unaffected by temperature between 2 and 100 K. Potential functions are calculated and the dynamics of the proton transfer are discussed. Infrared spectra are thus dominated by OH stretching transitions in asymmetric double-minimum potentials with low barriers, with relative intensities indicating a large electrical anharmonicity.

  12. Comparative study on pharmacokinetics and in vivo alpha1-adrenoceptor binding of [3H]tamsulosin and [3H]prazosin in rats.

    PubMed

    Ohkura, T; Yamada, S; Deguchi, Y; Kimura, R

    1999-04-01

    The plasma concentration, total radioactivity and in vivo alpha1-adrenoceptor binding in rat tissues after intravenous (i.v.) injection of [3H]tamsulosin were measured and they were compared with those obtained after the injection of [3H]prazosin. The plasma concentration of [3H]tamsulosin was consistently higher than that of [3H]prazosin, with 1.4 times greater areas under the curve (AUC(0-infinity)) of plasma concentration. As there was a significantly lower value of apparent volume of central compartment (Vd(c)) and distribution volume at steady state (Vd(ss)) for [3H]tamsulosin than [3H]prazosin with little difference in elimination rate constant (beta), the higher concentration of [3H]tamsulosin in plasma might be associated mainly with the smaller volume of distribution. The ratio of total radioactivity in tissues to the plasma unbound concentration of [3H]tamsulosin after i.v. injection of the ligand was consistently lower than that of [3H]prazosin. These observations suggest that [3H]tamsulosin is distributed in rat tissues in a more limited manner than [3H]prazosin. A significantly lower level of in vivo specific binding of [3H]tamsulosin than [3H]prazosin was observed in the spleen, heart and liver. Further, the apparent dissociation constant (Kd) and maximal number of binding sites (Bmax) for in vivo specific [3H]tamsulosin binding were considerably lower than those for [3H]prazosin binding. Therefore, these findings suggest that [3H]tamsulosin labels preferentially a subpopulation of the alpha1-adrenoceptor sites in rat tissues labeled by [3H]prazosin. In conclusion, the present study has shown that there is a significant difference in the pharmacokinetics and in vivo alpha1-adrenoceptor binding characteristics between tamsulosin and prazosin. PMID:10328564

  13. Rotational spectroscopy of 2H,3H-perfluoropentane

    NASA Astrophysics Data System (ADS)

    Duong, Chinh H.; Obenchain, Daniel A.; Cooke, S. A.; Novick, Stewart E.

    2016-06-01

    The structure of 2H,3H-perfluoropentane, CF3CHFCHFCF2CF3, has been determine by a combination of Chirp-pulsed Fourier transform microwave (CP-FTMW) spectroscopy and cavity FTMW spectroscopy. Of the four possible stereoisomers, only the enantiomeric pair (R,R)/(S,S) were observed experimentally; there was no spectroscopic evidence for the enantiomeric pair (R,S)/(S,R). The conformeric structure of the (R,R)/(S,S) stereoisomer(s) was that of partial helices with C-C-C-C dihedral angles of 12° (helical) and 1° (staggered).

  14. The use of laboratory-determined ion exchange parameters in the predictive modelling of field-scale major cation migration in groundwater over a 40-year period.

    PubMed

    Carlyle, Harriet F; Tellam, John H; Parker, Karen E

    2004-01-01

    An attempt has been made to estimate quantitatively cation concentration changes as estuary water invades a Triassic Sandstone aquifer in northwest England. Cation exchange capacities and selectivity coefficients for Na(+), K(+), Ca(2+), and Mg(2+) were measured in the laboratory using standard techniques. Selectivity coefficients were also determined using a method involving optimized back-calculation from flushing experiments, thus permitting better representation of field conditions; in all cases, the Gaines-Thomas/constant cation exchange capacity (CEC) model was found to be a reasonable, though not perfect, first description. The exchange parameters interpreted from the laboratory experiments were used in a one-dimensional reactive transport mixing cell model, and predictions compared with field pumping well data (Cl and hardness spanning a period of around 40 years, and full major ion analyses in approximately 1980). The concentration patterns predicted using Gaines-Thomas exchange with calcite equilibrium were similar to the observed patterns, but the concentrations of the divalent ions were significantly overestimated, as were 1980 sulphate concentrations, and 1980 alkalinity concentrations were underestimated. Including representation of sulphate reduction in the estuarine alluvium failed to replicate 1980 HCO(3) and pH values. However, by including partial CO(2) degassing following sulphate reduction, a process for which there is 34S and 18O evidence from a previous study, a good match for SO(4), HCO(3), and pH was attained. Using this modified estuary water and averaged values from the laboratory ion exchange parameter determinations, good predictions for the field cation data were obtained. It is concluded that the Gaines-Thomas/constant exchange capacity model with averaged parameter values can be used successfully in ion exchange predictions in this aquifer at a regional scale and over extended time scales, despite the numerous assumptions inherent in

  15. Effects of toxic substances on natural bacterial assemblages determined by means of ( sup 3 H)thymidine incorporation

    SciTech Connect

    Riemann, B., Lindgaard-Jorgensen, P. )

    1990-01-01

    The effects of 3,5-dichlorophenol, 2,4-dinitrophenol, and potassium dichromate on natural bacterial assemblages were examined by means of ({sup 3}H)thymidine incorporation into trichloroacetic acid-insoluble material. Results from a large number of coastal marine and freshwater samples suggest the following. (i) The effects of the three toxicants included reductions in the bacterial cell number as well as changes in rates of ({sup 3}H)thymidine incorporation and in ({sup 3}H)thymidine incorporation per cell. The concentrations that inhibited ({sup 3}H)thymidine incorporation by 50% ranged from 3 to 11 mg liter{sup {minus}1} for 3,5-dichlorophenol, 5 to 10 mg liter{sup {minus}1} for 2,4-dinitrophenol, and 21 to 123 mg liter{sup {minus}1} for potassium dichromate, with a tendency to higher values in bacterial assemblages from more eutrophic environments. (ii) The effects of 3,5-dichlorophenol and potassium dichromate determined by ({sup 3}H) leucine incorporation into bacterial protein were similar or larger than those obtained from ({sup 3}H) thymidine incorporation. (III) Two to four hours of exposure to the toxicants was necessary before stable maximum effects were found in ({sup 3}H)thymidine incorporation. (IV) Storage of natural environmental samples should be avoided, since tests with water stored for 1 to 3 days sometimes produced results different from results obtained from in situ tests. (V) The effects of 3,5-dichlorophenol, 2,4-dinitrophenol, and potassium dichromate on natural bacterial assemblages were relatively constant during periods with different growth rates in the assemblages, during various periods of the year, and between samples from freshwater and marine localities.

  16. Tritium concentrations in bees and honey at Los Alamos National Laboratory: 1979-1996

    SciTech Connect

    Fresquez, P.R.; Armstrong, D.R.; Pratt, L.H.

    1997-01-01

    Honeybees are effective monitors of environmental pollution. The objective of this study was to summarize tritium ({sup 3}H) concentrations in bees and honey collected from within and around Los Alamos National Laboratory (LANL) over an 18-year period. Based on the long-term average, bees from nine out of eleven hives and honey from six out of eleven hives on LANL lands contained {sup 3}H that was significantly higher (p <0.05) than background. The highest average concentration of {sup 3}H in bees (435 pCi mL{sup -1}) collected over the years was from LANL`s Technical Area (TA) 54-a low-level radioactive waste disposal site (Area G). Similarly, the highest average concentration of {sup 3}H in honey (709 pCi mL{sup - 1}) was collected from a hive located near three {sup 3}H storage ponds at LANL TA-53. The average concentrations of {sup 3}H in bees and honey from background hives was 1.0 pCi mL{sup -1} and 1.5 pCi ML{sup -1}, respectively. Although the concentrations of 3H in bees and honey from most LANL and perimeter (White Rock/Pajarito Acres) areas were significantly higher than background, most areas, with the exception of TA-53 and TA-54, generally exhibited decreasing 3H concentrations over time.

  17. An autoradiographic map of (3H)diprenorphine binding in rat brain: effects of social interaction

    SciTech Connect

    Panksepp, J.; Bishop, P.

    1981-10-01

    (3H)Diprenorphine binding was analyzed autoradiographically in the brains of 33 day old rat pups. A photographic atlas of diprenorphine binding in the coronal plane is provided to highlight the dispersion of opioid receptor systems through the brain. To determine whether brain opioid release may be induced by social interactions, half the animals were sacrificed following a 30 min period of social interaction while the other half were sacrificed following 30 min of social isolation. Opioid binding was higher in isolate-tested animals than socially-tested ones, suggesting that social interaction may promote endogenous brain opioid release.

  18. A Search for Interstellar Oxiranecarbonitrile (C3H3NO)

    NASA Technical Reports Server (NTRS)

    Dicken, J. E.; Irvine, W. M.; Ohishi, M.; Arrhenius, G.; Bauder, A.; Mueller, F.; Eschenmoser, A.

    1996-01-01

    We report a search in cold, quiescent and in 'hot core' type interstellar molecular clouds for the small cyclic molecule oxiranecarbonitrile (C3H3NO), which has been suggested as a precursor of important prebiotic molecules. We have determined upper limits to the column density and fractional abundance for the observed sources and find that, typically, the fractional abundance by number relative to molecular hydrogen Of C3H3NO is less than a few times 10(exp -10). This limit is one to two orders of magnitude less than the measured abundance of such similarly complex species as CH3CH2CN and HCOOCH3 in well-studied hot cores. A number of astrochemical discoveries were made, including the first detection of the species CH3CH2CN in the massive star-forming clouds G34.3+0.2 and W51M and the first astronomical detections of some eight rotational transitions of CH3CH2CN, CH3CCH, and HCOOCH3. In addition, we found 8 emission lines in the 89 GHz region and 18 in the 102 GHz region which we were unable to assign.

  19. Effective theory of 3H and 3He

    NASA Astrophysics Data System (ADS)

    König, Sebastian; Grießhammer, Harald W.; Hammer, H.-W.; van Kolck, U.

    2016-06-01

    We present a new perturbative expansion for pionless effective field theory with Coulomb interactions in which at leading order (LO) the spin-singlet nucleon–nucleon channels are taken in the unitarity limit. Presenting results up to next-to-leading order for the Phillips line and the neutron–deuteron doublet-channel phase shift, we find that a perturbative expansion in the inverse {}1{S}0 scattering lengths converges rapidly. Using a new systematic treatment of the proton–proton sector that isolates the divergence due to one-photon exchange, we renormalize the corresponding contribution to the {}3{{H}} –{}3{He} binding energy splitting and demonstrate that the Coulomb force in pionless EFT is a completely perturbative effect in the trinucleon bound-state regime. In our new expansion, the LO is exactly isospin-symmetric. At next-to-leading order, we include isospin breaking via the Coulomb force and two-body scattering lengths, and find for the energy splitting {({E}B{(}3{He})-{E}B{(}3{{H}}))}{NLO}\\quad =(-0.86+/- 0.17)\\quad {MeV}.

  20. A search for interstellar oxiranecarbonitrile (C3H3NO).

    PubMed

    Dickens, J E; Irvine, W M; Ohishi, M; Arrhenius, G; Pitsch, S; Bauder, A; Muller, F; Eschenmoser, A

    1996-04-01

    We report a search in cold, quiescent and in 'hot core' type interstellar molecular clouds for the small cyclic molecule oxiranecarbonitrile (C3H3NO), which has been suggested as a precursor of important prebiotic molecules. We have determined upper limits to the column density and fractional abundance for the observed sources and find that, typically, the fractional abundance by number relative to molecular hydrogen of C3H3NO is less than a few times 10(-10). This limit is one to two orders of magnitude less than the measured abundance of such similarly complex species as CH3CH2CN and HCOOCH3 in well-studied hot cores. A number of astrochemical discoveries were made, including the first detection of the species CH3CH2CN in the massive star-forming clouds G34.3+0.2 and W51M and the first astronomical detections of some eight rotational transitions of CH3CH2CN, CH3CCH, and HCOOCH3. In addition, we found 8 emission lines in the 89 GHz region and 18 in the 102 GHz region which we were unable to assign. PMID:11536752

  1. The 3H-3He Charge Radii Difference

    NASA Astrophysics Data System (ADS)

    Myers, L. S.; Arrington, J. R.; Higinbotham, D. W.

    2016-03-01

    The upcoming E12-14-009 [1] experiment at Jefferson Lab will determine the ratio of the electric form factors for the A=3 mirror nuclei 3He and 3H. The measurement will use a 1.1 GeV electron beam, a special collimator plate to allow for simultaneous optics measurements, and the low-activity tritium target being prepared for Jefferson Lab. By observing the dependence of the form factor ratio as a function of Q2 over 0.05-0.09 GeV2, the dependence of the radii extraction on the shape of the form factors is minimized. As a result, we anticipate the uncertainty of the extracted charge radii difference to be 0.03 fm, a reduction of 70% from the current measurement. Using precise measurements of the 3He charge radius from isotopic shift or μHe measurements [2-4], we can deduce the absolute 3H charge radius. The results will provide a direct comparison to recent calculations of the charge radii.

  2. Evidence for triangular D3h symmetry in 12C.

    PubMed

    Marín-Lámbarri, D J; Bijker, R; Freer, M; Gai, M; Kokalova, Tz; Parker, D J; Wheldon, C

    2014-07-01

    We report a measurement of a new high spin Jπ=5- state at 22.4(2) MeV in 12C which fits very well to the predicted (ground state) rotational band of an oblate equilateral triangular spinning top with a D3h symmetry characterized by the sequence 0+, 2+, 3-, 4±, 5- with almost degenerate 4+ and 4- (parity doublet) states. Such a D3h symmetry was observed in triatomic molecules, and it is observed here for the first time in nuclear physics. We discuss a classification of other rotation-vibration bands in 12C such as the (0+) Hoyle band and the (1-) bending mode band and suggest measurements in search of the predicted ("missing") states that may shed new light on clustering in 12C and light nuclei. In particular, the observation (or nonobservation) of the predicted ("missing") states in the Hoyle band will allow us to conclude the geometrical arrangement of the three alpha particles composing the Hoyle state at 7.654 MeV in 12C. PMID:25032922

  3. Beryllium-induced immune response in C3H mice

    SciTech Connect

    Benson, J.M.; Bice, D.E.; Nikula, K.J.

    1995-12-01

    Studies conducted at ITRI over the past several years have investigated whether Beagle dogs, monkeys, and mice are suitable models for human chronic beryllium-induced lung disease (CBD). Recent studies have focused on the histopathological and immunopathological changes occurring in A/J and C3H/HeJ mice acutely exposed by inhalation to Be metal. Lung lesions in both strains of mice included focal lymphocyte aggregates comprised primarily of B lymphocytes and lesser amounts of T-helper lymphocytes and microgranulomas consisting chiefly of macrophages and T-helper lymphocytes. The distribution of proliferating cells within the microgranulomas was similar to the distribution of T-helper cells. These results strongly suggested that A/J and C3H/HeJ mice responded to inhaled Be metal in a fashion similar to humans in terms of pulmonary lesions and the apparent in situ proliferation of T-helper cells. Results of these studies confirm lymphocyte involvement in the pulmonary response to inhaled Be metal.

  4. Dating degassed groundwater with 3H/3He

    NASA Astrophysics Data System (ADS)

    Visser, Ate; Broers, Hans Peter; Bierkens, Marc F. P.

    2007-10-01

    The production of gases in groundwater under contaminated locations by geochemical and biological processes is not uncommon. Degassing of these gases from groundwater and repartitioning of noble gases between water and gas phase distorts groundwater dating by 3H/3He. We observed noble gas concentrations below atmospheric equilibrium in 20 out of 34 groundwater samples from agriculturally polluted sandy areas in the Netherlands. From the absence of nitrate in degassed samples, we conclude that denitrification causes degassing. The 22Ne/20Ne ratios show that degassing had attained solubility equilibrium and had not caused isotopic fractionation by diffusion. To correct for the loss of tritiogenic 3He due to degassing, we present a single-step equilibrium degassing model. We use the total dissolved gas pressure at the monitoring screen to estimate the depth and timing of degassing, which is essential to estimate travel times from degassed samples. By propagating the uncertainties in the underlying measurements and assumptions through the travel time calculations, we found a travel time uncertainty of 3 years (a). We therefore conclude that 3H/3He dating can produce valuable information on groundwater flow even at sites with strong degassing.

  5. Microautoradiographic localisation of [3H]sucrose and [3H]mannitol in Robinia pseudoacacia pulvinar tissues during phytochrome-mediated nyctinastic closure.

    PubMed

    Moysset, L; Llambrich, E; López-Iglesias, C; Simón, E

    2006-11-01

    We have analysed the incorporation of [(3)H]sucrose and [(3)H]mannitol in pulvinar motor cells of Robinia pseudoacacia L. during phytochrome-mediated nyctinastic closure. Pairs of leaflets, excised 2 h after the beginning of the photoperiod, were fed with 50 mM [(3)H]sucrose or [(3)H]mannitol, irradiated with red (15 min) or far-red (5 min) light and placed in the dark for 2-3 h. Label uptake was measured in whole pulvini by liquid scintillation counting. The distribution of labelling in pulvinar sections was assessed by both light and electron microautoradiography. [(3)H]Sucrose uptake was twice that of [(3)H]mannitol incorporation in both red- and far-red-irradiated pulvini. In the autoradiographs, [(3)H]sucrose and [(3)H]mannitol labelling was localised in the area from the vascular bundle to the epidermis, mainly in vacuoles, cytoplasm, and cell walls. Extensor and flexor protoplasts displayed a different distribution of [(3)H]sucrose after red and far-red irradiation. Far-red light drastically reduced the [(3)H]sucrose incorporation in extensor protoplasts and caused a slight increase in internal flexor protoplasts. After red light treatment, no differences in [(3)H]sucrose labelling were found between extensor and flexor protoplasts. Our results indicate a phytochrome control of sucrose distribution in cortical motor cells and seem to rule out the possibility of sucrose acting as an osmoticum. PMID:17102931

  6. Bindings of /sup 3/H-prazosin and /sup 3/H-yohimbine to alpha adrenoceptors in the guinea-pig stomach

    SciTech Connect

    Taniguchi, T.; Nishikawa, H.

    1988-01-01

    Alpha adrenoceptor subtypes have been investigated by radioligand binding study in guinea-pig stomach using /sup 3/H-prazosin and /sup 3/H-yohimbine. The specific /sup 3/H-prazosin binding to guinea-pig stomach was saturable and of high affinity with a Bmax of 33 fmol/mg protein. Specific /sup 3/H-yohimbine binding to the tissue was also saturable and of high affinity with a Bmax of 150 fmol/mg protein. Adrenergic drugs competed for /sup 3/H-prazosin binding in order of prazosin > phentolamine > methoxamine > norepinephrine > clonidine > epinephrine > yohimbine. These drugs competed for /sup 3/H-yohimbine binding in order of yohimbine > phentolamine > clonidine > epinephrine > norepinephrine > prazosin > methoxamine. They also examined whether dopamine receptors exist in guinea-pig stomach, using radioligand binding study. Specific binding of /sup 3/H-spiperone, /sup 3/H-apomorphine, /sup 3/H-dopamine and /sup 3/H-domperidone was not detectable in the stomach. Dopaminergic drugs such as dopamine, haloperidol, domperidone and sulpiride competed for /sup 3/H-prazosin binding in order of haloperidol > domperidone > dopamine > sulpiride. Metoclopramide, sulpiride and dopamine competed for /sup 3/H-yohimbine binding in order of metoclopramide > sulpiride > dopamine.

  7. A Critical Examination of the l-C3H-2 Spectrum and the Diffuse Interstellar Bands

    NASA Astrophysics Data System (ADS)

    McCall, B. J.; Oka, T.; Thorburn, J.; Hobbs, L. M.; York, D. G.

    2002-03-01

    It has recently been suggested by J. P. Maier's group that the origin band and three vibronic bands of the linear propadienylidene anion l-C3H-2 match the diffuse interstellar bands (DIBs). We have examined the wavelength ranges in question using data from our ongoing DIB survey at the Apache Point Observatory. We find that the strongest DIB (λ6993) is not an acceptable wavelength match to the origin band of l-C3H-2, based on high-resolution laboratory data. The nondetection of interstellar features corresponding to the K=2<--1 and K=0<--1 branches of para l-C3H-2 also argues against the assignment of λ6993 to the K=1<--0 branch of ortho l-C3H-2. Two of the three DIBs that have been attributed to vibronic bands do not correlate in intensity with λ6993, providing further evidence against the assignment of this set of DIBs to l-C3H-2.

  8. Pressure Effects on Product Channels of the Allyl Radical Reactions; C3H5+C3H5 and C3H5+CH3

    NASA Astrophysics Data System (ADS)

    Halpern, J. B.; N'Doumi, M.; Fahr, A.

    2011-12-01

    Relatively large hydrocarbon molecules (C4, C6 and larger) have been detected in several planetary environments. The mechanism for the formation of such large molecular species and detailed mechanism for their potential destruction are not well understood and are of considerable current interest. Previously we have studied the kinetics and product channels of small unsaturated hydrocarbon radical (C2 and C3s) reactions relevant to planetary atmospheric modeling. Reactions of C2 radicals (such as vinyl, H2CCH and ethynyl C2H) and C3 radicals (such as propargyl, HCCCH2) can affect the abundances of a large number of stable observable C3, C4, C5, C6 and larger molecules, including linear, aromatic and even poly aromatic molecules. Pressure-dependent product yields have been determined experimentally for the self- and cross-radical reactions performed at 298 K and at pressures between ~4 Torr (0.5 kPa) and 760 Torr (101 kPa). Final reaction products were quantitatively determined using a gas chromatograph with mass spectrometry/flame ionization detection (GC/MS/FID). In some cases complementary computational studies extended the pressure and temperature range of the experiments and provided valuable information on the complex reaction mechanisms. Theses studies provide a systematic framework so that important energetic and structural parameters for radical-radical reactions can be assessed. Here we report recent results for the allyl radical reactions H2CCCH3+ H2CCCH3 and H2CCCH3+CH3. For the allyl radical self-reaction, at high pressures the "head -to-head", combination channel forming 1,5-hexadiene is dominant with a combination/disproportionation = 1,5-hexadiene/propyne ratio of about 24 at 500 Torr (67 kPa, T=298K). At low pressures the ratio is substantially reduced to about 1.2 (at 0.3 kPa) and other major products are observed including allene, propene, 1-butene and propyne.

  9. Exceedingly Low Freezing Rates of Aqueous Hno3 and Hno3/h2so4 Droplets Under Polar Stratospheric Conditions

    NASA Astrophysics Data System (ADS)

    Knopf, D. A.; Koop, T.; Luo, B.; Weers, U. G.; Peter, T.

    In the Arctic winter 1999/2000 large particles containing nitric acid were observed during in situ field measurements. These large particles are important for the deni- trification of the Arctic stratosphere. It has been proposed that such particles form by homogeneous nucleation of nitric acid hydrates from liquid stratospheric aerosol droplets. Homogeneous nucleation rates of NAT (Nitric Acid Trihydrate) and NAD (Nitric Acid Dihydrate) have been determined in laboratory experiments for binary HNO3/H2O solutions only at supersaturations much larger than observed in the stratosphere. Therefore, an extrapolation of such laboratory data is required for the modelling of stratospheric particle formation and subsequent denitrification. We will present new laboratory data of homogeneous nucleation rates of NAT and NAD from droplets consisting of both binary HNO3/H2O as well as ternary HNO3/H2O/H2SO4 solutions. Optical microscopy has been used to deduce the droplet freezing tempera- tures. The nature of the crystallized solids was identified by Raman spectroscopy. The freezing data have been analyzed within the framework of classical nucleation theory. Our results are consistent with previously published laboratory aerosol data. However, for stratospheric conditions, we infer homogeneous nucleation rates to be lower by orders of magnitude than the extrapolation currently in use. We conclude that homo- geneous nucleation of NAT and NAD is not sufficient to explain the observed number concentrations of large nitric acid containing particles in the stratosphere.

  10. One dimensional 1H, 2H and 3H

    NASA Astrophysics Data System (ADS)

    Vidal, A. J.; Astrakharchik, G. E.; Vranješ Markić, L.; Boronat, J.

    2016-05-01

    The ground-state properties of one-dimensional electron-spin-polarized hydrogen 1H, deuterium 2H, and tritium 3H are obtained by means of quantum Monte Carlo methods. The equations of state of the three isotopes are calculated for a wide range of linear densities. The pair correlation function and the static structure factor are obtained and interpreted within the framework of the Luttinger liquid theory. We report the density dependence of the Luttinger parameter and use it to identify different physical regimes: Bogoliubov Bose gas, super-Tonks–Girardeau gas, and quasi-crystal regimes for bosons; repulsive, attractive Fermi gas, and quasi-crystal regimes for fermions. We find that the tritium isotope is the one with the richest behavior. Our results show unambiguously the relevant role of the isotope mass in the properties of this quantum system.

  11. Encapsulated scintillators monitor /sup 3/H-solute concentrations

    SciTech Connect

    Kirk, G.; Gruner, S.

    1982-02-01

    The short range of the /sup 3/H beta allows shielding of microbeds of scintillator by a several um thick coating of a water based gel. Gels may be used which are permeable to a wide variety of tritiated molecules. Thus, the light output of a mixture of the coated beads and a solution of the tritiated compound is proportional to the solution concentration of the tritiated substance. The mixture may also contain particles to which the gel is impermeable, such as cells, vesicles, large proteins, etc., but which can alter the concentration of the tritiated compound by uptake or release. In this case, the light output monitors the fractional uptake of the tritiated material. The design criteria for encapsulating the scintillators and dynamically monitoring the scintillation output are discussed. A simple method for encapsulating plastic scintillator microbeads, suitable for monitoring slow concentration changes, is described and tested.

  12. Study of the $\\tau^- to 3h^- 2h^+ \

    SciTech Connect

    Aubert, Bernard; Barate, R.; Boutigny, D.; Couderc, F.; Karyotakis, Y.; Lees, J.P.; Poireau, V.; Tisserand, V.; Zghiche, A.; Grauges, E.; Palano, A.; Pappagallo, M.; Pompili, A.; Chen, J.C.; Qi, N.D.; Rong, G.; Wang, P.; Zhu, Y.S.; Eigen, G.; Ofte, I.; Stugu, B. /more authors..

    2005-05-04

    The branching fraction of the {tau}{sup -} {yields} 3h{sup -} 2h{sup +} {nu}{sub {tau}} decay (h = {pi}, K) is measured with the BABAR detector to be (8.56 {+-} 0.05 {+-} 0.42) x 10{sup -4}, where the first error is statistical and the second systematic. The observed structure of this decay is significantly different from the phase space prediction, with the {rho} resonance playing a strong role. The decay {tau}{sup -} {yields} f{sub 1}(1285){pi}{sup -}{nu}{sub {tau}}, with the f{sub 1}(1285) meson decaying to four charged pions, is observed and the branching fraction is measured to be (3.9 {+-} 0.7 {+-} 0.5) x 10{sup -4}.

  13. The 3H(d,γ)5He Reaction for Ec.m. ≤ 300 keV

    NASA Astrophysics Data System (ADS)

    Parker, C. E.; Brune, C. R.; Massey, T. N.; O'Donnell, J. E.; Richard, A. L.; Sayre, D. B.

    2016-03-01

    The 3H(d, γ)5He reaction has been measured using a 500-keV pulsed deuteron beam incident on a stopping titanium tritide target at Ohio University's Edwards Accelerator Laboratory. The time-of-flight (TOF) technique has been used to distinguish the γ-rays from neutrons detected in the bismuth germinate (BGO) γ-ray detector. A stilbene scintillator and an NE-213 scintillator have been used to detect the neutrons from the 3H(d, n)4He reaction using both the pulse-shape discrimination and TOF techniques. A newly-designed target holder with a silicon surface barrier detector to simultaneously measure α-particles to normalize the neutron count was incorporated for subsequent measurements. The γ-rays have been measured at laboratory angles of 0°, 45°, 90°, and 135°. Information about the γ-ray energy distribution for the unbound ground state and first excited state of 5He can be obtained experimentally by comparing the BGO data to Monte Carlo simulations. The 3H(d, γ)/3H(d, n) branching ratio has also been determined.

  14. Ascorbic acid and striatal transport of (/sup 3/H)1-methyl-4-phenylpyridine (MPP/sup +/) and (/sup 3/H)dopamine

    SciTech Connect

    Debler, E.A.; Hashim, A.; Lajtha, A.; Sershen, H.

    1988-01-01

    The inhibition of uptake of (/sup 3/H)dopamine and (/sup 3/H)1-methyl-4-phenylpyridine (MPP/sup +/) was examined in mouse striatal synaptosomal preparations. Kinetic analysis indicated that ascorbic acid is a noncompetitive inhibitor of (/sup 3/H)MPP/sup +/ uptake. No inhibition of (/sup 3/H)dopamine uptake is observed. The dopamine uptake blockers, GBR-12909, cocaine, and mazindol strongly inhibit (IC/sub 50/ < 1 ..mu..M) both (/sup 3/H)dopamine and (/sup 3/H)MPP/sup +/ transport. Nicotine, its metabolites, and other tobacco alkaloids are weak inhibitors except 4-phenylpyridine and lobeline, which are moderate inhibitors of both (/sup 3/H)dopamine and (/sup 3/H)MPP/sup +/ uptake. These similarities in potencies are in agreement with the suggestion that (/sup 3/H)MPP/sup +/ and (/sup 3/H) are transported by the same carrier. The differences observed in the alteration of dopaminergic transport and mazindol binding by ascorbic acid suggest that ascorbic acid's effects on (/sup 3/H)MPP/sup +/ transport are related to translocation and/or dissociation processes occurring subsequent to the initial binding event.

  15. 3,4-Methylenedioxyamphetamine (MDA) analogues exhibit differential effects on synaptosomal release of 3H-dopamine and 3H-5-hydroxytryptamine

    SciTech Connect

    McKenna, D.J.; Guan, X.M.; Shulgin, A.T. )

    1991-03-01

    The effect of various analogues of the neurotoxic amphetamine derivative, MDA (3,4-methylenedioxyamphetamine) on carrier-mediated, calcium-independent release of 3H-5-HT and 3H-DA from rat brain synaptosomes was investigated. Both enantiomers of the neurotoxic analogues MDA and MDMA (3,4-methylenedioxymethamphetamine) induce synaptosomal release of 3H-5-HT and 3H-DA in vitro. The release of 3H-5-HT induced by MDMA is partially blocked by 10(-6) M fluoxetine. The (+) enantiomers of both MDA and MDMA are more potent than the (-) enantiomers as releasers of both 3H-5-HT and 3H-DA. Eleven analogues, differing from MDA with respect to the nature and number of ring and/or side chain substituents, also show some activity in the release experiments, and are more potent as releasers of 3H-5-HT than of 3H-DA. The amphetamine derivatives {plus minus}fenfluramine, {plus minus}norfenfluramine, {plus minus}MDE, {plus minus}PCA, and d-methamphetamine are all potent releasers of 3H-5-HT and show varying degrees of activity as 3H-DA releasers. The hallucinogen DOM does not cause significant release of either 3H-monoamine. Possible long-term serotonergic neurotoxicity was assessed by quantifying the density of 5-HT uptake sites in rats treated with multiple doses of selected analogues using 3H-paroxetine to label 5-HT uptake sites. In the neurotoxicity study of the compounds investigated, only (+)MDA caused a significant loss of 5-HT uptake sites in comparison to saline-treated controls. These results are discussed in terms of the apparent structure-activity properties affecting 3H-monoamine release and their possible relevance to neurotoxicity in this series of MDA congeners.

  16. 3,4-Methylenedioxyamphetamine (MDA) analogues exhibit differential effects on synaptosomal release of 3H-dopamine and 3H-5-hydroxytryptamine.

    PubMed

    McKenna, D J; Guan, X M; Shulgin, A T

    1991-03-01

    The effect of various analogues of the neurotoxic amphetamine derivative, MDA (3,4-methylenedioxyamphetamine) on carrier-mediated, calcium-independent release of 3H-5-HT and 3H-DA from rat brain synaptosomes was investigated. Both enantiomers of the neurotoxic analogues MDA and MDMA (3,4-methylenedioxymethamphetamine) induce synaptosomal release of 3H-5-HT and 3H-DA in vitro. The release of 3H-5-HT induced by MDMA is partially blocked by 10(-6) M fluoxetine. The (+) enantiomers of both MDA and MDMA are more potent than the (-) enantiomers as releasers of both 3H-5-HT and 3H-DA. Eleven analogues, differing from MDA with respect to the nature and number of ring and/or side chain substituents, also show some activity in the release experiments, and are more potent as releasers of 3H-5-HT than of 3H-DA. The amphetamine derivatives (+/-)fenfluramine, (+/-)norfenfluramine, (+/-)MDE, (+/-)PCA, and d-methamphetamine are all potent releasers of 3H-5-HT and show varying degrees of activity as 3H-DA releasers. The hallucinogen DOM does not cause significant release of either 3H-monoamine. Possible long-term serotonergic neurotoxicity was assessed by quantifying the density of 5-HT uptake sites in rats treated with multiple doses of selected analogues using 3H-paroxetine to label 5-HT uptake sites. In the neurotoxicity study of the compounds investigated, only (+)MDA caused a significant loss of 5-HT uptake sites in comparison to saline-treated controls. These results are discussed in terms of the apparent structure-activity properties affecting 3H-monoamine release and their possible relevance to neurotoxicity in this series of MDA congeners. PMID:1829838

  17. Selective labeling of serotonin uptake sites in rat brain by (/sup 3/H)citalopram contrasted to labeling of multiple sites by (/sup 3/H)imipramine

    SciTech Connect

    D'Amato, R.J.; Largent, B.L.; Snowman, A.M.; Snyder, S.H.

    1987-07-01

    Citalopram is a potent and selective inhibitor of neuronal serotonin uptake. In rat brain membranes (/sup 3/H)citalopram demonstrates saturable and reversible binding with a KD of 0.8 nM and a maximal number of binding sites (Bmax) of 570 fmol/mg of protein. The drug specificity for (/sup 3/H)citalopram binding and synaptosomal serotonin uptake are closely correlated. Inhibition of (/sup 3/H)citalopram binding by both serotonin and imipramine is consistent with a competitive interaction in both equilibrium and kinetic analyses. The autoradiographic pattern of (/sup 3/H)citalopram binding sites closely resembles the distribution of serotonin. By contrast, detailed equilibrium-saturation analysis of (/sup 3/H)imipramine binding reveals two binding components, i.e., high affinity (KD = 9 nM, Bmax = 420 fmol/mg of protein) and low affinity (KD = 553 nM, Bmax = 8560 fmol/mg of protein) sites. Specific (/sup 3/H)imipramine binding, defined as the binding inhibited by 100 microM desipramine, is displaced only partially by serotonin. Various studies reveal that the serotonin-sensitive portion of binding corresponds to the high affinity sites of (/sup 3/H)imipramine binding whereas the serotonin-insensitive binding corresponds to the low affinity sites. Lesioning of serotonin neurons with p-chloroamphetamine causes a large decrease in (/sup 3/H)citalopram and serotonin-sensitive (/sup 3/H)imipramine binding with only a small effect on serotonin-insensitive (/sup 3/H)imipramine binding. The dissociation rate of (/sup 3/H)imipramine or (/sup 3/H)citalopram is not altered by citalopram, imipramine or serotonin up to concentrations of 10 microM. The regional distribution of serotonin sensitive (/sup 3/H)imipramine high affinity binding sites closely resembles that of (/sup 3/H)citalopram binding.

  18. C3H2 observations as a diagnostic probe for molecular clouds

    NASA Technical Reports Server (NTRS)

    Avery, L. W.

    1986-01-01

    Recently the three-membered ring molecule, cyclopropenylidene, C3H2, has been identified in the laboratory and detected in molecular clouds by Thaddeus, Vrtilek and Gottlieb (1985). This molecule is wide-spread throughout the Galaxy and has been detected in 25 separate sources including cold dust clouds, circumstellar envelopes, HII regions, and the spiral arms observed against the Cas supernova remnant. In order to evaluate the potential of C3H2 as a diagnostic probe for molecular clouds, and to attempt to identify the most useful transitions, statistical equilibrium calculations were carried out for the lowest 24 levels of the ortho species and the lowest 10 levels of the para species. Many of the sources observed by Matthews and Irvine (1985) show evidence of being optically thick in the 1(10)-1(01) line. Consequently, the effects of radiative trapping should be incorporated into the equilibrium calculations. This was done using the Large Velocity Gradient approximation for a spherical cloud of uniform density. Some results of the calculations for T(K)=10K are given. Figures are presented which show contours of the logarithm of the ratio of peak line brightness temperatures for ortho-para pairs of lines at similar frequencies. It appears that the widespread nature of C3H2, the relatively large strength of its spectral lines, and their sensitivity to density and molecular abundance combine to make this a useful molecule for probing physical conditions in molecular clouds. The 1(10)-1(01) and 2(20)-2(11) K-band lines may be especially useful in this regard because of the ease with which they are observed and their unusual density-dependent emission/absorption properties.

  19. Preservation of "peripheral" benzodiazepine receptors: differential effects of freezing on [3H]Ro 5-4864 and [3H]PK 11195 binding.

    PubMed

    Basile, A S; Skolnick, P

    1987-04-01

    The equilibrium binding constants of [3H]Ro 5-4864 (a "peripheral" benzodiazepine receptor ligand) to renal membranes preserved by various freezing techniques were investigated. The Bmax for [3H]Ro 5-4864 binding to membranes from kidneys preserved as unwashed homogenates stored at -80, -20, or 5 degrees C, whole kidneys stores at -20 or 5 degrees C or as washed homogenate stored at -20 degrees C was significantly decreased (approximately 35%). Only when kidneys were frozen intact (using a dry-ice/acetone slurry) and stored at -80 degrees C was the density of [3H]Ro 5-4864 binding unchanged. However, the Bmax of [3H]PK 11195 (a putative "peripheral" benzodiazepine receptor antagonist) binding to renal membranes was unchanged following storage techniques that reduced the density of [3H]Ro 5-4864 binding 38%. No change was observed in the Kd values for [3H]Ro 5-4864 and [3H]PK 11195 binding to renal membranes preserved under any condition tested. These results demonstrate a method for the preservation of [3H]Ro 5-4864 binding to renal membranes, and suggests that [3H]Ro 5-4864 and [3H]PK 11195 bind to unique sites on or near the "peripheral" benzodiazepine receptor. [corrected] PMID:3035290

  20. Alpha-adrenoceptors in dog mesenteric vessels--subcellular distribution and number of ( sup 3 H)prazosin and ( sup 3 H)rauwolscine binding sites

    SciTech Connect

    Shi, A.G.; Ahmad, S.; Kwan, C.Y.; Daniel, E.E. )

    1990-04-01

    Binding of the alpha-adrenergic antagonists ({sup 3}H)prazosin and ({sup 3}H)rauwolscine to well-characterized subcellular membrane fractions isolated from dog mesenteric arteries and veins was studied. Binding of both ligands was saturable with Kd values of 0.5 +/- 0.1 nM for ({sup 3}H)prazosin and 5.85 +/- 0.85 nM for ({sup 3}H)rauwolscine in arteries, and 0.87 +/- 0.4 nM for ({sup 3}H)prazosin and 6.6 +/- 1.5 nM for ({sup 3}H)rauwolscine in veins. In veins, the maximum number of binding sites for ({sup 3}H)rauwolscine was higher than that for ({sup 3}H)prazosin, whereas in arteries the maximum number of binding sites for each ligand was similar. In microsomes from dog aorta, the maximum number of bindings sites for ({sup 3}H)prazosin was higher than that for ({sup 3}H)rauwolscine. Neuronal membrane contamination in these studies was minimized by dissection procedures and evaluated by the comparison of ({sup 3}H)saxitoxin binding in various preparations. Only mesenteric veins responded functionally to agonists acting on alpha 2 adrenoceptors. This study thus identified two distinct populations of ({sup 3}H)prazosin and ({sup 3}H)rauwolscine binding sites in the plasma membranes of dog mesenteric vessels and suggests that a much higher density of alpha 2-compared to alpha 1-adrenoceptor binding sites is required for a contractile response.

  1. In vivo labeling of cocaine receptors with sup 3 H-(-) cocaine, sup 3 H-WIN 35,065-2 and sup 3 H-WIN 35,428

    SciTech Connect

    Scheffel, U.; Boja, J.W.; Stathis, M.; Kuhar, M.J. )

    1990-02-26

    {sup 11}C-(-)cocaine (-COC) has recently been employed to image -COC binding sites in vivo using PET. Two analogs of -COC, WIN 35,065-2 (WIN-2) and WIN 35,428 (CFT), have been shown in vitro to exhibit higher affinity for the -COC receptor than -COC. The present study evaluates {sup 3}H-WIN-2 and {sup 3}H-CFT as in vivo receptor labels in mice with a view towards the use of these compounds as PET ligands for -COC receptors in the living human brain. {sup 3}H-labeled -COC, WIN-2 and CFT were injected i.v. into mice and their specific binding in the CNS determined. Peak striatal/cerebellar (S/C) ratios were reached at 5 minutes post injection with -COC (1.56), at 45 minutes with {sup 3}H-WIN-2 (3.30) and 60 minutes with {sup 3}H-CFT (4.0). The specificity of in vivo binding of {sup 3}H-WIN-2 and {sup 3}H-CFT was tested by pre-injection of various drugs. Binding of {sup 3}H-WIN-2 and {sup 3}H-CFT was dose-dependently blocked by cold WIN-2 and CFT, and by dopamine uptake site inhibitors (mazindol, GBR 12,909, nomifensine), but not by (+)COC, paroxetine and desipramine. The data indicate that {sup 3}H-WIN-2 and {sup 3}H-CFT exhibit improved in vivo binding (higher S/C ratios, longer retention time at the -COC receptor/dopamine transporter) compared to -COC and support their testing in PET studies.

  2. Astrophysical S factors for radiative proton capture by {sup 3}H and {sup 7}Li nuclei

    SciTech Connect

    Dubovichenko, S. B.

    2011-03-15

    Within the potential cluster model where orbital states are classified according to Young diagrams and isospin, astrophysical S factors are considered for radiative proton capture by {sup 3}H and {sup 7}Li nuclei at energies of up to 1 and 10 keV, respectively. It is shown that the approach used, which takes into account only the E1 transition for the p{sup 3}H capture process, makes it possible to describe well the most recent experimental data at c.m. energies in the range from 50 keV to 5MeV. In the case of proton capture by {sup 7}Li nuclei, an M1 processwas taken into account in addition to the E1 transition, and a general behavior and the magnitude of the experimental S factor could be correctly reproduced owing to this at astrophysical energies, including the region around the resonance at 0.441 MeV (in the laboratory frame).

  3. Monte Carlo simulation of a photodisintegration of 3 H experiment in Geant4

    NASA Astrophysics Data System (ADS)

    Gray, Isaiah

    2013-10-01

    An upcoming experiment involving photodisintegration of 3 H at the High Intensity Gamma-Ray Source facility at Duke University has been simulated in the software package Geant4. CAD models of silicon detectors and wire chambers were imported from Autodesk Inventor using the program FastRad and the Geant4 GDML importer. Sensitive detectors were associated with the appropriate logical volumes in the exported GDML file so that changes in detector geometry will be easily manifested in the simulation. Probability distribution functions for the energy and direction of outgoing protons were generated using numerical tables from previous theory, and energies and directions were sampled from these distributions using a rejection sampling algorithm. The simulation will be a useful tool to optimize detector geometry, estimate background rates, and test data analysis algorithms. This work was supported by the Triangle Universities Nuclear Laboratory REU program at Duke University.

  4. Binding of dexetimide and levetimide to [3H](+)pentazocine- and [3H]1,3-di(2-tolyl)guanidine-defined sigma recognition sites.

    PubMed

    DeHaven-Hudkins, D L; Hudkins, R L

    1991-01-01

    The potent antimuscarinic benzetimide and its resolved stereoisomers dexetimide and levetimide were tested for their affinities at sigma sites labelled by [3H](+)pentazocine or [3H]1,3-di(2-tolyl)guanidine. Levetimide was a potent and stereoselective inhibitor of [3H](+)pentazocine binding, with a Ki of 2.2 nM, while dexetimide was nine-fold less potent (Ki = 19 nM). Dexetimide and levetimide potently inhibited [3H]DTG binding although without stereoselectivity (Ki values of 65 and 103 nM, respectively). Levetimide may be a useful tool with which to investigate sigma recognition sites and sigma subtypes. PMID:1656155

  5. Ethanol intake and sup 3 H-serotonin uptake II: A study in alcoholic patients using platelets sup 3 H-paroxetine binding

    SciTech Connect

    Daoust, M.; Boucly, P. ); Ernouf, D. ); Breton, P. ); Lhuintre, J.P.

    1991-01-01

    The kinetic parameters of {sup 3}H-paroxetine binding and {sup 3}H-serotonin uptake were studied in platelets of alcoholic patients. There was no difference between alcoholic and non alcoholic subjects in {sup 3}H-paroxetine binding. When binding and {sup 3}H-serotonin uptake were studied, in the same plasma of the same subjects, the Vmax of serotonin uptake was increased in alcoholics. The data confirm the involvement of serotonin uptake system in alcohol dependance and suggest that serotonin uptake and paroxetine binding sites may be regulated independently in this pathology.

  6. Phosphorus balance and mineral metabolism with 3 h daily hemodialysis.

    PubMed

    Ayus, J C; Achinger, S G; Mizani, M R; Chertow, G M; Furmaga, W; Lee, S; Rodriguez, F

    2007-02-01

    Poor control of mineral metabolism is independently associated with mortality in patients receiving hemodialysis. We analyzed data from a 12-month, prospective, non-randomized, controlled study of daily hemodialysis (DHD) (six sessions/week 3 h each) (n=26) vs conventional hemodialysis (CHD) (three sessions/week 4 h each) (n=51) for achievement of mineral metabolism goals and we performed a substudy of weekly dialytic phosphorus removal in DHD vs CHD. Phosphorus control was superior in the DHD group (% change from baseline to end-of-study -27+/-30% vs +7%+/-35% in the CHD group, P=0.0001). Percentage of patients using phosphate binders decreased from 77 to 40% among subjects on DHD, whereas these parameters did not change (76 vs 77%) in the CHD group (P=0.03 by Breslow-Day test for homogeneity of the odds ratios). Weekly mean phosphorus removal was higher in the DHD group (2452+/-720 mg/week vs 1572+/-366 mg/week, P=0.04). Mean normalized protein catabolic rate increased (0.90+/-0.43-1.22+/-0.26 g/kg/day, P=0.0013). DHD was also associated with an increase in the percent of subjects achieving three or more mineral metabolism goals (for phosphorus, calcium x phosphorus and parathyroid hormone) (15 vs 46%, P=0.046). In conclusion, DHD improves phosphorus control by increasing dialytic phosphorus removal while maintaining nutritional status and reducing the use of phosphate binders. The net effect allows for improved achievement of mineral metabolism goals. PMID:17191084

  7. Calculation of cell production from ( sup 3 H)Thymidine incorporation with freshwater bacteria

    SciTech Connect

    Smits, J.D. ); Riemann, B. )

    1988-09-01

    The conversion factor for the calculation of bacterial production from rates of ({sup 3}H)thymidine incorporation was examined with diluted batch cultures of freshwater bacteria. Natural bacterial assemblages were grown in aged, normal, and enriched media at 10 to 20{degree}C. The generation time during 101 growth cycles covered a range from 4 to >200 h. The average conversion factor was 2.15 {times} 10{sup 18} cells mol{sup {minus}1} of thymidine incorporated into the trichloroacetic acid (TCA) precipitate, when the generation time exceeded 20 h. At generation times of <20 h, the average conversion factor was 11.8 {times} 10{sup 18} cells mol{sup {minus}1} of thymidine incorporated into TCA precipitate. The amount of radioactivity in purified DNA increased with decreasing generation time and increasing conversion factor (calculated from the TCA precipitate), corresponding to a decrease in the percentage in protein. The conversion factors calculated from purified DNA or from the TCA precipitate gave the same variability. Conversion factors did not change significantly with the medium, but were significantly higher at 20{degree}C that at 15 and 10{degree}C. Results suggests that incorporation of ({sup 3}H)thymidine into DNA is probably limited by uptake during period with generation times of <20 h and that freshwater bacterioplankton cell production sometimes is underestimated when a conversion factor of 2.15 {times} 10{sup 18} cells mol{sup {minus}1} of thymidine incorporated is used.

  8. Measurement of the distribution of [3H]bicuculline microinjected into the rat hypothalamus.

    PubMed

    Segura, T; Martin, D S; Sheridan, P J; Haywood, J R

    1992-02-01

    The purpose of this study was to measure the distribution of a radiolabeled drug [3H]bicuculline methylchloride ([3H]BMC) following microinjection into the supraoptic nuclei (SON) and the dorsal hypothalamus of conscious rats. The anteroposterior (AP) distribution was measured using liquid-scintillation counting while computer-assisted densitometry was used to measure the mediolateral (ML) and dorsoventral (DV) distribution of silver grains on autoradiograms. Following a 50-nl microinjection into the SON, 90% of the detected tracer was found within 0.6 +/- 0.1 mm (n = 5) of the injection site. Using the same volume, the pattern of distribution of 90% of the detected tracer in the SON was not significantly altered when rats received a microinfusion over 10 min (n = 5) or a bolus microinjection with a 10 min waiting period (n = 6) prior to death. Following a 100-nl microinfusion over 20 min into the dorsal hypothalamus, 90% of the detected radiolabel was found within 0.6 +/- 0.1 mm (n = 7) of the injection site, in a spherical pattern of distribution. Although caution must be used in extrapolating these results to other drugs, these data suggest that intraparenchymal microinjections of 50- and 100-nl volumes are suitable for drug localization in studies using microinjection techniques for conscious rats. PMID:1564952

  9. Energy metabolism used as a tool to model the transfer of 14C and 3H in animals.

    PubMed

    Melintescu, A; Galeriu, D

    2010-11-01

    The transfer through the environment of (3)H and (14)C must be modelled differently than that of other radionuclides released from nuclear reactors because hydrogen and carbon enter straight into the life cycle. A solid understanding of the behaviour of (3)H and (14)C in the food chain is essential because (3)H may be released in large quantities from future thermonuclear reactors, and (14)C accumulates in the environment because of its long half-life. For the present study, the hypothesis that both (3)H and (14)C metabolism in mammals can be modelled based on the understanding of energy metabolism has been tested. Recently published results demonstrate that the loss rate of organically bound tritium and (14)C from tissues of laboratory and farm animals can be assessed based upon their specific metabolic rates and enthalpy of combustion; the same is true for human beings. The improved model presented here relates the dynamics of organically bound tritium and (14)C within organs to the whole body and has been expanded to account for the growth of ruminants. The improved model has been expanded and applied for (14)C transfer in wild mammals and has been modified to apply to birds. PMID:20532542

  10. Angiotensin II stimulates /sup 3/H-leucine and /sup 3/H-thymidine incorporation in cultured vascular smooth muscle cells

    SciTech Connect

    Dwyer, S.D.; Smith, J.B.

    1987-05-01

    Angiotensin II (ANG) stimulates the hydrolysis of phosphatidylinositol bisphosphate with the consequent formation of inositol trisphosphate and diacylglycerol in cultured smooth muscle cells derived from rat aorta. They have observed the effects of ANG on protein and DNA synthesis by measuring the incorporation of /sup 3/H-leucine and /sup 3/H-thymidine, respectively, into acid-precipitable material. Aortic muscle cells were grown to confluence in medium containing 10% fetal bovine serum (FBS) and incubated for 24 hours in serum-free medium to arrest growth. Then fresh serum-free medium was added with the following additions: ANG (100 nM), insulin (2 ..mu..g/ml), or 10% FBS. After an additional 24 hours the cells were pulse labeled for 30 min with either /sup 3/H-leucine or /sup 3/H-thymidine. FBS increased /sup 3/H-leucine incorporation by -2.5 fold and /sup 3/H-thymidine incorporation by 7-10 fold. ANG or insulin increased /sup 3/H-leucine incorporation by 40-50%, and the combination of ANG and insulin was nearly as effective as 10% FBS. ANG stimulated /sup 3/H-thymidine incorporation by -2.5 fold. Insulin, which was less effective than ANG, increased /sup 3/H-thymidine incorporation by about 50%. ANG and insulin added together synergistically increased /sup 3/H-thymidine incorporation by 5-6 fold. An ANG antagonist, Sarl,leu8-ANG, at 2 ..mu..M markedly decreased /sup 3/H-thymidine incorporation in the presence of ANG and insulin.

  11. Uptake and metabolism of L-(/sup 3/H)glutamate and L-(/sup 3/H)glutamine in adult rat cerebellar slices

    SciTech Connect

    de Barry, J.; Vincendon, G.; Gombos, G.

    1983-10-01

    Using very low concentrations (1 mumol range) of L-2-3-(/sup 3/H)glutamate, (/sup 3/H-Glu) or L-2-3-(/sup 3/H)glutamine (/sup 3/H-Gln), the authors have previously shown by autoradiography that these amino acids were preferentially taken up in the molecular layer of the cerebellar cortex. Furthermore, the accumulation of /sup 3/H-Glu was essentially glial in these conditions. Uptake and metabolism of either (/sup 3/H-Glu) or (/sup 3/H-Gln) were studied in adult rat cerebellar slices. Both amino acids were rapidly converted into other metabolic compounds: after seven minutes of incubation in the presence of exogenous /sup 3/H-Glu, 70% of the tissue accumulated radioactivity was found to be in compounds other than glutamate. The main metabolites were Gln (42%), alpha-ketoglutarate (25%) and GABA (1,4%). In the presence of exogenous /sup 3/H-Gln the rate of metabolism was slightly slower (50% after seven minutes of incubation) and the metabolites were also Glu (29%), alpha-ketoglutarate (15%) and GABA (5%). Using depolarizing conditions (56 mM KCl) with either exogenous /sup 3/H-Glu or /sup 3/H-Gln, the radioactivity was preferentially accumulated in glutamate compared to control. From these results we conclude: i) there are two cellular compartments for the neurotransmission-glutamate-glutamine cycle; one is glial, the other neuronal; ii) these two cellular compartments contain both Gln and Glu; iii) transmitter glutamate is always in equilibrium with the so-called ''metabolic'' pool of glutamate; iv) the regulation of the glutamate-glutamine cycle occurs at least at two different levels: the uptake of glutamate and the enzymatic activity of the neuronal glutaminase.

  12. DNA Mismatch Repair Interacts with CAF-1- and ASF1A-H3-H4-dependent Histone (H3-H4)2 Tetramer Deposition.

    PubMed

    Rodriges Blanko, Elena; Kadyrova, Lyudmila Y; Kadyrov, Farid A

    2016-04-22

    DNA mismatch repair (MMR) is required for the maintenance of genome stability and protection of humans from several types of cancer. Human MMR occurs in the chromatin environment, but little is known about the interactions between MMR and the chromatin environment. Previous research has suggested that MMR coincides with replication-coupled assembly of the newly synthesized DNA into nucleosomes. The first step in replication-coupled nucleosome assembly is CAF-1-dependent histone (H3-H4)2 tetramer deposition, a process that involves ASF1A-H3-H4 complex. In this work we used reconstituted human systems to investigate interactions between MMR and CAF-1- and ASF1A-H3-H4-dependent histone (H3-H4)2 tetramer deposition. We have found that MutSα inhibits CAF-1- and ASF1A-H3-H4-dependent packaging of a DNA mismatch into a tetrasome. This finding supports the idea that MMR occurs before the DNA mismatch is packaged into the tetrasome. Our experiments have also revealed that CAF-1- and ASF1A-H3-H4-dependent deposition of the histone (H3-H4)2 tetramers does not interfere with MMR reactions. In addition, we have established that unnecessary degradation of the discontinuous strand that takes place in both DNA polymerase δ (Pol δ)- and DNA polymerase ϵ (Pol ϵ)-dependent MMR reactions is suppressed by CAF-1- and ASF1A-H3-H4-dependent deposition of the histone (H3-H4)2 tetramers. These data suggest that CAF-1- and ASF1A-H3-H4-dependent deposition of the histone (H3-H4)2 tetramers is compatible with MMR and protects the discontinuous daughter strand from unnecessary degradation by MMR machinery. PMID:26945061

  13. Nucleation kinetics of nesquehonite (MgCO 3·3H 2O) in the MgCl 2-Na 2CO 3 system

    NASA Astrophysics Data System (ADS)

    Cheng, Wenting; Li, Zhibao

    2010-04-01

    The nucleation of nesquehonite (MgCO 3·3H 2O) in MgCl 2-Na 2CO 3 system with and without the addition of NaCl was studied within a supersaturation range of 1.06-1.48 at 288.15-308.15 K. The supersaturation ( S) of MgCO 3·3H 2O was exactly calculated by aqueous (H + ion) model through OLI platform. The conductivity method was applied in this experiment to determine the induction period of MgCO 3·3H 2O. The effects of temperature, supersaturation, and presence of additive (NaCl) on the induction period of MgCO 3·3H 2O were studied experimentally. As expected from theory, it was found that the induction period decreases when either temperature or supersaturation increases. The induction period was prolonged by adding NaCl in solutions at a constant supersaturation. From the dependence of the induction period on temperature and supersaturation, it was possible to distinguish between the homogeneous and heterogeneous nucleation mechanisms. At last, the activation energy ( Eact) for MgCO 3·3H 2O crystallization and the interfacial tension between MgCO 3·3H 2O and aqueous solutions of homogeneous ( γS,hom) and heterogeneous ( γS,het) nucleation were calculated from measurements of the induction period for the MgCO 3·3H 2O nucleation with and without the addition of NaCl.

  14. [[sup 3]H] Thymidine incorporation to estimate growth rates of anaerobic bacterial strains

    SciTech Connect

    Winding, A. )

    1992-08-01

    The incorporation of [[sup 3]H] thymidine by axenic cultures of anaerobic bacteria was investigated as a means to measure growth. The three fermentative strains and one of the methanogenic strains tested incorporated [[sup 3]H] thymidine during growth. It is concluded that the [[sup 3]H] thymidine incorporation method underestimates bacterial growth in anaerobic environments.

  15. (3H)domperidone binding to the kidney inner medullary collecting duct dopamine-2K (DA2K) receptor

    SciTech Connect

    Huo, T.; Healy, D.P. )

    1991-08-01

    Previous studies by the authors laboratory have indicated that inner medullary collecting ducts (IMCDs) express a novel dopamine (DA) receptor, designated DA2K, that is linked to stimulation of prostaglandin E2 production. This receptor has a distinct pharmacological profile and is similar in size, but not homologous to, the brain D2 receptor. Because the DA2-selective antagonist domperidone blocks DA-mediated stimulation of prostaglandin E2 production in IMCD cells, we utilized (3H)domperidone to study the binding characteristics of the DA2K receptor in IMCD cells. (3H)Domperidone binding was saturable and best fit to a single high density site (KD, 57.6 {plus minus} 10.5 nM; Bmax, 14.9 {plus minus} 2.7 pmol/mg protein). The specificity of (3H)domperidone binding in IMCD cells was verified by competition analysis with a variety of dopaminergic and nondopaminergic agents. Dopaminergic drugs were less potent competitors for (3H)domperidone binding in IMCD cells than previously reported for brain DA receptors, but the rank order was consistent with the labeling of a DA receptor (antagonists: domperidone greater than spiperone greater than haloperidol greater than Sch 23390 much greater than (-)-sulpiride; agonists: norapomorphine greater than fenoldopam much greater than dopamine = quinpirole), and was better correlated with the pharmacological profile for the brain D2 receptor than the brain D3 receptor. In addition, quinpirole, the most D3-selective ligand currently available, did not compete for (3H)domperidone binding in IMCD cells. These results add further support to the existence of a novel high density DA receptor, DA2K, expressed in IMCD cells.

  16. Photoaffinity labeling of opiate receptors using intrinsically photoactive /sup 3/H-opiates

    SciTech Connect

    Kooper, G.N.; Levinson, N.R.; Copeland, C.F.; Bowen, W.D.

    1988-03-01

    Opiate receptors in rat and cow brain membranes have been labeled irreversibly using the intrinsic photolability of 3H-opiates. Membranes were incubated with 3H-ligand and then irradiated with UV light of 254 nm. Nonspecific binding was determined in the presence of 10 microM unlabeled levallorphan. Irreversible binding was defined as binding which survived heat or acid denaturation of membranes. Specific incorporation of label into denatured samples was observed only when unbound or loosely bound 3H-ligand was washed free from the membranes prior to irradiation. There was a general correlation between photosensitivity of the 3H-ligand and its ability to photolabel receptors. Hence, photolabeling presumably results by covalent attachment of highly reactive species generated during photochemical decomposition of ligand. With 3H-etorphine, optimal irradiation time was 5 min. In addition to 3H-etorphine, receptors could be labeled irreversibly with 3H-oxymorphone, 3H-dihydromorphine, and 3H-ethylketocyclazocine. Of the specific binding present in irradiated, nondenatured samples, 45-60% remained attached to receptors upon denaturation. 3H-Ethylketocyclazocine exhibited an 86% yield of incorporation. Signal-to-noise levels of 50-80% could be achieved in denatured samples. Therefore, this method provides a means of covalently labeling opiate receptors in high yield and with high signal-to-noise ratios. The opioid peptides, 3H-D-Ala2,D-Leu5-enkephalin, 3H-D-Ser2,Leu5,Thr6-enkephalin, 3H-D-Ala2,Met5-enkephalin amide, and 3H-D-Ala2,N-MePhe4,Gly-ol5-enkephalin, as well as the benzomorphan, 3H-bremazocine, apparently lack the structural characteristics which allow photolabeling.

  17. Quantum chemical rovibrational data for the interstellar detection of c-C{sub 3}H{sup -}

    SciTech Connect

    Fortenberry, Ryan C.; Huang, Xinchuan; Crawford, T. Daniel; Lee, Timothy J. E-mail: Timothy.J.Lee@nasa.gov

    2014-12-01

    The anion chemistry of the interstellar medium (ISM) has almost exclusively been limited to linear hydrocarbons and cyanocarbons. Of the hydrocarbons, only the even n C {sub n}H{sup –} chains have been detected in the ISM, and lines hypothesized to originate with b-C{sub 3}H{sup –} have been conclusively linked to the corresponding cation, as originally claimed. However, no reason has yet been provided as to why other anions cannot form, and the cyclic form of C{sub 3}H{sup –} is actually the lowest-energy isomer on the anion's potential energy surface. As such, this work provides the necessary rovibrational reference data for the potential detection of this anion in the ISM or related laboratory experiments. Improvements over previously calculated rovibrational spectroscopic constants are contained herein along with graphical depictions of the pure rotational spectra at 100 K, 40 K, 20 K, and 2.7 K.

  18. Reaction channels and spectroscopic constants of astrophysical relevant Silicon bearing molecules SiC3H,+ and SiC3H

    NASA Astrophysics Data System (ADS)

    Inostroza Pino, N.; Cardenas, C.; Fuentealba, P.

    2014-10-01

    Reaction channels and spectroscopic properties of a series of silicon-carbon-bearing isomers of SiC3H+ and SiC3H, which are suitable species for astrophysical detection in carbon-rich sources, are calculated with correlated ab initio CCSD(T) and density functional theory methods. We present four isomers of SiC3H+ for which the electronic ground states have closed-shell configurations. For SiC3H, we considered the same structures in order to present a complete study. The global minimum among the SiC3H+ isomers corresponds to the rhomboidal structure with a transannular bond in a 1A1 electronic state (rb3-SiC3H+ C2v X1A1). The next minima correspond to a second rhomboid 1A1 isomer and a linear isomer (X1Σ+) with relative energies 0.86 and 0.93 eV, respectively at the CCSD(T)/cc-pvTZ level of theory. The most stable mono-hydrogenated silicon carbon isomer is linear, followed by two rhomboidal isomers, rb2-SiC3H and rb3-SiC3H (0.23 and 0.31 eV). For each structure, a set of spectroscopic parameters including their equilibrium structures, rotational constants, harmonic frequencies and dipole moment is presented. Furthermore, we discuss plausible formation pathways of SiC3H+ isomers which are classified as charge-exchange, ion-neutral and dissociative recombination reactions. These results show one favourable pathway to produce rb3-SiC3H+ from rb-SiC3-3s. The formation energy of the cation's isomers coming from neutral isomers as linear l1-SiC3H, rb3-SiC3H and rb2-SiC3H plus H+ as reactants (charge-exchange reaction) are 203.8 kcal mol-1 (8.84eV), 175.4 kcal mol-1 (7.60 eV) and 195.2 kcal mol-1 (8.46 eV), which provides us with evidence of the endergonic character of these reactions. As a consequence, it does not seem to be feasible to produce a cation from neutral reactant plus H+ by a charge-exchange reaction that was proposed by UMIST.

  19. Autoradiographic analysis of the in vivo distribution of 3H-imipramine and 3H-desipramine in brain: Comparison to in vitro binding patterns

    SciTech Connect

    Duncan, G.E.; Paul, I.A.; Fassberg, J.B.; Powell, K.R.; Stumpf, W.E.; Breese, G.R. )

    1991-03-01

    Using high resolution autoradiographic techniques, the distribution of radioactivity in forebrain and brainstem was assessed after 4 injection of 3H-impramine or 3H-desipramine. Results were compared with regional binding of the drugs to brain sections in vitro. Similar topographic binding of 3H-imipramine and 3H-desipramine was observed in vitro among brain regions, except in the paraventricular nucleus of the hypothalamus and locus coeruleus, where binding was greater for 3H-desipramine. For both 3H-desipramine and 3H-imipramine, some brain regions that exhibited high binding in vitro also showed high accumulation after in vivo injection. However, certain regions that contained high densities of binding sites for the antidepressant drugs as measured by in vitro binding showed very low accumulation of radioactivity after in vivo treatment. Such regions included the dentate gyrus of the hippocampus, layer 1 of piriform cortex, caudate-putamen, pontine and midbrain central gray, and cerebellar granular layer. Compared to in vitro binding of the drugs, the distribution of imipramine and desipramine in vivo appears more anatomically selective. For imipramine, primary sites of action in vivo, as indicated by the topographic distribution in brain, appear to be the locus coeruleus, hippocampus, lateral septal nucleus, and amygdala. For desipramine, the greatest accumulation in vivo was found in the locus coeruleus, paraventricular nucleus of the hypothalamus, and anterior thalamic nuclei.

  20. Rate constant measurement of the recombination reaction C[sub 3]H[sub 3] + C[sub 3]H[sub 3

    SciTech Connect

    Morter, C.L.; Farhat, S.K.; Adamson, J.D.; Glass, G.P.; Curl, R.F. )

    1994-07-14

    Using the technique of infrared kinetic absorption spectroscopy, the second-order rate constant for the recombination reaction of the propargyl radical (C[sub 3]H[sub 3] + C[sub 3]H[sub 3]) has been measured and found to have the value (1.2 [+-] 0.2) x 10[sup [minus]10] cm[sup 3] molecule[sup [minus]1] s[sup [minus]1] at 295 K. The radical was produced in a flow cell by excimer laser flash photolysis ([lambda] = 193 nm) of the precursors C[sub 3]H[sub 3]Cl or C[sub 3]H[sub 3]Br and detected using time-resolved IR absorption. Absolute concentrations of C[sub 3]H[sub 3] were determined by comparing the C[sub 3]H[sub 3] absorption intensity with that of the Br atom. This calibration scheme was checked by producing methyl radicals by photolysis of methyl bromide and comparing the rate constant for methyl recombination thus obtained with literature values. The quantum yield for HCl production from the photodissociation of C[sub 3]H[sub 3]Cl at 193 nm was determined to be 0.07 [+-] 0.01. 47 refs., 10 figs., 1 tab.

  1. An observational investigation of the identity of B11244 (l-C{sub 3}H{sup +}/C{sub 3}H{sup -})

    SciTech Connect

    McGuire, Brett A.; Carroll, P. Brandon; Gratier, Pierre; Guzmán, Viviana; Pety, Jerome; Roueff, Evelyne; Gerin, Maryvonne; Blake, Geoffrey A.; Remijan, Anthony J.

    2014-03-01

    Pety et al. have reported the detection of eight transitions of a closed-shell, linear molecule (B11244) in observations toward the Horsehead photodissociation region (PDR), which they attribute to the l-C{sub 3}H{sup +} cation. Recent high-level ab initio calculations have called this assignment into question; the anionic C{sub 3}H{sup –} molecule has been suggested as a more likely candidate. Here, we examine observations of the Horsehead PDR, Sgr B2(N), TMC-1, and IRC+10216 in the context of both l-C{sub 3}H{sup +} and C{sub 3}H{sup –}. We find no observational evidence of K{sub a} = 1 lines, which should be present were the carrier indeed C{sub 3}H{sup –}. Additionally, we find a strong anticorrelation between the presence of known molecular anions and B11244 in these regions. Finally, we discuss the formation and destruction chemistry of C{sub 3}H{sup –} in the context of the physical conditions in the regions. Based on these results, we conclude there is little evidence to support the claim that the carrier is C{sub 3}H{sup –}.

  2. Nicotinic binding in rat brain: autoradiographic comparison of (/sup 3/H)acetylcholine, (/sup 3/H)nicotine, and (/sup 125/I)-alpha-bungarotoxin

    SciTech Connect

    Clarke, P.B.; Schwartz, R.D.; Paul, S.M.; Pert, C.B.; Pert, A.

    1985-05-01

    Three radioligands have been commonly used to label putative nicotinic cholinoceptors in the mammalian central nervous system: the agonists (/sup 3/H)nicotine and (/sup 3/H)acetylcholine ((/sup 3/H)ACh--in the presence of atropine to block muscarinic receptors), and the snake venom extract, (/sup 125/I)-alpha-bungarotoxin((/sup 125/I)BTX), which acts as a nicotinic antagonist at the neuromuscular junction. Binding studies employing brain homogenates indicate that the regional distributions of both (/sup 3/H)nicotine and (/sup 3/H)ACh differ from that of (/sup 125/I)BTX. The possible relationship between brain sites bound by (/sup 3/H)nicotine and (/sup 3/H)ACh has not been examined directly. The authors have used the technique of autoradiography to produce detailed maps of (/sup 3/H)nicotine, (/sup 3/H)ACh, and (/sup 125/I)BTX labeling; near-adjacent tissue sections were compared at many levels of the rat brain. The maps of high affinity agonist labeling are strikingly concordant, with highest densities in the interpeduncular nucleus, most thalamic nuclei, superior colliculus, medial habenula, presubiculum, cerebral cortex (layers I and III/IV), and the substantia nigra pars compacta/ventral tegmental area. The pattern of (/sup 125/I)BTX binding is strikingly different, the only notable overlap with agonist binding being the cerebral cortex (layer I) and superior colliculus. (/sup 125/I)BTX binding is also dense in the inferior colliculus, cerebral cortex (layer VI), hypothalamus, and hippocampus, but is virtually absent in thalamus. Various lines of evidence suggest that the high affinity agonist-binding sites in brain correspond to nicotinic cholinergic receptors similar to those found at autonomic ganglia; BTX-binding sites may also serve as receptors for nicotine and are possibly related to neuromuscular nicotinic cholinoceptors.

  3. High affinity binding of [3H]-tyramine in the central nervous system.

    PubMed Central

    Vaccari, A.

    1986-01-01

    Optimum assay conditions for the association of [3H]-para-tyramine [( 3H]-pTA) with rat brain membranes were characterized, and a saturable, reversible, drug-specific, and high affinity binding mechanism for this trace amine was revealed. The binding capacity (Bmax) for [3H]-pTA in the corpus striatum was approximately 30 times higher than that in the cerebellum, with similar dissociation constants (KD). The binding process of [3H]-pTA involved the dopamine system, inasmuch as (a) highest binding capacity was associated with dopamine-rich regions; (b) dopamine and pTA equally displaced specifically bound [3H]-pTA; (c) there was a severe loss in striatal binding capacity for [3H]-pTA and, reportedly, for [3H]-dopamine, following unilateral nigrostriatal lesion; (d) acute in vivo reserpine treatment markedly decreased the density of [3H]-pTA and, reportedly, of [3H]-dopamine binding sites. In competition experiments [3H]-pTA binding sites, though displaying nanomolar affinity for dopamine, revealed micromolar affinities for the dopamine agonists apomorphine and pergolide, and for several dopamine antagonists, while having very high affinity for reserpine, a marker for the catecholamine transporter in synaptic vesicles. The binding process of [3H]-pTA was both energy-dependent (ouabain-sensitive), and ATP-Mg2+-insensitive; furthermore, the potencies of various drugs in competing for [3H]-pTA binding to rat striatal membranes correlated well (r = 0.96) with their reported potencies in inhibiting [3H]-dopamine uptake into striatal synaptosomes. It is concluded that [3H]-pTA binds at a site located on/within synaptic vesicles where it is involved in the transport mechanism of dopamine. PMID:3801770

  4. Regiospecific transfer of tritium into 3H2O from labeled estrogens by mushroom tyrosinase.

    PubMed

    Jellinck, P H; Norton, B; Fishman, J

    1984-10-01

    The specificity of mushroom tyrosinase in displacing 3H from estradiol and catechol estrogens labeled at C-1, C-2, C-4 or C-6,7 was investigated under various conditions. [2-3H]E2 Yielded significant amounts of 3H2O, in the presence of NADH, and the rate of 3H loss from the steroid paralleled that of the radioactivity remaining in the aqueous fraction after extraction with organic solvents. NADH had little effect on the release of 3H from [1-3H]E2 or [4-3H]E2 but glutathione was highly active in this respect, with considerable differences being observed between lyophilizable 3H2O and yields of water-soluble products. It is proposed that 3H losses from C-2 of estradiol reflects oxidative displacement of this isotope by tyrosinase while the loss observed from C-1 and C-4 is the result of non-enzymatic conjugation with glutathione after the formation of the catechol estrogen. The difference between lyophilizable 3H2O and the yield of water-soluble products obtained with [1-3H]E2 and [4-3H]E2 provided a measure of the relative amount of conjugation occurring at C-1 and C-4. These findings were confirmed by double label experiments with 3H- and 14C-labeled estrogens and the isolation of the glutathionyl derivatives. The catechol estrogens did not serve as substrates for further hydroxylation by the enzyme even when C-2 was available for this reaction. These experiments give further information about the specificity of tyrosinase in its reaction with aromatic steroids and provide a simple and rapid method for confirming the distribution of 3H at C-2 or C-4 of estradiol. PMID:6092783

  5. Hydrocalcite (CaCO3 * H2O) and Nesquehonite (MgCO3 * 3H2O) in Carbonate Scales.

    PubMed

    Marschner, H

    1969-09-12

    Hydrocalcite (CaCO(3) * H(2)O) with exactly one molecule of hydrate water is the main component of carbonate scales deposited from cold water in contact with air. When the magnesium content of the water is high, the hydrocalcite occurs together with MgCO(3) * 3H(2)O (nesquehonite). From the conditions under which hydrocalcite is transformed into calcite and aragonite, it appears that in some cases aragonite in nature may be formed by way of an intermediary of CaCO(3) * H(2)O. PMID:17779803

  6. EVALUATION OF WHO-IPCS CHEMICALS BY THE C3H10T1/2CL8 MORPHOLOGICAL TRANSFORMATION BIOASSAY

    EPA Science Inventory

    In the laboratory, the authors have utilized C3H10T1/2 cells to study the effects of environmental chemicals on mammalian cells. During the course of these studies, they bioassayed a wide variety of chemicals including polycyclic aromatic hydrocarbons, alkylating agents, aromatic...

  7. Binding of dexetimide and levetimide to ( sup 3 H)(+)pentazocine- and ( sup 3 H)1,3-Di(2-tolyl)guanidine-defined. sigma. recognition sites

    SciTech Connect

    Dehaven-Hudkins, D.L.; Hudkins, R.L. Virginia Commonwealth Univ., Richmond, VA )

    1991-01-01

    The potent antimuscarinic benzetimide and its resolved stereoisomers dexetimide and levetimide were tested for their affinities at {sigma} sites labelled by ({sup 3}H)(+)pentazocine or ({sup 3}H)1,3-di(2-tolyl)guanidine. Levetimide was a potent and stereoselective inhibitor of ({sup 3}H)(+)pentazocine binding, with a K{sub i} of 2.2 nM, while dexetimide was nine-fold less potent (K{sub i} = 19 nM). Dexetimide and levetimide potently inhibited ({sup 3}H)DTG binding although without stereoselectivity (K{sub i} values of 65 and 103 nM, respectively). Levetimide may be a useful tool with which to investigate {sigma} recognition sites and {sigma} subtypes.

  8. Compounds extracted from Phyllantus and Jatropha elliptica inhibit the binding of [3H]glutamate and [3H]GMP-PNP in rat cerebral cortex membrane.

    PubMed

    Martini, L H; Souza, C R; Marques, P B; Calixto, J B; Yunes, R A; Souza, D O

    2000-02-01

    Glutamate is to be considered a nociceptive neurotransmitter and glutamatergic antagonists present antinoceptive activity. In this study we investigated the effects of the naturally occurring antinociceptive compounds rutin, geraniin and quercetine extracted from Phyllanthus, as well as the diterpene jatrophone, extracted from Jatropha elliptica on the binding of [3H]glutamate and [3H]GMP-PNP [a GTP analogue which binds to extracellular site(s), modulating the glutamatergic transmission] in rat brain membrane. Jatrophone inhibited [3H]glutamate binding and geraniin inhibited [3H]GMP-PNP binding. Quercetine inhibited the binding of both ligands. These results may indicate a neurochemical parameter possibly related to the antinoceptive activity of these natural compounds. PMID:10786704

  9. Synthesis ofN-(2-chloro-5-methylthiophenyl)-N'-(3-methyl-thiophenyl)-N'-[3H3]methylguanidine, l brace [3H3]CNS-5161 r brace

    SciTech Connect

    Gibbs, Andrew R.; Morimoto, Hiromi; VanBrocklin, Henry F.; Williams, Philip G.; Biegon, Anat

    2001-09-28

    The preparation of the title compound, [{sup 3}H{sub 3}]CNS-5161, was accomplished in three steps starting with the production of [{sup 3}H{sub 3}]iodomethane (CT{sub 3}I). The intermediate N-[{sup 3}H{sub 3}]methyl-3-(thiomethylphenyl)cyanamide was prepared in 77% yield by the addition of CT{sub 3}I to 3-(thiomethylphenyl)cyanamide, previously treated with sodium hydride. Reaction of this tritiated intermediate with 2-chloro-5-thiomethylaniline hydrochloride formed the guanidine compound [{sup 3}H{sub 3}]CNS-5161. Purification by HPLC gave the desired labeled product in an overall yield of 9% with greater than 96% radiochemical purity and a final specific activity of 66 Ci mmol{sup -1}.

  10. Human platelet dense granules: Improved isolation preliminary characterization of ( sup 3 H)-serotonin uptake and tetrabanazine-displaceable ( sup 3 H)-ketanserin binding

    SciTech Connect

    Chatterjee, D.; Anderson, G.M.; Chakraborty, M.; Cohen, D.J. )

    1990-01-01

    An improved method for the isolation of human platelet dense granules was developed. A good yield of highly enriched dense granules was obtained after mild sonication and Percoll gradient centrifugation. The method has facilitated characterization of the granule, permitting the first report of K{sub m} and V{sub max} values for ({sup 3}H)-serotonin uptake, as well as the first determination of K{sub d} and B{sub max} values for tetrabenazine-displaceable ({sup 3}H)-ketanserin binding, in the human platelet dense granule. The rates and affinities of ({sup 3}H)-serotonin uptake were similar to those previously reported for porcine dense granules. Tetrabenazine-displaceable ({sup 3}H)-ketanserin binding was observed with a K{sub d} similar to, and a B{sub max} approximately 10-fold lower than, that previously seen in bovine chromaffin granules.

  11. Using 14C and 3H to understand groundwater flow and recharge in an aquifer window

    NASA Astrophysics Data System (ADS)

    Atkinson, A. P.; Cartwright, I.; Gilfedder, B. S.; Cendón, D. I.; Unland, N. P.; Hofmann, H.

    2014-06-01

    Knowledge of groundwater residence times and recharge locations are vital to the sustainable management of groundwater resources. Here we investigate groundwater residence times and patterns of recharge in the Gellibrand Valley, southeast Australia, where outcropping aquifer sediments of the Eastern View Formation form an "aquifer window" that may receive diffuse recharge and recharge from the Gellibrand River. To determine recharge patterns and groundwater flowpaths, environmental isotopes (3H, 14C, δ13C, δ18O, δ2H) are used in conjunction with groundwater geochemistry and continuous monitoring of groundwater elevation and electrical conductivity. Despite the water table fluctuating by 0.9-3.7 m annually producing estimated recharge rates of 90 and 372 mm yr-1, residence times of shallow (11-29 m) groundwater determined by 14C ages are between 100 and 10 000 years. 3H activities are negligible in most of the groundwater and groundwater electrical conductivity in individual areas remains constant over the period of study. Although diffuse local recharge is evident, the depth to which it penetrates is limited to the upper 10 m of the aquifer. Rather, groundwater in the Gellibrand Valley predominantly originates from the regional recharge zone, the Barongarook High, and acts as a regional discharge zone where upward head gradients are maintained annually, limiting local recharge. Additionally, the Gellibrand River does not recharge the surrounding groundwater and has limited bank storage. 14C ages and Cl concentrations are well correlated and Cl concentrations may be used to provide a first-order estimate of groundwater residence times. Progressively lower chloride concentrations from 10 000 years BP to the present day are interpreted to indicate an increase in recharge rates on the Barongarook High.

  12. Using 14C and 3H to understand groundwater flow and recharge in an aquifer window

    NASA Astrophysics Data System (ADS)

    Atkinson, A. P.; Cartwright, I.; Gilfedder, B. S.; Cendón, D. I.; Unland, N. P.; Hofmann, H.

    2014-12-01

    Knowledge of groundwater residence times and recharge locations is vital to the sustainable management of groundwater resources. Here we investigate groundwater residence times and patterns of recharge in the Gellibrand Valley, southeast Australia, where outcropping aquifer sediments of the Eastern View Formation form an "aquifer window" that may receive diffuse recharge from rainfall and recharge from the Gellibrand River. To determine recharge patterns and groundwater flow paths, environmental isotopes (3H, 14C, δ13C, δ18O, δ2H) are used in conjunction with groundwater geochemistry and continuous monitoring of groundwater elevation and electrical conductivity. The water table fluctuates by 0.9 to 3.7 m annually, implying recharge rates of 90 and 372 mm yr-1. However, residence times of shallow (11 to 29 m) groundwater determined by 14C are between 100 and 10 000 years, 3H activities are negligible in most of the groundwater, and groundwater electrical conductivity remains constant over the period of study. Deeper groundwater with older 14C ages has lower δ18O values than younger, shallower groundwater, which is consistent with it being derived from greater altitudes. The combined geochemistry data indicate that local recharge from precipitation within the valley occurs through the aquifer window, however much of the groundwater in the Gellibrand Valley predominantly originates from the regional recharge zone, the Barongarook High. The Gellibrand Valley is a regional discharge zone with upward head gradients that limits local recharge to the upper 10 m of the aquifer. Additionally, the groundwater head gradients adjacent to the Gellibrand River are generally upwards, implying that it does not recharge the surrounding groundwater and has limited bank storage. 14C ages and Cl concentrations are well correlated and Cl concentrations may be used to provide a first-order estimate of groundwater residence times. Progressively lower chloride concentrations from 10

  13. (3H)bunazosin, a novel selective radioligand of alpha 1 adrenoceptors in human prostates

    SciTech Connect

    Yamada, S.; Suzuki, M.; Matsuoka, Y.; Kato, Y.; Kimura, R.; Maruyama, M.; Kawabe, K. )

    1991-09-01

    The binding properties of a new radioligand, (3H)bunazosin, were studied in membranes of human prostates with benign prostatic hypertrophy (BPH). Specific binding of (3H)bunazosin was saturable, reversible, and of high affinity (Kd = 0.55 {plus minus} 0.04 nM). The density of (3H)bunazosin binding sites (Bmax) was 676 {plus minus} 33 fmol/mg. protein. (3H)Bunazosin rapidly associated with its binding sites in membranes of human prostates and reached steady state by 20 min. at 25C. The rate constants for association and dissociation of (3H)bunazosin binding were calculated to be 0.11 {plus minus} 0.01/nM/min. and 0.05 {plus minus} 0.02/min. (n = 4), respectively. Seven alpha 1 adrenoceptor antagonists competed with (3H)bunazosin for the binding sites in the rank order: R-(-)-YM-12617 greater than prazosin greater than SGB-1534 greater than bunazosin greater than terazosin greater than naftopidil greater than urapidil. In parallel studies with (3H)bunazosin, the Kd and Bmax values for (3H)prazosin binding in human prostates were slightly lower. There was a similarity in the potency and rank order of seven alpha 1, adrenoceptor antagonists for the inhibition of (3H) bunazosin and (3H)prazosin binding in human prostates. The new (3H)bunazosin binding assay in human prostates is remarkable for its low degree of nonspecific binding as compared to (3H)prazosin, especially at high ligand concentrations. Thus, (3H)bunazosin may become a useful radioligand for the further analysis of the alph 1 adrenoceptor binding sites in human prostates.

  14. In vivo formation of tritium-labeled lactic acid from (2-/sup 3/H)mannose or (15-/sup 3/H)retinol by hamster intestinal epithelial cells

    SciTech Connect

    Creek, K.E.; Shankar, S.; De Luca, L.M.

    1987-05-01

    In studies to reexamine the in vivo occurrence of retinyl phosphate mannose we injected hamsters with either (2-/sup 3/H)mannose or (15-/sup 3/H)retinol. The small intestine was removed, the epithelial cells were scraped, and a methanolic extract of the labeled cells was prepared and chromatographed on a Mono Q anion-exchange column. Intraperitoneal administration of either (2-/sup 3/H)mannose or (15-/sup 3/H)retinol lead to the formation of a tritium-labeled anionic compound with a retention time on the Mono Q column similar to that of standard retinyl phosphate mannose. However, the biochemical properties of this labeled anionic compound were those expected of an organic acid and not retinyl phosphate mannose. The compound was resistant to both strong acid hydrolysis and mild base hydrolysis, as well as digestion with alpha- or beta-mannosidase, phosphodiesterase I, nucleotide pyrophosphatase, or beta-glucuronidase. When chromatographed on an Aminex HPX-87H organic acid analysis column or a silicic acid column the labeled anionic compound derived from either (2-/sup 3/H)mannose or (15-/sup 3/H)retinol comigrated with standard lactic acid. Treatment of the anionic compound derived from (2-/sup 3/H)mannose with lactate oxidase or L-lactate 2-monooxygenase resulted in the formation of a tritium-labeled product that cochromatographed, respectively, with pyruvate or acetate on the Aminex HPX-87H column. However, treatment of the anionic compound derived from (15-/sup 3/H)retinol with these same two enzymes resulted in a labeled product that migrated on the Aminex column at the same position as tritiated water. This result demonstrated that the labeled hydrogen was removed during enzymatic digestion and suggested that it was present on the second carbon of lactic acid. During the course of these studies no evidence for the in vivo labeling of a compound with the properties of retinyl phosphate mannose was found.

  15. Insect Ryanodine Receptor: Distinct But Coupled Insecticide Binding Sites for [N-C3H3]Chlorantraniliprole, Flubendiamide, and [3H]Ryanodine

    PubMed Central

    Isaacs, André K.; Qi, Suzhen; Sarpong, Richmond; Casida, John E.

    2015-01-01

    Radiolabeled anthranilic diamide insecticide [N-C3H3]chlorantraniliprole was synthesized at high specific activity and compared with phthalic diamide insecticide flubendiamide and [3H]ryanodine in radioligand binding studies with house fly muscle membranes to provide the first direct evidence with a native insect ryanodine receptor that the major anthranilic and phthalic diamide insecticides bind at different allosterically coupled sites, i.e. there are three distinct Ca2+-release channel targets for insecticide action. PMID:22856329

  16. Changes in [3H]-PK 11195 and [3H]-8-OH-DPAT binding following forebrain ischaemia in the gerbil.

    PubMed Central

    Kenny, B. A.; MacKinnon, A. C.; Spedding, M.; Brown, C. M.

    1993-01-01

    1. A high density of [3H]-PK 11195 binding sites was present in gerbil cortical membranes (Bmax [3H]-PK 11195 1360 +/- 71 fmol mg-1 protein) in comparison to rat cortical membranes (254 +/- 21 fmol mg-1 protein). This effect was species-specific as similar findings were obtained with hippocampal membranes (Bmax 1430 +/- 111 fmol mg-1 protein in gerbil, compared to 196 +/- 31 in rat). 2. RO 5-4864, also a peripheral type benzodiazepine compound, displayed low affinity for the [3H]-PK 11195 site in the gerbil (pKi 6.57 +/- 0.02 and 6.70 +/- 0.12 in hippocampus and cortex respectively) compared to rat (pKi 8.16 +/- 0.07 and 8.48 +/- 0.02). Central benzodiazepine compounds, diazepam and flunitrazepam, also displayed this trend. 3. RO 5-4864 displaced [3H]-PK 11195 binding from gerbil and rat cortical membranes through a competitive interaction with Hill slopes close to unity. In both tissues, saturation isotherms of [3H]-PK 11195 binding indicated that the presence of RO 5-4864 caused changes in Kd without any effect on Bmax. In kinetic experiments, the presence of RO 5-4864 failed to modify the rate of dissociation of [3H]-PK 11195 from equilibrium in both rat and gerbil cortical membranes.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:8395288

  17. [The I.G. Farben laboratory at the Günzburg mental hospital. Epilepsy research during the NS-regime and the postwar period].

    PubMed

    Söhner, Felicitas; Winckelmann, Hans-Joachim; Becker, Thomas

    2015-01-01

    The purpose of this study is to evaluate the activities of the I.G. Farben laboratory at the former "Heil- und Pflegeanstalt" Günzburg. This laboratory was established to test the newly developed epilepsy drug "Citrullamon" and its derivatives. Specifically, the type and manner of the various experiments were examined to determine whether the suspicions of unethical human experimentation could be identified. The commercial and medical activities between I.G. Farben and the Heil- und Pflegeanstalt, including the specific roles of the senior physician Wilhelm Leinisch and the I.G. Farben chemist Arno Grosse, are reviewed. PMID:26536788

  18. [3H]benzo[a]pyrene utilization in rats following tracheal implant exposure.

    PubMed

    Marchok, A C; Fleming, G S; Tomkins, B A; Griest, W H

    1989-05-31

    Open-ended rat tracheal implants (OETI) were exposed to 40 micrograms [3H]benzo[a]pyrene (B[a]P)-gelatin pellets and the 3H activity in the OETI, the host's tissues and excretia was determined 3-96 h after insertion of the pellets. The radioactivity in the OETI reached near peak activity by 3 h, and decreased almost 10-fold by 24 h. Most of the activity was associated with parent B[a]P throughout the 95 h. The 3H activity in the surrounding tissue also was mostly associated with B[a]P, but the 3H activity in the liver, kidney, blood and urine was mostly associated with water-soluble plus conjugated metabolites. In the feces, 68% of the 3H activity was in B[a]P at 3 h, but mostly organic as well as water-soluble plus conjugated metabolites were extracted from it throughout the remaining 96 h. Forty-eight hours after insertion of the B[a]P pellets, the feces contained almost 16% of the total 3H activity. Pre-exposure of the OETI to B[a]P for 4 days before insertion of the [3H]B[a]P pellets stimulated metabolism of B[a]P in the tracheas approximately 2-fold, but had no significant effect on the host tissues. PMID:2728007

  19. [3H]-tetracaine binding on rat synaptosomes and sodium channels.

    PubMed Central

    Grima, M.; Schwartz, J.; Spach, M. O.; Velly, J.

    1985-01-01

    [3H]-tetracaine binding was studied in a rat synaptosomal preparation. [3H]-tetracaine bound to a single class of binding sites with a mean KD of 188 +/- 28 nM and a mean maximal binding capacity of 13 +/- 0.7 pmol mg-1 protein. [3H]-tetracaine binding was inhibited by tetracaine, procaine and by beta-adrenoceptor blocking agents which possess local anaesthetic properties. [3H]-tetracaine binding was not modified by neurotoxins interacting specifically with the sodium channels. PMID:2413934

  20. Induction of sister chromatid exchange in preimplantation mouse embryos in vitro by /sup 3/H-thymidine or ultraviolet light in combination with caffeine

    SciTech Connect

    Mueller, W.U.S.; Spindle, A.

    1986-01-01

    Preimplantation mouse embryos were exposed in vitro to /sup 3/H-thymidine (25, 100, or 250 Bq/ml) or ultraviolet (UV) light (1.35 or 4.05 J/m2), either alone or in combination with caffeine (1 mM with /sup 3/H-thymidine and 0.5 mM with UV light). Exposure to /sup 3/H-thymidine lasted for 2 days, from the two-cell stage to the late morula/early blastocyst stage, and UV radiation was applied acutely at the late morula/early blastocyst stage. The effects were quantified by the sister chromatid exchange (SCE) assay. All three agents induced SCEs when used singly. /sup 3/H-thymidine was effective in inducing SCEs only at 250 Bq/ml, whereas UV light was effective at both fluences. Although caffeine did not induce SCEs when it was added before exposure to bromodeoxyuridine (BrdUrd), which is used to visualize SCEs, it did induce SCEs when present during the entire culture period (/sup 3/H-thymidine experiments) or during incubation in BrdUrd (UV experiments). Caffeine markedly enhanced the SCE-inducing effect of UV light but did not influence the effect of /sup 3/H-thymidine.

  1. Coordinating activation strategy for C(sp(3))-H/C(sp(3))-H cross-coupling to access β-aromatic α-amino acids.

    PubMed

    Li, Kaizhi; Wu, Qian; Lan, Jingbo; You, Jingsong

    2015-01-01

    The past decade has witnessed significant advances in C-H bond functionalizations with the discovery of new mechanisms. Non-precious transition-metal-catalysed radical oxidative coupling for C(sp(3))-H bond transformations is an appealing strategy for C-C bond formations. The radical oxidative C(sp(3))-H/C(sp(3))-H cross-coupling reactions of α-C(sp(3))-H bonds of amines with free radicals represent a conceptual and practical challenge. We herein develop the coordinating activation strategy to illustrate the nickel-catalysed radical oxidative cross-coupling between C(sp(3))-H bonds and (hetero)arylmethyl free radicals. The protocol can tolerate a rich variety of α-amino acids and (hetero)arylmethanes as well as arylmethylenes and arylmethines, affording a large library of α-tertiary and α-quaternary β-aromatic α-amino acids. This process also features low-cost metal catalyst, readily handled and easily removable coordinating group, synthetic simplicity and gram-scale production, which would enable the potential for economical production at commercial scale in the future. PMID:26415985

  2. Metabolism of myo-[2-3H]Inositol and scyllo-[R-3H]Inositol in Ripening Wheat Kernels 1

    PubMed Central

    Sasaki, Ken; Loewus, Frank A.

    1980-01-01

    Injection of myo-[2-3H]inositol or scyllo-[R-3H]inositol into the peduncular cavity of wheat stalks about 2 to 4 weeks postanthesis led to rapid translocation into the spike and accumulation of label in developing kernels, especially the bran fraction. With myo-[2-3H]inositol, about 50 to 60% of the label was incorporated into high molecular weight cell wall substance in the region of the injection. That portion translocated to the kernels was utilized primarily for cell wall polysaccharide formation and phytate biosynthesis. A small amount was recovered as free myo-inositol and galactinol. When scyllo-[R-3H]inositol was supplied, most of the label was translocated into the developing kernels where it accumulated as free scyllo-inositol and O-α-d-galactopyranosyl-scyllo-inositol in approximately equal amount. None of the label from scyllo-[R-3H]inositol was utilized for either phytate biosynthesis or cell wall polysaccharide formation. PMID:16661513

  3. Chemical destruction of CH3I, C2H5I, 1-C3H7I, and 2-C3H7I in saltwater

    NASA Astrophysics Data System (ADS)

    Jones, Charlotte E.; Carpenter, Lucy J.

    2007-07-01

    Destruction of volatile iodocarbons in the oceans can potentially play an important role in determining the predominant chemical forms of iodine emitted to the atmosphere. Here we report chlorination and hydrolysis removal rates for CH3I, C2H5I, 1-C3H7I, and 2-C3H7I relevant to oceanic conditions. We have used these rates to calculate oceanic lifetimes for each iodocarbon with respect to total chemical destruction, as a function of seawater temperature. The resulting lifetimes are compared to typical iodocarbon oceanic residence times with respect to volatilization to the MBL. The rate of destruction of 2-C3H7I is much more rapid than chemical removal of the primary alkyl iodides, potentially explaining previous observations of lower 2-C3H7I concentrations in seawater compared to 1-C3H7I. Finally, in light of these results, we briefly discuss the potential impact of rising global seawater temperatures on oceanic iodocarbon concentrations.

  4. Self-oscillations in the laboratory periodic flow and the linear law for the dissipation rate in the single-frequency range

    NASA Astrophysics Data System (ADS)

    Batchaev, A. M.

    2016-05-01

    In this paper, a Reynolds number increase transition from self-oscillations close to single-frequency ones to the temporally chaotic regime in the flow in a cylindrical channel driven by a spatially periodic force with four half-periods is experimentally investigated. The parameter ɛ proportional to the mean rate of the kinetic energy dissipation in unit mass per unit time associated with perturbations in the fluid is used as a basic characteristic of self-oscillations. The Reynolds number dependence ɛ(Re) for single frequency self-oscillations is considered theoretically.

  5. The Macroscopic Rate of Nucleic Acid Translocation by Hepatitis C virus Helicase NS3h is Dependent on Both the Sugar and Base Moieties

    PubMed Central

    Khaki, Ali R.; Field, Cassandra; Malik, Shuja; Niedziela-Majka, Anita; Leavitt, Stephanie A.; Wang, Ruth; Hung, Magdeleine; Sakowicz, Roman; Brendza, Katherine M.; Fischer, Christopher J.

    2010-01-01

    The NS3 helicase (NS3h) of hepatitis C virus (HCV) is a 3′ to 5′ SF2 RNA and DNA helicase that is essential for the replication of HCV. We have examined the kinetic mechanism of translocation of NS3h along single-stranded nucleic acid with bases rU, dU and dT and have found that the macroscopic rate of translocation is dependent upon both the base and sugar moieties of the nucleic acid, with approximate macroscopic translocation rates of 3 nt/s (oligo-dT), 35 nt/s (oligo-dU), and 42 nt/s (oligo-rU), respectively. We found a strong correlation between the macroscopic translocation rates and the binding affinity of the translocating NS3h protein to the respective substrates such that weaker affinity corresponded to faster translocation. The values of K0.5 for NS3h translocation at a saturating ATP concentration are: (3.3 ± 0.4) μM nucleotide (poly-dT), (27 ± 2) μM nucleotide (poly-dU), and (36 ± 2) μM nucleotide (poly-rU). Furthermore, the results of isothermal titration of NS3h with these oligonucleotides suggest that differences in TΔS° are the principal source of the differences in the affinity of NS3h binding to these substrates. Interestingly, despite the differences in macroscopic translocation rates and binding affinities, the ATP coupling stoichiometry for NS3h translocation was identical for all three substrates, ~0.5 ATP molecules consumed per nucleotide translocated. This similar periodicity of ATP consumption implies a similar mechanism for NS3h translocation along RNA and DNA substrates. PMID:20451531

  6. The macroscopic rate of nucleic acid translocation by hepatitis C virus helicase NS3h is dependent on both sugar and base moieties.

    PubMed

    Khaki, Ali R; Field, Cassandra; Malik, Shuja; Niedziela-Majka, Anita; Leavitt, Stephanie A; Wang, Ruth; Hung, Magdeleine; Sakowicz, Roman; Brendza, Katherine M; Fischer, Christopher J

    2010-07-16

    The nonstructural protein 3 helicase (NS3h) of hepatitis C virus is a 3'-to-5' superfamily 2 RNA and DNA helicase that is essential for the replication of hepatitis C virus. We have examined the kinetic mechanism of the translocation of NS3h along single-stranded nucleic acid with bases uridylate (rU), deoxyuridylate (dU), and deoxythymidylate (dT), and have found that the macroscopic rate of translocation is dependent on both the base moiety and the sugar moiety of the nucleic acid, with approximate macroscopic translocation rates of 3 nt s(-1) (oligo(dT)), 35 nt s(-1) (oligo(dU)), and 42 nt s(-1) (oligo(rU)), respectively. We found a strong correlation between the macroscopic translocation rates and the binding affinity of the translocating NS3h protein for the respective substrates such that weaker affinity corresponded to faster translocation. The values of K(0.5) for NS3h translocation at a saturating ATP concentration are as follows: 3.3+/-0.4 microM nucleotide (poly(dT)), 27+/-2 microM nucleotide (poly(dU)), and 36+/-2 microM nucleotide (poly(rU)). Furthermore, results of the isothermal titration of NS3h with these oligonucleotides suggest that differences in TDeltaS(0) are the principal source of differences in the affinity of NS3h binding to these substrates. Interestingly, despite the differences in macroscopic translocation rates and binding affinities, the ATP coupling stoichiometries for NS3h translocation were identical for all three substrates (approximately 0.5 ATP molecule consumed per nucleotide translocated). This similar periodicity of ATP consumption implies a similar mechanism for NS3h translocation along RNA and DNA substrates. PMID:20451531

  7. Surgical Methods for Full-Thickness Skin Grafts to Induce Alopecia Areata in C3H/HeJ Mice

    PubMed Central

    Silva, Kathleen A; Sundberg, John P

    2013-01-01

    Alopecia areata is a cell-mediated autoimmune disease of humans and many domestic and laboratory animal species. C3H/HeJ inbred mice spontaneously develop alopecia areata at a low frequency (approximately 20% by 12 mo of age). Transferring full-thickness skin grafts from affected, older mice to young mice of the same strain reliably reproduces alopecia areata, thus enabling investigators to study disease pathogenesis or intervention with a variety of therapeutic approaches. We here describe in detail how to perform full-thickness skin grafts and the follow-up procedures necessary to consistently generate mice with alopecia areata. These engrafted mice can be used to study the pathogenesis of cell-mediated autoimmune disease and for drug-efficacy trials. This standard protocol can be used for many other purposes when studying abnormal skin phenotypes in laboratory mice. PMID:24210015

  8. Binding of (/sup 3/H)forskolin to solubilized preparations of adenylate cyclase

    SciTech Connect

    Nelson, C.A.; Seamon, K.B.

    1988-01-01

    The binding of (/sup 3/H)forskolin to proteins solubilized from bovine brain membranes was studied by precipitating proteins with polyethylene glycol and separating (/sup 3/H)forskolin bound to protein from free (/sup 3/H)forskolin by rapid filtration. The K/sub d/ for (/sup 3/H)forskolin binding to solubilized proteins was 14 nM which was similar to that for (/sup 3/H)forskolin binding sites in membranes from rat brain and human platelets. Forskolin analogs competed for (/sup 3/H)forskolin binding sites with the same rank potency in both brain membranes and in proteins solubilized from brain membranes. (/sup 3/H)forskolin bound to proteins solubilized from membranes with a Bmax of 38 fmolmg protein which increased to 94 fmolmg protein when GppNHp was included in the binding assay. In contrast, GppNHp had no effect on (/sup 3/H)forskolin binding to proteins solubilized from membranes preactivated with GppNHp. Solubilized adenylate cyclase from non-preactivated membranes had a basal activity of 130 pmolmgmin which was increased 7-fold by GppNHp. In contrast, adenylate cyclase from preactivated membranes had a basal activity of 850 pmolmgmin which was not stimulated by GppNHp or forskolin

  9. Characterization of Samples from the 3H Evaporator System Including Effects of Recycle

    SciTech Connect

    Wilmarth, W.R.

    2001-05-15

    Analysis of several series of samples from the 3H Evaporator System have been completed. The goal of this work was to determine the effects of 3H operation including recycle of concentrated supernate from Tank 30H into the sludge layer of Tank 32H.

  10. Morphine enhances the release of /sup 3/H-purines from rat brain cerebral cortical prisms

    SciTech Connect

    Wu, P.H.; Phillis, J.W.; Yuen, H.

    1982-10-01

    In vitro experiments have shown that /sup 3/H-purines can be released from /sup 3/H-adenosine preloaded rat brain cortical prisms by a KCl-evoked depolarization. The KCl-evoked release of /sup 3/H-purines is dependent on the concentration of KCl present in the superfusate. At concentrations of 10(-7) approximately 10(-5)M morphine did not influence the basal release of /sup 3/H-purines from the prisms, although it enhanced the KCl-evoked release of /sup 3/H-purines. The enhancement of KCl-evoked /sup 3/H-purine release by morphine was concentration-dependent and was antagonized by naloxone, suggesting the involvement of opiate receptors. Uptake studies with rat brain cerebral cortical synaptosomes show that morphine is a very weak inhibitor of adenosine uptake. Comparisons with dipyridamole, a potent inhibitor of adenosine uptake, suggest that this low level of inhibition of the uptake did not contribute significantly to the release of /sup 3/H-purine by morphine seen in our experiments. It is therefore suggested that morphine enhances KCl-evoked /sup 3/H-purine release by an interaction with opiate receptors and that the resultant increase in extracellular purine (adenosine) levels may account for some of the actions of morphine.

  11. Behavior of substances labeled with /sup 3/H-proline and /sup 3/H-fucose in the cellular processes of odontoblasts and ameloblasts

    SciTech Connect

    Warshawsky, H.; Josephsen, K.

    1981-05-01

    Odontoblasts are cells with single cytoplasmic processes that grow longer as more dentin is elaborated. Ameloblasts also have single processes and it has been postulated that they too grow longer as more enamel is made. Support for this hypothesis was obtained using rat incisors to investigate the behavior of substances labeled with /sup 3/H-proline and /sup 3/H-fucose. A comparison was made between odontoblasts, which have processes known to grow and remain within the dentin, and the ameloblasts whose Tomes' processes are hypothesized to grow and leave remnants in the completed enamel. With /sup 3/H-proline, the odontoblast bodies are labeled at the early time intervals. With /sup 3/H-fucose, the cell bodies are labeled at the early intervals and the newly formed glycoproteins are deposited into the predentin. Almost immediately, these are progressively added to the dentin at the calcification front. With time a gradient of labeling extends from the unlabeled dentin toward the odontoblast bodies. Unlike the behavior of labeled proteins, by 1 and 2 days labeled glycoproteins appear along the entire length of the odontoblast processes. In the enamel, no Tomes' processes are present during maturation. With /sup 3/H-proline, reactions are adjacent to the cells and diffuse toward, but do not reach the dentino-enamel junction by 1 and 2 days. With /sup 3/H-fucose, reactions appear over the enamel near the cells. By 1 and 2 days no diffusive pattern is seen, but grains are concentrated near the dentino-enamel junction, in a region containing holes known to be the beginning of Tomes' processes. Since odontoblast glycoproteins migrate along odontoblast processes, it was postulated that cytoplasmic remnants were present in enamel along which ameloblast glycoproteins could also migrate to reach the holes at the dentino-enamel junction.

  12. Volumetric Properties of the Mixture Propenenitrile C3H3N + C3H6O2 Methyl ethanoate (VMSD1511, LB4267_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 Propenenitrile C3H3N + C3H6O2 Methyl ethanoate (VMSD1511, LB4267_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).

  13. Volumetric Properties of the Mixture Propenenitrile C3H3N + C3H8O Propan-1-ol (VMSD1212, LB4918_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 Propenenitrile C3H3N + C3H8O Propan-1-ol (VMSD1212, LB4918_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  14. Volumetric Properties of the Mixture Propenenitrile C3H3N + C3H7NO N,N-Dimethylmethanamide (VMSD1412, LB4271_V)

    NASA Astrophysics Data System (ADS)

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

    This document is part of Subvolume A 'Binary Liquid Systems of Nonelectrolytes I' 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 Propenenitrile C3H3N + C3H7NO N,N-Dimethylmethanamide (VMSD1412, LB4271_V)' providing data by calculation of isentropic compressibility from low-pressure density and thermodynamic speed of sound data at variable mole fraction and constant temperature, in the single-phase region(s).

  15. Volumetric Properties of the Mixture Propenenitrile C3H3N + C3H7NO N,N-Dimethylmethanamide (VMSD1511, LB4265_V)

    NASA Astrophysics Data System (ADS)

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

    This document is part of Subvolume A 'Binary Liquid Systems of Nonelectrolytes I' 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 Propenenitrile C3H3N + C3H7NO N,N-Dimethylmethanamide (VMSD1511, LB4265_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).

  16. Volumetric Properties of the Mixture Propenenitrile C3H3N + C3H8O Propan-1-ol (VMSD1511, LB4926_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 Propenenitrile C3H3N + C3H8O Propan-1-ol (VMSD1511, LB4926_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).

  17. Volumetric Properties of the Mixture Propenenitrile C3H3N + C3H8O Propan-1-ol (VMSD1111, LB4910_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 Propenenitrile C3H3N + C3H8O Propan-1-ol (VMSD1111, LB4910_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  18. Volumetric Properties of the Mixture Propenenitrile C3H3N + C3H6O2 Methyl ethanoate (VMSD1111, LB4251_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 Propenenitrile C3H3N + C3H6O2 Methyl ethanoate (VMSD1111, LB4251_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  19. Volumetric Properties of the Mixture Propenenitrile C3H3N + C3H6O2 Methyl ethanoate (VMSD1212, LB4261_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 Propenenitrile C3H3N + C3H6O2 Methyl ethanoate (VMSD1212, LB4261_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  20. Volumetric Properties of the Mixture Propenenitrile C3H3N + C3H7NO N,N-Dimethylmethanamide (VMSD1212, LB4259_V)

    NASA Astrophysics Data System (ADS)

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

    This document is part of Subvolume A 'Binary Liquid Systems of Nonelectrolytes I' 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 Propenenitrile C3H3N + C3H7NO N,N-Dimethylmethanamide (VMSD1212, LB4259_V)' providing data by calculation of molar excess volume from low-pressure density measurements at variable mole fraction and constant temperature.

  1. Volumetric Properties of the Mixture Propenenitrile C3H3N + C3H6O2 Methyl ethanoate (VMSD1412, LB4273_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 Propenenitrile C3H3N + C3H6O2 Methyl ethanoate (VMSD1412, LB4273_V)' providing data by calculation of isentropic compressibility from low-pressure density and thermodynamic speed of sound data at variable mole fraction and constant temperature, in the single-phase region(s).

  2. Volumetric Properties of the Mixture Propenenitrile C3H3N + C3H7NO N,N-Dimethylmethanamide (VMSD1111, LB4254_V)

    NASA Astrophysics Data System (ADS)

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

    This document is part of Subvolume A 'Binary Liquid Systems of Nonelectrolytes I' 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 Propenenitrile C3H3N + C3H7NO N,N-Dimethylmethanamide (VMSD1111, LB4254_V)' providing data from direct low-pressure measurement of mass density at variable mole fraction and constant temperature, in the single-phase region(s).

  3. Problem Periods

    MedlinePlus

    ... gov/ Home Body Getting your period Problem periods Problem periods It’s common to have cramps or feel ... doctor Some common period problems Signs of period problems top One way to know if you may ...

  4. Localized binding of [3H]muscimol to synapses in chicken retina.

    PubMed Central

    Yazulla, S; Brecha, N

    1981-01-01

    Binding sites for [3H]muscimol, an analogue of gamma-aminobutyric acid (GABA) were localized in the synaptic layers of chicken retina by light microscopic and electron microscopic autoradiography. Light microscopic autoradiography of cryostat sections incubated in [3H]muscimol or [3H]GABA revealed identical binding patterns: a band over the inner plexiform layer (IPL) and a band over the outer plexiform layer (OPL). This binding pattern differed from the uptake pattern for [3H]GABA: labeling over horizontal, amacrine, and ganglion cell bodies as well as very intense labeling over lamina 5 in the proximal IPL. Statistical analysis of electron microscopic autoradiography data from the IPL indicated that only amacrine synapses bind [3H]muscimol (i.e., make GABAergic synapses). Processes of amacrine, bipolar, or ganglion cells can be postsynaptic to these amacrine synapses. The highest concentration of synapses binding [3H]muscimol occurred in laminae 2 and 4 of the IPL and not in lamina 5 as might be expected from the density of [3H]GABA uptake. In the OPL, [3H]muscimol binding occurred over specialized junctions proximal to photoreceptor terminals. In cone receptor terminals, [3H]muscimol binding was suspected near horizontal cell dendrite/receptor terminal membranes lateral to the synaptic ribbon, supporting the hypothesis that horizontal cells are involved in a GABAergic feedback loop with cone terminals. We conclude that the synaptic binding pattern provides a more accurate concept of GABAergic synaptic interaction than does the uptake pattern for [3H]GABA because the two patterns in the IPL are not related. Images PMID:6264454

  5. [3H]-lifarizine, a high affinity probe for inactivated sodium channels.

    PubMed Central

    MacKinnon, A. C.; Wyatt, K. M.; McGivern, J. G.; Sheridan, R. D.; Brown, C. M.

    1995-01-01

    1. [3H]-lifarizine bound saturably and reversibly to an apparently homogeneous class of high affinity sites in rat cerebrocortical membranes (Kd = 10.7 +/- 2.9 nM; Bmax = 5.10 +/- 1.43 pmol mg-1 protein). 2. The binding of [3H]-lifarizine was unaffected by sodium channel toxins binding to site 1 (tetrodotoxin), site 3 (alpha-scorpion venom) or site 5 (brevetoxin), Furthermore, lifarizine at concentrations up to 10 microM had no effect on [3H]-saxitoxin (STX) binding to toxin site 1. Lifarizine displaced [3H]-batrachotoxinin-A 20-alpha-benzoate (BTX) binding with moderate affinity (pIC50 7.31 +/- 0.24) indicating an interaction with toxin site 2. However, lifarizine accelerated the dissociation of [3H]-BTX and decreased both the affinity and density of sites labelled by [3H]-BTX, suggesting an allosteric interaction with toxin site 2. 3. The binding of [3H]-lifarizine was voltage-sensitive, binding to membranes with higher affinity than to synaptosomes (pIC50 for cold lifarizine = 7.99 +/- 0.09 in membranes and 6.68 +/- 0.14 in synaptosomes). Depolarization of synaptosomes with 130 mM KCl increased the affinity of lifarizine almost 10 fold (pIC50 = 7.86 +/- 0.25). This suggests that lifarizine binds selectively to inactivated sodium channels which predominate both in the membrane preparation and in the depolarized synaptosomal preparation. 4. There was negligible [3H]-lifarizine and [3H]-BTX binding to solubilized sodium channels, although [3H]-STX binding was retained under these conditions.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7582509

  6. Deficiencies in extrusion of the second polar body due to high calcium concentrations during in vitro fertilization in inbred C3H/He mice.

    PubMed

    Ohta, Yuki; Nagao, Yoshikazu; Minami, Naojiro; Tsukamoto, Satoshi; Kito, Seiji

    2016-08-01

    Successful in vitro fertilization (IVF) of all inbred strains of laboratory mice has not yet been accomplished. We have previously shown that a high calcium concentration improved IVF in various inbred mice. However, we also found that in cumulus-free ova of C3H/He mice such IVF conditions significantly increased the deficiency of extrusion of the second polar body (PBII) in a dose-dependent manner (2% at 1.71 mM and 29% at 6.84 mM, P < 0.05) and that PBII extrusion was affected by high calcium levels at 2-3 h post-insemination. While developmental competence of ova without PBII extrusion to blastocysts after 96 h culture was not affected, a significant reduction in the nuclear number of the inner cell mass was observed in blastocyst fertilized under high calcium condition. We also examined how high calcium concentration during IVF affects PBII extrusion in C3H/He mice. Cumulus cells cultured under high calcium conditions showed a significantly alleviated deficient PBII extrusion. This phenomenon is likely to be specific to C3H/He ova because deficient PBII extrusion in reciprocal fertilization between C3H and BDF1 gametes was observed only in C3H/He ova. Sperm factor(s) was still involved in deficient PBII extrusion due to high calcium concentrations, as this phenomenon was not observed in ova activated by ethanol. The cytoskeletal organization of ova without PBII extrusion showed disturbed spindle rotation, incomplete formation of contractile ring and disturbed localization of actin, suggesting that high calcium levels affect the anchoring machinery of the meiotic spindle. These results indicate that in C3H/He mice high calcium levels induce abnormal fertilization, i.e. deficient PBII extrusion by affecting the cytoskeletal organization, resulting in disturbed cytokinesis during the second meiotic division. Thus, use of high calcium media for IVF should be avoided for this strain. PMID:26503636

  7. Organic Compounds in the C3H6O3 Family: Microwave Spectrum of cis-cis Dimethyl Carbonate

    NASA Astrophysics Data System (ADS)

    McGuire, B. A.; Widicus Weaver, S. L.; Lovas, F. J.; Plusquellic, D. F.; Blake, G. A.

    2011-05-01

    A number of recent spectroscopic and observational efforts have focused on simple sugars and sugar alcohols because of their importance in prebiotic astro- chemistry. The simplest sugar-related species, glycolaldehyde, has been detected in Sgr B2(N), as have its C2H4O2 structural isomers acetic acid and methyl formate. Additional studies of the C3-sugars with empirical formula C3H6O3, glyceraldehyde and dihydroxyacetone, resulted in no clear interstellar detection. Structural isomerism is extensive in interstellar clouds, and there is a high level of correlation between the relative energies of isomers and their relative abundances, with the lowest energy isomers detected in greatest abundance. The detected members of the C2H4O2 family, however, defy this trend, having relative abundances of (acetic acid):(glycolaldehyde):(methyl formate) of about 2:1:52, despite acetic acid being the lowest energy isomer. These puzzling abundance ratios and the lack of detection of the C3H6O3 sugars gives rise to the question: "Which is the most likely isomer in the C3H6O3 family to be detectable in inter- stellar clouds?" In an attempt to answer this question, we carried out geometry optimization calculations to determine the relative binding energies of the 13 members of the C3H6O3 family. Of the four lowest- energy isomers, only lactic acid [CH3CH(OH)COOH] and dimethyl carbonate [(CH3)2CO3] are commercially available, and lactic acid has been previously investigated spectroscopically. We have therefore conducted a laboratory study of dimethyl carbonate, measuring its rotational spectrum from 8.4 - 25.3 GHz using a Fourier-Transform microwave spectrometer, and from 227 - 350 GHz using a direct absorption spectrometer. We report on the theoretical calculations performed on the C3H6O3 family of isomers, the experimental studies of cis-cis dimethyl carbonate, and the implica- tions of these results for interstellar chemistry. The details of this work are also reported in Lovas et

  8. A validation of the 3H/3He method for determining groundwater recharge

    NASA Astrophysics Data System (ADS)

    Solomon, D. K.; Schiff, S. L.; Poreda, R. J.; Clarke, W. B.

    1993-09-01

    Tritium and He isotopes have been measured at a site where groundwater flow is nearly vertical for a travel time of 100 years and where recharge rates are spatially variable. Because the mid-1960s 3H peak (arising from aboveground testing of thermonuclear devices) is well-defined, the vertical groundwater velocity is known with unusual accuracy at this site. Utilizing 3H and its stable daughter 3He to determine groundwater ages, we compute a recharge rate of 0.16 m/yr, which agrees to within about 5% of the value based on the depth of the 3H peak (measured both in 1986 and 1991) and two-dimensional modeling in an area of high recharge. Zero 3H/3He age occurs at a depth that is approximately equal to the average depth of the annual low water table, even though the capillary fringe extends to land surface during most of the year at the study site. In an area of low recharge (0.05 m/yr) where the 3H peak (and hence the vertical velocity) is also well-defined, the 3H/3He results could not be used to compute recharge because samples were not collected sufficiently far above the 3H peak; however, modeling indicates that the 3H/3He age gradient near the water table is an accurate measure of vertical velocities in the low-recharge area. Because 3H and 3He have different diffusion coefficients, and because the amount of mechanical mixing is different in the area of high recharge than in the low-recharge area, we have separated the dispersive effects of mechanical mixing from molecular diffusion. We estimate a longitudinal dispersivity of 0.07 m and effective diffusion coefficients for 3H (3HHO) and 3He of 2.4×10-5 and 1.3×10-4 m2/day, respectively. Although the 3H/3He age gradient is an excellent indicator of vertical groundwater velocities above the mid-1960s 3H peak, dispersive mixing and diffusive loss of 3He perturb the age gradient near and below the 3H peak.

  9. Annual summary report on the surveillance and maintenence plan for Waste Area Groupings at Oak Ridge National Laboratory for period ending September 30, 1992

    SciTech Connect

    Ford, M.K.; Holder, L. Jr.; Jones, R.G.

    1992-11-01

    Surveillance and maintenance (S M) of 75 sites was conducted by the Remedial Action Section for the Environmental Restoration Program for surplus facilities and sites contaminated with radioactive materials and/or hazardous chemicals at Oak Ridge National Laboratory. S M activities on these facilities and sites was started at the end of their operating life and will continue until final facility disposal or site stabilization. The objectives of the Waste Area Grouping S M Program are met by maintaining a program of routine S M as well as by implementing interim corrective maintenance when deemed necessary as a result of site surveillance. This report briefly presents this program's activities and includes tables indicating tank levels and dry well data for FY 1992.

  10. Annual summary report of the Decontamination and Decommissioning Surveillance and Maintenance Program at Oak Ridge National Laboratory for period ending September 30, 1993. Environmental Restoration Program

    SciTech Connect

    Not Available

    1993-11-01

    The Oak Ridge National Laboratory (ORNL) Decontamination and Decommissioning (D&D) Program has continued to provide surveillance and maintenance (S&M) support for 34 surplus facilities. The objectives are to (1) ensure adequate containment of residual radioactive materials remaining in the facilities, (2) provide safety and security controls to minimize the potential hazards to on-site personnel and the general public, and (3) manage the facilities in the most cost-effective manner while awaiting decommissioning. This support has included work in three principal areas: (1) S&M planning, (2) routine S&M, and (3) special projects designed to correct serious facility deficiencies beyond the scope of routine maintenance.

  11. Annual summary report of the Decontamination and Decommissioning surveillance and maintenance program at Oak Ridge National Laboratory for period ending September 30, 1992

    SciTech Connect

    Ford, M.K.; Holder, L. Jr.

    1992-09-01

    The Oak Ridge National Laboratory (ORNL) Decontamination and Decommissioning (D D) Program is part of the Department of Energy (DOE) Environmental Restoration D D Program and has continued to provide surveillance and maintenance (S M) support for 34 surplus facilities. The objectives are (1) to ensure adequate containment of residual radioactive materials remaining in the facilities, (2) to provide safety and security controls to minimize the potential hazards to on-site personnel and to the general public, and (3) to manage the facilities in the most cost-effective manner while awaiting decommissioning. This support has included work in three principal areas: (1) S M planning, (2) routine S M, and (3) special projects designed to correct serious facility deficiencies beyond the scope of routine maintenance.

  12. Annual summary report of the Decontamination and Decommissioning surveillance and maintenance program at Oak Ridge National Laboratory for period ending September 30, 1992. Environmental Restoration Program

    SciTech Connect

    Ford, M.K.; Holder, L. Jr.

    1992-09-01

    The Oak Ridge National Laboratory (ORNL) Decontamination and Decommissioning (D&D) Program is part of the Department of Energy (DOE) Environmental Restoration D&D Program and has continued to provide surveillance and maintenance (S&M) support for 34 surplus facilities. The objectives are (1) to ensure adequate containment of residual radioactive materials remaining in the facilities, (2) to provide safety and security controls to minimize the potential hazards to on-site personnel and to the general public, and (3) to manage the facilities in the most cost-effective manner while awaiting decommissioning. This support has included work in three principal areas: (1) S&M planning, (2) routine S&M, and (3) special projects designed to correct serious facility deficiencies beyond the scope of routine maintenance.

  13. Annual summary report on the surveillance and maintenence plan for Waste Area Groupings at Oak Ridge National Laboratory for period ending September 30, 1992. Environmental Restoration Program

    SciTech Connect

    Ford, M.K.; Holder, L. Jr.; Jones, R.G.

    1992-11-01

    Surveillance and maintenance (S&M) of 75 sites was conducted by the Remedial Action Section for the Environmental Restoration Program for surplus facilities and sites contaminated with radioactive materials and/or hazardous chemicals at Oak Ridge National Laboratory. S&M activities on these facilities and sites was started at the end of their operating life and will continue until final facility disposal or site stabilization. The objectives of the Waste Area Grouping S&M Program are met by maintaining a program of routine S&M as well as by implementing interim corrective maintenance when deemed necessary as a result of site surveillance. This report briefly presents this program`s activities and includes tables indicating tank levels and dry well data for FY 1992.

  14. Effect of antemortem and postmortem factors on ( sup 3 H)MK-801 binding in the human brain: Transient elevation during early childhood

    SciTech Connect

    Kornhuber, J.; Mack-Burkhardt, F.; Konradi, C.; Fritze, J.; Riederer, P. )

    1989-01-01

    The effect of a number of antemortem and postmortem factors on ({sup 3}H)MK-801 binding was investigated under equilibrium conditions in the frontal cortex of human brains of 38 controls. Binding values transiently increased during the early postnatal period reaching a maximum at the age of about 2 years. After age 10 years ({sup 3}H)MK-801 binding sites disappeared at 5.7% per decade. The storage time of brain tissue had a reducing effect on these binding sites. There was no effect of gender, brain weight or postmortem time interval and the binding sites were bilaterally symmetrically distributed in the frontal cortex.

  15. Effects of selected muscarinic cholinergic antagonists on [3H]acetylcholine release from rat hippocampal slices.

    PubMed

    Pohorecki, R; Head, R; Domino, E F

    1988-01-01

    A number of cholinergic muscarinic (M) agonists and antagonists were studied for their ability to enhance tritiated acetylcholine ([3H]ACh) release from electrically field-stimulated rat hippocampal slices. A Ca++-free medium and carbachol, but not nicotine, inhibited [3H]ACh release. Atropine, methylatropine and dexetimide produced concentration-dependent increases in [3H]ACh release to a maximum of about 50% above control. Aprophen and benactyzine produced a maximal response 25 to 35% above control. The selective M1 antagonist pirenzepine had the least effect on [3H]ACh release. Of the nonspecific M1-M2 antagonists studied, benactyzine produced the least amount of [3H]ACh release. The order of potency of the M antagonists in promoting a 15% increase in [3H]ACh release was aprophen greater than benactyzine greater than methylatropine greater than dexetimide greater than pirenzepine greater than atropine. However, the order of promoting maximal release of [3H]ACh was atropine greater than dexetimide greater than methylatropine greater than aprophen greater than benactyzine greater than pirenzepine. PMID:3335998

  16. APOBEC3H polymorphisms and susceptibility to HIV-1 infection in an Indian population.

    PubMed

    Naruse, Taeko K; Sakurai, Daisuke; Ohtani, Hitoshi; Sharma, Gaurav; Sharma, Surendra K; Vajpayee, Madhu; Mehra, Narinder K; Kaur, Gurvinder; Kimura, Akinori

    2016-03-01

    Human APOBEC3H (A3H) is a member of APOBEC cytidine deaminase family intensively constraining the HIV-1 replication. A3H is known to be polymorphic with different protein stability and anti-HIV-1 activity in vitro. We recently reported that A3H haplotypes composed of two functional polymorphisms, rs139292 (N15del) and rs139297 (G105R), were associated with the susceptibility to HIV-1 infection in Japanese. To confirm the association of A3H and HIV-1 infection in another ethnic group, a total of 241 HIV-1-infected Indian individuals and ethnic-matched 286 healthy controls were analyzed for the A3H polymorphisms. The frequency of 15del allele was high in the HIV-1-infected subjects as compared with the controls (0.477 vs 0.402, odds ratio (OR)=1.36, P=0.014). Haplotype analysis showed that the frequencies of 15del-105R was high (0.475 vs 0.400, OR=1.36, permutation P=0.037) in the HIV-1-infected subjects, confirming the association of A3H polymorphisms with the susceptibility to HIV-1 infection. PMID:26559750

  17. Quantitative autoradiography of /sup 3/H-nomifensine binding sites in rat brain

    SciTech Connect

    Scatton, B.; Dubois, A.; Dubocovich, M.L.; Zahniser, N.R.; Fage, D.

    1985-03-04

    The distribution of /sup 3/H-nomifensine binding sites in the rat brain has been studied by quantitative autoradiography. The binding of /sup 3/H-nomifensine to caudate putamen sections was saturable, specific, of a highly affinity (Kd = 56 nM) and sodium-dependent. The dopamine uptake inhibitors benztropine, nomifensine, cocaine, bupropion and amfonelic acid were the most potent competitors of /sup 3/H-nomifensine binding to striatal sections. The highest levels of (benztropine-displaceable) /sup 3/H-nomifensine binding sites were found in the caudate-putamen, the olfactory tubercle and the nucleus accumbens. 6-Hydroxy-dopamine-induced lesion of the ascending dopaminergic bundle resulted in a marked decrease in the /sup 3/H-ligand binding in these areas. Moderately high concentrations of the /sup 3/H-ligand were observed in the bed nucleus of the stria terminalis, the anteroventral thalamic nucleus, the cingulate cortex, the lateral septum, the hippocampus, the amygdala, the zona incerta and some hypothalamic nuclei. There were low levels of binding sites in the habenula, the dorsolateral geniculate body, the substantia nigra, the ventral tegmental area and the periaqueductal gray matter. These autoradiographic data are consistent with the hypothesis that /sup 3/H-nomifensine binds primarily to the presynaptic uptake site for dopamine but also labels the norepinephrine uptake site. 33 references, 2 figures, 1 table.

  18. High affinity binding of (/sup 3/H)cocaine to rat liver microsomes

    SciTech Connect

    El-Maghrabi, E.A.; Calligaro, D.O.; Eldefrawi, M.E.

    1988-01-01

    )/sup 3/H)cocaine bound reversible, with high affinity and stereospecificity to rat liver microsomes. Little binding was detected in the lysosomal, mitochondrial and nuclear fractions. The binding kinetics were slow and the kinetically calculated K/sub D/ was 2 nM. Induction of mixed function oxidases by phenobarbital did not produce significant change in (/sup 3/H)cocaine binding. On the other hand, chronic administration of cocaine reduced (/sup 3/H)cocaine binding drastically. Neither treatment affected the affinity of the liver binding protein for cocaine. Microsomes from mouse and human livers had less cocaine-binding protein and lower affinity for cocaine than those from rat liver. Binding of (/sup 3/H)cocaine to rat liver microsomes was insensitive to monovalent cations and > 10 fold less sensitive to biogenic amines than the cocaine receptor in rat striatum. However, the liver protein had higher affinity for cocaine and metabolites except for norcocaine. Amine uptake inhibitors displaced (/sup 3/H)cocaine binding to liver with a different rank order of potency than their displacement of (/sup 3/H)cocaine binding to striatum. This high affinity (/sup 3/H)cocaine binding protein in liver is not likely to be monooxygenase, but may have a role in cocaine-induced hepatotoxicity

  19. Quantitative autoradiography of (/sup 3/H)CTOP binding to mu opioid receptors in rat brain

    SciTech Connect

    Hawkins, K.N.; Knapp, R.J.; Gehlert, D.R.; Lui, G.K.; Yamamura, M.S.; Roeske, L.C.; Hruby, V.J.; Yamamura, H.I.

    1988-01-01

    (/sup 3/H)H-D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 ((/sup 3/H)CTOP), a potent and highly selective mu opioid antagonist, was used to localize the mu receptors in rat brain by light microscopic autoradiography. Radioligand binding studies with (/sup 3/H)CTOP using slide-mounted tissue sections of rat brain produced a Kd value of 1.1 nM with a Bmax value of 79.1 fmol/mg protein. Mu opioid agonists and antagonists inhibited (/sup 3/H)CTOP binding with high affinity (IC50 values of 0.2-2.4nM), while the delta agonist DPDPE, delta antagonist ICI 174,864, and kappa agonist U 69,593 were very weak inhibitors of (/sup 3/H)CTOP binding. Light microscopic autoradiography of (/sup 3/H)CTOP binding sites revealed regions of high density and regions of moderate labeling. The cerebral cortex showed a low density of (/sup 3/H)CTOP binding.

  20. ( sup 3 H)cytisine binding to nicotinic cholinergic receptors in brain

    SciTech Connect

    Pabreza, L.A.; Dhawan, S.; Kellar, K.J. )

    1991-01-01

    Cytisine, a ganglionic agonist, competes with high affinity for brain nicotinic cholinergic receptors labeled by any of several nicotinic {sup 3}H-agonist ligands. Here we have examined the binding of ({sup 3}H)cytisine in rat brain homogenates. ({sup 3}H)Cytisine binds with high affinity (Kd less than 1 nM), and specific binding represented 60-90% of total binding at all concentrations examined up to 15 nM. The nicotinic cholinergic agonists nicotine, acetylcholine, and carbachol compete with high affinity for ({sup 3}H)cytisine binding sites, whereas among nicotinic receptor antagonists only dihydro-beta-erythroidine competes with high affinity (in the nanomolar range). Comparison of binding in several brain regions showed that ({sup 3}H)cytisine binding is higher in the thalamus, striatum, and cortex than in the hippocampus, cerebellum, or hypothalamus. The pharmacology and brain regional distribution of ({sup 3}H)cytisine binding sites are those predicted for neuronal nicotinic receptor agonist recognition sites. The high affinity and low nonspecific binding of ({sup 3}H)cytisine should make it a very useful ligand for studying neuronal nicotinic receptors.

  1. In vivo binding of /sup 3/H-N-methylspiperone to dopamine and serotonin receptors

    SciTech Connect

    Frost, J.J.; Smith, A.C.; Kuhar, M.J.; Dannals, R.F.; Wagner, H.N. Jr.

    1987-03-09

    /sup 3/H-N-methylspiperone (/sup 3/H-NMSP) was used to label dopamine-2 and serotonin-2 in vivo in the mouse. The striatum/cerebellum binding ratio reached a maximum of 80 eight hours after intravenous administration of /sup 3/H-NMSP. The frontal cortex/cerebellum ratio was 5 one hour after injection. The binding of /sup 3/H-NMSP was saturable in the frontal cortex and cerebellum between doses of 10 and 1000 ..mu..g/kg. Between 0.01 and 10 ..mu..g/kg the ratio total/nonspecific binding increased from 14 to 21. Inhibition of /sup 3/H-NMSP binding in the frontal cortex and striatum by ketanserin, a selective serotonin-2 antagonist, demonstrated that 20% of the total binding in the striatum was to serotonin-2 rectors and 91% of the total binding in the frontal cortex was to serotonin-2 receptors. Compared to /sup 3/H-spiperone, /sup 3/H-NMSP 1) results in a much higher specific/nonspecific binding ratio in the striatum and frontal cortex and 2) displays more than a two-fold higher brain uptake. 18 references, 4 figures.

  2. Studies with the high-affinity antiestrogen, (/sup 3/H)HI285

    SciTech Connect

    Keene, J.L.

    1985-01-01

    Antiestrogens are compounds that inhibit some of the actions of estrogens. Certain antiestrogens, notably the triphenylethylene, tamoxifen, are useful in the treatment of female breast cancer. The triphenylethylene antiestrogen, HI285, was labelled with radioactive hydrogen ((/sup 3/H)) for use as a probe of antiestrogen action. Radioactive HI285 ((/sup 3/H)HI285) bound to the cytosolic estrogen receptor from both rat and calf uterus and competed with estradiol for the estrogen specific binding site. In both animals (/sup 3/H)HI285 displayed a higher affinity for the estrogen receptor and a slower dissociation rate from the receptor than did estradiol. (/sup 3/H)HI285, as well as estradiol, appeared to trigger receptor activation. Studies using the activation blocker, sodium molybdate, indicated that (/sup 3/H)HI285 triggered activation in a manner different from estradiol. The non-activated estrogen receptor from calf uterus, when occupied by (/sup 3/H)estradiol, existed as two discrete forms that could be separated by ion-exchange chromatography. In contrast, the (/sup 3/H)HI285-occupied receptor existed as a single form.

  3. Ascorbic acid enables reversible dopamine receptor /sup 3/H-agonist binding

    SciTech Connect

    Leff, S.; Sibley, D.R.; Hamblin, M.; Creese, I.

    1981-11-16

    The effects of ascorbic acid on dopaminergic /sup 3/H-agonist receptor binding were studied in membrane homogenates of bovine anterior pituitary and caudate, and rat striatum. In all tissues virtually no stereospecific binding (defined using 1uM (+)butaclamol) of the /sup 3/H-agonists N-propylnorapomorphine (NPA), apomorphine, or dopamine could be demonstrated in the absence of ascorbic acid. Although levels of total /sup 3/H-agonist binding were three to five times greater in the absence than in the presence of 0.1% ascorbic acid, the increased binding was entirely non-stereospecific. Greater amounts of dopamine-inhibitable /sup 3/H-NPA binding could be demonstrated in the absence of 0.1% ascorbic acid, but this measure of ''specific binding'' was demonstrated not to represent dopamine receptor binding since several other catecholamines and catechol were equipotent with dopamine and more potent than the dopamine agonist (+/-)amino-6,7-dihydroxy-1,2,3,4-tetrahydronapthalene (ADTN) in inhibiting this binding. High levels of dopamine-displaceable /sup 3/H-agonist binding were detected in fresh and boiled homogenates of cerebellum, an area of brain which receives no dopaminergic innervation, further demonstrating the non-specific nature of /sup 3/H-agonist binding in the absence of ascorbic acid. These studies emphasize that under typical assay conditions ascorbic acid is required in order to demonstrate reversible and specific /sup 3/H-agonist binding to dopamine receptors.

  4. Anti-retroelement Activity of APOBEC3H was Lost Twice in Recent Human Evolution

    PubMed Central

    OhAinle, Molly; Kerns, Julie A.; Li, Melody M.H.; Malik, Harmit S.

    2008-01-01

    SUMMARY The primate APOBEC3 gene locus encodes a family of proteins (APOBEC3A-H) with various antiviral and anti-retroelement activities. Here, we trace the evolution of APOBEC3H activity in hominoids to identify a human-specific loss of APOBEC3H antiviral activity. Reconstruction of the predicted ancestral human APOBEC3H protein shows that human ancestors encoded a stable form of this protein with potent antiviral activity. Subsequently, the antiviral activity of APOBEC3H was lost via two polymorphisms that are each independently sufficient to destabilize the protein. Nonetheless, an APOBEC3H allele that encodes a stably expressed protein is still maintained at high frequency, primarily in African populations. This stable APOBEC3H protein has potent activity against retroviruses and retrotransposons, including HIV and LINE-1 elements. The surprising finding that APOBEC3H antiviral activity has been lost in the majority of humans may have important consequences for our susceptibility to retroviral infections as well as ongoing retroelement proliferation in the human genome. PMID:18779051

  5. BMP treatment of C3H10T1/2 mesenchymal stem cells induces both chondrogenesis and osteogenesis.

    PubMed

    Shea, Colleen M; Edgar, Cory M; Einhorn, Thomas A; Gerstenfeld, Louis C

    2003-12-15

    The molecular mechanisms by which bone morphogenetic proteins (BMPs) promote skeletal cell differentiation were investigated in the murine mesenchymal stem cell line C3H10T1/2. Both BMP-7 and BMP-2 induced C3H10T1/2 cells to undergo a sequential pattern of chondrogenic followed by osteogenic differentiation that was dependent on both the concentration and the continuous presence of BMP in the growth media. Differentiation was determined by the expression of chondrogenesis and osteogenesis associated matrix genes. Subsequent experiments using BMP-7 demonstrated that withdrawal of BMP from the growth media led to a complete loss of skeletal cell differentiation accompanied by adipogenic differentiation of these cells. Continuous treatment with BMP-7 increased the expression of Sox9, Msx 2, and c-fos during the periods of chondrogenic differentiation after which point their expression decreased. In contrast, Dlx 5 expression was induced by BMP-7 treatment and remained elevated throughout the time-course of skeletal cell differentiation. Runx2/Cbfa1 was not detected by ribonuclease protection assay (RPA) and did not appear to be induced by BMP-7. The sequential nature of differentiation of chondrocytic and osteoblastic cells and the necessity for continuous BMP treatment to maintain skeletal cell differentiation suggests that the maintenance of selective differentiation of the two skeletal cell lineages might be dependent on BMP-7-regulated expression of other morphogenetic factors. An examination of the expression of Wnt, transforming growth factor-beta (TGF-beta), and the hedgehog family of morphogens showed that Wnt 5b, Wnt 11, BMP-4, growth and differentiation factor-1 (GDF-1), Sonic hedgehog (Shh), and Indian hedgehog (Ihh) were endogenously expressed by C3H10T1/2 cells. Wnt 11, BMP-4, and GDF-1 expression were inhibited by BMP-7 treatment in a dose-dependent manner while Wnt 5b and Shh were selectively induced by BMP-7 during the period of chondrogenic

  6. Autoradiographic localization of /sup 3/H-paroxetine-labeled serotonin uptake sites in rat brain

    SciTech Connect

    De Souza, E.B.; Kuyatt, B.L.

    1987-01-01

    Paroxetine is a potent and selective inhibitor of serotonin uptake into neurons. Serotonin uptake sites have been identified, localized, and quantified in rat brain by autoradiography with 3H-paroxetine; 3H-paroxetine binding in slide-mounted sections of rat forebrain was of high affinity (KD = 10 pM) and the inhibition affinity constant (Ki) values of various drugs in competing 3H-paroxetine binding significantly correlated with their reported potencies in inhibiting synaptosomal serotonin uptake. Serotonin uptake sites labeled by 3H-paroxetine were highly concentrated in the dorsal and median raphe nuclei, central gray, superficial layer of the superior colliculus, lateral septal nucleus, paraventricular nucleus of the thalamus, and the islands of Calleja. High concentrations of 3H-paroxetine binding sites were found in brainstem areas containing dopamine (substantia nigra and ventral tegmental area) and norepinephrine (locus coeruleus) cell bodies. Moderate concentrations of 3H-paroxetine binding sites were present in laminae I and IV of the frontal parietal cortex, primary olfactory cortex, olfactory tubercle, regions of the basal ganglia, septum, amygdala, thalamus, hypothalamus, hippocampus, and some brainstem areas including the interpeduncular, trigeminal, and parabrachial nuclei. Lower densities of 3H-paroxetine binding sites were found in other regions of the neocortex and very low to nonsignificant levels of binding were present in white matter tracts and in the cerebellum. Lesioning of serotonin neurons with 3,4-methylenedioxyamphetamine caused large decreases in 3H-paroxetine binding. The autoradiographic distribution of 3H-paroxetine binding sites in rat brain corresponds extremely well to the distribution of serotonin terminals and cell bodies as well as with the pharmacological sites of action of serotonin.

  7. Felbamate increases [3H]glycine binding in rat brain and sections of human postmortem brain.

    PubMed

    McCabe, R T; Sofia, R D; Layer, R T; Leiner, K A; Faull, R L; Narang, N; Wamsley, J K

    1998-08-01

    The anticonvulsant compound felbamate (2-phenyl-1,3-propanediol dicarbamate; FBM) appears to inhibit the function of the N-methyl-D-aspartate (NMDA) receptor complex through an interaction with the strychnine-insensitive glycine recognition site. Since we have demonstrated previously that FBM inhibits the binding of [3H]5, 7-dichlorokynurenic acid (DCKA), a competitive antagonist at the glycine site, we assessed the ability of FBM to modulate the binding of an agonist, [3H]glycine, to rat forebrain membranes and human brain sections. In contrast to its ability to inhibit [3H]5,7-DCKA binding, FBM increased [3H]glycine binding (20 nM; EC50 = 485 microM; Emax = 211% of control; nH = 1.8). FBM, but not carbamazepine, phenytoin, valproic acid or phenobarbital, also increased [3H]glycine binding (50 nM; EC50 = 142 microM; Emax = 157% of control; nH = 1.6) in human cortex sections. Autoradiographic analysis of human brain slices demonstrated that FBM produced the largest increases in [3H]glycine binding in the cortex, hippocampus and the parahippocampal gyrus. Because various ions can influence the binding of glycine-site ligands, we assessed their effects on FBM-modulation of [3H]glycine binding. FBM-enhanced [3H]glycine binding was attenuated by Zn++ and not inhibited by Mg++ in human brain. These results suggest that FBM increases [3H]glycine binding in a manner sensitive to ions which modulate the NMDA receptor. These data support the hypothesis that FBM produces anticonvulsant and neuroprotective effects by inhibiting NMDA receptor function, likely through an allosteric modulation of the glycine site. PMID:9694960

  8. Ligand-Promoted Borylation of C(sp(3))-H Bonds with Palladium(II) Catalysts.

    PubMed

    He, Jian; Jiang, Heng; Takise, Ryosuke; Zhu, Ru-Yi; Chen, Gang; Dai, Hui-Xiong; Dhar, T G Murali; Shi, Jun; Zhang, Hao; Cheng, Peter T W; Yu, Jin-Quan

    2016-01-11

    A quinoline-based ligand effectively promotes the palladium-catalyzed borylation of C(sp(3))-H bonds. Primary β-C(sp(3))-H bonds in carboxylic acid derivatives as well as secondary C(sp(3))-H bonds in a variety of carbocyclic rings, including cyclopropanes, cyclobutanes, cyclopentanes, cyclohexanes, and cycloheptanes, can thus be borylated. This directed borylation method complements existing iridium(I)- and rhodium(I)-catalyzed C-H borylation reactions in terms of scope and operational conditions. PMID:26611496

  9. FT-IR Measurements of Cross Sections of Cold C3H8 in the 7 - 15 µm for Titan

    NASA Astrophysics Data System (ADS)

    Sung, Keeyoon; Brown, L. R.; Toon, G. C.; Mantz, A. W.; Smith, M. A. H.

    2012-10-01

    To support atmospheric remote sensing of Titan, the absorption cross sections of N2-broadened C3H8 were obtained at temperatures between 145 and 296 K. For this, 17 spectra of pure- and N2-broadened propane were recorded in the 690 to 1550 cm-1 region using a Fourier transform spectrometer (Bruker IFS-125HR) at the Jet Propulsion Laboratory configured with a 20.38 cm long temperature-stabilized cryogenic absorption cell. The coolable cell was developed at Connecticut College and described previously [1]. We report the absorption cross sections at the various cold temperatures for nine strong propane bands (v26, v8, v21, v20, v7, v19, v18, v4, v24). In addition, we present results from ‘pseudo-line generation’, which includes positions, intensities, and effective lower state energies’ determined from high-resolution laboratory spectra, (see http://mark4sun.jpl.nasa.gov/data/spec/Pseudo/Readme). The resulting compilation will be compared to earlier work, including the C3H8+N2 spectra recorded at PNNL [2] and available line-by-line predictions [3,4]. Research described in this paper was performed at the Jet Propulsion Laboratory, and California Institute of Technology, Connecticut College, NASA Langley Research Center, under contracts and cooperative agreements with the National Aeronautics and Space Administration. References [1] K. Sung, A. W. Mantz, M. A. H. Smith, et al., J Mol Spectrosc 262, 122, 2010. [2] S. W. Sharpe, et al., Appl Spectrosc 58, 1452, 2004. [3] J. M. Flaud et al., Mol Phys 108, 699, 2010. [4] J. M. Flaud et al., J Chem Phys 114, 9361, 2001.

  10. Tethered gravity laboratories study

    NASA Technical Reports Server (NTRS)

    Lucchetti, F.

    1989-01-01

    Tethered gravity laboratories study is presented. The following subject areas are covered: variable gravity laboratory; attitude tether stabilizer; configuration analysis (AIT); dynamic analysis (SAO); and work planned for the next reporting period.

  11. An Electronics "Unit Laboratory"

    ERIC Educational Resources Information Center

    Davies, E. R.; Penton, S. J.

    1976-01-01

    Describes a laboratory teaching technique in which a single topic (in this case, bipolar junction transistors) is studied over a period of weeks under the supervision of one staff member, who also designs the laboratory work. (MLH)

  12. Influence of Two Depuration Periods on the Activity and Transcription of Antioxidant Enzymes in Tilapia Exposed to Repeated Doses of Cylindrospermopsin under Laboratory Conditions

    PubMed Central

    Ríos, Victoria; Guzmán-Guillén, Remedios; Moreno, Isabel M.; Prieto, Ana I.; Puerto, María; Jos, Angeles; Cameán, Ana M.

    2014-01-01

    The cyanobacterial toxin Cylindrospermopsin (CYN), a potent protein synthesis inhibitor, is increasingly being found in freshwater bodies infested by cyanobacterial blooms worldwide. Moreover, it has been reported to be implicated in human intoxications and animal mortality. Recently, the alteration of the activity and gene expression of some glutathione related enzymes in tilapias (Oreochromis niloticus) exposed to a single dose of CYN has been reported. However, little is known about the effects induced by repeated doses of this toxin in tilapias exposed by immersion and the potential reversion of these biochemical alterations after two different depuration periods (3 or 7 days). In the present study, tilapias were exposed by immersion to repeated doses of a CYN-containing culture of Aphanizomenon ovalisporum during 14 days, and then were subjected to depuration periods (3 or 7 days) in clean water in order to examine the potential reversion of the effects observed. The activity and relative mRNA expression by real-time polymerase chain reaction (PCR) of the antioxidant enzymes glutathione peroxidase (GPx) and soluble glutathione-S-transferases (sGST), and also the sGST protein abundance by Western blot analysis were evaluated in liver and kidney of fish. Results showed significant alterations in most of the parameters evaluated and their recovery after 3 days (GPx activity, sGST relative abundance) or 7 days (GPx gene expression, sGST activity). These findings not only confirm the oxidative stress effects produced in fish by cyanobacterial cells containing CYN, but also show the effectiveness of depuration processes in mitigating the CYN-containing culture toxic effects. PMID:24632554

  13. Electron irradiation and thermal driven chemistry on H2S-CH3OH-NH3-H2O and CH3OH-NH3-H2O ices: application to Jupiter Trojans

    NASA Astrophysics Data System (ADS)

    Mahjoub, A.; Poston, M.; Hand, K.; Brown, M.; Blacksberg, J.; Eiler, J.; Hodyss, R.; Carlson, R.; Ehlmann, B.; Choukroun, M.

    2015-10-01

    In this work we investigate chemical reactions driven by irradiation and thermal processing of outer solar system simulants and the resultant products. The main goal of this laboratory simulation work is testing migration hypotheses predicted by solar system formation models [1]. The ice samples are chosen to simulate the differences between chemistry in objects initially located inside and outside the stability line of H2S. CH3OH-NH3-H2O (3-ice) and H2S-CH3OH-NH3-H2O (4-ice) ice films was irradiated under ultrahigh vacuum conditions. Mid- IR analysis of the ice composition and mass spectrometry monitoring of the released volatiles during the heating of the irradiated mixtures show a rich chemistry for both mixtures. Our experimental work suggests that S-bearing molecules like OCS and SO2 could be formed under conditions expected for objects that initially contained near-surface frozen H2S and were then exposed to space weathering, particularly heating and irradiation while migrating to a position close to Jupiter's orbit.

  14. Angiotensin AT1 and AT2 receptor antagonists modulate nicotine-evoked [3H]dopamine and [3H]norepinephrine release

    PubMed Central

    Narayanaswami, Vidya; Somkuwar, Sucharita S.; Horton, David B.; Cassis, Lisa A.; Dwoskin, Linda P.

    2014-01-01

    Tobacco smoking is the leading preventable cause of death in the United States. A major negative health consequence of chronic smoking is hypertension. Untoward addictive and cardiovascular sequelae associated with chronic smoking are mediated by nicotine-induced activation of nicotinic receptors (nAChRs) within striatal dopaminergic and hypothalamic noradrenergic systems. Hypertension involves both brain and peripheral angiotensin systems. Activation of angiotensin type-1 receptors (AT1) release dopamine and norepinephrine. The current study determined the role of AT1 and angiotensin type-2 (AT2) receptors in mediating nicotine-evoked dopamine and norepinephrine release from striatal and hypothalamic slices, respectively. The potential involvement of nAChRs in mediating effects of AT1 antagonist losartan and AT2 antagonist, 1-[[4-(dimethylamino)-3-methylphenyl]methyl]-5-(diphenylacetyl)-4,5,6,7-tetrahydro-1H-imidazo[4,5-c]pyridine-6-carboxylic acid (PD123319) was evaluated by determining their affinities for α4β2* and α7* nAChRs using [3H]nicotine and [3H]methyllycaconitine binding assays, respectively. Results show that losartan concentration-dependently inhibited nicotine-evoked [3H]dopamine and [3H]norepinephrine release (IC50: 3.9±1.2 and 2.2±0.7 μM; Imax: 82±3 and 89±6%, respectively). In contrast, PD123319 did not alter nicotine-evoked norepinephrine release, and potentiated nicotine-evoked dopamine release. These results indicate that AT1 receptors modulate nicotine-evoked striatal dopamine and hypothalamic norepinephrine release. Furthermore, AT1 receptor activation appears to be counteracted by AT2 receptor activation in striatum. Losartan and PD123319 did not inhibit [3H]nicotine or [3H]methyllycaconitine binding, indicating that these AT1 and AT2 antagonists do not interact with the agonist recognition sites on α4β2* and α7* nAChRs to mediate these effects of nicotine. Thus, angiotensin receptors contribute to the effects of nicotine on

  15. Lack of [3H]quinuclidinyl benzylate binding to biologically relevant binding sites on mononuclear cells.

    PubMed

    Adams, E M; Lubrano, T M; Gordon, J; Fields, J Z

    1992-09-01

    We analyzed the binding characteristics of [3H]quinuclidinyl benzylate ([3H]QNB), a muscarinic cholinergic ligand, to rat and human mononuclear cells (MNC). Under various assay conditions, atropine-sensitive, saturable binding occurred with an apparent Kd of 10 nM. Conditions which disrupted the MNC membrane reduced total binding and eliminated specific binding. Muscarinic agonists were unable to inhibit [3H]QNB binding to MNC at concentrations up to 10(-2) M. Stereoisomers dexetimide and levetimide were equipotent inhibitors of binding (IC50 2 x 10(-5) M). We conclude that, although atropine-sensitive binding of [3H]QNB to MNC occurs, the binding is not consistent with the presence of a biologically relevant muscarinic cholinergic receptor. PMID:1392105

  16. Alpha 2 adrenergic receptors in hyperplastic human prostate: identification and characterization using (/sup 3/H) rauwolscine

    SciTech Connect

    Shapiro, E.; Lepor, H.

    1986-05-01

    (/sup 3/H)Rauwolscine ((/sup 3/H)Ra), a selective ligand for the alpha 2 adrenergic receptor, was used to identify and characterize alpha 2 adrenergic receptors in prostate glands of men with benign prostatic hyperplasia. Specific binding of (/sup 3/H)Ra to prostatic tissue homogenates was rapid and readily reversible by addition of excess unlabelled phentolamine. Scatchard analysis of saturation experiments demonstrates a single, saturable class of high affinity binding sites (Bmax = 0.31 +/- 0.04 fmol./microgram. DNA, Kd = 0.9 +/- 0.11 nM.). The relative potency of alpha adrenergic drugs (clonidine, alpha-methylnorepinephrine and prazosin) in competing for (/sup 3/H)Ra binding sites was consistent with the order predicted for an alpha 2 subtype. The role of alpha 2 adrenergic receptors in normal prostatic function and in men with bladder outlet obstruction secondary to BPH requires further investigation.

  17. Deuterated C3H2 as a clue to deuterium chemistry

    NASA Technical Reports Server (NTRS)

    Gerin, M.; Combes, F.; Wootten, H. A.; Boulanger, F.; Peters, W. L., III; Kuiper, T. B. H.

    1987-01-01

    The deuterated cyclopropenylidene ring molecule, C3HD, has been detected toward several sources in four rotational lines, at 19, 79, 104, and 107 GHz. The relative integrated intensities of the 2-sub-12 - 1-sub-01 lines of C3HD and C3H2 are found in the ratio 1:5, indicating a high deuterium fractionation ratio for cyclopropenylidene. The detection of the C-13 isotope of C3H2 at the same position allows a determination of the optical thickness (about 3) of the line. The detection of such a large enhancement in the deuterated form of C3H2 very strongly suggests that a molecular ion is the chemical precursor of the molecules. Consideration of the amount of the enhancement relative to that in other molecules suggests that the precursor ion is C3H3+.

  18. Phylogenetic distribution of (/sup 3/H)cyclohexyladenosine binding sites in nervous tissue

    SciTech Connect

    Siebenaller, J.F.; Murray, T.F.

    1986-05-29

    The specific binding of the A/sub 1/ adenosine receptor ligand. (/sup 3/H)CHA, was investigated in membrane fractions prepared from brains of eleven vertebrate species and ganglia of four invertebrate species. Substantial amounts of specific (/sup 3/H)CHA binding sites were demonstrated in brain membranes of all vertebrate species examined; however, (/sup 3/H)CHA binding sites were not detectable in nervous sites in vertebrate brains increase in higher vertebrates. Moreover, the pharmacological characteristics of the site labeled by (/sup 3/H)CHA in two divergent classes of vertebrates were similar. The broad phylogenetic distribution of A/sub 1/ adenosine receptors in primitive as well as advanced vertebrate species suggests a fundamental role for adenosine in neuronal modulation.

  19. Photodisintegration of /sup 3/H and /sup 3/He. [Threshold to 25 MeV

    SciTech Connect

    Faul, D.D.

    1980-09-01

    The photoneutron cross sections for /sup 3/H and /sup 3/He have been measured from threshold to approx. 25 MeV with monoenergetic photons from the annihilation in flight of fast positrons at the LLL Electron-Positron Linear Accelerator facility. These reactions include the two-body breakup of /sup 3/H and the three-body breakup of both /sup 3/H and /sup 3/He; these measurements for /sup 3/H are the first to span the energy region across the peaks of the cross sections. An efficient BF/sub 3/-tube-and-paraffin neutron detector and high-pressure gaseous samples of several moles each (the activity of the /sup 3/H sample was approx. 200,000 Ci) were employed in these measurements. Measurements on /sup 16/O and /sup 2/H also were performed to verify the absolute cross-section scale. The results, when compared with each other and with results for the two-body breakup cross section for /sup 3/He from the literature, show that the two-body breakup cross sections for /sup 3/H and /sup 3/He have nearly the same shape, but the one for /sup 3/He lies lower in magnitude; the three-body breakup cross section for /sup 3/He lies higher in magnitude and is broader in the peak region and also rises less sharply from threshold than that for /sup 3/H; and these measured differences between the cross sections for the breakup modes largely compensate in their sum, so that the total photon absorption cross sections for /sup 3/H and /sup 3/He are nearly the same in both size and shape at energies near and above their peaks. Theoretical results from the literature disagree with the experimental results to a certain extent over the entire photon-energy region for which the photoneutron cross sections were measured. 50 figures, 7 tables.

  20. 3H/3He age data in assessing the susceptibility of wells to contamination

    USGS Publications Warehouse

    Manning, A.H.; Solomon, D.K.; Thiros, S.A.

    2005-01-01

    Regulatory agencies are becoming increasingly interested in using young-ground water dating techniques, such as the 3H/3He method, in assessing the susceptibility of public supply wells (PSWs) to contamination. However, recent studies emphasize that ground water samples of mixed age may be the norm, particularly from long-screened PSWs, and tracer-based "apparent" ages can differ substantially from actual mean ages for mixed-age samples. We present age and contaminant data from PSWs in Salt Lake Valley, Utah, that demonstrate the utility of 3H and 3He measurements in evaluating well susceptibility, despite potential age mixing. Initial 3H concentrations (measured 3H + measured tritiogenic 3He) are compared to those expected based on the apparent 3H/3He age and the local precipitation 3H record. This comparison is used to determine the amount of modern water (recharged after ???1950) vs. prebomb water (recharged before ???1950) samples might contain. Concentrations of common contaminants were also measured using detection limits generally lower than those used for regulatory purposes. A clear correlation exists between the potential magnitude of the modern water fraction and both the occurrence and concentration of contaminants. For samples containing dominantly modern water based on their initial 3H concentrations, potential discrepancies between apparent 3H/ 3He ages and mean ages are explored using synthetic samples that are random mixtures of different modern waters. Apparent ages can exceed mean ages by up to 13 years for these samples, with an exponential age distribution resulting in the greatest discrepancies.

  1. Synthetic studies towards putative yuremamine using an iterative C(sp(3))-H arylation strategy.

    PubMed

    Calvert, Matthew B; Sperry, Jonathan

    2016-06-28

    An overview of an iterative, 8-aminoquinoline (AQ)-directed C(sp(3))-H arylation strategy towards the pyrroloindole structure initially assigned to the alkaloid yuremamine is described. During initial efforts using a model indane system, it was discovered that the iodoresorcinol unit was not a viable C(sp(3))-H arylation partner when masked as its dimethyl ether but upon switching to a MOM group, the ether oxygen served to stabilise the high valent Pd intermediate during the reaction, thus promoting reductive elimination and leading to acceptable yields of the C(sp(3))-H arylation product. The second C(sp(3))-H arylation with an iodopyrogallol gave a 1,3-diarylated model yuremamine system possessing the desired 1,3-cis relationship. When the successful model studies were applied to a pyrroloindole system in pursuit of yuremamine, it became apparent that C9 underwent competing C(sp(2))-H arylation if left vacant, but installing a tryptamine side chain at this site prevented the desired C(sp(3))-H arylation from occurring altogether. However, a C9-methyl pyrroloindole underwent iterative C(sp(3))-H arylation at C1 with an iodoresorcinol followed by C3 with an iodopyrogallol to give a diarylated product with the aryl groups in the undesired 1,3-trans-relationship, arising from epimerisation at C1 during the second C(sp(3))-H arylation event. Although the synthesis of putative yuremamine was not accomplished, several findings are disclosed that will serve as useful additions to the burgeoning field of directed C(sp(3))-H arylations and related C-H functionalization reactions. PMID:26891188

  2. Chemical integrity of ( sup 3 H)GABA used in binding studies

    SciTech Connect

    Balcar, V.J. )

    1989-07-01

    A method which is claimed to be able to determine the proportion of true GABA within radiolabeled GABA used in binding studies was tested using (3H)GABA. The method was found to be unsuitable for {sup 3}H-labeled GABA and, furthermore, both theoretical considerations and the present experimental data indicated that it could also produce misleading results with ({sup 14}C)GABA.

  3. N-(/sup 3/H)acetyl-labeling, a convenient method for radiolabeling of glycosaminoglycans

    SciTech Connect

    Hook, M.; Riesenfeld, J.; Lindahl, U.

    1982-01-15

    A method for the introduction of N-(/sup 3/H)acetyl groups into glycosaminoglycans is described. The procedure is based on (/sup 3/H)acetylation of N-unsubstituted hexosamine residues by treating the polysaccharides with (/sup 3/H)acetic anhydride. Preparations of heparin and heparin sulfate were found to contain significant numbers of N-unsubstituted hexosamine residues, as isolates. In contrast, such units could not be detected in chondroitin sulfate, dermatan sulfate, or hyaluronic acid. These polysaccharides were therefore subjected to partial N-deacetylation by reaction with hydrazine in the presence of hydrazine sulfate. After treatment with (/sup 3/H)acetic anhydride, the specific activities of the resulting labeled polysaccharide preparations ranged between 0.1 X 10/sup 6/ and 0.6 X 10/sup 6/ cpm /sup 3/H/..mu..g of uronic acid. The /sup 3/H-labeled polysaccharide preparations did not differ significantly from the corresponding unlabeled starting materials with regard to polyanion properties (chromatography on DEAE-cellulose) or polymer chain size (gel chromatography). Further, the radiolabeled polysaccharide derivatives were susceptible to specific enzymatic degradation (chondroitinase ABC and mammalian heparitinase) and retained their ability to interact specifically with certain proteins - for example, (/sup 3/H)heparin with antithrombin (/sup 3/H)hyaluronic acid oligosaccharides with chondroitin sulfate proteoglycan. These findings indicate that the labeling procedures did not induce any major structural derangement of the polysaccharide molecules. The method developed should be useful in providing labeled glycosaminoglycans for metabolic and enzymatic experiments as well as for studies on the interacion between glycosaminoglycans and other bilogical macromolecules.

  4. Purification of L-( sup 3 H) Nicotine eliminates low affinity binding

    SciTech Connect

    Romm, E.; Marks, M.J.; Collins, A.C. ); Lippiello, P.M. )

    1990-01-01

    Some studies of L-({sup 3}H) nicotine binding to rodent and human brain tissue have detected two binding sites as evidenced by nonlinear Scatchard plots. Evidence presented here indicated that the low affinity binding site is not stereospecific, is not inhibited by low concentrations of cholinergic agonists and is probably due to breakdown products of nicotine since purification of the L-({sup 3}H)nicotine eliminates the low affinity site.

  5. Ligand-Promoted C(sp(3) )-H Olefination en Route to Multi-functionalized Pyrazoles.

    PubMed

    Yang, Weibo; Ye, Shengqing; Schmidt, Yvonne; Stamos, Dean; Yu, Jin-Quan

    2016-05-17

    A Pd-catalyzed/N-heterocycle-directed C(sp(3) )-H olefination has been developed. The monoprotected amino acid ligand (MPAA) is found to significantly promote Pd-catalyzed C(sp(3) )-H olefination for the first time. Cu(OAc)2 instead of Ag(+) salts are used as the terminal oxidant. This reaction provides a useful method for the synthesis of alkylated pyrazoles. PMID:26991450

  6. High-affinity binding of (/sup 3/H)acetylcholine to muscarinic cholinergic receptors

    SciTech Connect

    Kellar, K.J.; Martino, A.M.; Hall, D.P. Jr.; Schwartz, R.D.; Taylor, R.L.

    1985-06-01

    High-affinity binding of (/sup 3/H)acetylcholine to muscarinic cholinergic sites in rat CNS and peripheral tissues was measured in the presence of cytisin, which occupies nicotinic cholinergic receptors. The muscarinic sites were characterized with regard to binding kinetics, pharmacology, anatomical distribution, and regulation by guanyl nucleotides. These binding sites have characteristics of high-affinity muscarinic cholinergic receptors with a Kd of approximately 30 nM. Most of the muscarinic agonist and antagonist drugs tested have high affinity for the (/sup 3/H)acetylcholine binding site, but pirenzepine, an antagonist which is selective for M-1 receptors, has relatively low affinity. The ratio of high-affinity (/sup 3/H)acetylcholine binding sites to total muscarinic binding sites labeled by (/sup 3/H)quinuclidinyl benzilate varies from 9 to 90% in different tissues, with the highest ratios in the pons, medulla, and heart atrium. In the presence of guanyl nucleotides, (/sup 3/H) acetylcholine binding is decreased, but the extent of decrease varies from 40 to 90% in different tissues, with the largest decreases being found in the pons, medulla, cerebellum, and heart atrium. The results indicate that (/sup 3/H)acetylcholine binds to high-affinity M-1 and M-2 muscarinic receptors, and they suggest that most M-2 sites have high affinity for acetylcholine but that only a small fraction of M-1 sites have such high affinity.

  7. Autoradiographic localization of specific (/sup 3/H)dexamethasone binding in fetal lung

    SciTech Connect

    Beer, D.G.; Butley, M.S.; Cunha, G.R.; Malkinson, A.M.

    1984-10-01

    The cellular and subcellular localization of specific (/sup 3/H)dexamethasone binding was examined in fetal mouse lung at various stages of development and in human fetal lung at 8 weeks of gestation using a rapid in vitro steroid incubation technique followed by thaw-mount autoradiography. Competition studies with unlabeled steroids demonstrate the specificity of (/sup 3/H)dexamethasone labeling, and indicate that fetal lung mesenchyme is a primary glucocorticoid target during lung development. Autoradiographs of (/sup 3/H)dexamethasone binding in lung tissue at early stages of development demonstrate that the mesenchyme directly adjacent to the more proximal portions of the bronchiolar network is heavily labeled. In contrast, the epithelium which will later differentiate into bronchi and bronchioles, is relatively unlabeled. Distal portions of the growing epithelium, destined to become alveolar ducts and alveoli, do show nuclear localization of (/sup 3/H)dexamethasone. In addition, by utilizing a technique which allows the simultaneous examination of extracellular matrix components and (/sup 3/H)dexamethasone binding, a relationship is observed between extensive mesenchymal (/sup 3/H)dexamethasone binding and extensive extracellular matrix accumulation. Since glucocorticoids stimulate the synthesis of many extracellular matrix components, these results suggest a role for these hormones in affecting mesenchymal-epithelial interactions during lung morphogenesis.

  8. Transmission of /sup 3/H-compounds corresponding to the senescence signal in soybean

    SciTech Connect

    Nooden, L.D.; Finkelstein, D.; Wetzel, P.

    1987-04-01

    To detect compounds transmitted from the pods to the leaves, the pods of explants at various stages were injected with /sup 3/H-acetate and incubated for 24 hr. To avoid /sup 3/H contamination, the leaf blades, pods, and stem were each vented separately with air (pods, leaves) or water (stem). The leaf blades were extracted with MeOH/CHCl/sub 3//formic acid/H/sub 2/O (12:2:1:2 v/v), and after reduction to an aqueous phase, the /sup 3/H was partitioned. Most /sup 3/H entered the acid ether (50%) and aqueous (30%) phases with much less in the neutral and basic phases. The most /sup 3/H was transmitted during mid and late podfill when the pods induce senescence. When chromatographed on TLC (silica gel) with n-BuOH/HAc/H/sub 2/O) (450:112:188 v/v), the acid ether phase gave one sharp peak of /sup 3/H, while the aqueous phase produced a broad peak. Most (80%) of the former peak, which corresponded to IAA and ABA, could be resolved from these compounds by reverse phase HPLC on a C/sub 8/ column with a MeOH/gradient. Thus, some compounds are transmitted from the pods to the leaves during induction of monocarpic senescence, and at least the acid ether-soluble compounds are of limited heterogeneity.

  9. Retinoic acid treatment of fibroblasts causes a rapid decrease in ( sup 3 H)inositol uptake

    SciTech Connect

    Sinha, R.; Creek, K.E.; Silverman-Jones, C.; de Luca, L.M. )

    1989-04-01

    NIH 3T3 fibroblasts treated with all-trans-retinoic acid (RA) showed a dramatic decrease in the uptake of ({sup 3}H)inositol compared to solvent-treated controls. The onset of RA-induced inhibition of ({sup 3}H)inositol uptake was rapid with a 10-15% decrease occurring after 2-3 h of RA exposure and 60-70% reduction after 16 h of RA treatment. A progressive dose-dependent decrease in inositol uptake was found as the concentration of RA increased from 10{sup {minus}8} to 10{sup {minus}5} M and the effect was fully reversible within 48 h after RA removal. RA inhibition of inositol uptake was also observed in 3T3-Swiss and Balb/3T3 cells but not in two virally transformed 3T3 cell lines. Phlorizin, amiloride, and monensin inhibited inositol uptake by 66, 74, and 58%, respectively, and this inhibition was additive when the cells were treated with RA as well as these inhibitors. A decreased incorporation of ({sup 3}H)inositol into polyphosphoinositides was also observed in RA-treated cells but not to the same extent as for ({sup 3}H)inositol uptake. In conclusion, RA treatment of 3T3 fibroblasts decreases the uptake of ({sup 3}H)inositol by up to 70% within 8 to 10 h at near physiological concentrations in a reversible and specific manner.

  10. FIRST DETECTION OF c-C{sub 3}H{sub 2} IN A CIRCUMSTELLAR DISK

    SciTech Connect

    Qi Chunhua; Wilner, David J.; Rosenfeld, Katherine A.; Oeberg, Karin I.

    2013-03-01

    We report the first detection of c-C{sub 3}H{sub 2} in a circumstellar disk. The c-C{sub 3}H{sub 2} J = 6-5 line (217.882 GHz) is detected and imaged through Atacama Large Millimeter Array (ALMA) Science Verification observations toward the disk around the Herbig Ae star HD 163296 at 0.''8 resolution. The emission is consistent with that arising from a Keplerian rotating disk. Two additional c-C{sub 3}H{sub 2} transitions are also tentatively detected, bolstering the identification of this species, but with insufficient signal-to-noise ratio to constrain the spatial distribution. Using a previously developed model for the physical structure of this disk, we fit a radial power-law distribution model to the c-C{sub 3}H{sub 2} 6-5 emission and find that c-C{sub 3}H{sub 2} is present in a ring structure from an inner radius of about 30 AU to an outer radius of about 165 AU. The column density is estimated to be 10{sup 12}-10{sup 13} cm{sup -2}. The clear detection and intriguing ring structure suggest that c-C{sub 3}H{sub 2} has the potential to become a useful probe of radiation penetration in disks.

  11. Synthesis of (plus or minus) [5-{sup 3}H] N'-Nitrosoanatabine, a tobacco-specific nitrosamine

    SciTech Connect

    Desai, Dhimant; Lin, Guoying; Morimoto, Hiromi; Williams, Philip G.; El-Bayoumy, Karam; Amin, Shantu

    2002-06-14

    Tobacco-specific N'-nitrosamines (TSNA) are a unique class of systemic organ-specific carcinogens. The TSNA are formed by N-nitrosation of nicotine and of the minor tobacco alkaloids after harvesting of tobacco and during smoking. The N-nitrosation of anatabine leads to N'-nitrosoanatabine (NAT; 1-nitroso-1,2,3,4-tetrahydro-2,3'-bipyridyl) which requires in-depth assays in laboratory animals other than the rat. Furthermore, delineation of its tissue distribution and metabolism is needed for structure:activity comparisons with other TSNA and for the assessment of potential human risk from this TSNA. We have, therefore, synthesized (+)[5-3H]NAT. 5-Bromo-3-pyridine-carboxaldehyde was condensed with ethyl carbamate prior to Diels-Alder reaction with 1,4-butadiene to give the racemic anatabine ring system. Hydrolysis followed by reduction with LiAlT4 and nitrosation, led to (+)[5-3H]NAT (60 percent yield, specific activity 266 mCi/mmol, radiochemical purity of >99 percent).

  12. Medicare program; payment policies under the physician fee schedule, five-year review of work relative value units, clinical laboratory fee schedule: signature on requisition, and other revisions to part B for CY 2012. Final rule with comment period.

    PubMed

    2011-11-28

    This final rule with comment period addresses changes to the physician fee schedule and other Medicare Part B payment policies to ensure that our payment systems are updated to reflect changes in medical practice and the relative value of services. It also addresses, implements or discusses certain statutory provisions including provisions of the Patient Protection and Affordable Care Act, as amended by the Health Care and Education Reconciliation Act of 2010 (collectively known as the Affordable Care Act) and the Medicare Improvements for Patients and Providers Act (MIPPA) of 2008. In addition, this final rule with comment period discusses payments for Part B drugs; Clinical Laboratory Fee Schedule: Signature on Requisition; Physician Quality Reporting System; the Electronic Prescribing (eRx) Incentive Program; the Physician Resource-Use Feedback Program and the value modifier; productivity adjustment for ambulatory surgical center payment system and the ambulance, clinical laboratory, and durable medical equipment prosthetics orthotics and supplies (DMEPOS) fee schedules; and other Part B related issues. PMID:22145186

  13. A validation of the [sup 3]H/[sup 3]He method for determining groundwater recharge

    SciTech Connect

    Solomon, D.K. ); Schiff, S.L. ); Poreda, R.J. ); Clarke, W.B. )

    1993-09-01

    Tritium and He isotopes have been measured at a site where groundwater flow is nearly vertical for a travel time of 100 years and where recharge rates are spatially variable. Because the mid-1960s [sup 3]H peak (arising from aboveground testing of thermonuclear devices) is well-defined, the vertical groundwater velocity is known with unusual accuracy at this site. Utilizing [sup 3]H and its stable daughter [sup 3]He to determine groundwater ages, we compute a recharge rate of 0.16 m/yr, which agrees to within about 5% of the value based on the depth of the [sup 3]H peak (measured both in 1986 and 1991) and two-dimensional modeling in an area of high recharge. Zero [sup 3]H/[sup 3]He age occurs at a depth that is approximately equal to the average depth of the annual low water table, even though the capillary fringe extends to land surface during most of the year at the study site. In an area of low recharge (0.05 m/yr) where the [sup 3]H peak (and hence the vertical velocity) is also well-defined, the [sup 3]H/[sup 3]He results could not be used to compute recharge because samples were not collected sufficiently far above the [sup 3]H peak; however, modeling indicates that the [sup 3]H/[sup 3]He age gradient near the water table is an accurate measure of vertical velocities in the low-recharge area. Because [sup 3]H and [sup 3]He have different diffusion coefficients, and because the amount of mechanical mixing is different in the area of high recharge than in the low-recharge area, we have separated the dispersive effects of mechanical mixing from molecular diffusion. We estimate a longitudinal dispersivity of 0.07 m and effective diffusion coefficients for [sup 3]H ([sup 3]HHO) and [sup 3]He of 2.4 x 10[sup [minus]5] and 1.3 x 10[sup [minus]4] m[sup 2]/day, respectively. 26 refs., 8 figs., 1 tab.

  14. Background considerations for the 2H(7Be,3H)6Be experimental data II: Three-body continuum

    NASA Astrophysics Data System (ADS)

    Chae, K. Y.; Guimarães, V.

    2015-11-01

    The present article reports second background considerations for the experimentally obtained 2H(7Be,3H)6Be differential cross sections. The one-neutron transfer reaction was measured in inverse kinematics by using radioactive 7Be ( t 1/2 = 53.2 days) beams at the Holifield Radioactive Ion Beam Facility of the Oak Ridge National Laboratory in 2004 in order to search for the resonances in the unbound 6Be nucleus. Resonances in this nucleus would affect the 3He(3He,2 p)4He reaction rate of the proton-proton chain occurring in stars such as our sun. The result shows, however, that the direct transfer to 6Be resonances is not particularly strong compared to other reaction channels that can produce tritons in the exit channels. The goals of the present work is to better understand the cross section data from transfer reaction measurements by adopting background considerations using the three-body continuum.

  15. Synthesis and biodistribution studies of (3)H- and (64)Cu-labeled dendritic polyglycerol and dendritic polyglycerol sulfate.

    PubMed

    Pant, Kritee; Gröger, Dominic; Bergmann, Ralf; Pietzsch, Jens; Steinbach, Jörg; Graham, Bim; Spiccia, Leone; Berthon, Fannely; Czarny, Bertrand; Devel, Laurent; Dive, Vincent; Stephan, Holger; Haag, Rainer

    2015-05-20

    Dendritic polyglycerol sulfate (dPGS) is a biocompatible, bioactive polymer which exhibits anti-inflammatory activity in vivo and thus represents a promising candidate for therapeutic and diagnostic applications. To investigate the in vivo pharmacokinetics in detail, dPGS with a molecular weight of approx. 10 kDa was radiolabeled with (3)H and (64)Cu, and evaluated by performing biodistribution studies and small animal positron emission tomography (PET). (3)H-labeling was accomplished by an oxidation-reduction process with sodium periodate and [(3)H]-borohydride. (64)Cu-labeling was achieved by conjugation of isothiocyanate- or maleimide-functionalized copper(II)-chelating ligands based on 1,4-bis(2-pyridinylmethyl)-1,4,7-triazacyclononane (DMPTACN) to an amino functionalized dPGS scaffold, followed by reaction with an aqueous solution containing (64)CuCl2. Independent biodistribution by radioimaging and PET imaging studies with healthy mice and rats showed that the neutral dPG was quantitatively renally eliminated, whereas the polysulfated analogues accumulated mainly in the liver and spleen. Small amounts of the dPGS derivatives were slowly excreted via the kidneys. The degree of uptake by the reticuloendothelial system (RES) was similar for dPGS with 40% or 85% sulfation, and surface modification of the scaffold with the DMPTACN chelator did not appear to significantly affect the biodistribution profile. On the basis of our data, the applicability of bioactive dPGS as a therapeutic agent might be limited due to organ accumulation even after 3 weeks. The inert characteristics and clearance of the neutral polymer, however, emphasizes the potential of dPG as a multifunctional scaffold for various nanomedical applications. PMID:25891152

  16. Cone outer segment shedding in the goldfish retina characterized with the /sup 3/H-fucose technique

    SciTech Connect

    Balkema, G.W. Jr.; Bunt-Milam, A.H.

    1982-09-01

    After an intravitreal injection of /sup 3/H-fucose, red- and blue-sensitive cone outer segments (OSs) in the goldfish retina became heavily labeled, green-sensitive cone OSs showed light labeling, and rod OSs showed virtually no labeling. Fish were maintained in white light (light/dark: 12 hr/12 hr; 6 to 10 weeks) and were injected with /sup 3/H-fucose 24 hr before sacrifice. After light onset, only phagosomes with no label were found in the retinal pigment epithelium (RPE); after light offset, phagosomes with heavy, light, or no label were found in the RPE. A broad peak of cone OS shedding derived from all cone types was found beginning 2 hr after light offset and returning to baseline levels after 12 hr, with a maximum at 4 to 6 hr. When the white light was replaced with red light during the final 24 hr (irradiance matched to the white light at 625 nm), the green cones showed a reduction in shedding by 62%, the rods showed a 48% reduction in shedding, and the number of heavily labeled phagosomes was reduced by 24% (a value that may reflect normal and red cone shedding and a reduction in blue cone shedding). The results suggest that chromatic stimulation during the light period may influence the shedding response of a given class of cone OS. Finally, the /sup 3/H-fucose technique is useful for determination of the photoreceptor OS from which a given phagosome in the RPE originates in this species.

  17. Sensitivity of early mouse embryos to (/sup 3/H)thymidine

    SciTech Connect

    Spindle, A.; Wu, K.; Pedersen, R.A.

    1982-12-01

    Effects of intranuclear radiation on the developmental capacity of early mouse embryos were studied by exposing embryos to (/sup 3/H)thymidine and counting the number of embryos forming blastocysts, trophoblast outgrowths, inner cell masses (ICMs), and two-layer ICMs (differentiated into primary endoderm and ectoderm). When embryos were cultured from the 2-cell stage for 8 days in the continuous presence of (/sup 3/H)thymidine, concentrations as low as 0.2 nCi/ml reduced the number of embryos forming two-layer ICMs. At 1 nCi/ml, the number of both ICMs and two-layer ICMs were reduced, and at 10 nCi/ml the number of embryos developing to all three post-blastocyst endpoints was reduced. Blastocyst formation was not affected even at the highst concentration (/sup 3/H)thymidine and then cultured further in unlabelled medium, the effects were similar to those of 8-day exposure. When embryos were exposed to (/sup 3/H)thymidine for 24 h at various developmental stages, effects were less severe than when they were exposed continuously for 3 or 8 days, and the sensitivity of embryos differed between stages. The 24-h exposure of immunosurgically isolated ICMS to (/sup 3/H)thymidine revealed that the high sensitivity of the ICM to (/sup 3/H)thymidine persists through the late blastocyst stage and declines progressively thereafter. Autoradiography indicated that the change in radiosensitivity of embryos or ICMs is generally related to their ability to incorporate (/sup 3/H)thymidine into the DNA.

  18. Whole-body autoradiographic localization of (/sup 3/H)phencyclidine and its metabolites in mice

    SciTech Connect

    Fand, I.; McNally, W.P.; Koul, O.; Yonekura, Y.; Som, P.; Brill, A.B.; Deutsch, D.G.

    1988-05-01

    When evaluated by whole-body autoradiography (WBAR) and quantitative densitometry, (3H)phencyclidine (PCP) equivalents were found to be removed rapidly from blood, after a single iv dose in mice, and avidly taken up as early as 1 min after dosage by glandular tissues including thyroid, salivary glands, pancreas, pituitary and, most prominently, by stomach mucosa. Stomach:blood (3H)PCP concentration ratios showed that rapid secretion of (3H)PCP from mucosa to the stomach contents occurred within 2 min after dosing. During early intervals, chromatographic analysis of tissue sections demonstrated that PCP was present in brain, liver, and gut primarily in its unaltered chemical form. Mice killed at 60 and 120 min showed persistently high levels of (3H)PCP equivalents within the stomach and intestines, these levels being the highest of all other tissues densitometrically measured. The early time course and magnitude of (3H)PCP uptake by stomach glandular mucosa strongly suggests that cycling of PCP occurs principally through gastroenteric recirculation. Very striking was the high concentration of (3H)PCP radioactivity observed within the adrenal as early as 5 min. The concentration of (3H)PCP equivalents in pituitary, choroid plexus, cortex, hippocampus, and thalamus was highest at 1-20 min following injection. Application of high-resolution quantitative WBAR was found to be a useful tool in the study of the biodistribution of labeled PCP, especially during very early post-treatment time points where alternative tissue counting techniques would not be feasible.

  19. Characterization and regulation of (/sup 3/H)-serotonin uptake and release in rodent spinal

    SciTech Connect

    Stauderman, K.A.

    1986-01-01

    The uptake and release of (/sup 3/H)-serotonin were investigated in rat spinal cord synaptosomes. In the uptake experiments, sodium-dependent and sodium-independent (/sup 3/H)-serotonin accumulation processes were found. Sodium-dependent (/sup 3/H)-serotonin accumulation was: linear with sodium concentrations up to 180 mM; decreased by disruption of membrane integrity or ionic gradients; associated with purified synaptosomal fractions; and reduced after description of descending serotonergic neurons in the spinal cord. Of the uptake inhibitors tested, the most potent was fluoxetine (IC/sub 50/ 75 nM), followed by desipramine (IC/sub 50/ 430 nM) and nomifensine (IC/sub 50/ 950 nM). The sodium-independent (/sup 3/H)-serotonin accumulation process was insensitive to most treatments and probably represents nonspecific membrane binding. Thus, only sodium-dependent (/sup 3/H)-serotonin uptake represents the uptake process of serotonergic nerve terminals in rat spinal cord homogenates. In the release experiments, K/sup +/-induced release of previously accumulated (/sup 3/H)-serotonin was Ca/sup 2 +/-dependent, and originated from serotonergic synaptosomes. Exogenous serotonin and 5-methyoxy-N,N-dimethyltryptamine inhibited (/sup 3/H)-serotonin release in a concentration-dependent way. Of the antagonists tested, only methiothepin effectively blocked the effect of serotonin. These data support the existence of presynaptic serotonin autoreceptors on serotonergic nerve terminals in the rat spinal cord that act to inhibit a voltage and Ca/sup 2 +/-sensitive process linked to serotonin release. Alteration of spinai cord serotonergic function may therefore be possible by drugs acting on presynaptic serotonin autoreceptors in the spinal cord.

  20. Tissue distribution of sup 3 H-nicotine in rats after bolus or constant injection

    SciTech Connect

    Chowdhury, P.; Pasley, J.N.; Rayford, P.L. )

    1989-01-01

    Two groups of rats, (N = 7), were fasted for 24 hrs prior to the study. On the day of the experiment, the animals were anesthetized and infused with either 5 ml nicotine solution (200 {mu}g/L) in saline containing 5 {mu}c {sup 3}H-nicotine, (sp. activity 50-80 mCi/mol) for 90 minutes or injected as a bolus with 0.5 ml of the same nicotine (200 {mu}g/L) solution. The animals were sacrificed 60 minutes after the injection or after the infusion was stopped. Blood and tissue samples were counted by liquid scintillation counting. Percent distribution of {sup 3}H-nicotine per gm of tissue was calculated from the total radioactivity recovered in individual tissues over the total activity injected into the rat and the values were compared using student's t test. Results: Distribution of {sup 3}H-nicotine was found highest in kidney (45-49%) among all tissues examined and was not different between routes of administration. Significantly higher retention of {sup 3}H-nicotine was found with continuous infusion in esophagus, fundus, antrum, spleen, cecum, pancreas, testes, heart and muscle when {sup 3}H-nicotine retentions were compared with bolus injection. In contrast, the distribution of {sup 3}H-nicotine in adrenal gland, was significantly lower in continuous infusion group. Distribution in blood was 6 fold higher in continuous infusion (7.26%) compared to bolus (1.11%) injection. The distribution {sup 3}H-nicotine in other tissues were not different by either routes of injection.

  1. Depletion of (/sup 3/H)methyltrienolone cytosol binding in glucocorticoid-induced muscle atrophy (42001)

    SciTech Connect

    Kurowski, T.T.; Capaccio, J.A.; Chatterton, R.T. Jr.; Hickson, R.C.

    1985-01-01

    The present study was undertaken to determine cytosol binding properties of (/sup 3/H)methyltrienolone, a synthetic androgen, in comparison with (/sup 3/)dexamethasone, a synthetic glucocorticoid, under conditions of glucocorticoid excess in skeletal muscle. Male hypophysectomized rats received either seven daily subcutaneous injections of cortisone acetate (CA) (100 mg x kg/sup -1/ body wt) or the vehicle, 1% carboxymethyl cellulose. Following treatment, both (/sup 3/H)dexamethansone and (/sup 3/H)methyltrienolone-receptor concentrations were decreased from those in vehicle-treated rats by more than 90 and 80%, respectively, in CA-treated animals. Scatchard analysis of (/sup 3/H)methyltrienolone binding in muscles of vehicle-treated animals became nonlinear at high concentrations of labeled ligand and were reanalyzed by a two-component binding model. The lower affinity, higher capacity component, which was attributed to binding of methyltrienolone to a dexamethasone component, which was attributed to binding of methyltrienolone to a dexamethasone component, disappeared in muscles of CA-treated rats and Scatchard plots were linear. Receptor concentrations of the higher affinity lower capacity methyltrienolone component were similar in muscles of vehicle-treated and CA-treated groups. From competition studies, the high relative specificities of glucocorticoids for (/sup 3/H)methyltrienolone binding in muscles of vehicle-treated animals were markedly reduced by CA treatment. In addition, the binding specificity data also showed strong competition by progesterone and methyltrienolone for (/sup 3/H)dexamethasone binding and estradiol-17..beta.. for (/sup 3/H)methyltrienolone binding.

  2. (/sup 3/H)-SK and F 101926, a novel radiolabeled vasopressin antagonist

    SciTech Connect

    Stassen, F.L.; Heckman, D.; Schmidt, D.; Landvatter, S.; Crooke, S.T.

    1986-05-01

    Vasopressin receptor binding studies have been carried out with radiolabeled agonists. They have labeled SK and F 101926 (desGlyd(CH2)5D-Tyr(Et)VAVP), a potent antagonist of vascular (V1) and renal (V2) vasopressin receptors, with (/sup 3/H)-Phe (37 Ci/mmol). They studied V1 receptors of cultured smooth muscle cells of rat aorta (A-10) and liver, and V2 receptors of pig kidney. (/sup 3/H)-SK and F 101926 binding to plasma membranes of A-10 cells was specific (non-specific binding with 10 ..mu..M AVP), saturable, and of high affinity. At 0.4nM, the specific binding was 50%. A linear Scatchard plot indicated one antagonist affinity (KD = 0.4nM; Bmax = 100-150 fmol/10/sup 6/ cells). In contrast, the Scatchard plot of (/sup 3/H)-AVP binding was curvilinear. Specific (/sup 3/H)-SK and F 101926 binding was inhibited by AVP and vasopressin antagonists d(CH2)5Tyr(Me)AVP > d(CH2)5DTyr(Et)VAVP > d(CH2)5Tyr(Et)VAVP > d(CH2)5D-IleVAVP. The rank orders of the antagonists for vasopressin receptors of rat liver and A-10 cells determined with (/sup 3/H)-SK and F 101926 and (/sup 3/H)-AVP were the same. GppNHp did not affect (/sup 3/H)-SK and F 101926 binding. In competition experiments with cell and liver membranes, GppNHp decreased the affinity of AVP but not of the antagonist d(CH2)5Tyr(Me)AVP. (/sup 3/H)-SK and F 101926 also appeared to bind specifically to crude membranes of pig kidney medulla. In conclusion, the antagonist (/sup 3/H)-SK and F 101926 binds specifically and with high affinity to vasopressin receptors and is, thus, a powerful new tool to study vasopressin receptors.

  3. An analysis of [3H]gamma-aminobutyric acid (GABA) binding in the human brain.

    PubMed

    Lloyd, K G; Dreksler, S

    1979-03-01

    The binding of [3H]GABA to membranes prepared from human brains obtained post morten was examined. This binding was independent of patient sex, age (16--80 years), postmortem interval (4--33 h) or storage time when frozen (0-64 months). In preparations from cerebellar cortex various compounds displaced [3H]GABA binding with the following order of potency: muscimol greater than 3-aminopropanesulfonic acid greater than GABA greater than imidazoleacet acid greater than delta-amino-n-valeric acid greater than 3-hydroxyGABA greater than bicuculline. Other compounds active 'in vitro' included strychnine, homocarnosine and some (e.g. clozapine, thioridazine, pimozide) but not all (chlorpromazine, haloperiodol) neuroleptics. Compounds inactive 'in vitro' included aminooxyacetic acid, baclofen, picrotoxin, anticholinergics, metrazole, anticonvulsants and naloxone. Triton X-100 augmented the [3H]GABA binding (25 nM) by about 10--20-fold in most brain regions. [3H]GABA binding (IC50) was altered in Huntington's chorea and Reye's syndrome, but not in schizophrenics (4-neuroleptic-treated patients) or sudden infant death syndrome. The data presented strongly support the proposal that the measurement of [3H]GABA binding in postmortem human brain offers a reflection of the state of the physiologically relevant GABA receptor. PMID:218679

  4. (4B-3H) NADH-H2O exchange reaction of the mitochondrial NADH dehydrogenase

    SciTech Connect

    Chen, S.; Guillory, R.J.

    1985-06-14

    The purified mitochondrial NADH dehydrogenase enzyme has been shown to catalyze a rapid (4B-/sup 3/H) NADH-H/sub 2/O exchange reaction. When the enzyme is subjected to a single freeze-thaw cycle there is a complete loss of NADH dehydrogenation without a measurable decrease in the (4B-/sup 3/H) NADH-H/sub 2/O exchange. Complete loss of the (4B-/sup 3/H) NADH-H/sub 2/O exchange follows brief exposure to ultraviolet photoirradiation. The differential sensitivity of the water exchange reaction and the dehydrogenase activity suggests a direct involvement of the enzymes flavin cofactor in the catalysis of the (4B-/sup 3/H) NADH-H/sub 2/O exchange. Arylazido-beta-alanyl NAD+ (A3'-0-(3-(N-4-azido-2-nitrophenyl)amino) propionyl)NAD+) is shown to be a potent photodependent inhibitor of the (4B-3H) NADH-H/sub 2/O exchange activity following photoirradiation with visible light. This is consistent with the observed photodependent inhibition of the dehydrogenase activity by this photoprobe.

  5. Characterization of ( sup 3 H)alprazolam binding to central benzodiazepine receptors

    SciTech Connect

    McCabe, R.T.; Mahan, D.R.; Smith, R.B.; Wamsley, J.K. )

    1990-10-01

    The binding of the triazolobenzodiazepine ({sup 3}H)alprazolam was studied to characterize the in vitro interactions with benzodiazepine receptors in membrane preparations of rat brain. Studies using nonequilibrium and equilibrium binding conditions for ({sup 3}H)alprazolam resulted in high specific to nonspecific (signal to noise) binding ratios. The binding of ({sup 3}H)alprazolam was saturable and specific with a low nanomolar affinity for benzodiazepine receptors in the rat brain. The Kd was 4.6 nM and the Bmax was 2.6 pmol/mg protein. GABA enhanced ({sup 3}H)alprazolam binding while several benzodiazepine receptor ligands were competitive inhibitors of this drug. Compounds that bind to other receptor sites had a very weak or negligible effect on ({sup 3}H)alprazolam binding. Alprazolam, an agent used as an anxiolytic and in the treatment of depression, acts in vitro as a selective and specific ligand for benzodiazepine receptors in the rat brain. The biochemical binding profile does not appear to account for the unique therapeutic properties which distinguish this compound from the other benzodiazepines in its class.

  6. Lack of specific (/sup 3/H) prazosin binding sites in dog and rabbit cerebral arteries

    SciTech Connect

    Ferron, P.M.; Banner, W. Jr.; Duckles, S.P.

    1984-11-19

    In order to explore the characteristics of alpha adrenergic receptors on cerebrovascular smooth muscle, specific binding sites for the alpha/sub 1/ adrenergic ligand, (/sup 3/H) prazosin, were studied in blood vessel homogenates. No specific (/sup 3/H) prazosin binding was found in either rabbit or dog cerebral arteries, but specific binding was demonstrated in the rabbit saphenous and ear arteries. In the ear artery /sup 3/H-prazosin binding was saturable with a K/sub d/ of 0.51 +/- 0.20 nM and a Bmax of 89 +/- 29 fmoles/mg protein. To confirm the adequacy of our membrane preparation, homogenates of both dog and rabbit cerebral arteries showed saturable specific binding with two different ligands: one for muscarinic receptors, (/sup 3/H)(-) quinuclidinyl benzilate (QNB) and one for alpha/sub 2/ adrenergic receptors, (/sup 3/H) yohimbine. The results of these studies demonstrate a lack of alpha/sub 1/ adrenergic receptors on cerebral blood vessels, confirming functional studies showing only a weak contractile response to norepinephrine. 29 references, 3 figures, 2 tables.

  7. Enkephalin convertase: Characterization and localization with ( sup 3 H)-guanidinoethylmercap-tosuccinic acid

    SciTech Connect

    Lynch, D.R.

    1988-01-01

    Enkephalin convertase (EC) has been characterized by the binding of its selective inhibitor ({sup 3}H)-guanidinoethylmercaptosuccinic acid (GEMSA). The pharmacology and affinity of ({sup 3}H)-GEMSA binding match the pharmacology of EC activity and the inhibition of EC activity by GEMSA. EC activity and ({sup 3}H)-GEMSA binding activity copurify to homogeneity demonstrating that ({sup 3}H)-GEMSA binds selectively to EC. The selective association of ({sup 3}H)-GEMSA for EC allows localization of membrane bound EC by in vitro autoradiography. EC is heterogeneously distributed in the rat brain with the highest levels in the outer zone of the median eminence and in the hypothalamic magnocellular nuclei. In the pituitary gland, autoradiography localizes EC to all three lobes with the highest levels in the intermediate lobe. In the adrenal EC is found exclusively in the medulla. In the gastrointestinal tract, EC is localized to epithelial surfaces where its function cannot be that of propeptide processing. In the heart EC is localized to atrium where it likely processes precursors of atrial natriuretic factor.

  8. Characteristics of central binding sites for ( sup 3 H) DAMGO in spontaneously hypertensive rats

    SciTech Connect

    Gulati, A.; Bhargava, H.N. )

    1990-01-01

    The binding of ({sup 3}H) DAMGO, a highly selective ligand for {mu}-opiate receptors, to membranes of discrete brain regions and spinal cord of 10 week old spontaneously hypertensive (SHR) and normotensive Wistar-Kyoto (WKY) rats were determined. The brain regions examined were hypothalamus, amygdala, hippocampus, corpus striatum, pons and medulla, midbrain and cortex. ({sup 3}H) DAMGO bound to membranes of brain regions and spinal cord at a single high affinity site. The receptor density (B{sub max} value) and apparent dissociation constant (K{sub d} value) of ({sup 3}H) DAMGO to bind to membranes of hippocampus, corpus striatum, pons and medulla, cortex and spinal cord of WKY and SHR rats did not differ. The B{sub max} value of ({sup 3}H) DAMGO in membranes of hypothalamus and midbrain of SHR rats was significantly higher than in WKY rats but the K{sub d} values in the two strains did not differ. On the other hand, the B{sub max} value of ({sup 3}H) DAMGO in membranes of amygdala of SHR rats was lower than that of WKY rats but the K{sub d} values in the two strains were similar.

  9. Potassium activation of [3H]-choline accumulation by isolated sympathetic ganglia of the rat.

    PubMed Central

    Higgins, A. J.; Neal, M. J.

    1982-01-01

    1 The effect of K-depolarization on the uptake of low and high concentrations of [3H]-choline by isolated superior sympathetic ganglia of the rat has been studied. 2 In unstimulated ganglia, the uptake of [3H]-choline (0.1 microM) ('high affinity uptake') was unaffected by denervation or by hemicholinium-3 (HC-3), suggesting uptake by structures other than cholinergic nerve terminals. 3 K-depolarization of the ganglia increased [3H]-choline accumulation by the high affinity uptake process but in contrast the 'low affinity' accumulation of [3H]-choline (100 microM) was decreased. 4 The K-activated, 'high affinity' component of choline uptake was highly sodium-dependent, inhibited by HC-3, and was abolished by denervation. 5 In incubation conditions designed to prevent transmitter release (Ca-free medium and high-Mg medium), the K-activated uptake of [3H]-choline was abolished. 6 It is concluded that in unstimulated ganglia, there is little choline uptake by nerve terminals. However, when the terminals are depolarized, choline uptake is increased by the activation of a sodium-dependent, HC-3-sensitive transport process. The activation of this uptake process is apparently associated with the release of acetylcholine from the terminals, or by changes in ionic fluxes, and not by the depolarization per se. PMID:7150866

  10. Pregnancy rates, prenatal and postnatal survival of offspring, and litter sizes after reciprocal embryo transfer in DBA/2JHd, C3H/HeNCrl and NMRI mice.

    PubMed

    Rose, C; Schwegler, H; Hanke, J; Yilmazer-Hanke, D M

    2012-06-01

    Success of embryo transfer is often a limiting factor in transgenic procedures and rederivation efforts, and depends on the genetic background of the donor and recipient strains used. Here we show that embryo transfer to DBA/2J females is possible, and present data on pre- and postnatal success rates after reciprocal embryo transfer using the inbred DBA/2J and C3H/HeN, and outbred NMRI strains. The highest embryo yield was achieved in outbred NMRI females, but embryo yields were similar in DBA/2J and C3H/HeN mice following superovulation despite poor estrus cycle synchronization in DBA/2J females. In-strain transfer of DBA/2J blastocysts (transfer of embryos to recipients from the same strain) resulted in pregnancy rates (57.1%) similar to those obtained following in-strain transfer of C3H/HeN (60.0%) and NMRI mice (83.3%), although the prenatal survival rate of blastocysts was low. Moreover, from the pups born only half survived the postnatal period after transfer of DBA/2J and C3H/HeN blastocysts to DBA/2J recipients. These problems were not observed when transferring NMRI-blastocysts to C3H/HeN and DBA/2J mothers. The number of blastocysts transferred also had a positive effect on the success of embryo transfer. In conclusion, C3H/HeN and DBA/2J females can be used as recipients for embryo transfer procedures for certain donor strains like NMRI, as one major determinant seems to be the genetic background of the embryos transferred. We also recommend to increase the number of DBA/2J blastocysts transferred, and to foster the DBA/2J pups to other DBA/2J mothers postnatally for in-strain transfer of DBA/2J mice. PMID:22401828

  11. Penetration of ( sup 3 H)T-2 mycotoxin through abraded and intact skin and methods to decontaminate ( sup 3 H)T-2 mycotoxin from abrasions

    SciTech Connect

    Solberg, V.B.; Broski, F.H.; Dinterman, R.E.; George, D.T.

    1990-01-01

    T-2 mycotoxin is a toxic metabolite of various fungi of the Fusarium species. T-2 is found naturally in moldy grain and concentrations as high as 2 ppm have been found in moldy corn. T-2 purportedly has been used as a biological warfare agent in Southeast Asia and Iran, causing human deaths and has been implicated in dermal diseases in grain handling workers. Radiolabeled T-2 has been shown to penetrate excised animal and human skin in liquid vehicles and while adsorbed onto corn dust. In experimental animals studies, (3H)T-2 penetration through skin caused symptoms ranging from erythema and skin lesions to death.

  12. (/sup 3/H)muscimol binding sites increased in autopsied brains of chronic schizophrenics

    SciTech Connect

    Hanada, S.; Mita, T.; Nishino, N.; Tanaka, C.

    1987-01-19

    (/sup 3/H)muscimol binding and glutamic acid decarboxylase (GAD) activity in the prefrontal cortex and caudate nucleus of autopsied brains from 19 chronic schizophrenics and 17 control subjects were investigated. In the schizophrenics, saturation analysis with varying concentrations of (/sup 3/H)muscimol revealed an increase in the number GABA/sub A/ receptors, but there was no significant difference in the affinity. In addition, the enhancement of (/sup 3/H)muscimol binding by diazepam was significantly greater in schizophrenics than in controls. GAD activity did not differ between controls and schizophrenics. The possibility that GABAergic mechanisms might play a role in case of chronic schizophrenia should be given further attention.

  13. Characterization of central alpha-adrenoceptors using /sup 3/H-clonidine and its derivatives

    SciTech Connect

    Jarrott, B.; Louis, W.J.; Summers, R.J.

    1983-02-01

    alpha-Adrenoceptors in brain can be studied readily by radioligand binding techniques. This provides valuable information not only on the distribution of receptors in brain regions, but also on the regulation of receptors. The usefulness of this technique is dependent in part on a radioligand with high specificity for the receptor under study. Researchers' studies have shown that /sup 3/H-clonidine does not bind exclusively to alpha 2-adrenoceptor subtypes, but also interacts with alpha 1-adrenoceptors. In contrast, /sup 3/H-guanfacine labels a high affinity alpha 2 subtype with good selectivity, but /sup 3/H-lofexidine probably labels with both alpha 2 and alpha 1-adrenoceptor binding sites.

  14. Synthesis and characterization of [N-methyl-3H]loperamide.

    PubMed

    Filer, Crist N; Egan, Judith A; Nugent, Richard P

    2014-05-30

    Loperamide is a piperidine butyramide mu-opiate receptor agonist and currently employed to treat diarrhea. Because a single past report of tritiating loperamide was limited to only a very low specific activity product without technical details or extensive analysis, the synthesis of [N-methyl-(3)H]loperamide at high specific activity is now described in detail. An imine precursor was alkylated with [(3)H]methyl iodide to obtain a quaternary intermediate, which was then reacted with 4-(4-chlorophenyl)-4-hydroxypiperidine to afford the desired product [N-methyl-(3)H]loperamide, characterized by thin layer chromatography (TLC), HPLC, MS, UV, and proton-decoupled tritium NMR. PMID:24753311

  15. Direct Acylation of C(sp(3))-H Bonds Enabled by Nickel and Photoredox Catalysis.

    PubMed

    Joe, Candice L; Doyle, Abigail G

    2016-03-14

    Using nickel and photoredox catalysis, the direct functionalization of C(sp(3))-H bonds of N-aryl amines by acyl electrophiles is described. The method affords a diverse range of α-amino ketones at room temperature and is amenable to late-stage coupling of complex and biologically relevant groups. C(sp(3))-H activation occurs by photoredox-mediated oxidation to generate α-amino radicals which are intercepted by nickel in catalytic C(sp(3))-C coupling. The merger of these two modes of catalysis leverages nickel's unique properties in alkyl cross-coupling while avoiding limitations commonly associated with transition-metal-mediated C(sp(3))-H activation, including requirements for chelating directing groups and high reaction temperatures. PMID:26890705

  16. Autoradiographic localization of adenosine uptake sites in rat brain using (/sup 3/H)nitrobenzylthioinosine

    SciTech Connect

    Bisserbe, J.C.; Patel, J.; Marangos, P.J.

    1985-02-01

    The adenosine uptake site has been localized in rat brain by an in vitro light microscopic autoradiographic method, using (/sup 3/H)nitrobenzylthioinosine ((/sup 3/H)NBI) as the probe. The binding characteristics of (/sup 3/H)NBI on slide-mounted sections are comparable to those seen in studies performed on brain homogenates. A very high density of uptake sites occurs in the nucleus tractus solitarius, in the superficial layer of the superior colliculus, in several thalamic nuclei, and also in geniculate body nuclei. A high density of sites are also observed in the nucleus accumbens, the caudate putamen, the dorsal tegmentum area, the substantia nigra, and the central gray. The localization of the adenosine uptake site in brain may provide information on the functional activity of the site and suggests the involvement of the adenosine system in the central regulation of cardiovascular function.

  17. Synthesis of 3,4-cis-[3H]leucocyanidin and enzymatic reduction to catechin.

    PubMed

    Tanner, G J; Kristiansen, K N

    1993-03-01

    A novel method is presented for the synthesis and purification of (+)-2,3-trans-3,4-cis-[4-3H]leucocyanidin. Soluble enzyme extracts from developing barley grains and leaves of the forage legume Onobrychis viciifolia (sainfoin) catalyzed the NAD(P)H-dependent reduction of (+)-2,3-trans-3,4-cis-[4-3H]leucocyanidin to (+)-[4-3H]catechin. NADPH was the preferred substrate. With extracts of barley the rate of reaction with 1 mM NADH was 20% of the rate found with NADPH. With extracts from both tissues there was a broad pH optimum around pH 6.6. PMID:8470799

  18. Amino­silanes derived from 1H-benzimidazole-2(3H)-thione

    PubMed Central

    Palomo-Molina, Juliana; García-Báez, Efrén V.; Contreras, Rosalinda; Pineda-Urbina, Kayim; Ramos-Organillo, Angel

    2015-01-01

    Two new mol­ecular structures, namely 1,3-bis­(tri­methyl­silyl)-1H-benzimidazole-2(3H)-thione, C13H22N2SSi2, (2), and 1-tri­methyl­silyl-1H-benzimidazole-2(3H)-thione, C10H14N2SSi, (3), are reported. Both systems were derived from 1H-benzimidazole-2(3H)-thione. Noncovalent C—H⋯π inter­actions between the centroid of the benzmidazole system and the SiMe3 groups form helicoidal arrangements in (2). Dimerization of (3) results in the formation of R 2 2(8) rings via N—H⋯S inter­actions, along with parallel π–π inter­actions between imidazole and benzene rings. PMID:26322611

  19. Plasmodium falciparum: assessment of in vitro growth by (/sup 3/H)hypoxanthine incorporation

    SciTech Connect

    Chulay, J.D.; Haynes, J.D.; Diggs, C.L.

    1983-02-01

    To evaluate rapidly Plasmodium falciparum growth in Vitro, (/sup 3/H)hypoxanthine was added to parasite microcultures and radioisotope incorporation was measured. When culture parameters were carefully controlled, (/sup 3/H)hypoxanthine incorporation was proportional to the number of parasitized erythrocytes present. Factors affecting (/sup 3/H)hypoxanthine incorporation included initial parasitemia, duration of culture, duration of radioisotope pulse, parasite stage, concentration of uninfected erythrocytes, the use of serum or plasma to supplement growth, and the concentration of a variety of purines in the culture medium. The method described can be used to measure inhibition of P. falciparum growth by immune serum and has previously been used to study antimalarial drug activity in vitro.

  20. Blood epididymal barrier to (/sup 3/H)-inulin in intact and vasectomized hamsters

    SciTech Connect

    Turner, T.T.; D'Addario, D.A.; Howards, S.S.

    1981-09-01

    The net transport of (/sup 3/H)-inulin into the fluids of the hamster seminiferous and caput, corpus, and cauda epididymal tubules was examined in both intact animals and those vasectomized 10 months previously. Mean isotope concentrations in reproductive tract tubule fluids did not exceeded 10 per cent of blood plasma isotope concentrations during the experiment. There were no significant differences in net transport of (/sup 3/H)-inulin into any of the tubule fluids sampled. Ten months after vasectomy, the seminiferous tubule, and all regions of the epididymal tubule retain the capacity to exclude (/sup 3/H)-insulin. Thus in the hamster 10 months after vasectomy, the blood testis and blood epididymal barriers to inulin are intact.

  1. Effect of membrane protein concentration on binding of /sup 3/H-imipramine in human platelets

    SciTech Connect

    Barkai, A.I.; Kowalik, S.; Baron, M.

    1985-02-01

    Binding of /sup 3/H-imipramine to platelet membranes has been implicated as a marker for depression. Comparing /sup 3/H-IMI binding between depressed patients and normal subjects we observed an increase in the dissociation constant Kd with increasing membrane protein. This phenomenon was studied more rigorously in five normal subjects. Platelet membranes were prepared and adjusted to four concentrations of protein ranging from 100 to 800 micrograms/ml. The /sup 3/H-IMI binding parameters of maximum binding sites number (Bmax) and Kd were obtained by Scatchard analysis at each membrane concentration. A positive linear relationship was found between K/sub d/ values and the concentration of membrane protein in the assay, but no change was observed in Bmax. The variability in Kd values reported in the literature may be accounted for in part by the different concentrations of membrane protein used in various studies.

  2. Production of inositol trisphosphates upon. cap alpha. -adrenergic stimulation in BC3H-1 muscle cells

    SciTech Connect

    Ambler, S.K.; Thompson, B.; Brown, J.H.; Taylor, P.

    1986-05-01

    Activation of ..cap alpha../sub 1/-adrenergic receptors in BC3H-1 muscle cells rapidly mobilizes intracellular and results in a paradoxically slower accumulation of inositol trisphosphate. A possible explanation for this discrepancy may be provided by the recent findings of Irvine et al. of additional Ins P3 isomers besides the Ca/sup + +/-mobilizing isomer, Ins 1,4,5-P3. They have eluted and separated the inositol phosphates of BC3H-1 cells with an NH/sub 4//sup +/ x HCO/sub 2//sup -//H/sub 3/PO/sub 4/ gradient on a Whatman Partisil 10SAX column using Hewlett-Packard HPLC. Commercial (/sup 3/H)Ins 1,4,5-P3 and (/sup 3/H)inositol phosphates from carbachol-stimulated parotid glands were used as standards. Little or no Ins 1,3,4-P3 could be detected in control or phenylephrine-treated BC3H-1 cells. Ins 1,4,5-P3 followed the pattern of agonist stimulation observed previously. As a positive control, Ins P3 isomers were also measured in 1321N1 astrocytoma cells. Muscarinic stimulation of 1321N1 cells results in both the rapid accumulation of Ins P3 and Ca/sup + +/ mobilization. There is no detectable basal Ins 1,3,4-P3, but carbachol stimulates a rapid production of this compound in 1321N1 cells. Agonist activation also results in a rapid increase in Ins 1,4,5-P3 above basal values. These studies indicate that Ins 1,3,4-P3 does not contribute to the InsP3 signal in BC3H-1 cells and multiple mechanisms may exist for the coupling of receptors to PI turnover.

  3. Distribution of 3H-GABA uptake sites in the nematode Ascaris

    SciTech Connect

    Guastella, J.; Stretton, A.O. )

    1991-05-22

    The distribution of uptake sites for the inhibitory neurotransmitter gamma-aminobutyric acid (GABA) in the nematode Ascaris suum was examined by autoradiography of 3H-GABA uptake. Single neural processes in both the ventral and dorsal nerve cords were labeled with 3H-GABA. Serial section analysis identified the cells of origin of these processes as the RMEV-like and RMED-like neurons. These cells belong to a set of four neurons in the nerve ring, all of which are labeled by 3H-GABA. 3H-GABA labeling of at least two other sets of cephalic neurons was seen. One of these pairs consists of medium-sized lateral ganglia neurons, located at the level of the amphid commissure bundle. A second pair is located in the lateral ganglia at the level of the deirid commissure bundle. The position and size of these lateral ganglia cells suggest that they are the GABA-immunoreactive lateral ganglia cells frequently seen in whole-mount immunocytochemical preparations. Four neuronal cell bodies located in the retrovesicular ganglion were also labeled with 3H-GABA. These cells, which are probably cholinergic excitatory motor neurons, do not contain detectable GABA-like immunoreactivity. Heavy labeling of muscle cells was also observed. The ventral and dorsal nerve cord inhibitory motor neurons, which are known to contain GABA-like immunoreactivity, were not labeled above background with 3H-GABA. Together with the experiments reported previously, these results define three classes of GABA-associated neurons in Ascaris: (1) neurons that contain endogenous GABA and possess a GABA uptake system; (2) neurons that contain endogenous GABA, but that either lack a GABA uptake system or possess a GABA uptake system of low activity; (3) neurons that possess a GABA uptake system, but that lack endogenous GABA.

  4. Interactions of ( sup 3 H)amphetamine with rat brain synaptosomes. II. Active transport

    SciTech Connect

    Zaczek, R.; Culp, S.; De Souza, E.B. )

    1991-05-01

    The accumulation of 5 nM d-({sup 3}H)amphetamine (d-({sup 3}H)AMPH) into rat brain synaptosomes was examined using physiological buffer conditions. The accumulation of d-({sup 3}H)AMPH into striatal synaptosomes was saturable, of high affinity, ouabain-sensitive and temperature-dependent, suggesting an active transport phenomenon. Eadee-Hofstee analysis of striatal d-({sup 3}H)AMPH transport (AMT) saturation isotherms indicated an apparent Km of 97 nM and a Vmax of 3.0 fmol/mg tissue/min. Lesion of the striatal dopaminergic innervation led to equivalent decreases of ({sup 3}H) dopamine (DA) transport and AMT, indicating that AMT occurs in DA terminals. Furthermore, AMT was not evident in cerebral cortex, a brain region with a paucity of DA terminals. In competition studies, AMT was stereospecific; d-AMPH (IC50 = 60 nM) was an 8-fold more potent inhibitor of the transport than its I-isomer (IC50 = 466 nM). DA(IC50 = 257 nM), DA uptake blockers and substrates were found to be potent inhibitors of AMT: GBR12909 IC50 = 5 nM; methamphetamine IC50 = 48 nM; methylphenidate IC50 = 53 nM; and cocaine IC50 = 172 nM. In contrast, serotonin was relatively weak in inhibiting AMT (IC50 = 7.9 microM). There was a highly significant (P less than .001; slope = 1.2) linear correlation between the AMT-inhibiting potencies of AMPH analogs and their potencies in stimulating locomotor activity in rodents. AMT may be important in the low dose effects of AMPH such as increased locomotor activity in rodents and stimulant activity in man. Differences between AMT and d-({sup 3}H)AMPH sequestration described earlier, as well as their possible relevance to behavioral and neurochemical sequelae of AMPH administration are also discussed.

  5. MR-guided focused ultrasound: enhancement of intratumoral uptake of [3H]-docetaxel in vivo

    NASA Astrophysics Data System (ADS)

    Chen, Lili; Mu, Zhaomei; Hachem, Paul; Ma, C.-M.; Wallentine, Annie; Pollack, Alan

    2010-12-01

    The purpose of this study is to quantify the enhancement of [3H]-docetaxel in implanted prostate tumors treated with MR-guided pulsed focused ultrasound (MRgFUS). Human prostate cancer, LNCaP cells in 25 µl, were implanted into the prostates of male nude mice. The tumor growth was directly monitored on MRI. When the tumor reached a designated size, MRgFUS treatment was performed using a focused ultrasound treatment system (InSightec ExAblate 2000) with a 1.5 T GE MR scanner. The tumor-bearing animals were randomly divided into three groups: group 1, MRgFUS treatment + [3H]-docetaxel; group 2, [3H]-docetaxel only and group 3, as a control. Animals in group 1 were treated with MRgFUS non-invasively. Immediately after the treatment, the animals received a single dose of tail vein injection of docetaxel at 15 mg kg-1 mixed with [3H]-docetaxel at 50 uCi kg-1 in a total volume of 150 µl. Animals in group 2 were treated the same as in group one, however without MRgFUS treatment. Animals in group 3 were treated as a control. Animals were sacrificed 30 min after i.v. injections regardless of whether or not they received focused ultrasound. Tumors were removed and processed. The radioactivity of [3H]-docetaxel in the tumor tissue was quantitatively measured by a liquid scintillation counter. Our study showed that all animals tolerated the MRgFUS treatment well. Our data showed increased 3H-docetaxel concentration in the tumor in the MRgFUS-treated group (1079 ± 132 cmp/75 mg) versus those without MRgFUS treatment (524 ± 201 cmp/75 mg) with P = 0.037.

  6. Autoradiographic localization of /sup 3/H-digoxin binding by neural cells in the medulla

    SciTech Connect

    Traurig, H.H.; Bhagat, A.; Bass, N.H.

    1985-01-01

    The purpose of this investigation was to localize binding sites for the cardiac glycoside digoxin in the medulla of the rat in vivo. Adult male Sprague-Dawley rats were injected (IV) with /sup 3/H-digoxin and killed 30 minutes later. Autoradiographs of medullas showed evidence of /sup 3/H-digoxin binding to small- and medium-sized neural cells in the regions of the nucleus solitarius, dorsal motor nucleus of the vagus, area postrema, and in the zone between the area postrema and the underlying neuropil. However, the parasympathetic preganglionic neurons of the dorsal motor nucleus were not labeled. The /sup 3/H-digoxin-labeled cells in the medulla were located mainly in the commissural and medial portions of nucleus solitarius at the level of the area postrema. Animals injected with unlabeled digoxin followed by /sup 3/H-digoxin showed reduced binding of radioactivity. The small- and medium-sized neurons of the caudal portions of the nucleus solitarius are internuncial in position with respect to cardiovascular afferents of the glossopharyngeal and vagus nerves and sympathetic and parasympathetic cardiovascular efferent neurons of the medulla. The results of this study suggest that these /sup 3/H-digoxin-labeled cells, presumably neurons of nucleus solitarius, may possess high affinity binding sites for digoxin. Further, the area postrema, which lacks a blood-brain barrier, may provide a portal of entry for /sup 3/H-digoxin into regions of the medulla known to contain neurons that play a role in the regulation of cardiac rhythm.

  7. Automated video analysis system reveals distinct diurnal behaviors in C57BL/6 and C3H/HeN mice.

    PubMed

    Adamah-Biassi, E B; Stepien, I; Hudson, R L; Dubocovich, M L

    2013-04-15

    Advances in rodent behavior dissection using automated video recording and analysis allows detailed phenotyping. This study compared and contrasted 15 diurnal behaviors recorded continuously using an automated behavioral analysis system for a period of 14 days under a 14/10 light/dark cycle in single housed C3H/HeN (C3H) or C57BL/6 (C57) male mice. Diurnal behaviors, recorded with minimal experimental interference and analyzed using phenotypic array and temporal distribution analysis showed bimodal and unimodal profiles in the C57 and C3H mice, respectively. Phenotypic array analysis revealed distinct behavioral rhythms in Activity-Like Behaviors (i.e. walk, hang, jump, come down) (ALB), Exploration-Like Behaviors (i.e. dig, groom, rear up, sniff, stretch) (ELB), Ingestion-Like Behaviors (i.e. drink, eat) (ILB) and Resting-Like Behaviors (i.e. awake, remain low, rest, twitch) (RLB) of C3H and C57 mice. Temporal distribution analysis demonstrated that strain and time of day affects the magnitude and distribution of the spontaneous homecage behaviors. Wheel running activity, water and food measurements correlated with timing of homecage behaviors. Subcutaneous (3 mg/kg, sc) or oral (0.02 mg/ml, oral) melatonin treatments in C57 mice did not modify either the total 24 h magnitude or temporal distribution of homecage behaviors when compared with vehicle treatments. We conclude that C3H and C57 mice show different spontaneous activity and behavioral rhythms specifically during the night period which are not modulated by melatonin. PMID:23337734

  8. Automated Video Analysis System Reveals Distinct Diurnal Behaviors in C57BL/6 and C3H/HeN Mice

    PubMed Central

    Adamah-Biassi, E. B.; Stepien, I.; Hudson, R.L.; Dubocovich, M.L.

    2013-01-01

    Advances in rodent behavior dissection using automated video recording and analysis allows detailed phenotyping. This study compared and contrasted 15 diurnal behaviors recorded continuously using an automated behavioral analysis system for a period of 14 days under a 14/10 light/dark cycle in single housed C3H/HeN (C3H) or C57BL/6 (C57) male mice. Diurnal behaviors, recorded with minimal experimental interference and analyzed using phenotypic array and temporal distribution analysis showed bimodal and unimodal profiles in the C57 and C3H mice, respectively. Phenotypic array analysis revealed distinct behavioral rhythms in activity-like behaviors (i.e. walk, hang, jump, come down) (ALB), exploration-like behaviors (i.e. dig, groom, rear up, sniff, stretch) (ELB), ingestion-like behaviors (i.e. drink, eat) (ILB) and resting-like behaviors (i.e. awake, remain low, rest, twitch) (RLB) of C3H and C57 mice. Temporal analysis demonstrated that strain and time of day affects the magnitude and distribution of the spontaneous homecage behaviors. Wheel running activity, water and food measurements correlated with timing of homecage behaviors. Subcutaneous (3 mg/kg, sc) or oral (0.02 mg/ml, oral) melatonin treatments in C57 mice did not modify either the total 24 hr magnitude or temporal distribution of homecage behaviors when compared with vehicle treatments. We conclude that C3H and C57 mice show different spontaneous activity and behavioral rhythms specifically during the night period which are not modulated by melatonin. PMID:23337734

  9. (/sup 3/H)AVP binding to rat renal tubular receptors during long-term treatment with an antagonist of arginine vasopressin

    SciTech Connect

    Mah, S.C.; Whitebread, S.E.; De Gasparo, M.; Hofbauer, K.G.

    1988-05-01

    The interaction of an antagonist of arginine vasopressin (AVP), d(CH2)5-D-Tyr(Et)VAVP, with renal tubular V2 receptors were studied in medullary membrane preparations from kidneys of Sprague-Dawley and Brattleboro rats. In both rat strains, V2 receptors had comparable KD and Bmax values for binding of (3H)AVP. In vitro studies revealed that the V2-antagonist was more potent than cold AVP in displacing (3H)AVP. In vivo treatment of Sprague-Dawley rats with the antagonist over one week resulted only in a transient state of diabetes insipidus (DI). No specific (3H)AVP binding was detectable throughout the period of administration. Chronic treatment of Brattleboro rats resulted in a complete normalization of water intake. This agonistic effect was also associated with undetectable (3H)AVP binding. After stopping the infusion of d(CH2)5-D-Tyr(Et)VAVP, Bmax values tended to rise but had still not reached base line values after 6 days. In contrast, the chronic infusion of AVP in Brattleboro rats resulted in a reduction in water intake which was accompanied by a decreased Bmax. (3H)AVP binding remained detectable during the entire treatment period. Thereafter Bmax was restored to base line values within 2 days of stopping the infusion. These results suggest that d(CH2)5-D-Tyr(Et)VAVP has a high affinity for V2 receptors in both Sprague-Dawley and Brattleboro rats. Its rate of dissociation from the receptor appears to be much slower than that of AVP. In Brattleboro rats, the binding of d(CH2)5-D-Tyr(Et)VAVP leads to an antidiuretic response. In Sprague-Dawley rats, a transient diuretic response is followed by a progressive normalization in water intake. This occurs despite persistent and complete blockade of renal medullary V2 receptors.

  10. Palladium-Catalyzed Intramolecular Carbene Insertion into C(sp(3) )-H Bonds.

    PubMed

    Solé, Daniel; Mariani, Francesco; Bennasar, M-Lluïsa; Fernández, Israel

    2016-05-23

    A palladium-catalyzed carbene insertion into C(sp(3) )-H bonds leading to pyrrolidines was developed. The coupling reaction can be catalyzed by both Pd(0) and Pd(II) , is regioselective, and shows a broad functional group tolerance. This reaction is the first example of palladium-catalyzed C(sp(3) )-C(sp(3) ) bond assembly starting from diazocarbonyl compounds. DFT calculations revealed that this direct C(sp(3) )-H bond functionalization reaction involves an unprecedented concerted metalation-deprotonation step. PMID:27079473

  11. Radiometric assay of ghrelin hydrolase activity and 3H-ghrelin distribution into mouse tissues.

    PubMed

    Chen, Vicky Ping; Gao, Yang; Geng, Liyi; Brimijoin, Stephen

    2015-12-15

    A high-throughput radiometric assay was developed to characterize enzymatic hydrolysis of ghrelin and to track the peptide's fate in vivo. The assay is based on solvent partitioning of [(3)H]-octanoic acid liberated from [(3)H]-octanoyl ghrelin during enzymatic hydrolysis. This simple and cost-effective method facilitates kinetic analysis of ghrelin hydrolase activity of native and mutated butyrylcholinesterases or carboxylesterases from multiple species. In addition, the assay's high sensitivity facilitates ready evaluation of ghrelin's pharmacokinetics and tissue distribution in mice after i.v. bolus administration of radiolabeled peptide. PMID:26514871

  12. Specific binding of /sup 3/H-naloxone with isolated rat enterocytes

    SciTech Connect

    Yarygin, K.N.; Shitin, A.G.; Suiridov, D.D.; Titov, M.I.; Vinogradov, V.A.

    1985-12-01

    This paper presents data on the specific binding of naloxone with isolated rat enterocytes. Naloxone was bound with the cells in medium 199 containing 1 mg/ml of BSA. The incubation mixture contained 5 x 100 mM /sup 3/H-naloxone and, if indicated, other substances also. Dose dependence of binding of naloxone with rat enterocytes is shown. The kinetics of specific binding of naloxone with enterocytes at different temperatures is also shown, as is the irreversibility of binding of /sup 3/H-naloxone with isolated rat enterocytes. It was found that different ligands of opioid receptors can inhibit binding of naloxone competitively.

  13. Erythrocyte /sup 3/H-ouabain binding and digitalis treatment in ethanol addicted patients

    SciTech Connect

    Battaini, F.; Govoni, S.; Mauri, A.; Civelli, L.; Trabucchi, M.

    1987-06-29

    The binding of /sup 3/H-ouabain to human erythrocytes was analyzed in a population of hospitalized male ethanol addicted patients under long term digitalis treatment. In the non-alcoholic patient group the long term digitalis treatment induced an increase in Bmax and Kd values; such modification was not observed in the alcoholic patients. Chronic alcohol intake itself induced an increase in /sup 3/H-ouabain kinetic parameters. These observations confirm that ouabain binding to human erythrocytes is subject to pharmacological and toxicological regulation and that adaptive changes in peripheral tissues can be useful in predicting possible parallel modifications in other less accessible tissues. 22 references, 1 table.

  14. Incineration and monitoring of low-level 3H and 14C wastes at a biological research institution

    SciTech Connect

    Hamrick, P.E.; Knapp, S.J.; Parker, M.G.; Watson, J.E. Jr.

    1986-10-01

    Low-level radioactive waste containing liquid scintillation fluid and known amounts of /sup 14/C and /sup 3/H has been incinerated in a modified pathological incinerator with the incinerator effluent, refractory surface and ash being monitored. The study relates the activity monitored to that incinerated and discusses how this relation was affected by a modification of the incinerator and monitoring conditions. No significant activity was found to be associated with the ash, particulates or the refractory surface. These data suggest that most of the activity is released as tritiated water vapor and /sup 14/C-labeled carbon dioxide. However, incomplete oxidation may occur for short periods of time depending on the amount of liquid scintillation fluid incinerated, with the possible release of /sup 14/C-labeled carbon monoxide.

  15. Tritritionikkomycin Z, (uracil-5- sup 3 H,pyridyl-2,4- sup 3 H sub 2 ): Radiolabeling of a potent inhibitor of fungal and insect chitin synthetase

    SciTech Connect

    Ando, Tetsu; Tecle, B.; Toia, R.F.; Casida, J.E. )

    1990-08-01

    Nikkomycin Z (NZ) (a potent fungicide, insecticide, miticide, and inhibitor of fungal and insect chitin synthetase) was converted to a mixture of specific mono-, di-, and tribromo derivatives (BrNZ, Br{sub 2}NZ, and Br{sub 3}NZ, respectively) on reaction with N-bromosuccinimide in N,N-dimethylformamide. Substitution by bromine occurred first at the 2-position of the 3-hydroxypyridyl moiety, second at the 5-position of the uracil moiety, and finally at the 4-position of the 3-hydroxypyridyl moiety as observed both for NZ and for mixtures of uridine and 3-hydroxy-6-methylpyridine as model compounds representative of the moieties of NZ. Following fractionation of the various bromonikkomycin derivatives by HPLC, their structures were assigned by NMR, MS, and UV analyses. Catalytic reductive debromination of Br{sub 3}NZ with tritium gas over palladium on carbon gave (uracil-5-{sup 3}H,pyridyl-2,4-{sup 3}H{sub 2})NZ. This material has sufficiently high specific activity ({approximately}60 Ci/mmol) and suitable positions of labeling to study its uptake, distribution, metabolism, and possible target site interactions in fungal and insect systems.

  16. (/sup 3/H)forskolin- and (/sup 3/H)dihydroalprenolol-binding sites and adenylate cyclase activity in heart of rats fed diets containing different oils

    SciTech Connect

    Alam, S.Q.; Ren, Y.F.; Alam, B.S.

    1988-03-01

    The characteristics of the cardiac adenylate cyclase system were studied in rats fed diets containing fish oil (menhaden oil) and other oils. Adenylate cyclase activity generally was higher in cardiac homogenates and membranes of rats fed diet containing 10% menhaden oil than in the other oils. The increase in enzyme activity, especially in forskolin-stimulated activity, was associated with an increase in the concentration of the (/sup 3/H) forskolin-binding sites in cardiac membranes of rats fed menhaden oil. The beta-adrenergic receptor concentration was not significantly altered although the affinity for (/sup 3/H)dihydroalprenolol-binding was lower in membranes of rats fed menhaden oil than those fed the other oils. omega-3 fatty acids from menhaden oil were incorporated into the cardiac membrane phospholipids. The results suggest that the observed increase in myocardial adenylate cyclase activity of rats fed menhaden oil may be due to an increase in the number of the catalytic subunits of the enzyme or due to a greater availability of the forskolin-binding sites.

  17. Reduced permeation of /sup 14/C-sucrose, /sup 3/H-mannitol and /sup 3/H-inulin across blood-brain barrier in nephrectomized rats

    SciTech Connect

    Preston, E.; Haas, N.; Allen, M.

    1984-01-01

    Experiments were carried out to determine if changes in the concentration-time profile of a blood-borne radiotracer such as /sup 14/C-sucrose would spuriously alter measurements of its permeation across the blood-brain barrier (permeability-area product, PA) based on a 2-compartment (plasma/brain) simple diffusion model. Anesthetized rats which were bilaterally nephrectomized and given a standard intravenous bolus injection of /sup 14/C-sucrose, /sup 3/H-mannitol or /sup 3/H-inulin exhibited an elevated plasma tracer concentration compared to control animals. However, tracer concentration measured in brain parenchyma after 30 min was not proportionally elevated, and PA calculated from the ratio, parenchymal tracer concentration: plasma concentration-time integral, was significantly reduced below control values. In control rats, distortion and elevation of the plasma /sup 14/C-sucrose profile by continuous intravenous infusion did not result in lowered PA values. This suggested that the lowering of PA by nephrectomy reflected reduced cerebrovascular permeability or area or other cerebral influence rather than a deficiency in the 2-compartment model for PA measurement.

  18. Crystal structures of [NEt3H]5[XCoIIW11O39]·3H2O (X = P or As)

    USGS Publications Warehouse

    Evans, H.T., Jr.; Weakley, T.J.R.; Jameson, G.B.

    1996-01-01

    The orthorhombic crystal structures of [NEt3H]5[XCoIIW11O39]·3H2O for X = P and As have been determined with data collected at room temperature, and for X = P at –100 °C, using Mo-Kα radiation. For the latter the space group is Pna21, a= 21.670(11), b= 14.805(4), c= 20.393(5)Å and Z= 4. The structure consists of chains of α-Keggin-type molecules joined by W–O–links aligned in the a-axis direction. The Co/W occupancy at the link is disordered, with 61% Co on one side and 39% on the other. Further probable disorder, by lamellar merohedral twinning on (001) and by misorientation of the triethylammonium ions, has obscured the ethyl groups and the water molecules. In polarized light the crystals are deep wine-red normal to the chains (in the b direction), but nearly colourless in the a and c directions. The structure of the arsenate is similar to that of the phosphate.

  19. Pentamidine analogs as inhibitors of [3H]MK-801 and [3H]ifenprodil binding to rat brain NMDA receptors

    PubMed Central

    Berger, Michael L.; Maciejewska, Dorota; Vanden Eynde, Jean Jacques; Mottamal, Madhusoodanan; Żabiński, Jerzy; Kaźmierczak, Paweł; Rezler, Mateusz; Jarak, Ivana; Piantanida, Ivo; Karminski-Zamola, Grace; Mayence, Annie; Rebernik, Patrick; Kumar, Arvind; Ismail, Mohamed A.; Boykin, David W.; Huang, Tien L.

    2016-01-01

    The anti-protozoal drug pentamidine is active against opportunistic Pneumocystis pneumonia, but in addition has several other biological targets, including the NMDA receptor (NR). Here we describe the inhibitory potencies of 76 pentamidine analogs at 2 binding sites of the NR, the channel binding site labeled with [3H]MK-801 and the [3H]ifenprodil binding site. Most analogs acted weaker at the ifenprodil than at the channel site. The spermine-sensitivity of NR inhibition by the majority of the compounds was reminiscent of other long-chain dicationic NR blockers. The potency of the parent compound as NR blocker was increased by modifying the heteroatoms in the bridge connecting the 2 benzamidine moieties and also by integrating the bridge into a seven-membered ring. Docking of the 45 most spermine-sensitive bisbenzamidines to a recently described acidic interface between the N-terminal domains of GluN1 and GluN2B mediating polyamine stimulation of the NR revealed the domain contributed by GluN1 as the most relevant target. PMID:26117647

  20. Pertussis toxin treatment attenuates some effects of insulin in BC3H-1 murine myocytes

    SciTech Connect

    Luttrell, L.M.; Hewlett, E.L.; Romero, G.; Rogol, A.D.

    1988-05-05

    The effects of pertussis toxin (PT) treatment on insulin-stimulated myristoyl-diacylglycerol (DAG) generation, hexose transport, and thymidine incorporation were studied in differentiated BC3H-1 mycocytes. Insulin treatment caused a biphasic increase in myristoyl-DAG production which was abolished in myocytes treated with PT. There was no effect of PT treatment on basal (nonstimulated) myristoyl-DAG production. Insulin-stimulated hydrolysis of a membrane phosphatidylinositol glycan was blocked by PT treatment. ADP-ribosylation of BC3H-1 plasma membranes with (/sup 32/P)NAD revealed a 40-kDa protein as the major PT substrate in vivo and in vitro. The time course and dose dependence of the effects of PT on diacylglycerol generation correlated with the in vivo ADP-ribosylation of the 40-kDa substrate. Pertussis toxin treatment resulted in a 71% attenuation of insulin-stimulated hexose uptake without effect on either basal or phorbol ester-stimulated uptake. The stimulatory effects of insulin and fetal calf serum on (/sup 3/H)thymidine incorporation into quiescent myocytes were attenuated by 61 and 59%, respectively, when PT was added coincidently with the growth factors. Nonstimulated and EGF-stimulated (/sup 3/H)thymidine incorporation was unaffected by PT treatment. These data suggest that a PT-sensitive G protein is involved in the cellular signaling mechanisms of insulin.

  1. Free water 3H concentrations in serum samples collected during 1969-1992 in Akita, Japan.

    PubMed

    Hisamatsu, Shun'ichi; Inoue, Yoshikazu; Hachiya, Noriyuki; Katoh, Kiyoshi; Nakagomi, Toyoko; Nakagomi, Osamu; Motohashi, Yutaka; Takizawa, Yukio

    2003-08-01

    The measurements for human and environmental samples from the 1960's and 1970's are important to understand the long-term transfer of 3H from the environment to the human body. The authors have previously reported 3H concentrations in diet samples collected in Akita Prefecture during 1969-1988. Serum samples from persons living in Akita Prefecture during 1969-1992 were recently obtained. The samples were originally gathered for medical examinations and stored in freezers at -20 degrees C. Composite samples from 100 persons on average were made for analysis. The free water 3H (FWT) concentrations in those samples were determined and compared with 3H concentrations in diet samples and precipitation. The long-term variation pattern of the FWT concentrations in the serum samples was similar to patterns in the diet samples and precipitation, but the FWT concentrations in the serum samples were slightly higher than those in the latter two. A single compartment model calculation showed that the apparent mean residence time of serum FWT was 1.4 y using precipitation as an input to the compartment. PMID:12938967

  2. IMPROVED SCORING OF CHEMICAL TRANSFORMATION OF C3H/10T1/2 CELLS

    EPA Science Inventory

    This research program was undertaken to improve the scoring of the transformation by chemical carcinogens of C3H/10T1/2 mouse embryo fibroblasts. (1) A probabilistic view of transformed focus formation in these cells induced by methylcholanthrene (MCA) treatment has been formulat...

  3. In Situ g-PHA Measurements of the 285-3H Cooling Tower Components

    SciTech Connect

    Salaymeh, S.R.

    2001-05-23

    The Analytical Development Section of Savannah River Technology Center was requested by the Facility Disposition Division to conduct in-situ gamma-ray pulse height analysis measurements to provide input toward the decision to unconditionally release the 285-3H cooling tower.

  4. Release of (/sup 3/H)-monoamines from superfused rat striatal slices by methylenedioxymethamphetamine (MDMA)

    SciTech Connect

    Levin, J.A.; Schmidt, C.J.; Lovenberg, W.

    1986-03-05

    MDMA is a phenylisopropylamine which is reported to have unique behavioral effects in man. Because of its structural similarities to the amphetamines the authors have compared the effects of MDMA and two related amphetamines on the spontaneous release of tritiated dopamine (DA) and serotonin (5HT) from superfused rat striatal slices. At concentrations of 10/sup -7/ - 10/sup -5/M MDMA and the serotonergic neurotoxin, p-chloroamphetamine, were equipotent releasers of (/sup 3/H)5HT being approximately 10x more potent than methamphetamine. However, methamphetamine was the more potent releaser of (/sup 3/H)DA by a factor of approximately 10x. MDMA-induced release of both (/sup 5/H)5HT and (/sup 3/H)DA was Ca/sup 2 +/-independent and inhibited by selective monoamine uptake blockers suggesting a carrier-dependent release mechanism. Synaptosomal uptake experiments with (+)(/sup 3/H)MDMA indicated no specific uptake of the drug further suggesting the effect of uptake blockers may be to inhibit the carrier-mediated export of amines displaced by MDMA.

  5. Biliary excretion of radioactivity after intravenous administration of (3H)25-hydroxyvitamin D3 in man

    SciTech Connect

    Ledger, J.E.; Watson, G.J.; Compston, J.E.

    1986-04-01

    The biliary excretion of radioactivity after intravenous (3H)25-hydroxyvitamin D3 was studied in nine patients with T-tube bile drainage. The mean +/- SD 24-hr radioactivity excretion in T-tube bile expressed as a percentage of the administered dose was 6.7 +/- 2.9%; after correction for incomplete bile collection, the value obtained was 16.0 +/- 11.1%. Chloroform solubility of biliary radioactivity increased from 27.4 +/- 8.9% to 72.9 +/- 10.1% following incubation with beta-glucuronidase. High-performance liquid chromatographic analysis of chloroform extracts of bile revealed that most of the eluted radioactivity was more polar than (3H)25-hydroxyvitamin D3. No free (3H)25-hydroxyvitamin D3 was demonstrated. Thus in man, most of the biliary radioactivity excreted following (3H)25-hydroxyvitamin D3 is in the form of water-soluble compounds, mainly glucuronides. However, our results suggest that glucuronides of metabolites other than 25-OHD3 are predominantly formed.

  6. Aminosilanes derived from 1H-benzimidazole-2(3H)-thione

    SciTech Connect

    Palomo-Molina, Juliana; García-Báez, Efrén V.; Pineda-Urbina, Kayim; Ramos-Organillo, Angel

    2015-08-12

    In two trimethylsilyl-substituted 1H-benzimidazole-2(3H)-thiones, noncovalent C—H⋯π interactions between the centroid of the benzmidazole system and the SiMe{sub 3} groups form helicoidal arrangements in one, and dimerization results in the formation of R{sub s} {sup 2}(8) rings via N—H⋯S interactions, along with parallel π–π interactions between imidazole and benzene rings, in the second compound. Two new molecular structures, namely 1,3-bis(trimethylsilyl)-1H-benzimidazole-2(3H)-thione, C{sub 13}H{sub 22}N{sub 2}SSi{sub 2}, (2), and 1-trimethylsilyl-1H-benzimidazole-2(3H)-thione, C{sub 10}H{sub 14}N{sub 2}SSi, (3), are reported. Both systems were derived from 1H-benzimidazole-2(3H)-thione. Noncovalent C—H⋯π interactions between the centroid of the benzmidazole system and the SiMe{sub 3} groups form helicoidal arrangements in (2). Dimerization of (3) results in the formation of R{sub 2}{sup 2}(8) rings via N—H⋯S interactions, along with parallel π–π interactions between imidazole and benzene rings.

  7. Anionic ordering and thermal properties of FeF3·3H2O.

    PubMed

    Burbano, Mario; Duttine, Mathieu; Borkiewicz, Olaf; Wattiaux, Alain; Demourgues, Alain; Salanne, Mathieu; Groult, Henri; Dambournet, Damien

    2015-10-01

    Iron fluoride trihydrate can be used to prepare iron hydroxyfluoride with the hexagonal-tungsten-bronze (HTB) type structure, a potential cathode material for batteries. To understand this phase transformation, a structural description of β-FeF3·3H2O is first performed by means of DFT calculations and Mössbauer spectroscopy. The structure of this compound consists of infinite chains of [FeF6]n and [FeF2(H2O)4]n. The decomposition of FeF3·3H2O induces a collapse and condensation of these chains, which lead to the stabilization, under specific conditions, of a hydroxyfluoride network FeF3-x(OH)x with the HTB structure. The release of H2O and HF was monitored by thermal analysis and physical characterizations during the decomposition of FeF3·3H2O. An average distribution of FeF4(OH)2 distorted octahedra in HTB-FeF3-x(OH)x was obtained subsequent to the thermal hydrolysis/olation of equatorial anionic positions involving F(-) and H2O. This study provides a clear understanding of the structure and thermal properties of FeF3·3H2O, a material that can potentially bridge the recycling of pickling sludge from the steel industry by preparing battery electrodes. PMID:26378743

  8. Anionic ordering and thermal properties of FeF3·3H2O

    DOE PAGESBeta

    Burbano, Mario; Duttine, Mathieu; Borkiewicz, Olaf; Wattiaux, Alain; Demourgues, Alain; Salanne, Mathieu; Groult, Henri; Dambournet, Damien

    2015-09-17

    In this study, iron fluoride tri-hydrate can be used to prepare iron hydroxyfluoride with the Hexagonal-Tungsten-Bronze (HTB) type structure, a potential cathode material for batteries. To understand this phase transformation, a structural description of β-FeF3·3H2O is first performed by means of DFT calculations and Mössbauer spectroscopy. The structure of this compound consists of infinite chains of [FeF6]n and [FeF2(H2O)4]n. The decomposition of FeF3·3H2O induces a collapse and condensation of these chains, which lead to the stabilization, under specific conditions, of a hydroxyfluoride network FeF3-x(OH)x with the HTB structure. The release of H2O and HF was monitored by thermal analysis andmore » physical characterizations during the decomposition of FeF3·3H2O. An average distribution of FeF4(OH)2 distorted octahedra in HTB-FeF3-x(OH)x was obtained subsequent to the thermal hydrolysis/olation of equatorial anionic positions involving F- and H2O. This study provides a clear understanding of the structure and thermal properties of FeF3·3H2O, a material that can potentially bridge the recycling of pickling sludge from the steel industry by preparing battery electrodes.« less

  9. MELATONIN ENHANCES JUNCTIONAL TRANSFER IN NORMAL C3H/1OT1/2 CELLS

    EPA Science Inventory

    There is strong evidence that pineal melatonin is involved in controlling neoplastic processes. e have reported that physiological, but not pharmacological or subphysiological, concentrations of melatonin enhance intercellular communication in normal C3H/1OT1/2 fibroblasts. ap ju...

  10. Comparison of sludge treatment by O3 and O3/H2O2.

    PubMed

    Yuxin, Zhao; Liang, Wang; Helong, Yu; Baojun, Jiang; Jinming, Jiang

    2014-01-01

    This work focuses on the comparison of sludge decomposition caused by ozone (O3) alone and by ozone/hydrogen peroxide (O3/H2O2). The content of carbonaceous organic materials, nitrogenous compounds and phosphoric substances in sludge supernatant were measured. The release of soluble chemical oxygen demand, total nitrogen (TN) and total phosphorus (TP) caused by O3/H2O2 treatment were more than by O3 alone. As a result, it can be concluded that the efficiency of sludge breakup in O3/H2O2 was better than that in O3 alone. However, a peak appeared in both systems for the biodegradable substances such as carbohydrate. Carbohydrate could be used as the carbon source for denitrification, and the releasing of TN and TP may become an additional burden for a subsequent biological system. So, it was of benefit for the enhancement of cryptic growth and cost reduction by raising and maintaining the content of biodegradable substance and reducing the concentrations of the nitrogenous and phosphoric substances as far as possible. Therefore, sludge treated by O3/H2O2 with lower O3 dose would be more suitable than O3 alone. PMID:25026588

  11. Synthesis of (+/-)-3H-epivincamine via a Rh(II)-triggered cyclization/cycloaddition cascade.

    PubMed

    England, Dylan B; Padwa, Albert

    2007-08-16

    A synthesis of (+/-)-3H-epivincamine is reported. Important steps include (1) a Rh(II)-catalyzed intramolecular [3+2]-cycloaddition of an alpha-diazo indolo amide, (2) a reductive ring opening of the cycloadduct, (3) a decarboethoxylation reaction, and (4) a base-induced keto-amide ring contraction. PMID:17658832

  12. DIBENZODIOXOCIN STRUCTURES INVOLVING P-HYDROXYPHENYL UNITS IN C3H DOWN-REGULATED LIGNINS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We previously reported that downregulation of the gene encoding 4-coumarate 3-hydroxylase (C3H) in alfalfa markedly increased the proportion of p-hydroxyphenyl (H) units relative to the normally dominant guaiacyl (G) and syringyl (S) units, as determined by 2D 13C-1H correlative NMR methods, thioaci...

  13. Cholecystokinin-8 suppressed /sup 3/H-etorphine binding to rat brain opiate receptors

    SciTech Connect

    Wang, X.J.; Fan, S.G.; Ren, M.F.; Han, J.S.

    1989-01-01

    Radioreceptor assay (RRA) was adopted to analyze the influence of CCK-8 on /sup 3/H-etorphine binding to opiate receptors in rat brain synaptosomal membranes (P2). In the competition experiment CCK-8 suppressed the binding of /sup 3/H-etorphine. This effect was completely reversed by proglumide at 1/mu/M. Rosenthal analysis for saturation revealed two populations of /sup 3/H-etorphine binding sites. CCK-8 inhibited /sup 3/H-etorphine binding to the high affinity sites by an increase in Kd and decrease in Bmax without significant changes in the Kd and Bmax of the low affinity sites. This effect of CCK-8 was also completely reversed by proglumide at 1/mu/M. Unsulfated CCK-8 produced only a slight increase in Kd of the high affinity sites without affecting Bmax. The results suggest that CCK-8 might be capable of suppressing the high affinity opioid binding sites via the activation of CCK receptor.

  14. TOOLS FOR LIGNIN STRUCTURAL ANALYSIS; APPLICATIONS TO C3H-DOWNREGULATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effects on lignification of downregulating most of the genes for enzymes on the monolignol biosynthetic pathway have been reasonably well studied. The exception to this is the crucial hydroxylase, cinnamate 3-hydroxylase (C3H), taking p-coumarate to caffeate. The Noble Foundation group has been ...

  15. Pharmacokinetics of buspirone as determined by ex vivo (/sup 3/H)-DPAT binding

    SciTech Connect

    Sethy, V.H.; Francis, J.W.

    1988-01-01

    Ex vivo (/sup 3/H)-8-hydroxy-2-(di-n-propylamino)-tetraline ((/sup 3/H)-DPAT) binding to the hippocampus has been utilized to determine the pharmacokinetic parameters of buspirone after i.v. and oral administration of this drug to rats. Intravenous buspirone rapidly penetrated the brain as demonstrated by a maximum inhibition of (/sup 3/H)-DPAT binding at 1 min. Elimination of drug from the brain was biphasic, with a first component half-life of 24.8 min and a second component half-life of 96 min. Oral buspirone at 3 times the i.v. dose produced less than one-third the maximum inhibition of (/sup 3/H)-DPAT binding compared to that observed with i.v. buspirone. The pharmacokinetic parameters of buspirone observed in the present study are in agreement with those reported previously. Thus, the ex vivo binding assay could be utilized to determine the bioavailability of the drug to the brain, and its duration of action. 20 references, 2 figures, 5 tables.

  16. Binding of /sup 3/H-acetylcholine to cholinergic receptors in bovine cerebral arteries

    SciTech Connect

    Shimohama, S.; Tsukahara, T.; Taniguchi, T.; Fujiwara, M.

    1985-11-18

    Cholinergic receptor sites in bovine cerebral arteries were analyzed using radioligand binding techniques with the cholinergic agonist, /sup 3/H-acetylcholine (ACh), as the ligand. Specific binding of /sup 3/H-ACh to membrane preparations of bovine cerebral arteries was saturable, of two binding sites, with dissociation constant (K/sub D/) values of 0.32 and 23.7 nM, and maximum binding capacity (Bmax) values of 67 and 252 fmol/mg protein, respectively. Specific binding of /sup 3/H-ACh was displaced effectively by muscarinic cholinergic agents and less effectively by nicotinic cholinergic agents. IC/sub 50/ values of cholinergic drugs for /sup 3/H-ACh binding were as follows: atropine, 38.5 nM; ACh, 59.8 nM; oxotremorine, 293 nM; scopolamine 474 nM; carbamylcholine, 990 nM. IC/sub 50/ values of nicotinic cholinergic agents such as nicotine, cytisine and ..cap alpha..-bungarotoxin exceeded 50 ..mu..M. Choline acetyltransferase activity was 1.09 nmol/mg protein/hour in the cerebral arteries. These findings suggest that the cholinergic nerves innervate the bovine cerebral arteries and that there are at least two classes of ACh binding sites of different affinities on muscarinic reporters in these arteries. 18 references, 2 figures, 2 tables.

  17. The discovery of CCR3/H1 dual antagonists with reduced hERG risk.

    PubMed

    Bahl, Ash; Barton, Patrick; Bowers, Keith; Brough, Steven; Evans, Richard; Luckhurst, Christopher A; Mochel, Tobias; Perry, Matthew W D; Rigby, Aaron; Riley, Robert J; Sanganee, Hitesh; Sisson, Adam; Springthorpe, Brian

    2012-11-01

    A series of dual CCR3/H(1) antagonists based on a bispiperidine scaffold were discovered. Introduction of an acidic group overcame hERG liability. Bioavailability was optimised by modulation of physico-chemical properties and physical form to deliver a compound suitable for clinical evaluation. PMID:23031591

  18. Irregular Periods

    MedlinePlus

    ... number of days after the last one. The Menstrual Cycle Most girls get their first period between the ... to skip periods or to have an irregular menstrual cycle. Illness, rapid weight change, or stress can also ...

  19. Excretion of (3H)prednisolone in clinically normal and experimentally infected bovine udders

    SciTech Connect

    Geleta, J.N.; Shimoda, W.; Mercer, H.D.

    1984-08-01

    The excretion rate of (3H)prednisolone from clinically normal and experimentally infected udders of 10 lactating cows was studied. Each quarter of 6 cows was injected with a single dose of (3H)prednisolone mixed with non-radioactive prednisolone equivalent to 10 mg in 10 ml of peanut oil base. Each of the remaining 4 cows was given 40 mg of nonradioactive prednisolone and (3H)prednisolone in 60% ethanol IV. Control and postadministration samples of blood, milk, and urine were examined for radioactivity. The effects of (3H)prednisolone were evaluated in the same cows, first in clinically normal udders, then 2 weeks later in udders experimentally infected with Streptococcus agalactiae. Absorption and elimination of prednisolone were the same before and after induced infection. Within 3 hours after intramammary injection, 95% of the labeled prednisolone was absorbed systemically, less than 5% of this dose was recovered in milk, and 29% was excreted in urine. After IV injection of (3H)prednisolone, less than 0.2% of the total radioactivity was recovered in milk and less than 46% was excreted in urine. Clinical mastitis induced by S agalactiae was moderate. Circulating blood leukocytes and somatic cells in the milk of normal cows remained essentially unchanged. The leukocyte response to induced infection was rapid in blood and milk. Large numbers of leukocytes were noticed in the milk and a severe leukopenia occurred. Prednisolone treatment did not alter the number of somatic cells in milk or reduce the inflammatory response of experimentally infected cows.

  20. Comparative hemostatic parameters in BALB/c, C57BL/6 and C3H/He mice.

    PubMed

    Barrios, Mariana; Rodríguez-Acosta, Alexis; Gil, Amparo; Salazar, Ana M; Taylor, Peter; Sánchez, Elda E; Arocha-Piñango, Carmen L; Guerrero, Belsy

    2009-07-01

    This study describes micro-methods to determine biological parameters in plasma of three strains of mice. Platelet count was significantly different among strains. C57BL/6 mice showed the highest values (988 x 10(3)/microL) and BALB/c the lowest (782 x 10(3)/microL). Fibrinogen levels were 2.55 (C57BL/6), 2.37 (BALB/c) and 2.28 g/L (C3H/He). Some inter-strain differences were observed in factor XIII (94, 118 and 114%) and plasminogen levels (142, 80 and 135%) in C57BL/6, BALB/c and C3H/He, respectively. Additionally, we observed individual mice factor XIII and plasminogen levels between 80 to 200% and 65 to 180%, respectively, in relation to pooled human plasma; and between 70 to 185% and 70 to 155%, respectively, against pooled mice plasma. To our knowledge, this is first report in the literature in diverse mice strains regarding hemostasis, mainly on factor XIII, plasminogen levels, and a very simple test that allows measurement of endogenous fibrinolytic activity present in the plasma. The different results are discussed in relationship with existing literature regarding if the animals in some studies were maintained under strict pathogen-free conditions, the collection of blood was from the heart or eye and if the analysis method was tested by counting manually or automatically. This work could contribute useful knowledge to the field of investigations regarding hemostatic disorders using mouse models, especially for laboratories that are not well equipped. PMID:19101712

  1. Measurements of Cyclotron Features and Pulse Periods in the High-Mass X-Ray Binaries 4U 1538-522 and 4U 1907+09 with the International Gamma-Ray Astrophysics Laboratory

    NASA Technical Reports Server (NTRS)

    Hemphill, Paul B.; Rothschild, Richard E.; Caballero, Isabel; Pottschmidt, Katja; Kuhnel, Matthias; Furst, Felix; Wilms, Jorn

    2013-01-01

    We present a spectral and timing analysis of International Gamma-Ray Astrophysics Laboratory (INTEGRAL) observations of two high-mass X-ray binaries, 4U 1538-522 and 4U 1907+09. Our timing measurements for 4U 1538-522 find the pulse period to have exhibited a spin-up trend until approximately 2009, after which there is evidence for a torque reversal, with the source beginning to spin down to the most recently measured period of 525.407 plus or minus 0.001 seconds. The most recent INTEGRAL observations of 4U 1907+09 are not found to yield statistically significant pulse periods due to the significantly lower flux from the source compared with 4U 1538-522. A spectral model consisting of a power-law continuum with an exponential cutoff and modified by two cyclotron resonance scattering features is found to fit both sources well, with the cyclotron scattering features detected at approximately 22 and approximately 49 kiloelectronvolts for 4U 1538-522 and at approximately 18 and approximately 36 kiloelectronvolts for 4U 1907+09. The spectral parameters of 4U 1538-522 are generally not found to vary significantly with flux and there is little to no variation across the torque reversal. Examining our results in conjunction with previous work, we find no evidence for a correlation between cyclotron line energy and luminosity for 4U 1538-522. 4U 1907+09 shows evidence for a positive correlation between cyclotron line energy and luminosity, which would make it the fourth, and lowest luminosity, cyclotron line source to exhibit this relationship.

  2. MEASUREMENTS OF CYCLOTRON FEATURES AND PULSE PERIODS IN THE HIGH-MASS X-RAY BINARIES 4U 1538–522 AND 4U 1907+09 WITH THE INTERNATIONAL GAMMA-RAY ASTROPHYSICS LABORATORY

    SciTech Connect

    Hemphill, Paul B.; Rothschild, Richard E.; Caballero, Isabel; Kühnel, Matthias; Wilms, Jörn; Fürst, Felix

    2013-11-01

    We present a spectral and timing analysis of International Gamma-Ray Astrophysics Laboratory (INTEGRAL) observations of two high-mass X-ray binaries, 4U 1538–522 and 4U 1907+09. Our timing measurements for 4U 1538–522 find the pulse period to have exhibited a spin-up trend until approximately 2009, after which there is evidence for a torque reversal, with the source beginning to spin down to the most recently measured period of 525.407 ± 0.001 s. The most recent INTEGRAL observations of 4U 1907+09 are not found to yield statistically significant pulse periods due to the significantly lower flux from the source compared with 4U 1538–522. A spectral model consisting of a power-law continuum with an exponential cutoff and modified by two cyclotron resonance scattering features is found to fit both sources well, with the cyclotron scattering features detected at ∼22 and ∼49 keV for 4U 1538–522 and at ∼18 and ∼36 keV for 4U 1907+09. The spectral parameters of 4U 1538–522 are generally not found to vary significantly with flux and there is little to no variation across the torque reversal. Examining our results in conjunction with previous work, we find no evidence for a correlation between cyclotron line energy and luminosity for 4U 1538–522. 4U 1907+09 shows evidence for a positive correlation between cyclotron line energy and luminosity, which would make it the fourth, and lowest luminosity, cyclotron line source to exhibit this relationship.

  3. Comparative potencies of 3,4-methylenedioxymethamphetamine (MDMA) analogues as inhibitors of [3H]noradrenaline and [3H]5-HT transport in mammalian cell lines

    PubMed Central

    Montgomery, T; Buon, C; Eibauer, S; Guiry, P J; Keenan, A K; McBean, G J

    2007-01-01

    Background and purpose: Illegal ‘ecstasy' tablets frequently contain 3,4-methylenedioxymethamphetamine (MDMA)-like compounds of unknown pharmacological activity. Since monoamine transporters are one of the primary targets of MDMA action in the brain, a number of MDMA analogues have been tested for their ability to inhibit [3H]noradrenaline uptake into rat PC12 cells expressing the noradrenaline transporter (NET) and [3H]5-HT uptake into HEK293 cells stably transfected with the 5-HT transporter (SERT). Experimental approach: Concentration–response curves for the following compounds at both NET and SERT were determined under saturating substrate conditions: 4-hydroxy-3-methoxyamphetamine (HMA), 4-hydroxy-3-methoxymethamphetamine (HMMA), 3,4-methylenedioxy-N-hydroxyamphetamine (MDOH), 2,5-dimethoxy-4-bromophenylethylamine (2CB), 3,4-dimethoxymethamphetamine (DMMA), 3,4-methylenedioxyphenyl-2-butanamine (BDB), 3,4-methylenedioxyphenyl-N-methyl-2-butanamine (MBDB) and 2,3-methylenedioxymethamphetamine (2,3-MDMA). Key results: 2,3-MDMA was significantly less potent than MDMA at SERT, but equipotent with MDMA at NET. 2CB and BDB were both significantly less potent than MDMA at NET, but equipotent with MDMA at SERT. MBDB, DMMA, MDOH and the MDMA metabolites HMA and HMMA, were all significantly less potent than MDMA at both NET and SERT. Conclusions and implications: This study provides an important insight into the structural requirements of MDMA analogue affinity at both NET and SERT. It is anticipated that these results will facilitate understanding of the likely pharmacological actions of structural analogues of MDMA. PMID:17891159

  4. Double labeling autoradiography. Cell kinetic studies with /sup 3/H- and /sup 14/C-thymidine

    SciTech Connect

    Schultze, B.

    1981-01-01

    Examples of the multiple applicability of the double labeling method with /sup 3/H- and /sup 14/C-TdR are demonstrated. Double labeling with /sup 3/H- and /sup 14/C-TdR makes it possible to determine the cycle and its phases with high precision by modifying the usual percent labeled mitoses method with a single injection of /sup 3/H-TdR. In addition, data is provided on the variances of the transit times through the cycle phases. For example, in the case of the jejunal crypt cells of the mouse, the transit times through successive cycle phases are uncorrelated. In the case of glial cells the double labeling method provides cell kinetic parameters despite the paucity of proliferating glial cells. In the adult untreated animal, glial cell mitoses are so rare that the percent labeled mitoses method can not be utilized. However, the S-phase duration can be measured by double labeling and the cycle time can be determined by the so-called method of labeled S phases. With the latter method the passage through the S phase of the /sup 3/H-TdR-labeled S phase cells can be registered by injecting /sup 14/C-TdR at different time intervals following /sup 3/H-TdR application. In this way an S-phase duration of about 10 hr and a cycle time of about 20 hr was found for glial cells in the adult untreated mouse. An exchange of glial cells between the growth fraction and the nongrowth fraction has also been shown by double labeling. A quite different application of the double labeling method with 3H- and /sup 14/C-TdR is the in vivo study of the cell cycle phase-specific effect of drugs used in chemotherapy of tumors. The effect of vincristine on these cells has been studied. Vincristine affects cells in S and G2 in such a manner that they are arrested during the next metaphase and subsequently become necrotic. It has no effect on G1 cells.

  5. Indirect Approach To The {sup 2}H(d,p){sup 3}H Reaction Study

    SciTech Connect

    Sparta, R.; Pizzone, R. G.; Spitaleri, C.; Cherubini, S.; Crucilla, V.; Gulino, M.; La Cognata, M.; Lamia, L.; Puglia, S. M. R.; Rapisarda, G. G.; Romano, S.; Sergi, M. L.; Aliotta, M.; Burjan, V.; Hons, Z.; Kroha, V.; Mrazek, J.; Kiss, G.; McCleskey, M.; Trache, L.

    2010-11-24

    In order to understand primordial and stellar nucleosynthesis, we have studied {sup 2}H(d,p){sup 3}H reaction at 0.4 MeV down to astrophysical energies. Knowledge of its S-factor is interesting also to plan reactions for fusion reactors to produce energy. The {sup 2}H(d,p)H reaction has been studied through the Trojan Horse Method applied to the three-body reaction {sup 2}H(He,pt)H, at beam energy of 17 MeV. Once selection of protons and tritons detected in coincidence and the selection of quasi-free events, the obtained S-factor is compared with direct measurements. Such data are in agreement with the direct ones and a pole invariance test has been obtained comparing the present results with another {sup 2}H(d,p){sup 3}H THM measurements, where a different spectator particle was employed.

  6. Metabolism of /sup 3/H-dopamine by human chorioamnion in vitro

    SciTech Connect

    Phillippe, M.; Niloff, J.M.

    1982-08-01

    Previous investigation has demonstrated biologically significant concentrations of catecholamines in amniotic fluid, which increase with gestation. The half life, metabolic clearance rate, and metabolic fate of these hormones in the amniotic compartment are yet to be established. This study was undertaken to demonstrate the ability of human chorioamnion to metabolize dopamine in vitro. Incubation experiments demonstrated that /sup 3/H-dopamine is rapidly metabolized to dihydroxyphenylacetic acid, 3-methoxy, 4-hydroxyphenylacetic acid, and 3-methoxy, 4-hydroxyphenylethanol-all products of monoamine oxidase. No significant 3-methoxytyramine, a catechol-o-methyltransferase product, was observed. Incubation experiments with pargyline, a monoamine oxidase inhibitor, resulted in significant reduction in /sup 3/H-dopamine metabolism. Catecholamines and their interaction with prostaglandin synthesis have been theorized to be a fetal signal for the initiation of parturition. The ability of chorioamnion to metabolize catecholamine could, therefore, provide another control mechanism by which fetal catecholamines are modulated.

  7. Synthesis of high specific activity (1- sup 3 H) farnesyl pyrophosphate

    SciTech Connect

    Saljoughian, M.; Morimoto, H.; Williams, P.G.

    1991-08-01

    The synthesis of tritiated farnesyl pyrophosphate with high specific activity is reported. trans-trans Farnesol was oxidized to the corresponding aldehyde followed by reduction with lithium aluminium tritide (5%-{sup 3}H) to give trans-trans (1-{sup 3}H)farnesol. The specific radioactivity of the alcohol was determined from its triphenylsilane derivative, prepared under very mild conditions. The tritiated alcohol was phosphorylated by initial conversion to an allylic halide, and subsequent treatment of the halide with tris-tetra-n-butylammonium hydrogen pyrophosphate. The hydride procedure followed in this work has advantages over existing methods for the synthesis of tritiated farnesyl pyrophosphate, with the possibility of higher specific activity and a much higher yield obtained. 10 refs., 3 figs.

  8. Fluoride stimulates ( sup 3 H)thymidine incorporation and alkaline phosphatase production by human osteoblasts

    SciTech Connect

    Khokher, M.A.; Dandona, P. )

    1990-11-01

    The effect of sodium fluoride on alkaline phosphatase (ALP) release and ({sup 3}H)thymidine uptake by human osteoblasts in culture was investigated. Sodium fluoride stimulated both ALP release and ({sup 3}H)thymidine uptake at concentrations of sodium fluoride greater than 250 mumol/L. This stimulation was similar in magnitude to that induced by 1,25-dihydroxycholecalciferol. The fluoride-induced increase in ALP was inhibited by verapamil, a calcium channel blocker. We conclude that sodium fluoride stimulates osteoblasts to proliferate and to release ALP. This stimulation by fluoride is dependent on calcium influx. Fluoride-induced stimulation of human osteoblasts may be relevant to its effect in enhancing bone formation in patients with osteoporosis.

  9. SO3H-functionalized ionic liquid: efficient catalyst for bagasse liquefaction.

    PubMed

    Long, Jinxing; Guo, Bin; Teng, Junjiang; Yu, Yinghao; Wang, Lefu; Li, Xuehui

    2011-11-01

    Liquefaction is a process for the production of biofuel or value-added biochemicals from non-food biomass. SO(3)H-, COOH-functionalized and HSO(4)-paired imidazolium ionic liquids were shown to be efficient catalysts for bagasse liquefaction in hot compressed water. Using SO(3)H-functionalized ionic liquid, 96.1% of bagasse was liquefied and 50.6% was selectively converted to low-boiling biochemicals at 543 K. The degree of liquefaction and selectivity for low-boiling products increased and the average molecular weight of the tetrahydrofuran soluble products decreased with increasing acidic strength of ionic liquids. Analysis of products and comparative characterization of raw materials and residues suggested that both catalytic liquefaction and hydrolysis processes contribute to the high conversion of bagasse. A possible liquefaction mechanism based on the generation of 3-cyclohexyl-1-propanol, one of the main products, is proposed. PMID:21906936

  10. Cytotoxic responses in BC3H1 myoblast cell lines exposed to 1-desulfoyessotoxin.

    PubMed

    Korsnes, Mónica Suárez; Espenes, Arild; Hermansen, Lene C; Loader, Jared I; Miles, Christopher O

    2013-09-01

    1-Desulfoyessotoxin (1-dsYTX) is a desulfated polyether compound belonging to the yessotoxin group of marine toxins. This analogue has been detected in mussels. There are so far no reports on the mechanisms of action of 1-dsYTX in in vitro cell systems. This work evaluates cytotoxic responses in BC3H1 cells exposed to 100 nM 1-dsYTX. The toxicity of 1-dsYTX seems to be similar to that of yessotoxin (YTX). 1-Desulfoyessotoxin induced morphological and biochemical traits typical of a non-apoptotic form of cell death resembling paraptosis. Treated BC3H1 cells showed extensive cytoplasmic vacuolation, enlargement of mitochondria and endoplasmic reticulum and lack of DNA fragmentation. Western blotting analysis revealed phosphorylation of the protein kinase p38 and involvement of the heat shock protein Hsp70. This activation suggests involvement of different signalling pathways for programmed cell death. PMID:23851005

  11. Synthesis of (3) H, (2) H4 and (14) C-SCH 417690 (Vicriviroc).

    PubMed

    Hesk, D; Borges, S; Hendershot, S; Koharski, D; McNamara, P; Ren, S; Saluja, S; Truong, V; Voronin, K

    2016-05-15

    Vicriviroc or SCH 417690 is a potent and selective antagonist of the CCR5 receptor. CCR5 receptor antagonists have the potential for the treatment of HIV infections. Four distinct isotopically labelled forms of SCH 417690 were synthesized. Low specific activity [(3) H]SCH 417690 was prepared for a preliminary absorption, distribution, metabolism and excretion evaluation of the compound and [(14) C]SCH 417690 for more definitive absorption, distribution, metabolism and excretion work, including an absorption, metabolism and excretion study in man. In addition, high specific activity [(3) H]SCH 417690 was prepared for CCR5 receptor binding work and [(2) H4 ]SCH 417690 was prepared as an internal standard for a liquid chromatography-mass spectrometry bioanalytical method. The paper discusses the synthesis of four isotopically labelled forms of SCH 417690. PMID:26991320

  12. Enhanced binding of /sup 3/H-arginine8-vasopressin in the Brattleboro rat

    SciTech Connect

    Shewey, L.M.; Dorsa, D.M.

    1986-07-01

    Specific binding sites for 3(H)-arginine8-vasopressin (AVP) were characterized using membrane preparations of liver, renal medulla and brain (septal) tissue of heterozygous (HE) and homozygous (HO) Brattleboro (BB) rats. Measurement of binding sites indicated that significantly greater numbers of AVP receptors are present in the liver and septum of HO-BB rats. Similar numbers of AVP receptors were present in renal medullary tissue from HO-BB and HE-BB rats. Higher equilibrium dissociation constants were measured in the HO-BB septal tissue indicating a lower affinity of the brain receptor for 3(H)-AVP than in heterozygotes. No significant differences in AVP receptor affinity were noted in liver or kidney tissue. It is concluded that up-regulation of AVP receptor number and, in the brain, alterations in AVP receptor affinity may occur in the absence of endogenous AVP.

  13. Enhanced striatial /sup 3/H-spiroperidol binding induced by chronic haloperidol treatment inhibited by peptides administered during the withdrawal phase

    SciTech Connect

    Bhargava, H.N.

    1984-02-27

    Chronic intragastric administration of haloperidol (1.5 mg/kg/day) for 21 days followed by a 3-day withdrawal period resulted in the development of enhanced locomotor activity response to apomorphine, and an increase in the number of binding sites for /sup 3/H-spiroperidol in the striatal membranes of the rat brain. Subcutaneous administration of Pro-Leu-Gly-NH/sub 2/ or cyclo-(Leu-Gly) in doses of 2 mg/kg/day given for 3-days after termination of haloperidol treatment inhibited the enhanced response to apomorphine, as well as the increases in the number of /sup 3/H-spiroperidol binding sites in the striatum. If indeed, the supersensitivity of striatal dopamine receptors is one of the mechanisms in the development of tardive dyskinesia symptoms, the present results suggest that the above peptides may be helpful in ameliorating some of the symptoms of tardive dyskinesia induced by neuroleptic drugs. 31 references, 3 figures.

  14. Synthesis and binding characteristics of [(3)H]neuromedin N, a NTS2 receptor ligand.

    PubMed

    Tóth, Fanni; Mallareddy, Jayapal Reddy; Tourwé, Dirk; Lipkowski, Andrzej W; Bujalska-Zadrozny, Magdalena; Benyhe, Sándor; Ballet, Steven; Tóth, Géza; Kleczkowska, Patrycja

    2016-06-01

    Neurotensin (NT) and its analog neuromedin N (NN) are formed by the processing of a common precursor in mammalian brain tissue and intestines. The biological effects mediated by NT and NN (e.g. analgesia, hypothermia) result from the interaction with G protein-coupled receptors. The goal of this study consisted of the synthesis and radiolabeling of NN, as well as the determination of the binding characteristics of [(3)H]NN and G protein activation by the cold ligand. In homologous displacement studies a weak affinity was determined for NN, with IC50 values of 454nM in rat brain and 425nM in rat spinal cord membranes. In saturation binding experiments the Kd value proved to be 264.8±30.18nM, while the Bmax value corresponded to 3.8±0.2pmol/mg protein in rat brain membranes. The specific binding of [(3)H]NN was saturable, interacting with a single set of homogenous binding sites. In sodium sensitivity experiments, a very weak inhibitory effect of Na(+) ions was observed on the binding of [(3)H]NN, resulting in an IC50 of 150.6mM. In [(35)S]GTPγS binding experiments the Emax value was 112.3±1.4% in rat brain and 112.9±2.4% in rat spinal cord membranes and EC50 values of 0.7nM and 0.79nM were determined, respectively. NN showed moderate agonist activities in stimulating G proteins. The stimulatory effect of NN could be maximally inhibited via use of the NTS2 receptor antagonist levocabastine, but not by the opioid receptor specific antagonist naloxone, nor by the NTS1 antagonist SR48692. These observations allow us to conclude that [(3)H]NN labels NTS2 receptors in rat brain membranes. PMID:26707235

  15. Evaluation of PM-3 Chemistry Data and Possible Interpretations of 3H Observations, Revision 0

    SciTech Connect

    Andrews, Robert; Marutzky, Sam J.

    2015-02-01

    This report summarizes the analyses of the groundwater results from sampling of PM-3-1 (deep) and PM-3-2 (shallow), with a particular focus of evaluating the groundwater geochemistry data in comparison to the geochemistry observed in other wells in the Thirsty Canyon area as well as to evaluate the potential source of 3H observed in these piezometers from previous sampling activities, which employed depth-discrete bailers or a Bennett submersible piston pump.

  16. Clonidine and morphine increase [3H]-noradrenaline overflow in mouse vas deferens.

    PubMed Central

    Forsyth, K. M.; Pollock, D.

    1988-01-01

    1. Field stimulation of mouse isolated vas deferens produced a biphasic contraction that consisted of an initial brief non-adrenergic, non-cholinergic (NANC) twitch, followed by a more prolonged noradrenergic component. 2. Field stimulation of vasa, previously loaded with [3H]-noradrenaline ([3H]-NA), increased the amount of radioactivity in the Krebs bathing solution; 77% of this radioactivity was derived from [3H]-NA. 3. Tetrodotoxin (3 x 10(-6) M) abolished the biphasic motor response to field stimulation and the accompanying increased overflow of [3H]-NA. 4. Morphine (10(-7)-10(-5) M) inhibited the initial NANC component but potentiated the secondary noradrenergic component of the motor response to field stimulation. Morphine also increased the field stimulation-induced overflow of radioactivity. Naloxone (10(-6) M) antagonized the effects of morphine on the motor response and also on the overflow of radioactivity. 5. Clonidine (10(-9)-10(-7) M) inhibited the initial NANC component but potentiated the secondary noradrenergic component of the motor response to field stimulation. Clonidine also increased the field stimulation-induced overflow of radioactivity. 6. The ability of morphine (10(-7) M) and of clonidine (10(-9) M) to potentiate the field stimulation-induced overflow of radioactivity persisted in the presence of a combination of tranylcypromine (10(-5) M), desmethylimipramine (10(-5) M) and 17-beta-oestradiol (10(-5) M). 7. The inhibition of the initial NANC component of the motor response to field stimulation produced by morphine and clonidine may be related to the ability of these drugs to potentiate both the secondary noradrenergic component and the overflow of radioactivity, if the NANC transmitter is involved in regulating NA release. PMID:3349232

  17. Cp*Co(III) -Catalyzed C(sp(3) )-H Bond Amidation of 8-Methylquinoline.

    PubMed

    Barsu, Nagaraju; Rahman, Md Atiur; Sen, Malay; Sundararaju, Basker

    2016-06-27

    An efficient and external oxidant-free, Cp*Co(III) -catalyzed C(sp(3) )-H bond amidation of 8-methylquinoline, using oxazolone as an efficient amidating agent, is reported for the first time under mild conditions. The reaction is selective and tolerates a variety of functional groups. Based on previous reports and experimental results, the deprotonation pathway proceeds through an external base-assisted concerted metalation and deprotonation process. PMID:27168249

  18. Taurine attenuates D-[3H]aspartate release evoked by depolarization in ischemic corticostriatal slices.

    PubMed

    Molchanova, Svetlana M; Oja, Simo S; Saransaari, Pirjo

    2006-07-12

    Taurine is thought to be protective in ischemia due to its neuroinhibitory effects. The present aim was to assess the ability of taurine to attenuate glutamate release evoked by ischemia and to determine which component of this release is affected. The release of preloaded D-[(3)H]aspartate (a non-metabolized analog of glutamate) from superfused murine corticostriatal slices was used as index of glutamate release. Preincubation of corticostriatal slices with 10 mM taurine reduced the D-[(3)H]aspartate release evoked by either chemical ischemia (0.5 mM NaCN in glucose-free medium) or oxygen-glucose deprivation. The taurine uptake inhibitor guanidinoethanesulfonate (5 mM), the glycine receptor antagonist strychnine (0.1 mM) and the GABA(A) receptor antagonist bicuculline (0.1 mM) did not block the taurine effect. To determine which component of ischemia-induced glutamate release is affected by taurine, three pathways of this release were pharmacologically modeled. Unlabeled D-aspartate (0.5 mM) and hypo-osmotic medium (NaCl reduced by 50 mM) evoked D-[(3)H]aspartate release via homoexchange and hypo-osmotic release pathways, respectively. Taurine did not influence these pathways. However, it suppressed the synaptic release of D-[(3)H]aspartate evoked by the voltage-gated sodium channel opener veratridine (0.1 mM). Taurine thus reduces glutamate release under ischemic conditions by affecting the depolarization-evoked component. PMID:16781687

  19. UPTAKE OF [3H]-COLCHICINE INTO BRAIN AND LIVER OF MOUSE, RAT, AND CHICK

    SciTech Connect

    Bennett, Edward L.; Alberti, Marie Hebert; Flood, James F.

    1980-07-01

    The uptake of [ring A-4-{sup 3}H] colchicine and [ring C-methoxy-{sup 3}H]colchicine has been compared in mice from 1 to 24 hr after administration. Less radioactivity was found in brain after administration of ring-labeled colchicine than after administration of the methoxy-labeled colchicine. Three hr after administration of ring-labeled colchicine, 5% of the label was in liver and about 0.01% of the label was present in brain. Forty percent of the brain radioactivity was bound to tubulin as determined by vinblastine precipitation. After 3 hr, an average of 8% of the radioactivity from methoxy-labeled colchicine was found in the liver and 0.16% in brain. However, less than 5% of the activity in brain was precipitated by vinblastine, and the colchicine equivalent was comparable to that found after administration of the ring-labeled colchicine. The amount of colchicine entering mouse brain after subcutaneous injection is comparable to the minimum behaviorally effective dose when administered to the caudate. The metabolism of [ring C-methoxy-{sup 3}H] and [ring A-{sup 3}H]colchicine was also studied in rats. the general pattern was similar to mice; less radioactivity was found in brain after administration of the ring-labeled alkoloid than after administration of methoxy-labeled colchicine. Again, 40-50% of ring-labeled colchicine was precipitated by vinblastine. A much smaller percentage of the methoxy-labeled drug was precipitated by vinblastine than of the ring A-labeled colchicine. These experiments, together with behavioral experiments [7], support the hypotheses that structural alteration in synapses by recently synthesized proteins which are transported down the axons and dendrites may be an essential process for long-term memory formation.

  20. Binding characteristics of [3H]14-methoxymetopon, a high affinity mu-opioid receptor agonist.

    PubMed

    Spetea, Mariana; Tóth, Fanni; Schütz, Johannes; Otvös, Ferenc; Tóth, Géza; Benyhe, Sandor; Borsodi, Anna; Schmidhammer, Helmut

    2003-07-01

    The highly potent micro -opioid receptor agonist 14-methoxymetopon (4,5alpha-epoxy-3-hydroxy-14beta-methoxy-5beta,17-dimethylmorphinan-6-one) was prepared in tritium labelled form by a catalytic dehalogenation method resulting in a specific radioactivity of 15.9 Ci/mmol. Opioid binding characteristics of [3H]14-methoxymetopon were determined using radioligand binding assay in rat brain membranes. [3H]14-Methoxymetopon specifically labelled a single class of opioid sites with affinity in low subnanomolar range (Ki = 0.43 nm) and maximal number of binding sites of 314 fmol/mg protein. Binding of [3H]14-methoxymetopon was inhibited by ligands selective for the micro -opioid receptor with high potency, while selective kappa-opioids and delta-opioids were weaker inhibitors. 14-Methoxymetopon increased guanosine-5'-O-(3-[35S]thio)-triphosphate ([35S]GTPgammaS) binding with an EC50 of 70.9 nm, thus, providing evidence for the agonist character of this ligand. The increase of [35S]GTPgammaS binding was inhibited by naloxone and selective micro -opioid antagonists, indicating a micro -opioid receptor-mediated action. [3H]14-Methoxymetopon is one of the few nonpeptide mu-opioid receptor agonists available in radiolabelled form up to now. Due to its high affinity and selectivity, high stability and extremely low nonspecific binding (<10%), this radioligand would be an important and useful tool in probing mu-opioid receptor mechanisms, as well as to promote a further understanding of the opioid system at the cellular and molecular level. PMID:12887410

  1. The Uranyl Cation as a Visible-Light Photocatalyst for C(sp(3) )-H Fluorination.

    PubMed

    West, Julian G; Bedell, T Aaron; Sorensen, Erik J

    2016-07-25

    The fluorination of unactivated C(sp(3) )-H bonds remains a desirable and challenging transformation for pharmaceutical, agricultural, and materials scientists. Previous methods for this transformation have used bench-stable fluorine atom sources; however, many still rely on the use of UV-active photocatalysts for the requisite high-energy hydrogen atom abstraction event. Uranyl nitrate hexahydrate is described as a convenient, hydrogen atom abstraction catalyst that can mediate fluorinations of certain alkanes upon activation with visible light. PMID:27320442

  2. Characterization Results For The 2013 HTF 3H Evaporator Overhead Samples

    SciTech Connect

    Washington, A. L. II

    2013-12-04

    This report tabulates the radiochemical analysis of the 3H evaporator overhead sample for {sup 137}Cs, {sup 90}Sr, and {sup 129}I to meet the requirements in the Effluent Treatment Project (ETP) Waste Acceptance Criteria (WAC) (rev. 6). This report identifies the sample receipt date, preparation method, and analysis performed in the accumulation of the listed values. All data was found to be within the ETP WAC (rev. 6) specification for the Waste Water Collection Tanks (WWCT).

  3. Uptake of (/sup 3/H)colchicine into brain and liver of mouse, rat, and chick

    SciTech Connect

    Bennett, E.L.; Alberti, M.H.; Flood, J.F.

    1981-01-01

    The uptake of (ring A-4-/sup 3/H) colchicine and (ring C-methoxy-/sup 3/H)colchicine has been compared in mice from 1 to 24 hr after administration. Less radioactivity was found in brain after administration of ring-labeled colchicine than after administration of the methoxy-labeled colchicine. Three hr after administration of ring-labeled colchicine, 5% of the label was in liver and about 0.01% of the label was present in brain. Forty percent of the brain radioactivity was bound to tubulin as determined by vinblastine precipitation. After 3 hr, an average of 8% of the radioactivity from methoxy-labeled colchicine was found in the liver and 0.16% in brain. However, less than 5% of the activity in brain was precipitated by vinblastine, and the colchicine equivalent was comparable to that found after administration of the ring-labeled colchicine. The amount of colchicine entering mouse brain after subcutaneous injection is comparable to the minimum behaviorally effective dose when administered to the caudate. The metabolism of (ring C-methoxy-/sup 3/H) and (ring A-/sup 3/H)colchicine was also studied in rats. The general pattern was similar to mice; less radioactivity was found in brain after administration of the ring-labeled alkaloid than after administration of methoxy-labeled colchicine. Again, 40-50% of ring-labeled colchicine was precipitated by vinblastine. A much smaller percentage of the methoxy-labeled drug was precipitated by vinblastine than of the ring A-labeled colchicine. These experiments, together with behavioral experiments, support the hypotheses that structural alterations in synapses by recently synthesized proteins which are transported down the axons and dendrites may be an essential process for long-term memory formation.

  4. Theoretical microwave spectral constants for C3H/+/ and C4H/+/

    NASA Technical Reports Server (NTRS)

    Wilson, S.; Green, S.

    1980-01-01

    A number of linear conjugated carbon chain molecules have been observed in the interstellar gas. It has been suggested that ion molecule chemistry schemes may explain the formation of these compounds. In the present paper, theoretical bond lengths and rotation constants are obtained for C3H(+) and C4H(+). Calculations for C3 are used to assess the accuracy of the former. Recent results for C2H(+) are examined.

  5. Photoaffinity labeling of insect nicotinic acetylcholine receptors with a novel [(3)H]azidoneonicotinoid.

    PubMed

    Tomizawa, M; Wen, Z; Chin, H L; Morimoto, H; Kayser, H; Casida, J E

    2001-09-01

    The nicotinic acetylcholine receptor (nAChR) is a ligand-gated ion channel in the insect CNS and a target for major insecticides. Here we use photoaffinity labeling to approach the functional architecture of insect nAChRs. Two candidate 5-azido-6-chloropyridin-3-yl photoaffinity probes are evaluated for their receptor potencies: azidoneonicotinoid (AzNN) with an acyclic nitroguanidine moiety; azidodehydrothiacloprid. Compared to their non-azido parents, both probes are of decreased potencies at Drosophila (fruit fly) and Musca (housefly) receptors but AzNN retains full potency at the Myzus (aphid) receptor. [(3)H]AzNN was therefore radiosynthesized at high specific activity (84 Ci/mmol) as a novel photoaffinity probe. [(3)H]AzNN binds to a single high-affinity site in Myzus that is competitively inhibited by imidacloprid and nicotine and further characterized as to its pharmacological profile with various nicotinic ligands. [(3)H]AzNN photoaffinity labeling of Myzus and Homalodisca (leafhopper) detects a single radiolabeled peak in each case displaceable with imidacloprid and nicotine and with molecular masses corresponding to approximately 45 and approximately 56 kDa, respectively. The photoaffinity-labeled receptor in both Drosophila and Musca has imidacloprid- and nicotine-sensitive profiles and migrates at approximately 66 kDa. These photoaffinity-labeled polypeptides are considered to be the insecticide-binding subunits of native insect nAChRs. PMID:11579144

  6. A manganese catalyst for highly reactive yet chemoselective intramolecular C(sp3)-H amination

    NASA Astrophysics Data System (ADS)

    Paradine, Shauna M.; Griffin, Jennifer R.; Zhao, Jinpeng; Petronico, Aaron L.; Miller, Shannon M.; Christina White, M.

    2015-12-01

    C-H bond oxidation reactions underscore the existing paradigm wherein high reactivity and high selectivity are inversely correlated. The development of catalysts capable of oxidizing strong aliphatic C(sp3)-H bonds while displaying chemoselectivity (that is, tolerance of more oxidizable functionality) remains an unsolved problem. Here, we describe a catalyst, manganese tert-butylphthalocyanine [Mn(tBuPc)], that is an outlier to the reactivity-selectivity paradigm. It is unique in its capacity to functionalize all types of C(sp3)-H bond intramolecularly, while displaying excellent chemoselectivity in the presence of π functionality. Mechanistic studies indicate that [Mn(tBuPc)] transfers bound nitrenes to C(sp3)-H bonds via a pathway that lies between concerted C-H insertion, observed with reactive noble metals such as rhodium, and stepwise radical C-H abstraction/rebound, as observed with chemoselective base metals such as iron. Rather than achieving a blending of effects, [Mn(tBuPc)] aminates even 1° aliphatic and propargylic C-H bonds, demonstrating reactivity and selectivity unusual for previously known catalysts.

  7. High affinity binding of (/sup 3/H)neurotensin of rat uterus

    SciTech Connect

    Pettibone, D.J.; Totaro, J.A.

    1987-11-01

    (/sup 3/H)Neurotensin (NT) was found to bind specifically and with high affinity to crude membranes prepared from rat uterus. Scatchard analysis of saturation binding studies indicated that (/sup 3/H)NT apparently binds to two sites (high affinity Kd 0.5 nM; low affinity Kd 9 nM) with the density of high affinity sites (41 fmoles/mg prot.) being about one-third that of the low affinity sites (100 fmoles/mg prot.). In competition studies, NT and various fragments inhibited (/sup 3/H)NT binding with the following potencies (approximately IC50): NT 8-13 (0.4 nM), NT 1-13 (4 nM), NT 9-13 (130 nM), NT 1-11, NT 1-8 (greater than 100 microM). Quantitatively similar results were obtained using brain tissue. These findings raise the possibility of a role for NT in uterine function.

  8. Quantitative autoradiographic distribution of L-(3H)glutamate-binding sites in rat central nervous system

    SciTech Connect

    Greenamyre, J.T.; Young, A.B.; Penney, J.B.

    1984-08-01

    Quantitative autoradiography was used to determine the distribution of L-(3H)glutamate-binding sites in the rat central nervous system. Autoradiography was carried out in the presence of Cl- and Ca2+ ions. Scatchard plots and Hill coefficients of glutamate binding suggested that glutamate was interacting with a single population of sites having a K-D of about 300 nM and a capacity of 14.5 pmol/mg of protein. In displacement studies, ibotenate also appeared to bind to a single class of non-interacting sites with a KI of 28 microM. However, quisqualate displacement of (3H)glutamate binding revealed two well-resolved sites with KIS of 12 nM and 114 microM in striatum. These sites were unevenly distributed, representing different proportions of specific glutamate binding in different brain regions. The distribution of glutamate-binding sites correlated very well with the projection areas of putative glutamatergic pathways. This technique provides an extremely sensitive assay which can be used to gather detailed pharmacological and anatomical information about L-(3H)glutamate binding in the central nervous system.

  9. Triangular D3h Symmetry in the Rotation-Vibration Spectrum of 12C

    NASA Astrophysics Data System (ADS)

    Gai, Moshe

    2015-02-01

    Our recent measurements of new states in 12C including the second 2+ at 10 MeV and the high spin 5- state at 22.4 MeV allow us to study the Rotation-Vibration spectrum of 12C from which evidence for a new (D3h) geometrical symmetry emerges. The data fit very well to the predicted (ground state) rotational band of an oblate equilateral triangular spinning top with a D3h symmetry characterized by the sequence of states: 0+, 2+, 3-, 4+/-, 5- with almost degenerate 4+ and 4- (parity doublet) states. Such a D3h symmetry was observed in triatomic molecules, and it is observed in 12C for the first time in nuclear physics. The triatomic like structure in nuclei is reminiscent of the discovery of diatomic α+14C structure in 18O. We discuss a classification of other rotation-vibration bands in 12C such as the (0+) Hoyle band and the (1-) bending mode band and suggest measurements in search of the predicted ("missing") states that may shed new light on clustering in 12C and light nuclei. In particular, the observation (or non observation) of the predicted ("missing") states in the Hoyle band will allow us to conclude the geometrical arrangement of the three alpha particles composing the Hoyle state at 7.654 MeV in 12C.

  10. Photoaffinity labeling of opiate receptors with /sup 3/H-etorphine: possible species differences in glycosylation

    SciTech Connect

    Bowen, W.D.; Kooper, G.

    1986-01-01

    Opiate receptors from whole rat brain (minus cerebellum) and cow striatum were labeled irreversibly using the intrinsic photolability of /sup 3/H-etorphine. After incubation with 2 nM /sup 3/H-etorphine and centrifugal washing, membranes were irradiated with light of 254 nm. Non-specific binding was determined by carrying out incubations in presence and absence of 10 microM levallorphan. Specific binding in photolabeled membranes was 75-80%, with a photo-incorporation yield of approximately 50%. Photolabeled membranes were extracted with CHAPS/Lubrol and unbound /sup 3/H-etorphine was removed by dialysis and passage over Sephadex G-25. Solubilized proteins were then subjected to chromatography on wheat germ agglutinin, and retained proteins were eluted with N-acetyl D-glucosamine (NAG). Protein profiles from rat brain and cow striatum were identical, with 89% of the total protein flowing through unretained and 11% eluted by NAG. However, the profile of radioactivity was markedly different in the two species. With rat, the specific activity (cpm/A280) was the same for flow-through and NAG-eluate. With cow, the specific activity of the NAG-eluate was 17 times greater than the flow-through. These results indicate that cow striatum and rat whole brain contain populations of opiate receptors which are glycosylated differently.

  11. Partial purification of the mu opioid receptor irreversibly labeled with (/sup 3/H)b-funaltrexamine

    SciTech Connect

    Liu-Chen, L.Y.; Phillips, C.A.; Tam, S.W.

    1986-03-01

    The mu opioid receptor in bovine striatal membranes was specifically and irreversibly labeled by incubation with 5 nM (/sup 3/H)..beta..-funaltrexamine (approx.-FNA) at 37/sup 0/C for 90 min in the presence of 100 mM NaCl. The specific and irreversible binding of (/sup 3/H)..beta..-FNA as defined by that blocked by 1 /sup +/M naloxone was about 60% of total irreversible binding. The specific irreversible binding was saturable, stereospecific, time-, temperature, and tissue-dependent. Mu opioid ligands were much more potent than delta or kappa ligands in inhibiting the specific irreversible labeling. SDS polyacrylamide gel electrophoresis of solubilized membranes in the presence of 2-mercaptoethanol yielded a major radiolabeled broad band of MW 68-97K daltons, characteristic of a glycoprotein band. This band was not observed in membranes labeled in the presence of excess unlabeled naloxone. The glycoprotein nature of the (/sup 3/H)..beta..-FNA-labeled opioid receptor was confirmed by its binding to a wheat germ agglutinin-Sepharose column and its elution with N-acetylglucosamine.

  12. ( sup 3 H)QNB binding and contraction of rabbit colonic smooth muscle cells

    SciTech Connect

    Ringer, M.J.; Hyman, P.E.; Kao, H.W.; Hsu, C.T.; Tomomasa, T.; Snape, W.J. Jr. )

    1987-11-01

    The authors used radioligand binding and studies of cell contraction to characterize muscarinic receptors on dispersed smooth muscle cells from rabbit proximal and distal colon. Cells obtained after serial incubations in collagenase were used to measure binding of tritiated quinuclidinyl benzilate (({sup 3}H)QNB). At 37{degree}C, specific ({sup 3}H)QNB binding was saturable and linearly related to cell number. Nonlinear regression analysis was used to determine the affinity of ({sup 3}H)QNB for its receptor. The IC{sub 50} for the muscarinic agonists bethanechol and oxotremorine were 80 and 0.57 {mu}M, respectively. Hill coefficients were 0.67 for both, suggesting more complex interaction involving receptors of different affinities. In studies of cell contraction, bethanechol stimulated a dose-dependent decrease in cell length with half the maximal contraction occurring at 100 pM. These results suggest that (1) contraction is mediated by binding of bethanechol to M{sub 2}-muscarinic receptors and that (2) there are a large number of spare receptors in colonic smooth muscle.

  13. Photochemical Modeling of the Distribution of C3H8 in the Atmosphere of Saturn

    NASA Astrophysics Data System (ADS)

    Edgington, S. G.; Simon-Miller, A.; Jennings, D.; Bjoraker, G.; Romani, P.; Achterberg, R.; Orton, G.; Flasar, M.; Cassini CIRS Team

    2005-08-01

    Cassini's Composite Infrared Spectrometer (CIRS) has measured the abundance of C2H2 and C3H8 (Propane) at several latitudes in the Southern hemisphere. An increase of radiance with latitude towards the pole has been observed, possibly implying a corresponding increase of C3H8. In an effort explain the observed distribution of both species, it is important to model the creation, destruction, and transport of these chemical species. Furthermore, since both molecules have overlapping absorption features in the same spectral region near 748 cm-1, such modeling will aid in refining derived abundances and separating temperature effects. The photochemistry model used in Edgington et al. (1998, 1999, 2000) to model simultaneously hydrocarbons, ammonia, and phosphine is updated and expanded to include paths relevant to the creation of C3H8. Destruction occurs through photolysis, while transport would tend to spread C3H8 from its source regions. With a series of exercises in 1- and 2- dimensions, we explore the extent to which photolysis, vertical, and/or meridional transport impacts the distribution of C2H2 and C3H8 with latitude. Thermal profiles derived from CIRS observations versus latitude are used as they have an impact on numerous reaction rates. We then compare these results with abundances derived from observations taken with the CIRS instrument. Edgington, S.G., West, R.A., Friedson, A.J., Atreya, S.K., 2000. A 2-D photochemical model with meridional circulation. Bull. American. Astron. Soc., 32, 1013. Edgington, S.G., S.K. Atreya, L.M. Trafton, J.J. Caldwell, R.F. Beebe, A.A. Simon, and R.A. West, 1999. Ammonia and eddy mixing variations in the southern hemisphere of Jupiter from HST Faint Object Spectrograph Observations. Icarus, 142, 342-357. Edgington, S.G., S.K. Atreya, L.M. Trafton, J.J. Caldwell, R.F. Beebe, A.A. Simon, R.A. West, and C. Barnet, 1998. On the latitude variation of ammonia, acetylene, and phosphine altitude profiles on Jupiter from HST Faint

  14. Monocyte chemotactic protein-1 provokes mast cell aggregation and [3H]5HT release.

    PubMed Central

    Conti, P; Boucher, W; Letourneau, R; Feliciani, C; Reale, M; Barbacane, R C; Vlagopoulos, P; Bruneau, G; Thibault, J; Theoharides, T C

    1995-01-01

    Monocyte chemotactic protein-1 (MCP-1) and MCP-3, the most active and representative compounds of the CC chemokine family, are proinflammatory cytokines that attract and activate specific types of leucocytes. We have used highly purified isolated rat peritoneal mast cells (RPMC) cultured for different lengths of time with and without MCP-1 (200, 100, 50 and 25 nM). Our data clearly show that MCP-1 (200 nM) causes a marked release of [3H]serotonin ([3H]5HT and histamine, which reach a peak at 40 min of incubation (56.6 +/- 5.3 and 34.7 +/- 6 above the control, respectively). In dose-response experiments, MCP-1 (200, 100, 50, 25, 12.5, 6.25 and 3.12 nM) provoked a dose-dependent release of [3H]5HT and histamine from RPMC, which was maximum at 200 nM. After preparation of the histidine decarboxylase (HDC) probe, a Northern blot analysis was determined for HDC mRNA. After 4 hr, steady-state levels of HDC mRNA were induced in a dose-dependent manner by MCP-1 (200-25 nM), compared to the controls. However, MCP-1 failed to prime RPMC in [3H]5HT and histamine release when C48/80 (0.05 micrograms/ml) or anti-IgE was used. In contrast, murine interleukin-3 (IL-3) in combination with MCP-1 (200 and 100 nM) provoked a greater release of histamine and [3H]5HT than the compounds alone. Moreover, RPMC treated with MCP-1 (200 nM) showed, under light microscopy (20x), greater clump formation, a phenomenon absent in the controls (untreated cells). The electron microscope studies revealed that treatment with MCP-1 (200 nM) promoted binding of RPMC and clearly demonstrated a communication between the cytoplasms of adjacent mast cells. Our report describes additional biological activities for MCP-1, suggesting for the first time that this human monocyte chemoattractant plays a fundamental role in histamine and serotonin release and cell aggregation in rat peritoneal mast cells. Images Figure 4 Figure 5 PMID:8550082

  15. Characterization of high affinity (/sup 3/H)triazolam binding in rat brain

    SciTech Connect

    Earle, M.; Concas, A.; Yamamura, H.I.

    1986-03-01

    The hypnotic Triazolam (TZ), a triazolo (1,4)-benzodiazepine, displays a short physiological half life and has been used for the treatment of insomnia related to anxiety states. Specific binding properties of this recently tritiated TZ were characterized. The authors major objectives were the direct measurement of the temperature dependence and the GABA effect on (/sup 3/H)TZ binding. Saturation studies showed a shift to lower affinity at 37/sup 0/C (K/sub d/ = 0.25 +/- 0.01 nM at O/sup 0/C; K/sub d/ = 1.46 +/- 0.03 nM at 37/sup 0/C) while the B/sub max/ values remained unchanged (1003 +/- 37 fmoles/mg prot. at 0/sup 0/C and 1001 +/- 43 fmoles/mg prot. at 37/sup 0/C). Inhibition studies showed that (/sup 3/H)TZ binding displayed no GABA shift at 0/sup 0/C(K/sub i/ 0.37 +/- 0.03 nM/- GABA and K/sub i/ = 0.55 +/- 0.13 nM/+GABA) but a nearly two-fold shift was apparent at 37/sup 0/C (K/sub i/ = 2.92 +/- 0.2 nM/-GABA; K/sub i/ = 1.37 +/- 0.11 mM/+GABA). These results were also confirmed by saturation studies in the presence or absence of GABA showing a shift to higher affinity in the presence of GABA only at 37/sup 0/C. In Ro 15-1788/(/sup 3/H)TZ competition experiments the presence of GABA did not affect the inhibitory potency of Ro 15-1788 on (/sup 3/H)TZ binding at both temperatures. In conclusion (/sup 3/H)TZ binding showed an extremely high affinity for benzodiazepine receptors. In contrast to reported literature, the findings suggest that TZ interacts with benzodiazepine receptors similar to other benzodiazepine agonists.

  16. Stereoselective L-[3H]quinuclidinyl benzilate-binding sites in nervous tissue of Aplysia californica: evidence for muscarinic receptors.

    PubMed

    Murray, T F; Mpitsos, G J; Siebenaller, J F; Barker, D L

    1985-12-01

    The muscarinic antagonist L-[3H]quinuclidinyl benzilate (L-[3H]QNB) binds with a high affinity (Kd = 0.77 nM) to a single population of specific sites (Bmax = 47 fmol/mg of protein) in nervous tissue of the gastropod mollusc, Aplysia. The specific L-[3H]QNB binding is displaced stereoselectively by the enantiomers of benzetimide, dexetimide, and levetimide. The pharmacologically active enantiomer, dexetimide, is more potent than levetimide as an inhibitor of L-[3H]QNB binding. Moreover, the muscarinic cholinergic ligands, scopolamine, atropine, oxotremorine, and pilocarpine are effective inhibitors of the specific L-[3H]QNB binding, whereas nicotinic receptor antagonists, decamethonium and d-tubocurarine, are considerably less effective. These pharmacological characteristics of the L-[3H]QNB-binding site provide evidence for classical muscarinic receptors in Aplysia nervous tissue. The physiological relevance of the dexetimide-displaceable L-[3H]QNB-binding site was supported by the demonstration of the sensitivity of the specific binding to thermal denaturation. Specific binding of L-[3H]QNB was also detected in nervous tissue of another marine gastropod, Pleurobranchaea californica. The characteristics of the Aplysia L-[3H]QNB-binding site are in accordance with studies of numerous vertebrate and invertebrate tissues indicating that the muscarinic cholinergic receptor site has been highly conserved through evolution. PMID:4078624

  17. Stereoselective L-(3H)quinuclidinyl benzilate-binding sites in nervous tissue of Aplysia californica: evidence for muscarinic receptors

    SciTech Connect

    Murray, T.F.; Mpitsos, G.J.; Siebenaller, J.F.; Barker, D.L.

    1985-12-01

    The muscarinic antagonist L-(/sup 3/H)quinuclidinyl benzilate (L-(/sup 3/H)QNB) binds with a high affinity (Kd = 0.77 nM) to a single population of specific sites (Bmax = 47 fmol/mg of protein) in nervous tissue of the gastropod mollusc, Aplysia. The specific L-(/sup 3/H)QNB binding is displaced stereoselectively by the enantiomers of benzetimide, dexetimide, and levetimide. The pharmacologically active enantiomer, dexetimide, is more potent than levetimide as an inhibitor of L-(/sup 3/H)QNB binding. Moreover, the muscarinic cholinergic ligands, scopolamine, atropine, oxotremorine, and pilocarpine are effective inhibitors of the specific L-(/sup 3/H)QNB binding, whereas nicotinic receptor antagonists, decamethonium and d-tubocurarine, are considerably less effective. These pharmacological characteristics of the L-(/sup 3/H)QNB-binding site provide evidence for classical muscarinic receptors in Aplysia nervous tissue. The physiological relevance of the dexetimide-displaceable L-(/sup 3/H)QNB-binding site was supported by the demonstration of the sensitivity of the specific binding to thermal denaturation. Specific binding of L-(/sup 3/H)QNB was also detected in nervous tissue of another marine gastropod, Pleurobranchaea californica. The characteristics of the Aplysia L-(/sup 3/H)QNB-binding site are in accordance with studies of numerous vertebrate and invertebrate tissues indicating that the muscarinic cholinergic receptor site has been highly conserved through evolution.

  18. Characterization of [3H]-diprenorphine binding in Rana pipiens: observations of filter binding enhanced by naltrexone.

    PubMed

    Newman, L C; Wallace, D R; Stevens, C W

    1999-02-01

    Initial studies were undertaken to examine the properties of [3H]-diprenorphine binding to Rana pipiens whole brain tissue using naltrexone for the definition of nonspecific binding. Saturation analysis demonstrated the binding of [3H]-diprenorphine to be saturable with a K(D) value of 0.65 nM and a Bmax value of 287.7 fmol/mg protein. Unlabeled diprenorphine dose-dependently displaced [3H]-diprenorphine from a single noninteractive site in competition studies which yielded a Ki of 0.22 nM. However, control studies in the absence of tissue revealed significant binding of [3H]-diprenorphine to the filter alone. Interestingly, [3H]-diprenorphine in the presence of unlabeled naltrexone as well as with unlabeled naloxone showed significantly greater binding to the filter than did [3H]-diprenorphine alone. Given this observation of increased nonspecific binding, an artificially low Bmax value would be expected. It is our hypothesis that the unlabeled nonspecific drug forms a complex with [3H]-diprenorphine preventing it from being effectively washed through the filter or the unlabeled drug itself is blocking the flow of [3H]-diprenorphine through the filter. The latter is unlikely however as other binding studies done in our lab using the radioligand [3H]-naloxone with unlabeled naltrexone do not show significant binding to the filter. PMID:10507757

  19. Preferential affinity of /sup 3/H-2-oxo-quazepam for type I benzodiazepine recognition sites in the human brain

    SciTech Connect

    Corda, M.G.; Giorgi, O.; Longoni, B.; Ongini, E.; Montaldo, S.; Biggio, G.

    1988-01-01

    The hypnotic drug quazepam and its active metabolite 2-oxo-quazepam (2-oxo-quaz) are two benzodiazepines (BZ) containing a trifluoroethyl moiety on the ring nitrogen at position 1, characterized by their preferential affinity for Type I BZ recognition sites. In the present study we characterized the binding of /sup 3/H-2-oxo-quaz in discrete areas of the human brain. Saturation analysis demonstrated specific and saturable binding of /sup 3/H-2-oxo-quaz to membrane preparations from human cerebellum. Hill plot analysis of displacement curves of /sup 3/H-flunitrazepam binding by 2-oxo-quaz yielded Hill coefficients of approximately 1 in the cerebellum and significantly less than 1 in the cerebral cortex, hippocampus, caudate nucleus, thalamus and pons. Self and cross displacement curves for /sup 3/H-FNT and /sup 3/H-2-oxo-quaz binding in these brain areas indicated that 2-oxo-quaz binds with different affinities to two populations of binding sites. High affinity binding sites were more abundant in the cerebellum, cerebral cortex, hippocampus and thalamus, whereas low affinity sites were predominant in the caudate nucleus and pons. Competition studies of /sup 3/H-2-oxo-quaz and /sup 3/H-FNT using unlabelled ligands indicated that compounds which preferentially bind to Type I sites are more potent at displacing /sup 3/H-2-oxo-quaz than /sup 3/H-FNT from cerebral cortex membrane preparations. 26 references, 2 figures, 3 tables.

  20. Helicobacter pylori Does Not Require Lewis X or Lewis Y Expression To Colonize C3H/HeJ mice

    PubMed Central

    Takata, Tohru; El-Omar, Emad; Camorlinga, Margarita; Thompson, Stuart A.; Minohara, Yutaka; Ernst, Peter B.; Blaser, Martin J.

    2002-01-01

    Helicobacter pylori strains frequently express Lewis X (Lex) and/or Ley on their cell surfaces as constituents of the O antigens of their lipopolysaccharide molecules. To assess the effect of Lex and Ley expression on the ability of H. pylori to colonize the mouse stomach and to adhere to epithelial cells, isogenic mutants were created in which fucT1 alone or fucT1 and fucT2, which encode the fucosyl transferases necessary for Lex and Ley expression, were deleted. C3H/HeJ mice were experimentally challenged with either wild-type 26695 H. pylori or its isogenic mutants. All strains, whether passaged in the laboratory or recovered after mouse passage, colonized the mice well and without consistent differences. During colonization by the mutants, there was no reversion to wild type. Similarly, adherence to AGS and KatoIII cells was unaffected by the mutations. Together, these findings indicate that Le expression is not necessary for mouse gastric colonization or for H. pylori adherence to epithelial cells. PMID:12011000

  1. Periodized wavelets

    SciTech Connect

    Schlossnagle, G.; Restrepo, J.M.; Leaf, G.K.

    1993-12-01

    The properties of periodized Daubechies wavelets on [0,1] are detailed and contrasted against their counterparts which form a basis for L{sup 2}(R). Numerical examples illustrate the analytical estimates for convergence and demonstrate by comparison with Fourier spectral methods the superiority of wavelet projection methods for approximations. The analytical solution to inner products of periodized wavelets and their derivatives, which are known as connection coefficients, is presented, and several tabulated values are included.

  2. (/sup 3/H)cholesteryl ester labeling and transfer among human and honhuman primate plasma lipoproteins

    SciTech Connect

    Thomas, M.S.; Rudel, L.L.

    1983-04-01

    Aliquots of human and nonhuman primate plasma containing 5,5'-dithiobis (2-nitrobenzoic acid) were incubated at 37/sup 0/C in tubes previously coated with trace amounts of tritium-labeled cholesteryl oleate ((/sup 3/H)CO). Initially, cholesteryl esters were transferred at a rapid rate into plasma after which the rate slowed. During 24 h of incubation, an average of 55% of the (/sup 3/H)CO transferred from the side of the tube into African green monkey plasma, 44% into human plasma and 21% into rat plasma. Greater than 98% of the radioactive ester transferred into plasma was found to be associated with plasma lipoproteins that were then rapidly separated using vertical rotor density gradient ultracentrifugation. In very low density lipoprotein (VLDL)-poor plasma after 30 min incubations, high density lipoproteins (HDL) contained most of the (/sup 3/H)CO while 5- to 24-h incubations resulted in increased labeling of low density proteins (LDL). In VLDL-rich plasma, it was found that in addition to the labeling of HDL, VLDL contained about 25% of the labeled cholesteryl esters after 30-min incubations and, as above, the proportion in LDL subsequently increased. Compositional analyses showed that intermediate-sized LDL (ILDL) were accumulating cholesteryl ester mass while transfer occurred. LDL labeled using this method were injected intravenously into monkeys and their removal from plasma was found to be similar to that found for LDL labeled in vivo. It was concluded that this method of plasma lipoprotein cholesteryl ester labeling, presumably a result of cholesteryl ester transfer protein activity, was efficient, resulted in lipoproteins labeled only in the cholesteryl ester moiety, and induced minimal modification of lipoprotein particles that did not alter their biological activity.

  3. THE MAGNETIZED ENVIRONMENT OF THE W3(H{sub 2}O) PROTOSTARS

    SciTech Connect

    Chen, Huei-Ru; Rao, Ramprasad; Liu, Sheng-Yuan; Wilner, David J.

    2012-05-20

    We present the first interferometric polarization map of the W3(OH) massive star-forming region observed with the Submillimeter Array (SMA) at 878 {mu}m with an angular resolution of 1.''5 (about 3 Multiplication-Sign 10{sup 3} AU). Polarization is detected in the W3(H{sub 2}O) hot core, an extended emission structure in the northwest of W3(H{sub 2}O), and part of the W3(OH) ultracompact H II region. The W3(H{sub 2}O) hot core is known to be associated with a synchrotron jet along the east-west direction. In this core, the inferred magnetic field orientation is well aligned with the synchrotron jet and close to the plane of sky. Using the Chandrasekhar-Fermi method with the observed dispersion in polarization angle, we estimate a plane-of-sky magnetic field strength of 17.0 mG. Combined with water maser Zeeman measurements, the total magnetic field strength is estimated to be 17.1 mG, comparable to the field strength estimated from the synchrotron model. The magnetic field energy dominates over turbulence in this core. In addition, the depolarization effect is discerned in both SMA and James Clerk Maxwell Telescope measurements. Despite the great difference in angular resolutions and map extents, the polarization percentage shows a similar power-law dependence with the beam averaged column density. We suggest that the column density may be an important factor to consider when interpreting the depolarization effect.

  4. Matrix isolation ESR spectroscopy and magnetic anisotropy of D{sub 3h} symmetric septet trinitrenes

    SciTech Connect

    Misochko, Eugenii Ya.; Akimov, Alexander V.; Masitov, Artem A.; Korchagin, Denis V.; Aldoshin, Sergei M.; Chapyshev, Sergei V.

    2013-05-28

    The fine-structure (FS) parameters D of a series of D{sub 3h} symmetric septet trinitrenes were analyzed theoretically using density functional theory (DFT) calculations and compared with the experimental D values derived from ESR spectra. ESR studies show that D{sub 3h} symmetric septet 1,3,5-trichloro-2,4,6-trinitrenobenzene with D=-0.0957 cm{sup -1} and E= 0 cm{sup -1} is the major paramagnetic product of the photolysis of 1,3,5-triazido-2,4,6-trichlorobenzene in solid argon matrices at 15 K. Trinitrenes of this type display in the powder X-band ESR spectra intense Z{sub 1}-transition at very low magnetic fields, the position of which allows one to precisely calculate the parameter D of such molecules. Thus, our revision of the FS parameters of well-known 1,3,5-tricyano-2,4,6-trinitrenobenzene [E. Wasserman, K. Schueller, and W. A. Yager, Chem. Phys. Lett. 2, 259 (1968)] shows that this trinitrene has Double-Vertical-Line D Double-Vertical-Line = 0.092 cm{sup -1} and E= 0 cm{sup -1}. DFT calculations reveal that, unlike C{sub 2v} symmetric septet trinitrenes, D{sub 3h} symmetric trinitrenes have the same orientations of the spin-spin coupling tensor D-caret{sub SS} and the spin-orbit coupling tensor D-caret{sub SOC} and, as a result, have negative signs for both the D{sub SS} and D{sub SOC} values. The negative magnetic anisotropy of septet 2,4,6-trinitrenobenzenes is considerably strengthened on introduction of heavy atoms in the molecules, owing to an increase in contributions of various excitation states to the D{sub SOC} term.

  5. Relationship between alpha 1-adrenergic receptor occupancy and response in BC3H-1 muscle cells

    SciTech Connect

    Brown, R.D.; Berger, K.D.; Taylor, P.

    1987-07-01

    The relationship between alpha 1-adrenergic receptor occupancy by agonists or antagonists and the regulation of intracellular Ca/sup 2 +/ was examined. Receptor occupancy was measured using the antagonist (/sup 3/H)prazosin and correlated with agonist-elicited /sup 45/Ca/sup 2 +/ fluxes. The agonists epinephrine (E), norepinephrine (NE), and phenylephrine (PE) coordinately activated Ca/sup 2 +/ efflux, reflecting a substantial mobilization of intracellular Ca/sup 2 +/, as well as a smaller /sup 45/Ca/sup 2 +/ influx. The agonist concentration dependences for influx and efflux were similar, with the order of potency expected for alpha 1 receptors (E greater than or equal to NE greater than PE). To determine the relationship between receptor occupancy and response, the slowly dissociating antagonist prazosin was used to inactivate specified fractions of the receptor population. A linear relationship was observed between the remaining activatable receptors and residual /sup 45/Ca/sup 2 +/ efflux elicited by E or NE, except at saturating agonist concentrations where some curvature was observed. Moreover, the concentration dependence for agonist-elicited /sup 45/Ca/sup 2 +/ efflux was shifted toward slightly higher concentrations of E or NE following prazosin inactivation. These results suggest the presence of a modest receptor reserve which is revealed by E or NE, but not by PE. Agonist occupation was measured over the same interval as receptor activation by competition with the initial rate of (/sup 3/H)prazosin association. All three agonists exhibited the major fraction of receptor occupation over the same concentration ranges required for the functional response. Exposure of receptors to specified agonist concentrations for 30 min had little effect on the number of receptors or their ligand affinities, whereas a 2.5-hr exposure to agonist decreased apparent agonist affinity as well as the number of receptors recognized by (/sup 3/H)prazosin.

  6. The 3 H and BMSEST Models for Spirituality in Multicultural Whole-Person Medicine

    PubMed Central

    Anandarajah, Gowri

    2008-01-01

    PURPOSE The explosion of evidence in the last decade supporting the role of spirituality in whole-person patient care has prompted proposals for a move to a biopsychosocial-spiritual model for health. Making this paradigm shift in today’s multicultural societies poses many challenges, however. This article presents 2 theoretical models that provide common ground for further exploration of the role of spirituality in medicine. METHODS The 3 H model (head, heart, hands) and the BMSEST models (body, mind, spirit, environment, social, transcendent) evolved from the author’s 12-year experience with curricula development regarding spirituality and medicine, 16-year experience as an attending family physician and educator, lived experience with both Hinduism and Christianity since childhood, and a lifetime study of the world’s great spiritual traditions. The models were developed, tested with learners, and refined. RESULTS The 3 H model offers a multidimensional definition of spirituality, applicable across cultures and belief systems, that provides opportunities for a common vocabulary for spirituality. Therapeutic options, from general spiritual care (compassion, presence, and the healing relationship), to specialized spiritual care (eg, by clinical chaplains), to spiritual self-care are discussed. The BMSEST model provides a conceptual framework for the role of spirituality in the larger health care context, useful for patient care, education, and research. Interactions among the 6 BMSEST components, with references to ongoing research, are proposed. CONCLUSIONS Including spirituality in whole-person care is a way of furthering our understanding of the complexities of human health and well-being. The 3 H and BMSEST models suggest a multidimensional and multidisciplinary approach based on universal concepts and a foundation in both the art and science of medicine. PMID:18779550

  7. Somatic hypermutations and isotype restricted exceptionally long CDR3H contribute to antibody diversification in cattle.

    PubMed

    Kaushik, Azad K; Kehrli, Marcus E; Kurtz, A; Ng, S; Koti, M; Shojaei, F; Saini, Surinder S

    2009-01-15

    Antibody diversification in IgM and IgG antibodies was analyzed in an 18-month old bovine (Bos taurus) suffering from naturally occurring chronic and recurrent infections due to bovine leukocyte adhesion deficiency (BLAD). The BLAD, involving impaired leukocyte beta2 integrin expression on leukocytes, develops due to a single point mutation in conserved region of the CD18 gene resulting in substitution of aspartic acid128 with glycine (D128G). Twenty four VDJCmu and 25 VDJCgamma recombinations from randomly constructed cDNA libraries, originating from peripheral blood lymphocytes, were examined for the variable-region structural characteristics in IgM and IgG antibody isotypes. These analyses led to conclude that: (a) expression of exceptionally long CDR3H is isotype restricted to cattle IgM antibody; (b) VDJ recombinations encoding IgM with exceptionally long CDR3H undergo clonal selection and affinity maturation via somatic mutations similar to conventional antibodies; (c) somatic mutations contribute significantly to both IgM and IgG antibody diversification but significant differences exist in the patterns of 'hot spot' in the FR1, FR3 and CDR1H and, also, position-dependant amino acid diversity; and (d) transition nucleotide substitutions predominate over transversions in both VDJCmu and VDJCgamma recombinations consistent with the evolutionary conservation of somatic mutation machinery. Overall, these studies suggest that both somatic mutations and exceptional CDR3H size generation contribute to IgM and IgG antibody diversification in cattle during the development of immune response to naturally occurring chronic and multiple microbial infections. PMID:19012969

  8. 3H- 3He dating: A case for mixing of young and old groundwaters

    NASA Astrophysics Data System (ADS)

    Kamensky, I. L.; Tokarev, I. V.; Tolstikhin, I. N.

    1991-10-01

    3He /4He and 20Ne /4He ratios were measured in shallow underground waters (opened by water-supplying wells) of the Large Vud-Javr intramountain artesian basin in the Khibiny alkaline massif, the Kola Peninsula. The ratios vary from 1.321 × 10 -6 to 2.065 × 10 -6 and from 1.412 to 2.941, respectively, and a well-defined correlation is observed between them. Both these ratios in aquifers are known to be time-dependent, the former increases with time due to accumulation of 3He, produced in waters by 3H β-decay; the latter decreases due to migration of helium from water-bearing rocks into the waters. The correlation is interpreted as a result of the mixing of two different types of waters. The approximation line enables us to estimate the isotopic ratios for the endmembers participating in the mixing and the mean residence time (τ) of tritigenic helium-3 in the water: (1) 3He /4He = 3.655 × 10 -6, 20Ne /4He = 4.03 , and taking into consideration 3H concentrations in the well waters, 3H = 31.1 TU (practically the same for all samples), τ = 15.8 ± 1.5 years for the young water; (2) 3He /4He = 0.20 × 10 -6, 20Ne /4He = 0.18 and T = 0.11 Ma for the old one, the contribution of the old water being less than 10%. In one well a considerable contribution of modern-day meteoric water, about 16%, is observed.

  9. Sensitizing Ability and Toxicity of Iodoacetamide in Radiotherapy of a C3H Mouse Mammary Carcinoma

    PubMed Central

    Urano, M.; Tanaka, N.; Hayashi, S.

    1973-01-01

    The radiosensitizing effect of iodoacetamide was studied in a C3H mouse mammary carcinoma together with its toxicity to the host. TCD50 or radiation dose to yield 50% tumour control frequency was determined in tumours treated or untreated with the agent. Results indicated that 15 mg/kg of iodoacetamide sensitized hypoxic tumour cells, as did atmospheric oxygen, and the sensitization was not detectable below this dose. Experiments with fractionated treatments suggested that the reoxygenation occurring during the treatment intervals of 24 hours might be more important in the sterilization of tumour cells than the agent. PMID:4730179

  10. Holographic recording physicochemical mechanism for PVA-FeCl3 + hν

    NASA Astrophysics Data System (ADS)

    Ordóñez-Padilla, M. J.; Olivares-Pérez, A.

    2016-03-01

    Photo-physicochemical processes involved in the images recording are described. A holographic grating in recording process generates photo-crosslinking through electron transfer, by the active and not active radical mobility ions in the system [PVA + FeCl3 + H2O + hv]. The electric charges reorientation by the polarity between atoms and molecules establish intramolecular crosslinks. This process is essential due to the photochemical reaction for reducing Fe3+ to Fe2+ ion. The optimal holographic film shows diffraction efficiency the order of 26%.

  11. Characterization Results for the 2014 HTF 3H & 2H Evaporator Overhead Samples

    SciTech Connect

    Washington, A.

    2015-05-11

    This report tabulates the radiochemical analysis of the 3H and 2H evaporator overhead samples for 137Cs, 90Sr, and 129I to meet the requirements in the Effluent Treatment Project (ETP) Waste Acceptance Criteria (WAC) (rev. 6). This report identifies the sample receipt date, preparation method, and analysis performed in the accumulation of the listed values. All data was found to be within the ETP WAC (rev. 6) specification for the Waste Water Collection Tanks (WWCT).

  12. Endogenous peptide(s) inhibiting [3H]cocaine binding in mouse brain.

    PubMed

    Reith, M E; Sershen, H; Lajtha, A

    1980-12-01

    The supernatant fraction of centrifuged homogenate of brain tissue contains material that inhibits the saturable binding of [3H]cocaine to crude mouse brain membranes. This material was subjected to heat treatment to remove protein; further purification was achieved by filtering through an Amicon UM-10 membrane ultrafilter and gel filtration of the ultrafiltrate on Sephadex G-25. Sensitivity to acid hydrolysis and peptidase action indicates that the inhibitory activity resides in peptide material with low molecular weight. The partially purified inhibitor has similar effects to that of cocaine on the specific binding of various ligands to opiate and nonopiate receptors in mouse brain membranes. PMID:6261176

  13. A 3H-flunitrazepam binding inhibitor is present in psychiatric patients' sera.

    PubMed

    Marazziti, D; Pietrini, P; Martini, C; Giannaccini, G; Perugi, G; Placidi, G F; Cassano, G B; Lucacchini, A

    1987-01-01

    We investigated the possible existence of endogenous compounds acting on benzodiazepine central receptors in the serum of patients with panic attacks or depression. Our results show the presence of a substance which inhibits the 3H-flunitrazepam binding specifically in the samples taken from the patients' groups, and which is not present in normal controls, in the range of concentrations used. This compound has a molecular weight below 1,000 daltons, is heat-stable, and resistant to proteolytic degradation. The demonstration of this inhibitor opens new perspectives in the study of the biochemistry of anxiety. PMID:2836759

  14. Retrograde transport of (/sup 3/H)-D-aspartate label by cochlear and vestibular efferent neurons

    SciTech Connect

    Schwarz, D.W.; Schwarz, I.E.

    1988-01-01

    (/sup 3/H)-D-aspartic acid was injected into the inner ear of rats. After a six hour survival time, labeled cells were found at all locations known to contain efferent cochlear or vestibular neurons. Most labeled neurons were found in the ipsilateral lateral superior olivary nucleus (LSO), although both ventral nuclei of the trapezoid body (VTB), group E, and the caudal pontine reticular nucleus (CPR) just adjacent to the ascending limb of the facial nerve also contained labeled cells. Because not all efferent neurons in the rat could be previously shown to be cholinergic, aspartate and glutamate are efferent transmitter candidates.

  15. Thermodynamic Modeling of the SRS Evaporators: Part II. The 3H System

    SciTech Connect

    Jantzen, C.M.

    2001-10-02

    Accumulations of two solid phases have formed scale deposits in the Savannah River Site 2H Evaporator system since late 1996. The aluminosilicate scale deposits caused the evaporator pot to become inoperable in October 1999. Accumulations of the diuranate phase have caused criticality concerns in the SRS 2H Evaporator. In order to ensure that similar deposits are not and will not form in the SRS 3H Evaporator, thermodynamically derived activity diagrams specific to the feeds processed from Tanks 30 and 32 are evaluated in this report.

  16. The C3H2 2(20)-2(11) transition - Absorption in cold dark clouds

    NASA Technical Reports Server (NTRS)

    Matthews, H. E.; Avery, L. W.; Madden, S. C.; Irvine, W. M.

    1986-01-01

    The first observations of the 2(20)-2(11) transition of cyclopropenylidene (C3H2) at 21.6 GHz are described. The most significant finding is that the 2(20)-2(11) transition line is always seen in absorption, in contrast to the 18.3-GHz 1(10)-1(01) resonance line of the ortho species which always appears in emission in cold dust clouds. Thus the former must have an excitation temperature less than the brightness temperature of the universal microwave background and becomes only the second molecule to exhibit such 'refrigeration' below this temperature in cold, dark dust clouds.

  17. Labeling cells in microtiter plates for determination of [3H]thymidine uptake.

    PubMed

    Shevach, E M

    2001-05-01

    A number of protocols in Current Protocols in Immunology use as their end-point the determination of cell proliferation by determining the incorporation of [(3)H]thymidine into cellular DNA. This appendix presents a protocol in which the radioactive label is added during the last 4 to 24 hr of the culture. A semiautomated cell harvesting apparatus is then used to lyse the cells with water and precipitate the labeled DNA on glass fiber filters. The filter pads are then dried and counted by standard liquid scintillation counting techniques in a scintillation counter. PMID:18432656

  18. Synthesis of some new tricyclic 4(3H)-quinazolinone derivatives

    PubMed Central

    Jafari, E.; Khodarahmi, G.A.; Hakimelahi, G.H.; Tsai, F.Y.; Hassanzadeh, F.

    2011-01-01

    Quinazolinones are interesting molecules with a wide range of biological activities. We prepared a number of quinazolinone derivatives by the condensation of 5-bromo- or 5-nitro-substituted anthranilic acids with chloro-acyl chlorides. Anthranilic acid derivatives were treated with either 3-chloro-propionyl chloride or 4-chloro-butyryl chloride to yield the corresponding N-acyl-anthranilic acids. The resultants were reacted with acetic anhydride to afford the benzoxazinone intermediates, which upon condensation with elected amines in either DMF or ethanol gave the corresponding tricyclic 4(3H)-quinazolinone derivatives. It was found that reactions in DMF produced higher yields. PMID:22224092

  19. Charge symmetry breaking effect for 3H and 3He within s-wave approach

    NASA Astrophysics Data System (ADS)

    Filikhin, I.; Suslov, V. M.; Vlahovic, B.

    2016-06-01

    Three-nucleon systems are considered assuming the neutrons and protons to be distinguishable particles. The configuration space Faddeev equations are exploited to calculate ground state energies of 3H and 3He nuclei within an s-wave approach applying the Malfliet-Tjon, Tamagaki G3RS and Afnan-Tang ATS3 NN potentials. We modify the potentials by scaling strength parameters to define nn, pp and np singlet components. The scaling parameters are fixed to reproduce experimental scattering lengths. The charge symmetry breaking energy is numerically evaluated. The relation between nn, pp and np singlet potentials is discussed.

  20. Short-term tissue distribution, depuration and possible gene expression effects of [{sup 3}H]TCDD exposure in soft-shell clams (Mya arenaria)

    SciTech Connect

    Rhodes, L.D.; Beneden, R.J. van; Gardner, G.R.

    1997-09-01

    A short-term, waterborne exposure and depuration study of Mya arenaria to [{sup 3}H]tetrachlorodibenzo-p-dioxin ([{sup 3}H]TCDD) was performed. Gill, digestive gland, foot, and gonad were sampled up to 2 weeks after a 24-h exposure to a low dose (10 parts per trillion [pptr]) or high dose (2,000 pptr) of [{sup 3}H]TCDD in the water. In the gill, peak concentrations occurred at the beginning of depuration (406 and 8,658 pg/g wet weight, low- and high-dose groups, respectively), whereas peak concentrations in the digestive gland and foot were found 12 to 24 h after exposure. In contrast, tissue concentrations in the gonad increased through the post-exposure period; at 2 weeks after exposure, tissue concentrations were highest in the gonad. Examination of gill and gonad by differential display polymerase chain reaction identified potential alterations in expression of genes that may be associated with increased cell cycling or translation initiation. This study shows that M. arenaria can accumulate TCDD in the gonad from an acute exposure, and it identifies several M. arenaria genes whose expression may be altered by TCDD exposure.

  1. Effect of colchicine on rat small intestinal absorptive cells. II. Distribution of label after incorporation of (/sup 3/H)fucose into plasma membrane glycoproteins

    SciTech Connect

    Ellinger, A.; Pavelka, M.; Gangl, A.

    1983-12-01

    By means of radioautography the influence was tested of various periods (5, 15, 30, 40 min, 2 hr) of pretreatment with colchicine, administered intraperitoneally to rats at a dosage of 0.5 mg/100 g of body weight, on the intracellular pathway of (/sup 3/H)fucose in absorptive cells of the small intestine. Administration of colchicine for 30 min and longer time intervals causes delay in the insertion of (/sup 3/H)fucose into the oligosaccharide chains of glycoconjugates in the Golgi apparatus, and results in redistribution of the label apparent over the different portions of the plasma membrane. In controls, at 2 and 4 hr after administration of (/sup 3/H)fucose the apical plasma membrane is strongly labeled. Colchicine causes equalization of the reaction of apical and basolateral regions of the plasma membrane: the number of silver grains attributable to the apical plasma membrane is reduced; following treatment with colchicine, apical portions of the plasma membrane comprise 31.6 +/- 1.8% of the silver grains, 38.6 +/- 3.8% are attributable to basolateral membrane regions. The colchicine-induced equalization of the density of label of apical and basolateral regions of the plasma membrane, in addition to the occurrence of basolateral microvillus borders, suggests microtubules to be important in the maintenance of the polar organization of small intestinal absorptive cells.

  2. Rhenium-catalysed dehydrogenative borylation of primary and secondary C(sp3)-H bonds adjacent to a nitrogen atom.

    PubMed

    Murai, Masahito; Omura, Tetsuya; Kuninobu, Yoichiro; Takai, Kazuhiko

    2015-03-18

    Rhenium-catalysed C(sp(3))-H bond borylation in the absence of any oxidant, hydrogen acceptor, or external ligand, with the generation of H2 as the sole byproduct is described. The transformation, which represents a rare example of rhenium-catalysed C(sp(3))-H bond functionalisation, features high atom efficiency and simple reaction conditions. PMID:25688385

  3. Autoradiographic localization of nicotinic receptor binding in rat brain using (/sup 3/H)methylcarbamylcholine, a novel radioligand

    SciTech Connect

    Yamada, S.; Gehlert, D.R.; Hawkins, K.N.; Nakayama, K.; Roeske, W.R.; Yamamura, H.I.

    1987-12-28

    Light microscopic autoradiography was used to visualize the neuroanatomical distribution of nicotinic receptors in rat brain using a novel radioligand, (/sup 3/H)methylcarbamylcholine (MCC). Specific (/sup 3/H)MCC binding to slide-mounted tissue sections of rat brain was saturable, reversible and of high affinity. Data analysis revealed a single population of (/sup 3/H)MCC binding sites with a K/sub d/ value or 1.8 nM and B/sub max/ of 20.1 fmol/mg protein. Nicotinic agonists and antagonists competed for (/sup 3/H)MCC binding sites in slide-mounted brain sections with much greater potency than muscarinic drugs. The rat brain areas containing the highest densities of (/sup 3/H)MCC binding were in thalamic regions, the medial habenular nucleus and the superior colliculus. Moderate densities of (/sup 3/H)MCC binding were seen over the anterior cingulate cortex, the nucleus accumbens, the zona compacta of substantia nigra and ventral tegmental area. Low densities of (/sup 3/H)MCC binding were found in most other brain regions. These data suggest that (/sup 3/H)MCC selectively labels central nicotinic receptors and that these receptors are concentrated in the thalamus, the medial habenular nucleus and the superior colliculus of the rat brain. 29 references, 6 figures, 2 tables.

  4. ADME studies of [5-(3)H]-2'-O-methyluridine nucleoside in mice: a building block in siRNA therapeutics.

    PubMed

    Lozac'h, Frederic; Christensen, Jesper; Faller, Thomas; van de Kerkhof, Esther; Krauser, Joel; Garnier, Maxime; Litherland, Karine; Catoire, Alexandre; Natt, Francois; Hunziker, Jurg; Swart, Piet

    2016-02-01

    The chemical modification 2'-O-methyl of nucleosides is often used to increase siRNA stability towards nuclease activities. However, the metabolic fate of modified nucleosides remains unclear. Therefore, the aim of this study was to determine the mass balance, pharmacokinetic, and absorption, distribution, metabolism, and excretion (ADME)-properties of tritium-labeled 2'-O-methyluridine, following a single intravenous dose to male CD-1 mice. The single intravenous administration of [5-(3)H]-2'-O-methyluridine was well tolerated in mice. Radioactivity was rapidly and widely distributed throughout the body and remained detectable in all tissues investigated throughout the observation period of 48 h. After an initial rapid decline, blood concentrations of total radiolabeled components declined at a much slower rate. [(3)H]-2'-O-Methyluridine represented a minor component of the radioactivity in plasma (5.89% of [(3)H]-AUC 0-48 h). Three [(3)H]-2'-O-methyluridine metabolites namely uridine (M1), cytidine (M2), and uracil (M3) were the major circulating components representing 32.8%, 8.11%, and 23.6% of radioactivity area under the curve, respectively. The highest concentrations of total radiolabeled components and exposures were observed in kidney, spleen, pineal body, and lymph nodes. The mass balance, which is the sum of external recovery of radioactivity in excreta and remaining radioactivity in carcass and cage wash, was complete. Renal excretion accounted for about 52.7% of the dose with direct renal excretion of the parent in combination with metabolism to the endogenous compounds cytidine, uracil, cytosine, and cytidine. PMID:26977299

  5. Calcium-dependent (/sup 3/H)acetylcholine release and muscarinic autoreceptors in rat cortical synaptosomes during development

    SciTech Connect

    Marchi, M.; Caviglia, A.; Paudice, P.; Raiteri, M.

    1983-05-01

    A number of presynaptic cholinergic parameters (high affinity (/sup 3/H)choline uptake, (/sup 3/H)acetylcholine synthesis, (/sup 3/H)acetylcholine release, and autoinhibition of (/sup 3/H)acetylcholine release mediated by muscarinic autoreceptors) were comparatively analyzed in rat brain cortex synaptosomes during postnatal development. These various functions showed a differential time course during development. At 10 days of age the release of (/sup 3/H)acetylcholine evoked by 15 mM KCl from superfused synaptosomes was Ca/sup 2 +/-dependent but insensitive to the inhibitory action of extrasynaptosomal acetylcholine. The muscarinic autoreceptors regulating acetylcholine release were clearly detectable only at 14 days, indicating that their appearance may represent a criterion of synaptic maturation more valuable than the onset of a Ca/sup 2 +/-dependent release.

  6. Pre-optic and hypothalamic neurons accumulate [3H]medroxyprogesterone acetate in male cynomolgus monkeys.

    PubMed

    Rees, H D; Bonsall, R W; Michael, R P

    1986-10-13

    Medroxyprogesterone acetate (MPA) is a synthetic progestin that is reported to be effective in the treatment of paraphilic behavior, including paraphilic aggression, in men. The mechanisms and sites of action for its behavioral effects are not known. Thaw-mount autoradiography was used to help identify sites in the brain at which MPA may act in a male primate. Two adult, castrated male cynomolgus monkeys were administered [3H]MPA and killed one hour later. Radioactivity was concentrated in the nuclei of many neurons in the medial preoptic nucleus (n.), anterior hypothalamic area, ventromedial hypothalamic n., and arcuate n. Virtually no labeled cells were observed in the bed n. of the stria terminalis, lateral septal n., or amygdala. Analysis by high performance liquid chromatography of brain samples from the same animals demonstrated that 84% of the extractable radioactivity in cell nuclei from the hypothalamus and preoptic area was in the form of unmetabolized [3H]MPA. The localization of MPA-concentrating neurons in regions of the brain known to be implicated in regulating both sexual behavior and pituitary function suggests that, among other sites of action, MPA may act directly upon the brain. PMID:2945066

  7. Allosteric modulation of ligand binding to [3H](+)pentazocine-defined sigma recognition sites by phenytoin.

    PubMed

    DeHaven-Hudkins, D L; Ford-Rice, F Y; Allen, J T; Hudkins, R L

    1993-01-01

    The allosteric modulation of sigma recognition sites by phenytoin (diphenylhydantoin) has been demonstrated by the ability of phenytoin to stimulate binding of various [3H] sigma ligands, as well as to slow dissociation from sigma sites and to shift sigma sites from a low- to a high-affinity state. Phenytoin stimulated the binding of the sigma 1- selective ligand [3H](+)pentazocine in a dose-dependent manner. Stimulation of binding at a final concentration of 250 microM phenytoin was associated with a decrease in the KD. The affinities of the sigma reference compounds caramiphen, dextromethorphan, dextrophan, (+)3-PPP and (+)SKF-10,047 were three- to eight-fold higher, while the affinities of benzetimide, BMY-14802, carbetapentane, DTG and haloperidol were unchanged in the presence of 250 microM phenytoin. The relative sensitivity of sigma compounds to allosteric modulation by phenytoin is not a property of all sigma ligands, and may provide an in vitro basis for distinguishing actions of sigma compounds and predicting sigma effects in vivo. PMID:8515681

  8. ( sup 3 H)rauwolscine binding to myometrial. alpha. sub 2 -adrenoceptors in pregnant guinea pig

    SciTech Connect

    Arkinstall, S.J.; Jones, C.T. )

    1988-09-01

    Uterine sympathetic nerves can exert an excitatory influence in late pregnancy and during parturition. Neuronal norepinephrine release is increased at these times and a diminished {alpha}{sub 2}-adrenoceptor-mediated prejunctional inhibition could account for this. To assess whether an altered receptor population may contribute, ({sup 3}H)rauwolscine was used to measure {alpha}{sub 2}-adrenoceptors in myometrial membranes at time intervals throughout pregnancy. High affinity ({sup 3}H)rauwolscine binding yielded linear Scatchard plots that in nonpregnant myometrium indicated a maximum binding density B{sub max} of 217 {plus minus} 42.4 fmol/mg protein. {alpha}{sub 2}-Adrenoceptor density was increased twofold at midpregnancy (31 days) and thereafter fell sharply by up to 90% toward term (67 {plus minus} 2 days). When uterine growth is accounted for and data are expressed in terms of total myometrial population, {alpha}{sub 2}-adrenoceptor number was eightfold (midpregnancy) and fourfold (term) greater than the nonpregnant value of 804 {plus minus} 322.4 fmol/uterus. {alpha}{sub 2}-Adrenoceptors were also found to bind dopamine with high affinity. These observations could indicate a pregnancy-related change in uterine sympathetic autoinhibitory capacity and, since {alpha}{sub 2}-adrenoceptors appear also to be located postjunctionally, explain in part reports of altered myometrial responsiveness to norepinephrine infusion and also the uterotonic actions of dopamine.

  9. Synthesis and antitumor evaluation of trimethoxyanilides based on 4(3H)-quinazolinone scaffolds.

    PubMed

    Mohamed, Menshawy A; Ayyad, Rezk R; Shawer, Taghreed Z; Abdel-Aziz, Alaa A-M; El-Azab, Adel S

    2016-04-13

    A novel series of 2-[(3-substituted-4(3H)-quinazolin-2-yl)thio]-N-(3,4,5-trimethoxyphenyl)acetamide (15-21) and 3-[(3-substituted-4(3H)-quinazolin-2-yl)thio])-N-(3,4,5-trimethoxyphenyl)propanamide (23-29) were designed, prepared and estimated for their anticancer activity in a solo dose 10 μM of the test compounds in the NCI 57 cell lines panel assay. Compounds 20, 23, 26, 27 and 28 revealed extensive-spectrum antitumor efficiency to numerous cell lines that belong to various tumor subpanels, while compounds 15, 16 and 19 possessed perceptive activity toward A498 and UO-31 renal cancer cell lines, and compound 17 showed selective effectiveness against NSC lung cancer NCI-H522 cell line. Additionally, compound 18 showed advanced activity against SR leukemia cell line, NSC lung cancer HOP-92 and renal cancer UO-31 cell lines. PMID:26890117

  10. Visible spectrum photofragmentation of O3-(H2O)n, n ≤ 16

    NASA Astrophysics Data System (ADS)

    Lehman, Julia H.; Lineberger, W. Carl

    2014-10-01

    Photofragmentation of ozonide solvated in water clusters, O3-(H2O)n, n ≤ 16, has been studied as a function of photon energy as well as the degree of solvation. Using mass selection, the effect of the presence of the solvent molecule on the O3- photodissociation process is assessed one solvent molecule at a time. The O3- acts as a visible light chromophore within the water cluster, namely the O3-(H2O) total photodissociation cross-section exhibits generally the same photon energy dependence as isolated O3- throughout the visible wavelength range studied (430-620 nm). With the addition of a single solvent molecule, new photodissociation pathways are opened, including the production of recombined O3-. As the degree of solvation of the parent anion increases, recombination to O3--based products accounts for close to 40% of photoproducts by n = 16. The remainder of the photoproducts exist as O--based; no O2--based products are observed. Upper bounds on the O3- solvation energy (530 meV) and the O--OO bond dissociation energy in the cluster (1.06 eV) are derived.

  11. Synthesis and β-glucuronidase inhibitory activity of 2-arylquinazolin-4(3H)-ones.

    PubMed

    Khan, Khalid Mohammed; Saad, Syed Muhammad; Shaikh, Nimra Naveed; Hussain, Shafqat; Fakhri, Muhammad Imran; Perveen, Shahnaz; Taha, Muhammad; Choudhary, Muhammad Iqbal

    2014-07-01

    2-Arylquinazolin-4(3H)-ones 1-25 were synthesized by reacting anthranilamide with various benzaldehydes using CuCl2·2H2O as a catalyst in ethanol under reflux. Synthetic 2-arylquinazolin-4(3H)-ones 1-25 were evaluated for their β-glucuronidase inhibitory potential. A trend of inhibition IC50 against the enzyme in the range of 0.6-198.2μM, was observed and compared with the standard d-saccharic acid 1,4-lactone (IC50=45.75±2.16μM). Compounds 13, 19, 4, 12, 14, 22, 23, 25, 15, 8, 17, 11, 21, 1, 3, 18, 9, 2, and 24 with the IC50 values within the range of 0.6-44.0μM, indicated that the compounds have superior activity than the standard. The compounds showed no cytotoxic effects against PC-3 cells. A structure-activity relationship is established. PMID:24844756

  12. Nuclear structure corrections to the Lamb shift in μHe3+ and μ3H

    NASA Astrophysics Data System (ADS)

    Nevo Dinur, N.; Ji, C.; Bacca, S.; Barnea, N.

    2016-04-01

    Measuring the 2S-2P Lamb shift in a hydrogen-like muonic atom allows one to extract its nuclear charge radius with a high precision that is limited by the uncertainty in the nuclear structure corrections. The charge radius of the proton thus extracted was found to be 7σ away from the CODATA value, in what has become the yet unsolved "proton radius puzzle". Further experiments currently aim at the isotopes of hydrogen and helium: the precise extraction of their radii may provide a hint at the solution of the puzzle. We present the first ab initio calculation of nuclear structure corrections, including the nuclear polarization correction, to the 2S-2P transition in μHe3+ and μ3H, and assess solid theoretical error bars. Our predictions reduce the uncertainty in the nuclear structure corrections to the level of a few percent and will be instrumental to the on-going μHe3+ experiment. We also support the mirror μ3H system as a candidate for further probing of the nucleon polarizabilities and shedding more light on the puzzle.

  13. Effect of pressure on (/sup 3/H)GABA release by synaptosomes isolated from cerebral cortex

    SciTech Connect

    Gilman, S.C.; Colton, J.S.; Hallenbeck, J.M.

    1986-12-01

    High hydrostatic pressure has been shown to produce neurological changes in humans which manifest, in part, as tremor, myoclonic jerks, electroencephalographic changes, and convulsions. This clinical pattern has been termed high-pressure nervous syndrome (HPNS). These symptoms may represent an alteration in synaptic transmission in the central nervous system with the inhibitory neural pathways being affected in particular. Since gamma-aminobutyric acid (GABA) transmission has been implicated in other seizure disorders, it was of interest to study GABAergic function at high pressure. Isolated synaptosomes were used to follow GABA release at 67.7 ATA of pressure. The major observation was a 33% depression in total (/sup 3/H)GABA efflux from depolarized cerebrocortical synaptosomes at 67.7 ATA. The Ca2+-dependent component of release was found to be completely blocked during the 1st min of (/sup 3/H)GABA efflux with a slow rise over the subsequent 3 min. These findings lead us to conclude that high pressure interferes with the intraterminal cascade for Ca2+-dependent release of GABA.

  14. Effects of bromocriptine on (/sup 3/H)estradiol binding in cytosol of anterior pituitary

    SciTech Connect

    De Nicola, A.F.; Weisenberg, L.S.; Arakelian, M.C.; Libertun, C.

    1981-07-01

    The hypothalamus may control hormone receptors in the anterior pituitary either by a direct trophic effect or indirectly by regulation of serum pituitary hormone levels. Rats whose medial basal hypothalamus had been destroyed in order to suppress neural control of the gland showed a reduction in (/sup 3/H)estradiol binding in the anterior pituitary and high serum PRL levels; both changes were reversed by treatment of the lesioned rats with daily injections of bromocriptine, a dopamine agonist. In nonlesioned animals, the same treatment did not modify significantly those parameters. In another hyperprolactinemic model (rats with anterior pituitaries transplanted under the kidney capsule), (/sup 3/H)estradiol binding by the in situ pituitaries of the host rats was similar to that in the nongrafted controls. These results suggest that changes due to median eminence lesion are reversible and that bromocriptine is able to act as a substitutive therapy which restores binding of estradiol in glands whose receptors have been decreased by the effect of the lesion. High PRL levels due to pituitary transplant do not account for the observed changes in the pituitary estradiol binding.

  15. 2-Arylquinazolin-4(3H)-ones: Inhibitory Activities Against Xanthine Oxidase.

    PubMed

    Zafar, Humaira; Saad, Syed M; Perveen, Shahnaz; Arshia; Malik, Rizwana; Khan, Ajmal; Khan, Khalid M; Choudhary, Muhammad I

    2016-01-01

    2-Arylquinazolin-4(3H)-ones (1-25) were synthesized, and evaluated for their xanthine oxidase inhibitory activity. Significant to moderate activities were exhibited by the compounds 1-3, 7, 9, 13-15, 19-21, and 23 with IC50 between 2.80 - 28.13 µM as compared to the standard allopurinol (IC50 (IC50 = 2.01 ± 0.01 µM). Compounds 4-6, 8, 11-12, 16-18, 22, and 24 demonstrated a weak activity with IC50 values 44.60 - 112.60 µM. Nonetheless, compounds 10 and 25 did not show any activity. Amongst all derivatives, compound 2, containing a C-4´ dimethylamino group, was the most potent inhibitor of the enzyme with an IC50 value comparable to the standard. Kinetics studies on the most active compounds (2, 7, 9, 14, 15, 19, and 20) were conducted in order to determine their modes of inhibition and dissociation constants Ki. Some of the compounds of 2-arylquinazolin-4(3H)-one series were thus identified as potential leads for further studies towards the treatment of hyperuricemia and gout. PMID:26256588

  16. H3(+) + H2 isotopic system at low temperatures: microcanonical model and experimental study.

    PubMed

    Hugo, Edouard; Asvany, Oskar; Schlemmer, Stephan

    2009-04-28

    State-to-state thermal rate coefficients for reactions of all H(3)(+) + H(2) isotopic variants are derived and compared to new experimental data. The theoretical data are also sought for astrochemical modeling of cold environments (<50 K). The rates are calculated on the basis of a microcanonical approach using the Langevin model and the conservation laws of mass, energy, angular momentum, and nuclear spin. Full scrambling of all five nuclei during the collision is assumed for the calculations and alternatively partial dynamical restrictions are considered. The ergodic principle of the collision is employed in two limiting cases, neglecting (weak ergodic limit) or accounting for explicit degeneracies of the reaction mechanisms (strong ergodic limit). The resulting sets of rate coefficients are shown to be consistent with the detailed balance and thermodynamical equilibrium constants. Rate coefficients, k(T), for the deuteration chain of H(3)(+) with HD as well as H(2)D(+)/H(3)(+) equilibrium ratios have been measured in a variable temperature 22-pole ion trap. In particular, the D(2)H(+) + HD --> D(3)(+) + H(2) rate coefficient indicates a change in reaction mechanism when going to higher temperatures. The good overall agreement between experiment and theory encourages the use of the theoretical predictions for astrophysical modeling. PMID:19405574

  17. Removal rate of ( sup 3 H)hyaluronan injected subcutaneously in rabbits

    SciTech Connect

    Reed, R.K.; Laurent, U.B.; Fraser, J.R.; Laurent, T.C. )

    1990-08-01

    Hyaluronan is an important constituent of the extracellular matrix in skin, and recent studies suggest that there is a pool of easily removable (free) hyaluronan drained by lymph. The removal rate of free hyaluronan in skin was measured from the elimination of ({sup 3}H)hyaluronan, injected subcutaneously in 13 rabbits. The removal of radioactivity was determined from appearance of {sup 3}H in plasma. During the first 24 h after injection, 10-87% of the tracer entered blood, less in injectates with high concentrations of hyaluronan. The removal was monoexponential with a half-life of 0.5-1 day when concentration of hyaluronan was 5 mg/ml or less. When hyaluronan concentration was 10 mg/ml or higher, the removal was slow for about 24 h and then became similar to that in experiments with low hyaluronan concentration. Free hyaluronan at physiological concentrations is thus turned over with the same rate as serum albumin, supporting the concept that hyaluronan is removed essentially by lymph flow to be degraded in lymph nodes and liver.

  18. Spin polarization effects in the /sup 3/H(d,n)/sup 4/He fusion reaction

    SciTech Connect

    Conzett, H.E.; Rioux, C.

    1985-06-01

    A recent investigation has shown that the /sup 3/H(d,n)/sup 4/He fusion reaction rate could be enhanced by a factor of 3/2 if the fusion plasma consisted of both polarized deuterons and tritons, forming exclusively the channel-spin S = 3/2, J = 3/2/sup +/ state. This result follows simply from the statistical weights of the quartet S = 3/2 and doublet S = 1/2 initial states, with the assumption of the single J = 3/2/sup +/ reaction amplitude. Since, with a small but nonzero J = 1/2/sup +/ amplitude, the maximum enhancement of the reaction occurs at the peak of the J = 3/2/sup +/ resonance, corresponding to a deuteron lab energy of 107 keV, it is of obvious interest to know what the enhancement would be at the lower energies that are typical of fusion plasmas. We are able to address this question by extending earlier calculations which gave the values of all of the spin-polarization observables at this J = 3/2/sup +/ resonance in both the /sup 3/H(d,n)/sup 4/He and the /sup 3/He(d,p)/sup 4/He reactions.

  19. Repeated resveratrol treatment attenuates methamphetamine-induced hyperactivity and [3H]dopamine overflow in rodents.

    PubMed

    Miller, Dennis K; Oelrichs, Clark E; Sage, Andrew S; Sun, Grace Y; Simonyi, Agnes

    2013-10-25

    Resveratrol (3,4',5-trihydroxy-trans-stilbene) has been investigated for its potential as a prophylactic against degenerative diseases. It is a sirtulin activator that has recently been shown to regulate dopaminergic systems that contribute to the behavioral effects of methamphetamine and cocaine. The present study examined the impact of resveratrol on stimulant neuropsychopharmacology in rodents. Acute resveratrol treatment (20-40mg/kg) was ineffective to alter methamphetamine (0.5mg/kg)-induced hyperactivity in mice. Rodents received resveratrol once-daily for seven days to determine the effect of repeated polyphenolic treatment. Repeated resveratrol treatment (1-20mg/kg) decreased methamphetamine (0.5mg/kg)-induced hyperactivity in mice. Methamphetamine's (0.1-60μM) efficacy to evoke [(3)H]overflow from rat striatal slices preloaded with [(3)H]dopamine was also attenuated by repeated resveratrol (1mg/kg) treatment. Repeated resveratrol treatment (10-20mg/kg) did not affect cocaine-induced hyperactivity in mice. Overall, these data suggest that resveratrol appears to have metaplastic and prophylactic activity to minimize the effects of methamphetamine to increase locomotor activity and evoke dopamine release. These data encourage future research to further investigate the relationship between polyphenolics and psychostimulant abuse and dependence. PMID:24012682

  20. Periodic cages.

    PubMed

    Diudea, Mircea V; Nagy, Csaba L; Silaghi-Dumitrescu, Ioan; Graovac, Ante; Janezic, Dusanka; Vikić-Topić, Drazen

    2005-01-01

    Various cages are constructed by using three types of caps: f-cap (derived from spherical fullerenes by deleting zones of various size), kf-cap (obtainable by cutting off the polar ring, of size k), and t-cap ("tubercule"-cap). Building ways are presented, some of them being possible isomerization routes in the real chemistry of fullerenes. Periodic cages with ((5,7)3) covering are modeled, and their constitutive typing enumeration is given. Spectral data revealed some electronic periodicity in fullerene clusters. Semiempirical and strain energy calculations complete their characterization. PMID:15807490

  1. Axon reaction in hypoglossal and dorsal motor vagal neurons of adult rat: incorporation of (3H)leucine

    SciTech Connect

    Aldskogius, H.; Barron, K.D.; Regal, R.

    1984-07-01

    Pairs of adult rats received (/sup 3/H)leucine 0.25, 1, and 16 h before killing and zero to 164 days after unilateral cervical vagotomy and hypoglossal neurotomy. Grain counts and morphometric measurements were made on axotomized and uninjured neurons in histoautoradiographs of the medullary nuclei. Axotomized hypoglossal neurons, which largely survive the injury, both enlarged and incorporated increased amounts of tritiated leucine at each labeling interval, 3 through 28 days postoperatively. In the vagal dorsal motor nucleus (DMN), axotomized cells, which frequently die after neurotomy, enlarged slightly through 28 days postoperatively, then atrophied; DMN neurons increased amino acid uptake for a shorter period (days 7 through 14) than hypoglossal neurons. Axotomized DMN neurons did not sustain increased protein synthesis as long as their hypoglossal counterparts and seemed to fail to increase synthesis of structural proteins with long half-lives (16-h labeling interval). The frequently necrobiotic response of axotomized DMN neurons may relate to these phenomena. From these and earlier results, the authors conclude that axon reaction appears to differ fundamentally in peripheral and central neurons. This difference may have significance for research on regeneration in the central nervous system.

  2. Structure of Complement C3(H2O) Revealed By Quantitative Cross-Linking/Mass Spectrometry And Modeling.

    PubMed

    Chen, Zhuo A; Pellarin, Riccardo; Fischer, Lutz; Sali, Andrej; Nilges, Michael; Barlow, Paul N; Rappsilber, Juri

    2016-08-01

    The slow but spontaneous and ubiquitous formation of C3(H2O), the hydrolytic and conformationally rearranged product of C3, initiates antibody-independent activation of the complement system that is a key first line of antimicrobial defense. The structure of C3(H2O) has not been determined. Here we subjected C3(H2O) to quantitative cross-linking/mass spectrometry (QCLMS). This revealed details of the structural differences and similarities between C3(H2O) and C3, as well as between C3(H2O) and its pivotal proteolytic cleavage product, C3b, which shares functionally similarity with C3(H2O). Considered in combination with the crystal structures of C3 and C3b, the QCMLS data suggest that C3(H2O) generation is accompanied by the migration of the thioester-containing domain of C3 from one end of the molecule to the other. This creates a stable C3b-like platform able to bind the zymogen, factor B, or the regulator, factor H. Integration of available crystallographic and QCLMS data allowed the determination of a 3D model of the C3(H2O) domain architecture. The unique arrangement of domains thus observed in C3(H2O), which retains the anaphylatoxin domain (that is excised when C3 is enzymatically activated to C3b), can be used to rationalize observed differences between C3(H2O) and C3b in terms of complement activation and regulation. PMID:27250206

  3. Presynaptic GABAB Autoreceptor Regulation of Nicotinic Acetylcholine Receptor Mediated [3H]-GABA Release from Mouse Synaptosomes

    PubMed Central

    McClure-Begley, Tristan D.; Grady, Sharon R.; Marks, Michael J.; Collins, Allan C.; Stitzel, Jerry A.

    2014-01-01

    Activation of nicotinic acetylcholine receptors (nAChRs) can elicit neurotransmitter release from presynaptic nerve terminals. Mechanisms contributing to cell-and-terminal specific regulation of nAChR-mediated neurotransmitter exocytosis are not fully understood. The experiments discussed here examine how activation of GABAB auto- and hetero-receptors suppress nAChR-mediated release of [3H]-GABA and [3H]-dopamine (3H-DA) from mouse striatal synaptosomes. Activation of presynaptic GABAB receptors with (R)-baclofen decreased both [3H]-GABA and [3H]-DA release evoked by potassium depolarization. However, when nAChRs were activated with ACh to evoke neurotransmitter release, (R)-baclofen had no effect on [3H]-DA release, but potently inhibited ACh-evoked [3H]-GABA release. Inhibition of nAChR-evoked [3H]-GABA release by (R)-baclofen was time sensitive and the effect was lost after prolonged exposure to the GABAB agonist. The early inhibitory effect of GABA activation on ACh-evoked [3H]-GABA release was partially attenuated by antagonists of the phosphatase, calcineurin. Furthermore, antagonists of protein kinase C (PKC) prevented the time-dependent loss of the inhibitory (R)-baclofen effect on [3H]-GABA release. These results suggest that α4β2*-nAChRs present on GABAergic nerve terminals in the striatum are subject to functional regulation by GABAB autoreceptors that is apparently cell-type specific, since it is absent from DAergic striatal nerve terminals. In addition, the functional modulation of α4β2*-type nAChRs on striatal GABAergic nerve terminals by GABAB autoreceptor activation is time-sensitive and appears to involve opposing actions of calcineurin and PKC. PMID:24953818

  4. Structure of Complement C3(H2O) Revealed By Quantitative Cross-Linking/Mass Spectrometry And Modeling*

    PubMed Central

    Pellarin, Riccardo; Sali, Andrej; Barlow, Paul N.

    2016-01-01

    The slow but spontaneous and ubiquitous formation of C3(H2O), the hydrolytic and conformationally rearranged product of C3, initiates antibody-independent activation of the complement system that is a key first line of antimicrobial defense. The structure of C3(H2O) has not been determined. Here we subjected C3(H2O) to quantitative cross-linking/mass spectrometry (QCLMS). This revealed details of the structural differences and similarities between C3(H2O) and C3, as well as between C3(H2O) and its pivotal proteolytic cleavage product, C3b, which shares functionally similarity with C3(H2O). Considered in combination with the crystal structures of C3 and C3b, the QCMLS data suggest that C3(H2O) generation is accompanied by the migration of the thioester-containing domain of C3 from one end of the molecule to the other. This creates a stable C3b-like platform able to bind the zymogen, factor B, or the regulator, factor H. Integration of available crystallographic and QCLMS data allowed the determination of a 3D model of the C3(H2O) domain architecture. The unique arrangement of domains thus observed in C3(H2O), which retains the anaphylatoxin domain (that is excised when C3 is enzymatically activated to C3b), can be used to rationalize observed differences between C3(H2O) and C3b in terms of complement activation and regulation. PMID:27250206

  5. Sequestration and microsomal C-25 hydroxylation of (/sup 3/H)-vitamin D3 by the rat liver

    SciTech Connect

    Gascon-Barre, M.; Elbaz, H.; Therrien-Ferland, D.

    1985-03-01

    A study of the vitamin D3 (D3) 25-hydroxylase was undertaken in an in vivo-in vitro model. (/sup 3/H)-D3 (0.7, 1.0, 10, or 100 nmol/100 g of body weight) was injected into the portal vein and the liver was excised 18 seconds later. The liver homogenate was then submitted to differential centrifugation and the amount of (/sup 3/H)-D3 incorporated in the subcellular fractions was evaluated. The microsomal fraction was also incubated in vitro and the appearance of (/sup 3/H)-25-hydroxyvitamin D3 (25(OH)D3) was determined by high performance liquid chromatography (HPLC). Results showed that the fractional liver (/sup 3/H)-D3 uptake varied between 37 percent and 48 percent of the dose injected. The intracellular distribution of (/sup 3/H)-D3 showed that most of the vitamin was incorporated into the microsomal fraction (45% to 50% of the intracellular (/sup 3/H)-D3) except at the highest dose of (/sup 3/H)-D3 where the cytosolic fraction contained the highest amount (56.4%) of the incorporated vitamin. Mathematical analysis of the intracellular (/sup 3/H)-D3 distribution showed that the microsomal fraction was the only subcellular fraction that was found to incorporate (/sup 3/H)-D3 in relation to the total liver uptake of the vitamin. The apparent Michaelis-Menten kinetics of the (/sup 3/H)-D3-25-hydroxylase showed that with substrate concentration of up to 88.5 nM, the apparent Km and Vmax were 28.2 nM and 25.8 fentomoles (fmol) X min-1 X mg microsomal pro-1, respectively, but the reaction lost considerable efficiency with higher substrate concentrations.

  6. A novel radioligand for the ATP-gated ion channel P2X7: [3H] JNJ-54232334.

    PubMed

    Lord, Brian; Ameriks, Michael K; Wang, Qi; Fourgeaud, Lawrence; Vliegen, Maarten; Verluyten, Willy; Haspeslagh, Pieter; Carruthers, Nicholas I; Lovenberg, Timothy W; Bonaventure, Pascal; Letavic, Michael A; Bhattacharya, Anindya

    2015-10-15

    The ATP-gated ion channel P2X7 has emerged as a potential central nervous system (CNS) drug target based on the hypotheses that pro-inflammatory cytokines such as IL-1β that are released by microglia, may contribute to the etiology of various disorders of the CNS including depression. In this study, we identified two closely related P2X7 antagonists, JNJ-54232334 and JNJ-54140515, and then tritium labeled the former to produce a new radioligand for P2X7. JNJ-54232334 is a high affinity ligand for the rat P2X7 with a pKi of 9.3±0.1. In rat cortical membranes, [3H] JNJ-54232334 reached saturable binding with equilibrium dissociation (Kd) constant of 4.9±1.3 nM. The compound displayed monophasic association and dissociation kinetics with fast on and off rates. In rat brain sections, specific binding of [3H] JNJ-54232334 was markedly improved compared to the previously described P2X7 radioligand, [3H] A-804598. In P2X7 knockout mouse brain sections, [3H] A-804598 bound to non-P2X7 binding sites in contrast to [3H] JNJ-54232334. In rat or wild type mouse brain sections [3H] JNJ-54232334 bound in a more homogenous and region independent manner. The ubiquitous expression of P2X7 receptors was confirmed with immunohistochemistry in rat brain sections. The partial displacement of [3H] A-804598 binding resulted in the underestimation of the level of ex vivo P2X7 occupancy for JNJ-54140515. Higher levels of P2X7 ex vivo occupancy were measured using [3H] JNJ-54232334 due to less non-specific binding. In summary, we describe [3H] JNJ-54232334 as a novel P2X7 radioligand, with improved properties over [3H] A-804598. PMID:26386289

  7. Steroid hormone modulation of 3H-prostaglanding E1 binding to bovine corpus leteum cell membranes.

    PubMed

    Rao, C V

    1975-04-01

    The specific binding of 3H-prostaglandin E1 (3H-PGE1) to bovine corpus luteum cell membranes was not affected by cholesterol or various progestins at concentrations of up to 9.0x10-minus-6M. At concentrations above 2.5 x 10-minus-6M; estrone, 17beta-estradiol (but not 17alpha-estradiol or 17beta-estradiol glucuronide), estroil, equilin, D-equilenin, 17-ethynyl estradiol, diethylstilbestrol, cortisol, corticosterone, deoxycorticosterone and aldosterone inhibited specific binding of 3H-PGE1. On the other hand, testosterone and dihydrotestosterone (DHT) (but not androstenedione) significantly enhanced 3H-PGE1 binding. These findings permitted the following correlations between steroid structure and modulation of 3H-PGE1 binding: steroids with a free phenolic ring and a 17beta-hydroxyl or 17-keto group or C-21 steroids with a C-20 ketone and a C-21 hydroxy group decrease, whereas C-19 steroids with a C-17 hydroxy group enhance specific binding of 3H-PGE1. PGE receptors are heterogeneous with respect to affinity for 3H-PGE1. The steroids that decreased 3H-PGE1 binding caused a lowering to a complete loss of low affinity PGE receptors. Steroids that increased 3H-PGE1 binding caused appearance of new low affinity PGE receptors. Association rate constants for 3H-PGE1 binding were decreased by 17beta-estradiol (61%) and increased by DHT (59%). PMID:168618

  8. Development of mRuby2-Transfected C3H10T1/2 Fibroblasts for Musculoskeletal Tissue Engineering

    PubMed Central

    Yang, Yunzhi Peter

    2015-01-01

    Mouse C3H10T1/2 fibroblasts are multipotent, mesenchymal stem cell (MSC)-like progenitor cells that are widely used in musculoskeletal research. In this study, we have established a clonal population of C3H10T1/2 cells stably-transfected with mRuby2, an orange-red fluorescence reporter gene. Flow cytometry analysis and fluorescence imaging confirmed successful transfection of these cells. Cell counting studies showed that untransfected C3H10T1/2 cells and mRuby2-transfected C3H10T1/2 cells proliferated at similar rates. Adipogenic differentiation experiments demonstrated that untransfected C3H10T1/2 cells and mRuby2-transfected C3H10T1/2 cells stained positive for Oil Red O and showed increased expression of adipogenic genes including adiponectin and lipoprotein lipase. Chondrogenic differentiation experiments demonstrated that untransfected C3H10T1/2 cells and mRuby2-transfected C3H10T1/2 cells stained positive for Alcian Blue and showed increased expression of chondrogenic genes including aggrecan. Osteogenic differentiation experiments demonstrated that untransfected C3H10T1/2 cells and mRuby2-transfected C3H10T1/2 cells stained positive for alkaline phosphatase (ALP) as well as Alizarin Red and showed increased expression of osteogenic genes including alp, ocn and osf-1. When seeded on calcium phosphate-based ceramic scaffolds, mRuby2-transfected C3H10T1/2 cells maintained even fluorescence labeling and osteogenic differentiation. In summary, mRuby2-transfected C3H10T1/2 cells exhibit mRuby2 fluorescence and showed little-to-no difference in terms of cell proliferation and differentiation as untransfected C3H10T1/2 cells. These cells will be available from American Type Culture Collection (ATCC; CRL-3268™) and may be a valuable tool for preclinical studies. PMID:26407291

  9. Development of mRuby2-Transfected C3H10T1/2 Fibroblasts for Musculoskeletal Tissue Engineering.

    PubMed

    Ker, Dai Fei Elmer; Sharma, Rashmi; Wang, Evelyna Tsi Hsin; Yang, Yunzhi Peter

    2015-01-01

    Mouse C3H10T1/2 fibroblasts are multipotent, mesenchymal stem cell (MSC)-like progenitor cells that are widely used in musculoskeletal research. In this study, we have established a clonal population of C3H10T1/2 cells stably-transfected with mRuby2, an orange-red fluorescence reporter gene. Flow cytometry analysis and fluorescence imaging confirmed successful transfection of these cells. Cell counting studies showed that untransfected C3H10T1/2 cells and mRuby2-transfected C3H10T1/2 cells proliferated at similar rates. Adipogenic differentiation experiments demonstrated that untransfected C3H10T1/2 cells and mRuby2-transfected C3H10T1/2 cells stained positive for Oil Red O and showed increased expression of adipogenic genes including adiponectin and lipoprotein lipase. Chondrogenic differentiation experiments demonstrated that untransfected C3H10T1/2 cells and mRuby2-transfected C3H10T1/2 cells stained positive for Alcian Blue and showed increased expression of chondrogenic genes including aggrecan. Osteogenic differentiation experiments demonstrated that untransfected C3H10T1/2 cells and mRuby2-transfected C3H10T1/2 cells stained positive for alkaline phosphatase (ALP) as well as Alizarin Red and showed increased expression of osteogenic genes including alp, ocn and osf-1. When seeded on calcium phosphate-based ceramic scaffolds, mRuby2-transfected C3H10T1/2 cells maintained even fluorescence labeling and osteogenic differentiation. In summary, mRuby2-transfected C3H10T1/2 cells exhibit mRuby2 fluorescence and showed little-to-no difference in terms of cell proliferation and differentiation as untransfected C3H10T1/2 cells. These cells will be available from American Type Culture Collection (ATCC; CRL-3268™) and may be a valuable tool for preclinical studies. PMID:26407291

  10. In vivo metabolism of [3H]equilin in the pregnant mare.

    PubMed

    Bhavnani, B R; Woolever, C A

    1981-01-01

    [3H]Equilin [3H-labeled 3-hydroxy-1,3,5(10), 7-estratetraen-17-one] was administered iv to a pregnant mare in the 10th month of gestation. Maternal urine was collected for 3 days, and blood samples were taken 35 min and 3, 6, 12, and 24 h after the injection. The half-life of the disappearance of radioactivity from the blood was approximately 2.5 h. Over 90% of the administered dose was excreted in the first 24 h. The urine was extracted, hydrolyzed, and fractionated. The bulk of the radioactive material (75%) was present in the phenolic sulfate fraction from which radiochemically pure equilin, equilenin [3-hydroxy-1,3,5(10),6,8-estrapentaen-17-one], 17 alpha-dihydroequilin [1,3,5(10), 7-estratetraen-3,17 alpha-diol], 17 beta-dihydroequilin [1,3,5-(10,7-estratetraen-3,17 beta-diol], 17 alpha-dihydroequilenin [1,3,5(10),6,8-estrapentaen-3,17 alpha-diol], and 17 beta-dihydroequilenin [1,3,5(10),6,8-estrapentaen-3,17 beta-diol] were isolated and identified. Except for equilenin, the above-named steroids were also isolated and identified from the glucuronide fraction. Along with these estrogens, the two classical estrogens, estrone and 17 alpha-estradiol, were also isolated, but both of these estrogens were devoid of any radioactivity. These results indicate that 1) the B ring unsaturated estrogens are not metabolized to the B ring saturated estrogens (classical estrogens), 2) all of the B ring unsaturated estrogens isolated and identified from the pregnant mare's urine are metabolites of equilin, 3) the major metabolite of equilin excreted in the urine was equilin sulfate, 4) from the specific activity of the isolated equilin sulfate and the amount of [3H]equilin injected, the secretion rate of equilin was calculated to be 96 mg/24 h, and 5) the major reduced metabolites of equilin are the biologically less active 17 alpha-reduced products. PMID:7460819

  11. Periodic Polymers

    NASA Astrophysics Data System (ADS)

    Thomas, Edwin

    2013-03-01

    Periodic polymers can be made by self assembly, directed self assembly and by photolithography. Such materials provide a versatile platform for 1, 2 and 3D periodic nano-micro scale composites with either dielectric or impedance contrast or both, and these can serve for example, as photonic and or phononic crystals for electromagnetic and elastic waves as well as mechanical frames/trusses. Compared to electromagnetic waves, elastic waves are both less complex (longitudinal modes in fluids) and more complex (longitudinal, transverse in-plane and transverse out-of-plane modes in solids). Engineering of the dispersion relation between wave frequency w and wave vector, k enables the opening of band gaps in the density of modes and detailed shaping of w(k). Band gaps can be opened by Bragg scattering, anti-crossing of bands and discrete shape resonances. Current interest is in our group focuses using design - modeling, fabrication and measurement of polymer-based periodic materials for applications as tunable optics and control of phonon flow. Several examples will be described including the design of structures for multispectral band gaps for elastic waves to alter the phonon density of states, the creation of block polymer and bicontinuous metal-carbon nanoframes for structures that are robust against ballistic projectiles and quasi-crystalline solid/fluid structures that can steer shock waves.

  12. In vivo labeling of nicotinic cholinergic receptors in brain with [3H]cytisine.

    PubMed

    Flesher, J E; Scheffel, U; London, E D; Frost, J J

    1994-01-01

    [3H]Cytisine was evaluated as an in vivo ligand for the nicotinic cholinergic receptor (nAchR) in mouse brain. The tracer was injected intravenously, and radioactivity in brain regions was analyzed. Radioactivity peaked in the brain at 30 minutes. It was highest in the thalamus, intermediate in the superior colliculi, prefrontal cortex and hippocampus, and low in the cerebellum. Pretreatment with unlabeled cytisine inhibited binding in the thalamus, but not in the cerebellum. Binding was displaced by l-nicotine, but not by d-nicotine or dexetimide. The results suggest that cytisine, appropriately labeled with a positron emitting radionuclide, may be useful for study of nicotinic cholinergic receptors in humans by emission computed tomography. PMID:8196506

  13. The dynamic transfer of 3H and 14C in mammals: a proposed generic model.

    PubMed

    Galeriu, D; Melintescu, A; Beresford, N A; Takeda, H; Crout, N M J

    2009-02-01

    Associated with the present debate regarding the potential revival of nuclear energy there is an increased interest in assessing the radiological risk to the public and also the environment. Tritium and (14)C are key radionuclides of interest in many circumstances (e.g. heavy water reactors, waste storage and fusion reactors). Because the stable analogues of these two radionuclides are integral to most biological compounds, their modelling should follow general principles from life sciences. In this paper, a model of the dynamics of (14)C and (3)H in mammals is proposed on the basis of metabolic understanding and of, as far as possible, readily available data (e.g. for organ composition and metabolism). The model is described together with validation tests (without calibration) for a range of farm animals. Despite simplifications, the model tests are encouraging for a range of animal types and products (tissues and milk), and further improvements are suggested. PMID:18830702

  14. Threshold groundwater ages and young water fractions estimated from 3H, 3He, and 14C

    NASA Astrophysics Data System (ADS)

    Kirchner, James; Jasechko, Scott

    2016-04-01

    It is widely recognized that a water sample taken from a running stream is not described by a single age, but rather by a distribution of ages. It is less widely recognized that the same principle holds true for groundwaters, as indicated by the commonly observed discordances between model ages obtained from different tracers (e.g., 3H vs 14C) in the same sample. Water age distributions are often characterized by their mean residence times (MRT's). However, MRT estimates are highly uncertain because they depend on the shape of the assumed residence time distribution (in particular on the thickness of the long-time tail), which is difficult or impossible to constrain with data. Furthermore, because MRT's are typically nonlinear functions of age tracer concentrations, they are subject to aggregation bias. That is, MRT estimates derived from a mixture of waters with different ages (and thus different tracer concentrations) will systematically underestimate the mixture's true mean age. Here, building on recent work with stable isotope tracers in surface waters [1-3], we present a new framework for using 3H, 3He and 14C to characterize groundwater age distributions. Rather than describing groundwater age distributions by their MRT, we characterize them by the fraction of the distribution that is younger or older than a threshold age. The threshold age that separates "young" from "old" water depends on the characteristics of the specific tracer, including its history of atmospheric inputs. Our approach depends only on whether a given slice of the age distribution is younger or older than the threshold age, but not on how much younger or older it is. Thus our approach is insensitive to the tails of the age distribution, and is therefore relatively unaffected by uncertainty in the distribution's shape. Here we show that concentrations of 3H, 3He, and 14C are almost linearly related to the fractions of water that are younger or older than specified threshold ages. These

  15. Crystal structure of 3-amino-2-propyl­quinazolin-4(3H)-one

    PubMed Central

    El-Hiti, Gamal A.; Smith, Keith; Hegazy, Amany S.; Alanazi, Saud A.; Kariuki, Benson M.

    2015-01-01

    In the title mol­ecule, C11H13N3O, the propyl group is almost perpendicular to the quinazolin-4(3H)-one mean plane, making a dihedral angle of 88.98 (9)°. In the crystal, mol­ecules related by an inversion centre are paired via π–π overlap, indicated by the short distances of 3.616 (5) and 3.619 (5) Å between the centroids of the aromatic rings of neighbouring mol­ecules. Inter­molecular N—H⋯N and N—H⋯O hydrogen bonds form R 6 6(30) rings and C(5) chains, respectively, generating a three-dimensional network. Weak C—H⋯O inter­actions are also observed. PMID:26396813

  16. Polarization Transfer in 4He(e-vector,e[prime]p-vector)3H

    SciTech Connect

    Michael Paolone

    2007-10-01

    Polarization transfer in quasi-elastic nucleon knockout is sensitive to the properties of the nucleon in the nuclear medium, including possible modification of the nucleon form factor and/or spinor. In our recently completed experiment E03-104 at Jefferson Lab we measured the proton recoil polarization in the 4He(e-vector,e[prime]p-vector)3H reaction at a Q2 of 0.8 (GeV/c)2 and 1.3 (GeV/c)2 with unprecedented precision. These data complement earlier data between 0.4 and 2.6 (GeV/c)2 from both Mainz and Jefferson Lab, in which the measured ratio of polarization-transfer coefficients differs from a fully relativistic DWIA calculation. Preliminary results hint at a possible unexpected Q2 dependence in the polarization transfer coefficient ratio. Final analysis will help constrain FSI models

  17. Structure-Activity Relationship for the 4(3H)-Quinazolinone Antibacterials.

    PubMed

    Bouley, Renee; Ding, Derong; Peng, Zhihong; Bastian, Maria; Lastochkin, Elena; Song, Wei; Suckow, Mark A; Schroeder, Valerie A; Wolter, William R; Mobashery, Shahriar; Chang, Mayland

    2016-05-26

    We recently reported on the discovery of a novel antibacterial (2) with a 4(3H)-quinazolinone core. This discovery was made by in silico screening of 1.2 million compounds for binding to a penicillin-binding protein and the subsequent demonstration of antibacterial activity against Staphylococcus aureus. The first structure-activity relationship for this antibacterial scaffold is explored in this report with evaluation of 77 variants of the structural class. Eleven promising compounds were further evaluated for in vitro toxicity, pharmacokinetics, and efficacy in a mouse peritonitis model of infection, which led to the discovery of compound 27. This new quinazolinone has potent activity against methicillin-resistant (MRSA) strains, low clearance, oral bioavailability and shows efficacy in a mouse neutropenic thigh infection model. PMID:27088777

  18. Structure–Activity Relationship for the 4(3H)-Quinazolinone Antibacterials

    PubMed Central

    2016-01-01

    We recently reported on the discovery of a novel antibacterial (2) with a 4(3H)-quinazolinone core. This discovery was made by in silico screening of 1.2 million compounds for binding to a penicillin-binding protein and the subsequent demonstration of antibacterial activity against Staphylococcus aureus. The first structure–activity relationship for this antibacterial scaffold is explored in this report with evaluation of 77 variants of the structural class. Eleven promising compounds were further evaluated for in vitro toxicity, pharmacokinetics, and efficacy in a mouse peritonitis model of infection, which led to the discovery of compound 27. This new quinazolinone has potent activity against methicillin-resistant (MRSA) strains, low clearance, oral bioavailability and shows efficacy in a mouse neutropenic thigh infection model. PMID:27088777

  19. Positron trapping and possible presence of SO3H clusters in dry fluorinated polymer electrolyte membranes

    NASA Astrophysics Data System (ADS)

    Mohamed, Hamdy F. M.; Kobayashi, Y.; Kuroda, S.; Ohira, A.

    2012-08-01

    The behavior of positrons that do not form positronium in dry fluorinated polymer electrolyte membranes (Nafion®, Fumapem® and Aquivion®) with various ion exchange capacities (IECs) was studied by the combined use of Doppler broadening of annihilation radiation (DBAR) and the positron lifetime technique. The drastic increase of the S parameter, measured by DBAR, with increasing IEC above 0.91 meq/g indicates that increasing numbers of positrons are trapped by oxygen atoms and annihilate with the electrons bound in them. Reversed micelle like SO3H nanoclusters to trap positrons possibly appear at IEC = 0.91 meq/g and their concentration increases with increasing IEC.

  20. Flexibility of C3h -Symmetrical Linkers in Tris-oligonucleotide-Based Tetrahedral Scaffolds.

    PubMed

    Panagiotidis, Christos; Kath-Schorr, Stephanie; von Kiedrowski, Günter

    2016-02-01

    Flexibility of tris-oligonucleotides is determined by the length of their connecting hydrocarbon chains. Tris-oligonucleotides are branched DNA building blocks with three oligonucleotide arms attached to a C3h -symmetrical linker core at these chains. Four tris-oligonucleotides hybridise into a tetrahedral nanocage by sequence-determined self-assembly. The influence of methylene, ethylene and propylene chains was studied by synthesising sets of tris-oligonucleotides and analysing the relative stability of the hybridisation products against digestion by mung bean nuclease by using gel electrophoresis. Linkers with ethylene chains showed sufficient flexibility, whereas methylene-chain linkers were too rigid. Tris-oligonucleotides based on the latter still formed tetrahedral scaffolds in intermixing experiments with linkers of higher flexibility. Thus, a new generation of versatile isocyanurate-based linkers was established. PMID:26593127

  1. Multiple sup 3 H-oxytocin binding sites in rat myometrial plasma membranes

    SciTech Connect

    Crankshaw, D.; Gaspar, V.; Pliska, V. )

    1990-01-01

    The affinity spectrum method has been used to analyse binding isotherms for {sup 3}H-oxytocin to rat myometrial plasma membranes. Three populations of binding sites with dissociation constants (Kd) of 0.6-1.5 x 10(-9), 0.4-1.0 x 10(-7) and 7 x 10(-6) mol/l were identified and their existence verified by cluster analysis based on similarities between Kd, binding capacity and Hill coefficient. When experimental values were compared to theoretical curves constructed using the estimated binding parameters, good fits were obtained. Binding parameters obtained by this method were not influenced by the presence of GTP gamma S (guanosine-5'-O-3-thiotriphosphate) in the incubation medium. The binding parameters agree reasonably well with those found in uterine cells, they support the existence of a medium affinity site and may allow for an explanation of some of the discrepancies between binding and response in this system.

  2. Autoradiographic localization of adenosine receptors in rat brain using (/sup 3/H)cyclohexyladenosine

    SciTech Connect

    Goodman, R.R.; Synder, S.H.

    1982-09-01

    Adenosine (A1) receptor binding sites have been localized in rat brain by an in vitro light microscopic autoradiographic method. The binding of (/sup 3/H)N6-cyclohexyladenosine to slide-mounted rat brain tissue sections has the characteristics of A1 receptors. It is saturable with high affinity and has appropriate pharmacology and stereospecificity. The highest densities of adenosine receptors occur in the molecular layer of the cerebellum, the molecular and polymorphic layers of the hippocampus and dentate gyrus, the medial geniculate body, certain thalamic nuclei, and the lateral septum. High densities also are observed in certain layers of the cerebral cortex, the piriform cortex, the caudate-putamen, the nucleus accumbens, and the granule cell layer of the cerebellum. Most white matter areas, as well as certain gray matter areas, such as the hypothalamus, have negligible receptor concentrations. These localizations suggest possible central nervous system sites of action of adenosine.

  3. Geometrical symmetries of nuclear systems: {{ D }}_{3h} and {{ T }}_{d} symmetries in light nuclei

    NASA Astrophysics Data System (ADS)

    Bijker, Roelof

    2016-07-01

    The role of discrete (or point-group) symmetries in α-cluster nuclei is discussed in the framework of the algebraic cluster model which describes the relative motion of the α-particles. Particular attention is paid to the discrete symmetry of the geometric arrangement of the α-particles, and the consequences for the structure of the corresponding rotational bands. The method is applied to study cluster states in the nuclei 12C and 16O. The observed level sequences can be understood in a simple way as a consequence of the underlying discrete symmetry that characterizes the geometrical configuration of the α-particles, i.e. an equilateral triangle with {{ D }}3h symmetry for 12C, and a tetrahedron with {{ T }}d symmetry for 16O. The structure of rotational bands provides a fingerprint of the underlying geometrical configuration of α-particles.

  4. Intravenous kinetics and metabolism of [15,16-3H]naltrexonium methiodide in the rat.

    PubMed

    Misra, A L; Pontani, R B; Vadlamani, N L

    1987-03-01

    After a 4 mg kg-1 bolus intravenous dose of [15,16-3H]naltrexonium methiodide to the rat, brain to plasma concentration ratios of the compound were 0.031 to 0.228 between 0.25 to 6 h after injection and the t 1/2 beta in plasma and brain were 2.92 and 7.61 h, respectively. Ethyl acetate-extracted radioactivity due to metabolites in plasma decayed with t 1/2 beta 1.83 h and the ratios of plasma concentration of metabolites to quaternary compound between 0.25 and 6 h were 0.014-0.026. Only unconjugated 7,8-dihydro-14-hydroxynormorphine, naltrexone and traces of 7,8-dihydro-14-hydroxynormorphinone were the metabolites in plasma. Naltrexone (but not normetabolites) was present only in traces in brain up to 0.5 h after injection and not at later times. PMID:2883290

  5. Classical-Reaction-Driven Stereo- and Regioselective C(sp(3) )-H Functionalization of Aliphatic Amines.

    PubMed

    Mahato, Sujit; Jana, Chandan K

    2016-06-01

    A large variety of synthetic methods have been developed for the synthesis of functionalized aliphatic amines because of their broad spectrum of application. Metallic reagents/catalysts and/or toxic oxidants are involved in most of the cases. Direct CH functionalization of aliphatic amines via their classical condensation reactions with suitable carbonyl compounds is advantageous because this method avoids hazardous metallic reagents, toxic oxidants and pre-activation/pre-functionalization step(s). In this account, the concept of direct CH functionalization of aliphatic amines based on the classical condensation-isomerization-addition (CIA) strategy followed by recent contributions from our ongoing research in the field along with relevant examples from other groups are described. Successes in stereo- and regioselective CC and CO bond formation via direct α- as well as β-C(sp(3) )-H functionalization are discussed. PMID:27185195

  6. Sulfonated poly(ether ether ketone)/clay-SO 3H hybrid proton exchange membranes for direct methanol fuel cells

    NASA Astrophysics Data System (ADS)

    Fu, Tiezhu; Cui, Zhiming; Zhong, Shuangling; Shi, Yuhua; Zhao, Chengji; Zhang, Gang; Shao, Ke; Na, Hui; Xing, Wei

    A new type of sulfonated clay (clay-SO 3H) was prepared by the ion exchange method with the sulfanilic acid as the surfactant agent. The grafted amount of sulfanilic acid in clay-SO 3H was 51.8 mequiv. (100 g) -1, which was measured by thermogravimetric analysis (TGA). Sulfonated poly(ether ether ketone) (SPEEK)/clay-SO 3H hybrid membranes which composed of SPEEK and different weight contents of clay-SO 3H, were prepared by a solution casting and evaporation method. For comparison, the SPEEK/clay hybrid membranes were produced with the same method. The performances of hybrid membranes for direct methanol fuel cells (DMFCs) in terms of mechanical and thermal properties, water uptake, water retention, methanol permeability and proton conductivity were investigated. The mechanical and thermal properties of the SPEEK membranes had been improved by introduction of clay and clay-SO 3H, obviously. The water desorption coefficients of the SPEEK and hybrid membranes were studied at 80 °C. The results showed that the addition of the inorganic part into SPEEK membrane enhanced the water retention of the membrane. Both methanol permeability and proton conductivity of the hybrid membranes decreased in comparison to the pristine SPEEK membrane. However, it was worth noting that higher selectivity defined as ratio of proton conductivity to methanol permeability of the SPEEK/clay-SO 3H-1 hybrid membrane with 1 wt.% clay-SO 3H was obtained than that of the pristine SPEEK membrane. These results showed that the SPEEK/clay-SO 3H hybrid membrane with 1 wt.% clay-SO 3H had potential usage of a proton exchange membrane (PEM) for DMFCs.

  7. Uncoupling of attenuated myo-(3H)inositol uptake and dysfunction in Na(+)-K(+)-ATPase pumping activity in hypergalactosemic cultured bovine lens epithelial cells

    SciTech Connect

    Cammarata, P.R.; Tse, D.; Yorio, T. )

    1991-06-01

    Attenuation of both the active transport of myo-inositol and Na(+)-K(+)-ATPase pumping activity has been implicated in the onset of sugar cataract and other diabetic complications in cell culture and animal models of the disease. Cultured bovine lens epithelial cells (BLECs) maintained in galactose-free Eagle's minimal essential medium (MEM) or 40 mM galactose with and without sorbinil for up to 5 days were examined to determine the temporal effects of hypergalactosemia on Na(+)-K(+)-ATPase and myo-inositol uptake. The Na(+)-K(+)-ATPase pumping activity after 5 days of continuous exposure to galactose did not change, as demonstrated by 86Rb uptake. The uptake of myo-(3H)inositol was lowered after 20 h of incubation in galactose and remained below that of the control throughout the 5-day exposure period. The coadministration of sorbinil to the galactose medium normalized the myo-(3H)inositol uptake. No significant difference in the rates of passive efflux of myo-(3H)inositol or 86Rb from preloaded galactose-treated and control cultures was observed. Culture-media reversal studies were also carried out to determine whether the galactose-induced dysfunction in myo-inositol uptake could be corrected. BLECs were incubated in galactose for 5 days, then changed to galactose-free physiological medium with and without sorbinil for a 1-day recovery period. myo-Inositol uptake was reduced to 34% of control after 6 days of continuous exposure to galactose. Within 24 h of media reversal, myo-inositol uptake returned to or exceeded control values in BLECs switched to either MEM or MEM with sorbinil.2+ reversible and occurred independently of changes in Na(+)-K(+)-ATPase pumping activity in cultured lens epithelium, indicating that the two parameters are not strictly associated and that the deficit in myo-inositol uptake occurs rapidly during hypergalactosemia.

  8. ( sup 3 H)SCH39166, a D1 dopamine receptor antagonist: Binding characteristics and localization

    SciTech Connect

    Wamsley, J.K.; Hunt, M.E.; McQuade, R.D.; Alburges, M.E. )

    1991-02-01

    Schering-Plough Research has developed a new, more specific analogue of SCH23390. This compound, SCH39166, has been shown to be a potent, specific, D1 receptor antagonist with several features which are advantageous over its predecessor. In this report, the binding characteristics of (3H)SCH39166 are described by in vitro analysis in rat brain tissues. The binding was shown to be of high affinity (Kd in the low nM range), saturable, and specific (readily displaceable with SCH23390, but not with the D2 receptor antagonists sulpiride or haloperidol). The binding of SCH39166 is more selective for binding to D1 receptors than SCH23390 with regard to overlap of the latter compound onto 5HT2 and 5HT1C receptors. Autoradiographic localization of D1 receptor sites labeled with (3H)SCH39166 showed a very specific distribution in areas known to contain high quantities of D1 receptors. These regions included the deepest layer of the cerebral cortex, the caudate-putamen, nucleus accumbens, olfactory tubercle, entopeduncular nucleus, and substantia nigra-pars reticulata, as well as less dense binding in a few other areas. At the concentration of ligand used (1 nM), there was a noticeable paucity of labeling in lamina IV of the cerebral cortex and in the choroid plexus, regions of high 5HT2 and 5HT1C receptor binding, respectively. Thus, SCH39166 represents a new D1 receptor antagonist which shows a greater specificity for the D1 receptor than its predecessor SCH23390. As previously shown, another distinct advantage of this compound is its stability in primates which should allow the determination of the effects and utility of D1 receptor antagonism in vivo.

  9. Cutaneous absorption and decontamination of ( sup 3 H)T-2 toxin in the rat model

    SciTech Connect

    Bunner, B.L.; Wannemacher, R.W. Jr.; Dinterman, R.E.; Broski, F.H. )

    1989-01-01

    Cutaneous absorption and decontamination of ({sup 3}H)T-2 mycotoxin using various treatment modalities incorporating water, detergent, sprays, and scrubbing of application sites were examined in the rat model at 5, 30, 60, and 1440 min (24 h) postexposure. Rats were killed immediately after treatment and radiolabeled T-2 remaining in full-thickness skin samples was determined. Absorption and decontamination were followed over time, and decontaminating treatment modalities were evaluated for efficacy. Less than 1% of the applied dose was absorbed in 5 min, and 50% was absorbed in 24 h. At 5 min, 99.5 {plus minus} 0.05% of nonabsorbed (residual) ({sup 3}H)T-2 was removed, and 58 {plus minus} 5.2% of residual toxin was removed at 24 h with a 2.5% detergent/water spray. When treatment modalities were evaluated at 60 min, a 2.5% detergent/water scrub followed by a detergent/water spray produced optimal decontamination by removing 81 {plus minus} 2.2% of residual toxin. All treatment modalities using detergent and/or water removed significant amounts of toxin, a dry scrub was not efficacious. Treatment should be initiated as soon as possible after exposure for best results. However, the stratum corneum acts as a reservoir for the toxin, and decontamination should be carried out even if delayed several hours or days after exposure. Dermal absorption pharmacokinetics found in these studies are similar to those described for other low-molecular-weight compounds, and the decontamination results from T-2 toxin should be applicable to other, similar toxic substances.

  10. Photoaffinity labeling of rat liver microsomal morphine UDP-glucuronosyltransferase by [3H]flunitrazepam.

    PubMed

    Thomassin, J; Tephly, T R

    1990-09-01

    Benzodiazepines have been shown to competitively inhibit morphine glucuronidation in rat and human hepatic microsomes. Flunitrazepam exerted a potent competitive inhibition of rat hepatic morphine UDP-glucuronosyltransferase (UDPGT) activity (Ki = 130 microM). It has no effect on the activity of p-nitrophenol, 17 beta-hydroxysteroid, 3 alpha-hydroxysteroid, or 4-hydroxybiphenyl UDPGTs. Because flunitrazepam is an effective photoaffinity label for benzodiazepine receptors, studied were performed in solubilized rat hepatic microsomes and with partially purified preparations of morphine UDPGT to determine the enhancement of flunitrazepam inhibition and binding to morphine UDPGT promoted by exposure to UV light. Under UV light, flunitrazepam inhibition was markedly enhanced. UV light exposure also led to a marked increase in binding of [3H]flunitrazepam to microsomal protein, which was protected substantially by preincubation with morphine. Testosterone, androsterone, and UDP-glucuronic acid did not protect against UV-enhanced flunitrazepam binding, and morphine did not reverse flunitrazepam binding once binding had occurred. As morphine UDPGT was purified, a good correlation was found between the increases in specific activity of morphine UDPGT and flunitrazepam binding to protein. Chromatofocusing chromatography showed that flunitrazepam bound only to fractions containing active morphine UDPGT, and no binding to 4-hydroxybiphenyl UDPGT was observed. Fluorography of a sodium dodecyl sulfate-polyacrylamide electrophoresis gel of solubilized hepatic microsomes that had been treated with [3H] flunitrazepam under UV light revealed a band with a monomeric molecular weight between 54,000 and 58,000. This monomeric molecular weight compares favorably with the reported monomeric molecular weight of homogeneous morphine UDPGT (56,000). These studies suggest that flunitrazepam binds rather selectively to the morphine binding site of morphine UDPGT and may prove to be a useful

  11. Partial phase diagram for the system NH3-H2O - The water-rich region

    NASA Technical Reports Server (NTRS)

    Johnson, M. L.; Schwake, A.; Nicol, M.

    1984-01-01

    Phase boundaries of the H2O-NH3 system for (NH3)/x/(H2O)/1-x/ have been determined with diamond-anvil cells for mixtures in two composition ranges: (1) for x in the range from 0 to 0.3, at pressures up to 4 GPa at 21 C, and (2) for x in the range from 0.46 to 0.50, at pressures up to 5 GPa from 150 to 400 K. Phases were identified visually with a microscope and polarized optics. The NH3.2(H2O) phase is strongly anisotropic with a much smaller refractive index than that of ice VII and cracks in two nonperpendicular networks. NH3.H2O has a refractive index closer to that of Ice VII and does not appear to form cracks. Both phases are colorless. Phase boundaries were determined on both increasing and decreasing pressures, and compositions of the ammonia ices were determined by estimating relative amounts of water and ammonia ices at known overall compositions. For low-ammonia compositions (x equal to or less than 0.15), the following assemblages succedd one another as pressure increases: liquid; liquid and Ice VI (at 1.0 + GPa); liquid and Ice VII (at 2.1 GPa); Ice VII and NH3.H2O (at 3.5 GPa). For x in the range from 0.15 to 0.30, the water ice and liquid fields are replaced by the NH3.2(H2O) and liquid field at pressures down to 1.0 GPa and lower.

  12. Photoaffinity labeling of rat liver microsomal morphine UDP-glucuronosyltransferase by ( sup 3 H)flunitrazepam

    SciTech Connect

    Thomassin, J.; Tephly, T.R. )

    1990-09-01

    Benzodiazepines have been shown to competitively inhibit morphine glucuronidation in rat and human hepatic microsomes. Flunitrazepam exerted a potent competitive inhibition of rat hepatic morphine UDP-glucuronosyltransferase (UDPGT) activity (Ki = 130 microM). It has no effect on the activity of p-nitrophenol, 17 beta-hydroxysteroid, 3 alpha-hydroxysteroid, or 4-hydroxybiphenyl UDPGTs. Because flunitrazepam is an effective photoaffinity label for benzodiazepine receptors, studied were performed in solubilized rat hepatic microsomes and with partially purified preparations of morphine UDPGT to determine the enhancement of flunitrazepam inhibition and binding to morphine UDPGT promoted by exposure to UV light. Under UV light, flunitrazepam inhibition was markedly enhanced. UV light exposure also led to a marked increase in binding of (3H)flunitrazepam to microsomal protein, which was protected substantially by preincubation with morphine. Testosterone, androsterone, and UDP-glucuronic acid did not protect against UV-enhanced flunitrazepam binding, and morphine did not reverse flunitrazepam binding once binding had occurred. As morphine UDPGT was purified, a good correlation was found between the increases in specific activity of morphine UDPGT and flunitrazepam binding to protein. Chromatofocusing chromatography showed that flunitrazepam bound only to fractions containing active morphine UDPGT, and no binding to 4-hydroxybiphenyl UDPGT was observed. Fluorography of a sodium dodecyl sulfate-polyacrylamide electrophoresis gel of solubilized hepatic microsomes that had been treated with (3H) flunitrazepam under UV light revealed a band with a monomeric molecular weight between 54,000 and 58,000. This monomeric molecular weight compares favorably with the reported monomeric molecular weight of homogeneous morphine UDPGT (56,000).

  13. Dissociation of insulin receptor phosphorylation and stimulation of glucose transport in BC3H-1 myocytes

    SciTech Connect

    Mojsilovic, L.P.; Standaert, M.L.; Rosic, N.K.; Pollet, R.J.

    1986-05-01

    The authors have investigated insulin receptor phosphorylation in differentiated cultured BC3H-1 myocytes. As for other insulin-responsive cell systems in partially purified wheat germ agglutinin receptor preparations, insulin stimulates the phosphorylation of its own receptor (95K ..beta..-subunits) in a dose dependent manner (0-400 nM), as identified by immunoprecipitation with antiinsulin receptor antibodies and SDS-PAGE. In the same preparations they show that 12-0-tetradecanyl phorbol acetate (TPA), which in many respect ..beta..-subunits in the same dose dependent manner (0-5 ..mu..M). In addition, antiinsulin receptor antibodies (B-10) also induced phosphorylation of mimics insulin action, also induced phosphorylation of the insulin receptor and HPLC tryptic maps of the /sup 32/P-labeled ..beta..-subunit were identical to those for insulin-induced receptor phosphorylation. However, while insulin and TPA are potent stimulators of glucose transport in these muscle cells, the antireceptor antibodies alone failed to provoke glucose transport at any concentration. The specificity and activity of these antibodies were confirmed in their system by their ability to inhibit insulin binding and insulin-stimulated glucose transport in a concentration-dependent manner. Their results indicate that phosphorylation of insulin receptor is not a crucial event in mediating insulin action, at least with respect to glucose transport. While the effects of the B-10 antibody in the BC3H-1 myocyte differ from those in the adipocyte, their results provide independent confirmation of their essential conclusion that phosphorylation of the insulin receptor may not be necessary nor sufficient for its acute action in promoting glucose transport.

  14. The Bond Energy of CH3-H: A Physical Chemistry Experiment.

    ERIC Educational Resources Information Center

    Dorain, Paul B.

    1979-01-01

    Describes an experiment, designed for use in the undergraduate laboratory, that measures the bond energies of molecules using a small commercial mass spectrometer and low-cost digital voltmeters. (BT)

  15. [3H]AF-DX 116 labels subsets of muscarinic cholinergic receptors in rat brain and heart.

    PubMed

    Wang, J X; Roeske, W R; Gulya, K; Wang, W; Yamamura, H I

    1987-10-01

    The in vitro binding properties of the novel muscarinic antagonist [3H]AF-DX 116 were studied using a rapid filtration technique. Association and dissociation rates of [3H]AF-DX 116 binding were rapid at 25 degrees C (2.74 and 2.70 X 10(7) min-1 M-1 for K+1; 0.87 and 0.93 min-1 for k-1) but 20-40 times slower at 0-4 degrees C (0.13 and 0.096 X 10(7) min-1 M-1 for k+1; 0.031 and 0.022 min-1 for k-1 in cerebral cortical and cardiac membranes, respectively). Kinetic dissociation constants (Kds) were estimated to be 31.8 nM and 30.9 nM at 25 degrees C; 23.1 nM and 0-4 degrees C for the cerebral cortex and heart, respectively. In saturation studies, [3H]AF-DX 116 labeled 29 percent of the total [3H](-)QNB binding sites in the cerebral cortical membranes and 87 percent in the cardiac membranes, with Kd values of 28.9 nM and 17.9 nM, respectively. Muscarinic antagonists inhibited [3H]AF-DX 116 binding in a rank order of potency of atropine greater than dexetimide greater than AF-DX 116 greater than PZ greater than levetimide in both tissues. Except for PZ/[3H]AF-DX 116 and AF-DX 116/[3H]AF-DX 116 in the cerebral cortex, all the antagonist competition curves had Hill coefficients close to one. Carbachol and oxotremorine produced shallow inhibition curves against [3H]AF-DX 116 binding in both tissues. Regional distribution studies with [3H](-)QNB, [3H]PZ and [3H]AF-DX 116 showed that most of the muscarinic receptors in the cerebral cortex, hippocampus, nucleus accumbens and corpus striatum are of the M1 subtype while those in the brainstem, cerebellum and other lower brain regions are of the M2 subtype. These results indicate that [3H]AF-DX 116 is a useful probe for the study of heterogeneity of muscarinic cholinergic receptors. PMID:3657382

  16. Ascorbic acid prevents nonreceptor specific binding of (/sup 3/H)-5-hydroxytryptamine to bovine cerebral cortex membranes

    SciTech Connect

    Hamblin, M.W.; Adriaenssens, P.I.; Ariani, K.; Cawthon, R.M.; Stratford, C.A.; Tan, G.L.; Ciaranello, R.D.

    1987-03-01

    (/sup 3/H)-5-Hydroxytryptamine ((/sup 3/H)-5-HT) decomposes rapidly when exposed to air in solution at physiological pH if antioxidants are not present. The decomposition products appear to bind to two saturable sites on brain membranes (apparent Kd values = 1-2 and 100-1000 nM). This binding mimics ''specific'' ligand/receptor binding in that it is inhibited by 10 microM unlabeled 5-HT. This inhibition is not competitive, but rather is due to the prevention of (/sup 3/H)-5-HT breakdown by excess unlabeled 5-HT. Unlike genuine ligand/receptor binding, the binding of (/sup 3/H)-5-HT breakdown products is essentially irreversible and does not display a tissue distribution consistent with binding to authentic 5-HT receptors. (/sup 3/H)-5-HT decomposition can be eliminated by the inclusion of 0.05 to 5 mM ascorbic acid. At these concentrations ascorbic acid is not deleterious to reversible (/sup 3/H)-5-HT binding. When (/sup 3/H) 5-HT exposure to air occurs in the presence of brain membranes, the apparent antioxidant activity of brain membranes themselves affords protection against (/sup 3/H)-5-HT degradation equal to ascorbic acid. This protection is effective below final (/sup 3/H)-5-HT concentrations of 10 nM. Above 10 nM (/sup 3/H)-5-HT, addition of ascorbic acid or other antioxidants is necessary to avoid the occurrence of additional low affinity (apparent Kd = 15-2000 nM) binding sites that are specific but nonetheless irreversible. When care is taken to limit (/sup 3/H)-5-HT oxidation, the only reversible and saturable specific binding sites observed are of the 5-HT1 high affinity (Kd = 1-2 nM) type. Radioligand oxidation artifacts may be involved in previous reports of low affinity (Kd = 15-250 nM) (/sup 3/H)-5-HT binding sites in brain membrane preparations.

  17. FT-IR measurements of mid-IR propene (C3H6) cross sections and far-IR ammonia (NH3) line intensities

    NASA Astrophysics Data System (ADS)

    Sung, Keeyoon; Toon, Geoffrey C.; Crawford, Timothy J.; Yu, Shanshan; Pearson, John C.; Kwabia Tchana, Fridolin; Manceron, Laurent; Pirali, Olivier

    2015-11-01

    We present spectroscopy measurements of propene (C3H6) in the mid-infrared and ammonia (NH3) in the far-infrared from two different laboratory studies. [1] For propene (CH2-CH-CH3, alias. propylene), which was detected in the stratosphere of Titan [Nixon et al. 2013], temperature dependent cross sections in the 650 - 1530 cm-1 (6.5 - 15.3 μm) have been measured from a series of high-resolution (0.0022 cm-1) spectra of pure and N2-mixture samples of C3H6 recorded at 150 - 296 K at Jet Propulsion Laboratory. The observed spectral features cover the strongest v19 band with its outstanding Q-branch peak at 912 cm-1 and three other strong bands of v18, v16 and v7 at 990, 1442, and 1459 cm-1, respectively. In addition, we have generated a HITRAN-format empirical ‘pseudoline list' containing line positions, intensities, and effective lower state energies by fitting all the observed spectra simultaneously. The results are compared with early work from relatively warm temperatures (278 - 323 K). [2] For ammonia (NH3), we obtained multiple sets of high-resolution spectra in the THz and far-infrared region (50 - 650 cm-1) at room temperature using AILES beamline at Synchrotron SOLEIL, France (NH3). In this work, we have measured line intensities for more than 4500 transitions, and made quantum assignments for ~2900 lines including ~960 very weak ΔK = 3 forbidden lines. Final results will be compared with the current databases (e.g., HITRAN, GEISA) and ab initio calculations. [Research described in this paper was performed at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. Sung and Yu acknowledge the Synchrotron Soleil for the AILES beam line time.

  18. The pharmacological modulation of [3H]-disaturated phosphatidylcholine overflow from perifused lung slices of adult rats: a new method for the study of lung surfactant secretion.

    PubMed Central

    Gilfillan, A. M.; Hollingsworth, M.; Jones, A. W.

    1983-01-01

    Lung slices from adult rats incubated in [methyl-3H]-choline chloride formed [3H]-disaturated phosphatidylcholine ( [3H]-DSPC) which was used as an index of lung surfactant. The slices were perifused after 3 h incubation in [methyl-3H]-choline chloride and the overflow of [3H]-DSPC, as a rate coefficient, was used as a measure of surfactant secretion. The basal overflow of [3H]-DSPC rapidly declined over the first 30 min of perifusion and then declined slowly. Salbutamol induced a prolonged, and sometimes delayed, increase in [3H]-DSPC overflow, which was reduced by (+/-)-propranolol. Potassium chloride produced an immediate, and usually transient, increase in [3H]-DSPC overflow which was not modified by atropine or (+/-)-propranolol. Adenosine 5'-triphosphate, but not phenylephrine, also increased [3H]-DSPC overflow. This method can measure the magnitude and time-course of lung surfactant secretion induced by drugs. PMID:6689133

  19. Regioselective synthesis of novel 3-allyl-2-(substituted imino)-4-phenyl-3H-thiazole and 2,2‧-(1,3-phenylene)bis(3-substituted-2-imino-4-phenyl-3H-thiazole) derivatives as antibacterial agents

    NASA Astrophysics Data System (ADS)

    Abbasi Shiran, Jafar; Yahyazadeh, Asieh; Mamaghani, Manouchehr; Rassa, Mehdi

    2013-05-01

    Several novel 3-allyl-2-(substituted imino)-4-phenyl-3H-thiazole derivatives were synthesized by the reaction of allyl-thioureas and 2-bromoacetophenone. We also report the synthesis of bis-allyl-3H thiazoles using the reaction of various isothiocyanates and 1,3-phenylenediamine. The structures of all compounds were characterized by spectral and elemental analysis. Most of the synthesized compounds exhibited efficient antibacterial activities against Salmonella enterica, Micrococcus luteus, Bacillus subtilis and Pseudomonas aeruginosa.

  20. Catechol estrogen formation by brain tissue: a comparison of the release of tritium from (2-3H)estradiol with (6,7-3H)2-hydroxyestradiol formation from (6,7-3H)estradiol by rabbit hypothalami in vitro

    SciTech Connect

    Hersey, R.M.; Gunsalus, P.; Lloyd, T.; Weisz, J.

    1981-12-01

    A detailed comparison was made between the formation of tritiated water (3H2O) and (6,7-3H)2-hydroxyestradiol (2-OHE2) by rabbit hypothalami in vitro from 2-3H- and 6,7-3H-labeled estradiol, respectively. Maximum activity for both functions was associated with the soluble fractions (S2, 17,500 X g supernatant, for tritium release; S3, 100,000 X g supernatant, for 2-OHE2 formation). In contrast, maximal 3H2O formation by rat liver was associated with the microsomal (P3, 100,000 X g pellet) fraction and was virtually abolished by Tween-80. The amount of 3H2O formed exceeded, up to severalfold, the amount of 2-OHE2 produced under all conditions examined and in all subcellular fractions. The bulk of the excess 3H2O formation, unrelated to the production of 2-OHE2, could be eliminated by adding ascorbic acid (10 mM) to the incubation medium. However, a second, smaller component of spurious 3H2O release could not be suppressed. This component was responsible for a persistent lack of stoichiometry between the formation of 3H2O and 2-OHE2, with the former exceeding the latter by up to 2-fold. This discrepancy was unaffected by ascorbic acid (up to 20 mM), unlabeled 2-OHE2 (up to 10 microM), and reducing the temperature of incubation from 37 to 30 C, measures that prolonged the t1/2 of 2-OHE2 during incubation with hypothalamic tissue from under 3 min to over 100 min.

  1. Results from Boiling Temperature Measurements for Saturated Solutions in the Systems NaCl + KNO{sub 3} + H{sub 2}O, NaNO{sub 3} + KNO{sub 3} + H{sub 2}O, and NaCl + NaNO{sub 3} + KNO{sub 3} + H{sub 2}O

    SciTech Connect

    Rard, J A

    2004-10-04

    Boiling temperature measurements have been made for saturated ternary solutions of NaCl + KNO{sub 3} + H{sub 2}O and NaNO{sub 3} + KNO{sub 3} + H{sub 2}O over the full solute mole fraction range, along with the limiting binary solutions NaCl + H{sub 2}O, NaNO{sub 3} + H{sub 2}O, and KNO{sub 3} + H{sub 2}O. Boiling temperatures have also been measured for the quaternary NaCl + NaNO{sub 3} + KNO{sub 3} + H{sub 2}O mixtures with KNO{sub 3}:NaNO{sub 3} mole ratios of 1.01 and 1.19, which corresponding to the eutectic ratio and a near-eutectic ratio for the NaNO{sub 3} + KNO{sub 3} + H{sub 2}O subsystem. The maximum boiling temperature found for the NaCl + KNO{sub 3} + H{sub 2}O system is 134 C and for the NaNO{sub 3} + KNO{sub 3} + H{sub 2}O system is 160 C, but boiling temperatures as high as 196 C were measured the NaCl + NaNO{sub 3} + KNO{sub 3} + H{sub 2}O system. These mixture compositions correspond to the major mineral assemblages that are predicted to control the deliquescence relative humidity of salts found by leaching dust samples from the proposed nuclear repository at Yucca Mountain, Nevada.

  2. (/sup 3/H) spiperone binding sites in rat primary cultures, C6 glioma, and B104 neuroblastoma

    SciTech Connect

    Severson, J.A.; de Vellis, J.S.; Finch, C.E.

    1980-01-01

    Binding sites for (/sup 3/H) spiperone were detected on membranes from primary glial cultures from neonatal rat cortex and striatum and from the C6 glioma cells. (/sup 3/H) spiperone binding was displacable by d-butaclamol. However, competition studies suggest that (/sup 3/H) spiperone binding to primary glial cultures was mainly to serotonergic sites, and binding to the C6 glioma was alpha-adrenergic. No specific binding was detected to membranes from B104 neuroblastoma cells. Although (/sup 3/H) spiperone binding to glial sites in whole striatum under generally used conditions is small (about 10%), the striatal glial hyperactivity which is often associated with neuronal degeneration could lead to an overestimation of presumed neuronal binding sites for dopaminergic ligands.

  3. RETROGRADE AXONAL TRANSPORT OF PHOSPHOINOSITIDES AFTER INTRANEURAL INJECTION OF [3H]MYO-INOSITOL INTO THE RAT SCIATIC NERVE

    EPA Science Inventory

    Although autoradiography has demonstrated local incorporation of [3H]inositol into axonal phospholipids after intraneural injection (Gould, 1976; Gould et at., 1987b), retrograde axonal transport of phosphatidylinositol has only been demonstrated after injection of lipid precurso...

  4. Imipramine treatment differentially affects platelet /sup 3/H-imipramine binding and serotonin uptake in depressed patients

    SciTech Connect

    Suranyi-Cadotte, B.E.; Quirion, R.; Nair, N.P.V.; Lafaille, F.; Schwartz, G.

    1985-02-25

    Uptake of serotonin and /sup 3/H-imipramine binding in platelets of depressed patients were investigated simultaneously with changes in clinical state. Both V/sub max/ for serotonin uptake and B/sub max/ for /sup 3/H-imipramine binding were significantly lower in unmedicated depressed patients with respect to normal subjects. Successful treatment with imipramine led to a significant increase in B/sub max/ for /sup 3/H-imipramine binding, without significant change in V/sub max/ for serotonin uptake. B/sub max/ values increased to the normal range following complete, rather than partial clinical improvement. These data indicate that successful antidepressant treatment may increase the density of /sup 3/H-imipramine binding sites on platelets by a process which is independent of the uptake of serotonin. 29 references, 1 table.

  5. Metaphit inhibits dopamine transport and binding of ( sup 3 H)methylphenidate, a proposed marker for the dopamine transport complex

    SciTech Connect

    Schweri, M.M. ); Jacobson, A.E.; Rice, K.C. ); Lessor, R.A.

    1989-01-01

    Metaphit, an acylating derivative of phencyclidine, was shown to interact with components of the dopamine nerve terminal in rat striatal tissue. This compound, previously demonstrated to be an irreversible inhibitor at the phencyclidine receptor, was shown in these experiments to irreversibly inhibit synaptosomal ({sup 3}H)dopamine uptake. It also inhibited binding of ({sup 3}H)methylphenidate to its recognition site, which is thought to be a subunit of the dopamine transporter. Although the inhibition was due primarily to a reduction in the binding and transport capacity of the systems studied, increases in the apparent K{sub D} of ({sup 3}H)methylphenidate and the K{sub m} of ({sup 3}H)dopamine were also observed. Differences in the behavior of Metaphit and phencylidine in these dopaminergic systems compared to their effects on the NMDA receptor-linked phencyclidine receptor suggest that Metaphit may be interacting with two distinct molecular sites in the rat striatum.

  6. Ft-Ir Measurements of Cross Sections of Cold C_3H_8 in the 7 - 15 μm for Titan

    NASA Astrophysics Data System (ADS)

    Sung, Keeyoon; Toon, Geoffrey C.; Brown, Linda R.; Mantz, Arlan W.; Smith, Mary Ann H.

    2013-06-01

    To support atmospheric remote sensing of Titan, the absorption cross sections of N_2-broadened C_3H_8 were obtained at temperatures between 145 and 296 K. For this, 35 spectra of pure- and N_2-broadened propane were recorded in the 670 to 1900 cm-1 region using a Fourier transform spectrometer (Bruker IFS-125HR) at the Jet Propulsion Laboratory. A 20.38 cm path temperature-stabilized cryogenic absorption cell was used, which was developed at Connecticut College and described previously [1]. We report the absorption cross sections at the various cold temperatures for nine strong fundamental bands (ν_{26}, ν_8, ν_{21}, ν_{20}, ν_7, ν_{19}, ν_{18}, ν_4, ν_{24}) as well as for many contributions from hot and combination bands. In addition, we present results from 'pseudo -line generation' (http://mark4sun.jpl.nasa.gov/data/spec/Pseudo/Readme), which includes mean intensities and effective lower state energies on a 0.005 cm^{-1} frequency grid determined in the 690 - 1536 cm^{-1} region from all 35 high-resolution laboratory spectra. It was observed that the pseudo lines reproduce all the observed spectral transmittances well within 3% and the C_3H_8 amounts within 4% on the average. The measured cross sections and synthetic spectra from the pseudoline compilation are compared to earlier work, including the C_3H_8+N_2 spectra recorded at PNNL [2] and line-by-line predictions available [3, 4]. [1] K. Sung, A. W. Mantz, M. A. H. Smith, et al., J Mol Spectrosc 262, 122, 2010.; [2] S. W. Sharpe, et al., Appl Spectrosc 58, 1452, 2004.; [3] J. M. Flaud et al., Mol Phys 108, 699, 2010.; [4] J. M. Flaud et al., J Chem Phys 114, 9361, 2001. The research described in this paper was performed at the Jet Propulsion Laboratory, California Institute of Technology and at The College of William and Mary under contracts with National Aeronautics and Space Administration. US Government Support Acknowledged.

  7. /sup 3/H-PAF-acether displacement and inhibition of binding in intact human platelets by BN 52021

    SciTech Connect

    Korth, R.; Le Couedic, J.P.; Benveniste, J.

    1986-03-05

    Intact washed human platelets incubated at 20/sup 0/C in Tyrode's buffer containing 0.25% (w/v) bovine serum albumin bound /sup 3/H paf-acether in a concentration (0-6.5 nM) and time (0-60 min) dependent manner (n=3). BN 52021 (60 ..mu..M) a chemically defined extract from Ginkgo biloba inhibited the binding of increasing concentrations of /sup 3/H paf-acether. Calculated differences between /sup 3/H paf-acether binding in the presence or absence of BN 52021 (60 ..mu..M) reached nearly a plateau in concentrations higher than 0.65 nM /sup 3/H paf-acether. Increasing concentrations of BN 52021 (0-60 ..mu..M) as well as of unlabelled paf-acether (0-50 nM) prevented within 15 min /sup 3/H paf-acether binding (0.65 nM) to platelets in a concentration-dependent way. Increasing BN 52021 concentrations (0-60 ..mu..M) also displaced platelet-bound /sup 3/H paf-acether (0.65 nM) in a concentration-dependent way. Displacement increased with the time length of platelet incubation with BN 52021 and reached a plateau at 15 min. Platelet-bound /sup 3/H paf-acether displacement of 28.3 +/- 6.3%, 31.1 +/- 4.0% and 26.7 +/- 5.6% was observed using 50 nM unlabelled paf-acether, 60 ..mu..M BN 52021 or both substances together (vs 4.3 +/- 7.2% for vehicle alone). No degradation of /sup 3/H paf-acether occurred as assessed by high pressure liquid chromatography. These results demonstrate that BN 52021 competes directly with paf-acether binding sites on human platelets.

  8. Glucose- and Cellulose-Derived Ni/C-SO3H Catalysts for Liquid Phase Phenol Hydrodeoxygenation

    SciTech Connect

    Kasakov, Stanislav; Zhao, Chen; Barath, Eszter; Chase, Zizwe A.; Fulton, John L.; Camaioni, Donald M.; Vjunov, Aleksei; Shi, Hui; Lercher, Johannes A.

    2015-01-19

    Sulfonated carbons were explored as functionalized supports for Ni nanoparticles to hydrodeoxygenate (HDO) phenol. Both hexadecane and water were used as solvents. The dual-functional Ni catalysts supported on sulfonated carbon (Ni/C-SO3H) showed high rates for phenol hydrodeoxygenation in liquid hexadecane, but not in water. Glucose and cellulose were precursors to the carbon supports. Changes in the carbons resulting from sulfonation of the carbons resulted in variations of carbon sheet structures, morphologies and the surface concentrations of acid sites. While the C-SO3H supports were active for cyclohexanol dehydration in hexadecane and water, Ni/C-SO3H only catalyzed the reduction of phenol to cyclohexanol in water. The state of 3 – 5 nm grafted Ni particles was analyzed by in situ X-ray absorption spectroscopy. The results show that the metallic Ni was rapidly formed in situ without detectable leaching to the aqueous phase, suggesting that just the acid functions on Ni/C-SO3H are inhibited in presence of water. Using in situ IR spectroscopy, it was shown that even in hexadecane, phenol HDO is limited by the dehydration step. Thus, phenol HDO catalysis was further improved by physically admixing C-SO3H with the Ni/C-SO3H catalyst to balance the two catalytic functions. The minimum addition of 7 wt.% C-SO3H to the most active of the Ni/C-SO3H catalysts enabled nearly quantitative conversion of phenol and the highest selectivity (90%) towards cyclohexane in 6 h, at temperatures as low as 473 K, suggesting that the proximity to Ni limits the acid properties of the support.

  9. In vivo labeling of phencyclidine (PCP) receptors with sup 3 H-TCP in the mouse brain

    SciTech Connect

    Maurice, T.; Vignon, J. )

    1990-07-01

    The phencyclidine (PCP) derivative N-(1-(2-thienyl)cyclohexyl)-piperidine (3H-TCP) was used to label in vivo the N-methyl-D-aspartate (NMDA) receptor-associated ionic channel in the mouse brain. After the injection of a tracer dose of 3H-TCP, a spread labeling throughout the brain was observed, but was the highest in the cerebellum. Preadministration of unlabeled TCP (30 mg/kg) resulted in a 90% reduction of 3H-TCP binding. PCP, TCP, MK-801, dexoxadrol, ketamine, and SKF 10,047 isomers dose-dependently prevented the in vivo 3H-TCP binding. ID50 determined in the cerebrum and the cerebellum were respectively correlated with K0.5 for 3H TCP high (rat cortex) and low affinity (rat cerebellum) sites in vitro. The pharmacological specificity of the 3H-TCP binding site in the cerebellum was significantly different from that in the cerebrum. ID50 values were generally higher than in the cerebrum and, particularly, MK-801, the most potent drug in the cerebrum, was without significant effect in the cerebellum, at any time and at doses as high as 30 mg/kg. N-(1-(2-benzo(b) thiophenyl)cyclohexyl)piperidine (BTCP), desipramine, and atropine showed a more efficient prevention of 3H-TCP binding in the cerebellum than in the cerebrum. The prevention of the binding by TCP or PCP, at doses close to their ID50 values, was rapid and then decreased slowly. The effect of MK-801 was long-lasting. This study confirm previous in vitro studies: 3H-TCP is an efficient tool for the labeling of the NMDA receptor-associated ionic channel.

  10. Structural basis for recognition of H3K56-acetylated histone H3-H4 by the chaperone Rtt106

    SciTech Connect

    Su, Dan; Hu, Qi; Li, Qing; Thompson, James R; Cui, Gaofeng; Fazly, Ahmed; Davies, Brian A; Botuyan, Maria Victoria; Zhang, Zhiguo; Mer, Georges

    2013-04-08

    Dynamic variations in the structure of chromatin influence virtually all DNA-related processes in eukaryotes and are controlled in part by post-translational modifications of histones. One such modification, the acetylation of lysine 56 (H3K56ac) in the amino-terminal α-helix (αN) of histone H3, has been implicated in the regulation of nucleosome assembly during DNA replication and repair, and nucleosome disassembly during gene transcription. In Saccharomyces cerevisiae, the histone chaperone Rtt106 contributes to the deposition of newly synthesized H3K56ac-carrying H3-H4 complex on replicating DNA, but it is unclear how Rtt106 binds H3-H4 and specifically recognizes H3K56ac as there is no apparent acetylated lysine reader domain in Rtt106. Here, we show that two domains of Rtt106 are involved in a combinatorial recognition of H3-H4. An N-terminal domain homodimerizes and interacts with H3-H4 independently of acetylation while a double pleckstrin-homology (PH) domain binds the K56-containing region of H3. Affinity is markedly enhanced upon acetylation of K56, an effect that is probably due to increased conformational entropy of the αN helix of H3. Our data support a mode of interaction where the N-terminal homodimeric domain of Rtt106 intercalates between the two H3-H4 components of the (H3-H4)2 tetramer while two double PH domains in the Rtt106 dimer interact with each of the two H3K56ac sites in (H3-H4)2. We show that the Rtt106-(H3-H4)2 interaction is important for gene silencing and the DNA damage response.

  11. Differential visualization of dopamine and norepinephrine uptake sites in rat brain using (/sup 3/H)mazindol autoradiography

    SciTech Connect

    Javitch, J.A.; Strittmatter, S.M.; Snyder, S.H.

    1985-06-01

    Mazindol is a potent inhibitor of neuronal dopamine (DA) and norepinephrine (NE) uptake. DA and NE uptake sites in rat brain have been differentially visualized using (/sup 3/H)mazindol autoradiography. At appropriate concentrations, desipramine (DMI) selectively inhibits (/sup 3/H)mazindol binding to NE uptake sites without significantly affecting binding to DA uptake sites. The localization of DMI-insensitive specific (/sup 3/H) mazindol binding, reflecting DA uptake sites, is densest in the caudate-putamen, the nucleus accumbens, the olfactory tubercle, the subthalamic nucleus, the ventral tegmental area, the substantia nigra (SN) pars compacta, and the anterior olfactory nuclei. In contrast, the localization of DMI-sensitive specific (/sup 3/H)mazindol binding, representing NE uptake sites, is densest in the locus coeruleus, the nucleus of the solitary tract, the bed nucleus of the stria terminalis, the paraventricular and periventricular nuclei of the hypothalamus, and the anteroventral thalamus. The distribution of DMI-insensitive specific (/sup 3/H)mazindol binding closely parallels that of dopaminergic terminal and somatodendritic regions, while the distribution of DMI-sensitive specific (/sup 3/H)mazindol binding correlates well with the regional localization of noradrenergic terminals and cell bodies. Injection of 6-hydroxydopamine, ibotenic acid, or colchicine into the SN decreases (/sup 3/H)mazindol binding to DA uptake sites in the ipsilateral caudate-putamen by 85%. In contrast, ibotenic acid lesions of the caudate-putamen do not reduce (/sup 3/H)mazindol binding to either the ipsilateral or contralateral caudate-putamen.

  12. The Ortho-to-Para Ratio and the Chemical Properties of C3 H2 in Dark Cloud Cores

    NASA Astrophysics Data System (ADS)

    Takakuwa, Shigehisa; Kawaguchi, Kentarou; Mikami, Hitomi; Saito, Masao

    2001-04-01

    We have observed cyclic C3H2 (JKaKc = 212-101, 202 - 111, 312 - 303) lines at the 3 mm wavelength region toward the starless TMC-1C cloud and the protostellar core of L 1527 with the 45 m telescope at Nobeyama Radio Observatory. In both clouds, the 212-101 and 202 - 111 lines are strongly detected, while the 312 - 303 line is only detected toward the center of the protostellar core L 1527. From our statistical equilibrium analyses of the ortho-C3H2(212-101) and the para-C3H2(202-111)lines, the ortho-to-para ratios of C3H2 are determined to be 2.4 +/- 0.1 and 2.5 +/- 0.5 in TMC-1C and L 1527, respectively. These values are lower than the statistical value of 3, although the error of the ratio in L 1527 is large. Since thermal equilibrium with a dust temperature of 10 K still gives a ratio of 3 in c-C3H2, this result should suggest the lower ortho-to-para ratio of the precursor molecule, c-C3H+3, which is thought to be mainly produced by C3H++H2. Thus, we conclude that the lower ortho-to-para ratio of c-C3H2 is due to a lower ortho-to-para ratio of H2 than the statistical value.

  13. ( sup 3 H)TA-3090, a selective benzothiazepine-type calcium channel receptor antagonist: In vitro characterization

    SciTech Connect

    Zobrist, R.H.; Mecca, T.E. )

    1990-05-01

    Binding of the new benzothiazepine calcium channel blocker, (+)-(2S,3S)-3-acetoxy-8-chloro-5-(2-(dimethylamino)ethyl)-2,3-dihydro-2- (4- methoxyphenyl)-1,5-benzothiazepine-4-(5H)-one maleate, (3H)TA-3090, was characterized and its specificity for rat myocardial benzothiazepine receptors described. Scatchard plots and nonlinear regression analysis of specific (3H)TA-3090 binding best fit a one-site binding model (Kd = 8.8 +/- 2.7 nM, Bmax = 132 +/- 38 fmol/mg protein). Kinetically derived affinity constants were in close agreement (Kd = 7.86 nM) with those obtained from analysis of equilibrium binding data. In comparison, under identical conditions (3H)diltiazem exhibited a Kd of 38 nM and Bmax, 106 fmol/mg protein. Specific binding was saturable, reversible and stereoselective (d-cis-TA-3090 Ki = 14 nM; 1-cis-TA-3090 Ki = 2700 nM). Competitions for (3H)TA-3090 binding were conducted with nifedipine, propranolol, prazosin, quinuclidinyl benzilate, verapamil and yohimbine. Only the calcium channel blockers nifedipine and verapamil inhibited specific (3H)TA-3090 binding. Nifedipine could maximally inhibit only 52% of specifically bound (3H)TA-3090 at 10 microM. In contrast, however, 10 microM verapamil completely inhibited specific radioligand binding (Ki = 93 +/- 28 nM) but with six times less efficacy than TA-3090. Thus, these data demonstrate that (3H)TA-3090 is a potent radioligand selective for the benzothiazepine binding site and is consistent with the hypothesis that (3H)TA-3090 interacts with a myocardial benzothiazepine receptor site.

  14. Psychotomimetic opiate receptors labeled and visualized with (+)-(/sup 3/H)3-(3-hydroxyphenyl)-N-(1-propyl)piperidine

    SciTech Connect

    Largent, B.L.; Gundlach, A.L.; Snyder, S.H.

    1984-08-01

    3-(3-Hydroxyphenyl)-N-(1-propyl)piperidine (3-PPP) has been proposed as a selective dopamine autoreceptor agonist in the central nervous system. This report describes the pharmacology and localization of specific high-affinity binding sites for (+)-(/sup 3/H)3-PPP in brain. The drug specificity of (+)-(/sup 3/H)3-PPP binding is identical to that of sigma receptors, which may mediate psychotomimetic effects of some opiates. Haloperidol and the opioid derivatives, pentazocine, cyclazocine, and SKF 10,047 are potent inhibitors of (+)-(/sup 3/H)3-PPP binding. Stereoselectivity is exhibited for the (+) isomers of cyclazocine and SKF 10.047 at the sigma site, opposite to the stereoselectivity seen at ..mu.., sigma, and k opiate receptors. (+)-(/sup 3/H)3-PPP does not label dopamine receptors, as potent dopamine agonists and antagonists are weak inhibitors of binding and the localization of specific (+)-(/sup 3/H)3-PPP binding sites does not parallel that of dopamine neurons. Discrete localizations of (+)-(/sup 3/H)3-PPP binding sites in many brain areas including limbic, midbrain, brainstem, and cerebellar regions may explain psychotomimetic actions of opiates and behavior effects of 3-PPP. 41 references, 2 figures, 1 table.

  15. Validation of ( sup 3 H)thymidine incorporation and its application to detecting natural transformation in the marine environment

    SciTech Connect

    Jeffrey, W.H.

    1989-01-01

    The ({sup 3}H)thymidine incorporation method to estimate bacterial DNA synthesis and heterotrophic production was examined by investigating the four major factors and assumptions associated with the technique. When compared to fluorometrically determined rates of DNA synthesis, ({sup 3}H)thymidine incorporation consistently underestimated DNA synthesis by 6 to 8-fold, indicating the inability of ({sup 3}H)thymidine incorporation and isotope dilution assays to accurately determine the amount of thymine bases incorporated into DNA. Non-specific labeling of macromolecules other than DNA was ubiquitous and the percentage of radioactivity incorporated into DNA was inversely related to total rates thymidine incorporation but independent of any other parameter examined. The use of specific inhibitors and a comparison of (methyl-{sup 3}H)thymidine with (6-{sup 3}H)thymidine indicated that non-specific labelling was not the result of a demethylation reaction but the result of ({sup 3}H)thymine catabolism. Four of the 41 marine bacterial isolates examined were incapable of incorporating thymidine into DNA and lacked thymidine transport and thymidine kinase activity. Transformation of an E. coli tdk into one of these organisms resulted in high levels of thymidine kinase activity but no capacity to incorporate or transport thymidine by this organism.

  16. Degassing of 3H/ 3He, CFCs and SF 6 by denitrification: Measurements and two-phase transport simulations

    NASA Astrophysics Data System (ADS)

    Visser, Ate; Schaap, Joris D.; Broers, Hans Peter; Bierkens, Marc F. P.

    2009-01-01

    The production of N 2 gas by denitrification may lead to the appearance of a gas phase below the water table prohibiting the conservative transport of tracer gases required for groundwater dating. We used a two-phase flow and transport model (STOMP) to study the reliability of 3H/ 3He, CFCs and SF 6 as groundwater age tracers under agricultural land where denitrification causes degassing. We were able to reproduce the amount of degassing ( R2 = 69%), as well as the 3H ( R2 = 79%) and 3He* ( R2 = 76%) concentrations observed in a 3H/ 3He data set using simple 2D models. We found that the TDG correction of the 3H/ 3He age overestimated the control 3He/ 3He age by 2.1 years, due to the accumulation of 3He* in the gas phase. The total uncertainty of degassed 3H/ 3He ages of 6 years (± 2 σ) is due to the correction of degassed 3He* using the TDG method, but also due to the travel time in the unsaturated zone and the diffusion of bomb peak 3He*. CFCs appear to be subject to significant degradation in anoxic groundwater and SF 6 is highly susceptible to degassing. We conclude that 3H/ 3He is the most reliable method to date degassed groundwater and that two-phase flow models such as STOMP are useful tools to assist in the interpretation of degassed groundwater age tracer data.

  17. Autoradiographic localization of dopamine DA1 receptors in rat kidney with ( sup 3 H)Sch 23390

    SciTech Connect

    Huo, T.; Healy, D.P. )

    1989-09-01

    Dopamine receptors in the rat kidney were characterized by homogenate binding and in vitro autoradiography using the dopamine 1 (DA1)-selective antagonist ({sup 3}H)Sch 23390. ({sup 3}H)Sch 23390 binding in cortical membrane preparations was saturable, stereoselective, and competed for by DA agonists and antagonists with a rank order of potency consistent with the labeling of the DA1 receptor. ({sup 3}H)Sch 22390 binding was best fit to a two-site model: a high affinity-low density site (KD1 4.9 +/- 1.4 nM, Bmax 1 31.4 +/- 13.8 fmol/mg protein) and a low affinity-high density site (KD2 86.4 +/- 23.9 nM, Bmax 2 848.0 +/- 227.4 fmol/mg protein). In vitro autoradiography indicated that ({sup 3}H)Sch 22390 binding sites were restricted to the cortex. High-resolution autoradiography further indicated that ({sup 3}H)Sch 22390 binding sites were localized primarily on proximal tubules. Glomeruli and other vascular elements were devoid of ({sup 3}H)Sch 23390 binding sites. These results suggest that DA and DA1 agonists may affect sodium excretion by a direct action on proximal tubule sodium reabsorption.

  18. Morphological and biochemical studies of canine progressive rod-cone degeneration. /sup 3/H-fucose autoradiography

    SciTech Connect

    Aguirre, G.; O'Brien, P.

    1986-05-01

    Visual cell pathology and rod outer segment renewal were investigated in normal and PRCD-affected miniature poodles using /sup 3/H-fucose autoradiography. Twenty-four hours following the intravitreal injection of /sup 3/H-fucose, label accumulated diffusely over cone OS and in a banded pattern at the rod OS base. In normal rods, the band of /sup 3/H-label was displaced sclerad with time. PRCD-affected rods in the early stages of the disease (stages 0-1) also showed a similar /sup 3/H-label pattern but a significantly (P less than 0.001) reduced renewal rate (control = 2.35 +/- 0.43 mu/24 hr; affected = 0.99 +/- mu/24 hr). This abnormal renewal rate was present in central, equatorial, and peripheral visual cells and was not associated with the presence or density of pigment in the RPE cell layer. Biochemical studies indicated that the /sup 3/H-label was present as an integral membrane component in the rod OS and confirmed that canine rhodopsin is a fucosylated glycoprotein. The /sup 3/H-band in the rod OS layer disappeared in stage 2 of the disease; diffuse label now was present over rod OS that had decreased length and were reduced in number. At this stage of the disease, interphotoreceptor space was invaded by phagocytic cells, and photoreceptor nuclei were lost from the outer nuclear layer. These late degenerative changes were more extensive in the superior and inferior retinal meridians.

  19. Monodispersed Hollow SO3H-Functionalized Carbon/Silica as Efficient Solid Acid Catalyst for Esterification of Oleic Acid.

    PubMed

    Wang, Yang; Wang, Ding; Tan, Minghui; Jiang, Bo; Zheng, Jingtang; Tsubaki, Noritatsu; Wu, Mingbo

    2015-12-01

    SO3H-functionalized monodispersed hollow carbon/silica spheres (HS/C-SO3H) with primary mesopores were prepared with polystyrene as a template and p-toluenesulfonic acid (TsOH) as a carbon precursor and -SO3H source simultaneously. The physical and chemical properties of HS/C-SO3H were characterized by N2 adsorption, TEM, SEM, XPS, XRD, Raman spectrum, NH3-TPD, element analysis and acid-base titration techniques. As a solid acid catalyst, HS/C-SO3H shows excellent performance in the esterification of oleic acid with methanol, which is a crucial reaction in biodiesel production. The well-defined hollow architecture and enhanced active sites accessibility of HS/C-SO3H guarantee the highest catalytic performance compared with the catalysts prepared by activation of TsOH deposited on the ordered mesoporous silicas SBA-15 and MCM-41. At the optimized conditions, high conversion (96.9%) was achieved and no distinct activity drop was observed after 5 recycles. This synthesis strategy will provide a highly effective solid acid catalyst for green chemical processes. PMID:26588826

  20. Effect of morphine on /sup 3/H-thymidine incorporation in the subependyma of the rat: an autoradiographic study

    SciTech Connect

    Miller, C.R.; O'Steen, W.K.; Deadwyler, S.A.

    1982-06-20

    Following morphine treatment, an autoradiographic study investigated the uptake of /sup 3/H-thymidine by the subependymal cells in the rat brain. /sup 3/H-thymidine was administered subcutaneously to adult, male Sprague-Dawley rats 30 minutes after saline or morphine (19 mg/kg) injection. The animals were sacrified 1 hour after /sup 3/H-thymidine administration. In some experiments the opioid antagonist, naloxone, was given alone 45 minutes before /sup 3/H-thymidine or 125 minutes before morphine treatment. Three areas of the subependyma were evaluated in terms of the percentage labeled cells and number of grains per nucleus, and a dorsal-to-ventral gradiant was described. Morphine treatment significantly increased the number of /sup 3/H-thymidine labeled subependymal cells and number of grains/nucleus within labeled cells. Examination of the distribution of grains/nucleus showed that morphine-treated animals had significantly more cells labeled with 30 or more grains than did saline-injected controls. Prior administration of naloxone blocked the increased /sup 3/H-thymidine uptake in morphine-treated animals but had no significant influence on cell proliferation when administered alone. The data are discussed in terms of morphine's possible dual influence on mechanisms which enhance cell transition from G to S phase and/or which accelerate DNA synthesis once these cells have entered the S phase of cell replication.

  1. (/sup 3/H)Spiroxatrine labels a serotonin/sub 1A/-like site in the rat hippocampus

    SciTech Connect

    Nelson, D.L.; Monroe, P.J.; Lambert, G.; Yamamura, H.I.

    1987-09-28

    (/sup 3/H)Spiroxatrine was examined as a potential ligand for the labeling of 5-HT/sub 1A/ sites in the rat hippocampus. Analysis o the binding of (/sup 3/H)spiroxatrine in the absence and presence of varying concentrations of three monoamine neurotransmitters revealed that serotonin (5-HT) had high affinity for the (/sup 3/H)spiroxatrine binding sites, consistent with the labeling of 5-HT/sub 1/ sites, while dopamine and norepinephrine had very low affinity. Saturation studies of the binding of (/sup 3/H)spiroxatrine revealed a single population of sites with a K/sub d/ = 2.21 nM. Further pharmacologic characterization with the 5-HT/sub 1A/ ligands 8-hydroxy-2-(di-ni-propylamino)tetralin, ipsapirone, and WB4101 and the butyrophenone compounds spiperone and haloperidol gave results that were consistent with (/sup 3/H)spiroxatrine labeling 5-HT/sub 1A/ sites. This ligand produced stable, reproducible binding with a good ratio of specific to nonspecific binding. The binding of (/sup 3/H)spiroxatrine was sensitive to GTP, suggesting that this ligand may act as an agonist. 21 references, 5 figures, 2 tables.

  2. Molecular evolution of NASP and conserved histone H3/H4 transport pathway

    PubMed Central

    2014-01-01

    Background NASP is an essential protein in mammals that functions in histone transport pathways and maintenance of a soluble reservoir of histones H3/H4. NASP has been studied exclusively in Opisthokonta lineages where some functional diversity has been reported. In humans, growing evidence implicates NASP miss-regulation in the development of a variety of cancers. Although a comprehensive phylogenetic analysis is lacking, NASP-family proteins that possess four TPR motifs are thought to be widely distributed across eukaryotes. Results We characterize the molecular evolution of NASP by systematically identifying putative NASP orthologs across diverse eukaryotic lineages ranging from excavata to those of the crown group. We detect extensive silent divergence at the nucleotide level suggesting the presence of strong purifying selection acting at the protein level. We also observe a selection bias for high frequencies of acidic residues which we hypothesize is a consequence of their critical function(s), further indicating the role of functional constraints operating on NASP evolution. Our data indicate that TPR1 and TPR4 constitute the most rapidly evolving functional units of NASP and may account for the functional diversity observed among well characterized family members. We also show that NASP paralogs in ray-finned fish have different genomic environments with clear differences in their GC content and have undergone significant changes at the protein level suggesting functional diversification. Conclusion We draw four main conclusions from this study. First, wide distribution of NASP throughout eukaryotes suggests that it was likely present in the last eukaryotic common ancestor (LECA) possibly as an important innovation in the transport of H3/H4. Second, strong purifying selection operating at the protein level has influenced the nucleotide composition of NASP genes. Further, we show that selection has acted to maintain a high frequency of functionally relevant

  3. Thrombin Ca(2+)-dependently stimulates protein tyrosine phosphorylation in BC3H1 muscle cells.

    PubMed Central

    Offermanns, S; Bombien, E; Schultz, G

    1993-01-01

    The proteinase thrombin, known to act via heptahelical G-protein-coupled receptors, is a mitogenic agent for different cell types, including the mouse muscle cell line BC3H1. In this study, the effect of thrombin on tyrosine phosphorylation was examined using anti-phosphotyrosine antibodies. Thrombin was found to induce phosphorylation of 65-70 and 110-120 kDa proteins in BC3H1 cells. The effect of thrombin was concentration-dependent, being half-maximal and maximal at concentrations of 0.03 and 1 unit/ml respectively. The thrombin-induced increase in phosphorylation was rapid (< or = 10 s) and transient, with a peak response after about 1-2 min. The effect of thrombin could be mimicked by the thrombin receptor agonist peptide SFLLRN-NH2. Preincubation of cells with pertussis toxin (PT) had no effect on thrombin-induced tyrosine phosphorylation. Epidermal growth factor, platelet-derived growth factor and insulin stimulated tyrosine phosphorylation of different proteins, among which were 65-70 and 110-120 kDa proteins. The phorbol ester 12-myristate 13-acetate (PMA) as well as the Ca2+ ionophore A23187 both stimulated tyrosine phosphorylation of proteins identical to those phosphorylated by thrombin, suggesting that activation of protein kinase C (PKC) and elevation of the cytosolic Ca2+ concentration alone are sufficient to induce tyrosine phosphorylation. However, calphostin C and other PKC inhibitors, which completely inhibited tyrosine phosphorylation induced by PMA, had no influence on the effect of thrombin, whereas loading of cells with the intracellular Ca2+ chelator bis-(O-aminophenoxy)ethane-NNN'N'-tetra-acetic acid totally blocked thrombin-stimulated tyrosine phosphorylation. Thus tyrosine phosphorylation stimulated by thrombin is an early PT-insensitive cellular response which is either directly mediated by elevation of cytosolic Ca2+ concentration or by a presently unknown mechanism that requires an elevated cytosolic Ca2+ concentration. Images Figure 1

  4. Origins of enigmatic C-3 methyl and C-3 H porphyrins in ancient sediments revealed from formation of pyrophaeophorbide d in simulation experiments

    NASA Astrophysics Data System (ADS)

    Pickering, Matthew D.; Keely, Brendan J.

    2013-03-01

    The reaction of methyl pyrophaeophorbide a with hydrogen sulfide and oxygen under mild conditions (low temperature, moderate pH), which resemble those in certain natural environments, leads to its near quantitative conversion into methyl pyrophaeophorbide d (82-89%). The transformation, via oxidative cleavage of the C-3 vinyl substituent of pyrophaeophorbide a to afford an aldehyde at C-3, results from co-oxidation of the vinyl group and hydrogen sulfide by molecular oxygen. The co-oxidation transformation pathway operating on vinyl substituted chlorophyll derivatives can explain the origins of C-3 methyl and C-3 H porphyrins in ancient sediments and oils, structures for which the origins were previously unresolved. Evaluation of previous reports of C-3 methyl and C-3 H porphyrins in ancient sediments and oils reveals that their distributions are consistent with insights provided from analysis of the reaction mechanisms revealed by the laboratory studies. Thus, the sedimentary distributions reveal key features of the depositional settings, in particular the presence of a deep or a shallow chemocline. The oxidative cleavage of the C-3 vinyl group also provides insight into the biosynthesis of chlorophyll d by the cyanobacterium Acaryochloris marina, and offers a mild alternative to classical methods for the synthetic manipulation of the vinyl substituents of tetrapyrroles.

  5. Kinetics and Mechanism of the Hydrogenation of CpCr(CO)3•/[CpCr(CO)3]2 Equilibrium to CpCr(CO)3H

    SciTech Connect

    Norton, Jack R.; Spataru, Tudor; Camaioni, Donald M.; Lee, Suh-Jane; Li, Gang; Choi, Jongwook; Franz, James A.

    2014-05-26

    The kinetics of the hydrogenation of 2 CpCr(CO)3•/[CpCr(CO)3]2 to CpCr(CO)3H has been investigated. The reaction is second-order in Cr and first-order in H2, with a rate constant of 45 M 2s 1 at 25 °C in benzene. DFT calculations rule out an H2 complex as an intermediate, and suggest (a) end-on approach of H2 to one Cr of [CpCr(CO)3]2 as the Cr-Cr bond undergoes heterolytic cleavage, (b) heterolytic cleavage of the coordinated H2 between O and Cr, and (c) isomerization of the resulting O-protonated CpCr(CO)2(COH) to CpCr(CO)3H. The work at Pacific Northwest National Laboratory (PNNL) was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences and Biosciences; Battelle operates PNNL for DOE.

  6. Comparison of the metabolism of [1,2,6,7-3H(N)]cholesteryl oleate, cholesteryl [9,10-3H]oleate, and cholesteryl [1-14C]oleate labeled lipoproteins in the rat.

    PubMed

    Terpstra, A H

    1994-04-01

    The intravascular metabolism of sterol labeled [1,2,6,7-3H(N)]cholesteryl oleate and acyl labeled cholesteryl [9,10-3H]oleate and cholesteryl [1-14C]oleate was compared in the rat, an animal species without plasma cholesteryl ester transfer activity (CETA). In a first series of studies, the metabolism of sterol labeled [1,2,6,7-3H(N)]cholesteryl oleate and acyl labeled cholesteryl [1-14C]oleate was compared, and the two tracers had identical plasma clearance rates when incorporated into human low density lipoproteins (LDL). The 3H sterol labeled cholesteryl ester (CE), however, had a plasma clearance rate lower than the 14C acyl labeled CE when incorporated into rat alpha- and beta-migrating LDL and human or rat high density lipoproteins (HDL). Unesterified 3H cholesterol reappeared in the plasma whereas the 14C radioactivity in the plasma remained associated with the CE. In a second set of studies, LDL and HDL were radiolabeled with cholesteryl [9,10-3H]oleate and cholesteryl [1-14C]oleate. Large amounts of 3H radioactivity that were dialyzable and not associated with the lipoprotein CE reappeared in the plasma during the kinetic studies. The two tracers had identical plasma disappearance rates when the plasma samples were dialyzed. The results of these studies indicate that the nature of the tracer used to trace lipoprotein CE can affect the estimated kinetic parameters of plasma CE. PMID:8060380

  7. Radioautographic visualization of differences in the pattern of (/sup 3/H)uridine and (/sup 3/H)orotic acid incorporation into the RNA of migrating columnar cells in the rat small intestine

    SciTech Connect

    Uddin, M.; Altmann, G.G.; Leblond, C.P.

    1984-05-01

    The epithelium of rat small intestine was radioautographed to examine whether RNA is synthesized by the salvage pathway as shown after (/sup 3/H)uridine injection or by the de novo pathway as shown after (/sup 3/H)orotic acid injection. The two modes of RNA synthesis were thus investigated during the migration of columnar cells from crypt base to villus top, and the rate of synthesis was assessed by counting silver grains over the nucleolus and nucleoplasm at six levels along the duodenal epithelium - that is, in the base, mid, and top regions of the crypts and in the base, mid, and top regions of the villi. Concomitant biochemical analyses established that, after injection of either (5-/sup 3/H)uridine or (5-/sup 3/H)orotic acid: (a) buffered glutaraldehyde fixative was as effective as perchloric acid or trichloroacetic acid in insolubilizing the nucleic acids of rat small intestine; (b) a major fraction of the nucleic acid label was in RNA, that is, 91% after (/sup 3/H)uridine and 72% after (/sup 3/H)orotic acid, with the rest in DNA; and (c) a substantial fraction of the RNA label was in poly A/sup +/ RNA (presumed to be messenger RNA). In radioautographs of duodenum prepared after (/sup 3/H)uridine injection, the count of silver grains was high over nucleolus and nucleoplasm in crypt base cells and gradually decreased at the upper levels up to the villus base. In the rest of the villus, the grain count over the nucleolus was negligible, while over the nucleoplasm it was low but significant.

  8. /sup 3/H)-(H-D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2) ((/sup 3/H)CTOP), a potent and highly selective peptide for mu opioid receptors in rat brain

    SciTech Connect

    Hawkins, K.N.; Knapp, R.J.; Lui, G.K.; Gulya, K.; Kazmierski, W.; Wan, Y.P.; Pelton, J.T.; Hruby, V.J.; Yamamura, H.I.

    1989-01-01

    The cyclic, conformationally restricted octapeptide (3H)-(H-D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2) ((3H)CTOP) was synthesized and its binding to mu opioid receptors was characterized in rat brain membrane preparations. Association rates (k+1) of 1.25 x 10(8) M-1 min-1 and 2.49 x 10(8) M-1 min-1 at 25 and 37 degrees C, respectively, were obtained, whereas dissociation rates (k-1) at the same temperatures were 1.93 x 10(-2) min-1 and 1.03 x 10(-1) min-1 at 25 and 37 degrees C, respectively. Saturation isotherms of (3H)CTOP binding to rat brain membranes gave apparent Kd values of 0.16 and 0.41 nM at 25 and 37 degrees C, respectively. Maximal number of binding sites in rat brain membranes were found to be 94 and 81 fmol/mg of protein at 25 and 37 degrees C, respectively. (3H)CTOP binding over a concentration range of 0.1 to 10 nM was best fit by a one site model consistent with binding to a single site. The general effect of different metal ions and guanyl-5'-yl-imidodiphosphate on (3H)CTOP binding was to reduce its affinity. High concentrations (100 mM) of sodium also produced a reduction of the apparent mu receptor density. Utilizing the delta opioid receptor specific peptide (3H)-(D-Pen2,D-Pen5)enkephalin, CTOP appeared to be about 2000-fold more specific for mu vs. delta opioid receptor than naloxone. Specific (3H)CTOP binding was inhibited by a large number of opioid or opiate ligands.

  9. Uptake of 3H-7-cholesterol along the arterial wall at an area of stenosis.

    PubMed

    Deng, X; Marois, Y; King, M W; Guidoin, R

    1994-01-01

    Abnormal uptake of atherogenic substances and lipid infiltration have been believed to contribute to the localized genesis and development of atherosclerosis, as well as to late failures of synthetic arterial prostheses. To verify the theoretical prediction that accumulation of lipoproteins on the luminal surface of arterial walls occurs in the regions of disturbed flow, we have carried out an in vitro mass transfer experiment to test the effect of a pseudo steady recirculation flow on the uptake of 3H-7-cholesterol by the arterial wall at a surgically created stenosis. It was found that, as predicted by the theory, in the flow field of the stenosis the uptake of labeled cholesterol reached a maximum around the reattachment point of the vortex distal to the stenosis, where the wall shear stress was lowest (zero). This value of the highest uptake rate was almost twice the average, whereas the uptake level was at a minimum at the stenosis itself where the wall shear stress was highest. The lowest uptake was only 60% of the average. These results provide strong support to our hypothesis, based upon the theory that, in addition to the flow induced changes to the biologic function of endothelial cells, the disturbed flow with slow recirculation itself favors the accumulation of atherogenic lipoproteins at the blood-endothelium boundary, therefore playing an important role in the localized pathogenesis and development of atherosclerosis. PMID:8003757

  10. 2-Arylquinazolin-4(3H)-ones: A novel class of thymidine phosphorylase inhibitors.

    PubMed

    Javaid, Sumaira; Saad, Syed Muhammad; Perveen, Shahnaz; Khan, Khalid Mohammed; Choudhary, M Iqbal

    2015-12-01

    Thymidine phosphorylase (TP) over expression plays an important role in several pathological conditions, such as rheumatoid arthritis, chronic inflammatory diseases, psoriasis, and tumor angiogenesis. In this regard, a series of twenty-five 2-arylquinazolin-4(3H)-one derivatives 1-25 were evaluated for thymidine phosphorylase inhibitory activity. Six compounds 5, 6, 20, 2, 23, and 3 were found to be active against thymidine phosphorylase enzyme with IC50 values in the range of 42.9-294.6μM. 7-Deazaxanthine (IC50=41.0±1.63μM) was used as a standard inhibitor. Compound 5 showed a significant activity (IC50=42.9±1.0μM), comparable to the standard. The enzyme kinetic studies on the most active compounds 5, 6, and 20 were performed for the determination of their modes of inhibition, and dissociation constants Ki. All active compounds were found to be largely non-cytotoxic against the mouse fibroblast 3T3 cell line. This study identifies a novel class of thymidine phosphorylase inhibitors which may be further investigated as leads to develop therapeutic agents. PMID:26547232

  11. Reaction paths in the system Al 2O 3-hBN-Y

    NASA Astrophysics Data System (ADS)

    Reichert, K.; Oreshina, O.; Cremer, R.; Neuschütz, D.

    2001-07-01

    As part of the investigations on the suitability of a new concept for a tailored fiber-matrix interface in sapphire fiber reinforced NiAl matrix composites for application as a high-temperature structural material, the interfacial reactions in the system alumina-hexagonal boron nitride-yttrium (Al 2O 3-hBN-Y) have been examined in the temperature range of 1100-1300°C. For this, alumina substrates were coated with hBN by means of CVD and subsequently with sputter deposited yttrium. Afterwards the samples were annealed for up to 16 h under inert atmosphere. Grazing incidence X-ray diffraction (GIXRD) served to analyze the phases formed by diffusion processes in the reaction zone. The peak intensities in these diffraction patterns were used to evaluate the sequence of phases formed due to diffusion and reaction. After the initial formation of YN and YB 2, the phases Y 2O 3, Al 2Y, and YB 4 were observed. Even longer annealing times or higher temperatures, respectively, led to the formation of the ternary oxides YAlO 3 and Y 3Al 5O 12 as well as metallic aluminum.

  12. Receptors for /sup 3/H-octopamine in the adult firefly light organ

    SciTech Connect

    Hashemzadeh, H.; Hollingworth, R.M.; Voliva, A.

    1985-08-05

    /sup 3/H-Octopamine binds reversibly and with high affinity to sites on adult firefly light organ membranes. The binding is characterized by multiple affinities. Scatchard analysis supported a two site binding model with a tentative Kd value of about 1 nM for the high affinity component. The more abundant lower affinity site had a Kd value of about 60 nM. Guanyl nucleotides (Gpp(NH)p and GTP) greatly reduced the apparent number of octopamine binding sites. Competition studies with known octopaminergic agonists including the formamidine pesticides chlordimeform (CDM) and N-demethylchlordimeform (DCDM) showed the following rank order of potencies in displacing octopamine: DCDM > octopamine = synephrine > naphazoline > clonidine > CDM. It was also observed that phentolamine was much more active than propranolol in antagonizing OA-binding. These relative activities are similar to the abilities of the same compounds to alter adenylate cyclase activity in light organ homogenates. Together with the effect of GTP on binding, these results suggest that the binding sites are functional octopamine receptors of the light organ. 27 references, 3 figures, 1 table.

  13. Localization of /sup 3/H-estradiol in the reproductive organs of male and female baboons

    SciTech Connect

    Weaker, F.J.; Sheridan, P.J.

    1982-05-01

    The uptake and retention of radiolabeled estradiol by both the male and female reproductive organs were examined in the baboon. Two male and two female baboons were injected intracardially with 1 microgram/kg body weight of /sup 3/H-estradiol and two animals, one male and one female, were injected with both labeled and 100 micrograms/kg body weight of unlabeled estradiol. One and a half hours after the injections, the animals were sacrificed and the uterus, cervix, vagina, oviduct, seminal vesicles, and prostate gland were removed and processed for autoradiography. The stratified squamous epithelia of the cervix and vagina demonstrated a light uptake of the label in the germinative, but not in the superficial cell layers. The columnar cells lining the oviduct and uterine glands were labeled, whereas the luminal epithelium of the uterus and the glandular epithelia of the seminal vesicles and prostate gland did not sequester the tritiated steroid. The interstitial cells of all the organs studied demonstrated a moderate to heavy uptake of the radioactivity, whereas the smooth muscle cells were lightly labeled except in the vagina, in which these cells displayed a moderate number of silver grains.

  14. Microsystem to evaluate the incorporation of 3H-uridine in macrophage RNA

    SciTech Connect

    Varesio, L.; Naglich, J.; Brunda, M.J.; Taramelli, D.; Eva, A.

    1981-01-01

    A method is described for the evaluation of the total 3H-uridine incorporated by macrophages in vitro into trichloroacetic acid (TCA)-precipitable material. The technique is based upon solubilization of the macrophage monolayers by guanidine-HC1, followed by TCA precipitation. The recovery of RNA into the precipitate and the reproducibility of the results were strictly dependent on the use of filtered reagents and on incubation of the TCA precipitate for 2 or more hours at 4 degree C before harvesting. Treatment with quanidine-HC1 did not affect the recovery of labeled RNA. Moreover, we observed that radioactive precipitate had the characteristics of RNA, since its recovery was sensitive to the addition of unlabeled uridine in the culture medium and to the treatment of the macrophages with inhibitors of RNA synthesis, but not of protein synthesis. Tritiated uridine incorporation in microcultures of macrophages can be assessed with this technique, by processing the cells directly in the wells. The main advantages of this procedure are: 1) the radioactivity can be measured by semiautomatic cell harvesters, 2) a small number of macrophages are required, and 3) many samples can be processed simultaneously. Overall, the technique is simple, rapid, and could be successfully adapted to study other metabolic pathways.

  15. Redetermination of kovdorskite, Mg2PO4(OH)·3H2O

    PubMed Central

    Morrison, Shaunna M.; Downs, Robert T.; Yang, Hexiong

    2012-01-01

    The crystal structure of kovdorskite, ideally Mg2PO4(OH)·3H2O (dimagnesium phosphate hydroxide trihydrate), was reported previously with isotropic displacement paramaters only and without H-atom positions [Ovchinnikov et al. (1980 ▶). Dokl. Akad. Nauk SSSR. 255, 351–354]. In this study, the kovdorskite structure is redetermined based on single-crystal X-ray diffraction data from a sample from the type locality, the Kovdor massif, Kola Peninsula, Russia, with anisotropic displacement parameters for all non-H atoms, with all H-atom located and with higher precision. Moreover, inconsistencies of the previously published structural data with respect to reported and calculated X-ray powder patterns are also discussed. The structure of kovdorskite contains a set of four edge-sharing MgO6 octa­hedra inter­connected by PO4 tetra­hedra and O—H⋯O hydrogen bonds, forming columns and channels parallel to [001]. The hydrogen-bonding system in kovdorskite is formed through the water mol­ecules, with the OH− ions contributing little, if any, to the system, as indicated by the long H⋯A distances (>2.50 Å) to the nearest O atoms. The hydrogen-bond lengths determined from the structure refinement agree well with Raman spectroscopic data. PMID:22346789

  16. Autophagic activity in BC3H1 cells exposed to yessotoxin.

    PubMed

    Korsnes, Mónica Suárez; Kolstad, Hilde; Kleiveland, Charlotte Ramstad; Korsnes, Reinert; Ørmen, Elin

    2016-04-01

    The marine toxin yessotoxin (YTX) can induce programmed cell death through both caspase-dependent and -independent pathways in various cellular systems. It appears to stimulate different forms of cellular stress causing instability among cell death mechanisms and making them overlap and cross-talk. Autophagy is one of the key pathways that can be stimulated by multiple forms of cellular stress which may determine cell survival or death. The present work evaluates a plausible link between ribotoxic stress and autophagic activity in BC3H1 cells treated with YTX. Such treatment produces massive cytoplasmic compartments as well as double-membrane vesicles termed autophagosomes which are typically observed in cells undergoing autophagy. The observed autophagosomes contain a large amount of ribosomes associated with the endoplasmic reticulum (ER). Western blotting analysis of Atg proteins and detection of the autophagic markers LC3-II and SQSTM1/p62 by flow cytometry and immunofluorescence verified autophagic activity during YTX-treatment. The present work supports the idea that autophagic activity upon YTX exposure may represent a response to ribotoxic stress. PMID:26743762

  17. ( sup 3 H)Dopamine uptake by platelet storage granules in schizophrenia

    SciTech Connect

    Rabey, J.M.; Graff, E.; Oberman, Z. ); Lerner, A.; Sigal, M. )

    1992-01-01

    ({sup 3}H)Dopamine (DA) uptake by platelet storage granules was determined in 26 schizophrenic male patients, paranoid type (14 acute stage; 12 in remission) and 20 age-matched, normal controls. maximum velocity (Vmax) of DA uptake was significantly higher in acute patients, than patients in remission or controls (p>0.05). The apparent Michaelis constant (kM) of DA uptake in acute patients was also significantly different from chronic patients a substantial diminution of DA uptake, while haloperidol produced a substantial diminution of DA uptake, while haloperidol (10{sup {minus}4}, 10{sup {minus}5} M) did not affect the assay. Considering that a DA disequilibrium in schizophrenia may be expressed not only in the brain, but also in the periphery and that an increased amount of DA accumulated in the vesicles, implies that an increased quantity of catecholamine is available for release, our findings suggest additional evidence for the role of DA overactivity in the pathophysiology of this disorder.

  18. Autoradiographic study of /sup 3/H-methylated elastase in hamster lungs

    SciTech Connect

    Morris, S.M.; Stone, P.J.; Snider, G.L.; Albright, J.T.; Franzblau, C.

    1983-05-01

    An emphysemalike condition can be induced in animal lungs by the instillation of a single dose of elastase. Autoradiography was used to determine the location of /sup 3/H-methylated porcine pancreatic elastase in hamster lungs at four time points. Six hours after instillation of radiolabeled enzyme the distribution of silver grains was very patchy, but in heavily labeled areas grains were concentrated over macrophages, connective tissue areas and over some fibroblasts. By 24 hr the labeling of connective tissue areas was no longer evident and almost all silver grains were associated with macrophages or with the edema fluid that filled many alveoli at this time. By 4 days only macrophages exhibited concentrations of silver grains. The labeling of macrophages was still evident at 7 days. Elastase inactivated by N-acetyl-(L-alanyl)3-L-alanine chloromethyl ketone showed a different distribution 6 hr after instillation. Silver grains were concentrated over macrophages and alveolar type II cells but showed no affinity for connective tissue areas or fibroblasts. By 24 hr almost all grains were located over heavily labeled macrophages.

  19. Group theoretical analysis of the H3+ +H2 ↔ H5+ reaction

    NASA Astrophysics Data System (ADS)

    Lin, Zhou

    2016-06-01

    The H3+ +H2 →H2 + H3+ proton transfer reaction is complicated due to the proton scrambling from the large amplitude motions in the H5+ intermediate. In order to understand this reaction, high-resolution spectroscopic studies are necessary for the reactants/products and the intermediate, and the group theoretical analysis is an essential aspect in the prediction and interpretation of these spectra. With five indistinguishable protons, H5+ is characterized using the G240 complete nuclear permutation-inversion (CNPI) group. For most of the configurations sampled by the reaction path, the feasible permutations depend on the distance between the H3+ and H2 fragments. Subgroups of G240 can be used to describe these feasible permutations. Specifically, we consider two limits of the molecular configurations. The equilibrium structure of H5+ , i.e., [H2 -H -H2 ]+, can be described using the G16 molecular symmetry group, while the dissociation products, i.e., H3+ ⋯H2 , require the G24 molecular symmetry group. In the present study, a group theoretical analysis is performed for both limits, providing the symmetries for the nuclear spins and rovibrational wave functions. Also, spectroscopic properties for [H2 -H -H2 ]+, particularly rovibrational couplings and electric dipole selection rules, as well as correlations of energy levels between [H2 -H -H2 ]+ and H3+ ⋯H2 , are obtained.

  20. Two nucleotide binding sites modulate ( sup 3 H) glyburide binding to rat cortex membranes

    SciTech Connect

    Johnson, D.E.; Gopalakrishnan, M.; Triggle, D.J.; Janis, R.A. State Univ. of New York, Buffalo )

    1991-03-11

    The effects of nucleotides on the binding of the ATP-dependent K{sup +}-channel antagonist ({sup 3}H)glyburide (GLB) to rat cortex membranes were examined. Nucleotide triphosphates (NTPs) and nucleotide diphosphate (NDPs) inhibited the binding of GLB. This effect was dependent on the presence of dithiothreitol (DTT). Inhibition of binding by NTPs, with the exception of ATP{gamma}S, was dependent on the presence of Mg{sup 2+}. GLB binding showed a biphasic response to ADP: up to 3 mM, ADP inhibited binding, and above this concentration GLB binding increased rapidly, and was restored to normal levels by 10 mM ADP. In the presence of Mg{sup 2+}, ADP did not stimulate binding. Saturation analysis in the presence of Mg{sup 2+} and increasing concentrations of ADP showed that ADP results primarily in a change of the B{sub max} for GLB binding. The differential effects of NTPS and NDPs indicate that two nucleotide binding sites regulate GLB binding.

  1. Medium Modifications from {sup 4}He(e-vector,e'p-vector){sup 3}H

    SciTech Connect

    Malace, S.; Paolone, M.; Strauch, S.

    2008-10-13

    Polarization transfer in quasi-elastic nucleon knockout is sensitive to the properties of the nucleon in the nuclear medium, including possible modification of the nucleon form factor and/or spinor. In our recently completed experiment E03-104 at Jefferson Lab we measured the proton recoil polarization in the {sup 4}He(e-vector,e'p-vector){sup 3}H reaction at a Q{sup 2} of 0.8 (GeV/c){sup 2} and 1.3 (GeV/c){sup 2} with unprecedented precision. These data complement earlier data between 0.4 and 2.6 (GeV/c){sup 2} from both Mainz and Jefferson Lab. The measured ratio of polarization-transfer coefficients differs from a fully relativistic calculation, favoring either the inclusion of a medium modification of the proton form factors predicted by a quark-meson coupling model or strong charge-exchange final-state interactions. The measured induced polarizations agree well with the fully relativistic calculation and indicate that these strong final-state interactions may not be applicable.

  2. Detection of the Elusive Triazane Molecule (N3 H5 ) in the Gas Phase.

    PubMed

    Förstel, Marko; Maksyutenko, Pavlo; Jones, Brant M; Sun, Bing-Jian; Chen, Shih-Hua; Chang, Agnes H-H; Kaiser, Ralf I

    2015-10-26

    We report the detection of triazane (N3 H5 ) in the gas phase. Triazane is a higher order nitrogen hydride of ammonia (NH3 ) and hydrazine (N2 H4 ) of fundamental importance for the understanding of the stability of single-bonded chains of nitrogen atoms and a potential key intermediate in hydrogen-nitrogen chemistry. The experimental results along with electronic-structure calculations reveal that triazane presents a stable molecule with a nitrogen-nitrogen bond length that is a few picometers shorter than that of hydrazine and has a lifetime exceeding 6±2 μs at a sublimation temperature of 170 K. Triazane was synthesized through irradiation of ammonia ice with energetic electrons and was detected in the gas phase upon sublimation of the ice through soft vacuum ultraviolet (VUV) photoionization coupled with a reflectron-time-of-flight mass spectrometer. Isotopic substitution experiments exploiting [D3 ]-ammonia ice confirmed the identification through the detection of its fully deuterated counterpart [D5 ]-triazane (N3 D5 ). PMID:26331382

  3. The equilibrium geometry of the SC3H radical: an ab initio study

    NASA Astrophysics Data System (ADS)

    Flores, J. R.; Gómez, F. J.

    The SC3 H radical is known by experiment to have a linear equilibrium structure, but even rather high-level ab initio computations give a bent equilibrium geometry. A theoretical study of the SCCCH radical has been carried out in order to analyse the influence of several factors in the computed equilibrium structure. Quadratic configuration interaction QCISD(T) and restricted coupled cluster RCCSD(T) computations have been performed in combination with large basis sets. Spin-orbit effects have been taken into account through the Breit-Pauli Hamiltonian using multi-configuration SCF and configuration interaction wavefunctions. Our final results indicate that the equilibrium structure must be linear, in agreement with the experimental studies [MCCARTHY, M. C., VRTILEK, J. M., GOTTLIEB, C. A., WANG, W., and THADDEUS, P., 1994, Astrophys. J., 431, L127; HIRAHARA, Y., OHSHIMA, Y., and ENDO, Y., 1994, J. chem. Phys., 101, 7342]. Both spin-orbit and electron correlation effects appear to be of comparable importance, but an adequate computation of the correlation energy has been much more difficult and has ultimately required bas.is set extrapolations.

  4. H2SO4/HNO3/H2O Phase Diagram in Regions of Stratospheric Importance

    NASA Astrophysics Data System (ADS)

    Beyer, K. D.; Hansen, A. R.; Raddatz, N.

    2003-12-01

    We have investigated the region of the H2SO4/HNO3/H2O ternary liquid/solid phase diagram bounded by ice, nitric acid trihydrate (NAT), and sulfuric acid tetrahydrate (SAT) using differential scanning calorimetry (DSC) and infrared spectroscopy of thin films. We report measurements and analysis of the eutectic melting curves in the ternary system of the hydrates mentioned as well as the temperature of the eutectics: ice/SAT/NAT, ice/sulfuric acid hemihexahydrate (SAH)/NAT, and SAT/NAT. We report for the first time an analysis of the content of the solid phase of completely frozen samples and find that sulfuric acid octahydrate (SAO) is often present in frozen ternary samples and can be a significant portion of the solid phase. We provide a description of how the melting path of a frozen ternary sample can be predicted using the ternary phase diagram. We have parameterized our melting point data and provide equations to generate the ternary melting surface. Finally, we compare our results to the historic work of Carpenter & Lehrmann (Carpenter, C. D.; Lehrman, A. Trans. AIChE 1925, 17, 35) and to other more recent work.

  5. Spinal cord distribution of sup 3 H-morphine after intrathecal administration: Relationship to analgesia

    SciTech Connect

    Nishio, Y.; Sinatra, R.S.; Kitahata, L.M.; Collins, J.G. )

    1989-09-01

    The distribution of intrathecally administered {sup 3}H-morphine was examined by light microscopic autoradiography in rat spinal cord and temporal changes in silver grain localization were compared with results obtained from simultaneous measurements of analgesia. After tissue processing, radio-activity was found to have penetrated in superficial as well as in deeper layers (Rexed lamina V, VII, and X) of rat spinal cord within minutes after application. Silver grain density reached maximal values at 30 min in every region of cord studied. Radioactivity decreased rapidly between 30 min and 2 hr and then more slowly over the next 24 hr. In rats tested for responses to a thermal stimulus (tail flick test), intrathecal administration of morphine (5 and 15 micrograms) resulted in significant dose dependent analgesia that peaked at 30 min and lasted up to 5 hr (P less than 0.5). There was a close relationship between analgesia and spinal cord silver grain density during the first 4 hr of the study. It is postulated that the onset of spinal morphine analgesia depends on appearance of molecules at sites of action followed by the activation of anti-nociceptive mechanisms.

  6. Distribution of /sup 3/H-morphine following lumbar subarachnoid injection in unanesthetized rabbits

    SciTech Connect

    Wang, B.C.; Hiller, J.M.; Simon, E.J.; Hillman, D.E.; Rosenberg, C.; Turndorf, H.

    1989-05-01

    Morphine sulfate (40-100 micrograms) and /sup 3/H-morphine (125-200 pmol) were injected into the lumbar subarachnoid space of 18 unanesthetized rabbits through a surgically implanted catheter. Radioactivity remaining in the spinal cord 2, 4, 6, and 12 h later revealed recovery (mean +/- SEM) of 45 +/- 5.6% (n = 3), 30.5 +/- 14.1% (n = 4), 11.23 +/- 4.4% (n = 3), and 3.7 +/- 1.1% (n = 3), respectively, of the injected radioactivity. Tritiated morphine was found to be predominantly centered around the injection site, with limited rostral and caudal spread in the cord. No significant radioactivity was detected in plasma or cerebrospinal fluid (CSF) samples from the cisterna magna taken at 5, 15, 30, min and 1, 2, 4, 6, 12, and 24 h after receiving radioactive labeled drug (with the exception of that in one rabbit). Of the injected radioactivity, 75% was recovered in the urine in 12 h. These results suggest that the persistence of morphine in the spinal cord could account for its prolonged analgesic effect following intrathecal administration.

  7. Hydride transfer reaction dynamics of OD{sup +}+C{sub 3}H{sub 6}

    SciTech Connect

    Liu, Li; Richards, Elizabeth S.; Farrar, James M.

    2007-06-28

    The hydride transfer reaction between OD{sup +} and C{sub 3}H{sub 6} has been studied experimentally and theoretically over the center of mass collision energy range from 0.21 to 0.92 eV using the crossed beam technique and density functional theory calculations. The center of mass flux distributions of the product ions at three different energies are highly asymmetric, with maxima close to the velocity and direction of the precursor propylene beam, characteristic of direct reactions. In the hydride transfer process, the entire reaction exothermicity is transformed into product internal excitation, consistent with mixed energy release in which the hydride ion is transferred with both the breaking and forming bonds extended. At higher collision energies, at least 85% of the incremental translational energy appears in product translation, providing a clear example of induced repulsive energy release. Compared to the related reaction of OD{sup +} with C{sub 2}H{sub 4}, reaction along the pathway initiated by addition of OD{sup +} to the C=C bond in propylene has a critical bottleneck caused by the torsional motion of the methyl substituent on the double bond. This bottleneck suppresses reaction through an intermediate complex in favor of direct hydride abstraction. Hydride abstraction appears to be a sequential process initiated by electron transfer in the triplet manifold, followed by rapid intersystem crossing and subsequent hydrogen atom transfer to form ground state allyl cation and HOD.

  8. Lifetime Distributions from Tracking Individual BC3H1 Cells Subjected to Yessotoxin

    PubMed Central

    Korsnes, Mónica Suárez; Korsnes, Reinert

    2015-01-01

    This work shows examples of lifetime distributions for individual BC3H1 cells after start of exposure to the marine toxin yessotoxin (YTX) in an experimental dish. The present tracking of many single cells from time-lapse microscopy data demonstrates the complexity in individual cell fate and which can be masked in aggregate properties. This contribution also demonstrates the general practicality of cell tracking. It can serve as a conceptually simple and non-intrusive method for high throughput early analysis of cytotoxic effects to assess early and late time points relevant for further analyzes or to assess for variability and sub-populations of interest. The present examples of lifetime distributions seem partly to reflect different cell death modalities. Differences between cell lifetime distributions derived from populations in different experimental dishes can potentially provide measures of inter-cellular influence. Such outcomes may help to understand tumor-cell resistance to drug therapy and to predict the probability of metastasis. PMID:26557641

  9. Evaluation of properties of apigenin and [G-3H]apigenin and analytic method development.

    PubMed

    Li, B; Robinson, D H; Birt, D F

    1997-06-01

    This study provides baseline data and analytical methods to assist in the evaluation of apigenin, a plant flavonoid with promising chemopreventive activity against skin cancer. Apigenin was freely soluble in dimethylsulfoxide (> 100 mg/mL), but it had low solubility (0.00135-1.63 mg/mL) in all the other solvents and surfactants tested, especially in highly hydrophilic or nonpolar solvents. The partition coefficient (log K) calculated from the solubility ratio of apigenin in n-octanol and water was 2.87. Apigenin strongly absorbed UV light, with three maximum absorption wavelengths at 212, 269, and 337 nm (epsilon = 29,800, 19,020, and 18,930 M-1 cm-1, respectively). Using quercetin as the internal standard, a reversed-phase HPLC method was developed to quantitatively analyze apigenin in epidermal cells obtained from SENCAR mice. Apigenin was labeled at position 6, 8, 3', and 5' with tritium by a platinum-catalyzed proton-tritium exchange as confirmed indirectly by 1H NMR analysis of the deuterated apigenin. The tritium label was stable in aqueous environments, especially under acidic and neutral conditions, so [G-3H]apigenin was considered suitable for subsequent absorption and metabolic studies. PMID:9188055

  10. Nanoparticles of mesoporous SO3H-functionalized Si-MCM-41 with superior proton conductivity.

    PubMed

    Marschall, Roland; Bannat, Inga; Feldhoff, Armin; Wang, Lianzhou; Lu, Gao Qing Max; Wark, Michael

    2009-04-01

    Nanometer-sized mesoporous silica particles of around 100-nm diameter functionalized with a large amount of sulfonic acid groups are prepared using a simple and fast in situ co-condensation procedure. A highly ordered hexagonal pore structure is established by applying a pre-hydrolysis step in a high-dilution synthesis approach, followed by adding the functionalization agent to the reaction mixture. The high-dilution approach is advantageous for the in situ functionalization since no secondary reagents for an effective particle and framework formation are needed. Structural data are determined via electron microscopy, nitrogen adsorption, and X-ray diffraction, proton conductivity values of the functionalized samples are measured via impedance spectroscopy. The obtained mesoporous SO(3)H-MCM-41 nanoparticles demonstrate superior proton conductivity than their equally loaded micrometer-sized counterparts, up to 5 x 10(-2) S cm(-1). The mesoporosity of the particles turns out to be very important for effective proton transport since non-porous silica nanoparticles exhibit worse efficient proton transport, and the obtained particle size dependence might open up a new route in rational design of highly proton conductive materials. PMID:19226596

  11. Pharmacokinetics of (/sup 3/H)levamisole in pigs after oral and intramuscular administration

    SciTech Connect

    Galtier, P.; Escoula, L.; Alvinerie, M.

    1983-04-01

    A single oral (10 mg/kg of body weight) or IM (7.5 mg/kg) dose of (/sup 3/H)levamisole was administered to pigs. Liquid scintillation counting and high performance liquid chromatography were used to determine total radioactivity and drug levels in plasma, duodenal and cecal contents, bile, and urine for 24 and 72 hours after dosing. Pharmacokinetic analysis indicated a 1-compartment open model with higher plasma bioavailability of levamisole after IM injection. Biological half-lives for elimination of the drug were 9.3 and 6.9 hours after oral and IM administration, respectively. Anthelmintic concentrations were higher in intestinal contents after oral gavage than after IM injection. The drug appeared extensively metabolized in all body fluids and particularly in bile, regardless of the route of administration. Biliary excretion of radioactivity and unchanged levamisole represented only slight percentages of the administered dose (approx 0.4% and 4.2%, respectively, in 72 hours). In contrast, about 60% and 20% of the dose were eliminated via urine as tritiated materials and unchanged drug. The choice of the most efficacious route of administration is discussed in regard to localization of helminthic disease.

  12. Laeve-[1-3H]Methadone disposition in tolerant dogs.

    PubMed

    Misra, A L; Bloch, R; Vadlamani, N L; Mulé, S J

    1975-04-01

    1. Following a subcutaneous dose (4mg/kg) of [3H]methadone, peak levels of drug occurred in plasma, tissues and selected areas of the central nervous system (CNS) 2h after injection in both non-tolerant and tolerant dogs. Highest concentrations of methadone were attained in bile and lung compared to other tissues. 2. Levels of methadone in plasma, tissue and CNS of tolerant and non-tolerant animals were not markedly different up to 8h after injection, but a much faster rate of egression of free drug (lower t1/2) was observed subsequently in tolerant dogs. 3. Peak levels of methadone in various areas of the CNS ranged between 2-7 (spinal cord) to 3-6 (thalamus) mug/g in non-tolerant and 3-0 -rebellum) to 4-1 (thalamus) mug/g in tolerant dogs 2h after injection. No marked accumulation of methadone occurred in selected areas of the CNS in spite of the persistence of drug in these areas. 4. The plasma protein electrophoretic profiles did not differ between control, non-tolerant and tolerant dogs. 5. Similar qualitative patterns of metabolites were observed in non-tolerant and tolerant dogs and the development of tolerance did not appear to modify the metabolic pathways of methadone. PMID:1154803

  13. Decreased seasonal mesor of platelet sup 3 H-imipramine binding in depression

    SciTech Connect

    DeMet, E.M.; Reist, C.; Bell, K.M.; Gerner, R.H.; Chicz-DeMet, A.; Warren, S.; Wu, J. )

    1991-03-01

    Seasonal cycles of platelet {sup 3}H-imipramine binding were compared in 49 endogenous unipolar depressed patients and 20 normal volunteers. A significant sinusoidal component was detected in the Bmax of binding in both patients and controls with similar amplitudes and seasonal peaks. However, the yearly average (mesor) of the patient group was significantly lower (20.0%) than that of the normal controls. The results support earlier claims of a diminished platelet binding in endogenous depression and indicate that this decrease was still evident in the presence of a 48.2% (controls) to 65.8% (patients) seasonal variation. Control Bmax values were normally distributed about a best-fit mean (cosinor fit). In contrast, patient values appeared to be bimodally distributed with one mode that was similar to controls and one mode that was substantially lower. In general, psychiatric symptoms failed to distinguish between patients with high and low platelet binding and no correlation was found between Bmax and severity of illness (HAM-D).

  14. Cholecystokinin receptors: Biochemical demonstration and autoradiographical localization in rat brain and pancreas using (/sup 3/H) cholecystokinin8 as radioligand

    SciTech Connect

    Van Dijk, A.; Richards, J.G.; Trzeciak, A.; Gillessen, D.; Moehler, H.

    1984-04-01

    Since cholecystokinin8 (CCK8) seems to be the physiological ligand of CCK receptors in the brain, it would be the most suitable probe for the characterization of CCK receptors in radioligand binding studies. (/sup 3/H)CCK8 was synthetized with a specific radioactivity sufficient for the detection of high affinity binding sites. (/sup 3/H)CCK8 binds saturably and reversibly to distinct sites in rat brain and pancreas with nanomolar affinity. While the C-terminal tetrapeptide of CCK is the minimal structure required for nanomolar affinity in the brain, the entire octapeptide sequence is required for binding affinity in pancreas. Desulfated CCK8 and several gastrin-I peptides, which are likewise unsulfated, show virtually no affinity to the binding sites in pancreas but high affinity in cerebral cortex. The ligand specificity of the CCK peptides corresponds to their electrophysiological potency in the brain and their stimulation of secretion in pancreas, respectively. Autoradiographically, high densities of (/sup 3/H)CCK8 binding sites were found in cerebral cortex and olfactory bulb, medium levels in nucleus accumbens, hippocampus, dentate gyrus, and striatum with virtually no labeling in cerebellum. This pattern is similar to the distribution of CCK-like immunoreactivity in the brain. In pancreas, equally high levels of (/sup 3/H)CCK8 labeling were found in the exocrine and endocrine region. (/sup 3/H)CCK8 binding sites differ from those identified previously with (/sup 125/I)Bolton-Hunter-CCK33 by their sensitivity to guanyl nucleotides in the brain, their ion dependency in the brain, and pancreas, and their different autoradiographical localization in some parts of the brain. The distribution of CCK binding sites labeled with (/sup 3/H)CCK8 appears to correlate better with the CCK immunoreactivity than those labeled with (/sup 125/I)Bolton-Hunter-CCK33. Thus, (/sup 3/H)CCK8 appears to be the radioligand of choice for the investigation of CCK receptors.

  15. In vivo labeling of 5-hydroxytryptamine uptake sites in mouse brain with ( sup 3 H)-6-nitroquipazine

    SciTech Connect

    Hashimoto, K.; Goromaru, T. )

    1990-10-01

    6-Nitroquipazine (DU 24565; 6-nitro 2-piperazinylquinoline) is a very potent 5-hydroxytryptamine (5-HT; serotonin) uptake inhibitor. It has been demonstrated very recently that (3H)-6-nitroquipazine is a suitable radioligand for studying 5-HT uptake sites. The present study evaluates (3H)6-nitroquipazine as a radioligand for in vivo labeling of 5-HT uptake sites in mouse brain. Very high uptake of radioactivity in the brain after i.v. administration of (3H)-6-nitroquipazine was shown. Regional distribution of the radioactivity in mouse brain 3 hr after injection of (3H)-6-nitroquipazine was in the order (highest to lowest) hypothalamus greater than midbrain greater than striatum greater than hippocampus greater than cerebral cortex greater than medulla oblongata greater than cerebellum. The regional distribution of in vivo (3H)-6-nitroquipazine binding in mouse brain was highly correlated with that in rat brain obtained from previous in vitro binding studies. Coadministration of carrier 6-nitroquipazine (5 mg/kg) significantly decreased the radioactivity in the hypothalamus, whereas that in the cerebellum and cerebral cortex was increased. Because the cerebellum has very low density of (3H)-6-nitroquipazine binding sites, the radioactivity in the cerebellum could, therefore, reflect the amount on nonspecific binding and free ligand. Kinetic studies showed highest in vivo specific binding 1 hr after injection of (3H)-6-nitroquipazine and slow clearance of specific binding. Specific binding in the hypothalamus was inhibited in a stereoselective manner by the stereoisomers of norzimelidine. Furthermore, specific binding in the hypothalamus was reduced by several 5-HT uptake inhibitors, in a dose-dependent manner.

  16. Biochemical characterization of high-affinity 3H-opioid binding. Further evidence for Mu1 sites

    SciTech Connect

    Nishimura, S.L.; Recht, L.D.; Pasternak, G.W.

    1984-01-01

    In saturation studies with (/sup 3/H)dihydromorphine, unlabeled D-Ala2-D-Leu5-enkephalin (1 nM) inhibited the high-affinity binding component far more potently than the lower-affinity one. Similarly, morphine (1 nM) inhibited the higher-affinity binding of /sup 3/H-D-Ala2-D-Leu5-enkephalin to a greater extent than its lower-affinity binding component, consistent with a common high-affinity binding site for opiates and enkephalins. Treatment of tissue with either trypsin (1 microgram/ml) or N-ethylmaleimide (25 microM) effectively eliminated the high-affinity binding component of a series of /sup 3/H-opiates and opioid peptides. Competition studies following both treatments were consistent with a common high-affinity binding site. Both treatments also eliminated the ability of low morphine concentrations (less than 1 nM) to inhibit /sup 3/H-D-Ala2-D-Leu5-enkephalin binding and of low D-Ala2-D-Leu5-enkephalin concentrations (less than 1 nM) to inhibit (/sup 3/H)dihydromorphine binding. Protection experiments examining N-ethylmaleimide (25 microM) inhibition of (/sup 3/H)dihydromorphine binding showed significant protection (p less than 0.002) by both unlabeled D-Ala2-D-Leu5-enkephalin and morphine (both at 1 nM). When studied together, both naloxonazine and N-ethylmaleimide inhibited (/sup 3/H)dihydromorphine binding to a similar extent. Equally important, tissue previously treated with naloxonazine was far less sensitive to N-ethylmaleimide than was untreated control tissue, consistent with the possibility that both treatments affected the same site. Together, these results support the concept of a common high-affinity binding site for opiates and opioid peptides.

  17. Laboratory Tests

    MedlinePlus

    Laboratory tests check a sample of your blood, urine, or body tissues. A technician or your doctor ... compare your results to results from previous tests. Laboratory tests are often part of a routine checkup ...

  18. Kinetics of killing Listeria monocytogenes by macrophages: correlation of /sup 3/H-DNA release from labeled bacteria and changes in numbers of viable organisms by mathematical model

    SciTech Connect

    Davies, W.A.

    1982-12-01

    Conventional methods of assessing antibacterial activities of macrophages by viable counting are limited by the precision of the statistics and are difficult to interpret quantitatively because of unrestrained extracellular growth of bacteria. An alternative technique based on the release of radioactive DNA from labeled bacteria has been offered as overcoming these drawbacks. To assess it for use with macrophages I have made a correlation with the conventional viable counting method using a mathematical model. Opsonized Listeria monocytogenes labeled with /sup 3/H-thymidine were exposed to rat macrophages for periods up to 4 hr. Numbers of viable bacteria determined after sonication increased exponentially in the absence of live cells and this growth rate was progressively inhibited by increasing numbers of macrophages. After a lag period of 30-60 min soluble /sup 3/H appeared in the supernatant, the amount increasing with time and numbers of macrophages. To correlate these data I developed a mathematical model that considered that changes in numbers of viable organisms were due to the difference between rates of 1) growth of extracellular bacteria and 2) killing within the macrophage. On the basis of this model curves of best fit to the viable counts data were used to predict the release of radioactivity, assuming that death of a bacterium led to the total release of its label. These predictions and the experimental data agreed well, the lag period of 30-60 min between death of the bacterium and release of radioactivity being consistent with intracellular digestion. Release of soluble radioactivity appears to be an accurate reflection of the number of bacteria killed within the macrophage.

  19. Substituent effects in intermolecular C(sp 3)-H ⋯ O(sp 3) contacts: how strong can a C(sp 3)-H ⋯ O(sp 3) hydrogen bond be?

    NASA Astrophysics Data System (ADS)

    Novoa, Juan J.; Mota, Fernando

    1997-02-01

    The dependence of the strength of the C(sp 3)-H ⋯ interaction, with functional groups attached to the carbon atom, has been investigated for various families of R 1R 2R 3CH ⋯ OH 2 model complexes, totalling 14 model complexes, the simplest of which is CH 4 ⋯ OH 2. The study has ben carried out using the Hartree-Fock and second-order Møller-Plesset methods, and also with the Becke-Lee-Yang-Parr (B-LYP) functional. The substituent effect can be important. Thus, the C(sp 3)-H ⋯ O(sp 3) interaction becomes eight times stronger (-2.41 kcal/mol) when R 1 = R 2 = R 3 = F than when R 1 = R 2 = R 3 = H. The B-LYP functional reproduces the trends but the energies are always 0.7-1.2 kcal/mol weaker.

  20. Interactions of ( sup 3 H)amphetamine with rat brain synaptosomes. I. Saturable sequestration

    SciTech Connect

    Zaczek, R.; Culp, S.; Goldberg, H.; Mccann, D.J.; De Souza, E.B. )

    1991-05-01

    Previous studies have identified a saturable site of d-({sup 3}H)amphetamine sequestration (AMSEQ) in rat brain synaptosomes. The present study characterized AMSEQ with respect to its subcellular, neuronal and regional distributions, ontogenetic development, pharmacological specificity and factors required for its maintenance. Although AMSEQ was reduced when assays were performed in Krebs' buffer incubated at 37{degree}C as compared to assays performed in isotonic Tris-sucrose buffer incubated at room temperature, the pharmacological profiles of AMSEQ were virtually identical under both conditions. AMSEQ was negligible in tissues outside the central nervous system, enriched in synaptosomes and partially reduced by striatal kainic acid lesion, indicating neuronal localization. The distribution of AMSEQ in the central nervous system was heterogenous. Highest levels were present in hypothalamus with progressively lower levels noted in parietal cortex, frontal cortex, striatum, thalamus, hippocampus, midbrain, cerebellum, pons-medulla and spinal cord. With regard to its ontogeny, AMSEQ increased early in neonatal life, reaching adult levels by postnatal day 14. Although the effects of amphetamine to abolish the transynaptosomal pH gradient suggest a possible role for this gradient in the maintenance of AMSEQ, the pharmacological profile of AMSEQ indicates that other factors are involved. An interaction with an intrasynaptosomal acid, such as N-acetylaspartate, may account for AMSEQ maintenance. AMSEQ did not possess a stereospecific preference for either d-(IC50 = 177 microM) or I-amphetamine (IC50 = 173 microM). However, the pharmacological profile of AMSEQ indicated structural specificity with antidepressants being relatively potent inhibitors. (Abstract Truncated)

  1. Peptide displacement of ( sup 3 H)5-hydroxytryptamine binding to bovine cortical membranes

    SciTech Connect

    Takeuchi, Y.; Root-Bernstein, R.S.; Shih, J.C. )

    1990-12-01

    Chemical studies have demonstrated that peptides such as the encephalitogenic (EAE) peptide of myelin basic protein (MBP) and luteinizing hormone-releasing hormone (LHRH) can bind serotonin (5-hydroxytryptamine, 5-HT) in vitro. The present research was undertaken to determine whether such binding interferes with 5-HT binding to its 5-HT1 receptors on bovine cerebral cortical membranes. EAE peptide and LHRH displaced ({sup 3}H)5-HT with IC50s of 4.0 x 10(-4) and 1.8 x 10(-3) M respectively. MBP itself also showed apparent displacing ability with an IC50 of 6.0 x 10(-5) M, though it also caused aggregation of cortical membranes that might have interfered with normal receptor binding. These results support previous suggestions that the tryptophan peptide region of MBP may act as a 5-HT receptor in the neural system. We also tested the effects of muramyl dipeptide (N-acetyl-muramyl-L-Ala-D-isoGln, MD), a bacterial cell-wall breakdown product that acts as a slow-wave sleep promoter, binds to LHRH and EAE peptide, and competes for 5-HT binding sites on macrophages. It showed no significant displacement of 5-HT binding to cortical membranes (IC50 greater than 10(-1) M), but its D-Ala analogue did (IC50 = 1.7 x 10(-3) M). Thus, it seems likely that the 5-HT-related effects of naturally occurring muramyl peptides are physiologically limited by receptor types.

  2. Anti-inflammatory and immunomodulatory properties of 2-amino-3H-phenoxazin-3-one.

    PubMed

    Kohno, Keizo; Miyake, Masaki; Sano, Osamu; Tanaka-Kataoka, Mari; Yamamoto, Shigeto; Koya-Miyata, Satomi; Arai, Norie; Fujii, Mitsukiyo; Watanabe, Hikaru; Ushio, Shimpei; Iwaki, Kanso; Fukuda, Shigeharu

    2008-10-01

    Accumulating evidence suggests that nitric oxide (NO) and prostaglandin E(2) (PGE(2)) are involved in the pathogenesis of various chronic inflammatory diseases and cancer. During the course of a screening program to identify natural anti-inflammatory substances, we isolated the compound 2-amino-3H-phenoxazin-3-one (APO) from an extract of the edible brown mushroom Agaricus bisporus IMBACH. APO inhibited NO production by mouse peritoneal macrophages in response to the pro-inflammatory stimuli lipopolysaccharide (LPS) and interferon (IFN)-gamma (LPS/IFN-gamma) at low concentrations (IC(50)=1.5 microM) through reduced inducible NO synthase protein expression. PGE(2) production by LPS/IFN-gamma-stimulated macrophages was inhibited by APO at much lower concentrations (IC(50)=0.27 microM) than those required for the inhibition of NO production. Mechanistic analysis showed that APO inhibited both cyclooxygenase (COX)-1 and COX-2 enzyme activities with almost equal selectivity. Secretion of NO and the pro-inflammatory cytokine IL-6 by IFN-gamma-activated RAW264.7 cells, a murine macrophage-like cell line, was also dose-dependently reduced by APO. Furthermore, APO increased the secretion of the anti-inflammatory cytokine IL-4 by antigen-stimulated T cells and promoted the polarization of CD4(+) Th cells toward the anti-inflammatory Th2 phenotype at equimolar concentrations that inhibited NO production. Our results suggested that APO induced polarization toward the Th2 subset, at least in part through the down-regulation of IL-12 production. Thus, APO appears to have potent anti-inflammatory and immunoregulatory properties that may provide a promising therapeutic strategy for the treatment of T cell-mediated inflammatory autoimmune diseases as well as for bacteria-induced chronic-inflammatory diseases. PMID:18827359

  3. Binding sites for L-(/sup 3/H)glutamate in hippocampus

    SciTech Connect

    Werling, L.L.

    1983-01-01

    Three binding sites for L-(/sup 3/H)glutamate on freshly-prepared hippocampal synaptic membranes were identified on the basis of their differing affinities for L-glutamate or quisqualate. The high affinity site yielded K/sub D/ and B/sub max/ values of 12 nM and 2.5 pmol/mg protein, respectively. Binding sites of lower affinity had K/sub D/ values of 200 nM (GLU A) and 1 ..mu..M (GLU B) and B/sub max/ values of about 30 and 60 pmol/mg protein, respectively. GLU A sites bound quisqualate with about 70 times the affinity fo GLU B sites, and thus quisoqualate could be used as a tool to discriminate them. Hill slopes indicated that each site represented a single population of non-interacting binding sites. Freezing drastically decreased GLU A binding, but nearly tripled GLU B binding. Both sites bound L-glutamate with 10-30 times the affinity of D-glutamate. The GLU A site also bound L-glutamate with about 10 times the affinity of L-asparate and discriminated poorly between L- and D-asparate. In contrast, the GLU B site bound L-aspartate with similar affinity to L-gluamate, and with much higher affinity than it bound D-aspartate. Both lesions of perforant path and destruction of the granule cells with colchicine markedly reduced radioligand binding to the GLU A site in the fascia dentata, but only the perforant path lesion significantly reduced binding to the GLU B site. The structural specificity of the GLU A site is consistent with its identification as a type of quisqualate receptor.

  4. Fate and distribution of 3H-labeled T-2 mycotoxin in guinea pigs. Interim report

    SciTech Connect

    Pace, J.G.; Watts, M.R.; Burrows, E.P.; Dinterman, R.E.; Matson, C.

    1984-08-03

    T-2 toxin is a potent cytotoxic metabolite produced by the Fusarium species. The fate and distribution of (3H)-labeled T-2 toxin were examined in male guinea pigs. Radioactivity was detected in all body tissues within 30 min after an im intection of an LD(50) dose (1.04 mg/kg) of T-2 toxin. The plasma concentration curve of radioactivity versus time was multiphasic, with an initial absorption half-life (T1/2,E) of less than 6 min. The initial half-life of elimination (T1/2,A) was 1.8 hr. Bile contained a large amount of radioactivity which was identified as HT-2,4-deacetylneosolaniol, 3'hydroxy HT-2, 3'hydroxy T-2 triol, and several more-polar unknowns. These T-2 metabolites are excreted from liver via bile into the intestine. Within 5 days, 75% of the total radioactivity was excreted in urine and feces at a ratio of 4 to 1. The appearance of radioactivity in the excreta was biphasic (T1/2,A=2.2 hr, 1.5 days and 8.2 hr, 1.7 days, for urine and feces, respectively). Metabolic derivatives of T-2 excreted in urine were T-2 tetraol, 4-deacetylneosolaniol, 3' hydroxy HT-2, and several unknowns. These studies showed a rapid appearance in and subsequent loss of radioactivity from tissues and body fluids. However, radioactivity (ten to the fifth power dpm) was still detectable in tissues at 28 days. The distribution patterns and excretion rates suggest that liver and kidney are the principal organs of detoxication and excretion of T-2 toxin and its metabolites.

  5. Uptake of (/sup 3/H)serotonin into plasma membrane vesicles from mouse cerebral cortex

    SciTech Connect

    O'Reilly, C.A.; Reith, M.E.A.

    1988-05-05

    Preparations of plasma membrane vesicles were used as a tool to study the properties of the serotonin transporter in the central nervous system. The vesicles were obtained after hypotonic shock of synaptosomes purified from mouse cerebral cortex. Uptake of (/sup 3/H)serotonin had a Na/sup +/-dependent and Na/sup +/-independent component. The Na/sup +/-dependent uptake was inhibited by classical blockers of serotonin uptake and had a K/sub m/ of 63-180 nM, and a V/sub max/ of 0.1-0.3 pmol mg/sup -1/ s/sup -1/ at 77 mM Na/sup +/. The uptake required the presence of external Na/sup +/ and internal K/sup +/. Replacement of Cl/sup -/ by other anions (NO/sub 2//sup -/, S/sub 2/O/sub 3//sup 2 -/) reduced uptake appreciably. Gramicidin prevented uptake. Although valinomycin increased uptake somewhat, the membrane potential per se could not drive uptake because no uptake was observed when a membrane potential was generated by the SCN/sup -/ ion in the absence of internal K/sup +/ and with equal (Na/sup +/) inside and outside. The increase of uptake as a function of (Na/sup +/) indicated a K/sub m/ for Na/sup +/ of 118 mM and a Hill number of 2.0, suggesting a requirement of two sodium ions for serotonin transport. The present results are accommodated very well by the model developed for porcine platelet serotonin transport except for the number of sodium ions that are required for transport.

  6. Quantum chemical study of ternary mixtures of: HNO3:H2SO4:H2O

    NASA Astrophysics Data System (ADS)

    Verdes, M. A.; Gómez, P. C.; Gálvez, O.

    2009-04-01

    Water, nitric acid and sulfuric acid are important atmospheric species as individual species and as hydrogen-bonded aggregates involved in many physical-chemical processes both superficial and bulk. The importance of heterogeneous chemical reactions taking place on ice surfaces, either solid water or solid water plus nitric or sulfuric acid, is well established now in relation to the ozone-depleting mechanisms. Also the importance of liquid droplets formed by HNO3.H2SO4.H2O as components of PSC was soon recognized [1-3]. Finally the physical properties of finely divided aqueous systems is an interesting and active field of research in which theoretical information on the microphysical domain systems may help to understand and rationalize the wealth of experimental information. This can also be the initial step in the study of more complex mixtures with higher amounts of water or variable proportions of their constituents. This kind of calculations have been successfully performed in the past[4]. We present here our results on the structure and spectroscopic and thermodynamic properties of the energy-lowest lying structures among those thermodynamically stable formed by linking the acids plus water. The calculations have been carried out by means of DFT methods (in particular the successful B3LYP) using different basis sets that contain appropriate sets of polarization and diffuse functions up to quadruple-Z quality (Dunninǵs aug-cc-pVQZ). Careful assessment of the dependability of the methodology used has been carried out. This work has been supported by the Spanish Ministry of Education, Projects FIS2007-61686 and CTQ2008-02578/BQU References: [1] Carslaw, K. S. et al.: Geophys. Res. Lett. 21, 2479-2482, 1994 [2] Drdla, K. Et al. :Geophys. Res. Lett. 21, 2473-2478, 1994 [3] Tabazadeh, A. et al.: Geophys. Res. Lett 21, 1619-1622, 1994 [4] Escribano, R et al.: J. J. Chem. Phys A 2003, 107, 652.

  7. [3H]-L-2-amino-4-phosphonobutyrate labels a metabotropic glutamate receptor, mGluR4a.

    PubMed Central

    Eriksen, L.; Thomsen, C.

    1995-01-01

    1. The ligand binding site of subtype mGluR4a of the metabotropic glutamate receptor family was characterized by using [3H]-L-2-amino-4-phosphonobutyrate ([3H]-L-AP4) binding. 2. Specific [3H]-L-AP4 binding to membranes prepared from baby hamster kidney (BHK) cells transfected with a vector encoding mGluR4a accounted for 60-70% of the total binding whereas no specific binding of [3H]-L-AP4 was observed to membranes prepared from BHK cells expressing the vector only. 3. Specific binding of [3H]-L-AP4 to mGluR4a was detectable at 0 degree C, was saturated with 10 min and enhanced by Cl(-)-ions but not by divalent cations (Mg2+, Ca2+, Mn2+). 4. [3H]-L-AP4 binding showed a maximal binding density (Bmax) of 3.0 +/- 0.5 pmol mg-1 protein and an affinity (KD) of 441 nM. A modest decrease in affinity was observed in the presence of 0.1 mM guanosine-5'-O-(3-thio)trisphosphate-gamma-S, the KD being 761 nM and the Bmax 3.4 +/- 0.6 pmol mg-1 protein. 5. The following rank order of affinity for mGluR4a was observed: L-AP4 = L-serine-O-phosphate > glutamate = (2S,1S,2S)-2-(carboxycyclopropyl)-glycine > 1-amino-3-(phosphonomethylene)cyclobitanecar-boxylate > > (1S,3R)-1-aminocyclopentane-1,3-dicarboxylate = quisqualate > ibotenate. 6. A highly significant correlation was observed between the potencies of the compounds to inhibit forskolin-stimulated cyclic AMP-formation in BHK cells expressing mGluR4a and the affinity for displacement of [3H]-L-AP4 binding from mGluR4a suggesting that this binding site is functionally relevant. 7. In conclusion, [3H]-L-AP4 is a suitable radioligand for characterizing mGluR4a when expressed in BHK cells. Interestingly, a significant correlation was found between the ability of various compounds to displace [3H]-L-AP4 binding from mGluR4a and the previously observed potencies for inhibition of synaptic transmission via L-AP4 sensitive glutamatergic pathways. These data support the hypothesis that the L-AP4 receptor is contained within the m

  8. Pharmacological characterization of binding sites identified in rat brain following in vivo administration of [3H]-spiperone.

    PubMed Central

    Chivers, J.; Jenner, P.; Marsden, C. D.

    1987-01-01

    [3H]-spiperone is commonly used to label dopamine receptors in vitro in brain tissue. However, spiperone also interacts with brain 5-hydroxytryptamine and noradrenaline receptors. In vivo, [3H]-spiperone has been used for identifying dopamine receptors in both animals and man but the nature of the sites identified is unknown. The in vivo administration of [3H]-spiperone to rats leads to a selective accumulation of radioactivity in the olfactory lobes, tuberculum olfactorium, nucleus accumbens, striatum, substantia nigra, hippocampus, frontal cortex and hypothalamus, when compared to the cerebellum. In vivo drug displacement studies suggest that the binding of [3H]-spiperone in these areas may be to dopamine, 5-HT or noradrenaline receptors. [3H]-spiperone in vivo mainly labels dopamine receptors in striatum, tuberculum olfactorium, hypothalamus, substantia nigra and olfactory lobes. However, in the frontal cortex and nucleus accumbens specific binding involves not only dopamine receptors but also 5-HT and/or noradrenaline receptors. Interpretation of in vivo studies in man using radioactive spiperone and its derivatives must take into account the fact that this ligand only labels dopamine receptors in some brain areas. PMID:2882801

  9. Measurement of local rates of brain protein synthesis by quantitative autoradiography: validation with L-(/sup 3/H)valine

    SciTech Connect

    Dwyer, B.E.; Donatoni, P.; Wasterlain, C.G.

    1982-12-01

    Following the injection of 4-day old rats with 150 mM L-(3,4-/sup 3/H)valine (10 mumol/g, IP) the incorporation of /sup 3/H into protein was linear 2 hours. Valine specific activity in the brain acid-soluble fraction was constant between 30 and 120 min after injection with a mean value of 82.3% of the injectate. Significant amounts of tritated metabolites accumulated in the brain acid-soluble fraction (41.4% of radioactivity at 120 min) but do not prove an impediment to measuring rates of protein synthesis. The rate of protein synthesis in cerebral cortex of the 4-day old rat was measured by quantitative autoradiography using (/sup 3/H)valine and /sup 3/H-sensitive film. The measured rate shows excellent agreement with that found previously using L-(1-/sup 14/C)valine. Our results suggest that (/sup 3/H)valine can be a useful precursor to measure local rates of brain protein synthesis by quantitative autoradiography.

  10. SMA observations of the W3(OH) complex: Dynamical differentiation between W3(H2O) and W3(OH)

    NASA Astrophysics Data System (ADS)

    Qin, Sheng-Li; Schilke, Peter; Wu, Jingwen; Liu, Tie; Wu, Yuefang; Sánchez-Monge, Álvaro; Liu, Ying

    2016-03-01

    We present Submillimeter Array observations of the HCN (3-2) and HCO+ (3-2) molecular lines towards the W3(H2O) and W3(OH) star-forming complexes. Infall and outflow motions in the W3(H2O) have been characterized by observing HCN and HCO+ transitions. High-velocity blue/red-shifted emission, tracing the outflow, show multiple knots, which might originate in episodic and precessing outflows. `Blue-peaked' line profiles indicate that gas is infalling on to the W3(H2O) dust core. The measured large mass accretion rate, 2.3 × 10-3 M⊙ yr-1, together with the small free-fall time-scale, 5 × 103 yr, suggest W3(H2O) is in an early evolutionary stage of the process of formation of high-mass stars. For the W3(OH), a two-layer model fit to the HCN and HCO+ spectral lines and Spizter/Infrared Array Camera (IRAC) images support that the W3(OH) H II region is expanding and interacting with the ambient gas, with the shocked neutral gas being expanding with an expansion time-scale of 6.4 × 103 yr. The observations suggest different kinematical time-scales and dynamical states for the W3(H2O) and W3(OH).

  11. Effects of NaCl and sultopride on striatal [(3)H]spiperone binding in neonatal, adult and senescent rats.

    PubMed

    Makihata, J; Nomura, Y

    1984-01-01

    Effects of NaCl, (+)-and (-)-sultopride on striatal [(3)H]spiperone binding was investigated in 7-day, 70-day and 2-year-old rats. The amount of specific [(3)H]spiperone binding was the highest at 70 days and the value at adult stage was significantly (P < 0.001) higher than those at 7 days and 2 years. NaCl (100 mM) significantly increased [(3)H]spiperone binding in neonatal (P < 0.01), adult (P < 0.05) and senescent (P < 0.05) animals. Scatchard analysis showed that the Bmax of low-affinity [(3)H]spiperone binding was significantly elevated by 100 mM NaCl compared to the value in control of adult animals. More potent inhibition of (-)-sultopride for [(3)H]spiperone binding than that of the (+)-enantiomer at adult stage was also observed at neonatal and senescent stages. NaCl (100 mM) significantly enhanced inhibitory activities of (+)- and (-)-sultopride at every stage. It is suggested that stabilizing effect of Na(+) on dopamine (DA) receptor complexes and increasing effect of Na(+) on binding affinity of benzamide to DA2 receptors keep functions through development and aging. PMID:24874236

  12. Estimating groundwater recharge in fractured rock from environmental 3H and 36Cl, Clare Valley, South Australia

    NASA Astrophysics Data System (ADS)

    Cook, P. G.; Robinson, N. I.

    2002-08-01

    Vertical profiles of 3H and 36Cl concentrations are obtained from piezometer nests installed in fractured metasedimentary aquifers in the Clare Valley, South Australia. Because 3H is lost during evapotranspiration with negligible fractionation, while 36Cl is retained within the soil, comparison of 3H and 36Cl concentrations allows estimation of the aquifer recharge rate. An analytical solution for the transport of 3H and 36Cl through planar, parallel fractures is used to investigate the effect of variations in matrix porosity, tortuosity, fracture aperture, fracture spacing and aquifer recharge rate on tracer profiles and then to reproduce observed profiles within piezometer nests. While the measured distributions of these tracers are not able to constrain most model parameters, they are able to tightly constrain the aquifer recharge rate. The broad nature of the 36Cl and 3H peaks measured at our sites is simulated using a constant fracture spacing, lognormal distributions of fracture apertures, and mean recharge rates of 60-75 mm yr-1.

  13. [{sup 3}H]-2,3,7,8-TCDD uptake and elimination kinetics of medaka (Oryzias latipes)

    SciTech Connect

    Schmieder, P.; Lothenbach, D.; Tietge, J.; Erickson, R.; Johnson, R.

    1995-10-01

    Uptake and elimination rate constants for [{sup 3}H]-2,3,7,8-tetrachlorodibenzo-p-dioxin ([{sup 3}H]TCDD) were estimated by exposing medaka (Oryzias latipes) to [{sup 3}H]TCDD in flowing water with no solvent carriers. Uptake was determined from body-burdens measured on exposure days 0, 2, 4, 6, 10, and 12. Elimination was quantified for whole fish after 28, 90, and 175 d in uncontaminated water. Medaka accumulated [{sup 3}H]TCDD at a rapid rate, achieving residues 24,000 times the water concentration after 12 d, with no indication of approach to steady state. After 6 months in uncontaminated water, the pg TCDD/g decreased by 69%, much of the decrease due to growth dilution as evidenced by only a 47% decrease in the pg TCDD/fish. Uptake and elimination rate constant (2,300 ml/g/d and 0.0045/d, respectively) were estimated by fitting a one-compartment, linear, mass-balance model to the data, adjusting for growth rate. The experimental design, including solvent-free delivery of [{sup 3}H]TCDD, exposure at concentrations below maximum water solubility, and measurement of fish growth and lipid content during a 6-month elimination phase, resulted in a predicted steady-state bioconcentration factor (BCF) for medaka of 510,000, a number considerably higher than previously reported for dioxin BCFs. Kinetic parameters were used to successfully predict TCDD BCF in medaka exposed independently.

  14. Human myometrial adrenergic receptors during pregnancy: identification of the alpha-adrenergic receptor by (/sup 3/H) dihydroergocryptine binding

    SciTech Connect

    Jacobs, M.M.; Hayashida, D.; Roberts, J.M.

    1985-07-15

    The radioactive alpha-adrenergic antagonist (/sup 3/H) dihydroergocryptine binds to particulate preparations of term pregnant human myometrium in a manner compatible with binding to the alpha-adrenergic receptor (alpha-receptor). (/sup 3/H) Dihydroergocryptine binds with high affinity (KD = 2 nmol/L and low capacity (receptor concentration = 100 fmol/mg of protein). Adrenergic agonists compete for (/sup 3/H) dihydroergocryptine binding sites stereo-selectively ((-)-norepinephrine is 100 times as potent as (+)-norepinephrine) and in a manner compatible with alpha-adrenergic potencies (epinephrine approximately equal to norepinephrine much greater than isoproterenol). Studies in which prazosin, an alpha 1-antagonist, and yohimbine, and alpha 2-antagonist, competed for (/sup 3/H) dihydroergocryptine binding sites in human myometrium indicated that approximately 70% are alpha 2-receptors and that 30% are alpha 1-receptors. (/sup 3/H) dihydroergocryptine binding to human myometrial membrane particulate provides an important tool with which to study the molecular mechanisms of uterine alpha-adrenergic response.

  15. Different components of /sup 3/H-imipramine binding in rat brain membranes: relation to serotonin uptake sites

    SciTech Connect

    Gobbi, M.; Taddei, C.; Mennini, T.

    1988-01-01

    In the present paper, the authors confirm and extend previous studies showing heterogeneous /sup 3/H-imipramine (/sup 3/H-IMI) binding sites. Inhibition curves of various drugs (serotonin, imipramine, desmethyl-imipramine, d-fenfluramine, d-norfenfluramine and indalpine, a potent serotonin uptake inhibitor) obtained using 2 nM /sup 3/H-IMI and in presence of 120 mM NaCl, confirmed the presence of at least three /sup 3/H-IMI binding sites: two of these were serotonin-insensitive while the third one was selectively inhibited by serotonin and indalpine with nanomolar affinities. Moreover this last component was found to be selectively modulated by chronic imipramine treatment thus suggesting a close relation to serontonin uptake mechanism. These data indicate that the use of a more selective inhibitors of the serotonin-sensitive component (like indalpine or serotonin itself) to define non specific /sup 3/H-IMI, may be of help in understanding its relation with serotonin uptake system. 22 references, 2 figures, 2 tables.

  16. Effect of ethanol on (/sup 3/H)dopamine release in rat nucleus accumbens and striatal slices

    SciTech Connect

    Russell, V.A.; Lamm, M.C.; Taljaard, J.J.

    1988-05-01

    Ethanol (10-200 mM) transiently increased tritium overflow from superfused rat nucleus accumbens slices previously incubated with (/sup 3/H)dopamine (DA) and (/sup 14/C)choline. The effect was greater in striatal tissue and did not appear to be a non-specific membrane effect since (/sup 14/C)acetylcholine (ACh) release was not affected. Lack of antagonism by picrotoxin suggested that gamma-aminobutyric acid (GABA) receptors were not involved. Calcium was not a requirement and the DA uptake blocker, nomifensine, was without effect. Ethanol appeared to be causing (/sup 3/H)DA release into the cytoplasm. K+ -stimulated release of (/sup 3/H)DA and (/sup 14/C)ACh from nucleus accumbens and striatal slices was not affected. Clonidine-mediated inhibition of the K+-evoked release of (/sup 3/H)DA remained unaltered. Ethanol attenuated the isoproterenol-induced enhancement of (/sup 3/H)DA release. Ethanol therefore appeared to interact with components of the DA terminal causing a transient increase in the release of neurotransmitter without impairing K+-evoked release but apparently interfering with the isoproterenol-induced effect.

  17. Observations of C3H2 (2(12) - 1(01)) toward the Sagittarius A molecular cloud

    NASA Technical Reports Server (NTRS)

    Lee, C. W.; Minh, Y. C.; Irvine, W. M.

    1993-01-01

    We have mapped the C3H2 2(12)-1(01) transition line toward the Sgr A molecular cloud on a 1' grid spacing and derived C3H2 column densities of 3 approximately 7 x 10(14) cm-2 for molecular clouds of Sgr A. The fractional abundances of C3H2 relative to H2 are obtained to be 3 approximately 6 x 10(-9), which are slightly lower than that for the cold dark cloud TMC-1 but are enhanced by factors of 5-60 compared to those for Sgr B2 and the Orion extended ridge. We also estimate from the C3H2 column densities total masses of approximately 10(6) M(solar) for two clouds (M - 0.13-0.08 and M - 0.02-0.07), which are thought to be close to the virial equilibrium. We suggest that the large abundance of C3H2 in Sgr A may be partly due to the activities of the Galactic center.

  18. Modulation of ( sup 3 H)-glutamate binding by serotonin in the rat hippocampus: An autoradiographic study

    SciTech Connect

    Mennini, T.; Miari, A. )

    1991-01-01

    Serotonin (5-HT) added in vitro increased ({sup 3}H)-glutamate specific binding in the rat hippocampus, reaching statistical significance in layers rich in N-Methyl-D-Aspartate sensitive glutamate receptors. This effect was explained by a significant increase in the apparent affinity of ({sup 3}H)-glutamate when 5-HT is added in vitro. Two days after lesion of serotonergic afferents to the hippocampus with 5,7- Dihydroxytryptamine ({sup 3}H)-glutamate binding was significantly decreased in the CA3 region and stratum lacunosum moleculare of the hippocampus, this reduction being reversed by in vitro addition of 10 {mu}M 5-HT. The decrease observed is due to a significant reduction of quisqualate-insensitive (radiatum CA3) and kainate receptors (strata oriens, radiatum, pyramidal of CA3). Five days after lesion ({sup 3}H)-glutamate binding increased significantly in the CA3 region of the hippocampus but was not different from sham animals in the other hippocampal layers. Two weeks after lesion ({sup 3}H)-glutamate binding to quisqualate-insensitive receptors was increased in all the hippocampal layers, while kainate and quisqualate-sensitive receptors were not affected. These data are consistent with the possibility that 5-HT is a direct positive modulator of glutamate receptor subtypes.

  19. Spermidine reverses arcaine's inhibition of N-methyl-D-aspartate-induced hippocampal ( sup 3 H)norepinephrine release

    SciTech Connect

    Sacaan, A.I.; Johnson, K.M. )

    1990-12-01

    The inhibition of N-methyl-D-aspartate (NMDA)-induced ({sup 3}H)norepinephrine (({sup 3}H)NE) release by a putrescine analog was studied. We report that arcaine, diguanidinobutane, a putative competitive polyamine antagonist, completely and noncompetitively antagonized NMDA-induced ({sup 3}H)NE release from rat hippocampal minces with an IC50 value of 102 microM. Arcaine did not alter kainate- or potassium-induced ({sup 3}H)NE release suggesting a specific effect on NMDA-mediated responses. Spermidine did not alter NMDA-induced ({sup 3}H)NE release, nor did it reverse the effect of arcaine when introduced in a normal physiologic superfusion buffer. However, spermidine reversed the effect of arcaine when superfusing with buffer that contained 5% (v/v) of the organic solvent dimethylsulfoxide. This finding suggests that the polyamine site may be located at the intracellular surface of the cell membrane. Our results provide the first evidence for polyamine modulation of the NMDA receptor ionophore complex in a functional physiologic system.

  20. (3H) 5,7-dichlorokynurenic acid, a high affinity ligand for the NMDA receptor glycine regulatory site

    SciTech Connect

    Hurt, S.D.; Baron, B.M. )

    1991-01-01

    The NMDA subtype of glutamate receptors is allosterically linked to a strychnine-insensitive glycine regulatory site. Kynurenic acid and its halogenated derivatives are non-competitive NMDA antagonists acting at the glycine site. The authors have prepared (3H) 5,7-dichlorokyrurenic acid (DCKA) as an antagonist radioligand and have characterized its binding. 3-Bromo-5,7-DCKA was catalytically dehalogenated in the presence of tritium gas and HPLC purified to yield (3H) 5,7-DCKA with a specific activity of 17.6 Ci/mmol. (3H) 5,7-DCKA bound to rat brain synaptosomes with a Kd of 69 {plus minus} 23 nM and Bmax = 14.5 {plus minus} 3.2 pmoles/mg protein. Binding was 65-70% specific at 10 nM (3H) 5,7-DCKA. This ligand is thus more selective and has higher affinity than (3H) glycine, in addition to being an antagonist.

  1. E2003 + 225 - A 3h 42m AM Herculis type binary system

    NASA Technical Reports Server (NTRS)

    Takalo, L. O.; Schmidt, G. D.; Tapia, S.; Hill, G. J.; Stern, R. A.; Agrawal, P. C.; Nousek, J. A.; Bond, H. E.; Grauer, A. D.

    1984-01-01

    The bright soft X-ray source E2003 + 225, originally discovered by the HEAO 1 low-energy detectors, has been found to be a new AM Herculis type binary. The optical counterpart shows a rich emission spectrum of He II, He I, and H as well as circular and linear polarization. Larger polarization in the near-infrared than in the ultraviolet argues for its origin as high harmonic cyclotron emission. Optical photometry, polarimetry, spectroscopy, and the X-ray light curves are all consistent with an orbital period of 222.51 m, the longest period known for AM Herculis systems, and only the second on the long side of the 2-3 hour cataclysmic variable period gap.

  2. An experimental guided-ion-beam and ab initio study of the ion-molecule gas-phase reactions between Li{sup +} ions and iso-C{sub 3}H{sub 7}Cl in their ground electronic state

    SciTech Connect

    Lucas, J. M.; Andres, J. de; Sogas, J.; Alberti, M.; Aguilar, A.; Bofill, J. M.; Bassi, D.; Ascenzi, D.; Tosi, P.

    2009-07-14

    Reactive collisions between Li{sup +} ions and i-C{sub 3}H{sub 7}Cl molecules have been studied in the 0.20-12.00 eV center-of-mass energy range using an octopole radio frequency guided-ion beam apparatus recently developed in our laboratory. At low collision energies, dehydrohalogenation reactions giving rise to Li(C{sub 3}H{sub 6}){sup +} and Li(HCl){sup +} are the main reaction channels, while at higher ones C{sub 3}H{sub 7}{sup +} and C{sub 2}H{sub 3}{sup +} become dominant, all their reactive cross sections having been measured as a function of the collision energy. To obtain information about the potential energy surfaces (PESs) on which the reactive processes take place, ab initio calculations at the MP2 level have been performed. For dehydrohalogenations, the reactive ground singlet PES shows ion-molecule adduct formation in both the reactant and product sides of the surface. Following the minimum energy path connecting both minima, an unstable intermediate and the corresponding barriers, both lying below the reactant's energy, have been characterized. The entrance channel ion-molecule adduct is also involved in the formation of C{sub 3}H{sub 7}{sup +}, which then generates C{sub 2}H{sub 3}{sup +} via an CH{sub 4} unimolecular elimination. A qualitative interpretation of the experimental results based on ab initio calculations is also included.

  3. Intrauterine stress induces bone loss in adult offspring of C3H/HeJ mice having high bone mass phenotype but not C57BL/6J mice with low bone mass phenotype.

    PubMed

    Raygorodskaya, M; Gabet, Y; Shochat, C; Kobyliansky, E; Torchinsky, A; Karasik, D

    2016-06-01

    In this study we examined to what extent and how genetics may modify osteoporosis risk arising due to environmental stresses which act during the antenatal period of life and have the potential to induce bone loss in adulthood. C57Bl/6J (C57) and C3H/HeJ (C3H) mice were used as a model system. The mice were exposed to a single injection of 5-aza-2'-deoxycytidine (5-AZA) on day 10 of pregnancy and the structure and bone mineral density (BMD) of the femur and 3rd lumbar vertebra of 3- and 6-month-old male and female offspring were evaluated by micro-computed tomography (μCT). Besides, we also attempted to evaluate whether 5-AZA affects the expression of some osteogenic genes in the embryonic limb buds. The main observation of this study is that 5-AZA-induced loss of bone quality was registered in 6-mo-old C3H offspring but not in their C57 counterparts. We also observed that C57 and C3H embryos may differ in their response to 5-AZA-induced detrimental stimuli: whereas 5-AZA treated C3H embryos exhibited a decreased expression of Col1a1, C57 embryos exhibit a decreased expression of Sox9. Overall, our study, by thorough characterization of bone homeostasis in 3- and 6-month-old offspring of 5-AZA-exposed C57 and C3H mice, allows hypothesizing that the adaptive response to antenatal insults may be stronger in offspring inherently exhibiting a low bone mass phenotype than in offspring inherently exhibiting a high bone mass phenotype. PMID:27072519

  4. Synthesis and cytotoxic evaluation of some new 4(3H)-quinazolinones on HeLa cell line.

    PubMed

    Khodarahmi, G A; Shamshiri, M; Hassanzadeh, F

    2012-04-01

    Quinazolinone backbone is present in a large number of bioactive substances. Since remarkable cytotoxic activity is associated with some 4(3H)-quinazolinones, in this study some 4(3H)-quinazolinone were synthesized and screened against HeLa cells. The synthesis was performed via reaction of anthranilic acid with dicarboxylic anhydrides to produce carboxylic acids derivatives. The products were heated in acetic anhydride to produce benzoxazinones. Finally, 4(3H)-quinazolinones were synthesized by reaction between benzoxazinones and primary amines. The assessment of the structure of the synthesized compounds was based on spectral data (FT-IR, Mass and (1)HNMR). Subsequently, cytotoxic activity of compounds 3, 6, 9 and 13 (individually and in combination with doxorubicin) was evaluated on HeLa cell line using MTT assay. The results indicated that the tested compounds did not show significant cytotoxicity alone and in combination with doxorubicin (1 and 20 μM). PMID:23181089

  5. Synthesis and cytotoxic evaluation of some new 4(3H)-quinazolinones on HeLa cell line

    PubMed Central

    Khodarahmi, G.A.; Shamshiri, M.; Hassanzadeh, F.

    2012-01-01

    Quinazolinone backbone is present in a large number of bioactive substances. Since remarkable cytotoxic activity is associated with some 4(3H)-quinazolinones, in this study some 4(3H)-quinazolinone were synthesized and screened against HeLa cells. The synthesis was performed via reaction of anthranilic acid with dicarboxylic anhydrides to produce carboxylic acids derivatives. The products were heated in acetic anhydride to produce benzoxazinones. Finally, 4(3H)-quinazolinones were synthesized by reaction between benzoxazinones and primary amines. The assessment of the structure of the synthesized compounds was based on spectral data (FT-IR, Mass and 1HNMR). Subsequently, cytotoxic activity of compounds 3, 6, 9 and 13 (individually and in combination with doxorubicin) was evaluated on HeLa cell line using MTT assay. The results indicated that the tested compounds did not show significant cytotoxicity alone and in combination with doxorubicin (1 and 20 μM). PMID:23181089

  6. Binding of [3H]-muscimol, a potent gamma-aminobutyric acid receptor agonist, to membranes of the bovine retina.

    PubMed Central

    Osborne, N. N.

    1980-01-01

    1 The binding of [3H]-muscimol, a potent gamma-aminobutyric acid (GABA) receptor agonist, to crude membrane preparations of bovine retina was studied, using a filtration method to isolate membrane-bound ligand. 2 Specific binding was found to be saturable and occurred at two binding sites with affinity constants of 4.3 nM and 38.2 nM. 3 Binding was sodium-independent, enhanced by both freezing and Triton X-100 treatment but abolished with sodium laurylsulphate. 4 The binding sites demonstrated a high degree of pharmacological specificity, GABA being a potent displacer of [3H]-muscimol. 5 A higher degree of [3H]-muscimol binding was associated with subcellular fractions enriched with photoreceptor synaptosomes rather than with fractions enriched with conventional synaptosomes. PMID:7470740

  7. Elevation of naloxone-sensitive /sup 3/H-dihydromorphine binding in hippocampal formation of genetically epilepsy-prone rats

    SciTech Connect

    Savage, D.D.; Mills, S.A.; Jobe, P.C.; Reigel, C.E.

    1988-01-01

    /sup 3/H-Dihydromorphine (DHM) binding sites were measured in the brain of non-epileptic control and GEPR rats using in vitro autoradiographic techniques. The number of naloxone-sensitive /sup 3/H-DHM binding sites was increased 38-57% in the pyramidal cell layer of ventral hippocampal CA/sub 3/ and CA/sub 1/ of GEPR-3 and GEPR-9 rats compared to non-epileptic controls. No significant differences in /sup 3/H-DHM binding were observed in dorsal hippocampal formation, lateral entorhinal cortex, lateral geniculate or cerebellum. The results suggest that an increase in the number of opioid receptors in ventral hippocampus of GEPR rats may be one factor contributing to the enhanced sensitivity of GEPR-9 rats to the proconvulsant effects of morphine.

  8. 3H)phenamil, a radiolabelled diuretic for the analysis of the amiloride-sensitive Na+ channels in kidney membranes

    SciTech Connect

    Barbry, P.; Frelin, C.; Vigne, P.; Cragoe, E.J. Jr.; Lazdunski, M.

    1986-02-26

    The interaction of amiloride and amiloride derivatives with the Na+ channels of pig kidney membranes was studied from 22Na+ uptake experiments. The order of potency of the different molecules tested is: phenamil greater than benzamil greater than amiloride, ethylisopropylamiloride. (3H)labelled phenamil was prepared and used to titrate Na+ channels in pig kidney membranes. Kinetics experiments, equilibrium binding studies and competition experiments between (3H)phenamil and unlabelled phenamil indicate that phenamil recognizes a single family of binding sites with a Kd value of 20 nM and a maximum binding capacity of 11.5 pmol/mg of protein. The order of potency of different amiloride analogs tested in (3H)phenamil competition experiments is identical to that found for the inhibition of 22Na+ uptake by apical Na+ channels.

  9. Schizophrenia: elevation of dopamine D4-like sites, using [3H]nemonapride and [125I]epidepride.

    PubMed

    Seeman, P; Guan, H C; Van Tol, H H

    1995-11-14

    We here report a three-fold elevation of dopamine D4-like sites in schizophrenia, using [3H]nemonapride to measure dopamine D2 and D3 receptors and D4-like sites, and using [125I]epidepride to measure D2 and D3 sites in ten control and nine schizophrenia post-mortem brain putamen tissues. This result differs from a recent report which did not detect significant D4-like sites in control or schizophrenia putamen (Reynolds and Mason, 1995, Eur. J. Pharmacol. 281, R5). The present finding agrees with other reports wherein an elevation in D4-like sites was found in schizophrenia, using [3H]nemonapride for D2, D3 and D4-like sites, but [3H]raclopride for D2 and D3 sites. The nature of these D4-like sites is not known. PMID:8605946

  10. Effects of some beta lactam antibiotics on (/sup 3/H)-methyl-yohimbine binding to intact human platelets

    SciTech Connect

    Borst, S.E.; Hui, K.K.; Conolly, M.E.

    1985-05-01

    Several antibiotics have been reported to cause a bleeding diathesis in man, characterized by reduced platelet aggregation. The authors investigated the effects of several of the penicillins and of moxalactam on the binding of (/sup 3/H)-methyl-yohimbine to intact human platelets. The (/sup 3/H)-methyl-yohimbine binding met the criteria for interaction at an alpha2 adrenergic binding site and showed low interindividual variability. Penicillin G, ticarcillin, carbenicillin, piperacillin and moxalactam all inhibited (/sup 3/H)-methyl-yohimbine binding, but at concentrations far in excess of clinically achievable plasma levels. They conclude that these compounds exert their antiplatelet effects by a mechanism other than competitive inhibition of catecholamine binding.

  11. Evidence that the (/sup 3/H)estradiol-binding protein in pancreas is localized in exocrine cells

    SciTech Connect

    Grossman, A.; Richardson, S.B.; Altszuler, N.; Lane, B.

    1985-06-01

    Extracts of rat pancreas contain significant amounts of an (/sup 3/H)estradiol-binding protein. The amount of steroid-binding activity that could be measured varied considerably depending on the tonicity of the homogenizing medium. High speed supernatants of homogenates initially prepared in isotonic buffer contained about 10% of the binding activity as homogenates prepared in hypotonic buffer. Extraction with hypotonic buffer of pellets obtained by the isotonic procedure yielded most of the remaining (/sup 3/H)estradiol-binding activity. In an attempt to avoid errors resulting from incomplete homogenization and to detect possible changes in intracellular distribution of (/sup 3/H)estradiol-binding activity, pancreata were initially homogenized in isotonic buffer and centrifuged at high speed (100,000 X g; 1 hr). The pellet was then extracted with hypotonic buffer and centrifuged again at high speed, and both supernatants were analyzed for (/sup 3/H)estradiol-binding and amylase activities. Two or 14 days after treatment of male rats with streptozotocin, no apparent decline or redistribution of (/sup 3/H)estradiol-binding activity to the cytosol was noted despite extensive alteration of beta-islet cells, as determined by electron microscopic examination of sections of these pancreata and significant loss of insulin, as measured by RIA. Amylase activity was unaffected 2 days after streptozotocin treatment, but was depressed to about 1% of control levels at 14 days. Administration of insulin to the latter group of animals resulted in return of amylase to normal levels and a modest increase (approximately 50%) in (/sup 3/H)estradiol-binding activity.

  12. Assessing the use of 3H-3He dating to determine the subsurface transit time of cave drip waters.

    PubMed

    Kluge, Tobias; Wieser, Martin; Aeschbach-Hertig, Werner

    2010-09-01

    (3)H-(3)He measurements constitute a well-established method for the determination of the residence time of young groundwater. However, this method has rarely been applied to karstified aquifers and in particular to drip water in caves, despite the importance of the information which may be obtained. Besides the determination of transfer times of climate signals from the atmosphere through the epikarst to speleothems as climate archives, (3)H-(3)He together with Ne, Ar, Kr, Xe data may also help to give new insights into the local hydrogeology, e.g. the possible existence of a perched aquifer above a cave. In order to check the applicability of (3)H-(3)He dating to cave drips, we collected drip water samples from three adjacent caves in northwestern Germany during several campaigns. The noble gas data were evaluated by inverse modelling to obtain recharge temperature and excess air, supporting the calculation of the tritiogenic (3)He and hence the (3)H-(3)He age. Although atmospheric noble gases were often found to be close to equilibrium with the cave atmosphere, several drip water samples yielded an elevated (3)He/(4)He ratio, providing evidence for the accumulation of (3)He from the decay of (3)H. No significant contribution of radiogenic (4)He was found, corresponding to the low residence times mostly in the range of one to three years. Despite complications during sampling, conditions of a perched aquifer could be confirmed by replicate samples at one drip site. Here, the excess air indicator ΔNe was about 10 %, comparable to typical values found in aquifers in mid-latitudes. The mean (3)H-(3)He age of 2.1 years at this site presumably refers to the residence time in the perched aquifer and is lower than the entire transit time of 3.4 years estimated from the tritium data. PMID:20812118

  13. Degassing of 3H/3He, CFCs and SF6 by denitrification: measurements and two-phase transport simulations.

    PubMed

    Visser, Ate; Schaap, Joris D; Broers, Hans Peter; Bierkens, Marc F P

    2009-01-26

    The production of N2 gas by denitrification may lead to the appearance of a gas phase below the water table prohibiting the conservative transport of tracer gases required for groundwater dating. We used a two-phase flow and transport model (STOMP) to study the reliability of 3H/3He, CFCs and SF6 as groundwater age tracers under agricultural land where denitrification causes degassing. We were able to reproduce the amount of degassing (R2=69%), as well as the 3H (R2=79%) and 3He (R2=76%) concentrations observed in a 3H/3He data set using simple 2D models. We found that the TDG correction of the 3H/3He age overestimated the control 3He/3He age by 2.1 years, due to the accumulation of 3He in the gas phase. The total uncertainty of degassed 3H/3He ages of 6 years (+/-2 sigma) is due to the correction of degassed 3He using the TDG method, but also due to the travel time in the unsaturated zone and the diffusion of bomb peak 3He. CFCs appear to be subject to significant degradation in anoxic groundwater and SF6 is highly susceptible to degassing. We conclude that 3H/3He is the most reliable method to date degassed groundwater and that two-phase flow models such as STOMP are useful tools to assist in the interpretation of degassed groundwater age tracer data. PMID:19042054

  14. Competition for in vitro ( sup 3 H)gibberellin A sub 4 binding in cucumber by substituted phthalimides

    SciTech Connect

    Yalpani, N.; Suttle, J.C.; Hultstrand, J.F. ); Rodaway, S.J. )

    1989-11-01

    Certain N-substituted phthalimides (NSPs) have gibberellin (GA)-like activity in a number of GA bioassays. The interaction between representative NSPs and a protein fraction from cucumber (Cucumis sativus L.) hypocotyls that has GA-binding characteristics consistent with those expected of GA receptors was studied. Analysis of in vitro equilibrium saturation data indicated the presence of only one class of high affinity ({sup 3}H)GA{sub 4} binding sites (K{sub d} {approximately}30 nanomolar, n = 0.25 picomole per milligram of protein). In the presence of 6 or 60 micromolar 1-(3-chlorophthalimido)-cyclohexanecarboximide (AC-94,377), the K{sub d} for ({sup 3}H)GA{sub 4} increased, whereas the maximum number of saturable ({sup 3}H)GA{sub 4} binding sites did not change significantly. The dissociation of ({sup 3}H)GA{sub 4} from its binding sites was complex and was best described by a bi-exponential equation. AC-94,377 did not affect the rates of ({sup 3}H)GA{sub 4} dissociation from its binding sites. These results implied that AC-94,377 and ({sup 3}H)GA{sub 4} compete for binding to the same sites. A correlation was observed between the activity of over 20 NSPs in the cucumber hypocotyl bioassay and their in vitro affinity for the GA binding sites. Our observations lend further support to the notion that certain GA binding proteins in cucumber cytosol are GA receptors and also provide a molecular explanation for the GA-like in vivo activity of some NSPs.

  15. Metabolism of (/sup 3/H)gibberellin A/sub 5/ by immature seeds of apricot (Prunus armeniaca L. )

    SciTech Connect

    De Bottini, G.A.; Bottini, R.; Koshioka, M.; Pharis, R.P.; Coombe, B.G.

    1987-01-01

    Immature seeds of apricot (Prunus armeniaca L.) were fed the native gibberellin A/sub 5/ (GA/sub 5/) as 1- and 1,2-(/sup 3/H)GA/sub 5/ at doses 2 to 530 times the expected endogenous level. After 4 days of incubation, seeds were extracted and free (/sup 3/H)GA-like metabolites were separated from the highly H/sub 2/O-soluble (/sup 3/H)metabolites. For high specific activity feeds the retention times (Rts) of radioactive peaks were compared with Rts of authentic GAs on sequential gradient-eluted ..-->.. isocratic eluted reversed-phase C/sub 18/ high performance liquid chromatography (HPLC)-radiocounting (RC). From high substrate feeds (530 and 230 x expected endogenous levels) HPLC-RC peak groupings were subjected to capillary gas chromatography-selected ion monitoring (GC-SIM), usually six characteristic ions. The major free GA metabolites of (/sup 3/H) GA/sub 5/ were identified as GA/sub 1/, GA/sub 3/, and GA/sub 6/ by GC-SIM. The major highly water soluble metabolite of (/sup 3/H)GA/sub 5/ at all levels of substrate GA/sub 5/ had chromatographic characteristics similar to authentic GA/sub 1/-glucosyl ester. Expressed as a percentage of recovered radioactivity, low substrate (/sup 3/H)GA/sub 5/ feeds (2 x expected endogenous level) yielded a broad spectrum of metabolites eluting at the Rts where GA/sub 1/, GA/sub 3/, GA/sub 5/ methyl ester, GA/sub 6/, GA/sub 22/, GA/sub 29/ (17, 14, 1.6, 7, 1.1, 0.5%, respectively) and GA glucosyl conjugates of GA/sub 1/, GA/sub 3/, GA/sub 5/, and GA/sub 8/ (33, 11, 1, 0.1%, respectively) elute.

  16. Kinetics and subcellular localization of specific [3H]phorbol 12, 13-dibutyrate binding by mouse brain.

    PubMed

    Dunphy, W G; Kochenburger, R J; Castagna, M; Blumberg, P M

    1981-07-01

    The specific binding of [3H]phorbol 12,13-dibutyrate ([3H]-PDBU) to particulate preparations from mouse brain has been further characterized. Kinetic analysis, using a filtration assay to measure binding, yielded a second-order rate constant at 23 degrees of 3.75 X 10(7) M-1 min-1 and a first-order dissociation rate constant of 0.21 min-1. The Kd of 5.6 nM calculated from the kinetic data agreed well with the value determined previously in equilibrium binding studies. The Kd for [3H]PDBU binding varied only slightly with temperature. From its temperature dependence, [3H]PDBU binding appeared to be associated with a small increase in enthalpy (delta H degrees = +0.4 kcal/mol) and a large increase in entropy (delta S degrees = +38 e.u.). Such values are characteristic for hydrophobic interactions. The dissociation rate constant for binding, in contrast to the Kd, varied dramatically with temperature. The half-time for release ranged from 1.75 min at 30 degrees to 62 min at 4 degrees. The Kd for binding was Ca2+ sensitive; chelation of Ca2+ by ethyleneglycolbis(beta-aminoethyl ether)N,N'-tetraacetic acid increased the Kd 2.4-fold. Upon subcellular fractionation, the specific [3H]PDBU binding activity was exclusively particulate; no binding to cytosol was detectable. Binding clearly did not correlate with nuclear or mitochondrial markers. On the other hand, a broader distribution of binding activity was seen on sucrose density gradients than for either Na+-K+-adenosine triphosphatase activity or binding of quinuclidinyl benzilate (a muscarinic cholinergic antagonist). The localization of specific [3H]PDBU binding to the plasma membrane therefore remains uncertain. PMID:6941848

  17. ( sup 3 H)phenamil binding protein of the renal epithelium Na+ channel. Purification, affinity labeling, and functional reconstitution

    SciTech Connect

    Barbry, P.; Chassande, O.; Marsault, R.; Lazdunski, M.; Frelin, C. )

    1990-01-30

    This paper describes a large-scale purification procedure of the amiloride binding component of the epithelium Na+ channel. (3H)Phenamil was used as a labeled ligand to follow the purification. The first two steps are identical with those previously described. A third step was a hydroxyapatite column. The purified material consisted of a homodimer of two 88-kDa proteins that migrated anomalously in SDS-PAGE to give an apparent Mr of 105,000. Deglycosylation by treatment with neuraminidase and endoglycosidase F or with neuraminidase and glycopeptidase F indicated that less than 5% of the mass of the native receptor was carbohydrate. Sedimentation analysis of the purified Na+ channel in H2O and D2O sucrose gradients and gel filtration experiments led to an estimated molecular weight of the (3H)phenamil receptor protein-detergent-phospholipid complex of 288,000 and of the native (3H)phenamil receptor protein of 158,000. (3H)Br-benzamil is another labeled derivative of amiloride that recognized binding sites that had the same pharmacological properties as (3H)phenamil binding sites and that copurified with them. Upon irradiation of kidney membranes, (3H)Br-benzamil incorporated specifically into a 185-kDa polypeptide chain under nonreducing electrophoretic conditions and a 105-kDa protein under reducing conditions. The same labeling pattern was observed at the different steps of the purification. Reconstitution of the purified phenamil receptor into large unilamellar vesicles was carried out. A low but significant phenamil- and amiloride-sensitive electrogenic Na+ transport was observed.

  18. In vivo (/sup 3/H)spiperone binding: evidence for accumulation in corpus striatum by agonist-mediated receptor internalization

    SciTech Connect

    Chugani, D.C.; Ackermann, R.F.; Phelps, M.E.

    1988-06-01

    The processes of receptor internalization and recycling have been well-documented for receptors for hormones, growth factors, lysosomal enzymes, and cellular substrates. Evidence also exists that these processes also occur for beta-adrenergic, muscarinic cholinergic, and delta-opiate receptors in frog erythrocytes or cultured nervous tissue. In this study, evidence is presented that agonist-mediated receptor internalization and recycling occurs at the dopamine receptor in rat corpus striatum. First, the in vivo binding of the dopamine antagonist (3H)spiperone was increased by both electrical stimulation and pharmacologically induced increases of dopamine release. Conversely, depletion of dopamine with reserpine decreased in vivo (3H)spiperone binding, but the same reserpine treatment did not alter its in vitro binding. Second, the rate of dissociation of (3H)spiperone from microsomal membranes prepared from rat striatum following in vivo binding was fivefold slower than its dissociation following in vitro equilibrium binding. Mild detergent treatment, employed to disrupt endocytic vesicle membranes, increased the rate of dissociation of in vivo bound (3H)spiperone from microsomal membranes to values not significantly different from its in vitro boun