Showing papers by "Research Triangle Park published in 1976"
TL;DR: To determine a standard for infants delivered at about sea level the 10th, 25th, 50th, 75th, and 90th percentiles of fetal weight for each menstrual week of gestation were calculated from 430 fetuses at 8 to 20 menstrual weeks' gestation aborted with prostaglandins.
835 citations
TL;DR: Most of the existing data on insulin binding and biological responses can be explained in terms of the mobile receptor hypothesis, and considerations may also be pertinent to interpretations of other hormone-receptor systems and of various ligand-macromolecule interactions.
230 citations
TL;DR: The effect of nonpolymer-forming plasma can be viewed as the following two reactions: reaction of active species with polymer, and formation of free radicals in polymer which is mainly due to the UV emitted by the plasma.
Abstract: The effect of nonpolymer-forming plasma (e.g., plasma of hydrogen, helium, argon, nitrogen) can be viewed as the following two reactions: 1) reaction of active species with polymer, and 2) formation of free radicals in polymer which is mainly due to the UV emitted by the plasma. The incorporation of nitrogen into the polymer surface by N2 plasma and the surface oxidation by O2 plasma are typical examples of the first effect. The latter effect generally leads to incorporation of oxygen in the form of carbonyl and hydroxyl and to some degree of cross-linking depending on the type of substrate; however, the degradation of polymer at the surface manifested by weight loss occurs in nearly all cases when polymers are exposed to plasma for a prolonged period of time. The effects of polymer-forming plasma is predominated by the deposition of polymer (plasma polymer); however, with some plasma-susceptible polymer substrates the effect of UV emission from polymer-forming plasma cannot be neglected. The mec...
179 citations
155 citations
TL;DR: Emissions from metropolitan St. Louis caused reduced visibilities and concentrations of ozone in excess of the federal ambient standard 160 kilometers or more downwind of the city on 18 July 1975.
Abstract: Emissions from metropolitan St. Louis caused reduced visibilities and concentrations of ozone in excess of the federal ambient standard (0.08 part per million) 160 kilometers or more downwind of the city on 18 July 1975. Atmospheric production of ozone and visibility-reducing aerosols continues long after their primary precursors have been diluted to low concentrations.
148 citations
Patent•
01 Mar 1976TL;DR: In this paper, 9-hydroxyethoxymethyl derivatives of certain 6-, and 2,6-substituted purines have been discovered to have potent anti-viral activities.
Abstract: 9-Hydroxyethoxymethyl (and related) derivatives of certain 6-, and 2,6-substituted purines have been discovered to have potent anti-viral activities. Novel compounds and their pharmaceutically acceptable salts, pharmaceutical formulation containing the compounds of this invention, and the treatment of viral infections with these formulations are all disclosed. 9-(2-hydroxyethoxymethyl) guanine and 2-amino-9-(2-hydroxyethoxymethyl)adenine are examples of especially active compounds of this invention.
144 citations
TL;DR: In a series of field measurements on atmospheric aerosols using cascade impactors, it was found that the nature of the impaction surface has a significant effect on the apparent size distribution as mentioned in this paper.
134 citations
TL;DR: The data suggest that the analgesia produced by aspirin and acetaminophen results from their anti-inflammatory activity whereas the morphine produced by phenacetin has two components, one dependent on and one independent of anti- inflammatory activity.
107 citations
TL;DR: In this paper, the electron spin resonance (ESR) spectroscopy has been used to detect free radicals in the polymers as detected by ESR spectrograms, and the concentrations of free radicals are directly correlated to the change of the properties of polymers with time of exposure to the atmosphere.
Abstract: Plasma polymerizations (under 13.5-MHz radiofrequency inductively coupled glow discharge) of some organic compounds are investigated by their properties (elemental analysis, surface energy, and infrared spectra) and their relations to the concentrations of free radicals in the polymers as detected by electron spin resonance (ESR) spectroscopy. Monomers that have been investigated are hexamethyldisiloxane, tetrafluoroethylene, acetylene, acetylene/N2, acetylene/H2O, acetylene/N2/H2O, allene, allene/N2, allene/H2O, allene/N2/H2O, ethylene, ethylene/N2, ethylene oxide, propylamine, allylamine, propionitrile, and acrylonitrile. Plasma-polymerized polymers generally contain oxygen, even if the starting monomers do not contain oxygen. This oxygen incorporation is related to the free-radical concentration in the polymer. Molecular nitrogen copolymerizes with other organic monomers such as acetylene, allene, and ethylene, and their properties are very similar to those of plasma-polymerized polymers from nitrogen-containing compounds such as amines and nitriles. The addition of water to the monomer mixture reduces in a dramatic manner the concentration of free radicals in the polymer and consequently the oxygen-incorporation after the polymer is exposed to air. The concentrations of free radicals (by ESR) are directly correlated to the change of the properties of plasma-polymerized polymers with time of exposure to the atmosphere. These changes are primarily the introduction of carbonyl (and possibly hydroxyl) groups. The addition of water to the plasma introduces these groups during the polymerization.
105 citations
TL;DR: In this article, the performances of several sorbents as collection media for the quantitative concentration and analysis of volatile, hazardous, vapor-phase compounds from ambient atmospheres were evaluated under a variety of conditions relevant to field sampling.
Abstract: The performances of several sorbents as collection media for the quantitative concentration and analysis of volatile, hazardous, vapor-phase compounds from ambient atmospheres were evaluated under a variety of conditions relevant to field sampling. Tenax GC was found to be superior to other sorbents in most cases. The effects of humidity, background air pollution, repeated re-use of sorbent, and transportation and storage of collected samples were investigated.
99 citations
TL;DR: 2,3,7,8-Tetrachlorodibenzofuran (TCDF), a contaminant of commercial polychlorinated biphenyl (PCB) mixtures, had no effects on hepatic ALA synthetase activity, porphyrin accumulation, or glucuronyl transferase, while TCDF did produce a slight increase in cytochrome P-450, but the increase was smaller than that produced by HCBs.
TL;DR: Purified PCNB showed more maternal toxicity than the contaminated PCNB and resulted in a few cleft palates in the fetuses; there were no kidney malformations with purified PCNB, so the teratogenic activity of contaminated PC NB was probably due to the HCB.
TL;DR: Caffeine has been found to potentiate the acute anti-inflammatory activity of aspirin, indomethacin, and phenylbuta-zone, but not the activity of sodium salicy-late or hydrocortisone, in the carrageenan pleurisy or hindlimb models of inflammation in the rat.
Abstract: Caffeine has been found to potentiate the acute anti-inflammatory activity of aspirin, indomethacin, and phenylbutazone, but not the activity of sodium salicylate or hydrocortisone, in the carrageenan pleurisy or hindlimb models of inflammation in the rat. The mobilization of inflammatory cells was not affected by aspirin in the presence or absence of caffeine. The mild analgesia produced by aspirin was confined to a hyperalgesic test in which this drug was able to reduce inflammation and concomitant hyperalgesia and thereby produce an "apparent" analgesic effect. This "apparent" analgesia produced by aspirin was potentiated by caffeine. The mechanism responsible for the potentiated anti-inflammatory and mild analgesic activity of aspirin remains unknown since caffeine did not alter the plasma salicylate levels or prostaglandin synthetase inhibition produced by aspirin.
TL;DR: Guanylate cyclase (GTP pyrophosphate-lyase (cyclizing), EC 4.6.1.2) activity was examined in preparations from normal rat liver and a series of Morris hepatomas.
TL;DR: Increased mortality rates and reduced survival times were observed in mice exposed daily for 3 or 4 days to MnO2 aerosol and challenged with airborne Klebsiella pneumoniae within 1 hour of termination of the last aerosol exposure.
TL;DR: It is proposed that toxin action involves the initial formation of an inactive toxin-ganglioside complex which subsequently migrates and is somehow transformed into an active species which involves relocation within the two-dimensional structure of the membrane with direct perturbation of adenylate cyclase molecules (virtually irreversibly).
Abstract: The enterotoxin from Vibrio cholerae is a protein of 100,000 mol wt which stimulates adenylate cyclase activity ubiquitously The binding of biologically active 125I-labeled choleragen to cell membranes is of extraordinary affinity and specificity The binding may be restricted to membrane-bound ganglioside GM1 This ganglioside can be inserted into membranes from exogenous sources, and the increased toxin binding in such cells can be reflected by an increased sensitivity to the biological effects of the toxin Features of the toxin-activated adenylate cyclase, including conversion of the enzyne to a GTP-sensitive state, and the increased sensitivity of activation by hormones, suggest analogies between the basic mechanism of action of choleragen and the events following binding of hormones to their receptors The action of the toxin is probably not mediated through intermediary cytoplasmic events, suggesting that its effects are entirely due to processes involving the plasma membrane The kinetics of activation of adenylate cyclase in erythrocytes from various species as well as in rat adipocytes suggest a direct interaction between toxin and the cyclase enzyme which is difficult to reconcile with catalytic mechanisms of adenylate cyclase activation Direct evidence for this can be obtained from the comigration of toxin radioactivity with adenylate cyclase activity when toxin-activated membranes are dissolved in detergents and chromatographed on gel filtration columns Agarose derivatives containing the "active" subunit of the toxin can specifically absorb adenylate cyclase activity, and specific antibodies against the choleragen can be used for selective immunoprecipitation of adenylate cyclase activity from detergent-solubilized preparations of activated membranes It is proposed that toxin action involves the initial formation of an inactive toxin-ganglioside complex which subsequently migrates and is somehow transformed into an active species which involves relocation within the two-dimensional structure of the membrane with direct perturbation of adenylate cyclase molecules (virtually irreversibly) These studies suggest new insights into the normal mechanisms by which hormone receptors modify membrane functions
TL;DR: In this paper, it was shown that physiological concentrations (10−7 M−10−9 M) of cyclic GMP oppose the cyclic AMP dependent phosphorylation of a tubulin-related brain protein, possibly by activation of a phosphoprotein phosphatase.
Abstract: CYCLIC AMP and cyclic GMP have been postulated to be in certain cases, antagonistic intracellular messengers of many hormones and neurotransmitters acting at the cell membrane1. At least part of their antagonism may be the result of their ability to affect, in opposite directions, specific protein kinases and phosphates which work on common substrates (enzymes, structural proteins). Cyclic AMP and cyclic GMP have been found to activate, and the former also to inhibit, specific protein kinases2–5; cyclic AMP can activate or inhibit5–8 specific protein phosphates, and both cyclic nucleotide-sensitive protein kinases and protein phosphates have been isolated forming a complex with their substrate5. Some of these effects of cyclic nucleotides, however, have been found to depend on the type and concentration (not necessarily physiological) of the ion used in the assay5 and no direct evidence exists to show that one of the cyclic nucleotides opposes the effects of the other on protein phosphorylation. We report here that physiological concentrations (10−7 M–10−9 M) of cyclic GMP oppose the cyclic AMP (10−6M) dependent phosphorylation of a soluble, perhaps tubulin-related brain protein, possibly by activation of a phosphoprotein phosphatase.
TL;DR: Total uterine length was found to be a less accurate prognostic indicator of IUD performance than endometrial cavity length alone.
TL;DR: In this article, the air-permeability of non-woven fabrics was investigated and the authors showed that nonwoven yarns are airpermeable in general.
Abstract: (1976). The Air-permeability of Non-woven Fabrics. The Journal of The Textile Institute: Vol. 67, No. 6, pp. 220-224.
TL;DR: An ir analyzer employing gas-filter correlation techniques has been designed and constructed to measure the concentrations of CO, NO, SO, SO(2), HCl, and HF in the stacks or ducts of stationary pollutant sources.
Abstract: An ir analyzer employing gas-filter correlation techniques has been designed and constructed to measure the concentrations of CO, NO, SO(2), HCl, and HF in the stacks or ducts of stationary pollutant sources. Use of a retroreflector allows the stack to be double passed, and no sample is extracted. For each gas, small interchangeable fixed-position grating polychromators are used as narrow (~1.5-cm(-1)) multiband spectral filters with the bands corresponding to locations of selected absorption lines. The approximate useful ranges (in parts per million-meters) over which this analyzer operates are 10-4000 for NO, 10-1500 for CO, 50-40,000 for SO(2), 10-2000 for HC1, and 5-200 for HF. The discrimination against other gases and particulates is excellent. The analyzer has been tested in the laboratory and on a variety of pollutant sources.
TL;DR: Differences in potency of the stereoisomers have been discussed in relationship to known metabolic conversions of thiopentone and its rapid penetration into body fat depots.
01 Jan 1976
TL;DR: In this article, the vibrational spectrum of a polymer reflects its detailed fine structure, and the potential advantages of applying this technique to the complex problems of protein chemistry have been realized for some time.
Abstract: The vibrational spectrum of a polymer reflects its detailed fine structure, and the potential advantages of applying this technique to the complex problems of protein chemistry have been realized for some time. However, until a few years ago only dispersive IR instruments could be used to obtain high quality spectra. Raman spectroscopy was only of marginal significance owing to the weak exciting sources then available. The advent of laser excitation meant that high quality Raman spectra could be obtained in a routine fashion, while in the field of IR spectroscopy the introduction of Fourier transform instruments with an on-line computer capability promises an equivalent breakthrough.
TL;DR: The effects of various salts of platinum of palladium were determined on the parameters of the microsomal mixed-function oxidase system from rat liver and generally decreased the aminopyrine demethylase and the content of cytochrome P-450 in isolated hepatic microsomes.
Abstract: The effects of various salts of platinum or palladium were determined on the parameters of the microsomal mixed‐function oxidase system from rat liver. The intraperitoneal injection of PtCl 4 or Pd(NO 3 ) 2 increased the hexobarbital‐induced sleeping time in vivo and generally decreased the aminopyrine demethylase and the content of cytochrome P‐450 in isolated hepatic microsomes. The dietary administration of various salts of platinum or palladium for 1 wk generally decreased or had no effect on the parameters of drug metabolism by isolated microsomes and after 4 or more wk generally had no effect on, or increased, the parameters. The addition of 0.15–0.2 mM PtCI 4 or 0.2–0.3 mM Pd(NO 3 ) 2 to the incubation medium (containing 5 mM MgCl 2 ) inhibited the aminopyrine demethylase of isolated hepatic microsomes by 50%.
TL;DR: Type I and Type II uridine phosphorylases (uridine: orthophosphate ribosyltransferase EC 2.4.2.3) are distinguished by their pH optima and the random mechanism of this Type I enzyme contrasts with the ordered mechanism of a Type II enzyme from rat liver.
TL;DR: In this article, the 13C shieldings and 13C 199Hg coupling constants of fourteen phenyl and seven alkyl- and alkenyl-mercury compounds have been obtained.
TL;DR: The substrate and inhibitor specificity of IMP dehydrogenase from Sarcoma 180 ascites tumor cells has been studied with twenty purine nucleotide analogs and arabinosylguanine and 2′-deoxyxanthosine are described.
TL;DR: In this article, the authors present the technique of coating application, the sensitivity relative to the amount of coating applied, a comparison of totally coated crystals to center coated ones, and a comparison with the new coating relative to triethanolamine.
Abstract: A considerable number of compounds have been shown to be sensitive to sulfur dioxide sorption using quartz crystals. To utilize the technique for the continuous measurement of SO2, coating loss has been shown to be a major limitation. For such a continuously flowing system a previous coating, triethanolamine, was found to evaporate at undesirable rates when used at high enough temperatures and flow rates for an adequate response time. Methods of remedying this problem have led to a new SO2 sensitive coating, ethylenedinitrilotetraethanol. This work presents the technique of coating application, the sensitivity relative to the amount of coating applied, a comparison of totally coated crystals to center coated ones, and a comparison of the new coating relative to the previously used triethanolamine.