Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027819 (neuroblastoma)
 27,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

N-bromosuccinimide-cytochromes c (Myer, Y. P. (1972), Biochemistry 11, 4195) and formyl-cytochrome c (Aviram, I and Schejter, A. (1971), Biochim. Biophys. Acta 229, 113) have been chromatographically purified, and the resulting components have been characterized in terms of their structure, conformation, and function. The activity measurements are considered in terms of the oxidizability, as the transference of an electron to solubilized cytochrome c oxidase, and reducibility, as the tendency to accept an electron from NADH-cytochrome c reductase. Conformational characterization has been carried out by absorption measurements, pH-spectroscopic behavior, circular dichroism, thermal denaturation, ionization of phenolic hydroxyls, the tendency to form the CO complex, and autoxidation with molecular oxygen. NBS-cytochrome c yields two major components, the relative proportions of which, with increasing modification of the protein, exhibit a pattern typical of the formation of the two in a consecutive manner. The first product contains the modification of the Trp-59 and Met-65 side chains, and the second contains the added modification of Met-80. The former in both valence states of iron is more or less like the native protein, except for an apparently slightly loosened heme crevice; the latter, as in other modifications involving modification of centrally coordinated Met-80, was found to be in a conformational state characteristic of the native protein with a disrupted central coordination complex, a loosened heme crevice, and small, but finite derangement of the polypeptide conformation. Functionally, the first component reflected 55% of the reducibility property and an unimpaired oxidizability property, while the latter exhibited derangement of both aspects of cytochrome c activity. Formyl-cytochrome c yielded a single component with modification of Trp-59. Conformationally, in both valence states, it is a molecular form with a disrupted central coordination complex, a loosened heme crevice, and gross derangement of the overall protein conformation. It exhibits a minimal reducibility property, 12%, whereas it retains a native-like tendency to transfer an electron to cytochrome c oxidase. The data from the NBS-cytochrome c components are analyzed with reference to the two forms in the earlier studies of the unpurified preparations. The results are found to be in agreement with one another. The selectivity between the reducibility and the oxidizability exhibited by the first NBS component and formyl-cytochrome c, irrespective of significant differences in the conformational and coordinational configurations of the two, has been viewed in light of a two-path, two-function model for oxidoreduction, as well as with reference to conformational and structural requirements for the oxidizability and reducibility properties of the molecule.
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PMID:Conformational and functional studies of chemically modified cytochromes: N-bromosuccinimide- and formyl-cytochromes c. 16 5

The free energies of immersion for three hydroxyapatite samples of different origin and method of preparation were determined from water adsorption isotherms at 20 and 25 C. The free energies varied with the temperature of the isotherm, changing linearly with the outgassing temperature in the range of 20 and 300 C. The samples outgassed at 300 C yielded free energy of immersion values of 365, 432, and 476 ergs/cm2 for the VIC-, NBS-, and TVA-HAP, respectively. Work of adhesion and work of spreading were calculated for water on these samples.
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PMID:Free surface energy change for water adsorbed on hydroxyapatite. 26 53

The specific, precise detection of volatile metal chelates has been obtained by coupling the effluent from a gas chromatograph directly to the burner head of a commerical atomic absorption spectrometer (AAS). Quantitation of chromium in the nanogram range has been accomplished with a detection limit of 1.0 ng. The chelation-extraction-gas chromatographic separation procedure coupled with the selective detection by AAS gives a relatively interference-free system that has been used to quantitatively analyse for chromium in standard biological materials NBS SRM 1571 Orchard Leaves and SRM 1569 Brewers Yeast. Metal chelates of iron, copper and cobalt have also been detected by this system.
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PMID:Coupled gas chromatography-atomic absorption spectrometry. 32 71

Filtration efficiency of high-efficiency particulate air (HEPA) filters is said to be over 99.97% of removal rate against the mist of thermogenerating-type of dioctyl phthalate with average particles diameter of 0.3 micrometer, as tested by the U.S. Military Standard 282 (1956). Filtration of bacterial aerosols through commercial air filters was tested to examine the efficiency of bacterial filtration with eight kinds of air filters. Percentage of bacterial filtration efficiency (% BFE) of three kinds of HEPA filters showed 100% BFE, while NBS-95 and NBS-85 showed over 99% BFE. BFE of NBS-75 air filter was 91.75%.
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PMID:Efficiency of bacterial filtration in various commercial air filters for hospital air conditioning. 35 87

The dimensional accuracy of porcelain fused to metal crown and bridge castings was determined on truncated cone-shaped steel dies. Ni-Cr castings produced in manufacturers' laboratories were consistently undersize, while precious metal castings were consistently oversize. Ni-Cr castings, produced in NBS laboratories using a modified investing technique, were routinely oversize.
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PMID:Fit of porcelain fused-to-metal crown and bridge castings. 38 80

The determination of protein nitrogen in feeds and wheat by microcomputer controlled titration is described. The method involves direct titration of ammonia with standard hypochlorite titrant in the presence of bromide. The titrant is delivered by an automatic buret, and the microcomputer controlled, automatically computed potentiometric end points are precise to 0.1% over a 5-fold concentration range of nitrogen. Digestions performed with both mercury and copper catalysts show comparable results. Samples are weighed before digestion by an electronic balance interfaced to the computer which records sample number and weight. An automatic pipet aliquots, dilutes, and buffers samples directly from the digestion tubes; the samples can be immediately titrated with the automatic titrator. The results for protein in NBS standards and check feed samples from an offical testing program compare closely with average values reported for these standards. Results show that feed and wheat samples contained 10-100% protein. Precision for successive aliquots of the same digests is 0.1-0.4%relative standard deviation; precision for multiple digestions of the same sample is 0.1-0.8%.
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PMID:Microcomputer controlled titration for determination of protein nitrogen in feeds and wheat. 39 95

Iodine ions exhibited the thyroxin-like effect on incorporation of 1-14C-leucine into proteins of isolated mitochondria and microsomes of thyroidectomized rats in vitro. Thyroxin, triiodothyronine (T3) and ICl increased the incorporation of 1-14C-leucine into proteins of isolated mitochondria of thyroidectomized rats, but did not affect the protein synthesis in microsomes in vitro. Rifampycin and olivomycin abolished completely the stimulating effect of T3 and ICl on incorporation of the label into mitochondrial proteins. The thyroid hormones and iodine ions stimulated protein synthesis in vitro in liver microsomes of thyroidectomized animals only after preincubation with mitochondria or nuclei. In these conditions preincubation with mitochondria elevated the rate of 1-14C-leucine incorporation into microsomal proteins 2--2.5-fold. In similar experiments with nuclei--4--4.8-fold stimulation was detected. Thyroid hormones and iodine ions stimulated synthesis of specific factors in mitochondria (MBS) and in nuclei (NBS) of thyroidectomized rat liver tissue, which increased the protein synthesis in isolated microsomes in vitro. Synthesis of MBS- and NBS-factor required the presence of all the four ribosetriphosphates (ATP, GTP, UTP, CTP) and was inhibited completely by olivomycin; rifampycin blocked only the MBS factor synthesis. NBS- and MBS-factors appear to be RNA (mRNA), synthesized in nuclei and mitochondria, which are transported into the incubation media and translated by ribosomes.
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PMID:[Effect of triiodothyronine and ICl on protein synthesis in cell-free systems]. 42 69

The authors examined both hard and soft glass evacuated blood-drawing tubes for possible effects on clinical chemistry measurements. Using routine laboratory procedures, no clinically or statistically significant difference could be detected in 34 analytes using 66 different methods. A special high-precision study utilizing an adaption of the NBS round-robin procedures for calcium, magnesium, sodium, and potassium detected no difference between paired sera when drawn or stored for 72 hours, or both, in the two types of glass. The authors conclude that the type of glass used in production of the evacuated blood-drawing tubes does not affect the clinical chemistry results obtained.
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PMID:A comparison of hard and soft glass blood-drawing tubes. 51 61

A simple and accurate method was developed for routine determination of fluoride in foods. Hydrogen fluoride is diffused 20 hr at 50 degrees C from fresh or freeze-dried samples (0.1 g dry wt) in polystyrene petri dishes containing 2 mL 40% HCIO4 and 0.3 g Ag2SO4, and is absorbed on the lids, previously spotted with 0.1 mL 0.5M NaOH. The absorbent layer is dissolved in 2 mL buffer solution, and the fluoride is measured potentiometrically. The method was verified by analysis of NBS Standard Reference Materials; recovery from 28 spiked infant foods (average = 99%, range = 75-135%); and comparison of results with colorimetry results for the same diffusates, after modification to handle 1 g samples. Relative standard deviations varied from 4 to 20% day to day. Detection limits were below 0.05 microgram/g dry weight.
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PMID:Microdiffusion and fluoride-specific electrode determination of fluoride in foods. 52 49

Instrumental neutron activation analysis by the monostandard method has been applied to the analyses of biological NBS standard reference materials; 1571 Orchard Leaves and 1577 Bovine Liver. Aluminum foils containing 0.100% gold or 2.00% cobalt were used as the monostandards. The gamma-ray spectral data were recorded on punched paper tape and were analyzed by a computer assisted data processing. The following 25 elements were determined: Al, Ca, Cl Cu, Mg, Mn, V (by short period irradiation), As, Ba, Br, Co, Cr, Cs, Eu, Fe, Hg, K, La, Na, Rb, Sb, Sc, Se, Sm and Zn (by long period irradiation). The results were compared with the certified values by NBS and the reported values in literatures to prove the reliability and accuracy of the monostandard method.
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PMID:Neutron activation analysis of biological materials by the monostandard method. 54 35


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