79,998 research outputs found
Cu(II)-catalyzed reactions in ternary [Cu(AA)(AA - H)]+ complexes (AA = Gly, Ala, Val, Leu, Ile, t-Leu, Phe).
No full textInternational audienceThe unimolecular chemistry of [Cu(II)AA(AA - H)](+) complexes, composed of an intact and a deprotonated amino acid (AA) ligand, have been probed in the gas phase by tandem and multistage mass spectrometry in an electrospray ionization quadrupole ion trap mass spectrometer. The amino acids examined include Gly, Ala, Val, Leu, Ile, t-Leu and Phe. Upon collisionally-activated dissociation (CAD), the [Cu(II)AA(AA - H)](+) complexes undergo decarboxylation with simultaneous reduction of Cu(II) to Cu(I); during this process, a radical site is created at the alpha-carbon of the decarboxylated ligand (H(2)N(1) - (*)C(alpha)H - C(beta)H(2) - R; R = side chain substituent). The radical site is able to move along the backbone of the decarboxylated amino acid to form two new radicals (HN(1)(*) - C(alpha)H(2) - C(beta)H(2) - R and H(2)N(1) - C(alpha)H(2) - (*)C(beta)H - R). From the complexes of Gly and t-Leu, only C(alpha) and N(1) radicals can be formed. The whole radical ligand can be lost to form [Cu(I)AA](+) from these three isomeric radicals. Alternatively, further radical induced dissociations can take place along the backbone of the decarboxylated amino acid ligand to yield [Cu(II)AA(AA - 2H - CO(2))](+), [Cu(I)AA((*)NH(2))](+), [Cu(I)AA(HN = C(alpha)H(2))](+), or [Cu(I)AA(H(2)N - C(alpha)H = C(beta)H - R'](+) (R' = partial side chain substituent). The sodiated copper complexes, [Cu(II)(AA - H + Na)(AA - H)](+), show the same fragmentation patterns as their non-sodiated counterparts; sodium ion is retained on the intact amino acid ligand and is not involved in the CAD pathways. The amino groups of both AA units, the carbonyl group of the intact amino acid, and the deprotonated hydroxyl oxygen coordinate Cu(II) in square-planar fashion. Ab initio calculations indicate that the metal ion facilitates hydrogen atom shuttling between the N(1), C(alpha) and C(beta) atoms of the decarboxylated amino acid ligand. The dissociations of the decarboxylated radical ions unveil important insight about the so far largely unknown intrinsic chemistry of alpha-amino acid and peptide radicals, which are implicated as intermediates in numerous pathogenic biological processes
Natural history and outcome in systemic AA amyloidosis
No full textBACKGROUND:Deposition of amyloid fibrils derived from circulating acute-phase reactant serum amyloid A protein (SAA) causes systemic AA amyloidosis, a serious complication of many chronic inflammatory disorders. Little is known about the natural history of AA amyloidosis or its response to treatment.METHODS:We evaluated clinical features, organ function, and survival among 374 patients with AA amyloidosis who were followed for a median of 86 months. The SAA concentration was measured serially, and the amyloid burden was estimated with the use of whole-body serum amyloid P component scintigraphy. Therapy for inflammatory diseases was administered to suppress the production of SAA.RESULTS:Median survival after diagnosis was 133 months; renal dysfunction was the predominant disease manifestation. Mortality, amyloid burden, and renal prognosis all significantly correlated with the SAA concentration during follow-up. The risk of death was 17.7 times as high among patients with SAA concentrations in the highest eighth, or octile, (greater/equal 155 mg per liter) as among those with concentrations in the lowest octile (< 4 mg per liter); and the risk of death was four times as high in the next-to-lowest octile (4 to 9 mg per liter). The median SAA concentration during follow-up was 6 mg per liter in patients in whom renal function improved and 28 mg per liter in those in whom it deteriorated (P < 0.001). Amyloid deposits regressed in 60% of patients who had a median SAA concentration of less than 10 mg per liter, and survival among these patients was superior to survival among those in whom amyloid deposits did not regress (P=0.04).CONCLUSIONS:The effects of renal dysfunction dominate the course of AA amyloidosis, which is associated with a relatively favorable outcome in patients with SAA concentrations that remain in the low-normal range (< 4 mg per liter)
Renal AA-amyloidosis in intravenous drug users - a role for HIV-infection?
No full textBackground: Chronic renal disease is a serious complication of long-term intravenous drug use (IVDU). Recent reports have postulated a changing pattern of underlying nephropathy over the last decades.
Methods: Retrospective investigation including all patients with prior or present IVDU that underwent renal biopsy because of chronic kidney disease between 01.04.2002 and 31.03.2012 in the city of Frankfurt/Main, Germany.
Results: Twenty four patients with IVDU underwent renal biopsy because of progressive chronic kidney disease or proteinuria. Renal AA-amyloidosis was the predominant cause of renal failure in 50% of patients. Membranoproliferative glomerulonephritis (GN) was the second most common cause found in 21%. Patients with AA-amyloidosis were more likely to be HIV infected (67 vs.17%; p=0.036) and tended to have a higher rate of repeated systemic infections (92 vs. 50%; p=0.069). Patients with AA-amyloidosis presented with progressive renal disease and nephrotic-range proteinuria but most patients had no peripheral edema or systemic hypertension. Development of proteinuria preceded the decline of GFR for approximately 1--2 years.
Conclusions: AA-amyloidosis was the predominant cause of progressive renal disease in the last 10 years in patients with IVDU. The highest rate of AA-amyloidosis observed was seen in HIV infected patients with IVDU. We speculate that chronic HIV-infection as well as the associated immunosuppression might promote development of AA-amyloidosis by increasing frequency and duration of infections acquired by IVDU
Título: Opera omnia.
No full textSign.: ]\p4\s, *\p4\s, 2*\p8\s, 3*-10*\p4\s, A-3Z\p4\s, 4A-4G\p4\s, 4H\p3\s.Error de col., repite la numeración de las col. 1105-1106.Texto a dos col.Port. a dos tintas con grab. calc.: "J. Goerce del. V. Baptist. scul."Cada tomo con antep. y port. propia.Front. calc.: "H.V. Aa Inv., W.V. Mieris del., I. Baptist sculp :" alegórica.Las h. de grab. calc. : "Hill. vander Aa Inv. et delin. I van Vianen Sculp." escudo nobiliario ; "H. rander AA delin, D. Stoopendaal scul.", estatua de tramo ; "H. Holbeen pinxit, A. vander Eryk delin, P. van Gunst sculps", retrato de Eramo las otras dos, epitafio y medallas
H. Ingham
No full text"Gnr. H. Ingham 2nd Hvy AA Bty Berrima Late December 1941 to March 1944".Gunner H. Ingham. 2nd Heavy Anti Aircraft Battery, Berrimah. Late December 1941 to March 1944
Thesaurus antiquitatum romanarum : in quo continentur lectissimi quinque scriptores...
No full textEn el frontis: Petrum Van Der AA. El lugar de edición es Utrecht: en el Espasa "Ultrajectum" traject. ad RhenSign.: [*]\p6\s, 2[*]-5[*]\p4\s, 6[*]\p2\s, (a)-(b)\p4\s, A-Z\p4\s, 2A-2Z\p4\s, 3A-3R\p4\s, 3S\p3\s, A-I\p4\sPort. a dos tintas, con grab. calc.: "J. Goeree delin., J. Baptist. sculp."AntepFrontis calc.: "J. Mulder fecit"Las h. de grab. pleg. calc., son mapas, del Imperio romano de Oriente y de Occidente respectivamente, entre las col. 344-34
POR enhances H-rev107-mediated AA release.
No full text<p>Recombinant H-rev107 (500 ng) was assayed in 50 mM Tris buffer along with 500 ng-1.5 μg of recombinant GST-POR or not for 30 min, and PLA<sub>2</sub> activity was performed as described in Materials and methods (A). HtTA cells were plated in triplicate into 6-well plates, incubated overnight, and then transfected with the indicated H-rev107 plasmid or control vector for 24 h (B). Cells were transfected with H-rev107 expression or control vector along with 0.5–1 μg of the POR-Flag plasmid (C), or indicated POR-Flag expression vector (D) for 24 h. Cells were serum-starved for 6 h and levels of AA were determined using enzyme immunoassays. Representative results of three independent experiments are shown. *Indicates <i>p</i> value <0.05. <sup>#</sup>Indicates <i>p</i> value <0.05 when cells transfected with wild type POR compared to cells transfected with indicated POR plasmid in H-rev107-expressing cells.</p
THE ANALYSIS OF FIVE ELECTRONIC EMISSION SYSTEMS OF NIOBIUM NITRIDE (NbN) IN THE REGION 5000{\AA} – 6200{\AA}
No full textK. H. Rao and T. M. Dunn, Nature 222, 266 (1969). J. L. Femenias, C. Athenour, and T. M. Dunn, J. Chem. Phys. 63, 2861 (1975).Author Institution:Niobium nitride emission systems have been found at 5l37{\AA}, 5582{\AA}, 5740{\AA}, 5840{\AA}, 5860{\AA}, in addition to the already systems with subbands at 5930{\AA}, 6043{\AA}, and 6192{\AA}. Most of These systems show marked nuclear hyperfine structure of the rotational lines add this has been of assistance in the analysis of all of the systems. Systems of triplet-triplet, singlet-singlet and singlet-triplet are all present and the hyperfine structure also allows assignment of the ground and excited state electron configuration to be made with some confidence
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Observations of the 57Fe+23 hyperfine transition in clusters of galaxies
No full textWe present a search for the hyperfine transition of the 57Fe+23 ion at 3.071 mm in clusters of galaxies with the ATNF Mopra telescope. The results are compared with a realistic estimate of the peak brightness temperature of the line in a cooling flow cluster A85, using the available X-ray data
AA-Score: a New Scoring Function Based on Amino Acid-Specific Interaction for Molecular Docking
No full textThe
protein–ligand scoring function plays an important role
in computer-aided drug discovery and is heavily used in virtual screening
and lead optimization. In this study, we developed a new empirical
protein–ligand scoring function with amino acid-specific interaction
components for hydrogen bond, van der Waals, and electrostatic interactions.
In addition, hydrophobic, π-stacking, π-cation, and metal–ligand
interactions are also included in the new scoring function. To better
evaluate the performance of the AA-Score, we generated several new
test sets for evaluation of scoring, ranking, and docking performances,
respectively. Extensive tests show that AA-Score performs well on
scoring, docking, and ranking as compared to other widely used traditional
scoring functions. The performance improvement of AA-Score benefits
from the decomposition of individual interaction into amino acid-specific
types. To facilitate applications, we developed an easy-to-use tool
to analyze protein–ligand interaction fingerprint and predict
binding affinity using the AA-Score. The source code and associated
running examples can be found at https://github.com/xundrug/AA-Score-Tool
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