148 research outputs found

    Structural elucidation of o-linked glycopeptides by high energy collision-induced dissociation

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    O-linked glycopeptides that bear a GalNAc core with and without the presence of sialic acid have been analyzed by high energy collision-induced dissociation (CID). We show that the CID spectra from the glycosylated precursor ions contain sufficient information to identify the peptide sequence and to determine the glycosylated site(s). Asialo O-linked glycopeptides, previously prepared from a tryptic digest of bovine fetuin were studied. One of the glycopeptides contained only a single Hex (hexose)-HexNAc (N-acetylhexosamine) substitution at Thr262, whereas the other exhibited Hex-HexNAc moieties at both Thr262 and Ser264. In addition, sialo and asialo fetuin glycopeptides from a pronase digest were derivatized with t-butoxycarbonyl-tyrosine, and characterized by high energy CID analysis. The presence of a Galβ(1,3)GalNAc core structure at Ser264 was confirmed by using the substrate specificity of endo-α-N-acetylgalactosaminidase. These studies revealed the presence of a β-galactosidase specific for β(1,4) linkages in the endo-α-N-acetylgalactosaminidase preparation employed. Finally, the relative stability of N-and O-glycosyl bonds to high energy CID is addressed based upon comparison of the behavior of a synthetic N-linked glycopeptide with analogous O-linked structures

    Fine-needle Aspiration Biopsy For Breast Lesions: A Comparison Between Two Devices For Obtaining Cytological Samples

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    Context and Objective: Fine-needle aspiration biopsy has been accepted worldwide for breast lesions. However, some questions remain, including the appropriateness of the puncture method. The objective of this work was to compare aspirates obtained by the auto-vacuum device and by the syringe pistol holder. Design and Setting: Randomized trial for validation of diagnostic method, at Hospital das Clinicas do Universidade Federal de Goiás and Hospital Araújo Jorge, Goiânio. Methods: 351 patients presenting breast lumps underwent fine-needle aspiration biopsy, either with the auto-vacuum device or the syringe pistol holder. A single cytopathologist analyzed all of the cytology slides. The rates of insufficient material, cellularity, cell distortion and background hemorrhage were evaluated. Results: The percentages of insufficient material were 16% and 22% (p = 0.18), for the auto-vacuum and pistol aspirates, respectively. Good cellularity was seen in 34% of autovacuum and 29% of pistol samples (p = 0.4). Cell distortion was seen in 31 and 26 cases, respectively (p = 07). Background hemorrhage occurred in 63 (35%) and 54 cases (31%) (p = 0.2), for auto-vacuum and pistol. The sensitivity was 88% and 86%; specificity 99% and 100%, positive predictive value 96% and and 100%, negative predictive value 96% and 95% and total occuracy 76% and 75% for the auto-vacuum and pistol, respectively. Conclusion: The results obtained from the two fine-needle aspiration biopsy methods were equivalent. Therefore, the auto-vacuum device is a good option for obtaining aspirates for cytology.1236271276Catania, S., Ciatto, S., Breast cytology: Instruments and technique (1992) Breast Cytology in Clinical Practice, pp. 11-60. , In: Ciatto S, editor. London: Martin DunitzDe Freitas Jr., R., Hamed, H., Fentiman, I., Fine needle aspiration cytology of palpable breast lesions (1992) Br J Clin Pract, 46 (3), pp. 187-190Franzen, S., Zajicek, J., Aspiration biopsy in diagnosis of palpable lesions of the breast. Critical review of 3479 consecutive biopsies Acta (1968) Radiol Ther Phys Biol, 7 (4), pp. 241-262Souza, J.A., Freitas Jr., R., Moreita, M.A.R., Philocreon, G.R., Acurácia da sensação tátil da PAAF no diagnóstico de less̄ocs mamárias (1995) Rev Bras Mastologia, 5 (3), pp. 7-10Freitas Júnior, R., Hamed, H., Millis, R.R., Tomas, N.M.A., Fentiman, I.S., Fine needle aspiration of breast lesions using auto-vacuum dispositive (1996) Rev Bras Mastologia, 6 (3), pp. 126-128de Freitas Júnior, R., Giraldo, P.C., Rerrori, O., Vieira-Matos, A.N., Tambascia, J.K., Fine needle aspiration biopsy of solid tumours by auto-vacuum system: A study in rats (1992) Eur J Surg Oncol, 18 (6), pp. 605-607Boccato, P., How to treat the aspirated material (1992) Breast Cytology in Clinical Practice, pp. 61-64. , In: Ciatto, S, editor London: Martin Dunitz(1987) International Union Against Cancer, , UICC. TNM classification of malignant tumors. Berlin: Springer-Verlag(1982) Am J Clin Pathol, 78 (6), pp. 806-816. , The World Health Organization Histological Typing of Breast Tumors - Second Edition. The World OrganizationGelabert, H.A., Hsiu, J.G., Mullen, J.T., Jaffe, A.H., D'Amato, N.A., Prospective evaluation of the rate of fine-needle aspiration biopsy in the diagnosis and management of patiencs with palpable solid breast lesions (1990) Am Surg, 56 (4), pp. 263-267Rouquayrol, M.Z., Epidemiologia e saúde (1988), Rio de Janeiro: Medsi - Editora CientíficaRoberts, J.C., Rainsbury, R.M., 'Tactile sensation: A new clinical sign during fine needle aspiration of breast lumps Ann (1994) R Coll Surg Eng, 76 (2), pp. 136-138Henderson, M.A., McCready, D.R., A simple technique for fine needle aspiration cytology (1994) J Am Coll Surg, 179 (4), pp. 471-473Sasaki, J., Izu, K., Automatic fine needle aspiration pistol specially designed for small tumors (1998) Acta Cytol, 42 (3), pp. 829-830Tao, L.C., Smith, J.W., Fine-needle aspiration biopsy using a newly-developed pencil-grip syringe holder (1999) Diagn Cytopathol, 20 (2), pp. 99-104Parel, J.J., Garrell, P.C., Smallwood, J.A., Fine needle aspiration cytology of breast masses: An evaluation of its accuracy and reasons for diagnostic failure (1987) Ann R Coll Surg Engl, 69 (4), pp. 156-159Abele, J., Stanley, M.W., Rollnis, S.D., Miller, T.R., What constitutes an adequate smear in fine-needle aspiration cytology of the breast? (1998) Cancer, 84 (1), pp. 57-61Zajdela, A., Ghossein, N.A., Pilleron, J.P., Ennuyer, A., The value of aspiration cytology in the diagnosis of breast cancer: Experience at the Fondation Curie (1975) Cancer, 35 (2), pp. 499-506Layfield, L.J., Dodd, L.G., Cytologically low grade malignancies: An important interpretative pitfall responsible for false negative diagnoses in fine-needle aspiration of the breast (1996) Diagn Cytopathol, 15 (3), pp. 250-259Feichter, G.E., Haberthür, F., Gobat, S., Dalquen, P., Breast cytology. Statistical analysis and cytohistologic correlations (1997) Acta Cytol, 41 (2), pp. 327-332Arisio, R., Cuccorese, C., Accinelli, G., Mano, M.P., Bordon, R., Fessia, L., Role of fine-needle aspiration biopsy in breast lesions: Analysis of a series of 4,110 cases (1998) Diagn Cytopathol, 18 (6), pp. 462-467Ariga, R., Bloom, K., Reddy, V.B., Fine-needle aspiration of clinically suspicious palpable breast masses with histopathologic correlation (2002) Am J Surg, 184 (5), pp. 410-41

    Surface Instability of Icicles

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    Quantitatively-unexplained stationary waves or ridges often encircle icicles. Such waves form when roughly 0.1 mm-thick layers of water flow down the icicle. These waves typically have a wavelength of 1cm approximately independent of external temperature, icicle thickness, and the volumetric rate of water flow. In this paper we show that these waves can not be obtained by naive Mullins-Sekerka instability, but are caused by a quite new surface instability related to the thermal diffusion and hydrodynamic effect of thin water flow.Comment: 11 pages, 5 figures, Late

    Influence of Gap Extrema on the Tunneling Conductance Near an Impurity in an Anisotropic Superconductor

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    Changes: figures added in postscript form, Eq. (7) and various typos corrected. We examine the effect of an impurity on the nearby tunneling conductance in an anisotropically-gapped superconductor. The variation of the conductance has pronounced spatial dependence which depends strongly on the Fermi surface location of gap extrema. In particular, different gap symmetries produce profoundly different spatial features in the conductance. These effects may be detectable with an STM measurement on the surface of a high-temperature superconductor.Comment: 12 pages (revtex) + 3 figures (included - postscript), NSF-ITP-93-8

    Error sources and data limitations for the prediction ofsurface gravity: a case study using benchmarks

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    Gravity-based heights require gravity values at levelled benchmarks (BMs), whichsometimes have to be predicted from surrounding observations. We use EGM2008 andthe Australian National Gravity Database (ANGD) as examples of model and terrestrialobserved data respectively to predict gravity at Australian national levelling network(ANLN) BMs. The aim is to quantify errors that may propagate into the predicted BMgravity values and then into gravimetric height corrections (HCs). Our results indicatethat an approximate ±1 arc-minute horizontal position error of the BMs causesmaximum errors in EGM2008 BM gravity of ~ 22 mGal (~55 mm in the HC at ~2200 melevation) and ~18 mGal for ANGD BM gravity because the values are not computed atthe true location of the BM. We use RTM (residual terrain modelling) techniques toshow that ~50% of EGM2008 BM gravity error in a moderately mountainous regioncan be accounted for by signal omission. Non-representative sampling of ANGDgravity in this region may cause errors of up to 50 mGals (~120 mm for the Helmertorthometric correction at ~2200 m elevation). For modelled gravity at BMs to beviable, levelling networks need horizontal BM positions accurate to a few metres, whileRTM techniques can be used to reduce signal omission error. Unrepresentative gravitysampling in mountains can be remedied by denser and more representative re-surveys,and/or gravity can be forward modelled into regions of sparser gravity

    Perspectives in visual imaging for marine biology and ecology: from acquisition to understanding

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    Durden J, Schoening T, Althaus F, et al. Perspectives in Visual Imaging for Marine Biology and Ecology: From Acquisition to Understanding. In: Hughes RN, Hughes DJ, Smith IP, Dale AC, eds. Oceanography and Marine Biology: An Annual Review. 54. Boca Raton: CRC Press; 2016: 1-72
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