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1.
Pituitary ; 16(4): 528-35, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23225120

RESUMEN

We aimed to study the occurrence of acute-onset symptoms at initial presentation in a national Danish cohort of patients with childhood- or adult-onset craniopharyngioma, and to investigate potential risk factors for acute presentation. Medical records of 189 consecutive patients (39 children, 150 adults) presenting with craniopharyngioma during the period 1985-2004 were reviewed, and data regarding initial symptoms, neuroimaging results, vision and pituitary function were systematically collected. Acute symptoms preceding hospital admission were noted. Subgroup analyses were based on age, gender and calendar year period. Potential risk factors for acute presentation were analysed through uni- and multivariate analyses. Acute symptoms were reported in 24 (13%) patients. Acute visual symptoms, headache, nausea or vomiting were most frequently reported, and acute symptoms were more frequent among children (28%) than among adults (9%) (P < 0.01). There were no differences according to sex or calendar year period. Hydrocephalus was present in half of childhood cases and one-fifth of adult patients (P < 0.001). Intra-tumour haemorrhage was seen in two cases. Acute symptoms were more frequent among patients with tumours occupying the third ventricle (P < 0.01), radiologic signs of calcification (P < 0.05) or hydrocephalus (P < 0.01). In multivariate analysis, however, only childhood onset (P < 0.05) and calcification (P < 0.05) were independent risk factors for acute presentation. Craniopharyngioma presented with acute symptoms in 13% of patients. Childhood onset and radiologic signs of calcification were independent risk factors for acute presentation. Intra-tumour haemorrhage was rare.


Asunto(s)
Craneofaringioma/diagnóstico , Adolescente , Adulto , Niño , Craneofaringioma/patología , Femenino , Humanos , Masculino , Neoplasias Hipofisarias/diagnóstico , Neoplasias Hipofisarias/patología , Factores de Riesgo , Adulto Joven
2.
J Neurooncol ; 104(3): 755-63, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21336771

RESUMEN

We studied the incidence of craniopharyngioma in Denmark during the period 1985-2004 and estimated worldwide incidence rates (IR) of craniopharyngioma based on a literature review. Craniopharyngioma patients diagnosed during the period 1985-2004 were identified from the Danish National Patient Registry, the Danish Cancer Registry and regional registries. Medical records were reviewed. Danish population data were obtained from Statistics Denmark. European and World population data were obtained from EU and WHO homepages. Prior studies providing data on craniopharyngioma IRs were identified via PubMed and, if appropriate, were included in a weighted analysis estimating overall and children's IRs of craniopharyngioma. IRs are given as new cases per million per year. We identified 189 patients with new verified (162) or probable craniopharyngioma. The overall WHO World-standardised incidence rate was 1.86 (1.60-2.14) for all ages and 2.14 (1.53-2.92) for children (age <15 years). Peak incidence rates were observed in age groups 5-9 and 40-44 years. Fifteen prior studies (including 1,232 craniopharyngioma cases) were identified. Seven and 11 studies, respectively, were eligible for weighted all-ages and childhood population IR analyses, yielding summary IRs of 1.34 (1.24-1.46) (all ages) and 1.44 (1.33-1.56) (children). We have provided a detailed survey of the incidence of craniopharyngioma in Denmark during a recent 20-year period. Overall IR of craniopharyngioma in Denmark was 1.86 (1.60-2.14) as compared to 2.14 (1.53-2.92) among children. Weighted estimates of craniopharyngioma world IRs were 1.34 (1.24-1.46) in all ages and 1.44 (1.33-1.56) among children.


Asunto(s)
Craneofaringioma/epidemiología , Adolescente , Adulto , Distribución por Edad , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Intervalos de Confianza , Dinamarca/epidemiología , Femenino , Humanos , Incidencia , Clasificación Internacional de Enfermedades , Masculino , Persona de Mediana Edad , Valores de Referencia , Sistema de Registros , Estudios Retrospectivos , Adulto Joven
3.
Pituitary ; 12(4): 352-9, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19130248

RESUMEN

For centuries tumors have been described which today with some confidence can be diagnosed as craniopharyngiomas. It was not until 1904 Erdheim described what he called 'hypophysial duct tumors', and which Cushing later gave the name craniopharyngioma. The first operation for this neoplasm took place in 1909. It soon became evident that the outcome of surgery was rather dismal with high mortality and morbidity rates-even after corticosteroid therapy became available around 1950. Radiotherapy was introduced and later refined as radiosurgery. This paper presents a short survey of the accumulation of knowledge of craniopharyngiomas.


Asunto(s)
Craneofaringioma/historia , Neoplasias Hipofisarias/historia , Craneofaringioma/diagnóstico , Craneofaringioma/radioterapia , Craneofaringioma/cirugía , Historia del Siglo XVIII , Historia del Siglo XIX , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Neoplasias Hipofisarias/diagnóstico , Neoplasias Hipofisarias/radioterapia , Neoplasias Hipofisarias/cirugía
4.
Clin Endocrinol (Oxf) ; 67(5): 693-7, 2007 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-17634076

RESUMEN

BACKGROUND: Increased mortality has been reported in patients with pituitary disease, with some studies showing higher standard mortality rates (SMR) in women than in men. OBJECTIVE: To assess overall SMR for men and women with benign pituitary disease without excessive ATCH or GH secretion and to investigate associations between SMR and time period of diagnosis. DESIGN: From searches in PubMed, Embase and Web of Science databases, and reference lists of major reviews and original articles, we included original studies providing SMR values and 95% confidence intervals (CI) for men and women separately. Thirty articles were studied in detail. Six studies were eligible for the meta-analysis of sex-specific mortality, and seven for the analysis of association between SMR and diagnosis period. RESULTS: Individual studies (total 5412 patients) reported total SMR values (men and women together) ranging from 1.21 to 3.80. SMR varied from 0.98 to 3.36 in men and from 2.11 to 4.54 in women. Weighted SMR values were significantly higher in women (2.80; CI 2.59-3.02) than in men (2.06; CI 1.94-2 20) (P < 0.0001). SMR was negatively correlated with first year of diagnosis in individual studies (partial correlation analysis controlling for sex, P = 0.017), and approached normal in recent studies in men but not in women. CONCLUSIONS: In our meta-analysis of patients with pituitary disease without ACTH or GH excess, SMR was significantly higher in women than in men. SMR reached normal levels in men treated in recent decades, but remained elevated in women.


Asunto(s)
Enfermedades de la Hipófisis/mortalidad , Adulto , Anciano , Intervalos de Confianza , Recolección de Datos , Femenino , Humanos , Hipopituitarismo/mortalidad , Masculino , Persona de Mediana Edad , Enfermedades de la Hipófisis/terapia , Neoplasias Hipofisarias/mortalidad , Análisis de Regresión , Distribución por Sexo , Estadística como Asunto
5.
Amyloid ; 6(4): 265-72, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10611947

RESUMEN

Complement activation (CA) has been reported to play a role in the pathogenesis of Alzheimer's disease (AD). To investigate whether CA may contribute to amyloidogenesis in general, the CA potential of different amyloid fibril proteins was tested. CA induced by A beta preparations containing soluble protein, protofilaments and some fibrils or only fibrils in a solid phase system (ELISA) was modest with a slow kinetics compared to the positive delta IgG control. Soluble A beta induced no detectable CA in a liquid phase system (complement consumption assay) while fibrillar A beta caused CA at 200 mg/ml and higher concentrations. Soluble beta 2-microglobulin (beta 2M) purified from peritoneal dialysates was found to be as potent a complement activator as A beta in both solid and liquid phase systems while beta 2M purified from urine exhibited lower activity, a difference which may be explained by differences observed in SDS-resistant oligomers and isoforms. Soluble Amyloid A-protein caused no significant CA. A beta and beta 2M activated complement via the classical pathway. The modifying influence by amyloid-associated molecules on A beta-induced CA was also investigated, but neither serum amyloid P component nor heparan sulfate did significantly alter the A beta-induced CA. The results indicate that not only fibrillar A beta but also oligomers of, in particular, beta 2M from patients with dialysis-associated amyloidosis are capable of inducing CA at supra-physiological concentrations.


Asunto(s)
Péptidos beta-Amiloides/farmacología , Activación de Complemento/efectos de los fármacos , Fragmentos de Péptidos/farmacología , Microglobulina beta-2/farmacología , Péptidos beta-Amiloides/ultraestructura , Amiloidosis/metabolismo , Hemólisis , Heparitina Sulfato/farmacología , Humanos , Cinética , Microscopía Electrónica , Fragmentos de Péptidos/ultraestructura , Proteína Amiloide A Sérica/farmacología , Componente Amiloide P Sérico/farmacología , Solubilidad , Espectrometría de Fluorescencia , Microglobulina beta-2/aislamiento & purificación , Microglobulina beta-2/orina
7.
Ugeskr Laeger ; 161(11): 1601-2, 1999 Mar 15.
Artículo en Danés | MEDLINE | ID: mdl-10202444

RESUMEN

PH1 is caused by deficiency of the liver-specific peroxisomal enzyme alanine: glycoxylate aminotransferase (AGT). Early onset with progressive renal failure and systemic oxalosis is typical. We report a case of a 42 year-old man with PH1 in whom liver biopsy and DNA-analysis showed reduced AGT-activity and homozygosity for the polymorphism C154T and the point mutation G630A. The patient seems to respond to pyridoxine treatment. We suggest that clinical suspicion of PH1 be pursued with a diagnostic liver biopsy.


Asunto(s)
Hiperoxaluria Primaria/patología , Hígado/patología , Adulto , Análisis Mutacional de ADN , Humanos , Hiperoxaluria Primaria/enzimología , Hiperoxaluria Primaria/genética , Hígado/enzimología , Masculino , Microsomas Hepáticos/enzimología , Microsomas Hepáticos/ultraestructura
10.
Scand J Immunol ; 48(4): 350-6, 1998 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9790304

RESUMEN

Isoelectric focusing (IEF) and immunofixation of murine serum amyloid P component (SAP), purified and in serum, showed a distinct and strain-dependent isoform pattern with up to seven bands (pI 5.1-5.7). Neuraminidase treatment caused a shift of the isoforms to more basic pI values, but did not affect their number. When the acute-phase response was analysed in three mouse strains, CBA/J and C3H/HeN initially showed seven SAP isoforms in serum and C57BL/6 J three or four. The responses in all three strains peaked at day 2 and were normalized within 14 days. On days 2 and 4, CBA/J and C3H/HeN mice showed one more acidic isoform and an increase in the concentration of the most basic isoform. C57BL/6 J mice exhibited two to three new isoforms during the acute-phase response. This appears to be the first demonstration of the physiological existence of SAP isoforms. In contrast, demonstration of isoforms of human SAP required the presence of urea and higher SAP concentrations. TEF and immunofixation of SAP monomers showed five to eight isoforms, ranging from pI 4.7-5.7. IEF of SAP in human serum resulted in a less distinct pattern and more acidic isoforms. As with murine SAP, neuraminidase treatment caused a shift of the isoforms, but no reduction in isoform number. Two-dimensional gel electrophoresis confirmed the existence of multiple isoforms of human SAP monomers.


Asunto(s)
Componente Amiloide P Sérico/química , Animales , Humanos , Focalización Isoeléctrica , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Ratones Endogámicos CBA , Isoformas de Proteínas , Componente Amiloide P Sérico/metabolismo
11.
Ugeskr Laeger ; 160(2): 162-5, 1998 Jan 05.
Artículo en Danés | MEDLINE | ID: mdl-9458701

RESUMEN

Vitamin D deficiency, often complicated by osteomalacia, among Asian immigrants (especially females) is now also recognized in the Nordic countries. The article reviews the history of vitamin D featuring its discovery as well as a contemporary perspective, and describes the complex etiology of the disease. The symptoms, diagnostic approach and recommended treatment are also summarized.


Asunto(s)
Emigración e Inmigración , Deficiencia de Vitamina D/epidemiología , Asia/etnología , Femenino , Humanos , Masculino , Países Escandinavos y Nórdicos/epidemiología , Países Escandinavos y Nórdicos/etnología
12.
APMIS ; 105(8): 603-8, 1997 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-9298097

RESUMEN

Different conditions for establishing a cell culture system for generation of AA-amyloid were investigated. The most effective system was based on peritoneal macrophages from CBA/J mice that had received repeated injections of Hammersten casein, with subsequent cultivation of the cells at high density, high levels of acute phase serum, and neutral pH. Staining with Congo red, thioflavin T, and anti-AA revealed amyloid-like structures associated with macrophage clusters. The structures increased in number and size from day 2 to 6 of cell cultivation. The concentration of apoSAA in the culture medium fell markedly in the amyloid-producing cell cultures, while the SAP concentration was not reduced. The described cell culture system can be useful in studies of the influence of chaperone molecules and other factors or the formation and degradation of amyloid fibrils.


Asunto(s)
Macrófagos Peritoneales/metabolismo , Proteína Amiloide A Sérica/biosíntesis , Proteínas de Fase Aguda/análisis , Animales , Apolipoproteínas/análisis , Caseínas/farmacología , Células Cultivadas , Técnicas de Cultivo/métodos , Femenino , Histocitoquímica , Hígado/citología , Activación de Macrófagos , Macrófagos Peritoneales/efectos de los fármacos , Ratones , Ratones Endogámicos CBA , Proteína Amiloide A Sérica/análisis , Componente Amiloide P Sérico/análisis , Bazo/citología
13.
Biochim Biophys Acta ; 1339(1): 73-8, 1997 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-9165101

RESUMEN

Serum amyloid P component (SAP), a member of the pentraxin family of proteins, binds calcium-dependently to several ligands including glycosaminoglycans (GAG's). We have investigated the influence of pH on the Ca2(+)-dependent binding of SAP to solid phase GAG's and amyloid fibril proteins (AA and beta2M) by ELISA. An increase in the dose-dependent binding of SAP to heparan sulfate, AA-protein and beta2M was observed as the pH decreased from 8.0 to 5.0. Furthermore, a lower, but significant Ca2(+)-independent binding of SAP to heparan sulfate, dermatan sulfate, AA protein and the amyloid precursor protein beta2M was observed. This binding was also enhanced at slightly acid pH, most pronounced at pH 5.0. The results of this study indicate that SAP can exhibit both Ca2(+)-dependent and -independent binding to ligands involved in amyloid fibril formation and that the binding is enhanced under conditions of slightly lowered pH.


Asunto(s)
Amiloide/metabolismo , Calcio/metabolismo , Glicosaminoglicanos/metabolismo , Precursores de Proteínas/metabolismo , Componente Amiloide P Sérico/metabolismo , Humanos , Concentración de Iones de Hidrógeno , Regulación hacia Arriba
14.
Scand J Immunol ; 44(4): 401-7, 1996 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8845035

RESUMEN

Serum amyloid P component (SAP), a member of the conserved pentraxin family of plasma proteins, binds calcium dependently to its ligands. The authors investigated SAPs interaction with the complement proteins C4b binding protein (C4bp) and C1q by ELISA, immunoelectrophoresis and electron microscopy. Binding of these proteins to SAP was demonstrated when SAP was immobilized using F(ab')2 anti-SAP, but not when SAP reacted with these proteins in liquid phase; thus the binding to human SAP was markedly phase state dependent. Presaturation of solid phase SAP with heparin, which binds SAP with high affinity, did not interfere with the subsequent binding of C4bp or C1q to SAP. In contrast, collagen I and IV showed partial competition with the binding of C1q to SAP. Using fresh serum, immobilized native SAP bound C4bp whereas binding of C1q/C1 could not be demonstrated. Altogether the results indicate that firm binding of C1q and C4bp to SAP requires that SAP is presented on a solid phase, that C1q and C4bp react with sites distinct from the heparin binding site, and that C1q and collagen I share binding sites on SAP. Immobilized native SAP, aggregated SAP and SAP-heparansulphate complexes induced no detectable complement activation.


Asunto(s)
Proteínas Portadoras/metabolismo , Complemento C1q/metabolismo , Componente Amiloide P Sérico/metabolismo , Animales , Unión Competitiva , Activación de Complemento , Electroforesis/métodos , Ensayo de Inmunoadsorción Enzimática , Heparitina Sulfato/metabolismo , Humanos , Integrina alfaXbeta2 , Unión Proteica , Conejos
15.
Scand J Immunol ; 43(3): 289-96, 1996 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-8602463

RESUMEN

The authors report on the purification and characterization of mannan- binding proteins (MBP) isolated from porcine serum. The MBPs were purified by use of PEG precipitation, affinity chromatography on mannan-Sepharose, protein A- and anti-porcine IgM-Sepharose followed by gel filtration. The MBP proteins were collagenase sensitive and showed gamma 1-gamma 2-electrophoretic mobility. The MBP designated pMBP-28 had a molecular mass of 28 kDa when analysed on SDS-PAGE under reducing conditions and eluted corresponding to a molecular mass of approximately 700 kDa on gel filtration chromatography. Electron micrographs of pMBP-28 revealed an oligomeric protein similar to rodent MBP-A and human MBP but with a predominance of penta- and hexameric molecules. Another protein designated pMBP-27 was composed of peptides of 27 kDa and had an Mr of 300-350 kDa on gel filtration chromatography. Electron microscopy of pMBP-27 showed dimer and trimer molecules; the trimers without distinct stalk regions. The N-terminal 26(pMBP-27) and 24(MBP-28) amino acid residues showed 54% and 58% identity with human MBP.pMBP-28 showed a higher degree of sequence similarity to rat and mouse MBP-A (60% identity) than to mouse and rat MBP-C (41-45% identity). Both pMBPs exhibited Ca2+-dependent binding to D-mannose immobilized on agarose but no significant binding to N-acetyl-D-glucosamine- or fucose-agarose. The results further suggested the presence of a third pMBP which copurified with pMBP-27 but this protein was not sequenced.


Asunto(s)
Proteínas Portadoras/química , Proteínas Portadoras/aislamiento & purificación , Lectinas/química , Mananos/química , Secuencia de Aminoácidos , Animales , Conformación de Carbohidratos , Proteínas Portadoras/ultraestructura , Cromatografía de Afinidad , Cromatografía en Gel , Colagenasas/farmacología , Colectinas , Inmunoelectroforesis Bidimensional , Datos de Secuencia Molecular , Peso Molecular , Unión Proteica/inmunología , Porcinos
16.
APMIS ; 103(9): 628-34, 1995 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-7488383

RESUMEN

An ultrastructural study of the epidermis from eight patients with clinical Paget's disease of the nipple supports the epidermotropic theory. There was no evidence that the Paget's cells originated from keratinocytes. We propose the hypothesis that Paget's cells represent transformed ductal cells, from the subjacent lactiferous ducts of the nipple, which have migrated into the epidermis, either as neoplastic cells or as normal ductal cells with secondary in situ transformation in the epidermis.


Asunto(s)
Neoplasias de la Mama/patología , Pezones/patología , Enfermedad de Paget Mamaria/patología , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/etiología , Neoplasias de la Mama/ultraestructura , Femenino , Humanos , Microscopía Electrónica , Persona de Mediana Edad , Pezones/ultraestructura , Enfermedad de Paget Mamaria/etiología , Enfermedad de Paget Mamaria/ultraestructura , Piel/ultraestructura
17.
Scand J Immunol ; 41(3): 263-7, 1995 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-7871385

RESUMEN

Serum amyloid P component (SAP) and C-reactive protein (CRP) are members of the pentraxin protein family. SAP is the precursor protein to amyloid P component present in all forms of amyloidosis. The prevailing notion is that SAP in circulation has the form of a double pentameric molecule (decamer) whereas CRP is a single pentameric molecule. We have investigated by gel permeation chromatography the M(r) of SAP in freshly collected human serum and of SAP purified by carbohydrate affinity chromatography and anion exchange chromatography. SAP was monitored by quantitative immunoelectrophoresis and ELISA, and SAP peak fractions were analysed by use of SDS-PAGE, Western blotting, and electron microscopy. The results indicate that native SAP circulates as a single pentamer, a part of which forms complexes with C4b-binding protein. The properties of SAP changed during purification as indicated by rocket immunoelectrophoresis and electron microscopy. Thus, electron micrographs of purified SAP showed a predominance of decamers. However, the decamer form of SAP reversed to single pentamers when purified SAP was incorporated into SAP-depleted serum.


Asunto(s)
Componente Amiloide P Sérico/química , Biopolímeros/química , Western Blotting , Cromatografía en Gel , Ensayo de Inmunoadsorción Enzimática , Humanos , Inmunoelectroforesis/métodos , Microscopía Electrónica , Componente Amiloide P Sérico/ultraestructura
18.
Int Arch Allergy Immunol ; 106(1): 25-31, 1995 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-7812162

RESUMEN

Human serum amyloid P component (SAP) isolated from 20 healthy individuals was analyzed by anion exchange chromatography and isoelectric focusing (IEF) in order to investigate the existence of multiple forms of SAP and interindividual structural differences. Anion exchange chromatography showed one major and several minor subpopulations of SAP. IEF of all SAP isolates showed a previously unreported degree of heterogeneity with six isoelectric forms (pKi range 5.5-6.1) and with minor interindividual differences in respect of isoelectric points. Total enzymatic deglycosylation of SAP reduced the number of bands in IEF to two indicating the existence of two types of polypeptide chains.


Asunto(s)
Componente Amiloide P Sérico/química , Proteínas Sanguíneas/química , Proteínas Sanguíneas/ultraestructura , Cromatografía por Intercambio Iónico , Femenino , Humanos , Focalización Isoeléctrica , Masculino , Microscopía Electrónica , Estructura Molecular , Componente Amiloide P Sérico/ultraestructura
19.
APMIS ; 102(6): 420-6, 1994 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8068301

RESUMEN

Serum amyloid P component (SAP) is a pentraxin found in the circulation and in all forms of amyloid deposits. Its physiological and pathophysiological functions are largely unknown. Electron microscopy showed purified human SAP to consist of double pentameric discs compatible with the results of size chromatography. The formation of double pentamers did not require calcium ions. The outer diameter of the discs arranged face-to-face was 11.6 nm and the inner diameter 3.2 nm. The thickness of single and double pentamers was 4.1 and 8.7 nm, respectively. Quadruple pentamers were occasionally seen. The self-aggregation of human SAP molecules was investigated in the presence and absence of calcium ions at different concentrations. In calcium-free solutions few and mostly small SAP aggregates were seen. After addition of calcium at increasing concentration the aggregates grew in size and crystalline-like structures were formed already at 2 mM calcium. At 25 mM calcium, large aggregates with a crystalline array occasionally exhibiting cylinders predominated. Binding of the ligands heparin and heparan sulphate to SAP completely abolished the calcium-enhanced aggregation, but the distribution of the SAP molecules was affected, resulting in strands or groups of adjacent molecules. The electrophoretic mobility of SAP was moreover significantly altered after its calcium-dependent reaction with these ligands. We conclude that purified SAP has a tendency to double pentamer formation and self-aggregation also in the absence of calcium ions. However, aggregation is greatly enhanced even at low concentrations (2 mM) of calcium. SAP's tendency to self-aggregation is abolished after its binding to heparin or heparin sulphate. Furthermore, our TEM studies indicate that purified human SAP freed of its natural ligands has the double pentameric form, whereas the electrophoretic investigations suggest that SAP's interaction with low-molecular-weight natural ligands in serum prevents homodimerization and self-aggregation.


Asunto(s)
Calcio/farmacología , Heparina/farmacología , Heparitina Sulfato/farmacología , Componente Amiloide P Sérico/antagonistas & inhibidores , Componente Amiloide P Sérico/análisis , Western Blotting , Relación Dosis-Respuesta a Droga , Ácido Edético/farmacología , Humanos , Inmunoelectroforesis Bidimensional , Microscopía Electrónica , Peso Molecular , Componente Amiloide P Sérico/ultraestructura
20.
J Struct Biol ; 109(3): 201-7, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1296754

RESUMEN

The aim of this study was to correlate the supramolecular organization of conglutinin (BK) with its primary and tertiary structure and to gain more knowledge of functionally important regions of the molecule. BK analyzed by SDS-PAGE under standard reducing conditions (40 mM DTT) showed a major band at 43 kDa and weaker bands at 86 and 180 kDa. In contrast, reduction with 6-50 mM L-cysteine resulted in 37-kDa subunits indicating the presence of intrachain disulfide bonds within this subunit. Hydroxylamine treatment indicated presence of ester bonds in the 86- and 180-kDa subunits. Collagenase digestion and SDS-PAGE under reducing and nonreducing conditions resulted in bands of 20 and 15 kDa, respectively, indicating the presence of intrachain, rather than interchain, disulfide bonds in the carboxy terminus. Deglycosylation and glycan differentiation analysis of BK revealed the presence of O-linked glycans of GalNAc and alpha (2-3) linked sialic acid type, whereas no N-linked glycans were demonstrated. Binding experiments with GlcNAc-gold suggested that multivalency is required for carbohydrate binding to BK. Electron microscopy showed mostly tetramers, 96 nm in diameter, but also mono-, di-, and trimers were seen. The tetramers consisted of 40-nm strands, each with a peripheral globular head composed of subunits and connected to a common central lobe built from four ring-formed structures. The strands occasionally showed two bends, one close to the central lobe and another 25 nm from the lobe. These bends most likely correspond to the interrupted Gly-Xaa-Yaa repeats at residues 38 and 123.


Asunto(s)
Colectinas , Lectinas/química , Seroglobulinas/química , Secuencia de Aminoácidos , Animales , Bovinos , Colagenasas , Glicosilación , Hidroxilamina , Hidroxilaminas , Lectinas/ultraestructura , Microscopía Electrónica , Modelos Moleculares , Datos de Secuencia Molecular , Oxidación-Reducción , Conformación Proteica , Seroglobulinas/ultraestructura
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