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1.
Int J Immunogenet ; 40(2): 131-9, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22672630

RESUMEN

The single nucleotide polymorphism (SNP) G949T in the mannose-binding lectin ( MBL ) 1 gene has been associated with low MBL-A concentration in serum and detected at different frequencies in various European pig populations. However, the origin of this SNP is not known. Part of the MBL1 gene was sequenced in 12 wild boar/Large White crossbred pigs from the second backcross (BC 2 ) generation in a family material originating from two wild boar x Large White intercrosses. Also, MBL-A serum concentration was measured in the entire BC 2 generation (n = 45). Furthermore, the genotypes of 68 wild boars from Sweden, Austria, the Czech Republic, and Japan were determined in regard to five previously described SNPs in MBL1 . The T allele of G949T was present among the BC 2 animals. MBL-A serum concentration in the BC 2 animals showed a bimodal distribution, with one-third of the animals at levels between 0.7 and 1.6 µg mL(-1) and the remaining pigs at levels around 13 µg mL(-1) . There was a co-variation between the presence of the T allele and low MBL-A concentration in serum. The genotyping of the wild boars revealed differences between populations. The T allele of G949T was not detected in the Austrian and Japanese samples and is thus unlikely to be an original feature of wild boars. In contrast, it was present at high frequency (0.35) among the Swedish wild boars, probably representing a founder effect. Five MBL1 haplotypes were resolved. Only two of these were present among the Japanese wild boars compared to four in each of the European populations. This difference may reflect differences in selection pressure and population history.


Asunto(s)
Lectina de Unión a Manosa/sangre , Lectina de Unión a Manosa/genética , Sus scrofa/genética , Animales , Austria , Secuencia de Bases , República Checa , Frecuencia de los Genes , Genotipo , Haplotipos , Japón , Polimorfismo de Nucleótido Simple , Receptores de Reconocimiento de Patrones/genética , Análisis de Secuencia de ADN/veterinaria , Suecia
2.
Vox Sang ; 102(2): 125-33, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21770955

RESUMEN

BACKGROUND AND OBJECTIVES: Keeping a small stock of liquid plasma readily available for transfusion is common practise in Sweden. We report data on complement activation markers in plasma components during storage in the liquid state and the kinetics of C3a-(desArg) after transfusion of autologous plasma with high content of C3a-(desArg). MATERIAL AND METHODS: Plasma components were prepared by apheresis or from whole blood. C3 fragments (C3a-(desArg), C3d,g, iC3), and soluble terminal complement complex (sC5b-9) were investigated. C3a-(desArg) kinetics was investigated in regular apheresis donors. RESULTS: Apheresis plasma prepared by membrane centrifugation had significantly higher level of C3a-(desArg), C3d,g and sC5b-9 from day 0 and low iC3, than plasma prepared by other methods. By storage day 7, C3a-(desArg)-levels were above the reference value in 88% of all components. After re-infusion of autologous plasma with high C3a-(desArg) content, there were rapid a(1) and a(2)-distribution followed by a slower b-elimination phase. CONCLUSION: Plasma components prepared by different methods and stored in the liquid phase differ significantly in the amount and timing of complement activation. C3a-(desArg) present in plasma is rapidly eliminated after transfusion. Autologous plasma could be used to study complement kinetics in different clinical situations.


Asunto(s)
Conservación de la Sangre/métodos , Transfusión Sanguínea/métodos , Activación de Complemento/inmunología , Complemento C3a/inmunología , Plasma/inmunología , Donantes de Sangre , Femenino , Humanos , Masculino
3.
Int J Immunogenet ; 39(1): 68-76, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22077964

RESUMEN

The great importance of the Toll-like receptors (TLRs) in innate immunity is well established, but one family member--TLR10--remains elusive. TLR10 is expressed in various tissues in several species, but its ligand is not known and its function is still poorly understood. The open reading frame of TLR10 was sequenced in 15 wild boars, representing three populations, and in 15 unrelated domestic pigs of Hampshire, Landrace and Large White origin. Amino acid positions corresponding to detected nonsynonymous single nucleotide polymorphisms (SNPs) were analysed in the crystal structures determined for the human TLR1-TLR2-lipopeptide complex and the human TLR10 Toll/Interleukin 1 receptor (TIR) dimer. SNP occurrence in wild boars and domestic pigs was compared, and haplotypes for the TLR10 gene and the TLR6-1-10 gene cluster were reconstructed. Despite the limited number of animals sequenced in the present study (N = 30), a larger number of SNPs were found in TLR10 than recently reported for TLR1, TLR6 and TLR2. Thirty-three SNPs were detected, of which 20 were nonsynonymous. The relative frequency of nonsynonymous (d(N) ) and synonymous (d(S) ) SNPs between wild boars and domestic pigs was higher in TLR10 than recently reported for TLR1, TLR6 and TLR2. However, the polymorphism reported in the present study seems to leave the function of the TLR10 molecule unaffected. Furthermore, no nonsynonymous SNPs were detected in the part of the gene corresponding to the hinge region of the receptor, probably reflecting rigorously acting functional constraint. The total number of SNPs and the number of nonsynonymous SNPs were significantly lower (P < 0.05) in the wild boars than in the domestic pigs, and fewer TLR10 haplotypes were present in the wild boars. The majority of the TLR6-1-10 haplotypes were specific for either wild boars or domestic pigs, probably reflecting differences in microbial environment and population history.


Asunto(s)
Polimorfismo de Nucleótido Simple , Porcinos/genética , Receptor Toll-Like 10/genética , Animales , Sitios de Unión , Femenino , Frecuencia de los Genes , Tamización de Portadores Genéticos , Haplotipos , Masculino , Sistemas de Lectura Abierta , Filogenia , Estructura Terciaria de Proteína , Alineación de Secuencia , Especificidad de la Especie , Porcinos/clasificación , Porcinos/inmunología , Receptor Toll-Like 1/genética , Receptor Toll-Like 2/genética , Receptor Toll-Like 6/genética
4.
J Viral Hepat ; 18(2): 106-18, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-20158602

RESUMEN

The spread of hepatitis C virus (HCV) in Sweden in the 1970s indicated that serious liver complications (SLC) would increase in the 2000s. The aim of this study was to analyse the burden of HCV-associated inpatient care in Sweden, to demonstrate the changes over time and to compare the findings with a noninfected population. The HCV-cohort (n: 43,000) was identified from the national surveillance database 1990-2006, and then linked to national registers to produce an age-, sex-, and region-matched noninfected comparison population (n: 215,000) and to obtain information on demographics, cancers, inpatient care and prescriptions. Cox regression was used to estimate the likelihood (hazard ratios) for admission to hospital in the HCV compared with the noninfected cohort. The hazard ratios were 4.03 (95% CI: 3.98-4.08) for all care, 77.52 (71.02-84.60) for liver-related care and 40.74 (30.58-54.27) for liver cancer care. The admission rate in the HCV-cohort compared with the noninfected cohort, the rate ratio (age- and sex-adjusted) for all inpatient care was 5.91 (95% CI: 5.87-5.94), and the rate ratio for liver-related care was 70.05 (66.06-74.28). In the HCV-cohort, 45% of all episodes were for psychiatric, mostly drug-related, care. Inpatient care for SLC increased in the 2000s. To conclude, drug-related care was common in the HCV-infected cohort, the demand for liver-related care was very high, and SLC increased notably in the 2000s, indicating that the burden of inpatient care from serious liver disease in HCV-infected individuals in Sweden is an increasing problem.


Asunto(s)
Hepatitis C/epidemiología , Hospitalización/estadística & datos numéricos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Femenino , Hepatitis C/patología , Hospitalización/tendencias , Humanos , Masculino , Persona de Mediana Edad , Suecia/epidemiología , Adulto Joven
5.
Euro Surveill ; 14(30): 19280, 2009 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-19643056

RESUMEN

Antibiotic resistance is a major European and global public health problem and is, for a large part, driven by misuse of antibiotics. Hence, reducing unnecessary antibiotic use, particularly for the treatment of certain respiratory tract infections where they are not needed, is a public health priority. The success of national awareness campaigns to educate the public and primary care prescribers about appropriate antibiotic use in Belgium and France stimulated a European initiative coordinated by the European Centre for Disease Prevention and Control (ECDC), and named European Antibiotic Awareness Day (EAAD), to take place each year on 18 November. Specific campaign materials, including key messages, logos, slogans and a media toolkit, were developed and made available for use in European countries. The focus of the first EAAD campaign was about not taking antibiotics for viral infections such as colds and flu. A post-campaign survey was conducted in January 2009. Thirty-two European countries participated in the first EAAD, producing information materials and implementing activities to mark EAAD. Media coverage peaked on 18 and 19 November. At EU level, EAAD was launched at a scientific meeting in the European Parliament, Strasbourg. The event received EU political engagement through support from the EU Commissioner for Health, the Slovenian and French EU Presidencies, and Members of the European Parliament. Critical factors that led to the success of the first EAAD were good cooperation and process for building the campaign, strong political and stakeholder support and development of campaign materials based on scientific evidence. Countries indicated wide support for another EAAD in 2009. For this purpose, ECDC is developing several TV spots as well as a second set of EAAD campaign materials targeting primary care prescribers.


Asunto(s)
Aniversarios y Eventos Especiales , Antibacterianos/uso terapéutico , Infecciones Bacterianas/tratamiento farmacológico , Recolección de Datos/métodos , Farmacorresistencia Bacteriana , Concienciación , Unión Europea , Educación en Salud/métodos , Conocimientos, Actitudes y Práctica en Salud , Promoción de la Salud/métodos , Humanos , Evaluación de Programas y Proyectos de Salud , Encuestas y Cuestionarios
6.
Euro Surveill ; 14(30): 19281, 2009 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-19643057

RESUMEN

Surveillance of communicable diseases is a public health corner stone. Routine notification data on communicable diseases are used as a basis for public health action as well as for policy making. While there are agreed standards for evaluating the performance of surveillance systems, it is rarely possible to analyse the validity of the data entered into these systems. In this study we compared data on all Swedish cases of methicillin-resistant Staphylococcus aureus (MRSA) routinely notified between 2000 and 2003 with follow-up information collected for each of these cases as part of a public health project. The variables Reason for testing (clinical sample, contact tracing, screening of risk group), Clinical presentation (disease, colonisation), Transmission setting (healthcare-acquired, community-acquired), Country of acquisition (Sweden, abroad) and Risk-occupation (yes, no) were analysed for sensitivity, positive predictive value and completeness of answers. The sensitivity varied between 23% and 83%, the positive predictive values were generally higher (55% to 97%), while missing answers varied from 11% to 59%. The proportion of community-acquired cases was markedly higher when excluding either cases of MRSA colonisation or cases found through public health-initiated activities (contact tracing or screening of risk groups). We conclude that the quality of routine surveillance data may be inadequate for in-depth epidemiological analyses. This should be taken into account when interpreting routine surveillance figures. Whether or not the case definition includes cases of MRSA colonisation may have a significant impact on population-wide estimates of MRSA occurrence.


Asunto(s)
Resistencia a la Meticilina , Vigilancia de la Población/métodos , Infecciones Estafilocócicas/epidemiología , Staphylococcus aureus , Femenino , Humanos , Masculino , Notificación Obligatoria , Valor Predictivo de las Pruebas , Estudios Prospectivos , Reproducibilidad de los Resultados , Infecciones Estafilocócicas/diagnóstico , Infecciones Estafilocócicas/microbiología , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/aislamiento & purificación , Suecia/epidemiología
7.
Biosens Bioelectron ; 21(10): 1973-80, 2006 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-16289605

RESUMEN

Real time interactions of antithrombin (AT) with Corline Heparin Surfaces (CHS) with one and two layers of heparin conjugate have been examined using a multi-wavelength TIRF spectroscopy technique with continuous flow. Fluorescently labeled AT, adsorbed from citrated human blood plasma, showed significantly higher signals on CHS compared to the cationic surface used to attach the heparin conjugate. The AT binding to CHS was very stable, also after exposure to soluble heparin at a concentration of 1.5 IU/mL. Only a few percent of the bound AT were displaced from the surfaces by AT present in plasma after long-term exposure to plasma. In contrast, larger amounts of the freshly added AT had adsorbed to the surfaces, especially to the surface with two layers of heparin conjugate, indicating the presence of unsaturated AT binding sites. The amount of AT bound to the different surfaces was quantified after elution using an enzyme immunoassay (EIA). Characteristic emission spectra of proteins and fluorophores of labeled proteins, obtained at the surfaces after a long-term exposure to plasma, confirmed their presence at the surfaces. The multi-wavelength TIRF technique proved to be a useful tool when combined with other techniques to study the time course of interactions of fluorescently labeled proteins with biomaterials, even in a complex environment such as plasma.


Asunto(s)
Antitrombinas/metabolismo , Heparina/metabolismo , Espectrometría de Fluorescencia/métodos , Antitrombinas/química , Técnicas Biosensibles , Heparina/química , Humanos
8.
Euro Surveill ; 16(14)2011 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-21492530
9.
Euro Surveill ; 11(5): 103-7, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16757847

RESUMEN

Electronic systems for communicable diseases surveillance enhance quality by simplifying reporting, improving completeness, and increasing timeliness. In this article we outline the ideas and technologies behind SmiNet-2, a new comprehensive regional/national system for communicable disease surveillance in Sweden. The system allows for reporting from physicians (web form) and laboratories (direct from lab data system) over the internet. Using a unique personal identification number, SmiNet-2 automatically merges clinical and laboratory notifications to case records. Privileged users, at national and county level, work against a common central server containing all notifications and case records. In addition, SmiNet-2 has separate county servers with tools for outbreak investigations, contact tracing and case management. SmiNet-2 was first used in September 2004. Individual counties receive up to 90% of all notifications electronically. In its first year, SmiNet-2 received 54 980 clinical notifications and 32,765 laboratory notifications, which generated 58,891 case records. Since most clinicians in Sweden have easy access to the internet, a general web-based reporting has been feasible, and it is anticipated that within a few years all reporting to SmiNet-2 will be over the internet. In this context, some of the major advantages of SmiNet-2 when compared with other systems are timeliness in the dataflow (up to national level), the full integration of clinical and laboratory notifications, and the capability to handle more than 50 diseases with tailor-made notification forms within one single system.


Asunto(s)
Enfermedades Transmisibles/epidemiología , Bases de Datos Factuales , Notificación de Enfermedades/métodos , Brotes de Enfermedades/estadística & datos numéricos , Internet , Sistemas de Registros Médicos Computarizados , Vigilancia de la Población/métodos , Sistemas de Administración de Bases de Datos , Brotes de Enfermedades/prevención & control , Humanos , Incidencia , Difusión de la Información/métodos , Almacenamiento y Recuperación de la Información/métodos , Medición de Riesgo/métodos , Factores de Riesgo , Suecia/epidemiología
10.
Euro Surveill ; 11(5): 15-16, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-29208143

RESUMEN

Electronic systems for communicable diseases surveillance enhance quality by simplifying reporting, improving completeness, and increasing timeliness. In this article we outline the ideas and technologies behind SmiNet-2, a new comprehensive regional/national system for communicable disease surveillance in Sweden. The system allows for reporting from physicians (web form) and laboratories (direct from lab data system) over the internet. Using a unique personal identification number, SmiNet-2 automatically merges clinical and laboratory notifications to case records. Privileged users, at national and county level, work against a common central server containing all notifications and case records. In addition, SmiNet-2 has separate county servers with tools for outbreak investigations, contact tracing and case management. SmiNet-2 was first used in September 2004. Individual counties receive up to 90% of all notifications electronically. In its first year, SmiNet-2 received 54 980 clinical notifications and 32 765 laboratory notifications, which generated 58 891 case records. Since most clinicians in Sweden have easy access to the internet, a general web-based reporting has been feasible, and it is anticipated that within a few years all reporting to SmiNet-2 will be over the internet. In this context, some of the major advantages of SmiNet-2 when compared with other systems are timeliness in the dataflow (up to national level), the full integration of clinical and laboratory notifications, and the capability to handle more than 50 diseases with tailor-made notification forms within one single system.

11.
J Thromb Haemost ; 14(3): 531-45, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26614707

RESUMEN

UNLABELLED: ESSENTIALS: The lectin pathway's MASP-1/2 activates coagulation factors but the trigger of the activation is unknown. MASP-1/2 activation was assessed by quantifying complexes between MASPs and antithrombin/C1-inhibitor. Activated platelets and fibrin were demonstrated to activate MASP-1 and MASP-2 both in vitro and in vivo. These findings may represent a crossroad between the complement and the coagulation systems. BACKGROUND: The activated forms of the complement lectin pathway (LP) proteases MASP-1 and MASP-2 are able to cleave the coagulation factors prothrombin, fibrinogen, factor XIII and thrombin-activatable fibrinolysis inhibitor in vitro. In vivo studies also show that MASP-1 is involved in thrombogenesis. OBJECTIVES: To clarify the not yet identified mechanisms involved in triggering activation of the LP during thrombotic reactions. METHODS: Novel sandwich-ELISAs for detection of complexes between MASP-1 or MASP-2 and the serpins C1 inhibitor (C1-INH) or antithrombin (AT), were used to specifically detect and quantify the activated forms of MASP-1 and MASP-2. RESULTS: Activated platelets were shown by flow cytometry to bind Ficolin-1, -2 and -3 but not MBL, which was associated with activation of MASP-1 and MASP-2. We also demonstrated that fibrin and the plasmin-generated fibrin fragment DD in plasma, bind and activate MASP-1 and MASP-2. As demonstrated by the ELISA and SDS-PAGE/Western blotting, the fibrin-associated activation was reflected in a specific inactivation by AT during clotting without the assistance of heparin. In all other cases the MASPs were, as previously reported, inactivated by C1-INH. In systemic lupus erythematosus patients with thrombotic disease and in polytrauma patients, the levels of activated MASP-1 and MASP-2 in complex with both AT and C1-INH were associated with markers of thrombotic disease and contact/coagulation system activation. CONCLUSIONS: MASP-1 and MASP-2 are activated during blood clotting. This activation is triggered by activated platelets and by the generation of fibrin during thrombotic reactions in vitro and in vivo, and may represent a novel activation/amplification mechanism in thromboinflammation.


Asunto(s)
Coagulación Sanguínea , Plaquetas/enzimología , Lectina de Unión a Manosa de la Vía del Complemento , Inflamación/enzimología , Serina Proteasas Asociadas a la Proteína de Unión a la Manosa/metabolismo , Activación Plaquetaria , Trombosis/enzimología , Adulto , Anciano , Anciano de 80 o más Años , Proteínas Antitrombina/metabolismo , Plaquetas/inmunología , Estudios de Casos y Controles , Proteína Inhibidora del Complemento C1/metabolismo , Activación Enzimática , Femenino , Fibrina/metabolismo , Humanos , Inflamación/sangre , Inflamación/inmunología , Lupus Eritematoso Sistémico/sangre , Lupus Eritematoso Sistémico/enzimología , Lupus Eritematoso Sistémico/inmunología , Masculino , Serina Proteasas Asociadas a la Proteína de Unión a la Manosa/inmunología , Persona de Mediana Edad , Traumatismo Múltiple/sangre , Traumatismo Múltiple/enzimología , Traumatismo Múltiple/inmunología , Unión Proteica , Transducción de Señal , Trombosis/sangre , Trombosis/inmunología , Factores de Tiempo , Adulto Joven
12.
Biochim Biophys Acta ; 929(3): 318-26, 1987 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-3038199

RESUMEN

The effects of epinephrine, glucagon and insulin on the activity and degree of phosphorylation of fructose-1,6-bisphosphatase in isolated hepatocytes maintained in cell culture for 24 h were investigated. Epinephrine caused a rapid decrease in the apparent Km monitored as the activity ratio between the activity at 12.5 and 83 microM fructose-1,6-bisphosphate, reaching a maximum after 5 min. Glucagon caused a slower and less pronounced activation, and insulin caused an equally slow increase in Km. The effect of epinephrine and glucagon was completely reciprocated by insulin and the action of insulin was totally erased by the other two. Glucagon stimulated the incorporation of [32P]phosphate into fructose-1,6-bisphosphatase from about 2.5 to 4.2 mol/mol enzyme and epinephrine to 3.5 mol/mol. The effect of the two hormones acting together was cumulative. Insulin brought about a decrease in the degree of phosphorylation to 2.0 mol/mol. The effect of epinephrine was shown to be caused by the beta-receptors, since it was completely blocked by propanolol (a beta-antagonist) and remained unaffected by the presence of phentolamine (an alpha-antagonist).


Asunto(s)
Epinefrina/farmacología , Fructosa-Bifosfatasa/metabolismo , Glucagón/farmacología , Insulina/farmacología , Hígado/enzimología , Fosfatos/metabolismo , Animales , Activación Enzimática/efectos de los fármacos , Hígado/efectos de los fármacos , Masculino , Fosforilación , Ratas , Ratas Endogámicas , Receptores Adrenérgicos alfa/fisiología , Receptores Adrenérgicos beta/fisiología
13.
Clin Microbiol Infect ; 11(2): 138-44, 2005 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-15679488

RESUMEN

The Swedish database on notifiable communicable diseases was used to identify 24 803 cases of travel-associated non-typhoidal salmonellosis from the period 1997-2003. Serotype data were available for 24 358 (98.2%) of these cases, which were compared with a data set from the same period of 16 255 randomly selected Swedish residents with a history of recent overnight travel outside Sweden. The highest risk of disease was seen in travellers returning from East Africa (471/100 000 travellers; 95% CI 294-755), or the Indian subcontinent (474/100 000; 95% CI 330-681). Children aged 0-6 years were at higher risk than travellers of other ages (OR 2.4; 95% CI 2.1-2.8). Some distinct seasonal patterns could be distinguished, with highest (adjusted) risk in December in East Asia, and in August in Europe. Marked geographical differences in serotype distribution were noted. Salmonella Enteritidis was especially dominant in Europe, but was much less common in Africa, Asia and America, where the variety of circulating serotypes was greater. Overall, the two data sets provided important information on travel risks which are also likely to apply to travellers from other western countries.


Asunto(s)
Infecciones por Salmonella/etiología , Salmonella/clasificación , Estaciones del Año , Viaje , Adolescente , Adulto , Anciano , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Persona de Mediana Edad , Factores de Riesgo , Infecciones por Salmonella/epidemiología , Infecciones por Salmonella/microbiología , Serotipificación
14.
Euro Surveill ; 10(12): 5-6, 2005 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29208153

RESUMEN

Sentinel surveillance usually underestimates the true burden of influenza in a population, as individuals must present to medical establishments to be included in the surveillance system. We carried out a telephone survey to estimate the national burden of influenza in the Swedish population for one week during the 2004/05 influenza season. Fixed-line telephone numbers were randomly sampled and households interviewed concerning influenza illness between 14-20 February 2005 (Week 7 of 2005). Questions regarding seasonal influenza vaccination status, symptoms and the impact of illness on daily life were also included. A self-defined influenza prevalence of 7.7% in week 7 of 2005 was estimated. On applying a case definition of 'cough and fever and muscle pain' for influenza like illness, the prevalence decreased to 3.6%. The survey provided insight into the burden of illness in the population further to that estimated through the sentinel surveillance system.

15.
Mol Immunol ; 36(4-5): 233-9, 1999.
Artículo en Inglés | MEDLINE | ID: mdl-10403476

RESUMEN

Phosphorylation of complement component C3 by different protein kinases in vitro has been demonstrated to alter the functional properties of the protein. Extracellular phosphorylation mediated by activated platelets is a newly described mechanism by which the function of plasma proteins can be regulated. Upon activation of platelets a casein kinase is released concomitant with large amounts of ATP and Ca2+. These components are sufficient to phosphorylate proteins e.g., C3 extracellularly. In vivo, in patients with SLE, the phosphate content in plasma proteins, including C3 has been demonstrated to increase during exacerbation. The changes were linked to platelet activation by a covariation with the levels of beta-thromboglobulin. The purpose of this review is to summarise the findings in this field.


Asunto(s)
Proteínas Sanguíneas/metabolismo , Complemento C3/metabolismo , Animales , Humanos , Fosforilación
16.
Mol Immunol ; 26(4): 383-90, 1989 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-2469949

RESUMEN

Binding of C3 to sheep erythrocytes in a serum-free milieu (EAC14oxy2, EAC142) has previously been shown to mimic the antigenic change that occurs upon denaturation of C3 in sodium dodecyl sulphate (SDS), whereby neoantigenic C3(D) epitopes are exposed. The present paper deals with C3 bound to various target surfaces which are known to modulate the functional properties of C3 in different ways. Bound C3 fragments on serum-treated human aggregated gammaglobulin, zymosan, rabbit and sheep erythrocytes, and on circulating immune complexes isolated from sera of patients with rheumatoid arthritis and systemic lupus erythematosus, were shown to be mainly in the iC3b form. By RIAs, employing polyclonal antibodies, the range of C3(D) antigenic epitopes of 125I-labelled SDS denatured C3 expressed by the particle-bound iC3b was monitored. The physiologically bound iC3b on all tested particles expressed wide range of C3(D) epitopes and each type of particle-bound C3 exposed its individual range. By competition ELISA specific C3(D) alpha epitopes were monitored, employing monoclonal antibodies. A distinct difference in the expression of these epitopes was observed in iC3b bound to various test particles in the presence of normal serum and in iC3b present on circulating immune complexes from pathological sera. Considering that the neoantigenic C3(D) epitopes have been shown to be associated with different functions of C3, the distinctive antigenic expression of each type of serum-treated particle might reflect different functional forms of the protein.


Asunto(s)
Enfermedades Autoinmunes/inmunología , Activación de Complemento , Complemento C3/inmunología , Epítopos/análisis , Anticuerpos Monoclonales , Complejo Antígeno-Anticuerpo , Artritis Reumatoide/inmunología , Electroforesis en Gel de Poliacrilamida , Humanos , Immunoblotting , Lupus Eritematoso Sistémico/inmunología , Radioinmunoensayo , Factor Reumatoide/inmunología
17.
FEBS Lett ; 167(2): 203-9, 1984 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-6321241

RESUMEN

Rat liver fructose-1,6-bisphosphatase was partially phosphorylated in vitro and separated into unphosphorylated and fully phosphorylated enzyme. The effects of fructose 2,6-bisphosphate and AMP on these two enzyme forms were examined. Unphosphorylated fructose-1,6-bisphosphatase was more easily inhibited by both effectors. Fructose 2,6-bisphosphate affected both K0.5 and Vmax, while the main effect of AMP was to lower Vmax. Fructose 2,6-bisphosphate and AMP together acted synergistically to decrease the activity of fructose-1,6-bisphosphatase, and since unphosphorylated and phosphorylated enzyme forms are affected differently, this might be a way to amplify the effect of phosphorylation.


Asunto(s)
Adenosina Monofosfato/farmacología , Fructosa-Bifosfatasa/antagonistas & inhibidores , Fructosadifosfatos/farmacología , Hexosadifosfatos/farmacología , Hígado/enzimología , Animales , Fosforilación , Ratas
18.
Thromb Haemost ; 82(4): 1283-8, 1999 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10544914

RESUMEN

Previous studies suggest that activated platelets facilitate the cleavage of factor XI by both factor XIIa and thrombin. Extracellular phosphorylation is a mechanism by which the function of plasma proteins can be regulated. Phosphorylation is mediated by a casein kinase which is released by activated platelets concomitant with large amounts of ATP and Ca2+. The purpose of this study was to investigate if factor XI is phosphorylated by a platelet casein kinase and whether phosphorylation may affect its activation properties. It was shown that supernatants from platelets which contain platelet casein kinase phosphorylated factor XI. By Western blot analysis it was shown that phosphorylation of factor XI substantially increased its susceptibility to cleavage by factor XIIa, and, to a lesser extent, by thrombin. The generated factor XIa was functionally active in that it cleaved the chromogenic substrate S2366, and in that factor XIa-antithrombin and thrombin-antithrombin complexes were generated when phosphorylated factor XI was added to blood plasma. The present study indicates that platelet-mediated phosphorylation of factor XI enhances the cleavage of factor XI into XIa and that the generated XIa possesses functional activity. Phosphorylation of factor XI might be an essential regulatory mechanism by which platelets mediate amplification of the coagulation cascade.


Asunto(s)
Factor XIIa/metabolismo , Factor XI/metabolismo , Hemostáticos/metabolismo , Activación Plaquetaria/efectos de los fármacos , Proteínas Quinasas/metabolismo , Trombina/metabolismo , Plaquetas/efectos de los fármacos , Plaquetas/fisiología , Caseína Quinasas , Factor XIIa/farmacología , Hemostáticos/farmacología , Humanos , Fosforilación , Transducción de Señal , Trombina/farmacología
19.
Thromb Haemost ; 82(1): 58-64, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10456455

RESUMEN

Titanium has superior osteointegrating properties compared to other biomaterials. The mechanism for this is unknown. During the initial phase of bone implantation the biomaterial comes into direct contact with whole blood. In this study we use a newly developed in vitro chamber model to compare different commonly used biomaterials in contact with whole blood. These materials were selected with respect to their different osteointegrating properties in order to correlate these properties with the response to whole blood. In the presence of 3 IU/ml of heparin only titanium induced macroscopic clotting. This was reflected by the generation of thrombin-antithrombin which was much increased in blood in contact with titanium compared with steel and PVC. The coagulation activation caused by titanium was triggered by the intrinsic pathway because the generation of FXIIa-AT/C1 esterase inhibitor paralleled that of thrombin-antithrombin, and both thrombin-antithrombin complex and FXIIa-AT/C1 esterase inhibitor generation were abrogated by corn trypsin inhibitor, which is a specific inhibitor of FXIIa. The binding of platelets was increased on the titanium surface compared to the other biomaterial surfaces and the state of platelet activation was much more pronounced as reflected by the levels of beta-thromboglobulin and PDGF. This study indicates that titanium is unsuitable as a biomaterial in devices which are in direct contact with blood for a prolonged period. Furthermore, PDGF and other alpha-granule proteins e.g. TGF-beta, are known to be potent promotors of osteogenesis which suggests that the pronounced thrombogenic properties of titanium might contribute to the good osteointegrating properties.


Asunto(s)
Sustitutos de Huesos , Trombosis/etiología , Titanio , Coagulación Sanguínea , Sustitutos de Huesos/efectos adversos , Factor XIIa , Humanos , Osteogénesis , Factor de Crecimiento Derivado de Plaquetas , Trombosis/prevención & control , Titanio/efectos adversos
20.
Immunol Lett ; 26(1): 51-8, 1990 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-2177450

RESUMEN

Soluble C3d applied to human blood-derived B lymphocytes inhibited anti-mu, T cell-produced growth factor, and EBV-induced DNA synthesis in serum-free culture. C3d added to the B cell cultures 1 and 2 days after the stimulus, still exerted inhibition, though with gradually diminishing efficiency. C3d, fixed on zymosan or attached to the culture wells, induced [3H]thymidine incorporation of the B cells in serum-free medium. The concentration of C3d used to coat the wells was critical, with optimal stimulatory effect of 8.3 micrograms/ml. These C3d molecules were shown to be denatured. Our results are in line with earlier data on B cells derived from mouse spleen and human tonsils showing that depending on the way of presentation and its amounts, the natural ligand of CR2 can exert negative or positive signals. Moreover, we demonstrate that C3d can inhibit even the proliferative stimulus of EBV.


Asunto(s)
Linfocitos B/inmunología , Complemento C3d/fisiología , Activación de Linfocitos/fisiología , Linfocitos B/microbiología , Línea Celular Transformada , Complemento C3/fisiología , ADN/biosíntesis , Herpesvirus Humano 4/crecimiento & desarrollo , Humanos , Fitohemaglutininas , Unión Proteica , Sefarosa , Acetato de Tetradecanoilforbol , Factor de Crecimiento Transformador beta
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