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1.
BJOG ; 129(3): 450-460, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34437763

RESUMO

OBJECTIVE: To assess the impact of lymphadenectomy and lymphoedema of the lower limbs (LLL) on health-related quality of life (HRQoL) 1 year after surgery for endometrial cancer (EC). DESIGN: Prospective longitudinal cohort multicentre study. SETTING: Departments of obstetrics and gynaecology at four university hospitals, six central hospitals and four county hospitals in Sweden. POPULATION: Two-hundred-and-thirty-five women with early stage EC were included; 116 with high-risk EC underwent surgery including lymphadenectomy (+LA), and 119 with low-risk EC had surgery without lymphadenectomy (-LA). METHODS: The generic SF-36 and EQ-5D-3L and the lymphoedema-specific LYMQOL questionnaire were used to assess HRQoL. LLL was assessed by systematic circumferential measurements of the legs enabling volume estimation, clinical evaluation and patient-reported perception of leg swelling. All assessments were carried out on four occasions; preoperatively, and 4-6 weeks, 6 months and 1 year postoperatively. MAIN OUTCOME MEASURE: HRQoL scores. RESULTS: No significant differences were seen in HRQoL between the +LA and -LA groups 1 year postoperatively. Irrespective of method of determining LLL, women with LLL were significantly more affected in the LYMQOL domains Function, Appearance/body image and Physical symptoms, but not in the domain Emotion/mood, than women without LLL. No such differences were seen in the generic HRQoL or in the LYMQOL global score between the groups with and without LLL. CONCLUSIONS: Lymphadenectomy did not seem to affect generic HRQoL adversely. Irrespective of the method of measuring, LLL affected the lymphoedema-specific HRQoL negatively, mainly in physical domains, but had no impact on the generic HRQoL. TWEETABLE ABSTRACT: Lymphoedema has impact on lymphoedema-specific, but not on generic, HRQoL, 1 year after surgery for EC.


Assuntos
Neoplasias do Endométrio/cirurgia , Excisão de Linfonodo , Linfedema/epidemiologia , Complicações Pós-Operatórias/epidemiologia , Qualidade de Vida , Idoso , Efeitos Psicossociais da Doença , Feminino , Humanos , Estudos Longitudinais , Linfedema/etiologia , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Período Pós-Operatório , Estudos Prospectivos , Inquéritos e Questionários , Suécia , Resultado do Tratamento
2.
Crit Rev Food Sci Nutr ; 59(2): 228-252, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-28846443

RESUMO

High pressure (HP) treatment often results in discoloration of beef, lamb, pork, and poultry. The degree of color changes depends on the physical and chemical state of the meat, especially myoglobin, and the atmospheric conditions during and after pressurization. A decreased redness is attributed to a large degree to the oxidation of the bright red oxymyoglobin or the purplish deoxymyoglobin into the brownish metmyoglobin, as well as to the denaturation of myoglobin. Surely, the high myoglobin content makes beef more exposed to this discoloration compared to the white chicken meat. In addition, HP treatment causes denaturation of myofibrillar proteins followed by aggregation, consequently, changing the surface reflectance and increasing lightness. Other intrinsic and extrinsic factors may affect the pressure-induced color changes positively or negatively. In this review, the pressure-induced color changes in meat are discussed in relation to modification of the myoglobin molecule, changes in the meat microstructure, and the impact of the presence of different chemical compounds and physical conditions during processing.


Assuntos
Cor , Manipulação de Alimentos/métodos , Produtos da Carne/análise , Carne/análise , Pressão , Animais , Bovinos , Galinhas , Metamioglobina/análise , Músculo Esquelético/química , Mioglobina/análise , Mioglobina/química , Oxirredução , Carne Vermelha/análise , Ovinos , Suínos
3.
Br J Dermatol ; 168(6): 1281-6, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23413840

RESUMO

BACKGROUND: Skin exposure to water is considered to contribute to hand eczema. Knowledge about total water exposure during a day is scanty. OBJECTIVES: To investigate self-reported water exposure at work as well as throughout the day. METHODS: Skin exposure to water was assessed from two questionnaire-based health surveys: the nationwide Environmental Health Survey 2007 (EHS), which enquired about water exposure throughout the day, and the Stockholm Public Health Survey 2006 (PHS), which probed water exposure at work. Answers from 19,667 individuals (EHS) and 18,318 individuals (PHS) were available for analysis. RESULTS: In total, 22% of respondents (women 30%, men 12%) reported skin exposure to water more than 20 times during an entire day (EHS) compared with 6% (women 8%, men 4%) at work (PHS). In a univariate analysis, using a merged file comprising data from the EHS and the PHS, water exposure more than 20 times a day was more common in the EHS (prevalence proportion ratio 3·570, 95% confidence interval 3·353-3·802). In multivariate models the variables studied did not fulfil the criteria for being confounders. Water exposure at work declined with increasing age in both women and men (P < 0·0001) as did water exposure during the entire day in men (P < 0·0001). However, women were equally exposed during the entire day across age groups (P = 0·205). CONCLUSIONS: High water exposure over the entire day was found to be considerably more frequent than exposure at work. Thus, a significant proportion of water exposure seems to occur outside work. This should be considered in prevention of hand eczema and when counselling patients with hand eczema in clinical practice.


Assuntos
Dermatite Ocupacional/epidemiologia , Eczema/epidemiologia , Dermatoses da Mão/epidemiologia , Exposição Ocupacional/estatística & dados numéricos , Água/efeitos adversos , Adolescente , Adulto , Dermatite Ocupacional/etiologia , Eczema/etiologia , Feminino , Dermatoses da Mão/etiologia , Inquéritos Epidemiológicos , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Inquéritos e Questionários , Suécia/epidemiologia , Fatores de Tempo , Adulto Jovem
4.
Br J Dermatol ; 158(2): 396-8, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18067479

RESUMO

BACKGROUND: Intact skin is under constant tension, transmitted from the underlying dermis, but when tension is lost (i.e. upon wounding) protease activity is upregulated. OBJECTIVES: To investigate the effect of mechanical strain on protease production by both normal and transformed keratinocytes in vitro. METHODS: Keratinocytes were seeded on to membranes precoated with either type I or type IV collagen. After 48 h medium was replaced with serum-free medium and mechanical strain was applied. RESULTS: Mechanical strain resulted in decreased urokinase-type plasminogen activator (uPA) production by normal human keratinocytes (P<0.05) but increased production by transformed keratinocytes (P<0.05) cultured on type I and type IV collagen. CONCLUSIONS: Differential production of uPA by normal and transformed keratinocytes is relevant in the context of normal function, wound healing and tumorigenesis.


Assuntos
Queratinócitos/metabolismo , Pele/metabolismo , Ativador de Plasminogênio Tipo Uroquinase/metabolismo , Células Cultivadas/metabolismo , Humanos , Estresse Mecânico , Cicatrização/fisiologia
5.
Arch Dis Child Fetal Neonatal Ed ; 91(6): F403-8, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17056838

RESUMO

BACKGROUND: Infection with group B streptococci (GBS) is a serious neonatal disease. The GBS cell surface proteins alpha and Rib elicit protective immunity in animal models and have been suggested as potential antigens in a vaccine against human GBS disease. AIMS: To test the hypothesis that transplacentally transferred maternal antibodies to GBS proteins contribute to the protection of the neonate from GBS infection. METHODS: Thirty neonates with invasive infection were included in a case-control study. IgG antibody concentrations were measured in sera from these neonates, their mothers, and from 60 non-infected controls, neonates as well as mothers. RESULTS: A clear association was found between concentrations of antibody to proteins alpha and Rib in neonatal and maternal sera, indicating that transplacental transfer had occurred. Moreover, low concentrations of antibodies to alpha and Rib in neonatal sera were associated with invasive GBS infection caused by strains expressing the Rib protein. The odds ratio was 0.0007 (95% confidence interval 0.000 to 0.54) for antibodies to alpha and 0.002 (95% confidence interval 0.000 to 0.57) for antibodies to Rib. CONCLUSION: These findings support the notion that antibodies to GBS surface proteins contribute to the protection against neonatal infection.


Assuntos
Anticorpos Antibacterianos/sangue , Proteínas de Bactérias/imunologia , Infecções Estreptocócicas/imunologia , Streptococcus agalactiae/imunologia , Adulto , Antígenos de Bactérias/imunologia , Antígenos de Superfície/imunologia , Ensaio de Imunoadsorção Enzimática , Feminino , Idade Gestacional , Humanos , Imunoglobulina G/sangue , Recém-Nascido , Proteínas de Membrana/imunologia
6.
Anim Genet ; 37(2): 156-62, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16573530

RESUMO

We report the identification of quantitative trait loci (QTL) affecting carcass composition, carcass length, fat deposition and lean meat content using a genome scan across 462 animals from a combined intercross and backcross between Hampshire and Landrace pigs. Data were analysed using multiple linear regression fitting additive and dominance effects. This model was compared with a model including a parent-of-origin effect to spot evidence of imprinting. Several precisely defined muscle phenotypes were measured in order to dissect body composition in more detail. Three significant QTL were detected in the study at the 1% genome-wide level, and twelve significant QTL were detected at the 5% genome-wide level. These QTL comprise loci affecting fat deposition and lean meat content on SSC1, 4, 9, 10, 13 and 16, a locus on SSC2 affecting the ratio between weight of meat and bone in back and weight of meat and bone in ham and two loci affecting carcass length on SSC12 and 17. The well-defined phenotypes in this study enabled us to detect QTL for sizes of individual muscles and to obtain information of relevance for the description of the complexity underlying other carcass traits.


Assuntos
Locos de Características Quantitativas , Suínos/genética , Criação de Animais Domésticos , Animais , Composição Corporal/genética , Mapeamento Cromossômico , Cruzamentos Genéticos , Feminino , Genoma , Endogamia , Masculino , Carne/normas , Fenótipo , Suínos/anatomia & histologia
7.
Biochemistry ; 45(14): 4559-68, 2006 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-16584191

RESUMO

Streptococcus pyogenes is a Gram-positive bacterium that causes several diseases, including acute tonsillitis and toxic shock syndrome. The surface-localized M protein, which is the most extensively studied virulence factor of S. pyogenes, has an approximately 50-residue N-terminal hypervariable region (HVR) that plays a key role in the escape of the host immunity. Despite the extensive sequence variability in this region, many HVRs specifically bind human C4b-binding protein (C4BP), a plasma protein that inhibits complement activation. Although the more conserved parts of M protein are known to have dimeric coiled-coil structure, it is unclear whether the HVR also is a coiled coil. Here, we use nuclear magnetic resonance (NMR) to study the conformational properties of HVRs from M4 and M22 proteins in isolation and in complex with the M protein binding portion of C4BP. We conclude that the HVRs of M4 and M22 are folded as coiled coils and that the folded nucleus of the M4 HVR has a length of approximately 27 residues. Moreover, we demonstrate that the C4BP binding surface of M4-N is found within a region of four heptad repeats. Using molecular modeling, we propose a model for the structure of the M4 HVR that is consistent with our experimental information from NMR spectroscopy.


Assuntos
Antígenos de Bactérias/química , Proteínas da Membrana Bacteriana Externa/química , Proteínas de Transporte/química , Regiões Determinantes de Complementaridade/química , Antígenos de Histocompatibilidade/química , Sequência de Aminoácidos , Dicroísmo Circular , Proteína de Ligação ao Complemento C4b , Humanos , Dados de Sequência Molecular , Ressonância Magnética Nuclear Biomolecular , Estrutura Secundária de Proteína , Proteínas Recombinantes/química , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
8.
Contact Dermatitis ; 53(6): 308-13, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16364116

RESUMO

The aim of this project was to study the long-term prognosis of occupational skin diseases in Sweden. In 1999, a questionnaire was sent to 623/655 individuals who in 1987 reported occupational skin disease to the Social Insurance Office. 394 answered the questionnaire, and 123 non-responders were interviewed by telephone, giving 517 participants (83%), 323 females and 194 males. 85% reported skin symptoms after 1987, 70% during the previous year. 28% considered themselves recovered, of those with nickel allergy only 12%. In a logistic regression model, skin atopy was the strongest unfavourable factor for the prognosis followed by contact allergy and female sex. 66% had consulted a doctor after 1987 and the majority, 82%, had performed occupational changes - most common was change of jobs, 44%. Those who had changed jobs reported less sick leave. The conclusion is that occupational skin diseases have a clear tendency to end up as chronic conditions with a majority reporting symptoms at a 12-year follow-up. The skin disease had influenced the occupational situation for the majority (82%) and for 15% resulted in exclusion from the labour market through unemployment or disability pension.


Assuntos
Dermatite Ocupacional/epidemiologia , Adolescente , Adulto , Comportamento de Escolha , Emprego , Feminino , Seguimentos , Dermatoses da Mão/epidemiologia , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Testes do Emplastro , Prognóstico , Recuperação de Função Fisiológica , Distribuição por Sexo , Inquéritos e Questionários , Suécia/epidemiologia
9.
Meat Sci ; 70(4): 717-25, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22063898

RESUMO

Increased creatine content in the muscle may delay post mortem lactate formation and postpone the pH decline, hence potentially improving the water-holding capacity (WHC). Duroc and Landrace pigs were supplemented with 0, 12.5, 25 or 50g creatine monohydrate (CMH)/d for 5 days prior to slaughter. Meat from Longissimus dorsi (LD) of Duroc pigs had a higher WHC and pH at all times, lower colour determinants; a* (redness), b* (yellowness), L* (lightness) and was more juicy compared to that of Landrace pigs. Furthermore, higher pH(2h), pH(24h) and decreased colour determinants were observed in carcass sides exposed to a faster cooling profile. Dietary supplementation with CMH increased the body weight gain of both breeds. However, only meat from Duroc pigs had higher pH(30min) and pH(45min) (at 50g CMH/d) and WHC, but reduced redness (reduced in both breeds) and juiciness when supplemented with CMH compared to non-supplemented controls.

10.
Mol Microbiol ; 42(2): 539-51, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11703674

RESUMO

The amino-terminal hypervariable region (HVR) of streptococcal M protein is required for the ability of this virulence factor to confer phagocytosis resistance. The function of the HVR has remained unknown, but the finding that many HVRs with extremely divergent sequences bind the human complement regulator C4b-binding protein (C4BP) has suggested that this ligand may play a role in phagocytosis resistance. We used the M22 system to study the function of bound C4BP and provide several lines of evidence that C4BP indeed contributes to phagocytosis resistance. First, the ability of anti-HVR antibodies to cause opsonization correlated with their ability to inhibit binding of C4BP. Secondly, a short deletion in the HVR eliminated C4BP binding and also reduced the ability of M22 to confer phagocytosis resistance. Thirdly, the addition of an excess of pure C4BP to a phagocytosis system almost completely blocked the effect of opsonizing anti-HVR antibodies. Together, our data indicate that binding of C4BP to the HVR of M22 plays an important role in phagocytosis resistance, but other properties of M22 also contribute. This study provides the first molecular insight into the mechanisms by which the HVR of an M protein confers phagocytosis resistance.


Assuntos
Variação Antigênica , Proteínas da Membrana Bacteriana Externa/química , Proteínas da Membrana Bacteriana Externa/metabolismo , Proteínas de Transporte/química , Proteínas de Transporte/metabolismo , Integrina alfaXbeta2/metabolismo , Fagocitose , Streptococcus pyogenes/imunologia , Streptococcus pyogenes/patogenicidade , Sequência de Aminoácidos , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/química , Antígenos de Bactérias/genética , Antígenos de Bactérias/imunologia , Antígenos de Bactérias/metabolismo , Proteínas da Membrana Bacteriana Externa/genética , Proteínas da Membrana Bacteriana Externa/imunologia , Sítios de Ligação , Proteínas de Transporte/genética , Proteínas de Transporte/imunologia , Humanos , Soros Imunes/imunologia , Integrina alfaXbeta2/imunologia , Dados de Sequência Molecular , Mutação , Ligação Proteica , Streptococcus pyogenes/genética
11.
Eur J Immunol ; 31(9): 2771-80, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11536176

RESUMO

Human complement regulators are important targets for pathogenic microorganisms. In one such interaction, Bordetella pertussis binds human C4b-binding protein (C4BP), a high-molecular-weight plasma protein that acts as inhibitor of the classical pathway of complement activation. At least two different B. pertussis surface components, one of which is the virulence factor filamentous hemagglutinin (FHA), contribute to the binding. We used a set of C4BP mutants and monoclonal antibodies to characterize the region in C4BP that binds B. pertussis and analyzed the salt sensitivity of the interaction. These studies indicated that positively charged residues at the interface between complement control protein modules 1-2 in the C4BP alpha-chain are important for binding, and that the site in C4BP that binds B. pertussis is very similar, but not identical, to the C4b-binding site. Bacteria-bound C4BP retained its complement regulatory function and B. pertussis selectively bound C4BP in human plasma, indicating that binding occurs also in vivo. Together, these findings indicate that B. pertussis exploits a site in C4BP, resembling that used by the natural ligand C4b.


Assuntos
Bordetella pertussis/metabolismo , Bordetella pertussis/patogenicidade , Complemento C4b/metabolismo , Proteínas Inativadoras do Complemento , Glicoproteínas , Receptores de Complemento/metabolismo , Anticorpos Monoclonais/imunologia , Antígenos de Bactérias/imunologia , Sítios de Ligação , Sangue/metabolismo , Bordetella pertussis/imunologia , Complemento C4b/imunologia , Reações Cruzadas , Análise Mutacional de DNA , Humanos , Ligantes , Modelos Moleculares , Receptores de Complemento/genética , Receptores de Complemento/fisiologia , Cloreto de Sódio/farmacologia
12.
J Immunol ; 167(7): 3870-7, 2001 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-11564804

RESUMO

Antigenic variation in microbial surface proteins represents an apparent paradox, because the variable region must retain an important function, while exhibiting extensive immunological variability. We studied this problem for a group of streptococcal M proteins in which the approximately 50-residue hypervariable regions (HVRs) show essentially no residue identity but nevertheless bind the same ligand, the human complement regulator C4b-binding protein (C4BP). Synthetic peptides derived from different HVRs were found to retain the ability to bind C4BP, implying that the HVR corresponds to a distinct ligand-binding domain that can be studied in isolated form. This finding allowed direct characterization of the ligand-binding properties of isolated HVRs and permitted comparisons between different HVRs in the absence of conserved parts of the M proteins. Affinity chromatography of human serum on immobilized peptides showed that they bound C4BP with high specificity and inhibition experiments indicated that different peptides bound to the same site in C4BP. Different C4BP-binding peptides did not exhibit any immunological cross-reactivity, but structural analysis suggested that they have similar folds. These data show that the HVR of streptococcal M protein can exhibit extreme variability in sequence and immunological properties while retaining a highly specific ligand-binding function.


Assuntos
Variação Antigênica , Antígenos de Bactérias/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Proteínas de Transporte/imunologia , Proteínas Inativadoras do Complemento , Glicoproteínas , Receptores de Complemento/metabolismo , Streptococcus pyogenes/imunologia , Sequência de Aminoácidos , Antígenos de Bactérias/química , Antígenos de Bactérias/metabolismo , Proteínas da Membrana Bacteriana Externa/química , Proteínas da Membrana Bacteriana Externa/metabolismo , Ligação Competitiva , Proteínas de Transporte/química , Proteínas de Transporte/metabolismo , Dicroísmo Circular , Humanos , Dados de Sequência Molecular , Peptídeos/metabolismo , Streptococcus pyogenes/patogenicidade
13.
J Biol Chem ; 276(32): 29880-90, 2001 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-11395503

RESUMO

Appropriate expression of collagen type I, a major component of connective tissue matrices, is dependent on tight transcriptional control and a number of trans-activating and repressing factors have been characterized. Here we identify the Y-box binding protein-1 (YB-1) as a novel repressor of the collagen type alpha1(I) (COL1A1) gene. Collagen type I mRNA and protein levels decreased upon overexpression of YB-1 by transfection in NRK fibroblasts. The human, rat, and mouse COL1A1 promoter -220/+115 contains three putative Y-boxes, one of these sites, designated collagen Y-box element (CYE), includes a Y-box plus an adjacent 3' inverted repeat. DNase-I footprinting and Southwestern blotting with fibroblast nuclear extract demonstrated binding of several nuclear proteins across the CYE, one of which was identified as YB-1. Recombinant YB-1 bound the CYE sequence in gel shift assays with a preference for single-stranded templates. The entire sequence (-88/-48) was required for high affinity binding. Complex formation of endogenous YB-1 with the CYE was established by supershift studies. COL1A1 promoter-reporter constructs were suppressed up to 80% by cotransfection with YB-1 in a variety of cell types. In addition, CYE conferred YB-1 responsiveness on two heterologous promoters further demonstrating the importance of this repressor region. Mung bean nuclease sensitivity analysis suggested that repression is most likely exerted through changes in DNA conformation.


Assuntos
Proteínas Estimuladoras de Ligação a CCAAT/química , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Colágeno Tipo I , Colágeno/genética , Proteínas de Ligação a DNA , Fatores de Transcrição , Transcrição Gênica , Animais , Sequência de Bases , Northern Blotting , Southern Blotting , Western Blotting , Linhagem Celular , Núcleo Celular/metabolismo , Cromatografia Líquida de Alta Pressão , Colágeno/metabolismo , Cadeia alfa 1 do Colágeno Tipo I , Desoxirribonuclease I/metabolismo , Relação Dose-Resposta a Droga , Fibroblastos/metabolismo , Regulação da Expressão Gênica , Camundongos , Dados de Sequência Molecular , Fatores de Transcrição NFI , Oligonucleotídeos/metabolismo , Plasmídeos/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica , Conformação Proteica , RNA Mensageiro/metabolismo , Ratos , Proteínas Recombinantes/metabolismo , Homologia de Sequência do Ácido Nucleico , Fatores de Tempo , Transfecção , Proteína 1 de Ligação a Y-Box
14.
J Immunol ; 166(11): 6764-70, 2001 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-11359834

RESUMO

C4b-binding protein (C4BP) is an important plasma inhibitor of the classical pathway of complement activation. Several bacterial pathogens bind C4BP, which may contribute to their virulence. In the present report we demonstrate that isolated type IV pili from Neisseria gonorrhoeae bind human C4BP in a dose-dependent and saturable manner. C4BP consists of seven identical alpha-chains and one beta-chain linked together with disulfide bridges. We found that pili bind to the alpha-chain of C4BP, which is composed of eight homologous complement control protein (CCP) domains. From the results of an inhibition assay with C4b and a competition assay in which we tested mutants of C4BP lacking individual CCPs, we concluded that the binding area for pili is localized to CCP1 and CCP2 of the alpha-chain. The binding between pili and C4BP was abolished at 0.25 M NaCl, implying that it is based mostly on ionic interactions, similarly to what have been observed for C4b-C4BP binding. Furthermore, the N-terminal part of PilC, a structural component of pili, appeared to be responsible for binding of C4BP. Membrane cofactor protein, previously shown to be a receptor for pathogenic N. gonorrhoeae on the surface of epithelial cells, competed with C4BP for binding to pili only at high concentrations, suggesting that different parts of pili are involved in these two interactions. Accordingly, high concentrations of C4BP were required to inhibit binding of N. gonorrhoeae to Chang conjunctiva cells, and no inhibition of binding was observed with cervical epithelial cells.


Assuntos
Complemento C4b/metabolismo , Proteínas Inativadoras do Complemento , Proteínas de Fímbrias , Fímbrias Bacterianas/metabolismo , Glicoproteínas , Neisseria gonorrhoeae/metabolismo , Receptores de Complemento/metabolismo , Antígenos CD/genética , Antígenos CD/metabolismo , Proteínas de Bactérias/metabolismo , Ligação Competitiva/genética , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Linhagem Celular , Células Epiteliais/metabolismo , Células Epiteliais/microbiologia , Fímbrias Bacterianas/classificação , HEPES/farmacologia , Humanos , Proteínas Ligantes de Maltose , Proteína Cofatora de Membrana , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Fragmentos de Peptídeos/metabolismo , Polissorbatos/farmacologia , Ligação Proteica/efeitos dos fármacos , Receptores de Complemento/sangue , Receptores de Complemento/isolamento & purificação , Receptores de Complemento/fisiologia , Soroalbumina Bovina/farmacologia , Cloreto de Sódio/farmacologia , Hidróxido de Sódio/farmacologia , Trometamina , Células Tumorais Cultivadas
15.
Meat Sci ; 59(2): 141-51, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22062672

RESUMO

The colour of loin, M. longissimus dorsi (LD), and ham, M. biceps femoris (BF), from pure breed Hampshire, Swedish Landrace and Swedish Yorkshire pigs was studied. The contribution of the pigment content, the myoglobin forms deoxymyoglobin (Mb), oxymyoglobin (MbO) and metmyoglobin (MetMb) and the internal reflectance to the colour of pork of normal meat quality was evaluated using partial least squares regression (PLS). The colour of LD and BF from the Hampshire breed was more red and yellow and more saturated than the colour of the same muscles from the Swedish Landrace and the Swedish Yorkshire breeds. Furthermore, BF from Hampshire was darker than BF from the other two breeds. These differences in colour were related to the lower pH in Hampshire, resulting in more blooming and in higher internal reflectance, and to the higher pigment content. The colour of BF was darker and more red than the colour of LD within each breed. No colour difference was found between gilts and castrates within each breed. Most of the variation (86-90%) in lightness (L* value), redness (a* value) and yellowness (b* value), chroma (saturation) and hue angle of pork of normal meat quality was explained by the pigment content, myoglobin forms and internal reflectance. The L* value, a* value, chroma and hue angle were influenced by both the pigment content and by the myoglobin forms to almost the same extent, while the internal reflectance was of no significance to these colour parameters. The b* value was influenced most by the myoglobin forms, less by the internal reflectance and almost not at all by the pigment content.

16.
J Biol Chem ; 276(11): 8197-204, 2001 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-11096107

RESUMO

Certain pathogenic bacteria express surface proteins that bind to the Fc part of human IgA or IgG. These bacterial proteins are important as immunochemical tools and model systems, but their biological function is still unclear. Here, we describe studies of three streptococcal proteins that bind IgA: the Sir22 and Arp4 proteins of Streptococcus pyogenes and the unrelated beta protein of group B streptococcus. Analysis of IgA domain swap and point mutants indicated that two loops at the Calpha2/Calpha3 domain interface are critical for binding of the streptococcal proteins. This region is also used in binding the human IgA receptor CD89, an important mediator of IgA effector function. In agreement with this finding, the three IgA-binding proteins and a 50-residue IgA-binding peptide derived from Sir22 blocked the ability of IgA to bind CD89. Further, the Arp4 protein inhibited the ability of IgA to trigger a neutrophil respiratory burst via CD89. Thus, we have identified residues on IgA-Fc that play a key role in binding of different streptococcal IgA-binding proteins, and we have identified a mechanism by which a bacterial IgA-binding protein may interfere with IgA effector function.


Assuntos
Antígenos CD/metabolismo , Proteínas de Bactérias/metabolismo , Proteínas de Transporte/metabolismo , Imunoglobulina A/metabolismo , Receptores Fc/metabolismo , Streptococcus agalactiae/química , Sequência de Aminoácidos , Proteínas de Bactérias/química , Sítios de Ligação , Proteínas de Transporte/química , Humanos , Fragmentos Fc das Imunoglobulinas/metabolismo , Dados de Sequência Molecular
17.
J Infect Dis ; 182(1): 142-9, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10882591

RESUMO

The R28 protein of group A streptococcus (GAS) and the Rib protein of group B streptococcus (GBS) are surface molecules that elicit protective immunity to experimental infection. These proteins are members of the same family and cross-react immunologically. In spite of extensive amino acid residue identity, the cross-reactivity between R28 and Rib was found to be limited, as shown by analysis with highly purified proteins and specific antisera. Nevertheless, immunization of mice with purified R28 conferred protection against lethal infection with Rib-expressing GBS strains, and immunization with Rib conferred protection against R28-expressing GAS. Thus, R28 and Rib elicited cross-protective immunity. Characterization of many clinical GAS and GBS isolates expressing R28 or Rib, respectively, indicated that most of them expressed proteins similar to those of the reference strains. Analysis of these data suggests that cross-protection may influence the outcome of natural infections with R28-expressing GAS and Rib-expressing GBS.


Assuntos
Proteínas de Bactérias/imunologia , Proteínas de Membrana/imunologia , Infecções Estreptocócicas/imunologia , Streptococcus agalactiae/imunologia , Streptococcus pyogenes/imunologia , Animais , Anticorpos Antibacterianos/imunologia , Antígenos de Bactérias/imunologia , Reações Cruzadas , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos C3H , Infecções Estreptocócicas/prevenção & controle , Streptococcus agalactiae/metabolismo , Streptococcus pyogenes/metabolismo , Vacinação
18.
J Immunol ; 164(10): 5328-36, 2000 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-10799895

RESUMO

Many strains of Streptococcus pyogenes bind C4b-binding protein (C4BP), an inhibitor of complement activation. The binding is mediated by surface M proteins in a fashion that has been suggested to mimic the binding of C4b. We have previously shown that a positively charged cluster at the interface between complement control protein domains 1 and 2 of C4BP alpha-chain is crucial for the C4b-C4BP interaction. To extend this observation, and to investigate the interaction with M proteins, we constructed and characterized a total of nine mutants of C4BP. We identified a key recognition surface for M proteins that overlaps with the C4b binding site because substitution of R64 and H67 by Gln dramatically reduces binding to both ligands. However, the analysis of all mutants indicates that the binding sites for C4b and M proteins are only overlapping, but not identical. Furthermore, M proteins were able to displace C4BP from immobilized C4b, whereas C4b only weakly affected binding of C4BP to immobilized M proteins. We found that the molecular mechanisms involved in these two interactions differ because the binding between M proteins and C4BP is relatively insensitive to salt in contrast to the C4BP-C4b binding. In addition, six mAbs directed against the alpha-chain interfered with C4b-C4BP interaction, whereas only two of them efficiently inhibited binding of C4BP to M proteins. Collectively, our results suggest that binding between C4b and C4BP is governed mostly by electrostatic interactions, while additional noncovalent forces cause tight binding of C4BP to streptococcal M proteins.


Assuntos
Antígenos de Bactérias , Proteínas da Membrana Bacteriana Externa , Proteínas de Bactérias/metabolismo , Proteínas de Transporte/metabolismo , Complemento C4b/metabolismo , Proteínas Inativadoras do Complemento , Glicoproteínas , Receptores de Complemento/metabolismo , Streptococcus pyogenes/imunologia , Substituição de Aminoácidos/genética , Substituição de Aminoácidos/imunologia , Anticorpos Monoclonais/metabolismo , Sítios de Ligação/efeitos dos fármacos , Sítios de Ligação/genética , Sítios de Ligação/imunologia , Sítios de Ligação de Anticorpos/imunologia , Ligação Competitiva/imunologia , Humanos , Ligantes , Proteínas de Membrana/metabolismo , Modelos Moleculares , Mutagênese Sítio-Dirigida , Mutação Puntual , Receptores de Complemento/biossíntese , Receptores de Complemento/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/metabolismo , Cloreto de Sódio/farmacologia , Streptococcus pyogenes/metabolismo
19.
Curr Opin Immunol ; 12(1): 44-51, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10679403

RESUMO

The C3 convertases of the human complement system are controlled by fluid-phase and membrane proteins in the RCA (regulators of complement activation) family. Accumulated data show that many pathogenic microorganisms interact with these complement regulators. Recent advances in this field include determination of the crystal structure of the binding domains in the measles virus receptor CD46 and identification of a CD46 transgenic mouse line that is sensitive to measles virus. Moreover, recent findings support the hypothesis that pathogenic bacteria binding fluid-phase RCA proteins exploit these proteins to escape complement attack. These studies provide novel insight into the interplay between pathogens and the innate immune system and may have implications for the plans to use animals expressing an RCA protein for xenotransplantation.


Assuntos
Antígenos CD/metabolismo , Ativação do Complemento , Convertases de Complemento C3-C5/metabolismo , Antígenos de Histocompatibilidade/metabolismo , Virulência/imunologia , Antígenos CD55/metabolismo , Proteína de Ligação ao Complemento C4b , Humanos , Proteína Cofatora de Membrana , Glicoproteínas de Membrana/metabolismo , Receptores de Complemento 3b/metabolismo , Receptores de Complemento 3d/metabolismo
20.
Infect Immun ; 68(1): 107-12, 2000 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10603375

RESUMO

Group A streptococcal M proteins are type-specific virulence factors that inhibit phagocytosis. We used two M proteins, M5 and Emm22, to analyze the influence of genetic background on the properties of M proteins. Mutant strains, engineered to lack these M proteins, were complemented with genes encoding the homologous or heterologous M protein, and the complemented strains were analyzed for phagocytosis resistance. Neither the M5 nor the Emm22 protein conferred phagocytosis resistance in the heterologous background, but they did do so in the homologous background. This was not due to lack of surface expression in the heterologous background. Moreover, the M5 and Emm22 proteins expressed in heterologous background appeared to have normal structure, since they were not affected in their ability to bind different human plasma proteins. In particular, M5 or Emm22 had normal ability to bind human complement inhibitors, a property that has been implicated in phagocytosis resistance. Results similar to those obtained with M5 and Emm22 were obtained in experiments with the M6 and Emm4 proteins. Together, these data suggest that the surface expression of M protein alone may not be sufficient to confer phagocytosis resistance and consequently that strain-specific factors other than M and Emm proteins may contribute to the ability of group A streptococci to resist phagocytosis.


Assuntos
Antígenos de Bactérias , Proteínas da Membrana Bacteriana Externa , Proteínas de Bactérias/toxicidade , Proteínas de Transporte/toxicidade , Fagocitose/efeitos dos fármacos , Streptococcus pyogenes/patogenicidade , Proteínas de Bactérias/genética , Proteínas de Bactérias/imunologia , Sequência de Bases , Proteínas de Transporte/genética , Proteínas de Transporte/imunologia , Primers do DNA/genética , Humanos , Técnicas In Vitro , Fagocitose/imunologia , Plasmídeos/genética , Engenharia de Proteínas , Ensaio Radioligante , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/toxicidade , Especificidade da Espécie , Streptococcus pyogenes/genética , Streptococcus pyogenes/imunologia , Virulência/genética , Virulência/imunologia
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