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1.
J Public Health (Oxf) ; 45(4): e746-e754, 2023 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-37580870

RESUMO

BACKGROUND: CenteringPregnancy (CP) has been expected to produce beneficial outcomes for women and their infants. However, previous studies paid little attention to testing variations in CP's effects across women from different demographic groups. This study aimed to test how multiple demographic factors (obesity, race, ethnicity, marital status and socioeconomic status) moderate CP's effects on health outcomes. METHODS: This study employed a quasi-experimental design. De-identified hospital birth data were collected from 216 CP participants and 1159 non-CP participants. We estimated the average treatment effect of CP on outcome variables as a baseline. Then we estimated the average marginal effect of CP by adding each of the moderating variables in regression adjustment models. RESULTS: CP produced salutary effects among those who were obese or overweight and unmarried as well as women with lower socioeconomic status. These salutary effects were also strengthened as maternal age increased. However, CP was ineffective for Hispanic/Latinx women. CONCLUSIONS: CP produced more beneficial health outcomes for high-risk women such as obese, unmarried women and those with lower socioeconomic status. These are meaningful findings from a public health perspective.


Assuntos
Resultado da Gravidez , Cuidado Pré-Natal , Gravidez , Feminino , Humanos , Lactente , Resultado da Gravidez/epidemiologia , Saúde do Lactente , Idade Materna , Obesidade/epidemiologia
2.
PLoS One ; 18(7): e0288188, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37498894

RESUMO

Evolving US media and political systems, coupled with escalating misinformation campaigns, have left the public divided over objective facts featured in policy debates. The public also has lost much of its confidence in the institutions designed to adjudicate those epistemic debates. To counter this threat, civic entrepreneurs have devised institutional reforms to revitalize democratic policymaking. One promising intervention is the Citizens' Initiative Review (CIR), which has been adopted into law in Oregon and tested in several other states, as well as Switzerland and Finland. Each CIR gathers a demographically stratified random sample of registered voters to form a deliberative panel, which hears from pro and con advocates and neutral experts while assessing the merits of a ballot measure. After four-to-five days of deliberation, each CIR writes an issue guide for voters that identifies key factual findings, along with the most important pro and con arguments. This study pools the results of survey experiments conducted on thirteen CIRs held from 2010 to 2018, resulting in a dataset that includes 67,120 knowledge scores collected from 10,872 registered voters exposed to 82 empirical claims. Analysis shows that reading the CIR guide had a positive effect on voters' policy knowledge, with stronger effects for those holding greater faith in deliberation. We found little evidence of directional motivated reasoning but some evidence that reading the CIR statement can spark an accuracy motivation. Overall, the main results show how trust in peer deliberation provides one path out of the maze of misinformation shaping voter decisions during elections.


Assuntos
Participação da Comunidade , Tomada de Decisões , Humanos , Participação da Comunidade/métodos , Formulação de Políticas , Resolução de Problemas , Dissidências e Disputas
3.
Neurosci Lett ; 644: 87-93, 2017 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-28237800

RESUMO

The conversion of α-synuclein from its natively unfolded and α-helical tetrameric forms to an amyloid conformation is central to the emergence of Parkinson's disease. Therefore, prevention of this conversion may offer an effective way of avoiding the onset of this disease or delaying its progress. At different concentrations, an aqueous extract from the edible winged kelp (Alaria esculenta), was shown to lower and to raise the melting point of α-synuclein. Size fractionation of the extract resulted in the separation of these distinct activities. The fraction below 5kDa decreased the melting point of α-synuclein, whereas the fraction above 10kDa raised the melting point. Both of these fractions were found to inhibit the formation of amyloid aggregates by α-synuclein, measured by thioflavin T dye-binding assays; this effect was further confirmed by transmission electron microscopy showing the inhibition of fibril formation. Circular dichroism analysis suggested that the incubation of α-synuclein under fibrillation conditions resulted in the loss of substantial native helical structure in the presence and absence of the fractions. It is therefore likely that the fractions inhibit fibrillation by interacting with the unfolded form of α-synuclein.


Assuntos
Amiloide/efeitos dos fármacos , Extratos Vegetais/farmacologia , Dobramento de Proteína/efeitos dos fármacos , Alga Marinha , alfa-Sinucleína/efeitos dos fármacos , Amiloide/química , Humanos , alfa-Sinucleína/química
4.
Biochim Biophys Acta ; 1830(1): 2129-38, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23032861

RESUMO

BACKGROUND: An Atlantic salmon (Salmo salar) C-type lectin (SSL) binds to mannose and related sugars as well as to the surface of Aeromonas salmonicida. To characterize this lectin as a pathogen recognition receptor in salmon, aspects of its interaction with molecules and with intact pathogens were investigated. METHODS: SSL was isolated using whole-yeast-affinity and mannan-affinity chromatography. The binding of SSL to the two major surface molecules of A. salmonicida, lipopolysaccharide (LPS) and A-layer protein was investigated by western blotting and enzyme-linked immunosorbent assays. Microbial binding specificity of SSL was examined by whole cell binding assays using a range of species. Carbohydrate ligand specificity of SSL was examined using glycan array analysis and frontal affinity chromatography. RESULTS: SSL showed binding to bacteria and yeast including, Pseudomonas fluorescens, A. salmonicida, A. hydrophila, Pichia pastoris, and Saccharomyces cerevisiae, but there was no detectable binding to Yersinia ruckeri. In antimicrobial assays, SSL showed no activity against Escherichia coli, Bacillus subtilis, S. cerevisiae, or A. salmonicida, but it was found to agglutinate E. coli. The major surface molecule of A. salmonicida recognized by SSL was shown to be LPS and not the A-layer protein. LPS binding was mannose-inhibitable. Glycans containing N-acetylglucosamine were shown to be predominant ligands. CONCLUSION: SSL has a distinct ligand preference while allowing recognition of a wide variety of related carbohydrate structures. GENERAL SIGNIFICANCE: SSL is likely to function as a wide-spectrum pattern recognition protein.


Assuntos
Bactérias/química , Proteínas de Peixes/química , Lectinas Tipo C/química , Lipopolissacarídeos/química , Salmo salar , Animais , Bactérias/metabolismo , Proteínas de Peixes/metabolismo , Furunculose/metabolismo , Lectinas Tipo C/metabolismo , Lipopolissacarídeos/metabolismo , Pichia/química , Pichia/metabolismo , Ligação Proteica , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/metabolismo
5.
Biochim Biophys Acta ; 1814(2): 283-9, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21109028

RESUMO

The Atlantic salmon (Salmo salar) serum lectin (SSL) is a C-type lectin that binds to bacteria including salmon pathogens. SSL has been shown to be oligomeric in salmon serum and it displays a stoichiometric band-laddering pattern when analyzed by SDS-PAGE under non-reducing conditions. In this study, a model was generated for SSL isoform 2 in silico in order to identify cysteines that are available to form intermolecular disulfide bonds facilitating oligomerization. Then, recombinant SSL was expressed in E. coli and mutants were produced at positions Cys72 and Cys149. The SSL preparations were purified by metal-affinity chromatography and shown to be functional by carbohydrate-affinity chromatography. The recombinant SSL formed oligomers, which were evident by non-reducing covalent cross-linking and non-reducing SDS-PAGE; however, the band patterns were different for the mutants, with the maximal and predominant multimer sizes distinct from the wild-type recombinant lectin. Further examination of oligomerization by size exclusion chromatography revealed a subunit number from 35 to at least 110 for the wild-type recombinant SSL and subunit numbers below 9 for each mutant SSL oligomer. Thus, both cysteines were found to contribute to oligomerization of SSL.


Assuntos
Proteínas de Peixes/sangue , Proteínas de Peixes/química , Lectinas Tipo C/sangue , Lectinas Tipo C/química , Salmo salar/sangue , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Sequência de Bases , Cromatografia de Afinidade , Reagentes de Ligações Cruzadas , Cistina/química , Primers do DNA/genética , Eletroforese em Gel de Poliacrilamida , Escherichia coli/genética , Proteínas de Peixes/genética , Imunidade Inata , Lectinas Tipo C/genética , Modelos Moleculares , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Dobramento de Proteína , Multimerização Proteica , Estrutura Quaternária de Proteína , Subunidades Proteicas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Salmo salar/genética , Salmo salar/imunologia , Homologia de Sequência de Aminoácidos , Homologia Estrutural de Proteína
6.
Mar Biotechnol (NY) ; 12(6): 650-63, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20107851

RESUMO

Rainbow smelt (Osmerus mordax) are freeze-resistant fish that accumulate glycerol and produce an antifreeze protein during winter. Quantitative reverse transcription PCR (qPCR) and subtractive hybridization studies have previously revealed five genes in rainbow smelt liver to be differentially regulated in winter in comparison with the fall when water temperatures are warmer. In order to further define the suite of processes that are regulated seasonally, we undertook a large-scale analysis of gene expression by hybridization of smelt cDNA to the salmonid 16K cGRASP microarray. In total, 69 genes were identified as up-regulated and 14 genes as down-regulated under winter conditions. A subset of these genes was examined for differential regulation by qPCR in the individual cDNA samples that were pooled for microarray analysis. Ten of the 15 genes tested showed significant change in the same direction as microarray results, whereas one showed significant change in the opposite direction. Fructose-bisphosphate aldolase B and the cytosolic NAD-dependent glycerol-3-phosphate dehydrogenase were among the most highly up-regulated genes, a result supporting a metabolic focus on glycerol synthesis during winter. Modulation of other processes, including endoplasmic reticulum stress, lipid metabolism and transport, and protein synthesis, was also suggested by the qPCR analysis of array-identified genes. The 15 genes were subsequently examined by qPCR for seasonal variation in expression over five sampling times between October and March, and ten showed significant variation in expression over the sampling period. Taken together, these results provide new understanding of the biochemical adaptations of vertebrates to an extremely low seasonal temperature.


Assuntos
Proteínas de Peixes/genética , Regulação da Expressão Gênica , Fígado/metabolismo , Osmeriformes/genética , Adaptação Fisiológica/genética , Animais , Proteínas Anticongelantes/genética , Proteínas Anticongelantes/metabolismo , Temperatura Baixa , Proteínas de Peixes/metabolismo , Perfilação da Expressão Gênica , Análise de Sequência com Séries de Oligonucleotídeos , Osmeriformes/metabolismo , Reação em Cadeia da Polimerase , RNA Mensageiro/metabolismo , Estações do Ano
7.
Mar Environ Res ; 68(1): 37-47, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19443023

RESUMO

Cellular defence against accumulation of toxic xenobiotics includes metabolism by phase I and II enzymes and export of toxicants and their metabolites via ATP-binding cassette (ABC) transporters. Liver gene expression of representatives of these three protein groups was examined in a population of multixenobiotic-resistant killifish (Fundulus heteroclitus) from the Sydney Tar Ponds, Nova Scotia, Canada. The Tar Ponds are heavily polluted with polycyclic aromatic hydrocarbons, polychlorinated biphenyls and heavy metals. The relationship among ABC transporters ABCB1, ABCB11, ABCC2, ABCG2, phase I enzyme cytochrome P4501A1 (CYP1A1) and phase II enzyme glutathione-S-transferase (GST-mu) was investigated by quantifying hepatic transcript abundance. In Tar Pond killifish, hepatic mRNA expression levels of ABCC2, ABCG2, CYP1A1 and GST-mu were elevated compared to reference sites, suggesting that hydrophobic contaminants undergo phase I and II metabolism and are then excreted into the bile of these fish. Hepatic ABCB1 and ABCB11 mRNA were not up-regulated in Tar Pond fish compared to two reference sites, indicating that these two proteins are not involved in conferring multixenobiotic resistance to Tar Pond killifish. The results suggest instead that liver up-regulation of phase I and II enzymes and complementary ABC transporters ABCC2 and ABCG2 may confer contaminant resistance to Tar Pond fish.


Assuntos
Transportadores de Cassetes de Ligação de ATP/metabolismo , Citocromo P-450 CYP1A1/metabolismo , Fundulidae/metabolismo , Glutationa Transferase/metabolismo , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Transportadores de Cassetes de Ligação de ATP/genética , Animais , Citocromo P-450 CYP1A1/genética , Resistência a Múltiplos Medicamentos/genética , Monitoramento Ambiental , Fundulidae/genética , Expressão Gênica , Sedimentos Geológicos/análise , Glutationa Transferase/genética , Inativação Metabólica/genética , Fígado/enzimologia , Proteína 2 Associada à Farmacorresistência Múltipla , Proteínas Associadas à Resistência a Múltiplos Medicamentos/genética , Nova Escócia , Bifenilos Policlorados/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Regulação para Cima , Poluentes Químicos da Água/metabolismo , Xenobióticos/metabolismo
8.
Gene ; 424(1-2): 56-62, 2008 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-18761395

RESUMO

The rainbow smelt (Osmerus mordax) is freeze-resistant and maintains swimming and feeding activity during winter. In order to identify genes differentially expressed in smelt liver response to winter water temperatures, a large-scale analysis of gene expression using suppression subtractive hybridization was carried out using samples obtained in fall and winter. Forward and reverse subtractions were performed, subtraction-enriched products were cloned, and clones were sequenced from both of the resulting libraries. When 27 of these genes were screened by semi-quantitative RT-PCR to identify candidates for differential expression based generally on 2-fold changes in expression, one encoding FK506-binding protein 5 was classified as up-regulated in response to seasonal change, another encoding the mitochondrial solute carrier 25 member 25 (ATP-Mg/Pi carrier) was similarly classified with seasonal change and low temperature shift, and the one encoding the 78 kDa glucose-regulated protein was provisionally classified as down-regulated with low temperature shift. Analysis of fall (warm) and winter (cold) seasonal samples by quantitative PCR (qPCR) revealed significant up-regulation of genes encoding FK506-binding protein 51 and the mitochondrial solute carrier, whereas the gene encoding the glucose-regulated protein showed no significant change in expression. The mitochondrial solute carrier and FK506-binding protein results may relate to changes in cortisol action, as both are regulated by cortisol in other species.


Assuntos
Etiquetas de Sequências Expressas , Regulação da Expressão Gênica/fisiologia , Osmeriformes/genética , Estações do Ano , Aclimatação , Sequência de Aminoácidos , Animais , Clonagem Molecular , Clima Frio , Enzimas/genética , Enzimas/metabolismo , Masculino , Chaperonas Moleculares/genética , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Reação em Cadeia da Polimerase , Proteínas/genética , Proteínas/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos , Proteínas de Ligação a Tacrolimo/genética
9.
Dev Comp Immunol ; 32(4): 380-90, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-17825909

RESUMO

Aeromonas salmonicida is a fish pathogen that causes furunculosis. Virulent strains of this bacterium are able to infect salmonid macrophages and survive within them, although mechanisms favouring intracellular survival are not completely understood. It is known that A. salmonicida cultured in vivo in the peritoneal cavity of the host undergoes changes in gene expression and surface architecture compared with cultures grown in vitro in broth. Therefore, in this study, the early macrophage responses to A. salmonicida grown in vivo and in vitro were compared. Macrophage-enriched cell preparations from head kidney of Atlantic salmon (Salmo salar) were infected in vitro in 96-well microtitre dishes and changes in gene expression during the infection process were monitored using a custom Atlantic salmon cDNA microarray. A. salmonicida cultures grown in tryptic soy broth and in peritoneal implants were used to infect the macrophages. The macrophages were harvested at 0.5, 1.0 and 2.0h after addition of the bacteria to the medium. Significant changes in gene expression were evident by microarray analysis at 2.0h post-infection in macrophages infected with broth-grown and implant-grown bacteria; however, qPCR analysis revealed earlier up-regulation of JunB and TNF-alpha in macrophages exposed to the implant-grown bacteria. Up-regulation of those genes and others is consistent with the effects of extracellular products of aeromonad bacteria on macrophages and also suggests initiation of the innate immune response.


Assuntos
Aeromonas salmonicida/crescimento & desenvolvimento , Aeromonas salmonicida/imunologia , Macrófagos/imunologia , Salmo salar/imunologia , Salmo salar/microbiologia , Animais , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Macrófagos/metabolismo , Macrófagos/microbiologia , Análise de Sequência com Séries de Oligonucleotídeos , Fagocitose , Salmo salar/genética , Salmo salar/metabolismo
10.
Physiol Biochem Zool ; 79(2): 411-23, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16555199

RESUMO

In winter, rainbow smelt (Osmerus mordax) accumulate glycerol and produce an antifreeze protein (AFP), which both contribute to freeze resistance. The role of differential gene expression in the seasonal pattern of these adaptations was investigated. First, cDNAs encoding smelt and Atlantic salmon (Salmo salar) phosphoenolpyruvate carboxykinase (PEPCK) and smelt glyceraldehyde-3-phosphate dehydrogenase (GAPDH) were cloned so that all sequences required for expression analysis would be available. Using quantitative PCR, expression of beta actin in rainbow smelt liver was compared with that of GAPDH in order to determine its validity as a reference gene. Then, levels of glycerol-3-phosphate dehydrogenase (GPDH), PEPCK, and AFP relative to beta actin were measured in smelt liver over a fall-winter-spring interval. Levels of GPDH mRNA increased in the fall just before plasma glycerol accumulation, implying a driving role in glycerol synthesis. GPDH mRNA levels then declined during winter, well in advance of serum glycerol, suggesting the possibility of GPDH enzyme or glycerol conservation in smelt during the winter months. PEPCK mRNA levels rose in parallel with serum glycerol in the fall, consistent with an increasing requirement for amino acids as metabolic precursors, remained elevated for much of the winter, and then declined in advance of the decline in plasma glycerol. AFP mRNA was elevated at the onset of fall sampling in October and remained elevated until April, implying separate regulation from GPDH and PEPCK. Thus, winter freezing point depression in smelt appears to result from a seasonal cycle of GPDH gene expression, with an ensuing increase in the expression of PEPCK, and a similar but independent cycle of AFP gene expression.


Assuntos
Proteínas Anticongelantes/genética , Regulação da Expressão Gênica , Glicerolfosfato Desidrogenase/genética , Osmeriformes/genética , Osmeriformes/metabolismo , Fosfoenolpiruvato Carboxiquinase (GTP)/genética , Estações do Ano , Sequência de Aminoácidos , Animais , Proteínas Anticongelantes/metabolismo , Sequência de Bases , DNA Complementar , Feminino , Congelamento , Glicerolfosfato Desidrogenase/química , Glicerolfosfato Desidrogenase/metabolismo , Masculino , Dados de Sequência Molecular , Fosfoenolpiruvato Carboxiquinase (GTP)/química , Fosfoenolpiruvato Carboxiquinase (GTP)/metabolismo
11.
Biochim Biophys Acta ; 1730(3): 245-52, 2005 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-16081168

RESUMO

A putative facilitative glucose transporter, GLUT3, cDNA was cloned from Atlantic cod. It is ubiquitously expressed, with substantial levels in kidney. The 519 aa protein has the highest sequence identity (66.3%) to grass carp GLUT3. Atlantic cod were exposed to a hypoxic challenge (45% DO2) for 24 h and the effects on GLUT1 and GLUT3 expression assessed. GLUT1 expression in gill is upregulated; however, in spleen, there is a significant decrease in both GLUT1 and GLUT3 expression. The increase in GLUT1 mRNA is considered to be associated with an increased energy demand on gill, whereas, the decrease in gene expression in spleen potentially reflects a general decrease in rates of transcription.


Assuntos
Clonagem Molecular , DNA Complementar , Gadus morhua/genética , Hipóxia/metabolismo , Proteínas de Transporte de Monossacarídeos/metabolismo , Proteínas do Tecido Nervoso , Regiões 3' não Traduzidas , Regiões 5' não Traduzidas , Sequência de Aminoácidos , Animais , Sequência de Bases , DNA Complementar/genética , Transportador de Glucose Tipo 1 , Transportador de Glucose Tipo 3 , Dados de Sequência Molecular , Proteínas de Transporte de Monossacarídeos/química , Proteínas de Transporte de Monossacarídeos/genética , Proteínas do Tecido Nervoso/química , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Fases de Leitura Aberta , Filogenia , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos , Distribuição Tecidual
12.
Dev Comp Immunol ; 29(4): 333-47, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-15859237

RESUMO

The response of Atlantic salmon, Salmo salar, to infection by the bacterial pathogen Aeromonas salmonicida (the causative agent of furunculosis), was investigated using a cohabitation model and a custom Atlantic salmon cDNA microarray consisting of over 4000 different amplicons. Pooled samples of each of three immune-relevant tissues (spleen, head kidney and liver) were obtained from fish exposed to infected salmon for 13 days. Reverse transcription-PCR assays were used to verify the differential expression of 12 candidate genes uncovered by microarray analysis. Among the differentially expressed genes were several previously revealed by suppression subtractive hybridization and EST surveys and that are recognized to encode humoral components of the innate immune system. Other genes identified in this study were not previously associated with infection. In addition, a number of genes with no known homologs were uncovered. Determination of their specific roles during infection may lead to a better understanding of innate immunity.


Assuntos
Furunculose/metabolismo , Salmo salar/genética , Salmo salar/microbiologia , Aeromonas salmonicida , Animais , DNA Complementar , Regulação da Expressão Gênica/fisiologia , Análise de Sequência com Séries de Oligonucleotídeos , Especificidade de Órgãos , Salmo salar/metabolismo
13.
Immunogenetics ; 56(8): 572-84, 2004 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-15490154

RESUMO

The diverse receptors of the C-type lectin superfamily play key roles in innate immunity. In mammals, cell surface receptors with C-type lectin domains are involved in pathogen recognition and in immune response, and in some cases are exploited by pathogens to gain entry into cells. This study reports on sequence and expression analysis of three paralogous group II C-type lectins from the teleost fish Atlantic salmon (Salmo salar). Each of the receptors showed similarity to immune-relevant mammalian receptors in terms of amino acid sequence and overall organization within the C-type lectin-like domain (CTLD). Two of the three have cytoplasmic motifs consistent with the immunoreceptor tyrosine-based activation motifs (ITAM), which are known to modulate downstream functions in leukocytes. All three C-type lectin receptors were expressed in multiple tissues of healthy fish, including peripheral blood leukocytes and salmon head kidney cells (SHK-1). Each receptor was up-regulated in salmon liver in response to infection by Aeromonas salmonicida and one receptor was substantially up-regulated in cultured SHK-1 cells in response to lipopolysaccharide (LPS). Putative binding sites for the CAAT-enhancer-binding protein (C/EBP) family of transcription factors in the regulatory regions of these C-type lectin genes may mediate their response to bacteria and LPS in salmon leukocytes. The identification of these types of receptors in distinct populations of cells within the immune system will provide important markers for identifying and categorizing the state of differentiation or activation of these cells and lead to further understanding of the interaction between the salmon host and multiple pathogens.


Assuntos
Lectinas Tipo C/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Sítios de Ligação , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Clonagem Molecular , Lectinas Tipo C/química , Dados de Sequência Molecular , Regiões Promotoras Genéticas , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Salmo salar
14.
Fish Shellfish Immunol ; 17(4): 315-23, 2004 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15312658

RESUMO

A C-type lectin was previously isolated from the blood of healthy Atlantic salmon (Salmo salar) and this salmon serum lectin (SSL) was found to opsonise bacteria. Selective binding to bacteria in vivo requires that the lectin be able to recognise a carbohydrate pattern on the bacterial surface distinguishable from that of the host. In order to investigate this selectivity in the lectin, a phage-display antibody was prepared and then used for detection of lectin by Western blotting. A carbohydrate binding-inhibition assay with Western blot detection of the lectin showed mannose to be the primary ligand and related sugars including glucose, N-acetylglucosamine and methyl alpha-D-mannopyranoside to be additional ligands of this lectin. The SSL in serum detected by Western blotting was shown to form a complex oligomer. These results show that the salmon serum lectin is oligomeric in blood and that it recognizes a broad spectrum of carbohydrates with optimal binding to mannose. The lectin might therefore be an ideal opsonin for multiple salmon pathogens with carbohydrate arrays on their surfaces. No similar lectins were identified in the sera of other fish by Western blotting using the phage-display antibody. Molecular analysis will be required in order to determine whether homologous lectins are expressed in related fish species. It is anticipated that similar lectins might have related pathogen recognition roles in divergent fish species.


Assuntos
Lectinas Tipo C/metabolismo , Manose/metabolismo , Salmo salar/metabolismo , Análise de Variância , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/metabolismo , Western Blotting , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Lectinas Tipo C/sangue , Proteínas Opsonizantes/imunologia , Proteínas Opsonizantes/metabolismo , Biblioteca de Peptídeos , Salmo salar/imunologia
15.
J Exp Biol ; 205(Pt 10): 1419-27, 2002 May.
Artigo em Inglês | MEDLINE | ID: mdl-11976353

RESUMO

Smelt (Osmerus mordax) were maintained at either ambient water temperature or approximately 5 degrees C and various aspects of their freeze-avoidance response were examined from early winter until early spring. Plasma levels of glycerol, trimethylamine oxide (TMAO) and urea were elevated by December 15 and continued to increase in fish held in ambient conditions. In contrast, fish held under warm conditions exhibited decreased glycerol and urea content in plasma, muscle and liver. Plasma and liver TMAO levels also decreased in these fish while muscle TMAO did not vary from the initial values. The activity of liver enzymes involved with the production of glycerol did not differ significantly between groups and had decreased by the end of the study. Antifreeze protein (AFP) expression increased over the duration of the experiment. In January samples, AFP activity (thermal hysteresis) did not vary significantly between groups but mRNA levels were significantly lower in the smelt held at warm temperatures.


Assuntos
Aclimatação/fisiologia , Glicerol/sangue , Metilaminas/sangue , Salmoniformes/fisiologia , Ureia/sangue , Animais , Temperatura Corporal , Congelamento , Fígado/metabolismo , Concentração Osmolar , Estações do Ano , Temperatura
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