RESUMO
AIMS: Multiple sclerosis (MS) is the leading cause of non-traumatic neurological disability in young adults, and its diagnosis is often delayed due to the lack of diagnostic markers. Initiation of disease -modifying therapy in the early stages of MS is especially critical because currently available therapy mostly target relapsing-remitting MS, and is less effective as disease progresses into the more chronic form of secondary-progressive MS. Therefore, exploring specific and sensitive biomarkers will facilitate an expedited and more accurate diagnosis to allow currently available therapies to be more effective. MAIN METHODS: Western blotting was conducted to detect the expression of neurolymphatic proteins in human brain endothelial cells in culture. Additionally, using a cohort of 150 patients with relapsing remitting MS, 26 with secondary progressive MS, and 60 healthy control samples, neurolymphatic protein expression was detected in serum samples using dot blot analysis. KEY FINDINGS: Human brain microvascular endothelial cells express neurolymphatic markers. Neurolymphatic protein abundance increases with tumor necrosis factor (TNF)-α stimulation but decreases with interferon (IFN)- γ or combined (TNFâ¯+â¯IFN) treatment. Circulating neurolymphatic protein levels is significantly lower in MS patients. Further, one of the markers, FOXC2, is associated with the clinical stages of MS, with significantly lower expression in secondary progressive MS compared to relapsing remitting MS. SIGNIFICANCE: Our findings describe brain endothelial expression of neurolymphatic proteins, which is altered under inflammatory stress, and provide a possibility of using a collective pool of circulating neurolymphatic proteins as a diagnostic and prognostic biomarker of MS.
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Biomarcadores/sangue , Encéfalo/metabolismo , Células Endoteliais/metabolismo , Inflamação/sangue , Esclerose Múltipla Crônica Progressiva/sangue , Esclerose Múltipla Recidivante-Remitente/sangue , Esclerose Múltipla/sangue , Adulto , Estudos de Casos e Controles , Células Cultivadas , Células Endoteliais/citologia , Células Endoteliais/imunologia , Endotélio Vascular/citologia , Endotélio Vascular/imunologia , Endotélio Vascular/metabolismo , Feminino , Humanos , Inflamação/diagnóstico , Inflamação/imunologia , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/diagnóstico , Esclerose Múltipla/imunologia , Esclerose Múltipla Crônica Progressiva/diagnóstico , Esclerose Múltipla Crônica Progressiva/imunologia , Esclerose Múltipla Recidivante-Remitente/diagnóstico , Esclerose Múltipla Recidivante-Remitente/imunologiaAssuntos
Endo-1,4-beta-Xilanases/metabolismo , Expressão Gênica , Oligossacarídeos/biossíntese , Rúmen/enzimologia , Animais , Bovinos , Clonagem Molecular , Endo-1,4-beta-Xilanases/genética , Escherichia coli/genética , Prebióticos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMO
Noroviruses (NoVs) are major causal agents of acute gastroenteritis in humans. NoV GII.4 is the predominant genotype globally. However, uncommon and minor types of NoVs are consistently detected and some have been shown to dominate over GII.4. Therefore, the prevalence of dominant and uncommon NoVs makes the identification of these viruses important for the prediction and prevention of pandemics. In this study, the full-genome sequence of a NoV (strain JW) detected in Korea was extensively characterized. The full-length genome was 7510 nucleotides long, and phylogenetic analysis based on the whole-genome sequences, including open reading frame (ORF)1, ORF2, and ORF3, indicated that it belonged to the GII.21 genotype. Strain JW showed maximum identity with strain YO284; however, comparison of the amino acid sequence of ORF2, which functions as an antigen, showed substitutions in several amino acids. GII.21 is not a prevalent epidemiological agent of acute gastroenteritis in humans, but it is consistently found in gastroenteritis patients from several countries. The present study provides the first full-genome sequence analysis of NoV GII.21 isolated from a patient in Korea. Our findings provide not only valuable genome information but also data for epidemiology studies, epidemic prevention, and vaccine development strategies.
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Infecções por Caliciviridae/virologia , Gastroenterite/virologia , Genoma Viral , Genótipo , Norovirus/genética , Proteínas Virais/genética , Sequência de Aminoácidos , Infecções por Caliciviridae/epidemiologia , Gastroenterite/epidemiologia , Filogenia , Prevalência , República da Coreia/epidemiologia , Alinhamento de SequênciaRESUMO
OBJECTIVES: The aim of this study was to explore the phenotypic differences underpinning obesity susceptibility or resistance based on the metabolic and transcriptional profiling of C57BL/6J mice fed a high-fat diet (HFD). METHODS: The mice were fed either a normal diet or HFD for 12 weeks. After 6 weeks, the mice on HFD were classified as either obesity-prone (OP) or obesity-resistant (OR) depending on the body weight gain. RESULTS: Lipid profiles from plasma and liver significantly improved in OR mice relative to the OP group. Energy expenditure was greater in OR mice than in OP mice, with a simultaneous decrease in body fat mass. Epididymal white adipose tissue (eWAT) and liver were enlarged in OP mice (with visible immune-cell infiltration), but these effects were attenuated in OR mice compared with OP mice. Overall glucose metabolism was enhanced in OR mice compared with OP mice, including homeostasis model assessment for insulin resistance, plasma glucose and insulin concentrations, glucokinase activity and hepatic glycogen. Plasma adipokines and proinflammatory cytokines were upregulated in OP mice, and these changes were attenuated in OR mice. Transcriptomic profiles of eWAT and liver revealed common and divergent patterns of transcriptional changes in OP and OR mice, and pointed to differential metabolic phenotypes of OP and OR mice. There were substantial differences between OP and OR mice in molecular pathways, including atherosclerosis signaling, sperm motility, cAMP-mediated signaling in eWAT; and fibrosis, agranulocyte adhesion and diapedesis, and atherosclerosis signaling in liver. CONCLUSIONS: Taken altogether, the results provide robust evidence of major divergence in the transcriptomes, phenotypes and metabolic processes between obesity susceptibility and obesity resistance in the HFD-fed C57BL/6J mice.
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Dieta Hiperlipídica , Predisposição Genética para Doença/genética , Obesidade/genética , Obesidade/metabolismo , Fenótipo , Transcriptoma , Tecido Adiposo Branco/metabolismo , Animais , Doença da Artéria Coronariana/genética , Modelos Animais de Doenças , Metabolismo Energético , Resistência à Insulina/genética , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , RNA Mensageiro/genética , Aumento de PesoRESUMO
AIMS: Salivary amylase gene (AMY1) copy number variations (CNVs) correlate directly with salivary amylase activity and serum amylase levels. Previously, individuals with high AMY1 CNVs exhibited low postprandial glucose levels and postprandial early insulin surge, suggesting that high AMY1 gene copy numbers may play a role in lowering the risk of insulin resistance. METHODS: We verified the relationship between AMY1 CNVs and homeostatic model assessment-insulin resistance (HOMA-IR) in a cohort of 1257 Korean men aged 20-65 years who visited two medical centres for regular health check-ups, and in subgroups of current smokers and regular alcohol drinkers. Individuals with fasting plasma glucose levels > 10.0 mmol/l, HbA1c ≥ 64 mmol/mol (8.0%) or who used oral hypoglycaemic agents or insulin were excluded. RESULTS: AMY1 CNVs correlated negatively with HOMA-IR even after adjusting for covariates (e.g. BMI, systolic blood pressure, triacylglycerol, alcohol consumption, smoking and physical activity). When the participants were divided according to current smoking and alcohol consumption habits, negative correlations between AMY1 CNVs and HOMA-IR were more evident among non-smokers and regular drinkers and were non-significant among smokers and non-regular drinkers. CONCLUSIONS: Low AMY1 CNVs correlated with high insulin resistance in asymptomatic Korean men, and such a relationship presented differently according to the status of smoking and alcohol consumption.
Assuntos
Variações do Número de Cópias de DNA , Diabetes Mellitus Tipo 2/genética , Predisposição Genética para Doença , Resistência à Insulina , Síndrome Metabólica/genética , Modelos Genéticos , alfa-Amilases Salivares/genética , Adulto , Idoso , Consumo de Bebidas Alcoólicas/efeitos adversos , Estudos de Coortes , Diabetes Mellitus Tipo 2/enzimologia , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/etiologia , Dosagem de Genes , Estudos de Associação Genética , Humanos , Masculino , Síndrome Metabólica/enzimologia , Síndrome Metabólica/epidemiologia , Síndrome Metabólica/etiologia , Pessoa de Meia-Idade , República da Coreia/epidemiologia , Fatores de Risco , alfa-Amilases Salivares/metabolismo , Fumar/efeitos adversos , Adulto JovemRESUMO
BACKGROUND: Galectin 1 (GAL1), an animal lectin is well characterized in the context of cancer, tumor environment, but its physiological roles in obesity remain to be demonstrated. In this study, we investigated whether targeted inhibition of GAL1 prevents obesity based on the previous observations that GAL1 is highly expressed in adipose tissues of high-fat diet (HFD)-induced obese rats. METHODS: Lipogenic capacity of Lgals1 knocked down adipocytes was evaluated by determining the expression levels of major lipogenic markers using real-time PCR and immunoblot analysis. GAL1 partner proteins were identified using co-immunoprecipitation followed by protein mass fingerprinting. Finally, inhibitory effect of GAL1 by thiodigalactoside (TDG) was assessed in adipocytes and HFD-induced obese rats. RESULTS: Knockdown of GAL1-encoding gene (Lgals1) attenuated adipogenesis and lipogenesis in both 3T3-L1 and HIB1B adipocytes. Further, direct treatment with TDG, a potent inhibitor of GAL1, to cultured adipocytes in vitro significantly reduced fat accumulation. Our animal experiment revealed that intraperitoneal injection of TDG (5 mg kg(-1)) once per week for 5 weeks in Sprague-Dawley (SD) rats resulted in dramatic inhibition of HFD-induced body weight gain (27.3% reduction compared with HFD-fed controls) by inhibiting adipogenesis and lipogensis as well as by increasing expression of the proteins associated with thermogenesis and energy expenditure. CONCLUSION: GAL1 has an essential role in HFD-induced obesity development. From a clinical viewpoint, pharmaceutical targeting of GAL1 using TDG and other inhibitor compounds would be a novel therapeutic approach for the treatment of obesity.
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Fármacos Antiobesidade/farmacologia , Galectina 1/antagonistas & inibidores , Galectina 1/metabolismo , Obesidade/prevenção & controle , Tiogalactosídeos/farmacologia , Aumento de Peso/efeitos dos fármacos , Células 3T3-L1 , Adipogenia/efeitos dos fármacos , Tecido Adiposo/efeitos dos fármacos , Tecido Adiposo/metabolismo , Animais , Dieta Hiperlipídica , Modelos Animais de Doenças , Immunoblotting , Lipogênese/efeitos dos fármacos , Masculino , Camundongos , Obesidade/etiologia , Obesidade/metabolismo , PPAR gama/metabolismo , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real , Termogênese/efeitos dos fármacosRESUMO
PURPOSE: Raoultella ornithinolytica is not well known as a clinical pathogen. We performed a retrospective review of R. ornithinolytica bacteremia to investigate its clinical features, antimicrobial susceptibility, and overall patient outcomes. METHODS: R. ornithinolytica bacteremia cases were collected from an electronic database of all cases of bacteremia over a 10-year period. Medical records were retrospectively reviewed. Demographic data, clinical information, the presence of underlying comorbidities, the results of antimicrobial susceptibility testing, and the antimicrobial regimen administered were investigated. RESULTS: R. ornithinolytica was isolated from blood culture specimens in 16 cases. The majority of these patients had an underlying malignant condition of advanced stage (15 patients, 94 %). Seven of these patients had a solid tumor with lesions or metastases that extended to the bile duct or biliary tract. Neutropenic fever following hematologic stem cell transplantation was found in three cases. No resistance to piperacillin/tazobactam or imipenem was found. Four cases showed resistance to cefoxitin, while one of these cases showed resistance to multiple cephalosporins. In overall outcomes, seven patients (44 %) did not recover from the infection and subsequently expired. CONCLUSIONS: R. ornithinolytica bacteremia occurs mainly in patients with underlying malignancies. The overall outcome was not favorable, despite favorable antimicrobial susceptibility test results. The findings of this study contradict those of other studies that demonstrated that infection from Raoultella species have good prognoses.
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Bacteriemia/epidemiologia , Infecções por Enterobacteriaceae/epidemiologia , Enterobacteriaceae/efeitos dos fármacos , Adulto , Idoso , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Bacteriemia/diagnóstico , Bacteriemia/tratamento farmacológico , Farmacorresistência Bacteriana , Infecções por Enterobacteriaceae/diagnóstico , Infecções por Enterobacteriaceae/tratamento farmacológico , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , República da Coreia/epidemiologia , Estudos Retrospectivos , Adulto JovemRESUMO
AIM: To provide the observation that hibicuslide C-induced cell death in yeast Candida albicans involves apoptosis mechanism. METHODS AND RESULTS: Hibicuslide C was isolated from Abutilon theophrasti by column chromatography. In reactive oxygen species (ROS) assay, C. albicans treated with hibicuslide C showed increase in ROS, and its accumulation induced fungal cell death. In particular, hydroxyl radicals were a large part of the ROS. Mitochondrial dysfunction including mitochondrial depolarization and release of cytochrome c, which is a pro-apoptotic factor, was detected by JC-1 assay and Western blot. CaspACE FITC-VAD-FMK staining using caspase inhibitor showed metacaspase activation. Also, the increase in intracellular Ca(2+), which is a signal molecule of apoptosis, was detected by Fura-2AM and Rhod-2AM assays. Finally, annexin V-FITC and PI double staining and TUNEL assay confirmed that hibicuslide C induces early apoptosis followed by secondary necrosis in C. albicans. CONCLUSIONS: Hibicuslide C exerts antifungal activity against C. albicans through new mechanism inducing apoptosis. SIGNIFICANCE AND IMPACT OF THE STUDY: Candida albicans is the common cause of nosocomial infections with high mortality. Our findings provide that hibicuslide C can be a model molecule that induces apoptosis in C. albicans.
Assuntos
Apoptose , Candida albicans/efeitos dos fármacos , Fenilpropionatos/farmacologia , Antifúngicos/química , Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Apoptose/efeitos dos fármacos , Cálcio/metabolismo , Candida albicans/metabolismo , Fragmentação do DNA , Malvaceae/química , Mitocôndrias/efeitos dos fármacos , Fenilpropionatos/química , Fenilpropionatos/isolamento & purificação , Espécies Reativas de Oxigênio/metabolismoRESUMO
PURPOSE: Numerous case reports regarding Raoultella planticola infection have accumulated in the literature; however, its significance as a clinical pathogen remains unknown. We performed a retrospective review of R. planticola bacteremia to characterize its clinical features, antimicrobial susceptibility, and patient outcome. METHODS: Raoultella planticola bacteremia cases were culled from an electronic database of all bacteremia cases occurring over a 4-year-period. Medical records were retrospectively reviewed and demographic data, clinical findings, presence of underlying disease, results of antimicrobial susceptibility testing, and the antibiotic regimens administered during the treatment were evaluated. RESULTS: Raoultella planticola was isolated from blood culture specimens in 20 cases. The majority of these patients had underlying malignant conditions (17 patients, 85%). The most prevalent causes of malignancy were adenocarcinoma involving the gallbladder or bile duct (7 patients) and hematologic malignancies (6 patients). No cases with resistance to carbapenem or third generation cephalosporins were found. All 14 patients with R. planticola as the sole microbial isolate recovered with the use of empirical antibiotics. Of the six patients with polymicrobial infection, three did not recover and subsequently expired. CONCLUSIONS: Raoultella planticola bacteremia seemed to occur mainly in immunocompromised patients, and was also frequently found in patients with lesions involving the gallbladder or bile duct. The overall outcome was favorable when R. planticola was treated with administration of empirical antibiotics. Mixed outcomes were found when blood cultures yielded multiple species of microbes.
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Bacteriemia/microbiologia , Infecções por Enterobacteriaceae/imunologia , Infecções por Enterobacteriaceae/microbiologia , Enterobacteriaceae/patogenicidade , Adolescente , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Farmacorresistência Bacteriana Múltipla , Enterobacteriaceae/efeitos dos fármacos , Enterobacteriaceae/isolamento & purificação , Feminino , Humanos , Hospedeiro Imunocomprometido , Masculino , Pessoa de Meia-Idade , República da Coreia/epidemiologia , Estudos Retrospectivos , Virulência , Adulto JovemRESUMO
Despite the fact that gender dimorphism in diet-induced oxidative stress is associated with steroid sex hormones, there are some contradictory results concerning roles of steroid hormones in gender dimorphism. To evaluate the role of gender dimorphism as well as the effects of sex steroid hormones in response to high-fat diet (HFD)-induced oxidative stress, we measured cellular levels of major antioxidant proteins in the liver, abdominal white adipose tissue, and skeletal muscles of Sprague-Dawley rats following HFD or sex hormone treatment using Western blot analysis. Animal experiments revealed that 17ß-estradiol, (E2) and dihydrotestosterone (DHT) negatively and positively affected body weight gain, respectively. Interestingly, plasma levels of malondialdehyde (MDA) increased in both E2- and DHT-treated rats. We also observed that cellular levels of classical antioxidant proteins, including catalase, glutathion peroxidase, peroxiredoxin, superoxide dismutase, and thioredoxin, were differentially regulated hormone- and gender-dependent manner in various metabolic tissues. In addition, tissue-specific expression of DJ-1 protein with respect to HFD-induced oxidative stress in association with sex steroid hormone treatment was observed for the first time. Taken together, our data show that females were more capable at overcoming oxidative stress than males through feasible expression of antioxidant proteins in metabolic tissues. Although the exact regulatory mechanism of sex hormones in diet-induced oxidative stress could not be fully elucidated, the current data will provide clues regarding the tissue-specific roles of antioxidant proteins during HFD-induced oxidative stress in association with sex steroid hormones.
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Estresse Oxidativo/efeitos dos fármacos , Animais , Antioxidantes/farmacologia , Dieta Hiperlipídica , Feminino , Masculino , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio , Caracteres SexuaisRESUMO
OBJECTIVE: The aim of this study was to establish the time-course of molecular events in intrascapular brown adipose tissue (iBAT) during the development of diet-induced obesity using microarrays and molecular network analysis. DESIGN: C57BL/6J male inbred mice were fed a high-fat diet (HFD) or normal diet (ND) and killed at multiple time-points over 24 weeks. METHODS: Global transcriptional changes in iBAT were determined by time-course microarrays of pooled RNA (n=6, pools per time-point) at 2, 4, 8, 20 and 24 weeks using Illumina MouseWG-6 v2.0 Beadchips. Molecular networks were constructed using the Ingenuity knowledgebase based on differentially expressed genes at each time-point. RESULTS: Body weight and subcutaneous adipose were progressively increased over 24 weeks, whereas iBAT was significantly increased between 6 and 12 weeks in HFD-fed C57BL/6J mice compared with controls. Blood glucose and insulin levels were increased between 16 and 24 weeks. Time-course microarrays, revealed 155 differentially expressed genes at one or more time-points over 24 weeks in the iBAT of HFD-fed mice compared with controls. Time-course network analysis revealed a network of skeletal muscle development genes that was activated between 2 and 4 weeks, subsequently a network of immune trafficking genes was activated at 8 weeks. After 20 and 24 weeks, multiple lipid metabolism and immune response networks were activated. Several target genes identified by time-course microarrays were independently validated using RT-qPCR. Tnnc1 was upregulated early between 2 and 4 weeks, later Cd68 and Col1a1 were upregulated between 20 and 24 weeks, whereas 11ß-hydroxysteroid dehydrogenase (Hsd11b1) was consistently downregulated during the development of diet-induced obesity. CONCLUSION: Molecular networks in iBAT are modulated in a time-dependent manner in response to a HFD. A broad range of gene targets exists to alter molecular changes within iBAT during the development of diet-induced obesity.
Assuntos
Imunidade Adaptativa/genética , Tecido Adiposo Marrom/patologia , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Redes Reguladoras de Genes , Metabolismo dos Lipídeos/imunologia , Obesidade/metabolismo , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Tecido Adiposo Marrom/imunologia , Animais , Colágeno Tipo I/metabolismo , Cadeia alfa 1 do Colágeno Tipo I , Dieta Hiperlipídica , Regulação para Baixo , Perfilação da Expressão Gênica , Resistência à Insulina/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Obesidade/etiologia , Obesidade/genética , Obesidade/imunologia , Tenascina/metabolismo , Fatores de Tempo , Regulação para CimaAssuntos
Cistos/patologia , Doenças do Esôfago/patologia , Esôfago/patologia , Cistos/diagnóstico por imagem , Cistos/cirurgia , Diagnóstico Diferencial , Duodenoscopia , Endossonografia , Epitélio/patologia , Doenças do Esôfago/diagnóstico por imagem , Doenças do Esôfago/cirurgia , Esofagoscopia , Gastroscopia , Humanos , Tecido Linfoide/patologia , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: It is unknown whether microalbuminuria is associated with non-alcoholic fatty liver disease (NAFLD) among patients with prediabetes and type 2 diabetes mellitus (DM). This study investigated the association of NAFLD with microalbuminuria among patients with prediabetes and diabetes. METHODS: We evaluated 1361 subjects who had an abnormal oral glucose tolerance test (OGTT) on routine screening. All participants were divided into two groups, prediabetes and newly diagnosed type 2 DM, and the association of NAFLD with metabolic parameters on microalbuminuria was analysed. RESULTS: The patients with NAFLD had higher prevalence rates of microalbuminuria (6.3% vs 19%; P = 0.001 in prediabetes, 4.5% vs 32.6%; P < 0.001 in diabetes) and also had a greater albumin-to-creatinine ratio (14.6 +/- 52.0 microg/mg Cr vs 27.7 +/- 63.9 microg/mg Cr; P = 0.051 in prediabetes, 11.4 +/- 21.4 microg/mg Cr vs 44.7 +/- 76.4 microg/mg Cr; P < 0.001 in diabetes) than those without NAFLD. The logistic regression analysis showed that NAFLD was associated with increased rates of microalbuminuria (odds ratio 3.66; 95%confidence interval (CI) 1.31-10.20, P = 0.013 in prediabetes, odds ratio 5.47;95% CI 1.01-29.61, P = 0.048 in diabetes), independently of age, sex, body mass index, waist circumference, liver enzymes, lipid profiles, HbA1c, insulin resistance as estimated by homeostasis model assessment, hypertension,smoking status and the metabolic syndrome. CONCLUSIONS: The results of our study revealed a strong relationship between microalbuminuria and NAFLD in the patients with prediabetes and newly diagnosed diabetes. Further studies are required to confirm whether NAFLD is a predictor of the development of microalbuminuria in patients with prediabetes and diabetes.
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Albuminúria/epidemiologia , Diabetes Mellitus Tipo 2/epidemiologia , Fígado Gorduroso/epidemiologia , Estado Pré-Diabético/epidemiologia , Adulto , Albuminúria/diagnóstico , Albuminúria/etiologia , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/diagnóstico , Fígado Gorduroso/complicações , Fígado Gorduroso/diagnóstico , Feminino , Teste de Tolerância a Glucose/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Estado Pré-Diabético/complicações , Estado Pré-Diabético/diagnósticoRESUMO
AIMS: The present study comparatively investigates the optimal culture conditions for the production of exopolysaccharides (EPS) and cordycepin during submerged mycelial culture of two entomopathogenic fungi Cordyceps militaris and Cordyceps sinensis. METHODS AND RESULTS: Fermentations were performed in flasks and in 5-l stirred-tank fermenters. In the case of C. militaris, the highest mycelial biomass (22.9 g l(-1)) and EPS production (5 g l(-1)) were achieved in a medium of 40 g l(-1) sucrose, 5 g l(-1) corn steep powder at 30 degrees C, and an initial pH 8.0. The optimum culture conditions for C. sinensis was shown to be (in g l(-1)) 20 sucrose, 25 corn steep powder, 0.78 CaCl2, 1.73 MgSO4.7H2O at 20 degrees C, and an initial pH 4.0, where the maximum mycelial biomass and EPS were 20.9 and 4.1 g l(-1) respectively. Cordycepin, another bioactive metabolite, was excreted at low levels during the early fermentation period (maximum 38.8 mg l(-1) in C. militaris; 18.2 mg l(-1) in C. sinensis). CONCLUSIONS: The two fungi showed different nutritional and environmental requirements in their submerged cultures. Overall, the concentrations of mycelial biomass, EPS and cordycepin achieved in submerged culture of C. militaris were higher than those of C. sinensis. SIGNIFICANCE AND IMPACT OF THE STUDY: C. militaris and C. sinensis are representative insect-born fungi which have been longstanding and widely used as traditional medicines in eastern Asia. Comparative studies between two fungi are currently not available and this is the first report on the optimum medium composition for submerged culture of C. sinensis.
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Cordyceps/metabolismo , Polissacarídeos/biossíntese , Antifúngicos/metabolismo , Biomassa , Carbono/metabolismo , Cromatografia em Gel/métodos , Meios de Cultura , Desoxiadenosinas/biossíntese , Eletroforese Capilar/métodos , Fermentação , Concentração de Íons de Hidrogênio , Micélio/metabolismo , Nitrogênio/metabolismo , TemperaturaRESUMO
The optimization of submerged culture conditions and nutritional requirements was studied for the production of exopolysaccharide (EPS) from Agrocybe cylindracea ASI-9002 using the statistically based experimental design in a shake flask culture. Both maximum mycelial biomass and EPS were observed at 25 degrees C. The optimal initial pH for the production of mycelial biomass and EPS were found to be pH 4.0 and pH 6.0, respectively. Subsequently, optimum concentration of each medium component was determined using the orthogonal matrix method. The optimal combination of the media constituents for mycelial growth was as follows: maltose 80 g/l, Martone A-1 6 g/l, MgSO4 x 7H2O 1.4 g/l, and CaCl2 1.1 g/l; for EPS production: maltose 60 g/l, Martone A-1 6 g/l, MgSO4 x 7H2O 0.9 g/l, and CaCl2 1.1 g/l. Under the optimal culture condition, the maximum EPS concentration achieved in a 5-l stirred-tank bioreactor indicated 3.0 g/l, which is about three times higher than that at the basal medium.
Assuntos
Agaricales/crescimento & desenvolvimento , Biomassa , Reatores Biológicos , Micélio/crescimento & desenvolvimento , Polissacarídeos/biossíntese , Agricultura/métodos , Técnicas de Cultura , Concentração de Íons de HidrogênioRESUMO
AIMS: The objective of this work was to investigate the morphological and rheological properties in submerged culture of the three different basidiomycetes Phellinus (P. baumii, P. gilvus and P. linteus) that produce pharmacologically important exopolysaccharides (EPS). METHODS AND RESULTS: In flask cultures, pH proved to be a critical factor affecting mycelial growth, morphological change and EPS production. The macroscopic morphologies observed under different pHs in flask cultures were also comparable: i.e. starfish-like pellets with a lesser extent of free mycelium appeared in P. baumii, whereas smooth pellets with higher amounts of free mycelium were observed in P. gilvus and P. linteus. The pelleted fermentations were further characterized in a 5-l stirred-tank fermenter by image analysis with respect to mean diameter, core area and pellet circularity. Phellinus baumii showed the largest pellet size (5.2 mm in diameter), whereas P. linteus had extremely small and spherical pellets. The culture broth of P. baumii and P. gilvus yielded extremely high apparent viscosities, ranging from 5 to 7 Pa s. CONCLUSIONS: Three important species of Phellinus showed significantly different morphological and rheological properties. The morphological variation of the three Phellinus species was closely linked to EPS productivity and the apparent viscosity of the whole broth. SIGNIFICANCE AND IMPACT OF THE STUDY: The morphological change in the three species of Phellinus was a good indicator for identifying cell activity for EPS production. Our finding may be beneficial for further optimization of other fungal fermentation processes for large-scale production of EPS.