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Osteoporosis is frequently found in chronic diabetic patients, and it results in an increased risk of bone fractures occurring. The underlying mechanism of osteoporosis in diabetic patients is still largely unknown. Annexin A2 (ANXA2), a family of calcium-binding proteins, has been reported to be involved in many biological process including bone remodeling. This study aimed to investigate the role of ANXA2 in mesenchymal stem cells (MSCs) during in vitro osteoinduction under high-glucose concentrations. Osteogenic gene expression, calcium deposition, and cellular senescence were determined. The high-glucose conditions reduced the osteogenic differentiation potential of the MSCs along with the lower expression of ANXA2. Moreover, the high-glucose conditions increased the cellular senescence of the MSCs as determined by senescence-associated ß-galactosidase staining and the expression of p16, p21, and p53 genes. The addition of recombinant ANXA2 could recover the glucose-induced deterioration of the osteogenic differentiation of the MSCs and ameliorate the glucose-induced cellular senescence of the MSCs. A Western blot analysis revealed an increase in p53 and phosphorylated p53 (Ser 15), which was decreased by recombinant ANXA2 in MSC osteoblastic differentiation under high-glucose conditions. Our study suggested that the alteration of ANXA2 in high-glucose conditions may be one of the plausible factors in the deterioration of bones in diabetic patients by triggering cellular senescence.
Assuntos
Anexina A2 , Células-Tronco Mesenquimais , Osteoporose , Humanos , Osteogênese/genética , Anexina A2/genética , Anexina A2/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Cálcio/metabolismo , Células-Tronco Mesenquimais/metabolismo , Diferenciação Celular , Senescência Celular/genética , Osteoporose/metabolismo , Glucose/farmacologia , Glucose/metabolismo , beta-Galactosidase/metabolismo , Células CultivadasRESUMO
Hepatitis C virus (HCV) is one of the major causes of liver disease affecting an estimated 170 million people culminating in 300,000 deaths from cirrhosis or liver cancer. NS5B is one of three potential therapeutic targets against HCV (i.e., the other two being NS3/4A and NS5A) that is central to viral replication. In this study, we developed a classification structure-activity relationship (CSAR) model for identifying substructures giving rise to anti-HCV activities among a set of 578 non-redundant compounds. NS5B inhibitors were described by a set of 12 fingerprint descriptors and predictive models were constructed from 100 independent data splits using the random forest algorithm. The modelability (MODI index) of the data set was determined to be robust with a value of 0.88 exceeding established threshold of 0.65. The predictive performance was deduced by the accuracy, sensitivity, specificity, and Matthews correlation coefficient, which was found to be statistically robust (i.e., the former three parameters afforded values in excess of 0.8 while the latter statistical parameter provided a value >0.7). An in-depth analysis of the top 20 important descriptors revealed that aromatic ring and alkyl side chains are important for NS5B inhibition. Finally, the predictive model is deployed as a publicly accessible HCVpred web server (available at http://codes.bio/hcvpred/) that would allow users to predict the biological activity as being active or inactive against HCV NS5B. Thus, the knowledge and web server presented herein can be used in the design of more potent and specific drugs against the HCV NS5B.
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Antivirais/farmacologia , Hepacivirus/efeitos dos fármacos , Inibidores de Proteases/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Antivirais/química , Hepacivirus/enzimologia , Modelos Moleculares , Análise Multivariada , Inibidores de Proteases/química , Relação Estrutura-Atividade , Proteínas não Estruturais Virais/metabolismoRESUMO
Patients with diabetes have been widely reported to be at an increased risk of secondary osteoporosis. Osteoporosis is caused by an imbalance in bone remodeling due to increased bone resorption and/or decreased osteoblast-dependent bone formation. In this study, mesenchymal stem cells (MSCs) were used as a disease model to determine the effects of high glucose levels on MSC-osteoblast development. The results indicated that under high glucose conditions, MSCs had reduced cell viability and increased number of ß-galactosidase-positive cells. Furthermore, in vitro osteogenesis was shown to be reduced in MSCs cultured in osteogenic differentiation medium at 10, 25, and 40 mM glucose as demonstrated by Alizarin red S staining and alkaline phosphatase activity assay. Moreover, a proteomic study was performed in MSCs cultured with 25 and 40 mM glucose. The proteomic results demonstrated that 12 proteins were up- and downregulated in bone marrow-derived mesenchymal stem cells cultured with high glucose in a dose-dependent manner. The findings presented here contribute to our understanding of the mechanism of diabetes mellitus responsible for bone loss. However, the exact mechanism of action of hyperglycemia on bone deformability requires additional studies.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Glucose/farmacologia , Células-Tronco Mesenquimais/metabolismo , Osteoblastos/metabolismo , Osteogênese/efeitos dos fármacos , Relação Dose-Resposta a Droga , Glucose/metabolismo , Humanos , Células-Tronco Mesenquimais/citologia , Osteoblastos/citologia , ProteômicaRESUMO
The ideal therapeutic uricase (UOX) is expected to have the following properties; high expression level, high activity, high thermostability, high solubility and low immunogenicity. The latter property is believed to depend largely on sequence identity to the deduced human UOX (dH-UOX). Herein, we explored L. menadoensis uricase (LM-UOX) and found that it has 65% sequence identity to dH-UOX, 68% to the therapeutic chimeric porcine-baboon UOX (PBC) and 70% to the resurrected ancient mammal UOX. To study its biochemical properties, recombinant LM-UOX was produced in E. coli and purified to more than 95% homogeneity. The enzyme had specific activity up to 10.45 unit/mg, which was about 2-fold higher than that of the PBC. One-litre culture yielded purified protein up to 132 mg. Based on homology modelling, we successfully engineered I27C/N289C mutant, which was proven to contain inter-subunit disulphide bridges. The mutant had similar specific activity and production yield to that of wild type (WT) but its thermostability was dramatically improved. Up on storage at -20 °C and 4 °C, the mutant retained ~100% activity for at least 60 days. By keeping at 37 °C, the mutant retained ~100% activity for 15 days, which was 120-fold longer than that of the wild type. Thus, the I27C/N289C mutant has potential to be developed for treatment of hyperuricemia.
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Cordados/genética , Proteínas Recombinantes/genética , Urato Oxidase/genética , Sequência de Aminoácidos , Animais , Hiperuricemia/genética , Indonésia , Engenharia de Proteínas/métodos , Alinhamento de SequênciaRESUMO
BACKGROUND: An increasing of prevalence and diversification of plasmid-mediated AmpC (pAmpC) has been emerged worldwide. The incidence of pAmpC resulted in increasing ß-lactamase production and conferred resistance to almost all ß-lactam antibiotics excluding carbapenems. The lack of standard method for pAmpC identification and classification exert a challenge in epidemiological surveillance and infection control practices. METHODS: A robust, single tube multiplex PCR has been developed to classify six different pAmpC groups including CIT (CMY-2 like, LAT and CFE), ECB (ACT, MIR), MOX & CMY-1 like, DHA, ACC, and FOX. The developed method was optimized and validated by testing of sensitivity and specificity. RESULTS: Developed method can detect crude extracted DNA template at nano-scale (2.5 ηg) and has high discriminatory power as compared to phenotypic and commercial genotypic method. CONCLUSION: The developed method can be utilized for tracking the changes of clinically important resistance patterns and further investigation of occurrence and distribution of plasmid-mediated AmpC types.
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Enterobacteriaceae/genética , Tipagem Molecular/métodos , Reação em Cadeia da Polimerase Multiplex/métodos , Plasmídeos/genética , beta-Lactamases/genética , Enterobacteriaceae/enzimologia , Fenótipo , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Among microcytic hypochromic anemias, the most common disorders are iron deficiency anemia and co-pathological conditions such as α- or ß-thalassemia (α- or ß-thal) traits. The aim of the present study was to determine the frequency and prevalence of iron deficiency anemia and α- or ß-thal traits based on clinical laboratory data across different ethnic groups in five districts of Sindh Province, Pakistan. The present retrospective study analyzed 3 years (2012-2015) of encoded and unlinked clinical laboratory data, and identified 3030 microcytic hypochromic anemia cases. The data contained complete blood counts (CBCs) with smear morphology examinations, serum ferritin levels, and hemoglobin (Hb) electrophoreses. After reviewing the data, 994 confirmed subjects (iron deficiency anemia and α- and ß-thal traits) were then selected for the present study. The prevalence of α- and ß-thal traits was highest in Badin district (35.27%), while the prevalence of iron deficiency anemia was highest in Larkana district (30.73%). According to the ethnic-wise distribution, higher numbers of α- and ß-thal trait cases were seen in the Sindhi ethnic group [375 (64.21%) and 283 (69.02%), respectively] than in the other ethnic groups. In addition, a higher distribution of ß-thal trait cases was observed in the Sindhi ethnic group [n = 327 (56%)] in α- and ß-thal cases overall. Findings from the present study strongly suggested that screening is important not only for ß-thal trait but also other traits as well. However, careful monitoring of CBC parameters, including red blood cell (RBC) indices and morphology, along with clinical findings are essential to diagnose carrier cases, especially in high prevalence areas.
Assuntos
Anemia Ferropriva/epidemiologia , Talassemia beta/epidemiologia , Adolescente , Adulto , Fatores Etários , Anemia Ferropriva/diagnóstico , Criança , Pré-Escolar , Índices de Eritrócitos , Feminino , Geografia , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Paquistão/epidemiologia , Paquistão/etnologia , Vigilância da População , Prevalência , Adulto Jovem , Talassemia beta/diagnósticoRESUMO
Neisseria gonorrhoeae infection threatens to become an untreatable sexually transmitted disease in the near future owing to the increasing emergence of N. gonorrhoeae strains with reduced susceptibility and resistance to the extended-spectrum cephalosporins (ESCs), i.e. ceftriaxone and cefixime, which are the last remaining option for first-line treatment of gonorrhea. Alteration of the penA gene, encoding penicillin-binding protein 2 (PBP2), is the main mechanism conferring penicillin resistance including reduced susceptibility and resistance to ESCs. To predict and investigate putative amino acid mutations causing ß-lactam resistance particularly for ESCs, we applied proteochemometric modeling to generalize N. gonorrhoeae susceptibility data for predicting the interaction of PBP2 with therapeutic ß-lactam antibiotics. This was afforded by correlating publicly available data on antimicrobial susceptibility of wild-type and mutant N. gonorrhoeae strains for penicillin-G, cefixime and ceftriaxone with 50 PBP2 protein sequence data using partial least-squares projections to latent structures. The generated model revealed excellent predictability (R2=0.91, Q2=0.77, QExt2=0.78). Moreover, our model identified amino acid mutations in PBP2 with the highest impact on antimicrobial susceptibility and provided information on physicochemical properties of amino acid mutations affecting antimicrobial susceptibility. Our model thus provided insight into the physicochemical basis for resistance development in PBP2 suggesting its use for predicting and monitoring novel PBP2 mutations that may emerge in the future.
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Proteínas de Transporte/química , Modelos Químicos , Resistência às Penicilinas/genética , Sequência de Aminoácidos/genética , Proteínas de Transporte/genética , Humanos , Mutação , Penicilinas/química , Penicilinas/metabolismo , D-Ala-D-Ala Carboxipeptidase Tipo SerinaRESUMO
Morganella morganii WA01/MUTU is a heavy metal tolerant strain capable of producing silver nanoparticles (AgNPs) from AgNO3. Here we present the draft genome sequence of M. morganii WA01/MUTU isolated from a water sample collected in Nakhon Pathom province, Thailand. The draft genome was sequenced on the Illumina NextSeq 550 sequencer. The genome consisted of 34 contigs with a total size of 3,991,804 bp, an N50 value of 364,423 bp and a GC content of 50.93%. The digital DNA-DNA hybridisation (dDDH) between WA01/MUTU and Morganella morganii (NBRC 3848) was 83.9%, identifying the strain as Morganella morganii. The data presented here can be used in comparative genomics to identify gene clusters involved in AgNP biosynthesis and secondary metabolite production. The draft genome sequence data was deposited at NCBI under Bioproject accession number PRJNA493966.
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Aromatase, a rate-limiting enzyme catalyzing the conversion of androgen to estrogen, is overexpressed in human breast cancer tissue. Aromatase inhibitors (AIs) have been used for the treatment of estrogen-dependent breast cancer in post-menopausal women by blocking the biosynthesis of estrogen. The undesirable side effects in current AIs have called for continued pursuit for novel candidates with aromatase inhibitory properties. This study explores the chemical space of all known AIs as a function of their physicochemical properties by means of univariate (i.e., statistical and histogram analysis) and multivariate (i.e., decision tree and principal component analysis) approaches in order to understand the origins of aromatase inhibitory activity. Such a non-redundant set of AIs spans a total of 973 compounds encompassing both steroidal and non-steroidal inhibitors. Substructure analysis of the molecular fragments provided pertinent information on the structural features important for ligands providing high and low aromatase inhibition. Analyses were performed on data sets stratified according to their structural scaffolds (i.e., steroids and non-steroids) and bioactivities (i.e., actives and inactives). These analyses have uncover a set of rules characteristic to active and inactive AIs as well as revealing the constituents giving rise to potent aromatase inhibition.
Assuntos
Inibidores da Aromatase/química , Antineoplásicos/química , Análise por Conglomerados , Humanos , Modelos Teóricos , Estrutura MolecularRESUMO
Citrobacter spp. are Gram-negative bacteria commonly found in environments and intestinal tracts of humans and animals. They are generally susceptible to third-generation cephalosporins, carbapenems and colistin. However, several antibiotic resistant genes have been increasingly reported in Citrobacter spp., which leads to the postulation that Citrobacter spp. could potentially be a reservoir for spreading of antimicrobial resistant genes. In this study, we characterized two colistin-resistant Citrobacter spp. isolated from the feces of a healthy individual in Thailand. Based on MALDI-TOF and ribosomal multilocus sequence typing, both strains were identified as Citrobacter sedlakii and Citrobacter amalonaticus. Genomic analysis and S1-nuclease pulsed field gel electrophoresis/DNA hybridization revealed that Citrobacter sedlakii and Citrobacter amalonaticus harbored mcr-3.5 gene on pSY_CS01 and pSY_CA01 plasmids, respectively. Both plasmids belonged to IncFII(pCoo) replicon type, contained the same genetic context (Tn3-IS1-ΔTnAs2-mcr-3.5-dgkA-IS91) and exhibited high transferring frequencies ranging from 1.03×10-4 - 4.6×10-4 CFU/recipient cell Escherichia coli J53. Colistin-MICs of transconjugants increased ≥ 16-fold suggesting that mcr-3.5 on these plasmids can be expressed in other species. However, beside mcr, other major antimicrobial resistant determinants in multidrug resistant Enterobacterales were not found in these two isolates. These findings indicate that mcr gene continued to evolve in the absence of antibiotics selective pressure. Our results also support the hypothesis that Citrobacter could be a reservoir for spreading of antimicrobial resistant genes. To the best of our knowledge, this is the first report that discovered human-derived Citrobacter spp. that harbored mcr but no other major antimicrobial resistant determinants. Also, this is the first report that described the presence of mcr gene in C. sedlakii and mcr-3 in C. amalonaticus.
Assuntos
Antibacterianos , Citrobacter , Colistina , Farmacorresistência Bacteriana , Proteínas de Escherichia coli , Animais , Humanos , Antibacterianos/farmacologia , Citrobacter/efeitos dos fármacos , Citrobacter/genética , Colistina/farmacologia , Farmacorresistência Bacteriana/genética , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Plasmídeos/genética , TailândiaRESUMO
Nowadays, a lot of produce (fruits and vegetables) sold in many countries are contaminated with pesticide residues, which cause severe effects on consumer health, such as cancer and neurological disorders. Therefore, this study aims to determine whether cooking processes can reduce the pesticide residues in commonly consumed vegetables (Chinese kale and yard long beans) in Thailand. For cooking experiments, the two vegetables were cooked using three different processes: boiling, blanching, and stir-frying. After the treatments, all cooked and control samples were subjected to extraction and GC-MS/MS analysis for 88 pesticides. The results demonstrated that pesticide residues were reduced by 18-71% after boiling, 36-100% after blanching, and 25-60% after stir-frying for Chinese kale. For yard long beans, pesticide residues were reduced by 38-100% after boiling, 27-28% after blanching, and 35-63% after stir-frying. Therefore, cooking vegetables are proven to protect consumers from ingesting pesticide residues.
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Spilanthes acmella Murr., a well-known Thai traditional medicine, has been used for treatment of toothache, rheumatism, and fever. Diverse pharmacological activities of S. acmella Murr. have been reported. In this study, antioxidative and neuroprotective effects of S. acmella Murr. extracts as well as bioactive scopoletin, vanillic acid, and trans-ferulic acid found in the aerial parts of this plant species have been described. Protective effect of S. acmella Murr. extracts and bioactive compounds on dexamethasone-induced neuronal cell death was investigated. Different plant crude ethyl acetate (EtOAc) and methanol (MeOH) extracts including pure compounds of S. acmella Murr. were evaluated in human neuroblastoma SH-SY5Y cells. Cytotoxic effects were performed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Mechanisms involved in the antioxidant effects of S. acmella Murr. regarding the activation of antioxidant marker proteins such as superoxide dismutase 2 (SOD2) and sirtuin 3 (SIRT3) were determined using 2',7'-dichlorodihydrofluorescein diacetate (DCFH-DA) assay, Western blot analysis, and immunocytochemistry. Dexamethasone significantly caused the decrease of SH-SY5Y cell viability. Conversely, the increases in reactive oxygen species (ROS), autophagy, and apoptosis were observed in dexamethasone-treated cells. S. acmella Murr. MeOH and EtOAc extracts, as well as the bioactive compounds, reversed the toxic effect of dexamethasone by increasing the cell viability, SIRT3 protein expression but reducing the ROS, autophagy, and apoptosis. This study demonstrated that S. acmella Murr. may exert its protective effects against ROS through SOD2 and SIRT3 signaling pathways in dexamethasone-induced neurotoxicity. S. acmella Murr. may be a candidate therapy for neuroprotection.
Assuntos
Asteraceae , Fármacos Neuroprotetores , Antioxidantes/farmacologia , Asteraceae/química , Morte Celular , Sobrevivência Celular , Humanos , Fármacos Neuroprotetores/farmacologia , Extratos Vegetais/uso terapêutico , Espécies Reativas de OxigênioRESUMO
Peroxidase-like activity of Vitreoscilla hemoglobin (VHb) has been recently disclosed. To maximize such activity, two catalytically conserved residues (histidine and arginine) found in distal pocket of peroxidases have successfully been introduced into that of the VHb. Fifteen-fold increase in catalytic constant (k(cat)) was obtained in P54R variant, which was presumably attributable to the lower rigidity and higher hydrophilicity of distal cavity arising from substitution of proline to arginine. None of the modifications altered the affinity towards either H(2)O(2) or ABTS substrate. Spectroscopic studies revealed that VHb variants harboring T29H mutation apparently demonstrated the spectral shift in both ferric and ferrous forms (406-408 to 411 nm and 432 to 424-425 nm, respectively). All VHb proteins in ferrous state had lambda(soret) peak at approximately 419 nm following the carbon monoxide (CO) binding. Expression of P54R mutant mediated the down-regulation of iron superoxide dismutase (FeSOD) as identified by 2-dimensional gel electrophoresis (2-DE) and peptide mass fingerprinting (PMF). According to the high peroxidase activity of P54R, it could effectively eliminate autoxidation-derived H2O2, which is a cause of heme degradation and iron release. This decreased the iron availability and consequently reduced the formation of Fe(2+)-ferric uptake regulator protein (Fe(2+)-Fur), an inducer of FeSOD expression.
Assuntos
Proteínas de Bactérias/metabolismo , Peroxidases/metabolismo , Hemoglobinas Truncadas/metabolismo , Vitreoscilla/enzimologia , Arginina/genética , Arginina/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Benzotiazóis/metabolismo , Eletroforese em Gel Bidimensional , Histidina/genética , Histidina/metabolismo , Peróxido de Hidrogênio/metabolismo , Cinética , Espectrometria de Massas , Modelos Moleculares , Mutagênese Sítio-Dirigida , Peroxidases/química , Peroxidases/genética , Plasmídeos/genética , Proteômica/métodos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Espectrofotometria Ultravioleta , Ácidos Sulfônicos/metabolismo , Hemoglobinas Truncadas/química , Hemoglobinas Truncadas/genética , Vitreoscilla/genéticaRESUMO
Diabetes mellitus is a chronic disease that affects > 180 million people worldwide. It is persistent in Thai communities in spite of much effort in prevention and control. This study examined the knowledge capacity of villagers in the Klongmai community of Nakhon Pathom, Thailand, regarding diabetes by way of action research. A health status assessment and a survey of the community were carried out and used as the basis for designing an educational video on diabetes that is accessible regardless of age and educational background. Evaluations of the pre- and poststudy questionnaires were carried out using statistical analysis. The results indicated that the devised educational materials were effective in encouraging the community's self-awareness and perception of diabetes at the significance level of 0.05. Most importantly, the participants demonstrated proficiency in adapting the knowledge gained from the workshop to their own lifestyle.
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Barreiras de Comunicação , Diabetes Mellitus/diagnóstico , Multimídia/estatística & dados numéricos , Educação de Pacientes como Assunto , Adolescente , Adulto , Idoso , Atitude Frente a Saúde , Estudos de Casos e Controles , Países em Desenvolvimento , Diabetes Mellitus/prevenção & controle , Escolaridade , Feminino , Educação em Saúde/métodos , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Cooperação do Paciente/estatística & dados numéricos , Valores de Referência , Inquéritos e Questionários , Tailândia , Adulto JovemRESUMO
Diabetic nephropathy, a major complication of diabetes mellitus (DM), is increasing worldwide and the large majority of patients have type 2 DM. Microalbuminuria has been used as a diagnostic marker of diabetic nephropathy. But owing to its insufficient sensitivity and specificity, other biomarkers are being sought. In addition, the pathophysiology of diabetic nephropathy is not fully understood and declines in renal function occur even without microalbuminuria. In this study, we investigated urinary proteins from three study groups (controls, and type 2 diabetic subjects with or without microalbuminuria). Non-targeted label-free Nano-LC QTOF analysis was conducted to discover underlying mechanisms and protein networks, and targeted label-free Nano-LC QTOF with SWATH was performed to qualify discovered protein candidates. Twenty-eight proteins were identified as candidates and functionally analyzed via String DB, gene ontology and pathway analysis. Four predictive mechanisms were analyzed: i) response to stimulus, ii) platelet activation, signaling and aggregation, iii) ECM-receptor interaction, and iv) angiogenesis. These mechanisms can provoke kidney dysfunction in type 2 diabetic patients via endothelial cell damage and glomerulus structural alteration. Based on these analyses, three proteins (kininogen-1, basement membrane-specific heparan sulfate proteoglycan core protein, and roundabout homolog 4) were proposed for further study as potential biomarkers. Our findings provide insights that may improve methods for both prevention and diagnosis of diabetic nephropathy.
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This study investigated bioactive extracts of Polyalthia debilis (Annonaceae) with antimicrobial, antimalarial and cytotoxic activities. Extensive chromatographic isolations provided azafluorenone alkaloids; onychine (1) and 7-methoxyonychine (2) together with a mixture of beta-sitosterol and stigmasterol. The two alkaloids were isolated from the P. debilis for the first time. Isolated fractions containing a mixture of triterpenoids (C7, C8 and C9) exhibited the most potent antimicrobial activity against many bacterial strains with minimum inhibitory concentration of 64 microg/mL. Fractions with antimalarial and cytotoxic activities were also observed. The findings suggest the potential use of P. debilis in medicinal applications.
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Alcaloides/química , Alcaloides/farmacologia , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polyalthia/química , Alcaloides/efeitos adversos , Anti-Infecciosos/efeitos adversos , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Antimaláricos/efeitos adversos , Antimaláricos/química , Antimaláricos/farmacologia , Linhagem Celular , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Flavanonas/química , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Plasmodium falciparum/efeitos dos fármacos , Piridonas/química , Sitosteroides/química , Estigmasterol/química , Triterpenos/químicaRESUMO
Bacterial lipopolysaccharides (LPS), also known as endotoxins, are major structural components of the outer membrane of Gram-negative bacteria that serve as a barrier and protective shield between them and their surrounding environment. LPS is considered to be a major virulence factor as it strongly stimulates the secretion of pro-inflammatory cytokines which mediate the host immune response and culminating in septic shock. Quantitative structure-activity relationship studies of the LPS neutralization activities of anti-endotoxins were performed using charge and quantum chemical descriptors. Artificial neural network implementing the back-propagation algorithm was selected for the multivariate analysis. The predicted activities from leave-one-out cross-validation were well correlated with the experimental values as observed from the correlation coefficient and root mean square error of 0.930 and 0.162, respectively. Similarly, the external testing set also yielded good predictivity with correlation coefficient and root mean square error of 0.983 and 0.130. The model holds great potential for the rational design of novel and robust compounds with enhanced neutralization activity.
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Anticorpos Antibacterianos , Endotoxinas , Lipopolissacarídeos , Relação Quantitativa Estrutura-Atividade , Idoso , Anticorpos Antibacterianos/química , Anticorpos Antibacterianos/imunologia , Criança , Citocinas/imunologia , Endotoxinas/química , Endotoxinas/imunologia , Bactérias Gram-Negativas/imunologia , Humanos , Lipopolissacarídeos/química , Lipopolissacarídeos/imunologia , Modelos Moleculares , Estrutura MolecularRESUMO
Molecular imprinting is a technology that facilitates the production of artificial receptors toward compounds of interest. The molecularly imprinted polymers act as artificial antibodies, artificial receptors, or artificial enzymes with the added benefit over their biological counterparts of being highly durable. In this study, we prepared molecularly imprinted polymers for the purpose of binding specifically to tocopherol (vitamin E) and its derivative, tocopherol acetate. Binding of the imprinted polymers to the template was found to be two times greater than that of the control, non-imprinted polymers, when using only 10 mg of polymers. Optimization of the rebinding solvent indicated that ethanol-water at a molar ratio of 6:4 (v/v) was the best solvent system as it enhanced the rebinding performance of the imprinted polymers toward both tocopherol and tocopherol acetate with a binding capacity of approximately 2 mg/g of polymer. Furthermore, imprinted nanospheres against tocopherol was successfully prepared by precipitation polymerization with ethanol-water at a molar ratio of 8:2 (v/v) as the optimal rebinding solvent. Computer simulation was also performed to provide mechanistic insights on the binding mode of template-monomer complexes. Such polymers show high potential for industrial and medical applications, particularly for selective separation of tocopherol and derivatives.
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Nanosferas/química , Tocoferóis/química , Simulação por Computador , Modelos Moleculares , Polímeros/química , Vitamina E/químicaRESUMO
BACKGROUND: Enterobacter cloacae (EC) is a Gram-negative bacterium that has been utilized extensively in biotechnological and environmental science applications, possibly because of its high capability for adapting itself and surviving in hazardous conditions. A search for the EC from agricultural and industrial areas that possesses high capability to tolerate and/or accumulate cadmium ions has been conducted in this study. Plausible mechanisms of cellular adaptations in the presence of toxic cadmium have also been proposed. METHODS: Nine strains of EC were isolated and subsequently identified by biochemical characterization and MALDI-Biotyper. Minimum inhibitory concentrations (MICs) against cadmium, zinc and copper ions were determined by agar dilution method. Growth tolerance against cadmium ions was spectrophotometrically monitored at 600 nm. Cadmium accumulation at both cellular and protein levels was investigated using atomic absorption spectrophotometer. Proteomics analysis by 2D-DIGE in conjunction with protein identification by QTOF-LC-MS/MS was used to study differentially expressed proteins between the tolerant and intolerant strains as consequences of cadmium exposure. Expression of such proteins was confirmed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Bioinformatics tools were applied to propose the functional roles of cadmium-binding protein and its association in cadmium tolerance mechanisms. RESULTS: The cadmium-tolerant strain (EC01) and intolerant strain (EC07) with the MICs of 1.6 and 0.4 mM, respectively, were isolated. The whole cell lysate of EC01 exhibited approximately two-fold higher in cadmium binding capability than those of the EC07 and ATCC 13047, possibly by the expression of Cd-binding proteins. Our proteomics analysis revealed the higher expression of DUF326-like domain (a high cysteine-rich protein) of up to 220 fold in the EC01 than that of the EC07. Confirmation of the transcription level of this gene by qRT-PCR revealed a 14-fold induction in the EC01. Regulation of the DUF326-like domain in EC01 was more pronounced to mediate rapid cadmium accumulation (in 6 h) and tolerance than the other resistance mechanisms found in the ATCC 13047 and the EC07 strains. The only one major responsive protein against toxic cadmium found in these three strains belonged to an antioxidative enzyme, namely catalase. The unique proteins found in the ATCC 13047 and EC07 were identified as two groups: (i) ATP synthase subunit alpha, putative hydrolase and superoxide dismutase and (ii) OmpX, protein YciF, OmpC porin, DNA protection during starvation protein, and TrpR binding protein WrbA, respectively. CONCLUSION: All these findings gain insights not only into the molecular mechanisms of cadmium tolerance in EC but also open up a high feasibility to apply the newly discovered DUF326-like domain as cadmium biosorbents for environmental remediation in the future.
RESUMO
Ischemic heart disease (IHD) is predominantly the leading cause of death worldwide. Early detection of IHD may effectively prevent severity and reduce mortality rate. Recently, magnetocardiography (MCG) has been developed for the detection of heart malfunction. Although MCG is capable of monitoring the abnormal patterns of magnetic field as emitted by physiologically defective heart, data interpretation is time-consuming and requires highly trained professional. Hence, we propose an automatic method for the interpretation of IHD pattern of MCG recordings using machine learning approaches. Two types of machine learning techniques, namely back-propagation neural network (BNN) and direct kernel self-organizing map (DK-SOM), were applied to explore the IHD pattern recorded by MCG. Data sets were obtained by sequential measurement of magnetic field emitted by cardiac muscle of 125 individuals. Data were divided into training set and testing set of 74 cases and 51 cases, respectively. Predictive performance was obtained by both machine learning approaches. The BNN exhibited sensitivity of 89.7%, specificity of 54.5% and accuracy of 74.5%, while the DK-SOM provided relatively higher prediction performance with a sensitivity, specificity and accuracy of 86.2%, 72.7% and 80.4%, respectively. This finding suggests a high potential of applying machine learning approaches for high-throughput detection of IHD from MCG data.