Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 504
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nature ; 530(7591): 453-6, 2016 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-26911781

RESUMO

In recent years, millisecond-duration radio signals originating in distant galaxies appear to have been discovered in the so-called fast radio bursts. These signals are dispersed according to a precise physical law and this dispersion is a key observable quantity, which, in tandem with a redshift measurement, can be used for fundamental physical investigations. Every fast radio burst has a dispersion measurement, but none before now have had a redshift measurement, because of the difficulty in pinpointing their celestial coordinates. Here we report the discovery of a fast radio burst and the identification of a fading radio transient lasting ~6 days after the event, which we use to identify the host galaxy; we measure the galaxy's redshift to be z = 0.492 ± 0.008. The dispersion measure and redshift, in combination, provide a direct measurement of the cosmic density of ionized baryons in the intergalactic medium of ΩIGM = 4.9 ± 1.3 per cent, in agreement with the expectation from the Wilkinson Microwave Anisotropy Probe, and including all of the so-called 'missing baryons'. The ~6-day radio transient is largely consistent with the radio afterglow of a short γ-ray burst, and its existence and timescale do not support progenitor models such as giant pulses from pulsars, and supernovae. This contrasts with the interpretation of another recently discovered fast radio burst, suggesting that there are at least two classes of bursts.

2.
Lett Appl Microbiol ; 74(4): 472-481, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34978719

RESUMO

Emergence and rapid spread of multidrug-resistant (MDR) bacteria including Vibrio cholerae are a global public health issue. Much attention has been paid to natural compounds, such as spices and herbs to find novel antimicrobial compounds as they are considered to be cheaper alternatives to develop as a drug. Here, we show that methanol extract of white pepper could inhibit the growth of V. cholerae O1 El Tor variant, responsible for the recent outbreaks/epidemics. Furthermore, we demonstrate for the first time that piperine, the major component of white pepper, showed a dose-dependent bactericidal effect on V. cholerae growth irrespective of their biotypes and serogroups in the presence of 200 and 300 µg ml-1 of piperine, respectively. Piperine also inhibited the growth of MDR strains of Pseudomonas aeruginosa, Escherichia coli isolated from poultry and enterohemorrhagic/enteroaggregative E. coli O104 in the presence of 200 µg ml-1 . Interestingly, we did not observe any significant inhibitory effect of piperine on E. coli strains isolated from healthy person even up to 200 µg ml-1 . Our data suggest that piperine could be a novel antimicrobial agent in therapeutic and preventive applications against infections caused by pathogenic bacteria including MDR strains.


Assuntos
Cólera , Piper nigrum , Vibrio cholerae O1 , Vibrio cholerae , Alcaloides , Benzodioxóis , Cólera/microbiologia , Escherichia coli , Variação Genética , Humanos , Piperidinas , Alcamidas Poli-Insaturadas
3.
Lett Appl Microbiol ; 74(1): 2-7, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34695222

RESUMO

It is well known that black and green tea extracts, particularly polyphenols, have antimicrobial activity against various pathogenic microbes including viruses. However, there is limited data on the antiviral activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which emerged rapidly in China in late 2019 and which has been responsible for coronavirus disease 2019 (COVID-19) pandemic globally. In this study, 20 compounds and three extracts were obtained from black and green tea and found that three tea extracts showed significant antiviral activity against SARS-CoV-2, whereby the viral titre decreased about 5 logs TCID50 per ml by 1·375 mg ml-1 black tea extract and two-fold diluted tea bag infusion obtained from black tea when incubated at 25°C for 10 s. However, when concentrations of black and green tea extracts were equally adjusted to 344 µg ml-1 , green tea extracts showed more antiviral activity against SARS-CoV-2. This simple and highly respected beverage may be a cheap and widely acceptable means to reduce SARS-CoV-2 viral burden in the mouth and upper gastrointestinal and respiratory tracts in developed as well as developing countries.


Assuntos
COVID-19 , Camellia sinensis , Catequina , Antivirais/farmacologia , Humanos , SARS-CoV-2 , Chá
4.
Nano Lett ; 19(9): 5915-5919, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31373825

RESUMO

Diamond has two crystallographically inequivalent sites in the unit cell. In doped diamond, dopant occupation in the two sites is expected to be equal. Nevertheless, preferential dopant occupation during growth under nonequilibrium conditions is of fundamental importance, for example, to enhance the properties of nitrogen-vacancy (N-V) centers; therefore, this is a promising candidate for a qubit. However, the lack of suitable experimental techniques has made it difficult to study the crystal- and chemical-site-resolved local structures of dopants. Here, we confirm the identity of two chemical sites with asymmetric dopant incorporation in the diamond structure, via the photoelectron holography (PEH) of heavily phosphorus (P)-doped diamond prepared by chemical vapor deposition. One is substitutionally incorporated P with preferential site occupations and the other can be attributed to a PV split vacancy complex with preferential orientation. The present study shows that PEH is a valuable technique to study the local structures around dopants with a resolution of crystallographically inequivalent but energetically equivalent sites/orientations. Such information provides strategies to improve the properties of dopant related-complexes in which alignment is crucial for sensing of magnetic field or quantum spin register using N-V centers in diamond.

5.
Clin Exp Immunol ; 192(3): 325-336, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29393507

RESUMO

RNA-binding proteins (RBPs) regulate mRNA stability by binding to the 3'-untranslated region (UTR) region of mRNA. Human antigen-R (HuR), one of the RBPs, is involved in the progression of diseases, such as rheumatoid arthritis, diabetes mellitus and some inflammatory diseases. Interleukin (IL)-6 is a major inflammatory cytokine regulated by HuR binding to mRNA. Periodontal disease (PD) is also an inflammatory disease caused by elevations in IL-6 following an infection by periodontopathogenic bacteria. The involvement of HuR in the progression of PD was assessed using in-vitro and in-vivo experiments. Immunohistochemistry of inflamed periodontal tissue showed strong staining of HuR in the epithelium and connective tissue. HuR mRNA and protein level was increased following stimulation with Porphyromonas gingivalis (Pg), one of the periodontopathogenic bacteria, lipopolysacchride (LPS)-derived from Pg (PgLPS) and tumour necrosis factor (TNF)-α in OBA-9, an immortalized human gingival epithelial cell. The luciferase activity of 3'-UTR of IL-6 mRNA was increased by TNF-α, Pg and PgLPS in OBA-9. Luciferase activity was also increased in HuR-over-expressing OBA-9 following a bacterial stimulation. Down-regulation of HuR by siRNA resulted in a decrease in mRNA expression and production of IL-6. In contrast, the over-expression of HuR increased IL-6 mRNA expression and production in OBA-9. The HuR inhibitor, quercetin, suppressed Pg-induced HuR mRNA expression and IL-6 production in OBA-9. An oral inoculation with quercetin also inhibited bone resorption in ligature-induced periodontitis model mice as a result of down-regulation of IL-6. These results show that HuR modulates inflammatory responses by regulating IL-6.


Assuntos
Proteína Semelhante a ELAV 1/metabolismo , Gengiva/patologia , Interleucina-6/genética , Periodontite/patologia , Regiões 3' não Traduzidas/genética , Adulto , Idoso , Animais , Reabsorção Óssea/tratamento farmacológico , Linhagem Celular , Proteína Semelhante a ELAV 1/genética , Células Epiteliais/metabolismo , Feminino , Gengiva/citologia , Humanos , Lipopolissacarídeos/imunologia , Luciferases/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Periodontite/tratamento farmacológico , Porphyromonas gingivalis/imunologia , Porphyromonas gingivalis/patogenicidade , Quercetina/farmacologia , Interferência de RNA , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/genética , Fator de Necrose Tumoral alfa
6.
Clin Exp Immunol ; 190(1): 54-67, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28640392

RESUMO

Calcineurin inhibitors (CNIs) have been used off-label for the treatment of refractory Kawasaki disease (KD). However, it remains unknown whether CNIs show protective effects against the development of coronary artery lesions in KD patients. To investigate the effects of CNIs on coronary arteries and the mechanisms of their actions on coronary arteritis in a mouse model of KD, we performed experiments with FK565, a ligand of nucleotide-binding oligomerization domain-containing protein 1 (NOD1) in wild-type, severe combined immunodeficiency (SCID), caspase-associated recruitment domain 9 (CARD9)-/- and myeloid differentiation primary response gene 88 (MyD88)-/- mice. We also performed in-vitro studies with vascular and monocytic cells and vascular tissues. A histopathological analysis showed that both cyclosporin A and tacrolimus exacerbated the NOD1-mediated coronary arteritis in a dose-dependent manner. Cyclosporin A induced the exacerbation of coronary arteritis in mice only in high doses, while tacrolimus exacerbated it within the therapeutic range in humans. Similar effects were obtained in SCID and CARD9-/- mice but not in MyD88-/- mice. CNIs enhanced the expression of adhesion molecules by endothelial cells and the cytokine secretion by monocytic cells in our KD model. These data indicated that both vascular and monocytic cells were involved in the exacerbation of coronary arteritis. Activation of MyD88-dependent inflammatory signals in both vascular cells and macrophages appears to contribute to their adverse effects. Particular attention should be paid to the development of coronary artery lesions when using CNIs to treat refractory KD.


Assuntos
Arterite/tratamento farmacológico , Inibidores de Calcineurina/uso terapêutico , Endotélio Vascular/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Síndrome de Linfonodos Mucocutâneos/tratamento farmacológico , Fator 88 de Diferenciação Mieloide/metabolismo , Oligopeptídeos/uso terapêutico , Animais , Proteínas Adaptadoras de Sinalização CARD/genética , Vasos Coronários/patologia , Citocinas/metabolismo , Modelos Animais de Doenças , Endotélio Vascular/imunologia , Humanos , Mediadores da Inflamação/metabolismo , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos SCID , Fator 88 de Diferenciação Mieloide/genética , Células RAW 264.7 , Transdução de Sinais
7.
J Evol Biol ; 30(6): 1110-1123, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28306172

RESUMO

Adaptation to different environments can promote population divergence via natural selection even in the presence of gene flow - a phenomenon that typically occurs during ecological speciation. To elucidate how natural selection promotes and maintains population divergence during speciation, we investigated the population genetic structure, degree of gene flow and heterogeneous genomic divergence in three closely related Japanese phytophagous ladybird beetles: Henosepilachna pustulosa, H. niponica and H. yasutomii. These species act as a generalist, a wild thistle (Cirsium spp.) specialist and a blue cohosh (Caulophyllum robustum) specialist, respectively, and their ranges differ accordingly. The two specialist species widely co-occur but are reproductively isolated solely due to their high specialization to a particular host plant. Genomewide amplified fragment-length polymorphism (AFLP) markers and mitochondrial cytochrome c oxidase subunit I (COI) gene sequences demonstrated obvious genomewide divergence associated with both geographic distance and ecological divergence. However, a hybridization assessment for both AFLP loci and the mitochondrial sequences revealed a certain degree of unidirectional gene flow between the two sympatric specialist species. Principal coordinates analysis (PCoA) based on all of the variable AFLP loci demonstrated that there are genetic similarities between populations from adjacent localities irrespective of the species (i.e. host range). However, a further comparative genome scan identified a few fractions of loci representing approximately 1% of all loci as different host-associated outliers. These results suggest that these three species had a complex origin, which could be obscured by current gene flow, and that ecological divergence can be maintained with only a small fraction of the genome is related to different host use even when there is a certain degree of gene flow between sympatric species pairs.


Assuntos
Besouros/genética , Fluxo Gênico , Deriva Genética , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , Animais , Especiação Genética , Seleção Genética
8.
J Dairy Sci ; 100(7): 5936-5944, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28457550

RESUMO

It has recently been reported that the rare sugar d-allulose has beneficial effects, including the suppression of postprandial blood glucose elevation in humans, and can be substituted for sucrose as a low-calorie food ingredient. To examine the applications of d-allulose in the dairy industry, we investigated the effects of d-allulose on the acid production of 8 strains of yogurt starter (Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus) and 4 strains of lactococci, including potential probiotic candidates derived from dairy products. Acid production by 2 L. delbrueckii ssp. bulgaricus yogurt starter strains in milk was suppressed by d-allulose, but this phenomenon was also observed in some strains with another sugar (xylose), a sugar alcohol (sorbitol), or both. In contrast, among the dairy probiotic candidates, Lactococcus lactis H61, which has beneficial effects for human skin when drunk as part of fermented milk, was the only strain that showed suppression of acid production in the presence of d-allulose. Strain H61 did not metabolize d-allulose. We did not observe suppression of acid production by strain H61 with the addition of xylose or sorbitol, and xylose and sorbitol were not metabolized by strain H61. The acid production of strain H61 after culture in a constituted medium (tryptone-yeast extract-glucose broth) was also suppressed with the addition of d-allulose, but growth efficiency and sugar fermentation style were not altered. Probiotic activities-such as the angiotensin-converting enzyme inhibitory activity of H61-fermented milk and the superoxide dismutase activity of H61 cells grown in tryptone-yeast extract-glucose broth-were not affected by d-allulose. d-Allulose may suppress acid production in certain lactic acid bacteria without altering their probiotic activity. It may be useful for developing new probiotic dairy products from probiotic strains such as Lactococcus lactis H61.


Assuntos
Frutose/metabolismo , Lactobacillus/metabolismo , Lactococcus/metabolismo , Probióticos , Animais , Bovinos , Fermentação , Ácido Láctico/metabolismo , Iogurte
9.
Clin Exp Immunol ; 186(2): 134-143, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27342882

RESUMO

Kawasaki disease (KD) is an acute systemic vasculitis of childhood that does not have a known cause or aetiology. The epidemiological features (existence of epidemics, community outbreaks and seasonality), unique age distribution and clinical symptoms and signs of KD suggest that the disease is caused by one or more infectious environmental triggers. However, KD is not transmitted person-to-person and does not occur in clusters within households, schools or nurseries. KD is a self-limited illness that is not associated with the production of autoantibodies or the deposition of immune complexes, and it rarely recurs. Regarding the underlying pathophysiology of KD, innate immune activity (the inflammasome) is believed to play a role in the development of KD vasculitis, based on the results of studies with animal models and the clinical and laboratory findings of KD patients. Animal studies have demonstrated that innate immune pathogen-associated molecular patterns (PAMPs) can cause vasculitis independently of acquired immunity and have provided valuable insights regarding the underlying mechanisms of this phenomenon. To validate this concept, we recently searched for KD-specific PAMPs and identified such molecules with high specificity and sensitivity. These molecules have structures similar to those of microbe-associated molecular patterns (MAMPs), as shown by liquid chromatography-tandem mass spectrometry. We propose herein that KD is an innate immune disorder resulting from the exposure of a genetically predisposed individual to microbe-derived innate immune stimulants and that it is not a typical infectious disease.


Assuntos
Síndrome de Linfonodos Mucocutâneos/etiologia , Animais , Meio Ambiente , Interação Gene-Ambiente , Predisposição Genética para Doença , Humanos , Imunidade Inata , Síndrome de Linfonodos Mucocutâneos/metabolismo
10.
Clin Exp Immunol ; 186(2): 177-189, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27465496

RESUMO

Epidemiological studies have linked periodontitis to rheumatoid arthritis (RA). Porphyromonas gingivalis (Pg) was reported recently to produce citrullinated protein (CP) and increase anti-cyclic CP antibody (ACPA), both of which have been identified as causative factors of RA. In the present study, we determined the effects of Pg infection on the exacerbation of RA in a mouse model. RA model mice (SKG mice) were established by an intraperitoneal (i.p.) injection of laminarin (LA). Mice were divided into six groups, Ctrl (PBS injection), LA (LA injection), Pg/LA (Pg + LA injection), Pg (Pg injection), Ec/LA (Escherichia coli and LA injection) and Ec (E. coli injection). In order to evaluate RA, joint swelling by the arthritis score, bone morphology by microcomputed tomography (microCT), haematoxylin and eosin staining, ACPA, matrix metalloproteinase-3 (MMP-3) and cytokine level in serum by enzyme-linked immunosorbent assay were determined. Osteoclast differentiation from bone marrow mononuclear cells (BMCs) was examined to clarify the underlying mechanisms of RA. The presence of Pg and CP in joint tissue was also investigated. The arthritis score was threefold higher in the Pg/LA group than in the LA group. Severe bone destruction was observed in joint tissue of the Pg/LA group. A microCT analysis of the Pg/LA group revealed a decrease in bone density. ACPA, MMP-3, interleukin (IL)-2, IL-6, CXCL1 and macrophage inflammatory protein (MIP)-1α levels from the Pg/LA group were the highest. The osteoclastogenesis of BMCs was enhanced in the Pg/LA group. Furthermore, large amounts of Pg components and CP were detected in the Pg/LA group. In conclusion, Pg infection has the potential to exacerbate RA.


Assuntos
Artrite Reumatoide/etiologia , Artrite Reumatoide/patologia , Infecções por Bacteroidaceae/complicações , Infecções por Bacteroidaceae/microbiologia , Porphyromonas gingivalis , Animais , Articulação do Tornozelo/diagnóstico por imagem , Articulação do Tornozelo/patologia , Artrite Reumatoide/diagnóstico por imagem , Biomarcadores , Diferenciação Celular , Citocinas/metabolismo , Modelos Animais de Doenças , Progressão da Doença , Feminino , Expressão Gênica , Camundongos , Osteoclastos/citologia , Osteoclastos/metabolismo , Microtomografia por Raio-X
11.
J Appl Microbiol ; 121(6): 1755-1765, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27522063

RESUMO

AIMS: To investigate the virulence of the Vp_PirAB-like genes in Vibrio parahaemolyticus- acute hepatopancreatic necrosis disease (AHPND)-causing strain and the factors that are associated with the virulence level. METHODS AND RESULTS: The virulence of Vp_PirAB-like was examined using a non-virulent strain FP11 of V. parahaemolyticus transformed with a plasmid harbouring Vp_PirAB-like genes and then it was used to challenge shrimp Litopenaeus vannamei and Marsupenaeus japonicus. Both species experienced 100% mortality at 10 days post infection. Analysis of a mutant strain (E1M), that was originally identified as virulent strain (E1) but lost its virulence to L. vannamei, revealed that it lacked a part of the Vp_PirA-like gene and all of the Vp_PirB-like gene. The copy numbers of Vp_PirA-like and Vp_PirB-like genes varied among virulent strains and were not correlated with their virulence. In Western blotting, Vp_PirA-like and Vp_PirB-like proteins were detected in both the cell lysate and the culture supernatant. The strongest intensity of detecting band in the culture supernatant was observed in the strain that caused the highest mortality. The V. parahaemolyticus AHPND-causing strain, unlike the human tdh-positive strain, did not show any enterotoxicity. CONCLUSION: Vibrio parahaemolyticus AHPND-causing strains secrete the Vp_PirA-like and Vp_PirB-like proteins during the growing phase. The amount of secreted proteins affects the shrimp mortality. SIGNIFICANCE AND IMPACT OF THE STUDY: The secreted proteins of Vp_PirAB-like are key factors of virulence in the V. parahaemolyticus AHPND-causing strain, but not gene copy.


Assuntos
Proteínas de Bactérias/metabolismo , Penaeidae/microbiologia , Vibrio parahaemolyticus/patogenicidade , Animais , Células CHO , Linhagem Celular , Cricetinae , Cricetulus , Dosagem de Genes , Células HeLa , Humanos , Masculino , Plasmídeos , Coelhos , Vibrio parahaemolyticus/genética , Vibrio parahaemolyticus/metabolismo , Fatores de Virulência/genética
12.
Complement Ther Med ; 72: 102909, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36526152

RESUMO

OBJECTIVES: Thermal therapy is used to manage various psychological diseases, such as depression. We investigated the relationship between hot spring bathing and depression in older adults using questionnaire responses. DESIGN AND SETTING: We comprehensively evaluated the preventive effects of long-term hot spring bathing in 10429 adults aged ≥ 65 years in Beppu, Japan, by conducting a questionnaire study on the prevalence of depression (n = 219). MAIN OUTCOME MEASURES: Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using a multivariable logistic regression model for history of depression. RESULTS: A separate multivariable logistic regression model for inference showed that female sex (OR, 1.56; 95 % CI, 1.17-2.08; p = 0.002), arrhythmia (OR, 1.73; 95 % CI, 1.18-2.52; p = 0.004), hyperlipidemia (OR, 1.63; 95 % CI, 1.14-2.32; p = 0.006), renal disease (OR, 2.26; 95 % CI, 1.36-3.75; p = 0.001), collagen disease (OR, 2.72; 95 % CI, 1.48-5.02; p = 0.001), allergy (OR, 1.97; 95 % CI, 1.27-3.04; p = 0.002), and habitual daily hot spring bathing (OR, 0.63; 95 % CI, 0.41-0.94; p = 0.027) were independently significantly associated with a history of depression. CONCLUSIONS: We found an inverse relationship between habitual daily hot spring bathing and history of depression. Prospective randomized controlled trials on habitual daily hot spring bathing as a treatment for depression are warranted to investigate whether the use of hot springs can provide relief to those with psychiatric and mental health disorders.


Assuntos
Fontes Termais , Humanos , Feminino , Idoso , Estudos Retrospectivos , Depressão/epidemiologia , Depressão/terapia , População do Leste Asiático , Estudos Prospectivos
13.
Intervirology ; 55(3): 185-93, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-21430354

RESUMO

OBJECTIVES: In countries where cholera is endemic, Vibrio cholerae O1 bacteriophages have been detected in sewage water. These have been used to serve not only as strain markers, but also for the typing of V. cholerae strains. Vibriophage N4 (ATCC 51352-B1) occupies a unique position in the new phage-typing scheme and can infect a larger number of V. cholerae O1 biotype El Tor strains. Here we characterized the complete genome sequence of this typing vibriophage. METHODS: The complete DNA sequence of the N4 genome was determined by using a shotgun sequencing approach. RESULTS: Complete genome sequence explored that phage N4 is comprised of one circular, double-stranded chromosome of 38,497 bp with an overall GC content of 42.8%. A total of 47 open reading frames were identified and functions could be assigned to 30 of them. Further, a close relationship with another vibriophage, VP4, and the enterobacteriophage T7 could be established. DNA-DNA hybridization among V. cholerae O1 and O139 phages revealed homology among O1 vibriophages at their genomic level. CONCLUSIONS: This study indicates two evolutionary distinctive branches of the possible phylogenetic origin of O1 and O139 vibriophages and provides an unveiled collection of information on viral gene products of typing vibriophages.


Assuntos
Bacteriófago N4/genética , DNA Viral/química , DNA Viral/genética , Genoma Viral , Vibrio cholerae O1/virologia , Composição de Bases , Análise por Conglomerados , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Fases de Leitura Aberta , Filogenia , Análise de Sequência de DNA
14.
Clin Exp Rheumatol ; 30(3): 332-7, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22325242

RESUMO

OBJECTIVES: Bone oedema is a pathological change in rheumatoid arthritis (RA) that is detectable by magnetic resonance imaging (MRI). Recent histological analyses revealed that a prominent feature of bone oedema is the replacement of adipose tissue with inflammatory cells. Here, we demonstrate the possible roles of mesenchymal stromal cells (MSCs) in bone oedema formation and the pathogenic potential of the cells in RA. METHODS: Adipogenesis of bone marrow-derived human MSCs was induced by a standard adipogenic induction medium in the presence or absence of cytokines. The cytokine productions from MSCs were screened by an antibody array system and confirmed by ELISA. The migration assay was performed to determine the locomotive abilities of undifferentiated MSCs or MSCs after adipogenesis. The expression of α smooth muscle actin (SMA) and F-actin was examined by immunostaining and phalloidin staining, respectively. RESULTS: TNF-α, interleukin (IL)-1ß, IL-6, and TGF-ß clearly inhibited the adipogenesis of MSCs. Production of IL-6 was markedly reduced, and IL-8 secretion was augmented in MSCs after adipogenesis. The mobility of MSCs after adipogenesis was clearly reduced in migration assays compared to that of undifferentiated MSCs. Consistent with these findings, SMA and F-actin expressions were clearly suppressed in MSCs committed to adipogenesis. CONCLUSIONS: Our data suggest that the inflammatory milieu promotes bone oedema by blocking adipogenesis of MSCs. In bone oedema, the enhanced IL-6 production and the increased mobility of MSCs may contribute to the progression of RA. Therefore, bone oedema may be an important target lesion in the treatment of RA.


Assuntos
Adipócitos/citologia , Adipogenia/fisiologia , Artrite Reumatoide/patologia , Edema/patologia , Células-Tronco Mesenquimais/citologia , Adipogenia/efeitos dos fármacos , Artrite Reumatoide/metabolismo , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Movimento Celular/efeitos dos fármacos , Movimento Celular/fisiologia , Células Cultivadas , Progressão da Doença , Humanos , Interleucina-1beta/farmacologia , Interleucina-6/metabolismo , Interleucina-6/farmacologia , Interleucina-8/metabolismo , Imageamento por Ressonância Magnética , Células-Tronco Mesenquimais/efeitos dos fármacos , Células-Tronco Mesenquimais/metabolismo , Fator de Crescimento Transformador beta/farmacologia , Fator de Necrose Tumoral alfa/farmacologia
15.
Br J Biomed Sci ; 69(1): 26-30, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22558801

RESUMO

The present study examines the expression of cytolethal distending toxin (cdt) gene encoding a cytotoxin in Campylobacter lari (n=6 urease-negative [UN] C. lari; n=4 urease-positive thermophilic Campylobacter [UPTC]). When reverse transcription polymerase chain reaction (RT-PCR) was carried out with 10 C. lari isolates using a primer pair to amplify the cdtB gene transcript segment, an approximate 260 bp RT-PCR amplicon was generated with all the isolates. In addition, cdtA, cdtB and cdtC gene operon was identified to be polycistronicly transcribed in the C. lari cells. The cdtB gene translation in the C. lari cells was also confirmed by Western blot analysis. Thus, the cdt gene operon in C. lari organisms, including UN C. lari and UPTC, was expressed at the transcriptional and translational levels in the cells. The present results suggest that all three cdt genes may be functional in the cells.


Assuntos
Toxinas Bacterianas/análise , Toxinas Bacterianas/genética , Campylobacter lari/genética , Animais , Toxinas Bacterianas/metabolismo , Sequência de Bases , Infecções por Campylobacter/genética , Infecções por Campylobacter/microbiologia , Campylobacter lari/metabolismo , Regulação Bacteriana da Expressão Gênica , Humanos , Dados de Sequência Molecular , Óperon , Biossíntese de Proteínas , Homologia de Sequência do Ácido Nucleico
16.
J Basic Microbiol ; 52(5): 559-65, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22359318

RESUMO

We aimed to clarify if Campylobacter lari exerts a cytolethal distending toxin (CDT) effect on HeLa cells. Campylobacter cell lysates (CCLys) from C. jejuni 81-176 and urease-positive thermophilic Campylobacter (UPTC) CF89-12 and UPTC NCTC12893 isolates were shown to exert a CDT effect on HeLa cells with morphological changes examined by Giemsa staining and microscopy. However, Campylobacter lari JCM2530(T) isolate showed no effect. In addition, Campylobacter cell culture supernatant wash gave low or absent toxic effects with both C. jejuni and C. lari organisms. When western blot analysis was carried out to clarify if there was a CDTB effect in the CCLys and soluble fractions from Campylobacter isolates, which had a CDT effect on HeLa cells or did not have any effect, anti-recombinant CjCDTB antibodies identified an immunoreactively positive signal at around approximately 25 kDa on all the C. lari isolates examined, as well as the C. jejuni 81116 strain. Thus, all the Campylobacter isolates including those without any CDT effect were shown to express CDTB at the translational level.


Assuntos
Toxinas Bacterianas/metabolismo , Toxinas Bacterianas/toxicidade , Campylobacter lari/patogenicidade , Células Epiteliais/efeitos dos fármacos , Western Blotting , Células HeLa , Humanos , Microscopia
17.
Indian J Med Res ; 134: 214-23, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21911975

RESUMO

BACKGROUND & OBJECTIVES: Diverse mechanisms have been identified in enteric bacteria for their adaptation and survival against multiple classes of antimicrobial agents. Resistance of bacteria to the most effective fluoroquinolones have increasingly been reported in many countries. We have identified that most of the enterotoxigenic Escherichia coli (ETEC) were resistant to several antimicrobials in a diarrhoea outbreak at Ahmedabad during 2000. The present study was done to identify several genes responsible for antimicrobial resistance and mobile genetic elements in the ETEC strains. METHODS: Seventeen ETEC strains isolated from diarrhoeal patients were included in this study. The antimicrobial resistance was confirmed by conventional disc diffusion method. PCR and DNA sequencing were performed for the identification of mutation in the quinolone resistance-determining regions (QRDRs). Efflux pump was tested by inhibiting the proton-motive force. DNA hybridization assay was made for the detection of integrase genes and the resistance gene cassettes were identified by direct sequencing of the PCR amplicons. RESULTS: Majority of the ETEC had GyrA mutations at codons 83 and 87 and in ParC at codon 80. Six strains had an additional mutation in ParC at codon 108 and two had at position 84. Plasmid-borne qnr gene alleles that encode quinolone resistance were not detected but the newly described aac(6')-Ib-cr gene encoding a fluoroquinolne-modifying enzyme was detected in 64.7 per cent of the ETEC. Class 1 (intI1) and class 2 (intI2) integrons were detected in six (35.3%) and three (17.6%) strains, respectively. Four strains (23.5%) had both the classes of integrons. Sequence analysis revealed presence of dfrA17, aadA1, aadA5 in class 1, and dfrA1, sat1, aadA1 in class 2 integrons. In addition, the other resistance genes such as tet gene alleles (94.1%), catAI (70.6%), strA (58.8%), bla TEM-1 (35.2%), and aphA1-Ia (29.4%) were detected in most of the strains. INTERPRETATION & CONCLUSIONS: Innate gene mutations and acquisition of multidrug resistance genes through mobile genetic elements might have contributed to the emergence of multidrug resistance (MDR) in ETEC. This study reinforces the necessity of utilizing molecular techniques in the epidemiological studies to understand the nature of resistance responsible for antimicrobial resistance in different species of pathogenic bacteria.


Assuntos
DNA Girase/genética , Diarreia/microbiologia , Farmacorresistência Bacteriana Múltipla/genética , Escherichia coli Enterotoxigênica/genética , Infecções por Escherichia coli/microbiologia , Genes MDR/genética , Integrons/genética , Antibacterianos/farmacologia , DNA Girase/efeitos dos fármacos , DNA Topoisomerase IV/efeitos dos fármacos , DNA Topoisomerase IV/genética , DNA Bacteriano/análise , DNA Bacteriano/genética , Diarreia/tratamento farmacológico , Diarreia/epidemiologia , Surtos de Doenças , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Escherichia coli Enterotoxigênica/isolamento & purificação , Escherichia coli Enterotoxigênica/patogenicidade , Escherichia coli/classificação , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/isolamento & purificação , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/epidemiologia , Infecções por Escherichia coli/genética , Fluoroquinolonas/farmacologia , Humanos , Índia/epidemiologia , Testes de Sensibilidade Microbiana , Mutação/efeitos dos fármacos , Mutação/genética , Quinolonas/farmacologia
18.
Nat Commun ; 12(1): 306, 2021 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-33436617

RESUMO

Quantum sensors are highly sensitive since they capitalise on fragile quantum properties such as coherence, while enabling ultra-high spatial resolution. For sensing, the crux is to minimise the measurement uncertainty in a chosen range within a given time. However, basic quantum sensing protocols cannot simultaneously achieve both a high sensitivity and a large range. Here, we demonstrate a non-adaptive algorithm for increasing this range, in principle without limit, for alternating-current field sensing, while being able to get arbitrarily close to the best possible sensitivity. Therefore, it outperforms the standard measurement concept in both sensitivity and range. Also, we explore this algorithm thoroughly by simulation, and discuss the T-2 scaling that this algorithm approaches in the coherent regime, as opposed to the T-1/2 of the standard measurement. The same algorithm can be applied to any modulo-limited sensor.

19.
J Hosp Infect ; 118: 20-26, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34536532

RESUMO

BACKGROUND: A new coronavirus (SARS-CoV-2) abruptly emerged in Wuhan, China, in 2019 and rapidly spread globally to cause the COVID-19 pandemic. AIM: To examine the anti-SARS-CoV-2 activity of the potent disinfectant Cleverin, the major disinfecting component of which is chlorine dioxide (ClO2); and to compare the results with that of sodium hypochlorite in the presence or absence of 0.5% or 1.0% foetal bovine serum (FBS). METHODS: Concentrated SARS-CoV-2 viruses were treated with various concentrations of ClO2 and sodium hypochlorite and 50% tissue culture infective dose was calcurated to evaluate the antiviral activity of each chemical. FINDINGS: When SARS-CoV-2 viruses were treated with 0.8 ppm ClO2 or sodium hypochlorite, viral titre was decreased only by 1 log10 TCID50/mL in 3 min. However, the viral titre was decreased by more than 4 log10 TCID50/mL when treated with 80 ppm of each chemical for 10 s regardless of presence or absence of FBS. It should be emphasized that treatment with 24 ppm of ClO2 inactivated more than 99.99% SARS-CoV-2 within 10 s or 99.99% SARS-CoV-2 in 1 min in the presence of 0.5% or 1.0% FBS, respectively. By contrast, 24 ppm of sodium hypochlorite inactivated only 99% or 90% SARS-CoV-2 in 3 min under similar conditions. Notably, except for ClO2, the other components of Cleverin such as sodium chlorite, decaglycerol monolaurate, and silicone showed no significant antiviral activity. CONCLUSION: Altogether, the results strongly suggest that although ClO2 and sodium hypochlorite are strong antiviral agents in absence of organic matter but in presence of organic matter, ClO2 is a more potent antiviral agent against SARS-CoV-2 than sodium hypochlorite.


Assuntos
COVID-19 , Compostos Clorados , Desinfetantes , Antivirais/farmacologia , Cloro , Compostos Clorados/farmacologia , Desinfetantes/farmacologia , Humanos , Óxidos/farmacologia , Pandemias , SARS-CoV-2 , Hipoclorito de Sódio/farmacologia
20.
J Clin Microbiol ; 48(11): 4283-6, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20810767

RESUMO

Vibrio cholerae O1 El Tor variant strains produced much more cholera toxin than did prototype El Tor strains. The amount of cholera toxin produced by El Tor variant strains both in vitro and in vivo was more or less equivalent to that produced by classical strains.


Assuntos
Toxina da Cólera/biossíntese , Vibrio cholerae O1/classificação , Vibrio cholerae O1/patogenicidade , Fatores de Virulência/biossíntese , Animais , Western Blotting , Toxina da Cólera/toxicidade , Meios de Cultura/química , Humanos , Íleo/patologia , Coelhos , Fatores de Virulência/toxicidade
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa