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1.
J Med Microbiol ; 72(6)2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37341468

RESUMEN

Introduction. Bacterial pneumonia is a common cause of morbidity and mortality in elderly individuals. While the incidence of edentulism is falling, approximately 19 % of the UK population wear a full or partial removable denture. Despite advances in denture biomaterials, the majority of dentures are fabricated using polymethyl-methacrylate. Growing evidence suggests that colonization of the oral cavity by putative respiratory pathogens predisposes individuals to respiratory infection, by translocation of these microorganisms along the respiratory tract.Hypothesis/Gap Statement. We hypothesized that denture surfaces provide a susceptible colonization site for putative respiratory pathogens, and thus could increase pneumonia risk in susceptible individuals.Aim. This study aimed to characterize the bacterial community composition of denture-wearers in respiratory health compared with individuals with a confirmed diagnosis of pneumonia.Methodology. This was an analytical cross-sectional study, comparing frail elderly individuals without respiratory infection (n=35) to hospitalized patients with pneumonia (n=26). The primary outcome was the relative abundance of putative respiratory pathogens identified by 16S rRNA metataxonomic sequencing, with quantitative PCR used to identified Streptococcus pneumoniae.Results. There was a statistically significant increase in the overall relative abundance of putative respiratory pathogens (P<0.0001), with a greater than 20-fold increase in the bioburden of these microorganisms. In keeping with these findings, there were significant shifts in bacterial community diversity (Chao index, P=0.0003) and richness (Inverse Simpson index P<0.0001) in the denture-associated microbiota of pneumonia patients compared with control subjects.Conclusion. Within the limitations of this study, our evidence supports the role of denture acrylic biomaterials as a potential colonization site for putative respiratory pathogens, which may lead to an increased risk of pneumonia in susceptible individuals. These findings support prior observational studies which have found denture-wearers to be at increased risk of respiratory infection. Further research is needed to confirm the sequence of colonization and translocation to examine potential causal relationships.


Asunto(s)
Neumonía , Infecciones del Sistema Respiratorio , Humanos , Anciano , Estudios Transversales , ARN Ribosómico 16S/genética , Bacterias/genética , Dentaduras/efectos adversos , Dentaduras/microbiología , Materiales Biocompatibles
2.
Redox Biol ; 41: 101933, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33721836

RESUMEN

Many oral bacteria reduce inorganic nitrate, a natural part of a vegetable-rich diet, into nitrite that acts as a precursor to nitric oxide, a regulator of vascular tone and neurotransmission. Aging is hallmarked by reduced nitric oxide production with associated detriments to cardiovascular and cognitive function. This study applied a systems-level bacterial co-occurrence network analysis across 10-day dietary nitrate and placebo interventions to test the stability of relationships between physiological and cognitive traits and clusters of co-occurring oral bacteria in older people. Relative abundances of Proteobacteria increased, while Bacteroidetes, Firmicutes and Fusobacteria decreased after nitrate supplementation. Two distinct microbiome modules of co-occurring bacteria, that were sensitive to nitrate supplementation, showed stable relationships with cardiovascular (Rothia-Streptococcus) and cognitive (Neisseria-Haemophilus) indices of health across both dietary conditions. A microbiome module (Prevotella-Veillonella) that has been associated with pro-inflammatory metabolism was diminished after nitrate supplementation, including a decrease in relative abundance of pathogenic Clostridium difficile. These nitrate-sensitive oral microbiome modules are proposed as potential pre- and probiotic targets to ameliorate age-induced impairments in cardiovascular and cognitive health.


Asunto(s)
Microbiota , Nitratos , Anciano , Cognición , Humanos , Óxido Nítrico , Nitritos , Óxidos de Nitrógeno
3.
Microorganisms ; 8(2)2020 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-32041100

RESUMEN

Candida spp. are the most prevalent fungi of the human microbiota and are opportunistic pathogens that can cause oral candidiasis. Management of such infections is limited due to the low number of antifungal drugs available, their relatively high toxicity and the emergence of antifungal resistance. Therefore, much interest in the antimicrobial potential of natural compounds has recently been evident. The use of hydrogels in the delivery of biocides has been explored due to their biocompatibility, ease with drug encapsulation, and due to their potential to confer mechanical and structural properties similar to biological tissue. Methylcellulose hydrogels (10% (w/v)) with 1% (v/v) and 2% (v/v) Melissa officinalis oil were synthesised. The rheological properties and gelation time of the hydrogels were evaluated. Antimicrobial action, the antifungal potential and ability to displace Candida were determined. Rheological tests revealed that the hydrogel jellified in three minutes at 37 °C. Loaded hydrogels successfully inhibited Candida albicans growth as evident by zone of inhibition and time-kill assays. A significant reduction in retained C. albicans was demonstrated with the hydrogel at 2% Melissa officinalis concentration. This work demonstrated that an essential oil-loaded hydrogel had the potential to provide a novel antimicrobial therapy for the treatment of oral candidiasis.

4.
Sci Rep ; 9(1): 10228, 2019 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-31308427

RESUMEN

Denture-associated stomatitis (DS) affects over two-thirds of denture-wearers. DS presents as erythema of the palatal mucosa in areas where denture-surface associated polymicrobial biofilms containing the fungus Candida albicans exist. The contribution of the oral bacterial microbiota toward the infection is unknown. Therefore, this study characterised the bacterial microbiota of sites within the oral cavity to identify potential associations with occurrence of DS. Denture-wearing patients were recruited (denture stomatitis (DS) n = 8; non-denture stomatitis (NoDS) n = 11) and the oral bacterial microbiota of the tongue, palate and denture-fitting surface was characterised using next-generation sequencing. Operational taxonomic units (OTUs) were identified to bacterial genera and species, and presence/absence and relative abundances were examined. A significant (P = 0.007) decrease in the number of OTUs and thus, diversity of the microbiota was observed in tongue samples of DS patients (vs non-DS). The microbiota of denture-fitting surfaces and palatal mucosae were similar. Large differences in the abundance of bacterial genera and species were observed at each sample site, and unique presence/absence of bacteria was noted. Presence/absence and relative abundance of specific bacteria associated with DS warrants further in vitro and in vivo evaluation, particularly as our previous work has shown C. albicans virulence factor modulation by oral bacteria.


Asunto(s)
Dentaduras/microbiología , Microbiota/genética , Estomatitis Subprotética/microbiología , Adulto , Anciano , Anciano de 80 o más Años , Bacterias , Biopelículas , Femenino , Humanos , Masculino , Persona de Mediana Edad , Boca/microbiología , Mucosa Bucal/microbiología , Hueso Paladar/microbiología , Estomatitis/microbiología , Factores de Virulencia
5.
Free Radic Biol Med ; 124: 21-30, 2018 08 20.
Artículo en Inglés | MEDLINE | ID: mdl-29807159

RESUMEN

Imbalances in the oral microbial community have been associated with reduced cardiovascular and metabolic health. A possible mechanism linking the oral microbiota to health is the nitrate (NO3-)-nitrite (NO2-)-nitric oxide (NO) pathway, which relies on oral bacteria to reduce NO3- to NO2-. NO (generated from both NO2- and L-arginine) regulates vascular endothelial function and therefore blood pressure (BP). By sequencing bacterial 16S rRNA genes we examined the relationships between the oral microbiome and physiological indices of NO bioavailability and possible changes in these variables following 10 days of NO3- (12 mmol/d) and placebo supplementation in young (18-22 yrs) and old (70-79 yrs) normotensive humans (n = 18). NO3- supplementation altered the salivary microbiome compared to placebo by increasing the relative abundance of Proteobacteria (+225%) and decreasing the relative abundance of Bacteroidetes (-46%; P < 0.05). After NO3-supplementation the relative abundances of Rothia (+127%) and Neisseria (+351%) were greater, and Prevotella (-60%) and Veillonella (-65%) were lower than in the placebo condition (all P < 0.05). NO3- supplementation increased plasma concentration of NO2- and reduced systemic blood pressure in old (70-79 yrs), but not young (18-22 yrs), participants. High abundances of Rothia and Neisseria and low abundances of Prevotella and Veillonella were correlated with greater increases in plasma [NO2-] in response to NO3- supplementation. The current findings indicate that the oral microbiome is malleable to change with increased dietary intake of inorganic NO3-, and that diet-induced changes in the oral microbial community are related to indices of NO homeostasis and vascular health in vivo.


Asunto(s)
Presión Sanguínea , Suplementos Dietéticos , Homeostasis , Microbiota , Óxido Nítrico/metabolismo , Saliva/microbiología , Rigidez Vascular/efectos de los fármacos , Adolescente , Adulto , Anciano , Bacterias/efectos de los fármacos , Estudios Cruzados , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Nitratos/metabolismo , Nitritos/metabolismo , ARN Ribosómico 16S , Estudios Retrospectivos , Saliva/efectos de los fármacos , Saliva/metabolismo , Rigidez Vascular/fisiología , Adulto Joven
6.
J Med Microbiol ; 67(3): 364-375, 2018 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29458673

RESUMEN

PURPOSE: In vitro analyses of virulence, pathogenicity and associated host cell responses are important components in the study of biofilm infections. The Candida-related infection, denture-associated oral candidosis, affects up to 60 % of denture wearers and manifests as inflammation of palatal tissues contacting the denture-fitting surface. Commercially available three-dimensional tissue models can be used to study infection, but their use is limited for many academic research institutions, primarily because of the substantial purchase costs. The aim of this study was to develop and evaluate the use of in vitro tissue models to assess infections by biofilms on acrylic surfaces through tissue damage and Candida albicans virulence gene expression. METHODOLOGY: In vitro models were compared against commercially available tissue equivalents (keratinocyte-only, SkinEthic; full-thickness, MatTek Corporation). An in vitro keratinocyte-only tissue was produced using a cancer-derived cell line, TR146, and a full-thickness model incorporating primary fibroblasts and immortalised normal oral keratinocytes was also generated. The in vitro full-thickness tissues incorporated keratinocytes and fibroblasts, and have potential for future further development and analysis. RESULTS: Following polymicrobial infection with biofilms on acrylic surfaces, both in-house developed models were shown to provide equivalent results to the SkinEthic and MatTek models in terms of tissue damage: a significant (P<0.05) increase in LDH activity for mixed species biofilms compared to uninfected control, and no significant difference (P>0.05) in the expression of most C. albicans virulence genes when comparing tissue models of the same type. CONCLUSION: Our results confirm the feasibility and suitability of using these alternative in vitro tissue models for such analyses.


Asunto(s)
Biopelículas/crecimiento & desarrollo , Candidiasis Bucal/microbiología , Dentaduras/microbiología , Interacciones Huésped-Patógeno , Mucosa Bucal/microbiología , Candida albicans/genética , Candida albicans/patogenicidad , Candida albicans/fisiología , Línea Celular , Coinfección/microbiología , Fibroblastos/microbiología , Humanos , Queratinocitos/microbiología , Polimetil Metacrilato , Estomatitis Subprotética , Virulencia
7.
Bioresour Technol ; 244(Pt 1): 641-649, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28810219

RESUMEN

This study takes combined field trial, lab experiment, and economic analysis approaches to evaluate the potential of industrial hemp in comparison with kenaf, switchgrass and biomass sorghum. Agronomy data suggest that the per hectare yield (5437kg) of industrial hemp stem alone was at a similar level with switchgrass and sorghum; while the hemp plants require reduced inputs. Field trial also showed that ∼1230kg/ha hemp grain can be harvested in addition to stems. Results show a predicted ethanol yield of ∼82gallons/dry ton hemp stems, which is comparable to the other three tested feedstocks. A comparative cost analysis indicates that industrial hemp could generate higher per hectare gross profit than the other crops if both hemp grains and biofuels from hemp stem were counted. These combined evaluation results demonstrate that industrial hemp has great potential to become a promising regional commodity crop for producing both biofuels and value-added products.


Asunto(s)
Biocombustibles , Cannabis , Panicum , Sorghum , Biomasa , Hibiscus
8.
J Crit Care ; 39: 149-155, 2017 06.
Artículo en Inglés | MEDLINE | ID: mdl-28259058

RESUMEN

PURPOSE: Mechanically ventilated patients are at risk for developing ventilator-associated pneumonia, and it has been reported that dental plaque provides a reservoir of respiratory pathogens that may aspirate to the lungs and endotracheal tube (ETT) biofilms. For the first time, metataxonomics was used to simultaneously characterize the microbiome of dental plaque, ETTs, and non-directed bronchial lavages (NBLs) in mechanically ventilated patients to determine similarities in respective microbial communities and therefore likely associations. MATERIAL AND METHODS: Bacterial 16S rRNA gene sequences from 34 samples of dental plaque, NBLs, and ETTs from 12 adult mechanically ventilated patients were analyzed. RESULTS: No significant differences in the microbial communities of these samples were evident. Detected bacteria were primarily oral species (e.g., Fusobacterium nucleatum, Streptococcus salivarius, Prevotella melaninogenica) with respiratory pathogens (Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcuspneumoniae, and Haemophilus influenzae) also in high abundance. CONCLUSION: The high similarity between the microbiomes of dental plaque, NBLs, and ETTs suggests that the oral cavity is indeed an important site involved in microbial aspiration to the lower airway and ETT. As such, maintenance of good oral hygiene is likely to be highly important in limiting aspiration of bacteria in this vulnerable patient group.


Asunto(s)
Bacterias/aislamiento & purificación , Biopelículas , Placa Dental/microbiología , Contaminación de Equipos , Intubación Intratraqueal/efectos adversos , Neumonía Asociada al Ventilador/microbiología , Adulto , Anciano , Anciano de 80 o más Años , Bacterias/genética , Femenino , Humanos , Pulmón/microbiología , Masculino , Persona de Mediana Edad , Boca/microbiología , ARN Ribosómico 16S/genética , Respiración Artificial , Adulto Joven
9.
BMC Anesthesiol ; 17(1): 36, 2017 03 04.
Artículo en Inglés | MEDLINE | ID: mdl-28257624

RESUMEN

BACKGROUND: Aspiration of subglottic secretions past the endotracheal tube (ETT) cuff is a prerequisite for developing ventilator-associated pneumonia (VAP). Subglottic secretion drainage (SSD) ETTs reduce aspiration of subglottic secretions and have demonstrated lower VAP rates. We compared the performance of seven SSD ETTs against a non-SSD ETT in preventing aspiration below inflated cuffs. METHODS: ETTs were positioned vertically in 2 cm diameter cylinders. Four ml of a standard microbial suspension was added above inflated cuffs. After 1 h, aspiration was measured and ETTs demonstrating no leakage were subjected to rotational movement and evaluation over 24 h. Collected aspirated fluid was used to inoculate agar media and incubated aerobically at 37 °C for 24 h. The aspiration rate, volume and number of microorganisms that leaked past the cuff was measured. Experiments were repeated (×10) for each type of ETT, with new ETTs used for each repeat. Best performing ETTs were then tested in five different cylinder diameters (1.6, 1.8, 2.0, 2.2 and 2.4 cm). Experiments were repeated as above using sterile water. Volume and time taken for aspiration past the cuff was measured. Experiments were repeated (×10) for each type of ETT. Results were analysed using non-parametric tests for repeated measures. RESULTS: The PneuX ETT prevented aspiration past the cuff in all experiments. All other ETTs allowed aspiration, with considerable variability in performance. The PneuX ETT was statistically superior in reducing aspiration compared to the SealGuard (p < 0.009), KimVent (p < 0.002), TaperGuard (p < 0.004), Lanz (p < 0.001), ISIS (p < 0.001), SACETT (p < 0.001) and Soft Seal (p < 0.001) ETTs. Of the 4 ETTs tested in differing cylinder sizes, the PneuX significantly reduced aspiration across the range of diameters compared to the SealGuard (p < 0.0001), TaperGuard (p < 0.0001) and KimVent (p < 0.0001) ETTs. CONCLUSIONS: ETTs showed substantial variation in fluid aspiration, relating to cuff material and design. Variability in performance was likely due to the random manner in which involutional folds form in the inflated ETT cuff. The PneuX ETT was the only ETT able to consistently prevent aspiration past the cuff in all experiments.


Asunto(s)
Intubación Intratraqueal/instrumentación , Modelos Biológicos , Paracentesis/instrumentación , Diseño de Equipo , Humanos , Técnicas In Vitro , Neumonía por Aspiración/prevención & control
10.
J Crit Care ; 37: 30-37, 2017 02.
Artículo en Inglés | MEDLINE | ID: mdl-27621110

RESUMEN

PURPOSE: In mechanically ventilated patients, the endotracheal tube is an essential interface between the patient and ventilator, but inadvertently, it also facilitates the development of ventilator-associated pneumonia (VAP) by subverting pulmonary host defenses. A number of investigations suggest that bacteria colonizing the oral cavity may be important in the etiology of VAP. The present study evaluated microbial changes that occurred in dental plaque and lower airways of 107 critically ill mechanically ventilated patients. MATERIALS AND METHODS: Dental plaque and lower airways fluid was collected during the course of mechanical ventilation, with additional samples of dental plaque obtained during the entirety of patients' hospital stay. RESULTS: A "microbial shift" occurred in dental plaque, with colonization by potential VAP pathogens, namely, Staphylococcus aureus and Pseudomonas aeruginosa in 35 patients. Post-extubation analyses revealed that 70% and 55% of patients whose dental plaque included S aureus and P aeruginosa, respectively, reverted back to having a predominantly normal oral microbiota. Respiratory pathogens were also isolated from the lower airways and within the endotracheal tube biofilms. CONCLUSIONS: To the best of our knowledge, this is the largest study to date exploring oral microbial changes during both mechanical ventilation and after recovery from critical illness. Based on these findings, it was apparent that during mechanical ventilation, dental plaque represents a source of potential VAP pathogens.


Asunto(s)
Biopelículas , Portador Sano/microbiología , Placa Dental/microbiología , Intubación Intratraqueal/instrumentación , Pulmón/microbiología , Microbiota/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Bacterias/genética , Enfermedad Crítica , ADN Bacteriano/análisis , Femenino , Humanos , Masculino , Persona de Mediana Edad , Neumonía Asociada al Ventilador/microbiología , Pseudomonas aeruginosa/genética , Respiración Artificial , Staphylococcus aureus/genética , Ventiladores Mecánicos , Adulto Joven
11.
BMJ Open Respir Res ; 3(1): e000150, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27843549

RESUMEN

INTRODUCTION: During critical illness, dental plaque may serve as a reservoir of respiratory pathogens. This study compared the effectiveness of toothbrushing with a small-headed toothbrush or a foam-headed swab in mechanically ventilated patients. METHODS: This was a randomised, assessor-blinded, split-mouth trial, performed at a single critical care unit. Adult, orally intubated patients with >20 teeth, where >24 hours of mechanical ventilation was expected were included. Teeth were cleaned 12-hourly using a foam swab or toothbrush (each randomly assigned to one side of the mouth). Cleaning efficacy was based on plaque scores, gingival index and microbial plaque counts. RESULTS: High initial plaque (mean=2.1 (SD 0.45)) and gingival (mean=2.0 (SD 0.54)) scores were recorded for 21 patients. A significant reduction compared with initial plaque index occurred using both toothbrushes (mean change=-1.26, 95% CI -1.57 to -0.95; p<0.001) and foam swabs (mean change=-1.28, 95% CI -1.54 to -1.01; p<0.001). There was significant reduction in gingival index over time using toothbrushes (mean change=-0.92; 95% CI -1.19 to -0.64; p<0.001) and foam swabs (mean change=-0.85; 95% CI -1.10 to -0.61; p<0.001). Differences between cleaning methods were not statistically significant (p=0.12 for change in gingival index; p=0.24 for change in plaque index). There was no significant change in bacterial dental plaque counts between toothbrushing (mean change 3.7×104 colony-forming units (CFUs); minimum to maximum (-2.5×1010 CFUs, 8.7×107 CFUs)) and foam swabs (mean change 9×104 CFUs; minimum to maximum (-3.1×1010 CFUs, 3.0×107 CFUs)). CONCLUSIONS: Patients admitted to adult intensive care had poor oral health, which improved after brushing with a toothbrush or foam swab. Both interventions were equally effective at removing plaque and reducing gingival inflammation. TRIAL REGISTRATION NUMBER: NCT01154257; Pre-results.

12.
Biofouling ; 32(2): 123-34, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26795585

RESUMEN

Whilst Candida albicans occurs in peri-implant biofilms, its role in peri-implantitis remains unclear. This study therefore examined the virulence of C. albicans in mixed-species biofilms on titanium surfaces. Biofilms of C. albicans (Ca), C. albicans with streptococci (Streptococcus sanguinis, S. mutans) (Ca-Ss-Sm) and those incorporating Porphyromonas gingivalis (Ca-Pg and Ca-Ss-Sm-Pg) were developed. Expression of C. albicans genes associated with adhesion (ALS1, ALS3, HWP1) and hydrolytic enzymes (SAP2, SAP4, SAP6, PLD1) was measured and hyphal production by C. albicans quantified. Compared with Ca biofilms, significant (p<0.05) up-regulation of ALS3, HWP1, SAP2 and SAP6, and hyphal production occurred in biofilms containing streptococci (Ca-Ss-Sm). In Ca-Pg biofilms, down-regulation of HWP1 and SAP4 expression, with reduced hyphal production occurred. Ca-Ss-Sm-Pg biofilms had increased hyphal proportions and up-regulation of ALS3, SAP2 and SAP6. In conclusion, C. albicans expressed virulence factors in biofilms that could contribute to peri-implantitis, but this was dependent on associated bacterial species.


Asunto(s)
Biopelículas/crecimiento & desarrollo , Candida albicans , Hifa/crecimiento & desarrollo , Porphyromonas gingivalis/fisiología , Streptococcus sanguis/fisiología , Titanio , Antibiosis/genética , Candida albicans/patogenicidad , Candida albicans/fisiología , Proteínas Fúngicas/genética , Humanos , Glicoproteínas de Membrana/genética , Periimplantitis/microbiología , Propiedades de Superficie , Virulencia , Factores de Virulencia/metabolismo
13.
J Med Microbiol ; 65(2): 147-159, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26690690

RESUMEN

Micro-organisms isolated from the oral cavity may translocate to the lower airways during mechanical ventilation (MV) leading to ventilator-associated pneumonia (VAP). Changes within the dental plaque microbiome during MV have been documented previously, primarily using culture-based techniques. The aim of this study was to use community profiling by high throughput sequencing to comprehensively analyse suggested microbial changes within dental plaque during MV. Bacterial 16S rDNA gene sequences were obtained from 38 samples of dental plaque sampled from 13 mechanically ventilated patients and sequenced using the Illumina platform. Sequences were processed using Mothur, applying a 97% gene similarity cut-off for bacterial species level identifications. A significant 'microbial shift' occurred in the microbial community of dental plaque during MV for nine out of 13 patients. Following extubation, or removal of the endotracheal tube that facilitates ventilation, sampling revealed a decrease in the relative abundance of potential respiratory pathogens and a compositional change towards a more predominantly (in terms of abundance) oral microbiota including Prevotella spp., and streptococci. The results highlight the need to better understand microbial shifts in the oral microbiome in the development of strategies to reduce VAP, and may have implications for the development of other forms of pneumonia such as community-acquired infection.


Asunto(s)
Bacterias/aislamiento & purificación , Placa Dental/microbiología , Neumonía Asociada al Ventilador/microbiología , Adulto , Anciano , Bacterias/clasificación , Bacterias/genética , Placa Dental/complicaciones , Femenino , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Filogenia , Neumonía Asociada al Ventilador/etiología , Respiración Artificial/efectos adversos , Adulto Joven
15.
J Immunol Res ; 2015: 328146, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26146640

RESUMEN

Candida albicans is a fungus that is an opportunistic pathogen of humans. Normally, C. albicans exists as a harmless commensal and does not trigger inflammatory responses by resident macrophages in skin mucosa, which may be caused by a tolerance of skin macrophage to C. albicans. IL-34 is a recently discovered cytokine, constitutively expressed by keratinocytes in the skin. IL-34 binds to the receptor of M-CSF, thereby stimulating tissue macrophage maturation and differentiation. Resident macrophages exhibit phenotypic plasticity and may transform into inflammatory M1 macrophages for immunity or anti-inflammatory M2 macrophages for tissue repair. M1 macrophages produce higher levels of inflammatory cytokines such as TNFα in response to C. albicans stimulation. In this study, it was demonstrated that IL-34 attenuated TNFα production by M1 macrophages challenged with heat killed Candida (HKC). The molecular mechanism of IL-34 mediated suppression of HKC induced TNFα production by M1 macrophages was by the inhibition of M1 macrophage expression of key C. albicans pattern recognition receptors (PPRs), namely, Toll-like receptor (TLR) 2 and Dectin-1. The results of this study indicated that constitutive IL-34 expressed by skin keratinocytes might suppress resident macrophage responses to C. albicans colonisation by maintaining low levels TLR2 and Dectin-1 expression by macrophages.


Asunto(s)
Candida albicans/fisiología , Candidiasis/inmunología , Candidiasis/metabolismo , Interleucinas/metabolismo , Lectinas Tipo C/metabolismo , Macrófagos/inmunología , Macrófagos/metabolismo , Receptor Toll-Like 2/metabolismo , Factor de Necrosis Tumoral alfa/biosíntesis , Animales , Candidiasis/genética , Candidiasis/microbiología , Membrana Celular/metabolismo , Regulación hacia Abajo , Regulación de la Expresión Génica , Lectinas Tipo C/genética , Ratones , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptor Toll-Like 2/genética
16.
Dalton Trans ; 44(29): 13359-68, 2015 Aug 07.
Artículo en Inglés | MEDLINE | ID: mdl-26133039

RESUMEN

The in situ formation and subsequent Cu(ii) ligation of the polydentate pro-ligands o-[(E)-(2-hydroxy-3-methoxyphenyl)methylideneamino]benzohydroxamic acid (L1H3), o-[(E)-(2-hydroxy-3-methoxy-5-bromophenyl)methylideneamino]benzohydroxamic acid (L2H3) and o-[(E)-(2-hydroxyphenyl)methylideneamino]benzohydroxamic acid (L3H3), leads to the self-assembly of the cages [Cu(ii)10(L1)4(2-aph)2(H2O)2](ClO4)4·5MeOH (), [Cu(ii)14(L1)8(MeOH)2.5(H2O)7.5](NO3)4·3MeOH·7H2O (), [Cu(ii)14(L2)8(MeOH)4(H2O)6](NO3)4·6H2O (), [Cu(ii)14(L3)8(MeOH)6(H2O)2](NO3)4·4MeOH·8H2O () and [Cu(ii)30O(OH)4(OMe)2(L1)16(MeOH)4(H2O)2](ClO4)4·2MeOH·30H2O (). Each member comprises a highly unusual topology derived from off-set, stacked, near planar layers of polynuclear subunits connected through long Cu(ii)-O contacts. The exact topology observed is dependent on the specific reaction conditions and methodologies employed. Dc magnetic susceptibility studies on , , and reveals strong antiferromagnetic exchange between the Cu(ii) centres in all siblings. We also present the 1D coordination polymer {[Cu(ii)(L4)]·H2O}n () comprising the pseudo macrocyclic ligand [[2-[(E)-(2-hydroxy-3-methoxy-phenyl)methyleneamino]benzoyl]amino]ethanimidate (L4H2), which is formed upon the incorporation of an MeCN unit at the hydroxamate group of precursor ligand L1H3.

17.
J Child Adolesc Psychopharmacol ; 24(8): 419-25, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25299355

RESUMEN

UNLABELLED: Abstract Objective: This study assessed the efficacy of atomoxetine on attention-deficit/hyperactivity disorder (ADHD) symptoms in children and adolescents having ADHD with comorbid dyslexia (ADHD+D) and the effects of the treatment on reading measures. METHODS: The analyses in this report used data from a study designed to examine the effects of a nonstimulant pharmacological agent, atomoxetine, on reading in children with ADHD+D. Patients ages 10-16 years with ADHD or ADHD+D received open-label atomoxetine for 16 weeks. The ADHD Rating Scale (ADHD-RS) and reading subtests of the Kaufman Test of Educational Achievement (K-TEA) were assessed. Changes in ADHD symptoms and reading scores were also analyzed by ADHD subtype. Treatment effect sizes and correlations between changes in ADHDRS and K-TEA scores were calculated. RESULTS: After atomoxetine treatment, both ADHD and ADHD+D patient groups showed significant reduction in ADHD symptom and improvements in K-TEA reading scores. The range of treatment effect sizes on K-TEA scores was 0.35-0.53 for the ADHD group and 0.50-0.62 for the ADHD+D group. Pearson's correlation coefficients revealed only a few weak correlations between changes in ADHD symptoms and reading scores, regardless of diagnostic group. CONCLUSIONS: ADHD symptoms and K-TEA reading scores improved for both the ADHD and ADHD+D groups following atomoxetine treatment. Correlation analyses indicate that improvements in reading outcomes cannot be explained by a reduction of ADHD symptoms alone. These findings support further exploration of the potential effects of atomoxetine on reading in children with ADHD and dyslexia or dyslexia alone.


Asunto(s)
Trastorno por Déficit de Atención con Hiperactividad/tratamiento farmacológico , Estimulantes del Sistema Nervioso Central/uso terapéutico , Dislexia/tratamiento farmacológico , Propilaminas/uso terapéutico , Lectura , Adolescente , Clorhidrato de Atomoxetina , Niño , Femenino , Humanos , Masculino , Resultado del Tratamiento
18.
Int J Med Microbiol ; 304(8): 1011-7, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25183575

RESUMEN

Candida albicans is responsible for the majority of cases of vulvovaginal candidiasis (VVC), an infection which occurs mainly during the luteal phase of the menstrual cycle or during the pregnancy, when levels of progesterone are elevated. One of the most important candidal virulence factors is the ability to adhere to host surfaces and form biofilms. The aim of this study was to determine the influence of progesterone on C. albicans virulence, namely biofilm formation and colonisation/invasion of a reconstituted human vaginal epithelium (RHVE). Biofilm formation on the RHVE was evaluated by enumeration of culturable cells, total mass quantification and scanning electron microscopy. The capacity of C. albicans strains to invade and colonise the tissue was examined by fluorescence microscopy using species-specific peptide nucleic acid (PNA) probe hybridisation, and quantitatively evaluated by RT-PCR Candida quantification methodology. Furthermore, gene (BCR1 and HWP1) expression of biofilm and RHVE-colonising cells was evaluated by quantitative RT-PCR. Results confirmed that progesterone reduced the capacity of C. albicans strains to form biofilms and to colonise and invade RHVE. Additionally, it was demonstrated that progesterone decreased expression of BCR1 and HWP1, which are important virulence determinants of C. albicans. In conclusion, it was evident that progesterone can have a major influence on C. albicans pathogenicity on vaginal epithelial cells and may partly explain susceptibility of women to VVC at different stages of the menstrual cycle.


Asunto(s)
Candida albicans/efectos de los fármacos , Candidiasis Vulvovaginal/microbiología , Epitelio/microbiología , Progesterona/metabolismo , Vagina/microbiología , Biopelículas/crecimiento & desarrollo , Candida albicans/crecimiento & desarrollo , Candida albicans/patogenicidad , Candida albicans/fisiología , Adhesión Celular , Recuento de Colonia Microbiana , Susceptibilidad a Enfermedades , Femenino , Perfilación de la Expresión Génica , Humanos , Microscopía Electrónica de Rastreo , Microscopía Fluorescente , Hibridación de Ácido Nucleico , Embarazo , Reacción en Cadena en Tiempo Real de la Polimerasa , Virulencia , Factores de Virulencia/análisis , Factores de Virulencia/genética
19.
PLoS One ; 9(8): e104175, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25148243

RESUMEN

OBJECTIVE: To evaluate the effect of atomoxetine treatment on executive functions in young adults with attention-deficit/hyperactivity disorder (ADHD). METHODS: In this Phase 4, multi-center, double-blind, placebo-controlled trial, young adults (18-30 years) with ADHD were randomized to receive atomoxetine (20-50 mg BID, N = 220) or placebo (N = 225) for 12 weeks. The Behavior Rating Inventory of Executive Function-Adult (BRIEF-A) consists of 75 self-report items within 9 nonoverlapping clinical scales measuring various aspects of executive functioning. Mean changes from baseline to 12-week endpoint on the BRIEF-A were analyzed using an ANCOVA model (terms: baseline score, treatment, and investigator). RESULTS: At baseline, there were no significant treatment group differences in the percentage of patients with BRIEF-A composite or index T-scores ≥60 (p>.5), with over 92% of patients having composite scores ≥60 (≥60 deemed clinically meaningful for these analyses). At endpoint, statistically significantly greater mean reductions were seen in the atomoxetine versus placebo group for the BRIEF-A Global Executive Composite (GEC), Behavioral Regulation Index (BRI), and Metacognitive Index (MI) scores, as well as the Inhibit, Self-Monitor, Working Memory, Plan/Organize and Task Monitor subscale scores (p<.05), with decreases in scores signifying improvements in executive functioning. Changes in the BRIEF-A Initiate (p = .051), Organization of Materials (p = .051), Shift (p = .090), and Emotional Control (p = .219) subscale scores were not statistically significant. In addition, the validity scales: Inconsistency (p = .644), Infrequency (p = .097), and Negativity (p = .456) were not statistically significant, showing scale validity. CONCLUSION: Statistically significantly greater improvement in executive function was observed in young adults with ADHD in the atomoxetine versus placebo group as measured by changes in the BRIEF-A scales. TRIAL REGISTRATION: ClinicalTrials.gov NCT00510276.


Asunto(s)
Inhibidores de Captación Adrenérgica/uso terapéutico , Trastorno por Déficit de Atención con Hiperactividad/tratamiento farmacológico , Trastorno por Déficit de Atención con Hiperactividad/psicología , Función Ejecutiva/efectos de los fármacos , Propilaminas/uso terapéutico , Inhibidores de Captación Adrenérgica/farmacología , Adulto , Clorhidrato de Atomoxetina , Femenino , Humanos , Masculino , Propilaminas/farmacología , Resultado del Tratamiento , Adulto Joven
20.
Med Microbiol Immunol ; 203(5): 341-55, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24924305

RESUMEN

Opportunistic oral infections caused by Candida albicans are frequent problems in immunocompromised patients. Management of such infections is limited due to the low number of antifungal drugs available, their relatively high toxicity and the emergence of antifungal resistance. Given these issues, our investigations have focused on novel derivatives of the antifungal antibiotic Nystatin A1, generated by modifications at the amino group of this molecule. The aims of this study were to evaluate the antifungal effectiveness and host cell toxicity of these new compounds using an in vitro model of oral candidosis based on a reconstituted human oral epithelium (RHOE). Initial studies employing broth microdilution, revealed that against planktonic C. albicans, Nystatin A1 had lower minimal inhibitory concentration than novel derivatives. However, Nystatin A1 was also markedly more toxic against human keratinocyte cells. Interestingly, using live/dead staining to assess C. albicans and tissue cell viability after RHOE infection, Nystatin A1 derivatives were more active against Candida with lower toxicity to epithelial cells than the parent drug. Lactate dehydrogenase activity released by the RHOE indicated a fourfold reduction in tissue damage when certain Nystatin derivatives were used compared with Nystatin A1. Furthermore, compared with Nystatin A1, colonisation of the oral epithelium by C. albicans was notably reduced by the new polyenes. In the absence of antifungal agents, confocal laser scanning microscopy showed that C. albicans extensively invaded the RHOE. However, the presence of the novel derivatives greatly reduced or totally prevented this fungal invasion.


Asunto(s)
Antifúngicos/química , Antifúngicos/farmacología , Candida albicans/efectos de los fármacos , Nistatina/análogos & derivados , Nistatina/farmacología , Antifúngicos/aislamiento & purificación , Antifúngicos/toxicidad , Línea Celular , Supervivencia Celular/efectos de los fármacos , Epitelio/microbiología , Humanos , Queratinocitos/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Nistatina/aislamiento & purificación , Nistatina/toxicidad , Técnicas de Cultivo de Órganos
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