Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 102
Filtrar
1.
PLoS Genet ; 20(8): e1011071, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39102428

RESUMO

Sortase-assembled pili contribute to virulence in many Gram-positive bacteria. In Enterococcus faecalis, the endocarditis and biofilm-associated pilus (Ebp) is polymerized on the membrane by sortase C (SrtC) and attached to the cell wall by sortase A (SrtA). In the absence of SrtA, polymerized pili remain anchored to the membrane (i.e. off-pathway). Here we show that the high temperature requirement A (HtrA) bifunctional chaperone/protease of E. faecalis is a quality control system that clears aberrant off-pathway pili from the cell membrane. In the absence of HtrA and SrtA, accumulation of membrane-bound pili leads to cell envelope stress and partially induces the regulon of the ceftriaxone resistance-associated CroRS two-component system, which in turn causes hyper-piliation and cell morphology alterations. Inactivation of croR in the OG1RF ΔsrtAΔhtrA background partially restores the observed defects of the ΔsrtAΔhtrA strain, supporting a role for CroRS in the response to membrane perturbations. Moreover, absence of SrtA and HtrA decreases basal resistance of E. faecalis against cephalosporins and daptomycin. The link between HtrA, pilus biogenesis and the CroRS two-component system provides new insights into the E. faecalis response to endogenous membrane perturbations.


Assuntos
Aminoaciltransferases , Proteínas de Bactérias , Biofilmes , Cisteína Endopeptidases , Enterococcus faecalis , Fímbrias Bacterianas , Chaperonas Moleculares , Fímbrias Bacterianas/genética , Fímbrias Bacterianas/metabolismo , Aminoaciltransferases/genética , Aminoaciltransferases/metabolismo , Enterococcus faecalis/genética , Cisteína Endopeptidases/genética , Cisteína Endopeptidases/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Biofilmes/crescimento & desenvolvimento , Membrana Celular/metabolismo , Regulação Bacteriana da Expressão Gênica , Virulência/genética , Antibacterianos/farmacologia , Ceftriaxona/farmacologia
2.
Mol Microbiol ; 121(5): 1021-1038, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38527904

RESUMO

Daptomycin is a last-line antibiotic commonly used to treat vancomycin-resistant Enterococci, but resistance evolves rapidly and further restricts already limited treatment options. While genetic determinants associated with clinical daptomycin resistance (DAPR) have been described, information on factors affecting the speed of DAPR acquisition is limited. The multiple peptide resistance factor (MprF), a phosphatidylglycerol-modifying enzyme involved in cationic antimicrobial resistance, is linked to DAPR in pathogens such as methicillin-resistant Staphylococcus aureus. Since Enterococcus faecalis encodes two paralogs of mprF and clinical DAPR mutations do not map to mprF, we hypothesized that functional redundancy between the paralogs prevents mprF-mediated resistance and masks other evolutionary pathways to DAPR. Here, we performed in vitro evolution to DAPR in mprF mutant background. We discovered that the absence of mprF results in slowed DAPR evolution and is associated with inactivating mutations in ftsH, resulting in the depletion of the chaperone repressor HrcA. We also report that ftsH is essential in the parental, but not in the ΔmprF, strain where FtsH depletion results in growth impairment in the parental strain, a phenotype associated with reduced extracellular acidification and reduced ability for metabolic reduction. This presents FtsH and HrcA as enticing targets for developing anti-resistance strategies.


Assuntos
Daptomicina , Enterococcus faecalis , Peptídeo Hidrolases , Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Proteínas de Bactérias/genética , Daptomicina/farmacologia , Farmacorresistência Bacteriana/genética , Enterococcus faecalis/genética , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/metabolismo , Enterococcus faecalis/enzimologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/metabolismo , Testes de Sensibilidade Microbiana , Mutação , Peptídeo Hidrolases/metabolismo , Peptídeo Hidrolases/genética
3.
PLoS Pathog ; 18(4): e1010434, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35390107

RESUMO

Enterococcus faecalis is a frequent opportunistic pathogen of wounds, whose infections are associated with biofilm formation, persistence, and recalcitrance toward treatment. We have previously shown that E. faecalis wound infection persists for at least 7 days. Here we report that viable E. faecalis are present within both immune and non-immune cells at the wound site up to 5 days after infection, raising the prospect that intracellular persistence contributes to chronic E. faecalis infection. Using in vitro keratinocyte and macrophage infection models, we show that E. faecalis becomes internalized and a subpopulation of bacteria can survive and replicate intracellularly. E. faecalis are internalized into keratinocytes primarily via macropinocytosis into single membrane-bound compartments and can persist in late endosomes up to 24 h after infection in the absence of colocalization with the lysosomal protease Cathepsin D or apparent fusion with the lysosome, suggesting that E. faecalis blocks endosomal maturation. Indeed, intracellular E. faecalis infection results in heterotypic intracellular trafficking with partial or absent labelling of E. faecalis-containing compartments with Rab5 and Rab7, small GTPases required for the endosome-lysosome trafficking. In addition, E. faecalis infection results in marked reduction of Rab5 and Rab7 protein levels which may also contribute to attenuated Rab incorporation into E. faecalis-containing compartments. Finally, we demonstrate that intracellular E. faecalis derived from infected keratinocytes are significantly more efficient in reinfecting new keratinocytes. Together, these data suggest that intracellular proliferation of E. faecalis may contribute to its persistence in the face of a robust immune response, providing a primed reservoir of bacteria for subsequent reinfection.


Assuntos
Enterococcus faecalis , Proteínas rab de Ligação ao GTP , Animais , Endossomos/metabolismo , Enterococcus faecalis/metabolismo , Lisossomos/metabolismo , Mamíferos , Proteínas rab de Ligação ao GTP/metabolismo , proteínas de unión al GTP Rab7
4.
PLoS Pathog ; 18(9): e1010766, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36067266

RESUMO

Wound infections are often polymicrobial in nature, biofilm associated and therefore tolerant to antibiotic therapy, and associated with delayed healing. Escherichia coli and Staphylococcus aureus are among the most frequently cultured pathogens from wound infections. However, little is known about the frequency or consequence of E. coli and S. aureus polymicrobial interactions during wound infections. Here we show that E. coli kills Staphylococci, including S. aureus, both in vitro and in a mouse excisional wound model via the genotoxin, colibactin. Colibactin biosynthesis is encoded by the pks locus, which we identified in nearly 30% of human E. coli wound infection isolates. While it is not clear how colibactin is released from E. coli or how it penetrates target cells, we found that the colibactin intermediate N-myristoyl-D-Asn (NMDA) disrupts the S. aureus membrane. We also show that the BarA-UvrY two component system (TCS) senses the environment created during E. coli and S. aureus mixed species interaction, leading to upregulation of pks island genes. Further, we show that BarA-UvrY acts via the carbon storage global regulatory (Csr) system to control pks expression. Together, our data demonstrate the role of colibactin in interspecies competition and show that it is regulated by BarA-UvrY TCS during interspecies competition.


Assuntos
Infecções por Escherichia coli , Proteínas de Escherichia coli , Proteínas de Membrana , Fosfotransferases , Policetídeos , Staphylococcus aureus , Fatores de Transcrição , Animais , Antibacterianos/metabolismo , Carbono/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Infecções por Escherichia coli/microbiologia , Proteínas de Escherichia coli/metabolismo , Humanos , Proteínas de Membrana/metabolismo , Camundongos , Mutagênicos/metabolismo , N-Metilaspartato/metabolismo , Peptídeos , Fosfotransferases/genética , Policetídeos/metabolismo , Staphylococcus/metabolismo , Staphylococcus aureus/genética , Staphylococcus aureus/metabolismo , Fatores de Transcrição/metabolismo , Infecção dos Ferimentos/microbiologia
5.
Graefes Arch Clin Exp Ophthalmol ; 262(8): 2651-2659, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38456927

RESUMO

PURPOSE: To analyze the radiological features of the lacrimal gland (LG) and extraocular muscle (EOM) in thyroid eye disease (TED) patients with severe subjective dry eye disease (DED) using magnetic resonance imaging (MRI) measurements. METHODS: In this cross-sectional study, mechanical ocular exposure, dry eye assessment and MRI data were collected. Patients were classified into non-severe subjective DED group with ocular surface disease index (OSDI) < 33 and severe subjective DED group with OSDI ≥ 33. Linear regression model was applied for comparing the OSDI < 33 and OSDI ≥ 33 group in TED patients. The predictive performance of MRI parameters and models was assessed by receiver operating characteristic curve (ROC) analysis. RESULTS: Consecutive 88 TED patients (176 eyes) were included in this study. In the OSDI < 33 group, 52 TED patients (104 eyes) with a mean clinical activity score (CAS) of 0.63 ± 0.75. In the OSDI ≥ 33 group, there are 36 TED patients (72 eyes), with a mean CAS of 1.50 ± 1.54. The age and sex of the patients were matched between the two groups. The OSDI ≥ 33 group had shorter tear break-up time, larger levator palpebrae superioris / superior rectus (LPS/SR), inferior rectus and lateral rectus, smaller LG, more inflammatory LPS/SR and inferior rectus than OSDI < 33 DED group (P < 0.05). In the linear regression analysis, compare to the OSDI < 33 DED group, the OSDI ≥ 33 group had larger medial rectus cross-sectional area (ß = 0.06, 95%CI: (0.02, 0.10), P = 0.008), larger inferior rectus cross-sectional area (ß = 0.06, 95%CI: (0.00, 0.12), P = 0.048), smaller LG cross-sectional area (ß = -0.14, 95%CI: (-0.25, -0.04), P = 0.008). In the ROC analysis, the area under curve of medial rectus, inferior rectus, LG, and combined model are 0.625, 0.640, 0.661 and 0.716, respectively. CONCLUSION: Multiparametric MRI parameters of the LG and EOM in TED patients with severe subjective DED were significantly altered. Novel models combining the cross-sectional area of LG, medial rectus and inferior rectus showed good predictive performance in TED patients with severe subjective DED.


Assuntos
Síndromes do Olho Seco , Oftalmopatia de Graves , Aparelho Lacrimal , Imageamento por Ressonância Magnética Multiparamétrica , Músculos Oculomotores , Curva ROC , Humanos , Músculos Oculomotores/diagnóstico por imagem , Masculino , Feminino , Estudos Transversais , Pessoa de Meia-Idade , Oftalmopatia de Graves/diagnóstico , Síndromes do Olho Seco/diagnóstico , Aparelho Lacrimal/diagnóstico por imagem , Imageamento por Ressonância Magnética Multiparamétrica/métodos , Adulto , Índice de Gravidade de Doença , Estudos Retrospectivos , Idoso
6.
Int Ophthalmol ; 44(1): 124, 2024 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-38430354

RESUMO

PURPOSE: Euthyroid Graves' ophthalmology (EGO) refers to the subgroup of thyroid eye disease patients with distinct clinical presentations. This study evaluated the ocular surface and meibomian gland changes in EGO patients. METHODS: A cross-sectional study was conducted at The Chinese University of Hong Kong including 34 EGO patients and 34 age-and sex- matched healthy controls. Outcome measures include anterior segment examination, keratographic and meibographic imaging. RESULTS: Between 34 EGO patients and 34 age and sex-matched healthy controls, EGO was associated with a higher ocular surface disease index (P < 0.01), higher severity of meibomian gland dropout (upper: P < 0.001, lower: P < 0.00001) and higher percentage of partial blinking (P = 0.0036). The worse affected eyes of the EGO patients were associated with corneal staining (P = 0.0019), eyelid telangiectasia (P = 0.0009), eyelid thickening (P = 0.0013), eyelid irregularity (P = 0.0054), meibomian gland plugging (P < 0.00001), expressibility (P < 0.00001), and meibum quality (P < 0.00001). When the two eyes of the same EGO patient were compared, the degree of meibomian gland dropout was higher among the worse affected eyes (upper: P < 0.00001, and lower: P < 0.00001). Tear meniscus height, lipid layer thickness, and noninvasive break-up time were comparable between the two eyes of EGO patients and also between EGO patients and healthy controls. TMH was positively correlated with the degree of exophthalmos (r = 0.383, P < 0.05). CONCLUSION: EGO patients have more ocular surface complications and meibomian gland dropouts than healthy controls. Almost 60% of them had dry eye symptoms, but aqueous deficiency was not apparent. Further studies are warranted to clarify the mechanism of dry eye in EGO. (249 words).


Assuntos
Síndromes do Olho Seco , Glândulas Tarsais , Humanos , Glândulas Tarsais/diagnóstico por imagem , Estudos Transversais , Síndromes do Olho Seco/diagnóstico , Síndromes do Olho Seco/etiologia , Piscadela , Lágrimas
7.
BMC Ophthalmol ; 23(1): 347, 2023 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-37550660

RESUMO

BACKGROUND: Thyroid eye disease is an extrathyroidal manifestation of Graves' disease and is associated with dry eye disease. This is the first systematic review and meta-analysis to evaluate the role of magnetic resonance imaging lacrimal gland parameters in thyroid eye disease diagnosis, activity grading, and therapeutic responses prediction. METHODS: Up to 23 August, 2022, 504 studies from PubMed and Cochrane Library were analyzed. After removing duplicates and imposing selection criteria, nine eligible studies were included. Risk of bias assessment was done. Meta-analyses were performed using random-effect model if heterogeneity was significant. Otherwise, fixed-effect model was used. Main outcome measures include seven structural magnetic resonance imaging parameters (lacrimal gland herniation, maximum axial area, maximum coronal area, maximum axial length, maximum coronal length, maximum axial width, maximum coronal width), and three functional magnetic resonance imaging parameters (diffusion tensor imaging-fractional anisotropy, diffusion tensor imaging-apparent diffusion coefficient or mean diffusivity, diffusion-weighted imaging-apparent diffusion coefficient). RESULTS: Thyroid eye disease showed larger maximum axial area, maximum coronal area, maximum axial length, maximum axial width, maximum coronal width, diffusion tensor imaging-apparent diffusion coefficient/ mean diffusivity, and lower diffusion tensor imaging-fractional anisotropy than controls. Active thyroid eye disease showed larger lacrimal gland herniation, maximum coronal area, diffusion-weighted imaging-apparent diffusion coefficient than inactive. Lacrimal gland dimensional (maximum axial area, maximum coronal area, maximum axial length, maximum axial width, maximum coronal width) and functional parameters (diffusion tensor imaging-apparent diffusion coefficient, diffusion tensor imaging-apparent diffusion coefficient) could be used for diagnosing thyroid eye disease; lacrimal gland herniation, maximum coronal area, and diffusion-weighted imaging-apparent diffusion coefficient for differentiating active from inactive thyroid eye disease; diffusion tensor imaging parameters (diffusion tensor imaging-fractional anisotropy, diffusion tensor imaging-mean diffusivity) and lacrimal gland herniation for helping grading and therapeutic responses prediction respectively. CONCLUSIONS: Magnetic resonance imaging lacrimal gland parameters can detect active thyroid eye disease and differentiate thyroid eye disease from controls. Maximum coronal area is the most effective indicator for thyroid eye disease diagnosis and activity grading. There are inconclusive results showing whether structural or functional lacrimal gland parameters have diagnostic superiority. Future studies are warranted to determine the use of magnetic resonance imaging lacrimal gland parameters in thyroid eye disease.


Assuntos
Oftalmopatia de Graves , Aparelho Lacrimal , Humanos , Oftalmopatia de Graves/diagnóstico por imagem , Oftalmopatia de Graves/patologia , Aparelho Lacrimal/diagnóstico por imagem , Aparelho Lacrimal/patologia , Imagem de Tensor de Difusão/métodos , Imageamento por Ressonância Magnética , Avaliação de Resultados em Cuidados de Saúde
8.
Int Ophthalmol ; 43(8): 2971-2981, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37000311

RESUMO

PURPOSE: The purpose of the study was to describe the cases of intraocular inflammation following COVID-19 vaccination (Comirnaty mRNA vaccine and CoronaVac vaccine) in Hong Kong. METHODS: This was a retrospective case series. RESULTS: This series includes 16 eyes among 10 female patients, with a mean age of 49.4 ± 17.4 years. Eight patients (80%) received the Pfizer-BioNTech mRNA vaccination. Anterior uveitis was the most common presentation of postvaccination uveitis (50%) observed in our series, followed by intermediate uveitis (30%) and posterior uveitis (20%), respectively. A case of retinal vasculitis in the form of frosted branch angiitis, previously only reported following COVID-19 infection, was observed following COVID-19 vaccination. The median time from vaccination to uveitis onset was 15.2 days (range: 0-6 weeks). Inflammation in 11 out 16 eyes (68.75%) was completely resolved with topical steroids. CONCLUSION: Anterior uveitis was the predominant presentations of uveitis flare-ups following COVID-19 in our case series, followed by intermediate uveitis. Aligning with the current global literature concerning this issue, most of the uveitis attacks presented as anterior uveitis and were completely resolved with topical steroids. Consequently, the risk of uveitis flare-ups should not deter the public from receiving COVID-19 vaccines.


Assuntos
COVID-19 , Uveíte Anterior , Uveíte Intermediária , Uveíte , Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Idoso , Vacinas contra COVID-19/efeitos adversos , Estudos Retrospectivos , COVID-19/prevenção & controle , Uveíte/diagnóstico , Uveíte/etiologia , Inflamação/etiologia , Uveíte Anterior/diagnóstico , Uveíte Anterior/etiologia , Vacinação/efeitos adversos
9.
Ophthalmic Physiol Opt ; 42(6): 1326-1337, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36102169

RESUMO

INTRODUCTION: To compare intrasession agreement and repeatability of wavefront aberration measurements from three different aberrometers obtained using Hartmann-Shack, ray tracing and automated retinoscopy methods, as well as their interdevice agreement. METHODS: Three consecutive measurements were obtained using the Pentacam AXL Wave, the iTrace and the OPD-Scan III in 47 eyes of 47 patients. Wavefront refractions, root mean square of total aberrations (RMS total), RMS of higher-order aberrations (HOA) and second-, third- and fourth-order HOAs were exported for 4-mm pupils. Wavefront refractions were converted into vector components: M, J0 and J45 . Intrasession agreement and repeatability were evaluated using intraclass correlation coefficients (ICCs) and repeatability coefficients (RCs); interdevice agreement was assessed using the Bland-Altman method. RESULTS: The intrasession agreement and repeatability of RMS HOA were comparable between the three devices; both the Pentacam AXL Wave and the OPD-Scan III had better intrasession agreement and repeatability for the RMS total than the iTrace (p ≤ 0.02). Intrasession repeatability for the majority of second- and third-order aberrations was better on the Pentacam AXL Wave than on the iTrace (p ≤ 0.01) and OPD-Scan III (p ≤ 0.04), although their agreement and repeatability in spherical aberration were comparable (p ≥ 0.24). Significant systematic differences and proportional bias were detected for almost all refraction power vectors and Zernike coefficients among the three devices. CONCLUSIONS: In this study, all three devices provided good-to-excellent agreement for aberration measurements. Most of the individual Zernike's components were not exchangeable between different aberrometers. Their relative intrasession performance in agreement and repeatability varied significantly across different ocular aberration parameters.


Assuntos
Aberrações de Frente de Onda da Córnea , Humanos , Aberrometria/métodos , Refração Ocular , Reprodutibilidade dos Testes , Retinoscopia
10.
Clin Exp Ophthalmol ; 50(4): 398-406, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35218134

RESUMO

BACKGROUND: We investigated the ocular surface disturbances in COVID-19 patients discharged from the hospital. METHODS: One hundred and seventy-nine eyes of 109 healthy participants and 456 eyes of 228 post-COVID-19 patients received comprehensive eye examinations; the latter were interviewed with questionnaires on ocular symptoms before and after COVID-19 diagnosis. Associations of ocular surface manifestations with virological and ophthalmic parameters were evaluated by multivariable mixed linear or logistic regression models. RESULTS: Mean interval between COVID-19 diagnosis and ophthalmic evaluation was 52.23 ± 16.12 days. The severity of meibomian gland dysfunction (MGD) based on clinical staging was higher in post-COVID-19 than healthy eyes (1.14 ± 0.67 vs. 0.92 ± 0.68, p = 0.002) and so was ocular surface staining score (0.60 ± 0.69 vs. 0.49 ± 0.68, p = 0.044). Patients requiring supplementary oxygen during hospitalisation had shorter tear break-up time (ß -1.63, 95% CI -2.61 to -0.65). Cycle threshold (Ct) value from upper respiratory samples (inversely correlated with viral load) at diagnosis had an OR = 0.91 (95% CI 0.84-0.98) with new ocular surface symptoms 4 weeks after diagnosis. The presence of ocular surface symptoms 1 week prior to COVID-19 diagnosis showed an OR of 20.89 (95% CI 6.35-68.66) of persistent or new ocular symptoms 4 weeks afterward. CONCLUSIONS: MGD and ocular surface staining are more common and severe in post-COVID-19 patients. Patients with higher viral loads have greater risks of ocular surface symptoms. Patients requiring supplementary oxygen are more likely to show tear film instability. Ocular surface evaluation should be considered 1-3 months following hospital discharge for any COVID-19 patient.


Assuntos
COVID-19 , Síndromes do Olho Seco , Doenças Palpebrais , Disfunção da Glândula Tarsal , COVID-19/epidemiologia , Teste para COVID-19 , Síndromes do Olho Seco/diagnóstico , Humanos , Glândulas Tarsais , Oxigênio , Lágrimas
11.
Orbit ; 41(3): 292-296, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33427549

RESUMO

PURPOSE: To describe a reproducible and easily available goat socket model for training of various oculoplastic operations, and to evaluate trainees' perception of this training model in terms of their learning progress and satisfaction. METHODS: Goat sockets including orbital rim and eye with eyelids were harvested in form of a split-head model. Ophthalmology residents underwent individual surgical training using the goat socket model, supervised by an oculoplastic attending. Participants completed a questionnaire in form of a 5-point Likert Scale to evaluate their learning progress and satisfaction. OUTCOME MEASURES: Types of oculoplastic operations performed using the goat socket models, and participants' rating of their learning progress and satisfaction were reported. RESULTS: A wide range of oculoplastic operations including both eyelid and orbital operations could be simulated because of similarities of the goat eye model to the human eye anatomy. Fifteen ophthalmic trainees participated in surgical training using the goat eye model. All (100%) participants agreed that surgical simulation using the goat socket model increased their skills in surgical instrumentation and carrying out surgical steps, and their confidence in operating on patients. Most (87%) agreed the model resembled reasonably well compared to surgeries in human, and 93% would recommend training with the model to fellow resident ophthalmologists before operating on human patients. CONCLUSIONS: Oculoplastic surgical training using goat sockets is simple, readily available, and inexpensive. Trainee users showed promising feedback and positive learning progress using the goat socket model.


Assuntos
Pálpebras , Cabras , Animais , Competência Clínica , Pálpebras/cirurgia , Humanos , Procedimentos Cirúrgicos Oftalmológicos , Órbita/cirurgia
12.
Clin Exp Ophthalmol ; 49(3): 228-241, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33667017

RESUMO

BACKGROUND: Standard epithelium-off collagen cross-linking using Dresden protocol (S-CXL) is the standard of care for progressive keratoconus. Despite its efficacy, epithelial debridement is associated with pain, delayed visual rehabilitation, stromal oedema and haze. Minimising these complications while achieving a comparable efficacy remains an unmet need. METHODS: Comparative studies between transepithelial iontophoresis-assisted CXL (I-CXL) and S-CXL reporting the outcomes of visual, refractive, topographic, aberrometry, demarcation line, endothelial cell density, confocal microscopy or complications were identified from databases. Assessments of publication bias, meta-analyses, sensitivity analysis, subgroup analysis, and meta-regressions were performed. RESULTS: In this meta-analysis, 586 eyes from three randomised controlled trials and seven comparative studies were analysed. No differences were found in the change in uncorrected/corrected distance visual acuities, mean/maximum keratometry, central corneal thickness, higher order aberration, spherical aberration, coma, subbasal nerve/anterior stromal keratocyte density and demarcation line depth in both CXL protocols (P ≥ .052). However, I-CXL resulted in less thinning at the minimum pachymetry (standardised mean difference 0.25; 95% confidence interval [CI] 0.06-0.44). More importantly, there was a significant reduction in complications following I-CXL (odds ratio 0.30; 95% CI 0.12-0.75). Meta-regression analyses on demarcation line depth and complication suggested that I-CXL was more effective than S-CXL when baseline maximum keratometry was >55.2 D and the risk of complication was independent of other baseline covariates. CONCLUSION: I-CXL has a more favourable safety profile, as evidenced by the available literature, with less thinning at the minimum pachymetry and reduced risk of complications while achieving comparable effects on visual, refractive, topographic, aberrometry, and morphological outcomes as S-CXL.


Assuntos
Ceratocone , Fotoquimioterapia , Colágeno , Topografia da Córnea , Reagentes de Ligações Cruzadas , Humanos , Iontoforese , Ceratocone/diagnóstico , Ceratocone/tratamento farmacológico , Metanálise como Assunto , Fármacos Fotossensibilizantes/uso terapêutico , Riboflavina/uso terapêutico , Raios Ultravioleta
13.
Infect Immun ; 88(6)2020 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-32229614

RESUMO

Bacterial pathogens encounter a variety of nutritional environments in the human host, including nutrient metal restriction and overload. Uptake of manganese (Mn) is essential for Enterococcus faecalis growth and virulence; however, it is not known how this organism prevents Mn toxicity. In this study, we examine the role of the highly conserved MntE transporter in E. faecalis Mn homeostasis and virulence. We show that inactivation of mntE results in growth restriction in the presence of excess Mn, but not other metals, demonstrating its specific role in Mn detoxification. Upon growth in the presence of excess Mn, an mntE mutant accumulates intracellular Mn, iron (Fe), and magnesium (Mg), supporting a role for MntE in Mn and Fe export and a role for Mg in offsetting Mn toxicity. Growth of the mntE mutant in excess Fe also results in increased levels of intracellular Fe, but not Mn or Mg, providing further support for MntE in Fe efflux. Inactivation of mntE in the presence of excess iron also results in the upregulation of glycerol catabolic genes and enhanced biofilm growth, and addition of glycerol is sufficient to augment biofilm growth for both the mntE mutant and its wild-type parental strain, demonstrating that glycerol availability significantly enhances biofilm formation. Finally, we show that mntE contributes to colonization of the antibiotic-treated mouse gastrointestinal (GI) tract, suggesting that E. faecalis encounters excess Mn in this niche. Collectively, these findings demonstrate that the manganese exporter MntE plays a crucial role in E. faecalis metal homeostasis and virulence.


Assuntos
Proteínas de Bactérias/metabolismo , Enterococcus faecalis/metabolismo , Infecções por Bactérias Gram-Positivas/microbiologia , Manganês/metabolismo , Animais , Biofilmes , Transporte Biológico , Modelos Animais de Doenças , Trato Gastrointestinal/microbiologia , Homeostase , Espaço Intracelular/metabolismo , Manganês/toxicidade , Metais/metabolismo , Camundongos
14.
Exp Eye Res ; 181: 185-189, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30721670

RESUMO

Periorbital adipose tissue expansion is a key pathological change in thyroid associated orbitopathy (TAO). Bone morphogenic protein 4 (BMP4) is instrumental in adipogenesis. We compared site-specific BMP4 expression and its effect on adipogenesis using donor-matched adipose tissue-derived stromal cells (ADSC) from TAO patients. In this study, ADSC were generated from periorbital (eyelid, orbital) and subcutaneous (abdominal) adipose tissue. BMP4 expression was characterized by RT-PCR and immunofluorescent staining and compared among ADSC from the three anatomic depots. Effects on adipogenesis after knocking down endogenous BMP4 were quantified by adipogenic markers PPARγ and perilipin. Exogenous BMP4 protein was added after BMP4 knockdown to study the role of BMP4 in adipogenesis. Our results showed that BMP4 staining in periorbital adipose tissue was stronger than those in subcutaneous. BMP4 mRNA expression was higher in eyelid (4.4-2489.4-fold) and orbital (6.9-1811-fold) than that of subcutaneous ADSC, whereas expression fell during induced adipogenesis. After BMP4 knockdown, both adipogenic markers PPARγ (eyelid: 1.7-fold, p = 0.038; orbital: 1.4-fold, p = 0.126) and perilipin (eyelid:1.7-fold, p = 0.001; orbital:2.6-fold, p = 0.066) increased in periorbital ADSC upon induction. These increased expression fell after adding exogenous BMP4 protein. Our findings demonstrated higher BMP4 expression was found in periorbital ADSC and adipose tissue compared to donor-matched subcutaneous counterparts, which fell during adipogenic induction. Knocking down BMP4 expression further enhanced adipogenesis in periorbital ADSC. This effect was reversed by adding exogenous BMP4 protein. We suggested a novel role of BMP4 in modulating site-specific adipogenesis in TAO patients.


Assuntos
Adipócitos/metabolismo , Adipogenia/genética , Proteína Morfogenética Óssea 4/genética , Regulação da Expressão Gênica , Oftalmopatia de Graves/genética , RNA/genética , Adipócitos/patologia , Adolescente , Adulto , Idoso , Proteína Morfogenética Óssea 4/biossíntese , Células Cultivadas , Feminino , Oftalmopatia de Graves/metabolismo , Oftalmopatia de Graves/patologia , Humanos
15.
Retina ; 39(9): 1742-1750, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29952919

RESUMO

PURPOSE: To characterize the choriocapillaris (CC) in highly myopic eyes with myopic maculopathy, using optical coherence tomographic angiography. METHODS: Prospective, clinic-based study of 42 eyes of 38 patients with high myopia (≤-6 diopters and axial length ≥26.5 mm). Myopic maculopathy was graded from fundus photographs according to the Meta-Analysis for Pathologic Myopia classification. Macular 3 × 3 mm en face optical coherence tomographic angiographic images were obtained with swept-source optical coherence tomographic angiography and graded for CC flow impairment as follows: 1) intact CC, 2) focal (<1 mm), and 3) extensive (>1 mm). RESULTS: Of the 42 eyes, 17 (39.5%) had tessellated fundus, 20 (46.5%) had diffuse, and 6 (14.0%) had patchy atrophy. Choriocapillaris flow impairment was observed in all eyes with diffuse and patchy atrophy. Even in eyes with tessellated fundus only, CC signal voids were seen in 3 eyes (17.6%). With increasingly severe myopic maculopathy, the pattern of CC flow impairment changed from predominantly focal to predominantly extensive. CONCLUSION: Choriocapillaris flow impairment was observed in many highly myopic eyes, even in those with mild fundus changes, and worsened with increasing severity of myopic maculopathy. Longitudinal studies are needed to assess whether CC flow impairment predicts the risk of myopic maculopathy progression.


Assuntos
Corioide/irrigação sanguínea , Degeneração Macular/patologia , Miopia Degenerativa/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Capilares/diagnóstico por imagem , Capilares/patologia , Estudos Transversais , Feminino , Angiofluoresceinografia , Humanos , Degeneração Macular/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Miopia Degenerativa/diagnóstico por imagem , Estudos Prospectivos , Estudos Retrospectivos , Tomografia de Coerência Óptica
17.
Clin Exp Ophthalmol ; 47(7): 918-924, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31034694

RESUMO

IMPORTANCE: To investigate the choroidal thickness (CT) in patients with thyroid-associated orbitopathy (TAO). BACKGROUND: To compare CT of TAO patients and healthy subjects. DESIGN: Prospective cross-sectional study in a public hospital. PARTICIPANTS: One hundred and four eyes of 52 TAO patients and 52 eyes of 26 healthy subjects. METHODS: CT was measured with enhanced-depth imaging optical coherence tomography (EDI-OCT) at the subfoveal, macular and peripapillary regions. Multivariate linear regression was used to evaluate the associations of subfoveal CT with systemic and ocular variables among TAO eyes. MAIN OUTCOME MEASURES: CT of both groups. RESULTS: CT of eyes with TAO was significantly increased at the subfoveal region, 1 and 2 mm from the fovea nasally, temporally and superiorly, and 1 mm inferior to the fovea (all P < .05). No significant difference was found in CT at 2 mm inferior to the fovea (P = .094) and all four quadrants of the peripapillary region (superior, P = .096; nasal, P = .732; inferior, P = .179; temporal, P = .052). Among TAO eyes, thinner subfoveal choroid was associated with worsening exophthalmos (P = .043), poorer visual acuity (P = .017), increasing age (P = .040) and axial length (P < .001). There was no association between CT and clinical activity score (P = .239). CONCLUSIONS AND RELEVANCE: TAO patients showed thicker choroid than controls over the macula, but not the peripapillary regions. Thinner subfoveal choroid was associated with worsening exophthalmos and poorer vision. EDI-OCT can monitor choroidal vascular changes associated with TAO and its complications.


Assuntos
Corioide/patologia , Oftalmopatia de Graves/patologia , Adulto , Corioide/diagnóstico por imagem , Estudos Transversais , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Estudos Prospectivos , Tomografia de Coerência Óptica , Acuidade Visual
19.
J Am Chem Soc ; 140(47): 16140-16151, 2018 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-30388366

RESUMO

New strategies are urgently needed to target MRSA, a major global health problem and the leading cause of mortality from antibiotic-resistant infections in many countries. Here, we report a general approach to this problem exemplified by the design and synthesis of a vancomycin-d-octaarginine conjugate (V-r8) and investigation of its efficacy in addressing antibiotic-insensitive bacterial populations. V-r8 eradicated MRSA biofilm and persister cells in vitro, outperforming vancomycin by orders of magnitude. It also eliminated 97% of biofilm-associated MRSA in a murine wound infection model and displayed no acute dermal toxicity. This new dual-function conjugate displays enhanced cellular accumulation and membrane perturbation as compared to vancomycin. Based on its rapid and potent activity against biofilm and persister cells, V-r8 is a promising agent against clinical MRSA infections.


Assuntos
Antibacterianos/uso terapêutico , Biofilmes/efeitos dos fármacos , Peptídeos Penetradores de Células/uso terapêutico , Staphylococcus aureus Resistente à Meticilina/fisiologia , Vancomicina/análogos & derivados , Vancomicina/uso terapêutico , Animais , Antibacterianos/síntese química , Antibacterianos/farmacologia , Antibacterianos/toxicidade , Linhagem Celular , Peptídeos Penetradores de Células/síntese química , Peptídeos Penetradores de Células/farmacologia , Peptídeos Penetradores de Células/toxicidade , Desenho de Fármacos , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Testes de Sensibilidade Microbiana , Oligopeptídeos/síntese química , Oligopeptídeos/farmacologia , Oligopeptídeos/uso terapêutico , Oligopeptídeos/toxicidade , Vancomicina/farmacologia , Vancomicina/toxicidade , Enterococos Resistentes à Vancomicina/efeitos dos fármacos , Enterococos Resistentes à Vancomicina/fisiologia
20.
Biotechnol Bioeng ; 115(8): 2000-2012, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29665026

RESUMO

Anhydrous polymers are actively explored as alternative materials to overcome limitations of conventional hydrogel-based antibacterial coating. However, the requirement for strong organic solvent in polymerization reactions often necessitates extra protection steps for encapsulation of target biomolecules, lowering encapsulation efficiency, and increasing process complexity. This study reports a novel coating strategy that allows direct solvation and encapsulation of antimicrobial peptides (HHC36) into anhydrous polycaprolactone (PCL) polymer-based dual layer coating. A thin 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) film is layered onto the peptide-impregnated PCL as a diffusion barrier, to modulate and enhance release kinetics. The impregnated peptides are eventually released in a controlled fashion. The use of 2,2,2-trifluoroethanol (TFE), as polymerization and solvation medium, induces the impregnated peptides to adopt highly stable turned conformation, conserving peptide integrity, and functionality during both encapsulation and subsequent release processes. The dual layer coating showed sustained antibacterial functionality, lasting for 14 days. In vivo assessment using an experimental mouse wounding model demonstrated good biocompatibility and significant antimicrobial efficacy of the coating under physiological conditions. The coating was translated onto silicone urinary catheters and showed promising antibacterial efficacy, even outperforming commercial silver-based Dover cather. This anhydrous polymer-based platform holds immense potential as an effective antibacterial coating to prevent clinical device-associated infections. The simplicity of the coating process enhances its industrial viability.


Assuntos
Anti-Infecciosos/farmacocinética , Peptídeos Catiônicos Antimicrobianos/farmacocinética , Preparações de Ação Retardada/administração & dosagem , Portadores de Fármacos/administração & dosagem , Sistemas de Liberação de Medicamentos , Poliésteres/administração & dosagem , Animais , Anti-Infecciosos/administração & dosagem , Peptídeos Catiônicos Antimicrobianos/administração & dosagem , Infecções Relacionadas a Cateter/prevenção & controle , Modelos Animais de Doenças , Camundongos , Infecções Urinárias/prevenção & controle , Infecção dos Ferimentos/prevenção & controle
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA