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1.
Int J Retina Vitreous ; 10(1): 37, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38671486

RESUMO

BACKGROUND: Code-free deep learning (CFDL) is a novel tool in artificial intelligence (AI). This study directly compared the discriminative performance of CFDL models designed by ophthalmologists without coding experience against bespoke models designed by AI experts in detecting retinal pathologies from optical coherence tomography (OCT) videos and fovea-centered images. METHODS: Using the same internal dataset of 1,173 OCT macular videos and fovea-centered images, model development was performed simultaneously but independently by an ophthalmology resident (CFDL models) and a postdoctoral researcher with expertise in AI (bespoke models). We designed a multi-class model to categorize video and fovea-centered images into five labels: normal retina, macular hole, epiretinal membrane, wet age-related macular degeneration and diabetic macular edema. We qualitatively compared point estimates of the performance metrics of the CFDL and bespoke models. RESULTS: For videos, the CFDL model demonstrated excellent discriminative performance, even outperforming the bespoke models for some metrics: area under the precision-recall curve was 0.984 (vs. 0.901), precision and sensitivity were both 94.1% (vs. 94.2%) and accuracy was 94.1% (vs. 96.7%). The fovea-centered CFDL model overall performed better than video-based model and was as accurate as the best bespoke model. CONCLUSION: This comparative study demonstrated that code-free models created by clinicians without coding expertise perform as accurately as expert-designed bespoke models at classifying various retinal pathologies from OCT videos and images. CFDL represents a step forward towards the democratization of AI in medicine, although its numerous limitations must be carefully addressed to ensure its effective application in healthcare.

2.
Int J Numer Method Biomed Eng ; 40(5): e3812, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38544307

RESUMO

The lack of in vivo studies on the delivery of doxorubicin within human skin, especially the absence of data on the doxorubicin diffusion coefficient, has made understanding its transdermal delivery kinetics challenging. In this study, as a first step, governing equations and finite element methods were employed to reproduce Franz diffusion cell experiment in human cadaver skin. The application of this experiment representative model with a fitting method resulted in approximate values for the diffusivity of doxorubicin across various skin layers. The estimated values were used later to conduct a comprehensive examination of doxorubicin administration for breast tumor treatments. In a 2D axisymmetric model using Fick's Law and then a microneedles array 3D model, crucial parameters effects on delivery efficiency were examined, such as the microneedle tip diameter, tip-to-tip distance, and tumor depth. As highlighted by the findings of this study, these parameters have an impact on the effectiveness of doxorubicin delivery for treating breast tumors. The focus of this research is on the potential of numerical methods in biomedical engineering, which addresses the urgent need for data on doxorubicin diffusion in human skin and offers valuable insights into optimizing drug delivery strategies for enhanced therapeutic outcomes.


Assuntos
Administração Cutânea , Neoplasias da Mama , Doxorrubicina , Sistemas de Liberação de Medicamentos , Agulhas , Doxorrubicina/administração & dosagem , Doxorrubicina/farmacocinética , Humanos , Neoplasias da Mama/tratamento farmacológico , Feminino , Análise de Elementos Finitos , Pele/metabolismo , Modelos Biológicos , Difusão
3.
Int J Med Inform ; 178: 105178, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37657204

RESUMO

BACKGROUND AND OBJECTIVE: The detection of retinal diseases using optical coherence tomography (OCT) images and videos is a concrete example of a data classification problem. In recent years, Transformer architectures have been successfully applied to solve a variety of real-world classification problems. Although they have shown impressive discriminative abilities compared to other state-of-the-art models, improving their performance is essential, especially in healthcare-related problems. METHODS: This paper presents an effective technique named model-based transformer (MBT). It is based on popular pre-trained transformer models, particularly, vision transformer, swin transformer for OCT image classification, and multiscale vision transformer for OCT video classification. The proposed approach is designed to represent OCT data by taking advantage of an approximate sparse representation technique. Then, it estimates the optimal features, and performs data classification. RESULTS: The experiments are carried out using three real-world retinal datasets. The experimental results on OCT image and OCT video datasets show that the proposed method outperforms existing state-of-the-art deep learning approaches in terms of classification accuracy, precision, recall, and f1-score, kappa, AUC-ROC, and AUC-PR. It can also boost the performance of existing transformer models, including Vision transformer and Swin transformer for OCT image classification, and Multiscale Vision Transformers for OCT video classification. CONCLUSIONS: This work presents an approach for the automated detection of retinal diseases. Although deep neural networks have proven great potential in ophthalmology applications, our findings demonstrate for the first time a new way to identify retinal pathologies using OCT videos instead of images. Moreover, our proposal can help researchers enhance the discriminative capacity of a variety of powerful deep learning models presented in published papers. This can be valuable for future directions in medical research and clinical practice.

4.
Pilot Feasibility Stud ; 9(1): 158, 2023 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-37689724

RESUMO

BACKGROUND: Diabetic retinopathy is a leading cause of preventable blindness in Canada. Clinical guidelines recommend annual diabetic retinopathy screening for people living with diabetes to reduce the risk and progression of vision loss. However, many Canadians with diabetes do not attend screening. Screening rates are even lower in immigrants to Canada including people from China, Africa, and the Caribbean, and these groups are also at higher risk of developing diabetes complications. We aim to assess the feasibility, acceptability, and fidelity of a co-developed, linguistically and culturally tailored tele-retinopathy screening intervention for Mandarin-speaking immigrants from China and French-speaking immigrants from African-Caribbean countries living with diabetes in Ottawa, Canada, and identify how many from each population group attend screening during the pilot period. METHODS: We will work with our health system and patient partners to conduct a 6-month feasibility pilot of a tele-retinopathy screening intervention in a Community Health Centre in Ottawa. We anticipate recruiting 50-150 patients and 5-10 health care providers involved in delivering the intervention for the pilot. Acceptability will be assessed via a Theoretical Framework of Acceptability-informed survey with patients and health care providers. To assess feasibility, we will use a Theoretical Domains Framework-informed interview guide and to assess fidelity, and we will use a survey informed by the National Institutes of Health framework from the perspective of health care providers. We will also collect patient demographics (i.e., age, gender, ethnicity, health insurance status, and immigration information), screening outcomes (i.e., patients with retinopathy identified, patients requiring specialist care), patient costs, and other intervention-related variables such as preferred language. Survey data will be descriptively analyzed and qualitative data will undergo content analysis. DISCUSSION: This feasibility pilot study will capture how many people living with diabetes from each group attend the diabetic retinopathy screening, costs, and implementation processes for the tele-retinopathy screening intervention. The study will indicate the practicability and suitability of the intervention in increasing screening attendance in the target population groups. The study results will inform a patient-randomized trial, provide evidence to conduct an economic evaluation of the intervention, and optimize the community-based intervention.

5.
BMC Health Serv Res ; 23(1): 302, 2023 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-36991464

RESUMO

BACKGROUND: Diabetic retinopathy is a sight-threatening ocular complication of diabetes. Screening is an effective way to reduce severe complications, but screening attendance rates are often low, particularly for newcomers and immigrants to Canada and people from cultural and linguistic minority groups. Building on previous work, in partnership with patient and health system stakeholders, we co-developed a linguistically and culturally tailored tele-retinopathy screening intervention for people living with diabetes who recently immigrated to Canada from either China or African-Caribbean countries. METHODS: Following an environmental scan of diabetes eye care pathways in Ottawa, we conducted co-development workshops using a nominal group technique to create and prioritize personas of individuals requiring screening and identify barriers to screening that each persona may face. Next, we used the Theoretical Domains Framework to categorize the barriers/enablers and then mapped these categories to potential evidence-informed behaviour change techniques. Finally with these techniques in mind, participants prioritized strategies and channels of delivery, developed intervention content, and clarified actions required by different actors to overcome anticipated intervention delivery barriers. RESULTS: We carried out iterative co-development workshops with Mandarin and French-speaking individuals living with diabetes (i.e., patients in the community) who immigrated to Canada from China and African-Caribbean countries (n = 13), patient partners (n = 7), and health system partners (n = 6) recruited from community health centres in Ottawa. Patients in the community co-development workshops were conducted in Mandarin or French. Together, we prioritized five barriers to attending diabetic retinopathy screening: language (TDF Domains: skills, social influences), retinopathy familiarity (knowledge, beliefs about consequences), physician barriers regarding communication for screening (social influences), lack of publicity about screening (knowledge, environmental context and resources), and fitting screening around other activities (environmental context and resources). The resulting intervention included the following behaviour change techniques to address prioritized local barriers: information about health consequence, providing instructions on how to attend screening, prompts/cues, adding objects to the environment, social support, and restructuring the social environment. Operationalized delivery channels incorporated language support, pre-booking screening and sending reminders, social support via social media and community champions, and providing using flyers and videos as delivery channels. CONCLUSION: Working with intervention users and stakeholders, we co-developed a culturally and linguistically relevant tele-retinopathy intervention to address barriers to attending diabetic retinopathy screening and increase uptake among two under-served groups.


Assuntos
Diabetes Mellitus , Retinopatia Diabética , Emigrantes e Imigrantes , Humanos , Retinopatia Diabética/diagnóstico , Canadá , Linguística , Região do Caribe
6.
Med Image Anal ; 82: 102608, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36150271

RESUMO

Vision Transformers have recently emerged as a competitive architecture in image classification. The tremendous popularity of this model and its variants comes from its high performance and its ability to produce interpretable predictions. However, both of these characteristics remain to be assessed in depth on retinal images. This study proposes a thorough performance evaluation of several Transformers compared to traditional Convolutional Neural Network (CNN) models for retinal disease classification. Special attention is given to multi-modality imaging (fundus and OCT) and generalization to external data. In addition, we propose a novel mechanism to generate interpretable predictions via attribution maps. Existing attribution methods from Transformer models have the disadvantage of producing low-resolution heatmaps. Our contribution, called Focused Attention, uses iterative conditional patch resampling to tackle this issue. By means of a survey involving four retinal specialists, we validated both the superior interpretability of Vision Transformers compared to the attribution maps produced from CNNs and the relevance of Focused Attention as a lesion detector.


Assuntos
Algoritmos , Doenças Retinianas , Humanos , Redes Neurais de Computação , Fundo de Olho , Doenças Retinianas/diagnóstico por imagem , Retina/diagnóstico por imagem
7.
Colloids Surf B Biointerfaces ; 217: 112676, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35797773

RESUMO

Nowadays, there is a growing demand for effective cosmetic skincare products that can address the specific skin problems of consumers. Delivery systems play an important role in the effective action of cosmetic skincare formulations. Delivery systems are attractive and smart technologies used as carriers for cosmetic ingredients, which are sensitive to various physical factors such as light, oxygen, pH and temperature. Delivery systems offer several advantages: transport and protection of sensitive active compounds, controlled and targeted release of active ingredients. Several delivery systems, varying in chemical composition, with adaptable physicochemical characteristics (size, morphology, zeta potential, structure) as well as great advantages as carriers, are developed and described in the literature. This article reviews the current cosmetic active ingredients used in skincare products due to their beneficial properties such as antioxidant, anti-aging, photo-protective, anti-inflammatory, anti-microbial, etc.). In addition, the main advantages of several classes of delivery systems (emulsions, lipid nanoparticles, polymeric particles) are described, as well as some recent approaches used to ensure their efficacy (long-term stability, controlled release of the active, skin penetration/permeation) are reviewed. Finally, new trends to be considered for the development of delivery systems and cosmetic formulations are discussed.


Assuntos
Cosméticos , Nanopartículas , Cosméticos/química , Composição de Medicamentos , Sistemas de Liberação de Medicamentos , Lipossomos/farmacologia , Nanopartículas/química , Pele , Higiene da Pele/métodos
8.
Therapie ; 75(6): 537-542, 2020.
Artigo em Francês | MEDLINE | ID: mdl-32409207

RESUMO

Good clinical practice (GCP) is an international ethical and scientific quality standard for the design, conduct, performance, monitoring, auditing, recording, analyses and reporting of clinical trials. Before the start of a clinical trial, investigators commit to perform the research in accordance with GCPs, regulatory dispositions and protocol. The sponsors are responsible for investigators' selection and for controlling their skills. Whereas industrial sponsors systematically require a certificate of GCP training, academic sponsors seem to be less demanding. We have carried out two surveys between April and June 2018. A first questionnaire was sent to the 40 French academic directions of clinical research and innovation in order to determine their requirements about the GCP training of the investigators participating in their trials. The second questionnaire was transmitted to physicians of the "Bretagne recherche clinique hospitalière network": Rennes, Saint-Malo, Saint-Brieuc, Vannes, Lorient and Pontivy hospitals, in order to determine the GCP certification rate, and their needs in terms of clinical research training. Twenty-eight (70%) directions of clinical research answered the first survey, among which 18 (64%) required systematically the investigators' GCP certification in case of category 1 interventional studies. This rate decreased for category 2 (50%) and non-interventional category 3 (18%) studies. A total of 345 physicians answered the second survey, among which 263 (76%) had already been clinical trial investigators. However, only 29% of all physicians and 54% of those who had been principal investigator were certified for GCP training. These results support the need for large campaigns of GCP training in public hospitals.


Assuntos
Médicos , Pesquisadores , Certificação , Hospitais , Humanos , Inquéritos e Questionários
9.
JMIR Diabetes ; 5(2): e17309, 2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32255431

RESUMO

BACKGROUND: With the high prevalence of diabetic retinopathy and its significant visual consequences if untreated, timely identification and management of diabetic retinopathy is essential. Teleophthalmology programs have assisted in screening a large number of individuals at risk for vision loss from diabetic retinopathy. Training nonophthalmological readers to assess remote fundus images for diabetic retinopathy may further improve the efficiency of such programs. OBJECTIVE: This study aimed to evaluate the performance, safety implications, and progress of 2 ophthalmology nurses trained to read and assess diabetic retinopathy fundus images within a hospital diabetic retinopathy telescreening program. METHODS: In this retrospective interobserver study, 2 ophthalmology nurses followed a specific training program within a hospital diabetic retinopathy telescreening program and were trained to assess diabetic retinopathy images at 2 levels of intervention: detection of diabetic retinopathy (level 1) and identification of referable disease (level 2). The reliability of the assessment by level 1-trained readers in 266 patients and of the identification of patients at risk of vision loss from diabetic retinopathy by level 2-trained readers in 559 more patients were measured. The learning curve, sensitivity, and specificity of the readings were evaluated using a group consensus gold standard. RESULTS: An almost perfect agreement was measured in identifying the presence of diabetic retinopathy in both level 1 readers (κ=0.86 and 0.80) and in identifying referable diabetic retinopathy by level 2 readers (κ=0.80 and 0.83). At least substantial agreement was measured in the level 2 readers for macular edema (κ=0.79 and 0.88) for all eyes. Good screening threshold sensitivities and specificities were obtained for all level readers, with sensitivities of 90.6% and 96.9% and specificities of 95.1% and 85.1% for level 1 readers (readers A and B) and with sensitivities of 86.8% and 91.2% and specificities of 91.7% and 97.0% for level 2 readers (readers A and B). This performance was achieved immediately after training and remained stable throughout the study. CONCLUSIONS: Notwithstanding the small number of trained readers, this study validates the screening performance of level 1 and level 2 diabetic retinopathy readers within this training program, emphasizing practical experience, and allows the establishment of an ongoing assessment clinic. This highlights the importance of supervised, hands-on experience and may help set parameters to further calibrate the training of diabetic retinopathy readers for safe screening programs.

10.
Can J Ophthalmol ; 55(1 Suppl 1): 2-7, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31712019

RESUMO

BACKGROUND: Although many diabetic retinopathy (DR) tele-screening projects have shown effectiveness for DR, timely follow-up care after screening is essential to achieve the expected visual benefits of screening. OBJECTIVE: To better understand the possible factors of non-compliance to follow-up care in diabetics after tele-screening for DR. METHOD: This cross-sectional retrospective descriptive study analyses the data of 148 diabetics referred to follow-up care following screening of 1185 diabetics through an urban community-based DR Teleophthalmology Project aimed at Type 2 diabetes. A telephone survey was conducted to assess the screening program appreciation and the sociodemographic characteristics of that population. RESULTS: This study achieved a 91,9% (n=136) compliance rate to follow-up care. Female sex, type 2 diabetes, lower general and DR education, telephone unreachability, age less than 60 years, knowledge of a visually impaired acquaintance and more severe DR were more prevalent in non-compliant patients. Age, ethnicity, economic status, level of precariousness, distance from home to the screening/examination sites, and previous adherence to the DR screening guidelines were similar in both compliants and noncompliants. A high satisfaction score (4,8/5, n=96) to the tele-screening program was measured. CONCLUSION: This study is applicable to other screening programs and suggests that an increase in the number of recall letters and a greater flexibility in the organization of follow-up care appointments as well as the addition of multilingual members to the recalling team may have further improved compliance to follow-up care. It measures a high level of satisfaction provided by this model of urban teleophthalmology screening.


Assuntos
Assistência ao Convalescente , Continuidade da Assistência ao Paciente/estatística & dados numéricos , Retinopatia Diabética/diagnóstico , Fidelidade a Diretrizes , Programas de Rastreamento/métodos , Oftalmologia/métodos , Retina/diagnóstico por imagem , Telemedicina/métodos , Idoso , Estudos Transversais , Diabetes Mellitus Tipo 2/complicações , Feminino , Guias como Assunto , Humanos , Masculino , Pessoa de Meia-Idade , Avaliação de Programas e Projetos de Saúde , Estudos Retrospectivos , Tomografia de Coerência Óptica
11.
J Clin Med ; 8(12)2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31817056

RESUMO

The aim of this study was to evaluate, using two independent polymerase chain reaction (PCR) formats, the results of Campylobacter detection by the BD MAXTM Enteric Bacterial Panel PCR (Becton Dickinson, Le Pont de Claix, France) in the absence of positive culture. A total of 77 samples found positive for Campylobacter on BD MAXTM but negative by culture were studied. Upon reception, one in-house real-time-PCR for Campylobacter sp. and a PCR with the RIDAGENE Bacterial Stool Panel (r-biopharm, Darmstadt, Germany) were performed. The data obtained using these two PCR formats were evaluated with respect to the cycle threshold (Ct) and fluorescence intensity values (FI) obtained on BD MAXTM. Ct and FI values were also obtained for 80 positive Campylobacter cases by culture. Among the 77 samples, 33 were positive with the two PCRs, and 37 remained negative. For the 33 double-positive PCRs samples, the Ct values obtained on BD MAXTM were lower than 30 in 93.9%, and FI > 2000 for 97% of cases. For the 37 double-negative PCRs samples, the Ct values obtained on BD MAXTM were <30 in only 18.9%, however FI were >2000 for 40.5% of cases. Positive culture cases had Ct values < 30 in 96.2% and FI > 2000 in 98.8%. We showed that the Ct values obtained on BD MAXTM can help to interpret the results. Almost 96% of the Campylobacter sp. cases detected by culture or with the two reference PCRs positive showed a Ct value on BD MAXTM, meaning that stools detected as positive with BD MAXTM and having a Ct > 30 may be false positives.

12.
Can J Ophthalmol ; 54(3): 359-366, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31109477

RESUMO

OBJECTIVE: To assess real-world results and the impact on a hospital service corridor for screening for DR through an urban community teleophthalmology service. METHODS: Retrospective analysis at the hospital service corridor of 148 diabetics referred to it following DR teleophthalmology screening of 1185 type II diabetics. RESULTS: Of the screened diabetics, 87.4% (n = 1036) were exempted from face-to-face clinical examination (FFCE) in a traditional hospital eye care pathway and continued monitoring through teleophthalmology under a watch-and-wait attitude, while 12.5% (n = 148) were recommended for an FFCE. The FFCEs revealed that significant DR was present in 48.2% or in 5.6% of this screened diabetic population. Reasons for referral were findings of significant DR in 40.5%, of which diabetic macular edema (DME) represented 86.6%, other incidental significant sight-threatening findings represented 32.4% (4% of the screened diabetics), and insufficient image quality was obtained for the other 27.0%. Optical coherence tomography (OCT) imaging at FFCE confirmed DME in 26.4% and led to treatment. Patients referred for insufficient image quality showed significant pathology in 90.2%, of whom 63.4% underwent further monitoring or treatment. The readers requested the FFCEs for 148 patients within 1 month of the reading in 19.6%, 3 months in 26.3%, 4-12 months in 47.3%, and 12 months in 6.7% over the 34 months of the study. Compliance with FFCEs was 91.9%, absolute in 78.4% and relative in 21.5%. The availability of OCT at the imaging site would have impacted 4.5% of the screened diabetics by enabling teleophthalmology monitoring of 91.6%, identifying just-in-time interventions for DME treatments in 26.4% and reducing by 25% the need for referral of OCT-negative reader-identified DME. CONCLUSION: The FFCEs generated at the hospital service corridor by an urban community DR screening teleophthalmology project did not impact negatively on its services; moreover, the service corridor was exempted from providing FFCEs to 87.4% of the diabetic population it serves. This study may help provide cost-efficiency indications for a screening protocol that would include OCT availability at the imaging site and measure its positive effects. While DR of which DME was the main cause of referral for FFCE, incidental significant sight-threatening findings were significant and approached DR as a cause of referral; this supports the recommendation of continued human intervention in DR teleophthalmology screening at this time and for this population, until automatic computer-aided diagnosis systems can recognise biomarkers associated with other significant fundus diseases. As a secondary gain this project benefited individuals in need of care who were lost to the traditional eye care pathway. Good compliance with the follow-up FFCE further supports teleophthalmology in its effort to provide better access to DR screening.


Assuntos
Retinopatia Diabética/diagnóstico , Programas de Rastreamento/métodos , Oftalmologia/métodos , Telemedicina/métodos , População Urbana , Adulto , Retinopatia Diabética/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Retrospectivos , Tomografia de Coerência Óptica/métodos
13.
Food Chem ; 262: 21-29, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29751911

RESUMO

Antioxidant and cytocompatible chemically modified polysaccharides and their hydrogels were obtained by a biomimetic approach. For this purpose, carboxymethylpullulan grafted with ferulic acid (CMP-FA) was firstly synthesized with different substitution degrees (DSFA). Their hydrogels were secondly obtained by enzymatic cross-linking with laccase. Hydrogel swelling has been found dependent on both DSFA and media ionic strength. The CMP-FA antioxidant properties were evaluated by the DPPH method and ABTS assays. The DPPH radical scavenging effect was high for CMP-FA solutions (80% after 30 min) and lower for the corresponding hydrogels (70% after 7 h). The antibacterial properties of ferulic acid and CMP-FA derivatives were tested against Staphylococcus aureus but the minimal inhibitory concentration of CMP-FA was not reached in the range of concentrations studied. Finally the CMP-FA derivatives showed no cytotoxicity towards mouse fibroblast cells.


Assuntos
Antioxidantes/farmacologia , Ácidos Cumáricos/química , Glucanos/farmacologia , Hidrogéis/química , Hidrogéis/farmacologia , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Antioxidantes/química , Linhagem Celular , Ácidos Cumáricos/farmacologia , Fibroblastos/efeitos dos fármacos , Sequestradores de Radicais Livres/química , Sequestradores de Radicais Livres/farmacologia , Glucanos/química , Concentração de Íons de Hidrogênio , Lacase/química , Camundongos , Testes de Sensibilidade Microbiana , Concentração Osmolar , Staphylococcus aureus/efeitos dos fármacos
15.
Biomacromolecules ; 18(10): 3238-3251, 2017 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-28745896

RESUMO

Aminoguaiacol, the aminated derivative of guaiacol, a natural phenolic compound, was chemically grafted onto a polysaccharide (carboxymethylpullulan, CMP) in the presence of the activator agent 1-ethyl-3-(3-(dimethylamino)propyl)carbodiimide hydrochloride (EDCI). The grafted polysaccharides were characterized by FTIR and 1H NMR spectroscopy to confirm and quantify the grafting. All polysaccharide derivatives (grafting rates of aminoguaiacol between 16% and 58%) were soluble in water. Their physicochemical properties were studied in a dilute regime and a semidilute regime by light scattering, fluorescence, and rheology, showing associative properties with peculiar polysoap behavior. The antibacterial activities of the synthesized products against Staphyloccocus aureus were assessed using a counting method. The antioxidant activities of the derivatives were also highlighted using the α,α-diphenyl-ß-picrylhydrazyl (DPPH) method. Finally, the cytotoxicity of the derivatives was studied with fibroblast cells and they showed a very good cytocompatibility. Such polymers could be used to replace chemical preservatives in food and cosmetic aqueous formulations.


Assuntos
Antibacterianos/síntese química , Antioxidantes/síntese química , Glucanos/química , Guaiacol/análogos & derivados , Aminas/química , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Camundongos , Staphylococcus aureus/efeitos dos fármacos
16.
Ophthalmologica ; 231(1): 2-15, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24246998

RESUMO

Recent advances in the therapeutic options and approaches for diabetic retinopathy (DR) and diabetic macular edema (DME) have resulted in improved visual outcomes for many patients with diabetes. Yet, they have also created many clinical dilemmas for treating ophthalmologists and retina specialists, including treatment selection, initiation, frequency and duration. With this in mind, a panel of Canadian retina specialists met and discussed the current clinical evidence as well as specific situations and scenarios commonly encountered in daily practice. They also shared their experiences and therapeutic approaches. This document, containing a consensus on treatment algorithms for various clinical scenarios, is the result of their lengthy and in-depth discussions and considerations. The intent is to provide a step-by-step approach to the treatment of DR and DME. Although clinicians are encouraged to use and refer to these algorithms as a guide for various situations, they are not meant to be a replacement for sound clinical judgment.


Assuntos
Algoritmos , Retinopatia Diabética/terapia , Edema Macular/terapia , Canadá , Complicações do Diabetes , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 2/complicações , Retinopatia Diabética/diagnóstico , Feminino , Humanos , Degeneração Macular/diagnóstico , Edema Macular/diagnóstico , Masculino , Oftalmologia/organização & administração , Gravidez , Complicações na Gravidez , Sociedades Médicas
20.
Can J Ophthalmol ; 43(6): 658-68, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19020631

RESUMO

BACKGROUND: This study aimed to describe and measure the health results of a Category 3 teleophthalmology screening project for diabetic retinopathy (DR). Implemented through mobile screening imaging units located within pharmacies, the project had the goal of reaching unscreened diabetic patients in urban communities while lowering barriers to screening and saving medical resources. METHODS: Image capture of both eyes of 3505 known diabetic individuals was performed in the provinces of Quebec, British Columbia, Alberta, Manitoba, and Saskatchewan. A photographer performed fundus imaging, and a nurse used mild pupil dilation only when necessary to secure image quality. Screening was provided free of cost in the context of DR health days for DR screening. Through teleophthalmology, ophthalmologists proceeded with data and image interpretation, and timely referral when indicated. RESULTS: This project allowed the resumption of screening of over 38% of the cohort of known diabetics who reported never having undergone any eye examination with pupil dilation, and an additional 30% who reported not having been examined for over 2 years. All known diabetics were under the care of a general physician, and their mean diabetes duration, when known, was 8 years. DR pathology was found in 22.5% (20%-28%) of the cohort, 1.8% requiring urgent referral (within 30 days) as a result of the severity of the DR and 0.6% (0%-1.8%) requiring urgent referral for other reasons. An additional 8.7% (8.1%-19.5%) required ophthalmologic attention within 6 months because of DR and another 2.0% (0%-6.3%) between 6 months and 1 year. Incidental findings were found in 23%, the majority of which were related to cataract and dry macular degeneration. Urgent or significant incidental findings were found in 0.6% of the screened eyes. Pupil dilation with tropicamide 1% was deemed useful or necessary in 33.7% of the cohort. For 0.7% of the cohort, the images could not be interpreted because of poor image quality and for that reason had to be referred for a traditional dilated eye examination. Ophthalmologists were relieved of the examination of 85.6% of the screened diabetic individuals who benefited from screening without requiring a traditional ophthalmologic examination. On the other hand, ophthalmologists were required to provide urgent (within 30 days) services to 2% of the cohort, either because of threatening DR or because of incidental findings requiring rapid ophthalmologic attention. INTERPRETATION: This screening strategy for DR through mobile teleophthalmology imaging units efficiently lowered barriers to screening and created new screening opportunities for a large number of known diabetic individuals who were lost to the traditional health system. It has the potential to provide better outreach to diabetic populations while identifying individuals truly in need of the services of an ophthalmologist; at the same time it maximizes the use of limited ophthalmologic resources while favouring multidisciplinary collaborations. The significant incidental findings associated with screening highlight the need for ophthalmologic competencies during DR screening within a teleophthalmology approach. Further involvement of government health authorities is pivotal in embracing the opportunities provided by emerging technologies such as teleophthalmology and translating them into better outreach services to diabetic populations and thus better visual health results.


Assuntos
Retinopatia Diabética/diagnóstico , Técnicas de Diagnóstico Oftalmológico , Oftalmologia/métodos , Consulta Remota/métodos , Telepatologia/métodos , Idoso , Canadá , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Unidades Móveis de Saúde , População Urbana
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