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1.
Proc Natl Acad Sci U S A ; 117(52): 33051-33060, 2020 12 29.
Artigo em Inglês | MEDLINE | ID: mdl-33318169

RESUMO

Microscopic evaluation of resected tissue plays a central role in the surgical management of cancer. Because optical microscopes have a limited depth-of-field (DOF), resected tissue is either frozen or preserved with chemical fixatives, sliced into thin sections placed on microscope slides, stained, and imaged to determine whether surgical margins are free of tumor cells-a costly and time- and labor-intensive procedure. Here, we introduce a deep-learning extended DOF (DeepDOF) microscope to quickly image large areas of freshly resected tissue to provide histologic-quality images of surgical margins without physical sectioning. The DeepDOF microscope consists of a conventional fluorescence microscope with the simple addition of an inexpensive (less than $10) phase mask inserted in the pupil plane to encode the light field and enhance the depth-invariance of the point-spread function. When used with a jointly optimized image-reconstruction algorithm, diffraction-limited optical performance to resolve subcellular features can be maintained while significantly extending the DOF (200 µm). Data from resected oral surgical specimens show that the DeepDOF microscope can consistently visualize nuclear morphology and other important diagnostic features across highly irregular resected tissue surfaces without serial refocusing. With the capability to quickly scan intact samples with subcellular detail, the DeepDOF microscope can improve tissue sampling during intraoperative tumor-margin assessment, while offering an affordable tool to provide histological information from resected tissue specimens in resource-limited settings.


Assuntos
Carcinoma/patologia , Aprendizado Profundo , Processamento de Imagem Assistida por Computador/métodos , Neoplasias Bucais/patologia , Algoritmos , Animais , Biópsia/instrumentação , Biópsia/métodos , Biópsia/normas , Calibragem , Humanos , Processamento de Imagem Assistida por Computador/instrumentação , Processamento de Imagem Assistida por Computador/normas , Microscopia de Fluorescência/instrumentação , Microscopia de Fluorescência/métodos , Microscopia de Fluorescência/normas , Suínos
2.
Int J Cancer ; 148(10): 2571-2578, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33368249

RESUMO

Cervical cancer remains a leading cause of cancer death for women in low- and middle-income countries. The goal of our study was to evaluate screening and triage strategies, including high-resolution microendoscopy (HRME), to detect cervical abnormalities concerning for precancer at the point of care. Women (n = 1824) were enrolled at the Instituto de Cáncer de El Salvador. All underwent screening by both human papillomavirus (HPV) testing using careHPV and visual inspection with acetic acid (VIA). Screen-positives, along with 10% of screen-negatives, were invited to return for a follow-up examination that included triage with VIA, colposcopy and HRME imaging. Biopsies were taken of any abnormalities identified. If no abnormalities were identified, then the worst scoring site by HRME was biopsied. The sensitivities of HPV testing and VIA to screen for cervical intraepithelial neoplasia Grade 2 or more severe diagnoses (CIN2+) were 82.1% and 75% (P = .77), while the specificities were 90.4% and 80.9% (P < .001), respectively. The sensitivities of VIA, colposcopy and HRME as triage tests for CIN2+ were 82.1%, 82.1% and 71.4%, respectively (P ≥ .38). HRME had a significantly higher specificity (66.7%) than VIA (51.9%) (P < .001) and colposcopy (53.3%) (P < .001). When evaluating different theoretical screening and triage strategies, screening with HPV testing followed by triage with HRME would result in more women receiving appropriate care (97%) compared to screening with VIA (75%) or HPV alone (90%). Our findings demonstrate that screening with HPV is superior to VIA, and that triage with HRME imaging increases the specificity of detecting CIN2+ at the point of care in a low-resource setting.

3.
Anal Chem ; 93(11): 4832-4840, 2021 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-33689292

RESUMO

Sickle cell disease (SCD) is a group of common, life-threatening disorders caused by a point mutation in the ß globin gene. Early diagnosis through newborn and early childhood screening, parental education, and preventive treatments are known to reduce mortality. However, the cost and complexity of conventional diagnostic methods limit the feasibility of early diagnosis for SCD in resource-limited areas worldwide. Although several point-of-care tests are commercially available, most are antibody-based tests, which cannot be used in patients who have recently received a blood transfusion. Here, we describe the development of a rapid, low-cost nucleic acid test that uses real-time fluorescence to detect the point mutation encoding hemoglobin S (HbS) in one round of isothermal recombinase polymerase amplification (RPA). When tested with a set of clinical samples from SCD patients and healthy volunteers, our assay demonstrated 100% sensitivity for both the ßA globin and ßS globin alleles and 94.7 and 97.1% specificities for the ßA globin allele and ßS globin allele, respectively (n = 91). Finally, we demonstrate proof-of-concept sample-to-answer genotyping of genomic DNA from capillary blood using an alkaline lysis procedure and direct input of diluted lysate into RPA. The workflow is performed in <30 min at a cost of <$5 USD on a commercially available benchtop fluorimeter and an open-source miniature fluorimeter. This study demonstrates the potential utility of a rapid, sample-to-answer nucleic acid test for SCD that may be implemented near the point of care and could be adapted to other disease-causing point mutations in genomic DNA.


Assuntos
Anemia Falciforme , Recombinases , Alelos , Anemia Falciforme/diagnóstico , Anemia Falciforme/genética , Pré-Escolar , Hemoglobina Falciforme/análise , Humanos , Recém-Nascido , Técnicas de Amplificação de Ácido Nucleico , Sistemas Automatizados de Assistência Junto ao Leito , Sensibilidade e Especificidade
4.
Gastrointest Endosc ; 93(4): 831-838.e2, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-32682812

RESUMO

BACKGROUND AND AIMS: High-resolution microendoscopy (HRME) is an optical biopsy technology that provides subcellular imaging of esophageal mucosa but requires expert interpretation of these histopathology-like images. We compared endoscopists with an automated software algorithm for detection of esophageal squamous cell neoplasia (ESCN) and evaluated the endoscopists' accuracy with and without input from the software algorithm. METHODS: Thirteen endoscopists (6 experts, 7 novices) were trained and tested on 218 post-hoc HRME images from 130 consecutive patients undergoing ESCN screening/surveillance. The automated software algorithm interpreted all images as neoplastic (high-grade dysplasia, ESCN) or non-neoplastic. All endoscopists provided their interpretation (neoplastic or non-neoplastic) and confidence level (high or low) without and with knowledge of the software overlay highlighting abnormal nuclei and software interpretation. The criterion standard was histopathology consensus diagnosis by 2 pathologists. RESULTS: The endoscopists had a higher mean sensitivity (84.3%, standard deviation [SD] 8.0% vs 76.3%, P = .004), lower specificity (75.0%, SD 5.2% vs 85.3%, P < .001) but no significant difference in accuracy (81.1%, SD 5.2% vs 79.4%, P = .26) of ESCN detection compared with the automated software algorithm. With knowledge of the software algorithm, the specificity of the endoscopists increased significantly (75.0% to 80.1%, P = .002) but not the sensitivity (84.3% to 84.8%, P = .75) or accuracy (81.1% to 83.1%, P = .13). The increase in specificity was among novices (P = .008) but not experts (P = .11). CONCLUSIONS: The software algorithm had lower sensitivity but higher specificity for ESCN detection than endoscopists. Using computer-assisted diagnosis, the endoscopists maintained high sensitivity while increasing their specificity and accuracy compared with their initial diagnosis. Automated HRME interpretation would facilitate widespread usage in resource-poor areas where this portable, low-cost technology is needed.


Assuntos
Esôfago , Neoplasias , Células Epiteliais , Esofagoscopia , Esôfago/diagnóstico por imagem , Humanos , Sensibilidade e Especificidade , Software
5.
Int J Exp Pathol ; 101(1-2): 45-54, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-32436348

RESUMO

Oral cancer causes significant global mortality and has a five-year survival rate of around 64%. Poor prognosis results from late-stage diagnosis, highlighting an important need to develop better approaches to detect oral premalignant lesions (OPLs) and identify which OPLs are at highest risk of progression to oral squamous cell carcinoma (OSCC). An appropriate animal model that reflects the genetic, histologic, immunologic, molecular and gross visual features of human OSCC would aid in the development and evaluation of early detection and risk assessment strategies. Here, we present an experimental PIK3CA + 4NQO transgenic mouse model of oral carcinogenesis that combines the PIK3CA oncogene mutation with oral exposure to the chemical carcinogen 4NQO, an alternate experimental transgenic mouse model with PIK3CA as well as E6 and E7 mutations, and an existing wild-type mouse model based on oral exposure to 4NQO alone. We compare changes in dorsal and ventral tongue gross visual appearance, histologic features and molecular biomarker expression over a time course of carcinogenesis. Both transgenic models exhibit cytological and architectural features of dysplasia that mimic human disease and exhibit slightly increased staining for Ki-67, a cell proliferation marker. The PIK3CA + 4NQO model additionally exhibits consistent lymphocytic infiltration, presents with prominent dorsal and ventral tongue tumours, and develops cancer quickly relative to the other models. Thus, the PIK3CA + 4NQO model recapitulates the multistep genetic model of human oral carcinogenesis and host immune response in carcinogen-induced tongue cancer, making it a useful resource for future OSCC studies.


Assuntos
Transformação Celular Neoplásica/induzido quimicamente , Transformação Celular Neoplásica/genética , Classe I de Fosfatidilinositol 3-Quinases/genética , Mutação , Quinolonas , Carcinoma de Células Escamosas de Cabeça e Pescoço/induzido quimicamente , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Neoplasias da Língua/induzido quimicamente , Neoplasias da Língua/genética , 4-Nitroquinolina-1-Óxido , Animais , Proliferação de Células , Transformação Celular Neoplásica/patologia , Modelos Animais de Doenças , Progressão da Doença , Linfócitos/patologia , Camundongos Endogâmicos CBA , Camundongos Transgênicos , Proteínas Oncogênicas Virais/genética , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Fatores de Tempo , Neoplasias da Língua/patologia
6.
Proc Natl Acad Sci U S A ; 114(51): E10965-E10971, 2017 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-29203650

RESUMO

Newborns are at increased risk of jaundice, a condition in which excess bilirubin accumulates in blood. Left untreated, jaundice can lead to neurological impairment and death. Jaundice resulting from unconjugated hyperbilirubinemia is easily treated with exposure to blue light, and phototherapy systems have been developed for low-resource settings; however, there are no appropriate solutions to diagnose and monitor jaundice in these settings. To address this need we present BiliSpec, a low-cost reader and disposable lateral flow card designed to measure the concentration of total bilirubin from several drops of blood at the point of care. We evaluated the performance of BiliSpec, using blood from normal volunteers spiked with varying amounts of bilirubin; results measured using BiliSpec correlated well with a reference laboratory bilirubinometer (r = 0.996). We then performed a pilot clinical study using BiliSpec to measure total bilirubin in neonates at risk for jaundice at Queen Elizabeth Central Hospital in Blantyre, Malawi. Concentrations measured using BiliSpec correlated well with those measured using a laboratory reference standard in 94 patient samples ranging from 1.1 mg/dL to 23.0 mg/dL in concentration (r = 0.973). The mean difference between bilirubin levels measured with BiliSpec and the reference standard was 0.3 mg/dL (95[Formula: see text] CI: -1.7-2.2 mg/dL).


Assuntos
Icterícia Neonatal/diagnóstico , Testes Imediatos , Feminino , Recursos em Saúde , Humanos , Recém-Nascido , Malaui , Masculino , Monitorização Fisiológica/instrumentação , Monitorização Fisiológica/métodos , Reprodutibilidade dos Testes
7.
Gynecol Oncol ; 154(3): 558-564, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31288949

RESUMO

OBJECTIVE: Cervical cancer rates in the United States have declined since the 1940's, however, cervical cancer incidence remains elevated in medically-underserved areas, especially in the Rio Grande Valley (RGV) along the Texas-Mexico border. High-resolution microendoscopy (HRME) is a low-cost, in vivo imaging technique that can identify high-grade precancerous cervical lesions (CIN2+) at the point-of-care. The goal of this study was to evaluate the performance of HRME in medically-underserved areas in Texas, comparing results to a tertiary academic medical center. METHODS: HRME was evaluated in five different outpatient clinical settings, two in Houston and three in the RGV, with medical providers of varying skill and training. Colposcopy, followed by HRME imaging, was performed on eligible women. The sensitivity and specificity of traditional colposcopy and colposcopy followed by HRME to detect CIN2+ were compared and HRME image quality was evaluated. RESULTS: 174 women (227 cervical sites) were included in the final analysis, with 12% (11% of cervical sites) diagnosed with CIN2+ on histopathology. On a per-site basis, a colposcopic impression of low-grade precancer or greater had a sensitivity of 84% and a specificity of 45% to detect CIN2+. While there was no significant difference in sensitivity (76%, p = 0.62), the specificity when using HRME was significantly higher than that of traditional colposcopy (56%, p = 0.01). There was no significant difference in HRME image quality between clinical sites (p = 0.77) or medical providers (p = 0.33). CONCLUSIONS: HRME imaging increased the specificity for detecting CIN2+ when compared to traditional colposcopy. HRME image quality remained consistent across different clinical settings.


Assuntos
Colonoscopia/economia , Colonoscopia/métodos , Área Carente de Assistência Médica , Lesões Pré-Cancerosas/diagnóstico por imagem , Neoplasias do Colo do Útero/diagnóstico por imagem , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Gradação de Tumores , Lesões Pré-Cancerosas/economia , Estudos Prospectivos , Sensibilidade e Especificidade , Texas , Estados Unidos , Neoplasias do Colo do Útero/patologia , Displasia do Colo do Útero/diagnóstico por imagem , Displasia do Colo do Útero/economia
8.
Proc Natl Acad Sci U S A ; 113(39): 10769-73, 2016 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-27621464

RESUMO

Fiber optic microendoscopy has shown promise for visualization of molecular contrast agents used to study disease in vivo. However, fiber optic microendoscopes have limited optical sectioning capability, and image contrast is limited by out-of-focus light generated in highly scattering tissue. Optical sectioning techniques have been used in microendoscopes to remove out-of-focus light but reduce imaging speed or rely on bulky optical elements that prevent in vivo imaging. Here, we present differential structured illumination microendoscopy (DSIMe), a fiber optic system that can perform structured illumination in real time for optical sectioning without any opto-mechanical components attached to the distal tip of the fiber bundle. We demonstrate the use of DSIMe during in vivo fluorescence imaging in patients undergoing surgery for cervical adenocarcinoma in situ. Images acquired using DSIMe show greater contrast than standard microendoscopy, improving the ability to detect cellular atypia associated with neoplasia.


Assuntos
Meios de Contraste/química , Endoscopia , Imageamento Tridimensional/métodos , Animais , Colo/anatomia & histologia , Epitélio/anatomia & histologia , Feminino , Camundongos Endogâmicos C57BL , Microesferas
9.
Anal Biochem ; 544: 64-71, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29229373

RESUMO

Regular HIV-1 viral load monitoring is the standard of care to assess antiretroviral therapy effectiveness in resource-rich settings. Persistently elevated viral loads indicate virologic failure (VF), which warrants HIV drug resistance testing (HIVDRT) to allow individualized regimen switches. However, in settings lacking access to HIVDRT, clinical decisions are often made based on symptoms, leading to unnecessary therapy switches and increased costs of care. This work presents a proof-of-concept assay to detect M184V, the most common drug resistance mutation after first-line antiretroviral therapy failure, in a paper format. The first step isothermally amplifies a section of HIV-1 reverse transcriptase containing M184V using a recombinase polymerase amplification (RPA) assay. Then, an oligonucleotide ligation assay (OLA) is used to selectively label the mutant and wild type amplified sequences. Finally, a lateral flow enzyme-linked immunosorbent assay (ELISA) differentiates between OLA-labeled products with or without M184V. Our method shows 100% specificity and 100% sensitivity when tested with samples that contained 200 copies of mutant DNA and 800 copies of wild type DNA prior to amplification. When integrated with sample preparation, this method may detect HIV-1 drug resistance at a low cost and at a rural hospital laboratory.


Assuntos
Fármacos Anti-HIV/análise , DNA Viral/genética , Ensaio de Imunoadsorção Enzimática , Transcriptase Reversa do HIV/genética , Análise de Sequência com Séries de Oligonucleotídeos , Papel , Fármacos Anti-HIV/farmacologia , DNA Viral/efeitos dos fármacos , Farmacorresistência Viral/efeitos dos fármacos , Transcriptase Reversa do HIV/antagonistas & inibidores
11.
Gastroenterology ; 149(2): 321-329, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25980753

RESUMO

BACKGROUND & AIMS: Esophageal squamous cell neoplasia has a high mortality rate as a result of late detection. In high-risk regions such as China, screening is performed by Lugol's chromoendoscopy (LCE). LCE has low specificity, resulting in unnecessary tissue biopsy with a subsequent increase in procedure cost and risk. The purpose of this study was to evaluate the accuracy of a novel, low-cost, high-resolution microendoscope (HRME) as an adjunct to LCE. METHODS: In this prospective trial, 147 consecutive high-risk patients were enrolled from 2 US and 2 Chinese tertiary centers. Three expert and 4 novice endoscopists performed white-light endoscopy followed by LCE and HRME. All optical images were compared with the gold standard of histopathology. RESULTS: By using a per-biopsy analysis, the sensitivity of LCE vs LCE + HRME was 96% vs 91% (P = .0832), specificity was 48% vs 88% (P < .001), positive predictive value was 22% vs 45% (P < .0001), negative predictive value was 98% vs 98% (P = .3551), and overall accuracy was 57% vs 90% (P < .001), respectively. By using a per-patient analysis, the sensitivity of LCE vs LCE + HRME was 100% vs 95% (P = .16), specificity was 29% vs 79% (P < .001), positive predictive value was 32% vs 60%, 100% vs 98%, and accuracy was 47% vs 83% (P < .001). With the use of HRME, 136 biopsies (60%; 95% confidence interval, 53%-66%) could have been spared, and 55 patients (48%; 95% confidence interval, 38%-57%) could have been spared any biopsy. CONCLUSIONS: In this trial, HRME improved the accuracy of LCE for esophageal squamous cell neoplasia screening and surveillance. HRME may be a cost-effective optical biopsy adjunct to LCE, potentially reducing unnecessary biopsies and facilitating real-time decision making in globally underserved regions. ClinicalTrials.gov, NCT 01384708.


Assuntos
Detecção Precoce de Câncer/métodos , Neoplasias Esofágicas/diagnóstico , Esofagoscopia/métodos , Neoplasias de Células Escamosas/diagnóstico , Imagem Óptica/métodos , Lesões Pré-Cancerosas/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Biópsia , China , Neoplasias Esofágicas/patologia , Feminino , Humanos , Iodetos , Masculino , Pessoa de Meia-Idade , Neoplasias de Células Escamosas/patologia , Lesões Pré-Cancerosas/patologia , Estudos Prospectivos , Sensibilidade e Especificidade , Estados Unidos
12.
Gastrointest Endosc ; 83(1): 107-14, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26253018

RESUMO

BACKGROUND AND AIMS: Previous studies show that microendoscopic images can be interpreted visually to identify the presence of neoplasia in patients with Barrett's esophagus (BE), but this approach is subjective and requires clinical expertise. This study describes an approach for quantitative image analysis of microendoscopic images to identify neoplastic lesions in patients with BE. METHODS: Images were acquired from 230 sites from 58 patients by using a fiberoptic high-resolution microendoscope during standard endoscopic procedures. Images were analyzed by a fully automated image processing algorithm, which automatically selected a region of interest and calculated quantitative image features. Image features were used to develop an algorithm to identify the presence of neoplasia; results were compared with a histopathology diagnosis. RESULTS: A sequential classification algorithm that used image features related to glandular and cellular morphology resulted in a sensitivity of 84% and a specificity of 85%. Applying the algorithm to an independent validation set resulted in a sensitivity of 88% and a specificity of 85%. CONCLUSIONS: This pilot study demonstrates that automated analysis of microendoscopic images can provide an objective, quantitative framework to assist clinicians in evaluating esophageal lesions from patients with BE. ( CLINICAL TRIAL REGISTRATION NUMBER: NCT01384227 and NCT02018367.).


Assuntos
Adenocarcinoma/patologia , Algoritmos , Esôfago de Barrett/patologia , Neoplasias Esofágicas/patologia , Esôfago/patologia , Adenocarcinoma/diagnóstico , Esôfago de Barrett/diagnóstico , Neoplasias Esofágicas/diagnóstico , Esofagoscopia , Humanos , Processamento de Imagem Assistida por Computador , Microscopia Intravital , Projetos Piloto , Sensibilidade e Especificidade
13.
J Oncol Pharm Pract ; 22(1): 21-5, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25113309

RESUMO

BACKGROUND AND PURPOSE: Proflavine hemisulfate solution is a fluorescence contrast agent to visualize cell nuclei using high-resolution optical imaging devices such as the high-resolution microendoscope. These devices provide real-time imaging to distinguish between normal versus neoplastic tissue. These images could be helpful for early screening of oral cancer and its precursors and to determine accurate margins of malignant tissue for ablative surgery. Extemporaneous preparation of proflavine solution for these diagnostic procedures requires preparation in batches and long-term storage to improve compounding efficiency in the pharmacy. However, there is a paucity of long-term stability data for proflavine contrast solutions. METHODS: The physical and chemical stability of 0.01% (10 mg/100 ml) proflavine hemisulfate solutions prepared in sterile water was determined following storage at refrigeration (4-8℃) and room temperature (23℃). Concentrations of proflavine were measured at predetermined time points up to 12 months using a validated stability-indicating high-performance liquid chromatography method. RESULTS: Proflavine solutions stored under refrigeration were physically and chemically stable for at least 12 months with concentrations ranging from 95% to 105% compared to initial concentration. However, in solutions stored at room temperature increased turbidity and particulates were observed in some of the tested vials at 9 months and 12 months with peak particle count reaching 17-fold increase compared to baseline. Solutions stored at room temperature were chemically stable up to six months (94-105%). CONCLUSION: Proflavine solutions at concentration of 0.01% were chemically and physically stable for at least 12 months under refrigeration. The solution was chemically stable for six months when stored at room temperature. We recommend long-term storage of proflavine solutions under refrigeration prior to diagnostic procedure.


Assuntos
Meios de Contraste/química , Estabilidade de Medicamentos , Soluções Farmacêuticas/química , Proflavina/química , Armazenamento de Medicamentos/métodos , Neoplasias Bucais/tratamento farmacológico , Soluções Farmacêuticas/uso terapêutico , Proflavina/uso terapêutico , Refrigeração/métodos
14.
Clin Gastroenterol Hepatol ; 13(2): 272-279.e2, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25066838

RESUMO

BACKGROUND & AIMS: High-resolution microendoscopy is an optical imaging technique with the potential to improve the accuracy of endoscopic screening for esophageal squamous neoplasia. Although these microscopic images can be interpreted readily by trained personnel, quantitative image analysis software could facilitate the use of this technology in low-resource settings. In this study, we developed and evaluated quantitative image analysis criteria for the evaluation of neoplastic and non-neoplastic squamous esophageal mucosa. METHODS: We performed an image analysis of 177 patients undergoing standard upper endoscopy for screening or surveillance of esophageal squamous neoplasia, using high-resolution microendoscopy, at 2 hospitals in China and at 1 hospital in the United States from May 2010 to October 2012. Biopsy specimens were collected from imaged sites (n = 375), and a consensus diagnosis was provided by 2 expert gastrointestinal pathologists and used as the standard. RESULTS: Quantitative information from the high-resolution images was used to develop an algorithm to identify high-grade squamous dysplasia or invasive squamous cell cancer, based on histopathology findings. Optimal performance was obtained using the mean nuclear area as the basis for classification, resulting in sensitivities and specificities of 93% and 92% in the training set, 87% and 97% in the test set, and 84% and 95% in an independent validation set, respectively. CONCLUSIONS: High-resolution microendoscopy with quantitative image analysis can aid in the identification of esophageal squamous neoplasia. Use of software-based image guides may overcome issues of training and expertise in low-resource settings, allowing for widespread use of these optical biopsy technologies.


Assuntos
Carcinoma de Células Escamosas/diagnóstico , Carcinoma de Células Escamosas/patologia , Neoplasias Esofágicas/diagnóstico , Neoplasias Esofágicas/patologia , Esofagoscopia/métodos , Processamento de Imagem Assistida por Computador/métodos , Biópsia , China , Carcinoma de Células Escamosas do Esôfago , Hospitais , Humanos , Programas de Rastreamento/métodos , Estados Unidos
15.
Malar J ; 14: 472, 2015 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-26611141

RESUMO

BACKGROUND: Isothermal amplification techniques are emerging as a promising method for malaria diagnosis since they are capable of detecting extremely low concentrations of parasite target while mitigating the need for infrastructure and training required by other nucleic acid based tests. Recombinase polymerase amplification (RPA) is promising for further development since it operates in a short time frame (<30 min) and produces a product that can be visually detected on a lateral flow dipstick. A self-sealing paper and plastic system that performs both the amplification and detection of a malaria DNA sequence is presented. METHODS: Primers were designed using the NCBI nBLAST tools and screened using gel electrophoresis. Paper and plastic devices were prototyped using commercial design software and parts were cut using a laser cutter and assembled by hand. Synthetic copies of the Plasmodium 18S gene were spiked into solution and used as targets for the RPA reaction. To test the performance of the device the same samples spiked with synthetic target were run in parallel both in the paper and plastic devices and using conventional bench top methods. RESULTS: Novel RPA primers were developed that bind to sequences present in the four species of Plasmodium which infect humans. The paper and plastic devices were found to be capable of detecting as few as 5 copies/µL of synthetic Plasmodium DNA (50 copies total), comparable to the same reaction run on the bench top. The devices produce visual results in an hour, cost approximately $1, and are self-contained once the device is sealed. CONCLUSIONS: The device was capable of carrying out the RPA reaction and detecting meaningful amounts of synthetic Plasmodium DNA in a self-sealing and self-contained device. This device may be a step towards making nucleic acid tests more accessible for malaria detection.


Assuntos
DNA de Protozoário/análise , Equipamentos e Provisões , Malária/diagnóstico , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Plasmodium/genética , Custos e Análise de Custo , DNA de Protozoário/genética , DNA Ribossômico/genética , Humanos , Técnicas de Diagnóstico Molecular/economia , Técnicas de Amplificação de Ácido Nucleico/economia , Papel , Plásticos , RNA Ribossômico 18S/genética , Fatores de Tempo
16.
J Trop Pediatr ; 61(6): 421-7, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26361989

RESUMO

OBJECTIVE: To describe the outcomes of infants and young children with respiratory distress when treated with a novel, low-cost, stand-alone bubble Continuous Positive Airway Pressure (bCPAP) system in a resource-limited setting. METHODS: A non-randomized, convenience sample study in a pediatric unit in Blantyre, Malawi, 2013. Patients weighing ≤10 kg with respiratory distress were eligible. We compared outcomes for patients with bronchiolitis, pneumonia and Pneumocystis jiroveci pneumonia (PJP) after treatment with bCPAP. RESULTS: Seventy percent of patients treated with bCPAP survived. Outcomes were best for patients with bronchiolitis and worst for those with PJP. Most survivors (80%) showed improvement within 24 h. All treating physicians found bCPAP useful, leading to a change in practice. CONCLUSIONS: Bubble CPAP was most beneficial to patients with bronchiolitis. Children, who were going to get well, tended to get well quickly. Physicians believed the bCPAP system provided a higher level of care than nasal oxygen.


Assuntos
Bronquiolite/terapia , Pressão Positiva Contínua nas Vias Aéreas/instrumentação , Pressão Positiva Contínua nas Vias Aéreas/métodos , Pneumonia/terapia , Síndrome do Desconforto Respiratório do Recém-Nascido/terapia , Bronquiolite/patologia , Pressão Positiva Contínua nas Vias Aéreas/economia , Análise Custo-Benefício , Feminino , Humanos , Lactente , Recém-Nascido , Malaui/epidemiologia , Masculino , Oxigenoterapia , Pneumocystis carinii , Pneumonia/patologia , Síndrome do Desconforto Respiratório do Recém-Nascido/mortalidade , Síndrome do Desconforto Respiratório do Recém-Nascido/patologia , Análise de Sobrevida , Taxa de Sobrevida/tendências , Resultado do Tratamento
17.
J Biomed Opt ; 29(5): 050501, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38774711

RESUMO

Significance: Fiber-optic microendoscopy is a promising approach to noninvasively visualize epithelial nuclear morphometry for early cancer and precancer detection. However, the broader clinical application of this approach is limited by a lack of topical contrast agents available for in vivo use. Aim: The aim of this study was to evaluate the ability to image nuclear morphometry in vivo with a novel fiber-optic microendoscope used together with topical application of methylene blue (MB), a dye with FDA approval for use in chromoendoscopy in the gastrointestinal tract. Approach: The low-cost, high-resolution microendoscope implements scanning darkfield imaging without complex optomechanical components by leveraging programmable illumination and the rolling shutter of the image sensor. We validate the integration of our system and MB staining for visualizing epithelial cell nuclei by performing ex vivo imaging on fresh animal specimens and in vivo imaging on healthy volunteers. Results: The results indicate that scanning darkfield imaging significantly reduces specular reflection and resolves epithelial nuclei with enhanced image contrast and spatial resolution compared to non-scanning widefield imaging. The image quality of darkfield images with MB staining is comparable to that of fluorescence images with proflavine staining. Conclusions: Our approach enables real-time microscopic evaluation of nuclear patterns and has the potential to be a powerful noninvasive tool for early cancer detection.


Assuntos
Azul de Metileno , Azul de Metileno/química , Animais , Humanos , Núcleo Celular , Tecnologia de Fibra Óptica/instrumentação , Desenho de Equipamento , Endoscopia/métodos , Endoscopia/instrumentação , Administração Tópica
18.
Nat Commun ; 15(1): 2935, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38580633

RESUMO

Histopathology plays a critical role in the diagnosis and surgical management of cancer. However, access to histopathology services, especially frozen section pathology during surgery, is limited in resource-constrained settings because preparing slides from resected tissue is time-consuming, labor-intensive, and requires expensive infrastructure. Here, we report a deep-learning-enabled microscope, named DeepDOF-SE, to rapidly scan intact tissue at cellular resolution without the need for physical sectioning. Three key features jointly make DeepDOF-SE practical. First, tissue specimens are stained directly with inexpensive vital fluorescent dyes and optically sectioned with ultra-violet excitation that localizes fluorescent emission to a thin surface layer. Second, a deep-learning algorithm extends the depth-of-field, allowing rapid acquisition of in-focus images from large areas of tissue even when the tissue surface is highly irregular. Finally, a semi-supervised generative adversarial network virtually stains DeepDOF-SE fluorescence images with hematoxylin-and-eosin appearance, facilitating image interpretation by pathologists without significant additional training. We developed the DeepDOF-SE platform using a data-driven approach and validated its performance by imaging surgical resections of suspected oral tumors. Our results show that DeepDOF-SE provides histological information of diagnostic importance, offering a rapid and affordable slide-free histology platform for intraoperative tumor margin assessment and in low-resource settings.


Assuntos
Aprendizado Profundo , Microscopia , Corantes Fluorescentes , Hematoxilina , Amarelo de Eosina-(YS)
19.
BMC Palliat Care ; 12(1): 31, 2013 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-23941694

RESUMO

BACKGROUND: The need for palliative care in sub-Saharan Africa is staggering: this region shoulders over 67% of the global burden of HIV/AIDS and cancer. However, provisions for these essential services remain limited and poorly integrated with national health systems in most nations. Moreover, the evidence base for palliative care in the region remains scarce. This study chronicles the development and evaluation of DataPall, an open-source electronic medical records system that can be used to track patients, manage data, and generate reports for palliative care providers in these settings.DataPall was developed using design criteria encompassing both functional and technical objectives articulated by hospital leaders and palliative care staff at a leading palliative care center in Malawi. The database can be used with computers that run Windows XP SP 2 or newer, and does not require an internet connection for use. Subsequent to its development and implementation in two hospitals, DataPall was tested among both trained and untrained hospital staff populations on the basis of its usability with comparison to existing paper records systems as well as on the speed at which users could perform basic database functions. Additionally, all participants evaluated this program on a standard system usability scale. RESULTS: In a study of health professionals in a Malawian hospital, DataPall enabled palliative care providers to find patients' appointments, on average, in less than half the time required to locate the same record in current paper records. Moreover, participants generated customizable reports documenting patient records and comprehensive reports on providers' activities with little training necessary. Participants affirmed this ease of use on the system usability scale. CONCLUSIONS: DataPall is a simple, effective electronic medical records system that can assist in developing an evidence base of clinical data for palliative care in low resource settings. The system is available at no cost, is specifically designed to chronicle care in the region, and is catered to meet the technical needs and user specifications of such facilities.

20.
Artigo em Inglês | MEDLINE | ID: mdl-38406798

RESUMO

Cancer continues to affect underserved populations disproportionately. Novel optical imaging technologies, which can provide rapid, non-invasive, and accurate cancer detection at the point of care, have great potential to improve global cancer care. This article reviews the recent technical innovations and clinical translation of low-cost optical imaging technologies, highlighting the advances in both hardware and software, especially the integration of artificial intelligence, to improve in vivo cancer detection in low-resource settings. Additionally, this article provides an overview of existing challenges and future perspectives of adapting optical imaging technologies into clinical practice, which can potentially contribute to novel insights and programs that effectively improve cancer detection in low-resource settings.

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