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1.
BMC Infect Dis ; 20(1): 825, 2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33176716

RESUMO

BACKGROUND: Light microscopy is often used for malaria diagnosis in the field. However, it is time-consuming and quality of the results depends heavily on the skill of microscopists. Automating malaria light microscopy is a promising solution, but it still remains a challenge and an active area of research. Current tools are often expensive and involve sophisticated hardware components, which makes it hard to deploy them in resource-limited areas. RESULTS: We designed an Android mobile application called Malaria Screener, which makes smartphones an affordable yet effective solution for automated malaria light microscopy. The mobile app utilizes high-resolution cameras and computing power of modern smartphones to screen both thin and thick blood smear images for P. falciparum parasites. Malaria Screener combines image acquisition, smear image analysis, and result visualization in its slide screening process, and is equipped with a database to provide easy access to the acquired data. CONCLUSION: Malaria Screener makes the screening process faster, more consistent, and less dependent on human expertise. The app is modular, allowing other research groups to integrate their methods and models for image processing and machine learning, while acquiring and analyzing their data.


Assuntos
Processamento de Imagem Assistida por Computador/métodos , Malária Falciparum/diagnóstico por imagem , Programas de Rastreamento/métodos , Microscopia/métodos , Plasmodium falciparum/isolamento & purificação , Smartphone , Confiabilidade dos Dados , Humanos , Aprendizado de Máquina , Malária Falciparum/parasitologia , Sensibilidade e Especificidade , Software
2.
Urologiia ; (5): 5-9, 2020 Nov.
Artigo em Russo | MEDLINE | ID: mdl-33185339

RESUMO

AIM: To carry out a comparative assessment of the efficiency of combination therapy for non-gonococcal urethritis (NGU) in men. MATERIALS AND METHODS: a total of 124 patients with NGU and laboratory-confirmed urogenital infection were included in the study. The diagnostic methods included microscopy of urethral smear, real-time polymerase chain reaction (PCR) for the detection of uropathogens and laser Doppler flowmetry for evaluating the urethral microcirculation. All patients were randomized into three groups matched for age, clinical manifestations, and disease duration. Patients of the group 1 received targeted antibiotic therapy. In the group 2, local peloid therapy was added, while patients in group 3 additionally received vibromagnetotherapy. The control group consisted of 22 patients aged 18 to 55 years. The study included 2 visits, at the baseline and 4 weeks after the end of treatment. RESULTS: After the treatment, the frequency of microbiological cure was 89%. In the group 3, more pronounced improvement in main symptoms of NGU was observed. The analysis of microcirculation after treatment in the groups 2 and 3 showed a significant increase in perfusion and modulation of urethral blood flow and a decrease in venous congestion after combined therapy. CONCLUSION: The combined treatment, including antibiotic, peloid therapy, and vibromagnetotherapy, promotes more pronounced clinical improvement, restoration of urethral microcirculation and relief of inflammatory process in patients with NGU and can be recommended for routine clinical practice.


Assuntos
Infecções por Chlamydia , Uretrite , Adolescente , Adulto , Antibacterianos , Chlamydia trachomatis , Terapia Combinada , Humanos , Masculino , Microscopia , Pessoa de Meia-Idade , Uretra , Uretrite/tratamento farmacológico , Adulto Jovem
3.
Ann Biol Clin (Paris) ; 78(5): 519-526, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33026347

RESUMO

Digital morphology hematology analyzers are becoming more prevalent in laboratories Aims: investigate practices and assess the benefits and limits of digital automated microscopy in hematology. METHODS: questionnaire sent by e-mail in 2018 to French public and private laboratories. RESULTS: out of 118 responses (56 private, 62 public), 117 participants had a CellaVision® microscope, 1 had a West Medica®. Practices were sometimes different, especially in the choice of smears to be digitized or for quality controls (16.1% had internal quality controls, 48.3% external quality controls); 62.1% never used the red blood cell (RBC) characterization tool; the number of cells counted varied from 100 to 400. The study reported a high rate of agreement for these benefits: traceability (95.7%), staff training (94.1%), eye strain (91.4%), risk of error (87.2%), time saving (83.6%). Among the disadvantages, apart from the inadequate search for platelets clumps (93.2%), the agreement rates were often lower: adaptation to digital images (61.2%), difficult assessment of atypical morphologies (49.6%) or RBC morphology (49.6%). CONCLUSION: despite well-established benefits, standardization of practices and technical improvement are still needed.


Assuntos
Automação Laboratorial , Testes Hematológicos/instrumentação , Hematologia/instrumentação , Processamento de Imagem Assistida por Computador , Microscopia/instrumentação , Atitude do Pessoal de Saúde , Automação Laboratorial/instrumentação , Automação Laboratorial/métodos , Automação Laboratorial/estatística & dados numéricos , Computadores , Testes Diagnósticos de Rotina/instrumentação , Testes Diagnósticos de Rotina/métodos , Testes Diagnósticos de Rotina/estatística & dados numéricos , Testes Diagnósticos de Rotina/tendências , França/epidemiologia , Testes Hematológicos/métodos , Testes Hematológicos/estatística & dados numéricos , Testes Hematológicos/tendências , Hematologia/métodos , Hematologia/estatística & dados numéricos , Hematologia/tendências , Humanos , Processamento de Imagem Assistida por Computador/instrumentação , Processamento de Imagem Assistida por Computador/métodos , Processamento de Imagem Assistida por Computador/estatística & dados numéricos , Processamento de Imagem Assistida por Computador/tendências , Satisfação no Emprego , Microscopia/métodos , Microscopia/estatística & dados numéricos , Microscopia/tendências , Prática Profissional/estatística & dados numéricos , Prática Profissional/tendências , Controle de Qualidade , Inquéritos e Questionários
4.
BMC Infect Dis ; 20(1): 791, 2020 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-33096996

RESUMO

BACKGROUND: Tuberculosis (TB) remains a major public health concern in many low-income countries accounting for approximately two-thirds of deaths in people living with human immunodeficiency virus (HIV) infection. With prompt, accurate and appropriate treatment, almost all TB disease can be cured. The present study was to evaluate the diagnostic performance of an in-house duplex PCR (D-PCR) using IS1610 and rpoB specific primers in sputum samples from TB suspected patients. METHODS: A hospital-based cross-sectional study was conducted at the Limbe and Buea Regional Hospitals of the South West Region of Cameroon from June 2016 to April 2017. Sputum samples, decontaminated with hypertonic saline/sodium hydroxide solution were centrifuged and pellets processed for smear microscopy, culture and DNA extraction. Suspected inhibition was resolved by serial dilution of genomic DNA. Results were compared to culture as gold standard as well as a Composite Reference Standard (CRS). RESULTS: A total of 129 participants aged between 5 to 82 years were enrolled in to the study. The median age of the participants was 37 years (interquartile range, IQR: 27-50 years), with 54.3% being male. Forty-seven samples (36.4%) were positive by direct sputum microscopy, 49 (38%) by microscopy after concentration, 51 (39.5%) by culture and 62 (40.1%) by D-PCR. PCR inhibition was resolved in 85.7% (18/21) of the samples that had inhibition. The overall sensitivity, specificity, positive and negative predictive values, positive and negative likelihood ratios and area under the curve AUC) of the D-PCR was 93.5, 94, 94, 94%, 15.6, 0.005 and 89.0% respectively using CRS as reference. The sensitivities of D-PCR observed among different sample categories were 95.7, 87.5 and 87.5% for smear-and culture-positives, smear-negative/culture-positive, and clinically diagnosed cases respectively. CONCLUSION: IS1610 and rpoB duplex PCR using relatively cheap decontamination and DNA extraction methods in addition to simple serial dilutions to resolve PCR inhibition shows high sensitivity in the diagnosis of paucibacillary tuberculosis.


Assuntos
Proteínas de Bactérias/genética , RNA Polimerases Dirigidas por DNA/genética , Genes Bacterianos , Mycobacterium tuberculosis/genética , Reação em Cadeia da Polimerase/métodos , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/epidemiologia , Infecções Oportunistas Relacionadas com a AIDS/diagnóstico , Infecções Oportunistas Relacionadas com a AIDS/virologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Camarões/epidemiologia , Criança , Pré-Escolar , Estudos Transversais , Primers do DNA , Feminino , HIV , Humanos , Masculino , Microscopia , Pessoa de Meia-Idade , Mycobacterium tuberculosis/isolamento & purificação , Sensibilidade e Especificidade , Escarro/microbiologia , Tuberculose Pulmonar/microbiologia , Adulto Jovem
5.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1392-1395, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018249

RESUMO

A recursive additive complement network (RacNet) is introduced to segment cell membranes in histological images as closed lines. Segmenting cell membranes as closed lines is necessary to calculate cell areas and to estimate N/C ratio, which is useful to diagnose early hepatocellular carcinoma. The RacNet is composed of a complement network and an element-wise maximization (EWM) process and is recursively applied to the network output. The complement network complements the lacking parts of cell membranes. The network, however, has a tendency to mistakenly delete some parts of the segmented cell membranes. The EWM process eliminates this unwanted effect.Experiments carried out using unstained hepatic sections showed that the accuracy for segmenting cell membranes as closed lines was significantly improved by using the RacNet.Three imaging methods, bright-field, dark-field, and phase-contrast, were used, as unstained sections show very low contrast in the bright-field imaging commonly used in pathological diagnosis. These imaging methods are available in optical microscopes used by pathologists. Among the three methods, phase-contrast imaging showed the highest accuracy.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Carcinoma Hepatocelular/diagnóstico por imagem , Membrana Celular , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Microscopia , Microscopia de Contraste de Fase
6.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1416-1419, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018255

RESUMO

Recent advances in digital imaging has transformed computer vision and machine learning to new tools for analyzing pathology images. This trend could automate some of the tasks in the diagnostic pathology and elevate the pathologist workload. The final step of any cancer diagnosis procedure is performed by the expert pathologist. These experts use microscopes with high level of optical magnification to observe minute characteristics of the tissue acquired through biopsy and fixed on glass slides. Switching between different magnifications, and finding the magnification level at which they identify the presence or absence of malignant tissues is important. As the majority of pathologists still use light microscopy, compared to digital scanners, in many instance a mounted camera on the microscope is used to capture snapshots from significant field- of-views. Repositories of such snapshots usually do not contain the magnification information. In this paper, we extract deep features of the images available on TCGA dataset with known magnification to train a classifier for magnification recognition. We compared the results with LBP, a well-known handcrafted feature extraction method. The proposed approach achieved a mean accuracy of 96% when a multi-layer perceptron was trained as a classifier.


Assuntos
Aprendizado de Máquina , Redes Neurais de Computação , Biópsia , Microscopia
7.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1820-1823, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018353

RESUMO

We present a new LSTM (P-LSTM: Progressive LSTM) network, aiming to predict morphology and states of cell colonies from time-lapse microscopy images. Apparent short-term changes occur in some types of time-lapse cell images. Therefore, long-term-memory dependent LSTM networks may not predict accurately. The P-LSTM network incorporates the images newly generated from cell imaging progressively into LSTM training to emphasize the LSTM short-term memory and thus improve the prediction accuracy. The new images are input into a buffer to be selected for batch training. For real-time processing, parallel computation is introduced to implement concurrent training and prediction on partitioned images.Two types of stem cell images were used to show effectiveness of the P-LSTM network. One is for tracking of ES cell colonies. The actual and predicted ES cell images possess similar colony areas and the same transitions of colony states (moving, merging or morphology changing), although the predicted colony mergers may delay in several time-steps. The other is for prediction of iPS cell reprogramming from the CD34+ human cord blood cells. The actual and predicted iPS cell images possess high similarity evaluated by the PSNR and SSIM similarity evaluation metrics, indicating the reprogramming iPS cell colony features and morphology can be accurately predicted.


Assuntos
Microscopia , Redes Neurais de Computação , Algoritmos , Humanos , Memória de Longo Prazo , Células-Tronco
8.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1859-1862, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018362

RESUMO

Quantitative descriptions of the morphology and structure of peripheral nerves is central in the development of bioelectronic devices interfacing the nerves. While histological procedures and microscopy techniques yield high-resolution detailed images of individual axons, automated methods to extract relevant information at the single-axon level are not widely available. We implemented a segmentation algorithm that allows for subsequent feature extraction in immunohistochemistry (IHC) images of peripheral nerves at the single fiber scale. These features include short and long cross-sectional diameters, area, perimeter, thickness of surrounding myelin and polar coordinates of single axons within a nerve or nerve fascicle. We evaluated the performance of our algorithm using manually annotated IHC images of 27 fascicles of the swine cervical vagus; the accuracy of single-axon detection was 82%, and of the classification of fiber myelination was 89%.


Assuntos
Axônios , Nervos Periféricos , Animais , Estudos Transversais , Microscopia , Bainha de Mielina , Suínos
9.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1903-1906, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018373

RESUMO

Tuberculosis (TB) is one of the top 10 causes of death worldwide. The diagnosis and treatment of TB in its early stages is fundamental to reducing the rate of people affected by this disease. In order to assist specialists in the diagnosis in bright field smear images, many studies have been developed for the automatic Mycobacterium tuberculosis detection, the causative agent of Tb. To contribute to this theme, a method to bacilli detection associating convolutional neural network (CNN) and a mosaic-image approach was implemented. The propose was evaluated using a robust image dataset validated by three specialists. Three CNN architectures and 3 optimization methods in each architecture were evaluated. The deeper architecture presented better results, reaching accuracies values above 99%. Other metrics like precision, sensitivity, specificity and F1-score were also used to assess the CNN models performance.


Assuntos
Bacillus , Microscopia , Redes Neurais de Computação , Sensibilidade e Especificidade , Software
10.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1907-1910, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018374

RESUMO

Two-photon microscopy (TPM) can provide a detailed microscopic information of cerebrovascular structures. Extracting anatomical vascular models from TPM angiograms remains a tedious task due to image degeneration associated with TPM acquisitions and the complexity of microvascular networks. Here, we propose a fully automated pipeline capable of providing useful anatomical models of vascular structures captured with TPM. In the proposed method, we segment blood vessels using a fully convolutional neural network and employ the resulting binary labels to create an initial geometric graph enclosed within vessels boundaries. The initial geometry is then decimated and refined to form graphed curve skeletons that can retain both the vascular shape and its topology. We validate the proposed method on 3D realistic TPM angiographies and compare our results with that obtained through manual annotations.


Assuntos
Algoritmos , Microvasos , Encéfalo/diagnóstico por imagem , Microscopia , Microvasos/diagnóstico por imagem , Redes Neurais de Computação
11.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 1954-1957, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018385

RESUMO

Water quality has a direct impact on industry, agriculture, and public health. Algae species are common indicators of water quality. It is because algal communities are sensitive to changes in their habitats, giving valuable knowledge on variations in water quality. However, water quality analysis requires professional inspection of algal detection and classification under microscopes, which is very time-consuming and tedious. In this paper, we propose a novel multi-target deep learning framework for algal detection and classification. Extensive experiments were carried out on a large-scale colored microscopic algal dataset. Experimental results demonstrate that the proposed method leads to the promising performance on algal detection, class identification and genus identification.


Assuntos
Aprendizado Profundo , Plantas , Agricultura , Microscopia , Qualidade da Água
12.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2213-2216, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-33018447

RESUMO

The Refractive Index (RI) is an important parameter of characterizing optical properties of particles. In a dual-beam optical trap, two counter-propagating laser beams are used to trap micro-particles suspended in an aqueous medium. When a ray of light passes from one medium of lower RI (e.g. aqueous suspension medium) to another medium of higher RI (e.g. suspended particle), its momentum changes which exerts a proportional trapping force on the surface of the particle. Thus, accurate knowledge of RI of the particles and the surrounding medium is needed to determine the behavior of particles in an optical trap. The RI of micro-sized beads can be experimentally measured using traditional optical methods such as absorption microscopy. We developed an alternative theoretical method to estimate the RI of trapped particles based on non-contact optical trapping experimental outcomes. In our study, a theoretical model was formulated based on the experimentally measured minimum trapping powers for polystyrene and polyethylene beads using a dual-beam optical setup. The tendencies of trapping power-RI curves predicted by our model agreed very well with those measured experimentally. Our technique provides an alternative approach to determining the RI of a certain micro-size particle regardless of its size or density. Our method is especially advantageous over traditional methods to determine RI of biological particles which exhibit significant variations based on physiological and environmental conditions.


Assuntos
Pinças Ópticas , Refratometria , Microscopia , Modelos Teóricos , Poliestirenos
13.
PLoS One ; 15(10): e0239342, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33027314

RESUMO

INTRODUCTION: Tuberculosis disease is the leading cause of death worldwide along with HIV/AIDS. Sputum smear microscopy plays an essential role for initial TB diagnosis and treatment follow up. But, misdiagnosis of sputum smear microscopy revealed a high economical crisis and missing of active TB cases. This study was aimed to determine blinded rechecking of sputum smear microscopy performance in public health facilities in Tigray region, Northern Ethiopia. MATERIALS AND METHODS: A cross sectional retrospective study was conducted from January, 2017 to December, 2018 year. Data was collected retrospectively using electronic and paper based in Tigray health research institute. The data was analyzed using the SPSS version 25 software. The sensitivity, specificity, positive predictive value, and negative predictive value of the smear readings were calculated using 2X2 contingency table. The reading agreement between the microscopic center and reference center was determined using kappa statistics. RESULTS: A total of 23,456 blinded rechecked smear results were reviewed. In average, the performances of sputum smear quality were 61%, 68%, 64%, 66%, 62% and 75% for specimen quality, staining quality, smear size, smear thickness, smear evenness and smear cleanliness respectively. Of the total error (0.48%) reported, 0.25%, 0.19% and 0.085% were false positive, false negative and quantification errors respectively. The concordance rate of health facilities for smear reading was increased to 90% by the end of 2018. Overall, the sensitivity, specificity, PPV, and NPV of the smear readings were 95%, 99.7%, 93% and 99.8% respectively. Likewise, the smear reading agreement was also perfect with kappa value, 0.87. CONCLUSION: The overall performance of public health facilities for blinded rechecking of smear microscopy was satisfactory. But, the high false positive and false negative errors found calls for continuous evaluation and monitoring of the health facilities by reference center.


Assuntos
Microscopia/métodos , Escarro/microbiologia , Tuberculose/diagnóstico , Estudos Transversais , Etiópia , Reações Falso-Negativas , Humanos , Microscopia/normas , Controle de Qualidade , Estudos Retrospectivos , Sensibilidade e Especificidade
14.
Brasília, D.F.; OPAS; 2020-10-26.
em Português | PAHO-IRIS | ID: phr2-52944

RESUMO

O volume de capacitação em Bases do diagnóstico microscópico da malária é composto por dois módulos, que servem como uma estrutura para que os instrutores montem o curso. Ele fornece as informações mínimas necessárias para capacitar alunos em diagnóstico microscópico da malária pelo método de Giemsa. O volume destina-se principalmente a pessoas com escolaridade relativamente baixa no momento do início do curso; os instrutores podem ajustar o curso para participantes com níveis mais altos de escolaridade. Técnicos atualmente responsáveis pelo diagnóstico microscópico da malária também se beneficiarão da leitura do Guia do aluno. Eles podem aprender o processo que leva à identificação dos parasitos da malária, seja participando de um curso de capacitação básica ou de um curso de reciclagem. O Guia do instrutor (Bases do diagnóstico microscópico da malária, Parte II) foi elaborado para ajudar os instrutores a capacitar profissionais de saúde em microscopia básica da malária. O ideal é que cada aluno também receba um exemplar das Pranchas para o diagnóstico microscópico da malária da OMS . Se isso não for possível, vários exemplares devem ser disponibilizados como material de referência para uso dos alunos.


Assuntos
Malária , Microscopia , Doenças Transmissíveis , Controle de Infecções
15.
Brasília, D.F.; OPAS; 2020-10-26.
em Português | PAHO-IRIS | ID: phr2-52941

RESUMO

Este manual (Parte I dos módulos de capacitação em Bases do diagnóstico microscópico da malária) ajudará os participantes durante seu treinamento em diagnóstico microscópico da malária humana. O manual foi concebido como base para um treinamento formal de quatro a cinco semanas de duração e destina-se a alunos com conhecimentos rudimentares de ciência. Ao concluir a capacitação, o aluno será responsável pelo diagnóstico de malária com lâminas de sangue de casos suspeitos na sua comunidade. Desse modo, decisões importantes referentes ao tratamento dependem da sua competência em garantir o diagnóstico de malária sem supervisão. Para ganhar a confiança do público e do sistema de saúde, a qualidade da formação desses agentes deve ser a mais alta possível e deve poder ser demonstrada. A estrutura do curso é “baseada em competências”, ou seja, apresenta informações técnicas essenciais para a aquisição de habilidades e instruções passo a passo em um formato facilmente compreensível. O treinamento é principalmente prático. Ao final do curso, os alunos devem demonstrar ter adquirido um alto nível de competência. A educação baseada em competências é uma maneira eficaz e comprovada para a aquisição das habilidades essenciais aos serviços públicos de saúde e de atenção à saúde. Além de capacitar os profissionais de saúde nos fundamentos do diagnóstico microscópico da malária, os módulos podem ser usados para a reciclagem de agentes já formados que realizam microscopia padrão da malária pelo método de Giemsa. Como esse pessoal já tem uma formação sólida e ampla experiência de trabalho, devem conseguir atingir os objetivos do curso em 11 ou 12 dias úteis. Para os laboratoristas e microscopistas de hospitais distritais ou estaduais/regionais já familiarizados com os procedimentos de laboratório, um curso mais curto pode ser benéfico, pois embora o diagnóstico microscópico da malária faça parte da rotina diária desses profissionais, os cursos de reciclagem ajudam a garantir a exatidão. Este manual está dividido em unidades de aprendizagem. As observações e instruções contidas em cada unidade são suficientes para reduzir ao mínimo possível a quantidade de anotações a serem tomadas pelos alunos, permitindo desse modo que participem plenamente das palestras e discussões. Ainda assim, há uma página em branco para anotações no final de cada unidade...


Assuntos
Malária , Microscopia , Doenças Transmissíveis
16.
Zootaxa ; 4768(3): zootaxa.4768.3.3, 2020 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-33055647

RESUMO

The female of eastern Nearctic Leuctra moha Ricker, 1952 is formally described for the first time. The identity of the female was confirmed with tree- and genetic distance-based phylogenetic methods. An emended description is also provided for the male. Digital images for both sexes are provided with scanning electronic and standard light microscopy. The female once tentatively associated with the male of L. moha is illustrated using standard light microscopy and refers to L. hicksi Harrison Stark, 2010. An updated distribution map is provided for both species.


Assuntos
Insetos , Neópteros , Animais , Feminino , Masculino , Microscopia , Filogenia
17.
Zootaxa ; 4790(3): zootaxa.4790.3.2, 2020 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-33056694

RESUMO

Slide mounted entomological specimens often require the aid of contrast techniques to improve the clarity of morphological characteristics. Methods can involve the use of techniques such as Phase contrast, Dark field or differential interference contrast microscopy (DIC), however where an entomologist may only have access to simple brightfield microscopy chemical staining of the specimen may be used to improve contrast. For whole mounts of entomological specimens, a single stain, occasionally two, are often used, in comparison to histological sections that often employ multiple stains in complex protocols. A number of authors have proposed different stains and staining methods for a number of insect groups with few considering the long term qualities of the stain, it has previously been shown that aniline dyes are prone to fading in Canada Balsam mounts, and that some stains fade even when protected from sunlight. This paper aims to summarise the knowledge of stains used for entomological specimens and provide details on the archival qualities.


Assuntos
Corantes , Insetos , Microscopia , Animais , Coloração e Rotulagem
18.
BMC Infect Dis ; 20(1): 726, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33008333

RESUMO

BACKGROUND: Ivermectin is an excellent microfilaricide against Onchocerca volvulus. However, in some regions, long term use of ivermectin has resulted in sub-optimal responses to the treatment. More data to properly document the phenomenon in various contexts of ivermectin mass drug administration (IVM-MDA) is needed. Also, there is a need to accurately monitor a possible repopulation of skin by microfilariae following treatment. Skin snip microscopy is known to have a low sensitivity in individuals with light infections, which can be the case following treatment. This study was designed with two complementary objectives: (i) to assess the susceptibility of O. volvulus microfilariae to ivermectin in two areas undergoing IVM-MDA for different lengths of time, and (ii) to document the repopulation of skin by the O. volvulus microfilariae following treatment, using 3 independent diagnostic techniques. METHOD: Identified microfilaridermic individuals were treated with ivermectin and re-examined after 1, 3, and 6 months using microscopy, actin real-time PCR (actin-qPCR) and O-150 LAMP assays. Susceptibility to ivermectin and trends in detecting reappearance of skin microfilariae were determined using three techniques. Microscopy was used as an imperfect gold standard to determine the performance of actin-qPCR and LAMP. RESULTS: In Bafia with over 20 years of IVM-MDA, 11/51 (21.6%) direct observe treated microfilaridemic participants were still positive for skin microfilariae after 1 month. In Melong, with 10 years of IVM-MDA, 2/29 (6.9%) treated participants were still positive. The microfilarial density reduction per skin biopsy within one month following treatment was significantly lower in participants from Bafia. In both study sites, the molecular techniques detected higher proportions of infected individuals than microscopy at all monitoring time points. LAMP demonstrated the highest levels of sensitivity and real-time PCR was found to have the highest specificity. CONCLUSION: Patterns in skin mirofilariae clearance and repopulation were established. O. volvulus worms from Bafia with higher number of annual MDA displayed a lower clearance and higher repopulation rate after treatment with ivermectin. Molecular assays displayed higher sensitivity in monitoring O. volvulus microfilaridemia within six months following treatment.


Assuntos
Antiparasitários/uso terapêutico , Ivermectina/uso terapêutico , Onchocerca volvulus/fisiologia , Oncocercose/tratamento farmacológico , Pele/patologia , Adolescente , Animais , Biópsia , Camarões , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Administração Massiva de Medicamentos , Microscopia , Reação em Cadeia da Polimerase em Tempo Real , Adulto Jovem
19.
Zootaxa ; 4819(2): zootaxa.4819.2.11, 2020 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-33055667

RESUMO

A new rove beetle species, Edrabius uruguayensis Martínez-Villar, González-Vainer Tomasco, sp. nov., associated with the subterranean rodent Ctenomys rionegrensis in Uruguay, is described and illustrated. Photographs, scanning electron micrographs and drawings of the diagnostic character states are provided. The new species is compared with other species of the genus. Nucleotide sequence of the cytochrome oxidase subunit I was reported for the first time for the genus and phylogenetic reconstruction confirms their close relationship with the other genus used from the tribe Amblyopinini (Heterothops).


Assuntos
Besouros , Distribuição Animal , Animais , Microscopia , Filogenia , Uruguai
20.
Zootaxa ; 4780(1): zootaxa.4780.1.5, 2020 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-33055758

RESUMO

Samples collected from Monte Hermoso, Buenos Aires Province, Argentina revealed the presence of specimens of the genus Franciscideres Dal Zotto et al., 2013, previously known only from Brazil. This morphotype seems to differ from the only known species, Franciscideres kalenesos Dal Zotto et al., 2013, in the following characters: (1) presence of ventrolateral tubes on segment 1, (2) introvert features, (3) each segment composed of a closed cuticular ring, (4) trunk cuticle ornamented by a secondary fringe of knob-like structures, (5) posterior margin of segment 10 ventrally terminating in two lateral and one broad triangular lobes, (6) posterior margin of segment 11 centrally terminating in four lobes (7) lateral terminal spines armed with thorn-like processes, (8) pores/sensory spots/gland cells distribution and (9) sexual dimorphism in segments 10 and 11. Because of the lack of full information about F. kalenesos from Brazil, we consider the new exemplars as Franciscideres cf. kalenesos. Additionally, we provide new information about the movement of this species using light microscopy and we compare these movements with those of other meiofaunal inhabitants.


Assuntos
Invertebrados , Movimento , Caracteres Sexuais , Animais , Argentina , Microscopia
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