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2.
Clin Anat ; 33(1): 108-112, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31576597

RESUMO

Deplastination is the process of reversing plastination such that a plastinated specimen can be reverted to its raw nature. This would enable its use in the field of histopathology. The present study aims to ascertain if deplastinates can be used for histopathological studies after a time period. Tissue samples were taken from patients undergoing maxillofacial surgeries for oral carcinomas after obtaining written informed consent. The 12 specimens obtained were divided into two groups. One set of tissues was processed for paraffin embedding after 10% formalin fixation. The other set was plastinated by S10 silicon plastination. After 3 months, the plastinates were deplastinated using sodium methoxide and processed for routine hematoxylin and eosin staining, similar to the formalin fixed specimens. The slides were quantitatively assessed on parameters like tissue architecture, staining property, and intracellular structure. In addition, the slides were qualitatively evaluated by a pathologist who was blinded to the mode of preservation to see if identification of pathological features was possible on a deplastinated slide. The formalin preserved specimens and deplastinated tissue slides compared closely in all three parameters tested with the need to identify the endpoint of deplastination. Qualitatively, deplastination did not hamper identification of tissue pathology. Deplastination increases the scope of a stored plastinate by allowing histological studies in the future without the need for any preservatives or special storage equipment. It preserves structure and maintains tissue pathology. An improved method of ensuring the endpoint of deplastination needs to be identified. Clin. Anat. 32:108-112, 2019. © 2019 Wiley Periodicals, Inc.


Assuntos
Técnicas Histológicas/métodos , Inclusão em Parafina , Inclusão em Plástico , Plastinação , Fixação de Tecidos/métodos , Formaldeído , Humanos
3.
J Mater Sci Mater Med ; 30(9): 103, 2019 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-31493091

RESUMO

Metal-on-metal (MoM) hip arthroplasties produce abundant implant-derived wear debris composed mainly of cobalt (Co) and chromium (Cr). Cobalt-chromium (Co-Cr) wear particles are difficult to identify histologically and need to be distinguished from other wear particle types and endogenous components (e.g., haemosiderin, fibrin) which may be present in MoM periprosthetic tissues. In this study we sought to determine whether histological stains that have an affinity for metals are useful in identifying Co-Cr wear debris in MoM periprosthetic tissues. Histological sections of periprosthetic tissue from 30 failed MoM hip arthroplasties were stained with haematoxylin-eosin (HE), Solochrome Cyanine (SC), Solochrome Azurine (SA) and Perls' Prussian Blue (PB). Sections of periprosthetic tissue from 10 cases of non-MoM arthroplasties using other implant biomaterials, including titanium, ceramic, polymethylmethacrylate (PMMA) and ultra-high molecular weight polyethylene (UHMWP) were similarly analysed. Sections of 10 cases of haemosiderin-containing knee tenosynovial giant cell tumour (TSGCT) were also stained with HE, SC, SA and PB. In MoM periprosthetic tissues, SC stained metal debris in phagocytic macrophages and in the superficial necrotic zone which exhibited little or no trichrome staining for fibrin. In non-MoM periprosthetic tissues, UHMWP, PMMA, ceramic and titanium particles were not stained by SC. Prussian Blue, but not SC or SA, stained haemosiderin deposits in MoM periprosthetic tissues and TSGT. Our findings show that SC staining (most likely Cr-associated) is useful in distinguishing Co-Cr wear particles from other metal/non-metal wear particles types in histological preparations of periprosthetic tissue and that SC reliably distinguishes haemosiderin from Co-Cr wear debris.


Assuntos
Benzenossulfonatos , Corantes/farmacologia , Análise de Falha de Equipamento/métodos , Articulação do Quadril/patologia , Nanopartículas Metálicas/análise , Próteses Articulares Metal-Metal , Coloração e Rotulagem/métodos , Artroplastia de Quadril/efeitos adversos , Artroplastia de Quadril/instrumentação , Azurina/química , Azurina/farmacologia , Benzenossulfonatos/química , Benzenossulfonatos/farmacologia , Cromo/química , Corantes/síntese química , Corantes/química , Amarelo de Eosina-(YS)/química , Amarelo de Eosina-(YS)/farmacologia , Ferrocianetos/química , Ferrocianetos/farmacologia , Células Gigantes de Corpo Estranho/efeitos dos fármacos , Células Gigantes de Corpo Estranho/patologia , Hematoxilina/química , Hematoxilina/farmacologia , Articulação do Quadril/química , Articulação do Quadril/efeitos dos fármacos , Prótese de Quadril , Técnicas Histológicas/métodos , Humanos , Macrófagos/efeitos dos fármacos , Macrófagos/patologia , Próteses Articulares Metal-Metal/efeitos adversos , Polietilenos/análise , Polietilenos/química
4.
Med Sci Monit ; 25: 5886-5891, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31390342

RESUMO

BACKGROUND To determine if histograms of ADC can be used to differentiate ventricular ependymomas, choroid plexus papillomas (CPPs), and central neurocytomas (CNCs). MATERIAL AND METHODS We retrospectively reviewed records from 185 patients from 1 January 2014 to 1 November 2018. We finally included a total of 60 patients: 36 (60.00%) had histologically confirmed ependymomas, 10 (16.67%) had CPPs, and 14 (23.33%) had CNCs, as determined by routine MRI scanning at 3.0T. The ADC histogram features were derived and then compared by Kruskal-Wallis test (they were not normally distributed). Bonferroni test was used to compare the 2 groups and then we determined the ROC. RESULTS Ependymomas had significantly higher mean, perc.01%, perc.10%, perc.50%, perc.90%, and perc.99% than CNCs. Ependymomas had significantly lower skewness than CNCs. Histogram metrics derived from mean, perc.01%, perc.10%, perc.50%, and perc.90% were significantly lower in the CNCs group than in the CPPs group. CPPs showed significantly lower skewness than CNCs. A threshold value of 86.50 for perc.50% to predict ependymomas from CNCs was estimated (AUC=0.97, sensitivity=97.20%, specificity=85.70%). Optimal diagnostic performance to predict CPPs from CNCs (AUC=0.96, sensitivity=100.00%, specificity=85.70%) was obtained when setting Perc.50%=84.00 as the threshold value. CONCLUSIONS The ADC histogram analysis may help to discriminate ependymomas, CPPs, and CNCs.


Assuntos
Ependimoma/diagnóstico , Técnicas Histológicas/métodos , Neurocitoma/diagnóstico , Papiloma do Plexo Corióideo/diagnóstico , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , China , Imagem de Difusão por Ressonância Magnética/métodos , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Lactente , Imagem por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Curva ROC , Estudos Retrospectivos , Sensibilidade e Especificidade
5.
IET Nanobiotechnol ; 13(6): 634-639, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31432798

RESUMO

In present study, the effective penetration of radiofrequency (RF) induced gold decorated iron oxide nanoparticles (GS@IONPs) hyperthermia was investigated. The effective penetration depth of RF also the damage potency of hyperthermia was evaluated during histopathology observations which were done on the chicken breast tissue and hepatocellular carcinoma (HCC) models. The thermal damages are well- documented in our previous cellular study which was engaged with potency of RF hyperthermia in Epithelial adenocarcinoma (MCF-7) and fibroblast (L-929) cells deaths [1]. In recent work, PEGylated iron oxide nanoparticles (IONPs) were used as base platform for gold magnetic nanoparticles (GS@IONPs) formation. The 144.00015 MHz, 180W RF generator was applied for stimulating the nanoparticles. The chicken breast tissue and the hepatocellular tumor model was considered in the experimental section. In histology studies, the structural changes also the effective penetration depth of RF induced nanoparticles was observed through microscopic monitoring of the tissue slices in histology observations (Gazi medical school). The highest damage level was seen in 8.0 µm tissue slices where lower damages were seen in depth of 1.0 cm and more inside tissue. The histology observations clarified the effective penetration depth of RF waves and irreversible damages in the 2.0 cm inside the tissue.


Assuntos
Ouro/farmacocinética , Hipertermia Induzida , Nanopartículas Metálicas , Ondas de Rádio , Animais , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Galinhas , Liberação Controlada de Fármacos , Ouro/química , Técnicas Histológicas/métodos , Humanos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Nanopartículas Metálicas/química , Terapia por Radiofrequência , Distribuição Tecidual
6.
Zhonghua Wei Chang Wai Ke Za Zhi ; 22(8): 796-800, 2019 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-31422622

RESUMO

The insufficiency of the examined number of lymph nodes after surgery for gastric cancer may undermine the stage of lymph node metastasis, which would have a significant impact on prognostic evaluation and strategy formulation of adjuvant therapy. Under the premise of standard D2 lymphadenectomy, the number of harvested lymph nodes is mainly dependent on the procedures of lymph node examination. Since 2013, our center has set up a special lymph node examination team. In the same year, the average number of harvested lymph nodes in each sample was 46, which was significantly higher than before (average 18 nodes/case in 2004-2012). After continuous quality improvement and regular quality control in 2014, average number of retrieved lymph nodes was 64 per specimen. Therefore, this paper summarizes the methods and experience of lymph node examination in gastric cancer specimens of general surgery in Southern Hospital. The overall construction of the lymph node examination team of gastric cancer in our center mainly includes three parts: establishment of a specialized lymph node examination team, effective standard operating procedures (SOP), and long-term and sustained quality control. The specialized lymph node examination team consists of postgraduate students who are not involved in surgery but have been trained by surgeons. Standard procedures include theoretical reserve of gastric anatomy, surgical observation to correspond to specimens in vitro and in vivo, and standardized specimen processing procedures. Long-term and sustained quality control requires periodic report of lymph node examination data and continuous feedback optimization of the process. Intraoperative lymph node tracing navigation and specimen lymph node intensification are carried out with nanocarbon and indocyanine green dye staining, and then lymph nodes are harvested based on the traditional methods, which can improve the examination rate of lymph nodes, especially for small lymph nodes. Research on lymph node tracing methods, requires multidisciplinary cooperation in particular, will become a hot topic.


Assuntos
Gastrectomia/métodos , Técnicas Histológicas/normas , Excisão de Linfonodo/normas , Linfonodos/patologia , Neoplasias Gástricas/patologia , Neoplasias Gástricas/cirurgia , Gastrectomia/normas , Técnicas Histológicas/métodos , Humanos , Excisão de Linfonodo/métodos , Linfonodos/cirurgia , Metástase Linfática , Estadiamento de Neoplasias , Prognóstico , Qualidade da Assistência à Saúde
7.
J Mater Sci Mater Med ; 30(9): 100, 2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-31468139

RESUMO

Nacre (mother of pearl) is a natural biomaterial used to prepare orthopedic devices. We have implanted screws and plates made with nacre in five sheeps. Bone were harvested after two months and embedded in poly(methyl methacrylate). Blocks were saws and the thick slabs were grinded, polished and surface stained. Sections were photographed at an ×1000 magnification. Giant cells were found in contact with nacre in eroded areas and true osteoclasts were found at distance in the neighboring bone in Howship lacunae. A texture analysis of the nuclei of giant cells and osteoclasts was done using the run-length method of the MaZda freeware. The size of the nuclei was reduced in osteoclast and their mean gray level appeared reduced. Texture analysis revealed that chromatin had a completely different pattern in giant cells when compared to osteoclasts. Giant cells had a fine repartition of the chromatin with large clear areas around prominent nucleoli. On the contrary, osteoclast nuclei had chromatin blocks evenly dispersed in the nuclei. This reflects the different origin of these cells expressing different functions.


Assuntos
Substitutos Ósseos/análise , Transplante Ósseo , Células Gigantes/patologia , Técnicas Histológicas/métodos , Nácar , Osteoclastos/patologia , Exoesqueleto/química , Animais , Transplante Ósseo/instrumentação , Transplante Ósseo/métodos , Prótese Ancorada no Osso , Núcleo Celular/química , Reação a Corpo Estranho/patologia , Citometria por Imagem/métodos , Nácar/química , Pinctada , Ovinos
8.
Genes Chromosomes Cancer ; 58(11): 783-797, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31334584

RESUMO

Aberrant methylation of DNA is supposed to be a major and early driver of colonic adenoma development, which may result in colorectal cancer (CRC). Although gene methylation assays are used already for CRC screening, differential epigenetic alterations of recurring and nonrecurring colorectal adenomas have yet not been systematically investigated. Here, we collected a sample set of formalin-fixed paraffin-embedded colorectal low-grade adenomas (n = 72) consisting of primary adenomas without and with recurrence (n = 59), recurrent adenomas (n = 10), and normal mucosa specimens (n = 3). We aimed to unveil differentially methylated CpG positions (DMPs) across the methylome comparing not only primary adenomas without recurrence vs primary adenomas with recurrence but also primary adenomas vs recurrent adenomas using the Illumina Human Methylation 450K BeadChip array. Unsupervised hierarchical clustering exhibited a significant association of methylation patterns with histological adenoma subtypes. No significant DMPs were identified comparing primary adenomas with and without recurrence. Despite that, a total of 5094 DMPs (false discovery rate <0.05; fold change >10%) were identified in the comparisons of recurrent adenomas vs primary adenomas with recurrence (674; 98% hypermethylated), recurrent adenomas vs primary adenomas with and without recurrence (241; 99% hypermethylated) and colorectal adenomas vs normal mucosa (4179; 46% hypermethylated). DMPs in cytosine-phosphate-guanine (CpG) islands were frequently hypermethylated, whereas open sea- and shelf-regions exhibited hypomethylation. Gene ontology analysis revealed enrichment of genes associated with the immune system, inflammatory processes, and cancer pathways. In conclusion, our methylation data could assist in establishing a more robust and reproducible histological adenoma classification, which is a prerequisite for improving surveillance guidelines.


Assuntos
Neoplasias Colorretais/genética , Ilhas de CpG/genética , Epigênese Genética/genética , Adenoma/genética , Idoso , Biomarcadores Tumorais/genética , Citosina , Metilação de DNA/genética , Detecção Precoce de Câncer/métodos , Epigenômica , Feminino , Regulação Neoplásica da Expressão Gênica/genética , Genoma Humano , Guanina , Técnicas Histológicas/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/genética , Fosfatos , Regiões Promotoras Genéticas/genética
9.
PLoS One ; 14(7): e0219006, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31329606

RESUMO

Transformation in chromatin organization is one of the most universal markers of carcinogenesis. Microscale chromatin alterations have been a staple of histopathological diagnosis of neoplasia, and nanoscale alterations have emerged as a promising marker for cancer prognostication and the detection of predysplastic changes. While numerous methods have been developed to detect these alterations, most methods for sample preparation remain largely validated via conventional microscopy and have not been examined with nanoscale sensitive imaging techniques. For these nanoscale sensitive techniques to become standard of care screening tools, new histological protocols must be developed that preserve nanoscale information. Partial Wave Spectroscopic (PWS) microscopy has recently emerged as a novel imaging technique sensitive to length scales ranging between 20 and 200 nanometers. As a label-free, high-throughput, and non-invasive imaging technique, PWS microscopy is an ideal tool to quantify structural information during sample preparation. Therefore, in this work we applied PWS microscopy to systematically evaluate the effects of cytological preparation on the nanoscales changes of chromatin using two live cell models: a drug-based model of Hela cells differentially treated with daunorubicin and a cell line comparison model of two cells lines with inherently distinct chromatin organizations. Notably, we show that existing cytological preparation can be modified in order to maintain clinically relevant nanoscopic differences, paving the way for the emerging field of nanopathology.


Assuntos
Carcinogênese/patologia , Cromatina/patologia , Técnicas Histológicas/métodos , Linhagem Celular , Cromatina/ultraestrutura , Etanol , Fixadores , Células HeLa , Humanos , Microscopia/métodos , Nanotecnologia , Preservação Biológica , Análise Espectral/métodos , Fixação de Tecidos/métodos
10.
Eur J Orthop Surg Traumatol ; 29(6): 1231-1234, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31041542

RESUMO

BACKGROUND: Neck of femur fractures is the most common fractures associated with low-velocity injury in the elderly. Some patients may require further histological examination of the femoral head due clinical suspicion of malignance as a cause of fracture. OBJECTIVES: To review whether standard screening question(s) could be used to identify patients that require histological examinations following neck of femur fracture. STUDY DESIGN AND METHODS: Femoral heads sent for histological examination over a period of 5 years were identified from hospital database. All patients presenting acutely with neck of femur fracture above the age of 70 were included, and their case notes were retrospectively reviewed. Reason for histopathological examination were categorised into three screening questions: (Q1) clinical suspicion based on history alone, i.e. neck of femur fracture with no clear history of fall or trauma or preceding hip pain, (Q2) radiological evidence of suspicious abnormality on admission radiographs, (Q3) previous history of malignancy or concurrent malignancy or (Q4) combination of above. RESULTS: In total, 119 samples of femoral head were sent and 18 patients had a positive histology. The sensitivity and specificity of these questions individually showed very poor correlation to positive histology with lowest for (Q3) previous history of malignancy (0.39 and 0.51, respectively). However, combining Q1 and Q2 the sensitivity is improved to 1.0 (95% CI 1.0-1.0) and specificity to 0.35 (95% CI 0.25-0.44) with a positive predictive value of 0.21 (95% CI 0.13-0.30) and negative predictive value of 1.00 (95% CI 1.00-1.00). CONCLUSION: History of previous malignancy poorly correlates with positive histology. Routine request based on these screening criteria is not cost-effective in patient management. LEVEL OF EVIDENCE: Prognostic level III.


Assuntos
Neoplasias Ósseas , Fraturas do Colo Femoral , Cabeça do Fêmur , Fixação Interna de Fraturas/métodos , Técnicas Histológicas/métodos , Radiografia/métodos , Idoso , Idoso de 80 Anos ou mais , Neoplasias Ósseas/complicações , Neoplasias Ósseas/patologia , Tomada de Decisão Clínica , Diagnóstico Diferencial , Feminino , Fraturas do Colo Femoral/diagnóstico , Fraturas do Colo Femoral/etiologia , Fraturas do Colo Femoral/cirurgia , Cabeça do Fêmur/diagnóstico por imagem , Cabeça do Fêmur/patologia , Humanos , Masculino , Fatores de Risco , Sensibilidade e Especificidade , Procedimentos Desnecessários/métodos
11.
Elife ; 82019 05 07.
Artigo em Inglês | MEDLINE | ID: mdl-31063133

RESUMO

Organismal phenotypes frequently involve multiple organ systems. Histology is a powerful way to detect cellular and tissue phenotypes, but is largely descriptive and subjective. To determine how synchrotron-based X-ray micro-tomography (micro-CT) can yield 3-dimensional whole-organism images suitable for quantitative histological phenotyping, we scanned whole zebrafish, a small vertebrate model with diverse tissues, at ~1 micron voxel resolutions. Micro-CT optimized for cellular characterization (histotomography) allows brain nuclei to be computationally segmented and assigned to brain regions, and cell shapes and volumes to be computed for motor neurons and red blood cells. Striking individual phenotypic variation was apparent from color maps of computed densities of brain nuclei. Unlike histology, the histotomography also allows the study of 3-dimensional structures of millimeter scale that cross multiple tissue planes. We expect the computational and visual insights into 3D cell and tissue architecture provided by histotomography to be useful for reference atlases, hypothesis generation, comprehensive organismal screens, and diagnostics.


Assuntos
Técnicas Histológicas/métodos , Imagem Tridimensional/métodos , Microtomografia por Raio-X/métodos , Peixe-Zebra/anatomia & histologia , Animais
12.
PLoS One ; 14(5): e0216064, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31075111

RESUMO

We have previously demonstrated that the use of a commercially-available immersion-based optical clearing agent (OCA) enables, within 3-6 hours, three-dimensional visualization of subsurface exogenous fluorescent and absorbing markers of vascular architecture and neurodegenerative disease in thick (0.5-1.0mm) mouse brain sections. Nonetheless, the relative performance of immersion-based OCAs has remained unknown. Here, we show that immersion of brain sections in specific OCAs (FocusClear, RIMS, sRIMS, or ScaleSQ) affects both their transparency and volume; the optical clearing effect occurs over the entire visible spectrum and is reversible; and that ScaleSQ had the highest optical clearing potential and increase in imaging depth of the four evaluated OCAs, albeit with the largest change in sample volume and a concomitant decrease in apparent microvascular density of the sample. These results suggest a rational, quantitative framework for screening and characterization of the impact of optical clearing, to streamline experimental design and enable a cost-benefit assessment.


Assuntos
Encéfalo/patologia , Técnicas Histológicas/métodos , Animais , Masculino , Camundongos , Microvasos/patologia , Doenças Neurodegenerativas/patologia , Espalhamento de Radiação
13.
Biotech Histochem ; 94(6): 459-468, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30983422

RESUMO

Mast cells are large cells with granular cytoplasm that participate in wound healing, angiogenesis and defense against pathogens. They also contribute to inflammation by initiating innate and acquired immunity. The granules of these cells exhibit characteristic staining properties. We investigated toluidine blue, astra blue, Alcian blue-pyronin Y and May-Grunwald Giemsa stains for mast cells in various oral lesions and assessed the efficacy of each for identifying mast cells. Sections were obtained from 10 each of diagnosed cases of inflammatory fibrous hyperplasia, periapical cyst, mild dysplasia, oral submucous fibrosis and oral squamous cell carcinoma and stained using the stains listed above. Mast cells were assessed for their presence, contrast of the mast cell in the connective tissue background and number. We found that May-Grunwald Giemsa stain was the best for identification of mast cells, although toluidine blue staining is less time-consuming. Overall we obtained better results using May-Grunwald Giemsa and toluidine blue for staining mast cells.


Assuntos
Carcinoma de Células Escamosas/patologia , Mastócitos/patologia , Neoplasias Bucais/patologia , Azul Alciano/farmacologia , Contagem de Células/métodos , Corantes/farmacologia , Técnicas Histológicas/métodos , Humanos , Coloração e Rotulagem/métodos , Cloreto de Tolônio/farmacologia
14.
J Immunol Res ; 2019: 7232781, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31016206

RESUMO

Background: Manual analysis of tissue sections, such as for pathological diagnosis, requires an analyst with substantial knowledge and experience. Reproducible image analysis of biological samples is steadily gaining scientific importance. The aim of the present study was to employ image analysis followed by machine learning to identify vascular endothelial growth factor (VEGF) in kidney tissue that had been subjected to hypoxia. Methods: Light microscopy images of renal tissue sections stained for VEGF were analyzed. Subsequently, machine learning classified the cells as VEGF+ and VEGF- cells. Results: VEGF was detected and cells were counted with high sensitivity and specificity. Conclusion: With great clinical, diagnostic, and research potential, automatic image analysis offers a new quantitative capability, thereby adding numerical information to a mostly qualitative diagnostic approach.


Assuntos
Automação Laboratorial , Técnicas Histológicas/métodos , Fator A de Crescimento do Endotélio Vascular/genética , Técnicas Histológicas/instrumentação , Humanos , Hipóxia , Processamento de Imagem Assistida por Computador , Rim/citologia , Rim/patologia , Aprendizado de Máquina , Microscopia , Inclusão em Parafina , Sensibilidade e Especificidade
15.
Toxicol Pathol ; 47(3): 221-234, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30844339

RESUMO

Pathologic evaluation is crucial to the study of medical devices and integral to the Food and Drug Administration and other regulatory entities' assessment of device safety and efficacy. While pathologic analysis is tailored to the type of device, it generally involves at a minimum gross and microscopic evaluation of the medical device and associated tissues. Due to the complex nature of some implanted devices and specific questions posed by sponsors, pathologic evaluation inherently presents many challenges in accurately assessing medical device safety and efficacy. This laboratory's experience in numerous collaborative projects involving veterinary pathologists, biomedical engineers, physicians, and other scientists has led to a set of interrelated assessments to determine pathologic end points as a means to address these challenges and achieve study outcomes. Thorough device evaluation is often accomplished by utilizing traditional paraffin histology, plastic embedding and microground sections, and advanced imaging modalities. Combining these advanced techniques provides an integrative, comprehensive approach to medical device pathology and enhances medical device safety and efficacy assessment.


Assuntos
Aprovação de Equipamentos/normas , Segurança de Equipamentos/normas , Equipamentos e Provisões/normas , Patologia/métodos , Animais , Aprovação de Equipamentos/legislação & jurisprudência , Equipamentos e Provisões/efeitos adversos , Técnicas Histológicas/métodos , Técnicas Histológicas/normas , Humanos , Modelos Animais , Estados Unidos , United States Food and Drug Administration
16.
Medicine (Baltimore) ; 98(11): e14870, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30882690

RESUMO

RATIONALE: Collagenous gastritis (CG) is a rare form of chronic gastritis defined histologically by a thickened subepithelial collageneous band in the lamina propria. However, the clinical features and endoscopic findings of CG have not been clearly established in the pediatric population. PRESENTING CONCERNS: We report the cases of 3 children who presented with intractable anemia and minimal or no gastrointestinal (GI) symptoms and were followed up without definitive diagnosis determination even through diagnostic endoscopic evaluations. DIAGNOSES: On repeated endoscopic examination, we determined thickened subepithelial collagen band, confirmed by Masson trichrome staining using targeted biopsies of the intervening mucosa between the prominent nodular lesions. INTERVENTIONS: Under the diagnosis of CG, a course of steroid was administrated in 1 patient, while all patients continued oral iron replacement therapy. OUTCOMES: All 3 patients remained asymptomatic and their anemia was alleviated with continued administration of oral iron. MAIN LESSONS: We recommend early endoscopic evaluation for patients with unexplained anemia, emphasizing a high index of suspicion for CG, despite the absence of definitive GI symptoms. Targeted gastric biopsies should be performed in the depressed mucosa surrounding the nodules, as well as the nodules themselves, to confirm CG, when presented with nodular gastric mucosa in endoscopy.


Assuntos
Anemia/etiologia , Colite Colagenosa/patologia , Endoscopia/métodos , Técnicas Histológicas/métodos , Administração Oral , Adolescente , Anemia/sangue , Anemia/diagnóstico , Criança , Colite Colagenosa/diagnóstico , Endoscopia/normas , Feminino , Gastrite/complicações , Gastrite/patologia , Técnicas Histológicas/normas , Humanos , Ferro/uso terapêutico , Masculino , Membrana Mucosa/patologia , Pediatria/métodos , Oligoelementos/uso terapêutico
17.
PLoS Comput Biol ; 15(3): e1006269, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30917113

RESUMO

Artificial Intelligence is exponentially increasing its impact on healthcare. As deep learning is mastering computer vision tasks, its application to digital pathology is natural, with the promise of aiding in routine reporting and standardizing results across trials. Deep learning features inferred from digital pathology scans can improve validity and robustness of current clinico-pathological features, up to identifying novel histological patterns, e.g., from tumor infiltrating lymphocytes. In this study, we examine the issue of evaluating accuracy of predictive models from deep learning features in digital pathology, as an hallmark of reproducibility. We introduce the DAPPER framework for validation based on a rigorous Data Analysis Plan derived from the FDA's MAQC project, designed to analyze causes of variability in predictive biomarkers. We apply the framework on models that identify tissue of origin on 787 Whole Slide Images from the Genotype-Tissue Expression (GTEx) project. We test three different deep learning architectures (VGG, ResNet, Inception) as feature extractors and three classifiers (a fully connected multilayer, Support Vector Machine and Random Forests) and work with four datasets (5, 10, 20 or 30 classes), for a total of 53, 000 tiles at 512 × 512 resolution. We analyze accuracy and feature stability of the machine learning classifiers, also demonstrating the need for diagnostic tests (e.g., random labels) to identify selection bias and risks for reproducibility. Further, we use the deep features from the VGG model from GTEx on the KIMIA24 dataset for identification of slide of origin (24 classes) to train a classifier on 1, 060 annotated tiles and validated on 265 unseen ones. The DAPPER software, including its deep learning pipeline and the Histological Imaging-Newsy Tiles (HINT) benchmark dataset derived from GTEx, is released as a basis for standardization and validation initiatives in AI for digital pathology.


Assuntos
Algoritmos , Inteligência Artificial , Técnicas Histológicas/métodos , Interpretação de Imagem Assistida por Computador/métodos , Software , Humanos , Reprodutibilidade dos Testes
18.
Biotech Histochem ; 94(6): 404-409, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30829549

RESUMO

We investigated the histological structure of the graylag goose (Anser anser) gall bladder. Sections of the gall bladder were stained with hematoxylin and eosin (H & E), Alcian blue (pH 2.5) for acid mucopolysaccharides, Gomori's method for reticular fibers, Masson's trichrome, periodic acid-Schiff (PAS) and Verhoeff's elastin stain. The goose gall bladder was composed of a tunica mucosa, tunica muscularis and tunica adventitia or tunica serosa. The tunica mucosa formed regularly distributed simple isometric folds plus larger, less numerous, branched folds. The luminal surface was lined by tall columnar epithelial cells that stained for both acid and neutral mucopolysaccharides. The epithelial cells formed a discontinuous striated border of interdigitating microvilli on the luminal surface. Neither a lamina muscularis nor goblet cells were observed in the tunica mucosa. Unusual findings included branched mucosal folds, discontinuous microvilli and absence of an outer longitudinal layer in the tunica muscularis. No marked sex-associated differences were found. The general histochemical and histological structures of the graylag goose gall bladder are similar to those of birds such as chukar partridge and quail, but with some unique elements that may reflect differences in organ function.


Assuntos
Células Epiteliais/metabolismo , Vesícula Biliar/metabolismo , Vesícula Biliar/patologia , Coloração e Rotulagem , Animais , Células Epiteliais/patologia , Feminino , Gansos , Técnicas Histológicas/métodos , Masculino , Caracteres Sexuais , Coloração e Rotulagem/métodos
19.
Toxicol Pathol ; 47(3): 358-378, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30700220

RESUMO

Bioabsorbable implants can be advantageous for certain surgical tissue bioengineering applications and implant-assisted tissue repair. They offer the obvious benefits of nonpermanence and eventual restoration of the native tissue's biomechanical and immunological properties, while providing a structural scaffold for healing and a route for additional therapies (i.e., drug elution). They present unique developmental, imaging, and histopathological challenges in the conduct of preclinical animal studies and in interpretation of pathology data. The bioabsorption process is typically associated with a gradual decline (over months to years) in structural strength and integrity and may also be associated with cellular responses such as phagocytosis that may confound interpretation of efficacy and safety end points. Additionally, as these implants bioabsorb, they become increasingly difficult to isolate histologically and thus imaging modalities such as microCT become very valuable to determine the original location of the implants and to assess the remodeling response in tandem with histopathology. In this article, we will review different types of bioabsorbable implants and commonly used bioabsorbable materials; additionally, we will address some of the most common challenges and pitfalls confronting histologists and pathologists in collecting, handling, imaging, preparing tissues through histology, evaluating, and interpreting study data associated with bioabsorbable implants.


Assuntos
Implantes Absorvíveis/efeitos adversos , Materiais Biocompatíveis/efeitos adversos , Segurança de Equipamentos/métodos , Teste de Materiais/métodos , Patologia/métodos , Tecidos Suporte/efeitos adversos , Implantes Absorvíveis/normas , Animais , Materiais Biocompatíveis/normas , Segurança de Equipamentos/instrumentação , Técnicas Histológicas/métodos , Humanos , Processamento de Imagem Assistida por Computador , Teste de Materiais/instrumentação , Especificidade da Espécie , Engenharia Tecidual , Tecidos Suporte/normas
20.
Toxicol Pathol ; 47(3): 213-220, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30727861

RESUMO

The terminal collection and histological processing of medical devices is an expensive, labor-, and material-intensive endeavor, which requires adequate experience, innovation, and preparation for success. It is also an exciting endeavor that continually challenges, intellectually engages, and improves the skills and knowledge of the pathologist. Awareness of the importance of the medical device pathologist's involvement, communication, and oversight throughout the development, implementation, and execution of a nonclinical assessment of a medical device is in the best interest of the test facility, the histopathology laboratory, the pathologist, the sponsor, and, ultimately, the patients. This article serves to present as a primer of key considerations for the approach and conduct of "nontoxicological" studies, defined as studies involving animal models of deployment or implantation of medical devices as well as surgical animal models.


Assuntos
Aprovação de Equipamentos/normas , Segurança de Equipamentos/métodos , Equipamentos e Provisões/normas , Patologia/métodos , Animais , Pesquisa Biomédica , Técnicas Histológicas/métodos , Técnicas Histológicas/normas , Modelos Animais , Patologia/normas , Testes de Toxicidade
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