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1.
Breast Cancer Res ; 22(1): 12, 2020 01 28.
Artículo en Inglés | MEDLINE | ID: mdl-31992350

RESUMEN

BACKGROUND: Breast cancer intrinsic molecular subtype (IMS) as classified by the expression-based PAM50 assay is considered a strong prognostic feature, even when controlled for by standard clinicopathological features such as age, grade, and nodal status, yet the molecular testing required to elucidate these subtypes is not routinely performed. Furthermore, when such bulk assays as RNA sequencing are performed, intratumoral heterogeneity that may affect prognosis and therapeutic decision-making can be missed. METHODS: As a more facile and readily available method for determining IMS in breast cancer, we developed a deep learning approach for approximating PAM50 intrinsic subtyping using only whole-slide images of H&E-stained breast biopsy tissue sections. This algorithm was trained on images from 443 tumors that had previously undergone PAM50 subtyping to classify small patches of the images into four major molecular subtypes-Basal-like, HER2-enriched, Luminal A, and Luminal B-as well as Basal vs. non-Basal. The algorithm was subsequently used for subtype classification of a held-out set of 222 tumors. RESULTS: This deep learning image-based classifier correctly subtyped the majority of samples in the held-out set of tumors. However, in many cases, significant heterogeneity was observed in assigned subtypes across patches from within a single whole-slide image. We performed further analysis of heterogeneity, focusing on contrasting Luminal A and Basal-like subtypes because classifications from our deep learning algorithm-similar to PAM50-are associated with significant differences in survival between these two subtypes. Patients with tumors classified as heterogeneous were found to have survival intermediate between Luminal A and Basal patients, as well as more varied levels of hormone receptor expression patterns. CONCLUSIONS: Here, we present a method for minimizing manual work required to identify cancer-rich patches among all multiscale patches in H&E-stained WSIs that can be generalized to any indication. These results suggest that advanced deep machine learning methods that use only routinely collected whole-slide images can approximate RNA-seq-based molecular tests such as PAM50 and, importantly, may increase detection of heterogeneous tumors that may require more detailed subtype analysis.


Asunto(s)
Biomarcadores de Tumor/genética , Neoplasias de la Mama/mortalidad , Neoplasias de la Mama/patología , Aprendizaje Profundo , Regulación Neoplásica de la Expresión Génica , Procesamiento de Imagen Asistido por Computador/métodos , Tipificación Molecular/métodos , Neoplasias de la Mama/clasificación , Neoplasias de la Mama/genética , Femenino , Humanos , Clasificación del Tumor , Receptor ErbB-2/metabolismo , Tasa de Supervivencia
2.
Anal Chem ; 88(5): 2792-8, 2016 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-26820161

RESUMEN

We report on HistoMosaic, a novel technique for genetic analysis of formalin-fixed, paraffin-embedded tissue slices. It combines microfluidic compartmentalization, in situ allele-specific PCR, and fluorescence microscopy. The experimental proof of principle was achieved by in situ detection of KRAS G12V mutation in colorectal cancer tissues and is presented herein. HistoMosaic offers the ability to detect mutations over the entire tissue slide simultaneously, rapidly, economically, and without selection bias, while coregistering the genetic information with the preserved morphological information. Thus, HistoMosaic has wide applicability in basic science as a tool to map genetic heterogeneity. It is also a platform to build companion diagnostics for targeted therapies in oncology, to help ensure that the right drug is given to the right patient, thereby saving healthcare resources and improving patient outcomes.


Asunto(s)
Neoplasias Colorrectales/patología , Genes ras , Mutación , Reacción en Cadena de la Polimerasa/métodos , Humanos , Microscopía Confocal
3.
Cell Tissue Res ; 360(1): 109-20, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25620411

RESUMEN

Companion diagnostics, tests that purport to classify patients into "responders" and "non-responders" for a specified targeted therapy, demand methods that quantify the actual amount of the corresponding target molecule in tumors from these patients. Various methods are employed depending upon the nature of the target. Many of the candidate therapeutic agents target the abnormal expression of a protein, the detection of which lends itself to an immunohistochemistry (IHC) approach. This review focuses on IHC with formalin-fixed paraffin-embedded (FFPE) tissues for purely pragmatic reasons; first, the morphologic information pertaining to the tumor is of value and should not be discarded as in extraction type assays; second, FFPE tissues are mostly what we have to hand at the time that the diagnostic question is posed. During the four decades of employment of IHC involving the production of a variety of special stains used in the diagnosis or classification of tumors, we have acquired some bad habits, essentially when judging the IHC result via the perception of a "good" stain that "pleases the eye" of the user pathologist, and nothing more. This review takes, as its basic premise, the notion that IHC can be upgraded from its use as a qualitative special staining method to an accurate and reliable quantitative "tissue-based immunologic assay". If accomplished, this enhanced IHC assay would serve accurately to quantify proteins in tissue sections, analogous to the use of the ELISA (enzyme-linked immunosorbent assay) method in the clinical laboratory. The necessary steps for converting IHC to a tissue-based ELISA-like immunoassay of immediate practical use are reviewed with constructive suggestions for steps that can be (must be) taken to achieve the practical reality of quantitative in situ proteomics.


Asunto(s)
Inmunohistoquímica/métodos , Microscopía/métodos , Proteómica/métodos , Animales , Ensayo de Inmunoadsorción Enzimática , Humanos , Estándares de Referencia
4.
Arch Pathol Lab Med ; 147(5): 584-590, 2022 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-36084252

RESUMEN

CONTEXT.­: The authors announce the launch of the Consortium for Analytic Standardization in Immunohistochemistry, funded with a grant from the National Cancer Institute. As with other laboratory testing, analytic standards are important for many different stakeholders: commercial vendors of instruments and reagents, biopharmaceutical firms, pathologists, scientists, clinical laboratories, external quality assurance organizations, and regulatory bodies. Analytic standards are customarily central to assay development, validation, and method transfer into routine assays and are critical quality assurance tools. OBJECTIVE.­: To improve immunohistochemistry (IHC) test accuracy and reproducibility by integrating analytic standards into routine practice. To accomplish this mission, the consortium has 2 mandates: (1) to experimentally determine analytic sensitivity thresholds (lower and upper limits of detection) for selected IHC assays, and (2) to inform IHC stakeholders of what analytic standards are, why they are important, and how and for what purpose they are used. The consortium will then publish the data and offer analytic sensitivity recommendations where appropriate. These mandates will be conducted in collaboration and coordination with clinical laboratories, external quality assurance programs, and pathology organizations. DATA SOURCES.­: Literature review and published external quality assurance data. CONCLUSIONS.­: Integration of analytic standards is expected to (1) harmonize and standardize IHC assays; (2) improve IHC test accuracy and reproducibility, both within and between laboratories; and (3) dramatically simplify and improve methodology transfer for new IHC protocols from published literature or clinical trials to clinical IHC laboratories.


Asunto(s)
Servicios de Laboratorio Clínico , Laboratorios , Humanos , Inmunohistoquímica , National Cancer Institute (U.S.) , Reproducibilidad de los Resultados , Estados Unidos
5.
Teach Learn Med ; 22(4): 307-11, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20936580

RESUMEN

BACKGROUND: In 2001, the Keck School of Medicine of the University of Southern California initiated a major curriculum reform with fully integrated teaching of the basic sciences. DESCRIPTION: The new curriculum integrated a set of selected clinical cases called the student practice profile (SPP). The SPP cases were designed to (a) define the core target knowledge base and essential clinical experience of all graduating students, (b) to improve the relevance of basic science teaching, and (c) to serve as the overarching organizational structure for the 4-year curriculum. EVALUATION: Evaluation data demonstrated that implementation of the SPP project has been moderately successful and students have reported high exposure to the SPP cases and confidence in their ability to diagnose and manage problems. Improvement in teaching the basic sciences in a clinically relevant manner is suggested by a small continued improvement in USMLE scores since the SPP project was fully implemented. CONCLUSIONS: The SPP design represents a uniquely successful pathway to curriculum redesign.


Asunto(s)
Competencia Clínica , Curriculum/normas , Educación Médica/normas , Facultades de Medicina/normas , Estudiantes de Medicina , California , Evaluación Educacional , Escolaridad , Humanos , Desarrollo de Programa , Evaluación de Programas y Proyectos de Salud , Estados Unidos
6.
Neuropathology ; 29(5): 521-7, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19019178

RESUMEN

J1-31 is one of the astrocytic proteins, the expression of which has not been evaluated in astrocytomas. In the present study, we studied the expression of J1-31 protein in astrocytes and astrocytomas in comparison with GFAP, p53 and Ki-67. Materials consisted of formalin-fixed paraffin-embedded tissue specimens that included five cases of normal brain, 17 of gliosis, 15 of pilocytic astrocytoma (WHO grade I), 26 of low-grade diffuse astrocytoma (WHO grade II), four of anaplastic astrocytoma (WHO grade III), and eight of glioblastoma (WHO grade IV). GFAP was highly expressed in all specimens examined. The anti-J1-31 antibody exhibited strong cytoplasmic staining of reactive gliosis in 17/17 (100%) cases with a higher intensity of staining than that observed in the adjacent normal astrocytes. The antibody showed reactivity with tumor cells in 12/15 (80%) cases of pilocytic astrocytoma, although intensity of staining was generally weaker and more focal than observed in reactive gliosis. J1-31-positive tumor cells were detected in only 9/26 (35%) cases of the low-grade diffuse astrocytoma and none of the cases of anaplastic astrocytoma and glioblastoma. Increasing Ki-67 indices paralleled advancing tumor grades. p53 protein was expressed more commonly in infiltrating astrocytomas compared to pilocytic astrocytoma. In conclusion, down-regulation of J1-31 expression correlates with advancing grade of astrocytomas. The result suggests this protein plays some role in astrocytes that is progressively lost in malignant progression. The anti-J1-31 antibody may help further our understanding of astrocytes in disease and may be useful as an aid in the pathologic diagnosis of astrocytic lesions.


Asunto(s)
Astrocitos/metabolismo , Astrocitoma/metabolismo , Proteínas del Tejido Nervioso/metabolismo , Citoplasma/metabolismo , Regulación hacia Abajo , Proteína Ácida Fibrilar de la Glía/metabolismo , Glioblastoma/metabolismo , Gliosis/metabolismo , Humanos , Antígeno Ki-67/metabolismo , Estadificación de Neoplasias , Proteína p53 Supresora de Tumor/metabolismo
7.
Appl Immunohistochem Mol Morphol ; 27(10): 715-721, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31107695

RESUMEN

This review article summarized recent advances in the heat-induced antigen retrieval technique with numerous scientific fields in addition to immunohistochemistry. Particularly, proteomics including imaging mass spectrometry, extraction of proteins from formalin-fixed, paraffin-embedded (FFPE) tissues. Some novel approaches such as FFPE tissue-based renal immunopathology based on modified double heating protocols are also introduced in this review for further development. In general, the FFPE tissue housed in pathology worldwide is an invaluable treasure, and the simple method of heat-induced antigen retrieval is the gold key to open the door of this treasure.


Asunto(s)
Antígenos/metabolismo , Inmunohistoquímica/métodos , Riñón/metabolismo , Animales , Antígenos/química , Calefacción , Humanos , Riñón/patología , Espectrometría de Masas , Adhesión en Parafina , Proteómica , Fijación del Tejido
8.
Appl Immunohistochem Mol Morphol ; 27(4): 263-269, 2019 04.
Artículo en Inglés | MEDLINE | ID: mdl-30640753

RESUMEN

Assessment of programmed death-ligand 1 (PD-L1) expression is a critical part of patient management for immunotherapy. However, studies have shown that pathologist-based analysis lacks reproducibility, especially for immune cell expression. The purpose of this study was to validate reproducibility of the automated machine-based Optra image analysis for PD-L1 immunohistochemistry for both tumor cells (TCs) and immune cells. We compared conventional pathologists' scores for both tumor and immune cell positivity separately using 22c3 antibody on the Dako Link 48 platform for PD-L1 expression in non-small cell lung carcinoma. We assessed interpretation first by pathologists and second by PD-L1 image analysis scores. Lin's concordance correlation coefficients (LCCs) for each pathologist were measured to assess variability between pathologists and between pathologists and Optra automated quantitative scores in scoring both tumor and immune cells. Lin's LCCs to evaluate the correlation between pathologists for TC was 0.75 [95% confidence interval (CI), 0.64-0.81] and 0.40 (95% CI, 0.40-0.62) for immune cell scoring. Pathologists were highly concordant for tumor scoring, but not for immune cell scoring, which is similar to previously reported studies where agreement is higher in TCs than immune cells. The LCCs between conventional pathologists' read and the machine score were 0.80 (95% CI, 0.74-0.85) for TCs and 0.70 (95% CI, 0.60-0.76) for immune cell population. This is considered excellent agreement for TCs and good concordance for immune cells. The automated scoring methods showed concordance with the pathologists' average scores that were comparable to interpathologist scores. This suggests promise for Optra automated assessment of PD-L1 in non-small cell lung cancer.


Asunto(s)
Automatización de Laboratorios , Antígeno B7-H1/biosíntesis , Biomarcadores de Tumor/biosíntesis , Carcinoma de Pulmón de Células no Pequeñas , Regulación Neoplásica de la Expresión Génica , Neoplasias Pulmonares , Proteínas de Neoplasias/biosíntesis , Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Carcinoma de Pulmón de Células no Pequeñas/patología , Humanos , Inmunohistoquímica , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patología
9.
Lab Chip ; 8(1): 68-74, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18094763

RESUMEN

The gene expression of human embryonic stem cells (hESC) is a critical aspect for understanding the normal and pathological development of human cells and tissues. Current bulk gene expression assays rely on RNA extracted from cell and tissue samples with various degree of cellular heterogeneity. These 'cell population averaging' data are difficult to interpret, especially for the purpose of understanding the regulatory relationship of genes in the earliest phases of development and differentiation of individual cells. Here, we report a microfluidic approach that can extract total mRNA from individual single-cells and synthesize cDNA on the same device with high mRNA-to-cDNA efficiency. This feature makes large-scale single-cell gene expression profiling possible. Using this microfluidic device, we measured the absolute numbers of mRNA molecules of three genes (B2M, Nodal and Fzd4) in a single hESC. Our results indicate that gene expression data measured from cDNA of a cell population is not a good representation of the expression levels in individual single cells. Within the G0/G1 phase pluripotent hESC population, some individual cells did not express all of the 3 interrogated genes in detectable levels. Consequently, the relative expression levels, which are broadly used in gene expression studies, are very different between measurements from population cDNA and single-cell cDNA. The results underscore the importance of discrete single-cell analysis, and the advantages of a microfluidic approach in stem cell gene expression studies.


Asunto(s)
Células Madre Embrionarias/citología , Células Madre Embrionarias/metabolismo , Perfilación de la Expresión Génica/métodos , Técnicas Analíticas Microfluídicas , Animales , Recuento de Células , ADN Complementario/genética , Humanos , Ratones , Reacción en Cadena de la Polimerasa , ARN Mensajero/genética , ADN Polimerasa Dirigida por ARN/metabolismo
10.
Br J Haematol ; 142(5): 717-31, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18540939

RESUMEN

Haemorrhagic cystitis (HC) is a common and, in its severe form, potentially life-threatening complication of Haematopoietic stem cell transplantation (HSCT) in children. Recent data indicate an important role of BK virus reactivation during the time of maximal post-transplant immune suppression in the pathogenesis of late-onset HC. Treatment of HC is mainly symptomatic and often frustrating. To give clinicians guidance on prevention and treatment options and their backing by scientific evidence, we have systematically assessed the available literature and devised evidence-based guidelines. Our comprehensive review demonstrates that evidence for the most commonly used interventions (such as cidofovir, oestrogen, hyperbaric oxygen, bladder instillation with formalin, alum salts or prostaglandin) is very limited. Some of these interventions also carry significant risks. Higher level evidence exists only for 2-mercaptoethane sodium (MESNA) and hyperhydration as a preventative intervention, and for systemic recombinant Factor VII as a treatment to stop acute haemorrhage. Further high-quality studies are required to establish effective and safe prevention and treatment options for HC.


Asunto(s)
Cistitis/terapia , Medicina Basada en la Evidencia , Hemorragia/terapia , Administración Intravesical , Antiinfecciosos/uso terapéutico , Antivirales/uso terapéutico , Virus BK , Niño , Cistectomía , Cistitis/etiología , Cistitis/prevención & control , Embolización Terapéutica , Estrógenos/uso terapéutico , Factor VIIa/uso terapéutico , Adhesivo de Tejido de Fibrina/uso terapéutico , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Hemorragia/etiología , Hemorragia/prevención & control , Humanos , Presión Hidrostática , Oxigenoterapia Hiperbárica , Inmunosupresores/uso terapéutico , Péptidos y Proteínas de Señalización Intercelular/uso terapéutico , Sustancias Protectoras/uso terapéutico
11.
Curr Med Chem ; 15(28): 2897-900, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-19075642

RESUMEN

The underlying gene interactions that collectively govern the regulation of cellular events can be studied by simultaneous measurement of the levels of mRNA from multiple involved genes. Ideally a single cell should be studied, for comparison with other cells, like and unlike. However, conventional gene expression profiling techniques require several thousands or even millions of cells in order to obtain a sufficient amount of mRNA for analysis. Obtaining this number of cells of a single type is difficult, especially in attempting to study rare stem cells. Single-cell gene expression profiling can, in theory, overcome this limitation. However, conventional analytic methods and equipment are not suitable for analyzing a single-cell, which has a volume of only one or two picoliters. Inexpensive microfluidic devices that can precisely manipulate several nanoliters of fluids are, in theory, ideal for single-cell analysis. By performing biochemical reactions in small volumes, microfluidic devices also minimize material loss in single-cell analysis. This review describes current microfluidic technology applied to single-cell analysis, with a primary focus upon study of single mammalian stem cells. Microfluidic devices have the potential to transform single-cell analysis from a major technological challenge task to a relatively routine procedure for research and clinical assays.


Asunto(s)
Técnicas Citológicas , Técnicas Analíticas Microfluídicas/instrumentación , Microfluídica/métodos , Células Madre/citología , Animales , Bioquímica/métodos , Electroquímica/métodos , Diseño de Equipo , Perfilación de la Expresión Génica , Humanos , Técnicas Analíticas Microfluídicas/métodos , ARN Mensajero/metabolismo , Células Madre/patología
12.
J Clin Microbiol ; 46(9): 3112-5, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18614656

RESUMEN

The aims of this study were to examine the extent of gastroenteric virus contamination in a pediatric primary immunodeficiency (PPI) ward and a general pediatric ward over a winter season and to determine whether changes to hospital infection control interventions would have an impact on environmental contamination levels within pediatric units. Environmental swabs were collected weekly from 11 sites in both wards from 15 December 2005 to 3 March 2006 and examined for the presence of norovirus (NoV), astrovirus, and rotavirus (RV) by reverse transcriptase PCR. Viruses were detected in 17% and 19% of swabs from both wards. Virus contamination for NoV and RV decreased from 20% to 6% and 15% to 10% of swabs, respectively, in the PPI ward from the 2004 study by Gallimore et al. (C. I. Gallimore, C. Taylor, A. R. Gennery, A. J. Cant, A. Galloway, M. Iturriza-Gomara, and J. J. Gray, J. Clin. Microbiol. 44:395-399, 2006). Overall, changes to cleaning protocols were deemed to have reduced the level of environmental contamination with gastroenteric viruses, but contamination still occurred due to a breakdown in infection control procedures indicated by contamination in areas frequented by parents but used only occasionally by staff.


Asunto(s)
Infecciones por Astroviridae/prevención & control , Infección Hospitalaria/prevención & control , Gastroenteritis/prevención & control , Departamentos de Hospitales/normas , Mamastrovirus , Norovirus , Pediatría/normas , Infecciones por Rotavirus/prevención & control , Rotavirus , Preescolar , Descontaminación , Humanos , Datos de Secuencia Molecular , Estaciones del Año
13.
Electrophoresis ; 29(24): 5010-6, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-19130581

RESUMEN

Herein we report on reliable reproducible quantification of protein analytes in human serum by fluorescence sandwich immunoassays in disposable PDMS microfluidic chips. The system requires 1,000 times less sample than typical clinical blood tests and is specifically shown to measure ferritin down to 250 pM in human serum. The in-built calibration method of spiking the serum with known concentrations of commercially available antigen avoids common sources of error and improves the reliability of the test results. The reported microfluidic system is an important new tool for fundamental scientific research, offering sensitive immunoassay measurements in small but complex biosamples. The system is also a further step towards comprehensive affordable "point-of-care" biomedical diagnostics.


Asunto(s)
Proteínas Sanguíneas/análisis , Inmunoensayo/instrumentación , Técnicas Analíticas Microfluídicas/instrumentación , Calibración , Fluorescencia , Humanos , Inmunoensayo/métodos , Técnicas Analíticas Microfluídicas/métodos , Reproducibilidad de los Resultados
14.
Am J Clin Pathol ; 129(3): 358-66, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18285257

RESUMEN

To examine the use of acetone- or ethanol-fixed frozen tissue sections as the "gold standard" for immunohistochemical analysis, we evaluated frozen sections with various conditions of fixation and antigen retrieval (AR). Fresh human tissues were frozen in OCT. An adjacent tissue block was fixed in 10% neutral buffered formalin (NBF) and paraffin embedded (FFPE). Frozen sections were fixed by 6 protocols: acetone, ethanol, NBF (2 durations), and NBF + calcium chloride (2 durations). AR was used for all NBF-fixed sections. More than half of the antibodies (16/26 [62%]) showed immunohistochemical results indistinguishable between acetone- and NBF-fixed sections; 8 (31%) showed better immunohistochemical signals following NBF and AR; 2 gave better immunohistochemical results for acetone-fixed sections. Most cytoplasmic proteins (10/13) showed comparable immunohistochemical signals between acetone- and NBF-fixed sections. For nuclear proteins, NBF-fixed sections gave better immunohistochemical signals than did acetone-fixed sections. In most cases, NBF yielded stronger signals with less background and better morphology. The data do not support the use of acetone-fixed frozen tissue sections as the gold standard for immunohistochemical analysis. In evaluating new antibodies, a combination of acetone- and NBF-fixed frozen sections should be used, although in practice, FFPE tissue sections may serve as the standard for most antigens for immunohistochemical analysis.


Asunto(s)
Secciones por Congelación/métodos , Inmunohistoquímica/métodos , Inmunohistoquímica/normas , Fijación del Tejido/métodos , Acetona/normas , Western Blotting , Cloruro de Calcio , Etanol/normas , Fijadores/normas , Formaldehído , Secciones por Congelación/normas , Humanos , Fijación del Tejido/normas
15.
Arch Pathol Lab Med ; 147(11): 1229-1231, 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37493520
16.
Appl Immunohistochem Mol Morphol ; 26(1): 6-12, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29189265

RESUMEN

Nivolumab is a monoclonal antibody that blocks the interaction between programmed cell death 1 (PD1) and programmed cell death 1-ligand 1 (PD-L1), resulting in enhanced antitumor activity by the immune system. Nivolumab is currently approved by the US Food and Drug Administration (FDA) for melanoma, non-small cell lung cancer (NSCLC), renal cell carcinoma, classical Hodgkin lymphoma, squamous cell carcinoma of the head and neck, and urothelial carcinoma. PD-L1 IHC 28-8 pharmDx is FDA-approved as a complementary diagnostic for immunohistochemical (IHC) detection of PD-L1 in non-squamous NSCLC and melanoma. We report validation of PD-L1 IHC 28-8 pharmDx for PD-L1 detection on formalin-fixed, paraffin-embedded human melanoma specimens using Autostainer Link 48. A prevalence assessment of 104 melanoma specimens indicated that PD-L1 was detected across the full expression level range (0% to 100% of tumor cells). Assay robustness and precision studies were conducted at Agilent Technologies, with additional reproducibility studies performed at 3 external laboratories. Precision studies evaluated at ≥1% and ≥5% expression levels revealed a range of average negative agreement from 89.5%, 95% CI (83.2, 93.6) to 100%, 95% CI (97.3, 100), and average positive agreement from 85.5%, 95% CI (77.6, 90.9) to 100%, 95% CI (97.9, 100). For external reproducibility, precise results were obtained. These results demonstrate PD-L1 IHC 28-8 pharmDx is a precise, robust, and reproducible assay for determining PD-L1 expression in melanoma. This is the first PD-L1 IHC test to receive FDA approval as a complementary diagnostic in melanoma patients whereby positive PD-L1 expression is correlated with the magnitude of nivolumab treatment effect.


Asunto(s)
Antígeno B7-H1/metabolismo , Inmunohistoquímica/métodos , Melanoma/diagnóstico , Melanoma/tratamiento farmacológico , Nivolumab/uso terapéutico , Humanos , Reproducibilidad de los Resultados , Resultado del Tratamiento
17.
Am J Surg Pathol ; 42(1): 39-52, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28961557

RESUMEN

Most prior studies of primary diagnosis in surgical pathology using whole slide imaging (WSI) versus microscopy have focused on specific organ systems or included relatively few cases. The objective of this study was to demonstrate that WSI is noninferior to microscopy for primary diagnosis in surgical pathology. A blinded randomized noninferiority study was conducted across the entire range of surgical pathology cases (biopsies and resections, including hematoxylin and eosin, immunohistochemistry, and special stains) from 4 institutions using the original sign-out diagnosis (baseline diagnosis) as the reference standard. Cases were scanned, converted to WSI and randomized. Sixteen pathologists interpreted cases by microscopy or WSI, followed by a wash-out period of ≥4 weeks, after which cases were read by the same observers using the other modality. Major discordances were identified by an adjudication panel, and the differences between major discordance rates for both microscopy (against the reference standard) and WSI (against the reference standard) were calculated. A total of 1992 cases were included, resulting in 15,925 reads. The major discordance rate with the reference standard diagnosis was 4.9% for WSI and 4.6% for microscopy. The difference between major discordance rates for microscopy and WSI was 0.4% (95% confidence interval, -0.30% to 1.01%). The difference in major discordance rates for WSI and microscopy was highest in endocrine pathology (1.8%), neoplastic kidney pathology (1.5%), urinary bladder pathology (1.3%), and gynecologic pathology (1.2%). Detailed analysis of these cases revealed no instances where interpretation by WSI was consistently inaccurate compared with microscopy for multiple observers. We conclude that WSI is noninferior to microscopy for primary diagnosis in surgical pathology, including biopsies and resections stained with hematoxylin and eosin, immunohistochemistry and special stains. This conclusion is valid across a wide variety of organ systems and specimen types.


Asunto(s)
Técnicas de Preparación Histocitológica/métodos , Patología Quirúrgica/métodos , Humanos , Microscopía , Variaciones Dependientes del Observador , Reproducibilidad de los Resultados , Método Simple Ciego
18.
J Histochem Cytochem ; 55(2): 105-9, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-16982846

RESUMEN

From a practical point of view, one of the most difficult issues in the standardization of IHC for FFPE tissue is the adverse influence of formalin upon antigenicity, as well as the great variation in fixation/processing procedures. Based on previous study, an additional study using four markers demonstrated the potential for obtaining equivalent IHC staining among FFPE tissue sections with periods of formalin fixation ranging from 6 hr to 30 days. On this basis, the following hypothesis is proposed. "The use of optimized AR protocols permits retrieval of specific proteins (antigens) from FFPE tissues to a defined and reproducible degree (expressed as R%), with reference to the amount of protein present in the original fresh/unfixed tissue". This hypothesis may also be presented mathematically: the protein amount in a fresh cell/tissue, expressed as Pf, produces an IHC signal in fresh tissue of integral(Pf). When the identical IHC staining plus AR treatment is applied to a FFPE tissue section, the IHC signal may be represented as integral (Pffpe). The degree of retrieval after AR (R%) is calculated as follows: R% = integral (Pffpe)/ integral (Pf) x 100%. The amount of protein in the FFPE tissue may then be derived as follows: Pffpe = Pf x R%. In a situation where optimized AR is 100% effective, the IHC signal would then be of equal strength in fresh tissue and FFPE tissue, and Pffpe= Pf. Further studies are designed to test the limitations of the proposed hypothesis.


Asunto(s)
Antígenos/metabolismo , Fijadores , Formaldehído , Inmunohistoquímica/normas , Adhesión en Parafina , Proteínas/metabolismo , Humanos , Reproducibilidad de los Resultados , Factores de Tiempo
19.
Pediatr Infect Dis J ; 26(2): 129-33, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17259874

RESUMEN

BACKGROUND: Patients with severe combined immunodeficiency and preexisting viral pneumonitis formally had a poor outcome from hematopoietic stem cell transplantation. With inhaled steroid and antitumor necrosis factor alpha antibody treatment, results improved. The poor outcome of patients with viral central nervous system infection prompted this retrospective single center review. RESULTS: Eight of 71 patients with severe combined immunodeficiency transplanted since 1987 were identified with viral central nervous system infection (adenovirus [1], cytomegalovirus [2], Epstein-Barr virus [2], parvovirus [1], varicella zoster virus [1], human herpesvirus 6 [1]). Nonspecific neurologic symptoms included drowsiness, irritability, head lag, fisting and floppiness. Later symptoms included unresponsiveness, apnea, posturing, hypotonia, hyperreflexia and seizures. All had neuroradiologic investigations. Only one had an initially normal computed tomography scan. Magnetic resonance image abnormalities included cerebral atrophy, basal ganglia changes, diffuse leukoencephalopathy, and multifocal mass lesions. Five patients had virus identified from cerebrospinal fluid by polymerase chain reaction and brain tissue examination from 3 patients identified human herpesvirus 6, adenovirus type 41 and varicella zoster virus. Three children remain alive, 2 received replete marrow and one remains untransplanted. Others who received T cell depleted marrow died of neurologic sequelae. CONCLUSION: Outcome of viral central nervous system infection after hematopoietic stem cell transplantation for severe combined immunodeficiency is poor, particularly associated with T cell depleted marrow.


Asunto(s)
Enfermedades Virales del Sistema Nervioso Central/complicaciones , Trasplante de Células Madre Hematopoyéticas , Inmunodeficiencia Combinada Grave/complicaciones , Inmunodeficiencia Combinada Grave/terapia , Enfermedades Virales del Sistema Nervioso Central/patología , Enfermedades Virales del Sistema Nervioso Central/fisiopatología , Niño , Preescolar , Femenino , Humanos , Lactante , Masculino , Estudios Retrospectivos , Resultado del Tratamiento
20.
J Virol Methods ; 144(1-2): 98-102, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17548117

RESUMEN

Retroviruses encode their genetic information with RNA molecules, and have a high genomic recombination rate which allows them to mutate more rapidly, thereby posting a higher risk to humans. One important way to help combat a pandemic of viral infectious diseases is early detection before large-scale outbreaks occur. The polymerase chain reaction (PCR) and reverse transcription-PCR (RT-PCR) have been used to identify precisely different strains of some very closely related pathogens. However, isolation and detection of viral RNA in the field are difficult due to the unstable nature of viral RNA molecules. Consequently, performing in-the-field nucleic acid analysis to monitor the spread of viruses is financially and technologically challenging in remote and underdeveloped regions that are high-risk areas for outbreaks. A simplified rapid viral RNA extraction method is reported to meet the requirements for in-the-field viral RNA extraction and detection. The ability of this device to perform viral RNA extraction with subsequent RT-PCR detection of retrovirus is demonstrated. This inexpensive device has the potential to be distributed on a large scale to underdeveloped regions for early detection of retrovirus, with the possibility of reducing viral pandemic events.


Asunto(s)
ARN Viral/aislamiento & purificación , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Virología/métodos , Línea Celular , Vectores Genéticos , VIH/genética , Humanos , Virología/instrumentación
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