4-hydroxy-2-nonenal as a marker of the oxidative stress in brains of dogs with canine distemper / 4-hidroxi-2-nonenal como marcador de estresse oxidativo no cérebro de cães com cinomose

Canine Distemper is a disease caused by Canine morbillivirus (CM), a pantropic virus that can affect the central nervous system (CNS), causing demyelination. However, the pathogenesis of this lesion remains to be clarified. Brain samples of 14 naturally infected dogs by CM were analyzed to evaluate the presence of oxidative stress and demyelination. RT-PCR assay was performed to confirm a diagnosis of canine distemper in the brain, immunohistochemistry anti-CM was used to localize the viral proteins in the tissue, and anti-4-hydroxy-2-nonenal (4-HNE) was a marker of a product of lipid peroxidation. The results showed the presence of viral proteins in the demyelinated area with the presence of 4-HNE. Our results suggest that the CM virus infection causes oxidative stress leading to lipid peroxidation, which causes tissue damage and demyelination. In conclusion, oxidative stress plays a significant role in canine distemper pathogenesis in the CNS.(AU)

A cinomose canina é uma doença causada pelo Morbilivírus canino (CM), um vírus pantrópico que pode afetar o sistema nervoso central (SNC), causando desmielinização. No entanto, a patogênese dessa lesão não está totalmente esclarecida. RT-PCR e imuno-histoquímica foram realizadas para confirmação do diagnóstico de cinomose em amostras de encéfalo de 14 cães naturalmente infectados. Após confirmação, foi realizada uma avaliação do estresse oxidativo por imuno-histoquímica com uso de anti-4-hidroxi-nonenal (4HNE) como marcador de produtos resultantes da peroxidação lipídica. Os resultados sugerem que a infecção pelo CM causa estresse oxidativo no tecido, levando a peroxidação lipídica, a qual causa danos ao tecido, culminando com desmielinização. Conclui-se que o estresse oxidativo tem papel importante na patogênese da cinomose canina no sistema nervoso central.(AU)

Expression of Vitamin D Receptor and Vitamin D Receptor Gene Polymorphisms (BsmI, FokI, and TaqI) in Patients with Pterygium / Expressão do gene do receptor da vitamina D e de seus polimorfismos (BsmI, FokI e TaqI) em pacientes com pterígio

ABSTRACT Purpose: This study aimed to determine the role of vitamin D receptor in the pathogenesis of pterygium. The vitamin D receptor eexpression levels in pterygium tissue, blood vitamin D levels, and frequency of selected vitamin D receptor gene polymorphisms (BsmI, FokI, and TaqI) were compared between patients with pterygium and healthy participants. Methods: The study included patients with pterygiumeee (n=50) and healthy volunteers (n=50). The serum vitamin D levels were measured for both groups. Immunohistochemical staining for vitamin D receptor ewas performed on sections obtained from the pterygium and adjacent healthy conjunctival tissues of the same individuals. The genomic existence of vitamin D receptor epolymorphisms (BsmI, FokI, and TaqI) were analyzed in DNA obtained from venous blood of participants using polymerase chain reaction and restriction fragment length polymorphism methods. Results: There was no difference found between the serum vitamin D levels of patients with pterygium and healthy controls. However, tissue expression of vitamin D receptor was higher in the pterygium endothelial cells of micro-vessels (p=0.002), subepithelial stromal (p=0.04), and intravascular inflammatory cells (p=0.0001), in comparison with the adjacent healthy conjunctival tissue. Moreover, while the BBtt haplotype was 2-fold higher, the bbTt haplotype was 2.5-fold lower, and the BbTT haplotype was 2.25-fold lower in the control group than in the pterygium group (p<0.001). Conclusions: Vitamin D serum levels did not differ between the healthy and pterygium groups. Vitamin D receptor expression was increased in the pterygium tissue versus the adjacent healthy tissue. However, vitamin D receptor polymorphism analysis in patients with pterygium did not reveal any significant difference in BsmI, FokI, or TaqI polymorphisms in comparison with the healthy volunteers.(AU)

RESUMO Objetivo: Determinar o papel do receptor da vitamina D na patogênese do pterígio. Os níveis de expressão do receptor da vitamina D no tecido do pterígio, os níveis sanguíneos de vitamina D e a frequência de alguns polimorfismos do gene do receptor da vitamina D (BsmI, FokI e TaqI) foram comparados entre pacientes com pterígio e participantes saudáveis. Métodos: Foram incluídos pacientes com pterígio (n=50) e voluntários saudáveis (n=50). Os níveis séricos de vitamina D foram medidos em ambos os grupos. Foi feita uma coloração imuno-histoquímica para o receptor da vitamina D em cortes obtidos do pterígio e dos tecidos conjuntivais saudáveis adjacentes dos mesmos indivíduos. A existência de polimorfismos do receptor da vitamina D (BsmI, FokI e TaqI) no genoma foi analisada em DNA obtido do sangue venoso dos participantes, usando métodos de Polymerase chain reaction (PCR) e RFLP. Resultados: Não foi observada nenhuma diferença entre os níveis séricos de vitamina D dos pacientes com pterígio e os dos controles saudáveis. Entretanto, a expressão tissular do receptor da vitamina D foi maior nas células endoteliais dos microvasos do pterígio (p=0,002), nas células estromais sub-epiteliais (p=0,04) e nas células inflamatórias intravasculares (p=0,0001), quando comparada à expressão no tecido conjuntival saudável adjacente. Além disso, embora o haplótipo BBtt tenha sido duas vezes mais frequente, o haplótipo bbTt foi 2,5 vezes menos frequente e o haplótipo BbTT foi 2,25 vezes menos frequente no grupo de controle do que no grupo com pterígio (p<0,001). Conclusões: Os níveis séricos de vitamina D não apresentaram diferenças entre o grupo de pessoas saudáveis e o com pterígio. A expressão do receptor da vitamina D mostrou-se maior no grupo com pterígio do que no tecido saudável adjacente. Entretanto, a análise dos polimorfismos do receptor da vitamina D nos pacientes com pterígio não revelou qualquer diferença significativa nos polimorfismos BsmI, FokI ou TaqI em comparação com os voluntários saudáveis.(AU)

The human-in-the-loop: an evaluation of pathologists' interaction with artificial intelligence in clinical practice.

AIMS: One of the major drivers of the adoption of digital pathology in clinical practice is the possibility of introducing digital image analysis (DIA) to assist with diagnostic tasks. This offers potential increases in accuracy, reproducibility, and efficiency. Whereas stand-alone DIA has great potential benefit for research, little is known about the effect of DIA assistance in clinical use. The aim of this study was to investigate the clinical use characteristics of a DIA application for Ki67 proliferation assessment. Specifically, the human-in-the-loop interplay between DIA and pathologists was studied. METHODS AND RESULTS: We retrospectively investigated breast cancer Ki67 areas assessed with human-in-the-loop DIA and compared them with visual and automatic approaches. The results, expressed as standard deviation of the error in the Ki67 index, showed that visual estimation ('eyeballing') (14.9 percentage points) performed significantly worse (P < 0.05) than DIA alone (7.2 percentage points) and DIA with human-in-the-loop corrections (6.9 percentage points). At the overall level, no improvement resulting from the addition of human-in-the-loop corrections to the automatic DIA results could be seen. For individual cases, however, human-in-the-loop corrections could address major DIA errors in terms of poor thresholding of faint staining and incorrect tumour-stroma separation. CONCLUSION: The findings indicate that the primary value of human-in-the-loop corrections is to address major weaknesses of a DIA application, rather than fine-tuning the DIA quantifications.

Reactivos de inmunohistoquímica para diagnóstico diferencial oncológico de neoplasias del sistema nervioso central / Immunohistochemical reagents for differential cancer diagnosis of central nervous system neoplasms

INTRODUCCIÓN: El Departamento de Equipo Funcional de Patología Quirúrgica y Necropsia del Instituto Nacional de Enfermedades Neoplásicas, en relación a nuevos reactivos de inmunohistoquímica para diagnóstico oncológico de tumores del sistema nervioso central, ha solicitado la opinión técnica de la UFETS. 2. Existen neoplasias del sistema nervioso central que presentan una pobre respuesta al tratamiento estandarizado y un peor pronóstico, por lo cual ameritan un diagnóstico eficaz y temprano. Los marcadores para inmunohistoquímica H3 K27M, H3 K27m3, GAB-1, YAP-1, H3.3G34R y MAP-2 permitirían un diagnóstico más eficaz e incluso influiría en su tratamiento y seguimiento. Estrategia de búsqueda de información: a) Pregunta Clínica: Sección A: SNC: En la población con tumores de SNC, ¿Cuál es la utilidad de los marcadores de H3 K27m3, GAB-1, YAP-1, H3.3G34R y MAP-2 como diagnóstico oncológico en tumores del SNC? b) Recolecciòn de los Manuscritos a Revisar: Tipos de estudios: La estrategia de búsqueda sistemática de información científica para el desarrollo del presente informe se realizó siguiendo las recomendaciones de la Pirámide jerárquica de la evidencia propuesta por Haynes y se consideró los siguientes estudios: Sumarios y guías de práctica clínica. Revisiones sistemáticas y/o meta-análisis. Ensayos Controlados Aleatorizados (ECA) Estudios Observacionales (cohortes, caso y control, descriptivos) No hubo limitaciones acerca de la fecha de publicación o el idioma para ningún estudio. DISCUSION: Tomando los criterios para un marco de valor de la Health Technology Assessment International (2018)13 para la toma de decisiones y formulación de la recomendación, se encontró una serie de estudios de los cuales no se encontraron revisiones sistemáticas ni estudios diagnósticos. La calidad de evidencia evaluada con metodología GRADE fue baja en todos los estudios evaluados, considerando el diseño de estudio observacional, y por el pequeño tamaño de las muestras estudiadas. Esta valoración indica que los resultados obtenidos en el mundo real por la aplicación de estas tecnologías pueden ser significativamente diferentes a los resultados diagnósticos de los estudios presentados. Los estudios que evaluaron el H3K27M y H3K27me3 evaluaron la utilidad diagnóstica de los anticuerpos para detección de estas mutaciones. El diagnóstico de glioma de línea media con mutación K27M permite reconocer una entidad de peor pronóstico y sólo se logra con la aplicación de estos marcadores. Si bien existe una cantidad limitada de evidencia, los estudios llevados por Tina Huang y col. evaluaron el rendimiento diagnóstico de estos marcadores comparándolos con estudios de mutación en muestras de tejido con diagnóstico de glioma (n=69) y tejido sano (n=4) en población pediátrica. Otro estudio por Sriram Venneti y col. tomaron como población 290 muestras de cáncer con mutación H3F3A K27M conocida. Los estudios reportan una sensibilidad 100% y una especificidad 100% para el marcador H3K27M y Sriram Venneti reportó una sensibilidad 100% y especificidad 98% para H3K27me3. Ambos marcadores cuentan con una utilidad diagnóstica importante su aplicación permitiría diagnosticar precozmente una enfermedad con mal pronóstico en edad pediátrica y adulta. El GAB-1 y el YAP-1 intervienen en el proceso de desarrollo del cáncer a nivel de sistema nervioso central. La detección de ambas mutaciones por inmnohistoquimica permite la clasificación molecular del meduloblastoma en SHH, WNT y no-SHH/WNT. El determinar el subtipo molecular es importante ya que cada uno cuenta con un pronóstico diferente y su reconocimiento permitiría realizar un mejor diagnóstico y hasta influir en el tipo de tratamiento que recibiría. David W. Ellison y su equipo reconocer al meduloblastoma como una enfermedad heterogenea y a través de inmunohistoquímica determinan los subtipos de meduloblastoma en una cohorte de 235 muestras en pacientes de un rango de edad 0.4 ­ 52 años. Los subtipos moleculares SHH, WNT, y no SHH/WNT correspondían al 31%, 14%, y 55% de los casos. Hye Sook Min y col. evaluaron la detección de mutaciones a través de anticuerpos para inmunohistoquímica en cada subtipo molecular de meduloblastoma. El GAB-1 fue hallado en el 100% de los subtipos SHH y en sólo el 25% del subtipo WNT. El YAP-1 se encontró en el 50% de los subtipos WNT, el 80%de SHH y sólo el 2% en los subtipos no-SHH/WNT. Ambos marcadores son relevantes para poder clasificar adecuadamente cada subtipo molecular de meduloblastoma. Las mutaciones H3.3G34R y MAP-2 están asociadas con la progresión de enfermedad oncológica. Farhana Haque y col. evaluaron la eficacia de la inmunotinción para la detección de H3.3G34R en una cohorte de 22 muestras de tumores incluidos en parafina con mutación H3.3 G34R conocida. 17 eran tumores supratentoriales de alto grado, 2 gangliomas anaplasicos, 2 oligoastrocitomas grado III y 1 glioma de alto grado. La IHC detectó con éxito la proteína mutante correspondiente en todos los casos (11/11 G34R). Los resultados demostraron una concordancia adecuada entre estudio diagnóstico con inmunohistoquímica y estudio mutacional correspondiente. Se reportó una sensibilidad del 100% y especificidad del 98% para diagnóstico. Con respecto al estudio de inmunohistoquímica del MAP-2, Ingmar Blümcke y su grupo de estudio demostraron que el análisis por inmunohistoquímica presentó una sensibilidad del 98% y una alta especificidad para la detección de esta mutación, la cual está asociada con la progresión de tumores astrocíticos de alto grado en el sistema nervioso central. En este momento el INEN no cuenta con marcadores que puedan diagnosticar los gliomas de línea media con mutación K27M, una entidad de pobre repuesta al tratamiento y peor pronóstico y que por ende ameritaría un diagnóstico precoz. De la misma forma, la clasificación molecular de los meduloblastomas es algo importante. Cada subtipo molecular cuenta con un pronóstico diferente lo cual podría impactar en el tratamiento y la forma de seguimiento de los pacientes. Tampoco se cuenta con una forma de detección de la mutación 3.3 G34R y el MAP-2 cuenta con una alta eficacia diagnóstica para el diagnóstico de astrocitomas de alto grado. Ninguno de estos procedimientos diagnósticos está siendo realizado en este momento por lo cual la aplicación de estos marcadores supone un impacto positivo al considerar la población de pacientes diagnosticados que contarían con un tratamiento adecuado. Todos estos marcadores se integrarían al arsenal diagnóstico, sin reemplazar otro marcador que ya se esté aplicando en el INEN. El impacto económico de esta prueba para el INEN es incierto y es necesario realizar un análisis de impacto presupuestario para estimar cuantitativamente el gasto sanitario del uso de esta prueba en la población con linfomas. CONCLUSIONES: Algunas patologías oncológicas del sistema nervioso centran tienen una mala respuesta al tratamiento convencional, lo cual les da un peor pronóstico y un curso más agressivo. Los marcadores H3 K27M y H3 K27m3 presentan una alta sensibilidad y especificidad para el diagnóstico de gliomas de la línea media con mutación K27M. Esta entidad cuenta con una peor respuesta a tratamiento y peor pronóstico. Su detección temprana podría permitir un mejor tratamiento y optimizar las pautas de seguimiento. Los marcadores H3.3G34R y MAP-2 reconocen mutaciones que intervienen con el desarrollo del cáncer. Ambos cuentan con una alta sensibilidad y especificidad para el diagnóstico de tumores astrocíticos de alto grado. Los marcadores GAB-1 y YAP-1 se utilizan para determinar los subtipos moleculares de meduloblastoma, teniendo el GAB-1 una sensibilidad alta para el tipo SHH. Cada subtipo molecular de meduloblastoma cuenta con un pronóstico diferente lo cual podría influenciar en la forma de tratamiento que recibirían. Los marcadores de inmunohistoquímica permitirían un eficaz y temprano diagnóstico, lo cual influiría positivamente en el pronóstico de los pacientes con estas patologías, las cuales hasta la fecha no han sido diagnosticadas adecuadamente.

Molecular Characterization of Testicular Germ Cell Tumors Using Tissue Microdissection.

Testicular germ cell tumors are among the most common malignancies seen in children and young adults. Genomic studies have identified characteristic molecular profiles in testicular cancer, which are associated with histologic subtypes and may predict clinical behavior including treatment responses. Emerging molecular technologies analyzing tumor genomics, transcriptomics, and proteomics may now guide precision management of testicular tumors. Laser-assisted microdissection methods such as laser capture microdissection efficiently isolate selected tumor cells from routine pathology specimens, avoiding contamination from nontarget cell populations. Laser capture microdissection in combination with next generation sequencing makes precise high throughput genetic evaluation effective and efficient. The use of laser capture microdissection (LCM) for molecular testing may translate into great benefits for the clinical management of patients with testicular cancers. This review discusses application protocols for laser-assisted microdissection to investigate testicular germ cell tumors.

Preparing Cell Smears for Staining.

Increasing use is being made of cell smears for cell-staining studies. Suspension cells can be attached to slides by drying, and cell smears can also be prepared from biopsy samples, such as needle aspirates, tissue scrapings, or freshly dissected tissues. In these procedures, a thin layer of cells is deposited on a dry slide by physical methods. The most important factor in obtaining good staining patterns is that the smear be only a single cell thick. Tissue smears do not preserve tissue architecture, but are useful for identifying pathological changes and infectious organisms in tissue samples. Cell smears are easily prepared and can be fixed readily by any of the methods used for attached cells.

Immunohistochemical identification of T and B lymphocytes in formalin-fixed paraffin-embedded chicken tissues using commercial antibodies.

Immunohistochemical method to detect avian lymphocytes is an efficient and reliable tool for accurate diagnosis, and immunological analysis of avian diseases. However, there are scarce studies reporting immunohistochemistry (IHC) using commercially available antibodies in formalin-fixed paraffin-embedded (FFPE) chicken tissues. In the present study, we established an immunohistochemical method to identify chicken T and B lymphocytes in FFPE chicken tissues using commercial antibodies against chicken or human antigens. For this IHC method, the five tested anti-T lymphocyte antibodies reacted with chicken T lymphocytes on the FFPE sections. Further, 10 commercial anti-B lymphocyte antibodies were tested; of these, three successfully detected chicken B lymphocytes for IHC. In particular, anti-human CD3 (clone F7.2.38) antibody was most suitable for the detection of chicken T lymphocytes, whereas anti-chicken B cell activating factor receptor (BAFF-R) antibody (clone 2C4) was most suitable for the detection of chicken B lymphocytes under our IHC staining conditions. These two antibodies reacted with numerous lymphocytes of all representative lymphoid tissues without problematic background staining and nonspecific reactions. Our results indicate that T and B lymphocytes in FFPE chicken tissues can be immunohistochemically detected using commercial antibodies.

In Vivo Analysis of Glial Immune Responses to Axon Degeneration in Drosophila melanogaster.

Axon degeneration elicits a range of immune responses from local glial cells, including striking changes in glial gene expression, morphology, and phagocytic activity. Here, we describe a detailed set of protocols to assess discrete components of the glial reaction to axotomy in the adult nervous system of Drosophila melanogaster. These methods allow one to visualize and quantify transcriptional, morphological, and functional responses of glia to degenerating axons in a model system that is highly amenable to genetic manipulation.

Detecting ß-Galactosidase-Labeled Cells.

ß-Galactosidase has been used extensively both as a label in enzyme immunoassays and for immunocytochemistry. One good substrate is 5-bromo-4-chloro-3-indolyl-ß-d-galactopyranoside (X-gal), which gives an intense blue product. The product is stable and insoluble in alcohol as well as H2O.

A proof-of-concept analysis of carbohydrate-deficient transferrin by imaged capillary isoelectric focusing and in-capillary immunodetection.

Carbohydrate-deficient transferrin (CDT) is a reliable biomarker for chronic alcohol abuse. We developed a method for CDT analysis by capillary isoelectric focusing, followed by immunodetection directly in the capillary, in an automated fashion and on a single platform (Peggy Sue™; ProteinSimple, CA, USA). Transferrin glycoforms in serum samples, including disialo-transferrin, were separated and their apparent isoelectric points and relative percentages were determined. The relative CDT values (percent of total transferrin) matched expected values for both healthy and alcoholic samples. Because the method leveraged the sensitivity of an immunoassay, CDT was measured when serum samples were diluted up to 1200-fold, reducing the volume of serum required. Finally, the process is fully automated, with up to 96 samples analyzed per batch.

Role of TFF3 as an adjunct in the diagnosis of Barrett's esophagus using a minimally invasive esophageal sampling device-The CytospongeTM.

The incidence of esophageal carcinoma continues to increase whilst its prognosis remains poor. The most dramatic reduction in mortality is likely to follow early diagnosis of the preinvasive precursor lesion, Barrett's esophagus (BE), coupled with treatment of dysplastic lesions. The major risk factor for BE is gastroesophageal reflux disease, however this is highly prevalent and only a small proportion of individuals have BE, therefore an endoscopy-based screening strategy to detect BE is unfeasible. Minimally invasive esophageal sampling devices offer an alternative, cost-effective strategy which can be deployed within an at-risk population in a primary care setting to identify individuals with probable BE who can then be referred for endoscopic confirmation. The device that has currently progressed furthest in clinical trials is the CytospongeTM which collects cells from the gastric cardia, gastroesophageal junction and along the whole esophageal length. The cell sample is processed into a formalin-fixed paraffin-embedded block and sections assessed for the presence of intestinal metaplasia. TFF3 immunohistochemistry has consistently been shown to be a valuable adjunct that increases the accuracy of the CytospongeTM test by highlighting early goblet cells which may be missed on morphological assessment and by allowing pseudogoblet cells to be differentiated from true goblet cells.

Membrane attack complex (C5b-9 complex or Mac), is strongly present in lesional skin from patients with endemic pemphigus foliaceus in El Bagre, Colombia.

BACKGROUND: El Bagre endemic pemphigus foliaceus (El Bagre-EPF) is a new variant of endemic pemphigus foliaceus present in the El Bagre area of Colombia, South America. Here, we investigate the presence of complement/C5-b9 in lesional skin of patients and matched controls from the endemic area. We also aim to compare the patient's autoantibody levels using indirect immunofluorescent titers (IIF) and correlate with the lesional presence of complement/C5b-9. METHODS: A case-control study was carried out by testing for the presence of complement/C5b-9 in lesional skin in 43 patients affected by El Bagre-EPF, as well as 43 matched, healthy controls from the endemic area. Skin biopsies were obtained and evaluated via hematoxylin and eosin staining, and immunohistochemistry. RESULTS: The presence of complement/C5b-9 was observed in all cases of the patients affected by El Bagre-EPF and was not observed in the controls from the endemic area (P < 0.001). The patients' autoantibody titers utilizing IIF for IgG and IgM showed correlation between higher autoantibody titers and stronger intensity of staining with complement/C5-b9 staining (P < 0.001). CONCLUSION: Patients affected by El Bagre-EPF have lesional deposition of complement/C5b, which correlates with disease severity and previously established serologies.

Interlaboratory concordance in HER2 testing: Results of a Serbian ring-study.

PURPOSE: The purpose of this study was to assess the immunohistochemistry and chromogenic in situ hybridization (CISH) inter-laboratory consensus between national pathology laboratories in Serbia. METHODS: This study was conducted between 2013 and 2016. In 2013, HER2 results were evaluated using two sets of four different breast cancer specimens in five laboratories. A total of 20 immunohistochemistry and 20 CISH cases were tested. In 2014, there were 6 testing rounds, and a total of 24 specimens were analyzed, whereas in 2015 and 2016, seven testing rounds were conducted, with four additional cases (i.e. a total of 28 specimens). In 2014, 2015 and 2016, all institutions performed immunohistochemical analysis only. RESULTS: We found discrepan¬cies in HER2 immunohistochemical (IHC) results in all four surveys. IHC testing resulted in diagnostic discordance between participating centers in two (2/17) cases in 2013, two (2/24) in 2014, four (4/27) cases in 2015 and three cases (3/27) in 2016. The overall agreement among the centers was 79%, 85.5%, 83.5% and 89.4%, respectively. For CISH analyses, the results for 16 (84.2%) of 19 samples were consistent for all participants. Three results were found to be discordant, indicating a misdiagnosis rate of 15.8%. In all the discrepant cases, interinstitutional discordances were related to technical and evaluation issues. CONCLUSIONS: Our study highlights the difficulty encountered during HER2 testing using immunohistochemistry and CISH. This also emphasizes the need for rigorous quality control procedures for specimen preparation and analysis.

Weak Cytotoxic T Cells Activation Predicts Low-Grade Dysplasia Persistence in Ulcerative Colitis.

INTRODUCTION: In patients with ulcerative colitis (UC), dysplasia develops in 10%-20% of cases. The persistence of low-grade dysplasia (LGD) in UC in 2 consecutive observations is still an indication for restorative proctocolectomy. Our hypothesis is that in the case of weak cytotoxic activation, dysplasia persists. We aimed to identify possible immunological markers of LGD presence and persistence. METHODS: We prospectively enrolled 112 UC patients who underwent screening colonoscopy (T0) who had biopsies taken from their sigmoid colon. Ninety of them had at least a second colonoscopy (T1) with biopsies taken in the sigmoid colon and 8 patients had dysplasia in both examinations suggesting a persistence of LGD in their colon. Immunohistochemistry and real time polymerase chain reaction for CD4, CD69, CD107, and CD8ß messenger RNA (mRNA) expression and flow cytometry for epithelial cells expressing CD80 or HLA avidin-biotin complex were performed. Non-parametric statistics, receiver operating characteristic curves analysis, and logistic multiple regression analysis were used. RESULTS: Thirteen patients had LGD diagnosed at T0. The mucosal mRNA expression of CD4, CD69, and CD8ß was significantly lower than in patients without dysplasia (P = 0.033, P = 0.046 and P = 0.007, respectively). A second colonoscopy was performed in 90 patients after a median follow-up of 17 (12-25) months and 14 of the patients were diagnosed with LGD. In these patients, CD8ß mRNA expression at T0 was significantly lower in patients without dysplasia (P = 0.004). A multivariate survival analysis in a model including CD8ß mRNA levels and age >50 demonstrated that both items were independent predictors of dysplasia at follow-up (hazard ratio [HR] = 0.47 [95% confidence interval [CI]: 0.26-0.86], P = 0.014, and HR = 13.32 [95% CI: 1.72-102.92], P = 0.013). DISCUSSION: These data suggest a low cytotoxic T cell activation in the colonic mucosa of UC patients who do not manage to clear dysplasia. Thus, low level of CD8ß mRNA expression in non-dysplastic colonic mucosa might be considered in future studies about the decision making of management of LGD in UC.

An Immunohistochemical Study of Gastric Mucosa and Critical Review Indicate that the Subepithelial Telocytes are Prelymphatic Endothelial Cells.

There are only a few studies regarding gut subepithelial telocytes (TCs). The telopodes, namely peculiar TCs' prolongations described on two-dimensional cuts, are not enough to differentiate this specific cell type. Subepithelial TCs were associated with the intestinal stem niche but a proper differential diagnosis with lymphatic endothelial cells (LECs) was not performed. In this study, we will critically review studies suggesting that distinctive TCs could be positioned within the lamina propria. Additionally, we performed an immunohistochemical study of human gastric mucosa to test the expression of D2-40, the lymphatic marker, as well as that of CD31, CD34, CD44, CD117/c-kit, α-smooth muscle actin (α-SMA) and vimentin in the gastric subepithelial niche. The results support the poorly investigated anatomy of intramural gastric lymphatics, with circumferential collectors located on both sides of the muscularis mucosae (mucosal and then submucosal) and myenteric collectors in the muscularis propria. We also found superficial epithelial prelymphatic channels bordered by D2-40+ but CD31-TC-like cells. Deep epithelial lymphatic collectors drain in collectors within the lamina propria. Blood endothelial cells expressed CD31, CD34, CD44, and vimentin. Therefore, the positive diagnosis of TC for subepithelial CD34+ cells should be regarded with caution, as they could also be artefacts, resulting from the two-dimensional examination of three dimensional structures, or as LECs. Lymphatic markers should be routinely used to discriminate TCs from LECs.

PD-L1 testing of non-small cell lung cancer using different antibodies and platforms: a Swiss cross-validation study.

With the approval of pembrolizumab for first- and second-line treatment of PD-L1+ non-small cell lung cancer (NSCLC), PD-L1 testing by immunohistochemistry (IHC) has become a necessity. However, the DAKO autostainer ASL48 for the FDA approved DAKO 22C3 pharmDx assay is not broadly available in Switzerland and other parts of Europe. The primary goal of this study was to cross-validate the 22C3 anti-PD-L1 antibody on Benchmark Ultra (VBMU) and Leica Bond (LBO) immunostainers. IHC protocols were developed for 22C3 on both platforms with the 22C3phDx using ASL48 as reference. A tissue microarray (TMA) was constructed from 23 NSCLC specimens with a range of PD-L1 staining results. Empty TMA sections and the 22C3 antibody were distributed to 16 participants for staining on VBMU (8 centers) and/or LBO (12 centers) using the centrally developed protocols. Additionally the performance of the Ventana SP263 assay was tested in five centers. IHC scoring was performed centrally. Categorical PD-L1 staining (0-49% vs. 50-100%) did not significantly differ between centers using VBMU, whereas data from LBO were highly variable (p < 0.001). The SP263 assay was well concordant with 22C3 on VBMU and with 22C3 pharmDx. PD-L1 IHC using a standardized 22C3 protocol on VBMU provides satisfactory results in most centers. The SP263 assay is confirmed as a valid alternative to 22C3 pharmDx. 22C3 PD-L1 IHC on LBO shows major staining variability between centers, highlighting the need for local validation and adjustment of protocols.

Intrinsic planar polarity mechanisms influence the position-dependent regulation of synapse properties in inner hair cells.

Encoding the wide range of audible sounds in the mammalian cochlea is collectively achieved by functionally diverse type I spiral ganglion neurons (SGNs) at each tonotopic position. The firing of each SGN is thought to be driven by an individual active zone (AZ) of a given inner hair cell (IHC). These AZs present distinct properties according to their position within the IHC, to some extent forming a gradient between the modiolar and the pillar IHC side. In this study, we investigated whether signaling involved in planar polarity at the apical surface can influence position-dependent AZ properties at the IHC base. Specifically, we tested the role of Gαi proteins and their binding partner LGN/Gpsm2 implicated in cytoskeleton polarization and hair cell (HC) orientation along the epithelial plane. Using high and superresolution immunofluorescence microscopy as well as patch-clamp combined with confocal Ca2+ imaging we analyzed IHCs in which Gαi signaling was blocked by Cre-induced expression of the pertussis toxin catalytic subunit (PTXa). PTXa-expressing IHCs exhibited larger CaV1.3 Ca2+-channel clusters and consequently greater Ca2+ influx at the whole-cell and single-synapse levels, which also showed a hyperpolarized shift of activation. Moreover, PTXa expression collapsed the modiolar-pillar gradients of ribbon size and maximal synaptic Ca2+ influx. Finally, genetic deletion of Gαi3 and LGN/Gpsm2 also disrupted the modiolar-pillar gradient of ribbon size. We propose a role for Gαi proteins and LGN in regulating the position-dependent AZ properties in IHCs and suggest that this signaling pathway contributes to setting up the diverse firing properties of SGNs.

Subtyping of IPMN.

Intraductal papillary mucinous neoplasms (IPMNs) characteristically consist of mucin-filled dilated ducts lined with neoplastic cells forming papillae with a diverse range of morphologies and varying grades of atypia. Based on morphological characteristics and immunohistochemical reaction against mucin proteins, IPMNs are classified into four distinct subtypes: gastric, intestinal, pancreatobiliary, and oncocytic. In this chapter, histomorphological criteria and techniques of immunohistochemical staining and its evaluation for subtyping IPMNs are described.

Reagent-saving immunohistochemistry for HER2 using non-contact alternating current electric field mixing.

AIMS: Human epidermal growth factor receptor 2 (HER2)-targeted agents are an effective approach to treating patients with HER2-positive breast cancer. However, the lack of survival benefit in HER2-negative patients, as well as the toxic effects and high cost of the drugs, highlight the need for accurate and prompt assessment of HER2 status. Our aim was to evaluate the clinical utility of a novel reagent-saving immunohistochemistry method (AC-IHC) that saves HER2 antibody by taking advantage of the non-contact mixing effect in microdroplets subjected to an alternating current electric field. METHODS: Ninety-five specimens were used from patients diagnosed with primary breast cancers identified immunohistochemically as HER2 0/1+, 2+ or 3+ using ASCO/CAP guideline-certified standard IHC. The specimens were all tested using the conventional IHC method (1:50 antibody dilution) as well as AC-IHC (1:50 dilution) and reagent-saving AC-IHC (1:100 dilution). RESULTS: The reagent-saving AC-IHC produced stable results with less non-specific staining using smaller amounts of labelled antibody. Moreover, the staining and accuracy of HER2 status evaluated with the reagent-saving AC-IHC method was equal to that achieved with standard IHC. CONCLUSIONS: These results suggest reagent-saving AC-IHC could be used as a clinical tool for accurate and stable HER2 IHC, even when reagent concentrations vary.

A novel high-content imaging-based technique for measuring binding of Dickkopf-1 to low-density lipoprotein receptor-related protein 6.

INTRODUCTION: Dickkopf-related protein 1 (Dkk1) is a secreted protein ligand of low-density lipoprotein receptor-related protein 6 (LRP6), which antagonises canonical Wnt signalling. Elevated Dkk1 levels have been linked to Alzheimer's disease (AD), with protein blockade protective in pre-clinical AD models, suggesting inhibitors of Dkk1-LRP6 binding may have therapeutic utility against AD. Cell-based Dkk1-LRP6 assays reported in the literature use either modified Dkk1 protein and/or do not possess suitable throughput for drug screening. Here we report a novel immunocytochemical-based assay utilising high-content imaging (HCI) and automated data analysis suitable for the screening of protein and small-molecule inhibitors of Dkk1-LRP6 binding. METHODS: We developed an immunocytochemical (ICC) protocol to detect specific binding of exogenous human Dkk1 protein to human LRP6 transiently expressed in HEK293 cells. Images were generated using the PerkinElmer Operetta HCI System, after which quantitative data was generated using the PerkinElmer Columbus™ System. RESULTS: Our ICC technique and analysis pipeline allowed measurement of cell membrane-localised, LRP6-specific Dkk1 binding, normalised at individual cellular events. Saturation binding demonstrated concentration-dependent Dkk1 binding to LRP6, with a KD in keeping with reported values. Association kinetic experiments demonstrated the utility of the technique to investigate Dkk1 binding kinetics. Human Dkk members Dkk2 and Dkk4 fully displaced Dkk1 binding in a competition assay, while Dkk3 and Soggy-1/DkkL1 exhibited non-complete displacement of Dkk1. Finally gallocyanine, a previously reported inhibitor of Dkk1-LRP6 binding, fully displaced Dkk1 near the expected IC50. DISCUSSION: In conclusion, we provide a validated cell-based assay, suitable for the screening of inhibitors of Dkk1-LRP6 binding, and provide the basis for additional assay development, investigating Dkk1-LRP6 pharmacology.