Formalin, an aqueous solution of formaldehyde, has been the gold standard for fixation of histological samples for over a century. Despite its considerable advantages, growing evidence points to objective toxicity, particularly highlighting its carcinogenicity and mutagenic effects. In 2016, the European Union proposed a ban, but a temporary permission was granted in consideration of its fundamental role in the medical-diagnostic field. In the present study, we tested an innovative fixative, glyoxal acid-free (GAF) (a glyoxal solution deprived of acids), which allows optimal tissue fixation at structural and molecular level combined with the absence of toxicity and carcinogenic activity. An open-label, non-inferiority, multicentric trial was performed comparing fixation of histological specimens with GAF fixative vs standard phosphate-buffered formalin (PBF), evaluating the morphological preservation and the diagnostic value with four binary score questions answered by both the central pathology reviewer and local center reviewers. The mean of total score in the GAF vs PBF fixative groups was 3.7 ± 0.5 vs 3.9 ± 0.3 for the central reviewer and 3.8 ± 0.5 vs 4.0 ± 0.1 for the local pathologist reviewers, respectively. In terms of median value, similar results were observed between the two fixative groups, with a median value of 4.0. Data collected indicate the non-inferiority of GAF as compared to PBF for all organs tested. The present clinical performance study, performed following the international standard for performance evaluation of in vitro diagnostic medical devices, highlights the capability of GAF to ensure both structural preservation and diagnostic value of the preparations.
Biomarker testing is crucial for treatment selection in advanced non-small cell lung cancer (NSCLC). However, the quantity of available tissue often presents a key constraint for patients with advanced disease, where minimally invasive tissue biopsy typically returns small samples. In Part 1 of this two-part series, we summarise evidence-based recommendations relating to small sample processing for patients with NSCLC. Generally, tissue biopsy techniques that deliver the greatest quantity and quality of tissue with the least risk to the patient should be selected. Rapid on-site evaluation can help to ensure sufficient sample quality and quantity. Sample processing should be managed according to biomarker testing requirements, because tissue fixation methodology influences downstream nucleic acid, protein and morphological analyses. Accordingly, 10% neutral buffered formalin is recommended as an appropriate fixative, and the duration of fixation is recommended not to exceed 24-48 h. Tissue sparing techniques, including the 'one biopsy per block' approach and small sample cutting protocols, can help preserve tissue. Cytological material (formalin-fixed paraffin-embedded [FFPE] cytology blocks and non-FFPE samples such as smears and touch preparations) can be an excellent source of nucleic acid, providing either primary or supplementary patient material to complete morphological and molecular diagnoses. Considerations on biomarker testing, reporting and quality assessment are discussed in Part 2.
- MeSH
- biologické markery MeSH
- fixace tkání metody MeSH
- fixativa MeSH
- formaldehyd MeSH
- lidé MeSH
- nádory plic * diagnóza patologie MeSH
- nemalobuněčný karcinom plic * diagnóza patologie MeSH
- nukleové kyseliny * MeSH
- zalévání tkání do parafínu MeSH
- znalecký posudek MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Microsatellite instability (MSI) is present in 15-20% of primary colorectal cancers. MSI status is assessed to detect Lynch syndrome, guide adjuvant chemotherapy, determine prognosis, and use as a companion test for checkpoint blockade inhibitors. Traditionally, MSI status is determined by immunohistochemistry or molecular methods. The Idylla™ MSI Assay is a fully automated molecular method (including automated result interpretation), using seven novel MSI biomarkers (ACVR2A, BTBD7, DIDO1, MRE11, RYR3, SEC31A, SULF2) and not requiring matched normal tissue. In this real-world global study, 44 clinical centers performed Idylla™ testing on a total of 1301 archived colorectal cancer formalin-fixed, paraffin-embedded (FFPE) tissue sections and compared Idylla™ results against available results from routine diagnostic testing in those sites. MSI mutations detected with the Idylla™ MSI Assay were equally distributed over the seven biomarkers, and 84.48% of the MSI-high samples had ≥ 5 mutated biomarkers, while 98.25% of the microsatellite-stable samples had zero mutated biomarkers. The concordance level between the Idylla™ MSI Assay and immunohistochemistry was 96.39% (988/1025); 17/37 discordant samples were found to be concordant when a third method was used. Compared with routine molecular methods, the concordance level was 98.01% (789/805); third-method analysis found concordance for 8/16 discordant samples. The failure rate of the Idylla™ MSI Assay (0.23%; 3/1301) was lower than that of referenced immunohistochemistry (4.37%; 47/1075) or molecular assays (0.86%; 7/812). In conclusion, lower failure rates and high concordance levels were found between the Idylla™ MSI Assay and routine tests.
- MeSH
- fixace tkání * MeSH
- fixativa MeSH
- formaldehyd MeSH
- imunohistochemie * MeSH
- kolorektální nádory chemie genetika patologie MeSH
- laboratorní automatizace MeSH
- lidé MeSH
- mikrosatelitní nestabilita * MeSH
- mutace * MeSH
- mutační analýza DNA * MeSH
- nádorové biomarkery * analýza genetika MeSH
- prediktivní hodnota testů MeSH
- reprodukovatelnost výsledků MeSH
- zalévání tkání do parafínu * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- multicentrická studie MeSH
- srovnávací studie MeSH
BACKGROUND: The aim of the study was to evaluate the usability of different fixative fluids in the detection of mast cells in ovaries and uteri of female dogs and cats. MATERIALS AND METHODS: Samples were fixed in 4% formaldehyde, Carnoy's fluid, Mota's basic lead acetate and isotonic formaldehyde-acetic acid (IFAA). RESULTS: Mast cells (MCs) were detected by acidified toluidine blue staining and counted for various parts of the ovaries and uteri. In the ovaries of both species, the numbers of MCs were significantly (p < 0.05) higher in Carnoy than in formalin. No significant differences were found between Carnoy and Mota (tested only in cats). In the uterus, numbers of MCs were significantly (p < 0.05) higher in Carnoy, Mota and IFAA compared to formalin (canine endometrium, feline endometrium and feline myometrium), in Carnoy and Mota compared to formalin (canine myometrium) and in Mota compared to IFAA (feline myometrium). The majority of MCs were formalin-sensitive in the canine and feline uterus, in the canine ovary and in the feline cortex ovarii. In the feline medulla ovarii, the majority of MCs were formalin-resistant. No formalin-resistant MCs were detected in the feline tunica albuginea ovarii. CONCLUSIONS: Thus, using Mota's or Carnoy's fluid in the canine or feline female reproductive organs is recommended. This study improves methodology for all studies which clarify the role of MCs in the reproductive organs of the domestic and laboratory animals.
INTRODUCTION: In this study we detail the effect of different fixation agents and the duration of storage has on the immunohistochemical staining positivity of samples of archival embryonic and fetal tissues. MATERIALS AND METHODS: The samples were stained by indirect two-step immunohistochemistry (IHC) method for Ki-67, cyclin A and β-actin. RESULTS: Irrespective of the length of tissue archiving, tissue fixation with 10% neutral buffered formalin had better IHC intensity results in all cases when compared to methacarn-fixed tissues. In the case of β-actin, this difference was statistically significant, while differences in Ki-67 and cyclin A were not. The second aspect studied was which effect tissue block archiving duration has on the IHC reactivity. We demonstrated a statistically significant decrease in IHC positivity for all studied antigens between the samples that were archived for 10-19 or 20-45 years, regardless the fixative solution. CONCLUSION: To the best of our knowledge, the influence that the duration of tissue block archiving has on IHC positivity in human embryo and fetal tissue material has not yet been studied. Although the causes of the IHC positivity decline in archived tissue blocks are not well understood, a possible decrease in IHC over time should be considered, particularly in retrospective studies.
- MeSH
- aktiny analýza MeSH
- antigen Ki-67 analýza MeSH
- barvení a značení normy MeSH
- časové faktory MeSH
- chloroform MeSH
- cyklin A analýza MeSH
- fixace tkání metody MeSH
- fixativa MeSH
- formaldehyd MeSH
- gestační stáří MeSH
- imunohistochemie normy MeSH
- játra embryologie MeSH
- králíci MeSH
- kyselina octová MeSH
- lidé MeSH
- methanol MeSH
- myši MeSH
- placenta embryologie MeSH
- střeva embryologie MeSH
- těhotenství MeSH
- zvířata MeSH
- Check Tag
- králíci MeSH
- lidé MeSH
- myši MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
MicroRNAs are considered as promising prognostic and diagnostic biomarkers of human cancer since their profiles differ between tumor types. Most of the tumor profiling studies were performed on rarely available fresh frozen (FF) samples. Alternatively, archived formalin-fixed paraffin-embedded (FFPE) tissue samples are also well applicable to larger-scale retrospective miRNA profiling studies. The aim of this study was to perform systematic comparison of the miRNA expression profiles between FF and macrodissected FFPE tonsillar tumors using the TaqMan Low Density Array system, with the data processed by different software programs and two types of normalization methods. We observed a marked correlation between the miRNA expression profiles of paired FF and FFPE samples; however, only 27-38% of the differentially deregulated miRNAs overlapped between the two source systems. The comparison of the results with regard to the distinct modes of data normalization revealed an overlap in 58-67% of differentially expressed miRNAs, with no influence of the choice of software platform. Our study highlights the fact that for an accurate comparison of the miRNA expression profiles from published studies, it is important to use the same type of clinical material and to test and select the best-performing normalization method for data analysis.
- MeSH
- analýza hlavních komponent MeSH
- fixace tkání MeSH
- fixativa MeSH
- formaldehyd MeSH
- krční mandle metabolismus MeSH
- kryoprezervace * MeSH
- lidé MeSH
- mikro RNA metabolismus MeSH
- mikročipová analýza MeSH
- počítačové zpracování signálu MeSH
- software MeSH
- stanovení celkové genové exprese MeSH
- tonzilární nádory metabolismus MeSH
- zalévání tkání do parafínu * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- srovnávací studie MeSH
Scanning electron microscopes are useful biological tools that can be used to image the surface of whole organisms, tissues, cells, cellular components, and macromolecules. Processes and structures that exist at surfaces can be imaged in pseudo, or real 3D at magnifications ranging from about 10× to 1,000,000×. Therefore a whole multicellular organism, such as a fly, or a single protein embedded in one of its cell membranes can be visualized. In order to identify that protein at high resolution, or to see and quantify its distribution at lower magnifications, samples can be labeled with antibodies. Any surface that can be exposed can potentially be studied in this way. Presented here is a generic method for immunogold labeling for scanning electron microscopy, using two examples of specimens: isolated nuclear envelopes and the cytoskeleton of mammalian culture cells. Various parameters for sample preparation, fixation, immunogold labeling, drying, metal coating, and imaging are discussed so that the best immunogold scanning electron microscopy results can be obtained from different types of specimens.
- MeSH
- antigeny genetika metabolismus MeSH
- barvení a značení metody MeSH
- buněčná membrána metabolismus ultrastruktura MeSH
- cytoskelet metabolismus ultrastruktura MeSH
- epoxidové pryskyřice chemie MeSH
- exprese genu MeSH
- fixace tkání metody MeSH
- fixativa chemie MeSH
- formaldehyd chemie MeSH
- imunohistochemie metody MeSH
- jaderný obal metabolismus ultrastruktura MeSH
- koloidní zlato chemie MeSH
- komplex proteinů jaderného póru genetika metabolismus MeSH
- mikroskopie elektronová rastrovací metody MeSH
- mikrotomie MeSH
- oocyty metabolismus ultrastruktura MeSH
- polymery chemie MeSH
- protilátky chemie MeSH
- Xenopus laevis MeSH
- zalévání tkání metody MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Immunolabeling electron microscopy is a challenging technique with demands for perfect ultrastructural and antigen preservation. High-pressure freezing offers an excellent way to fix cellular structure. However, its use for immunolabeling has remained limited because of the low frequency of labeling due to loss of protein antigenicity or accessibility. Here we present a protocol for immunogold labeling of the yeast Saccharomyces cerevisiae that gives specific and multiple labeling while keeping the finest structural details. We use the protocol to reveal the organization of individual nuclear pore complex proteins and the position of transport factors in the yeast Saccharomyces cerevisiae in relation to actual transport events.
- MeSH
- barvení a značení metody MeSH
- epoxidové pryskyřice chemie MeSH
- exprese genu MeSH
- fixace tkání metody MeSH
- fixativa chemie MeSH
- glutaraldehyd chemie MeSH
- imunoelektronová mikroskopie metody MeSH
- imunohistochemie metody MeSH
- komplex proteinů jaderného póru genetika metabolismus MeSH
- kryoprezervace metody MeSH
- mikrotomie MeSH
- mrazová substituce metody MeSH
- protilátky chemie MeSH
- Saccharomyces cerevisiae - proteiny genetika metabolismus MeSH
- Saccharomyces cerevisiae metabolismus ultrastruktura MeSH
- zalévání tkání metody MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
AIM: Organic anion-transporting polypeptides OATP1B1 and OATP1B3 are sinusoidal membrane transporters mediating liver uptake of a wide range of substrates including conjugated and unconjugated bilirubin, xenobiotics and drugs. Absence of OATP1Bs in the liver causes Rotor syndrome. Our aim was to correlate OATP1B expression with hyperbilirubinemia in common liver diseases. METHODS: Immunoreactivity of five antibodies against human OATP1Bs was tested on frozen and formalin-fixed paraffin-embedded liver tissue of mouse strains transgenic for SLCO1B1 or SLCO1B3 and on human specimens. The proportion of hepatocytes expressing OATP1Bs was then assessed immunohistologically in formalin-fixed paraffin-embedded liver samples obtained from patients with hepatocellular and primary biliary liver diseases. UGT1A1 promoter TATA-box and SLCO1B1 rs4149056 genotyping was performed to rule out individuals predisposed to hyperbilirubinemia. RESULTS: The most specific detection of OATP1B3 was achieved with the H-52 (sc-98981) antibody. OATP1B1 was specifically recognized with the ESL (ab15441) anti-OATP1B1 antibody, but only in frozen sections. The MDQ (ab15442) anti-OATP1B1 antibody cross-reacted with both OATP1B proteins in liver tissue of the transgenic mouse strains. Expression of the OATP1B proteins was decreased in advanced liver diseases and inversely correlated with serum bilirubin levels. The reduction was more pronounced in advanced primary biliary diseases (1.9±1.1 vs. 2.7±0.6; P=0.009). CONCLUSIONS: Down-regulation of OATP1B proteins may contribute to pathogenesis of jaundice accompanying advanced cholestatic liver diseases.
- MeSH
- bilirubin krev MeSH
- biologické markery krev MeSH
- cholestáza diagnóza genetika metabolismus MeSH
- down regulace MeSH
- fixace tkání metody MeSH
- fixativa MeSH
- formaldehyd MeSH
- hepatocyty metabolismus patologie MeSH
- hyperbilirubinemie diagnóza genetika metabolismus MeSH
- imunohistochemie MeSH
- játra metabolismus patologie MeSH
- lidé MeSH
- myši transgenní MeSH
- přenašeče organických aniontů nezávislé na sodíku genetika metabolismus MeSH
- přenašeče organických aniontů genetika metabolismus MeSH
- retrospektivní studie MeSH
- zalévání tkání do parafínu MeSH
- zmrazené řezy MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Keratocystic odontogenic tumour is relatively rare benign tumour. It is characterized by its fast aggressive growth and high risk of recurrence. Treatment is always surgical: conservative (enucleation, marsupialization) or aggressive (enucleation followed by application of Carnoy's solution, cryotherapy; peripheral ostectomy or en block resection of the jaw). Authors analysed retrospectively 22 patients who fulfilled inclusion criteria, i.e. had odontogenic keratocystic tumour of mandible, wherein antero-posterior dimension was at least 30 mm, and the tumour penetrated into the surrounding soft tissues. All patients underwent tumour enucleation, in 11 patients Carnoy's solution was given into the bone cavity after enucleation. The recurrence rate in the evaluation at least 36 months after surgery was both patient groups the same: 45.4%.
- MeSH
- chloroform terapeutické užití MeSH
- dítě MeSH
- dospělí MeSH
- ethanol terapeutické užití MeSH
- fixativa * MeSH
- kyselina octová terapeutické užití MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- nádory mandibuly patologie terapie MeSH
- odontogenní nádory patologie terapie MeSH
- retrospektivní studie MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
