Imprint cytology in tumor tissue bank quality control: an efficient method to evaluate tumor necrosis and to detect samples without tumor cells

Quality assessment of the tissue stored in a tumor biobank is crucial because it is estimated that approximately 10% of the frozen samples are unsuitable for a molecular analysis mainly because of sampling problems in the tissue. We studied the value of imprint cytology (IC) versus frozen section to quantify necrosis and tumor cells in the tissue. The amount of tumor cells and necrosis was assessed by one pathologist on the frozen sections and ICs independently on 100 consecutive tumor samples. It was expressed as a percentage on frozen sections and on a four-level semiquantitative scale for IC (0 to 3+). Overall agreement between the quantity of tumor cells on IC and on frozen section was fair (Κ = 0.23). Sensitivity and specificity of IC to detect the absence of tumor cell on the frozen section were 57% (4/7) and 98% (91/93), respectively. Overall agreement between necrosis quantification on IC and on frozen section was substantial (Κ = 0.66).Sensitivity and specificity of IC to detect significant necrosis (defined as more than 30% necrosis) were 100% (3/3) and 98% (95/97), respectively. We show that IC is efficient to semiquantify necrosis in a tumor sample and to detect significant necrosis. IC seems to be less efficient to quantify tumor cells.     

Formalin-fixed and paraffin-embedded nodal non-Hodgkin's lymphomas demonstrate the same chromosome changes as those found in frozen samples: a comparative study using interphase fluorescence in situ hybridization.

Cytogenetic studies in lymphomas classically require fresh or frozen tissue, whereas in many instances only paraffin-embedded biopsies are available. We applied an interphase FISH assay on nuclei extracted from thick paraffin sections to determine accuracy of molecular cytogenetics in such samples. Twenty-three lymphoma samples and 4 reactive lymph nodes were tested with various commercially available DNA probes, and hybridization patterns were compared with those obtained on frozen nuclei counterparts. Successful hybridization with all probes tested was observed for 23/27 (85%) paraffin-embedded tissues and for all (100%) frozen samples, and cut-off levels defining positivity were superimposable for both situations. Chromosome changes were detected in the same way, without any false-positive or false-negative cases. Hybridization signals observed on dewaxed samples were either those classically expected to define the relevant chromosome change or were atypical: all atypical changes could be demonstrated also into nuclei from the frozen counterpart. Moreover, all typical and atypical chromosome changes observed on frozen nuclei were also detected in paraffin-embedded tissues. Our study shows that our interphase FISH assay performed on paraffin-embedded samples is a valuable alternate to conventional methods to ascertain diagnosis of lymphomas as to include patients into therapeutic trials.     

Impact of Recurrent Floods on the Utilization of Maternal and Newborn Healthcare in Bangladesh

Maternal and Child Health Journal - Floods are one of the most common types of disasters in Bangladesh and lead to direct and indirect impacts on health. The aim of the study was to assess the...     

Comparative genomic hybridization is a powerful tool, complementary to cytogenetics, to identify chromosomal abnormalities in childhood acute lymphoblastic leukaemia

Cytogenetics has a strong prognostic value in childhood acute lymphoblastic leukaemia (ALL), but results are often incomplete because of the poor chromosome morphology. To improve this analysis, we tested comparative genomic hybridization (CGH) for the detection of chromosomal imbalances. 72 children were retrospectively analysed using CGH. Only 53% of the patients had been fully banded by standard methods. With CGH, 36 patients retained a normal chromosomal profile and 36 had unbalanced abnormalities. No amplification was detected. Fluorescence in situ hybridization (FISH) with centromeric and unique sequence probes was used in those cases with discrepancies or unsuccessful karyotype to validate CGH results. CGH enabled clear identification of unbalanced chromosomal abnormalities, even in some cases which had a normal karyotype. In view of the strong prognostic value of hyperdiploidy in childhood ALL, CGH appears to be a powerful technique, complementary to conventional cytogenetics.     

Biomarkers of Alzheimer's disease: The present and the future

A paradigm shift has occurred in the last ten years in the diagnostic field of Alzheimer's disease (AD). Scientific thought has enriched the concept of AD as a pathophysiological continuum and emphasized contribution of biological, morphological and functional brain imaging biomarkers for diagnosis, in particular during the early stages of the disease. We address here the present and the future of these biological biomarkers. Most of them are linked to the pathophysiological lesions of the Alzheimer process: aggregates of hyperphosphorylated tau proteins, also called neurofibrillary tangles (NFT), and extracellular deposit of amyloid-beta peptides (Aβ), also called senile plaques. The detection in the cerebrospinal fluid (CSF) of tau and Aβ represents the current diagnostic practice of AD. Improvement for a more accurate and earlier biological diagnosis is however expected using a new generation of biomarkers, mostly in relation with tau and Aβ metabolism.