Application of alternative fixatives to formalin in diagnostic pathology

Fixation is a critical step in the preparation of tissues for histopathology. The aim of this study was to investigate the effects of different fixatives vs formalin on proteins and DNA, and to evaluate alternative fixation for morphological diagnosis and nucleic acid preservation for molecular methods. Forty tissues were fixed for 24 h with six different fixatives: the gold standard fixative formalin, the historical fixatives Bouin and Hollande, and the alternative fixatives Greenfix, UPM and CyMol. Tissues were stained (Haematoxylin-Eosin, Periodic Acid Schiff, Trichromic, Alcian-blue, High Iron Diamine stainings), and their antigenicity was determined by immunohistochemistry (performed with PAN-CK, CD31, Ki-67, S100, CD68, AML antibodies). DNA extraction, KRAS sequencing, FISH for CEP-17, and flow cytometry analysis of nuclear DNA content were applied. For cell morphology the alternative fixatives (Greenfix, UPM, CyMol) were equivalent to formalin. As expected, Hollande proved to be the best fixative for morphology. The morphology obtained with Bouin was comparable to the one with formalin. Hollande was the best fixative for histochemistry. Bouin proved to be equivalent to formalin. The alternative fixatives were equivalent to formalin, although with greater variability in haematoxylin-eosin staining. It proved the possibility to obtain immunohistochemical staining largely equivalent to that following formalin-fixation with the following fixatives: Greenfix, Hollande, UPM and CyMol. The tissues fixed in Bouin did not provide results comparable to those obtained with formalin. The DNA extracted from samples fixed with alternative fixatives was found to be suitable for molecular analysis

Analysis of the genes coding for subunit 10 and 15 of cytochrome c oxidase in Alzheimer's disease.

Decay of mitochondria and oxidative stress are associated with normal aging, but many neurodegenerative diseases, and particularly Alzheimer’s disease (AD), are characterized by a significant increase in the intensity of these traits. Recent data suggest the possible contribution of heme deficiency to the progressive derangement of mitochondria in AD brain; shortage of heme, and particularly of heme-a, actually leads to loss of mitochondrial cytochrome c oxidase (COX), abnormal production of reactive oxygen species and altered amyloid precursor protein metabolism. We reasoned that differences in the amount and/or functioning of COX assembly subunit 10 (COX10) and 15 (COX15), the key enzymes involved in heme-a biosynthesis, could be linked to variations of the individual risk to develop AD. We analyzed their mRNA expression in the hippocampus from AD patients and controls, investigated the existence of nucleotide variations in their DNA sequences and analyzed their distribution in large groups of AD and control individuals. COX 15 mRNA was significantly more abundant in the cerebral tissue of AD patients (3.18 ± 1.70 vs. 1.22 ± 0.66 lg, normalized dose, P = 0.01). The IVS-178G[A SNP in COX10 and the c1120C[T SNP in COX15 were significantly less represented in the patient group (P\0.001 and P = 0.017, respectively) with respective odd ratios of 0.22 and 0.59, suggesting a possible protective role toward the risk for AD

Haematobium eggs detection in human bladder cancer and sporocysts in snail vectors: four cases and a review of the Burkina Faso literature.

Schistosoma haematobium plays a central role in the development of bladder cancer in Burkina Faso. The objective of this study was to determine the presence of S. haematobium in the bladder cancer and in vector snails. For the first time, formalin-fixed tissues embedded in paraffin were analyzed by immunohistochemistry and PCR. Molecular detection has resulted in 7/7 positive bladder cancer. Finally, as the snail vectors were positive. We suggest the use of molecular methods in the snail vectors for the detection of cysts and in cancerous tissues in larger studie