title: Microscopic observation of chemical modification in sections using scanning acoustic microscopy.
abstract: A scanning acoustic microscope (SAM) calculates the speed of sound (SOS) through tissues and plots the data on the screen to form images. Hard tissues result in greater SOS; based on these differences in tissue properties regarding SOS, SAM can provide data on tissue elasticity. The present study evaluated whether tissue modifications, such as formalin fixation, periodic acid-Schiff (PAS) reactions and protein degradation, changed the acoustic properties of the tissues and whether SAM could be a useful tool for following chemical changes in sections. The fixation process was observable by the increased SOS. During the PAS reaction, the glycosylation of tissues was characterized by an increased SOS. Mucous or glycogen distribution was visualized and was found to be statistically comparable among lesions and states. Protease digestion by pepsin led to a decreased SOS. Tissue sensitivity to proteases varied due to the stage, cause and duration of inflammation or ageing. Changes in acoustic properties were more sensitive than those in optical histology. SAM facilitates the visualisation of the time course or distribution of chemical modifications in tissue sections, thus aiding their comparison among tissues. SAM may be an effective tool for studying changes such as protein cross-linkage, tissue repair and ageing.
authors.affiliation: Department of Health Science, Pathology and Anatomy, Hamamatsu University School of Medicine, Hamamatsu, Japan.
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Miura
authors.affiliation: Department of Diagnostic Pathology, Shizuoka City Shizuoka Hospital, Shizuoka, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Egawa
authors.affiliation: Department of Diagnostic Pathology, Shizuoka City Shizuoka Hospital, Shizuoka, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Moriki
authors.affiliation: Department of Otorhinolaryngology, Hamamatsu University School of Medicine, Hamamatsu, Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Mineta
authors.affiliation: Division of Pathology, Hamamatsu University Hospital, Hamamatsu, Japan.
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Harada
authors.affiliation: Division of Pathology, Hamamatsu University Hospital, Hamamatsu, Japan.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Baba
authors.affiliation: Medical Photonics Research Center, Hamamatsu University School of Medicine, Hamamatsu, Japan.
authors.forename: Seiji
authors.initials: S
authors.lastname: Yamamoto
mesh_terms: D000431:Ethanol; D005557:Formaldehyde; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D033401:Microscopy, Acoustic; D010447:Peptide Hydrolases; D013194:Staining and Labeling / Q000379:methods; D016707:Tissue Fixation
chemical_list: D005557:Formaldehyde; D000431:Ethanol; D010447:Peptide Hydrolases
keywords: ageing; elasticity; formalin fixation; histochemistry; histopathology; imaging analysis; pepsin; periodic acid-Schiff reaction; ultrasound