Biomedical subjects

Hiroyasu Iwatsuki

Publications and source records attributed to Hiroyasu Iwatsuki.

5 recordsLinked to original sources

PubMed2005

Visualization of non-heme ferric and ferrous iron by highly sensitive non-heme iron histochemistry in the stress-induced acute gastric lesions in the rat.

Redox-active non-heme iron catalyzes hydroxyl radical [Formula: see text] generation through Haber-Weiss reaction. Oxidative tissue damage by OH* has been suggested in the development of stress-induced gastric lesion. Using highly sensitive non-heme iron histochemistry, the perfusion-Perls and -Turnbull methods plus DAB intensification, we studied the distribution of non-heme ferric and ferrous iron (NHF[III] and NHF[II]) in the normal stomach and its changes in the acute gastric lesions induced by restraint water immersion (RWI) stress in the rat. Both NHF[III] and NHF[II] staining increased in the oncotic parietal cells located at the erosive lesion which developed on the gastric mucosal folds after 3 h RWI. It was considered that increase in non-heme iron in these cells catalyzed OH* generation under the presence of O(2)(*-) released from abundant injured mitochondria. This was supported by the increase in H(2)O(2) staining in the erosive region and the obvious reduction of the gastric lesion following administration of deferoxamine before RWI. NHF[II] was stained in the arterial endothelium in the tela submucosa of the normal gastric wall and increase in the entire gastric mucosa after 3 h RWI suggests that the changes in the vascular non-heme iron metabolism were also involved in the response of the stomach to stressful conditions.

Animals↗

PubMed2005

The presence of ferric and ferrous iron in the nonheme iron store of resident macrophages in different tissues and organs: histochemical demonstrations by the perfusion-Perls and -Turnbull methods in the rat.

We previously developed the highly sensitive perfusion-Perls and -Turnbull methods to visualize nonheme ferric (Fe (III)) and ferrous (Fe (II)) iron, respectively. The present study used these methods to investigate the possible presence of nonheme iron in the redox (ferric/ferrous) state in the noneheme iron store (phagolysosomes and siderosomes) of resident macrophages in the rat. The perfusion-Perls and -Turnbull methods at pH 0.6 supplemented by DAB intensification intensely stained resident macrophages of different tissues and organs of normal and iron-overloaded rats. The perfusion-Turnbull method, which is specific for nonheme Fe (II), partly stained hemosiderin at pH 5.3, but hardly stained it at the physiological pH, suggesting the presence of some iron in the reduced form, free Fe2+ and/or loosely bound Fe (II), at the intravacuolar pH (5.4+/-0.2) of the phagolysosomes of macrophages. Electron microscopy of the splenic and hepatic macrophages treated by the perfusion-Perls or -Turnbull method showed that Fe (II) deposits were largely distributed along the margin of hemosiderin masses while Fe (III) deposits could also be found within hemosiderin masses.

3,3'-Diaminobenzidine↗

PubMed2004

Development of a telerehabilitation system for training physiotherapists in rural areas.

The purpose of this study was to assess the effectiveness of transmitting moving pictures via the Internet for processing by a three-dimensional motion analyser. The movements of two patients were filmed by a videocamera and transmitted from a hospital to a university department of physiotherapy. After advanced analysis using a three-dimensional motion analyser, physiotherapists prepared a treatment plan. The transmitted moving pictures were clear enough for analysis. The physiotherapists in the hospital were satisfied with the results of the motion analysis and found the guidance from an expert physiotherapist valuable. In the future, a large number of video-sequences could be transmitted during the night, stored at the university and then analysed later by an expert physiotherapist.

Education, Distance↗

PubMed2004

A pilot study of physiotherapy education using videoconferencing.

We investigated the possibility of instructing people in how to assist patients with activities of daily living via videoconferencing. A videoconference system was installed in two rooms to simulate a connection between a home and an institution. The subjects were five first-year university students. First, they saw a video-tape on several general assistance procedures to help a patient with sitting up, standing up and walking with a cane. Then they assisted a simulated patient who reproduced the effects of right hemiplegia due to a stroke. They also received instructions from a physiotherapist in another room using the videoconference system. The students experienced most difficulty in assisting the patient to stand up from sitting with legs stretched in a tatami room. Their mean score in the first session for this was 34.5 points out of 45, and this increased to 38.5 in a second session, after a question and answer period. The present study shows that the delivery of rehabilitation services is feasible in remote places.

Activities of Daily Living↗

PubMed2003

Perfusion-Perls and -Turnbull methods supplemented by DAB intensification for nonheme iron histochemistry: demonstration of the superior sensitivity of the methods in the liver, spleen, and stomach of the rat.

Perfusion-Perls and -Turnbull methods supplemented by the intensification with 3,3'-diaminobenzidine (+ DAB) enabled stronger and more extensive staining of nonheme iron than the Perls + and Turnbull + DAB methods carried out on tissue sections fixed with 10% formalin in 0.9% saline or PBS. The section- and perfusion-Perls + DAB methods are not specific for the demonstration of nonheme ferric iron but also stain nonheme ferrous iron. However, owing to its high sensitivity, the perfusion-Perls + DAB method would provide useful information about nonheme iron deposition regardless of oxidation states in normal and pathological conditions. The perfusion-Turnbull + DAB method is specifically demonstrable of nonheme ferrous iron and the results from this method showed significant stores of nonheme ferrous iron in the hepatocytes, Kupffer cells, splenic macrophages, and gastric parietal cells of the rat. Since nonheme ferrous iron is considered to be critically involved in free radical generation, the perfusion-Turnbull + DAB method would visualize such populations of cells that are at risk from free radical damage.

3,3'-Diaminobenzidine↗