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Biomedical subjects

Y Tamegai

Publications and source records attributed to Y Tamegai.

7 recordsLinked to original sources
PubMed2003

Newly developed 3D endoscopic system: preliminary experience.

Although there have been earlier reports on the use of three-dimensional endoscopic systems in the gastrointestinal tract, real-time three-dimensional imaging has not previously been described. This paper presents experience in three cases with a novel endoscopic system for three-dimensional observation in clinical situations. Case 1 was a hyperplastic gastric polyp, the shape of which was considerably enhanced in comparison with two-dimensional endoscopic viewing. Case 2 was an advanced esophageal cancer, in which the sense of depth was improved in the esophagus. Case 3 was a depressed early gastric cancer, the shape of which was also enhanced. Between July 2001 and March 2002, three experienced endoscopists also used this new system in a further 34 patients. A three-dimensional endoscopic environment was visible with the system in all patients, and all of the endoscopists were able to obtain visual information regarding spatial depth. This experience suggests that the three-dimensional video-endoscopic system used here can be of value in gastrointestinal endoscopy.

Endoscopy, Gastrointestinal↗
PubMed2003

Virtual histology of colorectal lesions using laser-scanning confocal microscopy.

BACKGROUND AND STUDY AIMS: Histological examination of gastrointestinal lesions is currently based on light-microscopic examination of thin-slice specimens, with hematoxylin and eosin staining. A study of the use of laser-scanning confocal microscopy (LCM) to obtain immediate microscopic images of untreated specimens for examining colorectal lesions was carried out. A probe-type LCM prototype endomicroscope that can be passed through the working channel of an endoscope has also been developed. MATERIALS AND METHODS: The study materials consisted of colorectal lesions resected either endoscopically or surgically at Showa University Northern Yokohama Hospital. One hundred untreated specimens were examined using LCM. The histopathological findings in the lesions were seven cases of normal colonic mucosa, five hyperplastic polyps, 68 adenomas with low-grade dysplasia, 10 adenomas with high-grade dysplasia, and 10 adenocarcinomas. An argon laser beam with a wavelength of 488 nm was used for the LCM study. Observation of the resected normal colonic mucosa (in vitro) and the rectal mucosa of a healthy volunteer (in vivo) was possible using the endomicroscope. The LCM images for each specimen were compared with the hematoxylin-eosin-stained histopathological cross-sections. RESULTS: The LCM images corresponded well with the conventional hematoxylin-eosin light-microscopic images. The nuclei were not visualized in normal mucosa or hyperplastic polyps. In adenomas with high-grade dysplasia and carcinomas, nuclei were more often visible than in adenomas with low-grade dysplasia. The rate of visualization of nuclei was significantly different ( P < 0.01) between these two groups (60.0 % vs. 10.3 %). In LCM images using endomicroscope, it was possible to recognize the orifices of the colonic glands and goblet cells both in vitro and in vivo. CONCLUSIONS: Laser-scanning confocal microscopy provides immediate images that correspond well with those of hematoxylin-eosin staining. An improved probe-type LCM endomicroscope is being developed which should provide better histological images of colorectal lesions in vivo.

Adenocarcinoma↗
PubMed2001

Endoscopic mucosal resection of the colon: the Japanese technique.

Early colorectal neoplasms, especially flat-type and depressed-type lesions, should be treated with an EMR technique. In general because depressed-type lesions, in contrast to flat-type or protruded-type lesions, tend to invade the submucosa rapidly, they ought to be treated by EMR at an early stage. Histopathologically in the case of lesions that only minimally invade the submucosa without vessel invasion (sm1a and sm1b without vessel invasion), a treatment can be completed with EMR. Massive submucosal invasive cancers ought to be resected by surgical treatment because of the risk of recurrence or metastasis. In addition, pit pattern diagnosis with magnifying colonoscopy is useful to determine a therapeutic method for colonic neoplasms. Lesions with the type VN pit pattern represent malignancy and usually invade the submucosa massively, so it is better to treat them surgically from the outset. Endoscopic mucosal resection should be conducted under fully controlled endoscopy to prevent complications. EMR is a superior therapeutic method and will be performed frequently in the future. It is necessary for colonoscopists to determine a suitable therapy for each colorectal neoplastic lesion. They also need to master the EMR technique in the correct manner.

Colonic Neoplasms↗
PubMed1993

[Two cases of stage IIIb breast cancer treated by intra-arterial infusion chemotherapy using implantable reservoir combined with rectus-abdominis musculocutaneous flap reconstruction after mastectomy].

Intra-arterial infusion chemotherapy was performed using implantable reservoir for 2 cases of Stage IIIb breast cancer followed by rectus-abdominis musculocutaneous flap reconstruction after mastectomy. The first case is a 47-year-old female. A total dose of 150 mg ADM was injected via reservoir. After satisfactory local response, mastectomy followed by giant rectus-abdominis musculocutaneous flap reconstruction was performed. The other case is a 64-year-old female. A total dose of 160 mg ADM was injected via reservoir. She was also operated in the same manner as in the first case. Complications of both cases were minimal. It was concluded that this combined treatment was useful for controlling local lesion and sustaining QOL.

Breast Neoplasms↗
PubMed1991

[Two cases of stage IV breast cancer with locally advanced lesion treated by intra-arterial infusion chemotherapy using implantable reservoir].

Intra-arterial infusion chemotherapy was used for 2 cases of Stage IV breast cancer with locally advanced lesions using implantable reservoir. The first case is a 64-year-old female who had multiple bone metastases with locally advanced breast lesion. A total dose of 220 mg ADM was injected via reservoir at outpatient department. The other case is a 66-year-old female who had multiple bone metastases with locally advanced breast lesions. A total dose of 235 mg ADM was injected via reservoir. After obtaining satisfactory response of local lesions, a standard radical mastectomy was performed for both cases. It was concluded that this method was useful for controlling locally advanced lesions of Stage IV breast cancer and beneficial for patient QOL.

Aged↗
PubMed1990

[Absorption disorders following gastric resection--morphological and enzyme-histochemical observations on the small intestinal mucosa].

For the purpose of studying digestion and absorption disorders following stomach surgery, particularly with respect to membrane digestive functional disorders, morphological and enzyme-histochemical observation of the small intestinal mucosa was performed, and a comparison was done between the partial gastrectomy group (59 cases), and the total gastrectomy group (52 cases). The following results were obtained: 1) The small intestinal mucosa showed a tendency to significant villous atrophy in post-operative groups. 2) There was a significant decrease in the disaccharidase activity, especially in the small intestine of the total gastrectomy group. ALP, LAP and gamma-GPT activity also decreased, or disappeared in the small intestines showing villous atrophy. 3) In the atrophied mucosa which showed a marked decrease in membraneous enzyme activity, poorly-formed, irregularly sized microvilli accompanied by glycocalyx irregularity and disappearance were recognized under the electron microscope. The above mentioned morphological and enzyme-histological findings in the small intestinal mucosa, were strongly reflected in both post-operative progress and clinical symptoms.

Atrophy↗