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Biomedical subjects

Kenichi Yoshida

Publications and source records attributed to Kenichi Yoshida.

43 records · Page 3Linked to original sources
PubMed2002

P53 labeling index in cholangioscopic biopsies is useful for determining spread of bile duct carcinomas.

BACKGROUND: Preoperative biopsy specimens obtained by means of percutaneous transhepatic cholangioscopy are useful for planning curative resection of bile duct carcinoma in an effort to improve survival. However, tissue diagnosis is sometimes difficult. This study evaluated the usefulness of p53 immunostaining of cholangioscopic specimens for determination of tumor spread. METHODS: A total of 107 biopsy specimens from 28 patients with bile duct carcinoma was selected. Before surgery, these specimens were diagnosed histopathologically (hematoxylin and eosin staining) as positive or negative for carcinoma. After definitive surgery, specimens were immunostained with anti-p53 antibody. RESULTS: Eighteen of 28 cases (64%) were positive for p53. Among these, 86% obtained from the main carcinomatous lesion or an area of superficial spread of the carcinoma exhibited a p53 labeling index (LI) over 25% as opposed to a p53 LI under 25% for all specimens obtained from noncarcinomatous lesions. Twelve specimens from 8 cases were classified before surgery as indeterminate (hematoxylin and eosin staining). The criterion of p53 LI over 25% was applicable in 11 of the 12 specimens. CONCLUSION: The p53 immunostaining of biopsy specimens obtained by means of percutaneous transhepatic cholangioscopy is helpful in determining tumor spread in bile duct carcinoma.

Adenocarcinoma↗
PubMed2002

Angiopoietin-like protein 4 is a potent hyperlipidemia-inducing factor in mice and inhibitor of lipoprotein lipase.

Studies with KK/San, obese and diabetic model mice having a unique hypotriglyceridemia phenotype, revealed that angiopoietin-like protein 3 (ANGPTL3) regulates lipid metabolism in mice. To determine the lipid-modulating role of other ANGPTLs, we focused on ANGPTL4, which overall shows a significant similarity to ANGPTL3. Surprisingly, an intravenous injection of the ANGPTL4 protein in KK/San mice rapidly increased the circulating plasma lipid levels at a higher rate than ANGPTL3 protein. Furthermore, the ANGPTL4 protein inhibited the lipoprotein lipase activity in vitro.

Angiopoietin-Like Protein 4↗
PubMedDate not supplied

An automated measuring system for fundus perimetry.

PURPOSE: In order to automate fundus perimetry, which is usually laborious because of the many manual operations and the frequent eye movements, we developed a new fundus perimeter with an automated measuring system using computer technology. METHODS: This fundus perimeter consists of an infrared fundus camera, a fundus-pursuit unit, and a target-display unit. Both units are personal computers operating on Windows. After presetting the measuring points on the fundus, perimetry is automatically performed. The fundus-pursuit unit recognizes and pursues the fundus reference region while calculating its coordinates in real time during perimetry. The target-display unit corrects the stimulus coordinates with data from the fundus-pursuit unit and even if eye movement occurs, automatically displays the stimulus targets at the correct retinal point that had been preset. RESULTS: Fundus perimetry can be automatically and precisely performed with this automated measuring system. It shortens the duration of the examination and frees the operator from the lengthy and laborious manual operations during perimetry. CONCLUSIONS: This automated measuring system will make fundus perimetry easier for the operator, as well as more popular for clinical use.

Adult↗
PubMedDate not supplied

Occlusion-free animation of driving routes for car navigation systems.

This paper presents a method for occlusion-free animation of geographical landmarks, and its application to a new type of car navigation system in which driving routes of interest are always visible. This is achieved by animating a nonperspective image where geographical landmarks such as mountain tops and roads are rendered as if they are seen from different viewpoints. The technical contribution of this paper lies in formulating the nonperspective terrain navigation as an inverse problem of continuously deforming a 3D terrain surface from the 2D screen arrangement of its associated geographical landmarks. The present approach provides a perceptually reasonable compromise between the navigation clarity and visual realism where the corresponding nonperspective view is fully augmented by assigning appropriate textures and shading effects to the terrain surface according to its geometry. An eye tracking experiment is conducted to prove that the present approach actually exhibits visually-pleasing navigation frames while users can clearly recognize the shape of the driving route without occlusion, together with the spatial configuration of geographical landmarks in its neighborhood.

Journal Article↗
PubMedDate not supplied

Oxygen metabolism of the liver during an HA clamp: HV saturation and free radicals.

BACKGROUND/AIMS: To clarify changes in the hepatic oxygen metabolism and tissue damage resulting from oxygen-derived free radical generation from polymorphonuclear cells during a hepatic arterial clamp. METHODOLOGY: Subjects were 32 male Wistar rats. Hepatic tissue blood flow, and hepatic venous chemiluminescence, indicating oxygen-derived free radicals from polymorphonuclear cells, and liver lipid peroxide were measured, and hepatic and portal venous blood gas analysis were performed before and after 130 minutes of hepatic arterial clamping. RESULTS: Hepatic tissue blood flow decreased by hepatic arterial clamp. The values of hepatic arterial oxygen pressure (HTBF), hepatic venous oxygen saturation (ShvO2), and O2 contents after hepatic arterial clamp were lower than those before hepatic arterial clamp (P = 0.035, 0.024, and 0.028, respectively). Hepatic venous chemiluminescence decreased and the lipid peroxide level of the liver increased by hepatic arterial clamp (P = 0.001). CONCLUSIONS: ShvO2 is useful for the evaluation of hepatic oxygen metabolism and hepatic tissue blood flow during acute hepatic arterial clamp. This condition should prepare the following tissue damage due to oxygen-derived free radicals from polymorphonuclear cells.

Animals↗
PubMedDate not supplied

Gastrointestinal fiberscopic findings after simple closure for perforated duodenal ulcer in the early postoperative phase: from experience to evidence by evaluation of the healing process.

BACKGROUND/AIMS: Today, in light of widespread adoption of H2-RA and PPI, the standard surgical procedure for perforated duodenal ulcer (PDU) is simple closure and/or omental patch (SC). However, the healing process after these techniques has not been fully examined. We have not yet confirmed the propriety of simple suture of the bottom of the ulcer. This technique has been performed based only on experience, and there is insufficient evidence to conclude that this procedure can be definitively considered a safe therapeutic technique for the majority of patients with PDU. The aim of this study is to clarify the macroscopic findings of the healing process after SC for PDU. METHODOLOGY: Thirteen patients with PDU who were treated with SC underwent postoperative gastroduodenal fiberscopy (GF) at the 7th-16th postoperative day and the healing process was monitored under sufficient informed consent. Patients with severe preoperative disease were excluded from the study. Healing condition of the ulcer and stitches, deformity, and stenosis were evaluated by postoperative endoscopy. Possible adverse effects that were evaluated included: perforation, rise in fever, worsening of inflammation on laboratory data, gastrointestinal symptoms such as abdominal pain, sense of fullness, and vomiting. The indications for SC were as follows: PDU with 1) no stenosis and 2) no prominent ulcer ridge. The surgical technique was as follows: 1) interrupted simple closure with no trimming and debridement of wound (4-5 stitches) with absorbable monofilament suture, and/or 2) omental patch, 3) administration of H2-RA (or PPI) just after operation, and 4) oral feeding 4-5 days after operation independent of postoperative GF. RESULTS: GF findings in 2 patients showed active and healing stage, in whom surgical technique was thought to be insufficient; the ulcer had been large and included a descending portion, or a small perforation had occurred in the large ulcer bottom (the distance between the stitches and the edge of the ulcer was insufficient). In the other 11 patients, GF findings showed scar phase. There was no morbidity related to endoscopic procedure. CONCLUSIONS: Sutured PDU with SC will be in the scar phase in 1 or 2 weeks. Postoperative GF 1 week after SC for PDU is thought to be a safe examination. This study is a primitive study of a small group, and more cases that can adequately show the frequency of complications and indicate the overall safety of the procedure are needed.

Adolescent↗