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Biomedical subjects

Keiichi Ikeda

Publications and source records attributed to Keiichi Ikeda.

26 records · Page 2Linked to original sources
PubMed2003

Cardiac expression of urocortin (Ucn) in diseased heart; preliminary results on possible involvement of Ucn in pathophysiology of cardiac diseases.

Recently, several studies reported that urocortin (Ucn) had beneficial effects on cardiovascular system and was expressed both in the normal heart and in the heart of dilated cardiomyopathy (DCM), yet the relationship between high expression of Ucn and pathophysiology of Ucn in diseased heart has been discussed. Thus, the present study was designed to elucidate the expression of Ucn in the diseased heart by immunohistochemical approach using endomyocardial biopsy specimens. The involvement of immunoreactive Ucn in pathophysiology of cardiac disease was evaluated using endomyocardial biopsy specimens obtained from the patients with some heart diseases, including DCM and hypertrophic cardiomyopathy (HCM). Ucn was detected in all endomyocardial biopsy specimens of ventricular tissue obtained from the patients with such cardiac diseases, a specimens of atrial tissue, and normal heart specimens obtained from autopsy cases. In DCM patients, left ventricular end-diastolic pressure significantly elevated in severely stained group. On the contrary, in HCM patients, left ventricular ejection fraction was higher in the severely stained group. Ucn was expressed more abundantly in the diseased heart, especially in HCM and DCM, than in the normal heart. In conclusion, such close relationship between Ucn expression in the heart and cardiac function indicated that clinical features of Ucn resembled those of norepinephrine and Ucn could play a certain pathophysiological roles in the cardiac diseases.

Aged↗
PubMed2003

Preclinical Cushing's syndrome presenting with isolated adrenocorticotropin (ACTH) deficiency-like manifestations and severe hypoalbuminemia without overt adrenal masses in a patient with Chilaiditi syndrome and mental retardation.

A 52-year-old man with Chilaiditi syndrome and mental retardation was admitted to Kanagawa Rehabilitation Hospital for severe hypoglycemic coma with malnutrition. This patient was first diagnosed as partial isolated adrenocorticotropin deficiency according to his symptoms and clinical course, but he was finally diagnosed as preclinical Cushing's syndrome. Manifestations of this case seemed unusual in spite of autonomic cortisol secretion and the detailed mechanisms of symptoms were unclear. The present case indicates that preclinical Cushing's syndrome may present with various manifestations, and careful diagnosis is necessary.

Adrenal Gland Neoplasms↗
PubMed2003

Development of an endoscopic robotic system with two hands for various gastric tube surgeries.

This paper presents the first report on an endoscopic robot with two manipulators which performed surgical work to resect the mucosal layer of the stomach of pigs without penetrating the body surface. We designed and developed an endoscopic surgical robot system which possesses two arm shaped manipulators for various kinds of surgery in the gastric tubes. The distal part of the manipulator functions as forceps and they are able to hold and handle soft tissues through the cooperative efforts of the right and left arms. And it is also able to incise the gastric wall by holding an electronic scalpel (brought in from the instrument channel) with the manipulator on the right side while opening the sectioning plane on the left side which was take out. With this system we succeeded in the mucosal resection of a large portion of the stomach wall of a pig during experimental surgery. It can be said that this is a new approach robotic surgery in the gastric tube with this kind of surgical robot.

Animals↗
PubMed2002

Urocortin has cell-proliferative effects on cardiac non-myocytes.

Urocortin (Ucn) is a member of the corticotropin-releasing hormone (CRH)-related peptides that has been reported to have cardiac inotropic and hypertrophic effects. In addition, Ucn mRNA was expressed in cardiac myocytes (MCs) and Ucn was suggested to have cardioprotective effects. Recently, it was reported that Ucn mRNA was expressed in cardiac non-myocytes (NMCs). Based on these facts, Ucn is assumed to affect not only MCs but also NMCs in an autocrine fashion. The present study was designed to elucidate a pathophysiological role of Ucn on NMCs. NMCs were prepared by the discontinuous Percoll gradient and adhesion method. Ucn increased [(3)H]-thymidine uptake into NMCs. Ucn also enhanced endothelin-1-induced increase of [(3)H]-thymidine uptake into NMCs. Effects of Ucn on [(3)H]-thymidine uptake into NMCs were significantly abolished by the protein kinase A inhibitor, H89 (10(-5) M), but not by a competitive antagonist of CRH receptors, astressin (10(-5) M). Ucn also increased intracellular cAMP accumulation more potently than CRH on a molar basis. Finally, both MCs and NMCs also secreted Ucn. Together with the recent findings, at least in NMCs, these data suggest that Ucn could exert its own actions via the cAMP signaling pathway, but not through known CRH type 2 receptors, in an autocrine fashion. In conclusion, the present study indicated that Ucn was secreted not only from MCs but also from NMCs and that the primary source of Ucn acting on heart was the heart itself. On the other hand, Ucn could proliferate NMCs as well as MCs, suggesting that Ucn could be involved in cardiac hypertrophy and fibrosis, i.e., cardiac remodeling, in spite of its putative cardioprotective actions.

Animals↗
PubMed2002

Localization of N-linked carbohydrate chains in glycoprotein ZPA of the bovine egg zona pellucida.

The zona pellucida, a transparent envelope surrounding the mammalian oocyte, consists of three glycoproteins, ZPA, ZPB and ZPC, and plays a role in sperm-egg interactions. In bovines, these glycoproteins cannot be separated unless the acidic N-acetyllactosamine regions of the carbohydrate chains are removed by endo-beta-Galactosidase digestion. Endo-beta-Galactosidase-digested ZPB retains stronger sperm-binding activity than ZPC. It is still unclear whether ZPA possesses significant activity. Recently, we reported that bovine sperm binds to Man5GlcNAc2, the neutral N-linked chain in the cow zona proteins. In this study, we investigated the localization of the sperm-ligand active high-mannose-type chain and the acidic complex-type chains in bovine ZPA. Three N-glycopeptides of ZPA, containing an N-glycosylation site at Asn83, Asn191 and Asn527, respectively, were obtained from endo-beta-Galactosidase-digested ZPA. Of these glycosylation sites, only Asn527 is present in the ZP domain common to all the zona proteins. The carbohydrate structures of the N-linked chains obtained from each N-glycopeptide were characterized by two-dimensional sugar mapping analysis, while considering the structures of the N-linked chains of the zona protein mixture reported previously. Acidic complex-type chains were found at all three N-glycosylation sites, while Man5GlcNAc2 was found at Asn83 and Asn191, but there was very little of this sperm-ligand active chain at Asn527 in the ZP domain of ZPA.

Amino Acid Sequence↗
PubMed2002

Hemodynamic assessment of the left gastric vein in patients with esophageal varices with color Doppler EUS: factors affecting development of esophageal varices.

BACKGROUND: An understanding of the development of esophageal varices is important in the evaluation of risk of variceal hemorrhage. To clarify factors affecting the development of esophageal varices, the morphology and hemodynamics of the left gastric vein were analyzed with color Doppler EUS. METHODS: Sixty-seven patients with esophageal varices underwent color Doppler EUS. Seventeen had small varices (F1), 32 had medium varices (F2), and 18 had large varices (F3). RESULTS: Hepatofugal blood flow velocity in the left gastric vein trunk increased as the size of the varices increased (p < 0.0001), whereas the diameter did not increase. The left gastric vein bifurcates into anterior and posterior branches. As the size of the varices enlarged, the branch pattern was more likely to be anterior branch dominant (p = 0.041). There was no significant difference between the 3 size groups of esophageal varices with respect to the size of the paraesophageal collaterals. The detection rate and diameter of the perforating vein increased as the size of the varices increased (p = 0.032 and 0.012, respectively). CONCLUSION: Blood flow velocity in the left gastric vein trunk, branches, and perforating veins may regulate blood flow supplying the esophageal varices and contribute to their development. These findings are important to understanding the pathogenesis of esophageal varices.

Adult↗
PubMedDate not supplied

Subjects older than 60 years with negative findings on sigmoidoscopy should still undergo colonoscopy.

BACKGROUND/AIMS: The objective of this study was to evaluate the impact of age on the prevalence of proximal clinically important lesions in subjects without any rectosigmoid neoplasm. METHODOLOGY: The present study involved 497 patients (aged > or = 50 years old) who underwent a colonoscopy because of abdominal symptoms or positive fecal occult blood test. A proximal colon was defined as one proximal to a sigmoid colon. Clinically important lesions were defined as adenocarcinoma, tubular adenoma > or = 1 cm in diameter, or adenoma with villous histology or high-grade dysplasia. RESULTS: Of the 497 patients, 83 had clinically important lesions in the proximal colon. Of those 83, 53 patients had no neoplasm in the distal colon or rectum. In patients with no distal neoplasm, the prevalence of proximal clinically important lesions in subjects over 60 years old significantly exceeded that in patients aged 50-60 (39/105 vs. 14/125; P < 0.0001). In patients with distal neoplasm, the prevalence of proximal clinically important lesions in subjects over 60 was similar to that in 50 to 60-year-old subjects (16/119 vs. 14/148; P = 0.406). CONCLUSIONS: Results suggest that subjects older than 60 years old should still undergo a colonoscopy even if they have no neoplasm on sigmoidoscopy.

Adenoma↗