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Biomedical subjects

S Ikeda

Publications and source records attributed to S Ikeda.

At least 433 records · Page 24Linked to original sources
PubMed1996

A case of choledocholithiasis with an endoclip nidus, 6 months after laparoscopic cholecystectomy.

A 69-year-old man developed obstructive jaundice 6 months after laparoscopic cholecystectomy. Endoscopic retrograde cholangiography suggested a common bile duct (CD) stone. A second operation was performed, and this revealed a CBD stone with an endoclip as a nidus. Since laparoscopic surgery has become a very common procedure, endoclips are used more frequently. Therefore, careful surveillance and strict follow-up are stressed to avoid CBD stone and various other complications caused by endoclips.

Aged↗
PubMed1996

Cell surface-associated extracellular distribution of a neural proteoglycan, 6B4 proteoglycan/phosphacan, in the olfactory epithelium, olfactory nerve, and cells migrating along the olfactory nerve in chick embryos.

The immunocytochemical and immuno-electron microscopic distribution of a neural proteoglycan (PG) was investigated with a monoclonal antibody, MAb 6B4, in the olfactory epithelium, the olfactory nerve, and the cells originating the epithelium and migrating along the olfactory nerve toward the forebrain in chick embryos. The PG recognized by MAb 6B4, that is 6B4 PG, in the brain of early postnatal rats, is identical to phosphacan. In chick embryos, immunoreactivity to 6B4 PG appeared on embryonic day (ED) 3-3.5 in a thin layer beneath the olfactory epithelium. It disappeared immediately, then becoming apparent in the bundles of the olfactory nerve. The immunoreactivity in the nerve bundles gradually increased during ED 5-11. On the other hand, cell surface-associated extracellular localization of the immunoreactivity was seen in the olfactory epithelium on ED 6 and afterwards. Immunofluorescent double-labeling of 6B4 PG and gonadotropin-releasing hormone (GnRH) revealed that the cell bodies of both GnRH-containing cells and other cells migrating along the olfactory nerve were surrounded by a rim immunoreactive to the PG. Under an electron microscope, the surfaces of the cell bodies and of the neurites in the nerve bundles were surrounded by deposits immunoreactive to 6B4 PG. These results indicate that 6B4 PG in chick embryos is one type of cell surface-associated extracellular matrix molecule, and that 6B4 PG covered the surfaces of migrating cells and of elongating olfactory nerve. The cell surface-associated extracellular localization of 6B4 PG found in the nasal region, taken together with the binding properties of this PG with cell adhesion molecules shown in rat brains, suggested that 6B4 PG played a role in guiding the migration of cells along the olfactory nerve in chick embryos.

Animals↗
PubMed1996

Preventive effects of probucol on restenosis after percutaneous transluminal coronary angioplasty.

This protocol was performed to elucidate the preventive effects of probucol on restenosis after percutaneous transluminal coronary angioplasty (PTCA). A total of 118 patients with 134 vessels undergoing successful PTCA was randomly and prospectively assigned to the probucol group (group P) or the control group (group C). The subjects consisted of 91 men and 27 women, with a mean age of 63.4 +/- 2.3 years. Sixty-six vessels of 59 patients in group P and 68 vessels of 59 patients in group C were evaluated by coronary angiography at 3 months after PTCA. Probucol (0.5 mg/day) was administered between >7 days before PTCA and 3 months after PTCA. The serum total cholesterol (TC) level and the formula low-density lipoprotein cholesterol (formula LDL-C) in group P decreased from 203.8 +/- 43.1 to 169.6 +/- 39.4 mg/dl and from 131.4 +/- 0.7 to 108.7 +/- 2.5 mg/dl, whereas in group C, the levels decreased only from 202.3 +/- 32.1 to 194.2 +/- 29.8 mg/dl and from 129.2 +/- 38.1 to 124.3 +/- 31.7 mg/dl, respectively. The restenosis rate was significantly lower in group P (19.7%; 13 of 66 vessels) than in group C (39.7%; 27 of 68 vessels; p < 0.05). In group P, the probucol blood concentration was significantly higher in the subjects without restenosis (31 +/- 9 microg/ml) than in those with restenosis (18 +/- 8 microg/ml; p < 0.01), but the serum TC and formula LDL-C levels were not significantly different between these two groups. In summary, long-term administration of probucol significantly reduces the incidence of restenosis after PTCA. it was suggested that the mechanism of this preventive effect was not reducing the serum TC or formula LDL-C levels, but rather an inhibitory action on smooth muscle cell proliferation.

Adult↗
PubMed1996

Divergent effects of endoscopic sphincterotomy on the long-term outcome of hepatolithiasis.

BACKGROUND: The long-term value of endoscopic sphincterotomy in patients with hepatolithiasis has not been established. METHODS: Long-term clinical effects of endoscopic sphincterotomy on hepatolithiasis were determined in 57 patients. All patients had sphincterotomy to remove their common bile duct stones. Intrahepatic stones were removed completely in 21 patients, while the stones partly remained in 36 patients despite combined use of surgery and/or percutaneous trans-hepatic choledochoscopy. Three patients of the latter group spontaneously passed all the remaining stones soon after the sphincterotomy. RESULTS: Follow-up at 66 to 183 months (mean, 114 months) was available in 54 patients (94.7%). Late complications occurred in 10 patients with the remaining stones, including seven cases of cholangitis (two fatalities) and three of liver abscess (one fatality). In contrast, those with complete clearance developed no complications. CONCLUSIONS: Endoscopic sphincterotomy has divergent effects on the long-term outcome of patients with hepatolithiasis. Every effort should be made to remove the intrahepatic stones as completely as possible shortly after sphincterotomy if the patient is to be managed endoscopically and adverse effects are to be avoided.

Adult↗
PubMed1996

Tuberculous pseudoaneurysm of the descending thoracic aorta: a case report and literature review of surgically treated cases.

Tuberculous aneurysm of the aorta is an extremely rare disease with a high mortality rate. Only 32 patients treated surgically have been reported in the literature. These reports indicate an 84.4% operative survival rate. We present a case of a tuberculous false aneurysm in the descending thoracic aorta that was successfully treated surgically with an extracorporeal circulation. The hole in the aorta within the false aneurysm was closed with a Dacron patch because the aortic wall appeared to be free of active infection as a result of long-term preoperative antituberculous chemotherapy.

Aneurysm, False↗
PubMed1996

Three brothers with progressive hepatic dysfunction and severe hepatic steatosis due to a patent ductus venosus.

Three Japanese brothers with progressive deterioration of hepatic function and fatty degeneration of the liver eventually leading to hepatic encephalopathy were recently encountered. Each of them had a congenital intrahepatic portosystemic venous shunt due to a patent ductus venosus. Liver dysfunction and hepatic steatosis reverted to normal with surgical correction of the ductus venosus. Our observations suggest that impairment of liver function occurs first in the presence of malnutrition related to a reduction of blood in the portal vein. Hepatic steatosis is a consequence of a depleted metabolism of hepatocytes. Congenital portosystemic venous shunt due to a patent ductus venosus in this family has a genetic background.

Angiography↗
PubMed1996

Identification and characterization of a mitochondrial endonuclease from yeast, Schizosaccharomyces pombe.

Schizosaccharomyces pombe mitochondria were isolated from the cells treated with Novozyme 234, and purified in a Percoll gradient. A zymographic assay in a SDS-polyacrylamide gel containing single-stranded DNA revealed that an endonuclease of 32 kDa is associated with the mitochondria. The endonuclease was extracted from the mitochondria with 0.5 M KCl and was partially purified. The 32-kDa enzyme degraded both DNA and RNA at a weak alkaline pH, but preferred single-stranded DNA. The enzyme required Mg2+ or Mn2+, but not Ca2+ or Zn2+ for activity, and was inhibited by 50% with a 150 mM salt solution. Nicks generated by the enzyme could be resealed with T4 DNA ligase, indicating that the enzyme produces 5'-P and 3'-OH ends.

DNA, Single-Stranded↗
PubMed1996

Ascorbic acid deficiency reduces hepatic apolipoprotein A-I mRNA in scurvy-prone ODS rats.

Using the ODS rat (genotype od/od) as a model, we investigated the effect of ascorbic acid deficiency on the expression of the apolipoprotein A-I gene. Male ODS rats (7 wk old, body weight approximately 140 g) were fed a basal diet containing ascorbic acid (300 mg/kg) or a diet without ascorbic acid for 14 d. Ascorbic acid deficiency lowered the serum apolipoprotein A-I concentration. The apolipoprotein A-I mRNA level in the liver of ascorbic acid-deficient rats was lowered to about 40% (P < 0.05) of that of control rats fed sufficient ascorbic acid. The mRNA level in jejunum was not affected by ascorbic acid deficiency. Ascorbic acid deficiency did not change the transcriptional rate of the hepatic apolipoprotein A-I gene, suggesting that post-transcriptional regulation was involved in lowering the mRNA level. The low level of hepatic apolipoprotein A-I mRNA was restored to the control level within 3 d after the administration of sufficient ascorbic acid. These data indicate that ascorbic acid deficiency lowers serum apolipoprotein A-I concentration through lowering its mRNA level and subsequent depression of its synthesis in liver.

Animals↗
PubMed1996

Pancreatic endocrine dysfunction in rats not expressing the cholecystokinin-A receptor.

Cholecystokinin (CCK) has been suggested to modulate insulin output. We have shown that Otsuka Long-Evans Tokushima Fatty (OLETF) rats show little or no expression of the CCK-A receptor gene in the pancreas. We examined whether the CCK-A and CCK-B receptor genes are expressed in the islets and the role of CCK-A receptor in insulin secretion. Gene expressions of CCK receptors were determined by the reverse-transcriptase polymerase chain reaction (RT-PCR) followed by Southern blot hybridization and Northern transfer analysis using LETO rats as controls. Pancreatic endocrine function was examined in perfusion (exogenous CCK stimulation) and meal ingestion (endogenous CCK stimulation) studies. CCK-A receptor mRNA was detected in the islets of LETO rats but not OLETF rats. Expression of the CCK-B receptor gene was detected in both strains by RT-PCR. Insulin secretion was impaired in OLETF rats, but the insulin contents of OLETF and LETO rats were not different. No abnormalities were detected histologically in either strain. These results suggest that the occurrence of pancreatic endocrine dysfunction in OLETF rats may be due to a defect in expression of the CCK-A receptor gene, not to insulin deficiency.

Animals↗
PubMed1996

Amelioration of hyperglycemia in streptozotocin-induced diabetic rats receiving a marginal mass of islet grafts by troglitazone, an oral antidiabetic agent.

Troglitazone, a novel oral antidiabetic agent, was evaluated to determine whether it could have hypoglycemic effects in streptozotocin (STZ)-induced diabetic rats when a marginal mass of islets was transplanted and hyperglycemia persisted after transplantation. Lewis rats (RT1(1)) were used as both donors and recipients. Five hundred fresh islets were transplanted beneath the kidney capsule of STZ-induced diabetic recipients. Troglitazone was administered orally (0.34 mmol/kg/day) for 7 days before and for 60 days after islet transplantation. Neither troglitazone treatment without islet transplantation (n = 8) nor islet transplantation alone (n = 7) could produce normoglycemia (< 11 mmol/L) in diabetic recipients by 60 days after transplantation. In marked contrast, seven of 10 rats receiving islet grafts and treated with troglitazone became normoglycemia at 26.9 +/- 16.4 days (mean +/- SD; n = 7) after transplantation. Removal of the kidney bearing the grafts promptly resulted in the normoglycemic recipients (n = 4) becoming diabetic again. Light and electron microscopically, the intact islets with well-granulated beta cells could be observed in the transplant site of the normoglycemic recipients. These findings clearly demonstrate that the hyperglycemia in STZ-induced diabetic rats receiving an insufficient number of islet grafts to reverse diabetes was ameliorated by troglitazone treatment.

Animals↗
PubMed1996

Localization of the Darier disease gene to a 2-cM portion of 12q23-24.1.

Positional cloning with microsatellite markers allowed further localization of the Darier disease gene to a 2-cM interval of chromosome 12, 12q23-24.1, between the polymorphic loci D12S234 and D12S129. A region this size is suitable for construction of a contig to identify the Darier disease gene. Use of a polymorphic intronic marker for nitric oxide synthetase 1 gene, which maps to the same chromosomal area as the Darier gene, allowed exclusion of that gene as the Darier disease gene.

Chromosome Mapping↗
PubMed1996

Serum concentration of 5-S-cysteinyldopa in pediatric patients with giant pigmented nevi.

The serum concentrations of 5-S-cysteinyldopa (5-S-CD) in pediatric patients with giant pigmented nevi (GPN) were investigated and compared with those of pediatric patients with small- or medium-sized congenital nevi (CN), or non-melanocytic benign skin tumor (control group). Serum 5-S-CD levels in the GPN group (N = 21), particularly in patients less than 5 years old, were significantly higher (highest concentration 38.4, mean +/- S.D. 16.6 +/- 9.4 nmol/L) than those in the CN (N = 22) or control groups (N = 26). Serum 5-S-CD levels in the CN group were not significantly different from those in the control group. There was a significant correlation between the serum 5-S-CD level and size (surface area) of the GNP. There was a significant inverse correlation between the serum 5-S-CD level and age in the CN and control groups, but not in the GPN group. Serum 5-S-CD levels were transiently elevated immediately after treatment of patients with GPN with a combination of skin abrasion and cryotherapy with solid carbon dioxide. These results suggest that serum 5-S-CD levels in the GPN group reflected the 5-S-CD derived from GPN, particularly in patients less than 5 years old. This indicates that melanogenesis may be accelerated in infant patients in the GPN group.

Adolescent↗
PubMed1996

Case report: hepatic adenoma with bone marrow metaplasia in a patient with glycogen storage disease type 1a.

A 34 year old man with glycogen storage disease type 1a had two hepatic tumours since 18 years of age. They had continued to grow until he was 24 years old, but showed no further growth since then. He underwent a right hepatic trisegmentectomy with caudate lobectomy under veno-venous bypass. The tumour in the posterior segment showed nodule-within-nodule appearance. Histologically, the inner adenoma with dysplasia, bone marrow metaplasia and lymphocytic infiltration was separated by a fibrous band from the outer adenoma of usual histology.

Adenoma↗
PubMed1996

Characterization of G proteins in obstructed kidneys.

BACKGROUND: Urinary tract obstruction has a marked effect on renal function. Activation of phospholipases which results in incremental production of vasoactive eicosanoids may contribute to the hemodynamic changes characteristic of an obstructed kidney. G proteins play an important role in transmembrane signal transduction, which control phospholipase activities and eicosanoid production. The present study was designed to determine the presence of G proteins in obstructed kidneys in rats, and to characterize the differences between unilateral ureteral obstruction (UUO) and bilateral ureteral obstruction (BUO). METHODS: Several G-protein alpha subunits (G alpha s, G alpha i1,2, and G alpha i3) and the beta subunit (G beta) were determined by immunoblotting and immunocytochemical techniques using specific antibodies against these G proteins. RESULTS: Immunoblots demonstrated a decreased G alpha i3 content in the outer medullary tubules and a significantly lower G beta level in the glomeruli of UUO. In BUO, there was an increased level of G beta in the cortical tubules, and the G alpha s level was markedly reduced in the inner medullary tubules. Immunocytochemical studies revealed that these G proteins were predominantly localized in the brush border side of the cortical tubules. However, we could not demonstrate staining differences between UUO and BUO. CONCLUSIONS: These results indicate that a modulation of G-protein-coupled transmembrane signal transduction may contribute to the renal functional changes in an obstructed kidney. A different level of expression of G-protein subunits between UUO and BUO may be a factor in the differences of hemodynamics and renal tubular damage between UUO and BUO.

Animals↗
PubMed1996

Acute pandysautonomia: mass spectrometric and histopathological studies of the sympathetic nervous system during long term L-threo-3,4-dihydroxyphenylserine treatment.

Stable isotope labelled L-threo-3,4-dihydroxyphenylserine (L-DOPS) infusion tests and histopathological studies of the rectal autonomic nerves were performed in a patient with acute pandysautonomia. A pronounced increase in blood pressure occurred and stable isotope labelled noradrenaline appeared in the plasma during L-DOPS infusion in the acute stage, but decreased during the next three years. Noradrenergic nerve fibres in the rectal mucosa showed no recovery, and so clinical improvement had occurred without apparent significant regeneration of the peripheral autonomic nerves.

Acute Disease↗
PubMed1996

Pulsed Doppler echocardiographic assessment of changes in pulmonary artery pressure during oxygen breathing.

To validate the use of pulsed Doppler echocardiography in detecting changes in pulmonary artery pressure (PAP), several parameters of flow velocity profiles of the right ventricular outflow tract were compared with changes in PAP and pulmonary vascular resistance measured directly by cardiac catheterization. The study was performed in 33 patients with chronic pulmonary disease (chronic obstructive pulmonary disease or pulmonary fibrosis) or pulmonary thromboembolism, during room air and 100% oxygen breathing. Inhalation of 100% oxygen for 15 min significantly reduced PAP in patients with mild pulmonary hypertension (20 < or = mean PAP < or = 24 mm Hg; control: 21.3 +/- 1.3, O2: 17.9 +/- 2.2 mm Hg, p < 0.05) and those with severe pulmonary hypertension (mean PAP > or = 25 mm Hg; control 44.9 +/- 16.8, O2: 35.4 +/- 13.5 mm Hg, p < 0.05). It also significantly reduced the pulmonary vascular resistance and cardiac output in both groups. The ratio of acceleration time to right ventricular ejection time (AT/RVET), a parameter measured by Doppler echocardiography, correlated significantly with mean PAP during room air (r = 0.73, p < 0.0001) and oxygen breathing (r = 0.64, p < 0.0001). Furthermore, AT/RVET increased significantly in patients with mild pulmonary hypertension and those with severe pulmonary hypertension. Our results suggest that the Doppler technique provides a clinically useful, noninvasive index for assessing changes in PAP during oxygen breathing in patients with pulmonary hypertension complicating chronic pulmonary disease or pulmonary thromboembolism.

Administration, Inhalation↗
PubMed1996

Synthesis and structure-activity relationships of novel phenylcyanoguanidine derivatives as potassium channel openers.

3,5-Di-substituted phenylcyanoguanidine derivatives with halogen, cyano and/or nitro groups at the 3- and 5-positions of the benzene ring exhibited very strong smooth muscle relaxation activity in vitro, as compared to pinacidil. Among them, N-(3-chloro-5-cyanophenyl)-N'-cyano-N" -tert-pentylguanidine (5s) showed 27-fold more potent activity than pinacidil, and exhibited a stronger and more lasting antihypertensive effect than pinacidil by oral administration to spontaneously hypertensive rats. We propose a new pharmacophore model in which the essential factors for binding to the potassium channel are an NH and a bulky alkyl group.

Animals↗