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N Aoyama

Publications and source records attributed to N Aoyama.

At least 55 records · Page 3Linked to original sources
PubMed1999

In vitro effect of amezinium on the rabbit urinary bladder: muscle strip and whole bladder evaluation.

Dose-response studies for norepinephrine and amezinium were obtained for isolated muscle strips and in vitro whole bladder preparations to investigate the effect of amezinium on the bladder. Specimens (strips from the bladder base and body, and the whole bladder) were obtained from mature female rabbits. By the muscle strip study, amezinium showed a weak contractile effect (up to 40% of spontaneous contraction) on strips from the bladder base. Muscle strips from the bladder body presented no response to amezinium. In the whole bladder preparation, administration of norepinephrine showed an increase in intravesical pressure in 4 out of 7 rabbits, whereas administration of amezinium had negligible effect on intravesical pressure. Administration of amezinium showed no influence on strips from the bladder body and the whole bladder preparation. Direct contractile response in muscle strips from the bladder base by amezinium appeared to be a favourable effect considering urinary storage.

Animals↗
PubMed1999

Gastric ulcer formation after the Hanshin-Awaji earthquake: a case study of Helicobacter pylori infection and stress-induced gastric ulcers.

BACKGROUND: Both Helicobacter pylori (H. pylori) infection and various stresses are known to induce peptic ulcer disease of the upper gastrointestinal tract. However, the pathogenetic relationship between the two factors has not yet been clarified. We conducted a case-control study to examine whether H. pylori infection played a role in the development of gastric ulcer (GU) induced by life-event stresses that were experienced after the Hanshin-Awaji earthquake. MATERIALS AND METHODS: Serum samples from patients in the devastated area who developed GUs during the 2 months following the Hanshin-Awaji earthquake and those from GU patients in the same area during the corresponding period of the previous year, and from gender-, age- and institute-matched ulcer-free controls were tested for the presence of the H. pylori IgG antibody. RESULTS: A significant association between H. pylori infection and the development of GU in uninjured patients was observed in all sets [matched odds ratio (OR) = 3.23, 95% confidence interval: 1.95-5.35]. Moreover, the prevalence of H. pylori infection in patients who developed GUs after the earthquake was not different from that for GU patients in the previous year. In contrast, there was no association between H. pylori infection and the development of GU in the physically injured patients after the earthquake. CONCLUSIONS: H. pylori infection may play an important role in the development of GUs that are induced by emotional life-event stresses.

Antibodies, Bacterial↗
PubMed1999

Effect of charcoal hemoperfusion on clearance of cibenzoline succinate (cifenline) poisoning.

BACKGROUND: Management of cibenzoline succinate (cifenline) poisoning by symptomatic treatment is recommended because it has been reported cibenzoline succinate is not effectively removed by hemodialysis. The use of charcoal hemoperfusion for patients with cibenzoline succinate poisoning has not been reported previously. CASE REPORT: An 80-year-old woman with permanent right ventricular pacing was admitted to our hospital with general fatigue and clouding of consciousness. She had been receiving cibenzoline succinate for 1 month. The patient was clearly in shock on admission. Electrocardiogram showed a prolonged QRS and QTc interval and pacing failure. Hemodynamic failure, electrocardiographic abnormalities including pacing failure, and liver and renal dysfunction were compatible with cibenzoline succinate poisoning. Symptomatic treatment was provided. On day 4, charcoal hemoperfusion was initiated because of the development of hypoglycemia accompanied by liver and renal dysfunction. After charcoal hemoperfusion, the hypoglycemia, liver and renal dysfunction, prolonged QRS and QTc interval, and pacing threshold resolved. She was discharged on digoxin. We present a case of cibenzoline succinate poisoning treated with charcoal hemoperfusion which resulted in a rapid reduction of cibenzoline plasma concentrations with a significant clinical improvement.

Aged↗
PubMed1999

Interaction of docetaxel ("Taxotere") with human P-glycoprotein.

The interaction of docetaxel ("Taxotere") with P-glycoprotein (P-gp) was examined using porcine kidney epithelial LLC-PK1 and LLC-GA5-COL150 cells, overexpressing human P-gp selectively on the apical plasma membrane by transfection of human MDR1 cDNA into the LLC-PK1 cells. The basal-to-apical transport of [14C]docetaxel in LLC-GA5-COL150 cells significantly exceeded that in LLC-PK1 cells, but the apical-to-basal transport was decreased in LLC-GA5-COL150 cells. The intracellular accumulation after its basal or apical application to LLC-GA5-COL150 cells was 4- to 20-fold lower than that of LLC-PK1 cells. Multidrug resistance (MDR) modulators, i.e., cyclosporin A and SDZ PSC 833, inhibited the basal-to-apical transport and increased the apical-to-basal transport of [14C]docetaxel in LLC-GA5-COL150 cells, but verapamil affected only apical-to-basal transport. The intracellular accumulation after basal or apical application to LLC-GA5-COL150 cells was also increased by these three MDR modulators. These observations demonstrated that docetaxel is a substrate for human P-gp, suggesting that docetaxel-drug interactions occur via P-gp. The inhibition of [14C]docetaxel transport by the MDR modulators, as well as daunorubicin and vinblastine, was also found in LLC-PK1 cells, which endogenously express P-gp at lower levels, and concentrations showing similar levels of inhibition were lower than those in the case of LLC-GA5-COL150 cells. These observations indicate that it is necessary to consider the pharmacokinetic and pharmacodynamic interactions of docetaxel via P-gp.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1999

Hypokalemia with syncope caused by habitual drinking of oolong tea.

A 61-year-old woman developed hypokalemia, atrioventricular block and ventricular tachycardia with syncope after habitual drinking 2 to 3 liters of oolong tea per day. She had been suffering from rheumatoid arthritis and Sjögren's syndrome and her serum albumin was decreased (2.9 g/dl). Oolong tea contains caffeine at approximately 20 mg/dl. Great quantities of caffeine can induce hypokalemia. The serum protein binding caffeine is albumin. Accordingly, in patients with hypoalbuminemia, caffeine is apt to induce hypokalemia. This case suggested that great quantities of oolong tea, one of the so-called "healthy" drinks, result in serious symptoms for patients with hypoalbuminemia.

Binding Sites↗
PubMed1999

[Characteristics of anti-microbial agents and its clinical choice for H. pylori treatment].

Eradication of Helicobacter pylori (H. pylori) is now established as main treatment of upper-gastrointestinal diseases. Resistance to H. pylori and acid condition in the stomach were important factors which influenced H. pylori eradication. Recolonized H. pylori strains will be easily resistant to metronidazole and clarithromycin, whereas almost all of H. pylori strains are sensitive to amoxicillin. On the other hand, amoxicillin targets cell wall biosynthesis and clarithromycin inhibits protein synthesis of Helicobacter pylori mainly in the growth phase which induced high intragastric pH condition, however, metronidazole targets DNA and, therefore, is independent of the stationary or growth phase distribution. To established a optimal regimen for Helicobacter pylori treatment, several factors included them should be account according to the parmacokinetical standings.

Anti-Bacterial Agents↗
PubMed1999

HLA-DQB1 locus and the development of atrophic gastritis with Helicobacter pylori infection.

Helicobacter pylori is known to be involved in digestive diseases such as peptic ulcer, atrophic gastritis, and gastric cancer. It is supposed that the incidence of these digestive diseases associated with H. pylori is influenced by the strain diversity of H. pylori, factors involving the host or environment, and the duration of infection. In this study, we directed our attention to HLA, a host factor, and investigated the relation between HLA-DQB1 genotype of H. pylori-infected patients and the development of atrophic gastritis. HLA-DQB1 genotyping was performed by the polymerase chain reaction-restriction fragment length polymorphism method on 122 H. pylori-infected patients with atrophic gastritis and 28 uninfected Japanese controls. Infected patients with developed atrophic gastritis were classified as the open type and those with undeveloped atrophic gastritis as the closed type. To estimate the grade of atrophic gastritis reliably, histological and serological evaluations were also undertaken. The allele frequency of DQB1*0401 was significantly higher in the open-type group compared to either the closed-type or the uninfected group. These results suggest that immunogenic factors play an important role in the development of atrophic gastritis in H. pylori-infected patients, and that DQB1*0401 is a useful marker for determining susceptibility to this disease.

Adolescent↗
PubMed1999

Sufficient effect of 1-week omeprazole and amoxicillin dual treatment for Helicobacter pylori eradication in cytochrome P450 2C19 poor metabolizers.

Omeprazole is widely used for the treatment of Helicobacter pylori infection. It is metabolized by cytochrome P450 2C19 enzyme (CYP2C19) in the liver. Because this enzyme exhibits a genetic polymorphism, patients with low metabolic activity (poor metabolizers) may be exposed to higher concentrations of this drug than are patients who are extensive metabolizers. Eighty-six patients with cultured H. pylori-positive gastritis or peptic ulcers who completed the treatment and assessment of anti-H. pylori therapy were analyzed for CYP2C19 genotyping using a polymerase chain reaction-restriction fragment length polymorphism method [the wild-type or two mutant genes (ml in exon 5 and m2 in exon 4), or both]. Patients were classified into three groups according to the H. pylori eradication regimen: group I (n = 21; omeprazole 40mg/ day and amoxicillin 2000mg/day for 1 week); group II (n = 21; group I regimen plus sucralfate 4000mg/day, for 1 week); group III (n = 44; group I regimen plus clarithromycin 800mg/day, for 1 week). The combination of two mutant alleles (ml/ml, ml/m2, m2/m2-poor metabolizers) was observed in 13 of 86 patients (15%), and all poor metabolizer patients achieved H. pylori eradication regardless of their treatment regimens. In addition, the eradication rates of the poor metabolizers were significantly higher than those of other genotypes who carry homozygous or heterozygous normal allele (extensive metabolizers) in group I or groups I and II combined. CYP2C19 genotyping can provide a new strategy to choose an optimal regimen, and this genotyping is especially useful for Japanese, as the frequency of poor metabolizers is five times greater than that found among Caucasians.

Amoxicillin↗
PubMed1998

Antioxidant, OPC-14117, attenuates edema formation, and subsequent tissue damage following cortical contusion in rats.

Oxygen free radicals contribute to various kinds of tissue injury processes within the central nervous system. It has been suggested that inhibition of free radical formation has the potential to attenuate secondary neural tissue damage involving ischemia or trauma, and antioxidant therapy may offer a promising approach. In the present study, employing a cortical contusion model in the rat, contusion-induced neural damage, was evaluated by investigating edema formation, behavioral activities and histological changes. The effects of the superoxide radical scavenger, OPC-14117, were also tested to determine how free radicals may contribute to such neural damage. The results demonstrated that cerebral contusion induces a progressive decrease in tissue specific gravity representing edema formation, and behavioral deficits in the Morris water maze test and habituation of exploratory activity. Histological examinations revealed necrotic cavity formation in the cortex and selective neuronal death of the hippocampal CA3 region. These changes were significantly attenuated by OPC-14117, which was administered as a single dose immediately following trauma induction. The above results indicate that oxygen free radicals are involved in contusion-induced edema formation, subsequent tissue damage and cognitive deficits. The superoxide radical scavenger, OPC-14117, has a powerful therapeutic potential for preventing secondary cell damage following traumatic brain injury.

Animals↗
PubMed1998

Genetic variations in recurrent astrocytic tumors detected by restriction landmark genomic scanning.

The genetic mechanisms associated with recurrence of advanced astrocytic tumors are poorly understood. We therefore analyzed 24 biopsy specimens from 12 patients with a recurrent astrocytic tumor by a two-dimensional gel electrophoresis method, termed restriction landmark genomic scanning (RLGS). Four spot changes were commonly present in the primary astrocytomas, indicating that the corresponding gene alterations were early events in the development of this tumor type. Altered spots were more frequent and of different distribution in recurrent tumors than in the primary astrocytomas. In particular, specifically increased intensity for spots on chromosomes 9-12 and 18 were observed in the secondary tumors, suggesting a relation with recurrence. The same spot changes observed in primary tumors were also found in the respective secondary lesions but with strikingly different densities in some cases, suggesting increased genetic instability. The altered segments provide important candidate regions for the search for genes involved in events leading to progression and more malignant recurrent tumors.

Astrocytoma↗
PubMed1998

Successful removal of large adrenal pheochromocytoma on the right side with liver mobilization.

We report a case of a large adrenal pheochromocytoma on the right side successfully removed with liver mobilization. Bilateral anterior subcostal incision with a ventral midline incision extending from the xiphoid and subsequent use of self-retraction system provided satisfactory exposure of liver and diaphragm. This incision is useful for easy mobilization of the liver and manipulation of the inferior caval vein in patients with large adrenal tumour on the right side.

3-Iodobenzylguanidine↗
PubMed1998

Correlations between urethral elastance and histological architecture in patients with benign prostatic hyperplasia.

To investigate whether the properties of the flow-controlling zone (FCZ) in obstructive benign prostatic hyperplasia (BPH) would be affected by differences in the histological architecture of the prostate, we evaluated relationships between morphometric and urodynamic data. BPH specimens from 14 patients undergoing transurethral surgery were analysed by quantitative morphometry. The cross-sectional area and mean elastance of FCZ, together with other parameters, were calculated on a preoperative pressure-flow study. Correlations between these parameters and tissue composition were determined. Our study group comprised men with clinical and urodynamic evidence of infravesical obstruction secondary to BPH. No correlations were found between the area density or total volume of each histological element and the cross-sectional area of FCZ at peak flow rate. Neither area density nor total volume of each element correlated with the mean urethral elastance. Our results indicate that the histological architecture of the prostate in patients with obstructive BPH cannot predict the urethral elastance.

Aged↗
PubMed1998

Peptic ulcers after the Hanshin-Awaji earthquake: increased incidence of bleeding gastric ulcers.

OBJECTIVE: Although physical stresses are known to induce peptic ulcers in the upper gastrointestinal tract, it remains controversial whether emotional stress can cause peptic ulcers. Therefore, we examined retrospectively the influence of the Hanshin-Awaji earthquake that occurred in Japan in January 1995 on the occurrence of peptic ulcer disease among noninjured residents. METHODS: Sixty-one hospitals, covering 70% of all endoscopy examinations performed in this area, joined the study and were divided into three areas according to the severity of the damage. A comparison was made between a group of 10,831 patients who underwent upper gastrointestinal endoscopy within 2 months after the earthquake and 16,100 who did so in the same hospitals during the corresponding period in 1994. RESULTS: In the most devastated area, in spite of a dramatic decrease in the total number of endoscopies (50.0%), patients with gastric ulcer (GU) were increased in 1995, whereas those with duodenal ulcer were decreased, resulting in a higher ratio of gastric to duodenal ulcers than in 1994 (3.07 vs 1.88). In particular, there was a marked increase in bleeding GU. The mean age of patients with GU was significantly higher in 1995 than in 1994. CONCLUSION: The Hanshin-Awaji earthquake-induced life event stress not only triggered but also exacerbated GU, particularly in the elderly.

Adult↗
PubMed1998

Urokinase type plasminogen activator receptor expression in colorectal neoplasms.

BACKGROUND: The urokinase type plasminogen activator receptor (uPAR) may play a critical role in cancer invasion and metastasis. AIMS: To study the involvement of uPAR in colorectal carcinogenesis. METHODS: The cellular expression and localisation of uPAR were investigated in colorectal adenomas and invasive carcinomas by in situ hybridisation, immunohistochemistry, and northern and western blot analyses. RESULTS: uPAR mRNA expression was found mainly in the cytoplasm of dysplastic epithelial cells of 30% of adenomas with mild (19%), moderate (21%), and severe (47%) dysplasia, and in that of carcinomatous cells of 85% of invasive carcinomas: Dukes' stages A (72%), B (93%), and C (91%). Some stromal cells in the adjacent neoplastic epithelium were faintly positive. Immunoreactivity for uPAR was detected in dysplastic epithelial cells of 14% of adenomas and in carcinomatous cells of 49% of invasive carcinomas. uPAR mRNA and protein concentrations were significantly higher in severe than in mild or moderate dysplasia (p<0.05); they were notably higher in Dukes' stage A than in severe dysplasia (p<0.05), and significantly higher in Dukes' stage B than in stage A (p<0.05), but those in stage B were not different from those in stage C or in metastatic colorectal carcinomas of the liver. CONCLUSIONS: Colorectal adenoma uPAR, expressed essentially in dysplastic epithelial cells, was upregulated with increasing severity of atypia, and increased notably during the critical transition from severe dysplasic adenoma to invasive carcinoma. These findings implicate uPAR expression in the invasive and metastatic processes of colorectal cancer.

Blotting, Northern↗
PubMed1998

[Telomerase activity in esophageal carcinoma and lesions unstained with Lugol's solution].

Telomerase is a specific enzyme required for the replication of telomeres. Its activity is detected in almost human cancers. We examined in esophageal carcinoma and lesions unstained with Lugol's solution telomerase activity by using telomeric repeat amplification protocol (TRAP) assay. Telomerase activity was detected in all 22 esophageal carcinomas, regardless of histopathological findings. In unstained lesions, telomerase activity was detected in 15 of 22; 10 squamous cell carcinomas, four dysplasia, one regenerative epithelium, no telomerase activity was found in seven; four normal esophageal epithelia, two Barrett's esophagi, one regenerative epithelium. These results suggest that telomerase activity may be a useful molecular marker for the diagnosis of esophageal carcinoma and of the early esophageal carcinoma in area unstained with Lugol's solution.

Carcinoma, Squamous Cell↗