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Biomedical subjects

S Asaki

Publications and source records attributed to S Asaki.

At least 19 recordsLinked to original sources
PubMed2006

Sensory innervation of temporomandibular joint disk.

PURPOSE: To investigate the nerve endings of the adult temporomandibular joint disk, in particular the presence and configuration of the sensory nerve endings by silver staining and electron microscopy. METHODS: 20 cadaveric temporomandibular joints impregnated with silver stain were studied using an optical microscope; 2 other joints were studied using a transmission electron microscope. RESULTS: Free nerve endings were found in the disk parenchyma of all joints. Golgi-Mazzoni corpuscles, Ruffini corpuscles, and articular corpuscles were also observed as sensory nerve end organs. Myelinated and nonmyelinated nerve fibres were visualised in the disk parenchyma using the transmission electron microscope. CONCLUSION: Free nerve endings and sensory nerve end organs are present in the disk parenchyma of the human temporomandibular joint and are associated with sensation and proprioception, just as they are in the acetabular labrum, glenoid labrum, triangular fibrocartilage complex, and meniscus.

Adult↗
PubMed2000

Efficacy of endoscopic pure ethanol injection method for gastrointestinal ulcer bleeding.

We reviewed endoscopic hemostatic effects of the pure ethanol injection (PEI) method for reducing emergency operations and deaths due to gastroduodenal ulcer bleeding. During 17 years beginning in June 1979 in Tohoku University Hospital, 331 patients underwent endoscopic hemostasis by the PEI method. Initial hemostasis was successfully obtained in all cases. Rebleeding occurred in about 4% of the patients, and rehemostasis was obtained successfully in all of them. Complete hemostasis was obtained in 330 of 331 patients (99. 7%) using the PEI method; there were no deaths. Only one patient required emergency operation after hemostasis because of repeated neogenetic bleeding complicated with a perforation and another because of an unidentifiable neogenetic ulcer bleeding located just above the Vater papilla. None required other endoscopic hemostasis or interventional radiology. Moreover, after introduction of "second-look" endoscopy, the rebleeding rate decreased to about 1% with PEI hemostasis. Based on these excellent hemostatic effects of the PEI method, we believe that a comparative study with other hemostatic methods is not needed.

Aged↗
PubMed2000

Peptic ulcer recurrence during maintenance therapy with H2-receptor antagonist following first-line therapy with proton pump inhibitor.

We investigated the peptic ulcer recurrence rates during maintenance therapy with H2-receptor antagonists (H2RAs) following first-line therapy with a proton pump inhibitor (PPI). Patients with gastric ulcer (GU) or duodenal ulcer (DU) were enrolled in this study; 583 eligible patients (GU, 325; DU, 258) were administered lansoprazole (30 mg/day for 8 weeks for GU, and the same dosage for 6 weeks for DU) as first-line therapy, and a half dose of H2RA as maintenance therapy for 12 months. Endoscopic photographs were taken before administration and after 8 (GU) and 6 (DU) weeks of lansoprazole administration. Ulcer stage was evaluated using the classification of Sakita and Miwa. Endoscopic examinations were performed 6 months or 12 months after the start of maintenance therapy or when a recurrence was suspected because of the appearance of subjective symptoms. The healing rates for GU and DU patients after completion of lansoprazole therapy were 79% in both groups, while the S2-stage healing rates were 18% and 31%, respectively. At 1 year after the start of maintenance therapy, the recurrence rates were 25% for GU and 39% for DU patients. In DU patients, the recurrence rates from S1-stage and S2-stage were 49% and 20%, respectively (P = 0.004), but no significant difference was found between these rates in GU patients. The recurrence rates in H. pylori-positive patients before lansoprazole administration were 27% for GU and 43% for DU patients. We concluded that the maintenance therapy with a half-dose of H2RA following PPI therapy was insufficient to prevent recurrences of GU and DU.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed2000

Changes in gastric acid secretion assayed by endoscopic gastrin test before and after Helicobacter pylori eradication.

BACKGROUND: It remains controversial whether or not Helicobacter pylori infection causes altered gastric acid secretion. A novel test for evaluating gastric acid secretion (endoscopic gastrin test; EGT) has recently been developed. AIM: To investigate by EGT the effects of H pylori eradication on the state of gastric acid secretion in patients with peptic ulcer. METHODS: Twenty six patients with duodenal ulcer and 33 with gastric ulcer, for all of whom H pylori infection had been documented, were studied by EGT, histological examination of gastric mucosa, and measurement of plasma gastrin levels before and one and seven months after H pylori eradication. RESULTS: In patients with duodenal ulcer, the mean EGT value before H pylori eradication was higher than that in H pylori negative controls, but it had decreased significantly seven months after the treatment. In contrast, the mean EGT value of patients with gastric ulcer before H pylori eradication was lower than that in H pylori negative controls, but it had increased one month after the treatment; this was followed by a slight decrease at seven months. In both groups, mean EGT values seven months after the treatment were not significantly different from the mean control value. CONCLUSIONS: The reduced acid secretion in gastric ulcer patients and gastric acid hypersecretion in duodenal ulcer patients were both normalised after the clearance of H pylori.

Adult↗
PubMed1998

A new endoscopic method of gastric acid secretory testing.

OBJECTIVE: To date, the effect of Helicobacter pylori on acid secretion remains controversial. To evaluate changes in the gastric acid secretory response before and after H. pylori eradication in a large number of patients, we devised a new endoscopic method of gastric acid secretory testing, the endoscopic gastrin test (EGT). METHODS: In EGT, endoscopy was begun 15 min after intramuscular injection of 4 microg/kg tetragastrin. Gastric fluid secreted between 20 and 30 min after gastrin injection was aspirated and collected during endoscopic examination. The amount of acid in the sample collected over this 10-min period was estimated by titration and expressed in H+ mEq/10 min. Fifteen subjects underwent a conventional secretory test using a nasogastric tube (conventional method) and EGT on different days to assess the correlation between results obtained with the two methods. In 10 of these subjects, EGT was repeated under the same conditions to assess its reproducibility. RESULTS: EGT values correlated very well with peak acid output determined by the conventional method (n = 15, r = 0.92) and had high reproducibility (n = 10, CV = 5.6). We noted that EGT takes just a little longer to perform than a routine endoscopic examination, and the influence of an endoscope in the stomach on acid secretion was not present. CONCLUSION: The EGT should be very useful as a rapid, simple substitute for conventional secretory testing when repeated gastric secretory tests are required, especially in investigating the effect of H. pylori on acid secretion in a larger population.

Adult↗
PubMed1998

Effect of rabeprazole (E3810), a novel proton pump inhibitor, on intragastric pH in healthy volunteers.

In this study, we examined the effect of rabeprazole (E3810), a novel proton pump inhibitor, on gastric acidity under physiological conditions in healthy volunteers using 24-hour intragastric pH monitoring. Twenty-four-hour intragastric pH monitoring was performed three times to seven subjects randomly assigned in a cross over fashion to one of the following groups; without drug administration (basal), and with 10 mg or 20 mg of rabeprazole for four days. The median pH for 24 hours was 2.15 in the basal study, while the corresponding median pH were 5.05 and 5.90 after treatment with 10 mg and 20 mg of rabeprazole, respectively. Significant differences in the median pH were observed between the basal study and that after administration of the 10 mg and 20 mg doses of rabeprazole. The cumulative percentage of pH readings above the threshold pH 4 value, was 34.1% in the basal study, and 72.6% and 78.3% after treatment with 10 mg and 20 mg doses of rabeprazole, respectively. This result indicates that the efficacy of rabeprazole allows for substantial control of gastric acidity with once-daily dosing, and that both the 10 mg and 20 mg doses result in potent inhibition of gastric acid secretion.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1998

[Correlation between 13C-urea breath test and gastric histological findings in Helicobacter pylori positive patients].

13C-urea breath test (UBT), available for diagnosis of Helicobacter pylori (HP) in the stomach, measures the 13CO in the breath in which 13C urea is resolved in the stomach by urease derived from HP. Accordingly UBT is useful for a test of HP infection. This study is aimed at clarifying the relationship between the UBT and gastric histological findings. For this study we selected 63 patients with HP infection who showed both positive UBT and positive histological diagnosis. Briefly in the UBT procedure, the patients were given 13C-urea (100 mg dissolved 100 ml water) in a fasting state and kept in the left decubitus position for 5 minutes, and then the patients were asked to expire into testing bags before and 20 minutes after administration of the urea. Biopsy specimens were taken endscopically from the gastric antrum and the body. The specimens of all patients showed positive CLO test. HP organisms, inflammation, activity, and atrophy of the gastric specimens, were expressed in score from 0 to 3 according to the Update Sydney system. The UBT values were high correlated with the increase of HP organisms. The UBT was 11.8, 26.3, and 37/1000 in the groups with the scores of 0.1, and 2 in the number of HP organisms from the gastric body, respectively. The UBT was 19.2, 22.2, 36.1, 26.7/1000 in the groups with scores of 0, 1, 2, and 3 for the specimens from the antrum, respectively. The results show that there is a positive correlation between the UBT values and HP organisms. As a result, the UBT correlated with the activity score. Grade of gastric mucosal atrophy was expressed histologically in scores of 0,1,2, and 3. The UBT was 29.4, 19.1, 17.5, and 9.3/1000 in the groups with scores 0,1,2, and 3 in the grades of gastric atrophy from the gastric body, respectively. There was a negative correlation between the UBT values and the grade of gastric atrophy. We conclude that the UBT values which indicate the number of HP organisms can be used not only for diagnosis of HP infection but also the quantitative index of HP load.

Adult↗
PubMed1998

[Immunohistochemical studies in depressed type adenomas of the stomach--comparison with protruded type adenomas and depressed type well differentiated mucosal gastric cancers].

In this study, we performed immunohistochemical studies using p53 and Ki-67 immunostaining in 48 depressed type adenomas, and compared with protruded type adenomas (n = 28) and depressed type well differentiated mucosal gastric cancers (mcancer: n = 46). Focal and diffuse p53 staining patterns were not noticed in depressed type adenomas and in protruded type adenomas, but were noticed in mcancers (focal: 4.3%, diffuse: 41.3%). Ki-67 positive cells were noticed in surface epithelium in 24.4% of depressed type adenomas, in 21.4% of protruded type adenomas and in 87.0% of mcancers. Ki-67 positive rate in foveolar epithelium (superior, middle, inferior) were noticed in (31.1%, 12.9%, 6.1%) of depressed type adenomas, in (33.4%, 15.4%, 6.9%) of protruded type adenomas and in (33.4%, 31.4%, 20.4%) of mcancers. These results suggest that from the point of immunohistochemistry, depressed type adenomas were similar to protruded type adenomas, but were different from mcancers.

Adenoma↗
PubMed1997

Gastric mucosal blood flow response to stress in streptozotocin diabetic rats: regulatory role of nitric oxide.

To investigate cytoprotection against mucosal injuries of the stomach in patients with diabetes, we investigated gastric mucosal blood flow (GMBF), its response to a burn stress, and the involvement of nitric oxide (NO) in streptozotocin (STZ) diabetic rats. GMBF was measured by laser-Doppler velocimetry (LDV) and by the hydrogen gas clearance technique (HGC). The steady-state GMBF of STZ rats decreased according to the duration of diabetes, and insulin treatment blocked this decrease. Burn stress caused a rapid decrease in the GMBF. Reduction of the GMBF and gastric mucosal leakage of Evans blue (EB) after the burn stress were greater in the STZ rats than in the controls, but insulin treatment completely blocked this increase in EB leakage in the STZ rats. There was a significant negative correlation between the percent GMBF 3 h after the burn stress and EB leakage at the same time point. In the controls and the insulin-treated STZ rats, N-nitro-L-arginine (L-NNA), an NO synthase inhibitor, enhanced the decrease in postburn GMBF and EB leakage, but was without effect in the STZ rats. These results suggest that NO may be involved in the regulation of GMBF, and that persistent hyperglycemia may impair this regulation. These findings suggest that patients with diabetes have reduced cytoprotection against a variety of gastric mucosal injuries.

Animals↗
PubMed1997

Immunohistochemical studies on EGF family growth factors in normal and ulcerated human gastric mucosa.

Expression of members of the epidermal growth factor family, including epidermal growth factor (EGF), transforming growth factor-alpha (TGF-alpha), amphiregulin (AR), and Cripto, as well as their putative receptor, epidermal growth factor receptor (EGFR), was studied immunohistochemically in human gastric mucosa to evaluate their possible roles in cell proliferation of normal and regenerative gastric mucosa. We also examined the correlation betwen cell proliferation and EGFR by double immunohistochemical staining for proliferating cell nuclear antigen (PCNA) and EGFR. In normal gastric mucosa, TGF-alpha, Cripto, and AR immunoreactivities were observed in the surface epithelial and parietal cells of gastric fundic glands, respectively. EGF immunoreactivity was not observed in any of normal mucosa examined. EGFR immunoreactivity was detected on foveolar cells in proliferative zones and in parietal cells. Double immunostaining revealed that EGFR immunoreactivity was distributed much more widely than PCNA immunoreactivity. PCNA positive epithelial cells adjacent to gastric ulcer margin expressed relatively intense EGFR but did not express any of the growth factors examined. On the other hand, relatively intense immunoreactivity of both TGF-alpha and Cripto was detected in PCNA-negative regenerative epithelium located distant from gastric ulcer margin. Relative immunoreactivity of AR in regenerative gastric epithelium associated with ulcer was not different from that in normal gastric mucosa. TGF-alpha, AR, and Cripto are considered to play important roles in normal gastric mucosal proliferation, and TGF-alpha and Cripto may be involved in ulcer healing, possibly via a paracrine mechanism.

Amphiregulin↗
PubMed1997

Analysis of cell damage and proliferation in Helicobacter pylori-infected human gastric mucosa from patients with gastric adenocarcinoma.

Helicobacter pylori (HP) infection, a cause of multifocal atrophic gastritis, is considered an important factor related to the evolution of the human gastric mucosa from normal to intestinal-type adenocarcinoma. We examined cell proliferation and both double and single strand DNA damage in situ in 35 patients undergoing gastrectomy for adenocarcinoma with HP-infected gastric mucosa by immunolocalization of Ki-67, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling, and in situ nick translation. We also studied the distribution of intraepithelial neutrophils by elastase immunolocalization. HP infection was confirmed in all cases by serum anti-HP antibodies, ureas testing, and histopathological examination. HP-infected gastric mucosa was classified according to the degree of inflammation and intestinal metaplasia. Ki-67, terminal deoxynucleotidyl transferase-mediated labeling, in situ nick translation, and intraepithelial neutrophil indices all increased with the progression of gastritis and were highest in glands with incomplete intestinal metaplasia. All indices were lowest in gastric glands with complete intestinal metaplasia. Significant positive correlations were observed among these markers. Increased proliferative activity in HP-associated chronic gastritis in response to cell damage or injury was clearly demonstrated, suggesting that both HP-associated toxins and intraepithelial neutrophils are important in HP-related gastric epithelial injury. Increased cell turnover associated with incomplete intestinal metaplasia may result in DNA instability and subsequent development of intestinal-type gastric adenocarcinoma in HP-infected mucosa.

Adenocarcinoma↗
PubMed1996

In situ analysis of tissue dynamics and p53 expression in human gastric mucosa.

In situ tissue dynamics were studied in 12 cases of human gastric mucosa, including normal gastric body mucosa and gastric glands with intestinal metaplasia, obtained from gastrectomy specimens of adenocarcinoma. Cell proliferation was determined by Ki67 immunoreactivity. DNA fragmentation was studied in situ by TdT-mediated dUTP-biotin nick end labelling (TUNEL). In addition, p53 expression was examined by both immunohistochemistry and mRNA in situ hybridization. In the oxyntic gastric glands, Ki67 immunoreactivity was observed exclusively in the proliferative zone and TUNEL-positive cells were present predominantly in the surface foveolar epithelium. In the gastric glands with complete intestinal metaplasia, Ki67-positive cells were present in the lower portion of the glands and TUNEL-positive cells in the superficial epithelium. In the gastric glands with incomplete intestinal metaplasia, TUNEL-positive cells were detected in the lower gastric glands adjacent to cells immunoreactive for Ki67; the proportion of these gastric glands with TUNEL-positive cells (40 out of 108 glands) was significantly higher than for oxyntic glands (94 out of 620 glands) or for glands with complete metaplasia (31 out of 254 glands). Relatively strong p53 immunoreactivity and mRNA hybridization were also observed in the proliferative and apoptotic areas of gastric glands with incomplete intestinal metaplasia. These results indicate that incomplete intestinal metaplasia is associated with increased cell turnover and p53 overexpression, possibly in response to various noxious or DNA-damaging stimuli.

Apoptosis↗
PubMed1996

[Gastric mucosal atrophy and prevalence of Helicobacter pylori in reflux esophagitis of the elderly].

This study is aimed at a role of Helicobacter pylori (HP) infection in reflux esophagitis of the elderly. 46 patients with reflux esophagitis aged at older than 60 years are selected for this study with informed consent. 43 patients without reflux esophagitis, peptic ulcer, and gastric cancer are used as a control group. In reflux esophagitis, gastric mucosal atrophy is judged as closed type of endoscopic findings in all cases. In control, 27 of 43 patients were judged as open type. Serum pepsinogen I, II ratio is 4.73 +/- 1.28 which is higher significantly than 3.39 +/- 1.69 in control. Serological positive rate of HP antibody is 39.1% in reflux esophagitis. This rate is significantly lower than 62.7% in control. In conclusion, low frequency of chronic HP infection protects gastric mucosa from atrophy, and keeps secretion of gastric acid, resulting in reflux esophagitis of the elderly accompanied with various abnormal esophago-gastric functions.

Aged↗
PubMed1996

[Expression of Bcl-2 and Bax in human gastric cancer tissue].

Deregulation of bcl-2 may function as a survival mechanism in cancer cells, predisposed to cell death. Aberrant Bcl-2 expression is a frequent occurrence in chronic atrophic gastritis, gastric epithelial dysplasia and gastric cancer. Inhibition of apoptosis through Bcl-2 expression appears to be specifically associated with promotion of gastric adenocarcinoma. In addition, loss of heterozygosity of the bcl-2 gene is a common event in well-differentiated adenocarcinoma, whereas overexpression of bcl-2 gene is observed in poorly differentiated adenocarcinoma. Bax, a homologue of Bcl-2, counters the death repressor activity of Bcl-2. In our study Bax immunostaining in gastric cancer tissue is not significantly correlated with tumor histology. Possible gene therapy using bax gene is discussed.

Adenocarcinoma↗
PubMed1996

[Methodological study of 13C-urea breath test for detection of Helicobacter pylori infection].

In this study, we investigate simple breath test for detection of Helicobacter pylori (HP) infection using 13C-urea. Thirty-nine patients (30 were HP positive, 9 were HP negative) were given three different doses (50, 100 and 150 mg) of 13C-urea at fasting, and keep sitting after mouth washing with water. Breath samples were taken before and 10, 20, 30, 45, and 60 minutes after urea administration. More than 100mg of 13C-urea was necessary for correct diagnosis of HP infection, because 2 HP positive cases were not detected by 50mg 13C-urea administration. In cases with patchy distribution of HP in the stomach, it may be necessary to change the posture to distribute urea within the whole stomach. In most of HP positive cases, peak delta 13CO2 were obtained within 30 minutes, but one HP negative case showed high delta 13CO2 at 10 minutes, which was probably caused by urease activity in the mouth. So it is appropriate to take breath sample at 20 minutes after urea administration. In this study, cut-off value for a positive test can be setted between 4 to 7 delta/1000, it is necessary to investigate much more cases to set exact cut-off value.

Adult↗