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Background and Aim Newly developed ultrathin transnasal endoscope, the GIF-XP290N, makes possible a resolving power similar to the GIF-H260 at a distance of 3 mm. We conducted surveillance of subjects with Barrett's esophagus using this ultrathin transnasal endoscopy. In Japan the lower margin of the lower esophageal palisade vessels is defined the gastroesophageal junction in deep inspiration. We diagnose Barrett's esophagus if columnar epithelium is present on the oral side of the gastroesophageal junction. Methods and Results Barrett's esophagus was confirmed in 116 out of 135 subjects (85.9%), with 17 cases of short-segment Barrett's esophagus (SSBE) and 99 of ultra-short-segment Barrett's esophagus. Close observation of the Barrett's esophagus mucosal structural pattern using narrow band imaging revealed 29 cases with an oval or round pattern, 29 with a long straight pattern, 47 with a villous pattern, 8 with a cerebriform pattern, and 6 with an irregular pattern according to Goda classification. Mucosal biopsies from all subjects with SSBE are examined. Histological examination revealed intestinal metaplasia in only eight subjects. We grouped the oval/round and long straight patterns as closed type, and the villous, cerebriform, and irregular patterns as open type. Analysis of the relationship between these mucosal patterns and background factors revealed a significant correlation between intestinal metaplasia and the open-type pattern. Conclusion We consider this new ultrathin transnasal endoscopy to be a useful technique for surveillance of Barrett's esophagus, especially SSBE.

Background and Aim Endoscopic sphincterotomy (ES) combined with large balloon dilation (ESLBD) can be useful for extracting large and multiple bile duct stones. Although there are many studies on the feasibility and short-term outcome, there are few reports about mid- to long-term outcome after ESLBD. The aim of our study is to prospectively evaluate the mid-term outcome of ESLBD. Methods One hundred eighty-three patients who underwent ESLBD between November 2006 and May 2012 were included. The patients were followed up periodically after the procedure until April 2013. Papillary dilation was performed at the time of initial ES or prior ES. Early and late adverse events and stone recurrence were evaluated in this study. Results The patients' mean age was 76.6 ± 10.7 years. Surgically altered anatomy was present: Billroth I gastrectomy (2), Billroth II gastrectomy (13), and gastrectomy with Roux-en Y reconstruction (18). Seventy-eight (42.6%) patients had periampullary diverticulum. Prior ES had been performed in 40 (21.9%) patients. The mean follow-up period was 43.5 ± 19.7 months (range 11–78). Eight (4.4%) patients had stone recurrence. There was rare stone recurrence after initial ESLBD treatment and native gastrointestinal anatomy. Univariate and multivariate analyses showed that prior ES and previous history of stone recurrence were predictive of stone recurrence (P

Background and Aim The new developed ultrathin transnasal endoscope, the GIF-XP290N, makes possible a resolving power similar to the GIF-H260 at a distance of 3 mm. In this study, using the GIF-XP290N, we evaluated whether endoscopic diagnosis (discrimination between benign and malignant) of gastric lesions is possible using nonmagnified narrow-band imaging (NBI) endoscopy. Methods The subjects were 255 consecutive patients who underwent screening of the gastrointestinal tract using new ultrathin transnasal endoscopy. Their average age was 65.2 ± 11.4 years. The male-female ratio was 2.5:1. All cases were examined using conventional white-light imaging (WLI) and nonmagnified NBI. When a depressed lesion was detected in the stomach, it was examined using WLI, then NBI close examination (at about 3 mm). We observed the mucosal structure of the lesion using close visualization with NBI. Concerning mucosal structural changes, we looked for a clear demarcation line between the lesion and the surrounding mucosa, and loss, irregularity, or nonuniformity of the lesion mucosal microsurface pattern. Results A total of 52 depressed lesions were examined. The histological diagnosis was cancer for 8 lesions, and noncancer for 44 lesions. WLI examination yielded a sensitivity of 50.0% (4/8), specificity of 63.6% (28/44), and accuracy 61.5% (32/52). On the other hand, NBI close examination yielded a sensitivity of 87.5% (7/8), specificity of 93.2% (41/44), and accuracy of 92.3% (48/52), significantly higher. Conclusion NBI close examination using ultrathin transnasal endoscopy enables mucosal diagnosis even without magnification and was considered to be an effective technique for improving endoscopic diagnosis.

Background and Aims Pancreatic duct guidewire placement (P-GW) techniques include both the injection cannulation technique with a contrast medium and wire-guided cannulation without contrast injection for selective biliary cannulation; the latter is the so-called “double-guidewire technique” (D-GW). The aim of this study was to compare the outcomes between P-GW and D-GW for biliary cannulation. Methods The procedures for biliary cannulation with a naive papilla were performed in a total of 363 cases. We divided the patients chronologically, according to the time period during which the procedures were performed, into two groups: group A, P-GW performed from March 2008 to June 2009; and group B, D-GW performed from July 2009 to December 2010. The success rates and complication rates were evaluated in each group. Results Biliary cannulation was successful in 31 (81.6%) patients in the P-GW group and 34 patients (82.9%) in the D-GW group. The onsets of postendoscopic retrograde cholangiopancreatography pancreatitis (PEP) occurred in the P-GW and D-GW groups were four (10.5%) and three (7.3%) patients, respectively, and all were mild cases (P = 0.616). The frequency of hyperamylasemia and the serum amylase level tended to be lower in the D-GW group than in the P-GW group (P = 0.213). There was a statistically significant difference on the onsets of PEP in the GW and non-GW groups (P = 0.04, 8.9% and 1.1%, respectively). Conclusions Both the D-GW and P-GW techniques were equally effective for difficult biliary cannulation. Furthermore, the complication rates, including PEP, were similar in both techniques. A prospective randomized trial is warranted.

Background and Aim Liver cirrhosis (LC) is accompanied by hepatic arterializations, intrahepatic shunts, and hyperdynamic circulations. These changes shorten the arrival time (AT) of ultrasound contrast agents to the hepatic vein (HV). Whether treatment of gastric fundal varices (GVs) by balloon-occluded transvenous obliteration (B-RTO) improves the AT in LC patients was prospectively investigated. Methods A total of 32 LC patients with GVs and 10 normal controls (NCs) were enrolled. This study was approved by the clinical research ethics committee. Images of hepatic artery (HA), portal vein (PV), and HV were monitored after an injection of a contrast agent using quantification software. The AT before and after B-RTO in LC patients and that in NCs were compared. Results All GVs were treated effectively, and indocyanine green retention rate was improved (P

Background and Aim: Ultrathin transnasal endoscopy, used extensively in Japan, is considered to have inferior image quality and suction performance, and questionable diagnostic performance. So the aim of the present study was to compare the diagnostic performance of white light (WL) examination and non-magnified narrow-band imaging (NBI) examination in screening for esophageal disorders with ultrathin transnasal endoscopy. Methods: A prospective case study of 105 consecutive patients screened for upper gastrointestinal disorders at a single clinic in Tokyo Medical University Hospital. All subjects were diagnosed using WL, NBI and Lugol-staining examinations. Areas ≥ 5 mm clearly not a Lugol-staining lesion were defined as esophageal disorders and the rates of detection of the two examination methods (WL vs NBI) were compared. Results: For WL examination, the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy (concordance rate) for esophageal disorders were 19.6%, 98.1%, 90.9%, 55.4%, and 59.2%, respectively, versus 60.8% 96.2%, 93.9%, 71.4%, and 78.6% for NBI. Conclusion: A useful level of diagnostic performance for esophageal disorders can be achieved with non-magnified narrow-band NBI ultrathin transnasal endoscopy.

Background and Aim: Low-dose aspirin (LDA), and Helicobacter pylori (HP) infection are considered the two primary causes of peptic ulceration. The interaction between HP infection and non-steroidal anti-inflammatory drugs is, however, a matter of considerable discussion and controversy. In this study, we investigated possible synergistic or negative interactions between HP infection and LDA in gastric mucosal lesions, according to lesion site. Methods: The subjects were 120 patients attending the Cardiology Outpatients Department (average age, 67.1 ± 8.9 years; male : female ratio 2.9:1). Endoscopic findings were graded using the Modified Lanza score. Lesions were scored for the antral, body and fundal regions. Ulcers were defined as mucosal defects ≥ 5 mm in size. Results: There were 55 HP-positive and 65 HP-negative subjects, and 91 subjects on LDA therapy. The gastric antral Lanza scores were HP(−) LDA(−): 0.2 ± 1.6, HP(−) LDA(+): 1.8 ± 1.5, HP(+) LDA(−): 0.3 ± 0.7, and HP(+) LDA(+): 0.5 ± 1.0. The gastric body and fundal Lanza scores were 0.0 ± 0.0, 0.8 ± 0.9, 0.4 ± 1.1, and 1.0 ± 1.5, respectively, and 0.1 ± 0.3, 0.5 ± 0.9, 0.1 ± 0.3, and 0.1 ± 0.3, respectively. Variance analysis of the correlation between HP infection and LDA by regional Lanza scores identified both HP infection and LDA use as factors that significantly influence the antral Lanza score. However, LDA was an aggressive factor, and HP infection a protective factor. In the gastric body, LDA was a non-significant, and HP infection a significant, aggressive factor. In the gastric fundus, neither HP infection nor LDA was a significant factor (LDA was an aggressive factor, and HP infection a protective factor). Conclusions: LDA had aggressive effects in all gastric lesions; on the other hand, HP infection had protective effects in the antrum and fundus in the stomach, and aggressive effects in the body in the stomach.

Background and Aims: Helicobacter pylori infection rates are reported to be high in people over the age of 40 years, but are decreasing in younger age groups. A negative correlation has been reported between H. pylori infection and reflux esophagitis (RE). Methods: The subjects were 418 patients who underwent esophagogastroduodenoscopy and measurement of serum immunoglobulin G H. pylori antibodies examined as part of their routine health checks. Their mean age was 39.2 ± 8.3 years (range 22–58). We analyzed the RE findings (Los Angeles classification: A, B, C, D). Results: The total H. pylori infection rate was 33.7% (141/418). By age group, infection rates were 15.7% in the 20–29 years group, 28.0% in the 30–39 group, 34.3% in the 40–49 group and 69.1% in the 50–59 group. The proportion of H. pylori-negative subjects with RE was 23.5% (20–29, 22.9%; 30–39, 31.7%; 40–49, 32.4%; 50–59, 41.7%), significantly higher than that (12.1%) in H. pylori-positive subjects (20–29, 0%; 30–39, 16.7%; 40–49, 12.2%; 50–59, 10.5%). The severity of RE increased with advancing age in H. pylori-positive subjects, but not in H. pylori-negative subjects. Conclusion: In this study, higher rates of RE were seen in H. pylori-negative subjects. It may be, however, that the presence of H. pylori infection influences the progression of RE.

Background: We used transnasal ultrathin esophagogastroduodenoscopy (UT-EGD) to simultaneously perform realtime esophageal manometry and observe esophageal peristalsis. Methods: The subjects were 22 healthy volunteers and 10 patients with proton-pump inhibitor (PPI) dependent gastroesophageal reflux disease (GERD). We induced the primary peristaltic wave associated with swallowing and observed it endoscopically in the lower esophagus, at the same time measuring the intraesophageal pressure using a manometry catheter. Results: The mean primary peristaltic amplitude associated with swallowing was 65.6 ± 47.4 mmHg in the volunteer group, and 28.0 ± 25.6 mmHg in the GERD group. Although peristalsis was observed endoscopically in the GERD group, in some cases incomplete peristalsis left a small but definite lumen and in these subjects, the primary peristaltic wave was almost flat. Conclusions: The use of an ultrathin transnasal endoscope makes possible simultaneous manometry and endoscopic observation of the esophagus. This combination should prove useful in the evaluation of esophageal peristaltic function, such as in the diagnosing of GERD.

Newly developed ultrathin transnasal endoscope, the GIF-XP290N, makes possible a resolving power similar to the GIF-H260 at a distance of 3 mm. We conducted surveillance of subjects with Barrett's esophagus using this ultrathin transnasal endoscopy. In Japan the lower margin of the lower esophageal palisade vessels is defined the gastroesophageal junction in deep inspiration. We diagnose Barrett's esophagus if columnar epithelium is present on the oral side of the gastroesophageal junction.Barrett's esophagus was confirmed in 116 out of 135 subjects (85.9%), with 17 cases of short-segment Barrett's esophagus (SSBE) and 99 of ultra-short-segment Barrett's esophagus. Close observation of the Barrett's esophagus mucosal structural pattern using narrow band imaging revealed 29 cases with an oval or round pattern, 29 with a long straight pattern, 47 with a villous pattern, 8 with a cerebriform pattern, and 6 with an irregular pattern according to Goda classification. Mucosal biopsies from all subjects with SSBE are examined. Histological examination revealed intestinal metaplasia in only eight subjects. We grouped the oval/round and long straight patterns as closed type, and the villous, cerebriform, and irregular patterns as open type. Analysis of the relationship between these mucosal patterns and background factors revealed a significant correlation between intestinal metaplasia and the open-type pattern.We consider this new ultrathin transnasal endoscopy to be a useful technique for surveillance of Barrett's esophagus, especially SSBE.

The new developed ultrathin transnasal endoscope, the GIF-XP290N, makes possible a resolving power similar to the GIF-H260 at a distance of 3 mm. In this study, using the GIF-XP290N, we evaluated whether endoscopic diagnosis (discrimination between benign and malignant) of gastric lesions is possible using nonmagnified narrow-band imaging (NBI) endoscopy.The subjects were 255 consecutive patients who underwent screening of the gastrointestinal tract using new ultrathin transnasal endoscopy. Their average age was 65.2 ± 11.4 years. The male-female ratio was 2.5:1. All cases were examined using conventional white-light imaging (WLI) and nonmagnified NBI. When a depressed lesion was detected in the stomach, it was examined using WLI, then NBI close examination (at about 3 mm). We observed the mucosal structure of the lesion using close visualization with NBI. Concerning mucosal structural changes, we looked for a clear demarcation line between the lesion and the surrounding mucosa, and loss, irregularity, or nonuniformity of the lesion mucosal microsurface pattern.A total of 52 depressed lesions were examined. The histological diagnosis was cancer for 8 lesions, and noncancer for 44 lesions. WLI examination yielded a sensitivity of 50.0% (4/8), specificity of 63.6% (28/44), and accuracy 61.5% (32/52). On the other hand, NBI close examination yielded a sensitivity of 87.5% (7/8), specificity of 93.2% (41/44), and accuracy of 92.3% (48/52), significantly higher.NBI close examination using ultrathin transnasal endoscopy enables mucosal diagnosis even without magnification and was considered to be an effective technique for improving endoscopic diagnosis.

Endoscopic sphincterotomy (ES) combined with large balloon dilation (ESLBD) can be useful for extracting large and multiple bile duct stones. Although there are many studies on the feasibility and short-term outcome, there are few reports about mid- to long-term outcome after ESLBD. The aim of our study is to prospectively evaluate the mid-term outcome of ESLBD.One hundred eighty-three patients who underwent ESLBD between November 2006 and May 2012 were included. The patients were followed up periodically after the procedure until April 2013. Papillary dilation was performed at the time of initial ES or prior ES. Early and late adverse events and stone recurrence were evaluated in this study.The patients' mean age was 76.6 ± 10.7 years. Surgically altered anatomy was present: Billroth I gastrectomy (2), Billroth II gastrectomy (13), and gastrectomy with Roux-en Y reconstruction (18). Seventy-eight (42.6%) patients had periampullary diverticulum. Prior ES had been performed in 40 (21.9%) patients. The mean follow-up period was 43.5 ± 19.7 months (range 11-78). Eight (4.4%) patients had stone recurrence. There was rare stone recurrence after initial ESLBD treatment and native gastrointestinal anatomy. Univariate and multivariate analyses showed that prior ES and previous history of stone recurrence were predictive of stone recurrence (P 0.001).At mid-term outcome, ESLBD is associated with a low rate of recurrent bile duct stones, although long-term follow up is needed.

Pancreatic duct guidewire placement (P-GW) techniques include both the injection cannulation technique with a contrast medium and wire-guided cannulation without contrast injection for selective biliary cannulation; the latter is the so-called "double-guidewire technique" (D-GW). The aim of this study was to compare the outcomes between P-GW and D-GW for biliary cannulation.The procedures for biliary cannulation with a naïve papilla were performed in a total of 363 cases. We divided the patients chronologically, according to the time period during which the procedures were performed, into two groups: group A, P-GW performed from March 2008 to June 2009; and group B, D-GW performed from July 2009 to December 2010. The success rates and complication rates were evaluated in each group.Biliary cannulation was successful in 31 (81.6%) patients in the P-GW group and 34 patients (82.9%) in the D-GW group. The onsets of postendoscopic retrograde cholangiopancreatography pancreatitis (PEP) occurred in the P-GW and D-GW groups were four (10.5%) and three (7.3%) patients, respectively, and all were mild cases (P = 0.616). The frequency of hyperamylasemia and the serum amylase level tended to be lower in the D-GW group than in the P-GW group (P = 0.213). There was a statistically significant difference on the onsets of PEP in the GW and non-GW groups (P = 0.04, 8.9% and 1.1%, respectively).Both the D-GW and P-GW techniques were equally effective for difficult biliary cannulation. Furthermore, the complication rates, including PEP, were similar in both techniques. A prospective randomized trial is warranted.

Liver cirrhosis (LC) is accompanied by hepatic arterializations, intrahepatic shunts, and hyperdynamic circulations. These changes shorten the arrival time (AT) of ultrasound contrast agents to the hepatic vein (HV). Whether treatment of gastric fundal varices (GVs) by balloon-occluded transvenous obliteration (B-RTO) improves the AT in LC patients was prospectively investigated.A total of 32 LC patients with GVs and 10 normal controls (NCs) were enrolled. This study was approved by the clinical research ethics committee. Images of hepatic artery (HA), portal vein (PV), and HV were monitored after an injection of a contrast agent using quantification software. The AT before and after B-RTO in LC patients and that in NCs were compared.All GVs were treated effectively, and indocyanine green retention rate was improved (P 0.0001). The mean values of the HA, PV, and HV ATs in the NCs were 21.9 ± 3.3, 28.2 ± 2.0, and 40.5 ± 2.1 s, respectively. Those in LC patients were 17.4 ± 4.4, 21.9 ± 5.6, and 26.3 ± 6.7, respectively, which were shorter than those in NCs (P 0.01, P 0.002, P 0.0001, respectively). However, these ATs were significantly prolonged 1 week after B-RTO, with mean values of 18.7 ± 4.8, 23.8 ± 6.0, and 30.0 ± 7.2 s (P = 0.043, P 0.01, P 0.001).Obliteration of GVs shifted the AT in LC patients to the normalization, raising the possibility of improvement of arterialization and intrahepatic shunt.

Low-dose aspirin (LDA), and Helicobacter pylori (HP) infection are considered the two primary causes of peptic ulceration. The interaction between HP infection and non-steroidal anti-inflammatory drugs is, however, a matter of considerable discussion and controversy. In this study, we investigated possible synergistic or negative interactions between HP infection and LDA in gastric mucosal lesions, according to lesion site.The subjects were 120 patients attending the Cardiology Outpatients Department (average age, 67.1 ± 8.9 years; male : female ratio 2.9:1). Endoscopic findings were graded using the Modified Lanza score. Lesions were scored for the antral, body and fundal regions. Ulcers were defined as mucosal defects ≥ 5 mm in size.There were 55 HP-positive and 65 HP-negative subjects, and 91 subjects on LDA therapy. The gastric antral Lanza scores were HP(-) LDA(-): 0.2 ± 1.6, HP(-) LDA(+): 1.8 ± 1.5, HP(+) LDA(-): 0.3 ± 0.7, and HP(+) LDA(+): 0.5 ± 1.0. The gastric body and fundal Lanza scores were 0.0 ± 0.0, 0.8 ± 0.9, 0.4 ± 1.1, and 1.0 ± 1.5, respectively, and 0.1 ± 0.3, 0.5 ± 0.9, 0.1 ± 0.3, and 0.1 ± 0.3, respectively. Variance analysis of the correlation between HP infection and LDA by regional Lanza scores identified both HP infection and LDA use as factors that significantly influence the antral Lanza score. However, LDA was an aggressive factor, and HP infection a protective factor. In the gastric body, LDA was a non-significant, and HP infection a significant, aggressive factor. In the gastric fundus, neither HP infection nor LDA was a significant factor (LDA was an aggressive factor, and HP infection a protective factor). LDA had aggressive effects in all gastric lesions; on the other hand, HP infection had protective effects in the antrum and fundus in the stomach, and aggressive effects in the body in the stomach.

Ultrathin transnasal endoscopy, used extensively in Japan, is considered to have inferior image quality and suction performance, and questionable diagnostic performance. So the aim of the present study was to compare the diagnostic performance of white light (WL) examination and non-magnified narrow-band imaging (NBI) examination in screening for esophageal disorders with ultrathin transnasal endoscopy.A prospective case study of 105 consecutive patients screened for upper gastrointestinal disorders at a single clinic in Tokyo Medical University Hospital. All subjects were diagnosed using WL, NBI and Lugol-staining examinations. Areas ≥ 5 mm clearly not a Lugol-staining lesion were defined as esophageal disorders and the rates of detection of the two examination methods (WL vs NBI) were compared.For WL examination, the sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy (concordance rate) for esophageal disorders were 19.6%, 98.1%, 90.9%, 55.4%, and 59.2%, respectively, versus 60.8% 96.2%, 93.9%, 71.4%, and 78.6% for NBI.A useful level of diagnostic performance for esophageal disorders can be achieved with non-magnified narrow-band NBI ultrathin transnasal endoscopy.

Background and Aim: Helicobacter pylori (H. pylori) eradication rates using the PPI/AC regimen (proton pump inhibitor + amoxicillin + clarithromycin) are declining. We trialed tailoring eradication regimens according to clarithromycin (CAM) susceptibility. Methods: The subjects were 70 H. pylori positive adults. They were randomly allocated to a tailored group and a control group. In the tailored group, subjects with CAM-sensitive strains were given PPI/AC eradication therapy, and those with CAM-resistant strains were given PPI/AM (metronidazole instead of clarithromycin) therapy. The control group were all given PPI/AC therapy. CAM sensitivity was measured by collecting fecal specimens, and extracting the DNA. The 23S rRNA domain, associated with CAM susceptibility in H. pylori, was amplified using a nested polymerase chain reaction (PCR), and DNA sequencing was used to detect point mutations at A2143G and A2144G. Results: Eradication rates were 94.3% in the tailored group and 71.4% in the control group. In particular, the eradication rate was 100% for CAM-resistant strains in the tailored group. Conclusions: In Japan, where CAM-resistant H. pylori strains are expected to continue to increase, tailored eradication therapy according to CAM sensitivity will be of benefit.

BACKGROUND: The amount of glucocorticoid (GC) receptors (GR) in immune cells might be critical for successful GC treatment of patients with Crohn's disease (CD). However, little is known about the expression of GR in CD; therefore, we carried out quantitative analyses for GR messenger (m)RNA expression in peripheral-blood mononuclear cells (PBMC) of CD. METHODS: Seventeen patients with CD and 33 healthy subjects entered into this study. We measured the GRalpha mRNA level in the PBMC of these subjects by a reverse transcription-competitive polymerase chain reaction procedure. Relative amounts for GRbeta mRNA were obtained semiquantitatively. RESULTS: The amounts of GRalpha-mRNA in the CD patients and healthy subjects were 0.053 +/- 0.052 and 0.130 +/- 0.108 (copies/copies of beta-actin mRNA), respectively. The former value was significantly lower than that of the latter (P < 0.01). The rates of the CD patients and healthy subjects expressing GRbeta-mRNA in PBMC were 41.2% and 45.5%, respectively, and there was no significant difference in the rates between the two groups (P = 0.339). However, the relative amounts of GRbeta-mRNA in the PBMC were estimated to be 1.053 x 10-5 +/- 2.540 x 10-5 for the CD patients, and 1.872 x 10-5 +/- 3.252 x 10-5 (fluorescence intensity/copies of beta-actin mRNA) for the healthy subjects, and the former was significantly smaller than the latter (P < 0.05). Moreover, there was an inverse correlation between the duration of disease (year) and the amounts of GRalpha-mRNA in the PBMC of the CD patients (P < 0.05). CONCLUSIONS: The amounts of GRalpha-mRNA and GRbeta-mRNA in the PBMC of the CD patients were lower than those of the healthy subjects. The duration of disease correlated with decreased amounts of GRalpha-mRNA in the PBMC. Furthermore, the clinical significance of the GR-mRNA status in the PBMC remains to be elucidated.

Backgorund: The renewal rates of parietal and chief cells in the gastric mucosa and smooth muscle cells of muscularis propria have not been examined as precisely as superficial epithelial cells. To examine cell renewal of these cells, continuous labeling with tritiated ([3H])-thymidine was performed. Methods: Mice received 112 repeated injections of [3H]-thymidine at 6-hour intervals for 28 days after birth and were killed immediately thereafter, or 60, 120, 200 or 300 days after the last injection. Results: After continuous labeling, most cells in the stomach were labeled. At 60 days, unlabeled parietal cells in the neck area of the gland and unlabeled chief cells in the middle part of the gland appeared. Thereafter, the area of unlabeled cells expanded downwards to the bottom of the gland. Times required for labeling of total cell populations of parietal and chief cells to half were less than 60 days and more than 200 days, respectively. At 300 days, most parietal cells and about half of the chief cells remained labeled in the bottom of the gland. The labeling index of smooth muscle cells was about 100% for 300 days. Conclusions: The time required for the newly formed parietal and chief cells to reach the lower end of the gland was more than 300 days. As a total cell population, the renewal rate of parietal cells was more rapid than that of chief cells. However, in terms of the downward migrating cell population, the renewal rate of parietal cells was a little slower than that of chief cells. Smooth muscle cells showed almost no renewal. © 2002 Blackwell Science Asia Pty Ltd