Discovery of ONO-8590580: A novel, potent and selective GABAA α5 negative allosteric modulator for the treatment of cognitive disorders.

The identification and SAR development of a series of negative allosteric modulators of the GABAA α5 receptor is described. This novel series of compounds was optimised to provide analogues with high GABAA α5 binding affinity, high α5 negative allosteric modulatory activity, good functional subtype selectivity and low microsomal turnover, culminating in identification of ONO-8590580.

Proton pump inhibitor after endoscopic resection for esophageal squamous cell cancer: multicenter prospective randomized controlled trial.

BACKGROUND: Whether proton pump inhibitors (PPIs) relieve heartburn or precordial pain after endoscopic resection (ER) for esophageal squamous cell carcinoma (ESCC) remains unclear. The aim of this study was to investigate the efficacy of PPI therapy for these symptoms after ER for ESCC. METHODS: We conducted a multicenter prospective randomized controlled trial among 15 hospitals in Japan. In total, 229 patients with cT1a ESCC were randomly assigned to receive PPI therapy for 5 weeks after ER (the PPI group, n = 115) or follow-up without PPI therapy (the non-PPI group, n = 114). The primary end point was the incidence of gastroesophageal reflux disease (GERD)-like symptoms after ER from a self-reported questionnaire (Frequency Scale for Symptoms of GERD). Secondary end points were ulcer healing rate at 5 weeks, incidence of pain, improvement rate of symptoms in those who started PPI therapy because of GERD-like symptoms in the non-PPI group, and adverse events. RESULTS: No significant difference was observed in the incidence of GERD-like symptoms after ER between the non-PPI and PPI groups (30 % vs 34 %, respectively). No significant differences were observed in the ulcer healing rate at 5 weeks (84 % vs 85 %) and incidence of pain within 1 week (36 % vs 45 %). In nine of ten patients (90 %) who started PPI therapy because of GERD-like symptoms in the non-PPI group, PPI administration relieved GERD-like symptoms. No adverse events related to PPI administration were observed. CONCLUSION: PPI therapy is not efficacious in reducing symptoms and did not promote healing of ulcers in patients undergoing ER for ESCC.

Low programmed cell death-1 (PD-1) expression in peripheral CD4(+) T cells in Japanese patients with autoimmune type 1 diabetes.

Programmed cell death-1 (PD-1) is a co-stimulatory molecule that inhibits T cell proliferation. We aimed to clarify PD-1 expression in CD4(+) T cells and the association between PD-1 expression and the 7785C/T polymorphism of PDCD1, with a focus on the two subtypes of type 1 diabetes, type 1A diabetes (T1AD) and fulminant type 1 diabetes (FT1D), in the Japanese population. We examined 22 patients with T1AD, 15 with FT1D, 19 with type 2 diabetes (T2D) and 29 healthy control (HC) subjects. Fluorescence-activated cell sorting (FACS) and real-time PCR were utilized to analyse PD-1 expression quantitatively. Genotyping of 7785C/T in PDCD1 was performed using the TaqMan method in a total of 63 subjects (21 with T1AD, 15 with FT1D and 27 HC). FACS revealed a significant reduction in PD-1 expression in CD4(+) T cells in patients with T1AD (mean: 4.2 vs. 6.0% in FT1D, P=0.0450; vs. 5.8% in T2D, P=0.0098; vs. 6.0% in HC, P=0.0018). PD-1 mRNA expression in CD4(+) T cells was also significantly lower in patients with T1AD than in the HC subjects. Of the 63 subjects, PD-1 expression was significantly lower in individuals with the 7785C/C genotype than in those with the C/T and T/T genotypes (mean: 4.1 vs. 5.9%, P=0.0016). Our results indicate that lower PD-1 expression in CD4(+) T-cells might contribute to the development of T1AD through T cell activation.

CD4⁺ CD45RA⁻ FoxP3high activated regulatory T cells are functionally impaired and related to residual insulin-secreting capacity in patients with type 1 diabetes.

Accumulating lines of evidence have suggested that regulatory T cells (T(regs)) play a central role in T cell-mediated immune response and the development of type 1A and fulminant type 1 diabetes. CD4(+) forkhead box protein 3 (FoxP3)(+) T cells are composed of three phenotypically and functionally distinct subpopulations; CD45RA(+) FoxP3(low) resting T(regs) (r-T(regs)), CD45RA(-) FoxP3(high) activated T(regs) (a-T(regs)) and CD45RA(-) FoxP3(low) non-suppressive T cells (non-T(regs)). We aimed to clarify the frequency of these three subpopulations in CD4(+) FoxP3(+) T cells and the function of a-T(regs) with reference to subtypes of type 1 diabetes. We examined 20 patients with type 1A diabetes, 15 patients with fulminant type 1 diabetes, 20 patients with type 2 diabetes and 30 healthy control subjects. A flow cytometric analysis in the peripheral blood was performed for the frequency analysis. The suppressive function of a-T(regs) was assessed by their ability to suppress the proliferation of responder cells in a 1/2:1 co-culture. A flow cytometric analysis in the peripheral blood demonstrated that the frequency of a-T(regs) was significantly higher in type 1A diabetes, but not in fulminant type 1 diabetes, than the controls. Further, the proportion of a-T(regs) among CD4(+) FoxP3(+) T cells was significantly higher in patients with type 1A diabetes with detectable C-peptide but not in patients with type 1A diabetes without it and with fulminant type 1 diabetes. A proliferation suppression assay showed that a-T(regs) were functionally impaired both in fulminant type 1 diabetes and in type 1A diabetes. In conclusion, a-T(regs) were functionally impaired, related to residual insulin-secreting capacity and may be associated with the development of type 1 diabetes.

Predominance of ß-cell neogenesis rather than replication in humans with an impaired glucose tolerance and newly diagnosed diabetes.

CONTEXT: A decrease in pancreatic ß-cell mass is involved in the development of type 2 diabetes. OBJECTIVE: The purpose of this study was to evaluate the ß-cell mass and the incidence of ß-cell neogenesis, replication, and apoptosis at both the prediabetic and diabetic stages. METHODS: We conducted a cross-sectional study of pancreatic tissues obtained from 42 patients undergoing a pancreatectomy who were classified into 4 groups: normal glucose tolerance (n = 11), impaired glucose tolerance (n = 11), newly diagnosed diabetes (n = 10), and long-standing type 2 diabetes (n = 10). RESULTS: The relative ß-cell area decreased and the ß-cell apoptosis increased during the development of diabetes. The number of single and clustered ß-cells, some of which coexpressed nestin, increased in the patients with impaired glucose tolerance and newly diagnosed diabetes. The prevalence of cells positive for both insulin and glucagon or somatostatin also increased in these patients compared with those with normal glucose tolerance. These double-positive cells were mainly localized in single and clustered ß-cells, rather than large islets, and were also positive for Pdx1 or Ngn3. The percentage of insulin-positive cells embedded within ducts increased in the impaired glucose tolerance group. There were no significant differences in the incidence of cells positive for both insulin and Ki67 among the groups. CONCLUSIONS: These results suggest that ß-cell neogenesis, rather than replication, predominates during impaired glucose tolerance and newly diagnosed diabetes in humans and may serve as a compensatory mechanism for the decreased ß-cell mass.

Negative predictors of clinical response to triptans in patients with migraine.

Moderate to severe migraine attacks are treated with triptans. However, about 25% of migraineurs fail to respond to triptans. We investigated the involvement of gene polymorphisms, personality traits and characteristics of headache, and made a scoring system for prediction of clinical response to triptans in patients with migraine. Gene polymorphisms including serotonin (5-HT)(1B) receptor G861C and dopamine receptor 2 (DRD2) C939T, personality traits and characteristics of headache were investigated in 46 consistent responders and 14 inconsistent responders to triptans. The multivariate stepwise logistic regression analysis revealed that age, periorbital/deep orbital pain and C/C genotype carrier at DRD2 C939T were significant factors that contributed independently to the negative response to triptans in patients with migraine. Their odds ratios were 6.329 (40-69 vs. 20-39 years, 95% CI 1.441-27.778), 6.772 (no vs. yes, periorbital/deep orbital pain, 95% CI 1.159-39.580) and 14.085 (non-C/C vs. C/C genotype at DRD2 C939T, 95% CI 1.253-166.667), respectively. The predictive index (PI) of clinical response to triptans in patients with migraine was calculated using these three factors. The score in inconsistent responders (1.6 ± 0.6) was significantly higher than that in consistent responders (0.8 ± 0.7, P < 0.001). Sensibility of low-score (RI = 0) group was 100%, and specificity of high-score (PI ≥ 2) group was 87%. The proposed scoring system should in the future be the object of larger studies to confirm its validity.

Measurement of adiponectin production from differentiated metabolic stem cells.

To treat metabolic syndrome, fat tissue dysfunction should be corrected rather than controlling conventional risk factors such as hypertension, dyslipidemia, and diabetes mellitus. For this purpose, accumulating evidence suggests increasing plasma adiponectin levels can be a key treatment strategy, especially in setting of food or drug selection. Here we report that adipocyte precursors obtained from several sites of fat tissue, which we call Metabolic Stem Cells (MSC), could be used as a novel screening system to identify adiponectin enhancing drugs or food for individual patients. MSC were prepared from fat tissues collected from 29 patients. They were differentiated in cultures into mature adipocytes. The time course of adiponectin production was independent of the number of mature adipocytes and gradually decreased at 48 h after differentiation. Pioglitazone, a full PPARgamma agonist, stabilized adiponectin production at days 8-16 after differentiation, whereas telmisartan, a partial PPARgamma agonist, showed variable response. Dividing the adiponectin secretion of day 12 by that of day 10 provided an estimate of adiponectin-producing activity irrespective of the number of MSC-derived adipocytes in culture. Using this score of adiponectin-production activity, we successfully assessed 16 agents in a 96-well plate. The effect of each agent on adiponectin production showed a similar pattern, independent of the site of isolated adipose tissue. Our results show that MSC can be used as a tool for selecting drugs that enhance adiponectin-production activity.

Differential association of HLA with three subtypes of type 1 diabetes: fulminant, slowly progressive and acute-onset.

AIM/HYPOTHESIS: We sought to clarify similarities and differences in the contribution of HLA to genetic susceptibility to three subtypes of type 1 diabetes: acute-onset, fulminant and slowly progressive. METHODS: We genotyped 545 Japanese patients with type 1 diabetes (338 acute-onset, 80 fulminant, 127 slowly progressive) and 396 control participants at HLA-DRB1, -DQB1, -A, -B and -C, and at 101 candidate single nucleotide polymorphisms (SNPs) in an 8.5 Mb region of the extended HLA. RESULTS: DRB1*0405-DQB1*0401, DRB1*0802-DQB1*0302 and DRB1*0901-DQB1*0303 were associated with acute-onset type 1 diabetes, with the DRB1*0405-DQB1*0401/DRB1*0802-DQB1*0302 genotype achieving the highest odds ratio of 42.7. DRB1*1501-DQB1*0602 and DRB1*1502-DQB1*0601 were negatively associated with acute-onset type 1 diabetes. A similar tendency was observed for slowly progressive type 1 diabetes. In contrast, only DRB1*0405-DQB1*0401 was associated with fulminant type 1 diabetes, with the DRB1*0405-DQB1*0401/DRB1*0405-DQB1*0401 genotype showing the highest odds ratio of 11.2. DRB1*0802-DQB1*0302, DRB1*0405-DQB1*0401/DRB1*0802-DQB1*0302 and DRB1*1501-DQB1*0602 were not associated with fulminant type 1 diabetes. The association of class I alleles and a panel of SNPs in an extended HLA region with fulminant type 1 diabetes was also different from that seen for the acute-onset and slowly progressive forms. The presence of both one and two susceptible haplotypes conferred susceptibility to slowly progressive type 1 diabetes, whereas the presence of two susceptible haplotypes was required to confer susceptibility to acute-onset and fulminant type 1 diabetes. CONCLUSIONS/INTERPRETATION: These data suggest that HLA associations with fulminant type 1 diabetes are qualitatively different from those with other subtypes of type 1 diabetes, whereas the HLA contribution to slowly progressive type 1 diabetes is qualitatively similar to, but quantitatively different from, that in acute-onset type 1 diabetes.

Satisfaction with bispectral index monitoring of propofol-mediated sedation during endoscopic submucosal dissection: a prospective, randomized study.

BACKGROUND AND STUDY AIMS: Endoscopic submucosal dissection (ESD) is one of the most complex and lengthy endoscopic procedures, so deep sedation during ESD is indispensable. Our study aims were to determine whether bispectral index (BIS) monitoring is useful in titrating and reducing the dose of the sedative propofol during ESD, and to measure the satisfaction of patients and endoscopists involved in this complex and lengthy endoscopic therapy. PATIENTS AND METHODS: We performed a prospective, randomized clinical trial from July 2006 to February 2008. A total of 156 patients, with gastric neoplasm to be treated using ESD, were randomized to two groups. The BIS group (n = 78) was monitored for propofol sedation using BIS, and the no-BIS group (n = 78) was monitored by standard methods only. The two groups were compared by evaluating the doses of propofol administered to patients and the satisfaction scores (scale of 0 - 10) of patients and endoscopists. RESULTS: Although there were no significant differences between the two groups in the mean dose of propofol used (BIS group vs. no-BIS group, 5.32 mg/kg/hour vs. 4.85 mg/kg/hour; P = 0.10), the satisfaction scores of the patients (9.15 vs. 7.94; P < 0.01) and endoscopists (8.53 vs. 6.42; P < 0.001) were significantly higher with BIS monitoring. CONCLUSIONS: Monitoring with BIS during the ESD procedure did not lead to a reduction in the dose of propofol required, but did lead to higher satisfaction scores from the patients and endoscopists. A complicated and prolonged endoscopic treatment such as ESD can be carried out with optimal safety, control, and comfort by using BIS to monitor propofol sedation.

Fulminant type 1 diabetes as a model of nature to explore the role of C-peptide.

Patients with fulminant type 1 diabetes almost completely lack C-peptide even soon after the onset of the disease, and the deficiency continues for the rest of their life. Thus, fulminant type 1 diabetes could serve as a good model of nature to explore the physiological role of C-peptide. For example, patients with fulminant type 1 diabetes have diabetic chronic complications more frequently than those with classical autoimmune type 1 diabetes 5 years after the onset of diabetes, and the higher prevalence could be partly attributable to the complete lack of C-peptide in fulminant type 1 diabetes.

Helicobacter pylori eradication reduced the incidence of gastric cancer, especially of the intestinal type.

BACKGROUND: Although Helicobacter pylori infection is closely associated with gastric cancer development, follow-up studies after H. pylori eradication are still scarce. AIM: To clarify the cancer preventive effect of H. pylori eradication, with special attention to differences in effect according to histology. METHODS: Patients who underwent H. pylori eradication therapy and were followed-up endoscopically for at least 1 year were analysed. The incidence of gastric cancer and factors associated with cancer development were investigated. RESULTS: A total of 1807 patients were enrolled. Six of 1519 H. pylori eradicated and five of 288 persistent subjects developed gastric cancer. Four of the eradicated subjects developed the intestinal type and two the diffuse type, while four of the persistent subjects developed the intestinal type and one the diffuse type. Kaplan-Meier analysis indicated a significantly lower incidence in eradicated patients than in persistent patients. The incidence of intestinal type was significantly lower than in eradicated patients, while the diffuse type could not be evaluated because of the low incidence. CONCLUSIONS: Helicobacter pylori-eradicated patients had a reduced incidence of gastric cancer compared with H. pylori-persistent patients, particularly the intestinal type, suggesting that H. pylori is strongly associated with intestinal-type gastric cancer.

Fulminant type 1 diabetes as a high risk group for diabetic microangiopathy--a nationwide 5-year-study in Japan.

AIMS/HYPOTHESIS: The aim of the present study was to assess the development of microangiopathy in patients with fulminant type 1 diabetes, a novel subtype of type 1B diabetes. MATERIALS AND METHODS: In a nationwide survey, we followed 41 patients with fulminant type 1 diabetes and 76 age- and sex-matched patients with type 1A diabetes for 5 years. The following data were recorded every 12 months after the onset of diabetes: seven-point blood glucose concentrations, HbA1c level, urinary albumin excretion, serum C-peptide level, blood pressure, daily dosages of insulin, frequency of severe hypoglycaemic episodes, and neurological and fundoscopic examination. RESULTS: The 5-year cumulative incidence of microangiopathy was 24.4% in fulminant type 1 diabetes and 2.6% in type 1A diabetes. In longitudinal studies using the Kaplan-Meier method, the cumulative incidence of each form of microangiopathy was significantly higher in fulminant type 1 diabetes than in type 1A diabetes; retinopathy was 9.8% vs 0% (p=0.014), nephropathy 12.2% vs 2.6% (p=0.015) and neuropathy 12.2% vs 1.3% (p=0.010), respectively. Mean HbA1c levels were similar in the fulminant and type 1A diabetes groups during the follow-up periods. However, the mean M-value, mean insulin dosages and the frequency of severe hypoglycaemic episodes were significantly higher, and the mean postprandial C-peptide level was significantly lower in the fulminant type 1 diabetes group. CONCLUSIONS/INTERPRETATION: These data suggest that patients with fulminant type 1 diabetes are a high-risk subgroup for diabetic microangiopathy associated with the lack of endogenous insulin secretion from the onset of diabetes.

Macrophages and dendritic cells infiltrating islets with or without beta cells produce tumour necrosis factor-alpha in patients with recent-onset type 1 diabetes.

AIMS/HYPOTHESIS: Type 1A diabetes results from autoimmune destruction of pancreatic beta cells. We examined the involvement of TNF-alpha and IL-1beta, as well as of T cells, macrophages and dendritic cells, in the destruction of beta cells in patients with recent-onset type 1 diabetes. MATERIALS AND METHODS: We obtained pancreatic biopsy specimens from six patients with recent-onset type 1 diabetes and analysed these by immunohistochemistry. RESULTS: T cell infiltration was less common in islets without beta cells (12.5 [0-33.3]%) than in those with beta cells (46.0 [17.4-83.3]%), while macrophages and dendritic cells showed a similar extent of infiltration into islets both with or without beta cells. TNF-alpha was detected in 25.0 (4.3-46.9)% of macrophages and 11.8 (0-40.0)% of dendritic cells infiltrating the islets in samples from each patient, but not at all in T cells. IL-1beta was detected in 1.8 (0-11.3)% of T cells infiltrating the islets with beta cells, while it was found in 19.2 (0-35.3)% of macrophages or 10.7 (0-31.3)% of dendritic cells infiltrating the islets in samples from each patient (all values median [range]). CONCLUSIONS/INTERPRETATION: Macrophages and dendritic cells infiltrate the islets and produce inflammatory cytokines (TNF-alpha and IL-1beta) during the development of type 1A diabetes.

Two cases of subacute thyroiditis presenting in pregnancy.

Subacute thyroiditis (SAT) is an extremely rare cause of thyrotoxicosis in pregnant women. Untreated, thyrotoxicosis may result in complications, such as prematurity and congenital malformations in the fetus. We report two cases of first trimester subacute thyroiditis, one mild and one severe. The severe case, as demonstrated by laboratory and ultrasound findings, was successfully treated with prednisolone. In this case, it was thought that the benefits of pharmacological therapy outweighed the risk of potential teratogenesis by the medication. In contrast, the milder case was managed conservatively and resolved without treatment. These cases illustrate how laboratory and ultrasound findings can be used to determine whether treatment should be initiated and, once begun, if medication levels need to be adjusted. In both cases, the pregnancies resulted in healthy full-term infants.

Endoscopic submucosal dissection for early gastric cancer: results and degrees of technical difficulty as well as success.

BACKGROUND AND STUDY AIMS: Endoscopic submucosal dissection (ESD) is a new method for the curative treatment of early gastrointestinal neoplasms, which was developed in order to increase the en bloc and R0 resection rate, especially for lesions larger than 20 mm in diameter. Drawbacks of ESD include the fact that it is technically a substantially more difficult procedure and that it is associated with a higher perforation rate. A retrospective study was therefore carried out to analyze cases in relation to the procedure time and resection success, and these factors were correlated with the characteristics of the lesions. PATIENTS AND METHODS: From January 2002 to November 2005, 196 lesions in 185 patients with early gastric cancer were treated using ESD in our hospital. The rates of curative en bloc resection, the incidence of perforation, and the procedure times were analyzed in relation to lesion size (small, 20 mm or less in diameter; large, over 20 mm), location (upper, middle, or lower third of the stomach) and the presence or absence of ulceration. RESULTS: The rate of curative en bloc resection was 84 % (93 % of the lesions overall were resected in one piece), with a perforation rate of 6.1 % (all perforations were managed endoscopically) and a mean procedure time of 68 min. The rate of curative en bloc resection differed significantly depending on the location of the lesion (upper vs. middle vs. lower, 74 % vs. 77 % vs. 91 %; P < 0.05), as well as on the size of the lesion (> 20 mm vs. 20 mm or less, 59 % vs. 89 %; P < 0.0001). There were also significant differences in the mean procedure times in relation to the location of the lesion (upper vs. middle vs. lower, 105 min vs. 81 min vs. 45 min; P < 0.0001) and the size of the lesion (> 20 mm vs. 20 mm or less, 124 min vs. 55 min; P < 0.0001), as well as the presence of ulceration (positive vs. negative, 97 min vs. 65 min; P < 0.05). With regard to perforation rates, significant differences were also observed in relation to the location of the lesion (upper vs. middle vs. lower, 22.6 % vs. 2.8 % vs. 3.2 %; P < 0.0005) and size of the lesion (> 20 mm vs. 20 mm or less, 16.2 % vs. 3.8 %; P < 0.005). No local recurrences of curatively resected lesions (n = 119) were observed after a follow-up period of 1 year. CONCLUSIONS: The difficulty of ESD depends on the location and size of the lesion, as well as on the presence of ulceration. We would recommend that trainees should begin by carrying out ESD on lesions with a diameter of less than 20 mm without ulceration that are located in the lower third of the stomach.

Treatment of post-dialytic orthostatic hypotension with an inflatable abdominal band in hemodialysis patients.

The purpose of this study was to ascertain whether abdominal compression with an inflatable abdominal band, a device we developed, improved post-dialytic orthostatic hypotension (OH) in hemodialysis (HD) patients. Twenty-five chronic HD patients with intractable post-dialytic OH were recruited. Post-HD changes in systolic blood pressure (DeltaSBP) in the supine and standing positions were compared in the patients, measured with or without the use of the band. The study showed DeltaSBP after HD without the band was significantly greater than that measured before HD (-36.1+/-18.2 vs -13.1+/-16.8 mm Hg; P<0.0001). DeltaSBP after HD with the band was reduced significantly in comparison to DeltaSBP after HD without the band (-19.4+/-21.2 vs -36.1+/-18.2 mm Hg; P<0.002). Use of the band did not cause an elevation in SBP in the supine position (149.0+/-29.6 vs 155.4+/-25.7 mm Hg); however, it did increase SBP upon standing (129.6+/-27.3 vs 117.2+/-22.6 mm Hg; P<0.05). Eight patients in whom an increase in SBP of 25 mm Hg or more was achieved with the band were classified as responders. Ejection fraction was significantly higher (76.4+/-11.1 vs 61.9+/-13.6%; P<0.02) and atrial natriuretic peptide concentration significantly lower (27.9+/-22.0 vs 68.9+/-47.5 pg/ml; P<0.02) in responders than in non-responders. We conclude that the abdominal band was effective for overcoming post-dialytic OH, without elevating supine SBP in some patients.

Restriction of dietary Iodine does not ameliorate the early effect of anti-thyroid drug therapy for Graves' disease in an area of excessive iodine intake.

The close relationship between iodine intake and the effects of anti-thyroid drugs (ATD) for Graves' disease (GD) has been well established. However, it remains unknown whether restriction of dietary iodine improves the effect of ATD. This study aimed to clarify this issue in Japanese patients with GD who routinely ingest large amounts of dietary iodine. We performed a prospective clinical study in 81 patients with newly diagnosed GD who were divided into an iodine restricted group and a control group. Urinary iodine, thyroid hormones and TSH receptor antibody were measured during the first 8 weeks of ATD therapy. Urinary iodine concentrations in the iodine restricted group were significantly lower than in the control group (p=0.043). However, there were no significant differences in the decrease of thyroid hormones and TSH receptor antibody between the two groups. Restriction of dietary iodine does not ameliorate the effect of ATD therapy for GD in an area of excessive iodine intake.

Histopathologic characteristics of gastric ulcers created by endoscopic submucosal dissection.

BACKGROUND AND STUDY AIM: We have previously reported that gastric ulcers artificially created by endoscopic submucosal dissection (ESD) would heal within 8 weeks regardless of size and location. The details of the healing process remain unclear, and we aimed to clarify the mechanism by histopathological investigation. PATIENTS AND METHODS: 21 post-ESD ulcers were examined histopathologically, using surgically resected specimens from patients who had subsequently undergone gastrectomy due to submucosal invasion and/or lymphovascular infiltration by the tumor. The grade of ulcer, appearance of regenerative mucosa, scar formation, and extent of fibrosis were evaluated. RESULTS: Fibrosis and wall thickening were observed from 2 weeks after ESD, but regenerative mucosa was not observed until 5 weeks. Among 12 patients who underwent gastrectomy later than 8 weeks after ESD, a mucosal defect was still observed in two patients. In these two patients the lesion was associated with severe fibrosis due to previous peptic ulcer or submucosal invasion by the lesion. CONCLUSION: Size reduction in these ulcers occurs by contraction in the early phase, then regenerative mucosa covers the remaining mucosal defect within 8 weeks. If there is fibrosis under the lesion before ESD, there is a possibility that the artificially created ulcer will not heal within 8 weeks.