Exploratory investigation of virtual lesions in gastrointestinal endoscopy using a novel phase-shift method for three-dimensional shape measurement.

Accurate measurement of the size of lesions or distances between any two points during endoscopic examination of the gastrointestinal tract is difficult owing to the fisheye lens used in endoscopy. To overcome this issue, we developed a phase-shift method to measure three-dimensional (3D) data on a curved surface, which we present herein. Our system allows the creation of 3D shapes on a curved surface by the phase-shift method using a stripe pattern projected from a small projecting device to an object. For evaluation, 88 measurement points were inserted in porcine stomach tissue, attached to a half-pipe jig, with an inner radius of 21 mm. The accuracy and precision of the measurement data for our shape measurement system were compared with the data obtained using an Olympus STM6 measurement microscope. The accuracy of the path length of a simulated protruded lesion was evaluated using a plaster model of the curved stomach and graph paper. The difference in height measures between the measurement microscope and measurement system data was 0.24 mm for the 88 measurement points on the curved surface of the porcine stomach. The error in the path length measurement for a lesion on an underlying curved surface was <1% for a 10-mm lesion. The software was developed for the automated calculation of the major and minor diameters of each lesion. The accuracy of our measurement system could improve the accuracy of determining the size of lesions, whether protruded or depressed, regardless of the curvature of the underlying surface.

Examination of 93 cases of perianal warts and suggestion of a new classification.

PURPOSE: The anatomical distribution of perianal warts is associated with patient characteristics such as sexual orientation. The purpose of this study is to confirm this experiential knowledge using a quantitative classification system and analysis and to obtain findings useful for future treatment. METHODS: From January 2014 to December 2020, 93 patients with perianal warts presented to our hospital. Patients were analyzed for age, sex, lesion site, and recurrence type, among other factors. The lesion site was divided into skin (S) and anal epithelium (anoderm, A), and the number and degree of each were classified into grades 0 to 3. The higher grade between S and A determines its dominant type, such as type S (e.g., S3A1) and type A (e.g., S0A2). RESULTS: The average age of the patients was 39.6 years, and the percentage of patients who were not married was 54.8%. In all, 95.8% of patients were positive for low-risk human papillomavirus (HPV). Type S accounted for 80.6%, whereas type A accounted for 9.7%. Type A cases were all male and were all presumed to be men who have sex with men (MSM). This indicates that the determination of type A may be highly specific for MSM. The type at the time of recurrence was the same type at the time of the first surgery in almost all cases. CONCLUSION: In cases of perianal warts, it is useful to analyze the lesion by considering the range and grade separately for daily clinical practice on proctologist.

Dietary protein restriction increases hepatic leptin receptor mRNA and plasma soluble leptin receptor in male rodents.

Leptin is an adipokine that regulates adipose tissue mass through membrane-anchored leptin receptor (Ob-R). Extracellular domain of Ob-R in plasma is called soluble leptin receptor (sOb-R), and is the main leptin-binding protein. Based on a previous DNA microarray analysis that showed induction of hepatic Ob-R mRNA in low-protein diet-fed mice, this study aimed to clarify the effect of dietary protein restriction on hepatic Ob-R mRNA and plasma sOb-R levels. First, the effect of protein restriction on hepatic Ob-R mRNA level was examined together with fasting and food restriction using male rats as common experimental model for nutritional research. Hepatic Ob-R mRNA level was increased by feeding low-protein diet for 7 d, although not significantly influenced by 12-h fasting and sixty percent restriction in food consumption. Then, effect of protein restriction on liver Ob-R and plasma sOb-R was investigated using male mice because specific sOb-R ELISA was more available for mice. Hepatic Ob-R mRNA level was also increased in protein restricted-mice although it did not increase in hypothalamus. Hepatic Ob-R protein was decreased, whereas plasma sOb-R was increased by protein restriction. Because the concentration of sOb-R increased without changing plasma leptin concentration, free leptin in plasma was significantly reduced. The direct effect of amino acid deprivation on Ob-R mRNA level was not observed in rat hepatoma cells H4IIE cultured in amino acid deprived medium. In conclusion, dietary protein restriction increased hepatic Ob-R mRNA, resulting in increased plasma sOb-R concentration, which in turn, reduces plasma free leptin level and may modulate leptin activity.

Effect of dietary vitamin E on oxidative stress-related gene-mediated differences in anxiety-like behavior in inbred strains of mice.

It has been reported that the degree of anxiety-like behavior differs between inbred strains of mice, and that this phenomenon was linked to the expression levels of the oxidative stress-related genes glyoxalase 1 (Glo1) and glutathione reductase 1 (Gsr) in the brain. Therefore, we investigated whether antioxidative activity in the brain affects the Glo1 and Gsr mRNA expressions and strain-dependent anxiety-like behavior using mice fed different amounts of vitamin E. First, we measured brain Glo1 and Gsr mRNA levels and evaluated the anxiety-like behaviors presented by C57BL/6J (B6) and DBA/2C (D2) mice. We demonstrated that D2 mice presented both significantly elevated Glo1 and Gsr mRNA levels as well as more prominent anxiety-like behavior in elevated plus-maze and open field tests. Next, we fed mice from these two strains either a control, vitamin E-free, or vitamin E-supplemented diet for four weeks. Plasma, liver, and brain α-tocopherol concentrations changed in a dose-dependent manner. However, neither brain Glo1 and Gsr mRNA levels nor anxiety-like behavior were affected by dietary vitamin E intake. These results demonstrated that while strain-dependent anxiety-like behavior in mice was related to oxidative stress-related gene expression, the regulatory mechanisms for these genes and anxiety-like behaviors were independent of antioxidative activity in the brain. Strain-dependent differences of the anxiety in mice are probably related to the anxiolytic effects of methylglyoxal, a substrate for Glo1 and Gsr.

Application of convolutional neural networks for evaluating Helicobacter pylori infection status on the basis of endoscopic images.

BACKGROUND AND AIM: We recently reported the role of artificial intelligence in the diagnosis of Helicobacter pylori (H. pylori) gastritis on the basis of endoscopic images. However, that study included only H. pylori-positive and -negative patients, excluding patients after H. pylori-eradication. In this study, we constructed a convolutional neural network (CNN) and evaluated its ability to ascertain all H. pylori infection statuses. METHODS: A deep CNN was pre-trained and fine-tuned on a dataset of 98,564 endoscopic images from 5236 patients (742 H. pylori-positive, 3649 -negative, and 845 -eradicated). A separate test data set (23,699 images from 847 patients; 70 positive, 493 negative, and 284 eradicated) was evaluated by the CNN. RESULTS: The trained CNN outputs a continuous number between 0 and 1 as the probability index for H. pylori infection status per image (Pp, H. pylori-positive; Pn, negative; Pe, eradicated). The most probable (largest number) of the three infectious statuses was selected as the 'CNN diagnosis'. Among 23,699 images, the CNN diagnosed 418 images as positive, 23,034 as negative, and 247 as eradicated. Because of the large number of H. pylori negative findings, the probability of H. pylori-negative was artificially re-defined as Pn -0.9, after which 80% (465/582) of negative diagnoses were accurate, 84% (147/174) eradicated, and 48% (44/91) positive. The time needed to diagnose 23,699 images was 261 seconds. CONCLUSION: We used a novel algorithm to construct a CNN for diagnosing H. pylori infection status on the basis of endoscopic images very quickly. ABBREVIATIONS: H. pylori: Helicobacter pylori; CNN: convolutional neural network; AI: artificial intelligence; EGD: esophagogastroduodenoscopies.

Application of artificial intelligence using a convolutional neural network for detecting gastric cancer in endoscopic images.

BACKGROUND: Image recognition using artificial intelligence with deep learning through convolutional neural networks (CNNs) has dramatically improved and been increasingly applied to medical fields for diagnostic imaging. We developed a CNN that can automatically detect gastric cancer in endoscopic images. METHODS: A CNN-based diagnostic system was constructed based on Single Shot MultiBox Detector architecture and trained using 13,584 endoscopic images of gastric cancer. To evaluate the diagnostic accuracy, an independent test set of 2296 stomach images collected from 69 consecutive patients with 77 gastric cancer lesions was applied to the constructed CNN. RESULTS: The CNN required 47 s to analyze 2296 test images. The CNN correctly diagnosed 71 of 77 gastric cancer lesions with an overall sensitivity of 92.2%, and 161 non-cancerous lesions were detected as gastric cancer, resulting in a positive predictive value of 30.6%. Seventy of the 71 lesions (98.6%) with a diameter of 6 mm or more as well as all invasive cancers were correctly detected. All missed lesions were superficially depressed and differentiated-type intramucosal cancers that were difficult to distinguish from gastritis even for experienced endoscopists. Nearly half of the false-positive lesions were gastritis with changes in color tone or an irregular mucosal surface. CONCLUSION: The constructed CNN system for detecting gastric cancer could process numerous stored endoscopic images in a very short time with a clinically relevant diagnostic ability. It may be well applicable to daily clinical practice to reduce the burden of endoscopists.

Application of Convolutional Neural Networks in the Diagnosis of Helicobacter pylori Infection Based on Endoscopic Images.

BACKGROUND AND AIMS: The role of artificial intelligence in the diagnosis of Helicobacter pylori gastritis based on endoscopic images has not been evaluated. We constructed a convolutional neural network (CNN), and evaluated its ability to diagnose H. pylori infection. METHODS: A 22-layer, deep CNN was pre-trained and fine-tuned on a dataset of 32,208 images either positive or negative for H. pylori (first CNN). Another CNN was trained using images classified according to 8 anatomical locations (secondary CNN). A separate test data set (11,481 images from 397 patients) was evaluated by the CNN, and 23 endoscopists, independently. RESULTS: The sensitivity, specificity, accuracy, and diagnostic time were 81.9%, 83.4%, 83.1%, and 198s, respectively, for the first CNN, and 88.9%, 87.4%, 87.7%, and 194s, respectively, for the secondary CNN. These values for the 23 endoscopists were 79.0%, 83.2%, 82.4%, and 230±65min (85.2%, 89.3%, 88.6%, and 253±92min by 6 board-certified endoscopists), respectively. The secondary CNN had a significantly higher accuracy than endoscopists (by 5.3%; 95% CI, 0.3-10.2). CONCLUSION: H. pylori gastritis could be diagnosed based on endoscopic images using CNN with higher accuracy and in a considerably shorter time compared to manual diagnosis by endoscopists.

Vonoprazan versus conventional proton pump inhibitor-based triple therapy as first-line treatment against Helicobacter pylori: A multicenter retrospective study in clinical practice.

OBJECTIVE: Vonoprazan is a potassium-competitive acid blocker, a new type of acid-suppressing drug, and has recently become available for peptic ulcers, gastroesophageal reflux disease, and Helicobacter pylori (H. pylori) eradication. Its efficacy for H. pylori eradication has been reported. However, the evidence for its efficacy and feasibility remains limited. We aimed to compare the feasibility, effectiveness and safety of vonoprazan-based triple therapy with conventional proton pump inhibitor (PPI)-based triple therapy in multicenter clinical practice. METHODS: We performed a multicenter retrospective study on patients receiving first-line H. pylori eradication therapy between March 2013 and November 2015 with either vonoprazan-based triple therapy or conventional PPI-based triple therapy. RESULTS: A total of 2715 patients aged 63.0 ± 12.1 years (1412 [52.0%] males) were analyzed. Eradication rates were 87.2% (368/422) for vonoprazan-based therapy and 72.4% (1661/2293) for conventional PPI-based therapy (P < 0.01). Among the former group, there were 10 cases of diarrhea, six of nausea/vomiting, and five of rash, but the rates of these adverse events were similar to those in the conventional PPI group. CONCLUSION: Vonoprazan-based triple therapy is feasible, and has a higher rate for H. pylori eradication than conventional PPI as a first-line regimen.

Potential utility of a new ulcerative colitis segmental endoscopic index combining disease severity and the extent of inflammation.

GOAL: To investigate the potential utility of a new scoring system, the Ulcerative Colitis Segmental Endoscopic Index (UCSEI), which combines measures of disease severity and extent of inflammation. BACKGROUND: Intestinal mucosal healing (MH) is a new therapeutic goal for ulcerative colitis (UC). Discontinuous lesions are common in UC and endoscopic observation of the entire colon is important. STUDY: Patients with active mild-to-moderate UC received daily treatment with oral mesalazine (4 g/d) and mesalazine enemas (1 g/d) for 8 weeks. Endoscopic evaluations, using the UCSEI and Mayo Endoscopic Score (MES), were performed in 5 colonic segments at baseline and week 8. The UCSEI criteria included erythema, vascular pattern, friability, and erosion/ulcer. The sum of 5 subscores, determined for each segment, was calculated as the UCSEI. Disease activity was also assessed using the UC Disease Activity Index (UCDAI). MH was defined as MES=0 to 1. RESULTS: Of 58 patients, 51 completed the scheduled endoscopic evaluations. At week 8, the UCDAI score had significantly decreased from 6.63 (baseline) to 2.73 (P<0.001). The remission and MH rates were 35.3% and 55.3%, respectively. Segmental endoscopic evaluation, using UCSEI, showed that baseline inflammation tended to be more severe in the distal colon. The baseline UCSEI increased with the extent of disease, which was not seen in MES. Improvements in UCSEI were observed, even in the patients without decreases in the MES. CONCLUSIONS: UCSEI, reflecting disease severity and extent of inflammation, provides useful information for UC management that is not available with MES.

Changes in bowel function following transanal and transvaginal rectocele repair.

AIM: This study was designed to compare preoperative and postoperative bowel functions in patients with rectocele repair. METHODS: Patients who underwent surgery for rectocele between October 1988 and October 2004 were enrolled. Prior to surgery, the patients were asked to complete a questionnaire regarding evacuation difficulty, itching, fecal incontinence, and the need for digitation. Surgery was performed either transanally (group I) or transvaginally (group II). At follow-up after 12 months, the same questionnaire was obtained in the outpatient clinic or by mail to evaluate preoperative and postoperative changes in bowel function. RESULTS: There were 71 patients in group I and 40 patients in group II. The median age was 56 years in group I and 67 years in group II. The evacuation difficulty was significantly improved in both group I (p < 0.001) and group II (p < 0.001). Incontinence to flatus was slightly increased in group I (p = 0.33) and group II (p = 0.6). Incontinence to solid stool was not statistically different in either group. The need for digitation was markedly improved in group I (p < 0.001) and group II (p = 0.0017). CONCLUSION: Although surgery for rectocele potentially increases the risk of fecal incontinence, it may be indicated if presented with evacuation difficulty necessitating digitation.