Gastric ectopic pancreas with a pseudocyst

Ectopic pancreas (EP) is defined as pancreatic tissue that lacks anatomical or vascular connections to the normal pancreas. EP is generally asymptomatic and is detected incidentally during endoscopy. However, due to pseudocyst formation, inflammation, or malignant transformation, it may cause non-specific gastrointestinal symptoms, such as abdominal pain, abdominal discomfort, nausea, vomiting, and bleeding. Pseudocyst formation in EP may result from the retention of exocrine secretions in the absence of connections between the glandular epithelium and gastric lumen. We herein report a case of EP with a pseudocyst associated with epigastric pain. EP with a pseudocyst, although rare, needs to be considered in a differential diagnosis of cystic lesions of the stomach.

Novel endoscopic approaches using the endocytoscopy for the target biopsy in esophageal eosinophilia

BACKGROUND AND AIMS

Multiple biopsies are recommended for the diagnosis of eosinophilic esophagitis (EoE) because inflammatory changes are frequently patchy. Reports on EoE using endocytoscopy (ECS) are limited. This present study aimed to assess if diagnostic yield improves by adding ECS on conventional white light imaging (WLI) in patients with esophageal eosinophilia (EE).

METHODS

A total of 284 biopsy specimens from 71 patients with a known diagnosis of EE were enrolled and divided into the WLI group (156 specimens) or the ECS group (128 specimens). Four biopsies from 5 and 10 cm proximal to the esophagogastric junction were taken from each patient. In the ECS group, the biopsy was performed where bilobed nuclei were observed. The biopsy sensitivity for EE, eosinophil count of a single specimen and the biopsy sensitivity of each endoscopic finding were evaluated between both groups.

RESULTS

The sensitivity of a single biopsy specimen was higher in the ECS group than that of the WLI group (62.5 vs. 41.7%, P < 0.001). In addition, the median eosinophil count in the ECS group was significantly higher [19 vs. 6.5/high-power field (HPF), P < 0.001]. For each endoscopic finding, ECS-based biopsy had higher sensitivity than that of WLI in the diagnosis of edema (33.1 vs. 11.3%, P = 0.007) and linear furrows (75.8 vs. 52%, P = 0.005).

CONCLUSION

This study showed that adding ECS to WLI improved the biopsy sensitivity and eosinophil detection in patients with EE.

Successful prevention of stenosis after circumferential endoscopic resection of esophageal cancer

Circumferential resection of a >5-cm longitudinal mucosal defect following esophageal endoscopic submucosal dissection (ESD) is a risk factor for refractory stenosis. Circumferential ESD was performed in 3 patients with 64, 69, and 70 mm longitudinal mucosal defects. A local steroid injection was used to treat the postoperative ulcer, followed by an oral steroid. In all three cases, the ulcer healed without the need for endoscopic dilation. A combination of local injection and oral steroids effectively prevented esophageal stenosis in patients with high-risk stenosis after ESD.

Diagnostic Performance of Endocytoscopy for Esophageal Eosinophilia

INTRODUCTION

Eosinophils in the esophageal epithelium are unevenly distributed in eosinophilic esophagitis (EoE). Esophageal eosinophilia (EE) may be observable by endocytoscopy (EC). This study aimed to evaluate the diagnostic performance of EC for the diagnosis of EE.

METHODS

A total of 33 EoE patients underwent EC with methylene blue staining from March 2020 to April 2021. A total of 194 EC images with corresponding biopsies were obtained. Three findings of EC, increased squamous cells (item I), increased inflammatory cells (item II), and cells with bilobed nuclei (item III), were established. These findings were reviewed by two endoscopists to diagnose EE. Another four endoscopists reviewed the images for interobserver agreement.

RESULTS

When all three items were met by EC, the sensitivity and the accuracy for the diagnosis of EE were 88% and 76%, respectively. The integrated diagnostic odds ratios (ORs) for the diagnosis of EE of the four endoscopists were significant (OR: 3.98, 95% CI: 2.94-5.40, p < 0.001). The results were similar when only item III was met. Interobserver agreement was good for item III to diagnose EE (kappa value = 0.653).

DISCUSSION/CONCLUSION

The diagnostic performance of EC for EE is acceptable and has good interobserver agreement. It may be useful for targeted biopsy in EoE patients.

A novel scoring system to predict therapeutic intervention for non-variceal upper gastrointestinal bleeding

Various scoring systems have been developed to predict the need for endoscopic treatment in patients with non-variceal upper gastrointestinal bleeding (NVUGIB). However, they have rarely been applied in clinical practice because the processes are complicated. The aim of this study was to establish a simple scoring system that predicts the need for endoscopic intervention in patients with NVUGIB. We retrospectively enrolled 509 consecutive patients with suspected NVUGIB who underwent emergency endoscopy. In the development cohort (from January 2016 to December 2018), risk factors that predict the need for endoscopic intervention were determined from 349 patients' data by multivariate logistic regression analysis. This led to the development of a novel scoring system named the Nagoya University score (N score). In the validation cohort (from January 2019 to September 2020), we evaluated the diagnostic value of the N score, the Hirosaki score, and the Glasgow-Blatchford scores (GBS) by receiver operating characteristic (ROC) curves using another 160 patients' data. Multivariate logistic regression analysis revealed syncope, hematemesis, blood urea nitrogen (BUN), and BUN/Cr as significant predictive factors for endoscopic intervention. In the validation study, the N score was superior to the GBS and equal to the Hirosaki score in predicting the endoscopic intervention (AUC, N score 0.776 [95% CI 0.702-0.851] vs. GBS 0.615 [0.523-0.708], Hirosaki 0.719 [0.636-0.803]). The N score revealed a sensitivity of 84.5% and a specificity of 61.8%. Our N score, which is consisted of only four factors, would select patients who require endoscopic intervention with high probability.

Collision Tumors of Gastric Adenocarcinoma and Mucosa-associated Lymphoid Tissue Lymphoma

A 65-year-old woman with a history of treatment for splenic marginal zone B-cell lymphoma and gastric mucosa-associated lymphoid tissue (MALT) lymphoma underwent esophagogastroduodenoscopy. A reddish elevated lesion was found in the fundus of the stomach. On image-enhanced endoscopy, several findings, such as glandular structures of varying sizes suggesting well-differentiated adenocarcinoma, pruned blood vessels, and dilated blood vessels in deeper mucosa suggesting MALT lymphoma, were observed. The final pathological diagnosis after surgical resection was collision tumors of well-differentiated adenocarcinoma and MALT lymphoma. The features of both tumors could be observed simultaneously with image-enhanced endoscopy.

Visual and tear function improvement after superficial phototherapeutic keratectomy (PTK) for mid-stromal corneal scarring

PURPOSE

To study the changes in visual and tear film function following superficial excimer laser phototherapeutic keratectomy in patients with mid-stromal corneal scars.

METHODS

Fourteen eyes of 14 patients with mid-stromal corneal scars seen at the Department of Ophthalmology at Kobe Kaisei Hospital underwent superficial phototherapeutic keratectomy (PTK). The subjects underwent routine ophthalmic examinations, corneal sensitivity measurements, tear film break-up time (BUT), Schrimer test and tear film lipid layer interferometry. Thirty eyes of 15 normal control subjects were also studied. The patients and the control subjects were compared for pre-PTK tear function parameters and tear film lipid layer interferometry grade. The alterations in these parameters within 6 months following PTK were also determined.

RESULTS

Visual improvement was achieved in 12 eyes (86%). A hyperopic shift was observed in all eyes. The average pre-PTK corneal sensitivity and tear film BUT were lower in patients compared with control subjects before PTK. Tear film lipid layer interferometry grades were also higher in the patients than the controls before PTK. All these parameters improved gradually and significantly after PTK. Schirmer test results did not show any significant alterations after PTK.

CONCLUSION

We conclude that PTK is an effective means of treating corneal scars and attaining visual improvement, even in cases with deeper corneal involvement, and may obviate the need for corneal transplantation. Simultaneous improvements in corneal sensitivity and tear film stability suggest favourable effects of PTK on the ocular surface.

Ocular surface changes after excimer laser phototherapeutic keratectomy

PURPOSE

To study the ocular surface disorder in patients with Avellino, granular, and lattice dystrophy, band keratopathy, and corneal leukoma before and after excimer laser phototherapeutic keratectomy.

DESIGN

A prospective case-controlled study.

PARTICIPANTS

A total of 45 eyes of 33 patients with superficial corneal opacities seen at Kobe Kaisei Hospital, Department of Ophthalmology, and 40 eyes of 20 normal control subjects were studied.

INTERVENTION

The subjects underwent routine ophthalmic examinations, corneal sensitivity measurements, tear film break up time (BUT), Schirmer test, tear film lipid layer interferometry, and conjunctival impression cytology.

MAIN OUTCOME MEASURES

The patients and the control subjects were compared for prephototherapeutic keratectomy (PTK) tear function parameters, tear film lipid layer interferometry grade, goblet cell density, and conjunctival squamous metaplasia grade. Alterations of these parameters within 3 months after PTK were also looked for.

RESULTS

The average pre-PTK corneal sensitivity and tear film break up time were lower in patients compared with control subjects before PTK. Tear film lipid layer interferometry grade and conjunctival squamous metaplasia grades were higher in the patients than the controls before PTK. All these parameters improved gradually and significantly after PTK. Goblet cell density was significantly lower in the patients compared with controls before PTK. Schirmer test results and goblet cell density did not show any significant alterations after PTK.

CONCLUSIONS

Concurrent improvements in corneal sensitivity, tear film break up time, lipid layer interference grades, and conjunctival squamous metaplasia grades all point to the favorable effects of PTK on the ocular surface by improving the stability of the tear film and ocular surface health through attainment of a regular corneal surface and probably inducing qualitatively/quantitatively better mucin production by a healthier epithelium after PTK.

MT neurons in the macaque exhibited two types of bimodal direction tuning as predicted by a model for visual motion detection

We previously proposed a model for detecting local image velocity on the magnocellular visual pathway (Kawakami & Okamoto (1996) Vision Research, 36, 117-147). The model detects visual motion in two stages using the hierarchical network that includes component and pattern cells in area MT. To validate the model, we predicted two types of bimodal direction tuning for MT neurons. The first type is characteristic of component cells. The tuning is bimodal when stimulated with high-speed spots, but unimodal for low-speed spots or for bars. The interval between the two peaks widens as the spot's speed increases. The second type is characteristic of pattern cells. The tuning is bimodal when stimulated with low-speed bars, but unimodal for high-speed bars or for spots. The interval widens as the bar's speed decreases. To confirm this prediction, we studied the change of direction tuning curves for moving spots and bars in area MT of macaque monkeys. Out of 35 neurons measured at various speeds, six component cells and four pattern cells revealed the predicted bimodal tunings. This result provided neurophysiological support for the validity of the model. We believe ours is the first systematic study that records the two types of bimodality in MT neurons.

Protonation of histidine groups inhibits gating of the quisqualate/kainate channel protein in isolated catfish cone horizontal cells

Increases in the extracellular hydrogen ion concentration ([H+]o) but not the intracellular concentration ([H+]i) antagonized the inward going membrane currents recorded from isolated cone horizontal cells during application of quisqualate, alpha-amino-3-hydroxy-5-methyl-isoxazole-4-propionic acid, and kainate. The pK determined from a titration curve was 6.5 with a slope greater than 1, indicating protonation of several histidines. The reduction in membrane current was voltage-independent. The affinity of the agonist for the receptor, the single-channel conductance, and the open time were unaffected by [H+]o. [H+]o antagonism was not the result of charge neutralization such as screening surface charge. Diethylpyrocarbonate, a histidine-modifying reagent, reduced the agonist-induced current, but disulfide- and sulfhydryl-modifying reagents were ineffective. These results suggest that histidine groups on the external face of the channel protein provide a functional site regulating channel gating.

Effects of dopamine on photopic L-type S-potentials in the catfish retina

Photopic L-type responses were recorded from the soma and the axon terminal of horizontal cells of the catfish (Ictalurus punctatus) retina in eye-cup preparations. The responses were produced by a spot of light with 100-micron diameter (intensity, 10 microW/cm2), which was flashed or steadily illuminated and swept along a 6-mm length over the retinal surface at a speed of 0.95 mm/sec. In some experiments, a traveling random bar stimulus was used instead of the sweeping spot. While recording the responses, dopamine (DA) was applied in a jet form via a nebulizer over the retinal preparation or as superfusate to the eye-cup preparation. DA increased the response amplitude by about 50% and markedly narrowed the spatial profile of the responses from the soma but not from the axon terminal. These DA effects were observed in both normal retinas and those from which DA cells had been deprived by prior intraocular injection of 6-hydroxydopamine. Deprival of DA cells from the retina resulted in a slightly wider spatial profile of the soma and axon terminal responses than that in normal retinas. The results indicate that the spatial properties of photopic L-type responses are modulated by DA at the soma level of horizontal cells.

A new photographic method for mapping spatio-temporal receptive field using television snow stimulation

A means was devised to measure simultaneously spatial as well as temporal characteristics of visual receptive fields by stimulating the retina with the noise obtained on an unused television channel. The input, television snow, and the output, neural response, were recorded on a video tape. The tape was played back to obtain the (linear) spatio-temporal Wiener kernel by cross-correlating the input with the output. This method can be applied to extract the linear part of the visual responses in time and space.

A comparison of spatio-temporal receptive fields of ganglion cells in the retinas of the tadpole and adult frog

Receptive fields formed by ganglion cells were measured simultaneously in time and space in the adult and tadpole retinas. The spatio-temporal receptive-fields (STRFs) were measured by cross-correlating the spatio-temporal white-noise stimulus with the cells' spike discharges. Crosscorrelation was made photographically to extract the first order STRF kernel (approximately linear component of the STRFs). The time-course of STRF formed by the frog ganglion cells was twice as fast as that of the tadpole cells. The STRF formed by the tadpole ganglion cells was either a center-brightening or a center-dimming type whereas in the frog there was another class of cells which produced either complex STRFs or did not show any linear component in their STRFs. Size of the STRFs in frog and tadpole was similar in both frog and tadpole retinas.

Spatio-temporal visual receptive fields as revealed by spatio-temporal random noise

A means was devised to visualize the retinal receptive fields in time and space using the noise on unused television channels as spatio-temporal inputs and performing correlation between the input and output photographically. The method was applied to characterize the receptive fields of catfish retinal ganglion cells. The results were 1) there were two major types of receptive fields, circular and elliptical, 2) shapes and sizes of the field components changed with time (latency), and 3) a field's surround was often localized as hot spots.