Visibility of esophageal squamous cell carcinoma under iodine staining on texture and color enhancement imaging

Objective

Iodine staining on white light imaging (WLI) is the gold standard for detecting and demarcating esophageal squamous cell carcinoma (ESCC). We examined the effects of texture and color enhancement imaging (TXI) on improving the endoscopic visibility of ESCC under iodine staining.

Methods

Twenty ESCC lesions that underwent endoscopic submucosal dissection were retrospectively included. The color difference between ESCC and the surrounding mucosa (ΔEe) on WLI, TXI, and narrow-band imaging was assessed, and ΔEe under 1% iodine staining on WLI and TXI. Furthermore, the visibility grade determined by endoscopists was evaluated on each imaging.

Result

The median ΔEe was greater on TXI than on WLI (14.53 vs. 10.71, respectively; p < 0.005). Moreover, the median ΔEe on TXI under iodine staining was greater than the median ΔEe on TXI and narrow-band imaging (39.20 vs. 14.53 vs. 16.42, respectively; p < 0.005 for both). A positive correlation in ΔEe under iodine staining was found between TXI and WLI (correlation coefficient = 0.61, p < 0.01). Moreover, ΔEe under iodine staining on TXI in each lesion was greater than the corresponding ΔEe on WLI. The visibility grade assessed by endoscopists on TXI was also significantly greater than that on WLI under iodine staining (p < 0.01).

Conclusions

The visibility of ESCC after iodine staining was greater on TXI than on WLI.

Rectal implantation cyst successfully diagnosed using endoscopic myotomy and endoscopic ultrasonography

An 81-year-old woman who underwent laparoscopic-assisted low anterior resection with instrumented anastomosis using the double stapling technique for rectal cancer 5 years ago was found to have an enlarged anastomotic mass on computed tomography. On colonoscopy, the anastomotic mass was observed as a 30-mm-sized subepithelial lesion, which was presumed to be the submucosa on endoscopic ultrasonography (EUS). EUS-guided fine-needle aspiration was performed; however, no cellular components were collected. Therefore, endoscopic submucosal dissection (ESD) was performed to remove the entire anastomotic mass. However, any lesion in the submucosa was not detected during ESD, and the lesion was suspected to be located deeper than the submucosa. Therefore, EUS was performed from the muscule layer just below the dissected submucosa, and the mass was detected outside the muscle layer in contact with the rectal wall. Upon endoscopic incision of the muscle layer, milky white mucus was excreted into the rectal lumen. Subsequently, the scope was advanced to an area outside the muscle layer where the mass was located, which was a closed lumen with mucus retention. Surface biopsy of the closed lumen revealed normal colonic mucosa. Therefore, the subepithelial lesion was diagnosed as an implantation cyst arising outside the rectal wall.

Factors Associated With Difficult Endoscopic Ultrasonography-guided Biliary Drainage

BACKGROUND AND AIMS

When endoscopic retrograde cholangiopancreatography-guided biliary drainage is challenging, endoscopic ultrasound-guided biliary drainage (EUS-BD) can be used as an alternate treatment; however, this method requires operator expertise. Therefore, this study aimed to clarify the factors that are associated with a difficult EUS-BD.

PATIENTS AND METHODS

Patients who successfully underwent EUS-BD were enrolled in this study. The patients were divided into the easy group and difficult group depending on whether the procedural time was more than 60 minutes, which was the cutoff value elicited from past reports. Patient characteristics and procedural factors were compared between the two groups. The factors associated with difficult procedures were also investigated.

RESULTS

The patient characteristics were not significantly different between the easy group (n=22) and the difficult group (n=19). The diameter of the punctured bile duct was significantly different between the two groups. In the multivariate analysis, the diameter of the punctured bile duct was the only factor associated with a difficult EUS-BD (odds ratio 0.65, 95% confidence interval 0.46-0.91, P value=0.012). The cutoff value for the diameter of the punctured bile duct in predicting a difficult EUS-BD was 7.0 mm (area under the curve: 0.83, sensitivity 84.2%, specificity 86.4%).

CONCLUSIONS

A nondilated bile duct might be a predictive factor for a difficult EUS-BD. For beginners of EUS-BD, the cutoff value for the punctured bile duct diameter found in this study, 7.0 mm, might become a barometer for puncture point selection.

Endoscopic ultrasound-guided fine-needle aspiration for gastrointestinal subepithelial lesions

Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is the first-choice procedure for obtaining pathological tissue samples from gastrointestinal (GI) subepithelial lesions (SELs). However, its diagnostic accuracy is lower than that for pancreatic masses owing to puncture difficulty and the need for immunostaining for definitive diagnosis. The advent of fine-needle biopsy needles, which have become well known in recent years, improves the diagnostic accuracy of EUS-FNA for GI SELs. The forward-viewing echoendoscope and rapid on-site evaluation (ROSE) have also helped to improve diagnostic accuracy. Furthermore, in facilities where ROSE is not available, endosonographers perform a macroscopic on-site evaluation. With these procedural innovations, EUS-FNA is now performed aggressively even for SELs smaller than 20 mm. The incidence of procedure-related adverse events such as bleeding and infection is low, and thus, EUS-FNA can be safely performed to diagnose SELs.

Esophageal squamous cell carcinoma complicated with varices successfully treated by endoscopic injection sclerotherapy and argon plasma coagulation: A case report

Treatment guidelines for esophageal squamous cell carcinoma (ESCC) with concomitant esophageal varices (EVs), which increase the risk of bleeding, are unavailable. A 66-year-old man with a history of total gastrectomy was admitted to the hospital owing to hematemesis. Emergency upper gastrointestinal endoscopy revealed variceal bleeding near the anastomosis between the esophagus and jejunum, and endoscopic clipping stopped the bleeding. Upper gastrointestinal endoscopy following hemostasis revealed four EVs and a two-thirds ESCC circumference. The ESCC depth was suspected to be up to the mucosa. The patient underwent intravariceal endoscopic injection sclerotherapy (EIS) for EVs, followed by paravariceal EIS. However, after these treatments, blood flow in the EVs just below the ESCC remained, and endoscopic resection of the ESCC was judged to be difficult to perform. Therefore, we prioritized EV treatment and performed a second EIS on the ESCC, followed by argon plasma coagulation (APC). APC was expected to not only solidify the EVs but also eliminate the ESCC existing in the mucosa. Finally, EVs and ESCC were treated by EIS and APC. EIS followed by APC may be useful for treating concurrent EVs and intramucosal ESCC in patients with liver cirrhosis when embolization of the EVs is ineffective.

L-Menthol for Color Difference Change Between Early Gastric Cancer and Surrounding Mucosa: A Prospective Study

BACKGROUND

L-Menthol sprayed on early gastric cancer (EGC) has been reported to improve the visibility of the lesion. However, its impact when used in combination with novel image-enhanced endoscopy has not been investigated.

AIM

This study aimed to evaluate the visual effect of spraying L-menthol on EGC under linked color imaging (LCI).

METHODS

This open-label, single-arm, prospective study investigated the color difference between EGC and the surrounding mucosa (ΔEG) before and after spraying L-menthol. The primary endpoint was the percentage of lesions with ΔEG ≥ 5 on LCI. The percentage of lesions with ΔEG  ≥ 5 on white light imaging (WLI) and blue laser imaging (BLI), ΔEG before and after spraying L-menthol, and percentage of lesions with increased ΔEG after spraying L-menthol constituted the secondary endpoints.

RESULTS

Sixty patients were included in the final analysis. 100% lesions had ΔEG ≥ 5, both before and after spraying L-menthol on LCI, with similar results observed in WLI as well as BLI. The median ΔEG on LCI, WLI, and BLI increased after spraying L-menthol (LCI: 16.9 vs. 21.5, p < 0.01; WLI: 10.4 vs. 13.4, p < 0.01; BLI; 12.1 vs. 15.7, before and after, respectively, p < 0.01); and LCI demonstrated the highest percentage of lesions with increased ΔEG (LCI, WLI, and BLI: 98.3%, 81.7%, and 76.7%, respectively, p < 0.01).

CONCLUSION

Although spraying L-menthol did not improve the visibility of EGC under LCI observation, a significant increase in ΔEG was observed in LCI (jRCTs 021200027).

Novel Photodynamic Therapy for Esophageal Squamous Cell Carcinoma following Radiotherapy

Radiotherapy (RT) or chemoradiotherapy (CRT) are frequently selected as treatments for esophageal squamous cell carcinoma (ESCC). However, salvage treatment remains challenging when endoscopic resection is not indicated for residual or recurrent ESCC following RT or CRT. Recently, owing to the emergence of second-generation photodynamic therapy (PDT) using talaporfin sodium, PDT can be performed with less phototoxicity and therefore has regained popularity in the treatment of ESCC. In this study, the effectiveness and safety of second-generation PDT in patients with residual or recurrent ESCC following RT or CRT were examined. Local complete response (L-CR) rates, procedure-related adverse events, and prognosis were evaluated. In 12 patients with 20 ESCC lesions, the L-CR rates were 95.0%. Perforation, postoperative bleeding, and photosensitivity were not observed. Esophageal stricture following PDT developed in one patient, but this could be addressed using balloon dilation. During a median follow-up period of 12 (range, 3-42) months, the 3-year cause-specific survival rate was 85.7%. Even in patients with a Charlson comorbidity index score ≥ 3, the 2-year overall survival rates were 100%. In conclusion, PDT was an efficacious and a safe salvage treatment in patients with local residual or recurrent ESCC following RT or CRT.

Clinical benefit of subsequent chemotherapy after drug-induced interstitial lung disease in pancreatic cancer patients: a multicenter retrospective study from Japan

PURPOSE

Drug-induced interstitial lung disease (ILD) is not a rare adverse event in the current chemotherapy strategy for pancreatic ductal adenocarcinoma (PDAC). Thus, we aimed to find the optimal management for PDAC patients with a history of ILD induced by a gemcitabine-based regimen.

METHODS

We conducted a multicenter retrospective study. The primary endpoint was the overall survival (OS) of patients who underwent either S-1 monotherapy or FOLFOX after the onset of ILD. Toxicity data was also analyzed in the 2 groups.

RESULTS

Twenty-four patients were diagnosed with ILD and 17 patients who received subsequent chemotherapy were enrolled in the study. Among 17 patients who were managed with subsequent chemotherapy after recovering from ILD, we did not observe significant difference in OS between S-1 and FOLFOX (290.0 days vs. undefined, p = 0.39). Relapse of drug-induced ILD was not observed in all cases during the course. Overall, severe adverse events (CTCAE Grade 3 or 4) were observed in 3 patients (23.1%) in S-1 treatment group and 1 patient (25.0%) in FOLFOX treatment group (p = 0.93).

CONCLUSIONS

S-1 monotherapy and FOLFOX are comparable as the subsequent chemotherapy after gemcitabine-based chemotherapy-induced ILD in unresectable PDAC.

Endoscopic submucosal dissection for superficial esophageal squamous cell carcinoma in patients with cirrhosis and esophageal varices

Endoscopic submucosal dissection (ESD) has become the standard treatment for superficial esophageal squamous cell carcinoma (SESCC). However, the treatment strategy for SESCC complicated by esophageal varices (EVs) has not been established. We report two cases of SESCC in patients with alcoholic cirrhosis complicated by EVs who underwent ESD. Case 1 presented with EVs on the anal side of the SESCC, and endoscopic variceal ligation (EVL) was performed before ESD. After EVL, the SESCC was successfully treated by ESD without any adverse events. Case 2 presented EVs from the anal side of the SESCC to the submucosa just below the SESCC. Then, EVL and endoscopic injection sclerotherapy with polidocanol were performed before ESD. However, ESD was not completed because of severe bleeding by uncontrolled blood flow below and around the SESCC. Bleeding during ESD was controlled in case 1, but not in case 2.

Comparison of time to recurrent biliary obstruction between plastic stents and metallic stents for endoscopic ultrasound‑guided biliary drainage

Endoscopic ultrasound-guided biliary drainage (EUS-BD) may prevent stent placement at the bile duct stricture. Therefore, whether a plastic stent (PS) or metallic stent (MS) should be used for EUS-BD remains to be undetermined. The present study aimed to clarify whether a PS or MS was more efficient for EUS-BD. Patients with malignant biliary obstruction who were successfully treated with EUS-BD were enrolled in the present study. The clinical characteristics, procedural outcomes and time to recurrent biliary obstruction (TRBO) were compared between patients treated with a PS (PS group) and patients treated with an MS (MS group). Consequently, 28 patients underwent PS placement and 11 patients underwent MS placement. In the PS group, 12 patients also underwent EUS-antegrade stenting (AGS) using an MS. The TRBO was not significantly different between the two groups (P=0.25). When the patients with AGS were excluded, the TRBO was significantly longer in the MS group than in the PS group (P=0.036). However, the TRBO was not significantly different between the patients in the MS group and those in the PS group who underwent AGS (P=0.61). In EUS-BD, MS is expected to be associated with a longer TRBO than PS. However, combining EUS-BD with AGS may help overcome the shorter TRBO associated with the use of PS.

Mixed high-grade serous and large cell neuroendocrine carcinoma arising from rectal endometriosis 11 years after hysterectomy

The malignant gastrointestinal endometriosis transformation is represented by endometriosis-associated intestinal tumors. Endometrioid adenocarcinoma and clear cell adenocarcinoma are most common among the endometrial cancers of all organs. Only four cases of mixed serous carcinoma and large cell neuroendocrine carcinoma have been reported, and all these cases originated from the uterus. A 59-year-old woman with a month's history of bloody stools was admitted. She was stable until the hematochezia occurred but is 11 years post-hysterectomy. A circumferential type-3 advanced upper rectum tumor was seen on colonoscopy. Adenocarcinoma was revealed from the forceps biopsies of the type-3 tumor component. Computed tomography showed narrowed lumen with a thickened rectum wall, a continuing mass, and a component on the anorectal side. Swollen lymph nodes were observed around the rectum, but no distant metastatic lymph nodes or organs were found. To treat the lesion, rectal surgical resection with D3 lymph node dissection was performed. Histological examination revealed combined high-grade serous and large cell neuroendocrine carcinomas. Tumor was contiguous to the endometrium in the sub-serosa. Endometriosis was determined to be the origin of both carcinomas. Therefore, endometriosis-associated intestinal tumors should be included in the differential diagnosis when rectal tumors with cystic structures are found post-hysterectomy.

Efficacy of a novel large-cell Niti-S stent with a slim delivery system for hilar biliary obstruction: a preliminary study

OBJECTIVES

The large-cell Niti-S stent is useful for multiple stenting in patients with malignant hilar biliary obstruction (MHBO). Recently, a novel uncovered self-expandable metallic stent (USEMS) (a Niti-S large-cell SR slim delivery system) was developed. In this study, we aimed to evaluate the efficacy of this USEMS slim delivery system in MHBO patients.

MATERIALS AND METHODS

Outcomes related to USEMS placement, the clinical course, and the period to recurrent biliary obstruction (RBO) were evaluated in MHBO patients who received multiple USEMSs with the Niti-S large-cell SR slim delivery system.

RESULTS

Twenty-two MHBO patients underwent the placement of multiple USEMSs, including the novel slim-delivery stent. Six patients had a past history of upper gastrointestinal reconstruction (Billroth I: 1, Billroth II: 4, Roux-en-Y: 1). The number of USEMSs placed in each patient was 2-6. Three procedures were reinterventions. The new slim delivery system was placed as the first stent in ten patients and as an additional stent in the remaining patients. Seven patients were drained using only Niti-S large-cell SR slim delivery stents. The technical and clinical success rates were both 100%.

CONCLUSIONS

Placing multiple USEMSs in patients with a past history of abdominal surgery or in reintervention is difficult. Although difficult cases were included in this study, stent-in-stent placement with the novel Niti-S large-cell SR slim delivery system was useful in treating MHBO patients. In addition, this novel stent might be the first choice for MHBO patients.KEY MESSAGESEndoscopic multistenting for MHBO is challenging. In addition, reintervention or multistenting for MHBO patients with a past history of abdominal surgery becomes more difficult.The novel Niti-S large-cell SR slim delivery USEMS is useful as an additional stent because the delivery system is thin and suitable for a 0.025 guidewire. In addition, the novel stent is of the braided type and has a large mesh. Therefore, the novel stent is expected to have strong radial force and can be used as the first SEMS.The Niti-S large-cell SR slim delivery stent is long enough to be used in patients with upper gastrointestinal reconstruction. Although this study included patients with reintervention or a past history of upper gastrointestinal reconstruction, the technical success rate of multiple stenting for MHBO patients was 100%. The slim-delivery stent might overcome several difficulties of endoscopic multistenting.

Association between Submucosal Fibrosis and Endoscopic Submucosal Dissection of Recurrent Esophageal Squamous Cell Cancers after Chemoradiotherapy

Simple Summary

The efficacy and safety of endoscopic submucosal dissection for early esophageal cancer after chemoradiotherapy have not been established. In this study, we focused on the fibrosis of the submucosa. As a result, we found that endoscopic submucosal dissection for early esophageal cancer can be performed reliably without adverse events, but the procedure takes longer for lesions with strong fibrosis of the submucosa.

Abstract

Endoscopic resection is a treatment of choice for a metachronous early-stage esophageal squamous cell carcinoma (ESCC) appearing after a radical cure of esophageal cancer by chemoradiotherapy (CRT). However, non-curative resection, and procedural complications including perforation due to radiation-induced submucosal fibrosis, are a concern. This study aimed to evaluate the association between submucosal fibrosis and the usefulness and safety of endoscopic submucosal dissection (ESD) in ESCC after CRT. This study retrospectively analyzed 13 lesions in 11 patients in our institute. Submucosal fibrosis under the lesion (F score) was classified into three levels (F0: none or mild, F1: moderate, and F2: severe) based on endoscopic and histopathologic findings. All lesions were F1 or greater (F1: 8 lesions and F2: 5 lesions). En bloc and R0 resection rates were both 100%. The procedural speed was slower in F2 than in F1 (F1 vs. F2; 15.1 mm²/min vs. 7.1 mm²/min, p = 0.019), without procedure-related adverse events. At a median follow-up of 42 months (range: 14–117 months) after ESD, 7 of 11 (63.6%) patients were alive without recurrence, and without ESCC-related death. ESCC after CRT reliably and safely resected en bloc by ESD but was more difficult in lesions with strong submucosal fibrosis.

Screening for hilar biliary invasion in ampullary cancer patients

BACKGROUND

The treatment for ampullary cancer is pancreatoduodenectomy or local ampullectomy. However, effective methods for the preoperative investigation of hilar biliary invasion in ampullary cancer patients have not yet been identified.

AIM

To determine the necessity of and an appropriate method for investigating hilar biliary invasion of ampullary cancer.

METHODS

Among 43 ampullary cancer patients, 34 underwent endoscopic treatment (n = 9) or surgery (n = 25). The use of imaging findings (thickening and enhancement of the bile duct wall on contrast-enhanced computed tomography, irregularity on endoscopic retrograde cholangiography, thickening of the entire bile duct wall on intraductal ultrasonography (IDUS), and partial thickening of the bile duct wall on IDUS) and biliary biopsy results for diagnosing hilar biliary invasion of ampullary cancer was compared.

RESULTS

Hilar invasion was not observed in every patient. Among the patients who did not undergo biliary stent insertion, the combination of partial thickening of the bile duct wall on IDUS and biliary biopsy results showed the highest accuracy (100%) for diagnosing hilar biliary invasion. However, each imaging method and biliary biopsy yielded some false-positive results.

CONCLUSION

Although some false-positive results were obtained with each method, the combination of partial thickening of the bile duct wall on IDUS and biliary biopsy results was useful for diagnosing hilar biliary invasion of ampullary cancer. However, hilar invasion of ampullary cancer is rare; therefore, the investigation of hilar biliary invasion of ampullary cancer might be unnecessary.

Nature and treatment outcomes of bleeding post-bulbar duodenal ulcers

BACKGROUND

Although post-bulbar duodenal ulcers (PBDUs) could become a source of upper gastrointestinal bleeding, the whole picture of the disease is unknown. We compared the characteristic features and treatment outcomes after endoscopic hemostasis between PBDUs and bulbar duodenal ulcers (BDUs).

METHODS

Data on duodenal ulcers with evidence of endoscopically-active bleeding were extracted from the data that were retrospectively collected from 12 institutes in Japan between 2011 and 2018. Rebleeding and in-hospital mortality were compared between patients with PBDUs and those with BDUs by logistic regression analyses.

RESULTS

Among 468 consecutive patients with bleeding duodenal ulcers, 96 (20.5%) had endoscopically-confirmed PBDUs. PBDUs were more frequently observed in patients with a poor general condition in comparison to BDUs. The rates of rebleeding and in-hospital mortality in patients with PBDUs were approximately three times higher than those in patients with BDUs (PBDU vs. BDU: 29.2% vs. 10.2% [P < 0.0001] and 14.6% vs. 5.1% [P = 0.0029], respectively). Although the high in-hospital mortality in PBDUs could be explained, to a lesser extent, by the likelihood of rebleeding, and, to a greater extent, by the patients' poor general condition, the presence of a PBDU itself was largely responsible for the high rebleeding rates in PBDUs.

CONCLUSION

This is the first study focusing on the nature and treatment outcomes of bleeding PBDUs. PBDUs were associated with much higher rebleeding and mortality rates in comparison to BDUs, and the likelihood of rebleeding may be derived from their unique anatomic location.

Biliary metal stents should be placed near the hilar duct in distal malignant biliary stricture patients

BACKGROUND

Endoscopic biliary drainage using a self-expandable metallic stent (SEMS) has been widely performed to treat distal malignant biliary obstruction (DMBO). However, the optimal position of the stent remains unclear.

AIM

To determine the ideal position for SEMS placement.

METHODS

In total, 135 DMBO patients underwent SEMS (uncovered or covered) placement over a ten-year period. A total of 127 patients with biliary obstruction between the junction of the cystic duct and Vater's papilla were enrolled. An SEMS was placed through the upper common bile duct 2 cm from the biliary hilar duct in 83 patients (Hilar group) or near the top of the biliary obstruction in 44 patients (Lower group). Technical and functional success, adverse events, and risk factors for SEMS dysfunction were evaluated.

RESULTS

The stent patency period was significantly longer in the Hilar group than in the Lower group (P value < 0.01). In multivariate analysis, the only statistically significant risk factor for SEMS dysfunction was being in the Lower group (hazard ratio: 9.94, 95% confidence interval: 2.25-44.0, P < 0.01).

CONCLUSION

A longer patency period was achieved by positioning the SEMS near the biliary hilar duct.

Transjejunal endoscopic ultrasound‐guided pancreatic drainage for pancreatic jejunostomy stricture using a forward‐viewing echoendoscope in a patient with altered anatomy

Pancreatic jejunostomy stricture (PJS) is one of the major late complications after pancreaticoduodenectomy. Endoscopic ultrasound‐guided pancreatic drainage (EUS‐PD) is considered a salvage treatment for symptomatic PJS after endoscopic retrograde pancreatography failure; however, the technical success rate of the endoscopic treatment of PJS remains unsatisfactory, mainly due to surgically altered anatomy. Herein, we describe a case of PJS successfully treated with transjejunal EUS‐PD using a forward‐viewing echoendoscope. A 62‐year‐old man who suffered from repetitive severe back pain due to PJS was referred to our hospital. Since transgastric EUS‐PD was difficult, we attempted transjejunal EUS‐PD using a forward‐viewing echoendoscope. To facilitate scope insertion, we first straightened the afferent jejunal loop and placed a stiff guidewire. With this scheme, we successfully performed transjejunal EUS‐PD and placed a 5‐Fr plastic stent. In conclusion, this technique is useful for treating patients with PJS when transgastric EUS‐PD is difficult.

Effects of anti-thrombotic drugs on all-cause mortality after upper gastrointestinal bleeding in Japan: A multicenter study with 2205 cases

OBJECTS

Although anti-thrombotic use is recognized as a risk factor for upper gastrointestinal bleeding (UGIB), there has been no clear evidence that it worsens the outcomes after the bleeding. The aim of this study is to investigate the effects of anti-thrombotic agents on in-hospital mortality following UGIB.

METHODS

Information on clinical parameters, including usage of anti-thrombotic agents, was retrospectively collected from consecutive patients with UGIB at 12 high-volume centers in Japan between 2011 and 2018. The all-cause in-hospital mortality rate was evaluated according to the usage of anti-thrombotic agents.

RESULTS

Clinical data were collected from 2205 patients with endoscopically confirmed UGIB. Six hundred and forty-five (29.3%) patients used anti-thrombotic agents. The all-cause in-hospital mortality rate was 5.7% (125 deaths). After excluding 29 cases in which death occurred due to end-stage malignancy, 96 deaths (bleeding-related, n = 22 ; non-bleeding-related, n = 74) were considered "preventable." Overall, the "preventable" mortality rate in anti-thrombotic users was significantly higher than that in non-users (6.0% vs. 3.7%, P < 0.05). However, the "preventable" mortality of anti-thrombotic users showed a marked improvement over time; although the rate in users remained significantly higher than that in non-users until 2015 (7.3% vs. 4.2%, P < 0.05), after 2016, the difference was no longer statistically significant (4.8% vs. 3.5%).

CONCLUSIONS

Although the usage of anti-thrombotic agents worsened the outcomes after UGIB, the situation has recently been improving. We speculate that the recent revision of the Japanese guidelines on the management of anti-thrombotic treatment after UGIB may have partly contributed to improving the survival of users of anti-thrombotic agents.

Usefulness of Endoscopic Ultrasound with the Jelly-Filling Method for Esophageal Varices

Although the importance of endoscopic ultrasound (EUS) for esophageal varices (EVs) has been demonstrated, it is difficult to obtain sufficient EUS images with the water-filling method because of poor water stagnation in the esophagus. In this study on EVs, we aimed to evaluate the usefulness of the jelly-filling method for EUS. Consecutive patients who underwent EUS for EVs were included. The quality of EUS images, the diagnostic ability of the presence of blood vessels inside and outside the esophageal wall, and the procedure time were compared between the jelly-filling and water-filling methods. Thirty cases were analyzed (jelly-filling method in 13 and water-filling method in 17). The EUS image quality score was significantly higher in the jelly-filling method (jelly vs. water; three points vs. two points, p < 0.001). Additionally, EUS image quality scores in both nonexperts and experts were significantly higher in the jelly-filling method. The diagnostic ability of the presence of perforation veins was significantly higher in the jelly-filling method (jelly vs. water; 100% vs. 52.9%, p = 0.004). However, the procedure time was significantly longer in the jelly-filling method (p = 0.024). In conclusion, EUS using the jelly-filling method for EVs provided sufficient image quality.

A simple prediction score for in-hospital mortality in patients with nonvariceal upper gastrointestinal bleeding

BACKGROUND

No prediction scores for the mortality of both inpatients and outpatients who developed nonvariceal upper gastrointestinal bleeding (UGIB) without endoscopic findings have been established. We aimed to derive and validate a novel prediction score for in-hospital mortality.

METHODS

We conducted a three-stage, multicenter retrospective study. In the derivation stage, patients with nonvariceal UGIB at six institutions were enrolled to derive the prediction score by logistic regression analysis. External validation of the score was performed to analyze discrimination by patients at six other institutions. Then the performance of this score was compared with that of four existing scores.

RESULTS

We enrolled 1380 and 825 patients in the derivation and validation cohorts, respectively. A prediction score (CHAMPS-R Score) comprising seven variables (Charlson Comorbidity Index ≥ 2, in-hospital onset, albumin < 2.5 g/dL, altered mental status, Eastern Cooperative Oncology Group performance status ≥ 2, steroids, and rebleeding) with equal-weight scores was established, with high discriminative ability in both derivation and validation cohorts (c statistic, 0.91 and 0.80, respectively). When rebeeding was excluded from the score (an onset model; CHAMPS Score), this score also achieved high discriminative ability (c statistic, 0.90 and 0.81, respectively). The prediction scores had significantly higher discriminative ability than the Glasgow Blatchford Score, AIMS65, ABC Score, and clinical Rockall Score in both cohorts (all, p < 0.05).

CONCLUSIONS

We derived and externally validated prediction scores for in-hospital mortality in patients with nonvariceal UGIB. The CHAMPS Score might be optimal for managing such patients. Its mobile application is freely available ( https://apps.apple.com/app/id1565716902 for iOS and https://play.google.com/store/apps/details?id=hatta.CHAMPS for Android).

Gap-junction-mediated Communication in Human Periodontal Ligament Cells

Periodontal tissue homeostasis depends on a complex cellular network that conveys cell-cell communication. Gap junctions (GJs), one of the intercellular communication systems, are found between adjacent human periodontal ligament (hPDL) cells; however, the functional GJ coupling between hPDL cells has not yet been elucidated. In this study, we investigated functional gap-junction-mediated intercellular communication in isolated primary hPDL cells. SEM images indicated that the cells were in contact with each other via dendritic processes, and also showed high anti-connexin43 (Cx43) immunoreactivity on these processes. Gap-junctional intercellular communication (GJIC) among hPDL cells was assessed by fluorescence recovery after a photobleaching (FRAP) analysis, which exhibited dye coupling between hPDL cells, and was remarkably down-regulated when the cells were treated with a GJ blocker. Additionally, we examined GJs under hypoxic stress. The fluorescence recovery and expression levels of Cx43 decreased time-dependently under the hypoxic condition. Exposure to GJ inhibitor or hypoxia increased RANKL expression, and decreased OPG expression. This study shows that GJIC is responsible for hPDL cells and that its activity is reduced under hypoxia. This is consistent with the possible role of hPDL cells in regulating the biochemical reactions in response to changes in the hypoxic environment.

SSEA-4 is a marker of human deciduous periodontal ligament stem cells

Although human deciduous teeth are an ideal source of adult stem cells, no method for identifying deciduous periodontal ligament (D-PDL) stem cells has so far been developed. In the present study, we investigated whether stage-specific embryonic antigen (SSEA)-4 is a marker that could be used to isolate D-PDL stem cells. The isolated D-PDL cells met the minimum criteria for mesenchymal stem cells (MSCs): They showed plastic adherence, specific-surface antigen expression, and multipotent differentiation potential. SSEA-4+ D-PDL cells were detected in vitro and in vivo. A flow cytometric analysis demonstrated that 22.7% of the D-PDL cells were positive for SSEA-4. SSEA-4+ clonal D-PDL cells displayed multilineage differentiation potential: They were able to differentiate into adipocytes, osteoblasts, and chondrocytes in vitro. A clonal assay demonstrated that 61.5% of the SSEA-4+ D-PDL cells had adipogenic, osteogenic, and chondrogenic potential. Our present study demonstrated that SSEA-4+ D-PDL cells are a subset of multipotent stem cells. Hence, SSEA-4 is a specific marker that can be used to identify D-PDL stem cells.

A case of granulosa cell tumor of the ovary detected from metastatic foci

The authors report a case of granulosa cell tumor of the ovary that followed a rare clinical course, where the primary focus did not appear as a mass, and disseminated foci grew in the abdominal cavity. In 2008, a 70-year-old patient, gravida 6 and para 3, was diagnosed with a perihepatic mass, peritoneal dissemination, and an abdominal wall mass as confirmed by computed tomography (CT) scanning. There was no mass lesion in the pelvis. The pathological diagnosis based on the resected mass in the abdominal wall was malignant mesothelioma. During follow-up, abdominal bloating developed from April 2009. CT scans indicated growth of the intraperitoneal lesions. Therefore, the patient received two cycles of combination therapy with cisplatin and pemetrexed. The treatment was discontinued due to lack of efficacy. The intraperitoneal lesions grew but the clinical course was slow and inconsistent with that of malignant mesothelioma. Central pathological review was requested in April 2011, and a granulosa cell tumor was diagnosed. The patient was referred to the department for detailed examination and treatment. The patient underwent incision of the intraperitoneal tumors, simple total hysterectomy, bilateral salpingo-oophorectomy, and omentectomy. The final pathological diagnosis was normal-size adult-type granulosa cell tumor originating from the left ovary. It was a case of granulosa cell tumor without ovarian enlargement where growth of the metastatic foci was the major observation. As complete surgical resection was achieved and no additional therapy was given, the subject was followed on an outpatient basis and no recurrence was identified.

Input-output relation of FitzHugh-Nagumo elements arranged in a trifurcated structure

In this study, the propagation of an action potential in a network of excitable elements is studied numerically. The network we consider consists of excitable elements arranged in the shape of a trifurcated structure having three cables. The system has a branch point, a Y junction, at which the three cables are joined. Two types of external stimulations are considered: a single impulsive stimulation at one of the cable terminals, and a pair of stimuli applied to two different terminals. We have found three basic phases depending on the excitability of the elements for a single external stimulus as follows: (1) signal distributor--as the excitability gets higher, the pulse generated by a stimulus splits into two at the branch point, and two pulses are transmitted to the opposite terminals, (2) propagation block--the pulse in the lower excitable chain is blocked at the branch point, and (3) transient propagation--as the excitability is decreased further, we see that the pulse vanishes before reaching the branch point. By the interaction between the pulses that originate from different sources, signal transmission is recovered if the pulses arrive at the branch point nearly synchronously or after a specific delay time. The effects of the repetition of these two types of stimulation are also investigated. Complex spatiotemporal patterns occur due to pulse-pulse interaction and collisions at the branch point. The input-output relationship, which depends crucially on the repetition period and the time lag between the pair of stimuli, is characterized by the stimulus-response ratio and the interspike interval. We also show the effects of noise on the distribution of the interspike interval.

Pair of excitable FitzHugh-Nagumo elements: synchronization, multistability, and chaos

We analyze a pair of excitable FitzHugh-Nagumo elements, each of which is coupled repulsively. While the rest state for each element is globally stable for a phase-attractive coupling, various firing patterns, including cyclic and chaotic firing patterns, exist in an phase-repulsive coupling region. Although the rest state becomes linearly unstable via a Hopf bifurcation, periodic solutions associated to the firing patterns is not connected to the Hopf bifurcation. This means that the solution branch emanating from the Hopf bifurcation is subcritical and unstable for any coupling strength. Various types of cyclic firing patterns emerge suddenly through saddle-node bifurcations. The parameter region in which different periodic solutions coexist is also found.

Feeding the nitric oxide synthase inhibitor L-N(omega)nitroarginine elevates serum very low density lipoprotein and hepatic triglyceride synthesis in rats

This study was conducted to study the influence of dietary L-N(omega)nitroarginine (L-NNA), a nitric oxide (NO) synthase inhibitor, on serum lipids and lipoproteins and on the activities of enzymes related to lipid metabolism in rats. Feeding rats a diet containing 0.2 g/kg L-NNA for 5 weeks elevated serum concentrations of triglyceride, cholesterol, phospholipid, and free fatty acid and reduced serum nitrate (an oxidation product of NO). The elevation in serum triglyceride was mainly due to the elevation in very low density lipoprotein (VLDL) triglyceride. Contents of cholesterol and phospholipid in the VLDL fraction also were elevated by L-NNA. L-NNA treatment caused significantly higher activity of hepatic microsomal phosphatidate phosphohydrolase (the rate-limiting enzyme in triglyceride synthesis) and lower activity of hepatic carnitine palmitoyltransferase (the rate-limiting enzyme in fatty acid oxidation). Activities of hepatic enzymes responsible for fatty acid synthesis such as glucose-6-phosphate dehydrogenase, malic enzyme, and fatty acid synthase were unaffected by L-NNA. The activity of hepatic microsomal phosphocholine cytidyltransferase (the rate-limiting enzyme in phosphatidylcholine synthesis) was reduced significantly by L-NNA. Our results suggest that lower NO production caused the elevations in hepatic triglyceride synthesis by higher esterification of fatty acid and lower fatty acid oxidation, leading to an enrichment of VLDL triglyceride.

Signal propagation and failure in one-dimensional FitzHugh-Nagumo equations with periodic stimuli

We analyze the effect of additive periodic stimuli in one-dimensional FitzHugh-Nagumo equations in an excitable regime. With a suitable stimulus interval, the suppression of the pulse propagation occurs in some parameter regime. This propagation failure comes from the formation of the "death spot" where successive pulses annihilate. In the parameter regime where the solitary pulse cannot propagate in space stably, however, periodic stimuli cause a propagation of envelope of a traveling pulse under a "resonance" condition, i.e., the pulse at the leading edge disappears successively, however, an envelope is formed and propagates with keeping its shape.

Expression of adrenomedullin and proadrenomedullin N-terminal 20 peptide in PC12 cells after exposure to nerve growth factor

Adrenomedullin (AM) and proadrenomedullin N-terminal 20 peptide (PAMP) are multi-functional peptides derived from the same precursor, proadrenomedullin. We have studied the regulatory mechanism of expression of these peptides during neuronal differentiation of rat pheochromocytoma PC12 cells by nerve growth factor (NGF). The cellular levels of the peptides increased slightly, and then progressively decreased below the control by NGF. Immunoreactive (ir)-AM in the medium was transiently increased by NGF. Cytochemical staining showed that ir-AM and ir-PAMP were abundantly present in cytoplasm in the undifferentiated cells, and were decreased during culture with NGF. There was no preferential localization of ir-AM or ir-PAMP in neurites in comparison with in cytoplasm in the differentiated cells. Northern blot analysis showed that mRNA encoding these peptides, as detected as a band of 1.6 kb, increased more than three-fold at 1 h after the addition of NGF and then progressively decreased to one fifth of the control during 72 h. Degradation rate of the mRNA was slowed by NGF even when mRNA level is decreased after 72 h of NGF treatment. The transcription rate of their gene increased transiently and then decreased by the long-term treatment with NGF. These results demonstrate that expression of AM and PAMP is regulated by NGF along with time-dependent differentiation: AM gene transcription is transiently activated by NGF, whereas it was suppressed during neuronal differentiation of the cells.

Induced HMGA1a expression causes aberrant splicing of Presenilin-2 pre-mRNA in sporadic Alzheimer's disease

The aberrant splicing isoform (PS2V), generated by exon 5 skipping of the Presenilin-2 (PS2) gene transcript, is a diagnostic feature of sporadic Alzheimer's disease (AD). We found PS2V is hypoxia-inducible in human neuroblastoma SK-N-SH cells. We purified a responsible trans-acting factor based on its binding to an exon 5 fragment. The factor was identified as the high mobility group A1a protein (HMGA1a; formerly HMG-I). HMGA1a bound to a specific sequence on exon 5, located upstream of the 5' splice site. HMGA1a expression was induced by hypoxia and the protein was accumulated in the nuclear speckles with the endogenous splicing factor SC35. Overexpression of HMGA1a generated PS2V, but PS2V was repressed by cotransfection with the U1 snRNP 70K protein that has a strong affinity to HMGA1a. HMGA1a could interfere with U1 snRNP binding to the 5' splice site and caused exon 5 skipping. HMGA1a levels were significantly increased in the brain tissue from sporadic AD patients. We propose a novel mechanism of sporadic AD that involves HMGA1a-induced aberrant splicing of PS2 pre-mRNA in the absence of any mutations.

Cerebral endothelial cells are a major source of adrenomedullin

Adrenomedullin is a peptide hormone with multifunctional biological properties. Its most characteristic effects are the regulation of circulation and the control of fluid and electrolyte homeostasis through peripheral and central nervous system actions. Although adrenomedullin is a vasodilator of cerebral vasculature, and it may be implicated in the pathomechanism of cerebrovascular diseases, the source of adrenomedullin in the cerebral circulation has not been investigated thus far. We measured the secretion of adrenomedullin by radioimmunoassay and detected adrenomedullin mRNA expression by Northern blot analysis in primary cultures of rat cerebral endothelial cells (RCECs), pericytes and astrocytes. We also investigated the expression of specific adrenomedullin receptor components by reverse transcriptase-polymerase chain reaction and intracellular cAMP concentrations in RCECs and pericytes. RCECs had approximately one magnitude higher adrenomedullin production (135 +/- 13 fmol/10(5) cells per 12 h; mean +/- SD, n = 10) compared to that previously reported for other cell types. RCECs secreted adrenomedullin mostly at their luminal cell membrane. Adrenomedullin production was not increased by thrombin, lipopolysaccharide or cytokines, which are known inducers of adrenomedullin release in peripheral endothelial cells, although it was stimulated by astrocyte-derived factors. Pericytes had moderate, while astrocytes had very low basal adrenomedullin secretion. In vivo experiments showed that adrenomedullin plasma concentration in the jugular vein of rats was approximately 50% higher than that in the carotid artery or in the vena cava. Both RCECs and pericytes, which are potential targets of adrenomedullin in cerebral microcirculation, expressed adrenomedullin receptor components, and exhibited a dose-dependent increase in intracellular cAMP concentrations after exogenous adrenomedullin administration. Antisense oligonucleotide treatment significantly reduced adrenomedullin production by RCECs and tended to decrease intraendothelial cAMP concentrations. These findings may suggest an important autocrine and paracrine role for adrenomedullin in the regulation of cerebral circulation and blood-brain barrier functions. Cerebral endothelial cells are a potential source of adrenomedullin in the central nervous system, where adrenomedullin can also be involved in the regulation of neuroendocrine functions.

Adrenomedullin regulates blood-brain barrier functions in vitro

Adrenomedullin (AM) is an important vasodilator in cerebral circulation, and cerebral endothelial cells are a major source of AM. This in vitro study aimed to determine the AM-induced changes in blood-brain barrier (BBB) functions. AM administration increased, whereas AM antisense oligonucleotide treatment decreased transendothelial electrical resistance. AM incubation decreased BBB permeability for sodium fluorescein (mol. wt 376 Da) but not for Evan's blue albumin (mol. wt 67 kDa), and it also attenuated fluid-phase endocytosis. AM treatment resulted in functional activation of P-glycoprotein efflux pump in vitro. Our results indicate that AM as an autocrine mediator plays an important role in the regulation of BBB properties of the cerebral endothelial cells.

Production of cAMP by adrenomedullin in human oligodendroglial cell line KG1C: comparison with calcitonin gene-related peptide and amylin

The actions and the presence of adrenomedullin (AM) were investigated in cultured human oligodendroglial cell line KG1C. AM and AM mRNA were detected in KG1C cells by immunohistochemistry and RT-PCR. mRNAs for calcitonin receptor-like receptor (CRLR) and receptor-activity-modifying proteins (RAMPs) 1, 2 and 3 but not for calcitonin receptors were detected in the cells, while mRNAs for CRLR, calcitonin receptors and all RAMPs were detected in the human cerebellum. Application of AM resulted in time- and concentration-dependent increases in the cAMP level of KG1C cells. Calcitonin gene-related peptide (CGRP) and amylin, peptides structurally related to AM, also increased cAMP. The potencies for the cAMP production of the three peptides were CGRP > or =AM >> amylin with EC(50) of 8, 18, 90 nM, respectively. The responses induced by AM were strongly inhibited by the CGRP(1) receptor antagonist human CGRP(8-37), and inhibited also by the AM receptor antagonist human AM(22-52). In contrast, the responses induced by CGRP or amylin were inhibited only by CGRP(8-37) and not by AM(22-52). The responses induced by all three peptides were unaffected by the amylin receptor antagonist human amylin(8-37). The CGRP(2) receptor agonist human [Cys(Acm)(2,7)]CGRP significantly increased the cAMP level but the increase was smaller than that caused by CGRP. This increase in cAMP was unaffected by CGRP(8-37), AM(22-52) or by amylin(8-37). These results suggest that in KG1C cells, AM increases cAMP through AM and CGRP(1) receptors, whereas CGRP does so through CGRP(1) and CGRP(2) receptors, and amylin exerts its effects through CGRP(1) receptors. Collectively, these findings imply that AM released from oligodendroglial cells may play a role in the regulation of oligodendrocytes via autocrine/paracrine through AM receptors and CGRP(1) receptors.

Adrenomedullin and proadrenomedullin N-terminal 20 peptide (PAMP) in adrenal chromaffin cells

Adrenomedullin (AM) and proadrenomedullin N-terminal 20 peptide (PAMP) are peptides having multiple physiological functions and are most abundantly expressed in the adrenal medulla. In addition to PAMP, PAMP12, a 12 amino acid peptide with sequence identity to PAMP between amino acids 9-20, has also been shown to be expressed in the adrenal medulla. AM, PAMP and PAMP12 are released along with catecholamines by regulated exocytosis upon stimulation of adrenal chromaffin cells. PAMP and PAMP12 regulate catecholamine release and synthesis by interfering with nicotinic cholinergic receptors in these chromaffin cells. AM may also cause gradual release of catecholamine from these cells. AM, PAMP and PAMP12 are endogenous peptides that modulate chromaffin cell function via different mechanisms.

Selective expression of aquaporin 1, 4 and 5 in the rat middle ear

The middle ear cavity is an air-filled space that must be maintained for effective sound transmission to the inner ear. To examine the mechanisms of water homeostasis in the middle ear, we investigated whether aquaporins (AQPs), a family of water-permeable channels, were expressed in the middle ear. Reverse transcription-polymerase chain reaction and immunoblot analyses revealed that mRNAs encoding AQP1, 4 and 5 (but not 2 or 3) subtypes were expressed in rat middle ear epithelium; AQP1, 4 and 5 were detected as 28-, 30- and 30-kDa proteins, respectively. Immunohistochemical analysis showed that AQP1 was localized at capillary endothelial cells and fibroblasts in lamina propria mucosae; AQP4 was present solely at the basolateral membrane of ciliated cells, whereas AQP5 was on the apical surface of ciliated cells as well as of flat and columnar epithelial cells. The characteristic different localizations of AQP1, 4 and 5 subtypes in the middle ear suggest that middle ear water homeostasis requires the coordinated operation of these AQPs.

Possible physiological roles of proteolytic products of actin in neutrophils of patients with Behçet's disease

A truncated actin with an N-terminus of Met-44 is known to be selectively increased in neutrophils of patients with Behçet's disease and to be generated proteolytically by PMN-elastase (Yamashita S. et al., Biol. Pharm. Bull., 23, 519-522 (2000); Biol. Pharm. Bull., 24, 119-122 (2001)). In this study, the functions of the N-terminal peptide consisting of Asp-2 to Val-43 of beta-actin (42-merP) and the truncated actin with an N-terminus of Met-44 were examined. We first confirmed that the 42-merP existed in the patient plasma. The motility of human peripheral blood neutrophils and neutrophilic granulocytes differentiated from HL-60 cells was suppressed by the 42-merP. Furthermore, when neutrophil-like cells from HL-60 cells were preincubated with 10 nm 42-merP, migration of the cells induced by chemotactic factors such as fMLP and IL-8 was suppressed. The release of PMN-elastase, which is a neutrophil granular enzyme that is responsible for the production of the 42-merP and truncated actin, was suppressed by pretreating the neutrophils with 42-merP before fMLP-stimulation. The truncated actin was unable to polymerize in 0.1 M KCl, suggesting that the increase of truncated actin damages the reconstitution capacity of actin in neutrophils of the patients. These results suggest that the increase of 42-merP and truncated actin in patients with Behçet's disease changes functions of neutrophils

Nicotine, alcohol, methamphetamine, and inhalant dependence: a comparison of clinical features with the use of a new clinical evaluation form

The purpose of the present study was to develop a new clinical evaluation form to compare the clinical features of nicotine dependence with those associated with alcohol, methamphetamine, and inhalant dependence. The clinical evaluation form consisted of six scoring items: subjective effects, tolerance, liking (of drug), social disturbance, withdrawal syndrome, and acute psychic and acute physical disorders. A preliminary clinical investigation was performed to test the validity of the evaluation form. Study subjects were those showing dependence on nicotine (n = 25), alcohol (n = 36), methamphetamine (n = 11), and inhalants (n = 6). All subjects met the Diagnostic and Statistical Manual of Mental Disorders (4th ed.) diagnostic criteria for drug dependence, as defined by the Work Group for the chapter "Substance-Related Disorders": M. A. Schuckit, J. E. Helzer, L. B. Cottler, T. Crowley, P. E. Nathan, & G. E. Woody. Nicotine produced subjective effects, tolerance, liking, and psychic withdrawal symptoms, all of which were mild in degree. However, nicotine did not produce social disturbance, physical withdrawal symptoms, or acute psychic or acute physical disorders. With alcohol, acute psychic and acute physical disorders were prominent, and alcohol also produced a moderate degree of influence on various other items that were evaluated. Methamphetamine produced the most serious acute psychic and acute physical disorders with intensive subjective effects. Inhalants were characterized by an intensive degree of acute psychic disorders and subjective effects with mild withdrawal syndrome. Our study findings revealed that the clinical features of drug dependence could be evaluated by using the new clinical evaluation form. Further study is required to clarify the clinical features of nicotine dependence compared with those of other drugs of dependence.

Neurobiological mechanisms of nicotine craving

Nicotine induces craving, but the degree of craving is believed to be milder than that with other abused drugs. In this article, the neurobiological mechanisms of craving for nicotine and other drugs are reviewed, focusing especially on three factors that can be involved in the development of craving. The first factor is the affective symptoms of withdrawal, the neural basis of which may involve neuroadaptations (desensitization) within the reward systems. Affective symptoms experienced during withdrawal from nicotine are milder than those experienced in withdrawal from other drugs, probably because of its mode of action on the reward systems, which is similar to that of natural rewards. The second factor is the conditioning process, in which environmental stimuli can gain properties of a secondary reinforcer. Nicotine has weak but reliable conditioning effects, and the brain region mediating those effects of nicotine involves the ventral tegmental area. The third factor is a cognitive (memory) process, but little is known about this area.

Up-regulation of cell surface sodium channels by cyclosporin A, FK506, and rapamycin in adrenal chromaffin cells

Treatment of cultured bovine adrenal chromaffin cells with cyclosporin A (CsA) increased cell surface [(3)H]saxitoxin ([(3)H]STX) binding by 56% in a time (t(1/2) = 15.2 h)- and concentration (EC(50) = 2.9 microM)-dependent manner but did not change the K(d) value. In CsA-treated cells, veratridine-induced (22)Na(+) influx was augmented with no change in the EC(50) of veratridine; also, alpha- and beta-scorpion venom and Ptychodiscus brevis toxin-3 enhanced veratridine-induced (22)Na(+) influx in a more than additive manner, as in nontreated cells. CsA treatment for 1 to 24 h inhibited calcineurin activity, measured by the in vitro assay, with the IC(50) of 0.6 microM but did not alter cellular level of calcineurin. FK506 or rapamycin elevated [(3)H]STX binding by 36 or 25%, whereas GPI-1046, an immunophilin ligand incapable to inhibit calcineurin, or okadaic acid, an inhibitor of protein phosphatases 1 and 2A, had no increasing effect. The rise of [(3)H]STX binding by CsA was attenuated by the coincident treatment with brefeldin A (BFA), an inhibitor of vesicular exit from the trans-Golgi network. The internalization rate of cell surface Na(+) channels, as determined in the presence of BFA, was decreased in CsA (but not rapamycin)-treated cells (t(1/2) = 20.3 h), compared with nontreated cells (t(1/2) = 13.7 h). CsA treatment, however, did not elevate cellular levels of Na(+) channel alpha-subunit and Na(+) channel alpha- and beta(1)-subunit mRNAs. In CsA-treated cells, veratridine-induced (45)Ca(2+) influx via voltage-dependent Ca(2+) channels and catecholamine secretion were enhanced, whereas high K(+)-induced (45)Ca(+) influx was not. Thus, the inhibition of calcineurin or rapamycin-binding protein causes up-regulation of cell surface functional Na(+) channels via modulating externalization and internalization of Na(+) channels, thus enhancing Ca(2+) channel gating and catecholamine secretion.

Effects of conjugated linoleic acid on serum leptin concentration, body-fat accumulation, and β-oxidation of fatty acid in OLETF rats

We investigated the efficacy of a 4-wk supplementation of conjugated linoleic acid (CLA) as free fatty acid (FFA) or triacylglycerol (TG) on serum leptin concentration, body-fat accumulation, and mitochondrial beta-oxidation in Otsuka Long-Evans Tokushima Fatty (OLETF) rats. A significant reduction of serum leptin concentration (42%) and a decrease in the wet weights of perirenal, epididymal, and omental/visceral-adipose tissue in TG-CLA and FFA-CLA groups were found in comparison with the OLETF control group. Both forms of CLA supplementation produced a 5.2% decrease in body weight compared with the control even though food intake was similar in the OLETF groups. Moreover, both forms of CLA enhanced carnitine-palmitoyltransferase activity in brown adipose tissue, perirenal adipose tissue, red gastrocnemius muscle, and liver in comparison with the OLETF control group. Serum concentrations of non-esterified fatty acid and TG also were reduced in rats fed diets supplemented with TG-CLA and FFA-CLA.

Down-regulation of cell surface insulin receptors by sarco(endo)plasmic reticulum Ca2+-ATPase inhibitor in adrenal chromaffin cells

Long-term (> or =12 h) treatment of cultured bovine adrenal chromaffin cells with thapsigargin (TG), an inhibitor of sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA), caused a time (t(1/2)=16.3 h)- and concentration (IC50=37.8 nM)-dependent decrease of cell surface 125I-insulin binding by 35%, but did not change the Kd value. TG caused a sustained increase of cytoplasmic concentration of Ca2+ ([Ca2+]c) in a biphasic manner, and the effect of TG on 125I-insulin binding was abolished by BAPTA-AM. Western blot analysis showed that TG lowered insulin receptor (IR) beta-subunit level in membrane, but did not alter total cellular levels of IR precursor and IR beta-subunit. Internalization of cell surface IR, as measured by using brefeldin A, an inhibitor of vesicular exit from the trans-Golgi network (TGN), was not changed by TG. These results suggest that inhibition of SERCA by TG and the subsequent increase of [Ca2+]c down-regulates cell surface IR by retarding externalization of IR from the TGN.

Selective inhibition of nicotinic cholinergic receptors by proadrenomedullin N-terminal 12 peptide in bovine adrenal chromaffin cells

We studied whether a novel proadrenomedullin derived peptide was present and what was its physiological function in cultured bovine adrenal chromaffin cells. We found a high level of proadrenomedullin N-terminal 12 peptide (PAMP-12) which consists of a peptide from 9th amino acid to 20th amino acid of proadrenomedullin N-terminal 20 peptide (PAMP-20). PAMP-12 was released from the cells along with catecholamine upon stimulation of nicotinic cholinergic receptors. When PAMP-12 was added in the incubation medium, this peptide inhibited nicotinic receptor-mediated catecholamine release and influx of Na(+) and Ca(2+) into the cells. PAMP-12 did not affect catecholamine release evoked by histamine or by depolarization by high concentration of potassium. PAMP-12 also inhibited synthesis of catecholamines as well as the activation of tyrosine hydroxylase by nicotinic stimulation. Thus, PAMP-12 is an endogenous peptide that regulates release and synthesis of catecholamines by acting on nicotinic cholinergic receptors in an autocrine manner in adrenal chromaffin cells.

Characterization of a protease responsible for truncated actin increase in neutrophils of patients with Behçet's disease

As described previously (Yamashita S. et al., Biol. Pharm. Bull., 23, 519-522 (2000)), high levels of a truncated actin with an N-terminus of Met-44 were detected in neutrophils of patients with Behcet's disease. Since the increase of the truncated actin in neutrophils of patients may be important for understanding the pathology of Behçet's disease, the mechanism of the truncated actin formation was studied. First, to investigate the presence of a specific protease, which cleaves the actin at the site between Val-43 and Met-44, a peptide with a partial amino acid sequence of actin from the N-terminal Pro-38 to Asp-51 was synthesized as the protease substrate. The synthesized peptide was digested with cytosolic fractions of neutrophils from patients and healthy volunteers, and digestion products were analyzed by C18-reverse phase HPLC. The chromatograms of these samples showed that an endoprotease, which cleaved the peptide at a specific site, was present in cytosolic fractions of neutrophils from patients with Behçet's disease. Then, the effects of various kinds of protease inhibitors on the digestion of the peptide were investigated in order to identify the responsible endoprotease. The digestion of the peptide was suppressed by 4-(2-aminoethyl) benzenesulfonylfluoride (AEBSF, a serine protease inhibitor) and N-methoxysuccinyl-Ala-Ala-Pro-Val chloromethylketone (CMK, a polymorphonuclear (PMN)-elastase inhibitor) in the presence of EDTA. Furthermore, PMN-elastase was found to cleave the substrate peptide and actin at the site between Val-43 and Met-44. These results lead to the conclusion that the PMN-elastase is responsible for cleavage of actin at the N-terminal site between Val-43 and Met-44 in neutrophils from patients with Behçet's disease.

Aquaporin subtypes in rat cerebral microvessels

We investigated the expression of aquaporin (AQP) subtypes in the rat cerebral microvessels by reverse transcription-polymerase chain reaction, immunoblotting and immunohistochemistry. mRNA for AQP4, but not for AQP1, 2, 3 or 5, was detected in the microvessels. Immunoblot analysis showed that AQP4 protein was detected as a 30 kDa band with higher molecular weight bands. Immunohistochemical staining showed that AQP4 was located on cell surface of the cerebral microvessels. These results suggest that AQP4 in the cerebral microvessels is involved in the regulation of water transport between blood and brain.

Adrenomedullin receptors in rat choroid plexus

To characterize transmembrane signaling of adrenomedullin (AM) in the choroid plexus, we studied the effects of AM on cyclic AMP (cAMP) and cyclic GMP (cGMP) levels as well as expression of mRNA for AM receptor in the rat choroid plexus slices. AM or calcitonin gene-related peptide (CGRP) increased cAMP (but not cGMP) level in a concentration-dependent manner, with AM being much more potently than CGRP. AM mRNA as well as calcitonin-receptor-like receptor mRNA and receptor-activity-modifying protein 2 mRNA, were highly expressed in the choroid plexus. Our biochemical and pharmacological studies may raise the possibility that choroid plexus secretes AM into the cerebrospinal fluid, and AM regulates choroid plexus function in an autocrine/paracrine manner via acting on AM-specific receptors.