Non-atrophic gastric mucosa is an independently associated factor for superficial non-ampullary duodenal epithelial tumors: a multicenter, matched, case-control study.

BACKGROUND/AIMS: The etiology of superficial non-ampullary duodenal epithelial tumors (SNADETs) remains unclear. Recent studies have reported conflicting associations between duodenal tumor development and Helicobacter pylori infection or endoscopic gastric mucosal atrophy. As such, the present study aimed to clarify the relationship between SNADETs and H. pylori infection and/or endoscopic gastric mucosal atrophy. METHODS: This retrospective case-control study reviewed data from 177 consecutive patients with SNADETs who underwent endoscopic or surgical resection at seven institutions in Japan over a three-year period. The prevalence of endoscopic gastric mucosal atrophy and the status of H. pylori infection were compared in 531 sex- and age-matched controls selected from screening endoscopies at two of the seven participating institutions. RESULTS: For H. pylori infection, 85 of 177 (48.0%) patients exhibited SNADETs and 112 of 531 (21.1%) control patients were non-infected (p<0.001). Non-atrophic mucosa (C0 to C1) was observed in 96 of 177 (54.2%) patients with SNADETs and 112 of 531 (21.1%) control patients (p<0.001). Conditional logistic regression analysis revealed that non-atrophic gastric mucosa was an independent risk factor for SNADETs (odds ratio, 5.10; 95% confidence interval, 2.44-8.40; p<0.001). CONCLUSION: Non-atrophic gastric mucosa, regardless of H. pylori infection status, was a factor independently associated with SNADETs.

Applicability of new proposed criteria for iron deficiency in Japanese patients with heart failure.

AIMS: Iron deficiency (ID) is a common co-morbidity in patients with heart failure (HF). A recent study showed that ID defined by the current guideline criteria was not associated with worse clinical outcomes, and new ID criteria was proposed in patients with HF. However, the external applicability of the new proposed criteria is unclear. We sought to investigate the applicability of the proposed ID criteria in Japanese patients with HF. METHODS AND RESULTS: We prospectively examined 763 patients with chronic HF from a Japanese multicentre registry. The proposed ID criteria were transferrin saturation (TSAT) < 20% and serum iron ≤13 mmol/L and the guideline ID criteria were serum ferritin <100 ng/mL or, when ferritin was 100-299 ng/mL, TSAT <20%. Among all patients (456 male, mean age 71 ± 13 years), 213 (28%) and 444 (58%) met the proposed and guideline ID criteria, respectively. During a median follow-up period of 436 days (interquartile range 297-565), the primary outcome of all-cause mortality occurred in 56 (7%) patients. There was no significant difference in the primary outcome between the patients with and without guideline ID criteria (P = 0.32), whereas patients with serum iron ≤10 µmol/L showed higher mortality (P = 0.002). In multivariable Cox regressions, the proposed ID criteria, but not guideline ID criteria, were independently associated with the risk of all-cause mortality (HR 2.01, 95% CI 1.16-3.51 and HR 1.32, 95% CI 0.76-2.28, respectively), even after adjustment for covariates. CONCLUSIONS: When defined by the proposed criteria and not the guideline criteria, ID was associated with higher mortality in patients with chronic HF, suggesting that the proposed ID criteria is applicable to the Japanese population.

Long-Term Results of Proton Therapy for Hepatocellular Carcinoma Using Four-Dimensional Computed Tomography Planning without Fiducial Markers.

We report here the long-term results of marker-less respiratory-gated proton therapy (PT), without fiducial markers for hepatocellular carcinoma (HCC), which was planned using a four-dimensional computed tomography technique. Local tumor control (LTC) and overall survival (OS) were estimated using the Kaplan-Meier method. Toxicity was graded per CTCAE v5.0. Patients (n = 105; median age 73 years, range 38-90 years) with 128 lesions were treated. The median radiation dose was 66 gray relative biological effectiveness (GyRBE) (range, 52.8-82.5 GyRBE) delivered in 2.0 to 6.6 GyRBE fractions, depending on lesion volume, the involved liver, and the patient's condition. The median follow-up of surviving patients was 63 months (range, 1-126 months), and the 5-year LTC and OS rates were 93.2% and 40.4%, respectively. Univariate and multivariate analyses identified tumors near the gastrointestinal tract as an independent risk factor for local recurrence and revealed that hepatic reserve, tumor stage, performance status, operability, sex, and portal vein thrombosis were independent risk factors for OS. Acute and late treatment-related grade 3 toxicities were experienced by eight patients (7.6%). Adverse events ≥ grade 4 were not evident. Marker-less respiratory-gated PT for HCC is a safe and effective treatment without severe complications.

Usefulness of the clip-and-snare method using the pre-looping technique for endoscopic submucosal dissection of gastric neoplasia: a randomized controlled trial.

BACKGROUND: The clip-and-snare method using the pre-looping technique (CSM-PLT) was developed as a traction method for endoscopic submucosal dissection (ESD) of gastric neoplasia. However, its usefulness has not been clearly established; thus, we aimed to assess the efficacy of CSM-PLT in gastric ESD. METHODS: In this multicenter, randomized controlled trial, patients with gastric adenoma or carcinoma with absolute or expanded indications for ESD were randomized into conventional ESD and CSM-PLT groups, using the minimization method based on operator experience, tumor location, tumor size, and excision device. The primary endpoint was ESD procedure time. Secondary endpoints were en bloc and R0 resection rates, and complications. RESULTS: We enrolled 402 patients between July 2017 and February 2020. After excluding patients with deviations from the protocol, we finally analyzed the data of 192 and 186 patients in the conventional and CSM-PLT groups, respectively. The procedure time was significantly shorter in the CSM-PLT group than in the conventional group (58.0 vs. 69.7 min; P=0.009). All lesions were resected en bloc. The R0 resection rate tended to be higher in the CSM-PLT group (P=0.09). No significant differences in complications were observed between the 2 groups. CONCLUSIONS: CSM-PLT is beneficial for gastric ESD when compared with the conventional technique. CSM-PLT significantly reduced procedure times and improved R0 resection rates.

Efficacy of polyglycolic acid sheeting with fibrin glue for perforations related to gastrointestinal endoscopic procedures: a multicenter retrospective cohort study.

OBJECTIVES: Gastrointestinal (GI) perforations are one of the major adverse events of endoscopic procedures. Polyglycolic acid (PGA) sheets with fibrin glue have been reported to close GI perforations. However, its clinical outcome has not yet been fully investigated; thus, we conducted a multicenter retrospective observational study to assess the efficacy of PGA sheeting for GI perforation. METHODS: The medical records of patients who underwent PGA sheeting for endoscopic GI perforations between April 2013 and March 2018 in 18 Japanese institutions were retrospectively analyzed. PGA sheeting was applied when the clip closure was challenging or failed to use. Perforations were filled with one or several pieces of PGA sheets followed by fibrin glue application through an endoscopic catheter. Nasal or percutaneous drainage and endoscopic clipping were applied as appropriate. Clinical outcomes after PGA sheeting for intraoperative or delayed perforations were separately evaluated. RESULTS: There were 66 intraoperative and 24 delayed perforation cases. In intraoperative cases, successful closure was attained in 60 cases (91%). The median period from the first sheeting to diet resumption was 6 days (interquartile range [IQR], 4-8.8 days). Large perforation size (≥ 10 mm) and duodenal location showed marginal significant relationship to higher closure failure of intraoperative perforations. In delayed perforation cases, all cases had successful closure. The median period from the first sheeting to diet resumption was 10 days (IQR, 6-37.8 days). No adverse events related to PGA sheeting occurred. CONCLUSION: Endoscopic PGA sheeting could be a therapeutic option for GI perforations related to GI endoscopic procedures.

Lenvatinib-induced tumor lysis syndrome in a patient with advanced hepatocellular carcinoma: a case report.

Tumor lysis syndrome (TLS) is an oncologic emergency caused by release of intracellular tumor components due to massive tumor lysis and is rare in patients with hepatocellular carcinoma (HCC). We describe a case of TLS with rupture of HCC induced by lenvatinib in a patient with advanced HCC. A 72-year-old man who presented with right upper abdominal pain was diagnosed as having advanced HCC with a high tumor burden by contrast-enhanced computed tomography and percutaneous hepatic tumor biopsy. He was started on lenvatinib 12 mg once daily when his tumor progressed despite one-shot hepatic arterial infusion chemotherapy. On day 2 of treatment with lenvatinib, he developed severe upper abdominal pain and was diagnosed as having TLS with HCC rupture by laboratory tests and contrast-enhanced computed tomography. Urgent treatment with transarterial embolization, hemodialysis, and blood transfusion therapy was successful. The patient was then restarted on oral lenvatinib at a reduced dose without recurrence of TLS. TLS is a rare potential complication of lenvatinib in patients with advanced HCC and a high tumor burden.

Efficacy of Endoscopic Evaluation of Acute Radiation Esophagitis during Chemoradiotherapy with Proton Beam Therapy Boost for Esophageal Cancer.

BACKGROUND/AIM: To evaluate the utility of endoscopy for assessing radiation esophagitis during chemoradiotherapy (CRT) with proton beam therapy (PBT) boost for esophageal cancer. METHODS: Between December 2012 and December 2016, 38 patients with esophageal cancer were treated with CRT with PBT boost. To evaluate radiation esophagitis, endoscopy was performed after administration of CRT with standard PBT boost (total dose 50-60 Gy relative biological effectiveness [RBE]). Radiation esophagitis was evaluated and classified into 5 newly developed endoscopic grades (Fukui Acute Radiation Esophagitis [FARE] grade). The additional PBT boost was then adjusted and delivered (2-20 Gy [RBE]) to a maximum total dose of 74.4 Gy (RBE) based on the degree of radiation esophagitis, probability of residual tumor, and patient's general condition. To evaluate the utility of endoscopic examination, the incidences of adverse events graded according to National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE, version 4.0) were determined at the time of endoscopic examination after CRT with standard PBT boost (50-60 Gy [RBE]) and at the completion of treatment (60-74.4 Gy [RBE]), as well as during the 90 days from the beginning of treatment. RESULTS: There was a significant correlation between FARE grade and CTCAE esophagitis grade (ρ = 0.48; p = 0.03). Moreover, endoscopy detected severe esophagitis in an asymptomatic patient. Radiation dose escalation was achieved without severe acute adverse events. There was no significant difference between the incidence of acute toxicity at the time of the CRT with standard PBT boost (50-60 Gy [RBE]) and the higher dose at the completion of treatment (60-74.4 Gy [RBE]), which suggests this dose escalation strategy is safe. CONCLUSION: Endoscopic evaluation of radiation esophagitis using FARE grades was safely performed and useful for adjusting added radiation to ensure the safety of escalations in CRT with PBT boost for esophageal cancer.

Is Additional Surgery Always Sufficient for Preventing Recurrence After Endoscopic Submucosal Dissection with Curability C-2 for Early Gastric Cancer?

BACKGROUND: When a lesion does not meet the curative criteria of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC), referred to as non-curative resection or curability C-2 in the guidelines, an additional surgery is the standard therapy because of the risk of lymph node metastasis (LNM). OBJECTIVE: This study aimed to identify high-risk patients for recurrence after additional surgery for curability C-2 ESD of EGC. METHODS: This multicenter retrospective cohort study enrolled 1064 patients who underwent additional surgery after curability C-2 ESD for EGC. We evaluated the recurrence rate and the risk factors for recurrence after additional surgery in these patients. RESULTS: The 5-year recurrence rate after additional surgery was 1.3%. Multivariate Cox analysis revealed that the independent risk factors for recurrence after additional surgery were LNM (hazard ratio [HR] 32.47; p < 0.001) and vascular invasion (HR 4.75; p = 0.014). Moreover, patients with both LNM and vascular invasion had a high rate of recurrence after additional surgery (24.6% in 5 years), with a high HR (119.32) compared with those with neither LNM nor vascular invasion. Among patients with no vascular invasion, a high rate of recurrence was observed in those with N2/N3 disease according to the American Joint Committee on Cancer TNM staging system (27.3% in 5 years), in contrast with no recurrence in those with N1 disease. CONCLUSIONS: Patients with both LNM (N1-N3) and vascular invasion, as well as those with N2/N3 disease but no vascular invasion, would be candidates for adjuvant chemotherapy after additional surgery for curability C-2 ESD of EGC.

Age Affects Clinical Management after Noncurative Endoscopic Submucosal Dissection for Early Gastric Cancer.

BACKGROUND: Additional surgery is recommended after noncurative endoscopic submucosal dissection (ESD) for early gastric cancer due to the risk of lymph node metastasis. However, age may affect the clinical management of these patients. OBJECTIVES: The aim of our retrospective multicenter study was to clarify whether age affects decision-making after noncurative ESD and if the decision affects long-term outcomes. METHODS: Age was classified as follows: non-elderly, <70 years (n = 811); elderly, 70-79 years (n= 760); and super-elderly, ≥80 years (n = 398). Age associations with the selection for additional surgery were evaluated using logistic regression analysis. Long-term outcomes were also evaluated in each age group. RESULTS: Age was inversely related to the rate of additional surgery, which ranged from 70.0% in the non-elderly group to 20.1% in the super-elderly group (p < 0.001). On multivariate analysis, age <70 years (versus age ≥80 years) was associated with the -selection of additional surgery (OR 18.6). Overall survival (OS) in patients who underwent additional surgery was -significantly higher in the non-elderly and elderly groups (p< 0.001), whereas the difference was not significant in the super-elderly group (p = 0.23). CONCLUSIONS: Despite the fact that almost 80% of super-elderly patients did not undergo additional surgery, the difference of OS between patients with and without additional surgery was not significant only in patients ≥80 years. Therefore, establishment of criteria for selecting treatment methods after noncurative ESD in elderly patients is required.

Long-term outcomes after non-curative endoscopic submucosal dissection for early gastric cancer according to hospital volumes in Japan: a multicenter propensity-matched analysis.

BACKGROUND: There is a lack of data regarding the long-term outcomes of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) without curative resection, and the relationship of these outcomes with hospital volumes remains unclear. This study evaluated long-term outcomes of patients who underwent ESD for EGC without curative resection according to hospital volumes in Japan. METHODS: This multicenter retrospective study evaluated 1,969 patients who did not meet the criteria of the Japanese Gastric Cancer Association for curative resection between January 2000 and August 2011. Hospitals were classified according to the annual number of ESD procedures: low- and medium-volume group (LMVG), high-volume group (HVG), and very high-volume group (VHVG). Clinicopathological features, overall survival (OS), disease-specific survival (DSS), and recurrence-free survival (RFS) were compared across groups after a generalized propensity score matching analysis. RESULTS: In 495 pairs of generalized propensity score-matched patients, the 5-year OS, DSS, and RFS rates were 81.5%, 97.9%, and 97.6% for LMVG; 86.9%, 98.2%, and 97.0% for HVG; and 85.4%, 98.5%, and 97.6% for VHVG, respectively. The 5-year DSS and RFS rates did not significantly differ among the three groups. However, 5-year OS was significantly worse in the LMVG than in the HVG and VHVG (P < 0.001 and P = 0.008, respectively). CONCLUSIONS: DSS and RFS in patients with EGC who did not meet the criteria for curative resection did not differ across hospital volumes in Japan. Even in cases in which ESD for EGC involved non-curative resection, the procedure is feasible across Japanese hospitals with different volumes.

The Role of an Undifferentiated Component in Submucosal Invasion and Submucosal Invasion Depth After Endoscopic Submucosal Dissection for Early Gastric Cancer.

BACKGROUND/AIMS: The role of an undifferentiated component in submucosal invasion and submucosal invasion depth (SID) for lymph node metastasis (LNM) of early gastric cancer (EGC) with deep submucosal invasion (SID ≥500 µm from the muscularis mucosa) after endoscopic submucosal dissection (ESD) has not been fully understood. This study aimed to clarify the risk factors (RFs), including these factors, for LNM in such patients. METHODS: We enrolled 513 patients who underwent radical surgery after ESD for EGC with deep submucosal invasion. We evaluated RFs for LNM, including an undifferentiated component in submucosal invasion and the SID, which was subdivided into 500-999, 1,000-1,499, 1,500-1,999, and ≥2,000 µm. RESULTS: LNM was detected in 7.6% of patients. Multivariate analysis revealed that an undifferentiated component in submucosal invasion (OR 2.22), in addition to tumor size >30 mm (OR 2.51) and lymphatic invasion (OR 3.07), were the independent RFs for LNM. However, the SID was not significantly associated with LNM. CONCLUSION: An undifferentiated component in submucosal invasion was one of the RFs for LNM, in contrast to SID, in patients who underwent ESD for EGC with deep submucosal invasion. This insight would be helpful in managing such patients.

Unclassified hepatocellular adenoma in a middle-aged woman with glucose intolerance.

The patient was a 43-year-old woman with obesity (body mass index: 29.1) and glucose intolerance who was not taking oral contraceptives. An ultrasound showed a hypoechoic hepatic mass. Dynamic contrast-enhanced computed tomography revealed a lesion in segment 6 that showed homogeneous and slight-to-moderate enhancement in the arterial phase with persistent enhancement during the portal and equilibrium phases. On magnetic resonance (MR) imaging, the lesion demonstrated hyperintensity on T2- and diffusion-weighted images and hypointensity in the hepatobiliary phase of gadoxetic-acid-enhanced MR imaging. In addition to the main lesion, approximately ten small hypointense lesions were seen in the hepatobiliary phase. The background liver was fatty without the deformity of chronic liver disease. Based on the pathological findings of the main lesion biopsy, it was initially suspected to be a non-neoplastic lesion with hematoxylin and eosin staining and initial immunohistochemical staining. However, the radiological findings indicated a neoplastic lesion. Additional immunohistochemical staining, including that for α-smooth muscle actin and organic anion transporter polypeptide 1B3, in combination with the radiological findings resulted in a diagnosis of unclassified hepatocellular adenoma. The other small lesions were presumed to be related to the main lesion.

Evaluation of an e-learning system for diagnosis of gastric lesions using magnifying narrow-band imaging: a multicenter randomized controlled study.

Background and study aim Magnifying narrow-band imaging (M-NBI) is useful for the accurate diagnosis of early gastric cancer (EGC). However, acquiring skill at M-NBI diagnosis takes substantial effort. An Internet-based e-learning system to teach endoscopic diagnosis of EGC using M-NBI has been developed. This study evaluated its effectiveness. Participants and methods This study was designed as a multicenter randomized controlled trial. We recruited endoscopists as participants from all over Japan. After completing Test 1, which consisted of M-NBI images of 40 gastric lesions, participants were randomly assigned to the e-learning or non-e-learning groups. Only the e-learning group was allowed to access the e-learning system. After the e-learning period, both groups received Test 2. The analysis set was participants who scored < 80 % accuracy on Test 1. The primary end point was the difference in accuracy between Test 1 and Test 2 for the two groups. Results A total of 395 participants from 77 institutions completed Test 1 (198 in the e-learning group and 197 in the non-e-learning group). After the e-learning period, all 395 completed Test 2. The analysis sets were e-learning group: n = 184; and non-e-learning group: n = 184. The mean Test 1 score was 59.9 % for the e-learning group and 61.7 % for the non-e-learning group. The change in accuracy in Test 2 was significantly higher in the e-learning group than in the non-e-learning group (7.4 points vs. 0.14 points, respectively; P < 0.001). Conclusion This study clearly demonstrated the efficacy of the e-learning system in improving practitioners' capabilities to diagnose EGC using M-NBI.Trial registered at University Hospital Medical Information Network Clinical Trials Registry (UMIN000008569).

A case of Trousseau syndrome associated with a mucosa-associated lymphoid tissue lymphoma disseminated to the mesenteric adipose tissue.

A 66-year-old man with recurrent stroke within a short period of time was referred to our department from the neurology department to rule out any malignancy. An endoscopic examination revealed a white depressed lesion in the body of the stomach, and computed tomography revealed a high-density area in the mesentery around the stomach. A mucosa-associated lymphoid tissue (MALT) lymphoma was detected from both the stomach biopsy and resected mesenteric specimen. Systemic chemotherapy was administered for the MALT lymphoma (Lugano classification stage IV). Cerebral infarction did not occur after the treatment. We concluded that Trousseau syndrome associated with the MALT lymphoma disseminated to the mesenteric adipose tissue. A MALT lymphoma has a small probability of occurring in Trousseau syndrome.

Interobserver agreement in detection of "white globe appearance" and the ability of educational lectures to improve the diagnosis of gastric lesions.

BACKGROUND: White globe appearance (WGA) refers to a small white lesion of globular shape underneath cancerous gastric epithelium that can be clearly visualized by magnifying endoscopy with narrowband imaging (M-NBI). WGA has been reported to be a novel endoscopic marker that is highly specific in differentiating early gastric cancer (GC) from low-grade adenoma, and has a significantly higher prevalence in early GCs than in noncancerous lesions. However, interobserver agreement in detecting WGA and whether training intervention can improve diagnostic accuracy are unknown. METHODS: Twenty sets of M-NBI images were examined by 16 endoscopists. The endoscopists attended a lecture about WGA, and examined the images again after the lecture. Interobserver agreement in detecting WGA in the second examination and increases in the proportion of correct diagnoses and the degree of confidence of diagnoses of cancerous lesions were evaluated. RESULTS: The kappa value for interobserver agreement in detecting WGA in the second examination was 0.735. The proportion of correct diagnoses was significantly higher in the second examination compared with the first examination when WGA was present (95.5% vs 55.4%; P < 0.001), but not when WGA was absent (61.6% vs 52.7%; P = 0.190). The proportion of correct diagnoses with a high degree of confidence was significantly higher in the second examination, both with WGA (91.1% vs 29.5%; P < 0.001) and without WGA (36.6% vs 20.5%; P = 0.031). CONCLUSIONS: The detection of WGA by endoscopists was highly reproducible. A brief educational lecture about WGA increased the proportion of correct diagnoses and the degree of confidence of diagnoses of GC with WGA.

[Case of acute necrotizing esophagitis associated with AA amyloidosis secondary to bronchiectasis].

An 82-year-old woman with a history of bronchiectasis for 20 years was admitted to our hospital with anorexia and diarrhea. Sigmoidoscopy showed multiple mucosal erythematous areas and erosions. Histologic examination with Congo red stain revealed massive amyloid deposition around the submucosal vessels as well as in the parenchyma of the mucosa and submucosa. With immunohistochemistry, the diagnosis of secondary/reactive AA amyloidosis was confirmed. Esophagogastroduodenoscopy demonstrated diffuse dark brown mucosa, establishing the diagnosis of acute necrotizing esophagitis. Ischemia associated with amyloid deposition of the vessels in the esophagus was considered to be a possible etiology of acute necrotizing esophagitis. Additionally, gastric outlet obstruction and gastroesophageal reflux associated with gastroduodenal erosions caused by amyloid deposition were supposed to be another factor. Amyloid deposition in the esophageal mucosa may cause a reduction in mucosal defense that is responsible for the pathogenesis. We report the first case of acute necrotizing esophagitis associated with amyloidosis.

Different binding property of STIM1 and its novel splice variant STIM1L to Orai1, TRPC3, and TRPC6 channels.

Stromal interaction molecule 1 (STIM1) is the endoplasmic reticulum (ER) Ca(2+) sensor to control ER Ca(2+) levels. A recent study has shown that STIM1L, a new splice variant of STIM1, is expressed in various tissues of rodent and in human skeletal muscle, and that the interaction of STIM1L with actin filament allows rapid activation of store-operated Ca(2+) entry (SOCE) mediated through Orai1 channels. Here, we characterize mRNA expression and function of human STIM1 and STIM1L, and compare their binding property to Orai1 functioning as store-operated Ca(2+) channels (SOCCs), and TRPC3 (transient receptor potential canonical 3) and TRPC6 channels functioning as endothelin type A receptor (ET(A)R)-operated Ca(2+) channels (ROCCs). Although mRNA for STIM1 was ubiquitously expressed in human tissues, STIM1L was detected only in skeletal muscle. STIM1L augmented thapsigargin- and endothelin-1-induced SOCE more strongly than STIM1 in human embryonic kidney 293 cells stably expressing ET(A)R, whereas, it tends to suppress ET(A)R-operated Ca(2+) entry (ROCE) via TRPC3 and TRPC6 more strongly than STIM1. Coimmunoprecipitation experiments have revealed that when compared with STIM1, STIM1L binds more abundantly to Orai1 and also to TRPC3 and TRPC6. These results suggest that the higher binding capacity of STIM1L to SOCCs and ROCCs plays an important role in the regulation of Ca(2+) signaling such as the augmentation of SOCE via Orai1 and the inhibition of ROCE via TRPC3 and TRPC6.

Adenylate cyclase/cAMP/protein kinase A signaling pathway inhibits endothelin type A receptor-operated Ca²âº entry mediated via transient receptor potential canonical 6 channels.

Receptor-operated Ca²âº entry (ROCE) via transient receptor potential canonical channel 6 (TRPC6) is important machinery for an increase in intracellular Ca²âº concentration triggered by the activation of G(q) protein-coupled receptors. TRPC6 is phosphorylated by various protein kinases including protein kinase A (PKA). However, the regulation of TRPC6 activity by PKA is still controversial. The purpose of this study was to elucidate the role of adenylate cyclase/cAMP/PKA signaling pathway in the regulation of G(q) protein-coupled endothelin type A receptor (ET(A)R)-mediated ROCE via TRPC6. For this purpose, human embryonic kidney 293 (HEK293) cells stably coexpressing human ET(A)R and TRPC6 (wild type) or its mutants possessing a single point mutation of putative phosphorylation sites for PKA were used to analyze ROCE and amino acids responsible for PKA-mediated phosphorylation of TRPC6. Ca²âº measurements with thapsigargin-induced Ca²âº-depletion/Ca²âº-restoration protocol to estimate ROCE showed that the stimulation of ET(A)R induced marked ROCE in HEK293 cells expressing TRPC6 compared with control cells. The ROCE was inhibited by forskolin and papaverine to activate the cAMP/PKA pathway, whereas it was potentiated by Rp-8-bromoadenosine-cAMP sodium salt, a PKA inhibitor. The inhibitory effects of forskolin and papaverine were partially cancelled by replacing Ser28 (TRPC6(S28A)) but not Thr69 (TRPC6(T69A)) of TRPC6 with alanine. In vitro kinase assay with Phos-tag biotin to determine the phosphorylation level of TRPC6 revealed that wild-type and mutant (TRPC6(S28A) and TRPC6(T69A)) TRPC6 proteins were phosphorylated by PKA, but the phosphorylation level of these mutants was lower (approximately 50%) than that of wild type. These results suggest that TRPC6 is negatively regulated by the PKA-mediated phosphorylation of Ser28 but not Thr69.

A novel approach for sentinel lymph node identification using fluorescence imaging and image overlay navigation surgery in patients with breast cancer.

BACKGROUND: We reported a novel technique of sentinel lymph node (SLN) identification using fluorescence imaging of indocyanine green injection. Furthermore, to obtain safe and accurate identification of SLN during surgery, we introduce the image overlay navigation surgery and evaluate its efficacy. METHODS: This study enrolled 50 patients with a tumors <2 cm in diameter. Initially, we obtained three-dimensional (3-D) imaging from multidetector-row computed tomography (MD-CT) by volume rendering. It was projected on the patient's operative field with the clear visualization of lymph node (LN) through projector. Then, the dye of indocyanine green (ICG) was injected subdermally in the areola. Subcutaneous lymphatic channels draining from the areola to the axilla were visible by fluorescence imaging immediately. Lymphatic flow was reached after LN revealed on 3-D imaging. After incising the axillary skin on the point of LN mapping, SLN was then dissected under the guidance of fluorescence imaging with adequate adjustment of sensitivity and 3-D imaging. RESULTS: Lymphatic channels and SLN were successfully identified by Photodynamic eye (PDE) in all patients. And the sites of skin incision also were identical with the LN being demonstrated by 3-D imaging in all patients. The mean number of SLN was 3.7. The image overlay navigation surgery was visually easy to identify the location of SLN from the axillary skin. There were no intra- or postoperative complications associated with SLN identification. CONCLUSIONS: This combined navigations of fluorescence and 3-D imaging revealed more easy and effective to detect SLN intraoperatively than fluorescence imaging alone.

Endothelin type B receptor-induced sustained Ca2+ influx involves G(q/11)/phospholipase C-independent, p38 mitogen-activated protein kinase-dependent activation of Na+/H+ exchanger.

The mechanism for sustained Ca2+ influx activated by G protein-coupled receptors was examined. In Chinese hamster ovary cells expressing recombinant human endothelin type B receptor (ET(B)R) and endogenous P2Y receptor (P2Y-R), endothelin-1 elicited a sustained Ca2+ influx depending on G(q/11 )protein, phospholipase C (PLC), Na+/H+ exchanger (NHE), and p38 mitogen-activated protein kinase (p38MAPK), whereas P2Y-R-induced sustained Ca2+ influx was negligible. Functional studies showed that NHE activation by ET(B)R was mediated via p38MAPK but not G(q/11)/PLC, while that by P2Y-R involves only G(q/11)/PLC/p38MAPK. These results suggest that G(q/11)/PLC-independent NHE activation via p38MAPK plays an important role in ET(B)R- mediated sustained Ca2+ influx.