The impact of sexual reproduction-induced vertical migration on the complexity of harmful algal blooms in Heterosigma akashiwo.

Vertical migration behaviour, which is integral to marine energy circulation, is a prevalent trait among marine organisms. However, the behaviour of phytoplankton, particularly beyond diel vertical migration (DVM), remain underexplored compared to groups like zooplankton. Through the lens of the harmful alga Heterosigma akashiwo, which exhibits unique vertical migrations and fluctuating red tide patterns, this study aimed to explore the ecological intricacies and diverse benefits of phytoplankton vertical migration behaviours. During the bloom period of H. akashiwo, we unexpectedly observed a dense concentration of cells at bottom layer during daytime. This phase coincided with the emergence of cells related to this species' sexual reproduction. Laboratory experiments further showed an elevated frequency of sexual reproduction in the cell populations that migrated to deeper depths compared to those at the surface. This finding implies a connection between dense bottom accumulation (BA) and the life cycle transitions of the species. This BA phase persisted for two days, after which the populations returned to their standard DVM behaviour, providing insight into the unique fluctuating red tide patterns of H. akashiwo. Our study suggests that phytoplankton vertical migrations are not strictly dictated by DVM, revealing diverse vertical migration behaviours that may contribute to the complexity of harmful algal bloom patterns.

Abiotic and biotic factors controlling sexual reproduction in populations of Pseudo-nitzschia pungens (Bacillariophyceae).

Pseudo-nitzschia pungens is a widely distributed marine pennate diatom. Hybrid zones, regions in which two different genotypes may interbreed, are important areas for speciation and ecology, and have been reported across the globe for this species. However, sexual reproduction between differing clades in the natural environment is yet to be observed and is difficult to predict. Here we carried out experiments using two mono-clonal cultures of P. pungens from different genotypes to measure the frequency and timing of sexual reproduction across varying biotic (growth phases and cell activity potential) and abiotic conditions (nutrients, light, turbulence). We found the mating rates and number of zygotes gradually decreased from exponential to late stationary growth phases. The maximum zygote abundance observed was 1,390 cells mL-1 and the maximum mating rate was 7.1%, both which occurred during the exponential growth phase. Conversely, only 9 cells mL-1 and a maximum mating rate of 0.1% was observed during the late stationary phase. We also found the higher the relative potential cell activity (rPCA) in parent cells, as determined by the concentration of chlorophyll a per cell and the ratio of colony formation during parent cultivations, revealed higher mating rates. Furthermore, sexual events were reduced under nutrient enrichment conditions, and mating pairs and zygotes were not formed under aphotic (dark) or shaking culture conditions (150 rpm). In order to understand the sexual reproduction of Pseudo-nitzschia in the natural environment, our results highlight that it is most likely the combination of both biotic (growth phase, Chl. a content) and abiotic factors (nutrients, light, turbulence) that will determine the successful union of intraspecific populations of P. pungens in any given region.

The prolongation effect of ilaprazole-based standard triple therapy for Helicobacter pylori.

BACKGROUND: Helicobacter pylori (HP) infection causes many diseases, such as peptic ulcers, gastritis and gastric cancer, and MALToma. It has been gradually accepted that all HP-infected patients should be treated because HP is regarded as an infection. Therefore, the importance of selecting the optimal treatment regimen has increased. Although the 14-day standard triple therapy (STT) is recommended in the current guidelines, prolonging treatment duration is controversial in real practice because of inconsistent results from previous data and the risk of adverse effects. Additionally, the effect of STT using ilaprazole has not been reported until now. We aimed to compare the eradication rate between 7 and 10 days STT using ilaprazole. METHODS: A prospective randomized controlled trial was conducted, which was divided into 2 treatment groups: the control group was 7 days of STT, and the test group was 10 days of STT. The eradication regimen was 10 mg ilaprazole, 500 mg clarithromycin, and 1000 mg amoxicillin twice daily. We included patients who were diagnosed with positive results of H pylori examination. We compared the HP eradication rate according to treatment duration, CYP2C19 subtype and endoscopic diagnosis. RESULTS: We enrolled a total of 254 patients consisting of 127 patients in each treatment arm. The eradication rates of the control and test groups were 65.4% (82/127) and 74.8% (95/127), respectively, in the intention-to-treat analysis (P = .1). In the per-protocol analysis, 70.3% (83/118) and 82.6% (94/115) were eradicated in each group, which was statistically significant (P = .027). The CYP2C19 subtype was examined in 230 patients. The eradication rate was 79.2% (57/72), 75.4% (92/122), and 72.2% (26/36) in each group, which was not significantly different (P = .704). CONCLUSION: Ten-day STT was more effective than 7-day STT for HP eradication. The eradication rate was not affected by the CYP2C19 genotype.

Evaluation of prognostic factor and nature of acute esophageal necrosis: Restropective multicenter study.

Acute esophageal necrosis (AEN) is a serious disease which can causes gastrointestinal bleeding and death. Although black color change is not essential factor of organ necrosis, AEN is also known as "black esophagus." Because of its rarity, there are limited studies regarding risk factors of mortality and recurrence. Thus, we conducted a multicenter retrospective study in order to evaluate the clinical characteristics of AEN. Method Clinical datum of AEN patients from 7 tertiary hospitals located in Daejeon-Choongcheong province were evaluated based on medical records. Our primary endpoint was risk factors for mortality and the secondary endpoint was risk factors for recurrence and clarifying whether "black esophagus" is a right terminology.Fourty one patients were enrolled. Thirty six patients were male, mean age was 69.5 years. Nine patients had died, and 4 patients showed recurrence. Sepsis and white color change in endoscopy were related to high mortality (Chi-Squared test, P < .05). Old age, high pulse rate, low hemoglobin, and low albumin were also related to high mortality. Unexpectedly, heavy drinking showed favorable a mortality. Septic condition and high pulse rate showed poor mortality in logistic regression test (P < .05). Coexisting duodenal ulcer was related to recurrence (Chi-Squared test, P < .05). There was no difference in the underlying condition except patients with a coexisting cancer and white-form displayed lower hemoglobin level. Conclusion: Our results imply that white color change, septic condition, high pulse rate, and low hemoglobin & albumin are poor prognostic factors in AEN. Further evaluation may help clarify the findings of our study.

Comparisons of therapeutic outcomes in patients with nonampullary duodenal neuroendocrine tumors (NADNETs): A multicenter retrospective study.

Duodenal neuroendocrine tumors (DNETs) are rare tumors that are occasionally found during upper endoscopies. The incidence of DNETs is increasing, although the data regarding treatment outcomes are insufficient. The aim of this study was to evaluate the treatment outcomes in patients with nonampullary DNETs who underwent endoscopic resection or surgery. We evaluated the medical records of patients who were diagnosed with nonampullary DNETs from 2004 to 2017 in 7 university hospitals. We retrospectively analyzed clinical characteristics and compared therapeutic outcomes based on the endoscopic lesion size and treatment method. We ultimately enrolled 60 patients with nonampullary DNETs who underwent endoscopic and surgical treatments. In the endoscopic treatment group, the en bloc resection, endoscopic complete resection (CR) and pathologic CR rates were 88%, 92%, and 50%, respectively. The endoscopic treatment group was divided into 3 subgroups based on the lesion size (1-5 mm, 6-10 mm, and ≥11 mm). The pathologic CR rate was significantly lower in the subgroup with a lesion size ≥11 mm (0%, P = .003) than those in the other 2 subgroups. Lymphovascular invasion occurred significantly more frequently (33.3%, P = .043) among those with a lesion size ≥11 mm. The pathologic CR rate in the surgical treatment group was higher (90.9%) than that in the endoscopic treatment group (50%, P = .017). Surgical treatment appears to be a more appropriate choice because of the risks of incomplete resection and lymphovascular invasion after endoscopic treatment for lesions larger than 11 mm.

Endovascular Management of Ruptured Middle Colic Artery Aneurysm and Review of the Literature.

A ruptured aneurysm of the middle colic artery (MCA) is extremely rare, and its etiology and optimal treatment are unclear. Previously, surgical intervention was the treatment of choice for ruptured visceral artery aneurysms. However, owing to recent advances in endovascular techniques, transcatheter arterial embolization has been recommended for the management of even ruptured splanchnic aneurysms in clinically stable patients without evidence of bowel ischemia. We report a case of a ruptured MCA aneurysm in a 52-year-old previously healthy man. Coil embolization was attempted successfully. In addition, 7 previously published cases of ruptured MCA aneurysms successfully treated by endovascular embolization were reviewed.

Endoscopic Prediction of Tumor Invasion Depth in Early Gastric Signet Ring Cell Carcinoma.

INTRODUCTION: Signet ring cell carcinoma (SRC) is a poorly differentiated cancer of the stomach. Recent studies imply that early gastric SRC can be well managed by endoscopic resection. Unfortunately, unlike differentiated cancers, the endoscopic features of early gastric SRC have not been well studied. This study evaluated the endoscopic features of early gastric SRC, as well as the risk factors for submucosal (SM) invasion. METHOD: The medical records of patients from 7 tertiary hospitals (Daejeon and Chungcheong province) were reviewed to examine endoscopic findings and clinical data. These patients underwent surgery or endoscopic resection between January 2011 and December 2016 and were divided into 2 groups (derivation group and validation group) in order to develop and validate an endoscopic scoring system for SM invasion. RESULTS: In total, 331 patients (129 in the derivation group and 202 in the validation group) were enrolled in this study. In the derivation group, the risk factors for SM invasion, namely, fold convergence, nodular mucosal change, and deep depression, were identified by logistic regression analysis (ORs 3.4, 5.9, and 6.0, p < 0.05). A depth-prediction score was created by assigning 1 point for fold convergence and 2 points for other factors. When validation lesions of 0.5 point or more were diagnosed as SM invasion, the sensitivity and specificity were 76.8-78.6% and 61.6-74.7% respectively. CONCLUSION: Fold convergence, nodular mucosal change, and deep depression are risk factors for SM invasion in early gastric SRC. Our depth-prediction scoring system may be useful for differentiating SM cancers.

Correction to: Pelagibaca bermudensis promotes biofuel competence of Tetraselmis striata in a broad range of abiotic stressors: dynamics of quorum-sensing precursors and strategic improvement in lipid productivity.

[This corrects the article DOI: 10.1186/s13068-018-1097-9.].

Pelagibaca bermudensis promotes biofuel competence of Tetraselmis striata in a broad range of abiotic stressors: dynamics of quorum-sensing precursors and strategic improvement in lipid productivity.

BACKGROUND: Amelioration of biofuel feedstock of microalgae using sustainable means through synthetic ecology is a promising strategy. The co-cultivation model (Tetraselmis striata and Pelagibaca bermudensis) was evaluated for the robust biofuel production under varying stressors as well as with the selected two-stage cultivation modes. In addition, the role of metabolic exudates including the quorum-sensing precursors was assessed. RESULTS: The co-cultivation model innovated in this study supported the biomass production of T. striata in a saline/marine medium at a broad range of pH, salinity, and temperature/light conditions, as well as nutrient limitation with a growth promotion of 1.2-3.6-fold. Hence, this developed model could contribute to abiotic stress mitigation of T. striata. The quorum-sensing precursor dynamics of the growth promoting bacteria P. bermudensis exhibited unique pattern under varying stressors as revealed through targeted metabolomics (using liquid chromatography-mass spectrometry, LC-MS). P. bermudensis and its metabolic exudates mutually promoted the growth of T. striata, which elevated the lipid productivity. Interestingly, hydroxy alkyl quinolones independently showed growth inhibition of T. striata on elevated concentration. Among two-stage cultivation modes (low pH, elevated salinity, and nitrate limitation), specifically, nitrate limitation induced a 1.5 times higher lipid content (30-31%) than control in both axenic and co-cultivated conditions. CONCLUSION: Pelagibaca bermudensis is established as a potential growth promoting native phycospheric bacteria for robust biomass generation of T. striata in varying environment, and two-stage cultivation using nitrate limitation strategically maximized the biofuel precursors for both axenic and co-cultivation conditions (T and T-PB, respectively). Optimum metabolic exudate of P. bermudensis which act as a growth substrate to T. striata surpasses the antagonistic effect of excessive hydroxy alkyl quinolones [HHQ, 4-hydroxy-2-alkylquinolines and PQS (pseudomonas quorum signal), 2-heptyl-3-hydroxy-4(1H)-quinolone].

Discovery of an Orally Bioavailable Benzofuran Analogue That Serves as a ß-Amyloid Aggregation Inhibitor for the Potential Treatment of Alzheimer's Disease.

We developed an orally active and blood-brain-barrier-permeable benzofuran analogue (8, MDR-1339) with potent antiaggregation activity. Compound 8 restored cellular viability from Aß-induced cytotoxicity but also improved the learning and memory function of AD model mice by reducing the Aß aggregates in the brains. Given the high bioavailability and brain permeability demonstrated in our pharmacokinetic studies, 8 will provide a novel scaffold for an Aß-aggregation inhibitor that may offer an alternative treatment for AD.

Effectiveness of cholangioscopy using narrow band imaging for hepatobiliary malignancies.

PURPOSE: Recently, cholangioscopy using narrow band imaging (NBI) has been used as a diagnostic modality for better visualization in hepatobiliary malignancies; however, there are few reports on it. Our aim is to evaluate the effectiveness of cholangioscopy using NBI in hepatobiliary malignancies. METHODS: Between January 2007 and December 2016, 152 cholangioscopies using percutaneous approach were conducted in total 123 patients. Among these, 36 patients were suspicious of hepatobiliary malignancies. Thirteen patients with an ambiguous margin on endoscopic retrograde cholangiopancreatography (ERCP) or magnetic resonance cholangiopancreatography (MRCP), for whom NBI tipped the balance in diagnosis of lesion and decision of lesion extent by adding NBI, were involved in our study. RESULTS: Underlying diseases were all malignant in 13 patients (11 bile duct cancers, 1 liver cancer, 1 pancreas cancer with common bile duct invasion). In 7 cases with papillary type tumor, minute superficial spreading tumor was detected by NBI more easily, and NBI provided a better visualization of tumor vessel and margin evaluation in 4 cases with infiltrative tumor. In 2 cases with mucin-hypersecreting tumor, NBI showed better penetration through the mucin and gave us a much clearer image. Nine patients ultimately underwent surgical resection. The margins predicted by NBI cholangioscopy were consistent with the pathological margins on the resected specimens. CONCLUSION: In conclusion, cholangioscopy using NBI is very useful for evaluation of suspected hepatobiliary malignancies with an ambiguous margin on ERCP or MRCP. It can give us an accurate pathologic mapping, and this information seems to be essential before deciding on a treatment strategy.

Phycospheric Native Bacteria Pelagibaca bermudensis and Stappia sp. Ameliorate Biomass Productivity of Tetraselmis striata (KCTC1432BP) in Co-cultivation System through Mutualistic Interaction.

Effective sustainable algal cultivation techniques are essential for mass production of the marine microalga Tetraselmis for biofuel and array of co-products. The phycospheric communities affect the microalgal growth and metabolism through various allelochemical and nutrient interactions; hence, their potential to affect the quantity and quality of both biomass and bioproducts is significant. In the present study, we have screened the phycospheric communities of biofuel producing Tetraselmis striata (KCTC1432BP). A total of 26 bacterial strains were isolated and identified from the phycosphere of T. striata mass culture. Then, each bacterial strain was tested in co-cultivation conditions with T. striata for evaluating its growth promoting and inhibitory effects. Among these all strains, two promising strains (Pelagibaca bermudensis KCTC 13073BP and Stappia sp. KCTC 13072BP) were selected because of their maximum growth promoting effects and mutualistic interactions. The growth rate, biomass productivity, lipid contents, and fatty acids were analyzed during their combined growth in O3 media and compared with axenic growth of T. striata. Later, growth promoting mechanisms in the co-cultivation environment were investigated for these promising bacterial strains under replete and limited conditions of nutrients (nitrate, phosphate, and vitamin B12). The growth promoting potential of P. bermudensis was illustrated by the two fold enhancement in biomass productivity. These bacteria are promising for microalgal cultivation without any negative effects on the native seawater bacterial communities, as revealed by next generation sequencing analysis. This study represents, to date, the first report highlighting the role of phycospheric growth promoting bacteria of promising biofuel feedstock T. striata.

High-Grade Mixed Adenoneuroendocrine Carcinoma in the Cecum: A Case Report.

Gastrointestinal neoplasms with an exocrine and a neuroendocrine component are rare. Such neoplasms are called "mixed adenoneuroendocrine carcinomas" (MANECs) according to the most recent World Health Organization classification of gastrointestinal tract neoplasms. MANECs have no specific findings that distinguish them from pure adenocarcinomas. In addition, the optimal management strategy of MANECs is largely unknown. We describe the case of a 32-year-old man with dizziness and abdominal bloating. A cecal mass was suspected based on an image study done at a local clinic. We evaluated the cecal mass by using colonoscopy, contrast enhanced computed tomography of the abdomen, positron emission tomography-computed tomography, and laboratory studies. The patient underwent a right hemicolectomy and adjuvant chemotherapy. The final histopathological diagnosis was a high-grade MANEC of the ascending colon, tumor stage T3N2M0.

Gastrointestinal Stromal Tumor of the Stomach Presenting as Multilobular with Diffuse Calcifications.

Gastrointestinal stromal tumors (GISTs) are the most common primary mesenchymal neoplasms of the gastrointestinal tract and usually appear as a well-circumscribed mass. However, it may be difficult to confirm the extent of the disease for some GISTs. A 70-year-old asymptomatic female presented for a regular physical exam. An esophagogastroduodenoscopy showed a 2.0 cm protruding mass on the gastric fundus. Endoscopic ultrasound revealed an ill-defined heterogenous hypoechoic lesion (3.0×1.5 cm). A computed tomography (CT) scan demonstrated a 4.5 cm multifocal calcified mass at the gastric body as well as at the gastric fundus. Laparoscopic gastric wedge resection was performed according to the extent of multifocal calcifications that are shown on the CT. Intraoperative specimen mammography and intraoperative biopsy might be helpful to obtain a tumor-free margin. Final pathologic diagnosis was an intermediate risk GIST in multilobular form. In patients with diffuse multifocal calcifications in the stomach, the possibility of GIST should be considered.

Incidence and Clinical Outcomes of Clostridium difficile Infection after Treatment with Tuberculosis Medication.

BACKGROUND/AIMS: To determine the incidence and clinical characteristics of tuberculosis (TB) medication-associated Clostridium difficile infection. METHODS: This multicenter study included patients from eight tertiary hospitals enrolled from 2008 to 2013. A retrospective analysis was conducted to identify the clinical features of C. difficile infection in patients who received TB medication. RESULTS: C. difficile infection developed in 54 of the 19,080 patients prescribed TB medication, representing a total incidence of infection of 2.83 cases per 1,000 adults. Fifty-one of the 54 patients (94.4%) were treated with rifampin. The patients were usually treated with oral metronidazole, which produced improvement in 47 of the 54 patients (87%). Twenty-three patients clinically improved with continuous rifampin therapy for C. difficile infection. There were no significant differences in improvement between patients treated continuously (n=21) and patients in whom treatment was discontinued (n=26). CONCLUSIONS: The incidence of C. difficile infection after TB medication was not low considering the relatively low TB medication dosage compared to other antibiotics. It may not be always necessary to discontinue TB medication. Instead, decisions concerning discontinuation of TB medication should be based on TB status.

Customized high-dose-rate brachytherapy using MRI planning for vaginal rhabdomyosarcoma.

PURPOSE: To report the technical aspects of customized high-dose-rate brachytherapy for vaginal rhabdomyosarcoma using MRI- and CT-based planning in a 20-month-old girl. METHODS AND MATERIALS: An impression of the vaginal cavity at the resection site was taken after adequate lubrication of the vagina with lidocaine jelly. The impression was processed in the dental laboratory to obtain an MRI-compatible device with three imbedded catheters 0.4 mm apart, assuring tumor coverage. An MRI- and CT-based simulation under anesthesia with the applicator in place were performed, and the images were registered for contouring and planning to deliver 40 Gy in 10 fractions daily. Dose to the ovaries was limited to a mean dose less than 4 Gy. Treatment was delivered daily under anesthesia with no acute complications. RESULTS: Brachytherapy using a customized applicator has many advantages over prefabricated vaginal cylinders for young girls. It allows greater dose distribution conformality with the possibility of contralateral vaginal wall sparing and more reproducible daily positioning. MRI-based planning is mainly performed to facilitate delineation of the target volume and the ovaries, which are easily identified on MRI. CONCLUSIONS: The customized applicator offers many advantages of which treatment reproducibility, inherent MRI compatibility, and excellent dose distribution conformality. Our brachytherapy technique using MRI and CT scan planning allows precise tumor and normal tissues delineation resulting in excellent tumor coverage and normal tissues sparing.

High-dose-rate brachytherapy for vaginal rhabdomyosarcoma using a personalized mold in a 20-month old patient.

Treatment of vaginal rhabdomyosarcoma (RMS) with conservative approaches is presently the standard of care. Intravaginal high-dose rate brachytherapy is a very effective treatment while sparing the normal tissue to preserve growth, fertility and prevent organ dysfunction. In this report, we describe the management of an infant with Stage I vaginal RMS, treated with chemotherapy, maximal safe resection and intravaginal brachytherapy using a customized mold and MRI and CT-based three-dimensional (3D) conformal planning, followed by a critical review of the literature.

Colonoscopy-induced ischemic colitis in patients without risk factors.

Ischemic colitis is the most common form of intestinal ischemia. It is a condition that is commonly seen in the elderly and among individuals with risk factors for ischemia. Common predisposing conditions for ischemic colitis are major vascular occlusion, small vessel disorder, shock, some medications, colonic obstructions and hematologic disorders. Ischemic colitis following colonoscopy is rare. Here, we report two cases of ischemic colitis after a routine screening colonoscopy in patients without risk factors for ischemia.

A case of variceal bleeding from the jejunum in liver cirrhosis.

While esophagogastric varices are common manifestations of portal hypertension, variceal bleeding from the jejunum is a rare complication of liver cirrhosis. In addition, ectopic variceal bleeding occurs in the duodenum and at sites of previous bowel surgery in most cases, including of stomas. We report a case of obscure overt gastrointestinal bleeding from jejunal varices in a 55-year-old woman who had not previously undergone abdominal surgery, who had liver cirrhosis induced by the hepatitis C virus. Emergency endoscopy revealed the presence of esophageal varices without stigmata of recent bleeding, and no bleeding focus was found at colonoscopy. She continued to produce recurrent melena with hematochezia and received up to 21 units of packed red blood cells. CT angiography revealed the presence of jejunal varices, but no active bleeding was found. Capsule endoscopy revealed fresh blood in the jejunum. The patient submitted to embolization of the jejunal varices via the portal vein, after which she had a stable hemoglobin level and no recurrence of the melena. This is a case of variceal bleeding from the jejunum in a liver cirrhosis patient without a prior history of abdominal surgery.

Double guidewire technique vs transpancreatic precut sphincterotomy in difficult biliary cannulation.

AIM: To compare the outcomes between double-guidewire technique (DGT) and transpancreatic precut sphincterotomy (TPS) in patients with difficult biliary cannulation. METHODS: This was a prospective, randomized study conducted in single tertiary referral hospital in Korea. Between January 2005 and September 2010. A total of 71 patients, who bile duct cannulation was not possible and selective pancreatic duct cannulation was achieved, were randomized into DGT (n = 34) and TPS (n = 37) groups. DGT or TPS was done for selective biliary cannulation. We measured the technical success rates of biliary cannulation, median cannulation time, and procedure related complications. RESULTS: The distribution of patients after randomization was balanced, and both groups were comparable in baseline characteristics, except the higher percentage of endoscopic nasobiliary drainage in the DGT group (55.9% vs 13.5%, P < 0.001). Successful cannulation rate and mean cannulation times in DGT and TPS groups were 91.2% vs 91.9% and 14.1 ± 13.2 min vs 15.4 ± 17.9 min, P = 0.732, respectively. There was no significant difference between the two groups. The overall incidence of post- endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis was 38.2% vs 10.8%, P < 0.011 in the DGT group and the TPS group; post-procedure pancreatitis was significantly higher in the DGT group. But the overall incidence of post-ERCP hyperamylasemia was no significant difference between the two groups; DGT group vs TPS group: 14.7% vs 16.2%, P < 1.0. CONCLUSION: When free bile duct cannulation was difficult and selective pancreatic duct cannulation was achieved, DGT and TPS facilitated biliary cannulation and showed similar success rates. However, post-procedure pancreatitis was significantly higher in the DGT group.