Morphology, Histology, and Histochemistry of the Digestive Tract of the Marbled Flounder Pseudopleuronectes yokohamae.

This study investigated the morphological, histological, and histochemical characteristics of the digestive tract of the marbled flounder (Pseudopleuronectes yokohamae). The relative length of the gut of the marbled flounder digestive tract was 1.54 ± 0.10 (n = 20), and it had a simple stomach and 6-9 pyloric caeca. The mucosal folds of the marbled flounder digestive tract exhibited a general branched morphology. The thickness and mucosal fold length of the intestinal muscularis externa showed similar aspects in all areas. The thickness of the intestinal muscularis externa was the thickest in the posterior intestine portion, and the length of mucosal folds was the longest in the anterior intestine portion. It was indicated that food digested by gastric acid in the stomach moves to the anterior portion (including pyloric caeca) and mid portion of the intestine, ensuring effective stimulation of cholecystokinin (CCK)-producing cells. In addition, the distribution pattern of CCK-producing cells in the intestine was very similar to that of mucus-secreting goblet cells. The CCK-producing cells and goblet cells in the marbled flounder were well-adapted to promote optimal control of the digestive process. Based on the morphological and histochemical studies, it was concluded that the marbled flounder displays a digestive tract comparable to that of fish species with carnivorous habits.

The complete mitochondrial genome and phylogenetic position of the Scalpel sawtail Prionurus scalprum Valenciennes, 1835 (Acanthuriformes: Acanthuridae) from Jeju Island, Korea.

Although the mitochondrial genomes of most Acanthuriformes fish have been sequenced, this has not been done for Prionurinae fish yet. The Scalpel sawtail (Prionurus scalprum Valenciennes, 1835) found in all tropical and sub-tropical seas, is an important link between primary producers and higher trophic levels. In this study, the complete mitochondrial genome of the Scalpel sawtail, Prionurus scalprum Valenciennes, 1835 (accession number: OK323243) was sequenced. The complete mitochondrial genome included 13 protein-coding genes (PCGs), 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes, and a control region; the total length was 16,522 bp. The nucleotide composition of the genome was as follows: A, 28.46%; T, 27.62%; G, 16.46%; and C, 27.46%. All genes were encoded on the H-strand, except for the eight tRNA genes and NADH dehydrogenase subunit (ND6). A phylogenetic tree was constructed using the neighbor-joining (NJ) method and the phylogenetic position of the Scalpel sawtail was established. This provides useful data for future research on Acanthuridae fish.

A Preliminary Study on the Effects of Taurine-Enriched Rotifers on the Growth and Survival of the Small Yellow Croaker Larimichthys polyactis Larvae.

The effect of feeding with taurine-enriched rotifers on larval growth and survival in the small yellow croaker Larimichthys polyactis was investigated. Rotifers, control (without taurine enrichment) or enriched with a commercial taurine supplement at two concentrations (400, and 800 mg/L), were used. The larvae (initial notochord length = 3.83 mm) were fed taurine-enriched rotifers in triplicate, from 3 days after hatching for 12 days. The average taurine contents of the rotifers were 0.31, 5.34, and 8.55 mg/g dry matter, respectively. The rotifers from all treatments had similar fatty acid composition. The growth and survival rates of the larvae fed rotifers enriched with 800 mg/L taurine supplementation were significantly higher than those of larvae fed rotifers without taurine enrichment (p = 0.005 and 0.002, respectively). The whole-body taurine content in the fish increased significantly with the increase in taurine level in the rotifers: 1.02, 3.48, and 4.11 mg/g in larvae fed control rotifers, and rotifers enriched with 400, and 800 mg/L taurine supplementation, respectively. The results of this study indicate that small yellow croaker larvae benefit from taurine concentrations above those typically reported in non-taurine-enriched rotifers.

A preliminary study of dietary protein requirement of juvenile marbled flounder (Pseudopleuronectes yokohamae).

An 8-week feeding trial was conducted to determine the optimal dietary protein level for juvenile marbled flounder. Five semi-purified test diets were formulated to contain different protein levels (CP) including 42.7%, 47.4%, 53.3%, 58.8%, and 64.5% (dry matter), named as CP42.7, CP47.4, CP53.3, CP58.8, and CP64.5, respectively. Five hundred and twenty-five juveniles (6.0 ± 0.1 g) were randomly distributed into 15 tanks (300 L tanks), resulting in 35 fish per tank (n = 3 tanks). Fish were fed the test diets 5 times per day until satiation. The CP58.8 resulted in the highest gain in weight and the best efficiency in feed utilization among the tested protein levels (P < 0.05). Fish fed the CP58.8 diet showed significantly higher whole-body protein and lipid contents than the fish that were fed the other diets (P < 0.05). Fish fed the CP53.3, CP58.8, and CP64.5 diets showed a significantly higher dorsal-muscle lipid content than the fish that were fed the CP42.7 and CP47.4 diets (P < 0.05). The one-slope straight broken-line regression analysis on the results of the thermal growth coefficient and feed conversion ratio indicated that the estimated optimum dietary protein level was 58.8%. Taken together, it is suggested that the dietary protein level of 58.8% is optimal for better growth and high efficiency in feed utilization for the juvenile marbled flounder.

Clinical outcomes of endoscopic surveillance for gastric ulcers in populations with a high prevalence of gastric cancer.

BACKGROUND/AIMS: Although surveillance endoscopy is recommended after the treatment of a benign gastric ulcer in Korea, improved survival, secondary to an endoscopic follow-up strategy, is controversial. Thus, the aim of this study was to understand the results of gastric ulcer surveillance endoscopy and to individualize surveillance endoscopy by analyzing known risk factors for gastric cancer. MATERIALS AND METHODS: In total, 599 (M:F=424:175, median age=55.4 years) patients who were diagnosed with a gastric ulcer and who underwent follow-up endoscopy between January 2003 and August 2014 were retrospectively enrolled in this study. The final results and risk factors of follow-up endoscopy were analyzed. RESULTS: Multivariate analysis of the data between the benign and malignant ulcer groups (benign: malignant=575:24) showed that an elevated border and irregular margins, among other risk factors, were significant indicators of malignancy (p<0.05). Of the 599 patients, 15 (2.5%) were histologically malignant based on the first biopsy results. Nine (1.5%) patients had malignant ulcers on surveillance endoscopy, and all nine were found to have atypia or dysplasia on the first biopsy. Eight of the nine patients had malignant endoscopic features. CONCLUSION: Surveillance endoscopy for gastric ulcers may be unnecessary, except in cases of malignant and pre-malignant endoscopic features on the initial endoscopy.

Usefulness of scheduled follow-up CT in discharged patients with acute pancreatitis.

BACKGROUND AND AIM: Follow-up computed tomography (CT) in patients with acute pancreatitis has been advocated but rarely studied. The aim of this study was to determine whether follow-up CT for acute pancreatitis might be helpful in establishing the prognosis or complications, and in determining a selected subgroup of patients for whom computed tomography could be beneficial. METHODS: Between January 2010 and December 2012, patients with acute pancreatitis who underwent follow-up CT in the outpatient department between one and three months after discharge were retrospectively enrolled. Events discovered on follow-up CT were defined as newly developed or increased pancreatic collection such as pseudocyst or walled off necrosis, and diagnosis of pancreatic cancer. RESULTS: Ultimately, 106 asymptomatic patients were enrolled (mean age 50.24 ± 16, 74.5% male, 31.1% moderately severe and severe acute pancreatitis). The median duration of follow-up CT was 69 (31-90) days. On follow-up CT, 23 patients showed events (2 pancreatic cancer, 21 increasing or developed pancreatic collections). In multivariate analysis, the predictive factors for events on follow-up CT were CTSI ≥3 (OR 4.46, CI 1.08-18.43, p = 0.039) and BISAP ≥ 2 (OR 4.83, CI 1.08-21.55, p = 0.039). CONCLUSIONS: Follow-up CT within three months after discharge may be helpful for acute pancreatitis patients with CTSI ≥ 3 points or BISAP score ≥ 2 points.