Evaluation of Gamma-Aminobutyric Acid (GABA) as a Functional Feed Ingredient on Growth Performance, Immune Enhancement, and Disease Resistance in Olive Flounder (Paralichthys olivaceus) under High Stocking Density.

Gamma-aminobutyric acid (GABA) is a non-protein amino acid that is found in the brain and central nervous system of animals as an inhibitory neurotransmitter. It has been shown to have a variety of physiological functions, including stress reduction and immune enhancement. This study investigated the effects of dietary supplementation with GABA on growth, serum biochemistry, innate immunity, and disease resistance in juvenile olive flounders (Paralichthys olivaceus) challenged with Edwardsiella tarda under high-stocking density. A control diet and three experimental diets were prepared, with 150 mg/kg (GABA150), 200 mg/kg (GABA200), and 250 mg/kg (GABA250) of GABA added to each diet, respectively. Each experimental diet was fed to olive flounders in triplicate with an initial weight of 12.75 g ± 0.3 g in 40 L tanks at two stocking densities: normal density (20 fish/tank) and high density (40 fish/tank). After 8 weeks of the feeding trial, growth, feed utilization, whole-body proximate compositions, blood analyses, and non-specific immune responses were measured, and challenge tests were performed. There were no significant differences in the weight gain (WG) and specific growth rate (SGR) among fish fed the GABA-supplemented diets at the two stocking densities. However, the normal-density groups showed significantly higher WG and SGR than the high-density groups (p < 0.05). There was no significant difference in feed efficiency and protein efficiency ratio among all groups. Moreover, there was no significant difference in the whole-body proximate composition analysis (p > 0.05). There were no significant differences in cortisol levels in fish fed the GABA at both densities, but the high-density group showed a significantly higher cortisol than the low-density group. Blood GABA significantly increased in a dose-dependent manner regardless of the density groups (p < 0.05). Superoxide dismutase activity showed significantly higher levels than the control group, but there was no significant effect of the stocking densities in fish fed the GABA diets (p < 0.05). Myeloperoxidase activities in fish fed the GABA200 and GABA250 diets showed significantly higher levels at both of the stocking densities (p < 0.05). Lysozyme activity was significantly higher in the GABA150 group than in the CON, GABA200, and GABA250 groups (p < 0.05). After 15 days of challenge tests with Edwardsiella tarda, the cumulative survival rates of the GABA150, GABA200, and GABA250 groups were significantly higher than that of the CON group (p < 0.05). The results suggested that the optimal dietary GABA level for juvenile olive flounder culture is 150 mg/kg, regardless of rearing density, to enhance growth, immunity, and disease resistance.

Tuna byproducts as a fish-meal in tilapia aquaculture.

Potentiality of the use of tuna byproducts as a fish-meal replacement on Nile tilapia (Oreochromis niloticus) was examined for 84 weeks by tracking the concentrations of cadmium and mercury in the internal organs, muscles and fish whole body through generation including their immature eggs and their larvae. The results confirmed that the tuna byproducts can be used as a fish-meal substitute in tilapia aquaculture, because their acceptable ranges for cadmium and mercury consequently did not exceed the food safety values (both < 0.5 mg kg-1), despite their proportional increases in the fish body. The use of tuna byproducts as a protein source is expected to reduce the cost of feed with other fishmeal substitutes in tilapia aquaculture. However, fish (flounder) indiscriminately consuming tuna byproduct feed were prohibited and recalls of sales were issued by the government (July 2018, Republic of Korea), as the threshold for mercury in the fish bodies had been exceeded (0.6-0.8 mg kg-1). Further study of the use of tuna byproducts as fishmeal replacements for other species in aquaculture is needed, as concentration ratios can vary depending on the species.

The Effect of Short Term Dutasteride Therapy on Microvessel Density in Benign Prostatic Hyperplasia / 대한비뇨기과학회지

PURPOSE: Several studies have shown that finasteride limits hematuria in patients with benign prostatic hyperplasia(BPH). However, there are few reports addressing dutasteride therapy. We evaluated the effect of dutasteride on intraoperative blood loss and on microvessel density(MVD) in patients with BPH. MATERIALS AND METHODS: We studied 39 patients with BPH who underwent transurethral resection of the prostate(TURP). Group I included 22 patients who received dutasteride 0.5mg daily for 2 weeks preoperatively, and group II included 17 patients who did not. Blood loss was evaluated by comparing preoperative and postoperative hemoglobin. Sections from the prostatic suburothelium and hyperplastic prostate were individually stained for CD 34. MVD was calculated by counting the number of positively stained blood vessels in 5 random high power fields. There were no significant differences between the groups in terms of age, total prostatic volume, resected prostatic weight, or prostate-specific antigen (PSA). RESULTS: The mean MVD in the suburethral portion in dutasteride-treated patients was significantly lower than that seen in untreated patients(14.47 versus 22.19 vessels per high power field, p=0.026). In nodular hyperplasia, there was no significant difference in MVD between the two group(14.72 versus 15.24 vessels per high power field, p=0.801). CONCLUSIONS: Short term pretreatment with dutasteride decreases suburethral prostatic MVD in patients with BPH and may help reduce blood loss during TURP, particularly in huge BPH, which sometimes bleeds excessively during operation.

Primary Bladder Signet Ring Cell Carcinoma Extended to Prostate / 대한비뇨기과학회지

A primary signet ring cell carcinoma (PSRCC) of the urinary bladder is a rare variant of a mucin-producing adenocarcinoma. The prognosis of a PSRCC is poor, as silent progression in a linitis platica fashion leads to delayed diagnosis. Herein, the case of a PSRCC of the bladder, which extended to the prostate, which was treated with a cystoprostatectomy, is reported.