In vivo and in vitro effect of recombinant salmon growth hormone treatment on IGF-I and IGFBPs in yellowtail <Emphasis Type="Italic">Seriola quinqueradiata</Emphasis>

The role of growth hormone (GH) in regulating hepatic mRNA expression of insulin-like growth factor-I (IGF-I) and IGF binding proteins (IGFBPs) in yellowtail Seriola quinqueradiata was examined using in vivo and in vitro assays. Yellowtail hepatic IGF-I, IGFBP-1, IGFBP-2, IGFBP-3, and IGFBP-5 mRNAs were measured by real-time quantitative RT-PCR. Intraperitoneal injection of recombinant GH of chum salmon Oncorhynchus keta (rsGH) at a dose of 1 μg/g body weight resulted in a significant increases in hepatic IGF-I, IGFBP-3, and IGFBP-5 mRNA levels, whereas significant reductions in hepatic IGFBP-1 and IGFBP-2 mRNA levels were observed. For in vitro assays, liver slices were incubated with rsGH at different concentrations (doses: 0, 1, 10, 100, 500, and 1,000 ng/ml). Liver slices incubated with 100 ng/ml rsGH elicited a significant increase in IGF-I mRNA level. Similarly, a slight increase in IGFBP-3 and IGFBP-5 mRNA levels were also observed in liver explants incubated with rsGH. In contrast, a significant decline in IGFBP-1 mRNA levels was observed in liver slices incubated with 1,000 ng/ml rsGH. A slight decline in the level of IGFBP-2 mRNA was noted in liver explants with rsGH treatment. This study demonstrates the modulating effect of GH on the IGF system.     

Effects of pretension in bolts on hysteretic responses of moment-carrying timber joints

The adoption of a concept similar to the prestressing technique used in laminated wood decks of bridge structures might increase the initial stiffness or ultimate resistance of dowel-type timber joints by applying pretension to their bolts. This study investigated the effect of pretension in bolts on hysteretic responses and ultimate properties of moment-carrying timber joints with steel side plates. A pretension of 20 kN that yielded a prestress level of 1600 kPa or about 90% of the allowable long-term end-bearing strength of spruce species was applied to the bolts of prestressed joints. The superiority of the prestressed joint over the non-pre-stressed joint was proved by very high hysteretic damping, equivalent viscous damping ratio, and cyclic stiffness. At any given rotation level, hysteretic damping reduction and moment resistance decrement due to continuously reversed loads were found to be small because bolt pretensioning minimized the pinching effect. This study showed that the hysteresis loop of the prestressed joint can be obtained by adding the frictional hysteresis loop due to pretension force into the hysteresis loop of the non-pre-stressed joint. Despite a great increase of initial stiffness, only slight increments in ductility coefficient and ultimate moment resistance were found in the prestressed joint.     

Weatherability and combustibility of fire-retardant-impregnated wood after accelerated weathering tests

The weatherability and combustibility of fireretardant-impregnated wood during accelerated weathering for up to 2000 h were evaluated. The ability of coating to retain fire-retardant chemicals against leaching was also examined using four coating systems (water-borne or solvent-borne, pigmented or clear, film-forming or penetrating). Furthermore, the distribution of fire retardants in the specimens was observed by scanning electron microscopy in combination with energy dispersive analysis of Xrays (SEM-EDX). The fire performance of the specimens during weathering depended on the chemical retention, and was maintained at a quasi-noncombustible material level if the chemical retention was above 150 kg/m³. The maximum duration of accelerated weathering to keep this retention was 250 h for the uncoated specimens, but increased to over 1000 h for pigmented coatings. SEM-EDX revealed that the fire retardants were accumulated in the cell lumina throughout the wood tissues. However, in the uncoated samples, the leaching of fire retardants occurred for surfaces exposed to light and water, and was observed down to a depth of ∼150 μm after 500 h. The leaching depth extended throughout the specimen after 1000 h. In contrast, the fire retardants still remained in samples finished with a solvent-borne pigmented penetrating coating even after 1000 h due to their relatively high chemical retention.     

Effect of dietary lipid level on growth performance and feed utilization of juvenile kelp grouper Epinephelus bruneus

A growth trial was conducted to evaluate the effect of dietary lipid level on juvenile kelp grouper Epinephelus bruneus. Juvenile kelp grouper were fed isonitrogenous diets (470 g/kg crude protein) with four levels of crude lipid at 60 g/kg (CL60), 130 g/kg (CL130), 210 g/kg (CL210), and 270 g/kg (CL270) for 56 days. The highest growth performance and feed utilization were found in the CL130 diet group. A high dietary lipid level (CL270 diet) significantly decreased growth performance and feed utilization. A significant difference in apparent digestibility was only observed in protein, which was highest in the CL130 diet groups. The highest retention for protein, energy, and lipid was found in the CL130 diet group. The dietary lipid levels significantly changed whole-body and liver compositions, the highest being the CL60 diet group for crude protein level and the CL210 diet group for crude lipid level. Based on a second-order polynomial regression analysis of crude lipid level against specific growth rate and protein efficiency ratio, the optimum dietary lipid level for kelp grouper was estimated to be 152 and 154 g/kg diet, respectively.     

Effects of cannabidiol without delta-9-tetrahydrocannabinol on canine atopic dermatitis: A retrospective assessment of 8 cases

Objective We aimed to examine the effects of cannabidiol (CBD)-containing hemp oil without delta-9-tetrahydrocannabinol (THC) as a supplemental treatment for canine atopic dermatitis (CAD), as well as its adverse effects, and effects on concurrent drug use in dogs.Animal In this retrospective case series, 8 dogs with CAD were diagnosed by veterinary dermatologists certified by the Japanese Society of Veterinary Dermatology.Procedure The medical records of dogs supplemented with CBD-containing hemp oil were evaluated with respect to signalment, physical examination, plasma C-reactive protein concentrations, pharmacologic management, the CAD Extent and Severity Index (4th iteration), and the Pruritus Visual Analog Scale.Results Overall, CBD, used as a supplement in combination with other drugs, was well-tolerated over a wide dose range and decreased the occurrence of pruritus in dogs with CAD when ingested twice a day.Conclusion This study provides the first report of supplementation with CBD without THC that was effective in controlling pruritic behavior in dogs with CAD.Clinical relevance Further controlled studies are required to investigate the dose range, efficacy, and safety.     

Effects of replacing fish oil with canola oil on the growth performance,fatty acid composition and metabolic enzyme activity of juvenile yellowtail Seriola quinqueradiata (Temminck & Schlegel, 1845)

In this study, fish oil (FO) was replaced with canola oil (CO) in juvenile yellowtail diets to establish the optimal replacement levels that ensure adequate feed quality for aquaculture. Juvenile yellowtails (initial body weight: 104.7 g) were fed one of four diets for 10 weeks: 100% FO (FO group) or FO replacement with 25%, 50% or 100% CO (CO25, CO50 and CO100 groups respectively). Body weight, specific growth rate and feed efficiency were significantly affected by the replacement of FO with CO. The final body weight of the CO100 group was significantly lower than that of the FO (control) and CO50 groups. Furthermore, the CO50 group showed significantly higher feed efficiency than the FO group during the first 4 weeks (long photoperiod and high water temperature conditions). Increasing dietary CO increased serum glucose and triglyceride concentrations in a dose‐dependent manner. Regarding the proximate composition of fillet and liver, only crude protein in fillet was affected by the replacement of FO with CO. Fatty acid compositions of fillet and liver were correlated to the amount of CO in each diet. The activities of the metabolic enzymes phosphofructokinase and alanine aminotransferase were lowest in the CO25 and CO50 groups respectively. Thus, FO replacement with CO affected growth performance, serum components, fatty acid composition and the activity of metabolic enzymes. Overall, results obtained in the present study suggest that partial replacement (50%) of FO with CO is effective and might increase juvenile yellowtail growth under long photoperiod and/or high water temperature conditions.     

Optimization of the supplemental essential amino acids to a fish meal-free diet based on fermented soybean meal for rainbow trout <Emphasis Type="Italic">Oncorhynchus mykiss</Emphasis>

To minimize the supplemental essential amino acids (EAAs) to a fish meal-free diet for rainbow trout Oncorhynchus mykiss, four types of fish meal-free diets and a control fish meal-based diet were fed to triplicate groups of trout (initial BW, 16 g) for 10 weeks. Two fish meal-free diets based on a fermented and an unfermented soybean meal were unsupplemented with EAAs (diet FSBM and SBM), and two fish meal-free diets based on the fermented soybean meal were supplemented with a combination of lysine and methionine (diet F + ML) and all EAAs (diet F + All), the EAA contents of which were lower than those of the control diet (diet FM). Although physiological conditions such as the biliary bile acid status and morphological features of fish fed diet FSBM were improved and similar to those of fish fed diet FM, the growth performance was not significantly different (P > 0.05) from fish fed diet SBM. The growth performances and whole body protein contents of fish fed F + ML and F + All diets were similarly improved compared to fish fed diet FSBM. These findings indicate that supplementation of lysine and methionine to a fermented soybean meal-based fish meal-free diet is enough to maximize the amino acid utilization of the diet.     

Effects of complete replacement of fish oil with plant oil mixtures and algal meal on growth performance and fatty acid composition in juvenile yellowtail Seriola quinqueradiata

Docosahexaenoic acid (DHA) is an essential fatty acid for marine carnivorous fish. Algal meal (AM), available as a new dietary DHA source, could completely replace dietary fish oil (FO). In this study, dietary FO was replaced with plant oil mixtures and AM in juvenile yellowtail Seriola quinqueradiata to investigate its effects on growth performance and fatty acid composition. The FO control diet was prepared with only pollack liver oil as the lipid source. For the non-FO diets, pollack liver oil was completely replaced with mixtures of canola oil and palm oil, with AM supplementation at 0% (AM0), 1% (AM1), 2% (AM2), 3% (AM3), and 4% (AM4). After completion of the 8-week feeding trial, the AM2 group showed significantly higher values for final body weight and feed efficiency than the AM0 group. No significant differences were observed in the other parameters of growth performance. Whole-body fatty acid composition reflected the dietary fatty acid composition in all dietary groups. These findings demonstrate that AM is useful as a DHA source in yellowtail aquaculture, thus contributing to a reduction in the use of FO in fish diets.

     

Evaluation from otolith Sr stable isotope ratios of possible juvenile growth areas of Japanese eels collected from the West Mariana Ridge spawning area

Fisheries Science - The widely distributed East Asian Japanese eel Anguilla japonica constitutes a single genetically homogeneous population with a single spawning area near the West Mariana Ridge....     

Cytological relationships among Eumelilotus species analysed using cytological observations of interspecific hybrids obtained by in vitro culture

Interspecific hybrid plants between Melilotus altissima (yellow flowers) and either M. alba (white flowers) or M. taurica (white flowers) and between M. suaveolens (yellow flowers) and M. wolgica (white flowers) which were inviable because of heavy chlorosis, were grown successfully by in vitro culture and reached the flowering stage. Pollen fertility of hybrid plants between M. altissima and M. alba was about 46% whereas hybrids between M. altissima and M. taurica and between M. suaveolens and M. wolgica showed about 25% and 18% of pollen fertility, respectively. All F₁s did not set any selfed seeds. Observing the pairing of chromosomes at metaphase I in the hybrid plants, it was revealed that the genomes of M. altissima and M. alba differ by a reciprocal translocation. This result could account for the partial sterility of pollen in the F₁ hybrids. On the other hand, hybrid plants between M. altissima and M. taurica and between M. suaveolens and M. wolgica showed normal pairing of chromosomes though pollen fertility of the hybrids was very low, suggesting that low pollen fertility was controlled by sterility gene(s). These results demonstrate that M. altissima and 7 other species of the subgenus Eumelilotus share the same chromosomal constitution. The only exception, M. alba, differs from the other 8 species by a segmental interchange. This revised version was published online in July 2006 with corrections to the Cover Date.