Apelin is involved in postprandial responses and stimulates secretion of arginine-vasopressin, adrenocorticotropic hormone, and growth hormone in the ruminant

Apelin and its mRNA are expressed in several tissues, including the supraoptic and paraventricular nuclei in the hypothalamus. Although apelin is reported to be involved in the regulation of fluid homeostasis, little is known about the postprandial dynamics of apelin in plasma and its regulatory effects on the anterior pituitary hormones of ruminants. Therefore, the aims of this study were to investigate the following: (1) changes in plasma apelin concentrations in response to food intake under conditions of hydration (free access to water) or dehydration (water restriction), and (2) the effects of intravenous administration of apelin on plasma concentrations of arginine-vasopressin (AVP), ACTH, GH, and insulin. In Experiment 1 with the use of goats, the postprandial plasma apelin concentration was significantly increased under the dehydration condition compared with the hydration condition, and this increase was accompanied by increased plasma concentrations of AVP and ACTH after 24 h of dehydration. In Experiment 2 with the use of sheep and hydration conditions, the intravenous administration of apelin ([Pyr(1)]-apelin-13; 0.5 mg/head) caused a tendency to increase or caused a significant increase in plasma concentrations of AVP, ACTH, GH, insulin, and glucose. On the basis of these findings, we concluded that apelin is involved in the feeding process, and it regulates endocrine functions in the anterior pituitary gland via AVP in ruminant animals.     

Mammary lipid-rich carcinoma with extensive amyloid deposition in a dog

A 6-year-old female Labrador retriever presented with a mass in the right mammary gland, and swollen right inguinal and axillary lymph nodes. Fine needle aspiration biopsy suggested a malignant lipid-producing tumor, such as liposarcoma. Histopathologically, the neoplasms were solid, lobulated nests of atypical epithelial cells with a large amount of extracellular deposits of amyloid in both mammary gland and lymph nodes. The proliferating cells contained large cytoplasmic vacuoles, positive for oil red-O. These cells were immunopositive for cytokeratin (AE1/AE3) and β-casein and negative for SMA. The amyloid deposits were immunopositive for β-casein. These findings suggested that the proliferating cells secreted β-casein forming amyloid deposits. This is the first report of mammary lipid-rich carcinoma with extensive amyloid deposition derived from β-casein.     

Seasonal changes in spermatogenesis and peripheral testosterone concentration in raccoons (Procyon lotor) in Hokkaido

Feral raccoons (Procyon lotor) have been increasing in number since 1979 and are currently subject to pest control in Hokkaido. One of the reasons for the increase in numbers is thought to be the high reproductive potential of raccoons, but little is known about their reproduction. The main aim of this study was to clarify seasonal changes in spermatogenesis and peripheral testosterone concentration of raccoons in Hokkaido. In the present study, external characteristics and histology of the testis and epididymis and the plasma testosterone concentration were investigated in 68 feral, male raccoons culled for pest control and once a month in one live, captive male. The feral males exhibited seasonal changes in spermatogenesis, showing active spermatogenesis in autumn, winter and spring (October-June) with noted spermatogenesis and inactive spermatogenesis in summer (July-September) with lower mean levels of spermatozoa in the cauda epididymis. Even in the inactive period, spermatozoa were observed in about half of the individuals (14/26); therefore, individuals producing spermatozoa existed every month throughout the year. Testosterone concentrations were significantly high in the winter mating season. In the captive male, the testosterone concentrations were low from June to August, and spermatozoa could not be observed from July to September. These results suggest that raccoons exhibit seasonality of reproduction, but the time and duration of spermatogenetic decline varies widely among individuals. This individual variation in the inactive period is a feature of male raccoon reproduction and is unique among seasonally breeding mammals.     

Oxidative stress and redox regulation on in vitro development of mammalian embryos

Many factors affect development of mammalian preimplantation embryos in vitro. It is well known that in vitro development of bovine embryos is highly affected by culture condition including energy source, growth factors, pH or gas environment. Many efforts have been made towards the suitable environments which can successfully support embryo development in vitro. For a rapid growth and differentiation, embryo requires energy by utilizing ATP, NADPH with oxygen molecules. These energy substrates are produced from the electron transport chain in the mitochondria. In addition to energy production, reactive oxygen species (ROS) are also generated as by-product of such energy production system. ROS production is sensitively controlled by the balance of oxidizing and reducing status and affected by several antioxidant enzymes such as superoxide dismutase (SOD), Catalase, glutathione peroxidase (GPx) or low molecular weight thiols such as glutathione (GSH). Imbalance of oxidation and reduction causes production of excess ROS, which causes the developmental arrest, physical DNA damage, apoptosis induction or lipid peroxidation. Environmental oxygen condition during embryo culture also highly affects embryo development as well as intracellular redox balance. Several studies have revealed that regulation of intra- and extra- cellular reducing environment by reducing excess ROS by using antioxidants, reducing oxygen concentration are effective for improving embryo development. Also, recent studies have demonstrated the difference in gene expression affected by oxidative stress. This review briefly summarizes the effects of ROS and the role of redox balance on preimplantation embryos for improving the efficiency of in vitro production of mammalian embryos.     

Effect of intramammary infusion of rbGM-CSF on SCC and expression of polymorphonuclear neutrophil adhesion molecules in subclinical mastitis cows

The effect of rbGM-CSF intramammary infusion on the subclinical mastitis was evaluated by the somatic cell count (SCC) and expression of adhesion molecules (CD62L and CD11b) on the surface of neutrophils (PMN) in blood and milk. Fifteen cows diagnosed to have subclinical mastitis were used in this study. Seven cows showed a decrease in the SCC (decreased group), whereas 8 cows showed an increase in the SCC (increased group) 7 days after infusion of rbGM-CSF compared to pre infusion level. The percentage of CD62+ cells tended to be lower and CD11b+cells tended to be higher at 6 h on blood PMN in the decreased group of cows. Increased group of cows showed opposite tendencies. The mean fluorescent intensity of these adhesion molecules expressed on PMN in blood and milk was similar in both groups. These results suggested some association between expression of adhesion molecules and changes in SCC by rbGM-CSF. Responsiveness of PMN adhesion molecules to rbGM-CSF might determine the changes in SCC of the subclinical mastitic cows after infusion of rbGM-CSF.     

Kujigamberol, a new dinorlabdane diterpenoid isolated from 85million years old Kuji amber using a biotechnological assay

A new compound, 15,20-dinor-5,7,9-labdatriene-18-ol (1), named kujigamberol, was isolated from amber, fossilized tree resin from the Kuji area in Japan, has been dated as being 85 million years old (late Cretaceous). Kujigamberol was identified using the hypersensitive mutant yeast (zds1? erg3? pdr1? pdr3?) with respect to Ca²⁺-signal transduction. The structure was elucidated on the basis of spectroscopic analysis including 1D NMR, 2D NMR and HR-EI-MS. It was different from known diterpenoids with a similar activity isolated from Baltic amber (agathic acid 15-monomethyl ester (2), dehydroabietic acid (3) and pimaric acid (4)). Kujigamberol showed glycogen synthase kinase-3β (GSK-3β) inhibition activity involving the growth restored activity against the mutant yeast and was cytotoxic to HL60 cells (IC₅₀ = 19.6 μM).     

Peripheral mononuclear cell response in Japanese black calves after oral administration of IFN-alpha

To investigate the effects of oral administration of an interferon (IFN)-alpha drug on the immune reaction of healthy Japanese Black (JB) calves, peripheral leukocyte populations and their ability to produce cytokine mRNA were analyzed after oral administration of IFN-alpha. Fourteen calves fed in one herd were divided into two groups; seven calves were orally administered 0.1 g/day of IFN-alpha from the day of birth to day 5 on each day (group 1, N=7), and the other seven calves were used as the control (group 2, N=7). Blood samples were collected from the jugular veins of all calves before administration and in weeks 1, 2, 4, 8, and 16 after birth. The number of MHC class II+CD14+ monocytes in the leukocytes population of group 1 increased gradually after birth, and significantly higher numbers were detected in week 4 compared with group 2. MHC class II-CD14+ monocytes in group 1 peaked in week 1, and a significant increase was detected compared with group 2. The level of IL-12 in the cytokine mRNA of group 1 increased gradually between weeks 1 and 2, and a significantly higher level of IL-12 was found compared with group 2. These results suggest that oral administration of IFN-alpha induces activation of the monocyte functions in JB calves.     

Antimicrobial resistance in Salmonella isolates from apparently healthy food-producing animal from 2000 to 2003: the first stage of Japanese veterinary antimicrobial resistance monitoring (JVARM)

Antimicrobial susceptibility of 183 Salmonella isolates from apparently healthy food-producing animals obtained during the period from 2000 to 2003 throughout Japan was examined. Of 29 serovars identified, Salmonella Infantis (37.7%) was the most prevalent, followed by S. Typhimurium (19.7%). Salmonella bacteria resistant to dihydrostreptomycin (77.6%) were about 10% more prevalent than those resistant to oxytetracycline (67.8%), though the nation-level veterinary use of tetracycline antibiotics is much greater than that of streptomycin in Japan. In seventeen isolates (9.3%) resistant to nalidixic acid, single point mutations were detected at 84 or 87 in the quinolone resistance-determining region of the gyrA gene.     

Predicting the price of Vietnamese shrimp products exported to the US market using machine learning

Accurately predicting the price of exported fishery products is an important task for fisheries because it will enable market trends to be determined, leading to the development of high-quality fishery products. In this study, we predicted prices in selected base periods (2, 3, 6, and 12 months) to investigate how historical data influenced the Vietnamese export price. A dataset (from May 1995 to May 2019) was collected from the US Department of Agriculture (USDA). We initially hypothesized that the dependent variable, Vietnamese export price, was affected by 33 independent variables, but ultimately used 15 key variables, which were chosen on the basis of Akaike information criterion (AIC) to train the models. A tree-based machine learning technique, including the random forest and gradient boosting tree algorithms, was applied for predictions. It was found that the random forest algorithm performed well for historical data for periods of more than 6 months, while the gradient boosting tree algorithm was better over short durations of less than 6 months.

     

An evaluation of the growth-promoting effects of green light on spotted halibut for its practical application in aquaculture

Fisheries Science - We examined the effects of tank color and stocking density on the growth of spotted halibut (Verasper variegatus) under a green light-emitting diode (LED). Fish reared for...