Serum progesterone and estradiol-17beta concentrations in captive and free-ranging adult female japanese black bears (Ursus thibetanus japonicus)

Progesterone (P4) and estradiol-17beta (E2) concentrations were measured in serum samples obtained from 23 captive and 23 free-ranging adult female Japanese black bears. We then determined the relationship between changes in these sex steroid hormones and pregnancy. In all captive bears, which included animals of both known and unknown reproductive status, serum P4 concentrations were low from April to July, then tended to become higher after August. The levels then became much higher still in November and December, but returned to low levels in March. Serum P4 concentrations in eight captive pregnant bears, which had parturitions the following spring, increased gradually from August (0.5-2.4 ng/ml) to October (0.9-3.6 ng/ml), and achieved significantly higher maximum levels in December (7.2-18.0 ng/ml). Thereafter, serum P4 concentrations tended to decrease (3.5-6.4 ng/ml in January and 0.3-0.7 ng/ml in March). In all captive bears, serum E2 concentrations varied from April to October but showed low levels in November and December, and became high in January. Serum E2 concentrations in the eight pregnant bears were high in May (95.6-191.4 pg/ml) and varied from August to October (35.6-143.3 pg/ml). Subsequently, serum E2 concentrations in December dropped to significantly lower minimum levels (5.3-11.9 pg/ml) and increased again in January (67.6-153.1 pg/ml). Among the free-ranging bears, the data on serum P4 concentrations in eight bears led to expectations of pregnancy, whereas serum E2 concentrations showed no distinct evidence related to pregnancy. These results, particularly in captive pregnant bears, indicate that a marked increase of P4 in December might be accompanied by reactivation of the corpus luteum preceding implantation. Furthermore, changes in E2 concentrations suggested the possibility that a decline in December and an increase in January are associated with implantation and parturition, respectively.     

A role of pituitary adenylate cyclase activating polypeptide (PACAP) as a regulator of paracrine interactions between folliculo-stellate cells and gonadotropes through the control of activin-follistatin interactions

Pituitary folliculo-stellate (FS) cells were able to modify the effect of activin-A on gonadotropes through the paracrine factor, follistatin. The present study was aimed to examine whether a hypothalamic peptide, pituitary adenylate cyclase activating polypeptide (PACAP), could be a regulator of this paracrine interaction. Co-culture of FS cell-originated cell line TtT/GF cells with rat anterior pituitary cells showed faint inhibitory effect on the stimulatory action of activin-A on FSH secretion. When PACAP was added to the culture during the co-culture period, however, the presence of TtT/GF cells caused significant suppression of the effect of activin-A on FSH secretion. Conditioned-media (CM) from TtT/GF cells, obtained by incubation of TtT/GF cells in the presence or absence of PACAP, were next added to the cultures of anterior pituitary cells alone. CM from TtT/GF cells without PACAP treatment revealed slight, but not significant, suppressive effect on activin-induced increases in FSH secretion and the percentage of FSH cells. Meanwhile, CM from PACAP-treated TtT/GF cells attenuated both effects of activin-A. Furthermore, the inhibitory effect of the CM was neutralized when follistatin antibody was present in the culture. These results suggest that PACAP is able to regulate the paracrine action of FS cells on pituitary gonadotropes. Besides expressing direct actions on pituitary endocrine cells, PACAP may have roles as a regulator of cell-to-cell interactions within the pituitary gland.     

Development of loop-mediated isothermal amplification (LAMP) method for diagnosis of equine piroplasmosis

Loop-mediated isothermal amplification (LAMP) is a novel nucleic acid method whereby DNA is amplified with high specificity, efficiency, and rapidity under isothermal conditions using a set of four specifically designed primers and a DNA polymerase with strand displacement activity. In this study, we used LAMP primer sets designed from EMA-1 and Bc 48 genes for detection of Theileria equi and Babesia caballi infections, respectively. These primer sets specifically amplified DNA of the respective parasites. Both primer sets amplified T. equi and B. caballi up to 10(-6) dilution of 10-fold serially diluted samples. Furthermore, DNA extracted from blood collected from a horse experimentally infected with T. equi was amplified by a T. equi LAMP primer set from days 2 to 35 post-infection, demonstrating the high sensitivity of these primers. Of 55 samples collected from China, 81.8% and 56.3% were positively detected by LAMP for T. equi and B. caballi infections, respectively. In contrast, 91.8% and 45.9% of the 37 samples collected from South Africa were LAMP positive for T. equi and B. caballi, respectively. These results suggest that LAMP could be a potential diagnostic tool for epidemiological studies of equine piroplasmosis.     

Effect of riverbed conditions on survival of planted eyed eggs in chum salmon <Emphasis Type="Italic">Oncorhynchus keta</Emphasis>

Wild stocks of chum salmon Oncorhynchus keta are supplemented by hatchery fry enhancement programs in northern Honshu, Japan. To maintain these programs, there is a need to reduce expenses and labor. Eyed egg planting is more cost effective than hatchery production of fry. Therefore, we evaluated the effect of environmental conditions on survival of chum salmon eyed eggs planted using Whitlock–Vibert boxes. We measured the percent cumulative weight of fine sediments, Fredle index (FI) as a measure of permeability, vertical hydraulic gradient, water depth (WD), and flow velocity at planting locations. Egg-to-fry survival averaged 92.7% (range: 57.2–100%) in 2013 (N = 19) and 71.5% (range: 6.4–100%) in 2014 (N = 23). Survival was significantly positively correlated with FI and flow velocity, negatively associated with percent cumulative weight of fine sediments and WD. Vertical hydraulic gradient had no effect on survival. Our results suggest that a higher FI (i.e., low amount of fine material and larger particle size), higher flow velocity, and shallower WD reduce the mortality of planted chum salmon eyed eggs. This is likely a result of increased permeability in the substrate and restriction of fine sediment intrusion into the incubation zone.     

Changes in the levels of circulating plasma free amino acids of carp (Cyprinus carpio) after feeding a protein and an amino acid diet of similar composition

A protein diet containing casein as the sole nitrogen source and an amino acid diet of similar composition (except isolated amino acids represented all of the nitrogen) were fed to triplicate groups of yearling carp. The sequence of appearance of free amino acids in the plasma of carp at 0, 2, 4, 8 and 16 h after feeding the two diets was examined.The circulating levels of all plasma free essential amino acids were in highest concentrations at 4 h after feeding the casein diet, except for arginine which declined slightly from 2 to 4 h. After feeding the amino acid diet, plasma free arginine and lysine were at peak levels at 2 h after feeding, while others peaked by 4 h.Glutamic acid and aspartic acid were detected in very low concentrations in the plasma relative to their levels in the diets, while proline was found in the highest concentrations of all other amino acids.Essential amino acid levels in the plasma were found to be positively correlated with their levels in the diets, while non-essential amino acids were not.     

Simplified procedure for the estimation of glomerular filtration rate following intravenous administration of iodixanol in cats

Objective-To compare the use of a single-sample method involving IV administration of iodixanol with a multisample method involving inulin for the estimation of glomerular filtration rate (GFR) in cats. Animals-24 cats, including 15 healthy cats and 9 cats with naturally occurring renal diseases. Procedures-Each cat was coadministered iodixanol (a nonionic contrast medium; dose providing 40 mg of I/kg) and inulin (50 mg/kg), IV, and blood samples were collected 60, 90, and 120 minutes later. Serum iodixanol and inulin concentrations were determined by means of high-performance liquid chromatography and colorimetry, respectively. Serum urea nitrogen and creatinine concentrations were also measured. Results-Analysis of the data from healthy cats and cats with naturally occurring renal diseases revealed an excellent correlation between GFR values estimated by the multisample and single-sample methods with iodixanol. Likewise, GFR values estimated from the single-sample method with iodixanol were closely correlated with those calculated from the multisample method with inulin. Conclusions and Clinical Relevance-For estimation of GFR in cats, use of a single-sample method with iodixanol, instead of a multisample procedure, may be an expedient tool in both clinical and research settings because of its benefits to patient well-being as a result of reduced stress associated with blood sample collection.     

Isolation of a new phlorotannin, a potent inhibitor of carbohydrate-hydrolyzing enzymes, from the brown alga Sargassum patens

Ethanol extracts from 15 kinds of marine algae collected from the coast of the Noto Peninsula in Japan were examined for their inhibitory effects on human salivary α-amylase. Four extracts significantly suppressed the enzyme activity. An inhibitor was purified from the extract of Sargassum patens . The compound was a new phloroglucinol derivative, 2-(4-(3,5-dihydroxyphenoxy)-3,5-dihydroxyphenoxy) benzene-1,3,5-triol (DDBT), which strongly suppressed the hydrolysis of amylopectin by human salivary and pancreatic α-amylases. The 50% inhibitory activity (IC(50)) for α-amylase inhibition of DDBT (3.2 μg/mL) was much lower than that of commercially available α-amylase inhibitors, acarbose (26.3 μg/mL), quercetagetin (764 μg/mL), and α-amylase inhibitor from Triticum aestivum (88.3 μg/mL). A kinetic study indicated that DDBT was a competitive α-amylase inhibitor with a K(i) of 1.8 μg/mL. DDBT also inhibited rat intestinal α-glucosidase with an IC(50) value of 25.4 μg/mL for sucrase activity and 114 μg/mL for maltase activity. These results suggest that DDBT, a potent inhibitor of carbohydrate-hydrolyzing enzymes, may be useful as a natural nutraceutical to prevent diabetes.     

Vertical Distribution of Carbonyl Sulfide at Mt. Fuji, Japan

Atmospheric carbonyl sulfide (COS) mixing ratios measured over 24 h during five summer campaigns (2003–2007) in a forest at the foot of Mt. Fuji, Japan (35°21′ N, 138°43′ E; 1,300 m above sea level, a.s.l.) and at the summit (3,776 m a.s.l.) were compared. COS levels were lower at the foot than at the summit during four out of five summer campaigns. The ratios of COS mixing ratios at the foot of Mt. Fuji to those at the summit ranged from 0.7 to 0.9. These results provide evidence of biological consumption of COS in the East Asian atmospheric boundary layer. We also measured the vertical profile of ambient COS below the forest canopy. These data showed a clear gradient of COS mixing ratio: in the lowermost 1 m of the boundary layer, COS mixing ratios decreased markedly downward. Two of the different kinds of vertical distribution of COS presented here support the role of soil as a sink of atmospheric COS described by previous research using dynamic enclosure experiments.