Effect of a single injection of gonadotropin-releasing hormone (GnRH) and human chorionic gonadotropin (hCG) on testicular blood flow measured by color doppler ultrasonography in male Shiba goats

Although color Doppler ultrasonography has been used to evaluate testicular blood flow in many species, very little has been done in goat. Eight male Shiba goats were exposed to a single intramuscular injection of either gonadotropin-releasing hormone (GnRH group; 1 µg/kg BW) or human chorionic gonadotropin (hCG group; 25 IU/kg BW). Plasma testosterone (T), estradiol (E2) and inhibin (INH) were measured just before (0 hr) and at different intervals post injection by radioimmunoassay. Testis volume (TV) and Doppler indices, such as resistive index (RI) and pulsatility index (PI) of the supratesticular artery, were measured by B-mode and color Doppler ultrasonography, respectively. The results indicated an increase in testicular blood flow in both groups, as RI and PI decreased significantly (P<0.05), but this increase was significant higher and earlier in hCG group (1 hr) than in the GnRH group (2 hr). A high correlation was found for RI and PI with both T (RI, r= −0.862; PI, r= −0.707) and INH in the GnRH group (RI, r=0.661; PI, r=0.701). However, a significant (P<0.05) correlation was found between E2 and both RI (r= −0.610) and PI (r= −0.763) in hCG group. In addition, TV significantly increased and was highly correlated with RI in both groups (GnRH, r= −0.718; hCG, r= −0.779). In conclusion, hCG and GnRH may improve testicular blood flow and TV in Shiba goats.     

Tooth brushing inhibits oral bacteria in dogs

In this study, scaling, polishing and daily tooth brushing were performed in 20 beagle dogs, and the number of oral bacteria was determined using a bacterial counter. The dogs were randomized into the scaling (S), scaling + polishing (SP), scaling + tooth daily brushing (SB) and scaling + polishing + tooth daily brushing (SPB) groups. Samples were collected from the buccal surface of the maxillary fourth premolars of the dogs immediately after scaling and every week thereafter from weeks 1 to 8. Throughout the study, the number of bacteria was significantly lower in the SB and SPB groups compared with the S group. The findings suggest that daily tooth brushing inhibited oral bacterial growth in the dogs.     

Acorn dispersal and predation patterns of four tree species by wood mice in abandoned cut-over land

We compared patterns of acorn dispersal and predation by wood mice among four tree species (Quercus serrata, Quercus crispula, Castanea crenata, and Juglans mandshurica var. sieboldiana) that are abundant in cool temperate woodlands. We devised an acorn dispersal experiment using 400 magnet-inserted acorns and a magnetic locator in a 1.8-ha study plot, which spanned a cut-over area and an adjacent deciduous forest. Ten wire mesh baskets, each containing 40 acorns (10 acorns per species), were placed on the border between these two habitat types. About 13.0% (n = 52) of the total acorns remained in the baskets, while 77.3% (n = 309) were dispersed throughout the study plot and subsequently retrieved using the magnetic locator. Microhabitat, distance, and burial depth of transported acorns were significantly different among species. In the cut-over area, J. mandshurica var. sieboldiana acorns were dispersed under fallen trees or branches and near stumps, and were buried deeply in the soil. Dispersal distances of J. mandshurica var. sieboldiana acorns were significantly greater than those of Q. serrata acorns. The number and microhabitat of transported acorns significantly differed between habitat types. J. mandshurica var. sieboldiana acorns were dispersed in the cut-over area rather than in the forest. For all four species, the numbers of acorns delivered to fallen trees or branches, stumps, and crumbled soil with overhang under any vegetation type were greater in the cut-over area than in the forest.     

Measuring consumer response to ‘Gala’ apples treated with 1-methylcyclopropene (1-MCP)

Post-harvest apple treatment with 1-methylcyclopropene (1-MCP) was previously found to inhibit fruit ripening but also to inhibit the production of volatile compounds that contribute to apple flavor. The first objective of this study was to determine if consumers could distinguish 1-MCP treated and untreated Gala apples [Malus sylvestris L. (Mill.) var. domestica Borkh. Mansf.] following long-term storage. Chemical analysis showed 1-MCP treated fruit had reduced flavor volatiles compared to untreated fruit. Consumer difference tests showed they could distinguish between 1-MCP treated and untreated fruit. A second objective was to compare consumers’ acceptance for 1-MCP treated to untreated apples. Both 1-MCP treated and untreated apples received high overall liking scores that were not significantly different. Equal numbers of consumers indicated preference for 1-MCP treated and untreated fruit and there was no difference in purchase intent. However, subsets of consumers who eat Gala, Fuji or Red Delicious apples showed preference for untreated over 1-MCP treated fruit compared to consumers who do not eat these varieties.     

Mutations in a human ROBO gene disrupt hindbrain axon pathway crossing and morphogenesis

The mechanisms controlling axon guidance are of fundamental importance in understanding brain development. Growing corticospinal and somatosensory axons cross the midline in the medulla to reach their targets and thus form the basis of contralateral motor control and sensory input. The motor and sensory projections appeared uncrossed in patients with horizontal gaze palsy with progressive scoliosis (HGPPS). In patients affected with HGPPS, we identified mutations in the ROBO3 gene, which shares homology with roundabout genes important in axon guidance in developing Drosophila, zebrafish, and mouse. Like its murine homolog Rig1/Robo3, but unlike other Robo proteins, ROBO3 is required for hindbrain axon midline crossing.     

Establishment of a Model of Spontaneously-Running-Tokushima-Shikoku Rats with Left Atrial Thrombosis

Studies that investigate the underlying mechanisms of disease and treatment options typically require the use of a suitable animal model. Few suitable animal models exist for left atrial thrombosis. Here, we demonstrated that the Spontaneously-Running-Tokushima-Shikoku (SPORTS) rat — a Wistar strain known for its running ability—is predisposed to the development of thrombi in the left atrium. We investigated the incidence of left atrial thrombosis in male (n = 16) and female (n = 17) SPORTS rats and observed organized atrial thrombosis in 57% and 38% of males and female rats, respectively. In the male rats, systolic blood pressures and heart rates were significantly higher in SPORTS rats than in control Wistar rats. We could not find any evidence of arrhythmias, such as atrial fibrillation, during electrocardiographic examination of SPORTS rats. We believe that the SPORTS rat could serve as a new research model for left atrial thrombosis; further, it may be suitable for research investigating the development of new antithrombotic approaches for the control of atrial thrombosis or familial thrombophilia in humans.     

Isolation of chicken taste buds for real‐time Ca2+ imaging

We isolated chicken taste buds and used a real‐time Ca²⁺ imaging technique to investigate the functions of the taste cells. With RT‐PCR, we found that isolated chicken taste bud‐like cell subsets express chicken gustducin messenger RNA. Immunocytochemical techniques revealed that the cell subsets were also immunopositive for chicken gustducin. These results provided strong evidence that the isolated cell subsets contain chicken taste buds. The isolated cell subsets were spindle‐shaped and approximately 61–75 μm wide and 88–98 μm long, and these characteristics are similar to those of sectional chicken taste buds. Using Ca²⁺ imaging, we observed the buds' response to 2 mmol/L quinine hydrochloride (a bitter substance) and their response to a mixture of 25 mmol/L L‐glutamic acid monopotassium salt monohydrate and 1 mmol/L inosine 5′‐monophosphate disodium salt, umami substances. The present study is the first morphological demonstration of isolated chicken taste buds, and our results indicate that the isolated taste buds were intact and functional approaches for examining the taste senses of the chicken using Ca²⁺ imaging can be informative.     

Pharmacokinetics of oxolinic acid and oxytetracycline in kuruma shrimp, Penaeus japonicus

The pharmacokinetics of oxolinic acid and oxytetracycline were examined in kuruma shrimp (Penaeus japonicus) after intra-sinus (10 and 25 mg/kg, respectively) and oral (50 mg/kg) administration. The shrimp were kept in tanks with recirculated artificial seawater at a salinity of 22–23 ppt. The water temperature was maintained at 25±0.6 °C. The hemolymph concentrations of both drugs after intra-sinus dosing were best described by a two-compartment open model. The distribution and elimination half-lives (t_1/2 and t_1/2β) were found to be 0.59 and 33.2 h for oxolinic acid and 0.45 and 24.7 h for oxytetracycline, respectively. The apparent volume of distribution at a steady state (V_ss) and total body clearance (CL_b) were estimated to be 1309 ml/kg and 28.8 ml/kg/h for oxolinic acid and 748 ml/kg and 22.7 ml/kg/h, respectively. The hemolymph concentration–time curves after oral administration did not fit by the nonlinear least squares method using one- and two-compartment model with first-order absorption in either of the drugs. The peak hemolymph concentration (C_max), the time to peak hemolymph concentration (t_max) and the elimination half-life were found to be 17.8 μg/ml, 7 h and 34.3 h for oxolinic acid and 24.3 μg/ml, 10 h and 33.6 h for oxytetracycline, respectively. The bioavailability (F) after oral administration was 32.9% for oxolinic acid and 43.2% for oxytetracycline. The hemolymph protein binding in vivo was determined to be 36.7±8.5% for oxolinic acid and 22.9±4.8% for oxytetracycline.