Seasonal changes of blood composition in captive bottlenose dolphins

To determine how blood values in bottlenose dolphins changed during the year, 504 blood samples were taken from 9 dolphins from 1991 to 1999 and clinical blood examinations were undertaken monthly including 3 hematological and 19 serum chemistry tests. In creatinine, significant seasonal changes were found among three groups of adult males, adult females and juveniles, and the average values in summer were 15-38% higher than those in winter. In two out of three groups the average total cholesterol value were highest in winter, and the lowest of all groups were in summer. In two other groups the peaks of average FFA value were recorded in summer, and the lows were in winter.     

Estimation of genetic parameters for growth and feed utilization traits in Japanese Black cattle

Performance test results of 3250 sire candidates were used to estimate the genetic parameters of growth and feed utilization traits in Japanese Black cattle. Growth traits analyzed were six body measurements at the end of the performance test and daily gain (DG) during the test. Feed utilization traits were intakes and conversions of concentrate, roughage, digestible crude protein and total digestible nutrient (TDN). Genetic (co)variance components were estimated by the restricted maximum likelihood procedure using an expectation maximization algorithm under the two‐trait animal model. Heritabilities for growth traits ranged from 0.40 to 0.70 and for feed utilization traits from 0.21 to 0.74. Genetic correlations of DG were positive with feed intake (0.15–0.77) and negative with feed conversions (?0.63 to ?0.30). These relationships indicate that the selection based on DG improves feed efficiency but it simultaneously increases feed intake. Feed conversions showed genetic correlations ranging from ?0.09 to 0.03 with total available energy consumption, TDN intake. Thus the results suggested that feed conversions were not efficient selection criteria to decrease TDN intake and to improve comprehensive feed utilization ability.     

Functional role of type VI collagen during early feather development of the chicken embryo in vitro

The regulatory function of type VI collagen during early feather development in embryonic chickens was investigated at the cellular and organ levels. Immunohistochemical studies of embryonic chicken skin showed that type VI collagen was distributed in spatial‐specific and temporal‐specific manners related to early feather development. To clarify the role of type VI collagen, we studied the feather development in intact, reconstituted and reconstituted gel skin cultures. When ethyl‐3,4‐dihydroxybenzoate (EDHB) was added to the medium of intact skin as an inhibitor of type VI collagen synthesis, the feather buds did not elongate and the number of neural cell adhesion molecule (NCAM)‐positive cells was reduced. However, the magnitudes of both suppressive effects of EDHB were reduced by the addition of liquid type VI collagen. Similar improvement was also observed in the reconstituted skin with liquid type VI collagen and in the reconstituted gel skin with solid type VI collagen at a low concentration. Moreover, type VI collagen promoted feather bud development in the absence of EDHB. However, a high concentration of solid type VI collagen in the reconstituted gel skin arrested the feather bud elongation, and antitype VI collagen antibodies caused feather buds to become longer and smaller in the reconstituted skin. At the cellular level, type VI collagen affected the proliferation, migration and NCAM expression of mesenchymal cells. These results suggest that type VI collagen regulates early feather development by controlling mesenchymal cell behavior.     

Paternity determination of captive bottlenose dolphins (Tursiops truncatus) using microsatellite DNA analysis

We applied previously published PCR primer pairs to amplify alleles at three polymorphic microsatellite loci to determine the genetic relationship of 6 bottlenose dolphins (Tursiops truncatus) that were living together in a Japanese aquarium. The three microsatellite loci were sufficient to determine the haplotype relationships of the six dolphins, which represented three different generations. It was confirmed that this genotyping method is simple and economical for assessing, establishing and maintaining genetic diversity in captive populations and will become a very effective technique for ex situ conservation in aquariums and zoos.     

Assessing diastolic function with Doppler echocardiography using a novel index: ratio of the transmitral early diastolic velocity to pulmonary diastolic velocity

We developed a novel index to assess left ventricular (LV) relaxation as the ratio of transmitral early diastolic velocity to pulmonary diastolic velocity (E/D ratio). Mixed breed dogs (n=7) were anesthetized and their respiration was controlled. A 3.5-Fr micromanometer-tipped catheter was placed into the left ventricle. Dobutamine (5.0 or 10 microg/kg/min) or esmolol (100 or 500 microg/kg/min) was administered via the cephalic vein. The transmitral flow (TMF) and pulmonary venous flow (PVF) were recorded using transthoracic echocardiography from the apical long-axis view. The heart rate, systolic LV pressure, +dP/dt, and -dP/dt were significantly elevated by dobutamine, but significantly reduced by esmolol. Dobutamine significantly decreased tau, whereas esmolol significantly increased tau. The TMF-derived E and PVF-derived D wave velocities increased significantly with dobutamine, but decreased significantly with esmolol. A significant correlation was detected between the E and D wave velocities (r=0.92). Consequently, the E/D ratio was decreased significantly with dobutamine, and increased significantly with esmolol. Furthermore, the E/D ratio was significantly correlated with -dP/dt (r= -0.64) and tau (r=0.84). Our results suggest that the E/D ratio reflects LV relaxation, and may potentially provide further information on LV relaxation.     

Evaluation of colostral immunity in swine with commercial anti-leptospira polyvalent whole-bacteria vaccine

The intensity and duration of passive immunity against swine leptospirosis were investigated by the microscopic agglutination test and in vitro leptospira growth inhibition. Twenty-one females at first parturition were divided into three groups: Group A (n=08): received two doses with 30 days interval of the commercial anti-leptospira bacterin A. Group B (n=06) received two doses with 30 days interval of the commercial anti-leptospira bacterin B and Group C (n=07) was the control. In all groups the colostrums were collected. Blood collection of piglets was performed in four different ages. Agglutinin antibodies were equally detected in sera and colostrums for serovars Canicola, Grippotyphosa, Copenhageni, Icterohaemorrhagiae and Pomona (Group A) and Canicola, Copenhageni, Icterohaemorrhagiae, Pomona and Hardjo (Group B). Mean neutralizing antibodies titers were low. Passive immunity was low duration.     

Assessing equine anxiety-related parameters using an isolation test in combination with a questionnaire survey

The aim of the study was to determine parameters reflecting equine anxiety trait by comparing results obtained in a behavior test and an anxiety score assessed by familiar caretakers in response to a questionnaire. In the behavior test, horses were individually led into a novel room by their caretakers and loosely tethered to decrease excessive movement using the common cross-tying technique with two leads and breakable plastic cords. The horses initially remained with their caretaker for 2 min; the caretaker then left and the subject animal was left alone for 2 min. The latency to break the plastic cords, heart rate, the number of steps and pawings were recorded. When the horses were left alone, most parameters changed significantly and some showed sexual differences. A correlation analysis revealed that anxiety score assessed by caretakers showed a negative correlation with the latency to break the plastic cord and a positive correlation with heart rate only when horses were isolated. These two were suggested feasible parameters for assessing the anxiety trait of unfamiliar horses. Both the behavioral results and the anxiety scores also indicated that females were more anxious than males. Our results suggest that it would be a useful strategy for assessing other temperament traits as well to combine behavior tests with a questionnaire survey.     

Genetic analysis of phosphoprotein and matrix protein of rabies viruses isolated in Brazil

To investigate the genetic characteristics of phosphoprotein (P) and matrix protein (M) genes of variable rabies virus (RV) prevalent in Brazil, the authors genetically characterized the P and M genes from 30 Brazilian RV field isolates. Phylogenetic analysis based on the P and M genes revealed the presence of six RV variants that consisted primarily of three insectivorous bats, the vampire bat, dog and fox in Brazil. Specific amino acid substitutions corresponding to these phylogenetic lineages were observed, with Asp(42) and Glu(62) in the P protein found to be characteristic of Brazilian chiroptera- and carnivora-related RVs, respectively. Amino acid sequence motifs predicted to associate with a viral function in the P and M proteins were conserved among Brazilian RV variants.     

Beta-2-microglobulin levels in the cerebrospinal fluid of normal dogs and dogs with neurological disease

BACKGROUND: Cerebrospinal fluid (CSF) analysis is the basis for establishing a diagnosis of central nervous system (CNS) inflammation. However, the information provided by routine CSF analysis is limited. Determination of CSF beta-2-microglobulin (beta2m) concentration has been used diagnostically in humans to identify inflammatory CNS disease; we hypothesized that it may have similar value in dogs. OBJECTIVES: The objective of this study was to measure (beta2m concentration in the CSF of clinically healthy dogs and compare the values to those observed in dogs with inflammatory CNS disease and intervertebral disc disease (IVDD). METHODS: CSF was collected from 10 clinically healthy laboratory dogs and 11 dogs each with inflammatory CNS disease and IVDD. Routine CSF analysis was performed, and (beta2m concentration was measured by ELISA. CSF (beta2m concentration and CSF:serum (beta2m ratio were compared between groups by ANOVA. Linear relationships between CSF total nucleated cell count (TNCC), RBC count, total protein concentration, and (beta2m concentration were assessed by regression analysis. RESULTS: The mean (+/- SD) CSF (beta2m concentration in clinically healthy dogs was 0.36 (+/- 0.05 microg/mL (cisternal) and 0.40 (+/- 0.07 microg/mL (lumbar). Median CSF (beta2m concentration in dogs with IVDD (0.46 microg/mL) and inflammatory CNS disease (0.85 microg/mL) differed from that of controls (0.36 microg/mL; P=.002). The concentration also differed between the 2 disease groups (P=.01). Five dogs with inflammatory CNS disease had CSF:serum (beta2m ratios >1. A correlation was identified between TNCC and (beta2m concentration (r=0.69, P=.0003). CONCLUSIONS: CSF (beta2m concentration is higher in dogs with IVDD and inflammatory CNS disease, with highest values seen with inflammatory disease. This may be attributed in part to the correlation between CSF (beta2m concentration and TNCC, but also may reflect intrathecal immune activation.     

Contrasting effect of perlecan on adipogenic and osteogenic differentiation of mesenchymal stem cells in vitro

Perlecan, a basement membrane component, shows diverse functions in different organs and tissues. However, the role of perlecan in differentiation of mesenchymal stem cells (MSCs) has been barely investigated. In this study, we examined the effect of perlecan on adipogenic and osteogenic differentiation of MSCs in vitro by adding extrinsic perlecan to culture media or blocking the function of intrinsic perlecan expressed into culture media by differentiating MSCs. Extrinsic perlecan suppressed adipogenic differentiation; however, it promoted osteogenic differentiation. These functions were further confirmed by a study of blocking intrinsic perlecan. Perlecan treated with heparitinase‐I also showed the suppressive effect on adipogenic differentiation. In contrast, the promotive effect on osteogenic differentiation was found to be heparan sulfate‐dependent. Intrinsic perlecan was suggested to be effective at the late stage of adipogenic differentiation by a study of perlecan‐blocking performed at distinct periods, but was suggested to be effective at the early stage of osteogenic differentiation. Our results showed perlecan has contrasting effect on adipogenic and osteogenic differentiation of MSCs due to its diverse actions. Based on these outcomes, we recognized that employing extrinsic perlecan or blocking intrinsic perlecan is effective for regulating adipogenic and osteogenic differentiation of MSCs by restricting its direction.