Plasma hormone and metabolite concentrations involved in the somatotropic axis of Japanese Black heifers in association with growth hormone gene polymorphism

Bovine growth hormone (bGH) gene polymorphism of leucine (Leu)-threonine (Thr) (allele A), valine (Val)-Thr (allele B), and Val-methionine (Met) (allele C) at codons 127 and 172 was shown to relate with carcass trait variations in Japanese Black cattle. In this study, 10-mo-old Japanese Black heifers with growth hormone (GH) genotypes AA, AB, BB, AC, BC, and CC (N = 141) were compared for basal GH, insulin-like growth factor-1 (IGF-1), insulin, ghrelin, glucose, and nonesterified fatty acid (NEFA) concentrations. Growth hormone release was also measured as response to growth hormone–releasing hormone (GHRH) (0.4 μg/kg body weight [BW]) using 18 heifers with GH genotypes AA, BB, and CC (n = 6 for each group). The genotype AA heifers showed the greatest BW among genotypes (P < 0.05). Genotype AC, BC, and CC heifers showed greater GH concentrations than genotype AA, AB, or BB heifers, in which genotype CC heifers had the highest concentrations (P < 0.05). However, IGF-1 concentrations did not significantly differ. The genotype AA and BB heifers had a greater GH release at 60 min following GHRH injection than did the genotype CC heifers. The area under the curve (AUC; P < 0.07) and incremental area (IA; P < 0.08) of GH responses to the GHRH challenge tended to be the highest in the genotype AA heifers and the lowest in the genotype CC heifers. In conclusion, GH gene polymorphism altered GH, which may have contributed to differences in BW and carcass traits among genotypes.     

Effect of nutritional conditions on changes in leukocyte populations in Japanese black calves

To clarify the effect of nutritive conditions on changes in immune cells in Japanese Black (JB) calves during the growth period, leukocyte populations were analyzed in ten healthy JB calves managed in one herd. The calves were divided into two groups: five calves in Group 1 were given insufficient nutrition, and the other five calves in Group 2 received adequate nutrition. The levels of serum total cholesterol and glucose were significantly lower in Group 1 than in Group 2 at 1 month. The numbers of CD3+, CD4+ and CD8+ cells tended to be lower in Group 1 than in Group 2 at months 1 and 2, and the difference in CD4+ was significant at month 2. The number of MHC class-II(+high) cells was significantly lower in Group 1 than in Group 2 at months 1 and 2. These results suggest that adequate nutrition might stimulate an increase in immune cells in calves during the growth period.     

Development of an efficient method for recovery of Puumala and Puumala-related viruses by inoculation of Mongolian gerbils

Puumala (PUU) virus and PUU-related viruses are difficult to isolate in cell culture. To determine whether animal inoculation would be a better alternative for virus recovery, the Sotkamo strain of PUU virus was inoculated into several animal species. Newborn Mongolian gerbils (MGs), mice, and rats were infected with the Sotkamo strain by intracerebral (ic), intraperitoneal (ip), and subcutaneous (sc) inoculation. Antibodies to PUU appeared in MGs at 30 days post-infection (dpi), and in mice and rats at 15 dpi. Interestingly, virus appeared at 7 dpi in lung and brain of MGs inoculated via ic and ip routes. Virus was detected in all tested tissues of MGs at 15 dpi, with a peak level of 1.36 x 10 (5) focus forming units (FFU)/g in brain tissue. The virus titer declined with the onset of the antibody response and became undetectable by 75 dpi, when the antibody titer reached the maximum level. The appearance of the virus in mice and rats was delayed as compared to MGs, and the virus titer was apparently lower, at approximately 4 to 8 x 10(3) FFU/g, at 15 dpi. In addition, lung homogenates of antibody-positive Clethrionomys (C.) rufocanus (captured in Tobetsu, Hokkaido, Japan) were inoculated into MGs by the ic route. PUU-related viral RNA was detected at 16 dpi in the brains of MG inoculated with the lung homogenate, and antibodies were detected at 45 dpi. These findings indicate that newborn MG inoculation is an efficient method to recover PUU and PUU-related viruses.     

Comparison of the effects of isotonic and hypertonic sodium bicarbonate solutions on acidemic calves experimentally induced by ammonium chloride administration

The objectives of this study were to evaluate and compare the effects of intravenously (IV) administered infusion of isotonic solution (ISB) or hypertonic sodium bicarbonate solution (HSB) on acid-base equilibrium and the plasma osmolarity in acidemic calves experimentally induced by 5 M-NH(4)Cl, IV infusion (1.0 ml/kg, over 1 hr). The ISB and HSB infusion induced progressive and significant increases in their HCO(3)(-) and BE levels that persisted throughout the period of fluid administration. The plasma osmolarity in the ISB groups was significantly decreased. The plasma osmolarity in the HSB group was significantly higher than in the calves in the other groups (p<0.05). ISB solution might be safe and effective for treating and reviving conscious calves from experimentally induced metabolic acidosis.     

Molecular characterization of Blastocystis isolates from primates

Twelve Blastocystis isolates from primates were analyzed genetically by polymerase chain reaction (PCR) using diagnostic primers and PCR-restriction fragment length polymorphism (RFLP) of SSUrDNA. Two distinct genotypes, subtype 1 and a variant of subtype 1, were detected in two and six of the 12 isolates, respectively. The RFLP profiles of the isolates designated as subtype 1 were identical to the profile of ribodeme 1. The RFLP profiles of the six isolates designated as variants of subtype 1 were different from the profile of the variant of subtype 1 from a human reported previously. The other four isolates were not amplified with any diagnostic primers, but three of them showed the same RFLP profiles as ribodeme 6. This study was the first genomic analysis of Blastocystis isolates from primates, and showed the genetic similarity between the isolates from primates and the genotypes of Blastocystis hominis. However, it was unclear whether the isolates examined were zoonotic or not. Therefore, it is necessary to reveal the phylogenetic relationships between the isolates from primates and the multiple genotypes of B. hominis.     

Experimental gizzard erosions in specific-pathogen-free chicks by serotype 1 group I avian adenoviruses from broilers

The pathogenicity of serotype 1 group I avian adenovirus (GIAAV) strains isolated from gizzard erosions for 1-wk-old specific-pathogen-free (SPF) chickens was investigated. In Experiment 1, SPF chickens inoculated orally with a serotype 1 strain (Tokushima2000/GE) of GIAAV isolated from gizzard erosion in broilers were euthanatized and necropsied from 3 to 12 days after inoculation. Clinically, there were no significant signs in the chickens inoculated with Tokushima strain. The gizzards were found macroscopically to be dilated with liquefied contents. The koilin layer of the gizzard exhibited multifocal white lesions with occasional erosions. Gross lesions of the koilin layer (white foci and erosion) appeared at 3 days after inoculation and persisted until 12 days after inoculation. The gross lesions were most severe at 9 days after inoculation. Histologically, multifocal degeneration, necrosis, and loss of the glandular epithelial cells with intranuclear inclusions, liquefactive change of koilin substance, and erosive lesions of koilin layers and surface epithelium of the gizzards were observed. Macrophages increased in the focal areas of the lamina propriabelow the liquefactive koilin substances. Immunohistochemically, intranudear inclusions were positive against GIAAV antigen. Histologic lesions of gizzards were most severe at 7 and 9 days after inoculation, but the frequency of intranuclear inclusions was greatest at 5 days after inoculation. In Experiment 2, the pathogenicities of four strains of serotype 1 GIAAV for 1-wk-old SPF chickens were compared. Three strains isolated from gizzard erosion had similar pathogenicities but one strain from a normal chicken was not pathogenic for chickens. These results suggest that gizzard erosions by serotype 1 GIAAV infection may occur in broiler chickens in Japan.     

Serum leptin levels during the periparturient period in cows

Serum leptin concentrations were measured in antenatal and postnatal cows housed at two different locations. The mean serum leptin concentration was 9.2 +/- 0.6 ng/m l (n=22) in one group, and was slightly lower in the other (7.4 +/- 0.4 ng/ml, n=54), probably because of the different nutritional conditions between the two groups. There was no consistent variation in relation to the menstrual cycle and the periparturient period in both groups. Moreover, serum leptin concentrations during the periparturient period were independent of the number of delivery and the incidence of mastitis and milk fever. These results are quite different from those in rodents and human, suggesting the different regulatory mechanism of circulating leptin concentration in cows.     

Phytotoxin produced by Streptomyces sp. causing potato russet scab in Japan

A phytotoxin isolated from the Stretomyces sp. causing potato russet scab in Japan (Kamenoko-byo in Japanese) was identified as a 16-membered macrolide, FD-891. It induced necrosis in potato tuber slices above 50 µg/disk, which is about 1/100 the activity of thaxtomin A. The phytotoxin was detected in potatoes infected by the pathogen and was produced by other pathogenic strains with different geographic origins.     

The possibility of factors other than phytoalexin accumulation preventing fungal growth in the incompatible interactions of soybean with Phytophthora megasperma f. sp. glycinea

Soybean ( Glycine max ) cv. Harosoy 63 is resistant to race 1 and susceptible to race 9 of Phytophthora megasperma f. sp. glycinea (Pmg). In detached primary leaves inoculated with zoospores, growth of race 1 was completely suppressed 16 h after inoculation, while race 9 was unaffected. The amount of the phytoalexin glyceollin that accumulated, however, was not significantly different in either the incompatible or compatible interaction 16 h after inoculation. At the circumference of the inoculated area, a slight accumulation of phytoalexin was observed only in the incompatible interaction 20 h or more after inoculation. Tolerance of race 9 to the phytoalexin was significantly higher than that of race 1 when the phytoalexin was added to agar. Moreover, race 9 degraded glyceollin faster than race 1. On leaves inoculated at separate points with either race, the lesion associated with race 9 never colonized areas inoculated with race 1. These results suggest that factor(s) other than the accumulation of phytoalexin in soybean tissue might cause cessation of growth of Pmg.     

Artificial insemination with canine spermatozoa frozen in a skim milk/glucose-based extender

Due to the recent outbreak of avian influenza, transportation of frozen canine semen with egg yolk has been sharply restricted. Thus, there is urgent need to develop a novel egg yolk-free extender for freezing canine spermatozoa. In the present study, the effect of using skim milk/glucose (SG)-based extender without egg yolk on the motility and fertilizing capacity of canine spermatozoa frozen-thawed in the presence of glycerol was examined. There was a tendency for the proportion of motile spermatozoa exposed to SG-based extender for 3 h to be higher than that exposed for 1 h, but the difference was not significant. The motility and other viability parameters of canine spermatozoa after thawing were similar to those obtained with an egg yolk-based extender. When spermatozoa frozen with SG-based extender containing glycerol after 3 h exposure were transcervically inseminated into 2 recipient bitches, a total of 6 pups were obtained. These results suggest that a simple extender composed of skim milk, glucose and glycerol is useful for cryopreservation of canine spermatozoa, which may contribute to improved exchange of genetic material and efficient production of companion and working dogs, such as guide dogs for the blind.