Prevalence of tick-borne Rickettsia and Ehrlichia in Ixodes persulcatus and Ixodes ovatus in Tokachi district, Eastern Hokkaido, Japan

DNA from 111 ticks collected by flagging in Tokachi district, Eastern Hokkaido, Japan were examined for infection with Rickettsia and Ehrlichia, by PCR and sequencing methodology. For Rickettsia, analysis of the partial sequence of the citrate synthase gene was successfully performed on 11 DNA samples from I. persulcatus, and 7 of them showed 99.8% identical with Rickettsia helvetica while the other 4 showed 99.8% identical with ;Candidatus Rickettsia tarasevichiae'. For Ehrlichia, a partial sequence of the 16S rRNA gene detected from I. persulcatus was 100% identical with that from Ehrlichia muris, and another DNA sample from I. ovatus showed 99.8% identical with Ehrlichia species detected from I. ovatus. The results suggest that the pathogens detected here might be distributed in this area.     

Detection of DNA closely related to 'Candidatus Rickettsia principis' in Haemaphysalis danieli recovered from cattle in Xinjiang Uygur Autonomous Region Area, China

Tick DNA samples from cattle in Xinjiang Uygur Autonomous Region Area, China, were examined for Rickettsia infection by citrate synthase gene-based PCR and sequencing. Four positive samples were detected from Haemaphysalis danieli and high levels of similarity were found with recently detected 'Candidatus Rickettsia principis.'     

Effects of topography and management history on natural forest recovery in abandoned forest after clear-cutting in Miyazaki, Japan

We investigated factors limiting the recovery of natural forest in former large-scale conifer plantations abandoned after clear-cutting in southwestern Japan. We analyzed forest recovery status (“recovered” sites covered by evergreen broad-leaved trees, and “unrecovered” sites covered by pioneer community or nonvegetated sites) using aerial photographs and field survey. We applied logistic regression analyses to evaluate the effects of topography, construction of harvesting roads, distance from remnant forest, stand condition before clear-cutting, and prior land-use history on forest recovery. Human factors, i.e., land use and clear-cutting age, were found to affect to forest recovery more than environmental factors such as topography. Harvesting roads had the strongest negative impact on forest recovery. Forest recovery after clear-cutting of young sugi plantations also took longer than after clear-cutting of old sugi plantations or evergreen broad-leaved forests. Furthermore, areas formerly utilized as meadows recovered less successfully than those that had been managed as coppices. The influences of these factors were thought to be promoted by the advance reproduction as the regeneration sources for forest recovery. The influence of stand age before logging suggested an effect of thinning, which might alter the abundance of advanced reproduction in the understory. However, distance from remnant forest appeared to be less important. An influence of topography was also detected, but this could be partly explained by the existence of advance reproduction in the understory in certain topographic positions. Thus, our analysis suggests that regeneration sources originating from advanced reproduction in plantations play a significant role for the recovery of natural forest after clear-cutting.     

Inhibition of growth hormone secretagogue receptor antagonist, [D-Lys-3]-GHRP-6, in adipogenesis of ovine and rat adipocytes

Ghrelin and growth hormone secretagogues receptor (GHS‐R or ghrelin receptor) have been reported as being one of the factors of adipogenesis in adipocytes. To investigate the involvement of ghrelin and GHS‐R in adipocytes, the effect of the GHS‐R antagonist, [D‐Lys‐3]‐GHRP‐6 (His‐D‐Trp‐D‐Lys‐Trp‐D‐Phe‐Lys‐NH₂), on the process of adipogenesis in ovine and rat adipocytes was evaluated. [D‐Lys‐3]‐GHRP‐6 (10^?7 mol/L) significantly inhibited adipogenic differentiation of ovine and rat preadipocytes prepared from adipose tissues. The level of peroxisome proliferator activated receptor (PPAR)‐γ2 mRNA, an adipogenic marker, was decreased during the differentiation of adipocytes treated with [D‐Lys‐3]‐GHRP‐6 for 10 days. Ghrelin stimulated adipogenesis, also causing an increment of glycerol‐3‐phosphate dehydrogenase and upregulation of PPAR‐γ2. Furthermore, the antilipolytic effect of ghrelin was attenuated by treatment with [D‐Lys‐3]‐GHRP‐6 in both types of isolated adipocytes. Overall, the results of the present study highlight that GHS‐R in adipogenesis can be blocked by treatment with [D‐Lys‐3]‐GHRP‐6.     

Lineage classification of canine inheritable disorders using mitochondrial DNA haplotypes

To estimate the maternal effects of dog breeds using mitochondrial DNA(mtDNA) haplotypes in the dogs with several clinical disorders, 600 base pairs of mtDNA D-loop region were amplified from 365 dogs and were determined for mtDNA sequences. The diversity of the 600-bp sequences was classified into 64 haplotypes, including 46 newly discovered haplotypes, and the haplotypes were grouped into four clusters I to IV. Lineage analysis using the mtDNA haplotype indicated that each dog breed genetically comprises one or a few mtDNA haplotypes. When the relationship between genetic background and occurrences of clinical diseases was estimated, canine lineage analysis using mtDNA haplotype revealed that the disorders distributed in the dominant mtDNA haplotypes of each dog breed, but no disorder closely associated with mtDNA haplotypes was detected.     

Outbreak of larval Echinococcus multilocularis infection in Japanese monkey (Macaca fuscata) in a zoo, Hokkaido: western blotting patterns in the infected monkeys

A high prevalence of larval Echinococcus multilocularis (Em) infection was found in zoo primates in Hokkaido, Japan. In October 1997, a Japanese monkey (Macaca fuscata) died and histopathologically diagnosed as alveolar hydatidosis. Serum samples were collected from the remaining Japanese monkeys and examined for antibodies against Em by enzyme-linked immunosorbent assay and western blotting. Serological tests showed 12 more animals of the remaining 57 monkeys were possibly infected. Ultrasonography revealed that nine of these 12 animals had a cystic lesion in the liver. The band patterns of western blotting in the monkeys were very similar to those in human.     

Radiographic evaluation of caudal vena cava size as a useful parameter for the diagnosis of heart disease in dairy cattle

To quantify the radiographic parameters of the caudal vena cava (CVC) in healthy cattle and demonstrate their clinical usefulness, the present study compared the ratios of the diameter of the thoracic CVC to the diameter of the aorta (Ao) and length of the thoracic vertebrae (VL), which are all positioned in the same intercostal space, in 81 healthy control cattle (43 growing, 38 adult) and 10 cattle with heart disease. The average diameter of the CVC (CVCave) was correlated with the size of the Ao and VL in the control cows. Although the diameter and pulsation index of the CVC differed significantly between the growing and adult cows, the ratios of CVC/Ao and CVC/VL were fixed values for both the growing and mature cattle. However, in the cattle with heart disease, the pulsation index of the CVC was significantly lower or there was absence of pulsation due to a dilated CVC, and the ratio of CVCave/Ao and CVCave/VL were significantly higher than those in the healthy cattle.