COMPARISON OF GROSS AND HISTOPATHOLOGIC FINDINGS WITH QUANTITATIVE COMPUTED TOMOGRAPHIC BONE DENSITY IN THE DISTAL THIRD METACARPAL BONE OF RACEHORSES

Comparison of subchondral bone density determined by quantitative computed tomography (CT) with gross and histopathologic changes have not been made in horses. The goal of this study was to determine if mean quantitative CT density and mean voxel standard deviation are associated with the presence and severity of osteochondral lesions in the palmar aspect of the distal third metacarpal bone in racing horses. Metacarpophalangeal joints from nine racehorses were imaged using CT and scored for gross damage. Four-millimeter-thick sagittal and 30 degrees palmar dorsal plane sections were cut, decalcified and stained with hematoxylin and eosin from the distal third metacarpal bone. Microscopic osteochondral lesions and subchondral remodeling were scored on a scale of 0-3. Percent subchondral bone, expressed as the ratio of bone volume to tissue volume, was also measured. Mean quantitative CT density and mean voxel standard deviation were measured from three-dimensional models of CT images comparable with histologic sections. Mean quantitative CT density was not associated with lesion severity or number of lesions. A weak correlation between mean quantitative CT density and gross score was found, but mean quantitative CT density was not predictive for gross score. Mean voxel standard deviation was not correlated with gross or histopathologic measures, but was predictive of mild osteochondral lesions. Results support the association of subchondral remodeling with the development of palmar metacarpal lesions. However, there was not a strong correlation between mean quantitative CT density or mean voxel standard deviation and histopathologic lesions of the distal third metacarpal bone.     

Supplementary effect of peppermint (Mentha × piperita) on dry matter intake, digestibility, ruminal fermentation and milk production in early lactating dairy cows

The aim of this research was to investigate the effect of peppermint feeding on dry matter intake, nutrient digestibility, ruminal fermentation and milk production in early lactating cows. Four Holstein cows were offered a diet with 5% dried peppermint and four Holstein cows remained on a diet without 5% of dried peppermint on a dry matter basis. The addition of peppermint to feed did not affect dry matter intake, although the eating time of feed was increased by mixing the feed with peppermint. There were no significant differences in the nutrient digestibilities between the two treatments. The ruminal ammonia and volatile fatty acids concentrations were similar in the two treatments, however, peppermint ingestion by cows led to a decrease in ruminal pH. The lowered pH value was within the stable pH condition range. No significant differences in the treatments were observed in milk production or milk composition except for the milk fat content. These results suggest that feeding peppermint to early lactating cows had little effect on their dry matter intake, nutrient digestibility, ruminal fermentation and milk production.     

Reactive oxygen species (ROS) generation and ROS-induced lipid peroxidation are associated with plasma membrane modifications in host cells in response to AK-toxin I from Alternaria alternata Japanese pear pathotype

AK-toxin I caused plasma membrane modifications with plasma membrane-derived membrane fragments only in sensitive Japanese pear tissues. H₂O₂ generation was abundant in both the membrane fragments and the plasma membranes of the toxin-treated sensitive tissues. Whether lipid peroxidation was induced in plasma membranes of the toxin-treated sensitive tissues was examined biochemically and histochemically. Lipid peroxidation was caused only in the toxin-treated sensitive tissues or the toxin-treated plasma membrane-enriched fractions from sensitive young pear fruits. The results indicated that the peroxidation was probably induced by reactive oxygen species in the modified plasma membranes by action of toxin, suggesting that peroxidation is closely associated with plasma membrane modifications.     

Responses of annual bluegrass (Poa annua L.) and creeping bentgrass (Agrostis palustris Huds.) seedlings to nitrogen,phosphorus and potassium†

The growth response to fertilizer under different soil texture (light clayey soil and composite soil consisting of the light clayey soil and sand), and the timing of N fertilization (early summer and fall fertilization) were determined for annual bluegrass (Poa annua L.) and creeping bentgrass (Agrostis palustris Huds., var. Penncross) in glasshouse experiments. At the three‐leaf stage, both plant species were treated with 30, 100, 300, 1,000, 3000 or 10 000 p.p.m. (w/v) of N, P₂O₅ and K₂O equivalent to ammonium sulfate (N), calcium superphosphate (P) and potassium chloride (K). Three weeks after fertilization, the dry weight of shoots or roots was measured. Both plant species were more sensitive to N than to P or K; however, creeping bentgrass required a higher rate of N (1000 p.p.m.) for maximum shoot and root growth than did the weed (300 p.p.m., N). Shoot growth of both plant species was strongly affected by the timing of N fertilization and soil texture; their shoot responses to N increased in the order: composite soil > light clayey soil, and early summer N fertilization > fall N fertilization, and this tendency was especially marked for creeping bentgrass. These results suggest that the response of annual bluegrass to fertilizer is similar to that of creeping bentgrass; however, the two plants are different in regard to the N requirement or their relationship between response to N and application timing and/or soil texture.     

A pathological study of the salivary glands of rabid dogs in the Philippines

Rabies is a zoonotic disease caused by the rabies virus. While the salivary glands are important as exit and propagation sites for the rabies virus, the mechanisms of rabies excretion remain unclear. Here, we investigated the histopathology of the salivary glands of rabid dogs and analyzed the mechanism of excretion into the oral cavity. Mandibular and parotid glands of 22 rabid dogs and three control dogs were used. Mild to moderate non-suppurative sialadenitis was observed in the mandibular glands of 19 of the 22 dogs, characterized by loss of acinar epithelium and infiltration by lymphoplasmacytic cells. Viral antigens were detected in the mucous acinar epithelium, ganglion neurons and myoepithelium. Acinar epithelium and lymphocytes were positive for anti-caspase-3 antibodies and TUNEL staining. In contrast, no notable findings were observed in the ductal epithelial cells and serous demilune. In the parotid gland, the acinar cells, myoepithelium and ductal epithelium all tested negative. These findings confirmed the path through which the rabies virus descends along the facial nerve after proliferation in the brain to reach the ganglion neurons of the mandibular gland, subsequently traveling to the acinar epithelium via the salivary gland myoepithelium. Furthermore, the observation that nerve endings passing through the myoepithelium were absent from the ductal system suggested that viral proliferation and cytotoxicity could not occur there, ensuring that secretions containing the virus are efficiently excreted into the oral cavity.     

Surveillance of classical swine fever in wild boar in South Korea from 2010–2014

Classical swine fever (CSF) is a highly contagious systemic hemorrhagic viral disease of pigs. Wild boar plays a crucial role in the epidemiology of CSF. Between 2010 and 2014, samples were collected nationwide from 6,654 wild boars hunted in South Korea. Anti-CSF antibodies were identified in 0.59% (39 of 6,654) of the wild boar samples using a virus neutralization test and were primarily detected in wild boars living close to the demilitarized zone and the area of the Taebaek Mountains surroundings. The CSF virus (subgroup 2.1b) was isolated from two wild boars captured in a nearby border area. The criteria used to define high-risk areas for targeted CSF surveillance in South Korea should be further expanded to include other regions nationwide.     

韩国牡蛎生产与贸易研究

牡蛎养殖在韩国海水养殖业中占有重要地位,韩国是世界上仅次于中国的第二大牡蛎生产国。由于苗种供应不稳定、养殖密度增加造成的环境污染等问题,韩国牡蛎产量近年来呈下降趋势。韩国与中国互为近邻,其牡蛎产业发展面临的问题和采取的对策,对中国牡蛎产业的健康发展具有一定借鉴意义。文章通过分析韩国牡蛎苗种采集、养殖过程与管理制度、流通渠道、价格与养殖生产经营情况、进出口贸易以及存在的问题和政府采取的对策等,为中国牡蛎养殖业的健康发展和管理提供参考。