Identification of potato scab-causing Streptomyces sp. occurring in strongly acidic soils in Saga Prefecture in Japan

Acid scab of potatoes occurs frequently in strongly acidic soils at pH 3.9–5.2. On the basis of the phylogenetic relationships derived from 16S rDNA sequences and physiological characteristics, we identified the organism causing this disease in potatoes grown in the Uwaba district of Saga Prefecture, Kyushu Island, southwest Japan, as Streptomyces acidiscabies. Another pathogen that occurred more frequently in weakly acidic to neutral soils, rather than strongly acidic soils, was identified as S. scabiei. Streptomyces acidiscabies tended to produce superficial lesions, while S. scabiei mostly produced raised and/or erumpent lesions.     

Emergence and frequency of highly benzimidazole-resistant Colletotrichum gloeosporioides, pathogen of Japanese pear anthracnose, after discontinued use of benzimidazole

From July to October 1999, two Japanese pear varieties, Housui and Niitaka, were unexpectedly infected with Colletotrichum gloeosporioides causing anthracnose in Saga Prefecture of Japan. More than 90?% of the anthracnose fungus strains collected in 1999 were highly benzimidazole-resistant and distributed at high frequencies across pear-producing areas. The control of anthracnose by benzimidazole fungicides could not be confirmed in orchards where the isolation frequency of resistant strains was high. The frequency of resistant strains did not significantly decline, even 2?C5?years after the last use of benzimidazole fungicides.     

A monoclonal antibody against chicken thrombocytes reacts with the cells of thrombocyte lineage

A new mouse monoclonal antibody (mAb), HUKT was raised against chicken peripheral blood thrombocytes. The mAb HUKT appeared to detect a specific marker on the surface of chicken thrombocytes. Flow cytometry (FCM) analysis revealed that it did not react with cells from the normal thymus, bursa of Fabricius, six kinds of chicken cell lines, chicken erythrocytes or human platelets. In addition, HUKT(+) cells in peripheral blood leukocytes (PBL) were CD45(low), Bu-1a(-) and CD3(-) cells. Immunoblotting analysis showed that the molecule recognized by HUKT is a monomer with an apparent molecular weight of 150 kDa under non-reducing and reducing conditions. Tissue distribution studies revealed that only cells of thrombocyte lineage in bone marrow and embryonic blood cells were stained by HUKT. The HUKT mAb presented here may be useful for both ontogenetic studies of thrombocyte lineage and immunological studies in the chicken.     

Experimental infection of cats with Chlamydophila felis

Cats experimentally infected with a British isolate of Chlamydophila felis (C. felis), B166 strain, by droplet into the eye and nose developed conjunctivitis, mild rhinitis and fever. The chlamydophila were first isolated from conjunctiva, nictitating membrane and then from lung, tonsil, liver, spleen, kidney, nasal and vaginal swabs and blood. These results indicate that C. felis B166 strain first infected and replicated in the conjunctiva and nictitating membrane in cats with symptoms which were mostly limited to conjunctivitis, and then pervaded the whole body by bacteremia.     

Chordoma of the thoracic vertebrae in a Bengal tiger (Panthera tigris tigris)

A 19-year-old female Bengal tiger (Panthera tigris tigris) was presented with hind limb weakness, ataxia and respiratory distress. Computed tomography revealed a mass between the left side of the T7 vertebra and the base of the left 7th rib. The tiger then died, and necropsy was performed. Grossly, the vertebral mass was 6 × 5.7 × 3 cm, and invaded the adjacent vertebral bone and compressed the T7 spinal cord. Histologically, the mass was composed of large, clear, vacuolated and polygonal cells with osteochondral matrix. Cellular and nuclear atypia were moderate. The vacuolated cells stained positively for cytokeratin and vimentin and negatively for S-100. Based on these findings, the present case was diagnosed as a vertebral chordoma; the first report in a tiger.     

Antioxidant properties of ferulic acid and its related compounds

Antioxidant activity of 24 ferulic acid related compounds together with 6 gallic acid related compounds was evaluated using several different physical systems as well as their radical scavenging activity. The radical scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH) decreased in the order caffeic acid > sinapic acid > ferulic acid > ferulic acid esters > p-coumaric acid. In bulk methyl linoleate, test hydroxycinnamic acids and ferulic acid esters showed antioxidant activity in parallel with their radical scavenging activity. In an ethanol-buffer solution of linoleic acid, the activity of test compounds was not always associated with their radical scavenging activity. Ferulic acid was most effective among the tested phenolic acids. Esterification of ferulic acid resulted in increasing activity. The activity of alkyl ferulates was somewhat influenced by the chain length of alcohol moiety. When the inhibitory effects of alkyl ferulates against oxidation of liposome induced by AAPH were tested, hexyl, octyl, and 2-ethyl-1-hexyl ferulates were more active than the other alkyl ferulates. Furthermore, lauryl gallate is most effective among the tested alkyl gallates. These results indicated that not only the radical scavenging activity of antioxidants, but also their affinity with lipid substrates, might be important factors in their activity.     

Nitrogen mineralization of silk waste applied to soil under aerobic conditions

Silk waste which is a byproduct of silk reeling consists mainly of silk proteins such as sericin and fibroin. Although silk waste has a high N content (164 g kg^-1) and low CjN ratio (2.16), net N mineralization in soil at 30°C under aerobic conditions was very slow (21.4% in 184 d). The N mineralization rate of silk waste applied to soil after hydrolysis with HCI was higher than that of untreated silk waste. The effect of hydrolysis with 0.2 M HCI for 60 min at 97°C on the net N mineralization for 56 d was twice as high as that with 1 M HCI for 60 min at 97°C. Molecular mass distribution of silk proteins shifted to the lower range by hydrolysis, whose effect with 1 M HCI was more pronounced than that with 0.2 M HCI. The content of the crystal region in silk protein was estimated to be approximately 45% based on the relationship between the reaction (acid hydrolysis) time and the weight of insoluble residues. X-ray diffraction patterns of these residues showed that the crystal structure persisted until at least 180 min after hydrolysis with 1 M HCI at 97°C. These results suggest that crystal regions and the scattered distribution in silk proteins inhibit the decomposition of silk waste in soil. Silk waste could thus be utilized as slow-release fertilizer.     

实验大鼠、小鼠胚胎的缓慢冷冻和玻璃化冷冻的比较

对3日龄小鼠胚胎和5日龄大鼠胚胎进行了玻璃化低温保存和缓慢冷冻保存的比较研究,从经过超数排卵的小鼠和大鼠中收集到了1897个8－16细胞的胚胎,经筛选后将I级和Ⅱ级胚计1738个（91．62%）分别进行两种低温保存试验,并对其中的881个冷冻胚胎分阶段进行复苏,复苏率分别为65．03％（小鼠69．59％,大鼠60．46％）和68．45％（小鼠72．61％,大鼠64．29％）,两者间无显著性差异（P＞0．05）。在复苏在胚胎中,选择其中的488个胚胎进行移植试验,结果,玻璃化冷冻保存胚胎的移植的受孕率为39．47％（89／222）,缓慢冷冻保存胚胎的移植的受孕率为42．56％（115／266）,两种低温保存方法经方差检验也无显著性差异（P＞0．05）。