Localization of sympathetic, parasympathetic and sensory neurons innervating the heart of the Beijing duck by means of the retrograde transport of horseradish peroxidase

Sympathetic, parasympathetic and sensory neurons were labeled by injections of horseradish peroxidase into various regions of the heart in 33 Beijing ducks. Sympathetic postganglionic neurons innervating the heart were located in the paravertebral ganglia C15 (C16 is the last cervical segment in the duck) to T3, especially in the ganglion T1. The coronary sulcus and ventricle were more abundantly innervated by sympathetic neurons than the atrium. The left side of the heart was preferentially innervated by sympathetic postganglionic neurons in the left side of paravertebral ganglia but the right side of the heart were equally supplied from the right and left ganglia. Within the medulla oblongata, the number of labeled vagal preganglionic neurons in the nucleus ambiguus was much greater than that in the dorsal motor nucleus of the vagus nerve. Labeled neurons of the nucleus ambiguus were found in many ducks injected into the coronary sulcus. Cardiac sensory neurons were observed in the dorsal root ganglia C15 to T2 (highest in the ganglion T1) and in the nodose and jugular ganglia of the vagus nerve. These labeled neurons probably form the afferent and efferent limbs of cardiac reflexes and control circulation in the Beijing duck.     

Studies of certain factors affecting the microenvironment and microflora of the external ear of the dog in health and disease

A total of 187 dogs, 110 with clinical signs of otitis externa (OE), and 77 without history or clinical signs of OE, were examined microenvironment and microbiological analysis of their ear exudates made. The aural temperature and humidity of 160 dogs were measured. There were no significant difference between healthy dogs and OE dogs. German shepherd showed relatively lower temperature (p<0.01) and higher humidity (p<0.01). The mean log(10) number of microbial organisms of ears of OE dogs (4.16 +/- 0.31 cfu/g) was significantly increased, compared to that from the ears of non-OE group (2.55 +/- 0.24 cfu/g). Pseudomonas spp. and Proteus spp. were detected only from OE dogs. In addition, three enterotoxigenic Staphylococcus aureus were isolated from ear specimens.     

Deleterious effects of fungi isolated from paddy soils on seminal root of rice

Soil samples were collected from rice paddies at 22 locations in northeastern Honshu, Japan. In 20 of the samples, seedling growth of rice was improved by soil pasteurization (aerated steaming at 60°C for 30 min), although no typical disease symptoms were observed in the seedlings grown in the untreated soil samples. In most locations, rice seedlings grew better in a potting medium containing root material from plants grown in the pasteurized portion of a soil sample than in a medium with root material from plants grown in the unpasteurized portion of the same sample. The results suggest that microorganisms that restrained rice seedling growth may be common in the soils of rice paddies. Approximately 800 isolates were obtained from seedling roots grown in unpasteurized soils and grouped by cultural and microscopic morphologies. The deleterious effects of 79 isolates from 21 major groups, most of which were soil-dwelling taxa, were examined after direct inoculation of the seminal roots. Isolates of Curvularia sp., Cirrenalia sp., Eppicoccum nigrum, Fusarium graminearum, F. oxysporum, Gliocladium virens, Humicola sp., Penicillium sp., Rhizoctonia oryzae-sativae, Sclerotium hydrophilum, Trichoderma aureoviride, and T. harzianum inhibited root growth, suggesting that deleterious root-infecting fungi were more common in paddy soil than previously thought. These fungi may be involved in the restraint of rice seedling growth.     

Histological disorders related to the focal disappearance of the epiphyseal growth plate in rats induced by high dose of vitamin A

The histological disorders related to the focal disappearance of the epiphyseal growth plate were examined histochemically in the proximal tibia of rats administered a high dose of vitamin A. Animals were given 100,000 IU/100 g body weight/day of vitamin A for 5 days from 4 weeks after birth (VA rats) or given deionized water as control and sacrificed on Day 12 and 19 of the experiment. Tibiae were examined by immunohistochemistry for type I, II and X collagens, lectin-histochemistry for Helix pomatia and backscattered electron imaging. On Day 12, the abnormally developed calcified cartilage matrix was detected within the epiphyseal growth plate in VA rats. The uncalcified cartilage matrix contained type I collagen but lacked type II collagen. In addition, the eroded regions accompanied with numerous osteoclasts and osteoblasts were detected in the epiphyseal growth plate. On day 19, eroded regions penetrated the epiphyseal growth plate to result in its focal disappearances with the eroded surfaces entirely covered with bone tissue in VA rats. These findings suggested that the cartilage matrix of the epiphyseal growth plate was abnormally calcified and showed the phenotypes like bone matrix. The eroded regions of the epiphyseal growth plate seemed to be caused by the invasion of osteoclasts into the altered cartilage matrix and might develop to the focal disappearances by the modeling or remodeling due to action of osteoclasts and osteoblasts.     

Incidence of viruses in <Emphasis Type="Italic">Alstroemeria</Emphasis> plants cultivated in Japan and characterization of <Emphasis Type="Italic">Broad bean wilt virus-2, Cucumber mosaic virus</Emphasis> and <Emphasis Type="Italic">Youcai mosaic virus</Emphasis>

Alstroemeria plants were surveyed for viruses in Japan from 2002 to 2004. Seventy-two Alstroemeria plants were collected from Aichi, Nagano, and Hokkaido prefectures and 54.2% were infected with some species of virus. The predominant virus was Alstroemeria mosaic virus, followed by Tomato spotted wilt virus, Youcai mosaic virus (YoMV), Cucumber mosaic virus (CMV), Alstroemeria virus X and Broad bean wilt virus-2 (BBWV-2). On the basis of nucleotide sequence of the coat protein genes, all four CMV isolates belong to subgroup IA. CMV isolates induced mosaic and/or necrosis on Alstroemeria. YoMV and BBWV-2 were newly identified by traits such as host range, particle morphology, and nucleotide sequence as viruses infecting Alstroemeria. A BBWV-2 isolate also induced mosaic symptoms on Alstroemeria seedlings.     

Nitrogen budget of a rehabilitated forest on a degraded granitic hill

Rehabilitated forests established about 100 years ago on denuded lands in a hilly granitic area are widespread in the Kyoto–Osaka area, the second largest megalopolis in Japan. From 2001 to 2003, we monitored the annual nitrogen (N) budget of a rehabilitated forest watershed dominated by Quercus serrata and Ilex pedunculosa. The ion concentrations of bulk rain in the watershed were similar to those of other watersheds in Japan. The annual bulk rain input of N ranged from 5.1 to 6.3 kg N ha⁻¹ year⁻¹, and the N deposition from throughfall and stem-flow ranged from 7.5 to 8.2 kg N ha⁻¹ year⁻¹. Estimated annual outputs of N from the stream ranged from 3.3 to 10.6 kg N ha⁻¹ year⁻¹. These results indicate that the amount of N deposition in this area is less than that in urban Tokyo (>10 kg N ha⁻¹ year⁻¹), but the N output of the watershed is comparable with that of the Tokyo area. We discuss the characteristics of N dynamics in rehabilitated forests, focusing on the biogeochemical processes of this watershed.     

Microhabitat use of wood mice ranging from a reserved belt with evergreen broad-leaved trees to a coniferous plantation

Wood mice Apodemus speciosus and Apodemus argenteus are potentially important seed dispersers and predators of Quercus and Castanopsis in Japan. We investigated the existence of two species of wood mice in warm-temperate forests ranging from a reserved belt of evergreen broad-leaved trees to a coniferous plantation, and analyzed the relationship between wood mouse occurrence and environmental factors to confirm their microhabitat use. We used two-way analysis of variance to analyze differences in the captured number of each wood mouse species in two trapping seasons as well as two stand types to confirm the interaction between the stand type and trapping season. Apodemus speciosus were often captured in the reserved belt, while captures of A. argenteus were independent of season and stand types. It is reasonable to conclude from the results of the trends in occurrence that the two species of wood mice showed different uses of the microhabitat. The result of linear discriminant analysis made it clear that the distance from the reserved belt had much to do with the difference in microhabitat use between the two species in the fruiting season of Quercus and Castanopsis. On average, A. speciosus moved 19.9 m during nonfruiting and 61.3 m during fruiting, while A. argenteus moved 8.1 m during nonfruiting, and 29.0 m during fruiting from analysis of the recapture position. The results indicate that both species of mice move around during the fruiting season more than in the nonfruiting season.