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51.
The fine structure of the spindle shape body (SSB) of boar spermatid was studied using testes samples fixed by perfusion. This structure appeared on the middle piece which served as the upper border of the fibrous sheath of principal piece during the transition period between the late acrosome phase to the maturation phase of spermiogenesis. The formation of this thread-like spindle form coincided with the development of the postnuclear sheath with perinuclear ring just prior to the growth of the equatorial segment of the acrosome. Likewise, the ribs of the fibrous sheath on the principal piece were observed to have already formed but have not yet completed the mitochondrial sheath. The total size of the SSB and its consisting microtubule were measured. The functional meaning of this transitory construction may involve a threshold condition on the sperm middle piece.  相似文献   
52.
Nine out of 19 newborn pups from 4 litters died or euthanatized on day 10 to 17 after birth in a specific-pathogen-free beagle colony which had been established by cesarean section and bottle-feeding. Necropsy showed congestion and edema of the lungs, congestion of the liver and splenomegaly, as well as many subcapsular petechiae and wedge-shaped areas of ecchymosis on the cut surface of the kidneys. A cytopathic agent isolated from the lungs, kidneys and liver was identified as a canine herpesvirus. The bitches in the animal house were seroconverted into positive for the isolate after the outbreak of the disease. Histopathological lesions in six cases were characterized by multiple necrosis and hemorrhage in various organs. In addition, fibrinoid necrosis was seen in the arterial walls in wedge-shaped necrotic areas of the kidneys. The outbreak appeared to be temporary, since the same disease has not occurred in the colony up to the present time.  相似文献   
53.
Single nucleotide polymorphism (SNP) arrays are widely used for genetic and genomic analyses in cattle breeding; thus, data derived from SNP arrays have accumulated on a large scale nationwide. Commercial SNP arrays contain a considerable number of unassigned SNPs on the chromosome/position on the genome; these SNPs are excluded in subsequent analyses. Notably, the position‐unassigned SNPs, or “buried SNPs” include some of the markers associated with genetic disease. In this study, we identified the position of buried SNPs using the Basic Local Alignment Search Tool against the surrounding sequences and characterized the relationship between SNPs and genetic diseases in Online Mendelian Inheritance in Animals based on the genomic position. We determined the position of 285 buried SNPs on the genome and surveyed the genotype and allele frequencies of these SNPs in 5,955 individual Japanese Black cattle. Eleven SNPs associated with genetic disease, which contained five buried SNPs, were found in the population with the risk allele frequency ranging from 0.00008396 to 0.46. These results indicate that buried SNPs in the bovine SNP array can be utilized to identify associations with genetic disorders from large scale accumulated SNP genotype data in Japanese Black cattle.  相似文献   
54.
Five generations of Landrace pigs selected for average daily gain, backfat thickness, Mycoplasmal pneumonia of swine (MPS) lesion score, and plasma cortisol levels, was executed to decrease the MPS lesion score. Genetic parameters and correlated genetic responses for respiratory disease and peripheral blood immune traits were estimated in 1395 Landrace pigs. We estimated the negative genetic correlation of MPS lesion score with phagocytic activity (PA) at 7 weeks of age (‐0.67). The breeding values of PA at 7 weeks of age and 105 kg body weight and the correlated selection response of the ratio of granular leukocytes to lymphocytes at 105 kg body weight were significantly increased, and sheep red blood cell‐specific antibody production (AP) was significantly decreased in a selection‐dependent manner. Increasing of natural immunological indicators (e.g. PA) and decreasing of humoral immunological indicator (e.g. AP) were observed due to genetically decreasing MPS lesion score.  相似文献   
55.
In vitro cultured shoots of three Chinese poplar species (Populus tomentosa, P. alba cv. Pyramidalis andP. euphratica) and an improved poplar (FS-51), as a control, were exposed to the stress of low osmotic potential, salinity and high pH, and the shoot growth was measured.P. tomentosa andP. euphratica could grow even under the high osmotic stress (0.5m mannitol; −1.7 MPa).P. euphratica shoots which were previously cultured on the medium containing 0.7m mannitol (−2.4 MPa) recovered its growth after being transplanted to the medium without mannitol. The shoot growth ofP. euphratica was not so reduced even on the medium containing 100 mM NaCl. However, growth of the other poplars markedly reduced with 10 mM NaCl. Medium pH (pH 5.8–10) also did not affect the shoot growth ofP. euphratica. These poplars have different tolerance to the stresses in cultured shootin vitro. P. euphratica was extremely tolerant to the stresses which are possible to damage plants in dry land. A part of this study was presented at the 104th Annual Meeting of the Japanese Forestry Society. (1993).  相似文献   
56.
 To predict the origin of longitudinal elasticity of the solid wood in relation to the composite structure of the wood cell wall, an analytical procedure was developed on the basis of the idea of “the reinforced-matrix hypothesis” originally introduced by Barber and Meylan (1964). A multi-layered circular cylinder, having the CML, the S1, and the S2 layers, was used as a model of the ligno-cellulosic (wood) fiber, and the elastic properties of an isolated wood fiber were formulated mathematically. In the formulation, not only the structural factors, such as the microfibril angle and the thickness of each layer, but also the environmental condition, e.g. the moisture content, were taken into consideration. The effects of the moisture content and the microfibril angle upon the longitudinal Young's modulus and the Poisson's ratio of the wood fiber were simulated by using the newly derived formulae. It is anticipated to give a start to estimate the fine structure and the internal properties of the cell wall constituents in relation to the macroscopic behaviors of the wood through simulating the mechanical behaviors of the wood fiber. Received 17 August 1999  相似文献   
57.
The extractives of shirakamba (Betula platyphylla Sukatchev var.japonica Hara) leaves were investigated. Two lignan glycosides were isolated, and their structures were elucidated to be 1-(4-hydroxy-3-methoxyphenyl)-2-[1-(3--l-rhamnopyranosyloxypropyl)-3-hydroxyphenoxy]-1,3-propanediol (I) and a new 2,3-dihydro-2-arylbenzofuran configuration neolignan,cis-2,3-dihydro-2-(4--l-rhamnopyranosyloxy-3-methoxyphenyl)-3-hydroxymethyl-7-hydroxy-5-benzofuranpropanol (II). These neolignan rhamnosides were newly found in shirakamba.  相似文献   
58.
59.
A total of 518 fecal samples collected from 183 apparently healthy cattle, 180 pigs and 155 broilers throughout Japan in 1999 were examined to determine the prevalence and antimicrobial susceptibility of Salmonella. The isolation rates were 36.1% in broilers, 2.8% in pigs and 0.5% in cattle. S. enterica Infantis was the most frequent isolate, found in 22.6% of broiler fecal samples. Higher resistance rates were observed against oxytetracycline (82.0%), dihydrostreptomycin (77.9%), kanamycin (41.0%) and trimethoprim (35.2%). Resistance rates to ampicillin, ceftiofur, bicozamycin, chloramphenicol and nalidixic acid were <10%. CTX-M-2 β-lactamase producing S. enterica Senftenberg was found in the isolates obtained from one broiler fecal sample. This is the first report of cephalosporin-resistant Salmonella directly isolated from food animal in Japan.  相似文献   
60.
The sensory innervation of the cardiopulmonary reflexes to nasal application of capsaicin (CAPS), distilled water (DW) and l-menthol (LM) was studied in anesthetized dogs breathing through tracheostomy. A marked cardiopulmonary reflex was observed by CAPS and DW into the nasal cavity, while a prolongation of expiration was induced by LM. All these reflexes were significantly decreased by bilateral section of the posterior nasal nerve (PNN) and completely abolished by topical nasal anesthesia with lidocaine. Responses of the whole nerve activity of the PNN to these substances corresponded to the magnitude of the reflexes. These results indicate that PNN afferents play an important role on the reflex elicitation of the noxious, water and cold stimuli from the nasal cavity.  相似文献   
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