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21.
Experiments were designed to compare the adipocyte cellularity of subcutaneous adipose tissue between growing Landrace (low backfat) and Meishan (high backfat) pigs at 1 week, 3 weeks, 6 weeks, 3 months and 5 months of age. As pigs aged, body weight and backfat thickness of both breeds significantly increased. When compared at equal ages, backfat thickness adjusted to equal body weight was greater for Meishan pigs. The mean diameter of fat cell size also increased with age, and by 6 weeks adipocytes from both outer and inner layers of subcutaneous adipose tissue were larger in Meishan pigs. At 5 months, approximately 80% of the adipose tissue mass in Meishan pigs was attributable to adipocytes measuring 95–165 µm in diameter, whereas adipocytes of 75–145 µm comprised most of the tissue mass in the Landrace. Although the contribution of smaller adipocytes (25–45 µm) to the tissue volume was negligible, both breeds showed a biphasic diameter distribution at all ages, suggesting that adipocyte hyperplasia is still active. Our results demonstrate that cellularity differences exist between the subcutaneous adipose tissues of Landrace and Meishan pigs, and adipocyte hypertrophy is the most overwhelming contributor to the greater backfat deposition for Meishan pigs.  相似文献   
22.
本文研究了1989-1993年不同降水年型(干旱、正常、湿润)条件下灌水和施肥对黑龙港地区旱作小麦产量的影响,结果表明,在正常和湿润年份,土壤贫瘠是限制产量的主要因子,施肥可以大幅度提高产量。但在干旱年份,土壤水分缺乏制约产量的增加,一次灌水可使产量翻一番,在灌一次水的基础上,每公顷施入100公斤氮和70公斤磷,产量则可以再翻一番。可见,增加肥料投入是旱作小麦产量提高的重要手段之一。  相似文献   
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Benign Theileria species of cattle are found in most parts of the world. The major piroplasm surface protein (MPSP), a conserved protein in all Theileria species, has been used as a maker for epidemiological and phylogenetical studies of benign Theileria species. Parasites with Ikeda- or Chitose-type MPSP genes are dominant in Japan, but we report here mixed infection cases of Theileria parasites with an additional MPSP type parasite infecting cattle in Abashiri District, Hokkaido. The MPSP gene sequence found in the additional type was closely related to MPSP genes of Theileria parasites found in Southeast Asian countries, including Thailand (Narathiwat) and Indonesia (Java). Theileria parasites from the blood sample were also distinguishable from the Ikeda or Chitose type parasites by the small subunit (SSU) rRNA gene sequence analysis, and they are grouped into the SSU rRNA types C/D found in Korea, North America, and Spain. The present finding of mixed infections of cattle with three different types of Theileria makes epidemiological feature of bovine theileriosis in Japan more complex. We have designed a set of primers specific to this MPSP type in order to conduct further epidemiological study.  相似文献   
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In Salmonidae, subordinate males are exposed to higher risks of sperm competition than dominant males and thus are expected to improve the sperm characteristics (sperm concentrations, sperm velocity and sperm longevity). In this study, we investigated the relationships between body size and secondary sexual characters (breeding colour, hump height and snout length), and sperm characteristics of one‐year‐old (newly matured) Dolly Varden char. Small males displayed higher sperm concentrations than large males. Moreover, males with dull breeding colours, but not with lesser snout length and hump height, displayed an increased sperm velocity compared to males with bright colours, suggesting a trade‐off between sperm quantity and the investment in breeding colour. In addition, sperm longevity decreased as sperm swimming velocity increased. These findings indicate that small males with dull breeding colours improve the quantity and quality of their sperm to a great extent to enhance their chances of reproductive success.  相似文献   
27.
GM2 gangliosidosis variant 0 (human Sandhoff disease) is a lysosomal storage disease caused by simultaneous deficiencies of acid beta-hexosaminidase (Hex) A and Hex B due to an abnormality of beta-subunit, a common component in these enzyme molecules, which is coded by the HEXB gene. In the present study, a retrospective diagnosis was performed in 2 previous suspected cases of feline Sandhoff-like disease using a DNA test to detect the causative mutation identified previously in 4 cats in 2 other families of Japanese domestic cats. Enzymic analysis was also performed using stored leukocytes and plasma collected from the subject families in order to investigate the usefulness of enzymic diagnosis and genotyping of carriers. The DNA test suggested that the 2 cases were homozygous recessive for the mutation. Consequently, 6 cats homozygous for the same mutation have been found in 4 separate locations of Japan, suggesting that this mutant allele may be spread widely in the Japanese domestic cat populations. In enzymic analysis, Hex A and Hex B activities in leukocytes and plasma measured using 4-methylumbelliferyl N-acetyl-beta-D-glucosaminide as a substrate were negligible in affected cats, compared with those in normal and carrier cats. However, there was a wide overlap in enzyme activity between normal and carrier cats. Therefore, it was concluded that enzymic analysis is useful for diagnosis of affected cats, but is not acceptable for genotyping of carriers.  相似文献   
28.
Abstract: A 1‐year‐old intact female miniature Dachshund was presented with hematochezia, vomiting, and diarrhea of more than 1‐week duration. An abdominal mass was palpated, which at exploratory surgery was found to be a 7‐cm‐long thickened section of ileum. The thickened ileum was resected. Impression smears revealed numerous small‐ to medium‐sized lymphocytes, with a smaller number of cells resembling Mott cells. The Mott‐like cells contained multiple pale vacuoles that were positive for periodic acid‐Schiff (PAS) in wet‐fixed smears, consistent with Russell bodies. Histologic evaluation of the surgically excised ileum revealed 2 populations of neoplastic lymphoid cells. The majority were uniform medium‐sized lymphocytes with hyperchromatic oval or round nuclei and inconspicuous nucleoli. The remaining cells resembled Mott cells, which contained several PAS‐positive eosinophilic globules in the cytoplasm, occasionally compressing the nucleus. The majority of neoplastic cells stained positively for vimentin, CD20, CD79a, and Pax‐5, but were negative for CD3 and lysozyme; 43.5% of cells stained positively for Ki‐67. The Mott cells were strongly positive for immunoglobulin but were negative for Pax‐5. Using electron microscopy, a homogenous substance of intermediate electron density was observed frequently in the cisternae of rough endoplasmic reticulum in the cytoplasm of the Mott cells, and rarely in the perinuclear cisternae of the lymphoid cells, corresponding to the site of immunoglobulin staining. Monoclonal rearrangement of immunoglobulin heavy‐chain (IgH) gene was observed by PCR testing for lymphocyte–antigen receptor rearrangement. The morphologic features, immunophenotype, and IgH gene rearrangement verified the lymphoid cells were neoplastic (mature cell type) and had a B‐cell phenotype, with evidence of immunoglobulin production and differentiation into Mott cells. This case was unusual because of the age of the dog and because most intestinal lymphomas are T‐cell phenotype. The Mott cell morphology also differed from typical mature B‐cell lymphoma types and may be a unique B‐cell lymphoma variant.  相似文献   
29.
The objectives of this study are to clarify physiological work loads and physical loads acting on the lumbar region of workers and to propose a safe work environment in tropical forestry operations. The research was conducted in the industrial forest plantations of East Kalimantan, Indonesia, in 1996. In this study, heart rates and the physical lumbar burden of industrial forest plantation workers were measured for three types of work, that is, weeding, planting and path clearing. In addition, the load moment at the L5/S1 and the disc compression force were calculated using low-back biomechanical models. As a result, compression forces at the L5/S1 disc during weeding, planting and path clearing were estimated and found to be below the Action Limit (AL) by National Institute for Occupational Safety and Health (NIOSH). However, it was also found that some work posture types during path clearing by chain saw were sometimes above the AL. A part of this paper was orally presented at the 108th Annual Meeting of the Japanese Forestry Society (1997).  相似文献   
30.
In Japan, Lactococcus garvieae infection has been the main fish disease in aquaculture. Although commercial oral and injectable vaccines have been used to prevent L. garvieae infection in Japan, L. garvieae has been isolated not only from unvaccinated fish but also from vaccinated fish in which immunity induced by vaccination had diminished. In order to obtain epidemiological information on this fish pathogen, we conducted biased sinusoidal field gel electrophoresis (BSFGE) pattern analysis and phage typing of L. garvieae isolates (n = 427) from fish in Japan. These isolates were obtained from 13 different fish species between 1980 and 2007. In the BSFGE analysis, L. garvieae isolates were classified into 17 groups (S1–S17) based on the SmaI digestion patterns and into four groups (A1–A4) based on the ApaI digestion patterns. Phage typing revealed five different phage susceptibility profiles (A–E) in L. garvieae isolates. Since 2005, comparisons of the results of phage typing and BSFGE have indicated the presence of a novel genotype (S16/A4) with phage type E. All the strains belonging to this type showed lincomycin sensitivity.  相似文献   
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