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51.
In rats with a high mesencephalic transection, isolating both the locus coeruleus and raphe nuclei from the forebrain, Electrocorticogram (ECoG) and Electromyogram (EMG) of the neck muscles were continuously recorded. Normal sleep-waking ECoG changes with a significant circadian rhythm reappeared in 4 to 9 days after transection. Neck muscle EMG and bodily movements were independent of the ECoG changes and did not show any significant circadian rhythm. In these high mesencephalic rats with sleep-waking ECoG changes, large bilateral hypothalamic lesions were made by passing DC current either in the preoptic area or in the posterior hypothalamus. After the preoptic area lesions the amount of low voltage fast ECoG per day markedly increased, whereas after the posterior hypothalamic lesions, the total amount of low voltate fast wave per day decreased showing long-lasting slow wave sleep pattern. These results support an idea that the forebrain, especially in the hypothalamus including the preoptic area, a mechanism inducing sleep-waking ECoG changes is localized.  相似文献   
52.
Polymerase chain reaction (PCR) was used to detect Rickettsia tsutsugamushi-specific DNA in clinical specimens. The primer pair used for PCR was designed from the nucleotide sequence of the gene encoding the 56-kDa antigen of the Gilliam strain. Theses primers led to a 78-bp fragment by amplifying the genomic DNAs from five serovariants, i.e., the Gilliam, Karp, Kato, Kawasaki, and Kuroki strains of R. tsutsugamushi, and also the DNA from blood clots of patients with scrub typhus, even at the early stage of onset of the disease. This indicates that this method is suitable for the diagnosis of scrub typhus.  相似文献   
53.
A survey of AFM1 residues in 58 commercial milk powder samples was carried out using an enzyme‐linked immunosorbent assay (ELISA) based on a monoclonal antibody against aflatoxin M1 (AFM1). The samples were collected from the USA (10), China (28), Italy (14), New Zealand (3) and Poland (3). The ELISA was performed without the need for clean‐up procedures. The data revealed that 4 (US), 21 (Chinese) and 1 (Polish) samples were positive for AFM1, with an average of 95.5, 102.8 and 85.0 pg g‐1 of the AFM1respectively.  相似文献   
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Protective immunity of mice against Listeria monocytogenes, which is mediated mainly by gamma interferon (IFN-gamma)-producing T cells, was induced by immunization with viable bacteria but not with killed bacteria. By comparing mice immunized with either viable or killed L. monocytogenes, it was found that IFN-gamma was produced at the initial stage only after immunization with viable bacteria. This finding prompted us to investigate the effect of neutralizing the IFN-gamma on the final generation of protective T cells against L. monocytogenes. When endogenous IFN-gamma was neutralized by administration of anti-IFN-gamma monoclonal antibody for the initial 2 days in mice immunized with viable bacteria, the generation of protective T cells on day 6 was completely blocked, as revealed by T-cell adoptive transfer. The generation of listeria-specific IFN-gamma-producing T cells was also abolished. These results clearly demonstrated that endogenous IFN-gamma, which is produced at the initial stage of immunization, actually plays a critical role in the generation of protective T cells against L. monocytogenes in vivo. Moreover, this study suggested that the lack of IFN-gamma-inducing ability is responsible for the inability of killed L. monocytogenes to induce protective T cells in mice.  相似文献   
57.
Intrabiliary growth of liver metastases from colorectal cancer has rarely been studied. A surgically resected case of a metastatic liver tumor with prominent intrabiliary growth derived from rectal cancer is reported. The patient was a 62-year-old man who had received a low anterior resection for rectal cancer in March 2000. He was re-admitted due to obstructive jaundice in January 2003, and was diagnosed with hepatic malignancy in segment II of the liver with an intrabiliary tumor extending from the intrahepatic bile duct of segment II to the common hepatic duct. He underwent a left hepatectomy, a partial resection of segment VI, and an extrahepatic bile duct resection with reconstruction of the biliary tract. In the resected specimen, there were whitish tumors of 3 cm and 1.5 cm in diameter in segments II and VI, respectively, and an intrabiliary tumor originating from the main tumor in segment II extended to the common hepatic duct. Both the liver tumors and the intrabiliary tumor consisted of a well- to moderately differentiated adenocarcinoma, which showed the same histological features as the rectal cancer. The immunohistochemical findings strongly supported that these tumors, including the intrabiliary growth, were liver metastasis from the rectal cancer. The intrabiliary invasion and growth of metastatic liver tumors has generally been overlooked, notwithstanding their frequently observed biological behavior. The present case is informative, and further investigation into this type of metastatic liver tumor may be warranted.  相似文献   
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In an attempt to better define the relationship between collagen matrices and vascular smooth muscle cells in vitro, proliferation of smooth muscle cells was observed in the early stages of culture. Cells spread on collagen gels had a longer doubling time and less incorporation of [3H]thymidine into DNA on the first day of culture than did cells grown on a plastic substrate. Cells on collagen gels were more elongated than were those on the plastic substrate and showed a "hills and valleys" arrangement from the first day in culture on the collagen type III gel. All cells were identified as smooth muscle having definite microfilaments, dense bodies, and pinocytotic vesicles. They had a distinct actin filament running from end to end when labeled with nitrobenzoxadiazole-phallacidin. Cells on the collagen gels had a larger number of actin filaments traveling parallel to the direction of the major axis of their cytoplasm than did those on the glass substrate. Therefore, cultured smooth muscle cells in the more physiological environment for cells in vitro, i.e., on collagen gels, show a suppression of cellular proliferation and an enhancement of differentiation in the early stages of culture. The effects of collagens on the differentiation of cells vary with the collagen phenotype.  相似文献   
60.
Results from the transplantation of donor male germ cells into xenogeneic recipient seminiferous tubules indicate that donor spermatogonia are capable of differentiating to form spermatozoa morphologically characteristic of the donor species. Germ cell transplantation procedures combined with developments in freezing, culturing or enriching germ cell populations have applications of paramount importance in medicine, basic sciences and animal reproduction. Additionally, these techniques can serve as an alternative approach for gonadal protection and fertility preservation in patients with cancer. This article is a chronological critical review of the technological advances that followed the initial successful transplantation of mouse germ cells into recipient mice. Furthermore, the factors responsible for the immunological privilege properties of the testis and the parameters influencing the potential of mammalian germ cells to undergo mitosis and meiosis within a xenogeneic testis are described. Finally, the role of human germ cell transplantation procedures in the therapeutic management of non-obstructive azoospermia is discussed.  相似文献   
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