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991.
Summary Horseradish peroxidase (HRP) was applied to the transected end of the pineal tract of the lamprey, Lampetra japonica. Distinct reaction products of HRP were observed in 2 types of cell other than ganglion cells. The first type of cell protrudes a knob-like process into the pineal lumen. This type of cell was clearly identified by electron microscopy as a photoreceptor cell; its outer segment was connected to the ellipsoid through a sensory cilium. The other type of cell was located among photoreceptor and supporting cells. The processes of these cells were thin and slender, and they obviously did not represent photoreceptor, supporting, or conventional ganglion cells. The present results indicate that, in the lamprey, some of the photoreceptor cells of the pineal organ project their axon-like processes toward the posterior commissure, but that there is also another type of cell displaying long axonal projections. HRP-containing cells were distributed randomly over the pineal organ and were occasionally also observed in the parapineal organ. 相似文献
992.
Summary The pineal complex of the river lamprey, Lampetra japonica, was examined by means of immunocytochemistry with antisera against serotonin, the precursor of melatonin, and two photoreceptor proteins, rod-opsin (the apoprotein of the photopigment rhodopsin) and S-antigen. Serotonin-immunoreactive cells were observed in both the pineal and the parapineal organ. The proximal portion of the pineal organ (atrium) comprised numerous serotonin-immunoreactive cells displaying spherical somata. In the distal end-vesicle of the pineal organ, the serotonin-immunoreactive elements resembled photoreceptors in their size and shape. These cells projecting into the pineal lumen and toward the basal lamina were especially conspicuous in the ventral portion of the end-vesicle. In addition, single serotonin-immunoreactive nerve cells were found in this location. Retinal photoreceptors were never seen to contain immunoreactive serotonin; amacrine cells were the only retinal elements exhibiting serotonin immunoreaction. Strong S-antigen immunoreactivity was found in numerous photoreceptors located in the pineal end-vesicle. In contrast, the S-antigen immunoreactivity was weak in the spherical cells of the atrium. Thus, the pattern of S-antigen immunoreactivity was roughly opposite to that of serotonin. Similar findings were obtained in the parapineal organ. The rod-opsin immunoreaction was restricted to the outer segments of photoreceptors in the pineal end-vesicle and parapineal organ. No rodopsin immunoreactive outer segments occurred in the proximal portion of the atrium. Double immunostaining was employed to investigate whether immunoreactive opsin and serotonin are colocalized in one and the same cell. This approach revealed that (i) most of the rodopsin-immunoreactive outer segments in the end-vesicle belonged to serotonin-immunonegative photoreceptors; (ii) nearly all serotonin-immunoreactive cells in the end-vesicle bore short rod-opsin-immunoreactive outer segments protruding into the pineal lumen; and (iii) the spherical serotonin-immunoreactive cells in the pineal stalk lacked rod-opsin immunoreaction and an outer segment. These results support the concept that multiple cell lines of the photoreceptor type exist in the pineal complex at an early evolutionary stage. 相似文献
993.
Interaction of RecA protein with pBR322 DNA modified by N-hydroxy-2-acetylaminofluorene and 4-hydroxyaminoquinoline 1-oxide.
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Interaction of RecA protein of Escherichia coli with pBR322 DNA modified by N-hydroxy-2-acetylaminofluorene (N-OH-AAF) and 4-hydroxyaminoquinoline 1-oxide (4HAQO) was investigated. RecA protein bound more efficiently to modified DNA than to unmodified DNA as judged by filter-binding and gel electrophoresis assay. The binding of RecA protein with modified DNA resulted in the stimulation of ATPase activity and the activation for RecA protein to stimulate the repressor cleavage. These abilities of RecA protein were increased proportionally to the number of adducts in the plasmid DNA (0-5 adducts). Apurinic and alkylated DNA did not activate RecA protein. We suggest that modification of DNA by N-OH-AAF and 4HAQO provides binding sites for RecA protein and may act as an activation signal for SOS response. 相似文献
994.
Analysis of natural killer activity and natural killer cell subsets in patients with bladder cancer 总被引:2,自引:0,他引:2
Tatsuo Morita Akihiko Tokue Nagahiro Minato 《Cancer immunology, immunotherapy : CII》1990,32(3):191-194
Summary In order to analyze the state of the natural resistance system of bladder cancer patients in vivo, we measured natural killer (NK) activity and NK cell subsets of peripheral blood lymphocytes (PBL) from 46 patients with bladder cancer and 25 age- and sex-matched healthy volunteers. The mean NK activity in patients with lowstage bladder cancer was similar to that in the controls, while NK activity in patients with high-stage bladder cancer was significantly depressed. The mean proportions of Leu7+ cells in patients with both low-stage and highstage bladder cancer were significantly higher than that in the controls. The mean proportion of Leu11a+ cells in patients with low-stage bladder cancer was similar to that in the controls, while in patients with high-stage bladder cancer it was significantly higher. This study demonstrates the abnormal immunological state of bladder cancer patients; namely, abnormalities exist not only in NK activity but also in the proportions of circulating NK cell subsets. 相似文献
995.
β-Galactosidase-deficient human fibroblasts: uptake and processing of the exogenous precursor enzyme expressed by stable transformant COS cells 总被引:1,自引:0,他引:1
Akihiro Oshima Kohji Itoh Yoshiro Nagao Hitoshi Sakuraba Yoshiyuki Suzuki 《Human genetics》1990,85(5):505-508
Summary COS-1 cells were transfected by electroporation with a cDNA for human acid -galactosidase cloned in our laboratory and stable transformants expressing the enzyme activity were selected. The precursor form of the enzyme was secreted in large quantities into the culture medium. The fibroblasts from patients with GM1-gangliosidosis or Morquio B disease showed a remarkable increase of enzyme activity, up to the normal level, after culture in this medium for 2 days; the amount of uptake was essentially the same as that for the precursor form in human fibroblasts. After endocytosis, the precursor molecules were processed normally to the mature form and remained as stable as those produced by human fibroblasts. On the other hand, cells from galactosialidosis patients did not show any increase of enzyme activity in a similar experiment. It was concluded that the transformants are useful as the source of precursor proteins for the study of intracellular turnover of enzyme molecules in mutant cells. 相似文献
996.
Beta-Amylase [1, 4-alpha-D-glucan maltohydrolase, EC 3.2.1.2] has been purified from defatted soybean meal by fractional precipation with ammonium sulfate, ion-exchange chromatography on CM- and DEAE-Sephadex and gel filtration chromatography on Sephadex G-100. Two different components of beta-amylase were crystallized from ammonium sulfate solutions, and the homogeneity of each preparation was confirmed by sedimentation and disc electrophoretic analyses. Both components of soybean beta-amylase formed large single crystals (trigonal crystal system) from 40--50 per cent saturated ammonium sulfate solution buffered at pH 5.4 on dialyzing concentrated protein solution in the apparatus of Zeppezauer et al. Preliminary X-ray diffraction data gave a hexagonal lattice with unit cell dimensions a=86.1 A and c=144.4 A. The space group corresponds to P3121 or P3221, and one asymmetric unit contains one molecule of beta-amylase, assuming a crystal density of 1.25 g/ml and a molecular weight of the enzyme of 60,000 daltons. In this case, the crystal has a volume of 2.53 A-3 per atomic mass unit, and the percentage of protein in the crystal is about 52. 相似文献
997.
998.
Secular changes of the main head dimensions in Japanese 总被引:1,自引:0,他引:1
999.
The distribution of vitamin B(12) within Upper Klamath Lake was surveyed at approximately monthly intervals during a period from September 1968 to November 1969. High concentrations (up to 1.8 mug/g of dry sediment) characteristically occurred at the water-sediment interface, with a sharp decline below this area. A heavy bloom of Aphanizomenon flos-aquae occurred from the latter part of May through October 1969. B(12) concentrations of the uppermost sediments, from all but one sampling site, increased gradually through the bloom, followed by a drastic increase during the die-off period. B(12) is probably not a limiting factor for primary productivity, since sufficient levels of this vitamin were found to occur throughout the year. Of 42 cultures isolated from Upper Klamath Lake water and sediments, 20 were found capable of producing 50 pg or more of B(12)/ml of medium. Phytoplankton samples were found to contain up to 5 mug of B(12)/g of dry material. Degradation of B(12) occurred in sterilized as well as fresh sediment samples. 相似文献
1000.