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71.
72.
Hisashi Nagata 《Ecological Research》1993,8(1):1-9
The breeding sites of Styan's grasshopper warblers are restricted to small islands and distributed discretely. The study on
the marked population was conducted on two islets, Okitsu-jima and Ohtsukue-jima, located near Fukuoka, Japan, from 1981 to
1989. About 20 and 70 birds bred on the two islets, respectively, and the mean density of breeding pairs was 25.5 ha−1. The dispersal pattern and population, structure were examined. Adult birds returned to the same breeding site. Males always
reoccupied the same territory as in previous years but females not. Males were more philopatric and only female yearlings
dispersed over long distances and moved between the breeding sites in Hakata Bay. The returning rate was 0.57 for adults,
and 0.21 for juveniles. The age distribution of birds at Ohtsukue-jima was almost stable, while that at Okitsu-jima was unstable
because it was a marginal habitat for the birds. Estimating from the dispersal pattern and age structure of this warbler the
population near Fukuoka consists of only four islets and is almost stable. 相似文献
73.
Kazuyoshi Masuda Shunji Nagata Koichiro Hirano Yasushi Takagishi Hidematsu Hirai 《生物化学与生物物理学报:疾病的分子基础》1993,1182(2):128-132
This study was carried out to clarify the reason for elevation of serum α-fetoprotein (AFP) level of nude mice bearing hepatoma cells after treatment with monoclonal antibodies (MoAbs) to AFP. MoAbs to AFP showed no effect on the cumulative amounts of AFP secreted from human hepatoma cell line, HuH-7, in vitro. However, the treatment of nude mice bearing HuH-7N cells (HuH-7 xenograft) with MoAbs to AFP led to elevation of the serum AFP level in spite of the fact that the growth curve of HuH-7N cells was similar to that for PBS treatment. This apparent elevation of the serum AFP level is thought to be due to the slow elimination of AFP-MoAb immune complexes with little lattice structure from circulation, but not the enhancement of AFP secretion of HuH-7N cells. Thus, when using a MoAb alone or MoAb-drug conjugate, the serum AFP level should only be cautiously used as a tumor marker for evaluating the targeting immunotherapy. 相似文献
74.
75.
Hiroshi Tauchi Eigo Matsumoto Kenta Iijima Daisuke Mochizuki Kenshi Komatsu Yusuke Ichimasa 《Biological Sciences in Space》2003,17(3):255-256
DNA double strand break (DSB) causes many cytotoxic effects such as cellular lethality, somatic mutation, and carcinogenesis. Fidelity of DSB repair is a important factor that determines the quality of genomic stability. It is known that the most of DSBs are properly repaired on the earth, however, little is known whether those are rejoined at the same fidelity even under the space environment. One of the DSB repair pathway, homologous recombination (HR), allows the cells to repair their DSBs with error free. Therefore, the efficiency of HR is a good index to assess the fidelity of DSB repair. In order to clarify the effect of gravity stress on HR pathway, we established a cell line that can detect a site-specific DNA repair via HR. The cells carrying a reporter construct for HR were incubated under hypergravity condition after induction of site specific DSB. Our preliminary results suggest that the gravity stress may affect the HR efficiency. 相似文献
76.
Podocytes outgrown from isolated glomeruli in vitro have failed to express fully differentiated in vivo phenotypes. In an
attempt to determine whether podocytes in metanephric culture accomplish terminal differentiation, as observed in vivo, we
investigated expression of their characteristic phenotypic features in rat metanephric organ cultures using immunohistochemistry
and electron microscopy. Rat metanephroi were harvested on embryonic day 12.5 and cultured on transmembrane filters for 9
days. Morphological examination revealed two maturation stages when the podocytes resembled those of the S-shaped body stage
and maturational stages of glomeruli in vivo. Electron microscopy revealed that, firstly podocytes lost their intercellular
contacts and, simultaneously, the tight junctions shifted into close proximity to cell bases, followed by foot process development.
Immunohistochemistry demonstrated that the tight junction protein, ZO-1, and specific podocytic markers, pp44, 5-1–6, podocalyxin
and vimentin were expressed in a cell maturity-dependent manner, as observed in newborn rat kidneys. Furthermore, glomerular
basement membrane components, collagen type IV and laminin, were expressed in the glomerular center. Our findings that cell
maturity-dependent expression of structural and functional phenotypes in podocytes in metanephric culture was the same as
that observed in developing kidneys in vivo indicate that podocyte differentiation during glomerulogenesis may be operated
by an intrinsic property, such as programmed cell fate. Furthermore, these highly differentiated podocytes in vitro may provide
clues that will help to establish a podocyte culture system.
Accepted: 26 February 1997 相似文献
77.
The substrate specificity of rice embryo benzoyl-L-argininep-nitroanilide hydrolase (BAPAase) was examined. No endopeptidaseactivity toward protein substrates was detectable. Small peptides(less than 8 residues) and amide, ester substrates, however,were hydrolyzed very well at the carboxyl side of the lysineor arginine residue. No other peptide bond was hydrolyzed. TheN-terminal arginine of the substrates was released very slowly.Peptides with lysine or arginine penultimate to the C-terminalposition were hydrolyzed well and released an amino acid. Theoxidized insulin B chain (30 residues) was cleaved very slowlyat the C-terminal Lys-Ala bond, whereas an Arg-Gly bond at aninner position was not cleaved. The hydrolytic rate increasedafter the chain length was shortened by chymotryptic digestion.These results show that the rice embryo BAPAase is a novel enzymewhich has mixed endopeptidase-carboxypeptidase activity towardthe Arg-X and Lys-X bonds of small peptides, a characteristicintermediate between trypsin and serine carboxypeptidase. Thisenzyme may act in the breakdown of small peptides that havephysiological functions. (Received May 26, 1984; Accepted August 29, 1984) 相似文献
78.
Benzoyl-L-arginine p-nitroanilide hydrolase (BAPAase), whichhas both endopeptidase and carboxypeptidase activity towardthe Arg-X or Lys-X bond of small peptides [Shibata and Doi (1984)Plant & Cell Physiol. 25: 1421], was purified from riceembryos by ammonium sulfate and polymin fractionations and byion exchange, gel exclusion and hydrophobic chromatographies.The purified enzyme was homogeneous when analyzed by polyacrylamidegel electrophoresis. It was unstable in the absence of surface-activereagents such as Triton X-100. Maximum activity for benzoyl-Largininep-nitroanilide (L-BAPA) or carboxypeptidase activity towardbutoxycarbonyl-Gly-Lys-Leu was obtained at pH 9.0. L-BAPA athigh concentrations inhibited the enzyme's activity. Di-isopropylphosphofluoridate, N-tosyl-L-lysine chloromethyl ketone, leupeptinand antipain, which are specific inhibitors of trypsin, inhibitedBAPAase activity, but soybean and rice bran trypsin inhibitorhad no effect on it. Sulfhydryl reagents strongly inhibitedthe BAPAase activity. (Received May 26, 1984; Accepted August 29, 1984) 相似文献
79.
Ultrastructural localization of glycogen in the granulocytes of normal rabbit bone marrow. 总被引:1,自引:0,他引:1
The glycogen of rabbit granulocytes has been studied in glutaraldehyde and osmium tetroxide fixed bone marrow by the periodic acid-thiocarbohydrazide-silver proteinate procedure (PA-TCH-SP). The PA-TCH-SP procedure involved the staining of intracytoplasmic glycogen more densely than the routine lead citrate staining. The PA-TCH-SP procedure demonstrated the intracytoplasmic glycogen in all three kinds of granulocytes. Though a sequence of intensity was observed in each stage of cell maturation, intracytoplasmic glycogen increased generally in accordance with cell maturation in the granulocytes. Functional significance of the glycogen in the granulocytes was discussed in relation to its staining. A very weak reaction in the granules of the granulocytes was described in relation to their contents. 相似文献
80.
Summary The glycogen of rabbit granulocytes has been studied in glutaraldehyde and osmium tetroxide fixed bone marrow by the periodic acid-thiocarbohydrazide-silver proteinate procedure (PA-TCH-SP). The PA-TCH-SP procedure involved the staining of intracytoplasmic glycogen more densely than the routine lead citrate staining. The PA-TCH-SP procedure demonstrated the intracytoplasmic glycogen in all three kinds of granulocytes. Though a sequence of intensity was observed in each stage of cell maturation, intracytoplasmic glycogen increased generally in accordance with cell maturation in the granulocytes. Functional significance of the glycogen in the granulocytes was discussed in relation to its staining. A very weak reaction in the granules of the granulocytes was described in relation to their contents. 相似文献