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41.
One hundred and eighteen algal isolates comprising seven classes were obtained from a range of sites from polluted rivers running through Cu or Zn mining regions, and from unpolluted rivers. All the isolates were tested for photosynthetic activity when exposed to Cu, Cd or Zn. The tolerance levels of Bacillariophyceae, Charophyceae, Cyanophyceae and Chlorophyceae to Cu showed significant positive correlations with Cu concentrations in the field. However the distribution of metal sensitivities of the algae from the sites with the same metal concentration was broad. Both Bacillariophyceae and Charophyceae had a number of strains whose sensitivity to Cu differed more widely in relation to Cu levels in the environment than Cyanophyceae and Chlorophyceae. Cyanophyceae were sensitive to all three metals, whether or not isolates were obtained from polluted sites, whereas Chlorophyceae tended to have high tolerance even in isolates from unpolluted sites. For Cd and Zn the correlation between tolerance levels and concentrations in the field was not so clear as for Cu. The occurrence of Cu tolerance was shown in 4 diatom species and one Charophyceae, whereas metal resistance occurred in some Chlorophyceae. Cu-tolerant isolates tended also to be Zn-tolerant in Bacillariophyceae, and Cd-resistant isolates tended also to be Zn-resistant in Chlorophyceae. 相似文献
42.
Mariyo F. Watanabe Ken-Ichi Harada Kennji Matsuura Masayuki Watanabe Makoto Suzuki 《Journal of applied phycology》1989,1(2):161-165
Changes in the content of cyclic heptapeptide hepatotoxins called microcystins were investigated during batch culture of two
Microcystis species using high performance liquid chromatography. After adsorption to ODS-silica gel cartridges and elution with methanol,
the toxins were analyzed and quantified by HPLC. 35 μg per 100 mg dry cells of microcystin-RR, 34 μg of -YR and 43 μg of -LR
were present at the beginning of the exponential growth phase of M. viridis. Microcystin-RR increased markedly towards the end of the exponential phase with the maximum content of 112 μg per 100 mg
cells was measured at the late stage of the exponential phase. A remarkable increase of microcystin-YR from 130 μg per 100
mg cells to 1020 μg was observed during the exponential phase of a highly toxic strain of M. aeruginosa. However no clear differences were found in the pattern of change among the three toxins during the growth course. 相似文献
43.
Ontogenesis of α2 -Adrenoceptor Coupling with GTP-Binding Proteins in the Rat Telencephalon 总被引:2,自引:2,他引:0
Yoshihisa Kitamura Makoto Mochii Ryuji Kodama Kiyokazu Agata Kenji Watanabe Goro Eguchi Yasuyuki Nomura 《Journal of neurochemistry》1989,53(1):249-257
The ontogenesis of alpha 2-adrenoceptors and GTP-binding proteins and their coupling activity were investigated in telencephalon membranes of developing rats. The manganese-induced elevation of [3H]clonidine binding was increased in an age-dependent manner but the guanosine 5'-O-(3-thio)triphosphate-induced decrease in binding did not change. The extent of the binding of [3H]clonidine at 15 nM (saturable concentration) increased in an age-dependent manner and reached the adult level at 4 days after birth. Cholera toxin and pertussis toxin catalyzed ADP-ribosylation of proteins of 46 and 41/39 kilodaltons (kDa) in solubilized cholate extracts of the membranes. The 41/39-kDa proteins ADP-ribosylated by pertussis toxin (Gi alpha + Go alpha) were increased with age and reached the adult level at day 12, whereas the 46-kDa protein (Gs alpha) reached its peak on day 12 and then decreased to the fetal level at the adult stage. The immunoblot experiments of the homogenates with antiserum (specific antibody against alpha- and beta-subunit of GTP-binding proteins) demonstrated that the 39-kDa alpha-subunit of (Go alpha) and the 36-kDa beta-subunit of GTP-binding protein (beta 36) increased with postnatal age. In contrast, 35-kDa beta-subunit (beta 35) did not change. From these results, it is suggested that the coupling activity of alpha 2-adrenoceptor with GTP-binding protein gradually develops in a manner parallel with the increase of alpha 2-adrenoceptor and pertussis toxin sensitive GTP-binding proteins, Gi, and that alpha 39 beta 36 gamma may be related to the differentiation and/or growth of nerve cells in rat telencephalon. 相似文献
44.
Close linkage of MEN2A with RBP3 locus in Japanese kindreds 总被引:7,自引:0,他引:7
Masayuki Yamamoto Shin-ichiro Takai Tetsuro Miki Kazuyoshi Motomura Makoto Okazaki Isamu Nishisho Hideo Tateishi Akira Miyauchi Tasuku Honjo A. J. Pakstis Takesada Mori 《Human genetics》1989,81(3):287-288
Summary The gene responsible for multiple endocrine neoplasia type 2A (MEN2A) has recently been assigned to the pericentromeric region of chromsome 10 in European Caucasian kindreds by linkage analysis using a DNA marker, interstitial retinol-binding protein 3 (RBP3). We have found tight linkage between the MEN2A and RBP3 loci in Japanese MEN2A kindreds. The maximum lod score is 5.19 at a recombination fraction of 0.00. This result suggests that mutation of a certain gene close to RBP3 is responsible for MEN2A irrespective of ethnic backgrounds. 相似文献
45.
Ikuo Saiki Hiroaki Maeda Jun Murata Nobuchika Yamamoto Makoto Kiso Akira Hasegawa Ichiro Azuma 《Cancer immunology, immunotherapy : CII》1989,30(3):151-157
Summary We have investigated the effect of endogenous production of tumor necrosis factor (TNF) induced by the combination of recombinant interferon (rIFN) as a primer followed by GLA-60 as a trigger (rIFN/GLA-60) on murine lung metastases caused by B16-BL6 melanoma. In order to examine the therapeutic effect of endogenous TNF on tumor metastasis, the ability of multiple administrations of rIFN/GLA-60 to induce TNF production was also tested. The multiple administrations of rIFN/GLA-60 at intervals of 2 days were effective for the induction of endogenous TNF in mice but continuous multiple administrations of them for 2–4 days were not. In tumor-bearing mice, the production of endogenous TNF by rIFN/GLA-60 was less than that of normal mice, but treatment 3 days after the surgical excision of primary tumors showed the endogenous TNF production to be similar to that in normal mice. In the experimental lung metastasis model, intravenous administration of rIFN followed by intravenous or intranasal administration of GLA-60 showed potent inhibition of lung metastases of B16-BL6 melanoma, whereas the reverse sequence of administration (GLA-60/rIFN) or administration of a mixture of rIFN and GLA-60, which cannot induce the production of TNF, caused no inhibition of lung metastases. These results indicated that the regression of tumor metastases by rIFN/GLA-60 was mediated by the production of endogenous TNF in addition to the direct effects of both immunostimulants. Furthermore, the administration of rIFN and GLA-60 significantly inhibited the tumor metastases in spontaneous lung metastasis model. These results may provide a promising approach for the treatment of cancer metastasis as a result of its ability to induce endogenous TNF. 相似文献
46.
Summary ExposingBacillus
subtilis cultures to high concentrations of alkali cations, especially K+, allows efficient transformation by plasmids. The method allows transformation with unfractionated plasmid DNA, monomeric plasmid DNA as well as linear plasmid DNA.B.
subtilis strains, not amenable to natural transformation, were also transformed by the present method. 相似文献
47.
Movement of the fluvial form of red-spotted masu salmon (1+ and older),Oncorhynchus masou rhodurus, was studied using mark-recapture methods in a Japanese mountain stream. Most (63–91%) adult salmon were recaptured in the
pool in which they were marked. The rest of the salmon moved upstream or downstream <20m during the non-breeding period. The
proportion of the salmon moving increased slightly during the breeding period, but did not exceed 66%. The distance moved
was also more variable during this period. The proportion of the smaller salmon which moved was larger than that of the larger
fish during the non-breeding period. Conversely, during the breeding period, larger fish moved more frequently. Sedentary
behaviour and local movements of adult salmon seem to be affected by their social relationships. 相似文献
48.
Takashi Kamaishi Tetsuo Hashimoto Yoshihiro Nakamura Fuminori Nakamura Shigenori Murata Norihiro Okada Ken-ichi Okamoto Makoto Shimizu Masami Hasegawa 《Journal of molecular evolution》1996,42(2):257-263
Partial regions of the mRNA encoding a major part of translation elongation factor 1 (EF-1) from a mitochondrion-lacking protozoan,Glugea plecoglossi, that belongs to microsporidians, were amplified by polymerase chain reaction (PCR) and their primary structures were analyzed. The deduced amino acid sequence was highly divergent from typical EF-1's of eukaryotes, although it clearly showed a eukaryotic feature when aligned with homologs of the three primary kingdoms. Maximum likelihood (ML) analyses on the basis of six different stochastic models of amino acid substitutions and a maximum parsimony (MP) analysis consistently suggest that among eukaryotic species being analyzed,G. plecoglossi is likely to represent the earliest offshoot of eukaryotes. Microsporidians might be the extremely ancient eukaryotes which have diverged before an occurrence of mitochondrial symbiosis.
Sequence availability: The nucleotide sequence data reported here appear in the GSDB, DDBJ, EMBL, and NCBI databases with the accession number D32139 相似文献
49.
50.
Yuichi Mazaki Makoto Mochii Ryuji Kodama Goro Eguchi 《Development, growth & differentiation》1996,38(4):429-437
When retinal pigmented epithelial cells (PEC) of chick embryos are cultured under appropriate conditions, the phenotype changes to that of lens cells through a process known as transdifferentiation. The first half of the process, characterized by dedifferentiation of PEC, is accompanied by a marked decrease in adhesiveness of PEC to collagen type I- or type IV-coated dishes. To understand the underlying mechanisms of this change, we analyzed the expression of integrins, which are major receptors for extracellular matrix components. Northern blot analysis with cDNA probes for chicken α3, α6, α8, αv, β1 and β5 integrin mRNA showed that the genes for all these integrins are transcribed at similar levels in PEC and dedifferentiated PEC (dePEC). Further analysis of β1 integrin, which is a major component of integrin heterodimers, showed that although the protein amount of β1 integrin was not changed, its localization at focal contacts seen in PEC was lost in dePEC. When anti-β1 integrin antibody was added to the PEC culture medium, a decrease of cell-substrate adhesiveness occurred, followed by a gradual change in both morphology and gene expression patterns to ones similar to those of dePEC. These findings suggest that an appropriate distribution of β1 integrin plays an essential role in maintaining the differentiated state of PEC through cell-substrate adhesion. 相似文献