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101.
102.
Photodynamic and non-photodynamic action of several porphyrins on the activity of some heme-enzymes 总被引:1,自引:0,他引:1
S G Afonso S Chinarro J J Mu?oz R E de Salamanca A M Batlle 《Journal of enzyme inhibition》1990,3(4):303-310
The action of porphyrins, uroporphyrin I and III (URO I and URO III), pentacarboxylic porphyrin I (PENTA I), coproporphyrin I and III (COPRO I and COPRO III), protoporphyrin IX (PROTO IX) and mesoporphyrin (MESO), on the activity of human erythrocytes delta-aminolevulinic acid dehydratase, porphobilinogenase, deaminase and uroporphyrinogen decarboxylase in the dark and under UV light was investigated. Both photoinactivation and light-independent inactivation was found in all four enzymes using URO I as sensitizer. URO III had a similar action as URO I on porphobilinogenase and deaminase and PROTO IX exerted equal effect as URO I on delta-aminolevulinic acid dehydratase and uroporphyrinogen decarboxylase. Photodynamic efficiency of the porphyrins was dependent on their molecular structure. Selective photodecomposition of enzymes by URO I, greater specificity of tumor uptake by URO I and enhanced porphyrin synthesis by tumors from delta-aminolevulic acid, with predominant formation of URO I, underline the possibility of using URO I in detection of malignant cells and photodynamic therapy. 相似文献
103.
DNA Segments Sensitive to Single-Strand-Specific Nucleases Are Present in Chromatin of Mitotic Cells
It was observed before that DNAin situin chromatin of mitotic cells is more sensitive to denaturation than DNA in chromatin of interphase cells. DNA sensitivity to denaturation, in these studies, was analyzed by exposing cells to heat or acid and using acridine orange (AO), the metachromatic fluorochrome which can differentially stain double-stranded (ds) vs single-stranded (ss) nucleic acids, as a marker of the degree of DNA denaturation. However, without prior cell treatment with heat or acid no presence of single-stranded DNA in either mitotic or interphase cells was detected by this assay. In the present experiments we demonstrate that DNAin situin mitotic cells, without any prior treatment that can induce DNA denaturation, is sensitive to ss-specific S1 and mung bean nucleases. Incubation of permeabilized human T cell leukemic MOLT-4, promyelocytic HL-60, histiomonocytic lymphoma U937 cells, or normal PHA-stimulated lymphocytes with S1 or mung bean nucleases generated extensive DNA breakage in mitotic cells. DNA strand breaks were detected using fluorochrome-labeled triphosphonucleotides in the reaction catalyzed by exogenous terminal deoxynucleotidyl transferase. Under identical conditions of the cells’ exposure to ss-specific nucleases, DNA breakage in interphase cells was of an order of magnitude less extensive compared to mitotic cells. The data indicate that segments of DNA in mitotic chromosomes, in contrast to interphase cells, may be in a conformation which is sensitive to ss nucleases. This may be a reflection of the differences in the torsional stress of DNA loops between interphase and mitotic chromatin. Namely, greater stress in mitotic loops may lead to formation of the hairpin-loop structures by inverted repeats; such structures are sensitive to ss nucleases. The present method of detection of such segments appears to be more sensitive than the use of AO. The identification of mitotic cells based on sensitivity of their DNA to ss nucleases provides an additional method for their quantification by flow cytometry. 相似文献
104.
Fully developed thalli of Chondrus crispus, Gracilaria chilensis, Gymnogongrus furcellatus and Mazzaella laminarioides were used to assess tissue compatibility. The effect of thallus polarity on grafting and regeneration was also evaluated. Fusion did occur between fragments of the same life history phase in C. crispus, G. chilensis, G. furcellatus and M. laminarioides. Fusion between sporophytic and gametophytic tissue occurred in C. crispus, G. chilensis and M. laminarioides. Intergeneric fusion was observed between C. crispus and M. laminarioides, but not between G. chilensis and G. furcellatus.Outer cell wall, cortex and medulla were continuous at the contact face in compatible combinations. Medullary cells in the attached fragments were thinner and longer than normal cells, forming an interwoven scar plate. Thallus polarity did not modify fusion and regeneration. 相似文献
105.
Xp-duplications with and without sex reversal 总被引:5,自引:0,他引:5
Annette Baumstark Gotthold Barbi Mahmoud Djalali Claudia Geerkens Beate Mitulla Torsten Mattfeldt José Carlos Cabral de Almeida Fernando Regla Vargas Juan Clinton Llerena Jr Walther Vogel Walter Just 《Human genetics》1996,97(1):79-86
Duplications in Xp including the DSS (dosage sensitive sex reversal) region cause male to female sex reversal. We investigated two patients from families with Xp duplications. The first case was one of two sisters with karyotype 46,XY, der(22), t(X;22)(p11.3;p11)mat and unambiguous female genitalia. The living sister was developmentally retarded, and showed multiple dysmorphic features and an acrocallosal syndrome. The second case was a boy with a maternally inherited direct duplication of Xp21.3-pter with the breakpoint close to the DSS locus. He had multiple abnormalities and micropenis, but otherwise unambiguous male genitalia. We performed quantitative Southern blot analysis with probes from Xp22.13 to p21.2 to define the duplicated region. Clinical, cytogenetic, and molecular data from both patients were compared with those of previously reported related cases. A comparison of the extragenital symptoms revealed no differences between patients with or without sex reversal. In both cases, the symptoms were non-specific. Among 22 patients with a duplication in Xp, nine had unambiguous female genitalia and a well-documented duplication of the DSS region. Two patients with duplication of DSS showed ambiguous external genitalia. From these data, we conclude that induction of testicular tissue may start in these patients, but that the type of genitalia depends on the degree of subsequent degeneration by a gene in DSS. 相似文献
106.
多胚水稻ApⅢ(双13)的胚胎学观察 总被引:6,自引:0,他引:6
对多胚水稻(Oryza sativa L.)ApⅢ的大量成熟颖果、人工萌发的幼苗和开花后3~5 d 的幼嫩颖果进行的整体解剖和显微制片观察表明:ApⅢ的5000粒成熟颖果中,89.0% 含单胚单苗,8.9% 和1.2%分别含双胚双苗和三胚三苗;700多粒幼嫩颖果中,90.0% ~95.0% 含单胚,5.0% ~7.0% 含双胚。因制片的数目有限,未见到含三胚的;在含单胚和多胚颖果中,胚均位于同一胚囊的珠孔端,未见到胚囊以外存在不定胚。根据上述结果,似可以认为ApⅢ单粒颖果的双胚和三胚是由同一胚囊内的卵细胞和1或2个助细胞受精或不受精发育而来的 相似文献
107.
冬虫夏草模式标本的研究 总被引:4,自引:0,他引:4
对冬虫夏草Cordycepssinensis(Berk.)Sacc.的模式标本进行了形态学和有关文献的研究,井与近邻的同种标本进行了比较;该模式现存英国皇家植物园,邱国标本馆,系1879年由M.J.Berkeley研究的标本。 相似文献
108.
Relationship between the levels of wheat-rye metaphase I chromosomal pairing and recombination revealed by GISH 总被引:3,自引:0,他引:3
The metaphase I and anaphase I stages of meiosis of wheat×rye hybrids carrying the ph1b mutation were analyzed by genomic in situ hybridization. This technique allows distinction between three different types of
wheat-rye associations in metaphase I configurations as well as detection of wheat-rye recombinant chromosomes in anaphase
I cells. The frequency of associations between wheat and rye chromosomes greatly exceeded the level of wheat-rye recombination
found in the three hybrids examined. Extremely distal associations, which account for about 50% of the total wheat-rye metaphase
I chromosomal pairing, can explain such a discrepancy between metaphase I and anaphase I data. It is further discussed whether
these associations reflect very distally located chiasmata or nonchiasmatic pairing. The sizes of the segments exchanged in
wheat-rye recombinant chromosomes provide cytological evidence that wheat-rye recombination is restricted to the distal chromosomal
regions.
Received: 24 August 1995; in revised form: 27 February 1996 / Accepted: 28 March 1996 相似文献
109.
Akihiro Ohira Eugene de Juan Jr Yasuo Tano Charles A. Wilson 《The Histochemical journal》1996,28(9):607-611
Summary It has been proposed that basic fibroblast growth factor (basic FGF) mediates the neovascular response in a variety of conditions,
including diabetic retinopathy and branch retinal vein occlusion. To test the hypothesis that basic FGF was released from
retinal stores as a result of retinal ischaemia, transient retinal ischaemia was induced, followed by 48 h of reperfusion,
in the rat by combined central retinal vasculature and optic nerve ligation. The immunolocalization of basic FGF was studied
in the retina. We found that basic FGF in the normal retina is present around the deeper retinal vessels and in the neuronal
tissue of the outer plexiform layer. In the eyes that had ischaemia followed by reperfusion, there was moderate cellular oedema
with retinal swelling, and mitoses in the inner nuclear and plexiform layers. There were no changes evident at the immunohistochemical
level either in the intensity or distribution of stores of basic FGF. We conclude from these data that stores of basic FGF
are not altered dramatically under the conditions of transient experimental ischaemia and reperfusion in the rat, despite
the presence of cellular proliferation. 相似文献
110.
Thehigh growth(hg) locus in mice produces a 30–50% increase in weight gain of homozygous individuals. Here we report that the microsatellite markerD10Mit69is deleted in high growth mice. The deletion ofD10Mit69was uncovered in a screen of the high growth mouse and its progenitor strains for available markers in thehgregion. We demonstrate thathgandD10Mit69cosegregate in a cross of congenic strains C57BL/6J-hghg× C57BL/6J. These results suggest that deletion of a region aroundD10Mit69is responsible for the high growth effect. MarkerD10Mit69will be utilized as an entry point to physical cloning of thehg-containing segment. A dense map of markers aroundhgconstructed here should allow identification of markers in homologous regions in domestic animals and humans, which may be utilized to assess the role of thehglocus in these other species. 相似文献