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101.
102.
Young-Yell Yang Janny L. Peters Richard E. Kendrick Marie-Michèle Cordonnier-Pratt Yuji Kamiya 《Planta》1998,206(4):685-688
A single pulse of red light (R) given to 4-d-old etiolated high-pigment-1 (hp-1) mutant tomato (Solanum lycopersicum L.) seedlings followed by a 3-d dark period is demonstrated to result in a block of greening in subsequent white light. Wild-type
seedlings green normally under this regime. The block of greening in the hp-1 mutant depends on the length of the dark period before and after the R pulse and operates via the low-fluence-response mode
of phytochrome action. This block of greening takes place in hp-1 double mutants lacking either phytochrome A or phytochrome B1, but is absent in the hp-1 triple mutant lacking both phytochromes A and B1. These observations enable a screen to be devised for new phytochrome B1
mutants either within the photoreceptor or mutants defective in phytochrome B1-signalling steps which result in loss of capacity
to green, by mutagenising the phytochrome A-deficient hp-1, fri double mutant.
Received: 20 February 1998 / Accepted: 18 June 1998 相似文献
103.
104.
Tomoo Kamiya A-Hon Kown Toshiki Kanemaki Yoichi Matsui Shouji Uetsuji Tadayoshi Okumura Yasuo Kamiyama 《In vitro cellular & developmental biology. Animal》1998,34(2):131-137
Summary The Anaeropack system for cell culture, which was originally designed for the growth of anaerobic bacteria, was used to produce
a hypoxic atmosphere for cultured hepatocytes. We measured changes in the oxygen and carbon dioxide concentrations and the
atmospheric temperature in an airtight jar. We also measured changes in the pH of the medium during hypoxia to assess the
accuracy of this system. Moreover, we used three durations (2, 3, and 4 h) of hypoxia and 8 h of reoxygenation in cultured
rat hepatocytes, and then measured the lactate dehydrogenase (LDH), ketone body concentration (acetoacetate + β-hydroxybutyrate),
and the ketone body ratio (KBR: acetoacetate/β-hydroxybutyrate) in the medium in order to assess the suitability of this system
as a model for reperfusion following liver ischemia. The oxygen concentration dropped to 1% or less within 1 h. The concentration
of carbon dioxide rose to about 5% at 30 min after the induction of the hypoxic conditions, and was maintained at this level
for 5 h. No effect of the reaction heat produced by the oxygen absorbent in the jar was recognized. The extent of cell injury
produced by changing the hypoxic parameters was satisfactorily reflected by the KBR, the ketone body concentration, and the
LDH activity released into the medium. Because this model can duplicate the conditions of the hepatocytes during revascularization
following ischemic liver, and the Anaeropack system for cell culture is easy to manipulate, it seems suitable for the experimental
study of hypoxic injury and revascularization in vitro. 相似文献
105.
Megumi Sasatani Yanbin Xu Hidehiko Kawai Lili Cao Satoshi Tateishi Tsutomu Shimura Jianxiang Li Daisuke Iizuka Asao Noda Kanya Hamasaki Yoichiro Kusunoki Kenji Kamiya 《PloS one》2015,10(2)
The ubiquitin ligase RAD18 is involved in post replication repair pathways via its recruitment to stalled replication forks, and its role in the ubiquitylation of proliferating cell nuclear antigen (PCNA). Recently, it has been reported that RAD18 is also recruited to DNA double strand break (DSB) sites, where it plays novel functions in the DNA damage response induced by ionizing radiation (IR). This new role is independent of PCNA ubiquitylation, but little is known about how RAD18 functions after IR exposure. Here, we describe a role for RAD18 in the IR-induced DNA damage signaling pathway at G2/M phase in the cell cycle. Depleting cells of RAD18 reduced the recruitment of the DNA damage signaling factors ATM, γH2AX, and 53BP1 to foci in cells at the G2/M phase after IR exposure, and attenuated activation of the G2/M checkpoint. Furthermore, depletion of RAD18 increased micronuclei formation and cell death following IR exposure, both in vitro and in vivo. Our data suggest that RAD18 can function as a mediator for DNA damage response signals to activate the G2/M checkpoint in order to maintain genome integrity and cell survival after IR exposure. 相似文献
106.
Deformation of the Outer Hair Cells and the Accumulation of Caveolin-2 in Connexin 26 Deficient Mice
Takashi Anzai Ichiro Fukunaga Kaori Hatakeyama Ayumi Fujimoto Kazuma Kobayashi Atena Nishikawa Toru Aoki Tetsuo Noda Osamu Minowa Katsuhisa Ikeda Kazusaku Kamiya 《PloS one》2015,10(10)
BackgroundMutations in GJB2, which encodes connexin 26 (Cx26), a cochlear gap junction protein, represent a major cause of pre-lingual, non-syndromic deafness. The degeneration of the organ of Corti observed in Cx26 mutant—associated deafness is thought to be a secondary pathology of hearing loss. Here we focused on abnormal development of the organ of Corti followed by degeneration including outer hair cell (OHC) loss.MethodsWe investigated the crucial factors involved in late-onset degeneration and loss of OHC by ultrastructural observation, immunohistochemistry and protein analysis in our Cx26-deficient mice (Cx26f/fP0Cre).ResultsIn ultrastructural observations of Cx26f/fP0Cre mice, OHCs changed shape irregularly, and several folds or notches were observed in the plasma membrane. Furthermore, the mutant OHCs had a flat surface compared with the characteristic wavy surface structure of OHCs of normal mice. Protein analysis revealed an increased protein level of caveolin-2 (CAV2) in Cx26f/fP0Cre mouse cochlea. In immunohistochemistry, a remarkable accumulation of CAV2 was observed in Cx26f/fP0Cre mice. In particular, this accumulation of CAV2 was mainly observed around OHCs, and furthermore this accumulation was observed around the shrunken site of OHCs with an abnormal hourglass-like shape.ConclusionsThe deformation of OHCs and the accumulation of CAV2 in the organ of Corti may play a crucial role in the progression of, or secondary OHC loss in, GJB2-associated deafness. Investigation of these molecular pathways, including those involving CAV2, may contribute to the elucidation of a new pathogenic mechanism of GJB2-associated deafness and identify effective targets for new therapies. 相似文献
107.
108.
109.
Purpose
To investigate the distribution of posterior corneal astigmatism in eyes with with-the-rule (WTR) and against-the-rule (ATR) anterior corneal astigmatism.Methods
We retrospectively examined six hundred eight eyes of 608 healthy subjects (275 men and 333 women; mean age ± standard deviation, 55.3 ± 20.2 years). The magnitude and axis orientation of anterior and posterior corneal astigmatism were determined with a rotating Scheimpflug system (Pentacam HR, Oculus) when we divided the subjects into WTR and ATR anterior corneal astigmatism groups.Results
The mean magnitudes of anterior and posterior corneal astigmatism were 1.14 ± 0.76 diopters (D), and 0.37 ± 0.19 D, respectively. We found a significant correlation between the magnitudes of anterior and posterior corneal astigmatism (Pearson correlation coefficient r = 0.4739, P<0.001). In the WTR anterior astigmatism group, we found ATR astigmatism of the posterior corneal surface in 402 eyes (96.6%). In the ATR anterior astigmatism group, we found ATR posterior corneal astigmatism in 82 eyes (73.9%). Especially in eyes with ATR anterior corneal astigmatism of 1 D or more and 1.5 D or more, ATR posterior corneal astigmatism was found in 28 eyes (59.6%) and 9 eyes (42.9%), respectively.Conclusions
WTR anterior astigmatism and ATR posterior astigmatism were found in approximately 68% and 91% of eyes, respectively. The magnitude and the axis orientation of posterior corneal astigmatism were not constant, especially in eyes having high ATR anterior corneal astigmatism, as is often the case in patients who have undergone toric IOL implantation. 相似文献110.
Hidenaga Kobashi Kazutaka Kamiya Mohamed A. Ali Akihito Igarashi Mohamed Ehab M. Elewa Kimiya Shimizu 《PloS one》2015,10(4)