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71.
Novel Subtype of Peroxisomal Acyl-CoA Oxidase Deficiency and Bifunctional Enzyme Deficiency with Detectable Enzyme Protein: Identification by Means of Complementation Analysis 总被引:4,自引:1,他引:3 下载免费PDF全文
Yasuyuki Suzuki Nobuyuki Shimozawa Shigehiro Yajima Shunji Tomatsu Naomi Kondo Yukikatsu Nakada Shinjiro Akaboshi Mizue Iai Yuzo Tanabe Takashi Hashimoto Ronald J. A. Wanders Ruud B. H. Schutgens Hugo W. Moser Tadao Orii 《American journal of human genetics》1994,54(1):36-43
We describe four infants with a novel subtype of an isolated deficiency of one of the peroxisomal β-oxidation enzymes with detectable enzyme protein. The patients showed characteristic clinical and biochemical abnormalities, including hypotonia, psychomotor retardation, hepatomegaly, typical facial appearance, accumulation of very-long-chain fatty acids, and decreased lignoceric acid oxidation. However, β-oxidation enzyme proteins were detected by immunoblot analyses, and large peroxisomes were identified by immunofluorescence staining. In order to identify the underlying defect in these patients, complementation analysis was introduced using fibroblasts from these patients and patients with an established deficiency of either acyl-CoA oxidase or bifunctional enzyme, as identified by immunoblotting. In the complementing combinations, fused cells showed increased lignoceric acid oxidation, resistance against 1-pyrene dodecanoic acid/UV selection, and normalization of the size and the distribution of peroxisomes. The results indicate that two patients with a more severe clinical course were suffering from bifunctional enzyme deficiency and that the other two infants, who were siblings and had a less severe clinical presentation, were the first patients with acyl-CoA oxidase deficiency with detectable enzyme protein. 相似文献
72.
In order to obtain the evolutionary distance data that are as purely additive as possible, we have developed a novel method
for evaluating the evolutionary distances from the base-pair changes in stem regions of ribosomal RNAs (rRNAs). The application
of this method to small-subunit (SSU) and large-subunit (LSU) rRNAs provides the distance data, with which both the unweighted
pair group method of analysis and the neighbor-joining method give almost the same tree topology of most organisms except
for some Protoctista, thermophilic bacteria, parasitic organisms, and endosymbionts. Although the evolutionary distances calculated
with LSU rRNAs are somewhat longer than those with SSU rRNAs, the difference, probably due to a slight difference in functional
constraint, is substantially decreased when the distances are converted into the divergence times of organisms by the measure
of the time scale estimated in each type of rRNAs. The divergence times of main branches agree fairly well with the geological
record of organisms, at least after the appearance of oxygen-releasing photosynthesis, although the divergence times of Eukaryota,
Archaebacteria, and Eubacteria are somewhat overestimated in comparison with the geological record of Earth formation. This
result is explained by considering that the mutation rate is determined by the accumulation of misrepairs for DNA damage caused
by radiation and that the effect of radiation had been stronger before the oxygen molecules became abundant in the atmosphere
of the Earth.
Received: 23 October 1997 / Accepted: 12 August 1998 相似文献
73.
Takayuki Hoson Kouichi Soga Ryuji Mori Mizue Saiki Kazuyuki Wakabayashi Seiichiro Kamisaka Shigeki Kamigaichi Sachiko Aizawa Izumi Yoshizaki Chiaki Mukai Toru Shimazu Keiji Fukui Masamichi Yamashita 《Journal of plant research》1999,112(4):477-486
Oryza sativa L.) and Arabidopsis (A. thaliana L.) were cultivated for 68.5 hr in the RICE experiment on board during Space Shuttle STS-95 mission, and changes in their
growth and morphology were analyzed. Microgravity in space stimulated elongation growth of both rice coleoptiles and Arabidopsis hypocotyls by making their cell walls extensible. In space, rice coleoptiles showed an inclination toward the caryopsis in
the basal region and also a spontaneous curvature in the same direction in the elongating region. These inclinations and curvatures
were more prominent in the Koshihikari cultivar compared to a dwarf cultivar, Tan-ginbozu. Rice roots elongated in various
directions including into the air on orbit, but two thirds of the roots formed a constant angle with the axis of the caryopsis.
In space, Arabidopsis hypocotyls also elongated in a variety of directions and about 10% of the hypocotyls grew into the agar medium. No clear
curvatures were observed in the elongating region of Arabidopsis hypocotyls. Such a morphology of both types of seedlings was fundamentally similar to that observed on a 3-D clinostat. Thus,
it was confirmed by the RICE experiment that rice and Arabidopsis seedlings perform an automorphogenesis under not only simulated but also true microgravity conditions.
Received 13 September 1999/ Accepted in revised form 12 October 1999 相似文献
74.
Saiki M Fujita H Soga K Wakabayashi K Kamisaka S Yamashita M Hoson T 《Journal of plant research》2005,118(3):199-205
Coleoptiles of rice (Oryza sativa L.) show a spontaneous (automorphic) curvature toward the caryopsis under microgravity conditions. The possible involvement of the reorientation of cortical microtubules in automorphic curvature was studied in rice coleoptiles grown on a three-dimensional clinostat. When rice seedlings that had been grown in the normal gravitational field were transferred to the clinostat in the dark, cortical microtubules of epidermal cells in the dorsal side of the coleoptiles oriented more transversely than the ventral side within 0.5 h. The rotation on the clinostat also increased the cell wall extensibility in the dorsal side and decreased the extensibility in the ventral side, and induced automorphic curvature. The reorientation of cortical microtubules preceded the changes in the cell wall extensibility and the curvature. The irradiation of rice seedlings with white light from above inhibited microtubule reorientation and changes in the cell wall extensibility, as well as curvature of coleoptiles. Also, colchicine, applied to the bending region of coleoptiles, partially inhibited the automorphic curvature. These results suggest that reorientation of cortical microtubules is involved in causing automorphic curvature in rice coleoptiles on the clinostat. 相似文献
75.
Leptin enhances TNF-alpha production via p38 and JNK MAPK in LPS-stimulated Kupffer cells 总被引:7,自引:0,他引:7
Leptin is now recognized as a proinflammatory cytokine and thought to be a progressive factor for non-alcoholic steatohepatitis (NASH). Here we showed the effects of leptin on the production of TNF-alpha (tumor necrosis factor-alpha) by Kupffer cells (KCs) with signal transduction. Leptin enhanced TNF-alpha production accompanied by a dose-dependent increase of MAPK activity in lipopolysaccharide (LPS)-stimulated KCs. SB203580 and JNK inhibitor I, specific inhibitors of P38 and JNK, inhibited TNF-alpha production in KCs but PD98059, an inhibitor of the ERK pathway, did not affect TNF-alpha production by KCs. Recombinant constitutively active adenovirus (Ad)-MKK6 and-MKK7 increased TNF-alpha production in KCs with activation of P38 and JNK without any change by Ad-MEK1 delivery. On the other hand, KCs isolated from the Zucker rat (fa/fa), a leptin receptor-deficient rat, showed reduced production of TNF-alpha on stimulation with LPS. The delivery of Ad-MKK6 and-MKK7, but not Ad-MEK1, increased TNF-alpha production in KCs of Zucker rats with activation of P38 and JNK. Addition of leptin to normal rats increased LPS-induced hepatic TNF-alpha production in vivo and leptin receptor-deficient Zucker rats showed reduced hepatic TNF-alpha production on addition of LPS in vivo. These findings indicate that P38 and JNK pathways are involved in the signal transduction of leptin enhancement of LPS-induced TNF-alpha production. 相似文献
76.
Ras binding opens c-Raf to expose the docking site for mitogen-activated protein kinase kinase 下载免费PDF全文
A key signalling molecule, c-Raf, is situated downstream from Ras and upstream from the mitogen-activated protein kinase kinase (MEK). We studied the mechanism underlying the signal transduction from Ras to MEK by using probes based on the principle of fluorescence resonance energy transfer. In agreement with previous models, it was found that c-Raf adopted two conformations: open active and closed inactive. Ras binding induced the c-Raf transition from closed to open conformation, which enabled c-Raf to bind to MEK. In the presence of a cytosolic Ras mutant, c-Raf bound to, but failed to phosphorylate, MEK in the cytoplasm. In contrast, the cytosolic Ras mutant significantly enhanced MEK phosphorylation by a membrane-targeted c-Raf. These results demonstrated the essential role of Ras-induced conformational change in MEK activation by c-Raf. 相似文献
77.
Proteomic profiling of proteins decreased in hepatocellular carcinoma from patients infected with hepatitis C virus 总被引:5,自引:0,他引:5
Yokoyama Y Kuramitsu Y Takashima M Iizuka N Toda T Terai S Sakaida I Oka M Nakamura K Okita K 《Proteomics》2004,4(7):2111-2116
Hepatocellular carcinoma (HCC) is a major cause of death in Japan. It has been suggested that hepatitis C virus (HCV) plays an important role in hepatocarcinogenesis, because of high incidence among the patients. To understand the mechanism of hepatocarcinogenesis after HCV infection, we performed a comparative study on the protein profiles between tumorous and nontumorous specimens from the patients infected with HCV by means of two-dimensional electrophoresis. Eleven spots were decreased in HCC tissues from over 50% of the patients. Eight proteins out of 11 spots were identified using peptide mass fingerprinting with matrix-assisted laser desorption/ionization-time of flight-mass spectrometry. These proteins were liver type aldolase, tropomyosin beta-chain, ketohexokinase, enoyl-CoA hydratase, albumin, smoothelin, ferritin light chain, and arginase 1. The intensity of enoyl-CoA hydratase, tropomyosin beta-chain, ketohexokinase, liver type aldolase, and arginase 1 was significantly different (p < 0.05). The decrease of 8 proteins was characteristic in HCC. We will discuss the implication of these proteins for the loss of function of hepatocytes and for the possibility of carcinogenesis of HCV-related HCC. 相似文献
78.
79.
Terasaki K Noda Y Itagaki T Shibahara T Tsuchiya K Fukuda K Inoue Y Iwamura M Hino A 《The Journal of parasitology》2002,88(5):1035-1037
Metacercariae of parthenogenetic Fasciola sp. triploid were inoculated into the rat-like hamster Tscherskia triton. Flukes at various stages of growth were found in the bile ducts of all 8 (50%) animals that survived from 42 to 90 days. The body length to width ratio ranged from 1.8 to 2.9, and flukes with the highest ratio were passed 68 days after inoculation. Our results indicate that T. triton is a suitable host for experimental infection when induced by a small number of metacercariae (less than 5) of Fasciola sp. 相似文献
80.
Contribution of root respiration to total soil respiration in a Japanese cedar (Cryptomeria japonica D. Don) artificial forest 总被引:2,自引:0,他引:2
Soil respiration was measured for 2 years in an artificial gap and in an undisturbed area in a Japanese cedar (Cryptomeria japonica D. Don) forest to estimate the contribution of root respiration to total soil respiration. Measurement plots were set up at the center of the gap, the edge of the gap, the edge of the surrounding stand and within the stand. Using a small gap (2.5 m × 2.5 m) enabled us to maintain the same soil temperature and soil moisture as found in the stand. Seasonal fluctuations in soil respiration, increasing in summer and decreasing in winter, corresponded to changes in the soil surface temperature. Soil respiration in the gap site did not differ significantly from those in the stand in the first year of gap formation. However, in the second year, the minimum CO2 flux was observed at the center of the gap and the maximum at the edge of the surrounding stand. Assuming that the differences between soil respiration in the center of the gap and that in the stand were equal to the root respiration, the root respiration rate was calculated from the relationship between the root respiration rates (Rr) and the soil surface temperature (Ts) by Ln(Rr) = 0.07Ts + 3.48. The average contribution of root respiration to total soil respiration, as estimated from the soil surface temperature in the stand by using the above equation, was 49%. After taking root decomposition into consideration, the contribution of root respiration to soil respiration increased from 49 to 57%. 相似文献