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S. H. Habib S.-E. Ooi Ond?ej Novák Danu?e Tarkowská Jakub Rol?ík Karel Dole?al S. S. R. Syed-Alwee C.-L. Ho P. Namasivayam 《Plant Growth Regulation》2012,68(2):313-317
Comparative mineral and hormonal analyses were made on tissue culture derived truncated leaf syndrome and wild type oil palm seedlings. Mineral analysis confirmed that Boron, Zinc and chlorophyll levels were significantly lower in truncated leaf syndrome leaves than those of wild type. Hormonal analysis also revealed various cytokinin derivatives such as trans-zeatin, trans-zeatin riboside, trans-zeatin O-glucoside and trans-zeatin riboside 5??mono phosphate were significantly higher in truncated leaf syndrome leaves compared to wild type leaves. Brassinolide level was also significantly higher in truncated leaf syndrome leaves than those of the wild type. These observations suggest that the truncated leaf syndrome abnormality could be associated to high cytokinin and brassinosteroid production which affects the uptake of Boron and Zinc. 相似文献
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Hyperthermic treatment at 43 degrees C suppressed the growth of Ehrlich ascites tumor (EAT) cells in vitro. Incubation of EAT cells at 43 degrees C for as little as 1.5 h totally abolished the transplantability of the tumor. At the same time, the rate of cellular glucose uptake, the density of glucose transporter on the cells as well as the extent of thymidine, uridine and leucine incorporation were significantly reduced. 相似文献
4.
Affinity labeling of delta-opiate receptors using [D-Ala2,Leu5,Cys6]enkephalin. Covalent attachment via thiol-disulfide exchange 总被引:1,自引:0,他引:1
W D Bowen S B Hellewell M Kelemen R Huey D Stewart 《The Journal of biological chemistry》1987,262(28):13434-13439
[D-Ala2,Leu5,Cys6]Enkephalin (DALCE) is a synthetic enkephalin analog which contains a sulfhydryl group. DALCE binds with high affinity to delta-receptors, with moderate affinity to mu-receptors, and with negligible affinity to kappa-receptors. Pretreatment of rat brain membranes with DALCE resulted in concentration-dependent loss of delta-binding sites. Using 2 nM [3H][D-Pen2,D-Pen5]enkephalin (where Pen represents penicillamine) to label delta-sites, 50% loss of sites occurred at about 3 microM DALCE. Loss of sites was not reversed by subsequent incubation in buffer containing 250 mM NaCl and 100 microM guanyl-5'-yl imidodiphosphate (Gpp(NH)p), conditions which cause dissociation of opiate agonists. By contrast, the enkephalin analogs [D-Ala2,D-Leu5]enkephalin, [D-Ser2,Leu5,Thr6]enkephalin, [D-Pen2,D-Pen5]enkephalin, and [D-Ala2,D-Leu5,Lys6]enkephalin were readily dissociated by NaCl and Gpp(NH)p, producing negligible loss at 3 microM. This suggests that DALCE binds covalently to the receptors. Pretreatment of membranes with the reducing agents dithiothreitol and beta-mercaptoethanol had no effect on opiate binding. Thus, loss of sites required both specific recognition by opiate receptors and a thiol group. The irreversible effect of DALCE was completely selective for delta-receptors. Pretreatment with DALCE had no effect on binding of ligands to mu- or kappa-receptors. The effect of DALCE on delta-binding was: 1) markedly attenuated by inclusion of dithiothreitol in the preincubation buffer, 2) partially reversed by subsequent incubation with dithiothreitol, 3) slightly enhanced when converted to the disulfide-linked dimer, and 4) prevented by blocking the DALCE sulfhydryl group with N-ethylmaleimide or iodoacetamide. These results indicate that DALCE binds covalently to delta-receptors by forming a disulfide bond with a sulfhydryl group in the binding site. The mechanism may involve a thiol-disulfide exchange reaction. 相似文献
5.
Human thrombomodulin: complete cDNA sequence and chromosome localization of the gene 总被引:20,自引:0,他引:20
A human umbilical vein endothelial cell cDNA library in lambda gt11 was screened for expression of thrombomodulin antigens with affinity-purified rabbit polyclonal anti-thrombomodulin immunoglobulin G (IgG) and mouse monoclonal anti-human thrombomodulin IgG. Among 7 million recombinant clones screened, 12 were recognized by both antibodies. Two of these, lambda HTm10 and lambda HTm12, were shown to encode thrombomodulin by comparison of the amino acid sequence deduced from the nucleotide sequence to the amino acid sequence determined directly from tryptic peptides of thrombomodulin. Thrombomodulin mRNA was estimated to be 3.7 kilobases in length by Northern blot analysis of endothelial cell and placental poly(A)+ RNA. Thrombomodulin mRNA was not detected in human brain, HepG2 hepatoma cells, or the monocytic U937 cell line. Additional cDNA clones were selected by hybridization with the 1.2-kilobase insert of lambda HTm10. One isolate, lambda HTm15, contained a 3693 base pair cDNA insert with an apparent 5'-noncoding region of 146 base pairs, an open reading frame of 1725 base pairs, a stop codon, a 3'-noncoding region of 1779 base pairs, and a poly(A) tail of 40 base pairs. The cDNA sequence encodes a 60.3-kDa protein of 575 amino acids. The predicted protein sequence includes a signal peptide of approximately 21 amino acids, an amino-terminal ligand-binding domain of approximately 223 amino acids, an epidermal growth factor (EGF) homology region of 236 amino acids, a serine/threonine-rich segment of 34 amino acids, a membrane-spanning domain of 23 amino acids, and a cytoplasmic tail of 38 amino acids. The EGF-homology region consists of six tandemly repeated EGF-like domains.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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Results of this investigation indicate that the ferret (Mustela putorius) closely resembles the dog (Canis familiaris) and should be a useful research animal alternative. The tapetum lucidum is a common structure present in the eyes of dogs, cats (Felis catus) and other nocturnal animals. Our study showed that this structure was present in ferret eyes. The color or reflection of the ferret and dog tapetum was remarkably reduced by the general fixation with glutaraldehyde. However, this color fading phenomenon was not observed in the cat tapetum. These observations led to this comparative study on several morphological, histochemical and biochemical parameters on mature ferrets, dogs and cats including: (1) the number of center tapetum cell layers, (2) thickness of center tapetum, (3) presence of a microtubule-like structure in each tapetal rod, (4) presence of electron-dense cores in tapetal rods after prolonged fixation in glutaraldehyde, (5) retention of reflection or color of tapetum after prolonged glutaraldehyde fixation, (6) zygomatic bones of eye orbits, (7) zinc content in tapetum, (8) cysteine in the tapetum, (9) cysteine sulfinic acid decarboxylase in liver, (10) thickness of retina from center tapetum, (11) anterior view of skull configuration, and (12) lateral view of skull configuration (jaw and teeth). Among these 12 parameters, ferret and dog were similar in the first nine points; ferret and cat were similar to each other only in the last two points. There was no difference in retinal thickness among these three animals. 相似文献
8.
Boon Seng Ooi Beatrice T. M. Chen Charles C. S. Toh Oon Teik Khoo 《BMJ (Clinical research ed.)》1970,3(5725):744-746
Of 127 hypertensive patients aged 12 to 40 investigated by intravenous pyelography, abdominal aortography, and renal biopsy an underlying cause was found in 57%. The proportion with secondary hypertension was higher in young patients and in those with severe hypertension. Primary arteritis of the aorta was an important cause of renovascular hypertension in an Asian population. 相似文献
9.
Induction of anti-EBNA-1 protein by 12-O-tetradecanoylphorbol-13-acetate treatment of human lymphoblastoid cells. 总被引:4,自引:2,他引:2 下载免费PDF全文
Binding of the Epstein-Barr virus (EBV) nuclear antigen (EBNA-1) to BamHI-C DNA was studied by affinity column chromatography followed by immunoblotting with human serum specific for EBNA-1. Two species of EBNA-1 (68 and 70 kilodaltons) were identified in nuclear extracts of the EBV-positive Burkitt's lymphoma cell line Raji and not in nuclear extracts of the EBV-negative Burkitt's lymphoma cell line BJAB. Both EBNA-1s bound specifically to the region required for EBV plasmid DNA maintenance (oriP) located in the BamHI-C fragment. Upon treatment with 12-O-tetradecanoylphorbol-13-acetate, which activates latent EBV genome in Raji cells, the 68-kilodalton EBNA-1 was uncoupled from binding to EBV oriP. Nuclear extracts from 12-O-tetradecanoylphorbol-13-acetate-treated BJAB cells also uncoupled the binding of both EBNA-1s to oriP. DNA-cellulose column chromatography identified two protein species which competed for and uncoupled the binding of EBNA-1 to oriP. The two cellular competitors we called anti-EBNA-1 proteins had molecular masses of 60 and 40 kilodaltons, respectively. They were not found in nuclear extracts of BJAB cells not activated by 12-O-tetradecanoylphorbol-13-acetate. 相似文献
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