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81.
The degradation of purified 35S-labelled rat liver isometallothioneins (MT) by lysosomal extracts was studied. Zn-MT-I was more readily hydrolysed than Zn-MT-II, but no significant degradation of the Cu-containing metallothioneins could be detected, even after 24 h incubation. The susceptibility of MT to degradation in vitro may be related to the strength of the metal-thiolate bonds. However, the turnover rates of cytosolic MT in vivo, as established by pulse-labelling techniques, are apparently subject to different controls. The half-lives of MT-I and -II in the liver cytosol of Cu2+-injected rats were only 15.4 +/- 1.5 and 18.2 +/- 1.1 h respectively. Approx. 25% of the total liver MT was present in particulate fractions (probably in lysosomes) of the liver and had a half-life of 25.1 +/- 4.1 h. 相似文献
82.
Metal determination in human tissues is the most common application of biological monitoring for screening, diagnosis and
assessment of metal exposures and their risks. Various biopsy-materials may be used. This paper deals with the quantitative
determination of Cd, Pb, Cr, Mn, Fe, Ni, Cu, and Zn concentrations in nails of male subjects exposed to these metals alongwith
their respective controls, while working in locomotive, carriage and roadways workshops, and lead battery factories. The levels
of Cd, Pb, Cr, Mn, Fe, Ni, Cu and Zn in fingernails, assayed by atomic absorption spectrophotometry, were compared with their
respective controls by student ‘t’ test. All the obtained values were correlated to the personal and medical history of the
subjects under study. Significantly high levels of Cd, Pb, Cr, Fe, Ni, Cu and Zn were present in smokers, compared to nonsmokers.
The concentrations of Cd, Pb, Cr, Mn and Fe were not significantly high in vegetarian subjects. It was also observed that
there is no contribution of liquor towards nail-metal concentration. Significant correlations were observed between skin disease
and Cr, Mn, Fe, Cu; hypertension and Cd, Mn, Cu; mental stress and Cd, Pb, Mn, Ni, Cu, Zn; diabetes and Cr, Mn, Ni; chest
pain and Pb; respiratory trouble and Cr, Mn, Fe, Ni, Zn; tuberculosis and Zn; acidity and Cd; and ophthalmic problems and
Mn, Fe, Ni, and Zn 相似文献
83.
The Drosophila type II receptor, Wishful thinking, binds BMP and myoglianin to activate multiple TGFbeta family signaling pathways 总被引:1,自引:0,他引:1
Wishful thinking (Wit) is a Drosophila transforming growth factor-beta (TGFbeta) superfamily type II receptor most related to the mammalian bone morphogenetic protein (BMP) type II receptor, BMPRII. To better understand its function, we undertook a biochemical approach to establish the ligand binding repertoire and downstream signaling pathway. We observed that BMP4 and BMP7, bound to receptor complexes comprised of Wit and the type I receptor thickveins and saxophone to activate a BMP-like signaling pathway. Further we demonstrated that both myoglianin and its most closely related mammalian ligand, myostatin, interacted with a Wit and Baboon (Babo) type II-type I receptor complex to activate TGFbeta/activin-like signaling pathways. These results thereby demonstrate that Wit binds multiple ligands to activate both BMP and TGFbeta-like signaling pathways. Given that myoglianin is expressed in muscle and glial-derived cells, these results also suggest that Wit may mediate myoglianin-dependent signals in the nervous system. 相似文献
84.
The von Hippel-Lindau tumor suppressor protein influences microtubule dynamics at the cell periphery
Lolkema MP Mehra N Jorna AS van Beest M Giles RH Voest EE 《Experimental cell research》2004,301(2):139-146
The von Hippel-Lindau (VHL) protein protects microtubules (MTs) from destabilization by nocodazole treatment. Based on this fixed-cell assay with static end points, VHL has been reported to directly stabilize the MT cytoskeleton. To investigate the dynamic changes in MTs induced by VHL in living cells, we measured the influence of VHL on tubulin turnover using fluorescence recovery after photobleaching (FRAP). To this end, we engineered VHL-deficient renal cell carcinoma cells to constitutively incorporate fluorescently labeled tubulin and to inducibly express VHL. Induction of VHL in these cells resulted in a decrease of tubulin turnover as measured by FRAP at the cell periphery, while minimally influencing MT dynamics around the centrosome. Our data indicates that VHL changes the behavior of MTs dependent on their subcellular localization implying a role for VHL in cellular processes such as migration, polarization, and cell-cell interactions. Here we propose a complementary method to directly measure VHL-induced subcellular changes in microtubule dynamics, which may serve as a tool to study the effect of MT binding proteins such as VHL. 相似文献
85.
Hair and fingernails of exposed and unexposed subjects were analyzed for their lead (Pb) and cadmium (Cd) contents by atomic absorption spectrophotometer with graphite furnace and air-acetylene flame. Hair and nail Pb concentrations in occupationally exposed subjects ranged between 1.020-409.726 and 8.130-765.306 microg/g and in environmentally unexposed subjects 0.123-25.160 and 1.076-65.613 microg/g, respectively. Similarly, hair and nail Cd concentrations in occupationally exposed subjects ranged between 0.014-22.086 and 0.214-35.714 microg/g and in environmentally unexposed subjects 0.113-1.627 and 0.028-8.108 microg/g, respectively. A significant correlation was observed between Pb hair and nail concentrations in exposed subjects at P < 0.05, as compared to unexposed subjects and Cd hair and nail in exposed, as well as unexposed subjects. With respect to exposure, levels of Pb in hair and nails were found to be significant in exposed subjects, compared to unexposed ones and levels of Cd were significant only in nails of exposed ones. With respect to age, no significant correlation was found between hair and nail Pb and Cd concentrations in both exposed and unexposed subjects. 相似文献
86.
87.
In the present study, the age-dependent doses due to inhalation of short lived decay progeny of radon, i.e., 214Po to different body organs have been calculated for the inhabitants of the Jammu district, Jammu &; Kashmir, India. The estimated age-dependent doses for different body organs due to inhalation of radon progeny through air for all age groups varied between 0.002E-06 and 0.10 n Svy?1 which were found to be well within the recommended limit of 1000 µ Svy?1 (ICRP). The progeny concentration of radon and thoron was calculated and compared by two different techniques. The attached and un-attached progeny concentration of radon and thoron was calculated by using a passive time integrating, deposition-based technique. The measured attached and un-attached radon and thoron progeny concentrations have been cross-checked by on-line active technique, i.e., Flow-mode Integrated Sampler. A weak positive correlation has been observed between the two devices. The median value of un-attached fraction was found to be 0.15 and 0.12 for thoron and radon progeny, respectively and found to have a log-normal distribution. A good positive correlation has been observed between radon and thoron progeny concentrations. 相似文献
88.
In the present study, the soil-gas radon concentration was assessed at different depth intervals, i.e., 15 cm, 30 cm, 60 cm, and 100 cm from the 30 villages of Jammu &; Kashmir, India using RAD7, an electrostatic solid state alpha detector. The radon mass exhalation and thoron surface exhalation rate has also been measured in the selected 18 soil samples out of 30 of different grain sizes (i.e., 1 mm, 300 µm, 150 µm). The active radon and thoron concentrations were also assessed in the 20 villages. Both the exhalation rates and active radon/thoron concentration were measured using SMART Rn Duo, a portable radon monitor. The average values of soil-gas radon concentration were 210 ± 84 Bq m?3, 1261 ± 963 Bq m?3, 4210 ± 1994 Bq m?3, and 671 ± 305 Bq m?3 at the depth intervals of 15 cm, 30 cm, 60 cm, and 100 cm, respectively. The exhalation rate of radon and thoron from soil was found to decrease with the increase of grain size, as smaller soil particles make relatively more contribution to radon and thoron exhalations from the ground surface than larger soil particles. The measured Pearson's correlation coefficient was obtained as statistically significant between different quantities under two-tailed test. 相似文献
89.
Cu(I) binding to the Schizosaccharomyces pombe gamma-glutamyl peptides varying in chain lengths 总被引:3,自引:0,他引:3
The metal-gamma-glutamyl peptide complex of Schizosaccharomyces pombe is an oligomer of peptides of the general structure (gamma-Glu-Cys)n-Gly with n defining the number of dipeptide repeats. The complexes induced with either cadmium or copper salts are heterogeneous with respect to the number of repeat units or n. Peptides isolated from two preparations of the Cd-gamma-Glu complex by reverse-phase HPLC at low pH were of an n range of 2 to 6 with n3 and n4 peptides being predominant. In addition to peptides of the mentioned structure, peptides of n3 and n4 without the terminal Gly were isolated. These n3 and n4 desGly peptides were present in an abundance of about 10-20% of the concentration of the parent peptide. Peptides of unique n were studied in Cu(I) reconstitution experiments in an attempt to understand the significance of the peptide length heterogeneity in the oligomeric metal-thiolate cluster. Cu-gamma-Glu complexes were formed with each peptide as determined by the characteristic 260-nm shoulder in the ultraviolet absorption spectrum and luminescence indicative of Cu(I)-thiolate coordination in a solvent-inaccessible environment. Cluster formation also occurs with desGly peptides, so the carboxyl-terminal Gly is not critical for cluster formation. Maximal Cu binding stoichiometry with n3 and n4 peptides was markedly less than the maximal Cu(I) stoichiometry of a peptide mixture or the native complex. Cu ions in complexes formed with unique n peptides were more reactive with bathocuproine than Cu ions in complexes with a peptide n mixture. The results suggest that metal-peptide complexes consisting of peptides differing in n probably exist and not all metal-peptide complexes have the same n peptide constituents. 相似文献
90.
Maria E. Sundaram Hasmot Ali Sucheta Mehra Abu Ahmed Shamim Barkat Ullah Mahbubur Rashid Saijuddin Shaikh Parul Christian Rolf D. W. Klemm Keith P. WestJr Alain Labrique 《International breastfeeding journal》2016,11(1):31