Severity: Warning
Message: file_get_contents(https://...@pubfacts.com&api_key=b8daa3ad693db53b1410957c26c9a51b4908&a=1): Failed to open stream: HTTP request failed! HTTP/1.1 429 Too Many Requests
Filename: helpers/my_audit_helper.php
Line Number: 176
Backtrace:
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 176
Function: file_get_contents
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 250
Function: simplexml_load_file_from_url
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 1034
Function: getPubMedXML
File: /var/www/html/application/helpers/my_audit_helper.php
Line: 3152
Function: GetPubMedArticleOutput_2016
File: /var/www/html/application/controllers/Detail.php
Line: 575
Function: pubMedSearch_Global
File: /var/www/html/application/controllers/Detail.php
Line: 489
Function: pubMedGetRelatedKeyword
File: /var/www/html/index.php
Line: 316
Function: require_once
The degree of inhibition of semiconservative DNA replication induced by nickel chloride (NiCl2) was analyzed by radiolabeled-thymidine incorporation alone or with cesium chloride (CsCl) density gradient centrifugation. The onset and duration of this Ni2+-induced inhibition was time- and concentration-dependent, but the degree of inhibition was not. A maximal reduction in the rate of DNA synthesis was observed within the first hour of treatment with 2.5 mM NiCl2, which was the highest noncytotoxic concentration utilized. After six hours, 500 microM and 1 mM as well as 2.5 mM NiCl2 all produced the same 50% to 60% reduction in [3H]-thymidine incorporation into DNA. The inhibitory effect of nickel ions on DNA synthesis was reversible. The rate of DNA synthesis following a 500 microM or 1 mM NiCl2 treatment began to increase after washout of nickel, but a six-hour exposure of cells to 2.5 mM NiCl2 produced a sustained 50% to 60% suppression of DNA synthetic activity for at least 36 hours. At all concentrations of NiCl2 used in this study, some inhibition of DNA synthesis persisted for at least 48 hours, but by 72 hours after treatment, the rate of [3H]-thymidine incorporation was actually 10% above the control. Examination of autoradiographic slides of cells treated with 2.5 mM NiCl2 for six hours demonstrated a 60% reduction of silver grains, but there was no preferential reduction in the quantity of grains in the nucleolus or any other region. Cesium chloride density gradient analysis of the replication of nucleolar DNA in cells treated with 2.5 mM nickel supported the autoradiographic findings. The inhibitory effect of NiCl2 on DNA replication was prevented by the addition of magnesium chloride (MgCl2) to cells maintained in a simple salts/glucose medium (SGM). This effect did not appear to be due to an antagonism of the cellular uptake of nickel by Mg2+, since the maximally effective dose of Mg2+ reduced 63Ni2+ uptake by no more than 25% while the inhibition of replication was completely reversed.
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Source |
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http://dx.doi.org/10.1002/jbt.2570010203 | DOI Listing |
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