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
Platelet counts in newborns are similar to those of adults and children. However, newborn infants admitted to intensive care nurseries have a high prevalence of thrombocytopenia. The mechanisms responsible for the increased susceptibility to thrombocytopenia are not known. In addition, some studies have documented functional abnormalities in newborn platelets. In an effort to understand differences between platelets in newborns and in adults, we examined megakaryocyte ploidy in bone marrow from fetuses and compared it with bone marrow from adults, using a modified Feulgen stain to measure DNA of individual megakaryocytes. Faced with small fixed tissue samples, we developed a technique for use on bone marrow biopsies to estimate megakaryocyte ploidy and compared the results obtained with this method to those obtained from bone marrow aspirates. This study demonstrated that the overall mean ploidy of fetal megakaryocytes is decreased compared with adults. Additionally, fetal megakaryocyte ploidy increases as megakaryocyte maturation increases, but not to the same extent that adult megakaryocyte ploidy increases with megakaryocyte maturation. Over the gestational period studied, there was no relationship between gestational age and mean ploidy. The small size, shift to a less mature population, and decreased ploidy of fetal megakaryocytes indicate that there are differences in the post mitotic phase of megakaryocyte development in the fetus. Such differences may be related to quantitative and qualitative platelet abnormalities in the newborn. Understanding the physiology and regulation of megakaryocytopoiesis in the fetus and newborn will be valuable in determining the pathophysiologic basis of platelet dysfunction in the newborn.
Download full-text PDF |
Source |
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http://dx.doi.org/10.1203/00006450-199601000-00026 | DOI Listing |
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