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Biomedical subjects

I Petersen

Publications and source records attributed to I Petersen.

132 records · Page 8Linked to original sources
PubMedDate not supplied

The effects of chronic violence on preschool children living in South African townships.

Violence in South Africa has reached endemic proportions. To date, more than 11,000 people have died in politically related violence. The present study is specifically concerned with researching the psychological sequelae of civil conflict and violence on preschool children. Using a combination of participatory and empirical methods, five creche teachers (also trained as field workers) took a random sample of 148 children in their creches. The Post Traumatic Stress Disorder Questionnaire for Children was completed by the creche teachers for each of the children under their care. Second, the children were asked to draw pictures of things they had experienced in their life. A significant finding of this study was that preschool children exposed to violence suffered from PTSD. Further, children's drawings showed severe emotional indicators. However, an interesting finding was that these drawings were not good predictors of PTSD; the more a child was able to express emotional trauma through drawings, the less likely he/she would suffer from PTSD. This finding has interesting ramifications for trauma intervention programs for preschool children.

Analysis of Variance↗
PubMedDate not supplied

The detection of pyrogens in blood products using an ex vivo whole blood culture assay.

Induction of interleukin-6 (IL-6) secretion by whole blood cultures (WBC) was used as an in vitro assay system for pyrogen-induced inflammatory reactions. The assay system was very sensitive to Eschericia coli (E coli) endotoxin (< 10 pg/ml). The potential pyrogenic effects of human serum albumin (HSA), Fibronectin (Fn) and stabilised human serum (SHS) solutions were analyzed using this system. None of the products assayed had an effect on the sensitivity of the WBC assay. Spike recovery studies with isolated endotoxin, gram positive and gram negative bacteria showed that none of the products had an effect on the spike recovery of these pyrogenic substances. Good correlations were found between the WBC assay and the rabbit assay for pyrogens for all the production batches tested. When these samples were analysed by the limulus amoebocyte lysate (LAL) assay, the LAL test gave anomalous results for 1 out of the 22 production batches tested. This batch gave a false negative result on the LAL assay and might be indicative of the inability of the LAL assay to detect pyrogens other than endotoxin.

Adult↗
PubMedDate not supplied

Differentiation between endotoxin and non-endotoxin pyrogens in human albumin solutions using an ex vivo whole blood culture assay.

Purified E.coli endotoxin, Gram negative bacteria and Gram positive bacteria induce IL-6 secretion by whole blood cultures (WBC's). Polymyxin B at concentrations greater than 2 U/ml completely inhibits IL-6 secretion caused by 10 EU/ml of endotoxin. Polymyxin B has no effect on IL-6 secretion by WBC's in the absence of endotoxin. The inhibition of endotoxin induced IL-6 secretion is Polymyxin B concentration dependent at concentrations less than 1 U/ml. IL-6 induction caused by E.coli is only partially inactivated by 8 U/ml Polymyxin B. Polymyxin B has no effect on IL-6 secretion caused by B.subtilis. Two pyrogenic batches of human serum albumin (HSA), as tested by the rabbit assay for pyrogens, were also investigated. Polymyxin B at 4 U/ml inhibits less than 40 % of IL-6 secretion caused by these pyrogenic HSA batches. All the endotoxin activity in HSA samples spiked with purified endotoxin is inhibited by Polymyxin B indicating that HSA does not protect endotoxin against Polymyxin B inhibition. These results indicate that the pyrogenicity of these HSA batches are caused by Polymyxin B inhibitable and non-inhibitable fractions. This study shows that pyrogenic substances other than endotoxin can contaminate batches of pharmaceutical products and that results obtained using the Limulus Amoebocyte Lysate (LAL) assay does not necessarily indicate the pyrogenic status of pharmaceutical products. The WBC assay for pyrogens, having a broader sensitivity range than the LAL assay, is a better indicator of the pyrogenic status of pharmaceutical products.

Animals↗
PubMedDate not supplied

Vaccination with inactivated poliovirus vaccine and oral poliovirus vaccine in Denmark.

In Denmark a polio vaccination program including both inactivated poliovirus vaccine (IPV) and oral poliovirus vaccine ( OPV ) has been in use since 1968. Three injections of IPV are given when the children are five, six, and 15 months of age. Subsequently, three vaccinations with trivalent OPV are administered at the age of three, four, and five years. The acceptance rate is high-93%-98%-and greater than 95% of the population has antibodies to poliovirus. The geometric mean titer of serum antibodies is much greater than 10 IU for all three types. The epidemiology of poliomyelitis and the background for the development of the present vaccination schedule are reviewed.

Antibodies, Viral↗