PAPP-A is a large glycoprotein with alpha2-electrophoretic mobility that is produced by the placenta during pregnancy. In this thesis a biochemical and molecular characterisation of PAPP-A was performed. The polyclonal antiserum (DAKO) directed against PAPP-A has been shown to also interact with proteins other than PAPP-A. These non-specific interactions were abolished by performing Western blotting immunodetection at a high salt concentration (0.6M NaCl). At this salt concentration a single band of 195 kDa was immunodetected and this corresponded to the monomeric PAPP-A molecule. It was also discovered that a subset of paratopes in this antiserum reacted, under the described high salt concentration conditions, with the glycan component of PAPP-A. A placental cDNA library was screened using this antibody for the PAPP-A cDNA but this did not yield a clone for PAPP-A. A possible explanation is that the interaction with this antibody requires carbohydrate components to be present on the PAPP-A molecule. It is known that proteins expressed in bacterial systems are not post-translationally modified. Therefore another approach to the isolation of the PAPP-A cDNA clone was adopted, but this required some primary amino acid sequence of this protein that was unavailable at the time. To generate this information, PAPP-A was purified using its previously unpublished affinity for L-arginine in combination with the already described procedures of ammonium sulphate precipitation, ion exchange and gel filtration. Final purification of PAPP-A was achieved by SDS-PAGE electrophoresis. The isolated monomeric PAPP-A gave a unique single N-terminal amino acid sequence: N-EARGATEEPS. The N terminal sequence combined with the sequence obtained from limited proteolytic digestion of PAPP-A were used to design oligonucleotide primers specific for PAPP-A. These primers were used in a PCR reaction that produced 500 and >1200 bp fragments using the cDNA library as DNA template; thus demonstrating that PAPP-A is synthesised in the placenta. PAPP-A was shown to have O and N-linked carbohydrate chains. Enzymatic deglycosylation demonstrated that the N-linked chains were 8% (w/w) of the molecule. The O-linked groups were extensively modified with the presence of oligomers of N-acetyl-glucosamine. It was also shown that it was these groups the PAPP-A antibodies bind to at high salt concentration. A physical interaction of PAPP-A with endoproteinase Arg-C (EGF-BP) was observed. It was seen that they form a 1:1 (PAPP-A: endoproteinase) sub-unit complex that was stable in SDS. A further investigation revealed that PAPP-A interacted with the endoproteinase Arg-C and this resulted in a 30% inhibition of the esterolytic activity of this enzyme.

Forty years ago, when an American woman wanted to know if she was pregnant, she made an appointment with a medical professional who would conduct a pregnancy test and tell her the result. Propelled by the medical establishment’s control, surveillance, and neglect of women’s health, the women’s health movement of the 1970s sought to put women’s health “into their own hands.” Encouraged in part by the rhetoric of the women’s health movement, pregnancy tests became available for purchase over-the-counter, without a prescription, and outside of the control of the medical establishment. This dissertation examines this passage of the pregnancy test from the hands of medical professionals to the hands of lay people and asks, has the pregnancy test really delivered on its promise to give women information, choice, and control? We think of women’s reproductive health tools in the hands of doctors as oppressive and in the hands of women as liberating; the central argument of this dissertation is that this view is naïve. Putting the informational power about women’s bodies into a mobile diagnostic technology did not change the nature of the beast. Through this examination of the pregnancy test in American life, we can trace the flow of reproductive power through various people, places, and things to better understand the character of women’s subordination.

This dissertation scrutinises the impact of pregnancy challenges on the mining industry, taking the right of equality and unfair discrimination into consideration. Pre-employment pregnancy testing is an acceptable practice within the current legal framework whereby the MHSA and section 26 of the BCEA place an obligation on the employer to protect employees before and after the birth of a child. This section provides that no work may be performed by an employee that is hazardous to her health or the health of her unborn child. The dissertation synthesises and reviews the practical implications of pregnancy and related challenges of underground employees and all the problems surrounding this matter are dissected. The liability of the employer and the failure of the employee to report her pregnancy status to the employer as soon as she becomes aware of it, can be justifiably treated as misconduct. The justification of the dismissal of an underground employee based on pregnancy is confirmed in light of the legislative obligations placed on the employer. Current legislative measures, which justify an automatically unfair dismissal due to pregnancy, cannot be implemented without considering the Constitution and the employers’ right to economical sustainability. A literature study will be done using current and relevant sources such as books, legislation, court decisions, conference papers and journal articles. Methodological issues will also render it necessary to weigh up different rights through literature sources. / Thesis (LLM (Labour Law))--North-West University, Potchefstroom Campus, 2013

This dissertation scrutinises the impact of pregnancy challenges on the mining industry, taking the right of equality and unfair discrimination into consideration. Pre-employment pregnancy testing is an acceptable practice within the current legal framework whereby the MHSA and section 26 of the BCEA place an obligation on the employer to protect employees before and after the birth of a child. This section provides that no work may be performed by an employee that is hazardous to her health or the health of her unborn child. The dissertation synthesises and reviews the practical implications of pregnancy and related challenges of underground employees and all the problems surrounding this matter are dissected. The liability of the employer and the failure of the employee to report her pregnancy status to the employer as soon as she becomes aware of it, can be justifiably treated as misconduct. The justification of the dismissal of an underground employee based on pregnancy is confirmed in light of the legislative obligations placed on the employer. Current legislative measures, which justify an automatically unfair dismissal due to pregnancy, cannot be implemented without considering the Constitution and the employers’ right to economical sustainability. A literature study will be done using current and relevant sources such as books, legislation, court decisions, conference papers and journal articles. Methodological issues will also render it necessary to weigh up different rights through literature sources. / Thesis (LLM (Labour Law))--North-West University, Potchefstroom Campus, 2013

Indiana University-Purdue University Indianapolis (IUPUI) / During pregnancy, maternal liver exhibits robust growth to meet the metabolic demands of the developing placenta and fetus. Although hepatocyte hypertrophy and hyperplasia are seen in the maternal liver, the molecular and cellular mechanisms mediating the maternal hepatic adaptations to pregnancy is poorly understood. Previous microarray analysis revealed a most upregulated gene named Ascl1, a transcription factor essential for neural development, in the maternal liver at mid-gestation. The aims of the study were to (1) validate the activation of Ascl1 gene; (2) identify Ascl1-expressing cells; and (3) determine the fate of Ascl1-expressing cells, in the maternal liver during the course of gestation. Timed pregnancy was setup in mice and the maternal livers were collected at various stages of gestation. Maternal hepatic Ascl1 mRNA expression was evaluated by qRT-PCR and northern blotting. The results demonstrated that the transcript level of maternal hepatic Ascl1 is exponentially increased during the second half of pregnancy in comparison with a non-pregnant state. Using a Ascl1-GFP mouse model generated by others to monitor the behavior of neural progenitor cells, we found that maternal hepatic Ascl1-expressing cells are non-parenchymal cells, very small in size, and expanding during pregnancy. To map the fate of this cell population, we generated an in vivo tracing mouse model named Ascl1-CreERT2/ROSA26-LacZ. Using this model, we permanently labeled maternal hepatic Ascl1-expressing cells at midgestation by giving tamoxifen and analyzed the labeled cells in the maternal liver prior to parturition. We observed that the initial small Ascl1-expressing cells undergoing expansion at mid-gestation eventually became hepatocyte-like cells at the end stage of pregnancy. Taken together, our findings strongly suggest that Ascl1-expressing cells represent a novel population of hepatic progenitor cells and they can differentiate along hepatocyte lineage and contribute to pregnancy-induced maternal liver growth. Further studies are needed to firmly establish the nature and property of maternal hepatic Ascl1-expressing cells. At this stage, we have gained significant insights into the cellular mechanism by which the maternal liver adapts to pregnancy.