Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Generative organs, Female --- Laparoscopic surgery --- Genitalia, Female --- Hysterectomy, Vaginal --- Laparoscopy --- Neoplasms --- Urinary Incontinence --- Endoscopic surgery --- surgery --- methods --- methods --- surgery --- surgery

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

The effects of maternal adiposity (high body mass index - high BMI -), nutrient intake and storage (gestational weight gain - GWG -) and (abnormal) glucose tolerance (gestational diabetes - GDM - ) are regarded important cornerstones in metabolic research in pregnancy. In Chapter 1, I explained, that they play an important role in the development of complications in the mother and the fetus, both short- and long-term. I also reported on how the current state ofnbsp;in pregnancy has evolved and how it can be used for detailed studies of the unborn child. In this field of research, the fetal period is often conveniently summarized by its resultant birthweight. This outcome parameter is used to compare intra-uterine effects on long- and short term complications in epidemiologic studies. High and low birth weight has been linked to future increased cardiovascular risk profiles, fitting the nbsp;origin of diseases’ theory.^ Beside birth weight, more detailed information on the neonates’ body composition (fat distribution), in both lean- and fat mass might reflect the in utero development better, although fetal predictors for neonatal adiposity still have to be developed. Furthermore, there is no generally accepted definitionnbsp;‘neonatal BMI’ or neonatal adiposity. At present ponderal index or fat-mass percentage fill this lacuna. Finally, ultrasound in pregnancy is capable of obtaining information on the unborn child and uses an estimation for fetal weight. Accuracy for this estimate fluctuates around 6-12% of the actual fetal weight. In the obese mother, on the other hand, visualization of the fetus is even more limited.As stated in Chapternbsp;the environment in utero and in early neonatal life may induce a permanent response in the fetus and the newborn, leading to enhanced susceptibility to later diseases. Fetal overgrowth is related to a diabetic intra-uterine environment.^ The increased prevalence of diabetes mellitus (DM) in children of diabetic mothers is consistent with an epigenetic effect of hyperglycemia in pregnancy acting in addition to genetic factors that induce diabetes in next generations (human and animal data). Fetal growth restriction due to malnutrition on the other hand, leads to a higher incidence of CVD and type-2 DM in later life. Particularly when catch-up growth is present by high caloric postpartum intake. The third trimester seems to be a vulnerable period for the influence of maternal malnutrition, and hence fetal growth restriction (human and animal data). The role of environmental influences, such as excessive nutrition, nutritional restriction or low folic acid and vitamin B12 levels, on DNA methylation in early life development is called epigenetics. The effects of maternal and fetal nutrition stresses the importance of the embryonic environment on epigenetic imprinting for metabolic mechanisms on the future generations.^ Not every overweight newborn and not every newborn with intra-uterine growth restriction will develop problems in later life. Other factors of course influence final outcomes: in general it depends on the extent of adaptation and on its plasticity later on.In view from the fetus, the intra-uterine period has been associated with gender different intra-uterine physical adaptations to a changed nutrient supply from the mother. The male infant body composition has been shown to be more sensitive to maternal influences such as higher pre-gestational BMI and excessive gestational weight gain. And although gender is recognized as a determining factor for differences in outcome in adult medicine, little information is available on fetal gender influence in the prenatal period.^ Given these complexities the World Health Organization (WHO) Multicentre Growth Reference Study Group (MGRS) recommended GAMLSS (Generalized Additive Model Location, Scale and Shape) for the construction of (WHO) Growth Standards. In Chapter 3, we constructed fetal growth curves in a Caucasian population (12368 pregnancies) and furthernbsp;for fetal gender. The fetal head measurements were significantly larger in boys compared to girls from 20 weeks’ gestation onwards, equating to a 3 day difference at 20-24 weeks. Boys were significantly heavier, longer and had greater head circumference than girls at birth. The Apgar score at one minute and arterial cord pH were lower in boys. These longitudinal fetal growth curves for the first time allow integration with neonatal and pediatric WHO gender specific growth curves.^ Immediate birth outcomes are worse in boys than girls, and gender differences in intra uterine growth is sufficiently distinct to have a clinically important effect on fetal weight estimation and second trimester dating. Gender differences might play a role in obstetric or immediate neonatal viability management. The implication of these findings is that anbsp;and a girl at exactly 24weeks gestation might, based on the current late second trimester dating protocols with head measurements, be assigned a gestation as much as 3 days different and an estimated weight difference of 21gram at 24weeks favoring the boys; The term difference adds to 121gram, favoring the boys. Also the boys’ head circumference is larger (+0.6cm) at birth. In conclusion, the boys seem to be more vulnerable around viability age (22-24weeks), since they are estimated older than they are in reality. The girls are more vulnerable for this erroneous estimate at the latter, post-term period in pregnancy.^ Because at this stage, decisions on ending the pregnancy are often taken and they are older than estimated. But around term, boys do worse for the immediate start (lower first minute Apgar Score and cord-pH) compared to girls.In Chapter 4, a prospective cohort analysis was performed for the influence of maternal GWG and BMI on fetal growth. These factors influence independently fetal growth development during pregnancy and birth weight. Cluster analysis discerned four total GWG clusters: I: ≤0kg, II: 0-4kg, III: 4-12kg and IV: >12kg. For each cluster there was a different fetal weight evolution and also finally, different birth size. When cluster IV was compared to cluster I, the additive effect of the cluster difference on birth weight was +477g. The maternal BMI class acted independently on the fetal weight evolution. A higher BMI class increased fetal growth and hence birth weight. When BMI of 35 was compared to a BMI of 17, the additive effect on birth weight was +334g.^ The total GWG effect had most impact from 180 to 200 days gestation when there was a separation between the different GWG clusters. By identifying this relationship between GWG, growth and birth weight, we may now have time potential to influence weight gain during pregnancy and so possibly prevent perinatal complications, improve the metabolic and vascular traits of the infant and possibly improve outcomes in future pregnancies.Since birthweight is the resultant of the fetal period, the aim of Chapter 5, was to increase knowledge on the intra-uterine development with regard to fetal body composition. This was prospectively monitored in a highly controlled glucose tolerant cohort of 126 mothers. GWG was regarded ‘excessive’ (e-GWG) if the revised-2009 IOM upper thresholds were crossed. If not, the GWG was considered non excessive GWG (ne-GWG).^ In the prepregnant obese group, the fetal liver size (LL) and the abdominal fat thickness (AFT) growth trajectory increased significantly compared to normal weight women. E-GWG positively correlated with the growth in fetal abdominal circumference , LL, subscapular fat thickness (SFT) and AFT as compared to the ne-GWG group. Birth outcomes were significantly different for weight, length and head circumference in the e-GWG group as compared to the ne-GWG. Obesity and e-GWG both positively affect adiposity during fetal and neonatal life, with e-GWG clearly affecting fetal size in general, which was confirmed by birth anthropometry. In the normoglycemic pregnant women, determinants of the fetal trunk (LL, SFT, AFT and AC) are potentially useful in the prediction of neonatal adiposity. Our longitudinal study determined early signs of fetal adiposity associated with maternal obesity and particularly e-GWG in normoglycemic women.^ Maternal high BMI correlated with fetal liver size and abdominal fat, where e-GWG additionally correlated with increased subscapular fat and abdominal circumference development. Furthermore, fetal adiposity emerged asnbsp;reflection of a nutritious environment in utero with effects detectable as early as 20 weeks. Especially the indicators of the fetal trunk (liver-length, AFT, SFT and AC) are discriminative of fetal adiposity and warrant further investigation as potential early predictors of neonatal adiposity.Given these results we correlated in Chapter 6 these measurements in 121, highly controlled glucose tolerant mothers, prospectively, with neonatal body composition indices: neonatal fat mass (NFM), ponderal index (PI) and birthweight. The mean NFM at birth was 11.0% (SD±3.4%), with a cut-off of 15% for the 90th percentile (P90). No association was found between the maternal body mass index (BMI) and NFM.^ However, children born to mothers who had an e-GWG had a significantly higher NFM (11.6%) as compared to the ne-GWG mothers (10.4%). Fetal measures were highly correlated with neonatal measurements. Fetal abdominal circumference (AC), liver length (LL), subscapular- and abdominal fat thickness, humerus and femur fat mass development correlated significantly with 90th NFM percentile. Fetal AFT did not correlate with the PI. In the normoglycemic woman, e-GWG was associated with an increased neonatal adiposity. The neonatal PI and high adiposity (>P90 NFM) were preceded by an increased development of fetal central- and peripheral fat mass parameters. The fetal abdominal tissue development (AC, LL), reflecting fetal central adiposity, correlated highly to the 90t

Choose an application

• Reference Manager
• EndNote
• RefWorks (Direct export to RefWorks)

Stem cells potential in regenerative medicine has gained attention in recent years. Stem cells obtained from different tissues retain the ability to self-renew and differentiate into several cell types. Amniotic fluid (AF) is a promising source of stem cells being accessible at routine amniocentesis whilst raising few ethical concerns . Not only for they have high proliferative capacity and they differentiate into cells from all the three germ layers not forming teratomas when injected in vivo.In the first part of this PhD project, a reproducible isolation protocol was established to derive monoclonal population of AFSC from amniocentesis samples collected between the 15th till the 22nd gestational week. Of the 120 colonies analysed all expressed the canonical mesenchymal stem cell markers and could differentiate into three mesenchymal lineages (adipogenic, osteogenic and chondrogenic). No link between morphology, marker expression and differentiation potential was observed, showing the heterogeneity of AFSC during development.In view of the clinical use of AFSC, effective cryopreservation of AFSC or fresh AF was investigated. Seven cryopreservation protocols were analysed in order to freeze AFSC and fresh AF. The best three protocols were also tested in a collaborating facility with no stem cell expertise proving their reproducibility. One of these applied the good manufacture practice (GMP)-legislation and so can be used in a clinical setting. Thawed stem cells retained their markers expression and differentiation potential.The second part of this PhD focused on the regenerative potential of AFSC, in particular in skeletal muscle and kidney regeneration. Our research group is interested in novel therapies for congenital diaphragmatic hernia (CDH). To tackle the issue of the diaphragmatic defect we investigated the myogenic potential of AFSC in vitro and in vivo. Since no myogenic precursor are found into the AF, AFSC were screened for pericyte markers in particular mesangioblast (Mab). Mab is a pericyte subpopulation founded in the skeletal muscle that can differentiated into myoblasts in vitro and in vivo. AFSC positively expressed pericyte markers and they were able to participate into the formation of new myotubes when cultivated with murine myogenic cells. In addition, AFSC showed a paracrine action on injured myotubes in a transwell assay. Specific growth factors and remodelling proteinase were modulated by AFSC. Same expression pattern was observed when AFSC were injected into an injured muscle with also a reduction in fibrosis process.Since the majority of AF during the second trimester is composed of foetal urine, characterisation of AFSC for renal markers was evaluated. Several AFSC populations showed renal-like characteristics with the expression of renal progenitor markers by qPCR, IF and flow cytometry. Renal-like AFSC were tested in an acute kidney injury (AKI) model and showed their renoprotective effect. When AFSC were genetically manipulated to over-express the therapeutic protein vascular endothelial growth factor (VEGF), this renoprotective effect was maximized. Moreover, we noticed an optimal therapeutic window as an exacerbation of the injury was observed when a high dose of VEGF-AFSC was administered.In conclusion this study has shown a reproducible isolation protocols to derive AFSC and suitable freezing procedures to store AFSC for future research and clinical applications. Moreover, our data suggest that a AFSc subtype with pericytic characteristics has the ability to modulate muscle regeneration in vitro and in vivo. Further to this, a monoclonal population of AFSC with renal-like characteristics were identified and showed renoprotective effect in AKI. This effect was increased when VEGF-AFSC were used, showing the possibility to use AFSC as a delivery of therapeutic protein.