Thesis (M.S.)--University of Michigan, 1991.

Thesis--Copenhagen. / Summary in Danish. Bibliography: p. 175-191.

Thesis (M.S.)--University of Michigan, 1989.

Thesis (MNutr (Interdisciplinary Health Sciences. Human Nutrition))--University of Stellenbosch, 2006. / INTRODUCTION: The objective of the study was to determine the prevalence of certain known risk factors for intra-uterine growth restriction (IUGR) in women who gave premature birth to growth-restricted infants at a large regional hospital (Kalafong) in the Gauteng province of South Africa and to investigate the possible associations between the presence of various risk factors and the severity of growth restriction found in these infants. METHOD: The study was designed as cross-sectional, descriptive and observational. The subjects included singleton growth-restricted premature infants (n=80), without congenital abnormalities and their mothers (n=80). Anthropometric data [weight, height, mid-upper arm circumference (MUAC) and triceps skinfold thickness (TSF)] were collected from these mothers three to four days post-partum. Infant birth weights were recorded at birth, while the lengths and head circumferences were recorded within 2 days post-partum. Additional information, such as birth spacing, maternal age, smoking habits and alcohol use, was collected by personal interview and blood pressure data and HIV status was obtained from medical records. Data capturing and descriptive statistics were done using Microsoft Excel and comparative analytical statistics were performed with the Statistical Package for the Social Sciences (SPSS), version 12.0. RESULTS: The study demonstrated a high prevalence (69%) of infants born with a birth weight <3rd percentile. In the sample, 81% of the mothers were aged 17-34 years and most (93%) had their children 18 months or longer apart. Malnutrition prevalence was moderate. In 58% of the mothers the BMI was normal (18.5-24.9 kg/m2) and in 47% the upper arm muscle area (UAMA) was between the 10th-85th percentile. Grade III overweight occurred in 3% and TSF ≤5th percentile occurred in 35% of the mothers. About half (51%) of the mothers in the sample population had hypertension during the second trimester of pregnancy. Smoking and alcohol use during pregnancy was rare (1% and 6% respectively) and the prevalence of HIV infection in the mothers was 26%. The prevalence (16%) of Grade II overweight among the mothers of symmetric growth-restricted (SGR) infants was higher than among the mothers of asymmetric growth-restricted (AGR) infants (7%). Of the hypertensive mothers, 55% had infants with SGR compared to 45% with AGR (p=0.47). Although rare, smoking occurred only in mothers with AGR infants (3%). No significant differences were found between the smoking and non-smoking group (p=0.21). Although the use of alcohol was more prevalent at 6% in mothers with SGA infants and 7% in mothers with AGR infants, no significant associations were found (p=0.95). Although not significant (p=0.76), there was a higher prevalence of HIV infection in mothers with SGR infants at 29%, compared to 23% of mothers of AGR infants. CONCLUSION: Although further studies are needed before intervention strategies can be planned and implemented, the findings of this study suggest that apart from the usual factors (maternal age and nutritional status, smoking and alcohol use during pregnancy and birth spacing) that may influence intra-uterine growth, hypertension may contribute greatly to IUGR in this study population.

Rapid and important cerebral developmental changes occur between the third trimester of gestation and the first postnatal months (Sidman and Rakic, 1982). Assessment of these changes in term and preterm infants is of great interest, as it provides insights into early brain development but also how early birth may affect normal brain development (Mewes et al. 2006).<p>Conventional brain magnetic resonance imaging (MRI) is a useful technique to provide structural information on brain development, and several studies have correlated brain structure modifications with specific learning or behavioral problems (Peterson et al. 2003, Woodward et al. 2005, Kapellou et al. 2006, Woodward et al. 2006). Nevertheless, this technique is not sensitive enough to evidence subtle microstructural changes. <p><p>Diffusion tensor imaging (DTI), which assesses and quantifies water diffusion in biological tissues at a microstructural level, may provide unique clues to the structure and geometric organization of the cerebral tissues (Le Bihan et al. 2001). DTI takes advantage of the fact that, in the brain, water molecules diffuse more easily in the direction of the fibers than orthogonally to study cortex and white matter (WM). DTI indices like fractional anisotropy (FA), which expresses the fraction of the magnitude of the diffusion tensor attributable to anisotropic diffusion, mean diffusivity (MD), which corresponds to the directionally averaged magnitude of water diffusion, and longitudinal and transverse diffusivity (λ// and λ⊥), which express respectively the parallel and perpendicular diffusion of water molecules, are used to indirectly quantify brain microstructure and evaluate brain damage (Hüppi et al. 1998, Miller et al. 2002, Ment et al. 2009, Liu et al. 2012). <p><p>Most previously published studies in neonates limited their analysis to particular zones of the WM, using regions of interest (ROI) to select regions where DTI values are expected to change. Approaches on the basis of ROIs have well-known limitations because strong a priori hypotheses about localization and extent of the effects of interest have to be made (Giuliani et al. 2005). Voxel-based methods of neuroimaging data analysis, such as statistical parametric mapping (SPM), do not have such limitations and have been successfully applied to study age-related DTI changes in adults, DTI differences between preterm and infants at term equivalent age, and brain structural asymmetries in infants (Ashtari et al. 2007, Snook et al. 2007, Gimenez et al. 2008, Dubois et al. 2010).<p>Studies correlating DTI indices at term equivalent age with later neurodevelopment are scarce and their analysis is limited to the WM, without exploring the cortex (Arzoumanian et al. 2003). Moreover, they use neuropsychological testing where language evaluation is combined with cognitive and motor scales to give an overall cognitive score (Krishnan et al. 2007, Rose et al. 2007, Rose et al. 2009).<p>The aims of this work were, using a voxel-based analysis of DTI sequences, 1) to evidence new brain regions that experience microstructural modifications along post-menstrual age (PMA) during early development of the human brain, and 2) to correlate regional brain microstructure at term equivalent age with subsequent cognitive, motor and language development at two years corrected age in a population of preterm infants.<p>We first investigated DTI changes in a population of 22 healthy preterm and 6 term infants covering the life period between 34 and 41 weeks PMA, and found that, besides the already-evidenced FA increase in the corticospinal tract (CST) and callosal radiations, the thalami and the thalamic radiations experienced linear microstructural changes. These changes were interpreted as a marker of regression of cytoplasmic arborization and proliferation of immature oligodendrocytes that wrapped around the axons well before the appearance of myelin (Aeby et al. 2009). Then we looked for nonlinear DTI changes, considering that many of biological processes that occur during development follow a nonlinear course. This yielded negative results, probably due to the small sample size. Therefore, in a second study, we searched for regional linear and nonlinear microstructural changes with PMA throughout the brain in a larger population (65 patients) composed exclusively of preterm neonates scanned between 35 and 43 weeks PMA. This study confirmed the linear FA changes with age previously described and, more importantly, evidenced nonlinear changes in brain structures around the right posterior superior temporal sulcus (STS) and in the right lateral occipitotemporal gyrus (LOTG), with FA decrease between 34 and 39 weeks followed by FA increase from 40 weeks to 43 weeks. The right STS belongs to the speech-processing network and is implicated in prosody but also in inter-individual communicative behavior and face processings in close association with the right LOTG. We suggest that the microstructural modifications in brain structures around the right STS and in the LOTG observed between 35 and 43 weeks of gestation in preterm infants could contribute to the functional maturation of these brain regions with increasing age, in a period of life where voices, prosody and faces represent extremely salient stimuli (Aeby et al. 2012).<p>In the second part of the thesis, we tested the hypothesis that abnormal local brain microstructure of preterm infants at term equivalent age would affect neurodevelopmental abilities at age 2 years. Therefore, we searched throughout the whole brain to correlate changes of the Bayley-III scores (cognitive, motor and language composite scores) with the regional distribution of MD, FA, λ// and λ⊥. We found that language abilities are negatively correlated to MD, λ// and λ⊥ in the left superior temporal gyrus (STG) in preterm infants. These findings suggest that higher MD, λ// and λ⊥ values at term- equivalent age in the left STG are associated with poorer language scores in later childhood. Consequently, this highlights the key role of the left STG for the development of language abilities in children and suggests that brain DTI might be an interesting tool to assess on an individual basis the development of language in the preterm.<p><p>To sum up, in this thesis, we showed that, besides the already-evidenced FA increase in the CST and corpus callosum, the thalami and the thalamic radiations experience linear microstructural changes in the early development of the human brain. We further showed that FA changes nonlinearly with age in brain structures around the right STS and in the right LOTG, which are key regions in verbal and non-verbal communicative behavior. We also showed that voxel-based DTI analysis is able to evidence microstructural changes in the lSTG that are negatively correlated with language development at two years in the preterm at the group level. These results highlight the key role of the lSTG in the development of language in the preterm and suggest that brain DTI might be an interesting tool to predict the development of language on an individual basis.<p> / Doctorat en Sciences médicales / info:eu-repo/semantics/nonPublished

Very low birth weight and extremely low birth weight neonates have tremendous risk of mortality. This is a grave concern; however, survival alone is not the goal of neonatal intensive care. Survival, along with a reduction or elimination of life long morbidity is the aim of neonatal intensive care. Human milk is known as the best nutrition for babies and a growing body of evidence supports that human milk is critical in helping these fragile neonates mitigate the overwhelming risks they face. Therefore, the purpose of this study was to examine the relationship between neonatal severity of illness and human milk, specifically mothers own milk (MOM), donor human milk (DHM), and total human milk (THM) intake in very low birth weight (VLBW) and extremely low birth weight (ELBW) infants over the first six weeks of life. Although there is a growing body of evidence that supports the use of human milk in this fragile neonatal population, information is lacking about the relationship between human milk and neonatal illness severity. The current study was a secondary data analysis from a National Institutes of Health (NIH) funded R21 study in a level three NICU in Florida. Multilevel modeling was used for data analysis to examine relationships between maternal dyad characteristics and severity of illness, operationalized by the Score for Neonatal Acute Physiology-II (SNAP-II), at 12 hours of life and at the end of each week of life for six weeks. Growth models (linear, quadratic, piecewise) were examined to determine the best model fit for the data, then predictor variables were added and model fit was tested. Birth weight was added to final models as a control as it is seen as a proxy for severity of illness in the literature. Model six demonstrated a significant inverse relationship between MOM(mL) (γMOM(mL)) = -.000079, p < .05) and SNAP-II scores (Deviance = 287.862, Δχ2(df) = 31.38(1), p < .001, AIC = 303.862, BIC = 336.930). Model 11 demonstrated a significant inverse relationship between THM(mL) (γTHM(mL) = -.000127, p < .001) and SNAP-II scores (Deviance = 279.280, Δχ2(df) = 30.859(1), p < .001, AIC = 295.280, BIC = 328.347). No relationships were noted between severity of illness and DHM(mL), MOM(%), DHM(%), or THM(%). Therefore the relationships noted between MOM(mL) and THM(mL) and neonatal severity of illness should be interpreted with caution.

Proteomics is the global study of proteins in an organism or a tissue/fluid and is clinically relevant since most disease states are accompanied by specific alterations in an organism's proteome. This review focuses on the application of proteomics to neonatology with particular emphasis on retinopathy of prematurity (ROP), which is a disease in which oxidative stress plays a key pathophysiological role. Oxidative stress is a physiologically relevant redox imbalance caused by an excess of reactive oxygen (ROS) or reactive nitrogen oxide species (RNOS). A major conclusion of this review is that proteomics may be the optimal technology for studying neonatal diseases such as ROP, particularly in the setting of a neonatal intensive care unit (NICU). Proteomics has already identified a number of ROP serum biomarkers. This review will also suggest novel therapeutic approaches to ROP and other neonatal oxidative stress diseases (NOSDs) based on a systems medicine approach.

No description available.

Thesis (M. (Nursing)) -- University of Limpopo, 2022 / Background Despite all the interventions that have been developed previously preterm labour remain to be the leading cause of perinatal morbidity and mortality worldwide. Preterm labour occurs before 37 weeks of gestation under two obstetric circumstances namely, ‗spontaneous preterm labour‘ and ‗indicated preterm labour‘. The aim of the study was to develop the strategies to enhance prevention of preterm labour in selected hospitals in Capricorn District, Limpopo Province. Research Method A sequential explanatory mixed method was adopted, the study was conducted in three phases, namely, quantitative study, qualitative study, and development of strategies. Self-developed questionnaires with 50 item questions each for mothers and registered midwives were administered. Both questionnaires were pre-tested prior to being administered to the respondents of the main study. The sample size of mothers was 77 mothers and 62 registered midwives. Data collected from the respondents were analysed using Statistical Package for Social Science (SPSS) version 25 with the help of the statistician. Tables, pie charts and bar graphs were drawn to present the results. The results of quantitative phase were utilized to formulate the Interview Guides that were used to explore the knowledge and practise of registered midwives and obstetricians regarding preterm labour. Interviews were conducted with 20 mothers, 6 registered midwives and 4 obstetricians until data saturation was reached. Data were analysed qualitatively using Tesch‘s Open-Coding method. v Quantitative Results The quantitative results for midwives revealed that about 60% of the mothers who had preterm labour were teenagers. Most of the respondents had ‗spontaneous preterm labour‘ and did not have any comorbidities while few had ‗indicated preterm labour‘ and were induced. All 62(100%) of the midwives showed that the facility does not offer an Outreach Programme on the prevention of preterm labour. Themes and Sub-Themes Results Themes and sub-themes were coded manually. Results that emerged from the integration and comparison of quantitative and qualitative results revealed that the mothers who went into preterm labour spontaneously had little information or no health education regarding preterm labour. Developed strategies The following strategies were developed based on the identified factors that might hinders the prevention of preterm labour and after exploring the knowledge and practice of midwives and obstetricians in the selected hospitals, Capricorn District, Limpopo Province. Strategies includes strengthening of BANC Plus, staff establishment, laboratory turnaround time, outreach programmes and improvement of counselling and support services. Recommendations of the Study The recommendation of the study is divided into three groups which includes recommendations for midwives at the PHC and hospital, recommendations for the obstetricians at the hospital and the recommendations for the Department of Health. The midwives to visit schools and community centres at least twice in a month to give information to the woman of childbearing age and reinforce health education on each Antenatal Care visit. The obstetricians to screen all mothers who are at risk of preterm labour for infections, follow up the results and treat the mothers accordingly. The Department of Health should hire enough staff so that quality care can be vi rendered to the pregnant woman at the PHC and hospital. The Department of Health should develop the electronic database, to register all mothers who have a history of preterm labour, so that when they are pregnant the database system will also help to identify them at the PHC, and they would then be referred to the hospital in time. If the developed strategies to enhance prevention of preterm labour may be adopted and adhered to by the midwives and obstetricians, these may help in reduction of high figures of preterm labour in the selected hospitals.

Preterm birth (PTB), defined as birth before 37 weeks of gestation, is the leading cause of neonatal morbidity, and survivors can face lifelong medical difficulties. PTB remains a clinical challenge worldwide, with rates of PTB rising in all countries with reliable data. A lack in understanding of the mechanisms that lead to PTB has made developing diagnostics and therapeutics challenging, and existing ones are often ineffective. For a successful pregnancy, the major reproductive organs and surrounding tissues must sustain the growing loads of pregnancy. The cervix is one of these major reproductive organs. The cervix sits at the base of the uterus and has a versatile mechanical function in pregnancy. First, it must stay closed during gestation while the fetus develops; second, the cervix must remodel sufficiently and timely to dilate and allow delivery. The proper timing and extent of remodeling are critical for a healthy pregnancy. Improper cervical remodeling is a final common pathway to PTB and is the tissue of focus in this thesis. To improve our ability to identify when a PTB birth will occur and ultimately be able to treat those at risk, this thesis will identify the mechanical role of three extracellular matrix (ECM) components at various gestational ages and evaluate the ability of two major hormones to alter cervix function. Using experimental techniques (large-deformation tensile testing, digital-image correlation, imaging, biochemical) and theoretical and computational techniques (constitutive modeling, finite element analysis), the mechanical behavior of whole mouse cervices will be characterized in wild type, genetic knockout, and hormone-treated animals. First, the loss of both Class-I small leucine rich proteoglycans (SLRPs), decorin and biglycan, is detrimental to cervix function in late gestation. When the cervix should be most compliant and extensible, cervices without decorin and biglycan cannot stretch and are as stiff as the nonpregnant cervix. The loss of these proteoglycans also slows the cervix’s stress dissipation mechanism in late gestation, which could put the cervix at increased risk for damage. The mechanism of stiffening and lost viscoelasticity indicates the fibril crosslinking associated with SLRPs is a structural mechanism of the ECM contributing to cervical remodeling. Second, the loss of hyaluronic acid diminishes the cervix’s mechanical function at every gestational age tested. For nonpregnant to mid-gestational age, the cervix is softer than normal. Though by late gestation, the loss of hyaluronic acid stiffens the cervix; this is at a point when the cervix should be at its softest. The loss of hyaluronic acid also decreases the cervix’s protective stress dissipation mechanism in late gestation. There is limited knowledge of the interaction of collagen, elastic fibers, and hyaluronic acid in the cervix. The significant mechanical role of hyaluronic acid in the cervix warrants exploration of the structural mechanisms of these functional changes. Third, the loss of endogenous hormones stiffens the tissue and increases extensibility compared to the nonpregnant cervix. The administration of estrogen recovers large amounts of extensibility (beyond the stretch level of a late gestation cervix), stiffens the tissue (such that it is stiffer than a nonpregnant cervix), and recovers a significant amount of cervix strength. Fourth, relaxin increases cervix extensibility in mid-gestation and endows the cervix with viscoelastic ability in late gestation. Altogether, understanding the correlation between these extracellular matrix components, hormones, and functional changes of the cervix is fundamental to teasing out mechanisms of cervical remodeling and developing improved PTB diagnostics and therapeutics.