Predictors and consequences of early growth trajectories in rural and urban Gambian infants; implications for chronic disease risk

The first 1000 days, running from conception to two-years of age, is well established as a critical window for growth, within which growth failure results in stunting and a range of associated health issues. It is also recognised as an important period for the programming of later disease risk. Low birth weight (LBW) - a marker of intrauterine growth restriction - has long been implicated as a predictor of later cardiometabolic susceptibility. More recently, early postnatal growth has been identified as playing an important role in this association. In particular, it seems that a combination of being born small and undergoing infant ‘catch-up growth’ predisposes to adverse adult metabolic outcomes.The precise pathways of, and mechanisms underpinning, these associations remain unclear. Studies making use of increasingly sophisticated methods of infant body composition assessment suggest programming of adiposity within the developmentally plastic first 1000 days to represent a plausible mediating link.Use of sophisticated methods for body composition assessment is still, however, limited in low- and middle-income country settings facing a burgeoning ‘double burden of malnutrition’ (DBM). The DBM is characterised by increasing adult overweight, obesity, and associated non-communicable diseases alongside persistently high rates of LBW and early growth faltering, manifested in stunting and wasting. Data are needed to inform strategies aiming to ensure adequate early growth whilst preventing later metabolic risk.The research presented in this thesis utilised data collected from two cohorts in The Gambia, West Africa. The first - the ‘HERO-G’ study - was a sample of mothers and infants residing in a rural subsistence agricultural community. The second - The ‘MILQ’ study - was a cohort of urban based, well-nourished mothers and infants. Both studies involved the collection of maternal anthropometry in pregnancy, detailed infant anthropometry at delivery, and repeated postnatal anthropometric and body composition assessment, by Air Displacement Plethysmography (ADP).First, the relationship was assessed between pre-conceptional (maternal pre-pregnancy BMI) and gestational (weight gain) determinants of infant size and body composition at birth and three months. Second, body composition in infancy, as assessed by ADP, was characterised and previously proposed anthropometric equations for the estimation of infant fat mass were validated against the ADP-derived data. Third, associations between statistically independent ‘conditional’ measures of weight and length gain within discrete windows of infancy and body composition at two years were assessed. Finally, growth and accompanying body composition of the two cohorts was compared in order to assess whether different patterns of growth between the two cohorts were apparent, and whether any such differences were accompanied by differences in infant body composition.Together, using data from two contrasting Gambian cohorts, the work presented in this Thesis draws novel insights into relationships between nutrition, growth, and body composition within the developmentally important first 1000 days. The findings are a particularly valuable contribution to the literature in that they are from a West African setting where data in this field is scarce.<br/

Industrial-Scale Manufacture of Oleosin 30G for Use as Contrast Agent in Echocardiography

In ultrasound sonography, microbubbles are used as contrasting agents to improve the effectiveness of ultrasound imaging. Monodisperse microbubbles are required to achieve the optimal image quality. In order to achieve a uniform size distribution, microbubbles are stabilized with surfactant molecules. One such molecule is Oleosin, an amphiphilic structural protein found in vascular plant oil bodies that contains one hydrophobic and two hydrophilic sections. Controlling the functionalization of microbubbles is a comprehensive and versatile process using recombinant technology to produce a genetically engineered form of Oleosin called Oleosin 30G. With the control of a microfluidic device, uniformly-sized and resonant microbubbles can be readily produced and stored in stable conditions up to one month. Currently, Oleosin microbubbles are limited to the lab-scale; however, through development of an integrated batch bioprocessing model, the overall product yield of Oleosin 30G can be increased to 7.39 kg/year to meet needs on the industrial-scale. An Oleosin-stabilized microbubble suspension as a contrast agent is in a strong position to take a competitive share of the current market, capitalizing on needs unmet by current market leader, Definity®. Based on market dynamics and process logistics, scaled-up production of Oleosin 30G for use as a contrast agent is expected to be both a useful and profitable venture

Patterns of injury and violence in Yaoundé Cameroon: an analysis of hospital data.

BackgroundInjuries are quickly becoming a leading cause of death globally, disproportionately affecting sub-Saharan Africa, where reports on the epidemiology of injuries are extremely limited. Reports on the patterns and frequency of injuries are available from Cameroon are also scarce. This study explores the patterns of trauma seen at the emergency ward of the busiest trauma center in Cameroon's capital city.Materials and methodsAdministrative records from January 1, 2007, through December 31, 2007, were retrospectively reviewed; information on age, gender, mechanism of injury, and outcome was abstracted for all trauma patients presenting to the emergency ward. Univariate analysis was performed to assess patterns of injuries in terms of mechanism, date, age, and gender. Bivariate analysis was used to explore potential relationships between demographic variables and mechanism of injury.ResultsA total of 6,234 injured people were seen at the Central Hospital of Yaoundé's emergency ward during the year 2007. Males comprised 71% of those injured, and the mean age of injured patients was 29 years (SD = 14.9). Nearly 60% of the injuries were due to road traffic accidents, 46% of which involved a pedestrian. Intentional injuries were the second most common mechanism of injury (22.5%), 55% of which involved unarmed assault. Patients injured in falls were more likely to be admitted to the hospital (p &lt; 0.001), whereas patients suffering intentional injuries and bites were less likely to be hospitalized (p &lt; 0.001). Males were significantly more likely to be admitted than females (p &lt; 0.001)DiscussionPatterns in terms of age, gender, and mechanism of injury are similar to reports from other countries from the same geographic region, but the magnitude of cases reported is high for a single institution in an African city the size of Yaoundé. As the burden of disease is predicted to increase dramatically in sub-Saharan Africa, immediate efforts in prevention and treatment in Cameroon are strongly warranted

Magnetic Hybrid-Materials

Externally tunable properties allow for new applications of suspensions of micro- and nanoparticles in sensors and actuators in technical and medical applications. By means of easy to generate and control magnetic fields, fluids inside of matrices are studied. This monnograph delivers the latest insigths into multi-scale modelling, manufacturing and application of those magnetic hybrid materials

A longitudinal study of the experiences and psychological well-being of Indian surrogates

Study question: What is the psychological well-being of Indian surrogates during and after the surrogacy pregnancy? Summary answer: Surrogates were similar to a matched group of expectant mothers on anxiety and stress. However, they scored higher on depression during and after pregnancy. What is known already: The recent ban on trans-national commercial surrogacy in India has led to urgent policy discussions regarding surrogacy. Whilst previous studies have reported the motivations and experiences of Indian surrogates no studies have systematically examined the psychological well-being of Indian surrogates, especially from a longitudinal perspective. Previous research has shown that Indian surrogates are motivated by financial payment and may face criticism from their family and community due to negative social stigma attached to surrogacy. Indian surrogates often recruited by agencies and mainly live together in a “surrogacy house.” Study design, size, duration: A longitudinal study was conducted comparing surrogates to a matched group of expectant mothers over two time points: (a) during pregnancy (Phase1: 50 surrogates, 70 expectant mothers) and (b) 4–6 months after delivery (Phase 2: 45 surrogates, 49 expectant mothers). The Surrogates were recruited from a fertility clinic in Mumbai and the matched comparison group was recruited from four public hospitals in Mumbai and Delhi. Data collection was completed over 2 years. Participants/materials, setting, methods: Surrogates and expectant mothers were aged between 23 and 36 years. All participants were from a low socio-economic background and had left school before 12–13 years of age. In-depth faceto-face semi-structured interviews and a psychological questionnaire assessing anxiety, stress and depression were administered in Hindi to both groups. Interviews took place in a private setting. Audio recordings of surrogate interviews were later translated and transcribed into English. Main results and the role of chance: Stress and anxiety levels did not significantly differ between the two groups for both phases of the study. For depression, surrogates were found to be significantly more depressed than expectant mothers at phase 1 (p = 0.012) and phase 2 (p = 0.017). Within the surrogacy group, stress and depression did not change during and after pregnancy. However, a non-significant trend was found showing that anxiety decreased after delivery (p = 0.086). No participants reported being coerced into surrogacy, however nearly all kept it a secret from their wider family and community and hence did not face criticism. Surrogates lived at the surrogate house for different durations. During pregnancy, 66% (N = 33/50) reported their experiences of the surrogate house as positive, 24% (N = 12/50) as negative and 10% (N = 5/50) as neutral. After delivery, most surrogates (66%, N = 30/45) reported their experiences of surrogacy to be positive, with the remainder viewing it as neutral (28%) or negative (4%). In addition, most (66%, N = 30/45) reported that they had felt “socially supported and loved” during the surrogacy arrangement by friends in the surrogate hostel, clinic staff or family. Most surrogates did not meet the intending parents (49%, N = 22/45) or the resultant child (75%, N = 34/45). Limitations, reasons for caution: Since the surrogates were recruited from only one clinic, the findings may not be representative of all Indian surrogates. Some were lost to follow-up which may have produced sampling bias. Wider implications of the findings: This is the first study to examine the psychological well-being of surrogates in India. This research is of relevance to current policy discussions in India regarding legislation on surrogacy. Moreover, the findings are of relevance to clinicians, counselors and other professionals involved in surrogacy. Trial registration number: N/A