Papers by Deborah Sloboda
Journal of Endocrinology
Prenatal exposure to glucocorticoids is associated with alterations in fetal growth and endocrine... more Prenatal exposure to glucocorticoids is associated with alterations in fetal growth and endocrine function. However, few studies have examined the effects of clinically relevant doses of glucocorticoids on postnatal hypothalamic-pituitary-adrenal (HPA) function. To determine the effects of maternal or fetal betamethasone administration (0.5 mg/kg maternal or estimated fetal weight) on postnatal HPA function at 6 months and 1 year postnatal age, pregnant ewes were randomized into the following treatment groups: no treatment (n=6); maternal saline (n=6); single maternal betamethasone (M1) (n=6); repeated maternal betamethasone (M4) (n=6); fetal saline (n=5); single fetal betamethasone (n=6) and repeated fetal betamethasone (F4) (n=6). Single injections were given at 104 days of gestation and repeated injections at 104, 111, 118 and 125 days. Lambs were born spontaneously and the ACTH and cortisol responses to i.v. corticotropin-releasing hormone (CRH) (0.5 microg/kg) plus arginine vas...
Exploration of the use of ICT's to provide effective teaching and learning experiences is a key g... more Exploration of the use of ICT's to provide effective teaching and learning experiences is a key goal for Liggins Education Network for Science. Specifically, it is envisaged that ICT's may provide a mechanism by which students from a range of geographic locations could be brought together for seminars designed to provide learning extension opportunities, and simultaneously increase student awareness of the work of NZ scientists. Following a concept trial in 2007 using simple data conferencing technology, a further concept trial using either interactive satellite television or multicast technology was launched in 2008. The results of these trials have shown that the concept of bringing students from a wide range of schools together for advanced seminars linking NZ science directly to the NZ curriculum and NZ national assessments is well received by both students and teachers; that communication of concepts to the student is most effective when pre-seminar readings are written by teachers in consultation with scientists, and seminar presentation is shared by teacher and scientist; that scientists appreciate the opportunity to communicate in this way with secondary students; that satellite television technology with interactivity via wiki and on-line chat provided effective communication for participant schools from a wide range of geographic locations both rural and urban, independent of the level of broadband capability in the school. Finally the trials have shown that students in the remote audience had an equivalent learning experience to students in the live audience.
Journal of Endocrinology
Prenatal glucocorticoid exposure has been associated with a reduction in birth weight and postnat... more Prenatal glucocorticoid exposure has been associated with a reduction in birth weight and postnatal alterations in glucose homeostasis and hypothalamic-pituitary-adrenal (HPA) axis function. The mechanisms underlying these responses are unknown, although changes in fetal hepatic development may play an important role. The fetal liver produces key regulators of fuel metabolism and of the developing HPA axis that are altered by glucocorticoids. The local availability of glucocorticoids is regulated, in part, by corticosteroid-binding protein (CBG), glucocorticoid receptors (GR) and by the enzyme 11beta-hydroxysteroid dehydrogenase (11betaHSD), but the effects of maternal glucocorticoid administration on the expression of these genes in the fetal liver are unknown. 11betaHSD1 is the predominant form of this enzyme present in the liver and is responsible for the conversion of cortisone to cortisol. To determine if prenatal glucocorticoid exposure alters fetal hepatic regulation of CBG, ...
Background / Purpose: Maternal obesity results in obese offspring with metabolic and reproductive... more Background / Purpose: Maternal obesity results in obese offspring with metabolic and reproductive dysfunction. Taurine ameliorates adverse metabolic outcomes in offspring of protein-malnourished mothers and improves insulin sensitivity in diet-induced obesity. We hypothesised that supplementing a maternal obesogenic diet with taurine will reverse metabolic compromise in male offspring. Main conclusion: Taurine supplementation reduced maternal weight gain in late pregnancy and prevented elevations in TNF-alpha, glutamate and leptin but not HcY or insulin in obese dams. Taurine modified metabolic dysfunction in the offspring of obese mothers in the presence of a postnatal obesogenic diet.
Human Reproduction
Diagnosing polycystic ovary syndrome (PCOS) in adolescence is clinically challenging. The prevale... more Diagnosing polycystic ovary syndrome (PCOS) in adolescence is clinically challenging. The prevalence of clinical, ultrasound and biochemical features of PCOS in a community-based adolescent population using current diagnostic criteria has not previously been described. This was a prospective cohort study with 244 unselected post-menarchal girls, mean age 15.2 years, of whom 91% were Caucasian. Subjects were recruited from a large population-based birth cohort (the Raine cohort). Clinical hyperandrogenism (HA) was quantified using Ferriman-Gallwey scores. In the early follicular phase (Day 2-6), we measured circulating androgens and sex hormone-binding globulin by immunoassay, and ovarian morphology was assessed by transabdominal ultrasound examination. BMI and waist-hip ratio were measured. Normal ranges for early follicular phase androgens in adolescence were derived for this population. The top 5 and 10% of circulating free testosterone levels were 45.6 and 34.5 pmol/l, respective...
International journal of gynaecology and obstetrics: the official organ of the International Federation of Gynaecology and Obstetrics, Jan 31, 2015
To determine the effects of betamethasone on fetal growth and neonatal outcomes. A retrospective ... more To determine the effects of betamethasone on fetal growth and neonatal outcomes. A retrospective cohort study was performed of deliveries that occurred at Charité University Hospital Berlin, Germany, between January 1996 and December 2008. The betamethasone group included women with preterm labor and symptomatic contractions, cervical insufficiency, preterm premature rupture of membranes, or vaginal bleeding. Women in the control group were matched for gestational age at time of delivery and had not received betamethasone. Fetal growth changes and neonatal anthropometry were compared. Among 1799 newborns in the betamethasone group and 42 240 in the control group, betamethasone was associated with significantly lower birth weight (154g lower on average) after adjusting for confounders (e.g. hypertension, smoking, and maternal weight), sex, and gestational age at delivery (P<0.05). The higher the dose, the greater the difference in mean birth weight versus controls in births before...
The Journal of nutritional biochemistry, 2015
Excessive fructose consumption is associated with insulin resistance (IR) and nonalcoholic fatty ... more Excessive fructose consumption is associated with insulin resistance (IR) and nonalcoholic fatty liver disease (NAFLD), and high fructose intake during pregnancy can lead to compromised fetal development in the rat. Evidence suggests that the amino acid taurine can ameliorate fructose-induced IR and NAFLD in nonpregnant animals. This study investigated the efficacy of taurine supplementation on maternal fructose-induced metabolic dysfunction and neonatal health. Time-mated Wistar rats were randomized to four groups during pregnancy and lactation: (a) control diet (CON), (b) CON supplemented with 1.5% taurine in drinking water (CT), (c) CON supplemented with fructose solution (F) and (d) F supplemented with taurine (FT). Maternal and neonatal weights, plasma cytokines and hepatic gene expression were analyzed. Maternal hyperinsulinemia, increased homeostasis model assessment of IR indices and elevated proinflammatory cytokines were observed in F group and normalized in FT group. Mate...
Reproductive sciences (Thousand Oaks, Calif.), Jan 20, 2014
The effects of endogenous cortisol on binucleate cells (BNCs), which promote fetal growth, may be... more The effects of endogenous cortisol on binucleate cells (BNCs), which promote fetal growth, may be mediated by glucocorticoid receptors (GRs), and exposure to dexamethasone (DEX) in early pregnancy stages of placental development might modify this response. In this article, we have investigated the expression of GR as a determinant of these responses. Pregnant ewes carrying singleton fetuses (n = 119) were randomized to control (2 mL saline/ewe) or DEX-treated groups (intramuscular injections of 0.14 mg/kg ewe weight per 12 hours) at 40 to 41 days of gestation (dG). Placental tissue was collected at 50, 100, 125, and 140 dG. Total glucocorticoid receptor protein (GRt) was increased significantly by DEX at 50 and 125 dG in females only, but decreased in males at 125 dG as compared to controls. Glucocorticoid receptor α (GRα) protein was not changed after DEX treatment. Three BNC phenotypes were detected regarding GRα expression (++, +-, --), DEX increased the proportion of (++) and de...
American journal of physiology. Regulatory, integrative and comparative physiology, 2001
Our aim was to determine the postnatal effects of single and repeated glucocorticoid injections d... more Our aim was to determine the postnatal effects of single and repeated glucocorticoid injections during late gestation. Repeated (104, 111, 118, 125 days) or single (104 days) injections of betamethasone or saline were given to the ewe or by ultrasound guided injection to the fetus (term 150 days). Lambs were born spontaneously and studied at 3 and 6 mo and 1 yr of age. Arterial pressure was measured at each age, and we performed intravenous glucose tolerance tests at 6 mo and 1 yr. Repeated maternal, but not single maternal or fetal, betamethasone injections prolonged gestation, reduced weight at birth and 3 mo, and was associated with low arterial pressure at 3 mo but not at 6 mo and 1 yr. Glucose metabolism was altered in all betamethasone treatment groups, regardless of the number or route of injections. Our data demonstrate that glucocorticoid-induced fetal growth restriction is associated with a transient reduction in postnatal arterial pressure, but glucocorticoid exposure wit...
Journal of Nutrition and Metabolism, 2013
Objective. Offspring born to mothers either fed an obesogenic diet throughout their life or restr... more Objective. Offspring born to mothers either fed an obesogenic diet throughout their life or restricted to pregnancy and lactation demonstrate obesity, hyperinsulinemia, and hyperleptinemia, irrespective of their postweaning diet. We examined whether timing of a maternal obesogenic diet results in differential regulation of pancreatic adipoinsular and inflammatory signaling pathways in offspring. Methods. Female Wistar rats were randomized into 3 groups: (1) control (CONT): fed a control diet preconceptionally and during pregnancy and lactation; (2) maternal high fat (MHF): fed an HF diet throughout their life and during pregnancy and lactation; (3) pregnancy and lactation HF (PLHF): fed a control diet throughout life until mating, then HF diet during pregnancy and lactation. Male offspring were fed the control diet postweaning. Plasma and pancreatic tissue were collected, and mRNA concentrations of key factors regulating adipoinsular axis signaling were determined. Results. MHF and PLHF offspring exhibited increased adiposity and were hyperinsulinemic and hyperleptinemic compared to CONT. Despite a similar anthropometric phenotype, MHF and PLHF offspring exhibited distinctly different expression for key pancreatic genes, dependent upon maternal preconceptional nutritional background. Conclusions. These data suggest that despite using differential signaling pathways, obesity in offspring may be an adaptive outcome of early life exposure to HF during critical developmental windows.
BMC Research Notes, 2015
The key to understanding changes in gene expression levels using reverse transcription real-time ... more The key to understanding changes in gene expression levels using reverse transcription real-time quantitative polymerase chain reaction (RT-qPCR) relies on the ability to rationalize the technique using internal control genes (ICGs). However, the use of ICGs has become increasingly problematic given that any genes, including housekeeping genes, thought to be stable across different tissue types, ages and treatment protocols, can be regulated at transcriptomic level. Our interest in prenatal glucocorticoid (GC) effects on fetal growth has resulted in our investigation of suitable ICGs relevant in this model. The usefulness of RNA18S, ACTB, HPRT1, RPLP0, PPIA and TUBB as ICGs was analyzed according to effects of early dexamethasone (DEX) treatment, gender, and gestational age by two approaches: (1) the classical approach where raw (i.e., not normalized) RT-qPCR data of tested ICGs were statistically analyzed and the best ICG selected based on absence of any significant effect; (2) used of published algorithms. For the latter the geNorm Visual Basic application was mainly used, but data were also analyzed by Normfinder and Bestkeeper. In order to account for confounding effects on the geNorm analysis due to co-regulation among ICGs tested, network analysis was performed using Ingenuity Pathway Analysis software. The expression of RNA18S, the most abundant transcript, and correlation of ICGs with RNA18S, total RNA, and liver-specific genes were also performed to assess potential dilution effect of raw RT-qPCR data. The effect of the two approaches used to select the best ICG(s) was compared by normalization of NR3C1 (glucocorticoid receptor) mRNA expression, as an example for a target gene.
Early Life Origins of Human Health and Disease, 2009
Reproductive sciences (Thousand Oaks, Calif.), 2015
Glucocorticoid treatment given in late pregnancy in sheep resulted in altered placental developme... more Glucocorticoid treatment given in late pregnancy in sheep resulted in altered placental development and function. An imbalance of placental survival and apoptotic factors resulting in an increased rate of apoptosis may be involved. We have now investigated the effects of dexamethasone (DEX) in early pregnancy on binucleate cells (BNCs), placental apoptosis, and fetal sex as a determinant of these responses. Pregnant ewes carrying singleton fetuses (n = 105) were randomized to control (n = 56, 2 mL saline/ewe) or DEX treatment (n = 49, intramuscular injections of 0.14 mg/kg ewe weight per 12 hours over 48 hours) at 40 to 41 days of gestation (dG). Placentomes were collected at 50, 100, 125, and 140 dG. At 100 dG, DEX in females reduced BNC numbers, placental antiapoptotic (proliferating cell nuclear antigen), and increased proapoptotic factors (Bax, p53), associated with a temporarily decrease in fetal growth. At 125 dG, BNC numbers and apoptotic markers were restored to normal. In m...
table of contents † Introduction † Methods † Female reproductive development: overview † Early li... more table of contents † Introduction † Methods † Female reproductive development: overview † Early life events: associations with female puberty Early post-natal period Prenatal period Interaction between pre-and post-natal periods † Early life events and age at menopause † Early life events and polycystic ovarian syndrome Prenatal origins of PCOS: prenatal androgen hypothesis Prenatal origins of PCOS: adipose tissue expandability hypothesis † Effects of nutrition on female reproductive maturation and function Human studies Undernutrition and nutritional transitions Nutritional excess Animal studies † Early life events and reproductive maturation and function: a life history interpretation † Future research directions and hypotheses to be tested † Conclusion
Current Gerontology and Geriatrics Research, 2009
Life history theory proposes that early-life cues induce highly integrated responses in traits as... more Life history theory proposes that early-life cues induce highly integrated responses in traits associated with energy partitioning, maturation, reproduction, and aging such that the individual phenotype is adaptively more appropriate to the anticipated environment. Thus, maternal and/or neonatally derived nutritional or endocrine cues suggesting a threatening environment may favour early growth and reproduction over investment in tissue reserve and repair capacity. These may directly affect longevity, as well as prioritise insulin resistance and capacity for fat storage, thereby increasing susceptibility to metabolic dysfunction and obesity. These shifts in developmental trajectory are associated with long-term expression changes in specific genes, some of which may be underpinned by epigenetic processes. This normative process of developmental plasticity may prove to be maladaptive in human environments in transition towards low extrinsic mortality and energy-dense nutrition, leading to the development of an inappropriate phenotype with decreased potential for longevity and/or increased susceptibility to metabolic disease.
Zeitschrift für Geburtshilfe und Neonatologie, 2013
Journal of Obesity, 2014
The consumption of artificially sweetened processed foods, particularly high in fructose or high ... more The consumption of artificially sweetened processed foods, particularly high in fructose or high fructose corn syrup, has increased significantly in the past few decades. As such, interest into the long term outcomes of consuming high levels of fructose has increased significantly, particularly when the exposure is early in life. Epidemiological and experimental evidence has linked fructose consumption to the metabolic syndrome and associated comorbidities-implicating fructose as a potential factor in the obesity epidemic. Yet, despite the widespread consumption of fructose-containing foods and beverages and the rising incidence of maternal obesity, little attention has been paid to the possible adverse effects of maternal fructose consumption on the developing fetus and long term effects on offspring. In this paper we review studies investigating the effects of fructose intake on metabolic outcomes in both mother and offspring using human and experimental studies.
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Papers by Deborah Sloboda