Growth retardation in King salmon Oncorhynchus tshawytscha (Walbaum) is a common and significant problem affecting marine farming operations in New Zealand. While the basic marine culture requirements for the King salmon species are well understood, the etiology of seawater adaptation and growth retardation remains understudied. Consequently, this study was established to investigate the physiological state and causative factors of growth retardation in collaboration with a leading New Zealand aquaculture company, New Zealand King Salmon Ltd (NZKS). Hypoosmoregulatory indicators are not currently used by marine farmers in New Zealand due to the belief that King salmon are more adaptable to seawater than their more highly cultured counterparts, Coho and Atlantic, and can be transferred to seawater anytime after a critical weight is achieved. This study sought to investigate changes in hypoosmoregulatory ability and its relation to water temperatures commonly used in the hatchery environment. This was determined by changes in the activity of the predominating seawater-adapting gill enzyme Na+/K+-ATPase, as an indirect measure of its abundance during smoltification. Changes in plasma ion profiles and the ability to regulate ions after abrupt transfer were also measured and compared with enzymatic activity throughout the austral springtime smoltification period in commercial strains of under-yearling King salmon. It was found that King salmon do undergo a distinct austral spring-time temporal increase in hypoosmoregulatory processes. This was characterised by a 2-fold increase Na+/K+-ATPase activity which was concomitant with reduced plasma Na+ in freshwater and following a seawater challenge in fish between fork lengths of 140-160 mm. Despite no consistent reduction in Na±/K+-ATPase activity during desmoltification, it was shown that the percent of ATP dependent activity specific to Na+/K+-ATPase diminished over time. Increased residual ATP dependent activity is hypothesised to be a result of apical H+-VATPase activity as a compensatory mechanism to rapidly normalise plasma Na+ during desmoltification concomitant with elevated basolateral Na+/K+-ATPase. Water temperature has been linked with the advancement and shortening of the smoltification period in several species. Gill Na+/K+-ATPase activity and hypoosmoregulatory ability in King salmon were negatively affected by increasing water temperatures above 12°C in contrast to a constant 12°C. The level of growth retardation was dependent on the time of transfer to seawater and was found to increase during a period of reducing hypoosmoregulatory ability. The transfer of growth retarded King salmon back to freshwater resulted in a complete reversal of the growth retarded state, comparable to that observed in Coho and Atlantic salmon. Growth retarded fish were able to readapt back to freshwater with higher survival and growth rates compared to the transfer of normal growing sub-adult King salmon, strongly demonstrating that growth retarded fish are more adapted to freshwater. Osmoregulatory physiology, and endocrinology during the transfer of growth retarded and normal growing fish were investigated. Overall, these results have fundamental implications for the aquaculture of King salmon that are able to be applied by industry to improve current husbandry practices.

Diss. (sammanfattning) Stockholm : Karol. inst., 2003. / Härtill 5 uppsatser.

Thesis (Ph.D.)--University of Adelaide, Dept. of Obstetrics and Gynaecology, 1999? / Bibliography: p. 190-234.

Thesis (M. Phil.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 182-187) Also available in print.

M.Tech. (Radiography) / Monitoring the growth and wellbeing of the foetus is a major purpose of antenatal care. The use of diagnostic ultrasound to assess foetal wellbeing has become an important part of prenatal care in both low and high risk pregnancies. Pre-eclampsia and foetal growth restriction (FGR) remains important causes of maternal and perinatal mortality and morbidity. Pre-eclampsia is characterised by an abnormal vascular response to placentation and is a multisystem disorder of unknown cause specific to pregnancy which affects the health of both mother and fetus. Prep-eclampsia complicates between 2 and B % of all pregnancies and is the second most common cause of maternal deaths in the developing world. The aim of this study was to assess the sensitivity of uterine artery spectral Doppler screening in the prediction of pregnancies with a high risk of developing pre-eclampsia or FGR before the clinical onset of the disease. The research objectives were to: 1) Determine the sensitivity of first and second trimester uterine artery spectral Doppler assessment in predicting pre-eclampsia or FGR Identify associations between normal and abnormal uterine artery Doppler waveforms and pregnancy outcomes. 2) Determine the most effective Doppler indices 3) Develop ultrasound management guidelines The data was statistically analyzed to determine the sensitivity of uterine artery Doppler screening. In this study uterine artery Doppler screening performed well. in the risk assessment of the most severe cases of pre-eclampsia and FGR. A larger prospective multicenter trial in South Africa is long overdue and therefore a follow-up study to assess Doppler as a screening tool in a high risk population, as per the guidelines formulated.

Diss. (sammanfattning) Stockholm : Karol. inst., 2002. / Härtill 5 uppsatser.

Diss. (sammanfattning) Linköping : Linköpings universitet, 2007. / Härtill 4 uppsatser.

Objectif : Établir le profil psychosocial des femmes enceintes de l'Estrie et évaluer de façon préliminaire si ce profil diffère parmi les grossesses avec issues défavorables. Méthode. Cohorte prospective de 120 femmes enceintes, rencontrées à deux reprises (10-20 et 25-30 semaines), entre août 2004 et mars 2006. Il s'agit d'un questionnaire auto-administré des données démographiques, anthropométriques, des facteurs de risques biomédicaux, ainsi qu'un profil psychosocial comportant 6 dimensions: stress psychologique perçu, ennuis quotidiens, détresse psychologique, locus de contrôle, soutien social, traumatismes dans l'enfance. Les paramètres psychosociaux sont présentés en moyennes ou pourcentages. Le profil psychosocial est comparé entre les grossesses normales et anormales avec les tests t de Student ou le test de Mann Whitney, lorsque approprié. Résultats. Trente trois grossesses (27,5%) ont présenté des issues défavorables (prématurité, restriction de croissance intra-utérine, hypertension gestationnelle, diabète gestationnel). L'analyse du profil psychosocial révèle un score de stress psychologique perçu plus élevé entre 10-20 semaines chez les femmes avec issues défavorables de grossesse (score : 34,2 « 12,3 ; P < 0,01) et chez les femmes avec prématurité (score : 36,1 « 11,2 ; P < 0,02) comparativement à celui des femmes avec grossesses normales (score : 28,6 « 9,6). Par ailleurs, les 5 autres dimensions ne semblaient pas différentes selon les issues de grossesse. Conclusion. Ces résultats préliminaires suggèrent une piste possible reliant la perception de stress maternel durant la grossesse et certaines issues défavorables de grossesse, dont l'accouchement prématuré.

ABSTRACT Ethanol is a classic teratogen capable of inducing a wide range of developmental abnormalities that vary in severity, from the barely perceptible to spontaneous abortion. These defects are collectively referred to as foetal alcohol spectrum disorders (FASD). Foetal alcohol syndrome (FAS) lies at the extreme end of this spectrum and is associated with three broad domains: prenatal and/or postnatal growth retardation, distinctive facial features and brain damage. Epidemiological and animal studies clearly indicate that the clinical variability of FASD is related to four distinct window periods: preconception, preimplantation, gastrulation and postorganogenesis. These developmental windows are correlated with peak periods of epigenetic reprogramming, suggesting a common mechanism of ethanol teratogenesis. Together with experimental evidence that ethanol inhibits DNA-methyltransferase, as well as folate metabolism, this suggests an ‘epigenetic model of FASD’. The aim of the present study was to explore the validity of this model by investigating the relationship between ethanol-induced growth retardation and imprinting, following ethanol exposure during the preimplantation period. Employing an experimental study design, together with a hybrid mouse model, embryos and placentae were harvested at 10.5 days post coitus (dpc). The weights of embryos and placentae, as well as methylation profiles at the H19 imprinting control region (ICR) – an important regulator of growth - were measured. It was found that ethanol-treated embryos and placentae were severely growth retarded in comparison to controls: r=-0.760 (p<0.01, one-tailed) and r=-0.816 (p<0.05, two-tailed), respectively. Bisulphite genomic sequencing revealed that the methylation profile at the H19 ICR was unaffected in ethanol-treated embryos, in comparison to saline-treated controls. Conversely, methylation at the paternal and maternal alleles in placentae was found to be reduced and increased, respectively, in comparison to embryos. These results imply that mechanisms for the maintenance of imprinting in the embryo are more robust than in the placenta. This is consistent with the relatively longlived nature of the embryo, which must maintain imprinting for a considerably longer period of time than the placenta. Bisulphite sequencing also revealed that the paternal allele of the H19 ICR had significantly decreased levels of methylation, while the maternal allele had increased levels of methylation, in ethanol treated-placentae, in comparison to saline controls. The changes observed at the paternal allele were localized to the CTCF1 DNA-binding site, while a trend for increased methylation at the maternal allele was observed at the CTCF2 site. A partial correlation further revealed that demethylation at the paternal allele in placentae partly mediated the effect of ethanol on placental weight. An ‘epigenetic switch model’, whereby paternal Igf2 is downregulated by the epigenetic switching of the paternal allele to the maternal epigenotype, is proposed to explain this relationship. However, partial correlations also indicated that demethylation at the paternal allele of the H19 ICR, as well as placental growth retardation, did not mediate the effect of ethanol on embryo growth. Collectively, these data suggest that imprinting at the H19 ICR is not a mechanism of embryo growth retardation prior to 10.5 dpc. In explaining these results, it is proposed that the growth retarded placenta was able to meet the nutritional demands of the similarly growth retarded embryo up until 10.5 dpc. However, an important question for future research would be to examine the relationship between ethanol-induced growth retardation and imprinting during late gestation. During the final growth spurt (>14.5 dpc) the growth retarded placenta may become unable to meet the increased demands for nutrition, which would exacerbate foetal growth restriction. In sum, the present study revealed a novel mechanism of ethanol-induced growth retardation in the placenta but indicated that imprinting at the H19 ICR does not mediate the effect of ethanol on the early embryo. Further research is required to resolve the relationship between imprinting and ethanol-induced growth retardation.

O objetivo deste estudo foi comparar a morbidade e a mortalidade entre prematuros tardios (34 a 36 semanas e 6 dias de idade gestacional ao nascimento) com e sem restrição do crescimento fetal (RCF). O estudo foi desenvolvido longitudinalmente, envolvendo gestantes que apresentaram parto prematuro, sendo 50 com RCF (Grupo I) e 36, sem RCF (Grupo II), no período de outubro de 2004 a outubro de 2006. Foram avaliados os seguintes resultados pós-natais: peso e idade gestacional (IG) ao nascimento, cesárea, Apgar de quinto minuto, pH do sangue da artéria umbilical ao nascimento, necessidade e tempo de intubação orotraqueal (IOT) e de internação na unidade de terapia intensiva neonatal (UTI). Foram também avaliados: síndrome do desconforto respiratório (SDR), sepse, plaquetopenia, hipoglicemia, hemorragia intracraniana (HIC), icterícia e necessidade de fototerapia, tempo de internação e ocorrência de óbito. Para análise estatística foram utilizados os testes de Qui-Quadrado, exato de Fisher e teste não paramétrico de Kruskal Wallis, adotado nível de significância de 5%. As idades gestacionais avaliadas foram semelhantes nos dois grupos, com média de 35,5 semanas. Observou-se, no grupo I, maior freqüência dos seguintes resultados pós-natais adversos: menor peso ao nascimento (p<0,001), maior incidência de cesárea (92% versus 25% do grupo II; p<0,0001), maior necessidade de internação em UTI (58% versus 33%; p=0,041), maior tempo de internação (p<0,001) e de internação em UTI neonatal (p<0,001), maior ocorrência de HIC (12% versus 0; p=0,037), maior ocorrência de hipoglicemia (p= 24% versus 6%; 0,047) e maior tempo de fototerapia (p=0,005). Os grupos não apresentaram diferenças nos índices de Apgar, pH de cordão, IOT, SDR, plaquetopenia, sepse e icterícia. Não houve casos de doença de membrana hialina, displasia broncopulmonar, hemorragia pulmonar ou óbito neonatal. Pode-se concluir que o grupo de prematuros tardios com RCF apresentou mais complicações neonatais do que o grupo sem RCF / The objective of this study was to compare neonatal morbidity and mortality between late-preterm infants (gestational age at birth: 34 to 36 weeks and 6 days) with and without fetal growth restriction (FGR). A longitudinal study was conducted between October 2004 and October 2006 involving 50 pregnant women with pre-term delivery associated with FGR (group I) and 36 women with spontaneous preterm delivery not associated with FGR (group II). The following postnatal outcomes were evaluated: weight and gestational age at birth, cesarean section rate, 5-minute Apgar score, umbilical artery pH at birth, and need for and duration of orotracheal intubation and hospitalization in the neonatal intensive care unit (NICU), as well as the presence of respiratory distress syndrome (RDS), sepsis, thrombocytopenia, hypoglycemia, intracranial hemorrhage (ICH) and jaundice, need for phototherapy, length of hospital stay, and occurrence of death. The chi-square test, Fishers exact test and nonparametric Kruskal-Wallis test were used for statistical analysis, adopting a level of significance of 5%. Gestational age was similar in groups I and II, with a mean of 35.5 weeks in both groups. A higher frequency of the following adverse postnatal outcomes was observed in group I: lower birth weight (p<0.001), higher incidence of cesarean section (92% versus 25% in group II; p<0.0001), greater need for NICU treatment (58% versus 33%; p=0.041), longer hospital (p<0.001) and NICU stay (p<0.001), higher frequency of ICH (12% versus 0; p=0.037) and hypoglycemia (24% versus 6%; p=0.047), and longer duration of phototherapy (p=0.005). No differences in Apgar scores, cord pH, orotracheal intubation, RDS, thrombocytopenia, sepsis, or jaundice were observed between groups. There were no cases of hyaline membrane disease, bronchopulmonary dysplasia, pulmonary hemorrhage, or neonatal death. In conclusion, the group of late-preterm infants with FGR presented more neonatal complications than the group without FGR