PubMed HealthSearch

Biomedical subjects

P Owens

Publications and source records attributed to P Owens.

17 recordsLinked to original sources

Placental control of fetal growth.

The placenta exerts its effects on the growth of the fetus from the beginning of pregnancy via metabolic and endocrine mechanisms. To achieve this, the placenta exchanges a wide array of nutrients, endocrine signals, cytokines and growth factors with the mother and the fetus. These exchanges modulate or programme fetal growth and development. This review concentrates on the function and structure of the placenta in humans and in animals, and the effects of experimental perturbation of placental size and function on fetal growth. The consequences for fetal growth of varying the abundance of peptides or, by deleting genes, insulin-like growth factors or cytokines, are also described. Maternal nutritional and hormonal state from as early as the first few days after fertilization, can influence the growth rate of the placenta and the fetus and also the length of gestation. Influences on placental development and their consequences will clearly have an impact on the placental control of fetal growth. Variations in the maternal environment and consequent perturbation of the metabolic and endocrine environment of the placenta and fetus are implicated as being responsible for the associations between prenatal growth of the placenta and its fetus and the subsequent risk of adult disease. The next challenge will be to determine the dominant influences at each stage of fetal and placental growth.

Animals

Administering, documenting, and tracking blood products and volume expanders.

A quality improvement program designed to facilitate the administration, tracking, and documentation of blood products and volume expanders resulted in improved patient safety, improved efficiency, more accurate documentation, and enhanced resource management. Key to the success of the program were the Transfusion Administration Record, the blood product administration guide, and on-line transfusion history recording.

Blood Transfusion

Mood changes, obstetric experience and alterations in plasma cortisol, beta-endorphin and corticotrophin releasing hormone during pregnancy and the puerperium.

The relationships between mood change, obstetric experience and alterations in plasma cortisol, beta-endorphin (beta-EP) and corticotrophin-releasing hormone (CRH) were examined in a prospective study of 97 primiparous Australian women. Psychological measures were administered between the 28th week of pregnancy and the 3rd postnatal month, including the Profile of Mood States (POMS) and the Montgomery Asberg Depressive Rating Scale (MADRS). Blood samples were collected for cortisol, beta-EP and CRH assay on most of these occasions and during labour. Factor analysis was used to identify key subsets of psychological variables for use in the subsequent analyses. 'Mood disturbance' and 'tiredness' factors peaked at 38 weeks' gestation, while 'difficulty falling asleep' was greatest around the time of birth. Cortisol, beta-EP and CRH concentrations rose significantly as pregnancy advanced and peaked at birth; plasma CRH correlated with plasma cortisol (r = 0.54) and beta-EP (r = 0.32). Women with the highest 'mood disturbance' and MADRS depression scores at 28 weeks' gestation received significantly more pain relief during labour. Those women whose mood deteriorated from 38 weeks' gestation to postnatal day 2 had larger falls in plasma beta-EP after delivery (p less than 0.01) than those women whose mood improved or remained constant. Women in this mood-deteriorated subgroup also had significantly higher MADRS depression scores at 3 months (p less than 0.01). Mild antenatal depression (MADRS greater than 13) occurred in 5.2% of women and mild postnatal depression in 4.7%. Overall, these data suggest a role for circulating CRH in the regulation of maternal cortisol secretion and significant relationships between maternal postnatal mood states and beta-EP and between antenatal mood states and obstetric events.

Adult

Secretion of N-terminal pro-opiomelanocortin-derived peptides in response to acute haemorrhagic stress in conscious sheep.

To determine whether peptides derived from the N-terminus of the corticotropin/melanotropin/endorphin precursor, pro-opiomelanocortin, are released into blood in response to acute haemorrhagic stress, we examined the effect of haemorrhage on plasma concentrations of immunoreactive gamma 3-melanotropin, beta-endorphin and cortisol. Plasma concentrations of immunoreactive gamma 3-melanotropin (mean +/- SEM) increased within 30 min of haemorrhage from 71.1 +/- 10.4 to 106.8 +/- 6.3 fmol/mL (p less than 0.01) and plasma cortisol increased from 16.2 +/- 3.8 to 85.9 +/- 22.4 pmol/mL (p less than 0.025). The changes in plasma immunoreactive gamma 3-melanotropin and beta-endorphin were positively correlated (p less than 0.025). This study shows that peptides derived from the N-terminus of pro-opiomelanocortin are co-secreted with the C-terminal peptide beta-endorphin during acute haemorrhagic stress in sheep.

Animals

Peripartum concentrations of beta endorphin and cortisol and maternal mood states.

Nineteen women were studied before, during and after labour by assessment of their mood using a variety of psychological tests and by measurement of their plasma concentrations of beta-endorphin and cortisol. Beta-endorphin and cortisol concentrations rose markedly during labour and were influenced by the type of analgesia used. A deterioration in cognitive performance between days 2 and 4 postpartum correlated positively with the fall in beta-endorphin concentrations from those in labour to those on the fourth day postpartum. The women were more anxious and depressed at 38 weeks' gestation than on days 1-4 postpartum and the elevation of mood on day 2 postpartum correlated with a measure of depression 8 weeks later. It is postulated that the phenomenon of postpartum blues is a reaction to the euphoria of delivery which in turn is a response to endorphin release during labour. Whilst these changes may have a role in promoting maternal-infant attachment it is at the expense of maternal depression some weeks later.

Anxiety

Effect of a high energy, low carbohydrate diet on serum levels of lipids and lipoproteins.

The effect of a high energy, low carbohydrate (ketogenic) diet on serum levels of lipids and lipoproteins was studied in two normal individuals. A marked rise in serum levels of cholesterol and phospholipid occurred during the diet, but serum triglyceride levels remained within the normal range. High density lipoprotein cholesterol level did not change, and the rise in serum level of cholesterol levels with its distribution in lipoproteins, these observed changes pose a potential atherogenic risk. Serum lipid and lipoprotein levels reverted to normal on discontinuation of the diet. A modest weight loss observed during the diet was regained within 24 hours of the diet's cessation.

Adult

Quinoline and methylquinolines in cigarette smoke: comparative data and the effect of filtration.

A method has been developed to determine quantitatively quinoline, isoquinoline, and each of the methylquinoline isomers in cigarette smoke. This method was applied to the smoke of several different commercial cigarettes with and without filter tips. Quantitative analyses were accomplished by capillary gas chromatography, using a 50-m OV-101 fused silica capillary column and a 50-m Dexsil 300 fused silica column. Quinoline, isoquinoline and all seven of the methylquinolines were found in cigarette smoke. When cigarettes were analyzed with and without filter tips, these compounds were reduced by filtration, but not as much as tar was reduced. The significance of these data is discussed in view of the biological activity of specific isomers of these environmental pollutants.

Chromatography, Gas

Möbius and Möbius-like syndromes (TTV-OFM, OMLH).

There exists a spectrum of syndromes characterized by cranial nerve palsies, limb anomalies, and craniofacial malformations. Criteria based on type and severity of limb anomaly or presence or absence of cranial nerve palsy may alter the syndrome nomenclature due to a selection bias but do not appear to benefit syndrome delineation to any extent. Patients with seventh nerve palsy and abduction weakness are usually diagnosed as having Möbius syndrome by ophthalmologists. The observed ocular motility findings range from primarily abduction deficiencies to patients who have a Duane or gaze palsy pattern of horizontal movements. Some cases previously described as "sixth nerve and partial third" may better fall into one of the latter groups, since an isolated adduction deficit as a manifestation of third nerve involvement is rare. The presence of clinical appearance of Duane syndrome in these Möbius-type patients raises the possibility of abnormal innervation of the lateral rectus as an explanation of some patterns of motility observed.

Abducens Nerve

Aiming for the top.

Explore the source record for details and available documents.

Administrative Personnel