Do improvements in clinical practice guidelines alter pregnancy outcomes in asthmatic women? A single-center retrospective cohort study

OBJECTIVE

Asthma occurs in ∼17% of Australian pregnancies and is associated with adverse perinatal outcomes, which worsen with poor asthma control . Consequently, the South Australian 'Asthma in Pregnancy' perinatal guidelines were revised in 2012 to address management according to severity. This study investigated if these revised guidelines reduced the impact of maternal asthma on risks of adverse perinatal outcomes before (Epoch 1, 2006-2011) and after the revision (Epoch 2, 2013-2018).

METHODS

Routinely collected perinatal and neonatal datasets from the Women's and Children's Hospital (Adelaide, Australia) were linked. Maternal asthma (prevalence:7.5%) was defined as asthma medication use or symptoms described to midwives. In imputation (n = 59131) and complete case datasets (n = 49594), analyses were conducted by inverse proportional weighting and multivariate logistic regression, accounting for confounders.

RESULTS

Overall, maternal asthma was associated with increased risks of any antenatal corticosteroid treatment for threatened preterm birth (aOR 1.319, 95% CI 1.078-1.614), any Caesarean section (aOR 1.196, 95% CI 1.059-1.351), Caesarean section without labor (aOR 1.241, 95% CI 1.067-1.444), intrauterine growth restriction (IUGR, aOR 1.285, 95% CI 1.026-1.61), and small for gestational age (aOR 1.324, 95% CI 1.136-1.542). After guideline revision, asthma-associated risks of any Caesarean section (p < 0.001), any antenatal corticosteroids (p = 0.041), and small for gestational age (p = 0.050), but not IUGR and Caesarean section without labour, were reduced.

CONCLUSIONS

Clinical practice guidelines based on the latest evidence do not guarantee clinical efficacy. Since adverse perinatal outcomes did not all improve, this work highlights the need to evaluate the ongoing impact of guidelines on clinical outcomes.

Maternal periconceptional and first trimester protein restriction in beef heifers: effects on placental parameters and fetal and neonatal calf development

Few studies have investigated the effects of nutrition during the periconception and early gestation periods on fetal and placental development in cattle. In this study, nulliparous yearling heifers (n=360) were individually fed a diet high or low in protein (HPeri and LPeri) beginning 60 days before conception. From 24 to 98 days after conception, half of each treatment group was changed to the alternative high- or low-protein diet (HPost and LPost) yielding four groups in a 2×2 factorial design. A subset of heifers (n=46) was necropsied at 98 days after conception and fetoplacental development assessed. Placentome number and volume decreased in response to LPeri and LPost diets respectively. Absolute lung, pancreas, septum and ventricle weights decreased in LPost versus HPost fetuses, whereas the post-conception diet altered absolute and relative liver and brain weights depending on sex. Similarly, changes in fetal hepatic gene expression of factors regulating growth, glucose output and lipid metabolism were induced by protein restriction in a sex-specific manner. At term, neonatal calf and placental measures were not different. Protein restriction of heifers during the periconception and early gestation periods alters fetoplacental development and hepatic gene expression. These changes may contribute to functional consequences for progeny, but this may not be apparent from gross morphometry at birth.

Spectrophotometric Determination of Roxarsone in Animal Feeds

Roxarsone is administered in the feed as a growth stimulant for chickens, turkeys, and swine. The drug is extracted with 2% dibasic potassium phosphate solution, the extract is centrifuged, the centrifugate is adjusted to the isoelectric point of proteins with hydrochloric acid, and the precipitated proteins are removed by centrifugation. Interferences are removed by treating the solution with activated charcoal at pH 12, which leaves a solution of roxarsone of intense color that can be measured spectrophotometrically at 410 nm. This method was subjected to a collaborative study. The average recovery from 13 collaborators was 99.25% with an average coefficient of variation of 6.91%. It is concluded that satisfactory results were reported and is therefore recommended that this method be adopted as official first action.

IUGR decreases cardiomyocyte endowment and alters cardiac metabolism in a sex- and cause-of-IUGR-specific manner

Intrauterine growth restriction (IUGR) increases the risk of ischemic heart disease in adulthood. Studies in rats suggest cardiac vulnerability is more pronounced in males and in offspring that were exposed to hypoxia in utero. Therefore, we aimed to test the hypotheses that 1) IUGR adolescent males, but not females, have fewer cardiomyocytes and altered expression of cardiometabolic genes compared with controls; and 2) IUGR due to hypoxia has a greater effect on these parameters compared with IUGR due to nutrient restriction. IUGR was induced in guinea pigs by maternal hypoxia (MH; 10% O₂, n = 9) or maternal nutrient restriction (MNR; ~30% reduction in food intake, n = 9) in the second half of pregnancy and compared with control ( n = 11). At 120 days of age, postmortem was performed and the left ventricle perfusion fixed for stereological determination of cardiomyocyte number or snap frozen to determine the abundance of cardiometabolic genes and proteins by quantitative RT-PCR and Western blotting, respectively. MH reduced the number of cardiomyocytes in female ( P < 0.05), but not male or MNR, adolescent offspring. Furthermore, IUGR males had decreased expression of genes responsible for fatty acid activation in the sarcoplasm ( FACS) and transport into the mitochondria ( AMPK-a₂ and ACC; P < 0.05) and females exposed to MH had increased activation/phosphorylation of AMP-activated protein kinase-α ( P < 0.05). We postulate that the changes in cardiomyocyte endowment and cardiac gene expression observed in the present study are a direct result of in utero programming, as offspring at this age did not suffer from obesity, hypertension, or left ventricular hypertrophy.

The early origins of obesity and insulin resistance: timing, programming and mechanisms

Maternal obesity is associated with an increased risk of developing gestational diabetes mellitus and it also results in an increased risk of giving birth to a large baby with increased fat mass. Furthermore, it is also contributes to an increased risk of obesity and insulin resistance in the offspring in childhood, adolescence and adult life. It has been proposed that exposure to maternal obesity may therefore result in an 'intergenerational cycle' of obesity and insulin resistance. There is significant interest in whether exposure to maternal obesity around the time of conception alone contributes directly to poor metabolic outcomes in the offspring and whether dieting in the obese mother before pregnancy or around the time of conception has metabolic benefits for the offspring. This review focusses on experimental and clinical studies that have investigated the specific impact of exposure to maternal obesity during the periconceptional period alone or extending beyond conception on adipogenesis, lipogenesis and on insulin signalling pathways in the fat, liver and muscle of the offspring. Findings from these studies highlight the need for a better evidence base for the development of dietary interventions in obese women before pregnancy and around the time of conception to maximize the metabolic benefits and minimize the metabolic costs for the next generation.

Effect of periconceptional nutrition on the growth, behaviour and survival of the neonatal lamb

Periconceptional nutrition (PCN) can influence foetal hypothalamo-pituitary adrenal (HPA) axis function and alter cortisol secretion with possible consequences for maturation and growth of major organs, gestation length and behaviour. We examined effects of PCN on phenotype and survival of the neonatal lamb in 466 Merino ewes allocated to treatments providing 70%, 100% and 150% respectively, of maintenance requirements for 17 days prior and 6 days after insemination. Gestation length and birth weight for lambs in PCN treatment groups was similar (P > 0.05) but low PCN decreased the size of the neonate (crown-rump-length and metacarpal length P < 0.05). A subset of lambs euthanased at 5 days of age further showed that low PCN decreased the amount of peri-renal fat (P < 0.05) and increased liver mass (P < 0.05) while high PCN increased neck thymus and ovary mass (P < 0.05). Neonatal lambs from low PCN ewes returned faster to their mothers after release (P < 0.05) and contacted the udder in the shortest time (P < 0.05). Significant interactions between PCN treatment and sex (P < 0.05) and between PCN treatment and ewe age (P < 0.05) were also observed for time lambs took to follow the ewe. Survival of lambs was similar but potential differences may have been masked by favourable weather conditions. In conclusion, this study provides evidence of significant changes in lamb growth and development dependent on PCN and, for the first time, links these changes with significant changes in behaviour of the neonate. The impact of these effects on lamb survival and potential reproductive capacity of female offspring remains to be determined.

The effect of placental restriction on insulin signaling and lipogenic pathways in omental adipose tissue in the postnatal lamb

Intrauterine growth restriction (IUGR) followed by accelerated growth after birth is associated with an increased risk of abdominal (visceral) obesity and insulin resistance in adult life. The aim of the present study was to determine the impact of IUGR on mRNA expression and protein abundance of insulin signaling molecules in one of the major visceral fat depots, the omental adipose depot. IUGR was induced by placental restriction, and samples of omental adipose tissue were collected from IUGR (n = 9, 5 males, 4 females) and Control (n = 14, 8 males, 6 females) neonatal lambs at 21 days of age. The mRNA expression of the insulin signaling molecules, AMP-kinase (AMPK) and adipogenic/lipogenic genes was determined by qRT-PCR, and protein abundance by Western Blotting. AMPKα2 mRNA expression was increased in male IUGR lambs (0.015 ± 0.002 v. 0.0075 ± 0.0009, P < 0.001). The proportion of the AMPK pool that was phosphorylated (%P-AMPK) was lower in IUGR lambs compared with Controls independent of sex (39 ± 9% v. 100 ± 18%, P < 0.001). The mRNA expression and protein abundance of insulin signaling proteins and adipogenic/lipogenic genes was not different between groups. Thus, IUGR is associated with sex-specific alterations in the mRNA expression of AMPKα2 and a reduction in the percentage of the total AMPK pool that is phosphorylated in the omental adipose tissue of neonatal lambs, before the onset of visceral obesity. These molecular changes would be expected to promote lipid accumulation in the omental adipose depot and may therefore contribute to the onset of visceral adiposity in IUGR animals later in life.

Early origins of heart disease: low birth weight and determinants of cardiomyocyte endowment

1. World-wide epidemiological and experimental animal studies demonstrate that adversity in fetal life, resulting in intrauterine growth restriction, programmes the offspring for a greater susceptibility to ischaemic heart disease and heart failure in adult life. 2. After cardiogenesis, cardiomyocyte endowment is determined by a range of hormones and signalling pathways that regulate cardiomyocyte proliferation, apoptosis and the timing of multinucleation/terminal differentiation. 3. The small fetus may have reduced cardiomyocyte endowment owing to the impact of a suboptimal intrauterine environment on the signalling pathways that regulate cardiomyocyte proliferation, apoptosis and the timing of terminal differentiation.

Microstructure evolution and photoluminescence in nanocrystalline Mg(x)Zn(1 - x)O thin films

The effects of Mg concentration and annealing temperature on the characteristics of nanocrystalline Mg(x)Zn(1 - x)O thin films (where x = 0-0.4) were studied using electron microscopy and photoluminescence. The films were prepared by a sol-gel method. The solid solubility limit of MgO in ZnO for the sol-gel-derived Mg(x)Zn(1 - x)O films in the present study was determined to be ∼ 20 at.%. Microstructural characterization of the films showed that the wurtzite crystallites decrease in size with increase in Mg concentration up to the solubility limit. Increasing Mg concentration beyond the solubility limit resulted in a decrease in crystallinity of the films. The bandgap energy was found to increase with Mg concentration whereas the linewidth first increased and then decreased when the Mg concentration was increased beyond the solubility limit. Photoluminescence properties have been correlated to the microstructure of the films. A growth mechanism for Mg(x)Zn(1 - x)O nanocrystalline films under the present processing conditions has also been proposed.

Maternal undernutrition alters fat cell size distribution, but not lipogenic gene expression, in the visceral fat of the late gestation guinea pig fetus

This study investigated the development of adipose tissue in the guinea pig and the impact of maternal undernutrition on the structural and functional characteristics of perirenal adipose tissue in the dam and fetus. Date-mated guinea pigs were provided with either ad libitum feed (Control, C) or 85% of food intake per body weight of the Controls (Undernutrition, UN). Maternal (C, n = 6; UN, n = 7) perirenal adipose tissue (PAT) was collected at 60 d gestation and fetal PAT was collected at 50 d (C, n = 4) and 60 d (C, n = 8 and UN, n = 7) gestation (term, 69 d). The expression of stearoyl-CoA desaturase (SCD-1), fatty acid synthase (FAS), lipoprotein lipase (LPL), leptin and glycerol 3 phosphate dehydrogenase (G3PDH) mRNA and glucose transporters 1 and 4 (GLUT1 and GLUT4) was determined by Real Time PCR. There was no effect of maternal UN on total or relative PAT mass in the pregnant dam. There was an increase in G3PDH, but not LPL, leptin, FAS or GLUT4 mRNA expression, in UN dams compared to Controls (P < 0.05). In the fetal guinea pig there was no effect of maternal UN on total or relative PAT mass, however, the UN fetuses had a higher percentage of larger lipid locules in their PAT compared to Controls (P < 0.05). The expression of FAS, LPL, SCD-1, leptin, G3PDH and GLUT4 mRNA in PAT was not different between the Control and UN fetuses. These results support previous studies which have demonstrated that maternal undernutrition is associated with an increased accumulation of visceral adipose tissue in utero, and extend them by showing that maternal undernutrition results in early changes in the size distribution of lipid locules in visceral fat depots that precede changes in lipogenic gene expression.

Rosiglitazone increases the expression of peroxisome proliferator-activated receptor-gamma target genes in adipose tissue, liver, and skeletal muscle in the sheep fetus in late gestation

Exposure to maternal overnutrition increases the expression of peroxisome proliferator-activated receptor-gamma (PPARgamma) in adipose tissue before birth, and it has been proposed that the precocial activation of PPARgamma target genes may lead to increased fat deposition in postnatal life. In this study, we determined the effect of intrafetal administration of a PPARgamma agonist, rosiglitazone, on PPARgamma target gene expression in fetal adipose tissue as well indirect actions of rosiglitazone on fetal liver and skeletal muscle. Osmotic pumps containing rosiglitazone (n = 7) or vehicle (15% ethanol, n = 7) were implanted into fetuses at 123-126 d gestation (term = 150 +/- 3 d gestation). At 137-141 d gestation, tissues were collected and mRNA expression of PPARgamma, lipoprotein lipase (LPL), adiponectin, and glycerol-3-phosphate dehydrogenase (G3PDH) in adipose tissue, PPARalpha and PPARgamma-coactivator 1alpha (PGC1alpha) in liver and muscle and phosphoenolpyruvate carboxykinase (PEPCK) in liver determined by quantitative real-time RT-PCR. Plasma insulin concentrations were lower in rosiglitazone-treated fetuses (P < 0.02). Rosiglitazone treatment resulted in increased expression of LPL and adiponectin mRNA (P < 0.01) in fetal adipose tissue. The expression of PPARalpha mRNA in liver (P < 0.05) and PGC1alpha mRNA (P < 0.02) in skeletal muscle were also increased by rosiglitazone treatment. Rosiglitazone treatment increased expression of PPARgamma target genes within fetal adipose tissue and also had direct or indirect actions on the fetal liver and muscle. The effects of activating PPARgamma in fetal adipose tissue mimic those induced by prenatal overnutrition, and it is therefore possible that activation of PPARgamma may be the initiating mechanism in the pathway from prenatal overnutrition to postnatal obesity.

The transition from fetal growth restriction to accelerated postnatal growth: a potential role for insulin signalling in skeletal muscle

A world-wide series of epidemiological and experimental studies have demonstrated that there is an association between being small at birth, accelerated growth in early postnatal life and the emergence of insulin resistance in adult life. The aim of this study was to investigate why accelerated growth occurs in postnatal life after in utero growth restriction. Samples of quadriceps muscle were collected at approximately 140 days gestation (term approximately 150 days gestation) from normally grown fetal lambs (Control, n = 7) and from growth restricted fetal lambs (placentally restricted: PR, n = 8) and from Control (n = 14) and PR (n = 9) lambs at 21 days after birth. The abundance of the insulin and IGF1 receptor protein was higher in the quadriceps muscle of the PR fetus, but there was a lower abundance of the insulin signalling molecule PKC, and GLUT4 protein in the PR group. At 21 days of postnatal age, insulin receptor abundance remained higher in the muscle of the PR lamb, and there was also an up-regulation of the insulin signalling molecules, PI3Kinase p85, Akt1 and Akt2 and of the GLUT4 protein in the PR group. Fetal growth restriction therefore results in an increased abundance of the insulin receptor in skeletal muscle, which persists after birth when it is associated with an upregulation of insulin signalling molecules and the glucose transporter, GLUT4. These data provide evidence that the origins of the accelerated growth experienced by the small baby after birth lie in the adaptive response of the growth restricted fetus to its low placental substrate supply.

No evidence for an enhanced role of endothelial nitric oxide in the maintenance of arterial blood pressure in the IUGR sheep fetus

The fetus makes a number of physiological adaptations to a restriction of placental substrate supply, including a decrease in body growth and an increase in peripheral vasoconstriction which maintains mean arterial pressure (MAP) and supports a redistribution of cardiac output to key fetal organs. It is not known, however, whether chronic restriction of placental substrate supply results in an enhanced or diminished role for vasodilators such as endothelial nitric oxide in the regulation of MAP. We hypothesised that there is an increased contribution of NO to blood pressure regulation in growth restricted fetuses and that a 2h infusion of a nitric oxide synthase inhibitor, N(omega)-nitro-l-arginine methyl ester (l-NAME) would result in an augmented rise in MAP in chronically hypoxemic, placentally restricted (PR, n=8) fetuses compared to controls (n=6) in late gestation. There was no difference in the increase in fetal MAP and decrease in HR during l-NAME infusion between Control and PR fetuses. In the PR group, fetuses with lower mean gestational PaO(2) had a lower increase in MAP during l-NAME infusion. Thus we have found no evidence for an enhanced role of NO in the maintenance of MAP in the chronically hypoxemic IUGR fetus.

Restriction of placental function alters heart development in the sheep fetus

Placental insufficiency, resulting in restriction of fetal substrate supply, is a major cause of intrauterine growth restriction (IUGR) and increased neonatal morbidity. Fetal adaptations to placental restriction maintain the growth of key organs, including the heart, but the impact of these adaptations on individual cardiomyocytes is unknown. Placental and hence fetal growth restriction was induced in fetal sheep by removing the majority of caruncles in the ewe before mating (placental restriction, PR). Vascular surgery was performed on 13 control and 11 PR fetuses at 110-125 days of gestation (term: 150 +/- 3 days). PR fetuses with a mean gestational Po(2) < 17 mmHg were defined as hypoxic. At postmortem (<135 or >135 days), fetal hearts were collected, and cardiomyocytes were isolated and fixed. Proliferating cardiomyocytes were counted by immunohistochemistry of Ki67 protein. Cardiomyocytes were stained with methylene blue to visualize the nuclei, and the proportion of mononucleated cells and length and width of cardiomyocytes were measured. PR resulted in chronic fetal hypoxia, IUGR, and elevated plasma cortisol concentrations. Although there was no difference in relative heart weights between control and PR fetuses, there was an increase in the proportion of mononucleated cardiomyocytes in PR fetuses. Whereas mononucleated and binucleated cardiomyocytes were smaller, the relative size of cardiomyocytes when expressed relative to heart weight was larger in PR compared with control fetuses. The increase in the relative proportion of mononucleated cardiomyocytes and the relative sparing of the growth of individual cardiomyocytes in the growth-restricted fetus are adaptations that may have long-term consequences for heart development in postnatal life.

Contractile and Ca2+-handling properties of the right ventricular papillary muscle in the late-gestation sheep fetus

The force-generating capacity of cardiomyocytes rapidly changes during gestation and early postnatal life coinciding with a transition in cardiomyocyte nucleation in both mice and rats. Changes in nucleation, in turn, appear to coincide with important changes in the excitation-contraction coupling architecture. However, it is not clear whether similar changes are observed in other mammals in which this transition occurs prenatally, such as sheep. Using small (70–300 μM diameter) chemically skinned cardiomyocyte bundles from the right ventricular papillary muscle of sheep fetuses at 126–132 and 137–140 days (d) gestational age (GA), we aimed to examine whether changes in cardiomyocyte nucleation during late gestation coincided with developmental changes in excitation-contraction coupling parameters (e.g., Ca2+uptake, Ca2+release, and force development). All experiments were conducted at room temperature (23 ± 1°C). We found that the proportion of mononucleate cardiomyocytes decreased significantly with GA (126–132d, 45.7 ± 4.7%, n = 7; 137–140d, 32.8 ± 1.6%, n = 6; P < 0.05). When we then examined force development between the two groups, there was no significant difference in either the maximal Ca2+-activated force (6.73 ± 1.54 mN/mm2, n = 14 vs. 6.55 ± 1.25 mN/mm2, n = 7, respectively) or the Ca2+sensitivity of the contractile apparatus (pCa at 50% maximum Ca2+-activated force: 126–132d, 6.17 ± 0.06, n = 14; 137–140d, 6.24 ± 0.08, n = 7). However, sarcoplasmic reticulum (SR) Ca2+uptake rates (but not Ca2+release) increased with GA ( P < 0.05). These data reveal that during late gestation in sheep when there is a major transition in cardiomyocyte nucleation, SR Ca2+uptake rates increase, which would influence total SR Ca2+content and force production.

Differential regulation of behavioral, genomic, and neuroendocrine responses by CRF infusions in rats

Studies suggest that behavioral, genomic, and endocrine functions mediated by central corticotropin-releasing factor (CRF)-containing circuits may be differentially regulated. However, this hypothesis has never been tested directly by simultaneous assessment of distinct CRF-mediated responses within the same animal. The present study addressed this issue by concurrently examining the effects of central CRF infusions on anxiety responses, plasma corticosterone release, and c-fos mRNA induction within limbic brain circuits. Bilateral intracerebroventricular (icv) infusions of CRF (0.1-10 microg total) dose-dependently reduced exploratory behavior in a novel open field, increased circulating corticosterone (CORT) levels and augmented c-fos mRNA expression in the central nucleus of the amygdala (CeA) and the hypothalamic paraventricular nucleus (PVN). Plasma CORT levels increased significantly after 0.1 microg CRF, whereas behavioral and genomic responses required at least 1 microg CRF, suggesting that the distinct responses mediated by CRF are differentially regulated. Further characterization of intracerebroventricular CRF at 1 microg also demonstrated a disruption of social interaction behavior. The majority of behavioral effects and the elevated c-fos mRNA expression were attenuated by 10 mg/kg DMP696, a CRF(1) antagonist. However, plasma CORT elevation required 30 mg/kg DMP696 for attenuation. Thus, our studies demonstrate a greater sensitivity of the hypothalamic-pituitary-adrenal axis to intracerebroventricular CRF compared with the induction of innate fear-like responses and associated genomic changes.

Eosinophilic "empyema" associated with crack cocaine use

Smoking of crystalline cocaine, known as "crack" cocaine, has been associated with eosinophilic pneumonitis, but not with pleural effusions. We describe a patient with eosinophilic pneumonitis with an eosinophilic "empyema" after using "crack" cocaine. The illness resolved with corticosteroids. We hypothesised that his effusion would have increased levels of eosinophil cytokines that promote oedema, and found a marked increase in pleural vascular endothelial growth factor (VEGF) and smaller increases in interleukins IL-5, IL-6, and IL-8. In the setting of "crack" use, we suggest that a pleural effusion that appears grossly to be pus should be evaluated for eosinophilic inflammation. Such eosinophilic effusions may respond to corticosteroids alone, consistent with a non-infectious process driven by proinflammatory cytokines.

Suppression of genioglossus muscle tone and activity during reflex hypercapnic stimulation by GABA(A) mechanisms at the hypoglossal motor nucleus in vivo

The genioglossus muscle is involved in the maintenance of an open airway for effective breathing. Inhibitory neurotransmitters may be responsible for the major suppression of hypoglossal motor output to genioglossus muscle that occurs in certain behaviours such as rapid-eye-movement sleep. There is evidence for GABA(A) receptor-mediated inhibition of hypoglossal motoneurons in vitro. However, comparable studies have not been performed in vivo and the interactions of such mechanisms with integrative reflex respiratory control have also not been determined. Urethane-anaesthetised, tracheotomized and vagotomized rats were studied whilst diaphragm and genioglossus muscle activities, blood pressure and the electroencephalogram were recorded. Microdialysis probes were implanted into the hypoglossal motor nucleus, with sites verified by histology. Genioglossus responses to microdialysis perfusion of muscimol (GABA(A) agonist: 0, 0.1, 1 and 10 microM in artificial cerebrospinal fluid) were recorded at inspired CO(2)s of 0, 5 and 7.5% in six rats. Responses to bicuculline (GABA(A) antagonist, 0, 1, 10, 100 and 1000 microM) were also studied in six rats with and without CO(2) stimulation. Genioglossus activity decreased with muscimol (P<0.0001), with major suppression at 1 and 10 microM during air breathing (decreases=70.2% and 92.8%, P<0.005). Genioglossus activity increased with CO(2) (P=0.003), but genioglossus activation with 5 and 7.5% CO(2) were almost abolished with 10-microM muscimol. Responses were specific to genioglossus muscle as there were no changes in diaphragm, respiratory rate or blood pressure with muscimol (P>0.144). Antagonism of GABA(A) receptors increased genioglossus activity (P<0.001). These results show that GABA(A) receptor stimulation at the hypoglossal motor nucleus suppresses both genioglossus muscle tone and activity in the presence of reflex stimulation produced by hypercapnia. Recruitment of such mechanisms may contribute to the major suppression of genioglossus activity observed with and without CO(2) stimulation in behaviours such as rapid-eye-movement sleep.

Bayes estimates of haplotype effects

We describe a Markov chain Monte Carlo implementation of a Bayesian approach to estimating associations of a trait with a large set of haplotypes recently introduced by Clayton and Jones [Am J Hum Genet 65:1161-9, 2000]. The model uses the length of the longest segment in common between any two haplotypes to define the prior correlation structure for the set of haplotype effects, using an intrinsic autocorrelation model. When applied to the Genetic Analysis Workshop 12 data for trait Q1, we found highly significant variation between haplotypes, using either a structured or unstructured covariance matrix.

Should we consider gene x environment interaction in the hunt for quantitative trait loci?

We address the question of whether one can obtain increased power for finding a quantitative trait locus (QTL) if a gene x environment (G x E) interaction is incorporated directly into the linkage analysis. We consider both parametric and nonparametric analysis approaches to including G x E interaction. For the former, we utilize joint segregation and linkage analysis to estimate simultaneously the recombination fraction and a G x E interaction effect, as well as the remaining model parameters. The nonparametric approach is based on an extension of the Haseman-Elston method applied to sib pairs to include a regression of the squared trait difference on marker-identity-by-descent (IBD) probability (pi), the sibling covariate sum (z), and pi x z. We utilize 50 replicates of the simulated data and compare empirical power of the various approaches to detect MG4, a locus that is involved in a strong interaction with age for Q4 and in a weaker interaction with environmental factor E2 for Q3. Using the parametric approach, including a G x age effect does increase power for detecting linkage between MG4 and Q4 compared with ignoring the interaction (powers 58% and 38%, respectively, to exceed a lod score of 3.0). On the other hand, including a G x E2 interaction has little effect on the power to detect linkage between MG4 and Q3. The nonparametric approach leads to qualitatively similar findings. We conclude that it is beneficial to incorporate G x E interaction into a linkage analysis, provided the interaction effect is of sufficiently strong magnitude.

Fetal behavioural state changes following maternal fluoxetine infusion in sheep

Clinical depression is diagnosed in 5-15% of women during pregnancy, increasing the risk of negative outcomes. Fluoxetine (FX), a selective serotonin reuptake inhibitor, is prescribed during pregnancy. In adults, FX alters sleep patterns with single doses decreasing total sleep time and rapid eye movement sleep. The effects of FX on sleep in the fetus are unknown. However, 5-hydroxytryptophan, the precursor of serotonin, has been reported to prolong high-voltage (HV) electrocortical (ECoG) activity and increase the incidence of fetal breathing movements (FBM) in the sheep fetus. We hypothesize that FX exposure will decrease the incidence of LV ECoG in the fetus. Twenty-one pregnant sheep were surgically prepared for chronic study of blood gases, ECoG activity, eye movements and FBM. After 3 days of recovery, ewes received a 70-mg bolus i.v. infusion of FX or sterile water followed by continuous infusion at a rate of 0.036 mg/min for 8 days. The incidence of low-voltage (LV) ECoG decreased from 54+/-4% on the preinfusion day to 45+/-5% on infusion day 1 in the FX group and remained decreased throughout the infusion period. In addition, the incidence of both eye movements and FBM was decreased on infusion day 1 compared to preinfusion day in the FX group. HV ECoG increased from 39+/-3% on preinfusion day to 68+/-14% on FX infusion day 1 and remained elevated throughout the infusion period. These data show that maternal FX administration alters fetal behavioural state.

A national survey of stress reactions after the September 11, 2001, terrorist attacks

BACKGROUND

People who are not present at a traumatic event may also experience stress reactions. We assessed the immediate mental health effects of the terrorist attacks on September 11, 2001.

METHODS

Using random-digit dialing three to five days after September 11, we interviewed a nationally representative sample of 569 U.S. adults about their reactions to the terrorist attacks and their perceptions of their children's reactions.

RESULTS

Forty-four percent of the adults reported one or more substantial stress symptoms; 91 percent had one or more symptoms to at least some degree. Respondents throughout the country reported stress syndromes. They coped by talking with others (98 percent), turning to religion (90 percent), participating in group activities (60 percent), and making donations (36 percent). Eighty-five percent of parents reported that they or other adults in the household had talked to their children about the attacks for an hour or more; 34 percent restricted their children's television viewing. Thirty-five percent of children had one or more stress symptoms, and 47 percent were worried about their own safety or the safety of loved ones.

CONCLUSIONS

After the September 11 terrorist attacks, Americans across the country, including children, had substantial symptoms of stress. Even clinicians who practice in regions that are far from the recent attacks should be prepared to assist people with trauma-related symptoms of stress.

Leucocytozoon toddi and Haemoproteus tinnunculi (Protozoa: Haemosporina) in the Chimango caracara (Milvago chimango) in southern Chile

Two species of blood protozoans were identified from blood smears collected from 15 specimens of the Chimango caracara (Milvago chimango) on Isla Grande de Chiloé in southern Chile. These included Leucocytozoon toddi in 13 birds, including all 5 of the 4-6 week old nestlings examined, and 8 of the subadults or adults. One of the nestlings also had a dual infection of L. toddi and Haemoproteus tinnunculi. These are the first reports of blood parasites from M. chimango.

Pedicle marrow signal intensity changes in the lumbar spine: a manifestation of facet degenerative joint disease

OBJECTIVE

Signal intensity changes in lumbar pedicles, similar to those described in vertebral body endplates adjacent to degenerated discs, have been described as an ancillary sign of spondylolysis on MRI. The purpose of this study was to determine whether pedicle marrow signal intensity changes also occur in association with facet degenerative joint disease.

DESIGN

Eighty-nine lumbar spine MRI examinations without spondylolysis were reviewed for marrow signal intensity changes in pedicles and vertebral bodies as well as for facet degenerative joint disease.

RESULTS

Five percent (46/890) of lumbar pedicles in 23 patients had marrow signal intensity changes. Ninety-one percent (42/46) of the abnormal pedicles had adjacent degenerative joint disease of the facets, while only 21% (189/890) of normal pedicles had adjacent facet degenerative joint disease (p<0.001). Eighty-nine percent (41/46) of the pedicles with marrow signal intensity changes had adjacent degenerative disc disease.

CONCLUSIONS

Pedicle marrow signal intensity changes are not a specific sign of spondylolysis; they are commonly seen with adjacent facet degenerative joint disease in the absence of spondylolysis. Pedicle marrow signal intensity changes are probably a response to abnormal stresses related to abnormal motion or loading caused by the degenerative changes in the spinal segment.

Joint segregation and linkage analysis of a quantitative trait compared to separate analyses

Our goal was to determine the degree to which joint segregation and linkage analysis leads to increased efficiency for estimating the recombination fraction and to greater power for detecting linkage, compared to separate analyses. We concentrated on the quantitative phenotype Q2 and analyzed linkage with a tightly linked marker, a loosely linked marker, and eight unlinked markers, the latter chosen to evaluate false positive rates. We considered both nuclear-family and extended-pedigree data, using the 200 replicates of each provided to GAW participants. We found joint analysis to be consistently more efficient, with relative efficiencies for the tightly linked marker of 1.16 and 1.06 in extended pedigrees and nuclear families, respectively. These relative efficiencies translated into modest but consistent gains in power to detect linkage. Both methods appear to produce unbiased parameter estimates and similar false positive rates.

Analysis of gene-smoking interaction in lung cancer

The Louisiana Lung Cancer Dataset, consisting of 337 extended pedigrees, is analyzed to determine whether a major Mendelian gene interacts with cumulative tobacco smoking (pack-years). The proportional hazards model is utilized, as it is a natural framework for estimating relative risks while adjusting for variability in age of disease onset. Segregation analyses show evidence that a Mendelian gene is segregating in these families, with the most parsimonious model, including sex, pack-years, pack-years squared, and a dominant major gene. The estimated frequency of the high-risk allele is 2% and carriers are estimated to have relative risk of 17.3 for developing lung cancer, compared to noncarriers. The addition of a gene x pack-years interaction does not significantly improve the fit of the model, indicating that on a multiplicative scale, these two factors independently influence lung cancer risk. Smoking history is missing for 23% of the study subjects and degree of "missingness" depends on disease status, age, and birth-year. To account for the nonrandomness of the missing data, a Markov chain Monte Carlo method for covariate imputation is proposed and implemented. Results from this analysis also support a nonsignificant gene-smoking interaction and an allele frequency of 2%, but a lower genetic relative risk (9.0) compared to the "complete case" analysis.

Water on the knee: cysts, bursae, and recesses

Many synovial-lined cavities occur around the knee, and MR imaging is capable of demonstrating the precise anatomic relationships of these spaces. Knowledge of normal anatomy, however, is necessary to accurately assess abnormal, fluid-filled structures. This article reviews the MR imaging appearance of normal and pathologic bursae and joint recesses, and the appearance of common cystic masses. Distinguishing features of several noncystic lesions occurring around the knee also are discussed because these can mimic bursae, recesses, and cysts.

Herpesviruses and periodontopathic bacteria in Trisomy 21 periodontitis

BACKGROUND

Little is known about the etiology and pathogenesis of periodontal disease in Trisomy 21 patients. This study determined the occurrence of herpesviruses and putative periodontopathic bacteria in Trisomy 21 periodontitis.

METHODS

Nineteen Trisomy 21 patients (17 to 37 years of age) contributed subgingival samples from molar and bicuspid teeth presenting interproximal periodontitis lesions (probing depths, 5 to 8 mm) and from shallow periodontal sites (probing depths, 1 to 3 mm). Samples were obtained at baseline, and at 1 and 4 weeks after subgingival debridement by means of hand instruments and ultrasonic scalers. Epstein-Barr virus type 1 and 2 (EBV-1 and EBV-2), human cytomegalovirus (HCMV), and herpes simplex virus (HSV) were identified by sensitive and specific nested polymerase chain reaction. Putative periodontopathic bacteria were identified by means of non-selective and selective culture.

RESULTS

Of 19 Trisomy 21 periodontitis lesions, 6 (32%) were positive for EBV-1, 5 (26%) were positive for HCMV, 3 (16%) were positive for HSV, and 2 (11%) showed viral co-infection. Of 19 shallow periodontal sites, only one revealed HCMV. Prevotella intermedia, Bacteroides forsythus, and Capnocytophaga species were detected in higher proportions in deep than in shallow periodontal pockets (P = 0.02). Subgingival debridement did not reduce genomic herpesvirus presence but caused a decrease in proportions of Porphyromonas gingivalis and Capnocytophaga species.

CONCLUSIONS

Periodontal herpesvirus-bacteria coinfections may play important roles in the pathogenesis of destructive periodontal disease in Trisomy 21 patients. Herpesviruses may reduce the periodontal defense and promote growth of subgingival bacteria capable of causing periodontal breakdown.

Evidence for age-specific genetic relative risks in lung cancer

Recent studies of familial aggregation suggest that family history of lung cancer among first-degree relatives is associated with increased risk for early-onset, but not late-onset, lung cancer. To assess whether this could be explained by variability in genetic relative risk across age, segregation analysis was performed on the Louisiana Lung Cancer Dataset. This data set consisted of 337 probands who died of lung cancer between 1976 and 1979 and their first-degree relatives. A variation of the Cox proportional hazards model was used that allowed estimation of age- and genotype-specific incidence rates, from which the authors obtained estimates of age-specific genetic relative risks. The best-fitting model included an autosomal dominant locus (allele frequency, 0.043), with carrier-to-noncarrier relative risks that exceeded 100 for ages less than 60 years and declined monotonically to 1.6 by age 80. The hypothesis of proportional genetic relative risk across age was rejected (p = 0.009). The estimated proportion of persons with lung cancer who carry the high-risk allele exceeds 90% for cases with onset at age 60 years or less and decreases to approximately 10% for cases with onset at age 80 years or older. These findings support previous evidence of a major susceptibility locus for lung cancer and suggest that linkage studies should preferentially recruit young lung cancer cases and their relatives.

A generalized estimating equations approach to linkage analysis in sibships in relation to multiple markers and exposure factors

We describe a multiple regression approach to nonparametric linkage analysis in sibships incorporating multiple genetic loci, environmental covariates, and interactions. The covariance in trait residuals between sib pairs is treated as the dependent variable, regressed upon identical-by-descent sharing probabilities and interaction effects, using generalized estimating equations to allow for the correlations among multiple sib pairs within a sibship. Individual covariates can also be introduced in the model for the trait means. An application to the GAW11 simulated data revealed linkage with each of the four simulated loci, as well as gene x environment interactions of E1 with loci C and D and gene x gene interactions among the cluster of loci A, B, and D.

A joint test of linkage and gene x environment interaction, with affected sib pairs

In the presence of gene x environment (G x E) interaction, the expected proportion of alleles shared identical by descent at a linked marker locus by a pair of affected sibs depends on the exposure profile of the two sibs, i.e., whether both are exposed to E, only one is exposed, or neither are exposed. In this paper, we propose an extension of the commonly used mean test of linkage to test for differential identical-by-descent (IBD) sharing across sib-exposure profiles. The method can be viewed as a test for linkage in the presence of G x E interaction, or as a test for G x E interaction in the presence of linkage. Applied to the simulated GAW11 data, our method successfully localized disease locus C and its interactive relationship with environmental factor E1. At the 5% significance level, use of our method led to increased power to detect linkage (56%) to this disease locus compared to use of the standard mean test (32%); at the 0.001 significance level, the corresponding power estimates were 20% and 4%, respectively. For a gene that interacts with an environmental factor, we conclude that use of the environmental factor in linkage analysis can improve detection rates while also providing information about underlying mechanisms.

Tetracycline-coated polytetrafluoroethylene barrier membranes in the treatment of intraosseous periodontal lesions

BACKGROUND

Periodontal pathogens are detrimental to periodontal healing in barrier membrane-assisted periodontal therapy. Tetracycline-coating of barrier membranes may reduce levels of infecting pathogens. This study evaluated the clinical and microbiological effects of tetracycline-coated expanded polytetrafluoroethylene (T-ePTFE) barrier membranes in the treatment of 2- to 3-wall intraosseous periodontal lesions around mandibular molars.

METHODS

Eleven patients received non-coated barrier membranes (ePTFE) and 11 patients received T-ePTFE barrier membranes. Tetracycline coating was performed by placing ePTFE membranes first in a 5% tridodecylmethylammonium chloride solution and then in a basic 3% tetracycline solution. Microbiological examination included conventional culture and DNA probe analyses. Barrier membranes were removed 6 weeks after insertion.

RESULTS

At baseline, the periodontal lesion depth averaged 8.0 mm in the ePTFE treated group and 7.4 mm in the T-ePTFE group. At 1 year post-treatment, the mean gain of probing attachment was 1.9 mm in the ePTFE group and 3.3 mm in the T-ePTFE group (P = 0.02). At 3 minutes after membrane placement, suspected periodontal pathogens were detected in several ePTFE membranes but only in one T-ePTFE membrane. At 6 weeks, all membranes showed periodontal pathogens, including Porphyromonas gingivalis, Fusobacterium species, Peptostreptococcus micros, Bacteroides forsythus, and motile rods.

CONCLUSIONS

This study suggests that the use of tetracycline-coated ePTFE barrier membranes can result in additional gain of clinical periodontal attachment, most likely due to the antimicrobial properties of tetracycline during initial healing.

Relationship between herpesviruses and adult periodontitis and periodontopathic bacteria

BACKGROUND

Various mammalian viruses and specific bacteria seem to play important roles in the pathogenesis of human periodontitis. This study examined the relationship between subgingival herpesviruses and periodontal disease and potential periodontopathic bacteria in 140 adults exhibiting either periodontitis or gingivitis.

METHODS

A nested-polymerase chain reaction (PCR) method determined the presence of Epstein-Barr virus type 1 and type 2 (EBV-1, EBV-2), human cytomegalovirus (HCMV), and herpes simplex virus (HSV) and a 16S rRNA PCR detection method identified Actinobacillus actinomycetemcomitans, Porphyromonas gingivalis, Bacteroides forsythus, Prevotella intermedia, Prevotella nigrescens, and Treponema denticola.

RESULTS

Using a logistic analysis, EBV-1 showed significant positive association with P. gingivalis (odds ratio [OR] 3.37), and with coinfections of P. gingivalis and P. intermedia (OR 4.03); P. gingivalis and B. forsythus (OR 3.84); P. gingivalis and T. denticola (OR 4.17); P. gingivalis, B. forsythus, and T. denticola (OR 4.06); and P. gingivalis, P. nigrescens, and T. denticola (OR 3.29). EBV-1 also showed positive association with severe periodontitis (OR 5.09), with increasing age (OR 1.03), and with periodontal probing depth at the sample sites (OR 1.77). HCMV was positively associated with coinfections of P. gingivalis and P. nigrescens (OR 3.23); P. gingivalis, B. forsythus, and P. nigrescens (OR 3.23); and P. gingivalis, P. nigrescens, and T. denticola (OR 2.59); with severe periodontitis (OR 4.65); and with age (OR 1.03). Patients with mixed viral infections revealed significant associations with P. gingivalis (OR 2.27), and with coinfections of P. gingivalis and B. forsythus (OR 2.06); P. gingivalis and P. nigrescens (OR 2.91); P. gingivalis, B. forsythus, and P. nigrescens (OR 2.91); and P. gingivalis, P. nigrescens, and T. denticola (OR 2.70) with the clinical diagnosis of slight (OR 3.73), moderate (OR 3.82), or severe periodontitis (OR 4.36), and with probing depth at the sample sites (OR 1.39). HSV and EBV-2 showed no significant associations with any of the variables tested.

CONCLUSIONS

The results indicate that subgingival EBV-1, HCMV, and viral coinfections are associated with the subgingival presence of some periodontal pathogens and periodontitis. Herpesviruses may exert periodontopathic potential by decreasing the host resistance against subgingival colonization and multiplication of periodontal pathogens.

Risk indicators for harboring periodontal pathogens

The risk for harboring 6 putative periodontal pathogens in 4 selected periodontal pockets, in whole saliva, or in either site (i.e., orally) was determined in 52 Caucasians, 49 African-Americans, 48 Asian-Americans, and 50 Hispanics living in Los Angeles. 16S rRNA PCR analysis assessed the presence of Actinobacillus actinomycetemcomitans, Bacteroides forsythus, Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, and Treponema denticola. Step-wise regression analysis determined the relationship between the occurrence of each organism and various explanatory variables (risk indicators). Periodontal probing depth or disease severity was positively associated with all 6 study organisms. African-Americans carried an increased risk for harboring P. gingivalis in saliva (odds ratio [OR] 2.95) and orally (OR 2.66), and a reduced risk for harboring T. denticola orally (OR 0.34). Asian-Americans showed an increased risk for harboring A. actinomycetemcomitans in periodontal pockets (OR 6.63) and P. gingivalis in periodontal pockets (OR 5.39), in saliva (OR 5.74), and orally (OR 5.81). Hispanics demonstrated an increased risk for harboring A. actinomycetemcomitans in periodontal pockets (OR 12.27) and P. gingivalis in periodontal pockets (OR 6.07), in saliva (OR 8.72), and orally (OR 7.98). Age was positively associated with the prevalence of P. gingivalis in saliva (OR 1.20) and orally (OR 1.20), and of A. actinomycetemcomitans orally (OR 1.18). The male gender was a risk factor for harboring P. intermedia in periodontal pockets (OR 2.40), in saliva (OR 3.31), and orally (OR 4.25), and for harboring P. nigrescens in saliva (OR 2.85). The longer the subjects resided in the United States, the less likely A. actinomycetemcomitans was detected orally (OR 0.82). Former smokers demonstrated a decreased risk for harboring A. actinomycetemcomitans in saliva (OR 0.23). Current smokers displayed an increased risk for harboring T. denticola in periodontal pockets (OR 4.61). The number of dental visits in the past 10 years was inversely related to the prevalence of P. intermedia orally (OR 0.96). The prevalence of P. intermedia in saliva was positively associated with the length of time from the last dental visit (OR 1.01). This study suggests that genetic and/or environmental factors predispose subjects to oral colonization by putative periodontal pathogens.

The effects of 'sleep promoting agents' on behavioural state in the ovine fetus

Fetal behavioural states, with similarities to adult sleep states, exist in both the human and ovine fetus near term. The purpose of the present study was to determine the effects of intracerebral administration of pharmacologic agents, known to affect sleep states in the adult, on fetal behavioural states and physiologic correlates using the chronically catheterized ovine fetus near term. Each drug was infused into either the cisterna magna or lateral ventricle for 90 min in one of two doses. Carbachol (1.35 x 10(-5) and 4.25 x 10(-6) M) led to an increase in low-voltage ECOG, eye movement and FBM activities, while scopolamine (4.68 x 10(-4) and 1.56 x 10(-4) M) led to a decrease in low-voltage ECOG and eye movement activity with an increase in high-voltage ECOG activity. L-5-Hydroxytryptophan (5-HTP) (2.04 x 10(-3) and 6.81 x 10(-4) M) infusion led to an increase in FBM, while VIP (3.00 x 10(-7) and 1.00 x 10(-7) M) infusion had no effect on fetal behavioural state parameters. Study results indicate that fetal behavioural states can be altered pharmacologically and in a manner similar to that seen in the adult but with notable differences that may relate to species, developmental or dose-response issues.

The dynamics of microbial colonization of barrier membranes for guided tissue regeneration

The microbial colonization of expanded polytetrafluoroethylene membrane by putative periodontopathogens at 3 minutes of intraoral manipulation was determined in 42 patients with 42 mandibular posterior two- to three-wall defects. Twenty patients exhibited no periodontal pockets of > or = 5 mm, other than the study site, and low levels of pathogens (group A). Twenty-two patients revealed multiple periodontal pockets of 5 mm or more and numerous pathogens (group B). Within the preceding 3 months of regenerative surgery, group A patients had received apically positioned flap surgery with osseous recontouring (except for the study site), and group B patients had been enrolled in a non-surgical maintenance program. The subgingival microbiota was examined prior to regenerative therapy, and the membrane microbiota was examined at 3 minutes and at the time of removal at 6 weeks by culture, DNA probes, and phase-contrast microscopy. The mean initial defect depth was 7.4 mm for group A and 7.2 mm for group B. At 6 months, the difference in mean clinical attachment gain was statistically significant (P < 0.001; group A: 3.4 mm; group B: 1.4 mm). At 3 minutes, putative pathogens were detected in seven (16.7%) membranes in group B (group Binfected), and the associated sites gained only 0.6 mm in clinical attachment at 6 months. Clinical attachment gain was modeled as a linear function of the explanatory variables (r2 = 86%). The presence of Porphyromonas gingivalis detected by DNA probe at 3 minutes was associated with 1.5 mm less expected gain (P = 0.0002). Total microbial counts and the percentage of Peptostreptococcus micros and Capnocytophaga species at baseline, and of motile rods on the membrane surface facing the gingiva at 6 weeks, were statistically significant negative predictors of clinical attachment. For each week the membrane remained covered, an additional 0.5 mm gain could be expected (P = 0.002); and for every 10 sites that exhibited bleeding on probing, the clinical attachment gain was 0.6 mm less at the site of regeneration (P < 0.0001). The present results showed that putative pathogens may colonize membranes within 3 minutes of intraoral manipulation. The patient group treated with periodontal osseous surgery revealed the lowest levels of periodontal pathogens in the membranes and exhibited the most gain in clinical attachment.

Drug information skills for pharmacy students: curriculum integration

For pharmacy students to provide optimal and complete pharmaceutical care, it is vital that they develop drug information skills. At the University of Southern California, the School of Pharmacy and the Norris Medical Library have established an interactive educational program. Library programs support an increasingly complex progression of information retrieval, evaluation, organization, application, and communication. Librarians are systematically involved in all four years of coursework for the doctor of pharmacy degree. Training and experience in computer literacy and online database searching are included in the library components. Description of the educational program covers its beginning a decade ago, current status, and future in an environment of rapidly advancing technology.