Embryonic and early postnatal abnormalities contributing to the development of hippocampal malformations in a rodent model of dysplasia

While there are many recent examples of single gene deletions that lead to defects in cortical development, most human cases of cortical disorganization can be attributed to a combination of environmental and genetic factors. Elucidating the cellular or developmental basis of teratogenic exposures in experimental animals is an important approach to understanding how environmental insults at particular developmental junctures can lead to complex brain malformations. Rats with prenatal exposure to methylazoxymethanol (MAM) reproduce many anatomical features seen in epilepsy patients. Previous studies have shown that heterotopic clusters of neocortically derived neurons exhibit hyperexcitable firing activity and may be a source of heightened seizure susceptibility; however, the events that lead to the formation of these abnormal cell clusters is unclear. Here we used a panel of molecular markers and birthdating studies to show that in MAM-exposed rats the abnormal cell clusters (heterotopia) first appear postnatally in the hippocampus (P1-2) and that their appearance is preceded by a distinct sequence of perturbations in neocortical development: 1) disruption of the radial glial scaffolding with premature astroglial differentiation, and 2) thickening of the marginal zone with redistribution of Cajal-Retzius neurons to deeper layers. These initial events are followed by disruption of the cortical plate and appearance of subventricular zone nodules. Finally, we observed the erosion of neocortical subventricular zone nodules into the hippocampus around parturition followed by migration of nodules to hippocampus. We conclude that prenatal MAM exposure disrupts critical developmental processes and prenatal neocortical structures, ultimately resulting in neocortical disorganization and hippocampal malformations.

Renal function in juvenile rats subjected to prenatal malnutrition and chronic salt overload

Dietary sodium may contribute to hypertension and to cardiovascular and renal disease if a primary deficiency of the kidney to excrete sodium exists. In order to investigate whether chronic 1% NaCl in the drinking water changes blood pressure and renal haemodynamics in juvenile Wistar rats subjected to prenatal malnutrition, an evaluation of plasma volume, oxidative stress in the kidney, proteinuria and renal haemodynamics was carried out. Malnutrition was induced by a multideficient diet. Mean arterial pressure, renal blood flow and glomerular filtration rate (GFR) were measured using a blood pressure transducer, a flow probe and inulin clearance, respectively. Plasma volume and oxidative stress were measured by means of the Evans Blue method and by monitoring thiobarbituric acid reactive substances (TBARS) in the kidneys, respectively. Urinary protein was measured by precipitation with 3% sulphosalicylic acid. It was observed that prenatally malnourished rats presented higher values of plasma volume (26%, P < 0.05), kidney TBARS (43%, P < 0.01) and blood pressure (10%, P < 0.01) when compared with the control group. However, they showed no change in renal haemodynamics or proteinuria. Neither prenatally malnourished nor control rats treated with sodium overload presented plasma volume or blood pressure values different from their respective control groups, but both groups presented elevated proteinuria (P < 0.01). The prenatally malnourished group treated with sodium overload presented higher values of kidney TBARS, GFR and filtration fraction (58, 87 and 72% higher, respectively, P < 0.01) than its respective control group. In summary, sodium overload did not exacerbate the hypertension in juvenile prenatally malnourished rats, but induced renal haemodynamic adjustments compatible with the development of renal disease.

Long term effects of antenatal betamethasone on lung function: 30 year follow up of a randomised controlled trial

BACKGROUND

Antenatal betamethasone is routinely used for the prevention of neonatal respiratory distress syndrome in preterm infants. However, little is known of the long term effects of exposure to antenatal betamethasone on lung function in adulthood.

METHODS

Five hundred and thirty four 30 year olds whose mothers had participated in the first and largest randomised controlled trial of antenatal betamethasone were followed. Lung function was assessed by portable spirometric testing. The prevalence of asthma symptoms was assessed using the European Community Respiratory Health Survey questionnaire.

RESULTS

Fifty (20%) betamethasone exposed and 53 (19%) placebo exposed participants met the criteria for current asthma (relative risk 0.98 (95% CI 0.74 to 1.30), p = 0.89). 181 betamethasone exposed and 202 placebo exposed participants had acceptable spirometric data. There were no differences in lung function between betamethasone and placebo exposed groups (mean (SD) forced vital capacity in the betamethasone and placebo groups 105.9 (12.0) v 106.6 (12.6)% predicted, difference = -0.7 (95% CI -3.2 to 1.8), p = 0.59; mean (SD) forced expiratory volume in 1 second in the betamethasone and placebo groups 98.9 (13.4) v 98.5 (13.6)% predicted, difference = 0.3 (95% CI -2.4 to 3.1, p = 0.80)).

CONCLUSIONS

Antenatal exposure to a single course of betamethasone does not alter lung function or the prevalence of wheeze and asthma at age 30.

Prenatal exposure to excess testosterone modifies the developmental trajectory of the insulin-like growth factor system in female sheep

Experimental elevation of maternal testosterone (T) from 30 to 90 days of gestation leads to intrauterine growth retardation (IUGR) and increased prepubertal growth rate in female lambs. This study tested the hypothesis that prenatal T treatment during mid-gestation alters the trajectory of the fetal insulin-like growth factor (IGF)-insulin-like growth factor binding protein (IGFBP) system to promote IUGR and subsequent postnatal catch-up growth in female lambs. Plasma IGF-I and IGFBPs were measured by radioimmunoassay and Western ligand blot, respectively, on 65, 90 and 140 days (d) of gestation, at birth, approximately 5 months (prepubertal, the catch-up growth period), and approximately 9.5 months (postpubertal). Northern blot analysis was used to measure hepatic mRNA content of IGF system components during fetal stages. At fetal 65 d, plasma protein and hepatic mRNA content of IGFBP-1, an inhibitor of IGF bioactivity, was elevated in prenatal T-treated fetuses although body weight did not differ. There was a transient increase in plasma IGF-I and IGFBP-3 concentrations at fetal 90 d in prenatal T-treated fetuses. Hepatic IGF-I mRNA and plasma IGFBP-3 content were reduced by 140 d when body weight was reduced in prenatal T-treated fetuses. Plasma IGFBP-2 content was significantly reduced in prenatal T-treated newborns, but by 4 months these females had significantly higher circulating IGF-I and IGFBP-3 concentrations and faster growth rates than control females. After puberty, plasma IGF-I remained elevated in prenatal T-treated females. These findings provide evidence that prenatal T excess programmes the developmental trajectory of the IGF/IGFBP system in female sheep to reduce IGF bioavailability during IUGR and increase IGF bioavailability during prepubertal catch-up growth.

Glucose tolerance at age 58 and the decline of glucose tolerance in comparison with age 50 in people prenatally exposed to the Dutch famine

AIMS/HYPOTHESIS

People who were small at birth have an increased risk of type 2 diabetes in later life. People who were in utero during the Dutch famine had decreased glucose tolerance and raised insulin concentrations at age 50. We aimed to evaluate whether prenatal famine exposure leads to more rapid progression of impaired glucose/insulin homeostasis with increasing age.

METHODS

We performed an OGTT in 702 men and women at age 50 and in 699 men and women at age 58, all born as term singletons immediately before, during or after the 1944-1945 Dutch famine.

RESULTS

People who had been exposed to famine in utero had significantly higher 120-min glucose concentrations at age 58 compared with people who had not been exposed to famine (difference=0.4 mmol/l, 95% CI 0.1 to 0.7, adjusted for sex and BMI). Glucose tolerance deteriorated between the age of 50 and 58. The unadjusted 120-min glucose concentrations rose by 0.2 mmol/l (95% CI 0.0 to 0.4), while 120-min insulin concentrations had increased by 64 pmol/l (95% CI 48 to 82). There were no differences in the rates of glucose and insulin level increase between the famine-exposed group and the unexposed group (p=0.28 for the difference in increase in glucose concentrations and p=0.09 for insulin concentrations).

CONCLUSIONS/INTERPRETATION

Although we confirmed that undernutrition during gestation is linked to decreased glucose tolerance, the effect does not seem to become more pronounced at age 58 as compared with age 50.

[Effects of prenatal alcohol exposure on auditory brainstem response in rats]

OBJECTIVE

To study the effects of prenatal alcohol exposure, with an animal model of auditory brainstem response recorded in the conditions of various alcohol dosages administrated during embryonic period, on auditory nervous system in rats.

METHOD

Normal female rats were divided into 2 groups. From the days 8.5 after mating, pregnant rats were fed 50% analytical reagent alcohol via intragastric administration with 2.0 and 1.0 g/(kg x d) respectively in consecutive 6 days. On the days 40 after birth, ABR was recorded in young rats under anesthesia. Normal young rats with parallel age were chosen as the normal group.

RESULT

Prenatal alcohol exposure had effects on ABR, manifesting the incidence rate of I wave lowing (14%, 30%), latency delaying (P<0.05) and amplitude reducing.

CONCLUSION

Prenatal alcohol exposure had conspicuous effects on auditory nervous system in rats, by step down nerve impulse conduction.

Effects of maternal immobilization stress on birth weight and glucose homeostasis in the offspring

Recent epidemiological studies have shown strong associations between low birth weight and the incidence of diabetes in the adult offspring. It has been hypothesized that exposure to maternal glucocorticoids programs cellular changes in the fetus which increases the susceptibility of the offspring to diabetes. Stressors produces large increases in maternal glucocorticoids. The present study determined the effects of immobilization stress during weeks one, two or three of pregnancy on offspring birth weight, glucose homeostasis, and the ability of the offspring to cope with metabolic stress. Immobilization stress produced large increases in maternal levels of ACTH and corticosterone, but did not affect birth weight of the pups. Chronic administration of high fructose diet, a metabolic stressor, to 60 days old control and prenatally stressed offspring produced large increases in plasma levels of triglyceride and insulin. However, there were no differences between the groups either in peak levels, or in the rates of increase and decrease (upon discontinuation of the diet) of plasma triglyceride and insulin concentrations. Basal levels of glucose and insulin, and areas under the glucose and insulin plasma concentration-time curves after an i.p. glucose dose were similar between 120 days old control and prenatally stressed offspring. These results suggest that in young adult rats prenatal immobilization stress did not affect glucose homeostasis or the ability of these rats to cope with chronic metabolic stress.

Maternal stress produces learning deficits associated with impairment of NMDA receptor-mediated synaptic plasticity

Stress in adulthood can have a profound effect on physiology and behavior, but the extent to which prolonged maternal stress affects the brain function of offspring when they are adult remains primarily unknown. In the present work, chronic immobilization stress to pregnant mice affected fetal growth and development. When pups born from stressed mice were reared to adulthood in an environment identical to that of nonstressed controls, several physiological parameters were essentially unaltered. However, spatial learning and memory was significantly impaired in the maternally stressed offspring in adulthood. Furthermore, electrophysiological examination revealed a significant reduction in NMDA receptor-mediated long-term potentiation in the CA1 area of hippocampal slices. Subsequent biochemical analysis demonstrated a substantial decrease in NR1 and NR2B subunits of the NMDA receptor in synapses of the hippocampus, and the interaction between these two subunits appeared to be reduced. These results suggest that prolonged maternal stress leads to long-lasting malfunction of the hippocampus, which extends to and is manifested in adulthood.

[Study on reproductive and developmental toxicity of the pregnant mice and their foetus co-administered by p, p'-DDE and beta-BHC]

OBJECTIVE

To explore effects of p, p'-DDE and beta-BHC on reproduction and development in mice.

METHODS

The pregnant Kunming SPF mice of 12 to 14 days were co-administered by oral gavage for 3 days at different concentrations of 0, 1, 5 and 10 mg/kg bw of p, p'-DDE and beta-BHC. The concentrations of estradiol (E2) and progesterone (P) in sera of the dosed mice were determined by the Serozyme kits (Bio-Ekon biotechnology Co., Beijing, China), following the procedures described by the manufacturer. RT-PCR was employed to detect abundant expression of alpha-estrogen receptor (alpha-ER) gonadtropin releasing hormone (GnRH) and beta-endorphin (beta-EP) mRNA in placentae.

RESULTS

(1) Reproductive effects: with increase of the administered p,p'-DDE and P-BHC,the organ coefficient of uterus and its intraluminal fluid increased, the unterine nidation quantity decreased, the anogenital distance (AGD) and ratio of female to male raised, the concentration of estradiol and progesterone in sera of the dosed mice went up, and the abundant expression of alpha-ER and GnRH mRNA rised while beta-EP dropped in placentae in a dose-dependant manner. Significant difference of these indexes were found between the treat groups and control (P < 0.05). (2) Developmental effects: with increase of the administered p,p'-DDE and beta-BHC, the gained weights of pregnant mice reduced, organ coefficient of liver increased,the quantity of live foetus decreased, the times of adverse pregnancy outcome went up, and the percent of female foetus increased. They all presented a dose-effect relation and significance of difference (P < 0.05).

CONCLUSION

p, p'-DDE and beta-BHC disrupt reproductive function, thereby result in dysreproduction and maldevelopment, and unbalance of ratio of female to male.

Prenatal alcohol exposure delays the development of the cortical barrel field in neonatal rats

In-utero alcohol exposure produces sensorimotor developmental abnormalities that often persist into adulthood. The rodent cortical barrel field associated with the representation of the body surface was used as our model system to examine the effect of prenatal alcohol exposure (PAE) on early somatosensory cortical development. In this study, pregnant female rats were intragastrically gavaged daily with high doses of alcohol (6 gm/kg body weight) throughout the first 20 days of pregnancy. Blood alcohol levels were measured in the pregnant dams on gestational days 13 (G13) and G20. The ethanol treated group (EtOH) was compared to the normal control chowfed (CF) group, nutritionally matched pairfed (PF) group, and cross-foster (XF) group. Cortical barrel development was examined in pups across all treatment groups from G25, corresponding to postnatal day 2 (P2), to G32 corresponding to P9. The EtOH and control group pups were weighed, anesthetized, and perfused. Brains were removed and weighed with, and without cerebellum and olfactory bulbs, and neocortex was removed and weighed. Cortices were then flattened, sectioned tangentially, and stained with a metabolic marker, cytochrome oxidase (CO) to reveal the barrel field. Progression of barrel development was distinguished into three categories: (a) absent, (b) cloudy barrel-like pattern, and (c) well-formed barrels with intervening septae. The major findings are: (1) PAE delayed barrel field development by one or more days, (2) the barrel field first appeared as a cloudy pattern that gave way on subsequent days to an adult-like pattern with clearly demarcated intervening septal regions, (3) the barrel field developed differentially in a lateral-to-medial gradient in both alcohol and control groups, (4) PAE delayed birth by one or more days in 53% of the pups, (5) regardless of whether pups were born on G23 (normal expected birth date for non-alcohol controls) or as in the case for the alcohol-delayed pups born as late as G27, the barrel field was never present at birth suggesting the importance of postnatal experience on barrel field development, and (6) PAE did not disrupt the normal barrel field pattern, although both total body and brain weights were compromised. These findings suggest that PAE delays the development of the somatosensory cortex (SI); such delays may interfere with timing and formation of cortical circuits. It is unknown whether other nuclei along the somatosensory pathway undergo similar delays in development or if PAE selectively disrupts cortical circuitry.

The stamp of ancestry: roots of behavioral and neuronal impairment in adulthood

Exposure of pregnant animals to noxious conditions affects neuronal function in the offspring. However, exposure or treatment of the maternal animal during pregnancy affects both ancestor and offspring. In the present study, female CD-1 mice were repetitively treated with 3-nitropropionate (3-np), a selective inhibitor of succinic dehydrogenase, exclusively prior to mating. Clinically, mice appeared normal during treatment. Five days after cessation of treatment animals were mated with control male animals. At 4 months of age spatial learning, LTP, NADH autofluorescence, and hypoxic tolerance were alike in controls and the offspring of treated female ancestors. However, an additional metabolic challenge in the offspring unmasks impairment of spatial learning, diminution of long-term potentiation (LTP), an altered protein microenvironment of mitochondrial enzymes, and reduced hypoxic tolerance. We conclude that the exposure of maternal ancestors to subclinical repetitive impairment of oxidative phosphorylation fosters impairment of behavior and neuronal function in the adult offspring, becoming apparent only on additional challenge. This finding may ultimately help to understand the causes of neuronal impairment or even neuropsychiatric disease in old age.

Neuropsychological effects of exposure to anticonvulsant medication in utero

OBJECTIVE

To investigate the long-term differential drug effects on cognitive functioning in school-aged children exposed to antiepileptic drugs (AEDs) in utero.

METHODS

Mothers with epilepsy were recruited from specialist epilepsy clinics and obstetric clinics from the Liverpool and Manchester region. The mothers and their children were recruited without prior knowledge of their AED treatment during pregnancy or the health of the offspring. A battery of neuropsychological tests was applied to each mother-child pair in order to obtain a neuropsychological profile for each child.

RESULTS

Neuropsychological investigation was performed on 249 children between the ages of 6 and 16. Children exposed to sodium valproate had a significantly lower verbal IQ when compared to children exposed to other antiepileptic drugs or not exposed at all. The same children were more likely to have an IQ below 69 and more likely to have memory impairment when compared to the other groups. The mothers' IQ, exposure to sodium valproate, and the number of tonic-clonic seizures during pregnancy were significant predictors of verbal IQ in this population.

CONCLUSIONS

This retrospective study highlights the potential harmful effects of sodium valproate exposure in utero on neuropsychological development.

Increased rate of major malformations in offspring exposed to valproate during pregnancy

OBJECTIVE

To determine the rate of occurrence of major malformations in infants whose mothers had taken the drug valproic acid (VPA) as monotherapy during the first trimester of pregnancy and had enrolled in the North American Antiepileptic Drug Pregnancy Registry.

METHODS

Data were collected from pregnant women throughout the United States and Canada through telephone-based interviews. Each woman was interviewed at enrollment, at 7 months' gestation, and postpartum. With her written permission, the medical records of each mother and her infant were obtained. The major malformations tabulated were those identified at or before 5 days of age. The prevalence of congenital malformations among offspring of monotherapy VPA-exposed women was compared with that among infants of women exposed to all other antiepileptic drugs (internal comparison group) and with that among newborns in the Active Malformations Surveillance Program at Brigham and Women's Hospital (external comparison group).

RESULTS

Sixteen affected cases were identified among 149 VPA-exposed women (proportion: 10.7%; 95% CI: 6.3 to 16.9%). The prevalence in the internal comparison group was 2.9% (95% CI: 2.0 to 4.1%; odds ratio: 4.0, 95% CI: 2.1 to 7.4; p < 0.001). Assuming a 1.62% prevalence in the external comparison group, the relative risk of having an affected offspring for VPA-exposed women was 7.3 (95% CI: 4.4 to 12.2; p < 0.001).

CONCLUSION

Maternal exposure to valproic acid during the first trimester of pregnancy significantly increased the risk of major malformations.

Fetal exposure to excess glucocorticoid is unlikely to explain the effects of periconceptional undernutrition in sheep

Periconceptional undernutrition alters fetal growth, metabolism and endocrinology in late gestation. The underlying mechanisms remain uncertain, but fetal exposure to excess maternal glucocorticoids has been hypothesized. We investigated the effects of periconceptional undernutrition on maternal hypothalamic-pituitary-adrenal axis function and placental 11beta-hydroxysteroid dehydrogenase type 2 (11betaHSD2) activity. Ewes received maintenance feed (N, n= 20) or decreased feed from -60 to +30 days from mating to achieve 15% weight loss after an initial 2-day fast (UN, n= 21). Baseline plasma samples and arginine vasopressin (AVP)-corticotrophin-releasing hormone (CRH) challenges were performed on days -61, -57, -29, -1, +29, 33, and 49 from mating (day 0). Maternal adrenal and placental tissue was collected at 50 days. Baseline plasma levels of adrenocorticotrophic hormone (ACTH) and cortisol decreased in the UN group (P < 0.0001). ACTH response to AVP-CRH was greater in UN ewes during undernutrition (P= 0.03) returning to normal levels after refeeding. Cortisol response to AVP-CRH was greater in UN ewes after the initial 2-day fast, but thereafter decreased and was lower in UN ewes from mating until the end of the experiment (P= 0.007). ACTH receptor, StAR and p450c17 mRNA levels were down-regulated in adrenal tissue from UN ewes. Placental 11betaHSD2 activity was lower in UN than N ewes at 50 days (P= 0.014). Moderate periconceptional undernutrition results in decreased maternal plasma cortisol concentrations during undernutrition and after refeeding, and adrenal resistance to ACTH for at least 20 days after refeeding. Fetal exposure to excess maternal cortisol is unlikely during the period of undernutrition, but could occur later in gestation if maternal plasma cortisol levels return to normal while placental 11betaHSD2 activity remains low.

Fetal programming of hypothalamo-pituitary-adrenal function: prenatal stress and glucocorticoids

Prenatal stress (PS) and maternal exposure to exogenous glucocorticoids can lead to permanent modification of hypothalamo-pituitary-adrenal (HPA) function and stress-related behaviour. Both of these manipulations lead to increased fetal exposure to glucocorticoids. Glucocorticoids are essential for many aspects of normal brain development, but exposure of the fetal brain to an excess of glucocorticoids can have life-long effects on neuroendocrine function. Both endogenous glucocorticoid and synthetic glucocorticoid exposure have a number of rapid effects in the fetal brain, including modification of neurotransmitter systems and transcriptional machinery. Such fetal exposure permanently alters HPA function in prepubertal, postpubertal and ageing offspring, in a sex-dependent manner. Prenatal stress and exogenous glucocorticoid manipulation also lead to the modification of behaviour, brain and organ morphology, as well as altered regulation of other endocrine systems. It is also becoming increasingly apparent that the timing of exposure to PS or synthetic glucocorticoids has tremendous effects on the nature of the phenotypic outcome. Permanent changes in endocrine function will ultimately impact on health in both human and animal populations.

Anatomical evidence for in utero androgen exposure in women with polycystic ovary syndrome

OBJECTIVE

To determine whether women with polycystic ovary syndrome (PCOS) have masculinized finger length patterns compared to women without PCOS.

DESIGN

A case control study.

SETTING

University teaching hospital and in vitro fertilization unit.

PATIENT(S)

Seventy women aged between 18 and 40 years with PCOS were compared to 70 women without PCOS.

INTERVENTION(S)

Measurement of the second to fourth finger length ratio on the ventral surface of the left and right hand from the basal crease of the digit to the tip was made using Vernier calipers.

MAIN OUTCOME MEASURE(S)

The second to fourth finger length ratio.

RESULT(S)

We found a significantly reduced ratio in the right hand of the women with PCOS compared to the controls. The geometric mean right finger length ratio in the PCOS group was 98.3% that of the controls (95% confidence interval, 99.3%-97.3%).

CONCLUSION(S)

Here we show a subtle difference in the finger length pattern of women with PCOS. This may constitute anatomical evidence of in utero androgen exposure in PCOS.

Fetal programming of autonomic and HPA function: do people who were small babies have enhanced stress responses?

Studies in several species have demonstrated that an adverse early environment can influence the development of the autonomic nervous system and hypothalamic-pituitary-adrenal (HPA) axis. The autonomic nervous system and HPA axis are key components of the neuroendocrine response to stress and many of these animal models show altered biological responses to stress. Recent research now suggests that these processes operate in humans. An adverse early environment, as evidenced by reduced birth or infant weight, is associated with enhanced autonomic and HPA responses to experimental psychological stress. However, there appear to be marked sex differences in the mechanisms involved. Epidemiological studies demonstrate that physiological changes in these neuroendocrine systems may predispose to cardiovascular disease through their influence on risk factors such as plasma glucose and lipid concentrations and blood pressure. Thus the combination of enhanced stress susceptibility and the psychosocial stressors to which people are exposed may be an important component of the disease risk in human populations.

Long-term evaluation of cardiac function in children who received anthracyclines during pregnancy

BACKGROUND

The use of anthracyclines in patients with cancer has been associated with the presence, even when standard doses were employed, of cardiac toxicity, most frequently after 5 years of therapy. Treatment of cancer during pregnancy remains a dilemma because cytotoxic therapy has been associated with the presence of severe side-effects. The outcome of children that received antracyclines during pregnancy, including during the first trimester, remain unknown because long-term follow-up is not available.

PATIENTS AND METHODS

Eighty-one children whose mothers (29 acute leukemia, 33 malignant lymphoma and 19 Hodgkin's disease) were treated with cytotoxic drugs, including anthracyclines, during pregnancy were evaluated to detect cardiac toxicity, including clinical evaluation and echocardiogram [all parameters were evaluated, but fraction shortening (FS) was taking as the best parameter to evaluate cardiac toxicity in children] every 5 years after birth until 29 years of age.

RESULTS

Children with actual age of 9.3-29.5 years (mean 17.1) did not show any clinical date of cardiac disfunction, in all cases echocardiogram was normal and FS did not showed any abnormality during the follow-up.

CONCLUSIONS

The use of anthracyclines did not show any clinical or echocardiogram evidence of late cardiac toxicity. We hope that the present report increases the number of reports of the long-term follow-up of children who received cytotoxic drugs, in order to define the best treatment in this special patient setting.

Single, intense prenatal stress decreases emotionality and enhances learning performance in the adolescent rat offspring: interaction with a brief, daily maternal separation

Perinatal manipulations can lead to neurobehavioural changes in the progeny. In this study we investigated, in adolescent male rat offspring, the consequences of a single, intense prenatal stress induced by a 120 min-maternal immobilization at gestational day 16, and of a daily, brief maternal separation from postnatal day 2 until 21, on: unconditioned fear/anxiety-like behaviour in open field and in elevated plus-maze; learning performance in the "Can test", a non-aversive spatial and tactile/visual task; corticosterone plasma levels under basal and stress-induced conditions. Our results indicate that both prenatal stress and maternal separation procedures decrease emotionality and enhance learning performance. Maternal separation potentiates prenatal stress-induced effects in enhancing learning performance. Both basal and stress-induced corticosterone plasma levels are reduced following prenatal stress, maternal separation and the combination of two procedures. These findings suggest that a single, intense prenatal stress can enhance the adaptive stress-related responses in the progeny, probably due to the involvement of maternal factors. The synergistic effect of prenatal stress and maternal separation on learning performance may be due to a further damping of hypothalamic-pituitary-adrenal axis response in the progeny that better cope with the task administered.

Associations of maternal prenatal smoking with child adiposity and blood pressure

OBJECTIVE

To examine the extent to which maternal prenatal smoking is associated with adiposity, central adiposity, and blood pressure in 3-year-old children.

RESEARCH METHODS AND PROCEDURES

We studied 746 mother-child pairs in Project Viva, a prospective cohort study, and categorized mothers as never, early pregnancy, or former smokers. Main outcome measures were overweight (BMI for age and sex > 85th percentile), BMI z-score, sum of subscapular (SS) and triceps (TR) skinfolds, SS:TR skinfold ratio, and systolic blood pressure (SBP).

RESULTS

One hundred sixty-one (22%) mothers quit smoking before pregnancy, 71 (10%) smoked in early pregnancy, and 514 (69%) never smoked. At age 3 years, 204 (27%) children were overweight. On multivariable analysis, compared with children of never smokers, children of early pregnancy smokers had an elevated risk for overweight [odds ratio (OR), 2.2; 95% confidence interval (CI), 1.2, 3.9] and higher BMI z-score (0.30 units; 95% CI, 0.05, 0.55), SS + TR (2.0 mm; 95% CI, 0.9, 3.0), and SBP (2.4 mm Hg; 95% CI, -0.1, 4.9). Children of former smokers were not more overweight (BMI z-score, 0.02 units; 95% CI, -0.15, 0.19) but had higher SBP (1.5 mm Hg; 95% CI, -0.1, 3.2). We saw no relationship of smoking with central adiposity (SS:TR).

DISCUSSION

Former and early pregnancy smokers had children with somewhat higher SBP, but only early pregnancy smokers had children who were more overweight. Mechanisms linking smoking with child adiposity and blood pressure may differ. A long-term impact of maternal smoking on offspring cardiovascular risk provides further reason to reduce smoking in women.

Prenatal alcohol exposure (PAE) reduces the size of the forepaw representation in forepaw barrel subfield (FBS) cortex in neonatal rats: relationship between periphery and central representation

Prenatal alcohol exposure (PAE) alters limb development that may lead to structural and functional abnormalities of the limb reported in children diagnosed with Fetal Alcohol Spectrum Disorder. To determine whether PAE alters the central representation of the forelimb we used the rodent barrel cortex as our model system where it was possible to visualize and quantitatively measure the size of the forepaw representation in the forepaw barrel subfield (FBS) in first somatosensory cortex. In the present study, we examined the effects of PAE on pattern and size of the forepaw and forepaw representation in FBS in neonatal rats at gestational day 32 that corresponds to postnatal day 9. Pregnant Sprague-Dawley rats were chronically intubated with binge doses of ethanol (6 g/kg) from gestational day 1 through gestational day 20. The offspring of the ethanol treated dams comprised the ethanol (EtOH) group. The effect of PAE on the EtOH group was compared with a nutritional-controlled pairfed (PF) group and a normal chowfed (CF) group. The ventral (glabrous) surface area of the forepaw digits, length of digit 2 through digit 5, and the corresponding glabrous forepaw digit representations in the FBS were measured and compared between treatment groups. In rats exposed to in utero alcohol, the sizes of the overall glabrous forepaw and forepaw digits were significantly reduced in EtOH pups compared to CF and PF pups; overall glabrous forepaw area was 11% smaller than CF controls. Glabrous digit lengths were also smaller in EtOH rats compared to CF controls and significantly smaller in digit 2 through digit 4. The glabrous digit representation in FBS was 18% smaller in the EtOH group when compared to the CF treatment. However, PAE did not produce malformations in the forepaw or alter the pattern of the forepaw representation in FBS; instead, PAE significantly reduced both body and brain weights compared to controls. Unexpectedly, little or no correlation was observed between the size of the glabrous forepaw compared to the size of the glabrous forepaw representation in the FBS for any of the treatment groups. The present findings of PAE-related alterations in sensory periphery and the central cortical representation may underlie deficits in sensorimotor integration reported among children with Fetal Alcohol Spectrum Disorder.

Co-consumption of selenium and vitamin E altered the reproductive and developmental toxicity of methylmercury in rats

Methylmercury (MeHg), an environmental contaminant primarily found in fish and seafood, may pose long-term health risks to pregnant women and their developing children. The objective of this study was to determine whether co-consumption of nutritional supplements would alter the effects of MeHg on reproductive and developmental toxicity using a rodent model. Adult female rats were fed a diet containing additional selenium (1 ppm), additional vitamin E (225 IU/kg) or a combination of the two for 4 weeks before oral dosing of MeHg (1.25 mg/kg/day). Treatment with MeHg and dietary supplementation continued throughout pregnancy after which the dams were allowed to deliver their offspring. In addition to routine evaluations including periodic body weight measurements and daily clinical signs observations, dams and pups were evaluated for auditory startle habituation and pups were evaluated for developmental landmarks and reflexology. The dams and offspring were euthanized approximately 4 weeks after birth of the offspring. Results indicated that treatment with MeHg caused adverse effects on both reproduction of the dams and decreased progeny survival. However, the dams showed significant improvement in body weight gain during lactation and average auditory startle response time when the diet was enriched with both selenium and vitamin E. The combination of both vitamin E and Se also resulted in a significant increase in post-natal survival when compared to MeHg-treated group. There was no nutrient effect on the MeHg toxicity shown in offspring physical landmarks, performance in reflex tests and assessment of simple auricular startle response. Also, accelerated development as indicated by earlier opening in the pups of the supplemental diet groups was observed. These results suggest that antioxidant nutrients in the diet may alter MeHg reproductive and developmental toxicity. The underlying and human health implications warrant further investigations.

Aetiology of childhood leukemia

Leukemia is the most common cancer to affect children, accounting for approximately a third of all childhood cancers. The major morphological subtypes of leukemia, acute lymphoblastic leukemia (ALL), and acute myeloblastic leukemia (AML), are characterized by chromosomal translocations involving over 200 genes including mixed lineage leukemia (MLL), TEL, and AML1. Chromosomal translocations involving the MLL gene at 11q23 are a common feature of infant acute leukemia, found in up to 80% of all cases, and there is strong evidence that rearrangements involving the MLL gene or the TEL-AML1 gene fusion can originate in utero. As with most other cancers, the mechanism by which leukemia arises is likely to involve gene-environment interactions. Accordingly, it is important to identify exposures that cause DNA damage and induce chromosome breaks which are inadequately repaired, ultimately leading to the initiation and disease progression. Exposures acting before birth and early in life has long been thought to be important determinants of leukemia, and the list of suspected chemical, physical, and biological agents continues to increase. Unfortunately, the evidence regarding the majority of suggested exposures is limited and often contradictory, and there are areas, which clearly warrant further investigation in order to further our understanding of the aetiology of childhood leukemia.

Maternal and early life influences on calcaneal ultrasound parameters and metacarpal morphometry in 7- to 9-year-old children

We investigated the relationship between maternal and early life influences, calcaneal ultrasound parameters, and metacarpal morphometry in 7- to 9-year-old children (n = 109) of mixed ancestral origin from a working class community. Their mothers had participated in a nutrition and pregnancy study at the time of the birth. Demographic and maternal data were collected. Anthropometry was assessed. Broadband ultrasound attenuation (BUA) and speed of sound (SOS) were measured in the children and a subsample of the mothers (n = 94), using calcaneal ultrasound. Hand radiographs were used to measure metacarpal morphometry. There was no relationship between the ultrasound parameters, birthweight, current weight, or height. The ponderal index was correlated with BUA (r = 0.25; P = 0.036). BUA was lower in children whose mothers smoked during pregnancy compared to children whose mothers did not smoke (P = 0.054). Children whose mothers consumed alcohol during pregnancy had a lower Barnett-Nordin metacarpal index compared to children whose mothers did not consume alcohol (P < 0.05), after covarying for sex, age, gestational age, weight, and height of the child. Children's BUA was negatively correlated with housing density (r = -0.23; P = 0.021). In this study, we found an association between maternal and early life influences on calcaneal ultrasound parameters and metacarpal morphometry in prepubertal children, an association that was also influenced by sociodemographic and environmental factors.

Birth Weight and Adult Hypertension Cross-Sectional Study in a Japanese Workplace Population

BACKGROUND

Low birth weight has been associated with adult hypertension in several Western populations. This association needs to be evaluated in Japanese people.

METHODS AND RESULTS

A population-based cross-sectional study of 3,107 subjects (2,303 males and 804 females) aged 35-66 years was conducted. The participants responded to a questionnaire about their birth weights, blood pressure, medical history, parental history, and lifestyle factors. Hypertension was defined as systolic blood pressure > or =140 mmHg and/or diastolic blood pressure > or =90 mmHg and/or under treatment by anti-hypertensives. Multiple logistic regression analysis adjusted for age, sex, body mass index, parental history, and lifestyle revealed the adjusted odds ratios for hypertension were 1.26 (95% confidence interval: 0.88-1.80), 1.00 (reference), 0.89 (0.73-1.08) and 0.70 (0.49-1.00) in subjects in birth weight categories of <2,500 g, 2,500-<3,000 g, 3,000-<3,500 g, 3,500- g, respectively (p-value for trend =0.009). Furthermore, this inverse association was clearly pronounced in normal-weight subjects.

CONCLUSION

Low birth weight was independently associated with adult hypertension in the Japanese workplace population. Our results support the inverse association observed previously in Western populations and suggest that intrauterine environmental insults might lead to permanent changes in the metabolism and structure of the fetal organs influencing the regulation of blood pressure.

Astrocyte–neuron vulnerability to prenatal stress in the adult rat brain

Chronic activation of the stress response during pregnancy has been shown to be injurious to the development of the offspring. We have previously demonstrated that restraint prenatal stress inflicted during the last week of pregnancy in rats increased dopamine and glutamate receptors in forebrain areas of the adult offsprings. In this study, the same prenatal insult was employed to assess morphological changes in astrocytes and in the dendritic arborization in frontal cortex, striatum, and hippocampus of the adult rat brain. On postnatal day 90, brains were processed for immunocytochemistry using primary antibodies to glial fibrillary acidic protein (GFAP; the main cytoskeletal astroglial protein), S100B protein (an astroglial-derived neurotrophic factor), MAP-2 (a microtubule-associated protein present almost exclusively in dendrites), and synaptophysin (Syn; one major integral protein of the synaptic vesicles membrane). The results show a significant increase in the cell area of GFAP-immunoreactive (-IR) astrocytes, with high levels of S100B protein and a significant decrease in the relative area of MAP-2-IR neuronal processes in prenatally stressed adult rats. The expression of synaptophysin decreased in all areas studied. These results demonstrate that prenatal stress induces a long-lasting astroglial reaction and a reduced dendritic arborization, with synaptic loss in the brain of adult offspring. In addition to the neurochemical alterations previously reported, these morphological changes might be underlying the behavioral and learning impairment previously observed in prenatally stressed rats.

Long-term effects of lanthanum intake on the neurobehavioral development of the rat

The effects of subchronic exposure to lanthanum on rats' physical and neurobehavioral development were investigated. Wistar rats were exposed to lanthanum through oral administration at 0, 0.1, 2, and 40 mg/kg concentrations from gestation day 0 through 5 months of age. Prior to weaning of the pups, physical parameters and neurobehaviors were assessed, including body weight gain, pinna detachment, eye opening, surface righting reflex and swimming endurance. At 30 days of age, DNA concentration and protein/DNA ratio of the whole brain were determined. At 150 days of age, the Morris water maze test was carried out to study the memory and learning abilities of the rats. Differences were found in the body weight gain, surface righting reflex and swimming endurance. Moreover, lanthanum exposure significantly altered the DNA concentration and Protein/DNA in brain. The Morris water maze test showed that lanthanum exposure at 40 mg/kg significantly impaired memory and learning abilities. These findings indicate that lanthanum is a potential behavior teratogen. The information provided by this work should be considered in future applications of lanthanides.

Perinatal exposure to endocrine disrupting compounds alters behavior and brain in the female pine vole

Endocrine-disrupting chemicals (EDCs) are synthetic chemicals that arise from sources such as pesticides and have the ability to mimic or inhibit gonadal steroid hormones. The objective of this research was to examine the effects of EDCs on the behaviors associated with monogamy and the expression of related neuropeptide receptors. Pine voles, a novel experimental mammal, were chosen because they display strong monogamous pair bonding. Female pine voles were orally administered estrogenic diethylstilbestrol (DES) and methoxychlor (MXC) or oil control throughout gestation and lactation of pups. Exposed pups were tested as adults. Preference for the mate and maternal behaviors were assessed. While the ability to form partner preferences was intact, DES-exposed females showed increased aggression toward a stranger, while MXC exposed females showed a strong trend toward spending more time alone. Oxytocin (OT) receptor binding in the brain was assessed for possible effects on this behaviorally important neuropeptide signaling system. The cingulate cortex showed a reduction in OT binding in the MXC group. These findings demonstrate that exposure to EDCs during pre- and neonatal development can alter female adult neural phenotype and behavior related to monogamous behavior traits.

[Altered ability to learn of rat offspring with iodine deficiency]

Experimental data demonstrate that hypothyroidism could result in depressive behavior and subsequently thyroid hormones could act as antidepressants. Postnatal changes in learning ability, memory and emotional status in posterity of rats, which have experienced different level of iodine deficiency before conception and during all gestation period were investigated in this study. Results obtained suggest that sudden iodine deprivation before and during gestation led to a significant neurological defect, which was represented by loss of ability to learn, one of the most important functions of brain in newborn and by evidence of depression. Iodine supply to the diet of female rats eliminates these effects completely.

Gestational exposure to methylmercury and n-3 fatty acids: Effects on high- and low-rate operant behavior in adulthood

Fish in the diet is the major source of methylmercury (MeHg) exposure, but eating fish also provides important nutrients. Many fish species contain essential long chain polyunsaturated fatty acids, especially docosahexaenoic acid (DHA), an omega-3 (or n-3) fatty acid, that is important for neural development and function. To examine interactions between MeHg and n-3 fatty acids, female Long-Evans rats were exposed, in utero, to 0, 0.5, or 5 ppm MeHg via drinking water, approximating exposures of 0, 40, and 400 mug/kg/day. They also received pre- and postnatal exposure to a diet containing either fish oil or coconut oil, creating a 2 (Diet)x3 (MeHg) full factorial design, with 6-8 rats per cell. The diets were high or marginal, respectively, in n-3 fatty acids but approximately equal in n-6 fatty acids. No exposure-related effects on developmental milestones or growth were noted. Behavior was evaluated using a series of rapidly increasing fixed ratio (FR) schedules of sucrose reinforcement; 1, 5, 25 and 75 lever presses were required for sucrose delivery, with three sessions provided at each requirement. This phase was followed by four sessions of a differential-reinforcement-of-low-rate-behavior (DRL) schedule, in which presses preceded by 10 s (or more) without a press were reinforced. Subsequently, several progressive ratio (PR) schedules that increased response requirements throughout a single session by a rate of 5%, 10%, or 20% were imposed. Rats exposed during gestation to MeHg had significantly higher response rates than controls under the large FR schedules, during the first session of DRL, and the PR 5% schedule, but neither fish oil nor coconut oil modified MeHg's effects. This finding is consistent with hypotheses that developmental MeHg exposure produced perseverative responding or altered the sensitivity of behavior to its reinforcing consequences and that certain reinforcement contingencies can unmask MeHg's effects.

Ontogeny of hippocampal corticosteroid receptors: Effects of antenatal glucocorticoids in human and mouse

Women at risk for preterm delivery are treated with synthetic glucocorticoids (GCs) to enhance fetal lung maturation. GCs can bind to two intracellular receptors, the glucocorticoid receptor (GR) and the mineralocorticoid receptor (MR), which function as transcription factors. Both are highly expressed in the hippocampus. Several studies have focused on adverse side effects of antenatal GC treatment. However, relatively little is known about the ontogeny of GR and MR, especially in human. Therefore, we studied the ontogeny of both receptors in the human and mouse hippocampus and investigated the effects of antenatal dexamethasone (dex) treatment, a synthetic glucocorticoid, on MR and GR mRNA levels during hippocampal development. The results demonstrate that MR mRNA was first expressed in mouse hippocampus at embryonic day (E)15.5, at the timepoint when dex was administered. In contrast, GR mRNA expression was first observed after birth at postnatal day (P)5. However, in the human hippocampus both receptors are expressed at 24 weeks of gestation, when antenatal GCs are administered in clinical practice. Quantitative in situ hybridization demonstrated that MR mRNA levels were reduced only shortly after dex treatment at E16, but were unaffected from E18 onwards. These findings indicate that a single antenatal dex administration at E15.5 transiently affects MR mRNA levels in the mouse hippocampus. No effect of antenatal dex treatment was found on the human hippocampus at the third trimester of pregnancy. These data on the prenatal ontogeny of both corticosteroid receptors in the human hippocampus is important for understanding the significance of fetal glucocorticoid or stress exposure and its potential effects on health and disease.

Purkinje cell and cerebellar effects following developmental exposure to PCBs and/or MeHg

We recently reported that rats exposed to PCBs and MeHg during development were impaired on the rotating rod, a test of balance and coordination that is often indicative of cerebellar damage. In addition, developmental PCB exposure is known to dramatically reduce circulating thyroid hormone concentrations, which may have a negative impact on cerebellar development. Therefore, we investigated the effects of combined PCB and MeHg exposure on Purkinje cells and the cerebellum. The serum and brains from littermates of the animals tested on the rotating rod were collected at weaning, and we also collected brains from the adult animals at the end of motor testing. Four groups were studied: 1) vehicle controls, 2) PCBs only (Aroclor 1254, 6 mg/kg/d, oral), 3) MeHg only (0.5 ppm, in dams' drinking water), and 4) PCB+MeHg (at the same doses as in individual toxicant exposures). Female Long-Evans rats were exposed beginning 4 weeks prior to breeding with an unexposed male and continuing until postnatal day (PND) 16. There was a significant reduction in serum T4 and T3 concentrations in the PCB and PCB+MeHg pups on PND21. Golgi-impregnated Purkinje cells were examined in PND21 brains, but there were no significant exposure-related effects on primary dendrite length, branching area, or structural abnormalities. However, all three male exposure groups had a marginally significant increase in Purkinje cell height, which may suggest a subtle thyromimetic effect in the cerebellum. Cresyl-violet stained sections from the adult brains showed no exposure-related effects within paramedian lobule in Purkinje cell number, total lobule volume or layer volumes (molecular, granule cell and white matter layers). Evidence is provided for the dysregulation of expression of cerebellar ryanodine receptor (RyR) isoforms in PCB-exposed brains, and this could contribute to the rotating rod deficit by changing critical aspects of intracellular calcium signaling within the cerebellum.

Intrauterine environment and later disease development: Infertility treatment and the risk of diabetes in offspring

The phenotype of an individual, including their susceptibility to disease, is governed by several factors including parental genes and intrauterine environment. Thus, the risk of developing Type 2 diabetes is modulated by the inheritance of specific genetic variants that are slowly being characterised by the techniques of linkage analysis and population association studies using either a candidate gene or genome-wide scan approach. At the same time, evidence has accrued that alterations in the nutritional status of the developing foetus also increase the risk of diabetes in later life. Restricting protein intake in pregnant dams or interfering with placental function increases the risk of diabetes in offspring and light weight babies are more likely to develop Type 2 diabetes as adults than heavier ones. The oocyte plays a key role, since it contains not only the maternal haplotype but other information such as mitochondrial DNA and factors that modulate the expression of genes in the developing foetus. Although the ovaries contain a huge number of primordial follicles, generally each month only one oocyte matures to ovulation. Little is known about the processes that control this phenomenon. Certainly, primordial follicles and oocytes are not all the same, differing especially in mitochondrial DNA content. As women age, the oocytes released are more likely to contain genetic errors, explaining the increased risk of Trisomy 21 with maternal age. It is generally assumed that primordial follicle development and the selection of a single ooctye for ovulation is a random process. This paper suggests that this may not be the case but that a carefully controlled system may allow the mother to release an oocyte that is best suited to the prevailing environment. This would represent an important mechanism for species adaptation. Many human infertility treatments involve pharmacological superovulation, egg harvesting and culture prior to in vitro fertilisation and reimplantation. These will bypass any system of controlled ovulation and therefore might alter the risk of diseases such as Type 2 diabetes mellitus in later life. Although the offspring of human infertility treatments are generally born healthy, it is important to note that the oldest "test-tube" baby is still less than 30-years old, so the risk of late-onset diseases is still unknown.

Disruption of the development of cholinergic-induced translocation/activation of PKC isoforms after prenatal heroin exposure

Prenatal exposure of mice to heroin resulted in behavioral deficits present at adulthood, and related to septohippocampal cholinergic innervation accompanied by both pre- and postsynaptic cholinergic hyperactivity; including an increase in membrane PKC activity, and a desensitization of PKC to cholinergic input, which correlated highly with the behavioral performance, and was reversed by cholinergic grafting. The effect was shown in the behaviorally relevant PKCgamma and beta whereas the less behaviorally relevant PKCalpha isoform was not affected. The present study was designed to establish the effect of heroin exposure on the expression of the PKC isoforms level and on the more functionally relevant cholinergic translocation/activation of the isoforms throughout postnatal development. The hippocampi of mice pups, exposed to heroin transplacentally, were assayed after incubation with carbachol for PKC isoforms on postnatal days (PN) 1, 7, 14, 21, 30 and 50. Prenatal heroin exposure increased basal PKCgamma, beta and alpha levels. PKCgamma and alpha levels returned to control levels on PN50. While in PKCbeta, this increase lasted until PN50. Translocation/activation of the PKC isoforms gamma and beta by cholinergic receptor stimulation was present from PN1, concurrent with the presence of the isoforms. Prenatal exposure to heroin completely abolished the translocation/activation throughout the entire postnatal development. This defect was shown from the very beginning, PN1, the day when the PKC isoforms appear. The results suggest that the PKCgamma and beta isoforms are functional concurrent with their developmental appearance. Unlike findings on some other teratogens, the prenatal heroin effect on the isoforms function is similar throughout postnatal development.

Molecular mechanisms of hydroxyurea(HU)-induced apoptosis in the mouse fetal brain

Hydroxyurea (HU), a potent mammalian teratogen, affects proliferating embryonic cells and inhibits DNA synthesis. The teratogenic potential of HU has been well known in experimental animals for several decades. In this study, we investigated molecular mechanisms of HU-induced apoptosis in the telencephalon of the fetal brain by exposing pregnant mice to HU on day 13 of gestation. The number of TUNEL-positive cells began to increase at 3 h, peaked at 12 h, and rapidly decreased at 24 h. Although changes of p53 mRNA expression were not observed by RT-PCR, a p53-positive reaction was detected immunohistochemically in the nuclei of neuroepithelial cells from 1 h to 6 h, and p53-protein expression was simultaneously identified by Western blot analysis. The expression of p53-target genes was detected at both the mRNA and protein. The mRNA levels of apotosis-related genes (fas, fasL, and bax) and cell cycle-related genes (mdm2 and p21) were significantly elevated, and the degree to and sequence in which these target genes expressed was similar to those for fas, fasL, mdm2 and p21. Flow-cytometric and Western blot analyses of cell cycle-related proteins suggested that neuroepithelial cells are arrested at the S checkpoint from 3 to 6 h and at the G2/M checkpoint at 12 h, respectively. HU-induced apoptosis is considered to be mediated by p53 in the fetal brain.

A low maternal protein diet during pregnancy and lactation has sex- and window of exposure-specific effects on offspring growth and food intake, glucose metabolism and serum leptin in the rat

Extensive epidemiological and experimental evidence indicates that a sub-optimal environment during fetal and neonatal development in both humans and animals may programme offspring susceptibility to later development of chronic diseases including obesity and diabetes that are the result of altered carbohydrate metabolism. We determined the effects of protein restriction during pregnancy and/or lactation on growth, serum leptin, and glucose and insulin responses to a glucose tolerance test in male and female offspring at 110 days postnatal life. We fed Wistar rats a normal control 20% casein diet (C) or a restricted diet (R) of 10% casein during pregnancy. Female but not male R pups weighed less than C at birth. After delivery, mothers received the C or R diet during lactation to provide four offspring groups: CC (first letter maternal pregnancy diet and second maternal lactation diet), RR, CR and RC. All offspring were fed ad libitum with C diet after weaning. Relative food intake correlated inversely with weight. Offspring serum leptin correlated with body weight and relative, but not absolute, food intake in both male and female pups. Serum leptin was reduced in RR female pups compared with CC and increased in RC males compared with CC at 110 days of age. Offspring underwent a glucose tolerance test (GTT) at 110 days postnatal life. Female RR and CR offspring showed a lower insulin to glucose ratio than CC. At 110 days of age male RR and CR also showed some evidence of increased insulin sensitivity. Male but not female RC offspring showed evidence of insulin resistance compared with CC. Cholesterol was similar and triglycerides (TG) higher in male compared with female CC. Cholesterol and TG were higher in males than females in RR, CR and RC (P < 0.05). Cholesterol and TG did not differ between groups in females. Cholesterol and TG were elevated in RC compared with CC males. Nutrient restriction in lactation increased relative whole protein and decreased whole lipid in both males and females. RC females showed decreased relative levels of protein and increased fat. We conclude that maternal protein restriction during either pregnancy and/or lactation alters postnatal growth, appetitive behaviour, leptin physiology, TG and cholesterol concentrations and modifies glucose metabolism and insulin resistance in a sex- and time window of exposure-specific manner.

Purkinje cell loss accompanies motor impairment in rats developing at altered gravity

We have previously reported that the developmental exposure of rats to altered gravity (1.65 g) from gestational day 8 to postnatal day 21 impacts motor functions and cerebellar structure. The present study examined whether the decrease in cerebellar mass accompanied by impaired performance on a rotorod in hypergravity-exposed rats was related to a decrease in Purkinje cell number. The total number of Purkinje cells was determined on postnatal day 21 using a stereological analysis applied to paraformaldehyde-fixed cerebellar samples subsequently embedded in celloidin. Total Purkinje cell number was decreased by 17.7-25.3%. These results imply that exposure to altered gravity during Purkinje cell birth may affect their proliferation, resulting in a decrease in Purkinje cell number, which, in turn, leads to motor impairment.

Bone mass in childhood is related to maternal diet in pregnancy

Evidence that birth weight is related to bone mass in later life suggests that the intrauterine environment programs the trajectory of subsequent bone development. To explore this hypothesis, we examined whether maternal diet in pregnancy, as assessed by the maternal food frequency questionnaire (FFQ) completed at 32 weeks gestation, is related to bone mass of the child, as measured by total body DXA carried out at age 9 years in the Avon Longitudinal Study of Parents and Children (ALSPAC). Diet records were linked to DXA scan results for the total body and spine sub-region and pooled between pre- and early pubertal boys and girls (n=4,451). Regression analysis was carried out between DXA values and dietary factors following adjustment for social and other confounding factors. Maternal magnesium intake was related to total body BMC (beta=4.9, 7.4-23.1; g) and BMD (beta=4.9, 2.5-7.3; g/cm2 x10(3)) (standardized regression coefficient with 95% confidence limits; P<0.001). An equivalent relationship was no longer observed after adjusting for the height of the child, to which magnesium intake was also related (beta=0.48, 0.20-0.77; cm; P=0.001). Maternal intake of potassium was related to spinal BMC (beta=1.8, 0.8-2.9; g) and BMD (beta=10.5, 4.9-16.0; g/cm2 x10(3)) (P=0.001), which was no longer observed after adjusting for the weight of the child, to which potassium intake was also related (beta=0.52, 0.16-0.88, P=0.005; kg). A significant association was also observed between maternal dietary folate intake and spinal BMC adjusted for bone area using a linear regression model (beta=0.55, 0.16-0.94; g; P=0.006), which persisted after adjusting for height and weight. Our observation that constituents of maternal diet are related to DXA measures at age 9 is consistent with the hypothesis that the trajectory of bone development in childhood is programmed by early life factors.

Prenatal stress elicits regionally selective changes in basal FGF-2 gene expression in adulthood and alters the adult response to acute or chronic stress

Exposure to stress during pregnancy influences the trajectory of brain development resulting in permanent alterations that may contribute to increased susceptibility to subsequent cognitive or neuropsychiatric disorders. In this manuscript, we examined the effects of prenatal stress on the expression of basic fibroblast growth factor (FGF-2), an important molecular regulator of development and plasticity, in adult male rats under basal conditions as well as in response to acute or chronic stress. Baseline FGF-2 mRNA levels were differentially influenced by gestational stress in a variety of brain regions, with significant decreases in prefrontal cortex and increases in entorhinal cortex and striatum. By itself, postnatal stress similarly decreased trophic factor expression in prefrontal cortex while evoking stimulation elsewhere. Gestational stress altered the pattern of FGF-2 expression in response to adult stress, completely reversing the pattern in the prefrontal cortex (stimulatory instead of inhibitory), blunting the response in the entorhinal cortex and desensitizing the response in the striatum. These effects point to a unique interference of chronic prenatal stress with both ongoing FGF-2 expression and its responses to subsequent stressors, lasting into adulthood. Given the multifaceted role of FGF-2 in synaptic development, maintenance and plasticity, these data provide detailed mechanistic evidence as to how prenatal stress elicits lifelong effects on synaptic function. The abnormal modulation of FGF-2 gene expression in specific brain regions in response to subsequent stress in adulthood may impair the normal adaptive responses of the cell to challenging situations.

The effects of prenatal stress on the Purkinje cell neurogenesis

In the developing cerebellum, generation times of macroneurons and microneurons occur during pre- and postnatal period, respectively. In this study, to investigate the effects of prenatal stress exposure on cerebellar neuronal development, the granule-to-Purkinje cell ratio of stressed animals was compared with their age-matched controls. In the experimental group, pregnant dams were immobilized on their gestational day 7 and 14, for 6 h. The cerebella of the offspring were removed at postnatal day (P) 30, and granule-to-Purkinje cell ratios, obtained by dividing the numerical density of granule cells (NVg) by that of Purkinje cells (NVP), were found significantly reduced (24%) in the stressed animals. Since volume fraction of granular to molecular layer or white matter to whole cortex was not affected from stress exposure, the deficit seen in this ratio reflects an existent increase in the numerical density of Purkinje cells, rather than a decrease in the number of granule cells. In parallel, the linear density of Purkinje cells (NBP) and the percentage of proliferating cells, immunolabeled with BrdU, were also found significantly higher in stressed animals. Taken together, our results demonstrate that intrauterine stress changes the morphology and numerical density of cerebellar neurons by primarily affecting the actively dividing cells during the selected stress period.

Auditory deficits in rats exposed to an environmental PCB mixture during development

Previous studies have indicated that developmental exposure to polychlorinated biphenyls (PCBs) may result in hearing impairment in rats. The cochlea is the suggested site of action, based upon one study demonstrating a loss of outer hair cells on the basilar membrane, and another demonstrating deficits in distortion product otoacoustic emissions (DPOAEs). The current study was conducted to assess the possible ototoxic effects of a unique PCB mixture formulated to model the congener profile of PCBs found in fish consumed by a human population in northeastern Wisconsin. Female Long-Evans rats were dosed orally with the PCB mixture beginning 28 days prior to breeding and continuing until the pups were weaned. Dams were fed one-half of a cookie onto which was pipetted 0, 1, 3, or 6 mg/kg of the PCB mixture dissolved in a corn oil vehicle. On postnatal day (PND) 21, pups were weaned, and one male and one female from each litter were randomly selected for auditory assessment. DPOAEs were measured to assess cochlear function, and auditory brainstem responses (ABRs) were measured to determine effects on central nervous system auditory pathways. DPOAE amplitudes were decreased, and DPOAE and ABR thresholds were elevated across a range of frequencies in PCB-exposed rats. These results support and extend previous reports of auditory impairment in PCB-exposed rats. Developmental exposure to PCBs may also result in subtle auditory impairments in humans, and if so, this may contribute to some of the cognitive deficits that have been observed in epidemiological studies.

Placental insufficiency leads to developmental hypertension and mesenteric artery dysfunction in two generations of Sprague-Dawley rat offspring

It is generally accepted that preeclampsia results from reduction in perfusion to the uteroplacental unit leading to maternal hypertension and fetal growth restriction. Placental insufficiency creates an environment of fetal undernutriton, predisposing the fetus to the development of adult disease. In this study, we characterized the development and perpetuation of hypertension in two generations of male and female offspring subjected to an environment of fetal undernutrition via reduced uteroplacental perfusion pressure. Further, we examined vascular responses of resistance arteries in these animals to determine the influence of placental insufficiency on the development and perpetuation of hypertension. Experimental dams underwent a surgical procedure to reduce uteroplacental perfusion pressure, with resulting offspring comprising the first generation (F1). One male and one female from each of the F1 experimental litters served as breeders of the second generation (F2). Weekly systolic blood pressure measurements were obtained from 4 to 24 wk in control, F1, and F2 offspring. Vascular responsiveness to the vasoconstrictors phenylephrine and potassium chloride and the vasorelaxants acetylcholine and sodium nitroprusside was determined in the three offspring groups at 6, 9, and 12 wk of age. Our findings indicate that placental insufficiency during a critical developmental window in late gestation leads to hypertension in juvenile Sprague-Dawley rat offspring and is perpetuated in a second generation of offspring in a gender-specific manner. Further, exposure to placental insufficiency during late gestation leads to developmental alterations characterized by vascular hyperresponsiveness, perpetuated to a second generation of offspring in the absence of persistent environmental stimuli, contributing to hypertension.

The neurotoxic effects of prenatal cardiac glycoside exposure: a hypothesis

Cardiac glycosides (CGs) are beneficial in treating cardiac conditions; depending on time and dosage, they can also be toxic as they regularly cross the blood brain barrier and the placenta and may affect the unborn baby. This paper therefore focuses on the effects of CGs administered to the mother on normal cellular physiology of the foetus with specific reference to neural tissue. CGs act by binding to the Na+/K+-ATPase and decrease or inhibit Na+-K+ pump activity. In the foetus, CGs may disrupt ion homeostasis. An over-dosage of CGs or when it is taken during pregnancy, can also affect the neuro-energy levels of brain tissue in particular. We conclude and hypothesize that CGs in this case will not only cause severe alterations in neuronal function due to disruption of membrane activity, but also in glutamate clearance, affecting neurotransmission in general. Furthermore, elevated cytosolic Ca2+ will lead to permeabilization of the mitochondrial membranes, resulting ultimately in mitochondrial dysfunction. This will result in neurotoxicity--ensuing in neural cell damage or death, and we propose the mechanism to be due to neuro-necrapoptosis.

Effects of prenatal paraquat and mancozeb exposure on amino acid synaptic transmission in developing mouse cerebellar cortex

The goal of this study was to analyze the effects of prenatal exposure to the pesticides paraquat (PQ) and mancozeb (MZ) on the development of synaptic transmission in mouse cerebellar cortex. Pregnant NMRI mice were treated with either saline, 10 mg/kg PQ, 30 mg/kg MZ or the combination of PQ + MZ, between gestational days 12 (E12) and E20. Variation in the levels of amino acid neurotransmitters was determined by HPLC, between postnatal day 1 (P1) and P30. Motor coordination was assessed by locomotor activity evaluation of control and experimental pups at P14, P21 and P30. Significant reductions in the levels of excitatory neurotransmitters, aspartate and glutamate, were observed in PQ-, MZ- or combined PQ + MZ-exposed pups, with respect to control, during peak periods of excitatory innervation of Purkinje cells: between P2-P5 and P11-P15. However, at P30, lower aspartate contents, in contrast with increased glutamate levels, were detected in all experimental groups. During the first two postnatal weeks, delays in GABA and glycine ontogenesis were observed in PQ- and PQ + MZ-exposed pups, whereas notable decrements in GABA and glycine levels were seen in PQ + MZ-exposed animals. Decreased taurine contents were detected at P3 and P11 in PQ- and PQ + MZ-exposed mice. Pups in different experimental groups all showed hyperactivity at P14 and then exhibited reduced locomotor activity at P30. Taken together, our results indicate that prenatal exposure to either PQ or MZ or the combination of both could alter the chronology and magnitude of synaptic transmission in developing mouse cerebellar cortex.

Adverse effects of prenatal tobacco smoke exposure on biological parameters of the developing brainstem

We aimed to study the consequences of chronic exposure to tobacco smoke in utero on the morphological and functional maturation of the brainstem by comparing stillbirths of smoker mothers versus nonsmoker mothers. A total of 42 stillbirths, aged 25-40 gestational weeks, underwent autopsy according to our guidelines (). The brainstem was studied on serial sections and by immunohistochemistry to assay the expression of the EN2 gene, somatostatin (SS) and the tyrosine hydroxylase enzyme (TH). We observed a significant correlation between maternal smoking and sudden intrauterine unexplained death (SIUD), hypoplasia of the ArcN, no immunostaining of the EN2 in the arcuate nucleus (ArcN), and of TH in the locus coeruleus (LC) (P < 0.05). An increased incidence of maternal smoking was also observed in fetuses with SS negativity in the hypoglossus nucleus (HypoglN). Exposure in utero to maternal smoking may strongly interfere with brain biological parameters, giving rise not only to structural developmental abnormalities of the arcuate nucleus, but also to a decrease of noradrenergic activity in the LC, of EN2 gene expression in the ArcN and of SS in the HypoglN.

Does Exposure to Antiretroviral Therapy Affect Growth in the First 18 Months of Life in Uninfected Children Born to HIV-Infected Women?

Uninfected children born to HIV-infected women are exposed antenatally to antiretroviral therapy, but it is uncertain whether this affects growth in early life. We analyzed weight, height, and occipitofrontal circumference (OFC) in 1912 children from a cohort study: 1304 had no or monotherapy exposure and 608 had combination therapy exposure. The mean z-score for birth weight or OFC did not differ by exposure category in 1513 term children or in 78 born at <34 weeks; the 266 born from 34 to 36 weeks were heavier if exposed to combination therapy. Children with combination therapy exposure born at 34 to 36 weeks reached the 25th centile for weight and OFC earlier than those not exposed born at 34 to 36 weeks (median: birth vs. 3 months; P = 0.003 [weight], P = 0.004 [OFC]), whereas children exposed to combination therapy born at <34 weeks reached the 25th centile for OFC later than those born at <34 weeks not exposed (median: 15 vs. 7 months; P = 0.004). Gestational age and maternal illicit drug use were strongly associated with growth, but the effect of combination therapy exposure was marginal (adjusted coefficients: weight, -0.10 [P = 0.019]; height, -0.12 [P = 0.008]; and OFC, -0.14 [P = 0.001]). Although the effect of combination therapy exposure is minimal, long-term monitoring of these children is important.

Seizure susceptibility in prenatally methamphetamine-exposed adult female rats

The purpose of the present study was to examine the effect of prenatal methamphetamine (MA) exposure on seizures induced by bicuculline and N-methyl-d-aspartate in adult female rats. The present results show that prenatal MA exposure alters seizures in a model-specific manner and that the seizure susceptibility of adult female rats may be affected by the stage of their estrous cycle.

Postnatal intermittent hypoxia alters baroreflex function in adult rats

Chronic perinatal intermittent hypoxia (IH) could have long-term cardiovascular effects by altering baroreflex function. To examine this hypothesis, we exposed rats (n = 6/group) for postnatal days 1-30 or prenatal embryonic days 5-21 to IH (8% ambient O2 for 90 s after 90 s of 21% of O2, 12 h/day) or to normoxia (control). Baroreflex sensitivity (BRS) and cardiac chronotropic responses were examined in anesthetized animals 3.5-5 mo later by infusing phenylephrine or sodium nitroprusside (6-12 microg/min iv, 1-2 min) during normoxia and after 18 min of acute IH (IHA). In controls after IHA, baroreflex gain was 42% (P < 0.05) less than during normoxia. BRS in the postnatal IH group during normoxia was approximately 50% less than in control rats and similar to controls after IHA. The heart rate response to phenylephrine in the IH group was also less than in controls (P < 0.05) and was not changed by IHA. BRS and heart rate responses in the prenatal IH group were similar to the normoxic control group. Vagal efferent projections to atrial ganglia neurons in rats after postnatal IH (n = 4) were examined by injecting tracer into the left nucleus ambiguous. After 35 days of postnatal IH, basket ending density was reduced by 17% (P < 0.001) and vagal axon varicose contacts by 56% (P < 0.001) compared with controls. We conclude that reduction of vagal efferent projections in cardiac ganglia could be a cause of long-term modifications in baroreflex function.