Análisis epidemiológico del programa de vigilancia activa de Piscirickettsia salmonis del Servicio Nacional de Pesca y Acuicultura de Chile.

Piscirickettsia salmonis is the causative agent of piscirickettsiosis, a disease that causes significant economic losses in salmonid sea farms in Chile. The objective of this study was to determine and describe the geographical distribution, seasonality and time period when P. salmonis was first detected in farms studied under the active surveillance programme for piscirickettsiosis of the National Fisheries and Aquaculture Service of Chile (SERNAPESCA), which was conducted from January 2013 to March 2017. A 0.28% prevalence of piscirickettsiosis was determined in freshwater fish and one of 58.1% in sea farms. The prevalence of P. salmonis was 61.1% in the Aysén region, 59.8% in the Los Lagos region, 5.1% in the Los Ríos region and 3.0% in the Magallanes region. In Los Lagos and Aysén, eight clusters of sea farms were identified, in space and time, as having a positive diagnosis of P. salmonis, whereas, in Magallanes, none was identified, confirming the absence of horizontal transmission or spread of the agent in this geographical area. A seasonal variation was found in the monthly prevalence of P. salmonis, with increases in Salmo salar and Oncorhynchus mykiss in summer and autumn, and in Oncorhynchus kisutch in winter, spring and summer. It was determined that the average time required to detect the agent after fish had been transferred to the sea was 105 days (minimum, 7 days; maximum, 351 days), and no differences were found either between regions or species. Thus the results obtained from the active surveillance programme have helped to increase knowledge of the epidemiology of P. salmonis.

Piscirickettsia salmonis est l'agent étiologique de la piscirickettsiose, une maladie à l'origine de lourdes pertes économiques pour la filière de la salmoniculture marine du Chili. Les auteurs présentent les résultats d'une étude visant à déterminer et à décrire la distribution géographique, les variations saisonnières et le moment où P. salmonis est détectée pour la première fois dans les fermes salmonicoles couvertes par le programme de surveillance active de la piscirickettsiose mis en oeuvre par le Service national de la pêche et de l'aquaculture (Sernapesca) du Chili de janvier 2013 à mars 2017. Les taux de prévalence de la piscirickettsiose étaient de 0,28 % chez les poissons d'eau douce et de 58,1% dans les sites marins. Au niveau des régions, le taux de prévalence de P. salmonis était de 61,1 % à Aysén, de 59,8 % à Los Lagos, de 5,1 % à Los Ríos et de 3,0 % à Magallanes. À Los Lagos et à Aysén huit groupements de fermes salmonicoles marines ont été identifiés dans l'espace et le temps comme ayant été infectés par l'agent pathogène, tandis qu'à Magallanes aucune détection n'a eu lieu, ce qui confirme l'absence de transmission horizontale et de dissémination de l'agent pathogène dans cette zone géographique. La prévalence mensuelle de P. salmonis fait ressortir une variation saisonnière, avec une prévalence accrue en été et en automne chez Salmo salar et Oncorhynchus mykiss, et en hiver, au printemps et en été chez O. kisutch. Il a été établi que le laps de temps nécessaire pour détecter l'agent pathogène après le transfert en mer des poissons était de 105 jours en moyenne (minimum 7 jours, maximum 351 jours), moyenne non affectée par la région ou l'espèce. Ces résultats ont donc permis de mieux appréhender l'épidémiologie de l'agent pathogène grâce au programme de surveillance active.

Piscirickettsia salmonis es el agente causal de la piscirickettsiosis, enfermedad que causa importantes pérdidas económicas en los centros marinos de cultivos de salmónidos de Chile. Este estudio tuvo como objetivo determinar y describir la distribución geográfica, la estacionalidad y momento de la primera detección de P. salmonis en los centros de cultivo estudiados en el programa de vigilancia activa de la piscirickettsiosis del Servicio Nacional de Pesca y Acuicultura (Sernapesca) de Chile, que se llevó a cabo entre enero de 2013 y marzo de 2017. Se determinó una prevalencia de piscicrickettsiosis del 0,28% en peces de agua dulce y del 58,1% en centros marinos. En la región de Aysén, la prevalencia de P. salmonis fue del 61,1%, en Los Lagos, del 59,8%, en Los Ríos, del 5,1%, y en Magallanes, del 3,0%. En Los Lagos y Aysén, se identificaron ocho conglomerados de centros marinos, en el espacio y en el tiempo, con diagnóstico positivo del agente, en cambio, en Magallanes no se detectó, lo cual confirma la inexistencia de transmisión horizontal y de diseminación del agente en esta área geográfica. Se observó una variación estacional en la prevalencia mensual de P. salmonis, en la cual se comprueba un alza en verano y otoño en el caso de Salmo salar y Oncorhynchus mykiss, y en invierno, primavera y verano en el caso de O. kisutch. Se determinó que la media de tiempo necesario para la detección del agente desde la transferencia de los peces al mar era de 105 días (mínimo, 7; máximo, 351 días), y no se observaron diferencias entre regiones o especies. Así los resultados contribuyen a conocer la epidemiología del agente a través del programa de vigilancia activa.

Correlation of placental pathology with the postoperative outcomes and white matter injury in preterm infants following necrotizing enterocolitis.

BACKGROUND: To determine the association of placental pathologic lesions with postoperative outcomes, survival, and white matter injury (WMI) in preterm infants with NEC. METHODS: A retrospective chart review of 107 neonates with NEC (Bell stage > IIa) from Jan 2013- June 2020 was completed. Demographic, clinical, and outcome data were compared between infants with or without placental pathologic lesions. RESULTS: In this cohort, 59/107 (55%) infants had medical NEC, and 48 (45%) had surgical NEC. The infants had a mean gestational age of 28.1±3.7 weeks and a birth weight of 1103±647 g. Maternal vascular malperfusion (82/107, 76.6%) and acute histological chorioamnionitis (42, 39.3%) were the most common pathological placental lesions. Acute histologic chorioamnionitis with fetal inflammatory response was more common in infants with surgical NEC vs. medical NEC (35.4% vs. 15.3%; p = 0.02). The NEC Infants with WMI on brain MRI scans had a significantly higher incidence of acute histological chorioamnionitis (52% vs. 27.8%; P = 0.04). No significant differences in mortality, length of stay and postoperative outcomes in neonates with and without acute histologic chorioamnionitis with fetal inflammatory response were noted. On unadjusted logistic regression, acute histologic chorioamnionitis without fetal inflammatory response was also associated with higher odds of WMI (OR 2.81; 95% CI 1.05-7.54; p = 0.039). CONCLUSION: Acute histological chorioamnionitis without fetal inflammatory response was associated with higher odds of WMI in infants with NEC, with no significant impact on mortality and other postoperative outcomes.

Toxicity and exposure of an adenovirus containing human interferon alpha-2b following intracystic administration in cynomolgus monkeys.

The safety and toxicokinetics of SCH 721015, an adenovirus encoding the human interferon alpha-2b gene, and Syn3 (SCH 209702), a novel excipient, were assessed in cynomolgus monkeys administered intravesical doses of 2.5 × 10E11 or 1.25 × 10E13 particles SCH 721015 in 25 mg Syn3 or 25 mg Syn3 alone on study days 1 and 91. There was no systemic toxicity. Monkeys dosed with SCH 721015 in Syn3 were positive for SCH 721015-specific DNA in the urine for 2 to 3 days following each dose and had interferon alpha-2b protein in the urine for 1-3 days after a single dose and in fewer animals after a second dose. Intracystic administration was associated with inflammation and focal/multifocal ulceration in the urinary bladder and irritation in the ureters and urethra at necropsy. The physical trauma from catheterization and filling/emptying of the bladder was likely a contributing factor and Syn3 exacerbated the trauma. There was nearly complete resolution of these findings 2 months after the last dose. The trauma to the bladder likely contributed to low, transient systemic exposure to Syn3, SCH 721015 and human interferon protein. The results of this study support the clinical investigation of SCH 721015 in Syn3.

Effect of glucose concentration during in vitro culture of mouse embryos on development to blastocyst, success of embryo transfer, and litter sex ratio.

A high-glucose concentration in the reproductive tract during early development may result in aberrant embryo or fetal development, with effects that could have a greater impact on one sex than the other. Here, we determine if a high-glucose concentration impacts embryo development and pregnancy outcomes in a sex-specific manner in the mouse. Zygotes were cultured in potassium simple optimized medium, which typically contains 0.2 mM D-glucose, with and without additional glucose supplementation to a concentration of 28 mM. Zygote cleavage and blastocyst rate did not differ between treatments, but total and trophectoderm cell counts were reduced in blastocysts cultured in a high glucose. No differences between sexes nor inner cell mass cell number were observed within each treatment. Blastocysts developed in both media were transferred to recipients. The percentage of blastocysts resulting in viable pups was significantly reduced when the blastocysts were cultured in 28 mM glucose (74 ± 4%, controls vs. 55.8 ± 7.1%, 28 mM glucose), but conceptus loss affected both sexes equally as litter sex ratio did not differ between treatments (52.7% and 52.2% males for controls and high glucose, respectively). Pup body weight at birth was higher for males than females, but was not affected by earlier culture in high glucose. In conclusion, in vitro culture in medium with a glucose concentration approximating that of diabetic serum reduces total and trophectoderm cell numbers at the blastocyst stage and conceptus development to term, but these detrimental effects are not sex-specific.

Effects of maternal diet and exposure to bisphenol A on sexually dimorphic responses in conceptuses and offspring.

Whereas sexual differentiation is considered as the onset of differentiation of the male or female gonads, mounting evidence indicates that sex differences in developmental programming are established as early as the zygotic stage. Genetic and epigenetic differences between the sexes might govern how each responds to shifts in their early environment, including in the uterus or culture dish, as in the case of in vitro cultured pre-implantational embryos. Even if no differences are evident between the sexes at birth, divergent conceptus responses to surrounding changes, such as maternal diet and exposure to endocrine disrupting compounds (EDC), such as bisphenol A (BPA), might predispose one sex over the other to later adult-onset diseases, otherwise termed developmental origin of health and disease (DOHaD). Overall, males subjected to less than optimal in utero conditions tend to be at greater risk for various diseases, including neurobehavioural disorders. As the placenta is the primary nutrient acquisition and communication organ between the dam and foetus, its ability to adapt rapidly to environmental shifts might buffer the conceptus against environmental insults. The placenta of one sex over the other might possess greater ability to respond to environmental fluctuations. In utero environmental changes, including maternal nutrient excess or reduction or exposure to the EDC, BPA, might govern sex-dependent behavioural alterations. In sum, this review examines the evidence to date that male and female zygotes and conceptuses diverge in their responses to shifting environmental conditions and whether these contrasting sexually dimorphic responses underpin later DOHaD outcomes, namely neurobehavioural changes.

Isolation and propagation of a human enteric coronavirus.

Coronavirus-like particles were found by electron microscopy in stools from infants with necrotizing enterocolitis. Stool samples from these infants as well as control specimens were passaged in cultures of human fetal intestinal organs. Two samples yielded virus-like particles and these have now been passaged 14 times (HEC 14). Gradient-purified HEC 14 strains had typical coronavirus morphology on electron microscopy and contained five major proteins with molecular sizes ranging from 190 to 23 kilodaltons. Infants with necrotizing enterocolitis developed specific antibody to the viral antigens between the acute and convalescent stages of the disease, as shown by examining serum specimens by single radial hemolysis, immunoenzymatic assay, and Western immunoblotting. No cross-reactivity was shown with other coronavirus strains tested, or with the newly isolated viruses of the Breda-Berne group, responsible for calf or horse diarrhea.

The chronically instrumental ewe: a model for studying vascular reactivity to angiotensin II in pregnancy.

Vascular refractoriness to the systemic pressor effects of angiotension II (AII) develops normally during human pregnancy. To ascertain if the ewe might provide a suitable animal model to study the mechanisms responsible for this response (unique to pregnancy) we studied this phenomenon in unanesthetized, chronically instrumented nonpregnant and pregnant sheep, 68-143 d gestation. In these studies dose-response curves were established for changes in both mean arterial pressure and uterine blood flow. The pressor response to continuous infusions of AII increases as a function of the dose of AII in both nonpregnant and pregnant animals (P less than 0.001), R = 0.943 and 0.879, respectively. However, the pregnant animals were refractory to the pressor effects of AII, requiring 0.016 microgram of AII/min per kg to elicit a 20 mm HG rise in mean arterial pressure, in contrast to 0.009 for nonpregnant animals. The slope and intercept for the regression lines are different at P less than 0.001. In pregnant animals the dose-response curve for uterine blood flow was also determined. Increases in uterine blood flow were observed at doses of AII less than 0.016 microgram/min per kg, while larger doses resulted in a progressively greater reduction in blood flow. It appears likely that the ewe may serve as an animal model suitable for the further study of the unique pregnancy-modified systemic and uteroplacental vascular responses elicited by AII.

Effect of angiotensin II on uterine and systemic vasculature in pregnant sheep.

The response of uteroplacental blood flow (UBF) to angiotensin II is controversial. Moreover, the relationship of the uterine and systemic responses to infused angiotensin II is not well understood. Thus, in eight chronically instrumented, near-term pregnant sheep, we have determined the relationships between the dose and duration of constant systemic infusions of angiotensin II ([Val5] ANG II) and changes in UBF, uterine vascular resistance (UVR), mean arterial pressure (MAP), and systemic vascular resistance (SVR). [Val5] ANG II caused dose-dependent increases in UVR and MAP at all doses studied (P less than 0.05). The response in UBF was bidirectional, with increases at doses less than or equal to 1.15 microgram/min and decreases at greater than or equal to 2.29 micrograms/min (P less than 0.05). Increases in UBP occurred when the relative rise (delta) in MAP greater than delta UVR, whereas UBF was unchanged when delta MAP = delta UVR and decreased when delta MAP less than delta UVR. SVR also rose in a dose-dependent fashion (P less than 0.05); delta SVR was greater than delta UVR at doses less than or equal to 2.29 micrograms [Val5] ANG II/min (P less than 0.01). In studies of the effect of duration of [Val5] ANG II infusions, UBF increased at all doses during the 1st min, followed by stabilization at 4--5 min, with eventual decreases at doses greater than or equal to 2.29 micrograms/min and increases at doses less than 2.29 micrograms/min. The relationship between the changes in MAP and UVR to the response of UBF was as noted above. It is evident that (a) [Val5] NAG II is uterine vasoconstrictor, (b) changes in UBF are dependent upon relative changes in perfusion pressure and UVR, which in turn are dependent upon both the dose and duration of a [Val5] ANG II infusion, and (c) the uteroplacental vasculature is relatively refractory to the vasoconstricting effects of low doses of [Val5] ANG II.

In vitro prostacyclin production by ovine uterine and systemic arteries. Effects of angiotensin II.

Normal pregnancy is associated with reduced systemic pressor responses to infused angiotensin II (ANG II); furthermore, the uterine vascular bed is even less responsive to vasoconstriction by ANG II than the systemic vasculature overall. The mechanism(s) for this refractoriness remains unknown. To determine if vessel production of prostacyclin may be responsible, uterine and omental artery segments were obtained from four groups of sheep, nonpregnant (NP), pregnant (P; 131 +/- 4 d), early postpartum (2.2 +/- 0.4 d), and late postpartum (16 +/- 2 d), and incubated in Krebs-Henseleit alone or with ANG II in the absence or presence of Saralasin. Prostacyclin was measured as 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha). Synthesis of 6-keto-PGF1 alpha was de novo, since aspirin inhibited its formation. P and early uterine arteries produced more 6-keto-PGF1 alpha than NP and late vessels (P less than 0.05): 386 +/- 60 (X +/- SE) and 175 +/- 23 vs. 32 +/- 5 and 18 +/- 4 pg/mg X h, respectively. A similar relationship was observed for omental arteries: 101 +/- 14 and 74 +/- 14 vs. 36 +/- 10 and 22 +/- 4 pg/mg X h, respectively. Furthermore, synthesis by arteries from P and early animals was greater in uterine than omental vessels (P less than 0.05); this was not observed in NP or late vessels. ANG II increased 6-keto-PGF1 alpha production 107 +/- 20% and 92 +/- 16% in P and early uterine arteries only; the threshold dose was between 5 X 10(-11) and 5 X 10(-9) M ANG II. This ANG II-induced increase in 6-keto-PGF1 alpha by uterine arteries was inhibited by Saralasin, which by itself had no effect. During pregnancy, the reduced systemic pressor response to ANG II and the even greater refractoriness of the uterine vascular bed may be reflective of vessel production of the potent vasodilator, prostacyclin. Furthermore, in the uterine vasculature, this antagonism may be potentiated by specific ANG II receptor-mediated increases in prostacyclin.

Nitric oxide contributes to estrogen-induced vasodilation of the ovine uterine circulation.

Estradiol-17beta (E2beta), a potent vasodilator, has its greatest effects on the uterine vasculature, blood flow (UBF) increasing > or = 10-fold. The mechanism(s) responsible for E2beta-induced vasodilation is unclear. We determined if nitric oxide (NO)-induced increases in cGMP modulate estrogen-induced increases in UBF, and if cyclooxygenase inhibition modifies E2beta responses. Nonpregnant (n = 15) and pregnant (n = 8) ewes had flow probes implanted on main uterine arteries and catheters in branches of the uterine vein and artery bilaterally for blood sampling and infusion of the NO synthase inhibitor L-nitro-arginine methyl ester (L-NAME), respectively. In nonpregnant ewes E2beta (1 microg/kg) caused parallel increases (P < 0.001) in UBF (15+/-3 to 130+/-16 ml/min) and uterine cGMP secretion (23+/-10 to 291+/-38 pmol/min); uterine venous cGMP also rose (4.98+/-1.4 to 9.43+/-3.2 pmol/ml; P < 0.001). Intra-arterial L-NAME partially inhibited increases in UBF dose-dependently (r = 0.66, n = 18, P < 0.003) while completely inhibiting cGMP secretion (P = 0.025). Indomethacin, 2 mg/kg intravenously, did not alter E2beta-induced responses. After E2beta-induced increases in UBF, intraarterial L-NAME partially decreased UBF dose dependently (r = 0.73, n = 46, P < 0.001) while inhibiting cGMP secretion (178+/-48 to 50+/-24 pmol/min; n = 5, P = 0.006); both were reversed by L-arginine. In pregnant ewes, E2beta increased UBF and venous cGMP (9.1+/-0.96 to 13.2+/-0.96 pmol/ml, P < 0.01); however, intraarterial L-NAME decreased basal cGMP secretion 66% (P = 0.02), but not UBF. Acute estrogen-induced increases in UBF are associated with NO-dependent increases in cGMP synthesis, but other mechanisms may also be involved. However, vasodilating prostanoids do not appear to be important. In ovine pregnancy NO is not essential for maintaining uteroplacental vasodilation.

Myometrial angiotensin II receptor subtypes change during ovine pregnancy.

Although regulation of angiotensin II receptor (AT) binding in vascular and uterine smooth muscle is similar in nonpregnant animals, studies suggest it may differ during pregnancy. We, therefore, examined binding characteristics of myometrial AT receptors in nulliparous (n = 7), pregnant (n = 24, 110-139 d of gestation), and postpartum (n = 21, 5 to > or = 130 d) sheep and compared this to vascular receptor binding. We also determined if changes in myometrial binding reflect alterations in receptor subtype. By using plasma membrane preparations from myometrium and medial layer of abdominal aorta, we determined receptor density and affinity employing radioligand binding; myometrial AT receptor subtypes were assessed by inhibiting [125I]-ANG II binding with subtype-specific antagonists. Compared to nulliparous ewes, myometrial AT receptor density fell approximately 90% during pregnancy (1,486 +/- 167 vs. 130 +/- 16 fmol/mg protein) and returned to nulliparous values > or = 4 wk postpartum; vascular binding was unchanged. Nulliparous myometrium expressed predominantly AT2 receptors (AT1/AT2 congruent to 15%/85%), whereas AT1 receptors predominated during pregnancy (AT1/AT2 congruent to 80%/20%). By 5 d postpartum AT1/AT2 congruent to 40%/60%, and > 4 wk postpartum AT2 receptors again predominated (AT1/AT2 congruent to 15%/85%). In studies of ANG II-induced force generation, myometrium from pregnant ewes (n = 10) demonstrated dose-dependent increases in force (P < 0.001), which were inhibited with an AT1 receptor antagonist. Postpartum myometrial responses were less at doses > or = 10(-9) M (P < 0.05) and unaffected by AT2 receptor antagonists. Vascular and myometrial AT receptor binding are differentially regulated during ovine pregnancy, the latter primarily reflecting decreases in AT2 receptor expression. This is the first description of reversible changes in AT receptor subtype in adult mammals.

Maternal diet composition alters serum steroid and free fatty acid concentrations and vaginal pH in mice.

We examined the effects of three maternal diets (very high fat (VHF), low fat (LF), and control (Purina 5015)) on serum steroids, free fatty acids (FFA), and vaginal pH in National Institutes of Health Swiss mice. Females were fed (VHF, n = 33; LF, n = 33; 5015, n = 48) from 4 to 16 weeks of age. Following breeding, female serum was collected at 0.5 (pre-implantation, early diestrus) or 8.5 (post-implantation, mid-diestrus) days post-coitus (dpc). The serum concentrations of 17beta-estradiol, testosterone, progesterone, and FFA were analyzed at both collection points, and vaginal pH at 0.5 dpc. Striking differences in steroids and FFA were observed at 0.5 dpc among the groups. Estradiol was higher in the VHF (14.1 +/- 3.0 pg/ml), compared with LF mice (5.2 +/- 2.3 pg/ml; P< or = 0.05). In contrast, 0.5 dpc testosterone was lower in the VHF (10.5 +/- 3.0 pg/ml) versus the LF group (32.7 +/- 8.4 pg/ml; P< or = 0.05). At 8.5 dpc, progesterone was higher in the VHF (89.6 +/- 6.7 ng/ml) versus the 5015 group (60.1 +/- 4.9 ng/ml; P< or = 0.05). VHF mice had higher FFA concentrations at 0.5 dpc (1.0 +/- 0.2 mmol/l) than LF and control mice (0.5 +/- 0.1 and 0.6 +/- 0.1 mmol/l respectively; P< or = 0.05). At 8.5 dpc, VHF females had higher serum FFA (0.8 +/- 0.1 mmol/l) than LF and control females (0.4 +/- 0.1 and 0.6 +/- 0.1 mmol/l; P< or = 0.05). Mean vaginal pH of VHF females (6.41 +/- 0.09) was lower than 5015 females (6.76 +/- 0.10; P< or = 0.05). These diet-induced alterations in serum steroid and FFA concentrations might affect several reproductive processes, including preferential fertilization by one class of sperm over the other and sex bias in pre- and post-implantational embryonic development.

Fluorescent in situ hybridization for sex chromosome determination before and after fertilization in mice.

In mice, the relative numbers of male and female pups per litter not only can vary but can probably change over the course of pregnancy in response to numerous environmental and physiological factors. As such, a technique is required to determine gender at several developmental stages. Here we describe a robust and accurate fluorescent in situ hybridization (FISH) procedure for determining chromosomal sex that can be applied with minimal modification to sperm, pre-and post-implantation conceptuses and recovered dead post-natal pups. Sperm was prepared for FISH analysis y using a modified microwave decondensation-denaturation technique. Preimplantation conceptuses (0.5dpc) were cultured to the morula stage before sexing. They were then acid-treated to remove the zona pellucida. Tissue homogenates from postimplantational conceptuses (8.5dpc) and stillborn pups were fixed to pre-etched slides. Specimens were hybridized with identical, commercially available DNA probes for the X (FITC) and Y (Cy3) chromosomes. Sperm ratios met the expected value of 0.5 when determined by using XY FISH. Preimplantation conceptuses pre-treated with pepsin yielded distinct fluorescence of X and Y chromosomes in morulae, whereas microwave decondensation resulted in loss of conceptuses from the slide. Both 4.0 and 8.5dpc conceptuses displayed mean sex ratios of 0.5. Post-natal FISH analysis allowed gender identification of pups that could not be sexed due to developmental abnormalities or partial cannibalism. FISH analysis of sperm and of multiple conceptuses or post-natal tissue provided a cost-effective, accurate alternative to PCR-based sex determination.

Homage to the 'H' in developmental origins of health and disease.

Abundant evidence exists linking maternal and paternal environments from pericopconception through the postnatal period to later risk to offspring diseases. This concept was first articulated by the late Sir David Barker and as such coined the Barker Hypothesis. The term was then mutated to Fetal Origins of Adult Disease and finally broadened to developmental origins of adult health and disease (DOHaD) in recognition that the perinatal environment can shape both health and disease in resulting offspring. Developmental exposure to various factors, including stress, obesity, caloric-rich diets and environmental chemicals can lead to detrimental offspring health outcomes. However, less attention has been paid to date on measures that parents can take to promote the long-term health of their offspring. In essence, have we neglected to consider the 'H' in DOHaD? It is the 'H' component that should be of primary concern to expecting mothers and fathers and those seeking to have children. While it may not be possible to eliminate exposure to all pernicious factors, prevention/remediation strategies may tip the scale to health rather than disease. By understanding disruptive DOHaD mechanisms, it may also illuminate behavioral modifications that parents can adapt before fertilization and throughout the neonatal period to promote the lifelong health of their male and female offspring. Three possibilities will be explored in the current review: parental exercise, probiotic supplementation and breastfeeding in the case of mothers. The 'H' paradigm should be the focus going forward as a healthy start can indeed last a lifetime.

Selenium (IV,VI) reduction and tolerance by fungi in an oxic environment.

Microbial processes are known to mediate selenium (Se) oxidation-reduction reactions, strongly influencing Se speciation, bioavailability, and transport throughout the environment. While these processes have commonly been studied in anaerobic bacteria, the role that aerobic fungi play in Se redox reactions could be important for Se-rich soil systems, dominated by microbial activity. We quantified fungal growth, aerobic Se(IV, VI) reduction, and Se immobilization and volatilization in the presence of six, metal-tolerant Ascomycete fungi. We found that the removal of dissolved Se was dependent on the fungal species, Se form (i.e., selenite or selenate), and Se concentration. All six species grew and removed dissolved Se(IV) or Se(VI) from solution, with five species reducing both oxyanions to Se(0) biominerals, and all six species removing at least 15%-20% of the supplied Se via volatilization. Growth rates of all fungi, however, decreased with increasing Se(IV,VI) concentrations. All fungi removed 85%-93% of the dissolved Se(IV) within 10 d in the presence of 0.01 mm Se(IV), although only about 20%-30% Se(VI) was removed when grown with 0.01 mm Se(VI). Fungi-produced biominerals were typically 50- to 300-nm-diameter amorphous or paracrystalline spherical Se(0) nanoparticles. Our results demonstrate that activity of common soil fungi can influence Se form and distribution, and these organisms may therefore play a role in detoxifying Se-polluted environments.

Exposure to extrinsic stressors, social defeat or bisphenol A, eliminates sex differences in DNA methyltransferase expression in the amygdala.

Chemical and psychological stressors can exert long lasting changes in brain function and behaviour. Changes in DNA methylation have been shown to be an important mechanism mediating long lasting changes in neural function and behaviour, especially for anxiety-like or stress responses. In the present study, we examined the effects of either a social or chemical stressor on DNA methyltransferase (DNMT) gene expression in the amygdala, an important brain region modulating stress responses and anxiety. In adult California mice (Peromyscus californicus) that were naïve to social defeat, females had higher levels of Dnmt1 expression in punch samples of the central amygdala (CeA) than males. In addition, mice that underwent social defeat stress showed reduced Dnmt1 and Dnmt3a expression in the CeA of females but not males. A second study using more anatomically specific punch samples replicated these effects for Dnmt1. Perinatal exposure (spanning from periconception through lactation) to bisphenol A or ethinyl oestradiol (oestrogens in birth control pills) also abolished sex differences in Dnmt1 expression in the CeA but not the basolateral amygdala. These findings identify a robust sex difference in Dnmt1 expression in the CeA that is sensitive to both psychological and chemical stressors. Future studies should aim to examine the impact of psychological and chemical stressors on DNA methylation in the CeA and also investigate whether Dnmt1 may have an underappreciated role in plasticity in behaviour.

Effects of a maternal high-fat diet on offspring behavioral and metabolic parameters in a rodent model.

Maternal diet-induced obesity can cause detrimental developmental origins of health and disease in offspring. Perinatal exposure to a high-fat diet (HFD) can lead to later behavioral and metabolic disturbances, but it is not clear which behaviors and metabolic parameters are most vulnerable. To address this critical gap, biparental and monogamous oldfield mice (Peromyscus polionotus), which may better replicate most human societies, were used in the current study. About 2 weeks before breeding, adult females were placed on a control or HFD and maintained on the diets throughout gestation and lactation. F1 offspring were placed at weaning (30 days of age) on the control diet and spatial learning and memory, anxiety, exploratory, voluntary physical activity, and metabolic parameters were tested when they reached adulthood (90 days of age). Surprisingly, maternal HFD caused decreased latency in initial and reverse Barnes maze trials in male, but not female, offspring. Both male and female HFD-fed offspring showed increased anxiogenic behaviors, but decreased exploratory and voluntary physical activity. Moreover, HFD offspring demonstrated lower resting energy expenditure (EE) compared with controls. Accordingly, HFD offspring weighed more at adulthood than those from control fed dams, likely the result of reduced physical activity and EE. Current findings indicate a maternal HFD may increase obesity susceptibility in offspring due to prenatal programming resulting in reduced physical activity and EE later in life. Further work is needed to determine the underpinning neural and metabolic mechanisms by which a maternal HFD adversely affects neurobehavioral and metabolic pathways in offspring.

Comparative cytogenetic studies of normal and leukemic lymphoblastoid cell lines during the course of their establishment.

A comparative chromosomal analysis was made of 10 human lymphoblastoid cell lines, four of which originated from normal donor lymphocytes and six of which were from leukemic peripheral blood. For comparison of lymphoblastoid cells with respect to their normal or leukemic origin, cytogenetic studies have been carried out regularly since the beginning of the culture during more than 3 years. Samples were drawn during the three phases previously described for the establishment of these lines. The chromosome distribution remained diploid for at least 2 years in normal cell lines, and the cells were euploid. In contrast, an important variability of the chromosome set was demonstrated during the same period in leukemic cell lines. Moreover, in these lines, it was always possible to observe a nonsystemic pseudodiploidy. After 2 years, a clonal evolution was described in both types of cell lines that carried at least one marker. With a controlled-heating denaturation technique, it was possible to identify the markers as specific to each cell line. The cells with marker chromosomes appeared to have a selective advantage of growth.

Metabolism of proline in a human leukemic lymphoblastoid cell line.

Amino acid analysis of the culture medium was carried out in a human leukemic lymphoblastoid cell line (REH) established from the lymphoblasts of a patient with acute lymphoid leukemia. The results are compared with those of a reference cell line (LHN13) established from normal human lymphocytes. The most striking difference between these two cell lines concerns proline. In LHN13 the concentration of this amino acid in the culture medium increases by 40 microgram/ml/10(6) cells during a 72-hr incubation. In REH there is a decrease under the same culture conditions. In both cell lines proline is derived from glutamic acid and from arginine, as found with the use of 14C-labeled precursors. Synthesis of proline in the REH line represents approximately 26% of the value measured in LHN13 when the precursor is glutamic acid and 15% when the precursor is arginine. The radioisotopic assay for delta1-pyrroline-5-carboxylate reductase showed that there is a deficiency of this enzyme in the REH cells. The defect in proline synthesis of REH was found at the establishment of this line and constitutes a metabolic marker that has persisted for more than 2 years.

Area contact networks and the spatio-temporal spread of infectious salmon anemia virus (ISAV) in Chile.

Area management, the coordination of production and biosecurity practices across neighboring farms, is an important disease control strategy in aquaculture. Area management in aquaculture escalated in prominence in response to outbreaks of infectious salmon anemia (ISA) internationally. Successes in disease control have been attributed to the separation achieved through area-level synchronized stocking, fallowing, movement restrictions, and fomite or pest control. Area management, however, is costly; often demanding extra biosecurity, lengthy or inconveniently timed fallows, and localization of equipment, personnel, and services. Yet, this higher-order organizational structure has received limited epidemiologic attention. Chile's National Fisheries and Aquaculture Service instigated area management practices in response to the 2007 emergence of ISA virus (ISAV). Longitudinal data simultaneously collected allowed retrospective evaluation of the impact of component tenets on virus control. Spatiotemporal analyses identified hydrographic linkages, shared ports, and fish transfers from areas with recent occurrence of ISAV as the strongest predictors of virus spread between areas, though specifics varied by ISAV type (here categorized as HPR0 for the non-virulent genotypes, and HPRv otherwise). Hydrographic linkages were most predictive in the period before implementation of enhanced biosecurity and fallowing regulations, suggesting that viral load can impact spread dynamics. HPR0 arose late in the study period, so few HPRv events were available by which to explore the hypothesis of HPR0 as progenitor of outbreaks. However, spatiotemporal patterns in HPRv occurrence were predictive of subsequent patterns in HPR0 detection, suggesting a parallel, or dependent, means of spread. Better data precision, breadth and consistency, common challenges for retrospective studies, could improve model fit; and, for HPR0, specification of diagnostic test accuracy would improve interpretation.