The Long-Term Impairment in Redox Homeostasis Observed in the Hippocampus of Rats Subjected to Global Perinatal Asphyxia (PA) Implies Changes in Glutathione-Dependent Antioxidant Enzymes and TIGAR-Dependent Shift Towards the Pentose Phosphate Pathways: Effect of Nicotinamide.

We have recently reported that global perinatal asphyxia (PA) induces a regionally sustained increase in oxidized glutathione (GSSG) levels and GSSG/GSH ratio, a decrease in tissue-reducing capacity, a decrease in catalase activity, and an increase in apoptotic caspase-3-dependent cell death in rat neonatal brain up to 14 postnatal days, indicating a long-term impairment in redox homeostasis. In the present study, we evaluated whether the increase in GSSG/GSH ratio observed in hippocampus involves changes in glutathione reductase (GR) and glutathione peroxidase (GPx) activity, the enzymes reducing glutathione disulfide (GSSG) and hydroperoxides, respectively, as well as catalase, the enzyme protecting against peroxidation. The study also evaluated whether there is a shift in the metabolism towards the penthose phosphate pathway (PPP), by measuring TIGAR, the TP53-inducible glycolysis and apoptosis regulator, associated with delayed cell death, further monitoring calpain activity, involved in bax-dependent cell death, and XRCC1, a scaffolding protein interacting with genome sentinel proteins. Global PA was induced by immersing fetus-containing uterine horns removed by a cesarean section from on term rat dams into a water bath at 37 °C for 21 min. Asphyxia-exposed and sibling cesarean-delivered fetuses were manually resuscitated and nurtured by surrogate dams. Animals were euthanized at postnatal (P) days 1 or 14, dissecting samples from hippocampus to be assayed for glutathione, GR, GPx (all by spectrophotometry), catalase (Western blots and ELISA), TIGAR (Western blots), calpain (fluorescence), and XRCC1 (Western blots). One hour after delivery, asphyxia-exposed and control neonates were injected with either 100 µl saline or 0.8 mmol/kg nicotinamide, i.p., shown to protect from the short- and long-term consequences of PA. It was found that global PA produced (i) a sustained increase of GSSG levels and GSSG/GSH ratio at P1 and P14; (ii) a decrease of GR, GPx, and catalase activity at P1 and P14; (iii) a decrease at P1, followed by an increase at P14 of TIGAR levels; (iv) an increase of calpain activity at P14; and (v) an increase of XRCC1 levels, but only at P1. (vi) Nicotinamide prevented the effect of PA on GSSG levels and GSSG/GSH ratio, and on GR, GPx, and catalase activity, also on increased TIGAR levels and calpain activity observed at P14. The present study demonstrates that the long-term impaired redox homeostasis observed in the hippocampus of rats subjected to global PA implies changes in GR, GPx, and catalase, and a shift towards PPP, as indicated by an increase of TIGAR levels at P14.

Vulnerability to a Metabolic Challenge Following Perinatal Asphyxia Evaluated by Organotypic Cultures: Neonatal Nicotinamide Treatment.

The hypothesis of enhanced vulnerability following perinatal asphyxia was investigated with a protocol combining in vivo and in vitro experiments. Asphyxia-exposed (AS) (by 21 min water immersion of foetuses containing uterine horns) and caesarean-delivered control (CS) rat neonates were used at P2-3 for preparing triple organotypic cultures (substantia nigra, neostriatum and neocortex). At DIV 18, cultures were exposed to different concentrations of H2O2 (0.25-45 mM), added to the culture medium for 18 h. After a 48-h recovery period, the cultures were either assessed for cell viability or for neurochemical phenotype by confocal microscopy. Energy metabolism (ADP/ATP ratio), oxidative stress (GSH/GSSG) and a modified ferric reducing/antioxidant power assay were applied to homogenates of parallel culture series. In CS cultures, the number of dying cells was similar in substantia nigra, neostriatum and neocortex, but it was several times increased in AS cultures evaluated under the same conditions. A H2O2 challenge led to a concentration-dependent increase in cell death (>fourfold after 0.25 mM of H2O2) in CS cultures. In AS cultures, a significant increase in cell death was only observed after 0.5 mM of H2O2. At higher than 1 mM of H2O2 (up to 45 mM), cell death increased several times in all cultures, but the effect was still more prominent in CS than in AS cultures. The cell phenotype of dying/alive cells was investigated in formalin-fixed cultures exposed to 0 or 1 mM of H2O2, co-labelling for TUNEL (apoptosis), MAP-2 (neuronal phenotype), GFAP (astroglial phenotype) and TH (tyrosine hydroxylase; for dopamine phenotype), counterstaining for DAPI (nuclear staining), also evaluating the effect of a single dose of nicotinamide (0.8 nmol/kg, i.p. injected in 100 µL, 60 min after delivery). Perinatal asphyxia produced a significant increase in the number of DAPI/TUNEL cells/mm3, in substantia nigra and neostriatum. One millimolar of H202 increased the number of DAPI/TUNEL cells/mm3 by ≈twofold in all regions of CS and AS cultures, an effect that was prevented by neonatal nicotinamide treatment. In substantia nigra, the number of MAP-2/TH-positive cells/mm3 was decreased in AS compared to CS cultures, also by 1 mM of H202, both in CS and AS cultures, prevented by nicotinamide. In agreement, the number of MAP-2/TUNEL-positive cells/mm3 was increased by 1 mM H2O2, both in CS (twofold) and AS (threefold) cultures, prevented by nicotinamide. The number of MAP-2/TH/TUNEL-positive cells/mm3 was only increased in CS (>threefold), but not in AS (1.3-fold) cultures. No TH labelling was observed in neostriatum, but 1 mM of H2O2 produced a strong increase in the number of MAP-2/TUNEL-positive cells/mm3, both in CS (>2.9-fold) and AS (>fourfold), decreased by nicotinamide. In neocortex, H2O2 increased the number of MAP-2/TUNEL-positive cells/mm3, both in CS and AS cultures (≈threefold), decreased by nicotinamide. The ADP/ATP ratio was increased in AS culture homogenates (>sixfold), compared to CS homogenates, increased by 1 mM of H202, both in CS and AS homogenates. The GSH/GSSG ratio was significantly decreased in AS, compared to CS cultures. One millimolar of H2O2 decreased that ratio in CS and AS homogenates. The present results demonstrate that perinatal asphyxia induces long-term changes in metabolic pathways related to energy and oxidative stress, priming cell vulnerability with both neuronal and glial phenotype. The observed effects were region dependent, being the substantia nigra particularly prone to cell death. Nicotinamide administration in vivo prevented the deleterious effects observed after perinatal asphyxia in vitro, a suitable pharmacological strategy against the deleterious consequences of perinatal asphyxia.

Retracted: Nrf2: a novel therapeutic target in fragile X syndrome is modulated by NNZ2566.

Retraction: "Nrf2: a novel therapeutic target in fragile X syndrome is modulated by NNZ2566" by R. M. J. Deacon, M. J. Hurley, C. M. Rebolledo, M. Snape, F. J. Altimiras, L. Farías, M. Pino, R. Biekofsky, L. Glass and P. Cogram. The above article, from Genes, Brain and Behavior, published online on 12th May 2017 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal Editor in Chief, Andrew Holmes and John Wiley & Sons Ltd. The retraction has been agreed as all authors cannot agree on a revised author order, and at least one author continues to dispute the original order. In this case, the original article is being retracted on the grounds that the journal does not have permission to publish. Reference: Deacon, R. M. J., Hurley, M. J., Rebolledo, C. M., Snape, M., Altimiras, F. J., Farías, L., Pino, M., Biekofsky, R., Glass, L. and Cogram, P. (2017), Nrf2: a novel therapeutic target in fragile X syndrome is modulated by NNZ2566. Genes, Brain and Behavior. doi:10.1111/gbb.12373.

Modulation of Postnatal Neurogenesis by Perinatal Asphyxia: Effect of D1 and D2 Dopamine Receptor Agonists.

Perinatal asphyxia (PA) is associated to delayed cell death, affecting neurocircuitries of basal ganglia and hippocampus, and long-term neuropsychiatric disabilities. Several compensatory mechanisms have been suggested to take place, including cell proliferation and neurogenesis. There is evidence that PA can increase postnatal neurogenesis in hippocampus and subventricular zone (SVZ), modulated by dopamine, by still unclear mechanisms. We have studied here the effect of selective dopamine receptor agonists on cell death, cell proliferation and neurogenesis in organotypic cultures from control and asphyxia-exposed rats. Hippocampus and SVZ sampled at 1-3 postnatal days were cultured for 20-21 days. At day in vitro (DIV) 19, cultures were treated either with SKF38393 (10 and 100 µM, a D1 agonist), quinpirole (10 µM, a D2 agonist) or sulpiride (10 µM, a D2 antagonist) + quinpirole (10 µM) and BrdU (10 µM, a mitosis marker) for 24 h. At DIV 20-21, cultures were processed for immunocytochemistry for microtubule-associated protein-2 (MAP-2, a neuronal marker), and BrdU, evaluated by confocal microscopy. Some cultures were analysed for cell viability at DIV 20-21 (LIVE/DEAD kit). PA increased cell death, cell proliferation and neurogenesis in hippocampus and SVZ cultures. The increase in cell death, but not in cell proliferation, was inhibited by both SKF38393 and quinpirole treatment. Neurogenesis was increased by quinpirole, but only in hippocampus, in cultures from both asphyxia-exposed and control-animals, effect that was antagonised by sulpiride, leading to the conclusion that dopamine modulates neurogenesis in hippocampus, mainly via D2 receptors.

Gonadectomy inhibits development of experimental amoebic liver abscess in hamsters through downregulation of the inflammatory immune response.

Incidence of amoebic liver abscess (ALA) in human males is considerably higher than in females, suggesting a role for sex hormones in this parasite infection. We describe here the effect of hamster gonadectomization on the development of ALA. After monitoring the decrease of oestradiol in females and testosterone in males to undetectable levels by ELISA and Radio Immuno Assay (RIA) in serum, hamsters were intraportally infected with Entamoeba histolytica trophozoites and killed 7 days later. ALA was absent in 50% of male and 15% of female gonadectomized (Gdx) hamsters, in comparison with 100% infection in non-Gdx controls. This protection against ALA in Gdx hamsters was concomitant to a comparatively scarce inflammatory infiltrate and necrosis surrounding clusters of trophozoites in the liver tissue, as well as to a lack of response of spleen cells to Con A, evaluated in proliferation assays. As tissue damage in ALA has been associated with a local inflammatory Th1 response, we determined the profile of response in hamsters by immunohistochemistry on liver sections. In contrast to strong Th1 responses in non-Gdx animals, Gdx females and males exhibited Th2 and Th3 profiles of cytokines, respectively, suggesting that protection against ALA following gonadectomization, could be related to downregulation of liver Th1 response during amoebic infection.

The role of the secretory immune response in the infection by Entamoeba histolytica.

Intestinal infection with the protozoan parasite Entamoeba histolytica elicits a local immune response with rising of specific secretory IgA (sIgA) antibodies detectable in several compartments associated to mucosa. Anti-amoebic sIgA antibodies have been reported in faeces, saliva, bile and breast milk from dysenteric patients and research trying to elucidate their role in protection has recently intensified. IgA antibodies inhibit the in vitro adherence of E. histolytica trophozoites to epithelial cell monolayers by recognizing several membrane antigens, including the galactose-binding lectin (Gal-lectin), main surface molecule involved in adherence, and the serine and cystein-rich proteins, all of them potential vaccine candidates. In fact, the presence of sIgA anti-Gal lectin in faeces of patients recovered from amoebic liver abscess (ALA) was associated with immunity to E. dispar. Moreover, the combined nasal and intraperitoneal vaccination of C3H/HeJ mice with native and recombinant Gal-lectin protected mice against an intracecal challenge with virulent E. histolytica trophozoites, protection that seemed to be associated with the induction of specific intestinal sIgA antibodies. Therefore, the stimulation of intestinal secretory response by mucosal delivery of amoebic antigens has been positioned as a promising strategy for inducing protection against human amoebiasis.

Effect of diazepam on EEG power and coherent activity: sex differences.

Benzodiazepine-steroid interactions and sex differences in brain and circulating levels of gonadal steroids, lead to hypothesized differential effects of DZ on EEG in women and men. Coherent activity has been shown to be relevant for binding information into global percepts therefore diazepam effects on EEG correlation and sex differences were assessed in a double-blind crossover study. Healthy males (9) and females (9) received a single-dose (5 mg) of diazepam or placebo. EEG was recorded with eyes open (FP1, FP2, F3, F4, C3, C4, P3, P4, O1, O2) before and 2 h after drug administration in two counterbalanced sessions. DZ selectively increased delta and theta EEG correlation among frontal regions and decreased it between right parieto-occipital (theta) and fronto-central regions (alpha2) in addition to an increase in beta2 interhemispheric correlation in men and women. Men showed increased beta1 interhemispheric correlation, decreased alpha1 and increased beta power; women showed in addition, decreased theta and alpha2 power. theta rhythm was more sensitive to DZ in women, whereas interhemispheric correlation was more affected in men. DZ had a sexually dimorphic effect on waking EEG and a disrupting effect on coherent activity, increasing balance among frontal regions and decreasing temporal coupling between anterior-posterior regions. These sex differences might be related to differences in brain organization and activational effects of female gonadal steroids which are higher in women than in men.

[Parasitism in fishes and human riverside communities of the Huillinco and Natri lakes (Great Island of Chiloé), Chile]. / Parasitismo en peces y comunidades humanas ribereñas de los lagos Huillinco y Natri (Isla Grande de Chiloé), Chile.

In April and December 1989, 35 fish from Lake Huillinco (42 degrees 48'S, 74 degrees 02'W) and 36 fish from Lake Natri (42 degrees 48'S, 73 degrees 50'W), in the Great Island of Chiloé (Chile) were examined. Coprological samples from 159 persons, 17 dogs, 19 pigs and 4 cats from around both lakes were examined for Diphyllobothrium spp. infection. In the Lake Huillinco the following helminths of fishes were determined: Contracaecum sp. and Hysterothylacium sp. in Salmo trutta, Cauque mauleanum and Eleginops maclovinus; Dichelyne (Cucullanellus) dichelyneformis in S. trutta and E. maclovinus and Scolex pleuronectis in S. trutta. One specimen of Mugil cephalus did not show helminth parasites. Prevalence of infection were greater for Contracaecum sp. in S. trutta (75.0%) and C. mauleanum (76.0%); and Hysterothylacium sp. in E. maclovinus (75.0%). Mean intensity was higher for D. (C.) dichelyneformis in E. maclovinus. Contracaecum sp. in S. trutta, Oncorhynchus mykiss, Oncorhynchus kisutch and Galaxias maculatus; Acanthocephalus sp. in S. trutta and G. maculatus, S. pleuronectis in O. mykiss and Cystidicoloides sp. in G. maculatus were determined at Lake Natri. Prevalence and intensity of infection were higher for Contracaecum sp. in S. trutta and O. kisutch. Infection by Diphyllobothrium sp. was determined in one domestic cat. Prevalence of infection by intestinal protozoan and helminths in human population only showed significative differences for Ascaris lumbricoides and Trichuris trichiura that were higher in the Lake Huillinco. Importance of natural infection by helminth parasites for fish in cultured condition and possible mechanisms of infections in relation to the diet of fishes are discussed.

Cobertura del programa de vacunacion en menores de cinco anos de la ciudad de Valdivia. / Range of the vaccination program in children less than five years old in the city of Valdivia

El Programa Ampliado de Inmunizaciones, PAI, es el resultado de una accion conjunta de las naciones que integran la OMS, cuya meta es de que todos los ninos del mundo tengan acceso a servicios de vacunacion antes del ano 2000.Al considerar la meta senalada, surge la interrogante que motivo el presente estudio, cual es la cobertura de vacuanacion en Valdivia? Una encuesta por muestreo directo establecio que el 73,2% de los ninos tenian su esquema de inmunizaciones cumplido, cifra que se redujo a un 63,6% en los menores de un ano