Plagioscion squamosissimus (Sciaenidae) and Parachromis managuensis (Cichlidae): a threat to native fishes of the Doce River in Minas Gerais, Brazil

The middle section of the lake basin of the Doce River in Minas Gerais State, Brazil is plagued by grave environmental problems, including the introduction of non-native fish, which reduces the biodiversity of this region. This study reports the presence of two newly-detected non-native species in the Doce River Basin. Sampling efforts included gill nets with mesh size of 3 to 12 mm (measured diagonally) and trawling nets, both of which were used in independent field campaigns in 2002 and 2011. The two new invasive Perciform fishes, Plagioscion squamosissimus (Heckel 1840) and Parachromis managuensis (Günther 1867) were collected in Caratinga and Rio Doce municipalities. These records and other reports on non-native fishes suggest favorable environmental conditions for the establishment of invasive species in this drainage. These invasive species have behavior and diet observed in other wide distribution exotic fish of Rio Doce Basin representing a threat to the 77 native fishes of this region, 37 of which are endangered.     

Phenotypic plasticity to light of two congeneric trees from contrasting habitats: Brazilian Atlantic Forest versus cerrado (savanna)

The Brazilian Atlantic Forest is a typically multi-layer tropical forest, while cerrado (savanna) is a patchy habitat with different physiognomy. Despite these differences, both habitats have high light heterogeneity. Functional traits of Dalbergia nigra and D. miscolobium from the Atlantic Forest and cerrado, respectively, were evaluated under shade (25% of full sunlight) and full sunlight in a nursery experiment. We hypothesised that both species should benefit from high phenotypic plasticity in relation to light. Plasticity was estimated using the relative distance phenotypic index (RDPI). D. miscolobium had lower shoot growth under both light conditions, suggesting it has low competitive capacity in the forest environment, which could explain its limited ability to expand over areas of Atlantic Forest. The studied species exhibited photoprotection strategies under high light and improved light capture under low light. Stomatal conductance, ETR(max) (maximum electron transport rate), PPFD(sat) (saturating photosynthetically active photon flux density), chlorophyll and carotenoid content had higher RDPI than stem morphological traits. Although both species showed considerable phenotypic plasticity, D. miscolobium had higher RDPI for eight of 11 evaluated traits. This high plasticity could be one of the factors that explain the occurrence of this species in a wide range of environmental conditions, from open grassland to dense woodlands, and it could also reflect its adaptation to high light. D. nigra also had considerable plasticity and good growth performance in both shade and full sunlight, but its absence in areas of cerrado suggests that factors other than light limit its occurrence in these habitats.     

Mimosa pudica,Dionaea muscipula and anesthetics

Some studies showed that anesthetics reduce the response of physical stimuli in Mimosa pudica and in Venus Flytrap (Dionaea muscipula), peculiar plants that have the ability to respond to touch stimuli. In this research we tested the effects of ketamine, lidocaine, diethyl ether, and amlodipine on the movements of Mimosa pudica and Venus Flytrap. With a literature review, we tried to bring elements to theorize about the interaction of these substances with these plants. The angular displacement in Mimosa´s petiole and in Dionaea leaves is what was measured to compare the drugs group with control groups.     

Variation in functional leaf traits among beech provenances during a Spanish summer reflects the differences in their origin

We assessed the response of 11-year-old saplings from six beech provenances growing in a common-garden trial at the southwestern range limit. Provenances from distinct climatic regions across the European beech distribution were selected. The local Spanish provenance appeared well suited to the site conditions, maintaining high rates of assimilation even in midsummer, but so did the provenance of southern continental origin, from Gotze-Delchev, Bulgaria. Those provenances from cooler sites in central Europe, a continental mountain climate in the Czech Republic and a continental range-edge site in eastern Poland, along with a German provenance of mild maritime origin, had good physiological functionality in early summer but reduced carbon assimilation (A _area) and apparent soil?Cleaf hydraulic conductivity (K _L) in midsummer. The northern maritime provenance from Sweden demonstrated severely-reduced photosynthetic capacity. These groupings of provenances according to their photosynthetic performance, stable carbon isotope composition (??¹³C; a proxy for water-use efficiency) and leaf water potential under marginal conditions, during late summer in the trial, suggest that they have divergent strategies for water use. The research highlights large intraspecific differences among beech provenances of distinct origin and strategies which are expected to modify their response to drought, requiring future genetic studies to explicitly determine the basis of this ecophysiological differentiation.     

A Genome-Scale RNA–Interference Screen Identifies RRAS Signaling as a Pathologic Feature of Huntington's Disease

A genome-scale RNAi screen was performed in a mammalian cell-based assay to identify modifiers of mutant huntingtin toxicity. Ontology analysis of suppressor data identified processes previously implicated in Huntington''s disease, including proteolysis, glutamate excitotoxicity, and mitochondrial dysfunction. In addition to established mechanisms, the screen identified multiple components of the RRAS signaling pathway as loss-of-function suppressors of mutant huntingtin toxicity in human and mouse cell models. Loss-of-function in orthologous RRAS pathway members also suppressed motor dysfunction in a Drosophila model of Huntington''s disease. Abnormal activation of RRAS and a down-stream effector, RAF1, was observed in cellular models and a mouse model of Huntington''s disease. We also observe co-localization of RRAS and mutant huntingtin in cells and in mouse striatum, suggesting that activation of R-Ras may occur through protein interaction. These data indicate that mutant huntingtin exerts a pathogenic effect on this pathway that can be corrected at multiple intervention points including RRAS, FNTA/B, PIN1, and PLK1. Consistent with these results, chemical inhibition of farnesyltransferase can also suppress mutant huntingtin toxicity. These data suggest that pharmacological inhibition of RRAS signaling may confer therapeutic benefit in Huntington''s disease.     

Polymorphisms in the mitochondrial ribosome recycling factor EF-G2mt/MEF2 compromise cell respiratory function and increase atorvastatin toxicity

Mitochondrial translation, essential for synthesis of the electron transport chain complexes in the mitochondria, is governed by nuclear encoded genes. Polymorphisms within these genes are increasingly being implicated in disease and may also trigger adverse drug reactions. Statins, a class of HMG-CoA reductase inhibitors used to treat hypercholesterolemia, are among the most widely prescribed drugs in the world. However, a significant proportion of users suffer side effects of varying severity that commonly affect skeletal muscle. The mitochondria are one of the molecular targets of statins, and these drugs have been known to uncover otherwise silent mitochondrial mutations. Based on yeast genetic studies, we identify the mitochondrial translation factor MEF2 as a mediator of atorvastatin toxicity. The human ortholog of MEF2 is the Elongation Factor Gene (EF-G) 2, which has previously been shown to play a specific role in mitochondrial ribosome recycling. Using small interfering RNA (siRNA) silencing of expression in human cell lines, we demonstrate that the EF-G2mt gene is required for cell growth on galactose medium, signifying an essential role for this gene in aerobic respiration. Furthermore, EF-G2mt silenced cell lines have increased susceptibility to cell death in the presence of atorvastatin. Using yeast as a model, conserved amino acid variants, which arise from non-synonymous single nucleotide polymorphisms (SNPs) in the EF-G2mt gene, were generated in the yeast MEF2 gene. Although these mutations do not produce an obvious growth phenotype, three mutations reveal an atorvastatin-sensitive phenotype and further analysis uncovers a decreased respiratory capacity. These findings constitute the first reported phenotype associated with SNPs in the EF-G2mt gene and implicate the human EF-G2mt gene as a pharmacogenetic candidate gene for statin toxicity in humans.     

Effects of different cryopreservation methods on post-thaw culture conditions of in vitro produced bovine embryos

The aim of this work was to evaluate the effect of cryopreservation protocols on subsequent development of in vitro produced bovine embryos under different culture conditions. Expanded in vitro produced blastocysts (n = 600) harvested on days 7-9 were submitted to controlled freezing [slow freezing group: 10% ethylene glycol (EG) for 10 min and 1.2°C/min cryopreservation]; quick-freezing [rapid freezing group: 10% EG for 10 min, 20% EG + 20% glycerol (Gly) for 30 s]; or vitrification [vitrification group: 10% EG for 10 min, 25% EG + 25% Gly for 30 s] protocols. Control group embryos were not exposed to cryoprotectant or cryopreservation protocols and the hatching rate was evaluated on day 12 post-insemination. In order to evaluate development, frozen-thawed embryos were subjected to granulosa cell co-culture in TCM199 or SOFaa for 4 days. Data were analyzed by PROC MIXED model using SAS Systems for Windows?. Values were significant at p < 0.05. The hatching rate of the control group was 46.09%. In embryos cultured in TCM199, slow freezing and vitrification group hatching rates were 44.65 ± 5.94% and 9.43 ± 6.77%, respectively. In embryos cultured in SOFaa, slow freezing and vitrification groups showed hatching rates of 11.65 ± 3.37 and 8.67 ± 4.47%, respectively. In contrast, the rapid freezing group embryos did not hatch, regardless of culture medium. The slow freezing group showed higher hatching rates than other cryopreservation groups. Under such conditions, controlled freezing (1.2°C/min) can be an alternative to cryopreservation of in vitro produced bovine embryos.     

Hypoganglionosis in pregnancy: a case report

ABSTRACT: INTRODUCTION: We report a very rare case of isolated hypoganglionosis first diagnosed during early pregnancy, which should be discussed from an obstetric and a gastroenterological point of view. CASE PRESENTATION: A pregnant 18-year-old Caucasian woman presented at twelve weeks of gestation with lower abdominal pain, mild constipation and a large abdominal mass. Abdominal and pelvic magnetic resonance imaging demonstrated a megarectum and megasigmoid, and our patient was managed with medical therapy during her pregnancy, which occurred without major incidents. At the onset of labor, a fecaloma obstructing the pelvic outlet was detected, which required manual disimpaction. However, during the procedure a sudden continuous fetal bradycardia was detected. An emergency Cesarean section was performed but the fetus suffered hypoxic ischemic encephalopathy. One year after the delivery, our patient underwent a sigmoid resection. A histopathological analysis revealed a reduction of nerve cells in the myenteric and submucous plexus, suggesting hypoganglionosis. CONCLUSION: Although there are some reports of pregnancies complicated by megacolon, they are too few and too old to delineate guidelines for clinical orientation. In our article, we discuss several issues regarding the management of these rare intestinal innervation disorders during pregnancy that we believe will enhance their obstetric and gastroenterological management during pregnancy.     

New cytogenetic aberrations found in a case of aggressive retinoblastoma

We describe a case of retinoblastoma with an atypical presentation and previously unreported cytogenetic aberrations. A 19-month-old girl with left intraocular retinoblastoma was treated with enucleation and chemotherapy. The disease showed aggressive evolution within a short period between diagnosis and relapse. Eight months after diagnosis, a new large tumor was present in the orbit of the right eye, with diffuse bone pain, pancytopenia and diffuse infiltration into the bone marrow and the central nervous system. The child did not respond to treatment and died. Cytogenetic studies made with G-banding, FISH and SKY analysis showed chromosomal aberrations commonly associated with retinoblastoma, including del(13q), i(6p), +1, and monosomy 16, along with others that had not been reported previously, including dup(5q), dic(15;22) and add(14q). The new chromosomal aberrations may be related to the aggressiveness of the disease in this case.