NMDA Receptors Mediate Consolidation of Contextual Memory in the Hippocampus after Context Preexposure

Male Wistar rats received bilateral infusions of vehicle (VEH) or aminophosphonopentanoic acid (AP5), an N-metil-D-aspartate (NMDA) receptor antagonist, into the dorsal hippocampus immediately after inhibitory avoidance (IA) training. Intrahippocampal infusion of AP5 blocked 24 h IA retention. In the second experiment, animals were preexposed to the IA training context 24 h prior to training and received an infusion of either VEH or AP5 immediately after the preexposure trial and a second infusion of VEH or AP5 immediately after IA training. AP5 did not affect retention in animals preexposed to the IA box and given VEH after preexposure, but blocked retention when given after both preexposure and training. AP5 impaired retention in rats preexposed to an environment distinct from the IA box. These results suggest that NMDA receptors in the dorsal hippocampus mediate the formation of a contextual representation of the task environment.     

Association of human papillomavirus and Chlamydia trachomatis with intraepithelial alterations in cervix samples

The influence of different infectious agents and their association with human papillomavirus (HPV) in cervical carcinogenesis have not been completely elucidated. This study describes the association between cytological changes in cervical epithelium and the detection of the most relevant aetiological agents of sexually transmitted diseases. Samples collected from 169 patients were evaluated by conventional cytology followed by molecular analysis to detect HPV DNA, Chlamydia trachomatis, herpes simplex virus 1 and 2,Neisseria gonorrhoeae, Mycoplasma genitalium, Trichomonas vaginalis, andTreponema pallidum, besides genotyping for most common high-risk HPV. An association between cytological lesions and different behavioural habits such as smoking and sedentariness was observed. Intraepithelial lesions were also associated with HPV and C. trachomatis detection. An association was also found between both simple and multiple genotype infection and cytological changes. The investigation of HPV and C. trachomatisproved its importance and may be considered in the future for including in screening programs, since these factors are linked to the early diagnosis of patients with precursor lesions of cervical cancer.     

Can otoliths of <Emphasis Type="Italic">Genidens genidens</Emphasis> (Cuvier 1829) (Siluriformes: Ariidae) reveal differences in life strategies of males and females?

Determination of the growth parameters of a species is an indispensable requirement for understanding its biology and consequently the management of its fishery. In fisheries science, calculations of longevity, mortality rates and stock-assessment models depend on the availability of growth data. Genidens genidens, one of the most common ariid species in Brazil, is a potential sentinel species for biomonitoring in Guanabara Bay, one of the country’s most degraded estuarine ecosystems. The present study investigated the growth parameters of G. genidens, providing supporting information for its management. Individuals were measured, sexed, and the number of rings in the lapillus otolith counted. The periodicity in the formation of the rings was determined by the monthly ratio of the edge type. Individuals from 0 to 11.5 years old were captured, including some that were older than previously reported. Our results showed that this species forms two growth rings per year, one in summer and the other in winter; the summer ring is formed one month later in males than in females, due to the period of oropharyngeal incubation of the offspring. Sexual dimorphism was also observed in the growth rate: males grow faster, and consequently reach smaller sizes than females. We can conclude that the parental care carried out by males and the high energy expenditure in forming the large oocytes by females mark the otoliths and reveal life-cycle particularities differently in each sex.     

Oxidative stress during the cryopreservation of Passiflora suberosa L. shoot tips using the V-Cryo-plate technique: determination of the critical stages of the protocol

Plant Cell, Tissue and Organ Culture (PCTOC) - Ceratostigma willmottianum Stapf is an endemic species of China. Although it has high ornamental and medical value, its use is greatly limited by the...     

Screening of waste biomass from Saccharomyces cerevisiae,Aspergillus oryzae and Bacillus lentus fermentations for removal of Cu,Zn and Cd by biosorption

Three by-products of fermentations containing Bacillus lentus, Aspergillus oryzae or Saccharomyces cerevisiae biomass were tested for the capacity to absorb Cu, Cd and Zn. The composition of the three biomasses was first determined and showed high contents of ashes in both B. lentus and A. oryzae biomass and high amounts of lipids in the bacterial biomass. Metal ion binding experiments were performed by contact of 0.1 g of biomass (protonated for all the metal tests and not protonated only for the Cd test) with 50 ml of solutions containing each of the metals in the concentration range from 10 to 500 mg/ml, at pH 4.5, 3.5 and 2.5. The final metal ion concentrations were determined using a plasma absorption spectrometer, and the metal removal levels for isotherm plots were determined using the Langmuir model. The results showed that B. lentus protonated biomass had the best sorption capacity for Cu and Cd, followed by protonated A. oryzae and S. cerevisiae biomass. The sorption of Zn was low for all tested biomasses, as also was the binding of all metals at acidic pH (2.5 and 3.5). A significant increase in Cd sorption was obtained using non-protonated biomass from B. lentus and A. oryzae.     

On the spread of the Russian sturgeon Acipenser gueldenstaedtii (Acipenseriformes: Acipenseridae) in the Neotropics: A marine path to invade freshwater drainages in South America?

Acipenser gueldenstaedtii is a species of sturgeon described from Caspian Sea and Black Sea and their tributaries, occurring in the Eastern Atlantic, Europe and Middle East. This and other two sturgeon species have been accidentally introduced in the Rio Negro, Uruguay, a tributary of the Rio de La Plata. Recently, it has been demonstrated the presence and establishment of A. gueldenstaedtii widespread in the Rio Paraná basin, the largest tributary of the Rio de La Plata, corresponding to the second largest river drainage in the Neotropics. We herein register the presence of the species in the next northern freshwater drainage in South America, representing the first record for Brazil. We further discuss the possibility of dispersal through marine environments to other freshwater drainages in South America through the analysis of its documented occurrence and marine ecoregions in southwestern Atlantic.     

Effect of genistein and coenzyme Q10 in oxidative damage and mitochondrial membrane potential in an attenuated type II mucopolysaccharidosis cellular model

Mucopolysaccharidosis type II (MPS II) is an inborn error of the metabolism resulting from several possible mutations in the gene coding for iduronate-2-sulfatase (IDS), which leads to a great clinical heterogeneity presented by these patients. Many studies demonstrate the involvement of oxidative stress in the pathogenesis of inborn errors of metabolism, and mitochondrial dysfunction and oxidative stress can be related since most of reactive oxygen species come from mitochondria. Cellular models have been used to study different diseases and are useful in biochemical research to investigate them in a new promising way. The aim of this study is to develop a heterozygous cellular model for MPS II and analyze parameters of oxidative stress and mitochondrial dysfunction and investigate the in vitro effect of genistein and coenzyme Q10 on these parameters for a better understanding of the pathophysiology of this disease. The HP18 cells (heterozygous c.261_266del6/c.259_261del3) showed almost null results in the activity of the IDS enzyme and presented accumulation of glycosaminoglycans (GAGs), allowing the characterization of this knockout cellular model by MPS II gene editing. An increase in the production of reactive species was demonstrated (p < .05 compared with WT vehicle group) and genistein at concentrations of 25 and 50 µm decreased in vitro its production (p < .05 compared with HP18 vehicle group), but there was no effect of coenzyme Q10 in this parameter. There was a tendency for lysosomal pH change in HP18 cells in comparison to WT group and none of the antioxidants tested demonstrated any effect on this parameter. There was no increase in the activity of the antioxidant enzymes superoxide dismutase and catalase and oxidative damage to DNA in HP18 cells in comparison to WT group and neither genistein nor coenzyme q10 had any effect on these parameters. Regarding mitochondrial membrane potential, genistein induced mitochondrial depolarization in both concentrations tested (p < .05 compared with HP18 vehicle group and compared with WT vehicle group) and incubation with coenzyme Q10 demonstrated no effect on this parameter. In conclusion, it is hypothesized that our cellular model could be compared with a milder MPS II phenotype, given that the accumulation of GAGs in lysosomes is not as expressive as another cellular model for MPS II presented in the literature. Therefore, it is reasonable to expect that there is no mitochondrial depolarization and no DNA damage, since there is less lysosomal impairment, as well as less redox imbalance.