Freeze tolerance of the yeast Torulaspora delbrueckii : cellular and biochemical basis

The freeze-stress responses to prolonged storage at - 20 °C in Torulaspora delbrueckii PYCC5323 were investigated. In this yeast no loss of cell viability was observed for at least 120 days during freezing at - 20ºC, whereas a loss of 80% was observed in a commercial baker's yeast after 15 days. In the former strain, freeze resistance was dependent on an adaptation process. The primary cell target of freeze stress was the plasma membrane, preservation of it’s integrity being related with a lower increase of lipid peroxidation and with higher resistance to H2O2, but not with intracellular trehalose concentration.Fundação para a Ciência e a Tecnologia (FCT) - grant (PRAXIS XXI/BD/21543/99)

Molecular and biochemical characterization of glucose transport in Torulaspora delbrueckii

Apresentação efectuada no "XIV Congresso Nacional de Bioquímica", em Vilamoura, Portugal, em Dezembro de 2004

Early-life stress affects drug abuse susceptibility in adolescent rat model independently of depression vulnerability

The development of substance abuse problems occurs due to a diverse combination of risk factors. Among these risks, studies have reported depression and early-life stress as of importance. These two factors often occur simultaneously, however, there is a lack of understanding of how their combined effect may impact vulnerability to drug abuse in adolescence. The present study used rats with different vulnerability to depression (Wistar and Wistar-Kyoto) to investigate the impact of maternal separation (MS) on emotional state and drug addiction vulnerability during the adolescence period. Mothers and their litters were subjected to MS (180 min/day) from postnatal day 2 to 14. The offspring emotional state was assessed by observing their exploratory behavior. Drug abuse vulnerability was assessed through conditioning to cocaine. MS impacted the emotional state in both strains. Wistar responded with increased exploration, while Wistar-Kyoto increased anxiety-like behaviours. Despite the different coping strategies displayed by the two strains when challenged with the behavioural tests, drug conditioning was equally impacted by MS in both strains. Early-life stress appears to affect drug abuse vulnerability in adolescence independently of a depression background, suggesting emotional state as the main driving risk factor.info:eu-repo/semantics/publishedVersio

Study of Mechanisms for Acetyl-L-Carnitine Neuroprotective Action

Introduction: Acetyl-L-Carnitine (ALC) has been proposed to have beneficial effects in chronic neurodegenerative disorders caused by production of abnormal proteins, mitochondrial dysfunction and oxidative stress. Recently, our group demonstrated that pre-treatment with ALC confers effective neuroprotection against 3,4- methylenedioximethamphetamine (MDMA)-induced neurotoxicity. These pre-clinical studies reinforce the beneficial potential of ALC as a neuroprotectant in neurodegenerative disorders. However, little is known about the molecular mechanisms underlying ALC action

Evaluation of 99mTc-Sestamibi as a potential tool to investigate PgP activity in inflammation

In the XXI Century’s Society the scientific investigation process has been rowing steadily, and the field of the pharmaceutical research is one of the most enthusiastic and relevant. Here, it is very important to correlate bserved functional alterations with possibly modified drug bio distribution patterns. Cancer, inflammation and infection are processes that induce many olecular intermediates like cytokines, chemokines and other chemical complexes that an alter the pharmacokinetics of many drugs. One cause of such changes is hought to be the modulator action of these complexes in the P-Glycoprotein activity, because they can act like inducers/inhibitors of MDR-1 expression. This protein results from the expression of MDR-1 gene, and acts as an ATP energy-dependent efflux pump, withtheir substrates including many drugs, like antiretrovirals, anticancers, anti-infectives, immunosuppressants, steroids or opioids. Because of the lack of methods to provide helpful information in he investigation of in vivo molecular changes in Pgp activity during fection/infl ammation processes, and its value in the explanation of the altered drug harmacokinetic, this paper want to evaluate the potential utility of 99m Tc-Sestamibi scintigraphy during this kind of health sciences investigation. Although the aim is indeed to create a technique to the in vivo study of Pgp activity, this preliminary Project only reaches the in vitro study phase, assumed as the first step in a n evaluation period for a new tool development. Materials and Methods: For that reason , we are performing in vitro studies of influx and efflux of 99m Tc - Sestamibi ( that is a substrate of Pgp) in hepatocytes cell line (HepG2). We are interested in clarify the cellular behavior of this radiopharmaceutical in Lipopolysaccharide(LPS) stimulated cells ( well known in vitro model of inflammation) to possibly approve this methodology. To validate the results, the Pgp expression will be finally evaluated using Western Blot technique. Results: Up to this moment , we still don’t have the final results, but we have already enough data to let us believe that LPS stimulation induce a downregulation of MDR - 1, and consequently Pgp, which could conduce to a prolonged retention of 99m Tc - Sestamibi in the inflamed cells . Conclusions: If and when this methodology demonstrate the promising results we expect, one will be able to con clude that Nuclear Medicine is an important tool to help evidence based research also on this specific field

Maternal stress and vulnerability to depression: coping and maternal care strategies and its consequences on adolescent offspring

Depressive mothers often find mother-child interaction to be challenging. Maternal stress may further impair mother-child attachment, which may increase the risk of negative developmental consequences. We used rats with different vulnerability to depressive-like behavior (Wistar and Kyoto) to investigate the impact of stress (maternal separation-MS) on maternal behavior and adolescent offspring cognition. MS in Kyoto dams increased pup-contact, resulting in higher oxytocin levels and lower anxiety-like behavior after weaning, while worsening their adolescent offspring cognitive behavior. Whereas MS in Wistar dams elicited higher quality of pup-directed behavior, increasing brain-derived neurotrophic factor (BDNF) in the offspring, which seems to have prevented a negative impact on cognition. Hypothalamic oxytocin seems to affect the salience of the social environment cues (negatively for Kyoto) leading to different coping strategies. Our findings highlight the importance of contextual and individual factors in the understanding of the oxytocin role in modulating maternal behavior and stress regulatory processes.info:eu-repo/semantics/publishedVersio

Methamphetamine mimics the neurochemical profile of aging in rats and impairs recognition memory

Brain neurochemistry and cognition performance are thought to decline with age. Accumulating data indicate that similar events occur after prolonged methamphetamine (MA) exposure. Using the rat as a model, the present study was designed to uncover common alteration patterns in brain neurochemistry and memory performance between aging and prolonged MA exposure. To this end, animals were treated with a chronic binge MA administration paradigm (20 mg/kg/day from postnatal day 91 to 100). Three-age control groups received isovolumetric saline treatment and were tested at the MA age-matched period, and at 12 and 20 months. We observed that both MA and aged animals presented a long, but not short, time impairment in novelty preference and an increased anxiety-like behavior. Neurochemical analysis indicated similar MA- and age-related impairments in dopamine, serotonin and metabolites in the striatum, prefrontal cortex and hippocampus. Thus, the present data illustrate that MA may be used to mimic age-related effects on neurotransmitter systems and advocate MA treatment as a feasible animal model to study neuronal processes associated with aging.info:eu-repo/semantics/publishedVersio

Sustainable plant polyesters as substrates for optical gas sensors

UIDB/04378/2020 PTDC/BII-BIO/28878/2017 PTDC/SAU-SER/30388/2017 SFRH-BD-110467-2015The fast and non-invasive detection of odors and volatile organic compounds (VOCs) by gas sensors and electronic noses is a growing field of interest, mostly due to a large scope of potential applications. Additional drivers for the expansion of the field include the development of alternative and sustainable sensing materials. The discovery that isolated cross-linked polymeric structures of suberin spontaneously self-assemble as a film inspired us to develop new sensing composite materials consisting of suberin and a liquid crystal (LC). Due to their stimuli-responsive and optically active nature, liquid crystals are interesting probes in gas sensing. Herein, we report the isolation and the chemical characterization of two suberin types (from cork and from potato peels) resorting to analyses of gas chromatography–mass spectrometry (GC-MS), solution nuclear magnetic resonance (NMR), and X-ray photoelectron spectroscopy (XPS). The collected data highlighted their compositional and structural differences. Cork suberin showed a higher proportion of longer aliphatic constituents and is more esterified than potato suberin. Accordingly, when casted it formed films with larger surface irregularities and a higher C/O ratio. When either type of suberin was combined with the liquid crystal 5CB, the ensuing hybrid materials showed distinctive morphological and sensing properties towards a set of 12 VOCs (comprising heptane, hexane, chloroform, toluene, dichlormethane, diethylether, ethyl acetate, acetonitrile, acetone, ethanol, methanol, and acetic acid). The optical responses generated by the materials are reversible and reproducible, showing stability for 3 weeks. The individual VOC-sensing responses of the two hybrid materials are discussed taking as basis the chemistry of each suberin type. A support vector machines (SVM) algorithm based on the features of the optical responses was implemented to assess the VOC identification ability of the materials, revealing that the two distinct suberin-based sensors complement each other, since they selectively identify distinct VOCs or VOC groups. It is expected that such new environmentally-friendly gas sensing materials derived from natural diversity can be combined in arrays to enlarge selectivity and sensing capacity.publishersversionpublishe

First records of two mealybug species in Brazil and new potential pests of papaya and coffee

Five mealybug (Hemiptera: Pseudococcidae) plant pest species: Dysmicoccus grassii (Leonardi), Ferrisia malvastra (McDaniel), Ferrisia virgata (Cockerell), Phenacoccus tucumanus Granara de Willink, and Pseudococcus elisae Borchsenius are recorded for the first time in the state of Espírito Santo, Brazil. These are the first records of D. grassii in Brazil, from papaya (Carica papaya, Caricaceae), and from coffee (Coffea canephora, Rubiaceae). Ferrisia malvastra is also newly recorded in Brazil, where it was found on Bidens pilosa (Asteraceae). Ferrisia virgata was collected from an unidentified weed and Phenacoccus tucumanus from Citrus sp. (Rutaceae). Plotococcus capixaba Kondo was found on pitanga (Eugenia cf. pitanga, Myrtaceae) and Pseudococcus elisae on Coffea canephora, which are new host records for these mealybugs