bluuebunny/crossref_metadata_2025 huggingface dataset:
Serotonin-induced brain glycogenolysis in rainbow trout (Oncorhynchus mykiss)
Authors: Pérez-Maceira Jorge J. , Mancebo María J. , Aldegunde Manuel
Published: August 2012

In this study, we evaluated the serotonin-mediated control of cerebral glycogen levels in the rainbow trout, Oncorhynchus mykiss. Intracerebroventricular (i.c.v.) administration of serotonin (5-HT) to normoglycemic trout (time and dose response) decreased glycogen levels in the brain and increased brain glycogen phosphorylase activity (time response). In hypoglycemic fish (that had been fasted for 5 and 10 days), there was a time-dependent decrease in brain glycogen levels; under these conditions, i.c.v. administration of 5-HT also reduced the brain glycogen content in fish that had been fasted for 5 days. In fish with local cerebral hypoglycemia (induced by 2-DG administration), the glycogen levels decreased and, as above, i.c.v. administration of 5-HT also lowered the glycogen content. In hyperglycemic fish, 5-HT did not affect glycogen levels. Administration of receptor agonists 5-HT1A (8-OH-DPAT), 5-HT1B (anpirtoline and CP93129) or 5-HT2 (α-m-5-HT) decreased the brain glycogen levels. This effect was antagonized by the administration of receptor antagonists 5-HT1A (WAY100135 and NAN190), 5-HT1B (NAS181) and 5-HT2B/C (SB206553). Administration of the receptor agonists (±)-DOI (5-HT2A/2C), m-CPP (5-HT2B/2C), BW723C86 (5-HT2B) and WAY 161503 (5-HT2C) led to decreases in the levels of brain glycogen. We found that 5-HT is involved in the modulation of brain glycogen homeostasis in the rainbow trout, causing a glycogenolytic effect when fish are in a normoglycemic or hypoglycemic state, but not when they are in a hyperglycemic state. 5-HT1A, 5-HT1B, 5HT2B and 5-HT2C-like receptors appeared to be involved in the glycogenolytic action of 5-HT, although the effect mediated by 5-HT1A or 5-HT1B was apparently stronger.
Bilateral coordination and the motor basis of female preference for sexual signals in canary song
Authors: Suthers Roderick A. , Vallet Eric , Kreutzer Michel
Published: August 2012

The preference of female songbirds for particular traits in the songs of courting males has received considerable attention, but the relationship of preferred traits to male quality is poorly understood. Female domestic canaries (Serinus canaria, Linnaeus) preferentially solicit copulation with males that sing special high repetition rate, wide-band, multi-note syllables, called ‘sexy’ or A-syllables. Syllables are separated by minibreaths but each note is produced by pulsatile expiration, allowing high repetition rates and long duration phrases. The wide bandwidth is achieved by including two notes produced sequentially on opposite sides of the syrinx, in which the left and right sides are specialized for low or high frequencies, respectively. The emphasis of low frequencies is facilitated by a positive relationship between syllable repetition rate and the bandwidth of the fundamental frequency of notes sung by the left syrinx, such that bandwidth increases with increasing syllable repetition rate. The temporal offset between notes prevents cheating by unilaterally singing a note on the left side with a low fundamental frequency and prominent higher harmonics. The syringeal and respiratory motor patterns by which sexy syllables are produced support the hypothesis that these syllables provide a sensitive vocal–auditory indicator of a male's performance limit for the rapid, precisely coordinated interhemispheric switching, which is essential for many sensory and motor processes involving specialized contributions from each cerebral hemisphere.
Evolution of high duty cycle echolocation in bats
Authors: Fenton M. Brock , Faure Paul A. , Ratcliffe John M.
Published: August 2012

Duty cycle describes the relative ‘on time’ of a periodic signal. In bats, we argue that high duty cycle (HDC) echolocation was selected for and evolved from low duty cycle (LDC) echolocation because increasing call duty cycle enhanced the ability of echolocating bats to detect, lock onto and track fluttering insects. Most echolocators (most bats and all birds and odontocete cetaceans) use LDC echolocation, separating pulse and echo in time to avoid forward masking. They emit short duration, broadband, downward frequency modulated (FM) signals separated by relatively long periods of silence. In contrast, bats using HDC echolocation emit long duration, narrowband calls dominated by a single constant frequency (CF) separated by relatively short periods of silence. HDC bats separate pulse and echo in frequency by exploiting information contained in Doppler-shifted echoes arising from their movements relative to background objects and their prey. HDC echolocators are particularly sensitive to amplitude and frequency glints generated by the wings of fluttering insects. We hypothesize that narrowband/CF calls produced at high duty cycle, and combined with neurobiological specializations for processing Doppler-shifted echoes, were essential to the evolution of HDC echolocation because they allowed bats to detect, lock onto and track fluttering targets. This advantage was especially important in habitats with dense vegetation that produce overlapping, time-smeared echoes (i.e. background acoustic clutter). We make four specific, testable predictions arising from this hypothesis.
Medication Use and Associated Risk of Falling in a Geriatric Outpatient Population
Authors: Freeland Kathryn N , Thompson Amy N , Zhao Yumin , Leal Julie E , Mauldin Patrick D , Moran William P
Published: August 2012

BACKGROUND:

Studies have shown that approximately one third of community-dwelling people aged 65 years and older will experience a fall each year. Many studies indicate that use of multiple medications may put patients at an increased risk of falling, but few studies have been conducted to correlate the number of medications with the risk of falls.

OBJECTIVE:

To determine the medications most frequently used in patients aged 65 years or older who have experienced a fall within the past year, with particular attention to type or number of medications most commonly associated with multiple falls or a fall with injury.

METHODS:

We conducted a chart review in an outpatient internal medicine clinic over a 13-month period. A total of 118 patients 65 years of age or older who were taking 4 or more medications and had experienced at least 1 fall in the previous 12 months were included. Data relating to sex, age, race, diagnoses, medications, and number and type of falls were obtained during the chart review. The primary end point of the study was number and type of medications most commonly used in patients experiencing a fall.

RESULTS:

A total of 116 patients were examined for trends in fall risk. A logistic regression model and receiver operating characteristic curve demonstrated significant fall risk with the addition of medications, with patients experiencing a 14% increase in fall risk with the addition of each medication beyond a 4-medication regimen (OR 1.14; 95% CI 1.02 to 1.27; p = 0.027).

CONCLUSIONS:

The addition of medications is associated with a significant increase in risk of falls in elderly patients, regardless of drug class. Further studies are needed to assess the possible increased risk of falls with increasing number of medications.
Tonic Inhibition Enhances Fidelity of Sensory Information Transmission in the Cerebellar Cortex
Authors: Duguid Ian , Branco Tiago , London Michael , Chadderton Paul , Häusser Michael
Published: August 2012

Tonic inhibition is a key regulator of neuronal excitability and network function in the brain, but its role in sensory information processing remains poorly understood. The cerebellum is a favorable model system for addressing this question as granule cells, which form the input layer of the cerebellar cortex, permit high-resolution patch-clamp recordingsin vivo, and are the only neurons in the cerebellar cortex that express the α6δ-containing GABAAreceptors mediating tonic inhibition. We investigated how tonic inhibition regulates sensory information transmission in the rat cerebellum by using a combination of intracellular recordings from granule cells and molecular layer interneuronsin vivo, selective pharmacology, andin vitrodynamic clamp experiments. We show that blocking tonic inhibition significantly increases the spontaneous firing rate of granule cells while only moderately increasing sensory-evoked spike output. In contrast, enhancing tonic inhibition reduces the spike probability in response to sensory stimulation with minimal effect on the spontaneous spike rate. Both manipulations result in a reduction in the signal-to-noise ratio of sensory transmission in granule cells and of parallel fiber synaptic input to downstream molecular layer interneurons. These results suggest that under basal conditions the level of tonic inhibitionin vivoenhances the fidelity of sensory information transmission through the input layer of the cerebellar cortex.
Organization of Cerebral Projections to Identified Cerebellar Zones in the Posterior Cerebellum of the Rat
Authors: Suzuki Lucia , Coulon Patrice , Sabel-Goedknegt Erika H. , Ruigrok Tom J. H.
Published: August 2012

The cerebrocerebellar connection makes use of two of the largest fiber tracts in the mammalian brain, i.e., the cerebral and medial cerebellar peduncles. Neuroanatomical approaches aimed to elucidate the organization of this important connection have been hindered by its multisynaptic nature, the complex organization of its components, and the dependency of conventional tracers on precisely placed injections. To overcome these problems, we used rabies virus (RV) as a retrograde transneuronal tracer. RV was injected simultaneously with cholera toxin β subunit (CTb) into selected areas of the cerebellar cortex of 18 male Wistar rats. A survival time of 48–50 h resulted in first- and second-order labeling of RV in combination with first-order labeling of CTb. The distribution of CTb-labeled neurons in the inferior olive established the zonal identity of the injection site. In this way, it was possible to examine the cortical distribution of neurons from which disynaptic cerebrocerebellar projections to specific cerebellar loci originate.

The results show that this distribution covaries with the identity of the injected cerebellar lobule. More subtle changes were present when different zones of the same lobule were injected. The C1 zone of lobule VIII receives a more prominent projection from the somatosensory cortex compared with the C2/D zones. The laterally positioned D zones receive information from more rostral regions of the cerebral cortex. The vermis of lobule VII receives a prominent input from the retrosplenial and orbitofrontal cortices. Different injection sites also result in differences in laterality of the connections.
How Preparation Changes the Need for Top–Down Control of the Basal Ganglia When Inhibiting Premature Actions
Authors: Jahfari Sara , Verbruggen Frederick , Frank Michael J. , Waldorp Lourens J. , Colzato Lorenza , Ridderinkhof K. Richard , Forstmann Birte U.
Published: August 2012

Goal-oriented signals from the prefrontal cortex gate the selection of appropriate actions in the basal ganglia. Key nodes within this fronto-basal ganglia action regulation network are increasingly engaged when one anticipates the need to inhibit and override planned actions. Here, we ask how the advance preparation of action plans modulates the need for fronto-subcortical control when a planned action needs to be withdrawn. Functional magnetic resonance imaging data were collected while human participants performed a stop task with cues indicating the likelihood of a stop signal being sounded. Mathematical modeling of go trial responses suggested that participants attained a more cautious response strategy when the probability of a stop signal increased. Effective connectivity analysis indicated that, even in the absence of stop signals, the proactive engagement of the full control network is tailored to the likelihood of stop trial occurrence. Importantly, during actual stop trials, the strength of fronto-subcortical projections was stronger when stopping had to be engaged reactively compared with when it was proactively prepared in advance. These findings suggest that fronto-basal ganglia control is strongest in an unpredictable environment, where the prefrontal cortex plays an important role in the optimization of reactive control. Importantly, these results further indicate that the advance preparation of action plans reduces the need for reactive fronto-basal ganglia communication to gate voluntary actions.
Role of Dopamine Tone in the Pursuit of Brain Stimulation Reward
Authors: Hernandez Giovanni , Trujillo-Pisanty Ivan , Cossette Marie-Pierre , Conover Kent , Shizgal Peter
Published: August 2012

Dopaminergic neurons contribute to intracranial self-stimulation (ICSS) and other reward-seeking behaviors, but it is not yet known where dopaminergic neurons intervene in the neural circuitry underlying reward pursuit or which psychological processes are involved. In rats working for electrical stimulation of the medial forebrain bundle, we assessed the effect of GBR-12909 (1-[2-[bis(4-fluorophenyl)-methoxy]ethyl]-4-[3- phenylpropyl]piperazine), a specific blocker of the dopamine transporter. Operant performance was measured as a function of the strength and cost of electrical stimulation. GBR-12909 increased the opportunity cost most subjects were willing to pay for a reward of a given intensity. However, this effect was smaller than that produced by a regimen of cocaine administration that drove similar increases in nucleus accumbens (NAc) dopamine levels in unstimulated rats. Delivery of rewarding stimulation to drug-treated rats caused an additional increase in dopamine concentration in the NAc shell in cocaine-treated, but not GBR-12909-treated, rats. These behavioral and neurochemical differences may reflect blockade of the norepinephrine transporter by cocaine but not by GBR-12909. Whereas the effect of psychomotor stimulants on ICSS has long been attributed to dopaminergic action at early stages of the reward pathway, the results reported here imply that increased dopamine tone boosts reward pursuit by acting at or beyond the output of the circuitry that temporally and spatially summates the output of the directly stimulated neurons underlying ICSS. The observed enhancement of reward seeking could be attributable to a decrease in the value of competing behaviors, a decrease in subjective effort costs, or an increase in reward-system gain.
Fezf2 Regulates Multilineage Neuronal Differentiation through Activating Basic Helix-Loop-Helix and Homeodomain Genes in the Zebrafish Ventral Forebrain
Authors: Yang Nan , Dong Zhiqiang , Guo Su
Published: August 2012

Transcription factors of theachaete-scuteandatonalbHLH proneural gene family play important roles in neuronal differentiation. They are also involved in neuronal subtype specification through collaboration with homeodomain (HD) transcription factors. However, concerted regulation of these genes and in turn progenitor fate toward distinct lineages within the developing vertebrate brain is not well understood. Fezf2 is an evolutionarily conserved zinc finger protein important for monoaminergic neuronal development in zebrafish. Here, we show that Fezf2 is also critical for GABAergic neuronal fate and investigate how a single transcription factor regulates the identity of multiple neuronal lineages in the developing ventral forebrain. First, our genetic analyses reveal the requirement of theachaete-scute-like genesascl1aand1bin serotonergic and GABAergic neuron development, but they are dispensable for the specification of dopaminergic neurons, which is dependent on theatonal-like geneneurog1. Second, the expression offezf2,ascl1a/1b, andneurog1demarcates distinct progenitor subpopulations, wherefezf2is required for activating but not maintaining the expression of bHLH genes. Third, Fezf2 is required to activate HD genesotpbanddlx2, which are involved in dopaminergic and GABAergic neuronal development, respectively. Finally, we uncover that Fezf2 is sufficient to increase dopaminergic neuronal numbers but not serotonergic or GABAergic lineages. Together, these findings reveal new mechanisms by which multilineage differentiation is coordinately regulated by a single transcription factor in the vertebrate ventral forebrain.
Enhanced NMDA Receptor-Dependent Thalamic Excitation and Network Oscillations in Stargazer Mice
Authors: Lacey Carolyn J. , Bryant Astra , Brill Julia , Huguenard John R.
Published: August 2012

Disturbances in corticothalamic circuitry can lead to absence epilepsy. The reticular thalamic nucleus (RTN) plays a pivotal role in that it receives excitation from cortex and thalamus and, when strongly activated, can generate excessive inhibitory output and epileptic thalamocortical oscillations that depend on postinhibitory rebound. Stargazer (stg) mice have prominent absence seizures resulting from a mutant form of the AMPAR auxiliary protein stargazin. Reduced AMPAR excitation in RTN has been demonstrated previously in stg, yet the mechanisms leading from RTN hypoexcitation to epilepsy are unknown and unexpected because thalamic epileptiform oscillatory activity requires AMPARs. We demonstrate hyperexcitability in stg thalamic slices and further characterize the various excitatory inputs to RTN using electrical stimulation and laser scanning photostimulation. Patch-clamp recordings of spontaneous and evoked EPSCs in RTN neurons demonstrate reduced amplitude and increased duration of the AMPAR component with an increased amplitude NMDAR component. Short 200 Hz stimulus trains evoked a gradual approximately threefold increase in NMDAR EPSCs compared with single stimuli in wild-type (WT), indicating progressive NMDAR recruitment, whereas in stg cells, NMDAR responses were nearly maximal with single stimuli. Array tomography revealed lower synaptic, but higher perisynaptic, AMPAR density in stg RTN. Increasing NMDAR activity via reduced [Mg2+]oin WT phenocopied the thalamic hyperexcitability observed in stg, whereas changing [Mg2+]ohad no effect on stg slices. These findings suggest that, in stg, a trafficking defect in synaptic AMPARs in RTN cells leads to a compensatory increase in synaptic NMDARs and enhanced thalamic excitability.
Chronic-Pain-Associated Astrocytic Reaction in the Spinal Cord Dorsal Horn of Human Immunodeficiency Virus-Infected Patients
Authors: Shi Yuqiang , Gelman Benjamin B. , Lisinicchia Joshua G. , Tang Shao-Jun
Published: August 2012

Studies with animal models have suggested that reaction of glia, including microglia and astrocytes, critically contributes to the development and maintenance of chronic pain. However, the involvement of glial reaction in human chronic pain is unclear. We performed analyses to compare the glial reaction profiles in the spinal dorsal horn (SDH) from three cohorts of sex- and age-matched human postmortem tissues: (1) HIV-negative patients, (2) HIV-positive patients without chronic pain, and (3) HIV patients with chronic pain. Our results indicate that the expression levels of CD11b and Iba1, commonly used for labeling microglial cells, did not differ in the three patient groups. However, GFAP and S100β, often used for labeling astrocytes, were specifically upregulated in the SDH of the “pain-positive” HIV patients but not in the “pain-negative” HIV patients. In addition, proinflammatory cytokines, TNFα and IL-1β, were specifically increased in the SDH of pain-positive HIV patients. Furthermore, proteins in the MAPK signaling pathway, including pERK, pCREB and c-Fos, were also upregulated in the SDH of pain-positive HIV patients. Our findings suggest that reaction of astrocytes in the SDH may play a role during the maintenance phase of HIV-associated chronic pain.
Die Magische Dimension: Be-Greifbare Interaktion auf und über Tabletops
Authors: Spindler Martin , Dachselt Raimund
Published: August 2012

Aktuelle technische Entwicklungen am Smartphone- und Tablet-Markt zeigen, dass die Verschmelzung von Eingabe und Ausgabe im selben Gerät zu einer direkteren und als natürlicher empfundenen Interaktion führt. Während sich ein Grossteil bisheriger Forschung der Entwicklung von Touchtechniken auf derartigen berührungsempfindlichen Displays widmet, lösen wir uns von den Beschränkungen einer interaktiven Oberfläche und erweitern den Interaktionsraum auf den physischen dreidimensionalen (3D) Raum oberhalb eines Tabletops. Mit lagebewussten, in der Hand gehaltenen Papierdisplays stellen wir einen vielversprechenden Ansatz vor, der diesen Raum nutzt. Durch die zusätzliche Verwendung der Position und Orientierung dieser Papierdisplays (be-greifbare Linsen) mit unterschiedlicher Form und Grösse können Nutzer eine sehr direkte, greifbare Interaktion mit verschiedenen Informationsräumen erleben. Der gleichzeitige Einsatz multipler Linsen unterstützt kollaboratives Arbeiten explizit. Der Artikel stellt neben grundlegenden Interaktionskonzepten auf und mit den Linsen auch konkrete Anwendungsfälle vor, diskutiert die Vor- und Nachteile aktiver und passiver Displays und erläutert den technischen Aufbau des Systems.
Be-greifbare Interaktionen mit grössenveränderbaren Bildschirmen
Authors: Steimle Jürgen , Lissermann Roman , Olberding Simon , Khalilbeigi Mohammadreza , Kleine Wolfgang , Mühlhäuser Max
Published: August 2012

Neue Technologien für flexible Bildschirme ermöglichen Bildschirme, die physisch verformbar sind. Dies eröffnet das Potenzial, Bildschirme und deren Inhalte auf neue Art be-greifbar zu machen. In diesem Artikel untersuchen wir, wie Nutzer mit Inhalten auf Bildschirmen interagieren können, die durch Rollen oder Falten in ihrer Grösse verändert werden können. Dies ist insbesondere im Kontext von mobilen Endgeräten relevant, deren Nutzbarkeit durch grössen-veränderbare Bildschirme deutlich verbessert werden kann. Wir führen diese neue Klasse be-greifbarer Interaktionen ein, identifizieren grundsätzliche Funktionen der Grössenveränderung und stellen diese anhand von Beispielanwendungen vor.
Was erwarten Usability Experten von Anforderungsdokumenten?
Authors: Gross Anne , Hess Steffen
Published: August 2012

Die Erreichbarkeit einer hohen Usability sowie User Experience in Softwareprodukten setzt ein detailliertes Verständnis über Benutzer und deren Aufgaben voraus. Daher bilden Anforderungsdokumente für die Aktivitäten von Usability Experten eine wichtige Arbeitsgrundlage. Aber auch für die Aufgaben anderer Rollen wie Softwarearchitekten und Tester bilden diese Dokumente eine wichtige Informationsquelle. Dies bringt jedoch die Herausforderung mit sich, dass in Anforderungsdokumenten unterschiedliche Informationsbedarfe adressiert werden müssen, was deren Nutzbarkeit für die einzelnen Rollen negativ beeinflusst. Um geeignete Lösungen für dieses Problem zu entwickeln, ist empirisch fundiertes Wissen über Informationsbedarfe eine unabdingbare Voraussetzung. In diesem Beitrag werden Aufbau und Ergebnisse erster Studien vorgestellt, welche Informationsbedarfe an Anforderungsdokumente aus Sicht von Usability Experten untersucht haben. Dabei konnten erste Erkenntnisse hinsichtlich der Relevanz von Artefakten wie Beschreibungen von Endnutzern und Interaktionen gewonnen werden. Unterschiede innerhalb der Teilnehmergruppe, insbesondere im Hinblick auf den Detaillierungsgrad der relevanten Artefakte erfordern weitere Studien, welche Einflussfaktoren auf Informationsbedarfe genauer untersuchen.
Growth differentiation factor-15 upregulates interleukin-6 to promote tumorigenesis of prostate carcinoma PC-3 cells
Authors: Tsui Ke-Hung , Chang Ying-Ling , Feng Tsui-Hsia , Chung Li-Chuan , Lee Tzu-Yi , Chang Phei-Lang , Juang Horng-Heng
Published: August 2012

Growth differentiation factor-15 (GDF15), a member of the transforming growth factor-β superfamily, is associated with human cancer progress. We evaluated the role GDF15 plays in tumorigenesis of prostate carcinoma PC-3 cells. Results from real-time RT-PCR and ELISA revealed that expression of GDF15 was approximately threefold higher in LNCaP cells than in PC-3 cells. Other prostate cell lines (PZ-HPV-7, CA-HPV-10, and DU145 cells) expressed extremely low levels of GDF15. Stable overexpression of GDF15 in PC-3 cells enhanced the degree of cell proliferation and invasion as shown in the 3H-thymidine incorporation assay and in the Matrigel invasion assay respectively. Soft agar assays and xenograft animal studies indicated that overexpression of GDF15 in PC-3 cells increased tumorigenesis in vitro and in vivo. Results from RT-PCR, immunoblot, and reporter assays revealed that overexpression of GDF15 resulted in decreased expression of maspin and upregulation of interleukin-6 (IL6), matriptase, and N-myc downstream-regulated gene 1 (NDRG1) expression. Further studies revealed that overexpression of IL6 enhanced GDF15 expression in LNCaP cells while knockdown of IL6 blocked the expression of GDF15 in PC-3 cells, suggesting that expression of GDF15 is upregulated by IL6. This study demonstrated that expression of GDF15 induces cell proliferation, invasion, and tumorigenesis of prostate carcinoma PC-3 cells. The enhancement of tumorigenesis and invasiveness of prostate carcinoma cells that stably overexpress GDF15 may be caused by the dysregulation of maspin, matriptase, and IL6 gene expression. The expression of GDF15 and IL6 is controlled via a positive feedback loop in PC-3 cells.
Chromatin immunoprecipitation: advancing analysis of nuclear hormone signaling
Authors: Vinckevicius Aurimas , Chakravarti Debabrata
Published: August 2012

Recent decades have been filled with groundbreaking research in the field of endocrine hormone signaling. Pivotal events like the isolation and purification of the estrogen receptor, the cloning of glucocorticoid receptor cDNA, or dissemination of nuclear hormone receptor (NHR) DNA binding sequences are well recognized for their contributions. However, the novel genome-wide and gene-specific information obtained over the last decade describing NHR association with chromatin, cofactors, and epigenetic modifications, as well as their role in gene regulation, has been largely facilitated by the adaptation of the chromatin immunoprecipitation (ChIP) technique. Use of ChIP-based technologies has taken the field of hormone signaling from speculating about the transcription-enabling properties of acetylated chromatin and putative transcription (co-)factor genomic occupancy to demonstrating the detailed, stepwise mechanisms of factor binding and transcriptional initiation; from treating hormone-induced transcription as a steady-state event to understanding its dynamic and cyclic nature; from looking at the DNA sequences recognized by various DNA-binding domainsin vitroto analyzing the cell-specific genome-wide pattern of nuclear receptor binding and interpreting its physiological implications. Not only have these events propelled hormone research, but, as some of the pioneering studies, have also contributed tremendously to the field of molecular endocrinology as a whole. In this review, we give a brief summary of some of the most important discoveries in hormone signaling using ChIP and other derivative techniques and speculate on what the future may hold.
Enhanced insulin secretion and improved glucose tolerance in mice with homozygous inactivation of the Na+K+2Cl− co-transporter 1
Authors: Alshahrani Saeed , Di Fulvio Mauricio
Published: August 2012

The intracellular chloride concentration ([Cl−]i) in β-cells plays an important role in glucose-stimulated plasma membrane depolarisation and insulin secretion. [Cl−]iis maintained above equilibrium in β-cells by the action of Cl−co-transporters of the solute carrier family 12 group A (Slc12a). β-Cells expressSlc12a1andSlc12a2, which are known as the bumetanide (BTD)-sensitive Na+-dependent K+2Cl−co-transporters 2 and 1 respectively. We show that mice lacking functional alleles of theSlc12a2gene exhibit better fasting glycaemia, increased insulin secretion in response to glucose, and improved glucose tolerance when compared with wild-type (WT). This phenomenon correlated with increased sensitivity of β-cells to glucosein vitroand with increased β-cell mass. Further, administration of low doses of BTD to mice deficient inSlc12a2worsened their glucose tolerance, and low concentrations of BTD directly inhibited glucose-stimulated insulin secretion from β-cells deficient inSlc12a2but expressing intactSlc12a1genes. Together, our results suggest for the first time that theSlc12a2gene is not necessary for insulin secretion and that its absence increases β-cell secretory capacity. Further, impairment of insulin secretion with BTDin vivoandin vitroin islets lackingSlc12a2genes unmasks a potential new role forSlc12a1in β-cell physiology.
Iodothyronine deiodinases: a functional and evolutionary perspective
Authors: Orozco Aurea , Valverde-R Carlos , Olvera Aurora , García-G Carlota
Published: August 2012

From an evolutionary perspective, deiodinases may be considered pivotal players in the emergence and functional diversification of both thyroidal systems (TS) and their iodinated messengers. To better understand the evolutionary pathway and the concomitant functional diversification of vertebrate deiodinases, in the present review we summarized the highlights of the available information regarding this ubiquitous enzymatic component that represents the final, common physiological link of TS. The information reviewed here suggests that deiodination of tyrosine metabolites is an ancient feature of all chordates studied to date and consequently, that it precedes the integration of the TS that characterize vertebrates. Phylogenetic analysis presented here points to D1 as the oldest vertebrate deiodinase and to D2 as the most recent deiodinase gene, a hypothesis that agrees with the notion that D2 is the most specialized and finely regulated member of the family and plays a key role in vertebrate neurogenesis. Thus, deiodinases seem to be major participants in the evolution and functional expansion of the complex regulatory network of TS found in vertebrates.
Myostatin inhibits myosatellite cell proliferation and consequently activates differentiation: evidence for endocrine-regulated transcript processing
Authors: Garikipati Dilip K , Rodgers Buel D
Published: August 2012

Myostatin is a potent negative regulator of muscle growth in mammals. Despite high structural conservation, functional conservation in nonmammalian species is only assumed. This is particularly true for fish due to the presence of several myostatin paralogs: two in most species and four in salmonids (MSTN-1a, -1b, -2a, and -2b). Rainbow trout are a rich source of primary myosatellite cells as hyperplastic muscle growth occurs even in adult fish. These cells were therefore used to determine myostatin's effects on proliferation whereas our earlier studies reported its effects on quiescent cells. As in mammals, recombinant myostatin suppressed proliferation with no changes in cell morphology. Expression of MSTN-1a was several fold higher than the other paralogs and was autoregulated by myostatin, which also upregulated the expression of key differentiation markers: Myf5, MyoD1, myogenin, and myosin light chain. Thus, myostatin-stimulated cellular growth inhibition activates rather than represses differentiation. IGF-1 stimulated proliferation but had minimal and delayed effects on differentiation and its actions were suppressed by myostatin. However, IGF-1 upregulated MSTN-2a expression and the processing of its transcript, which is normally unprocessed. Myostatin therefore appears to partly mediate IGF-stimulated myosatellite differentiation in rainbow trout. This also occurs in mammals, although the IGF-stimulated processing of MSTN-2a transcripts is highly unique and is indicative of subfunctionalization within the gene family. These studies also suggest that the myokine's actions, including its antagonistic relationship with IGF-1, are conserved and that the salmonid gene family is functionally diverging.
Oogenesis pattern and type of ovariole of the parasitoid Palmistichus elaeisis (Hymenoptera: Eulophidae)
Authors: Andrade Gilberto S. , Sousa Adalberto H. , Santos Juliana C. , Gama Farah C. , Serrão José E. , Zanuncio José C.
Published: August 2012

The knowledge on ovigeny in parasitoids is important for basic studies on physiology and applied biological control. The ovigeny pattern and type of ovariole of the parasitoid Palmistichus elaeisis Delvare & LaSalle (Hymenoptera: Eulophidae) were studied in newly-emerged females at seven, 14, 24 and 48 h intervals after their emergence from Tenebrio molitor L. pupae (Coleoptera: Tenebrionidae). Females of P. elaeisis presented ovaries composed by four ovarioles of the meroistic polytrophic type. The yolk accumulation and chorionogenesis in P. elaeisis were concluded 24 h after the female emergence. The 48 h-old females show a high quantity of egg ready for oviposition. These findings can help to improve the mass production of P. elaeisis and the augmentative biological control by using this natural enemy.
Gonadal development in the freshwater crab Sylviocarcinus pictus (H. Milne Edwards, 1853) (Brachyura: Trichodactylidae) from the Guamá river, state of Pará, Brazil
Authors: Silva Leiliane S. , Martinelli-Lemos Jussara M. , Ferreira Maria Auxiliadora P. , Rocha Rossineide M.
Published: August 2012

The development stages of male and female gonads in the freshwater crab Sylviocarcinus pictus (H. Milne Eduards, 1853) were described through macroscopic and microscopic (histology) examinations. The histological description was based on 40 specimens (20 each sex). Four gonadal development stages were found for females: immature, ripening, mature and spawned. The following female cells were found: ovogonia, oocytes in initial vitellogenesis, oocytes in advanced vitellogenesis, follicular cells and post-ovulatory follicles. Three development stages were found for males: immature, maturing and mature, with the indication of: spermatogonia, spermatocytes, spermatids, spermatozoids and spermatophores. These data suggest the pattern described in the literature. Size at sexual maturity was 32.3 mm of carapace width for males and 31.5 mm for females. The gonadal stages observed macroscopically by volume and color were validated through histological analysis and proved to be useful method for the rapid identification of sexual maturity in the species. The present study offers previously unpublished data on the reproductive biology of Sylviocarcinus pictus.
Restinga forests of the Brazilian coast: richness and abundance of tree species on different soils
Authors: Magnago Luiz F.S. , Martins Sebastião V. , Schaefer Carlos E.G.R. , Neri Andreza V.
Published: August 2012

The aim of this study was to determine changes in composition, abundance and richness of species along a forest gradient with varying soils and flood regimes. The forests are located on the left bank of the lower Jucu River, in Jacarenema Natural Municipal Park, Espírito Santo. A survey of shrub/tree species was done in 80 plots, 5x25 m, equally distributed among the forests studied. We included in the sampling all individuals with >3.2 cm diameter at breast height (1.30 m). Soil samples were collected from the surface layer (0-10 cm) in each plot for chemical and physical analysis. The results indicate that a significant pedological gradient occurs, which is influenced by varying seasonal groundwater levels. Restinga forest formations showed significant differences in species richness, except for Non-flooded Forest and Non-flooded Forest Transition. The Canonical Correlation Analysis (CCA) showed that some species are distributed along the gradient under the combined influence of drainage, nutrient concentration and physical characteristics of the soil. Regarding the variables tested, flooding seems to be a more limiting factor for the establishment of plant species in Restinga forests than basic soil fertility attributes.
Probiotics prevent growth deficit of colon wall strata of malnourished rats post-lactation
Authors: Lima Dirlene P. , Azevedo Jorge F. de , Hermes-Uliana Catchia , Alves Gilberto , Sant'ana Débora M.G. , Araújo Eduardo J.A.
Published: August 2012

The objective of this study was to analyze morphometrically the colon wall strata of malnourished rats supplemented with probiotics. Sixteen recently weaned Wistar rats (Rattus norvegicus) were distributed into four groups: animals that received commercial chow (G1, n = 4); animals that received the same feed as G1 and were supplemented with probiotics (G2, n = 4); animals that received chow with 4% of proteins (G3, n = 4); animals that received the same feed as G3 and were supplemented with probiotics (G4, n = 4). After 12 weeks, the proximal colon was collected and submitted to histological processing. Three-µm cuts were stained with H.E., Periodic Acid Schifff (P.A.S.) + diasthasis solution and Alcian Blue (A.B.) pH 2.5 and pH 1.0. The morphometric analysis of the intestinal wall showed that the supplementation with ABT-4 probiotic culture prevents the growth deficit of colon wall strata that normally occurs in malnourished rats right after lactation. Besides, no alteration was observed in the proportion of the number of globet cells in relation to the number of enterocytes in malnourished rats, regardless of the supplementation with probiotics.
Fossil woods (Coniferales) from the Baqueró Group (Aptian), Santa Cruz Province, Argentina
Authors: Vera Ezequiel I. , Césari Silvia N.
Published: August 2012

Two new conifer morphospecies represented by a secondary xylem are reported for the Lower Cretaceous Baqueró Group (Santa Cruz Province, Argentina). Agathoxylon sp. is characterized by poorly defined growth rings, predominantly uniseriate pitting in the radial wall of the tracheids, cross fields with 1-6 pits and uniseriate rays. These features are shared with the leafy branches described for the unit as Araucaria grandifolia Feruglio emend. Del Fueyo and Archangelsky. The second taxon, Brachyoxylon sp. cf. B. boureaui, possesses poorly defined growth rings, mixed wood with predominantly uniseriate radial pitting, cross fields with 8-26 pits and uniseriate rays. These taxa represent the first fossil woods described for Baqueroan strata.
Que importância tem a dimensão econômica para a psicanálise contemporânea?: um estudo aprofundado sobre o objeto primário e a ambivalência das pulsões em Freud
Authors: De Martini André , Coelho Junior Nelson Ernesto
Published: August 2012

No presente trabalho, através de um percurso pelos textos freudianos, iremos acompanhar os engendramentos entre sujeito e objeto que se dão pelos caminhos pulsionais, dentro de uma perspectiva econômica. Ora, o que nos interessa aqui é colocar em questão o que nos parece ser um certo enfraquecimento ou "desvitalização" da teoria, em que tanto a sexualidade como os elementos mais "crus" do psiquismo vão sendo deixados de lado em nome de uma pretensa ênfase dos aspectos relacionais. Interessa-nos, especificamente, pensar que papel pode ter a dimensão econômica (tal como formulada por Freud) nos debates psicanalíticos contemporâneos em que a ética é trazida para o primeiro plano. Parece-nos que a dimensão econômica ou pulsional em psicanálise, longe de ser avessa ao lugar do outro na constituição do psiquismo, pode trazer esclarecimentos únicos a esse respeito, evidenciando a sustentação mútua entre Eu e Outro num campo compartilhado de instalação de subjetividades.
Possibilidades éticos-estéticas da perversão: a sexualidade perverso-polimorfa como prática de liberdade em Marcuse
Authors: Hilário Leomir Cardoso , Cunha Eduardo Leal
Published: August 2012

Este artigo visa explorar a compreensão ético-estética do fenômeno perverso realizada por Marcuse em Eros e Civilização. No registro ético, destacamos o caráter necessariamente moral da categoria de perversão e seu vínculo com a normatização da experiência sexual, com a disciplinarização e controle dos corpos, no quadro da leitura foucaultiana do biopoder, situando Marcuse como crítico de tais processos em sua ligação com o modo de produção capitalista. No segundo registro, da estética, expomos como Marcuse, através da reconfiguração da relação entre Eros e Logos e da afirmação de um ethos estético, propõe que a perversão sexual implica a contestação da ordem vigente e a produção de novos modos de relações consigo e com os outros, em contraste com a regulação instrumental do erotismo. Por fim, indicamos como o campo de possibilidades aberto por Marcuse no domínio da transgressão aponta para a necessidade de retomar criticamente a categoria de perversão.
Adaptação da “The Resilience Scale” para a população adulta portuguesa
Authors: Ng Deep Cláudia Alexandra Ferreira de Carvalho , Leal Isabel Pereira
Published: August 2012

Este artigo descreve a adaptação da “The Resilience Scale” para portugueses adultos. Procedeu-se à retradução e validação psicométrica. Fez-se pré-teste e reteste. Obteve-se equivalência linguística/conceptual e validação psicométrica com alpha de Cronbach 0,868 para 23 itens, sugerindo consistência interna. A análise fatorial agrupou 23 variáveis em 4 fatores: I - Perseverança; II - Sentido de vida; III - Serenidade; IV - Autossuficiência e autoconfiança, com valores alpha de Cronbach satisfatórios para cada fator. Verificou-se sensibilidade dos itens através do coeficiente de assimetria e achatamento e comprovou-se a estabilidade temporal. A escala revela boas características psicométricas aferindo níveis de resiliência nesta população.
Estresse laboral e raciocínio inferencial: um estudo correlacional
Authors: Noronha Ana Paula Porto , Fernandes Dario Cecilio
Published: August 2012

O objetivo desse estudo foi verificar as relações entre estresse laboral e raciocínio inferencial, sexo e idade. Os instrumentos utilizados foram a escala de vulnerabilidade a estressores no trabalho (EVET) e raciocínio inferencial (RIn). Participaram da pesquisa 64 alunos de Psicologia e Engenharia de uma instituição privada do interior do Estado de São Paulo, sendo que, no total, 81,2% eram do sexo masculino, e 18,8%, do sexo feminino, com idade variando de 18 a 45 anos (M=24, DP=5,78). Em relação aos fatores da escala de estresse, encontrou-se correlação negativa significativa entre o fator três (falta de suporte organizacional) e o RIn. Dentre as demais análises realizadas, destaca-se a correlação negativa significativa entre EVET e RIn (r =-0,25; p=0,047), o que indica que, quanto maior o estresse, menor a capacidade de raciocínio inferencial.
Saúde mental e saúde do trabalhador: análise das conferências nacionais brasileiras
Authors: Ramminger Tatiana , Nardi Henrique Caetano
Published: August 2012

No presente artigo, analisamos os principais documentos que sustentam as políticas de Saúde Mental e de Saúde doTrabalhador no Brasil, quais sejam, os relatórios das Conferências Nacionais, sublinhando como a Saúde Mental, enquanto tema, aparece no discurso da Saúde doTrabalhador e vice-versa: como a Saúde doTrabalhador é apresentada no discurso da Saúde Mental. Percebemos que a Saúde Mental, enquanto tema, é apresentada em ambas as Conferências Nacionais de Saúde do Trabalhador, embora com ênfases distintas e direcionadas à discussão do trabalho na iniciativa privada. Já a Saúde doTrabalhador, enquanto objeto das Conferências Nacionais de Saúde Mental, foi paulatinamente adquirindo importância e passou de uma reivindicação pela inclusão do tema da Saúde Mental do trabalhador na legislação e nas empresas até a uma preocupação específica com a Saúde Mental do trabalhador da saúde e com o servidor público. Concluímos que as conferências denotam o jogo técnico e político da construção de uma nova cidadania brasileira, a partir da disputa pela forma de institucionalização do SUS.
Psicologia da saúde e psicologia positiva: perspectivas e desafios
Authors: Calvetti Prisla Ücker , Muller Marisa Campio , Nunes Maria Lúcia Tiellet
Published: August 2012

O presente artigo visa a discutir a interface entre Psicologia da saúde e Psicologia positiva, destacando a relevância dos aspectos positivos do desenvolvimento humano como foco de pesquisas e intervenções. Salienta-se a necessidade de avanços nos estudos relacionados aos fatores protetores e de manutenção do desenvolvimento humano saudável. Na discussão em foco neste artigo, a Psicologia da saúde e a Psicologia positiva têm importante papel na compreensão dos aspectos envolvidos no enfrentamento da doença bem como na manutenção da saúde da pessoa, e apontam a relevância do investimento científico na investigação dos fatores de proteção da saúde.
Significado do tempo livre para adolescentes de classe popular
Authors: Sarriera Jorge Castellá , Paradiso Ângela Carina , Mousquer Paula Nunes , Marques Luciana Fernandes , Hermel Júlia Schneider , Coelho Roberta P. Schell
Published: August 2012

O presente artigo é uma pesquisa descritiva de cunho qualitativo sobre os significados que adolescentes de classe popular atribuem ao tempo livre. Participaram da pesquisa 120 adolescentes escolarizados de ambos os sexos, entre 12 e 18 anos, de Porto Alegre (RS - Brasil). Os resultados colhidos através de 15 grupos focais identificaram a dissonância entre as crenças e os conhecimentos sobre o tempo livre e as práticas dos adolescentes assim como os diversos sentidos atribuídos às mesmas atividades em termos de liberdade e prazer. Os significados estão unidos às experiências dos participantes e sua complexidade depende das contingências contextuais, e estão permeados pelas interligações entre diferentes conceitos emergidos. Observamos diferenças entre os grupos etários em relação à percepção de liberdade de escolha no tempo livre. Às vezes, o ócio objetiva desenvolvimento, e é um período produtivo no qual há investimentos no âmbito social, cultural ou pessoal. Por vezes, há também uma percepção do ócio como descanso, na medida em que relacionam tempo livre com idéias de compensação do cansaço oriundo das tarefas cotidianas. Observamos diferenças entre os grupos etários em relação à percepção de liberdade de escolha no tempo livre.
O resgate do vínculo mãe-bebê: estudo de caso de maus tratos
Authors: Esteves Carolina Marocco , Borges Edson Sá
Published: August 2012

Este artigo dedica-se a refletir sobre maus-tratos e a vinculação entre a mãe e seu bebê, sendo importante destacar que uma das principais conseqüências da má formação desse vínculo são os maus-tratos. O artigo expõe uma discussão teórico/prática relacionada aos aspectos teóricos da experiência clínica de dois anos de estágio profissional de Psicologia na enfermaria de queimados, no Hospital de Pronto Socorro de Porto Alegre. Foram estudados, durante o período, cinqüenta casos. O presente artigo descreve um dos atendimentos. O critério utilizado para a escolha foi a de que o caso é típico e oferece possibilidade de aprendizagem para o leitor. A abordagem utilizada no atendimento da díade foi a psicoterapia breve, com enfoque psicanalítico. Com base no acompanhamento desse caso clínico, pode-se concluir que a forma como a mãe atendida consegue se relacionar com o filho evidencia que a mesma se encontra incapacitada para desempenhar uma função materna adequada ao desenvolvimento da criança. Um dos fatores que contribui para isso é a história pregressa da mãe, observada durante os atendimentos psicológicos: doença mental devido a maus-tratos no passado. É importante destacar que o atendimento psicoterápico funcionou, no estudo, como um dispositivo de saúde e resgate desse vínculo. Diante desse quadro, elaborou-se uma proposta que tem como objetivo promover a saúde e/ou prevenir a doença, tanto do bebê quanto da mãe, iniciando o mais breve possível, o diagnóstico e o acompanhamento psicológico (ou psiquiátrico), que deverá ter continuidade após a internação e durante o desenvolvimento da criança.