192 research outputs found
A Method of Estimating Fishing Pressure and Harvest as Used on Logan River, Utah
Completely accurate statements of fishing pressure and harvest can only result from an ennumeration of all anglers and their catch. On most bodies of water it has not been economically feasible for management agencies to effect a complete census of fishermen and harvest. Practically, absolute accuracy is not necessary for management. The development of creel census methods resulting in estimates of known accuracy, yet requiring only a practical outlay of time and money, would be a step toward more effective management
Expulsos, como os atores italianos do Palais de Bourgogne: Missão, peripécias e triste fim do Teatro Novo (Rio de Janeiro, 1968)
A trajetória do Teatro Novo, reconstruída a partir de fontes inéditas do Arquivo Gianni Ratto (SP), implanta no Rio de Janeiro em pleno 1968 um projeto de “teatro estável” que resiste ao autoritarismo do regime sendo por ele esmagado, após oito meses de intensa atividade. Analisamos as ideias que estruturavam o projeto e seus encaminhamentos, com os quais Ratto pretendia consolidar a autossuficiência do empreendimento por meio da produção em equipe, de um espaço polivalente para um repertório eclético que incluía dança e música além do teatro dramático e de um centro de formação permanente, seja da classe artística e seja do público. As discrepâncias ente projeto e práticas são sintomas da possível relevância que o Teatro Novo significou no panorama contra cultural (inclusive motivando a seu triste fim) embora seu diferencial e legados tenham sido omitidos até agora nas histórias do teatro e da cultura no Brasil.Teatro Novo trajectory, restored by research in unpublished sources of the Gianni Ratto Archive (SP), fixed a “stable theatre” project in Rio de Janeiro (1968) opposing dictatorship and being closed, after eight mounts of intense activity. We analise the implanting ideas and resources, by which Ratto aimed a self-reliable production and a resident team, a multipurpose repertoire that included dance and music besides dramatic theatre, a living school for public as well as artistic class formation. Inconsistencies between project and practices are symptoms of Teatro Novo possible relevance in the counter-cultural panorama although his legacy has been ignored, so far, in Brazilian theatre and culture history
Atypical cytomorphology of Gaucher cells is frequently seen in bone marrow smears from untreated patients with Gaucher disease type 1
Introduction. Gaucher cells (GCs), the lipid-laden storage macrophages, are the pathologic hallmark of Gaucher disease (GD). They are typically 20–100 μm in diameter with eccentrically placed nuclei and cytoplasm with characteristic crinkles and striations. A few previous observations have indicated that sometimes GD patients may display morphology of GCs which is different from this classical description. The aim of our study was to explore the morphological polymorphism of GCs in patients with untreated GD type 1 (GD1). Material and methods. May-Grünwald Giemsa stained bone marrow smears (BM-S) from 6 patients with sporadic GD1 were analysed; each patient sample consisted of two slides where all GCs and non-Gaucher cell macrophages were counted. We have defined for the study purposes and examined the following features of GCs which were considered as atypical: (1) foamy cytoplasm, (2) centrally placed nucleus, (3) cell diameter > 100 μm, (4) multinuclearity, (5) syncytial morphology, (6) unusually large cytoplasmic projections, and (7) apparent haemophagocytosis. Results. All analysed patients showed 22–40% GCs with atypical cytomorphology (median 29%). The median number of atypical features of GCs was 10 per patient (range 6–13). Multinuclearity was the most common atypical feature of GCs, followed by erythrophagocytosis and foamy cytoplasm. There was a strong positive correlation between erythrophagocytosis and foamy cytoplasm in GCs (Spearman’s rank correlation coefficient: 0.9). Although majority of atypical GCs had one atypical feature, there was a considerable amount of GCs presenting ≥ 2 atypical features. Conclusions. Untreated patients with GD1 often show a considerable proportion of GCs with atypical cytomorphology. The knowledge of possible atypical variant forms of GCs can contribute to a quicker and accurate diagnosis of GD, and minimize the risk for misdiagnosis. To the best of our knowledge, this is the first published report on atypical cytomorphology of GCs in untreated patients with GD1.
A Pharmacokinetic and Metabolism Study of the TRPC6 Inhibitor SH045 in Mice by LC-MS/MS
TRPC6, the sixth member of the family of canonical transient receptor potential (TRP)
channels, contributes to a variety of physiological processes and human pathologies. This study
extends the knowledge on the newly developed TRPC6 blocker SH045 with respect to its main target
organs beyond the description of plasma kinetics. According to the plasma concentration-time course
in mice, SH045 is measurable up to 24 h after administration of 20 mg/kg BW (i.v.) and up to 6 h
orally. The short plasma half-life and rather low oral bioavailability are contrasted by its reported
high potency. Dosage limits were not worked out, but absence of safety concerns for 20 mg/kg
BW supports further dose exploration. The disposition of SH045 is described. In particular, a high
extravascular distribution, most prominent in lung, and a considerable renal elimination of SH045
were observed. SH045 is a substrate of CYP3A4 and CYP2A6. Hydroxylated and glucuronidated
metabolites were identified under optimized LC-MS/MS conditions. The results guide a reasonable
selection of dose and application route of SH045 for target-directed preclinical studies in vivo with
one of the rare high potent and subtype-selective TRPC6 inhibitors availabl
A single dose of escitalopram blunts the neural response in the thalamus and caudate during monetary loss
Background: Selective serotonin reuptake inhibitors (SSRIs) show acute effects on the neural processes associated with negative affective bias in healthy people and people with depression. However, whether and how SSRIs also affect reward and punishment processing on a similarly rapid time scale remains unclear. Methods: We investigated the effects of an acute and clinically relevant dose (20 mg) of the SSRI escitalopram on brain response during reward and punishment processing in 19 healthy participants. In a doubleblind, placebo-controlled study using functional MRI, participants performed a well-established monetary reward task at 3 time points: at baseline; after receiving placebo or escitalopram; and after receiving placebo or escitalopram following an 8-week washout period. Results: Acute escitalopram administration reduced blood-oxygen-level-dependent (BOLD) response during punishment feedback in the right thalamus (family-wise error corrected [FWE] p = 0.013 at peak level) and the right caudate head (pFWE = 0.011 at peak level) compared to placebo. We did not detect any significant BOLD changes during reward feedback. Limitations: We included only healthy participants, so interpretation of findings are limited to the healthy human brain and require future testing in patient populations. The paradigm we used was based on monetary stimuli, and results may not be generalizable to other forms of reward. Conclusion: Our findings extend theories of rapid SSRI action on the neural processing of rewarding and aversive stimuli and suggest a specific and acute effect of escitalopram in the punishment neurocircuitry
Validation of an LC-MS/MS Method to Quantify the New TRPC6 Inhibitor SH045 (Larixyl N-methylcarbamate) and Its Application in an Exploratory Pharmacokinetic Study in Mice
TRPC6 (transient receptor potential cation channels; canonical subfamily C, member 6) is widespread localized in mammalian tissues like kidney and lung and associated with progressive proteinuria and pathophysiological pulmonary alterations, e.g., reperfusion edema or lung fibrosis. However, the understanding of TRPC6 channelopathies is still at the beginning stages. Recently, by chemical diversification of (+)-larixol originating from Larix decidua resin traditionally used for inhalation, its methylcarbamate congener, named SH045, was obtained and identified in functional assays as a highly potent, subtype-selective inhibitor of TRPC6. To pave the way for use of SH045 in animal disease models, this study aimed at developing a capable bioanalytical method and to provide exploratory pharmacokinetic data for this promising derivative. According to international guidelines, a robust and selective LC-MS/MS method based on MRM detection in positive ion mode was established and validated for quantification of SH045 in mice plasma, whereby linearity and accuracy were demonstrated for the range of 2–1600 ng/mL. Applying this method, the plasma concentration time course of SH045 following single intraperitoneal administration (20 mg/kg body weight) revealed a short half-life of 1.3 h. However, the pharmacological profile of SH045 is promising, as five hours after administration, plasma levels still remained sufficiently higher than published low nanomolar IC50 values. Summarizing, the LC-MS/MS method and exploratory pharmacokinetic data provide essential prerequisites for experimental pharmacological TRPC6 modulation and translational treatment of TRPC6 channelopathies
One‐week escitalopram intake alters the excitation–inhibition balance in the healthy female brain
Neural health relies on cortical excitation-inhibition balance (EIB). Previous research suggests a link between increased cortical excitation and neuroplasticity induced by selective serotonin reuptake inhibitors (SSRIs). Whether there are modulations of EIB following SSRI-administration in the healthy human brain, however, remains unclear. Thus, in a randomized double-blind study, we administered a clinically relevant dose of 20 mg escitalopram for 7 days (time when steady state is achieved) in 59 healthy women (28 escitalopram, 31 placebo) on oral contraceptives. We acquired resting-state electroencephalography data at baseline, after a single dose, and at steady state. We assessed 1/f slope of the power spectrum as a marker of EIB, compared individual trajectories of 1/f slope changes contrasting single dose and 1-week drug intake, and tested the relationship of escitalopram plasma levels and cortical excitatory and inhibitory balance shifts. Escitalopram-intake was associated with decreased 1/f slope, indicating an EIB shift in favor of excitation. Furthermore, 1/f slope at baseline and after a single dose of escitalopram was associated with 1/f slope at steady state. Higher plasma escitalopram levels at a single dose were associated with better maintenance of these EIB changes throughout the drug administration week. These findings demonstrate the potential for 1/f slope to predict individual cortical responsivity to SSRIs and widen the lens through which we map the human brain by testing an interventional psychopharmacological design in a clearly defined endocrinological state
The attention-emotion interaction in healthy female participants on oral contraceptives during 1-week escitalopram intake
Previous findings in healthy humans suggest that selective serotonin reuptake inhibitors (SSRIs) modulate emotional processing via earlier changes in attention. However, many previous studies have provided inconsistent findings. One possible reason for such inconsistencies is that these studies did not control for the influence of either sex or sex hormone fluctuations. To address this inconsistency, we administered 20 mg escitalopram or placebo for seven consecutive days in a randomized, double-blind, placebo-controlled design to sixty healthy female participants with a minimum of 3 months oral contraceptive (OC) intake. Participants performed a modified version of an emotional flanker task before drug administration, after a single dose, after 1 week of SSRI intake, and after a 1-month wash-out period. Supported by Bayesian analyses, our results do not suggest a modulatory effect of escitalopram on behavioral measures of early attentional-emotional interaction in female individuals with regular OC use. While the specific conditions of our task may be a contributing factor, it is also possible that a practice effect in a healthy sample may mask the effects of escitalopram on the attentional-emotional interplay. Consequently, 1 week of escitalopram administration may not modulate attention toward negative emotional distractors outside the focus of attention in healthy female participants taking OCs. While further research in naturally cycling females and patient samples is needed, our results represent a valuable contribution toward the preclinical investigation of antidepressant treatment
Decreased thalamo-cortico connectivity during an implicit sequence motor learning task and 7 days escitalopram intake
Evidence suggests that selective serotonin reuptake inhibitors (SSRIs) reorganize neural networks via a transient window of neuroplasticity. While previous findings support an effect of SSRIs on intrinsic functional connectivity, little is known regarding the influence of SSRI-administration on connectivity during sequence motor learning. To investigate this, we administered 20 mg escitalopram or placebo for 1-week to 60 healthy female participants undergoing concurrent functional magnetic resonance imaging and sequence motor training in a double-blind randomized controlled design. We assessed task-modulated functional connectivity with a psycho-physiological interaction (PPI) analysis in the thalamus, putamen, cerebellum, dorsal premotor, primary motor, supplementary motor, and dorsolateral prefrontal cortices. Comparing an implicit sequence learning condition to a control learning condition, we observed decreased connectivity between the thalamus and bilateral motor regions after 7 days of escitalopram intake. Additionally, we observed a negative correlation between plasma escitalopram levels and PPI connectivity changes, with higher escitalopram levels being associated with greater thalamo-cortico decreases. Our results suggest that escitalopram enhances network-level processing efficiency during sequence motor learning, despite no changes in behaviour. Future studies in more diverse samples, however, with quantitative imaging of neurochemical markers of excitation and inhibition, are necessary to further assess neural responses to escitalopram
Predicting beneficial effects of atomoxetine and citalopram on response inhibition in Parkinson's disease with clinical and neuroimaging measures.
Recent studies indicate that selective noradrenergic (atomoxetine) and serotonergic (citalopram) reuptake inhibitors may improve response inhibition in selected patients with Parkinson's disease, restoring behavioral performance and brain activity. We reassessed the behavioral efficacy of these drugs in a larger cohort and developed predictive models to identify patient responders. We used a double-blind randomized three-way crossover design to investigate stopping efficiency in 34 patients with idiopathic Parkinson's disease after 40 mg atomoxetine, 30 mg citalopram, or placebo. Diffusion-weighted and functional imaging measured microstructural properties and regional brain activations, respectively. We confirmed that Parkinson's disease impairs response inhibition. Overall, drug effects on response inhibition varied substantially across patients at both behavioral and brain activity levels. We therefore built binary classifiers with leave-one-out cross-validation (LOOCV) to predict patients' responses in terms of improved stopping efficiency. We identified two optimal models: (1) a "clinical" model that predicted the response of an individual patient with 77-79% accuracy for atomoxetine and citalopram, using clinically available information including age, cognitive status, and levodopa equivalent dose, and a simple diffusion-weighted imaging scan; and (2) a "mechanistic" model that explained the behavioral response with 85% accuracy for each drug, using drug-induced changes of brain activations in the striatum and presupplementary motor area from functional imaging. These data support growing evidence for the role of noradrenaline and serotonin in inhibitory control. Although noradrenergic and serotonergic drugs have highly variable effects in patients with Parkinson's disease, the individual patient's response to each drug can be predicted using a pattern of clinical and neuroimaging features.The BCNI is supported by the Wellcome Trust and Medical Research Council. We are grateful to Dr Gordon Logan for advice on stop-signal reaction time estimation and to Dr Marta Correia for advice on diffusion-weighted imaging data analysis. Conflict of interest: Prof. Sahakian has received grants from Janssen/J&J, personal fees from Cambridge Cognition, personal fees from Lundbeck, and personal fees from Servier, outside the submitted work. Prof. Robbins has received personal fees and royalties from Cambridge Cognition, personal fees and grants from Eli Lilly Inc, personal fees and grants from Lundbeck, grants from GSK, personal fees from Teva Pharmaceuticals, personal fees from Shire Pharmaceuticals, grants from Medical Research Council, editorial honorarium from Springer Verlag Germany, and personal fees from Chempartners, outside the submitted work. Prof. Rowe has received grant funding from AZ-Medimmune unrelated to the current work. Dr Housden is an employee of Cambridge Cognition. Other authors reported no biomedical financial interests or potential conflict of interest.This is the final version of the article. It was first available from Wiley via http://dx.doi.org/10.1002/hbm.2308
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