1,721,037 research outputs found
Metrological characterization of a diagnostic test extending the Receiving Operating Curve analysis using Supplement 2 recommendations
No full textReceiving Operating Curve (ROC) analysis is a powerful and statistical accepted method to assess the performance of a diagnostic test. ROC curve plots true positive rate against false positive rate, evaluated on a certain population. Instrumental and model uncertainty contributions can strongly affect the performance of the ROC analysis especially in the evaluation of performance metrics such as Area Under ROC (AUC) and Optimal Operating Points. Supplement 2 reports detailed instructions to handle and propagate uncertainty through a Multiple Input Multiple Output system, in case of correlate output variables, such as TPR and FPR. After a detailed revision of the existing literature, the present paper describes and applies a novel methodology, totally framed in the GUM and its supplements, to represent and propagate the uncertainty contributions estimated in a medical context, throughout the ROC analysis, providing new concepts such as ROC confidence region and Optimal Operating Region
Blockade of neurotensin receptors affects differently hypo-locomotion and catalepsy induced by haloperidol in mice
No full textAntipsychotic drug treatment increases neurotensin (NT) neurotransmission, and the exogenous administration of NT produces antipsychotic-like effects in rodents. In order to investigate whether "endogenous" NT may act as a natural occurring antipsychotic or may mediate antipsychotic drug activity, the effects of the selective NT receptor antagonists SR 48692 and SR 142948A were analyzed in different behavioural tests of locomotor activity using vehicle, amphetamine, or haloperidol in mice. SR 48692 (0.1-1 mg/kg, i.p.) and SR 142948A (0.03-0.1 mg/kg, i.p.) failed to affect mouse spontaneous locomotor activity and amphetamine-induced (2.5 mg/kg, i.p.) hyper-locomotion. However, SR 48692 (0.1 and 0.3 mg/kg, i.p.) and SR 142948A (0.03 and 0.05 mg/kg, i.p.) significantly alleviated the reduction of locomotor activity elicited by haloperidol (0.01 and 0.04 mg/kg, s.c.) in vehicle- or amphetamine-treated mice. Finally, SR 48692 (0.3 mg/kg, i.p.) and SR 142948A (0.05 and 0.1 mg/kg, i.p.) increased mouse catalepsy produced by haloperidol (0.3 mg/kg, s.c.). The present results indicate that while endogenous NT is not involved in the modulation of either mouse spontaneous locomotor activity or amphetamine-induced hyper-locomotion, it might act by enhancing the therapeutic effects of haloperidol and by attenuating the extrapyramidal side effects elicited by this antipsychotic. © 2004 Elsevier Ltd. All rights reserved
Bilateral asymmetry identification for the early detection of breast cancer
No full textBreast cancer is the second most common cancer overall and the leading cause of cancer deaths in women. Mammography is, at present, the only viable method for detecting most of tumors early enough for effective treatment. The secret of setting up the accurate diagnosis is to detect and understand the most subtle signs of breast lesions. Analysis of asymmetry between the left and right mammograms can provide clues about the presence of early signs of tumors. In this work we present an automated procedure for bilateral asymmetry detection composed of the following steps: (1) mammography density analysis and fibro-glandular disc detection through adaptive clustering techniques, (2) analysis and implementation of bilateral asymmetries detection algorithms based on Gabor filters analysis, (3) use of a linear Bayes classifier with the leave-one-out method to asses the asymmetry degree of the two breasts, (4) metrological evaluation of the whole system through random and systematic measurement uncertainty contributions modeling
Haloperidol, but not clozapine, produces dramatic catalepsy in delta9-THC-treated rats: possible clinical implications
No full text1. The effect on rat catalepsy induced by Δ 9- tetrahydrocannabinol (Δ 9-THC) in association with haloperidol (HP) or clozapine (CLOZ) administration was investigated. 2. Δ 9-THC dose-dependently increased HP (0.05 -1 mg kg -1, s.c.)-induced rat catalepsy, while no catalepsy was observed after CLOZ (1-20mg kg -1, s.c.) or Δ 9-THC + CLOZ administration. 3. The CB 1 antagonist SR141716A (0.5-5 mg kg -1, i.p.) reversed the increase mediated by Δ 9-THC on HP-induced catalepsy. 4. The D 2 agonist quinpirole completely reversed the catalepsy induced by both HP and HP + Δ 9-THC; however, higher doses of quinpirole were needed in the presence of Δ 9-THC. 5. The M 1 antagonist scopolamine and α 2 antagonist yohimbine were able to reduce the catalepsy induced by HP and HP + Δ 9-THC in a similar manner. 6. CLOZ and the 5-HT 2A/2C antagonists ritanserin, RS102221 and SB242084 were more effective in antagonizing HP than HP + Δ 9-THC-induced catalepsy. 7. HP and CLOZ failed to inhibit in vitro [ 3H]CP-55,940 binding, while Δ 9-THC and SR141716A did not show an appreciable affinity for the D 2 receptor. 8. It was suggested that the different effects on rat catalepsy induced by Δ 9-THC following HP or CLOZ administration may depend on the receptor-binding profiles of the two antipsychotics. 9. The preferential use of CLOZ rather than HP in the treatment of psychotic symptoms in cannabis abusers was discussed
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Ritanserin counteracts both rat vacuous chewing movements and nigro-striatal tyrosine hydroxylase-immunostaining alterations induced by haloperidol
No full textThe effect of subchronic co-administration of ritanserin (1.5 mg/kg, i.p., twice a day) and haloperidol (1 mg/kg, i.p., twice a day) on rat vacuous chewing movements and on tyrosine hydroxylase-immunostaining was investigated. Ritanserin significantly reduced rat vacuous chewing movements observed following 2, 3 and 4 weeks of haloperidol administration and after 5 days of haloperidol withdrawal. Furthermore, ritanserin prevented the reduction of striatal tyrosine hydroxylase-immunostaining and the shrinkage of nigral dopaminergic cell bodies induced by haloperidol. The present results indicate that ritanserin may possess protective properties on both dopaminergic nigro-striatal neuron alterations and vacuous chewing movements induced by haloperidol, and provide further evidence indicating a possible association between these two haloperidol-induced effects. © 2003 Elsevier B.V. All rights reserved
Effect of the amisulpride isomers on rat prolactinemia
No full textThe effects on rat serum prolactin level of the two isomers constituting the racemic form of amisulpride were compared. (S-)-amisulpride induced hyperprolactinemia at lower doses (ED50=0.09±0.01 mg/kg) than racemic- (ED50=0.24±0.03 mg/kg) and (R+)-amisulpride (ED50=4.13±0.05 mg/kg), in accord with their affinities for pituitary dopamine D2 receptor (Ki=3.8±0.2, 6.4±0.2 and 143.3±2.3 nM, respectively). At doses twice the ED50, (S-)-amisulpride produced a maximal increase in prolactin level similar to that of the racemic form (403±21% and 425±15%, respectively), but higher than that of (R+)-amisulpride (198±8%). These results suggest that the hyperprolactinemia induced by the racemic-amisulpride is mostly due to its (S-)-isomer. © 2002 Elsevier Science B.V. All rights reserved
Carmoxirole is able to reduce amisulpride-induced hyperprolactinemia without affecting its central effect
No full textProlactin blood level and apomorphine-induced yawning were studied in rats treated with the substituted benzamide amisulpride in association with bromocriptine or carmoxirole; two dopamine D2 receptor agonists with high or low propensity to cross the brain-blood barrier, respectively. Administration of amisulpride produced a maximum increase in rat serum prolactin level (315±18%) vs. vehicle-treated animals (ED50=0.25±0.017 mg/kg, s.c.). The concurrent administration of carmoxirole or bromocriptine completely reversed the hyperprolactinemia induced by amisulpride (0.5 mg/kg, s.c.) (ID50=14.9±0.8 mg/kg and 0.81±0.03 mg/kg, respectively). Carmoxirole (15 mg/kg, i.p.) did not affect yawning induced by apomorphine (0.08 mg/kg, s.c.) nor amisulpride (0.5 mg/kg, s.c.) blockade of apomorphine-induced yawning. Conversely, a significant increase in the number of yawns was observed when bromocriptine (0.8 mg/kg, i.p.) was associated with apomorphine in the absence or presence of amisulpride. These results suggested that a peripheral dopamine D2 receptor agonists could be a useful tool in alleviating amisulpride-induced hyperprolactinemia without possibly affecting its central effect. © 2002 Elsevier Science B.V. All rights reserved
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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