144 research outputs found

    Effects of ecstasy/polydrug use on memory for associative information

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    Rationale Associative learning underpins behaviours that are fundamental to the everyday functioning of the individual. Evidence pointing to learning deficits in recreational drug users merits further examination. Objectives A word pair learning task was administered to examine associative learning processes in ecstasy/polydrug users. Methods After assignment to either single or divided attention conditions, 44 ecstasy/polydrug users and 48 non-users were presented with 80 word pairs at encoding. Following this, four types of stimuli were presented at the recognition phase: the words as originally paired (old pairs), previously presented words in different pairings (conjunction pairs), old words paired with new words, and pairs of new words (not presented previously). The task was to identify which of the stimuli were intact old pairs. Results Ecstasy/ploydrug users produced significantly more false-positive responses overall compared to non-users. Increased long-term frequency of ecstasy use was positively associated with the propensity to produce false-positive responses. It was also associated with a more liberal signal detection theory decision criterion value. Measures of long term and recent cannabis use were also associated with these same word pair learning outcome measures. Conjunction word pairs, irrespective of drug use, generated the highest level of false-positive responses and significantly more false-positive responses were made in the divided attention condition compared to the single attention condition. Conclusions Overall, the results suggest that long-term ecstasy exposure may induce a deficit in associative learning and this may be in part a consequence of users adopting a more liberal decision criterion value

    A Greek validation study of the Multiple Sclerosis Work Difficulties Questionnaire-23

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    The Multiple Sclerosis Work Difficulties Questionnaire-23 (MSWDQ-23) is a self-reportinstrument developed to assess barriers faced by People with Multiple Sclerosis (PwMS) in theworkplace. The aim of this study was to explore the psychometric properties of the Greek versionof the MSWDQ-23. The study sample consisted of 196 PwMS, all currently working in part- orfull-time jobs. Participants underwent clinical examination and cognitive screening with the BriefInternational Cognitive Assessment for Multiple Sclerosis (BICAMS) and completed self-reportmeasures of fatigue, psychological functioning, and quality of life, along with the MSWDQ-23questionnaire. Confirmatory Factor Analysis (CFA) was performed, and goodness-of-fit measureswere used to evaluate construct validity. Convergent validity was checked by correlating MSWDQ-23scores with study measures. Cronbach’s alpha value was produced to assess internal consistency.CFA yielded a model with a fair fit confirming the three-factor structure of the instrument. Higherwork difficulties were associated with higher Expanded Disability Status Scale (EDSS) scores, poorercognitive function, more fatigue, stress, anxiety, and depression, and poorer health status, supportingthe convergent validity of MSWDQ-23. Internal consistency (Cronbach’s alpha = 0.94) and test–retest reliability (ICC = 0.996, 95%, CI = 0.990–0.998) were excellent. The Greek MSWDQ-23 can beconsidered a valid patient-reported outcome measure and can be used in interventions aiming toimprove the vocational status of PwMS

    Ovarian cancer risk in premenopausal and perimenopausal women treated with Tamoxifen: a case–control study

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    As tamoxifen stimulates ovarian steroidogenesis in premenopausal women, induces ovulation and increases the incidence of benign ovarian cysts, there has been concern that it might also increase ovarian cancer risk in women treated premenopausally. In a national case–control study in Britain, treatment histories were collected for 158 cases of ovarian cancer after breast cancer diagnosed at ages under 55 years and 464 controls who had breast cancer at these ages without subsequent ovarian cancer. Risk of ovarian cancer was not raised for women overall who had taken tamoxifen (odds ratio (OR)=0.9, 95% confidence interval (CI) 0.6–1.3) or for those treated when premenopausal (OR=1.0, 95% CI 0.6–1.6) or perimenopausal (OR=0.7, 95% CI 0.2–2.4). There was also no relation of risk to daily dose, duration or cumulative dose of tamoxifen, or time since last use. There was, however, a significantly raised risk in relation to non-hormonal chemotherapy. The results suggest that tamoxifen treatment of premenopausal or perimenopausal women does not materially affect ovarian cancer risk, but that non-hormonal chemotherapy might increase risk

    Alternating Gyroid Network Structure in an ABC Miktoarm Terpolymer Comprised of Polystyrene and Two Polydienes

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    The synthesis, molecular and morphological characterization of a 3-miktoarm star terpolymer of polystyrene (PS, M¯¯¯¯n = 61.0 kg/mol), polybutadiene (PB, M¯¯¯¯n = 38.2 kg/mol) and polyisoprene (PI, M¯¯¯¯n = 29.2 kg/mol), corresponding to volume fractions (φ) of 0.46, 0.31 and 0.23 respectively, was studied. The major difference of the present material from previous ABC miktoarm stars (which is a star architecture bearing three different segments, all connected to a single junction point) with the same block components is the high 3,4-microstructure (55%) of the PI chains. The interaction parameter and the degree of polymerization of the two polydienes is sufficiently positive to create a three-phase microdomain structure as evidenced by differential scanning calorimetry and transmission electron microscopy (TEM). These results in combination with small-angle X-ray scattering (SAXS) and birefringence experiments suggest a cubic tricontinuous network structure, based on the I4132 space group never reported previously for such an architecture

    Follicular fluid content and oocyte quality: from single biochemical markers to metabolomics

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    The assessment of oocyte quality in human in vitro fertilization (IVF) is getting increasing attention from embryologists. Oocyte selection and the identification of the best oocytes, in fact, would help to limit embryo overproduction and to improve the results of oocyte cryostorage programs. Follicular fluid (FF) is easily available during oocyte pick-up and theorically represents an optimal source on non-invasive biochemical predictors of oocyte quality. Unfortunately, however, the studies aiming to find a good molecular predictor of oocyte quality in FF were not able to identify substances that could be used as reliable markers of oocyte competence to fertilization, embryo development and pregnancy. In the last years, a well definite trend toward passing from the research of single molecular markers to more complex techniques that study all metabolites of FF has been observed. The metabolomic approach is a powerful tool to study biochemical predictors of oocyte quality in FF, but its application in this area is still at the beginning. This review provides an overview of the current knowledge about the biochemical predictors of oocyte quality in FF, describing both the results coming from studies on single biochemical markers and those deriving from the most recent studies of metabolomic

    From Broca and Wernicke to the Neuromodulation Era: Insights of Brain Language Networks for Neurorehabilitation

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    Communication in humans activates almost every part of the brain. Of course, the use of language predominates, but other cognitive functions such as attention, memory, emotion, and executive processes are also involved. However, in order to explain how our brain "understands,""speaks,"and "writes,"and in order to rehabilitate aphasic disorders, neuroscience has faced the challenge for years to reveal the responsible neural networks. Broca and Wernicke (and Lichtheim and many others), during the 19th century, when brain research was mainly observational and autopsy driven, offered fundamental knowledge about the brain and language, so the Wernicke-Geschwind model appeared and aphasiology during the 20th century was based on it. This model is still useful for a first approach into the classical categorization of aphasic syndromes, but it is outdated, because it does not adequately describe the neural networks relevant for language, and it offers a modular perspective, focusing mainly on cortical structures. During the last three decades, neuroscience conquered new imaging, recording, and manipulation techniques for brain research, and a new model of the functional neuroanatomy of language was developed, the dual stream model, consisting of two interacting networks ("streams"), one ventral, bilaterally organized, for language comprehension, and one dorsal, left hemisphere dominant, for production. This new model also has its limitations but helps us to understand, among others, why patients with different brain lesions can have similar language impairments. Furthermore, interesting aspects arise from studying language functions in aging brains (and also in young, developing brains) and in cognitively impaired patients and neuromodulation effects on reorganization of brain networks subserving language. In this selective review, we discuss methods for coupling new knowledge regarding the functional reorganization of the brain with sophisticated techniques capable of activating the available supportive networks in order to provide improved neurorehabilitation strategies for people suffering from neurogenic communication disorders. © 2019 Grigorios Nasios et al
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