89 research outputs found

    Functional MRI in Awake Unrestrained Dogs

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    Because of dogs' prolonged evolution with humans, many of the canine cognitive skills are thought to represent a selection of traits that make dogs particularly sensitive to human cues. But how does the dog mind actually work? To develop a methodology to answer this question, we trained two dogs to remain motionless for the duration required to collect quality fMRI images by using positive reinforcement without sedation or physical restraints. The task was designed to determine which brain circuits differentially respond to human hand signals denoting the presence or absence of a food reward. Head motion within trials was less than 1 mm. Consistent with prior reinforcement learning literature, we observed caudate activation in both dogs in response to the hand signal denoting reward versus no-reward

    How Emotion Strengthens the Recollective Experience: A Time-Dependent Hippocampal Process

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    Emotion significantly strengthens the subjective recollective experience even when objective accuracy of the memory is not improved. Here, we examine if this modulation is related to the effect of emotion on hippocampal-dependent memory consolidation. Two critical predictions follow from this hypothesis. First, since consolidation is assumed to take time, the enhancement in the recollective experience for emotional compared to neutral memories should become more apparent following a delay. Second, if the emotion advantage is critically dependent on the hippocampus, then the effects should be reduced in amnesic patients with hippocampal damage. To test these predictions we examined the recollective experience for emotional and neutral photos at two retention intervals (Experiment 1), and in amnesics and controls (Experiment 2). Emotional memories were associated with an enhancement in the recollective experience that was greatest after a delay, whereas familiarity was not influenced by emotion. In amnesics with hippocampal damage the emotion effect on recollective experience was reduced. Surprisingly, however, these patients still showed a general memory advantage for emotional compared to neutral items, but this effect was manifest primarily as a facilitation of familiarity. The results support the consolidation hypothesis of recollective experience, but suggest that the effects of emotion on episodic memory are not exclusively hippocampally mediated. Rather, emotion may enhance recognition by facilitating familiarity when recollection is impaired due to hippocampal damage

    Co-morbidity and drug treatment in Alzheimer's disease. A cross sectional study of participants in the Dementia Study in Northern Norway

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    Inappropriate medical treatment of co-morbidities in Alzheimer’s disease (AD) is an increasing concern in geriatric medicine. The objective of this study was to compare current drug use related to co-morbidity between individuals with a recent diagnosis of AD and a cognitively healthy control group in a population based clinical trial in Northern Norway. Setting: Nine rural municipalities with 70 000 inhabitants in Northern Norway. Participants: Participants with and without AD recruited in general practice and by population based screening. 187 participants with a recent diagnosis of AD were recruited among community dwellers. Of 791 respondents without cognitive symptoms, 500 were randomly selected and invited to further clinical and cognitive testing. The final control group consisted of 200 cognitively healthy individuals from the same municipalities. Demographic characteristics, data on medical history and current medication were included, and a physical and cognitive examination was performed. The statistical analyses were carried out by independent sample t-test, chi-square, ANCOVA and logistic regression. A co-morbidity score was significantly higher in AD participants compared to controls. The mean number of drugs was higher for AD participants compared to controls (5.1 ± 3.6 and 2.9 ± 2.4 respectively, p < 0.001 age and gender adjusted), also when adjusted for co-morbidity. AD participants used significantly more anticholinergic, sedative and antidepressant drugs. For nursing home residents with AD the mean number of drugs was significantly higher compared to AD participants living at home (6.9 ± 3.9 and 4.5 ± 3.3, respectively, p < 0.001). AD participants were treated with a significantly higher number of drugs as compared to cognitively healthy controls, even after adjustment for co-morbidity. An inappropriate use of anticholinergic and sedative drugs was identified, especially among nursing home residents with AD. The drug burden and the increased risk of adverse reactions among individuals suffering from AD need more attention from prescribing doctors

    Understanding Clinical Dehydration and Its Treatment

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    Dehydration in clinical practice, as opposed to a physiological definition, refers to the loss of body water, with or without salt, at a rate greater than the body can replace it. We argue that the clinical definition for dehydration, ie, loss of total body water, addresses the medical needs of the patient most effectively. There are 2 types of dehydration, namely water loss dehydration (hyperosmolar, due either to increased sodium or glucose) and salt and water loss dehydration (hyponatremia). The diagnosis requires an appraisal of the patient and laboratory testing, clinical assessment, and knowledge of the patient's history. Long-term care facilities are reluctant to have practitioners make a diagnosis, in part because dehydration is a sentinel event thought to reflect poor care. Facilities should have an interdisciplinary educational focus on the prevention of dehydration in view of the poor outcomes associated with its development. We also argue that dehydration is rarely due to neglect from formal or informal caregivers, but rather results from a combination of physiological and disease processes. With the availability of recombinant hyaluronidase, subcutaneous infusion of fluids (hypodermoclysis) provides a better opportunity to treat mild to moderate dehydration in the nursing home and at home.David R. Thomas, Todd R. Cote, Larry Lawhorne, Steven A. Levenson, Laurence Z. Rubenstein, David A. Smith, Richard G. Stefanacci, Eric G. Tangalos, John E. Morley and Dehydration Councilhttp://www.elsevier.com/wps/find/journaldescription.cws_home/704824/description#descriptio

    Adjuvant hypofractionated radiation therapy for breast cancer after conserving surgery

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    AIMS: To evaluate the incidence of locoregional recurrence (LRR) and the cosmetic results in a group of patients with breast cancer treated with a hypofractionated schedule of adjuvant radiotherapy after conservative surgery. MATERIALS AND METHODS: In total, 539 patients with pTis-pT1-pT2 breast cancer underwent radiotherapy treatment after conservative surgery at the University of Florence and at the Pistoia Hospital. The dose delivered was 44 Gy (2.75 Gy daily fraction). The tumour bed boost (10 Gy) was given by electrons. RESULTS: At the time of the analysis, 1.8% of patients (10/539) had breast relapse. No patients developed nodal recurrence (supraclavicular, axillary and internal mammary nodes). The 3- and 5-year actuarial rates for LRR were 1.2% (+/- 0.5% standard error) and 2.1% (+/- 0.6% standard error), respectively. Considering the late toxicity, we found that 412 (76.4%) patients had grade 0 or grade 1 late toxicity, 113 patients (20.9%) had grade 2 late toxicity and 14 patients (2.5%) had grade 3 late toxicity. No patients developed grade 4 toxicity. CONCLUSION: This type of approach resulted in an effective treatment in terms of local control in patients with negative or one to three positive axillary nodes and negative surgical margins. Patients treated with a hypofractionated schedule showed very good cosmesis
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