99 research outputs found
Brain Serotonin Synthesis in Adult Males Characterized by Physical Aggression during Childhood: A 21-Year Longitudinal Study
Adults exhibiting severe impulsive and aggressive behaviors have multiple indices of low serotonin (5-HT) neurotransmission. It remains unclear though whether low 5-HT mediates the behavior or instead reflects a pre-existing vulnerability trait.C-AMT bilaterally in the orbitofrontal cortex and self-reported more impulsiveness. Despite this, in adulthood there were no group differences in plasma tryptophan levels, genotyping, aggression, emotional intelligence, working memory, computerized measures of impulsivity, psychosocial functioning/adjustment, and personal and family history of mood and substance abuse disorders.These results force a re-examination of the low 5-HT hypothesis as central in the biology of violence. They suggest that low 5-HT does not mediate current behavior and should be considered a vulnerability factor for impulsive-aggressive behavior that may or may not be expressed depending on other biological factors, experience, and environmental support during development
Functional sex differences in human primary auditory cortex
Background We used PET to study cortical activation during auditory stimulation and found sex differences in the human primary auditory cortex (PAC). Regional cerebral blood flow (rCBF) was measured in 10 male and 10 female volunteers while listening to sounds (music or white noise) and during a baseline (no auditory stimulation). Results and discussion We found a sex difference in activation of the left and right PAC when comparing music to noise. The PAC was more activated by music than by noise in both men and women. But this difference between the two stimuli was significantly higher in men than in women. To investigate whether this difference could be attributed to either music or noise, we compared both stimuli with the baseline and revealed that noise gave a significantly higher activation in the female PAC than in the male PAC. Moreover, the male group showed a deactivation in the right prefrontal cortex when comparing noise to the baseline, which was not present in the female group. Interestingly, the auditory and prefrontal regions are anatomically and functionally linked and the prefrontal cortex is known to be engaged in auditory tasks that involve sustained or selective auditory attention. Thus we hypothesize that differences in attention result in a different deactivation of the right prefrontal cortex, which in turn modulates the activation of the PAC and thus explains the sex differences found in the activation of the PAC. Conclusion Our results suggest that sex is an important factor in auditory brain studies
Transcranial Magnetic Stimulation Intensities in Cognitive Paradigms
BACKGROUND: Transcranial magnetic stimulation (TMS) has become an important experimental tool for exploring the brain's functional anatomy. As TMS interferes with neural activity, the hypothetical function of the stimulated area can thus be tested. One unresolved methodological issue in TMS experiments is the question of how to adequately calibrate stimulation intensities. The motor threshold (MT) is often taken as a reference for individually adapted stimulation intensities in TMS experiments, even if they do not involve the motor system. The aim of the present study was to evaluate whether it is reasonable to adjust stimulation intensities in each subject to the individual MT if prefrontal regions are stimulated prior to the performance of a cognitive paradigm. METHODS AND FINDINGS: Repetitive TMS (rTMS) was applied prior to a working memory task, either at the 'fixed' intensity of 40% maximum stimulator output (MSO), or individually adapted at 90% of the subject's MT. Stimulation was applied to a target region in the left posterior middle frontal gyrus (pMFG), as indicated by a functional magnetic resonance imaging (fMRI) localizer acquired beforehand, or to a control site (vertex). Results show that MT predicted the effect size after stimulating subjects with the fixed intensity (i.e., subjects with a low MT showed a greater behavioral effect). Nevertheless, the individual adaptation of intensities did not lead to stable effects. CONCLUSION: Therefore, we suggest assessing MT and account for it as a measure for general cortical TMS susceptibility, even if TMS is applied outside the motor domain
As cold as a fish? Relationships between the Dark Triad personality traits and affective experience during the day: A day reconstruction study
The Dark Triad of personality is a cluster of three socially aversive personality traits: Machiavellianism,
narcissism and psychopathy. These traits are associated with a selfish, aggressive
and exploitative interpersonal strategy. The objective of the current study was to
establish relationships between the Dark Triad traits (and their dimensions) and momentary
affect. Machiavellianism, grandiose narcissism, vulnerable narcissism and the dimensions
of the Triarchic model of psychopathy (namely, boldness, meanness and disinhibition) were
examined. We used the Day Reconstruction Method, which is based on reconstructing
affective states experienced during the previous day. The final sample consisted of 270 university
students providing affective ratings of 3047 diary episodes. Analyses using multilevel
modelling showed that only boldness had a positive association with positive affective states
and affect balance, and a negative association with negative affective states. Grandiose
narcissism and its sub-dimensions had no relationship with momentary affect. The other
dark traits were related to negative momentary affect and/or inversely related to positive
momentary affect and affect balance. As a whole, our results empirically demonstrated distinctiveness
of the Dark Triad traits in their relationship to everyday affective states. These
findings are not congruent with the notion that people with the Dark Triad traits, who have a
dispositional tendency to manipulate and exploit others, are generally cold and invulnerable
to negative feelings. The associations between the Dark Triad and momentary affect were
discussed in the contexts of evolutionary and positive psychology, in relation to the role and
adaptive value of positive and negative emotions experienced by individuals higher in
Machiavellianism, narcissism and psychopathy
The impact of immediate breast reconstruction on the time to delivery of adjuvant therapy: the iBRA-2 study
Background:
Immediate breast reconstruction (IBR) is routinely offered to improve quality-of-life for women requiring mastectomy, but there are concerns that more complex surgery may delay adjuvant oncological treatments and compromise long-term outcomes. High-quality evidence is lacking. The iBRA-2 study aimed to investigate the impact of IBR on time to adjuvant therapy.
Methods:
Consecutive women undergoing mastectomy ± IBR for breast cancer July–December, 2016 were included. Patient demographics, operative, oncological and complication data were collected. Time from last definitive cancer surgery to first adjuvant treatment for patients undergoing mastectomy ± IBR were compared and risk factors associated with delays explored.
Results:
A total of 2540 patients were recruited from 76 centres; 1008 (39.7%) underwent IBR (implant-only [n = 675, 26.6%]; pedicled flaps [n = 105,4.1%] and free-flaps [n = 228, 8.9%]). Complications requiring re-admission or re-operation were significantly more common in patients undergoing IBR than those receiving mastectomy. Adjuvant chemotherapy or radiotherapy was required by 1235 (48.6%) patients. No clinically significant differences were seen in time to adjuvant therapy between patient groups but major complications irrespective of surgery received were significantly associated with treatment delays.
Conclusions:
IBR does not result in clinically significant delays to adjuvant therapy, but post-operative complications are associated with treatment delays. Strategies to minimise complications, including careful patient selection, are required to improve outcomes for patients
Is schizophrenia disappearing? The rise and fall of the diagnosis of functional psychoses: an essay
Ectopic pregnancy secondary to in vitro fertilisation-embryo transfer: pathogenic mechanisms and management strategies
Role of free fatty acids and insulin in determining free fatty acid and lipid oxidation in man
Plasma FFA oxidation (measured by infusion of 14C-palmitate) and net lipid
oxidation (indirect calorimetry) are both inhibited by insulin. The present study
was designed to examine whether these insulin-mediated effects on lipid
metabolism resulted from a decline in circulating FFA levels or from a direct
action of the hormone on FFA/lipid oxidation. Nine subjects participated in two
euglycemic insulin clamps, performed with and without heparin. During each
insulin clamp study insulin was infused at two rates, 4 and 20 mU/m2.min for 120
min. The studies were performed with indirect calorimetry and 3-3H-glucose and
14C-palmitate infusion. During the control study plasma FFA fell from 610 +/- 46
to 232 +/- 42 to 154 +/- 27 mumol/liter, respectively. When heparin was infused
basal plasma FFA concentration remained constant. During the control study,
FFA/lipid oxidation rates decreased in parallel with the fall in the plasma FFA
concentration. During the insulin/heparin study, plasma 14C-FFA oxidation
remained unchanged while net lipid oxidation decreased. In conclusion, when the
plasma FFA concentration is maintained unchanged by heparin infusion, insulin has
no direct effect on FFA turnover and disposal. These results thus suggest that
plasma FFA oxidation is primarily determined by the plasma FFA concentration,
while net lipid oxidation is regulated by both the plasma FFA and the insulin
level
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