Major depressive disorder (MDD) has been associated with abnormal prefrontal-limbic interactions and altered catecholaminergic neurotransmission. The val158met polymorphism on the catechol-O-methyltransferase (COMT) gene has been shown to influence prefrontal cortex (PFC) activation during both emotional processing and working memory (WM). Although COMT-genotype is not directly associated with MDD, it may affect MDD pathology by altering PFC activation, an endophenotype associated with both COMT and MDD. 125 participants, including healthy controls (HC, n=28) and MDD patients were genotyped for the COMT val158met polymorphism and underwent functional magnetic resonance imaging (fMRI-neuroimaging) during emotion processing (viewing of emotional facial expressions) and a WM task (visuospatial planning). Within HC, we observed a positive correlation between the number of met-alleles and right inferior frontal gyrus activation during emotional processing, whereas within patients the number of met-alleles was not correlated with PFC activation. During WM a negative correlation between the number of met-alleles and middle frontal gyrus activation was present in the total sample. In addition, during emotional processing there was an effect of genotype in a cluster including the amygdala and hippocampus. These results demonstrate that COMT genotype is associated with relevant endophenotypes for MDD. In addition, presence of MDD only interacts with genotype during emotional processing and not working memory.
The aim of this study is to report our 6-year single-center experience with L5–S1 axial lumbar interbody fusion (AxiaLIF).
A total of 131 patients with symptomatic degenerative disc disease refractory to nonsurgical treatment were treated with AxiaLIF at L5–S1, and were followed for a minimum of 1 year (mean: 21 months). Main outcomes included back and leg pain severity, Oswestry Disability Index score, working status, analgesic medication use, patient satisfaction, and complications. Computed tomography was used to determine postoperative fusion status.
No intraoperative complications, including vascular, neural, urologic, or bowel injuries, were reported. Back and leg pain severity decreased by 51% and 42%, respectively, during the follow-up period (both P < 0.001). Back function scores improved 50% compared to baseline. Clinical success, defined as improvement ≥30%, was 67% for back pain severity, 65% for leg pain severity, and 71% for back function. The employment rate increased from 47% before surgery to 64% at final follow-up (P < 0.001). Less than one in four patients regularly used analgesic medications postsurgery. Patient satisfaction with the AxiaLIF procedure was 83%. The fusion rate was 87.8% at final follow-up. During follow-up, 17 (13.0%) patients underwent 18 reoperations on the lumbar spine, including pedicle screw fixation (n = 10), total disc replacement of an uninvolved level (n = 3), facet screw fixation (n = 3), facet screw removal (n = 1), and interbody fusion at L4–L5 (n = 1). Eight (6.1%) reoperations were at the index level.
Single-level AxiaLIF is a safe and effective means to achieve lumbosacral fusion in patients with symptomatic degenerative disc disease.
AxiaLIF; interbody; fusion; lumbosacral; minimally invasive; presacral
Treatment with N-acetylcysteine (NAC) normalizes glutamate (Glu) homeostasis and prevents relapse in drug-dependent animals. However, the effect of NAC on brain Glu levels in substance-dependent humans has not yet been investigated. Proton magnetic resonance spectroscopy (1H MRS) was used to investigate Glu changes in the dorsal anterior cingulate cortex (dACC) after a single dose of NAC in cocaine-dependent patients and normal controls. In an open-label, randomized, crossover study, 8 cocaine-dependent patients and 14 healthy controls underwent two scan sessions: one group receiving no compound and the other following a single administration of 2400 mg NAC. The Barratt Impulsiveness Scale was administered to examine the relation between dACC Glu levels and impulsivity. In the medication-free condition, Glu levels in the dACC were significantly higher in cocaine-dependent patients compared with healthy controls. After administration of NAC, Glu levels were reduced in the cocaine-dependent group, whereas NAC had no effect in healthy controls. Higher baseline Glu levels were associated with higher impulsivity, and both were predictive of greater NAC-induced Glu reduction. The current findings indicate that NAC can normalize elevated Glu levels in cocaine-dependent patients. These findings may have important implications for treatment, because abnormal Glu levels are related to relapse, and treatment with NAC prevented relapse in animal studies. Furthermore, clinical studies have indicated beneficial effects of NAC in cocaine-dependent patients, and the current study suggests that these beneficial effects might in part be mediated by the ability of NAC to normalize glutamatergic abnormalities.
cocaine dependence; N-acetylcysteine; glutamate; magnetic resonance spectroscopy; impulsivity; cocaine dependence; N-acetylcysteine; glutamate; magnetic resonance spectroscopy; impulsivity
Obsessive-compulsive disorder (OCD) and major depressive disorder (MDD) are frequently co-morbid, and dysfunctional frontal-striatal circuits have been implicated in both disorders. Neurobiological distinctions between OCD and MDD are insufficiently clear, and comparative neuroimaging studies are extremely scarce. OCD and MDD may be characterized by cognitive rigidity at the phenotype level, and frontal-striatal brain circuits constitute the neural substrate of intact cognitive flexibility. In the present study, 18 non-medicated MDD-free patients with OCD, 19 non-medicated OCD-free patients with MDD, and 29 matched healthy controls underwent functional magnetic resonance imaging during performance of a self-paced letter/digit task switching paradigm. Results showed that both patient groups responded slower relative to controls during repeat events, but only in OCD patients slowing was associated with decreased error rates. During switching, patients with OCD showed increased activation of the putamen, anterior cingulate and insula, whereas MDD patients recruited inferior parietal cortex and precuneus to a lesser extent. Patients with OCD and MDD commonly failed to reveal anterior prefrontal cortex activation during switching. This study shows subtle behavioral abnormalities on a measure of cognitive flexibility in MDD and OCD, associated with differential frontal-striatal brain dysfunction in both disorders. These findings may add to the development of biological markers that more precisely characterize frequently co-morbid neuropsychiatric disorders such as OCD and MDD.
Major depressive disorder (MDD) has been associated with biased memory formation for mood-congruent information, which may be related to altered monoamine levels. The piccolo (PCLO) gene, involved in monoaminergic neurotransmission, has previously been linked to depression in a genome-wide association study. Here, we investigated the role of the PCLO risk allele on functional magnetic resonance imaging (MRI) correlates of emotional memory in a sample of 89 MDD patients (64 PCLO risk allele carriers) and 29 healthy controls (18 PCLO risk allele carriers). During negative word encoding, risk allele carriers showed significant lower activity relative to non-risk allele carriers in the insula, and trend-wise in the anterior cingulate cortex and inferior frontal gyrus. Moreover, depressed risk allele carriers showed significant lower activity relative to non-risk allele carriers in the striatum, an effect which was absent in healthy controls. Finally, amygdalar response during processing new positive words vs. known words was blunted in healthy PCLO+ carriers and in MDD patients irrespective of genotype, which may indicate that signalling of salient novel information does not occur to the same extent in PCLO+ carriers and MDD patients. The PCLO risk allele may increase vulnerability for MDD by modulating local brain function with regard to responsiveness to salient stimuli (i.e. insula) and processing novel negative information. Also, depression-specific effects of PCLO on dorsal striatal activation during negative word encoding and the absence of amygdalar salience signalling for novel positive information further suggest a role of PCLO in symptom maintenance in MDD.
Introduction. Reduction of preterm birth is a major goal in obstetric care. We performed a systematic review of randomized controlled trials and cohort studies on the effectiveness of the cervical pessary to prevent preterm birth. Methods. We searched the electronic databases of MEDLINE and Embase from inception until April 2012 to identify studies investigating treatment with a cervical pessary to prevent preterm birth. We constructed two-by-two tables for delivery before 28, 34, and 37 weeks of gestation and calculated relative risks (RRs) with 95% confidence intervals. Results. The search revealed 103 potentially eligible abstracts of which six cohort studies and four randomized controlled trials (RCTs) investigated the effectiveness of the pessary. One RCT (n = 380) demonstrated a lower delivery rate prior to 34 weeks (RR 0.24; 95% CI 0.13–0.43) in the pessary group, while another RCT (n = 108) showed no positive effect of pessary for delivery before 34 weeks (RR 1.73; 95% CI 0.43–6.88). Two older quasi randomized studies and cohort studies indicated potential effect of the pessary. Conclusions. Available randomized and nonrandomized studies indicate potential effectiveness of a cervical pessary in the prevention of preterm birth. More randomized clinical trials are needed before this device can be used in clinical practice.
Motivational and cognitive abnormalities are frequently reported in pathological gambling. However, studies simultaneously investigating motivational and cognitive processing in problematic gamblers are lacking, limiting our understanding of the interplay between these systems in problematic gambling. Studies in non-clinical samples indicate that interactions between dorsal “executive” and ventral “affective” processing systems are necessary for adequate responses in various emotive situations.
We conducted a generalized Psycho-Physiological Interaction (gPPI) analysis to assess the influence of affective stimuli on changes in functional connectivity associated with response inhibition in 16 treatment seeking problematic gamblers (PRGs) and 15 healthy controls (HCs) using an affective Go-NoGo fMRI paradigm including neutral, gambling-related, positive and negative pictures as neutral and affective conditions.
Across groups, task performance accuracy during neutral inhibition trials was positively correlated with functional connectivity between the left caudate and the right middle frontal cortex. During inhibition in the gambling condition, only in PRGs accuracy of task performance was positively correlated with functional connectivity within sub-regions of the dorsal executive system. Group interactions showed that during neutral inhibition, HCs exhibited greater functional connectivity between the left caudate and occipital cortex than PRGs. In contrast, during inhibition in the positive condition, PRGs compared to HCs showed greater functional connectivity between the left caudate and occipital cortex. During inhibition trials in the negative condition, a stronger functional connectivity between the left caudate and the right anterior cingulate cortex in PRGs compared to HCs was present. There were no group interactions during inhibition in the gambling condition.
During gamble inhibition PRGs seem to benefit more from functional connectivity within the dorsal executive system than HCs, because task accuracy in this condition in PRGs is positively correlated with functional connectivity, although the groups show similar connectivity patterns during gamble inhibition. Greater functional connectivity between the ventral affective system and the dorsal executive system in PRGs in the affective conditions compared to HCs, suggests facilitation of the dorsal executive system when affective stimuli are present specifically in PRGs.
This study aimed to assess oral health-related quality of life (OHRQoL) related to dental status.
Material and methods
One thousand four hundred sixty-two Chinese subjects over 40 years, dentate in both jaws, were categorized in a hierarchical functional classification system with and without tooth replacements. OHIP-14CN scores were used to assess OHRQoL and analyzed using multivariable logistic regression including five dental conditions (‘≥10 teeth in each jaw’; ‘complete anterior regions’; ‘sufficient premolar regions’ (≥3 posterior occluding pairs (POPs)); ‘sufficient molar regions’ (bilaterally ≥1 POP); and tooth replacement) after adjustment for five background variables. Likelihood ratios for impaired OHRQoL (OHIP total score ≥5) were assessed at each level of the classification system.
In the hierarchical scheme, OHIP-14CN total scores were highest in branch ‘<10 teeth in each jaw’ (8.5 ± 9.5 to 12.3 ± 13.2). In branch ‘≥10 teeth’ scores ranged from 6.2 ± 7.7 to 8.3 ± 9.3. The most important dental condition discriminating for impact on OHRQoL was ‘≥10 teeth in each jaw’ (Likelihood ratio 1.59). In this branch subsequent levels were discriminative for impaired OHRQoL (Likelihoods 1.29–1.69), in the branch ‘<10 teeth in each jaw’ they were not (Likelihoods 0.99–1.04). Tooth replacements were perceived poorer as their natural counterparts (odd ratios, 1.30 for fixed and 1.47 for removable appliances).
OHRQoL was strongly associated with the presence of at least 10 teeth in each jaw. The hierarchical classification system predicted approximately 60 % of subjects correctly with respect to impaired OHRQoL.
From an OHRQoL perspective, natural teeth were preferred over artificial teeth.
Oral health-related quality of life; Occlusal status; Hierarchical dental functional classification system; Chinese adults
A potentially powerful predictor for the course of drug (ab)use is the approach-bias, that is, the pre-reflective tendency to approach rather than avoid drug-related stimuli. Here we investigated the neural underpinnings of cannabis approach and avoidance tendencies. By elucidating the predictive power of neural approach-bias activations for future cannabis use and problem severity, we aimed at identifying new intervention targets. Using functional Magnetic Resonance Imaging (fMRI), neural approach-bias activations were measured with a Stimulus Response Compatibility task (SRC) and compared between 33 heavy cannabis users and 36 matched controls. In addition, associations were examined between approach-bias activations and cannabis use and problem severity at baseline and at six-month follow-up. Approach-bias activations did not differ between heavy cannabis users and controls. However, within the group of heavy cannabis users, a positive relation was observed between total lifetime cannabis use and approach-bias activations in various fronto-limbic areas. Moreover, approach-bias activations in the dorsolateral prefrontal cortex (DLPFC) and anterior cingulate cortex (ACC) independently predicted cannabis problem severity after six months over and beyond session-induced subjective measures of craving. Higher DLPFC/ACC activity during cannabis approach trials, but lower activity during cannabis avoidance trials were associated with decreases in cannabis problem severity. These findings suggest that cannabis users with deficient control over cannabis action tendencies are more likely to develop cannabis related problems. Moreover, the balance between cannabis approach and avoidance responses in the DLPFC and ACC may help identify individuals at-risk for cannabis use disorders and may be new targets for prevention and treatment.
This study aimed to assess chewing ability related to dental status.
Material and methods
One thousand four hundred sixty-two Chinese subjects over 40 years, dentate in both jaws, were categorized in a hierarchical functional classification system with and without tooth replacements. Chewing ability was analyzed using multivariable logistic regression including five dental conditions (≥10 teeth in each jaw’; ‘complete anterior regions’; “sufficient premolar regions’ (≥3 posterior occluding pairs (POPs)); ‘sufficient molar regions’ (bilaterally ≥1 POP); and tooth replacement), adjusted for six background variables. Likelihood ratios for chewing problems were assessed at each level of the hierarchical classification system based on these dental conditions.
Seventy-eight to 91 % of subjects reported no or minor chewing problems. The conditions ‘≥10 teeth in each jaw’, and ‘complete anterior regions’ were not associated, whereas ‘sufficient’ premolar regions’ and ‘sufficient molar regions’ were associated with chewing problems (Ors, 0.33–0.58). If classified hierarchically, the condition ‘≥10 teeth in each jaw’ was relevant for chewing problems (likelihood ratios 3.3–3.7). ‘Sufficient premolar region’ and ‘sufficient molar region’ were relevant to reduce the likelihood ratios for having chewing problems (both approximately with a factor 2), both for soft and for hard foods. Subjects with artificial teeth added had similar chance for chewing problems compared to counterparts with natural teeth only. However, if comparing replaced teeth with natural teeth, subjects with tooth replacement showed higher chance for chewing problems.
Chewing ability was strongly associated with dental conditions.
The presence of at least 10 teeth in each jaw had highest impact on chewing ability.
Chewing ability; Occlusal status; Hierarchical dental functional classification system; Chinese adults
Humans vary in their ability to delay gratification and impulsive decision making is a common feature in various psychiatric disorders. The level of delay discounting is a relatively stable psychological trait, and therefore neural processes implicated in delay discounting are likely to be based on the overall functional organization of the brain (under task-free conditions) in which state-dependent shifts from baseline levels occur. The current study investigated whether delay discounting can be predicted by intrinsic properties of brain functioning. Fourteen healthy male subjects performed a delay discounting task. In addition, resting state functional magnetic resonance imaging (fMRI) and magnetic resonance spectroscopy (¹H MRS) were used to investigate the relationship between individual differences in delay discounting and molecular and regional measures of resting state (baseline) activity of dorsal anterior cingulate cortex (dACC). Results showed that delay discounting was associated with both dACC glutamate concentrations and resting state functional connectivity of the dACC with a midbrain region including ventral tegmental area and substantia nigra. In addition, a neural pathway was established, showing that the effect of glutamate concentrations in the dACC on delay discounting is mediated by functional connectivity of the dACC with the midbrain. The current findings are important to acknowledge because spontaneous intrinsic brain processes have been proposed to be a potential promising biomarker of disease and impulsive decision making is associated with several psychiatric disorders.
Anterior cingulate cortex; delay discounting; glutamate; impulsive decision making; magnetic resonance spectroscopy; resting state fMRI
The odorous steroid compound 4,16-androstadien-3-one (androstadienone), found in axillary sweat, was previously reported to evoke hypothalamic activation in heterosexual women, but not in heterosexual men. However, subjects were exposed to the pure crystalline form of androstadienone, which raised the question whether the observed hypothalamic response is physiologically relevant. Therefore, in the present study, we asked whether sexually dimorphic hypothalamic responses could be measured when subjects were exposed to lower, more physiologically relevant concentrations of androstadienone. A total of 21 women and 16 men, all heterosexual, participated in our functional magnetic resonance imaging study (fMRI). Three different concentrations of androstadienone diluted in propylene glycol (10 mM “high,” 0.1 mM “medium” and 0.001 mM “low”) were delivered to the subjects’ nostrils using a computer-controlled stimulator. When exposed to the “high” androstadienone concentration, women showed stronger hypothalamic activation than men. By contrast, men showed more hypothalamic activation when exposed to the “medium” androstadienone concentrations in comparison to women. Thus, we replicated that smelling the chemo-signal androstadienone elicits a hypothalamic activation. However, this effect does not seem to be gender-specific, because androstadienone activated the hypothalamus in both men and women, suggesting that androstadienone exerts specific effects in heterosexual individuals of both sexes.
Stimulant dependence is associated with neuropsychological impairments. Here, we summarize and integrate the existing neuroimaging literature on the neural substrates of neuropsychological (dys)function in stimulant dependence, including cocaine, (meth-)amphetamine, ecstasy and nicotine dependence, and excessive caffeine use, comparing stimulant abusers (SAs) to nondrug using healthy controls (HCs). Despite some inconsistencies, most studies indicated altered brain activation in prefrontal cortex (PFC) and insula in response to reward and punishment, and higher limbic and anterior cingulate cortex (ACC)/PFC activation during craving and attentional bias paradigms in SAs compared with HCs. Impulsivity in SAs was associated with lower ACC and presupplementary motor area activity compared with HCs, and related to both ventral (amygdala, ventrolateral PFC, insula) and dorsal (dorsolateral PFC, dorsal ACC, posterior parietal cortex) systems. Decision making in SAs was associated with low dorsolateral PFC activity and high orbitofrontal activity. Finally, executive function in SAs was associated with lower activation in frontotemporal regions and higher activation in premotor cortex compared with HCs. It is concluded that the lower activations compared with HCs are likely to reflect the neural substrate of impaired neurocognitive functions, whereas higher activations in SAs compared with HCs are likely to reflect compensatory cognitive control mechanisms to keep behavioral task performance to a similar level as in HCs. However, before final conclusions can be drawn, additional research is needed using neuroimaging in SAs and HCs using larger and more homogeneous samples as well as more comparable task paradigms, study designs, and statistical analyses.
Addiction; fMRI; functional imaging; magnetic resonance imaging; stimulant dependence; stimulants
The objective of this study was to investigate the clinical course of shortened dental arches (‘SDA group’) compared to SDAs plus removable denture prosthesis (‘SDA plus RDP group’) and complete dental arches (‘CDA group’, controls).
Materials and methods
Data (numbers of direct and indirect restorations, endodontic treatments, tooth loss and tooth replacements) were extracted from patient records of subjects attending the Nijmegen Dental School who previously participated in a cohort study on shortened dental arches with three to four posterior occluding pairs (POPs).
Records of 35 % of the original cohort were retrievable. At the end of the follow-up (27.4 ± 7.1 years), 20 out of 23 SDA subjects still had SDA with 3–4 POPs compared to 6 out of 13 for SDA plus RDP subjects (follow-up 32.6 ± 7.3 years). Sixteen out of 23 CDA subjects still had CDA; none of them lost more than one POP (follow-up 35.0 ± 5.6 years). SDA group lost 67 teeth: 16 were not replaced, 16 were replaced by FDP and 35 teeth (lost in three subjects) replaced by RDP. Mean number of treatments per year in SDA subjects differed not significantly compared to CDA subjects except for indirect restorations in the upper jaw.
Shortened dental arches can last for 27 years and over. Clinical course in SDA plus RDP is unfavourable, especially when RDP-related interventions are taken into account.
The shortened dental arch concept seems to be a relevant approach from a cost-effective point of view. Replacement of absent posterior teeth by free-end RDP cannot be recommended.
Shortened dental arches; Complete dental arches; Cohort study; Removable denture prosthesis; Tooth loss; Clinical course
Sleep complaints increase profoundly with age; prevalence estimates of insomnia in the elderly reach up to 37%. The three major types of nocturnal complaints are difficulties initiating (DIS) and maintaining (DMS) sleep and early morning awakening (EMA), of which the latter appears most characteristic for aging. The neural correlates associated with these complaints have hardly been investigated, hampering the development of rational treatment and prevention. A recent study on structural brain correlates of insomnia showed that overall severity, but not duration, of insomnia complaints is associated with lower gray matter (GM) density in part of the left orbitofrontal cortex (OFC). Following up on this, we investigated, in an independent sample of people not diagnosed with insomnia, whether individual differences in GM density are associated with differences in DIS, DMS, and EMA. Sixty five healthy participants (mean age = 41 years, range 18–56) filled out questionnaires and underwent structural magnetic resonance imaging. Three compound Z-scores were computed for questionnaire items relating to DIS, DMS, and EMA. Whole-brain voxel-based morphometry was used to investigate their association with GM density. Results show that participants with lower GM density in a region where the left inferior OFC borders the insula report more EMA, but not DIS or DMS. This is the first study to investigate structural brain correlates of specific sleep characteristics that can translate into complaints in insomniacs. The selective association of EMA with orbitofrontal GM density makes our findings particularly relevant to elderly people, where EMA represents the most characteristic complaint. It is hypothesized that low GM density in aforementioned orbitofrontal area affects its role in sensing comfort. An intact ability to evaluate comfort may be crucial to maintain sleep, especially at the end of the night when sleep is vulnerable because homeostatic sleep propensity has dissipated.
insomnia; aging; early morning awakening; orbitofrontal cortex; voxel-based morphometry; structural magnetic resonance imaging
This study aimed to determine variations in the dental status of a dentate adult population in terms of “decayed,” “missing,” and “filled” teeth in relation to several sociodemographic and behavioral factors. Quota sampling was used to draw 2531 subjects aged 20 years and over. Data were collected by means of a questionnaire and an oral examination. Multiple logistic regression analyses were performed to observe associations between “decayed,” “missing,” and “filled” teeth and the factors of interest. The mean numbers of “decayed,” “missing,” and “filled” teeth were 2.2, 6.7, and 4.9, respectively. Molar teeth were significantly more often “missing” than premolar and anterior teeth. Age, gender, education, and tooth brushing revealed most noticeable associations. Increasing age was associated with a lower chance of having “decayed” and “filled” teeth, but with a higher chance of having “missing” teeth. Females were more likely to have “missing” and “filled” teeth. Higher education was associated with a lower chance of having “missing” teeth. More frequent tooth brushing was associated with a lower chance of having “decayed” and “missing” teeth, but with a higher chance of having “filled” teeth. These risk indicators should be considered in prevention program planning if reduction of tooth loss is to be achieved.
Maladaptive impulsivity is a core symptom in various psychiatric disorders. However, there is only limited evidence available on whether different measures of impulsivity represent largely unrelated aspects or a unitary construct. In a cross-species translational study, thirty rats were trained in impulsive choice (delayed reward task) and impulsive action (five-choice serial reaction time task) paradigms. The correlation between those measures was assessed during baseline performance and after pharmacological manipulations with the psychostimulant amphetamine and the norepinephrine reuptake inhibitor atomoxetine. In parallel, to validate the animal data, 101 human subjects performed analogous measures of impulsive choice (delay discounting task, DDT) and impulsive action (immediate and delayed memory task, IMT/DMT). Moreover, all subjects completed the Stop Signal Task (SST, as an additional measure of impulsive action) and filled out the Barratt impulsiveness scale (BIS-11). Correlations between DDT and IMT/DMT were determined and a principal component analysis was performed on all human measures of impulsivity. In both rats and humans measures of impulsive choice and impulsive action did not correlate. In rats the within-subject pharmacological effects of amphetamine and atomoxetine did not correlate between tasks, suggesting distinct underlying neural correlates. Furthermore, in humans, principal component analysis identified three independent factors: (1) self-reported impulsivity (BIS-11); (2) impulsive action (IMT/DMT and SST); (3) impulsive choice (DDT). This is the first study directly comparing aspects of impulsivity using a cross-species translational approach. The present data reveal the non-unitary nature of impulsivity on a behavioral and pharmacological level. Collectively, this warrants a stronger focus on the relative contribution of distinct forms of impulsivity in psychopathology.
Disinhibition over drug use, enhanced salience of drug use and decreased salience of natural reinforcers are thought to play an important role substance dependence. Whether this is also true for pathological gambling is unclear. To understand the effects of affective stimuli on response inhibition in problem gamblers (PRGs), we designed an affective Go/Nogo to examine the interaction between response inhibition and salience attribution in 16 PRGs and 15 healthy controls (HCs).
Four affective blocks were presented with Go trials containing neutral, gamble, positive or negative affective pictures. The No-Go trials in these blocks contained neutral pictures. Outcomes of interest included percentage of impulsive errors and mean reaction times in the different blocks. Brain activity related to No-Go trials was assessed to measure response inhibition in the various affective conditions and brain activity related to Go trials was assessed to measure salience attribution.
PRGs made fewer errors during gamble and positive trials than HCs, but were slower during all trials types. Compared to HCs, PRGs activated the dorsolateral prefrontal cortex, anterior cingulate and ventral striatum to a greater extent while viewing gamble pictures. The dorsal lateral and inferior frontal cortex were more activated in PRGs than in HCs while viewing positive and negative pictures. During neutral inhibition, PRGs were slower but similar in accuracy to HCs, and showed more dorsolateral prefrontal and anterior cingulate cortex activity. In contrast, during gamble and positive pictures PRGs performed better than HCs, and showed lower activation of the dorsolateral and anterior cingulate cortex.
This study shows that gambling-related stimuli are more salient for PRGs than for HCs. PRGs seem to rely on compensatory brain activity to achieve similar performance during neutral response inhibition. A gambling-related or positive context appears to facilitate response inhibition as indicated by lower brain activity and fewer behavioural errors in PRGs.
Background Improvements in knowledge of molecular mechanisms in cancer are the basis for new studies combining chemotherapy with targeted drugs. Inhibition of the epidermal growth factor receptor (EGFR) by erlotinib or cetuximab has limited or no activity, respectively, in pancreatic cancer. The crosstalk between EGFR and mammalian target of rapamycin (mTOR) pathways is a potential mechanism of resistance; therefore we conducted a study to explore safety and efficacy of multiple pathway inhibition by cetuximab and everolimus in combination with capecitabine. Methods Safety and efficacy of fixed standard dose cetuximab in combination with various dose levels of everolimus (5–10 mg/day) and capecitabine (600–800 mg/m2 bid, 2 weeks every 3 weeks) were investigated in a phase I/II study in patients with advanced pancreatic cancer. The primary endpoint was objective response. Results Sixteen patients were treated in the phase I part at two dose levels. Mucositis, rash and hand-foot syndrome were dose-limiting toxicities. Dose level 1 (everolimus 5 mg/day, capecitabine 600 mg/m2 bid for 2 weeks every 3 weeks and cetuximab 250 mg/m2 weekly) was considered the maximum tolerated dose (MTD). Of 31 patients in the phase II part, partial response was documented in two patients (6.5%) and five (16.1%) had stable disease. Median overall survival was 5.0 months (CI 3.1–6.8). Conclusion The schedule of capecitabine, everolimus and cetuximab resulted in considerable epidermal and mucosal toxicities and prevented escalation to optimal dose levels. Because of toxicity and low efficacy this treatment combination cannot be recommended for treatment in pancreatic cancer patients.
Pancreatic cancer; Everolimus; Cetuximab; Capecitabine; Phase I; Phase II
The epithelial lining of the intestine is characterized by an immense cellular turn-over ascertaining an extensive regenerative capacity. Multiple reports suggest that besides the local intestinal stem cell pool, circulating cells of bone marrow origin (BMDCs) contribute to this process by fusing with the epithelial lineage. However, the functional relevance of these observations is unknown. In the present study we employ a model system in which we cannot only detect cell fusion but also examine the functional importance of this process in vivo. Our results indicate that fusion between BMDCs and intestinal epithelial cells is an extremely rare event under physiological conditions. More importantly, by employing a system in which fusion-derived cells can be specifically deleted after extensive tissue damage, we present evidence that cell fusion is not relevant for tissue regeneration. Our data decisively demonstrates that intestinal epithelial homeostasis and regeneration is not dependent on cell fusion involving BMDCs.
Neuroticism and extraversion are personality factors associated with the vulnerability for developing depression and anxiety disorders, and are possibly differentially related to brain structures implicated in the processing of emotional information and the generation of mood states. To date, studies on brain morphology mainly focused on neuroticism, a dimension primarily related to negative affect, yielding conflicting findings concerning the association with personality, partially due to methodological issues and variable population samples under study. Recently, extraversion, a dimension primarily related to positive affect, has been repeatedly inversely related to with symptoms of depression and anxiety disorders. In the present study, high resolution structural T1-weighted MR images of 65 healthy adults were processed using an optimized Voxel Based Morphometry (VBM) approach. Multiple regression analyses were performed to test for associations of neuroticism and extraversion with prefrontal and subcortical volumes. Orbitofrontal and right amygdala volume were both positively related to extraversion. Extraversion was differentially related to volume of the anterior cingulate cortex in males (positive) and females (negative). Neuroticism scores did not significantly correlate with these brain regions. As extraversion is regarded a protective factor for developing anxiety disorders and depression and has been related to the generation of positive affect, the present results indicate that the reduced likelihood of developing affective disorders in individuals high on extraversion is related to modulation of emotion processing through the orbitofrontal cortex and the amygdala.
The objective of this study is to investigate the prevalence of missing teeth and prosthodontic replacements in a Chinese adult population using a hierarchical dental functional classification system. A total of 1,462 dentate subjects over 40 years from Shandong Province, China were included and categorized in the functional classification system with and without tooth replacements. Depending on replacements, subjects could be reclassified (promoted) to categories reflecting higher functionality. “Promotions” were considered indicators for prosthodontic effectiveness. Homogeneities after dichotomization into functional categories appeared to be moderate to good. In the “≥10 teeth in each jaw” branch, mean number of teeth and posterior occluding pairs were 27.93 ± 2.74 and 7.10 ± 1.94, respectively. In the branch “<10 teeth in each jaw,” these figures were 16.17 ± 5.54 and 1.49 ± 1.45. Fixed dental prostheses (FDPs) added on average 3.5 artificial teeth; 46% of subjects with FDP promoted to a higher functional level. For removable dental prostheses (RDPs), these numbers were 8.5% and 79%, respectively. Promotion value per tooth added was significantly higher for FDPs. The classification system was able to quantify the effectiveness of teeth replacements. It was shown that RDPs were more effective when higher numbers of teeth were replaced, while FDPs were more effective per artificial tooth added.
Tooth loss; Tooth replacement; Hierarchical dental functional classification; Posterior occluding pairs
In children who are born small for gestational age (SGA), an adverse intrauterine environment has led to underdevelopment of both the body and the brain. The delay in body growth is (partially) restored during the first two years in a majority of these children. In addition to a negative influence on these physical parameters, decreased levels of intelligence and cognitive impairments have been described in children born SGA. In this study, we used magnetic resonance imaging to examine brain anatomy in 4- to 7-year-old SGA children with and without complete bodily catch-up growth and compared them to healthy children born appropriate for gestational age. Our findings demonstrate that these children strongly differ on brain organisation when compared with healthy controls relating to both global and regional anatomical differences. Children born SGA displayed reduced cerebral and cerebellar grey and white matter volumes, smaller volumes of subcortical structures and reduced cortical surface area. Regional differences in prefrontal cortical thickness suggest a different development of the cerebral cortex. SGA children with bodily catch-up growth constitute an intermediate between those children without catch-up growth and healthy controls. Therefore, bodily catch-up growth in children born SGA does not implicate full catch-up growth of the brain.