Conscious and subliminal conflicts in normal subjects and patients with schizophrenia: the role of the anterior cingulate

The human anterior cingulate cortex (ACC), which is active during conflict-monitoring tasks, is thought to participate with prefrontal cortices in a distributed network for conscious self-regulation. This hypothesis predicts that conflict-related ACC activation should occur only when the conflicting stimuli are consciously perceived. To dissociate conflict from consciousness, we measured the behavioral and brain imaging correlates of a motor conflict induced by task-irrelevant subliminal or conscious primes. The same task was studied in normal subjects and in patients with schizophrenia in whom the ACC and prefrontal cortex are thought to be dysfunctional. Conscious, but not subliminal, conflict affected anterior cingulate activity in normal subjects. Furthermore, patients with schizophrenia, who exhibited a hypoactivation of the ACC and other frontal, temporal, hippocampal, and striatal sites, showed impaired conscious priming but normal subliminal priming. Those findings suggest that subliminal conflicts are resolved without ACC contribution and that the ACC participates in a distributed conscious control network that is altered in schizophrenia.     

Overt Rectal Prolapse and Fecal Incontinence

PURPOSE  Rectal prolapse is frequently associated with fecal incontinence; however, the relationship is questionable. The study was designed to evaluate fecal incontinence in a large consecutive series of patients who suffered from rectal prolapse, focusing on both past history, anal physiology, and imaging. METHODS  Eighty-eight consecutive patients who suffered from an overt rectal prolapse (72 women, 16 men; mean age, 51.1 ± 19.5 years) as a main symptom were analyzed; 48 patients also experienced fecal incontinence compared with 40 without incontinence. Logistic regression analyses were performed. RESULTS  The two groups of patients did not differ with respect to parity, weekly stool frequency, main duration of symptoms before referral, occurrence of dyschezia, and digital help to defecate. Patients with prolapse who were older than 45 years (odds ratio (OR), 4.51 (1.49–13.62); P = 0.007) and those with a past history of hemorrhoidectomy (OR, 9.05 (1.68–48.8); P = 0.01) were significantly more incontinent. Incontinent group showed frequent internal anal sphincter defect compared with the continent group (60 vs. 6.2 percent; P = 0.0018). CONCLUSIONS  In patients with overt rectal prolapse, the occurrence of fecal incontinence needs special consideration for age and previous hemorrhoid surgery as causative factors. Anal weakness and sphincter defects are frequently observed.     

Repeated Nitrogen Dioxide Exposures and Eosinophilic Airway Inflammation in Asthmatics: A Randomized Crossover Study

Background: Nitrogen dioxide (NO₂), a ubiquitous atmospheric pollutant, may enhance the asthmatic response to allergens through eosinophilic activation in the airways. However, the effect of NO₂ on inflammation without allergen exposure is poorly studied.Objectives: We investigated whether repeated peaks of NO₂, at various realistic concentrations, induce changes in airway inflammation in asthmatics.Methods: Nineteen nonsmokers with asthma were exposed at rest in a double-blind, crossover study, in randomized order, to 200 ppb NO₂, 600 ppb NO₂, or clean air once for 30 min on day 1 and twice for 30 min on day 2. The three series of exposures were separated by 2 weeks. The inflammatory response in sputum was measured 6 hr (day 1), 32 hr (day 2), and 48 hr (day 3) after the first exposure, and compared with baseline values measured twice 10–30 days before the first exposure.Results: Compared with baseline measurements, the percentage of eosinophils in sputum increased by 57% after exposure to 600 ppb NO₂ (p = 0.003) but did not change significantly after exposure to 200 ppb. The slope of the association between the percentage of eosinophils and NO₂ exposure level was significant (p = 0.04). Eosinophil cationic protein in sputum was highly correlated with eosinophil count and increased significantly after exposure to 600 ppb NO₂ (p = 0.001). Lung function, which was assessed daily, was not affected by NO₂ exposure.Conclusions: We observed that repeated peak exposures of NO₂ performed without allergen exposure were associated with airway eosinophilic inflammation in asthmatics in a dose-related manner.Citation: Ezratty V, Guillossou G, Neukirch C, Dehoux M, Koscielny S, Bonay M, Cabanes PA, Samet JM, Mure P, Ropert L, Tokarek S, Lambrozo J, Aubier M. 2014. Repeated nitrogen dioxide exposures and eosinophilic airway inflammation in asthmatics: a randomized crossover study. Environ Health Perspect 122:850–855; http://dx.doi.org/10.1289/ehp.1307240     

Comparative genomic hybridization reveals a specific pattern of chromosomal gains and losses during the genesis of colorectal tumors

Comparative genomic hybridization was used to screen the DNA extracted from histologically defined tissue sections from consecutive stages of colorectal carcinogenesis for chromosomal aberrations. No aberrations were detected in normal epithelium (n = 14). Gain of chromosome 7 occurred as a single event in low-grade adenomas (n = 14). In high-grade adenomas (n = 12), an overrepresentation of chromosomes 7 and 20 was present in 30% of the cases analyzed. The transition to colon carcinomas (n = 16) was characterized by the emergence of multiple chromosomal aberrations. Chromosomes 1, 13, and 20 and chromosome arms 7p and 8q were frequently gained, whereas chromosome 4 and chromosome arms 8p and 18q were recurrently underrepresented. The same tissue sections that were used for CGH were analyzed by means of DNA-ploidy measurements and immunohistochemical staining to quantify proliferative activity and p21/WAF-I and TP53 expression. We observed that crude aneuploidy and increased proliferative activity are early events in colorectal carcinogenesis, followed by TP53 overexpression and the acquisition of recurrent chromosomal gains and losses during the progression from high-grade adenomas to invasive carcinomas. Genes Chromosom Cancer (1996). © 1996 Wiley-Liss, Inc.     

Transient cortico-cortical disconnection during psychogenic nonepileptic seizures (PNES)

Psychogenic nonepileptic seizures (PNES) are paroxysmal clinical events that are often misdiagnosed as epileptic seizures, but which are not associated with electrographic discharge. Brain connectivity changes occurring during PNES are not known. We studied functional connectivity (Fc) in two patients with drug-resistant epilepsy, explored by stereotactic electroencephalography (EEG), in whom we recorded both epileptic seizures (ES) and PNES. Functional connectivity using pair-wise nonlinear correlation was computed between signals from seven brain areas: amygdala, hippocampus, lateral temporal cortex, anterior insula, orbitofrontal cortex, prefrontal cortex, and lateral parietal cortex. We assessed changes in global Fc during PNES in comparison with a background period. During PNES, a global decrease of Fc occurred between the different brain regions studied, compared with the interictal period. In both patients, decreased Fc was prominent in connections involving the anterior insula and parietal cortex. In conclusion, some PNES are associated with ictal functional disconnection between brain areas, particularly involving the parietal cortices and the anterior insula.