Effect of attention bias modification on event-related potentials in patients with irritable bowel syndrome: A preliminary brain function and psycho-behavioral study.

BACKGROUND: Attention bias modification normalizes electroencephalographic abnormalities in alpha and beta power percentages related to attention in patients with irritable bowel syndrome (IBS). Yet, it is unknown whether ABM contributes to the normalization of event-related potentials (ERP) in these patients. We hypothesized that ERP related to attention deficit would be normalized after ABM implementation in individuals with IBS. METHODS: Thirteen patients with IBS and 10 control subjects completed a 2-month intervention that included five ABM sessions. Each session included 128 trials, resulting in a total of 640 trials during the study period. Event-related potentials were measured at the first and fifth sessions. As per the international 10-20 system for electroencephalographic electrode placement, right parietal P4 was evaluated to measure the attention component of facial expression processing. KEY RESULTS: A group comparison of P100 latency at P4 revealed that latencies were significantly different between groups in session 1 (IBS vs control, 108 ± 8 vs 97 ± 14; t = -2.51, P = .0203). This difference was absent in session 5 (94 ± 11 vs 93 ± 11, respectively; t = -0.397, P = .6954, r = .09), indicating an effect of ABM in the IBS group. CONCLUSIONS AND INFERENCES: Attention bias modification may have clinical utility for normalizing brain function and specifically attentional abnormalities in patients with IBS.

Effect of attention bias modification on brain function and anxiety in patients with irritable bowel syndrome: A preliminary electroencephalogram and psycho-behavioral study.

BACKGROUND: Gastrointestinal symptoms of irritable bowel syndrome (IBS) show a reciprocal relationship with anxiety. In this intervention-based study, we investigated the utility of attention bias modification (ABM) therapy in patients with IBS. We hypothesized that IBS-related electroencephalographic abnormalities would be normalized after ABM therapy. METHODS: Seventeen patients with IBS and 13 healthy subjects completed five ABM intervention sessions over a 2-month period. Each session included 128 ABM trials, resulting in a total of 640 trials across the intervention period. For each trial, subjects viewed a pair of facial expression images and were instructed to indicate the position of the neutral face as quickly and accurately as possible by pressing one of two buttons on a button box. Electroencephalography data (alpha and beta power percentages) were collected during the 1st and 5th sessions. KEY RESULTS: Generalized estimating equations of relative alpha power revealed a significant effect of period was identified at O2 (P=.036). Paired t tests revealed that ABM significantly increased relative alpha power at O2 in patients with IBS. Generalized estimating equation of relative beta power revealed a significant effect of the group × period interaction was identified at Pz (P=.035). Paired t tests revealed that ABM significantly decreased relative beta power at Pz in patients with IBS. CONCLUSIONS & INFERENCES: Attention bias modification may normalize brain function related to attention and anxiety in patients with IBS.

Queen and worker policing in monogynous and monandrous colonies of a primitively eusocial wasp.

Kin-selection theory predicts that a worker prefers to produce her own sons in a colony with monandry and monogyny because relatedness to her sons (0.5) and nephews (0.375) exceeds that to brothers (0.25). In spite of this prediction, recent studies reveal that workers police each other (mutual-worker egg removal) even in monandrous and monogynous colonies. We conducted field and laboratory studies to evaluate queen and worker policing in queen-right colonies of the primitively eusocial wasp Polistes chinensis antennalis. Genetic studies using microsatellite markers, as well as extensive observations of natural colonies, revealed that both queen and workers removed both queen- and worker-laid eggs in monogynous and monandrous colonies. The queen's eggs survived to hatching more successfully than those of the workers (88.5% versus 1.4%). We discuss the likely factors to explain these worker-policing behaviours.

Copper as a controlling factor of anaerobic growth under N2O and biosynthesis of N2O reductase in denitrifying bacteria.

In order to determine the specific mineral requirement for N2O-anaerobic growth of the denitrifying bacteria Alcaligenes sp. NGIB 11015 and Alcaligenes faecalis IAM 1015, investigations were done using dithizone-treated KNO3-free modified Giltay's medium (dithizone-treated medium). When grown aerobically, the bacteria exhibited equally good growth in the presence or absence of an appropriate amount of copper. Anaerobic growth under N2O was stimulated by the addition of a proper amount of copper in both denitrifying bacteria. Growth in the medium demetalated by various treatments showed that copper was specifically necessary for the maximum growth under N2O. The optimum concentration of copper was between 0.5 to 1 µm and 20 to 40 µm for the anaerobic growth rate under N2O. Copper was indispensable for the biosynthesis of N2O reductase and is very likely to be a functional part of N2O reductase in denitrifying bacteria.