Objective assessment of the human visual attentional state

Primary objective

The purpose of this study was to develop an objective way to assess human visual attention using the alpha-band component of the visual-evoked potential (VEP).

Design and methods

Six different attentional conditions were tested: eyes-open, eyes-closed, eyes-closed with backwards number counting, and three rapid-serial visual presentation (RSVP) tasks. Eighteen visually normal, young-adult subjects (ages 21–28 years) were tested binocularly at 1 m for each condition on two separate days. The Diopsys? NOVA-TR system was used to obtain the visual-evoked potential (VEP) and extracted alpha wave and its related power spectrum. Additionally, the Visual Search and Attention Test (VSAT) was administered as a subjective measure of visual attention.

Results

Subjects exhibited significant decreases in power in the alpha band when comparing the eyes-closed with the eyes-open conditions, with power in the eyes-closed condition being, on average, twice as large. The response from the other four conditions did not reflect the differential attentional demands. The ratio of the power in the eyes-closed condition to the eyes-open condition in the lower-alpha frequencies (8–10 Hz) was found to be significantly correlated with the group’s performance on the VSAT, especially the 10-Hz component.

Conclusions

An individual’s ability to attenuate their alpha component during visual processing may be a predictor of their visual attentional state. These findings solidify the role of the VEP alpha subcomponent as an objective electrophysiological correlate of visual attention, which may be useful in the diagnosis and treatment of human visual attention disorders in the future.     

A methoxylated fatty acid isolated from the brown seaweed Ishige okamurae inhibits bacterial phospholipase A2

A methoxylated fatty acid that inhibits phospholipase A(2) (PLA(2); EC 3.1.1.4) was purified from the brown seaweed Ishige okamurae. Approximately 8.1 mg of the inhibitory compound, 7-methoxy-9-methylhexadeca-4,8-dienoic acid, was isolated from 1 kg of I. okamurae powder. Recombinant PLA(2) derived from the pathogenic bacterium Vibrio mimicus was used as the target enzyme. The methoxylated fatty acid compound competitively inhibited PLA(2) with a Ki value of 3.9 microg/mL. The concentrations required for 50% inhibition of PLA(2), oedema and erythema were 1.0 microg/mL, 3.6 mg/mL and 4.6 mg/mL, respectively. The compound strongly inhibited PLA(2) activity in vitro and had potent antiinflammatory activity in vivo.     

Pesticide-induced changes in peripheral thyroid hormone levels during different reproductive phases in Heteropneustes fossilis

Effects of gamma-BHC (an organochlorine) and malathion (an organophosphorus) exposure on plasma triiodothyronine (T3) and thyroxine (T4) levels have been studied in the freshwater catfish, Heteropneustes fossilis, during its annual reproductive cycle. After 4 weeks exposure of gamma-BHC (8 and 16 ppm) and malathion (10 and 20 ppm), the effects on plasma T3, T4, and T3/T4 ratio varied during different reproductive phases. Malathion seems to have a stimulatory effect, while gamma-BHC seems to have an inhibitory effect on extrathyroidal conversion of T4 to T3. Changes in levels of various thyroid hormones during different reproductive phases occurred most probably due either to inhibited (in response to gamma-BHC) or to stimulated (in response to malathion) extrathyroidal T4 monodeiodination and their altered excretion or consumption rate.     

Leukocyte adhesion defect‐I: rare primary immune deficiency

Leukocyte adhesion defect I is a rare disorder (1:1,000,000) caused by diminished expression of CD‐18 β2 integrins on leukocytes leading to abnormal adhesion, migration, and chemotaxis. Clinical manifestations include delayed separation of umbilical cord, omphalitis, recurrent severe infections, impaired wound healing, persistent oral ulcers, and severe periodontitis in primary and permanent dentition. A 5‐year‐old girl, second‐born child to parents with consanguinity, presented with pain and mobility of lower teeth. There was history of recurrent infections and multiple hospital admissions with CD18 level‐3% and frame shift mutation in ITGB2, on 21q22.3. There were scars on hands and feet. Oral examination revealed multiple missing teeth and periodontitis in primary dentition. Oral prophylaxis and palliative treatments were performed with periodic follow‐ups. Interdisciplinary care is ubiquitous for patients with immune deficiencies. Early consultation with pediatric dentists and exploration of medical history is essential for diagnosis and treatment of rare diseases.     

Fixation of subcondylar fractures of the mandible: a randomized clinical trial comparing one trapezoidal plate with two miniplates

Subcondylar fracture of the mandible accounts for 25–35% of all mandibular fractures. In the past, most subcondylar fractures were managed non-surgically. The traditional method of fixation for subcondylar fractures uses two miniplates; however some bench studies have reported that trapezoidal plates are superior. The aim of this study was to compare the outcomes of subcondylar fractures fixed either with two non-parallel straight miniplates or with one trapezoidal plate. A randomized clinical trial was designed and implemented. Fifty-two consecutive patients with subcondylar fractures were recruited. All patients underwent surgery via a retromandibular approach. The time taken for fixation of the plate after fracture reduction and postoperative outcomes and complications were compared between the groups. The trapezoidal plates were superior in terms of ease of adaptation and time taken for fixation (P =  0.0001). Plate fracture was observed only in the two miniplates group, in four (16%) patients. Outcomes were similar in the two groups in terms of occlusion, mouth opening, protrusion, and lateral excursion. In conclusion, both systems – two miniplates and the trapezoidal plate – provide functionally stable fixation. The outcome was significantly better for the trapezoidal plate than for two miniplates regarding the time taken for insertion and ease of adaptation, but not for other parameters.     

Violent Crime in the Lives of Homeless Female Ex-Offenders

The cyclical pattern of violence in the lives of homeless female ex-offenders may precipitate ongoing substance use and recidivism; all of which have shown to be mounting public health issues affecting successful reentry. This paper, which analyzed baseline data from a longitudinal study of 126 female ex-offenders in Los Angeles and Pomona, California, highlighted the factors found to be associated with violent crime among homeless female ex-offenders. A multiple logistic regression model for whether or not the last conviction was for a violent offense indicated that poor housing (p = .011) and self-reported anger or hostility (p < .001) were significant correlates. An ordinal regression model for the number of violent offenses also indicated that affectionate support was associated with committing fewer number of violent crimes (p = .001), while positive social interactions (p = .007), and anger/hostility (p = .015) were associated with greater number of violent crimes. Implications for developing a comprehensive array of strategies that can mitigate the pattern of violence often seen in the lives of homeless female who have recently exited jails and prisons is discussed.     

Loss of orally administered drugs in GI tract

The aim of this review is to provide a broad perspective on intestinal absorption and the impact of intestinal first-pass metabolism on both clearance and drug–drug interaction prediction along with its historical perspectives. The review also considers abilities to bridge the gap between the increasing amount of intestinal in vitro data and the importance of intestinal first-pass metabolism in vivo. The significance of efflux transporters on the intestinal absorption is also discussed.